Hanging drop cultures of human testis and testis cancer samples

DEFF Research Database (Denmark)

Jørgensen, Anne; Young, J; Nielsen, J E

2014-01-01

cultured in 'hanging drops' and effects of activin A and follistatin treatment were investigated in seminoma cultures. RESULTS: Testis fragments with normal spermatogenesis or CIS cells were cultured for 14 days with sustained proliferation of germ cells and CIS cells and without increased apoptosis....... Seminoma cultures survived 7 days, with proliferating cells detectable during the first 5 days. Activin A treatment significantly reduced KIT transcript and protein levels in seminoma cultures, thereby demonstrating a specific treatment response. CONCLUSIONS: Hanging drop cultures of human testis...

Controlling Vapor Pressure In Hanging-Drop Crystallization

Science.gov (United States)

Carter, Daniel C.; Smith, Robbie

1988-01-01

Rate of evaporation adjusted to produce larger crystals. Device helps to control vapor pressure of water and other solvents in vicinity of hanging drop of solution containing dissolved enzyme protein. Well of porous frit (sintered glass) holds solution in proximity to drop of solution containing protein or enzyme. Vapor from solution in frit controls evaporation of solvent from drop to control precipitation of protein or enzyme. With device, rate of nucleation limited to decrease number and increase size (and perhaps quality) of crystals - large crystals of higher quality needed for x-ray diffraction studies of macromolecules.

Adding the 'heart' to hanging drop networks for microphysiological multi-tissue experiments.

Science.gov (United States)

Rismani Yazdi, Saeed; Shadmani, Amir; Bürgel, Sebastian C; Misun, Patrick M; Hierlemann, Andreas; Frey, Olivier

2015-11-07

Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid-air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip.

[Culture of pancreatic progenitor cells in hanging drop and on floating filter].

Science.gov (United States)

Ma, Feng-xia; Chen, Fang; Chi, Ying; Yang, Shao-guang; Lu, Shi-hong; Han, Zhong-chao

2013-06-01

To construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method. Murine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR). One day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose. In hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

A PDMS-Based Microfluidic Hanging Drop Chip for Embryoid Body Formation.

Science.gov (United States)

Wu, Huei-Wen; Hsiao, Yi-Hsing; Chen, Chih-Chen; Yet, Shaw-Fang; Hsu, Chia-Hsien

2016-07-06

The conventional hanging drop technique is the most widely used method for embryoid body (EB) formation. However, this method is labor intensive and limited by the difficulty in exchanging the medium. Here, we report a microfluidic chip-based approach for high-throughput formation of EBs. The device consists of microfluidic channels with 6 × 12 opening wells in PDMS supported by a glass substrate. The PDMS channels were fabricated by replicating polydimethyl-siloxane (PDMS) from SU-8 mold. The droplet formation in the chip was tested with different hydrostatic pressures to obtain optimal operation pressures for the wells with 1000 μm diameter openings. The droplets formed at the opening wells were used to culture mouse embryonic stem cells which could subsequently developed into EBs in the hanging droplets. This device also allows for medium exchange of the hanging droplets making it possible to perform immunochemistry staining and characterize EBs on chip.

A PDMS-Based Microfluidic Hanging Drop Chip for Embryoid Body Formation

Directory of Open Access Journals (Sweden)

Huei-Wen Wu

2016-07-01

Full Text Available The conventional hanging drop technique is the most widely used method for embryoid body (EB formation. However, this method is labor intensive and limited by the difficulty in exchanging the medium. Here, we report a microfluidic chip-based approach for high-throughput formation of EBs. The device consists of microfluidic channels with 6 × 12 opening wells in PDMS supported by a glass substrate. The PDMS channels were fabricated by replicating polydimethyl-siloxane (PDMS from SU-8 mold. The droplet formation in the chip was tested with different hydrostatic pressures to obtain optimal operation pressures for the wells with 1000 μm diameter openings. The droplets formed at the opening wells were used to culture mouse embryonic stem cells which could subsequently developed into EBs in the hanging droplets. This device also allows for medium exchange of the hanging droplets making it possible to perform immunochemistry staining and characterize EBs on chip.

Experimental and theoretical analysis of the rate of solvent equilibration in the hanging drop method of protein crystal growth

Science.gov (United States)

Fowlis, William W.; Delucas, Lawrence J.; Twigg, Pamela J.; Howard, Sandra B.; Meehan, Edward J.

1988-01-01

The principles of the hanging-drop method of crystal growth are discussed, and the rate of water evaporation in a water droplet (containing protein, buffer, and a precipitating agent) suspended above a well containing a double concentration of precipitating agent is investigated theoretically. It is shown that, on earth, the rate of evaporation may be determined from diffusion theory and the colligative properties of solutions. The parameters affecting the rate of evaporation include the temperature, the vapor pressure of water, the ionization constant of the salt, the volume of the drop, the contact angle between the droplet and the coverslip, the number of moles of salt in the droplet, the number of moles of water and salt in the well, the molar volumes of water and salt, the distance from the droplet to the well, and the coefficient of diffusion of water vapor through air. To test the theoretical equations, hanging-drop experiments were conducted using various reagent concentrations in 25-microliter droplets and measuring the evaporation times at 4 C and 25 C. The results showed good agreement with the theory.

Characterization and reproducibility of HepG2 hanging drop spheroids toxicology in vitro.

Science.gov (United States)

Hurrell, Tracey; Ellero, Andrea Antonio; Masso, Zelie Flavienne; Cromarty, Allan Duncan

2018-02-21

Hepatotoxicity remains a major challenge in drug development despite preclinical toxicity screening using hepatocytes of human origin. To overcome some limitations of reproducing the hepatic phenotype, more structurally and functionally authentic cultures in vitro can be introduced by growing cells in 3D spheroid cultures. Characterisation and reproducibility of HepG2 spheroid cultures using a high-throughput hanging drop technique was performed and features contributing to potential phenotypic variation highlighted. Cultured HepG2 cells were seeded into Perfecta 3D® 96-well hanging drop plates and assessed over time for morphology, viability, cell cycle distribution, protein content and protein-mass profiles. Divergent aspects which were assessed included cell stocks, seeding density, volume of culture medium and use of extracellular matrix additives. Hanging drops are advantageous due to no complex culture matrix being present, enabling background free extractions for downstream experimentation. Varying characteristics were observed across cell stocks and batches, seeding density, culture medium volume and extracellular matrix when using immortalized HepG2 cells. These factors contribute to wide-ranging cellular responses and highlights concerns with respect to generating a reproducible phenotype in HepG2 hanging drop spheroids. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adding the ‘heart’ to hanging drop networks for microphysiological multi-tissue experiments†

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Yazdi, Saeed Rismani; Shadmani, Amir; Bürgel, Sebastian C.; Misun, Patrick M.; Hierlemann, Andreas; Frey, Olivier

2017-01-01

Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid–air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip. PMID:26401602

Mouse ES cells have a potential to differentiate into odontoblast-like cells using hanging drop method.

Science.gov (United States)

Kawai, R; Ozeki, N; Yamaguchi, H; Tanaka, T; Nakata, K; Mogi, M; Nakamura, H

2014-05-01

We examined whether mouse embryonic stem (ES) cells can differentiate into odontoblast-like cells without epithelial-mesenchymal interaction. Cells were cultured by the 'hanging drop' method using a collagen type-I scaffold (CS) combined with bone morphogenetic protein (BMP)-4 (CS/BMP-4). Expression of odontoblast-related mRNA and protein, and cell proliferation were performed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and WST-1 assay, respectively. Cells potently expressed odontoblast-related cell marker mRNAs following induction of odontoblastic differentiation. Dentin sialophosphoprotein, a marker of mature odontoblasts, was strongly expressed in differentiated ES cells. The cells also acquired an odontoblast-like functional phenotype, as evidenced by the appearance of alkaline phosphatase activity and calcification. The cell-surface expression of α2, α6, αV and αVβ3 integrin proteins was rapidly upregulated in differentiated cells. Finally, anti-α2 integrin antibody suppressed the expression of odontoblastic markers in cells grown using this culture system, suggesting that α2 integrin expression in ES cells triggers their differentiation into odontoblast-like cells. Mouse ES cells cultured by the 'hanging drop' method are able to differentiate into cells with odontoblast-specific physiological functions and cell-surface integrin protein expression. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Enrichment of cardiac differentiation of mouse embryonic stem cells by optimizing the hanging drop method.

Science.gov (United States)

Chen, Ming; Lin, Yong-Qing; Xie, Shuang-Lun; Wu, Hong-Fu; Wang, Jing-Feng

2011-04-01

Hanging drop (HD) culture is used to induce differentiation of embryonic stem cells (ESCs) into other cell types including cardiomyocytes. However, the factors affecting cardiac differentiation of ESCs with this method remain incompletely understood. We have investigated the effects of the starting number of ESCs in embryoid bodies (EBs) and the time of EB adherence to gelatin-coated plates on cardiac differentiation: cardiac differentiation was increased in the EBs by a larger number of ESCs and was decreased by plating EBs at day 4 or earlier. These two factors can thus be optimized to enrich the cardiac differentiation in ESCs using the HD method.

The preparation of Drosophila embryos for live-imaging using the hanging drop protocol.

Science.gov (United States)

Reed, Bruce H; McMillan, Stephanie C; Chaudhary, Roopali

2009-03-13

Green fluorescent protein (GFP)-based timelapse live-imaging is a powerful technique for studying the genetic regulation of dynamic processes such as tissue morphogenesis, cell-cell adhesion, or cell death. Drosophila embryos expressing GFP are readily imaged using either stereoscopic or confocal microscopy. A goal of any live-imaging protocol is to minimize detrimental effects such as dehydration and hypoxia. Previous protocols for preparing Drosophila embryos for live-imaging analysis have involved placing dechorionated embryos in halocarbon oil and sandwiching them between a halocarbon gas-permeable membrane and a coverslip. The introduction of compression through mounting embryos in this manner represents an undesirable complication for any biomechanical-based analysis of morphogenesis. Our method, which we call the hanging drop protocol, results in excellent viability of embryos during live imaging and does not require that embryos be compressed. Briefly, the hanging drop protocol involves the placement of embryos in a drop of halocarbon oil that is suspended from a coverslip, which is, in turn, fixed in position over a humid chamber. In addition to providing gas exchange and preventing dehydration, this arrangement takes advantage of the buoyancy of embryos in halocarbon oil to prevent them from drifting out of position during timelapse acquisition. This video describes in detail how to collect and prepare Drosophila embryos for live imaging using the hanging drop protocol. This protocol is suitable for imaging dechorionated embryos using stereomicroscopy or any upright compound fluorescence microscope.

The effect of body position on the 'hanging drop' method for identifying the extradural space in anaesthetized dogs.

Science.gov (United States)

Naganobu, Kiyokazu; Hagio, Mitsuyoshi

2007-01-01

To assess the accuracy of the 'hanging drop method' for identifying the extradural space in anaesthetized dogs positioned in sternal or lateral recumbency. Prospective randomized-experimental study. Seventeen clinically healthy adult dogs, 10 females and seven males weighing 8.4-26.2 kg. Dogs were positioned in either sternal (n = 8) or lateral (n = 9) recumbency under general anaesthesia. A 20 SWG spinal needle pre-filled with 0.9% saline was advanced through the skin into the lumbosacral extradural space and the response of the saline drop recorded, i.e. whether it: 1) was aspirated from the hub into the needle; 2) remained within the hub, or 3) moved synchronously with i) spontaneous respiration, ii) heart beat or iii) manual lung inflation. The position of the needle tip was ultimately determined by positive contrast radiography. One dog positioned in lateral recumbency was excluded from the study because bleeding occurred from the needle hub. Saline was aspirated into the needle in seven of eight dogs held in sternal recumbency but in none of the dogs positioned in lateral recumbency. Accurate needle tip placement in the extradural space was confirmed by positive contrast radiography in all dogs. The 'hanging drop' method, when performed with a spinal needle, appears to be a useful technique for identifying the location of the extradural space in anaesthetized medium-sized dogs positioned in sternal, but not in lateral recumbency. The technique may yield 'false negative' results when performed in dogs positioned in sternal recumbency.

Reconfigurable microfluidic hanging drop network for multi-tissue interaction and analysis.

Science.gov (United States)

Frey, Olivier; Misun, Patrick M; Fluri, David A; Hengstler, Jan G; Hierlemann, Andreas

2014-06-30

Integration of multiple three-dimensional microtissues into microfluidic networks enables new insights in how different organs or tissues of an organism interact. Here, we present a platform that extends the hanging-drop technology, used for multi-cellular spheroid formation, to multifunctional complex microfluidic networks. Engineered as completely open, 'hanging' microfluidic system at the bottom of a substrate, the platform features high flexibility in microtissue arrangements and interconnections, while fabrication is simple and operation robust. Multiple spheroids of different cell types are formed in parallel on the same platform; the different tissues are then connected in physiological order for multi-tissue experiments through reconfiguration of the fluidic network. Liquid flow is precisely controlled through the hanging drops, which enable nutrient supply, substance dosage and inter-organ metabolic communication. The possibility to perform parallelized microtissue formation on the same chip that is subsequently used for complex multi-tissue experiments renders the developed platform a promising technology for 'body-on-a-chip'-related research.

Application of hanging drop technique to optimize human IgG formulations.

Science.gov (United States)

Li, Guohua; Kasha, Purna C; Late, Sameer; Banga, Ajay K

2010-01-01

The purpose of this work is to assess the hanging drop technique in screening excipients to develop optimal formulations for human immunoglobulin G (IgG). A microdrop of human IgG and test solution hanging from a cover slide and undergoing vapour diffusion was monitored by a stereomicroscope. Aqueous solutions of IgG in the presence of different pH, salt concentrations and excipients were prepared and characterized. Low concentration of either sodium/potassium phosphate or McIlvaine buffer favoured the solubility of IgG. Addition of sucrose favoured the stability of this antibody while addition of NaCl caused more aggregation. Antimicrobial preservatives were also screened and a complex effect at different buffer conditions was observed. Dynamic light scattering, differential scanning calorimetry and size exclusion chromatography studies were performed to further validate the results. In conclusion, hanging drop is a very easy and effective approach to screen protein formulations in the early stage of formulation development.

Colony, hanging drop, and methylcellulose three dimensional hypoxic growth optimization of renal cell carcinoma cell lines.

Science.gov (United States)

Matak, Damian; Brodaczewska, Klaudia K; Lipiec, Monika; Szymanski, Łukasz; Szczylik, Cezary; Czarnecka, Anna M

2017-08-01

Renal cell carcinoma (RCC) is the most lethal of the common urologic malignancies, comprising 3% of all human neoplasms, and the incidence of kidney cancer is rising annually. We need new approaches to target tumor cells that are resistant to current therapies and that give rise to recurrence and treatment failure. In this study, we focused on low oxygen tension and three-dimensional (3D) cell culture incorporation to develop a new RCC growth model. We used the hanging drop and colony formation methods, which are common in 3D culture, as well as a unique methylcellulose (MC) method. For the experiments, we used human primary RCC cell lines, metastatic RCC cell lines, human kidney cancer stem cells, and human healthy epithelial cells. In the hanging drop assay, we verified the potential of various cell lines to create solid aggregates in hypoxic and normoxic conditions. With the semi-soft agar method, we also determined the ability of various cell lines to create colonies under different oxygen conditions. Different cell behavior observed in the MC method versus the hanging drop and colony formation assays suggests that these three assays may be useful to test various cell properties. However, MC seems to be a particularly valuable alternative for 3D cell culture, as its higher efficiency of aggregate formation and serum independency are of interest in different areas of cancer biology.

Hanging Drop, A Best Three-Dimensional (3D) Culture Method for Primary Buffalo and Sheep Hepatocytes.

Science.gov (United States)

Shri, Meena; Agrawal, Himanshu; Rani, Payal; Singh, Dheer; Onteru, Suneel Kumar

2017-04-26

Livestock, having close resemblance to humans, could be a better source of primary hepatocytes than rodents. Herein, we successfully developed three-dimensional (3D) culturing system for primary sheep and buffalo hepatocytes. The 3D-structures of sheep hepatocytes were formed on the fifth-day and maintained until the tenth-day on polyHEMA-coated plates and in hanging drops with William's E media (HDW). Between the cultured and fresh cells, we observed a similar expression of GAPDH, HNF4α, ALB, CYP1A1, CK8 and CK18. Interestingly, a statistically significant increase was noted in the TAT, CPS, AFP, AAT, GSP and PCNA expression. In buffalo hepatocytes culture, 3D-like structures were formed on the third-day and maintained until the sixth-day on polyHEMA and HDW. The expression of HNF4α, GSP, CPS, AFP, AAT, PCNA and CK18 was similar between cultured and fresh cells. Further, a statistically significant increase in the TAT and CK8 expression, and a decrease in the GAPDH, CYP1A1 and ALB expression were noted. Among the culture systems, HDW maintained the liver transcript markers more or less similar to the fresh hepatocytes of the sheep and buffalo for ten and six days, respectively. Taken together, hanging drop is an efficient method for 3D culturing of primary sheep and buffalo hepatocytes.

Voltammetry of Aluminum Nanoparticles in Aqueous Media with Hanging Mercury Drop Electrode

Czech Academy of Sciences Publication Activity Database

Korshunov, A.; Heyrovský, Michael

2010-01-01

Roč. 22, 17-18 (2010), s. 1989-1993 ISSN 1040-0397. [International Conference on Modern Electroanalytical Methods. Prague, 09.12.2009-14.12.2009] R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : linear cyclic voltammetry * Hanging mercury drop electrode * Aluminum nanoparticles dispersion Subject RIV: CG - Electrochemistry Impact factor: 2.721, year: 2010

Effectiveness of mesenchymal stems cells cultured by hanging drop vs. conventional culturing on the repair of hypoxic-ischemic-damaged mouse brains, measured by stemness gene expression

Directory of Open Access Journals (Sweden)

Lou Yongli

2016-01-01

Full Text Available In this study, we investigated the therapeutic effects of Human Mesenchymal Stem Cells (hMSCs cultured by hanging drop and conventional culturing methods on cerebellar repair in hypoxic-ischemic (HI brain injured mice. Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR was used to analyze the expression levels of three stemness genes, Oct4, Sox2 and Nanog, and the migration related gene CXCR4. MSC prepared by hanging drop or conventional techniques were administered intranasally to nine day old mice, and analyzed by MRI at day 28. Results indicate that the MSCs, especially the hanging drop cultured MSCs, significantly improved the mice’s cerebellar damage repair. MSCs derived from the hanging drop culture were smaller than those from the conventional culture. The gene expression levels were significantly increased for the MSCs derived from the hanging drop culture. The mechanism might relate to the fact that the hanging drop cultured MSCs can be kept in an undifferentiated state, resulting in its higher expression level of migration receptor of CXCR4.

Comparison of the hanging-drop technique and running-drip method for identifying the epidural space in dogs.

Science.gov (United States)

Martinez-Taboada, Fernando; Redondo, José I

2017-03-01

To compare the running-drip and hanging-drop techniques for locating the epidural space in dogs. Prospective, randomized, clinical trial. Forty-five healthy dogs requiring epidural anaesthesia. Dogs were randomized into four groups and administered epidural anaesthesia in sternal (S) or lateral (L) recumbency. All blocks were performed by the same person using Tuohy needles with either a fluid-prefilled hub (HDo) or connected to a drip set attached to a fluid bag elevated 60 cm (RDi). The number of attempts, 'pop' sensation, clear drop aspiration or fluid dripping, time to locate the epidural space (TTLES) and presence of cerebrospinal fluid (CSF) were recorded. A morphine-bupivacaine combination was injected after positive identification. The success of the block was assessed by experienced observers based on perioperative usage of rescue analgesia. Data were checked for normality. Binomial variables were analysed with the chi-squared or Fisher's exact test as appropriate. Non-parametric data were analysed using Kruskal-Wallis and Mann-Whitney tests. Normal data were studied with an anova followed by a Tukey's means comparison for groups of the same size. A p-value of Drop aspiration was observed more often in SHDo (nine of 11 dogs) than in LHDo (two of 11 dogs) (p = 0.045). Mean (range) TTLES was longer in LHDo [47 (18-82) seconds] than in SHDo [20 (14-79) seconds] (p = 0.006) and SRDi [(34 (17-53) seconds] (p = 0.038). There were no differences in 'pop' sensation, presence of CSF, rescue analgesia or pain scores between the groups. The running-drip method is a useful and fast alternative technique for identifying the epidural space in dogs. The hanging-drop technique in lateral recumbency was more difficult to perform than the other methods, requiring more time and attempts. Copyright © 2017 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

An optimized protocol for handling and processing fragile acini cultured with the hanging drop technique.

Science.gov (United States)

Snyman, Celia; Elliott, Edith

2011-12-15

The hanging drop three-dimensional culture technique allows cultivation of functional three-dimensional mammary constructs without exogenous extracellular matrix. The fragile acini are, however, difficult to preserve during processing steps for advanced microscopic investigation. We describe adaptations to the protocol for handling of hanging drop cultures to include investigation using confocal, scanning, and electron microscopy, with minimal loss of cell culture components. Copyright © 2011 Elsevier Inc. All rights reserved.

Determination of trace arsenic on hanging copper amalgam drop electrode.

Science.gov (United States)

Piech, Robert; Baś, Bogusław; Niewiara, Ewa; Kubiak, Władysław W

2007-04-30

Hanging copper amalgam drop electrode has been applied for trace determination of arsenic by cathodic stripping analysis. Detection limit for As(III) as low as 0.33nM (0.02mug/L) at deposition time (240s) could be obtained. For seven successive determinations of As(III) at concentration of 5nM relative standard deviation was 2.5% (n=7). Interferences from selected metals and surfactant substances were examined. Absence of copper ions in sample solution causes easier optimization and makes method less vulnerable on contamination. The developed method was validated by analysis of certified reference materials (CRMs) and applied to arsenic determinations in natural water samples.

The formation of intestinal organoids in a hanging drop culture.

Science.gov (United States)

Panek, Malgorzata; Grabacka, Maja; Pierzchalska, Malgorzata

2018-01-25

Recently organoids have become widely used in vitro models of many tissue and organs. These type of structures, originated from embryonic or adult mammalian intestines, are called "mini guts". They organize spontaneously when intestinal crypts or stem cells are embedded in the extracellular matrix proteins preparation scaffold (Matrigel). This approach has some disadvantages, as Matrigel is undefined (the concentrations of growth factors and other biologically active components in it may vary from batch to batch), difficult to handle and expensive. Here we show that the organoids derived from chicken embryo intestine are formed in a hanging drop without embedding, providing an attractive alternative for currently used protocols. Using this technique we obtained compact structures composed of contiguous organoids, which were generally similar to chicken organoids cultured in Matrigel in terms of morphology and expression of intestinal epithelial markers. Due to the simplicity, high reproducibility and throughput capacity of hanging drop technique our model may be applied in various studies concerning the gut biology.

Hanging colloidal drop: A new photonic crystal synthesis route

Science.gov (United States)

Sandu, Ion; Dumitru, Marius; Fleaca, Claudiu Teodor; Dumitrache, Florian

2018-05-01

High-quality photonic crystals (hundreds of micrometres in thickness) were grown by the free evaporation of a colloidal drop consisting of silica and polystyrene nanospheres with dimensions of 300 nm, 500 nm, and 1000 nm. The essence of experimental findings is that the drop has to hang on a pillar. This leads to the inhibition of the droplet spreading, the minimisation of the convective force, and the zeroing of the static frictional force between nanospheres and the liquid/air interface, where the first layer is formed. The theoretical essence is the continuous adjustment of nanospheres positions during the growth of photonic crystal, a key condition of the self-assembling phenomenon.

Headspace Hanging Drop Liquid Phase Microextraction and Gas Chromatography-Mass Spectrometry for the Analysis of Flavors from Clove Buds

Energy Technology Data Exchange (ETDEWEB)

Jung, Mi Jin; Shin, Yeon Jae; Oh, Se Yeon; Kim, Nam Sun; Kim, Kun; Lee, Dong Sun [Seoul Women' s University, Seoul (Korea, Republic of)

2006-02-15

A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 μL. 60 min extraction time at 25 .deg. C was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant (K{sub lh}) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, β-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.

VOLTAMMETRY OF AQUEOUS CHLOROAURIC ACID WITH HANGING MERCURY DROP ELECTRODE

Czech Academy of Sciences Publication Activity Database

Korshunov, A.; Josypčuk, Bohdan; Heyrovský, Michael

2011-01-01

Roč. 76, č. 7 (2011), s. 929-936 ISSN 0010-0765 R&D Projects: GA ČR GAP206/11/1638; GA AV ČR IAA400400806; GA MŠk(CZ) LC06063 Institutional research plan: CEZ:AV0Z40400503 Keywords : aqueous chloauric acid * voltammetry * hanging mercury drop electrode Subject RIV: CG - Electrochemistry Impact factor: 1.283, year: 2011

Digital microfluidics for automated hanging drop cell spheroid culture.

Science.gov (United States)

Aijian, Andrew P; Garrell, Robin L

2015-06-01

Cell spheroids are multicellular aggregates, grown in vitro, that mimic the three-dimensional morphology of physiological tissues. Although there are numerous benefits to using spheroids in cell-based assays, the adoption of spheroids in routine biomedical research has been limited, in part, by the tedious workflow associated with spheroid formation and analysis. Here we describe a digital microfluidic platform that has been developed to automate liquid-handling protocols for the formation, maintenance, and analysis of multicellular spheroids in hanging drop culture. We show that droplets of liquid can be added to and extracted from through-holes, or "wells," and fabricated in the bottom plate of a digital microfluidic device, enabling the formation and assaying of hanging drops. Using this digital microfluidic platform, spheroids of mouse mesenchymal stem cells were formed and maintained in situ for 72 h, exhibiting good viability (>90%) and size uniformity (% coefficient of variation <10% intraexperiment, <20% interexperiment). A proof-of-principle drug screen was performed on human colorectal adenocarcinoma spheroids to demonstrate the ability to recapitulate physiologically relevant phenomena such as insulin-induced drug resistance. With automatable and flexible liquid handling, and a wide range of in situ sample preparation and analysis capabilities, the digital microfluidic platform provides a viable tool for automating cell spheroid culture and analysis. © 2014 Society for Laboratory Automation and Screening.

Micro-ring structures stabilize microdroplets to enable long term spheroid culture in 384 hanging drop array plates.

Science.gov (United States)

Hsiao, Amy Y; Tung, Yi-Chung; Kuo, Chuan-Hsien; Mosadegh, Bobak; Bedenis, Rachel; Pienta, Kenneth J; Takayama, Shuichi

2012-04-01

Using stereolithography, 20 different structural variations comprised of millimeter diameter holes surrounded by trenches, plateaus, or micro-ring structures were prepared and tested for their ability to stably hold arrays of microliter sized droplets within the structures over an extended period of time. The micro-ring structures were the most effective in stabilizing droplets against mechanical and chemical perturbations. After confirming the importance of micro-ring structures using rapid prototyping, we developed an injection molding tool for mass production of polystyrene 3D cell culture plates with an array of 384 such micro-ring surrounded through-hole structures. These newly designed and injection molded polystyrene 384 hanging drop array plates with micro-rings were stable and robust against mechanical perturbations as well as surface fouling-facilitated droplet spreading making them capable of long term cell spheroid culture of up to 22 days within the droplet array. This is a significant improvement over previously reported 384 hanging drop array plates which are susceptible to small mechanical shocks and could not reliably maintain hanging drops for longer than a few days. With enhanced droplet stability, the hanging drop array plates with micro-ring structures provide better platforms and open up new opportunities for high-throughput preparation of microscale 3D cell constructs for drug screening and cell analysis.

Thermostatic tissue platform for intravital microscopy: 'the hanging drop' model.

Science.gov (United States)

Pavlovic, Dragan; Frieling, Helge; Lauer, Kai-Stephan; Bac, Vo Hoai; Richter, Joern; Wendt, Michael; Lehmann, Christian; Usichenko, Taras; Meissner, Konrad; Gruendling, Matthias

2006-11-01

Intravital microscopy imposes the particular problem of the combined control of the body temperature of the animal and the local temperature of the observed organ or tissues. We constructed and tested, in the rat ileum microcirculation preparation, a new organ-support platform. The platform consisted of an organ bath filled with physiological solution, and contained a suction tube, a superfusion tube, an intestine-support hand that was attached to a micromanipulator and a thermometer probe. To cover the intestine we used a cover glass plate with a plastic ring glued on its upper surface. After a routine procedure (anaesthesia, monitoring and surgery), the intestine segment (2-3 cm long) was gently exteriorized and placed on the 'hand' of the organ support. A small part of the intestine formed a small 'island' in the bath that was filled with physiological salt solution. The cover glass was secured in place. The physiological salt solution from the superfusion tube, which was pointed to the lower surface of the cover glass, formed a 'hanging drop'. The objective of the microscope was then immersed into distilled water that was formed by the cover glass plastic ring. The 'hanging drop' technique prevented any tissue quenching, ensured undisturbed microcirculation, provided for stable temperature and humidity, and permitted a clear visual field.

Perbandingan Ko-kultur 2D dan 3D dengan Metode Hanging Drop untuk Menghasilkan Micro-environment yang Lebih Relevan Secara Klinis

Directory of Open Access Journals (Sweden)

Radiana Dhewayani Antarianto

2017-09-01

Full Text Available Ko-kultur sel 2 dimensi (2D kurang menyerupai micro-environment seperti in vivo sedangkan ko-kultur 3 dimensi (3D membentuk mikromassa yang lebih mirip micro-environment in vivo sehingga bermanfaat dalam penelitian biologi dasar. Penelitian ini membandingkan ko-kultur 2D dan 3D sel punca serta sel stelata hepatik dengan metode hanging drop untuk menilai morfologi sel dan pembentukan sferoid dari mikromassa yang terbentuk. Studi in vitro ini dilakukan di Pusat Virologi dan Kanker Patobiologi (PRVKP UI dan laboratorium histologi FKUI pada bulan September 2015 sampai Oktober 2016 menggunakan sel punca yang diisolasi dari darah tali pusat manusia dan sel lestari LX2 (stelata hepatik manusia. Darah tali pusat disortir dengan MACS CD34 dan dianalisis flowcytometry. Ko-kultur sel punca sumsum tulang atau darah tali pusat dan LX2 dilakukan dengan metode hanging drop untuk ko-kultur 2D dan ko-kultur 3D. Triplikasi eksperimen dilakukan untuk tiap set ko-kultur. Hasilnya menunjukkan terdapat perbedaan morfologi ko-kultur 2D dan 3D hanging drop dibandingkan monokultur. Di ko-kultur 2D terdapat mikromassa dan di monokultur 2D tidak terbentuk mikromassa. Di ko-kultur 3D hanging drop, terdapat sferoid yang lebih kecil dibandingkan monokultur 3D hanging drop. Morfologi sel ko-kultur 2D dan 3D dengan metode hanging drop dibandingkan monokultur menunjukkan perubahan fenotip sel-sel yang tergabung dalam mikromassa. Normal 0 false false false false IN X-NONE X-NONE Normal 0 false false false false IN X-NONE X-NONE Transfer, imaging, and analysis plate for facile handling of 384 hanging drop 3D tissue spheroids.

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Cavnar, Stephen P; Salomonsson, Emma; Luker, Kathryn E; Luker, Gary D; Takayama, Shuichi

2014-04-01

Three-dimensional culture systems bridge the experimental gap between in vivo and in vitro physiology. However, nonstandardized formation and limited downstream adaptability of 3D cultures have hindered mainstream adoption of these systems for biological applications, especially for low- and moderate-throughput assays commonly used in biomedical research. Here we build on our recent development of a 384-well hanging drop plate for spheroid culture to design a complementary spheroid transfer and imaging (TRIM) plate. The low-aspect ratio wells of the TRIM plate facilitated high-fidelity, user-independent, contact-based collection of hanging drop spheroids. Using the TRIM plate, we demonstrated several downstream analyses, including bulk tissue collection for flow cytometry, high-resolution low working-distance immersion imaging, and timely reagent delivery for enzymatic studies. Low working-distance multiphoton imaging revealed a cell type-dependent, macroscopic spheroid structure. Unlike ovarian cancer spheroids, which formed loose, disk-shaped spheroids, human mammary fibroblasts formed tight, spherical, and nutrient-limited spheroids. Beyond the applications we describe here, we expect the hanging drop spheroid plate and complementary TRIM plate to facilitate analyses of spheroids across the spectrum of throughput, particularly for bulk collection of spheroids and high-content imaging.

Effectiveness of mesenchymal stems cells cultured by hanging drop vs. conventional culturing on the repair of hypoxic-ischemic-damaged mouse brains, measured by stemness gene expression

OpenAIRE

Lou Yongli; Guo Dewei; Zhang Hui; Song Laijun

2016-01-01

In this study, we investigated the therapeutic effects of Human Mesenchymal Stem Cells (hMSCs) cultured by hanging drop and conventional culturing methods on cerebellar repair in hypoxic-ischemic (HI) brain injured mice. Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to analyze the expression levels of three stemness genes, Oct4, Sox2 and Nanog, and the migration related gene CXCR4. MSC prepared by hanging drop or conventional techniques were adminis...

Study of electrochemical behavior of desatinib using hanging mercury drop electrode and gold disc electrode

Czech Academy of Sciences Publication Activity Database

Nováková, Kateřina; Navrátil, Tomáš; Jaklová Dytrtová, Jana; Jakl, M.

2015-01-01

Roč. 11, č. 1 (2015), s. 116-116 ISSN 1336-7242 Institutional support: RVO:61388955 ; RVO:61388963 Keywords : electrochemistry * hanging mercury drop electrode * gold electrode Subject RIV: CG - Electrochemistry

Hanging drop crystal growth apparatus and method

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Carter, Daniel C. (Inventor); Smith, Robbie E. (Inventor)

1989-01-01

An apparatus (10) is constructed having a cylindrical enclosure (16) within which a disc-shaped wicking element (18) is positioned. A well or recess (22) is cut into an upper side (24) of this wicking element, and a glass cover plate or slip (28) having a protein drop disposed thereon is sealably positioned on the wicking element (18), with drop (12) being positioned over well or recess (22). A flow of control fluid is generated by a programmable gradient former (16), with this control fluid having a vapor pressure that is selectively variable. This flow of control fluid is coupled to the wicking element (18) where control fluid vapor diffusing from walls (26) of the recess (22) is exposed to the drop (12), forming a vapor pressure gradient between the drop (12) and the control fluid vapor. Initially, this gradient is adjusted to draw solvent from the drop (12) at a relatively high rate, and as the critical supersaturation point is approached (the point at which crystal nucleation occurs), the gradient is reduced to more slowly draw solvent from the drop (12). This allows discrete protein molecules more time to orient themselves into an ordered crystalline lattice, producing protein crystals which, when processed by X-ray crystallography, possess a high degree of resolution.

Imaging transport phenomena during lysozyme protein crystal growth by the hanging drop technique

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Sethia Gupta, Anamika; Gupta, Rajive; Panigrahi, P. K.; Muralidhar, K.

2013-06-01

The present study reports the transport process that occurs during the growth of lysozyme protein crystals by the hanging drop technique. A rainbow schlieren technique has been employed for imaging changes in salt concentration. A one dimensional color filter is used to record the deflection of the light beam. An optical microscope and an X-ray crystallography unit are used to characterize the size, tetragonal shape and Bravais lattice constants of the grown crystals. A parametric study on the effect of drop composition, drop size, reservoir height and number of drops on the crystal size and quality is reported. Changes in refractive index are not large enough to create a meaningful schlieren image in the air gap between the drop and the reservoir. However, condensation of fresh water over the reservoir solution creates large changes in the concentration of NaCl, giving rise to clear color patterns in the schlieren images. These have been analyzed to obtain salt concentration profiles near the free surface of the reservoir solution as a function of time. The diffusion of fresh water into the reservoir solution at the early stages of crystal growth followed by the mass flux of salt from the bulk solution towards the free surface has been recorded. The overall crystal growth process can be classified into two regimes, as demarcated by the changes in slope of salt concentration within the reservoir. The salt concentration in the reservoir equilibrates at long times when the crystallization process is complete. Thus, transport processes in the reservoir emerge as the route to monitor protein crystal growth in the hanging drop configuration. Results show that crystal growth rate is faster for a higher lysozyme concentration, smaller drops, and larger reservoir heights.

Media additives to promote spheroid circularity and compactness in hanging drop platform.

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Leung, Brendan M; Lesher-Perez, Sasha Cai; Matsuoka, Toshiki; Moraes, Christopher; Takayama, Shuichi

2015-02-01

Three-dimensional spheroid cultures have become increasingly popular as drug screening platforms, especially with the advent of different high throughput spheroid forming technologies. However, comparing drug efficacy across different cell types in spheroid culture can be difficult due to variations in spheroid morphologies and transport characteristics. Improving the reproducibility of compact, circular spheroids contributes to standardizing and increasing the fidelity of the desired gradient profiles in these drug screening three-dimensional tissue cultures. In this study we discuss the role that circularity and compaction has on spheroids, and demonstrate the impact methylcellulose (MethoCel) and collagen additives in the culture media can contribute to more compact and circular spheroid morphology. We demonstrate that improved spheroid formation is not a simple function of increased viscosity of the different macromolecule additives, suggesting that other macromolecular characteristics contribute to improved spheroid formation. Of the various macromolecular additives tested for hanging drop culture, MethoCel provided the most desirable spheroid formation. Additionally, the higher viscosity of MethoCel-containing media improved the ease of imaging of cellular spheroids within hanging drop cultures by reducing motion-induced image blur.

3D Hanging Drop Culture to Establish Prostate Cancer Organoids.

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Eder, Theresa; Eder, Iris E

2017-01-01

Three-dimensional (3D) cell culture enables the growth of cells in a multidimensional and multicellular manner compared to conventional cell culture techniques. Especially in prostate cancer research there is a big need for more tissue-recapitulating models to get a better understanding of the mechanisms driving prostate cancer as well as to screen for more efficient drugs that can be used for treatment. In this chapter we describe a 3D hanging drop system that can be used to culture prostate cancer organoids as tumor epithelial monocultures and as epithelial-stromal cocultures.

Comparison of spring-loaded, loss of resistance and hanging drop techniques in lumbar epidural blocks.

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Gülen, Güven; Akkaya, Taylan; Ozkan, Derya; Kaydul, Mehmet; Gözaydin, Orhan; Gümüş, Haluk

2012-01-01

The spring-loaded syringe is a loss of resistance syringe that provide a more objective sign that the epidural space has been entered compared with the traditional techniques. The aim of this study was to compare the time required to locate the epidural space and the backache incidence with the spring-loaded (SL), loss of resistance (LOR) and the hanging drop (HD) techniques for epidural blocks in patients undergoing transurethral resection procedure. Sixty patients undergoing transurethral resections were enrolled in the study. The patients were randomly assigned to one of three groups. Epidural block was performed in the first group with a spring-loaded syringe (n=20), in the second group with loss-of-resistance syringe (n=20), and in the third group with the hanging drop technique (n=20). The required time to locate the epidural space, the number of attempts, the incidence of dural puncture and the backache incidence were assessed during the procedure and for four weeks after the procedure in all patients. The required time to locate the epidural space was 29.1 ± 9.16 seconds in Group 1; 45.25 ± 19.58 seconds in Group 2, and 47.35 ± 11.42 seconds in Group 3 (p0.05). The use of SL syringe was found to have a shorter time period to locate the epidural space when compared with the LOR syringe and hanging drop technique.

Determination of nitrobenzene in wastewater using a hanging mercury drop electrode.

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Liang, Shu-Xuan; Zhang, Huan-Kun; Lu, Da

2007-06-01

The determination of trace amount nitrobenzene in wastewater on a hanging mercury drop electrode was studied. The determination conditions of pH, supporting electrolyte, accumulation potential, accumulation time, and voltammetric response were optimized. The sharp peak of the nitrobenzene was appeared at 0.05 V. The peak electric current was proportional to the concentration of nitrobenzene in the range of 1.47 x 10(-5) approximately 1.0 x 10(-3) mol/l with relative standard deviations of 3.99 approximately 8.94%. The detection limit of the nitrobenzene in water was 5 x 10(-6) mol/l. The proposed method offered low limit of determination, easy operation, the use of simple instrumentation, high sensitivity and good reproducibility. It was applied to the determination of nitrobenzene in wastewater with an average recovery of 94.0% approximately 105%. The proposed method provided fast, sensitive and sometimes real time detection of nitrobenzene.

Enhanced differentiation of human embryonic stem cells into cardiomyocytes by combining hanging drop culture and 5-azacytidine treatment.

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Yoon, Byung Sun; Yoo, Seung Jun; Lee, Jeoung Eun; You, Seungkwon; Lee, Hoon Taek; Yoon, Hyun Soo

2006-04-01

Cell replacement therapy is a promising approach for the treatment of cardiac diseases. It is, however, challenged by a limited supply of appropriate cells. Therefore, we have investigated whether functional cardiomyocytes can be efficiently generated from human embryonic stem cells (hESCs). In this study, we developed an efficient protocol for the generation of functional cardiomyocytes from hESCs by combining hanging drop culture and 5-azacytidine, a well-known demethylating agent, and then evaluated the expression of cardiac-specific markers. hESCs were cultured both in the medium without or with 0.1, 1, or 10 microM of 5-azacytidine under a hanging drop culture. The expression of several cardiac-specific markers was determined by real-time PCR, RT-PCR, immunofluorescence, and confocal microscopy. To verify the structural and functional properties of hESC-derived cardiomyocytes, we performed electron microscopy and electrophysiological recording. The efficiency of beating cell generation was significantly improved in the hanging drop culture compared with that in suspension culture. Treatment of hESCs with 0.1 microM of 5-azacytidine for 1-3 days significantly increased the number of beating cells and simultaneously enhanced the expression of cardiac-specific markers. Transmission electron microscopy and electrophysiological recording showed that hESC-derived cardiomyocytes acquired structural and functional properties of cardiomyocytes. In conclusion, these results suggest that differentiation of hESCs into cardiomyocytes can be enhanced by the combination of hanging drop culture and 5-azacytidine treatment. Also the methylation status of genes related to cardiomyocyte development may play an important role in the differentiation of hESCs into cardiomyocytes.

Hanging drop culture enhances differentiation of human adipose-derived stem cells into anterior neuroectodermal cells using small molecules.

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Amirpour, Noushin; Razavi, Shahnaz; Esfandiari, Ebrahim; Hashemibeni, Batoul; Kazemi, Mohammad; Salehi, Hossein

2017-06-01

Inspired by in vivo developmental process, several studies were conducted to design a protocol for differentiating of mesenchymal stem cells into neural cells in vitro. Human adipose-derived stem cells (hADSCs) as mesenchymal stem cells are a promising source for this purpose. At current study, we applied a defined neural induction medium by using small molecules for direct differentiation of hADSCs into anterior neuroectodermal cells. Anterior neuroectodermal differentiation of hADSCs was performed by hanging drop and monolayer protocols. At these methods, three small molecules were used to suppress the BMP, Nodal, and Wnt signaling pathways in order to obtain anterior neuroectodermal (eye field) cells from hADSCs. After two and three weeks of induction, the differentiated cells with neural morphology expressed anterior neuroectodermal markers such as OTX2, SIX3, β-TUB III and PAX6. The protein expression of such markers was confirmed by real time, RT-PCR and immunocytochemistry methods According to our data, it seems that the hanging drop method is a proper approach for neuroectodermal induction of hADSCs. Considering wide availability and immunosuppressive properties of hADSCs, these cells may open a way for autologous cell therapy of neurodegenerative disorders. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Sizing of colloidal particle and protein molecules in a hanging fluid drop

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Ansari, Rafat R.; Suh, Kwang I.

1995-01-01

We report non-invasive particle size measurements of polystyrene latex colloidal particles and bovine serum albumin (BSA) protein molecules suspended in tiny hanging fluid drops of 30 micro-Liter volume using a newly designed fiber optic probe. The probe is based upon the principles of the technique of dynamic light scattering (DLS). The motivation for this work comes from growing protein crystals in outer space. Protein crystals have been grown previously in hanging drops in microgravity experiments on-board the space shuttle orbiter. However, obtaining quantitative information on nucleation and growth of the protein crystals in real time has always been a desired goal, but hitherto not achieved. Several protein researchers have shown interest in using DLS to monitor crystal growth process in a droplet, but elaborate instrumentation and optical alignment problems have made in-situ applications difficult. We demonstrate that such an experiment is now possible. Our system offers fast (5 seconds) determination of particle size, utilize safe levels of very low laser power (less than or equal to 0.2 mW), a small scattering volume (approximately 2 x 10(exp -5) cu mm) and high spatial coherence (Beta) values. This is a major step forward when compared to currently available DLS systems.

Seamless Combination of Fluorescence-Activated Cell Sorting and Hanging-Drop Networks for Individual Handling and Culturing of Stem Cells and Microtissue Spheroids.

Science.gov (United States)

Birchler, Axel; Berger, Mischa; Jäggin, Verena; Lopes, Telma; Etzrodt, Martin; Misun, Patrick Mark; Pena-Francesch, Maria; Schroeder, Timm; Hierlemann, Andreas; Frey, Olivier

2016-01-19

Open microfluidic cell culturing devices offer new possibilities to simplify loading, culturing, and harvesting of individual cells or microtissues due to the fact that liquids and cells/microtissues are directly accessible. We present a complete workflow for microfluidic handling and culturing of individual cells and microtissue spheroids, which is based on the hanging-drop network concept: The open microfluidic devices are seamlessly combined with fluorescence-activated cell sorting (FACS), so that individual cells, including stem cells, can be directly sorted into specified culturing compartments in a fully automated way and at high accuracy. Moreover, already assembled microtissue spheroids can be loaded into the microfluidic structures by using a conventional pipet. Cell and microtissue culturing is then performed in hanging drops under controlled perfusion. On-chip drop size control measures were applied to stabilize the system. Cells and microtissue spheroids can be retrieved from the chip by using a parallelized transfer method. The presented methodology holds great promise for combinatorial screening of stem-cell and multicellular-spheroid cultures.

Voltammetric Determination of Carcinogenic Nitrobiphenyls at a Hanging Mercury Drop Electrode

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Jiří Zima

2003-02-01

Full Text Available Differential pulse voltammetry (DPV and adsorptive stripping voltammetry (AdSV at a hanging mercury drop electrode (HMDE was used for the determination of trace amounts of carcinogenic nitrobiphenyls, namely 2-nitrobiphenyl (2-NBP, 3-nitrobiphenyl (3-NBP and 4-nitrobiphenyl (4-NBP within the concentration range from 2.10-8 to 1.10-5 mol⋅L-1 for DPV and from 2.10-9 to 1.10-7 mol⋅L-1 for AdSV using a Britton-Robinson buffer – methanol (1:1 mixture with resulting pH 12 as a base electrolyte. The practical applicability of newly developed methods was verified using model samples of drinking and river water and liquid-liquid extraction for a preliminary separation and preconcentration.

Increased sensitivity of anodic stripping voltammetry at the hanging mercury drop electrode by ultracathodic deposition.

Science.gov (United States)

Rodrigues, José A; Rodrigues, Carlos M; Almeida, Paulo J; Valente, Inês M; Gonçalves, Luís M; Compton, Richard G; Barros, Aquiles A

2011-09-09

An improved approach to the anodic stripping voltammetric (ASV) determination of heavy metals, using the hanging mercury drop electrode (HMDE), is reported. It was discovered that using very cathodic accumulation potentials, at which the solvent reduction occurs (overpotential deposition), the voltammetric signals of zinc(II), cadmium(II), lead(II) and copper(II) increase. When compared with the classical methodology a 5 to 10-fold signal increase is obtained. This effect is likely due to both mercury drop oscillation at such cathodic potentials and added local convection at the mercury drop surface caused by the evolution of hydrogen bubbles. Copyright © 2011 Elsevier B.V. All rights reserved.

Human HepaRG Cells can be Cultured in Hanging-drop Plates for Cytochrome P450 Induction and Function Assays.

Science.gov (United States)

Murayama, Norie; Usui, Takashi; Slawny, Nicky; Chesné, Christophe; Yamazaki, Hiroshi

2015-01-01

Recent guidance/guidelines for industry recommend that cytochrome P450 induction can be assessed using human hepatocyte enzyme activity and/or mRNA levels to evaluate potential drug- drug interactions. To evaluate time-dependent cytochrome P450 induction precisely, induction of CYP1A2, CYP2B6, and CYP3A4 mRNA was confirmed (>2-fold) by the treatment with omeprazole, phenobarbital, and rifampicin, respectively, for 24 or 48 h on day 3 from the start of culture. After 24 h, the fold induction of CYP1A2 with 3.6 and 1.8x10(4) HepaRG cells per well was lower than that for 7.2x10(4) cells. CYP1A2 induction levels at 24 h were higher than those after 48 h. In contrast, higher CYP2B6 inductions were confirmed after 48 h exposure than after 24 h, independent of the number of cells per well. To help reduce the use of human cryopreserved hepatocytes, typical P450-dependent enzyme activities were investigated in human HepaRG cells cultured in commercial hanging-drop plates. Newly designed 96-well hanging-drop plates were capable of maintaining human CYP3A-dependent midazolam hydroxylation activities for up to 4 days using only 10% of the recommended initial 7.2x10(4) cells per well. Favorable HepaRG function using hanging-drop plates was confirmed by detecting 1'- hydroxymidazolam O-glucuronide on day 3, suggesting an improvement over traditional control plates in which this metabolite can be detected for 24-well plates. These results suggest that the catalytic function and/or induction of CYP1A2, CYP2B6, and CYP3A4 can be readily assessed with reduced numbers of starting HepaRG cells cultured in three-dimensional cultures in drops prepared with hanging-drop plates.

High-throughput 3D spheroid culture and drug testing using a 384 hanging drop array.

Science.gov (United States)

Tung, Yi-Chung; Hsiao, Amy Y; Allen, Steven G; Torisawa, Yu-suke; Ho, Mitchell; Takayama, Shuichi

2011-02-07

Culture of cells as three-dimensional (3D) aggregates can enhance in vitro tests for basic biological research as well as for therapeutics development. Such 3D culture models, however, are often more complicated, cumbersome, and expensive than two-dimensional (2D) cultures. This paper describes a 384-well format hanging drop culture plate that makes spheroid formation, culture, and subsequent drug testing on the obtained 3D cellular constructs as straightforward to perform and adapt to existing high-throughput screening (HTS) instruments as conventional 2D cultures. Using this platform, we show that drugs with different modes of action produce distinct responses in the physiological 3D cell spheroids compared to conventional 2D cell monolayers. Specifically, the anticancer drug 5-fluorouracil (5-FU) has higher anti-proliferative effects on 2D cultures whereas the hypoxia activated drug commonly referred to as tirapazamine (TPZ) are more effective against 3D cultures. The multiplexed 3D hanging drop culture and testing plate provides an efficient way to obtain biological insights that are often lost in 2D platforms.

Energy stability of droplets and dry spots in a thin film model of hanging drops

Science.gov (United States)

Cheung, Ka-Luen; Chou, Kai-Seng

2017-10-01

The 2-D thin film equation describing the evolution of hang drops is studied. All radially symmetric steady states are classified, and their energy stability is determined. It is shown that the droplet with zero contact angle is the only global energy minimizer and the dry spot with zero contact angle is a strict local energy minimizer.

Cervical spine injuries in suicidal hanging without a long-drop--patterns and possible underlying mechanisms of injury: an autopsy study.

Science.gov (United States)

Nikolić, Slobodan; Zivković, Vladimir

2014-06-01

The incidence of cervical spine injuries in suicidal hangings with a short-drop has been reported to be extremely low or non-existent. The aim of this study was to determine the frequency and pattern of cervical spine injuries in suicidal hanging. A retrospective autopsy study was performed and short-drop suicidal hanging cases with documented cervical spine injuries were identified. This group was further analyzed with regard to the gender and age of the deceased, the position of the ligature knot, the presence of hyoid-laryngeal fractures, and the level of cervical spine injury. Cervical spine injuries were present in 25 of the 766 cases, with an average age of 71.9 ± 10.7 years (range 39-88 years). In 16 of these 25 cases, the ligature knot was in the anterior position. The most common pattern of cervical spine injury included partial or complete disruption of the anterior longitudinal ligament and widening of the lower cervical spine disk spaces, associated with absence of hyoid-laryngeal fractures. Cervical spine injuries are not commonly found in short-drop suicidal hanging, occurring in only 3.3 % of all observed cases. Cervical spine injury may be occurring in 80 % of subjects aged 66.5 years and above. The most common pattern of cervical spine injury included anterior longitudinal ligament disruption of the lower cervical spine, disk space widening, and no vertebral body displacement. These injuries were mainly associated with an anterior knot position, and may be a consequence of loop pressure to the posterior neck and cervical spine hyperextension.

Voltammetric behavior of amfepramone (diethylpropion) at the hanging mercury drop electrode and its analytical determination in pharmaceutical formulations

OpenAIRE

Carvalho, Leandro M. de; Nascimento, Paulo C. do; Bohrer, Denise; Correia, Daniele; Bairros, André V. de; Pomblum, Valdeci J.; Pomblum, Solange G.

2007-01-01

This paper describes a systematic study of the voltammetric behavior of amfepramone at the hanging mercury drop electrode (HMDE) by cyclic (CV) and alternating current (AC) voltammetric methods. The studies showed the adsorptive behavior of amfepramone at the HMDE and were performed in H2SO4 0.1 mol L-1 (pH 1.0) and Ringer buffer (pH 11.0) as supporting electrolytes. The linear range for the amfepramone determination by differential pulse voltammetry (DPV) was 0.05 to 2.0 mg L-1 (r = 0.998) i...

Life-History Traits of the Model Organism Pristionchus pacificus Recorded Using the Hanging Drop Method: Comparison with Caenorhabditis elegans.

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Gilarte, Patricia; Kreuzinger-Janik, Bianca; Majdi, Nabil; Traunspurger, Walter

2015-01-01

The nematode Pristionchus pacificus is of growing interest as a model organism in evolutionary biology. However, despite multiple studies of its genetics, developmental cues, and ecology, the basic life-history traits (LHTs) of P. pacificus remain unknown. In this study, we used the hanging drop method to follow P. pacificus at the individual level and thereby quantify its LHTs. This approach allowed direct comparisons with the LHTs of Caenorhabditis elegans recently determined using this method. When provided with 5×10(9) Escherichia coli cells ml(-1) at 20°C, the intrinsic rate of natural increase of P. pacificus was 1.125 (individually, per day); mean net production was 115 juveniles produced during the life-time of each individual, and each nematode laid an average of 270 eggs (both fertile and unfertile). The mean age of P. pacificus individuals at first reproduction was 65 h, and the average life span was 22 days. The life cycle of P. pacificus is therefore slightly longer than that of C. elegans, with a longer average life span and hatching time and the production of fewer progeny.

Life-History Traits of the Model Organism Pristionchus pacificus Recorded Using the Hanging Drop Method: Comparison with Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Patricia Gilarte

Full Text Available The nematode Pristionchus pacificus is of growing interest as a model organism in evolutionary biology. However, despite multiple studies of its genetics, developmental cues, and ecology, the basic life-history traits (LHTs of P. pacificus remain unknown. In this study, we used the hanging drop method to follow P. pacificus at the individual level and thereby quantify its LHTs. This approach allowed direct comparisons with the LHTs of Caenorhabditis elegans recently determined using this method. When provided with 5×10(9 Escherichia coli cells ml(-1 at 20°C, the intrinsic rate of natural increase of P. pacificus was 1.125 (individually, per day; mean net production was 115 juveniles produced during the life-time of each individual, and each nematode laid an average of 270 eggs (both fertile and unfertile. The mean age of P. pacificus individuals at first reproduction was 65 h, and the average life span was 22 days. The life cycle of P. pacificus is therefore slightly longer than that of C. elegans, with a longer average life span and hatching time and the production of fewer progeny.

Developing a continuous flow-square wave voltammetry method for determination of atrazine in soil solutions using the hanging mercury drop electrode

Directory of Open Access Journals (Sweden)

Santos Luciana B. O. dos

2006-01-01

Full Text Available This work describes the development of a Continuous Flow-Square Wave Voltammetry method for determination of atrazine using the hanging mercury drop electrode. The best signal to noise ratio was obtained at the square wave frequency of 350 Hz and flow rate of 0.47 mL min-1. Under these conditions, the analytical curve obtained in 0.010 mol L-1 CaCl2 soil extracts in presence of 40 mmol L-1 BR buffer and 0.25 mol L-1 NaNO3 was linear for atrazine concentrations between 0.10 and 2.0 µg mL-1, with detection and quantification limits of 0.030 and 0.10 µg mL-1, respectively. The proposed method increased the analytical throughput in comparison with the batch methodology, allowing a sampling frequency of 72 h-1 to be accomplished. Besides, the sample consumption is significantly reduced, and only 341 µL are necessary for each analysis. The results obtained were similar to the ones obtained by HPLC, but the proposed method is faster and does not use organic solvents.

Increased sensitivity of anodic stripping voltammetry at the hanging mercury drop electrode by ultracathodic deposition

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Jose A.; Rodrigues, Carlos M.; Almeida, Paulo J.; Valente, Ines M.; Goncalves, Luis M. [Requimte - Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, no. 687, 4169-007 Porto (Portugal); Compton, Richard G. [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ (United Kingdom); Barros, Aquiles A., E-mail: ajbarros@fc.up.pt [Requimte - Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, no. 687, 4169-007 Porto (Portugal)

2011-09-09

Highlights: {yields} At very cathodic accumulation potentials (overpotential deposition) the voltammetric signals of Zn{sup 2+}, Cd{sup 2+}, Pb{sup 2+} and Cu{sup 2+} increase. {yields} 5 to 10-fold signal increase is obtained. {yields} This effect is likely due to mercury drop oscillation at such cathodic potentials. {yields} This effect is also likely due to added local convection at the mercury drop surface caused by the evolution of hydrogen bubbles. - Abstract: An improved approach to the anodic stripping voltammetric (ASV) determination of heavy metals, using the hanging mercury drop electrode (HMDE), is reported. It was discovered that using very cathodic accumulation potentials, at which the solvent reduction occurs (overpotential deposition), the voltammetric signals of zinc(II), cadmium(II), lead(II) and copper(II) increase. When compared with the classical methodology a 5 to 10-fold signal increase is obtained. This effect is likely due to both mercury drop oscillation at such cathodic potentials and added local convection at the mercury drop surface caused by the evolution of hydrogen bubbles.

Optimal formation of genetically modified and functional pancreatic islet spheroids by using hanging-drop strategy.

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Kim, H J; Alam, Z; Hwang, J W; Hwang, Y H; Kim, M J; Yoon, S; Byun, Y; Lee, D Y

2013-03-01

Rejection and hypoxia are important factors causing islet loss at an early stage after pancreatic islet transplantation. Recently, islets have been dissociated into single cells for reaggregation into so-called islet spheroids. Herein, we used a hanging-drop strategy to form islet spheroids to achieve functional equivalence to intact islets. To obtain single islet cells, we dissociated islets with trypsin-EDTA digestion for 10 minutes. To obtain spheroids, we dropped various numbers of single cells (125, 250, or 500 cells/30 μL drop) onto a Petri dish, that was inverted for incubation in humidified air containing 5% CO(2) at 37 °C for 7 days. The aggregated spheroids in the droplets were harvested for further culture. The size of the aggregated islet spheroids depended on the number of single cells (125-500 cells/30 μL droplet). Their morphology was similar to that of intact islets without any cellular damage. When treated with various concentrations of glucose to evaluate responsiveness, their glucose-mediated stimulation index value was similar to that of intact islets, an observation that was attributed to strong cell-to-cell interactions in islet spheroids. However, islet spheroids aggregated in general culture dishes showed abnormal glucose responsiveness owing to weak cell-to-cell interactions. Cell-to-cell interactions in islet spheroids were confirmed with an anti-connexin-36 monoclonal antibody. Finally, nonviral poly(ethylene imine)-mediated interleukin-10 cytokine gene delivered beforehand into dissociated single cells before formation of islet spheroids increased the gene transfection efficacy and interleukin-10 secretion from islet spheroids >4-fold compared with intact islets. These results demonstrated the potential application of genetically modified, functional islet spheroids with of controlled size and morphology using an hanging-drop technique. Copyright © 2013 Elsevier Inc. All rights reserved.

Rat pancreatic islet size standardization by the "hanging drop" technique.

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Cavallari, G; Zuellig, R A; Lehmann, R; Weber, M; Moritz, W

2007-01-01

Rejection and hypoxia are the main factors that limit islet engraftment in the recipient liver in the immediate posttransplant period. Recently authors have reported a negative relationship of graft function and islet size, concluding that small islets are superior to large islets. Islets can be dissociated into single cells and reaggregated into so called "pseudoislets," which are functionally equivalent to intact islets but exhibit reduced immunogenicity. The aim of our study was develop a technique that enabled one to obtain pseudoislets of defined, preferably small, dimensions. Islets were harvested from Lewis rats by the collagenase digestion procedure. After purification, the isolated islets were dissociated into single cells by trypsin digestion. Fractions with different cell numbers were seeded into single drops onto cell culture dishes, which were inverted and incubated for 5 to 8 days under cell culture conditions. Newly formed pseudoislets were analyzed for dimension, morphology, and cellular composition. The volume of reaggregated pseudoislets strongly correlated with the cell number (r(2) = .995). The average diameter of a 250-cell aggregate was 95 +/- 8 microm (mean +/- SD) compared with 122 +/- 46 microm of freshly isolated islets. Islet cell loss may be minimized by performing reaggregation in the presence of medium glucose (11 mmol/L) and the GLP-1 analogue Exendin-4. Morphology, cellular composition, and architecture of reaggregated islets were comparable to intact islets. The "hanging drop" culture method allowed us to obtain pseudoislets of standardized size and regular shape, which did not differ from intact islets in terms of cellular composition or architecture. Further investigations are required to minimize cell loss and test in vivo function of transplanted pseudoislets.

Etiology and use of the "hanging drop" technique: a review.

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Todorov, Ludmil; VadeBoncouer, Timothy

2014-01-01

Background. The hanging drop (HD) technique presumably relies on the presence of subatmospheric epidural pressure. It is not clear whether this negative pressure is intrinsic or an artifact and how it is affected by body position. There are few data to indicate how often HD is currently being used. Methods. We identified studies that measured subatmospheric pressures and looked at the effect of the sitting position. We also looked at the technique used for cervical and thoracic epidural anesthesia in the last 10 years. Results. Intrinsic subatmospheric pressures were measured in the thoracic and cervical spine. Three trials studied the effect of body position, indicating a higher incidence of subatmospheric pressures when sitting. The results show lower epidural pressure (-10.7 mmHg) with the sitting position. 28.8% of trials of cervical and thoracic epidural anesthesia that documented the technique used, utilized the HD technique. When adjusting for possible bias, the rate of HD use can be as low as 11.7%. Conclusions. Intrinsic negative pressure might be present in the cervical and thoracic epidural space. This effect is more pronounced when sitting. This position might be preferable when using HD. Future studies are needed to compare it with the loss of resistance technique.

Imprinted polymer-modified hanging mercury drop electrode for differential pulse cathodic stripping voltammetric analysis of creatine.

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Lakshmi, Dhana; Sharma, Piyush S; Prasad, Bhim B

2007-06-15

The molecularly imprinted polymer [poly(p-aminobenzoicacid-co-1,2-dichloroethane)] film casting was made on the surface of a hanging mercury drop electrode by drop-coating method for the selective and sensitive evaluation of creatine in water, blood serum and pharmaceutical samples. The molecular recognition of creatine by the imprinted polymer was found to be specific via non-covalent (electrostatic) imprinting. The creatine binding could easily be detected by differential pulse, cathodic stripping voltammetric signal at optimised operational conditions: accumulation potential -0.01 V (versus Ag/AgCl), polymer deposition time 15s, template accumulation time 60s, pH 7.1 (supporting electrolyte< or =5 x 10(-4)M NaOH), scan rate 10 mV s(-1), pulse amplitude 25 mV. The modified sensor in the present study was found to be highly reproducible and selective with detection limit 0.11 ng mL(-1) of creatine. Cross-reactivity studies revealed no response to the addition of urea, creatinine and phenylalanine; however, some insignificant magnitude of current was observed for tryptophan and histidine in the test samples.

Growth factors mediated differentiation of mesenchymal stem cells to cardiac polymicrotissue using hanging drop and bioreactor.

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Konstantinou, Dimitrios; Lei, Ming; Xia, Zhidao; Kanamarlapudi, Venkateswarlu

2015-04-01

Heart disease is the major leading cause of death worldwide and the use of stem cells promises new ways for its treatment. The relatively easy and quick acquisition of human umbilical cord matrix mesenchymal stem cells (HUMSCs) and their properties make them useful for the treatment of cardiac diseases. Therefore, the main aim of this investigation was to create cardiac polymicrotissue from HUMSCs using a combination of growth factors [sphingosine-1-phosphate (S1P) and suramin] and techniques (hanging drop and bioreactor). Using designated culture conditions of the growth factors (100 nM S1P and 500 µM suramin), cardiomyocyte differentiation medium (CDM), hanging drop, bioreactor and differentiation for 7 days, a potential specific cardiac polymicrotissue was derived from HUMSCs. The effectiveness of growth factors alone or in combination in differentiation of HUMSCs to cardiac polymicrotissue was analysed by assessing the presence of cardiac markers by immunocytochemistry. This analysis demonstrated the importance of those growth factors for the differentiation. This study for the first time demonstrated the formation of a cardiac polymicrotissue under specific culture conditions. The polymicrotissue thus obtained may be used in future as a 'patch' to cover the injured cardiac region and would thereby be useful for the treatment of heart diseases. © 2014 International Federation for Cell Biology.

Water collection behavior and hanging ability of bioinspired fiber.

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Hou, Yongping; Chen, Yuan; Xue, Yan; Zheng, Yongmei; Jiang, Lei

2012-03-13

Since the water-collecting ability of the wetted cribellate spider capture silk is the result of a unique fiber structure, bioinspired fibers have been researched significantly so as to expose a new water-acquiring route in fogging-collection projects. However, the design of the geometry of bioinspired fiber is related to the ability of hanging drops, which has not been investigated in depth so far. Here, we fabricate bioinspired fibers to investigate the water collection behavior and the influence of geometry (i.e., periodicity of spindle knot) on the hanging-drop ability. We especially discuss water collection related to the periodicity of geometry on the bioinspired fiber. We reveal the length of the three phase contact line (TCL) at threshold conditions in conjunction with the maximal volume of a hanging drop at different modes. The study demonstrates that the geometrical structure of bioinspired fiber induces much stronger water hanging ability than that of uniform fiber, attributed to such special geometry that offers effectively an increasing TCL length or limits the contact length to be shorted. In addition, the geometry also improves the fog-collection efficiency by controlling tiny water drops to be collected in the large water drops at a given location.

Hematopoietic Stem and Progenitor Cell Expansion in Contact with Mesenchymal Stromal Cells in a Hanging Drop Model Uncovers Disadvantages of 3D Culture.

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Schmal, Olga; Seifert, Jan; Schäffer, Tilman E; Walter, Christina B; Aicher, Wilhelm K; Klein, Gerd

2016-01-01

Efficient ex vivo expansion of hematopoietic stem cells with a concomitant preservation of stemness and self-renewal potential is still an unresolved ambition. Increased numbers of methods approaching this issue using three-dimensional (3D) cultures were reported. Here, we describe a simplified 3D hanging drop model for the coculture of cord blood-derived CD34(+) hematopoietic stem and progenitor cells (HSPCs) with bone marrow-derived mesenchymal stromal cells (MSCs). When seeded as a mixed cell suspension, MSCs segregated into tight spheroids. Despite the high expression of niche-specific extracellular matrix components by spheroid-forming MSCs, HSPCs did not migrate into the spheroids in the initial phase of coculture, indicating strong homotypic interactions of MSCs. After one week, however, HSPC attachment increased considerably, leading to spheroid collapse as demonstrated by electron microscopy and immunofluorescence staining. In terms of HSPC proliferation, the conventional 2D coculture system was superior to the hanging drop model. Furthermore, expansion of primitive hematopoietic progenitors was more favored in 2D than in 3D, as analyzed in colony-forming assays. Conclusively, our data demonstrate that MSCs, when arranged with a spread (monolayer) shape, exhibit better HSPC supportive qualities than spheroid-forming MSCs. Therefore, 3D systems are not necessarily superior to traditional 2D culture in this regard.

Comparative Analysis of 3D Bladder Tumor Spheroids Obtained by Forced Floating and Hanging Drop Methods for Drug Screening

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Robson L. F. Amaral

2017-08-01

Full Text Available Introduction: Cell-based assays using three-dimensional (3D cell cultures may reflect the antitumor activity of compounds more accurately, since these models reproduce the tumor microenvironment better.Methods: Here, we report a comparative analysis of cell behavior in the two most widely employed methods for 3D spheroid culture, forced floating (Ultra-low Attachment, ULA, plates, and hanging drop (HD methods, using the RT4 human bladder cancer cell line as a model. The morphology parameters and growth/metabolism of the spheroids generated were first characterized, using four different cell-seeding concentrations (0.5, 1.25, 2.5, and 3.75 × 104 cells/mL, and then, subjected to drug resistance evaluation.Results: Both methods generated spheroids with a smooth surface and round shape in a spheroidization time of about 48 h, regardless of the cell-seeding concentration used. Reduced cell growth and metabolism was observed in 3D cultures compared to two-dimensional (2D cultures. The optimal range of spheroid diameter (300–500 μm was obtained using cultures initiated with 0.5 and 1.25 × 104 cells/mL for the ULA method and 2.5 and 3.75 × 104 cells/mL for the HD method. RT4 cells cultured under 3D conditions also exhibited a higher resistance to doxorubicin (IC50 of 1.00 and 0.83 μg/mL for the ULA and HD methods, respectively compared to 2D cultures (IC50 ranging from 0.39 to 0.43.Conclusions: Comparing the results, we concluded that the forced floating method using ULA plates was considered more suitable and straightforward to generate RT4 spheroids for drug screening/cytotoxicity assays. The results presented here also contribute to the improvement in the standardization of the 3D cultures required for widespread application.

Comparative Analysis of 3D Bladder Tumor Spheroids Obtained by Forced Floating and Hanging Drop Methods for Drug Screening.

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Amaral, Robson L F; Miranda, Mariza; Marcato, Priscyla D; Swiech, Kamilla

2017-01-01

Introduction: Cell-based assays using three-dimensional (3D) cell cultures may reflect the antitumor activity of compounds more accurately, since these models reproduce the tumor microenvironment better. Methods: Here, we report a comparative analysis of cell behavior in the two most widely employed methods for 3D spheroid culture, forced floating (Ultra-low Attachment, ULA, plates), and hanging drop (HD) methods, using the RT4 human bladder cancer cell line as a model. The morphology parameters and growth/metabolism of the spheroids generated were first characterized, using four different cell-seeding concentrations (0.5, 1.25, 2.5, and 3.75 × 10 4 cells/mL), and then, subjected to drug resistance evaluation. Results: Both methods generated spheroids with a smooth surface and round shape in a spheroidization time of about 48 h, regardless of the cell-seeding concentration used. Reduced cell growth and metabolism was observed in 3D cultures compared to two-dimensional (2D) cultures. The optimal range of spheroid diameter (300-500 μm) was obtained using cultures initiated with 0.5 and 1.25 × 10 4 cells/mL for the ULA method and 2.5 and 3.75 × 10 4 cells/mL for the HD method. RT4 cells cultured under 3D conditions also exhibited a higher resistance to doxorubicin (IC 50 of 1.00 and 0.83 μg/mL for the ULA and HD methods, respectively) compared to 2D cultures (IC 50 ranging from 0.39 to 0.43). Conclusions: Comparing the results, we concluded that the forced floating method using ULA plates was considered more suitable and straightforward to generate RT4 spheroids for drug screening/cytotoxicity assays. The results presented here also contribute to the improvement in the standardization of the 3D cultures required for widespread application.

Hematopoietic Stem and Progenitor Cell Expansion in Contact with Mesenchymal Stromal Cells in a Hanging Drop Model Uncovers Disadvantages of 3D Culture

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Olga Schmal

2016-01-01

Full Text Available Efficient ex vivo expansion of hematopoietic stem cells with a concomitant preservation of stemness and self-renewal potential is still an unresolved ambition. Increased numbers of methods approaching this issue using three-dimensional (3D cultures were reported. Here, we describe a simplified 3D hanging drop model for the coculture of cord blood-derived CD34+ hematopoietic stem and progenitor cells (HSPCs with bone marrow-derived mesenchymal stromal cells (MSCs. When seeded as a mixed cell suspension, MSCs segregated into tight spheroids. Despite the high expression of niche-specific extracellular matrix components by spheroid-forming MSCs, HSPCs did not migrate into the spheroids in the initial phase of coculture, indicating strong homotypic interactions of MSCs. After one week, however, HSPC attachment increased considerably, leading to spheroid collapse as demonstrated by electron microscopy and immunofluorescence staining. In terms of HSPC proliferation, the conventional 2D coculture system was superior to the hanging drop model. Furthermore, expansion of primitive hematopoietic progenitors was more favored in 2D than in 3D, as analyzed in colony-forming assays. Conclusively, our data demonstrate that MSCs, when arranged with a spread (monolayer shape, exhibit better HSPC supportive qualities than spheroid-forming MSCs. Therefore, 3D systems are not necessarily superior to traditional 2D culture in this regard.

Voltammetric analysis of N-containing drugs using the hanging galinstan drop electrode (HGDE).

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Channaa, H; Surmann, P

2009-03-01

The electrochemical behaviour of several N-containing voltammetric active drugs such as 1,4-benzodiazepines (chlordiazepoxide, nitrazepam and diazepam) as well as one nitro-compound (nitrofurantoin) and one azo-compound (phenazopyridine) is described using a new kind of liquid electrode, the hanging galinstan drop electrode. Concentrations of 10(-5) - 10(-8) mol L(-1) are generally measurable. Differential pulse and adsorptive stripping voltammograms are recorded in different supporting electrolytes, like 0.1 M KNO3, acetate buffer solution pH = 4.6 and phosphate buffer solution pH = 7.0. The effects of varying the starting potentials, U(start) for DPV and accumulation times, t(acc) for AdSV are considered. Briefly, it is shown that the novel galinstan electrode is suitable for reducing several functional groups in organic substances, here presented for N-oxide-, azomethine-, nitro- and azo-groups.

Laser scattering in a hanging drop vapor diffusion apparatus for protein crystal growth in a microgravity environment

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Casay, G. A.; Wilson, W. W.

1992-01-01

One type of hardware used to grow protein crystals in the microgravity environment aboard the U.S. Space Shuttle is a hanging drop vapor diffusion apparatus (HDVDA). In order to optimize crystal growth conditions, dynamic control of the HDVDA is desirable. A critical component in the dynamically controlled system is a detector for protein nucleation. We have constructed a laser scattering detector for the HDVDA capable of detecting the nucleation stage. The detector was successfully tested for several scatterers differing in size using dynamic light scattering techniques. In addition, the ability to detect protein nucleation using the HDVDA was demonstrated for lysozyme.

Formation and hematopoietic differentiation of human embryoid bodies by suspension and hanging drop cultures.

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Cerdan, Chantal; Hong, Seok Ho; Bhatia, Mickie

2007-10-01

The in vitro aggregation of human embryonic stem cells (hESCs) into clusters termed embryoid bodies (EBs) allows for the spontaneous differentiation of cells representing endoderm, mesoderm, and ectoderm lineages. This stochastic process results however, in the generation of low numbers of differentiated cells, and can be enhanced to some extent by the addition of exogenous growth factors or overexpression of regulatory genes. In the authors' laboratory, the use of hematopoietic cytokines in combination with the mesoderm inducer bone morphogenetic protein-4 (BMP-4) was able to generate up to 90% of CD45(+) hematopoietic cells with colony-forming unit (CFU) activity. This unit describes two protocols that have been successfully applied in the authors' laboratory for the generation of EBs in (1) suspension and (2) hanging drop (HD) cultures from enzymatically digested clumps of undifferentiated hESC colonies.

Hanging drop cultures of human testis and testis cancer samples: a model used to investigate activin treatment effects in a preserved niche.

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Jørgensen, A; Young, J; Nielsen, J E; Joensen, U N; Toft, B G; Rajpert-De Meyts, E; Loveland, K L

2014-05-13

Testicular germ cell tumours of young adults, seminoma or non-seminomas, are preceded by a pre-invasive precursor, carcinoma in situ (CIS), understood to arise through differentiation arrest of embryonic germ cells. Knowledge about the malignant transformation of germ cells is currently limited by the lack of experimental models. The aim of this study was to establish an experimental tissue culture model to maintain normal and malignant germ cells within their niche and allow investigation of treatment effects. Human testis and testis cancer specimens from orchidectomies were cultured in 'hanging drops' and effects of activin A and follistatin treatment were investigated in seminoma cultures. Testis fragments with normal spermatogenesis or CIS cells were cultured for 14 days with sustained proliferation of germ cells and CIS cells and without increased apoptosis. Seminoma cultures survived 7 days, with proliferating cells detectable during the first 5 days. Activin A treatment significantly reduced KIT transcript and protein levels in seminoma cultures, thereby demonstrating a specific treatment response. Hanging drop cultures of human testis and testis cancer samples can be employed to delineate mechanisms governing growth of normal, CIS and tumorigenic germ cells retained within their niche.

Suicidal Decapitation by Hanging-A Population-based Study.

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Byard, Roger W; Gilbert, John D

2018-05-01

A prospective study was undertaken at Forensic Science SA over a 15-year period from July 2002 to June 2017 for all cases of adult (>18 years) suicidal hangings with decapitation. A total of 1446 cases of suicidal hangings were identified from a general population of approximately 1.5 million (1206 males-age range 18-97 years, average 42.6; and 240 females-age range 18-96 years, average 40.1). Only three cases of decapitation were found, all from long-drop hangings; these consisted of three males (ages 32-55 years; average 45 years). Spinal transections had occurred between the first and second, second and third, and third and fourth cervical vertebrae, respectively. In this study, the number of suicidal hangings with decapitation represented only 0.2% of the total number of hangings. These events are therefore extremely rare, most likely due to most suicidal hangings occurring from relatively low levels in a domestic environment. © 2017 American Academy of Forensic Sciences.

Studying electron transfer through alkanethiol self-assembled monolayers on a hanging mercury drop electrode using potentiometric measurements.

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Cohen-Atiya, Meirav; Mandler, Daniel

2006-10-14

A new approach based on measuring the change of the open-circuit potential (OCP) of a hanging mercury drop electrode (HMDE), modified with alkanethiols of different chain length conducted in a solution containing a mixture of Ru(NH3)6(2+) and Ru(NH3)6(3+) is used for studying electron transfer across the monolayer. Following the time dependence of the OCP allowed the extraction of the kinetic parameters, such as the charge transfer resistance (R(ct)) and the electron transfer rate constant (k(et)), for different alkanethiol monolayers. An electron tunneling coefficient, beta, of 0.9 A(-1) was calculated for the monolayers on Hg.

Creatinine sensor based on a molecularly imprinted polymer-modified hanging mercury drop electrode.

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Lakshmi, Dhana; Prasad, Bhim Bali; Sharma, Piyush Sindhu

2006-09-15

Molecularly imprinted polymers (MIP) have been elucidated to work as artificial receptors. In our present study, a MIP was applied as a molecular recognition element to a chemical sensor. We have constructed a creatinine sensor based on a MIP layer selective for creatinine and its differential pulse, cathodic stripping voltammetric detection (DPCSV) on a hanging mercury drop electrode (HMDE). The creatinine sensor was fabricated by the drop coating of dimethylformamide (DMF) solution of a creatinine-imprinted polymer onto the surface of HMDE. The modified-HMDE, preanodised in neutral medium at +0.4V versus Ag/AgCl for 120s, exhibited a marked enhancement in DPCSV current in comparison to the less anodised (

Preparation of anti-inflammatory mesenchymal stem/precursor cells (MSCs) through sphere formation using hanging-drop culture technique.

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Bartosh, Thomas J; Ylostalo, Joni H

2014-02-06

Herein, we describe a protocol for preparation of pre-activated anti-inflammatory human mesenchymal stem/precursor cells (MSCs) in 3-D culture without addition of exogenous chemicals or gene-transfer approaches. MSCs are an easily procurable source of multipotent adult stem cells with therapeutic potential largely attributed to their paracrine regulation of inflammation and immunity. However, the culture conditions to prepare the ideal MSCs for cell therapy remain elusive. Furthermore, the reported lag time for activation in experimental models has prompted investigations on pre-activating the cells prior to their administration. In this protocol, standard 2-D culture-expanded MSCs are activated by aggregation into 3-D spheres using hanging-drop cultures. MSC activation is evaluated by real-time PCR and/or ELISA for anti-inflammatory factors (TSG-6, STC-1, PGE2), and by a functional assay using lipopolysaccharide-stimulated macrophage cultures. Further, we elucidate methods to prepare MSC-sphere conditioned medium, intact spheres, and suspension of single cells from spheres for experimental and clinical applications. Copyright © 2014 John Wiley & Sons, Inc.

Preparation of anti-inflammatory mesenchymal stem/precursor cells (MSCs) through sphere formation using hanging drop culture technique

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Bartosh, Thomas J.

2014-01-01

Herein, we describe a protocol for preparation of pre-activated anti-inflammatory human mesenchymal stem/precursor cells (MSCs) in 3D culture without addition of exogenous chemicals or gene transfer approaches. MSCs are an easily procurable source of multipotent adult stem cells with therapeutic potential largely attributed to their paracrine regulation of inflammation and immunity. However, the culture conditions to prepare the ideal MSCs for cell therapy remain elusive. Furthermore, reported lag time for activation in experimental models have prompted investigations to pre-activate the cells prior to their administration. In this protocol, standard 2D culture expanded MSCs are activated by aggregation into 3D spheres using hanging drop cultures. MSC activation is evaluated by real-time PCR and/or ELISA for anti-inflammatory factors (TSG-6, STC-1, PGE2), and by a functional assay using lipopolysaccharide-stimulated macrophage cultures. Furthermore, we elucidate methods to prepare MSC sphere conditioned medium, intact spheres, and suspension of single cells from spheres for experimental and clinical applications. PMID:24510769

First steps towards the successful surface-based cultivation of human embryonic stem cells in hanging drop systems.

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Schulz, Julia C; Stumpf, Patrick S; Katsen-Globa, Alisa; Sachinidis, Agapios; Hescheler, Jürgen; Zimmermann, Heiko

2012-11-01

Miniaturization and parallelization of cell culture procedures are in focus of research in order to develop test platforms with low material consumption and increased standardization for toxicity and drug screenings. The cultivation in hanging drops (HDs) is a convenient and versatile tool for biological applications and represents an interesting model system for the screening applications due to its uniform shape, the advantageous gas supply, and the small volume. However, its application has so far been limited to non-adherent and aggregate forming cells. Here, we describe for the first time the proof-of-principle regarding the adherent cultivation of human embryonic stem cells in HD. For this microcarriers were added to the droplet as dynamic cultivation surfaces resulting in a maintained pluripotency and proliferation capacity for 10 days. This enables the HD technique to be extended to the cultivation of adherence-dependent stem cells. Also, the possible automation of this method by implementation of liquid handling systems opens new possibilities for miniaturized screenings, the improvement of cultivation and differentiation conditions, and toxicity and drug development.

Hanging drop monoculture for selection of optimal antioxidants during in vitro maturation of porcine oocytes.

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Ishikawa, S; Machida, R; Hiraga, K; Hiradate, Y; Suda, Y; Tanemura, K

2014-04-01

We analysed the effect of three antioxidants that have different functional mechanisms on the in vitro maturation (IVM) of porcine oocytes. Single oocyte monoculture using the hanging drop (HD) system has some advantages such as improving analysis efficiency brought by the smaller number of samples than the number of oocytes cultured in one drop. Direct effects of ligands on single oocytes could also be detected without considering the effects of paracrine factors from other oocytes. After 22 h of pre-culture, denuded oocytes were cultured for 22 h with 0.01 and 0.1 μg/ml of L-carnitine (LC), lactoferrin (LF) or sulforaphane (SF) in the presence/non-presence of oxidant stress induced by H2O2 supplementation to evaluate the reducing effects against oxidative stress on nuclear maturation. As a result, compared with LC and SF, LF showed effective reduction in oxidative stress at a lower concentration (0.01 μg/ml), suggesting that LF is a more effective antioxidant in porcine oocyte IVM. Additionally, LF also increased maturation rate even in culture without H2O2. Our results clearly suggest that the HD monoculture system is useful for screening the substances that affect porcine oocyte culture. © 2014 Blackwell Verlag GmbH.

Pendent_Drop: An ImageJ Plugin to Measure the Surface Tension from an Image of a Pendent Drop

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Adrian Daerr

2016-01-01

Full Text Available The pendent drop method for surface tension measurement consists in analysing the shape of an axisymmetric drop hanging from a capillary tube. This software is an add-on for the public domain image processing software ImageJ which matches a theoretical profile to the contour of a pendent drop, either interactively or by automatically minimising the mismatch. It provides an estimate of the surface tension, drop volume and surface area from the best matching parameters. It can be used in a headless setup. It is hosted on http://fiji.sc/List_of_update_sites with the source code on https://github.com/adaerr/pendent-drop

A simple hanging drop cell culture protocol for generation of 3D spheroids.

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Foty, Ramsey

2011-05-06

Studies of cell-cell cohesion and cell-substratum adhesion have historically been performed on monolayer cultures adherent to rigid substrates. Cells within a tissue, however, are typically encased within a closely packed tissue mass in which cells establish intimate connections with many near-neighbors and with extracellular matrix components. Accordingly, the chemical milieu and physical forces experienced by cells within a 3D tissue are fundamentally different than those experienced by cells grown in monolayer culture. This has been shown to markedly impact cellular morphology and signaling. Several methods have been devised to generate 3D cell cultures including encapsulation of cells in collagen gels or in biomaterial scaffolds. Such methods, while useful, do not recapitulate the intimate direct cell-cell adhesion architecture found in normal tissues. Rather, they more closely approximate culture systems in which single cells are loosely dispersed within a 3D meshwork of ECM products. Here, we describe a simple method in which cells are placed in hanging drop culture and incubated under physiological conditions until they form true 3D spheroids in which cells are in direct contact with each other and with extracellular matrix components. The method requires no specialized equipment and can be adapted to include addition of any biological agent in very small quantities that may be of interest in elucidating effects on cell-cell or cell-ECM interaction. The method can also be used to co-culture two (or more) different cell populations so as to elucidate the role of cell-cell or cell-ECM interactions in specifying spatial relationships between cells. Cell-cell cohesion and cell-ECM adhesion are the cornerstones of studies of embryonic development, tumor-stromal cell interaction in malignant invasion, wound healing, and for applications to tissue engineering. This simple method will provide a means of generating tissue-like cellular aggregates for measurement of

Reassembly of anterior pituitary organization by hanging drop three-dimensional cell culture.

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Tsukada, Takehiro; Kouki, Tom; Fujiwara, Ken; Ramadhani, Dini; Horiguchi, Kotaro; Kikuchi, Motoshi; Yashiro, Takashi

2013-08-29

The anterior pituitary gland comprises 5 types of hormone-producing cells and non-endocrine cells, such as folliculostellate (FS) cells. The cells form a lobular structure surrounded by extracellular matrix (ECM) but are not randomly distributed in each lobule; hormone-producing cells have affinities for specific cell types (topographic affinity), and FS cells form a homotypic meshwork. To determine whether this cell and ECM organization can be reproduced in vitro, we developed a 3-dimensional (3D) model that utilizes hanging drop cell culture. We found that the topographic affinities of hormone-producing cells were indeed maintained (ie, GH to ACTH cells, GH to TSH cells, PRL to LH/FSH cells). Fine structures in hormone-producing cells retained their normal appearance. In addition, FS cells displayed well-developed cytoplasmic protrusions, which interconnected with adjacent FS cells to form a 3D meshwork. In addition, reassembly of gap junctions and pseudofollicles among FS cells was observed in cell aggregates. Major ECM components-collagens and laminin-were deposited and distributed around the cells. In sum, the dissociated anterior pituitary cells largely maintained their in vivo anterior pituitary architectures. This culture system appears to be a powerful experimental tool for detailed analysis of anterior pituitary cell organization.

Three-dimensional spheroid culture targeting versatile tissue bioassays using a PDMS-based hanging drop array.

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Kuo, Ching-Te; Wang, Jong-Yueh; Lin, Yu-Fen; Wo, Andrew M; Chen, Benjamin P C; Lee, Hsinyu

2017-06-29

Biomaterial-based tissue culture platforms have emerged as useful tools to mimic in vivo physiological microenvironments in experimental cell biology and clinical studies. We describe herein a three-dimensional (3D) tissue culture platform using a polydimethylsiloxane (PDMS)-based hanging drop array (PDMS-HDA) methodology. Multicellular spheroids can be achieved within 24 h and further boosted by incorporating collagen fibrils in PDMS-HDA. In addition, the spheroids generated from different human tumor cells exhibited distinct sensitivities toward drug chemotherapeutic agents and radiation as compared with two-dimensional (2D) cultures that often lack in vivo-like biological insights. We also demonstrated that multicellular spheroids may enable key hallmarks of tissue-based bioassays, including drug screening, tumor dissemination, cell co-culture, and tumor invasion. Taken together, these results offer new opportunities not only to achieve the active control of 3D multicellular spheroids on demand, but also to establish a rapid and cost-effective platform to study anti-cancer therapeutics and tumor microenvironments.

Development of a sequential injection-square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode.

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dos Santos, Luciana B O; Infante, Carlos M C; Masini, Jorge C

2010-03-01

This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level.

Electrochemical behavior of phytochelatins and related peptides at the hanging mercury drop electrode in the presence of cobalt(II) ions.

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Dorcák, Vlastimil; Sestáková, Ivana

2006-01-01

Direct current voltammetry and differential pulse voltammetry have been used to investigate the electrochemical behaviour of two phytochelatins: heptapeptide (gamma-Glu-Cys)3-Gly and pentapeptide (gamma-Glu-Cys)2-Gly, tripeptide glutathione gamma-Glu-Cys-Gly and its fragments: dipeptides Cys-Gly and gamma-Glu-Cys at the hanging mercury drop electrode in the presence of cobalt(II) ions. Most interesting results were obtained with direct current voltammetry in the potential region of -0.80 V up to -1.80 V. Differential pulse voltammetry of the same solutions of Co(II) with peptides gives more complicated voltammograms with overlapping peaks, probably in connection with the influence of adsorption at slow scan rates necessarily used in this method. However, in using Brdicka catalytic currents for analytical purposes, differential pulse voltammograms seem to be more helpful. Presented investigations have shown that particularly the prewave of cobalt(II) allows distinguishing among phytochelatins, glutathione, and its fragments.

Linear scan voltammetric indirect determination of Al(III) by the catalytic cathodic response of norepinephrine at the hanging mercury drop electrode.

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Zhang, Fuping; Ji, Ming; Xu, Quan; Yang, Li; Bi, Shuping

2005-09-01

The biological effects of aluminum (Al) have received much attention in recent years. Al is of basic relevance as concern with its reactivity and bioavailability. In this paper, the electrochemical behaviors of norepinephrine (NE) in the absence and presence of Al(III) at the hanging mercury drop electrode have been studied and applied to the practical analysis. Highly selective catalytic cathodic peak of NE is yielded by linear scan voltammetry (LSV) at -1.32 V (vs. SCE). A linear relationship holds between the cathodic peak current and the Al(III) concentration. It has been successfully applied to the determination of Al(III) in real waters and synthetic biological samples with satisfying results, which are in accordance with those obtained by ICP-AES method. The electrochemical properties and the mechanisms of the peaks in the presence and absence of Al(III) have been explored. The results show that they are irreversible adsorptive hydrogen catalytic waves. These studies not only enrich the methods of determining Al, but also lay foundations of further understanding of the mechanisms of neurodementia.

Low-level determination of silicon in steels by anodic stripping voltammetry on a hanging mercury drop electrode.

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Rahier, A H; Lunardi, S; Nicolle, F; George, S M

2010-10-15

The sensitive differential pulse anodic stripping voltammetry (DPASV) proposed originally by Ishiyama et al. (2001) has been revised and improved to allow the accurate measurement of silicon on a hanging mercury drop electrode (HMDE) instead of a glassy carbon electrode. We assessed the rate of formation of the partially reduced β-silicododecamolybdate and found that metallic mercury promotes the reaction in the presence of a large concentration of Fe(3+). The scope of the method has been broadened by carrying out the measurements in the presence of a constant amount of Fe(3+). The limit of detection (LOD) of the method described in the present paper is 100 μg Sig(-1) of steel, with a relative precision ranging from 5% to 12%. It can be further enhanced to 700 ng Sig(-1) of steel provided the weight of the sample, the dilution factors, the duration of the electrolysis and the ballast of iron are adequately revised. The tolerance to several interfering species has been examined, especially regarding Al(3+), Cr(3+) and Cr VI species. The method was validated using four low-alloy ferritic steels certified by the National Institute of Standards and Technology (NIST). Its application to nickel base alloys as well as to less complicated matrixes is straightforward. It has also been successfully applied to the determination of free silicon into silicon carbide nano-powder. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of hanging drop culture conditions on embryoid body formation and neuronal cell differentiation using mouse embryonic stem cells: optimization of culture conditions for the formation of well-controlled embryoid bodies.

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Ohnuki, Yoshitsugu; Kurosawa, Hiroshi

2013-05-01

Hanging drop (HD) cultures were carried out with a drop volume of either 20 or 30 μl. An incubation period of 3 days was determined to be appropriate for the formation of well-controlled embryoid bodies (EBs), and the initial cell number was identified as the most critical factor in the growth and neuronal cell differentiation of EBs. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Direct voltammetric specific recognition of dopamine using AlIII-DA complexes at the hanging mercury drop electrode.

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Zhang, Fuping; Zhang, Min; Cheng, Jiongjia; Yang, Li; Ji, Ming; Bi, Shuping

2007-11-01

In this paper, we firstly report the direct voltammetric recognition and determination of dopamine (DA) by using Al(III)-DA complexes at the hanging mercury drop electrode (HMDE). A new sensitive cathodic peak of Al(III)-DA can be detected at -900 mV (vs. SCE) in 0.1 M NH(4)Cl-NH(3).H(2)O-0.1 M KCl buffer solution at pH 8.5. This unique -900 mV cathodic peak arises from the specific interaction between Al(III) and DA on the HMDE, whereas other substances with similar structures, such as L-dopa, epinephrine (EP), norepinephrine (NE), catechols, caffeic acid (CA), trihydric phenols and tiron, do not yield any new peak on the voltammograms in the potential range from -100 to -1200 mV when Al(III) is added. The distinct voltammetric characteristic of the recognition of DA can effectively inhibit the interferences of both ascorbic acid and uric acid in the DA determination by the direct electrochemistry, which is a major difficulty when a solid electrode is used. The proposed method can be anticipated as an effective means for the recognition of DA in the elucidation of the mechanisms of Parkinson's disease (PD) and Alzheimer's disease (AD) in the presence of Al(III).

Formation of stable small cell number three-dimensional ovarian cancer spheroids using hanging drop arrays for preclinical drug sensitivity assays.

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Raghavan, Shreya; Ward, Maria R; Rowley, Katelyn R; Wold, Rachel M; Takayama, Shuichi; Buckanovich, Ronald J; Mehta, Geeta

2015-07-01

Ovarian cancer grows and metastasizes from multicellular spheroidal aggregates within the ascites fluid. Multicellular tumor spheroids are therefore physiologically significant 3D in vitro models for ovarian cancer research. Conventional hanging drop cultures require high starting cell numbers, and are tedious for long-term maintenance. In this study, we generate stable, uniform multicellular spheroids using very small number of ovarian cancer cells in a novel 384 well hanging drop array platform. We used novel tumor spheroid platform and two ovarian cancer cell lines (A2780 and OVCAR3) to demonstrate the stable incorporation of as few as 10 cells into a single spheroid. Spheroids had uniform geometry, with projected areas (42.60×10(3)μm-475.22×10(3)μm(2) for A2780 spheroids and 37.24×10(3)μm(2)-281.01×10(3)μm(2) for OVCAR3 spheroids) that varied as a function of the initial cell seeding density. Phalloidin and nuclear stains indicated cells formed tightly packed spheroids with demarcated boundaries and cell-cell interaction within spheroids. Cells within spheroids demonstrated over 85% viability. 3D tumor spheroids demonstrated greater resistance (70-80% viability) to cisplatin chemotherapy compared to 2D cultures (30-50% viability). Ovarian cancer spheroids can be generated from limited cell numbers in high throughput 384 well plates with high viability. Spheroids demonstrate therapeutic resistance relative to cells in traditional 2D culture. Stable incorporation of low cell numbers is advantageous when translating this research to rare patient-derived cells. This system can be used to understand ovarian cancer spheroid biology, as well as carry out preclinical drug sensitivity assays. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel hanging spherical drop system for the generation of cellular spheroids and high throughput combinatorial drug screening.

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Neto, A I; Correia, C R; Oliveira, M B; Rial-Hermida, M I; Alvarez-Lorenzo, C; Reis, R L; Mano, J F

2015-04-01

We propose a novel hanging spherical drop system for anchoring arrays of droplets of cell suspension based on the use of biomimetic superhydrophobic flat substrates, with controlled positional adhesion and minimum contact with a solid substrate. By facing down the platform, it was possible to generate independent spheroid bodies in a high throughput manner, in order to mimic in vivo tumour models on the lab-on-chip scale. To validate this system for drug screening purposes, the toxicity of the anti-cancer drug doxorubicin in cell spheroids was tested and compared to cells in 2D culture. The advantages presented by this platform, such as feasibility of the system and the ability to control the size uniformity of the spheroid, emphasize its potential to be used as a new low cost toolbox for high-throughput drug screening and in cell or tissue engineering.

Comparative study of P19 EC stem cell differentiation in between conventional hanging drop and the zebrafish chorion as a bio-derived material.

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Dae Seok Na; Lee, Hwang; Sun Uk Kim; Chang Nam Hwang; Sang Ho Lee; Ji Yoon Kang; Jai Kyeong Kim; James Jungho Pak

2008-07-01

Various materials including glass and polymers have been widely used for stem cell culture due to their biocompatibility. However, the roles of these materials are fundamentally limited because they cannot realize or imitate the complex biological functions of living tissues, except in very simple cases. Here, the development of a bio-derived material suitable for stem cell culture and improvement of differentiation efficiency to specific cell lineages with no stimulating agents by using a chorion obtained from a fertilized zebrafish egg through the removal of the yolk and embryonic cell mass from the egg is reported. Mouse P19 EC stem cells introduced into the empty chorion form a uniform embryoid body (EB) without addition of any inducing agent. It is demonstrated that the zebrafish chorion with nanopores improves efficiencies greatly in the EB formation, cell proliferation, and lineage-specific differentiations compared to those of the conventional hanging drop culture method.

Study of the voltammetric behaviour of the ethalfluralin and methalpropalin and its determination in environmental matrices at hanging mercury drop electrode.

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Thriveni, T; Kumar, J Rajesh; Lee, Jin Young; Sreedhar, N Y

2009-04-01

An electroanalytical method has been developed for the determination of the herbicides ethalfluralin[N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) bezenamine] and methalpropalin [N-(2-methyl-2-propenyl)-2, 6-dinitro-N-propyl-4 (trifluoromethyl) benzenamine] by differential pulse adsorptive stripping voltammetry (DP-AdSV) on a hanging mercury drop electrode (HMDE) with universal buffer as supporting electrolyte. The optimum adsorption conditions were found to be pH 6.0, an accumulation potential of -0.6 V (HMDE vs SCE), an accumulation time of 80 s. and scan rate 45 mVs(-1). Calibration curve is linear in the range 1.30 x 10(-9) to 1.32 x 10(-5) M of ethalfluralin and 1.13 x 10(-5) to 2.0 x 10(-8) M of methalpropalin with detection limits of 1.08 x 10(-9) and 1.87 x 10(-8) M, respectively. The relative SD and correlation coefficients were found to be 1.24%, 0.998 and 1.34%, 0.995, respectively for ten replicates. The method is applied to the determination of the ethalfluralin and methalpropalin in formulations and environmental matrices.

Differential pulse cathodic stripping voltammetric determination of uranium with arsenazo-III at the hanging mercury dropping electrode

Energy Technology Data Exchange (ETDEWEB)

Kadi, M.W.; El-Shahawi, M.S. [Chemistry Dept., King Abdulaziz Univ., Jeddah (Saudi Arabia)

2009-07-01

An accurate, inexpensive and less laborious controlled adsorptive accumulation of uranium(VI)-arsenazo-III on a hanging mercury drop electrode (HMDE) has been developed for uranium(VI) determination. The method is based upon the collection of uranium(VI)-arsenazo-III complex at pH 5-6 at the HMDE and subsequent direct stripping measurement of the element in the nanomolar concentration level. The cathodic peak current (i{sub p,c}) of the adsorbed complex ions of uranium(VI) was measured at -0.35 V vs. Ag/AgCl reference electrode by differential pulse cathodic stripping voltammetry (DP-CSV), proceeded by an accumulation period of 150s2.5 in Britton-Robinson buffer of pH 5. The plot of the resulting i{sub p,c} vs. uranium(VI) concentration was linear in the range 2.1 x 10{sup -9} to 9.60 x 10{sup -7} mol L{sup -1} uranium(VI) and tended to level off at above 9.6 x 10{sup -7} mol L{sup -1}. The limits of detection and quantification of uranium(VI) were found to be 4.7 x 10{sup -10} and 1.5 x 10{sup -9} mol L{sup -1}, respectively. A relative standard deviation of {+-}2.39% (n = 5) at 8.5 x 10{sup -7} mol L{sup -1} uranium(VI) was obtained. The method was validated by comparing the results with that obtained by ICP-MS method with RSD less than {+-}3.3%. The method was applied successfully for the analysis of uranium in certified reference material (IAEA soil-7), and in phosphate fertilizers. (orig.)

Capillary Thinning of Particle-laden Drops

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Wagoner, Brayden; Thete, Sumeet; Jahns, Matt; Doshi, Pankaj; Basaran, Osman

2015-11-01

Drop formation is central in many applications such as ink-jet printing, microfluidic devices, and atomization. During drop formation, a thinning filament is created between the about-to-form drop and the fluid hanging from the nozzle. Therefore, the physics of capillary thinning of filaments is key to understanding drop formation and has been thoroughly studied for pure Newtonian fluids. The thinning dynamics is, however, altered completely when the fluid contains particles, the physics of which is not well understood. In this work, we explore the impact of solid particles on filament thinning and drop formation by using a combination of experiments and numerical simulations.

Hanging drop: an in vitro air toxic exposure model using human lung cells in 2D and 3D structures.

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Liu, Faye F; Peng, Cheng; Escher, Beate I; Fantino, Emmanuelle; Giles, Cindy; Were, Stephen; Duffy, Lesley; Ng, Jack C

2013-10-15

Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX(®) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50cell for 1h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kgdry weight, which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method. Copyright © 2013 Elsevier B.V. All rights reserved.

Modified adjustable suture hang-back recession: Description of technique and comparison with conventional adjustable hang-back recession

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Siddharth Agrawal

2017-01-01

Full Text Available Purpose: This study aims to describe and compare modified hang-back recession with the conventional hang-back recession in large angle comitant exotropia (XT. Methods: A prospective, interventional, double-blinded, randomized study on adult patients (>18 years undergoing single eye recession-resection for large angle (>30 prism diopters constant comitant XT was conducted between January 2011 and December 2015. Patients in Group A underwent modified hang-back lateral rectus recession with adjustable knot while in Group B underwent conventional hang-back recession with an adjustable knot. Outcome parameters studied were readjustment rate, change in deviation at 6 weeks, complications and need for resurgery at 6 months. Results: The groups were comparable in terms of age and preoperative deviation. The patients with the modified hang back (Group A fared significantly better (P < 0.05 than those with conventional hang back (Group B in terms of lesser need for adjustment, greater correction in deviation at 6 weeks and lesser need for resurgery at 6 months. Conclusion: This modification offers several advantages, significantly reduces resurgery requirement and has no added complications.

Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

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Dos Santos, Luciana B O; Masini, Jorge C

2007-05-15

This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

In vitro culture of early secondary preantral follicles in hanging drop of ovarian cell-conditioned medium to obtain MII oocytes from outbred deer mice.

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Choi, Jung Kyu; Agarwal, Pranay; He, Xiaoming

2013-12-01

The ovarian follicle (each contains a single oocyte) is the fundamental functional tissue unit of mammalian ovaries. In humans, it has been long held true that females are born with a maximum number of follicles (or oocytes) that are not only nonrenewable, but also undergoing degeneration with time with a sharply decreased oocyte quality after the age of ∼35. Therefore, it is of importance to isolate and bank ovarian follicles for in vitro culture to obtain fertilizable oocytes later, to preserve the fertility of professional women who may want to delay childbearing, young and unmarried women who may lose gonadal function because of exposure to environmental/occupational hazards or aggressive medical treatments, such as radiation and chemotherapy, and even endangered species and breeds. Although they contributed significantly to the understanding of follicle science and biology, most studies reported to date on this topic were done using the man-made, unnatural inbred animal species. It was found in this study that the conventional two-dimensional microliter drop and three-dimensional hanging drop (HD) methods, reported to be effective for in vitro culture of preantral follicles from inbred mice, are not directly transferrable to outbred deer mice. Therefore, a modified HD method was developed in this study to achieve a much higher (>5 times compared to the best conventional methods) percentage of developing early secondary preantral follicles from the outbred mice to the antral stage, for which, the use of an ovarian cell-conditioned medium and multiple follicles per HD were identified to be crucial. It was further found that the method for in vitro maturation of oocytes in antral follicles obtained by in vitro culture of preantral follicles could be very different from that for oocytes in antral follicles obtained by hormone stimulation in vivo. Therefore, this study should provide important guidance for establishing effective protocols of in vitro follicle

Identification of Hedgehog signaling outcomes in mouse testis development using a hanging drop-culture system.

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Szczepny, Anette; Hogarth, Cathryn A; Young, Julia; Loveland, Kate L

2009-02-01

The Hedgehog (Hh) signaling pathway affects fetal testis growth. Recently, we described the dynamic cellular production of Hh signaling pathway components in juvenile and adult rodent testes. The Hh signaling is understood to regulate cord formation in the fetal testis, but minimal knowledge exists regarding how Hh signaling impacts the postnatal testis. To investigate this, we employed hanging drop cultures, which are used routinely in embryoid body formation. This approach has the advantage of using small media volume, and we examined its suitability for short-term culture of both murine embryonic gonads and adult testis tubules. The effects of cyclopamine, a specific Hh signaling inhibitor, were examined following culture of Embryonic Day 11.5 urogenital ridges (as control) and adult seminiferous tubule fragments for 24-48 h using histological, cell proliferation, and gene expression analyses. Cultured embryonic testes displayed generally normal cord structure, anti-Müllerian hormone (Amh) expression, and cell proliferation; known Hh target gene expression (Gli1, osteopontin, official symbol Spp1, and Amh) was altered in response to cyclopamine. Cultured adult tubules exhibited some loss of seminiferous epithelium organization over 48 h. Spermatogonia continued to proliferate, however, and no significant loss of viability was noted overall. Addition of cyclopamine significantly affected levels of Gli1, Igfbp6, Ccnd2 (cyclin D2), Ccnb1 (cyclin B1), Spp1, Kit, and Amh mRNAs; these genes have been shown previously to be expressed in Sertoli and germ cells. These novel results identify Hh target genes in the testis and demonstrate this signaling pathway likely affects cell survival and differentiation in the context of normal adult testis.

Non-Judicial Hanging in Guilan Province, Iran between 2011 and 2013

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Vahid Monsef Kasmaee

2014-09-01

Full Text Available Introduction: Hanging is one of the most commonly used way to commit suicide in many countries. This method used in suicide is considered a problem in Iran too, but no clear data exists regarding hanging in different regions or the country as a whole. Because of the epidemiologic differences in non-judicial hanging in different regions, this study aimed to assess it in Gilan province, Iran between 2011 and 2013. Methods: In this cross-sectional study, profiles of hanging cases registered in Poorsina hospital in Gilan, Iran between 2011 and 2013 were evaluated. Age, sex, marital status, place of residency, level of education, occupation, history of suicide, history of clinical illness, season of suicide and hanging outcome were evaluated. Results: 59 cases of hanging (mean age 31.4 ± 13.1 years and 83.0% male were evaluated. 12 (20.34% suffered from psychological disorders, and 9 (15.2% confessed to substance abuse. 7 (11.9% had a history of suicide attempts by hanging. Hanging was significantly higher in men (p<0.001, people with an education level of less than high school diploma (p=0.02 and the unemployed (p<0.05 patients. In the end, 20 (33.9% of these attempts resulted in death. Conclusion: The results of this study showed that in 2 years, 59 cases committed suicide by hanging themselves, 33.9% of which finally died. Committing suicide by hanging was significantly more prevalent in men, people with an education level of less than high school diploma and the unemployed.

Comparison of the lateral retention forces on sessile and pendant water drops on a solid surface

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de la Madrid, Rafael; Whitehead, Taylor; Irwin, George M.

2015-06-01

We present a simple experiment that demonstrates how a water drop hanging from a Plexiglas surface (pendant drop) experiences a lateral retention force that is comparable to, and in some cases larger than, the lateral retention force on a drop resting on top of the surface (sessile drop). The experiment also affords a simple demonstration of the Coriolis effect in two dimensions.

Headspace liquid-phase microextraction of methamphetamine and amphetamine in urine by an aqueous drop

International Nuclear Information System (INIS)

He Yi; Vargas, Angelica; Kang, Youn-Jung

2007-01-01

This study developed a headspace liquid-phase microextraction (LPME) method by using a single aqueous drop in combination with high performance liquid chromatography (HPLC)-UV detection for the determination of methamphetamine (MAP) and amphetamine (AP) in urine samples. The analytes, volatile and basic, were released from sample matrix into the headspace first, and then protonated and dissolved in an aqueous H 3 PO 4 drop hanging in the headspace by a HPLC syringe. After extraction, this drop was directly injected into HPLC. Parameters affecting extraction efficiency were investigated and optimized. This method showed good linearity in the investigated concentration range of 1.0-1500 μg L -1 , repeatability of the extraction (R.S.D. -1 for both analytes). Enrichment factors of about 400-fold and 220-fold were achieved for MAP and AP, respectively, at optimum conditions. The feasibility of the method was demonstrated by analyzing human urine samples

Length of a Hanging Cable

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Eric Costello

2011-01-01

Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

Universal method for opnimal design main structural assemblies of steel structures stationary conveyor with hanging ribbon

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Boslovyak P.V.

2015-10-01

Full Text Available The technique and the detailed algorithm for optimal design of steel structures hospitaltion of the conveyor with hang-ing ribbon. Developed a universal objective function together with the system-limited-subject to limits of main components of steel structures of stationary conveyor with hanging ribbon.

Near hanging: Early intervention can save lives

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Ritika Gandhi

2011-01-01

Full Text Available Hanging is a common method of suicide/homicide in the Indian scenario. We report three successive cases of attempted suicidal hangings seen over a period of 4 months in our intensive care wards. All of them presented gasping with poor clinical status and required immediate intubation, resuscitation, assisted ventilation and intensive care treatment. None had cervical spine injury, but one patient developed aspiration pneumonia. All the three patients received standard supportive intensive care and made full clinical recovery without any neurological deficit. We conclude that the cases of near hanging should be aggressively resuscitated and treated irrespective of dismal initial presentation. This is well supported by the excellent outcomes in our cases despite their poor initial condition.

Propelling a water drop with the vapor-mediated Marangoni effect

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Kim, Seungho; Kim, Ho-Young

2013-11-01

We show that a water drop on solid surfaces can be propelled just by placing a volatile alcohol drop nearby. It is found to be because the water-air interface near the alcohol drop mixes with alcohol vapor, thereby locally lowering the surface tension. The surface-tension-gradient induces the motion of the water drop, enabling the trajectory control of water drops through the motion of remote alcohol drops. This vapor-mediated Marangoni effect also gives rise to other interesting interfacial flow phenomena, such as nucleation of holes on a water film and ballooning of a water drop hanging from a syringe needle with the approach of an alcohol drop. We visualize such interfacial dynamics with a high-speed camera and rationalize their salient features by scaling analysis. This work was supported by the National Research Foundation of Korea (grant no. 2012-008023).

Headspace liquid-phase microextraction of methamphetamine and amphetamine in urine by an aqueous drop

Energy Technology Data Exchange (ETDEWEB)

He Yi [Department of Sciences, John Jay College of Criminal Justice, City University of New York, 445 W 59th Street, New York, NY 10019 (United States)]. E-mail: yhe@jjay.cuny.edu; Vargas, Angelica [Department of Sciences, John Jay College of Criminal Justice, City University of New York, 445 W 59th Street, New York, NY 10019 (United States); Kang, Youn-Jung [Department of Sciences, John Jay College of Criminal Justice, City University of New York, 445 W 59th Street, New York, NY 10019 (United States)

2007-04-25

This study developed a headspace liquid-phase microextraction (LPME) method by using a single aqueous drop in combination with high performance liquid chromatography (HPLC)-UV detection for the determination of methamphetamine (MAP) and amphetamine (AP) in urine samples. The analytes, volatile and basic, were released from sample matrix into the headspace first, and then protonated and dissolved in an aqueous H{sub 3}PO{sub 4} drop hanging in the headspace by a HPLC syringe. After extraction, this drop was directly injected into HPLC. Parameters affecting extraction efficiency were investigated and optimized. This method showed good linearity in the investigated concentration range of 1.0-1500 {mu}g L{sup -1}, repeatability of the extraction (R.S.D. < 5%, n = 6), and low detection limits (0.3 {mu}g L{sup -1} for both analytes). Enrichment factors of about 400-fold and 220-fold were achieved for MAP and AP, respectively, at optimum conditions. The feasibility of the method was demonstrated by analyzing human urine samples.

Identification of Hedgehog Signaling Outcomes in Mouse Testis Development Using a Hanging Drop-Culture System1

Science.gov (United States)

Szczepny, Anette; Hogarth, Cathryn A.; Young, Julia; Loveland, Kate L.

2008-01-01

The Hedgehog (Hh) signaling pathway affects fetal testis growth. Recently, we described the dynamic cellular production of Hh signaling pathway components in juvenile and adult rodent testes. The Hh signaling is understood to regulate cord formation in the fetal testis, but minimal knowledge exists regarding how Hh signaling impacts the postnatal testis. To investigate this, we employed hanging drop cultures, which are used routinely in embryoid body formation. This approach has the advantage of using small media volume, and we examined its suitability for short-term culture of both murine embryonic gonads and adult testis tubules. The effects of cyclopamine, a specific Hh signaling inhibitor, were examined following culture of Embryonic Day 11.5 urogenital ridges (as control) and adult seminiferous tubule fragments for 24–48 h using histological, cell proliferation, and gene expression analyses. Cultured embryonic testes displayed generally normal cord structure, anti-Müllerian hormone (Amh) expression, and cell proliferation; known Hh target gene expression (Gli1, osteopontin, official symbol Spp1, and Amh) was altered in response to cyclopamine. Cultured adult tubules exhibited some loss of seminiferous epithelium organization over 48 h. Spermatogonia continued to proliferate, however, and no significant loss of viability was noted overall. Addition of cyclopamine significantly affected levels of Gli1, Igfbp6, Ccnd2 (cyclin D2), Ccnb1 (cyclin B1), Spp1, Kit, and Amh mRNAs; these genes have been shown previously to be expressed in Sertoli and germ cells. These novel results identify Hh target genes in the testis and demonstrate this signaling pathway likely affects cell survival and differentiation in the context of normal adult testis. PMID:18843087

3-D simulation of hanging wall effect at dam site

Science.gov (United States)

Zhang, L.; Xu, Y.

2017-12-01

Hanging wall effect is one of the near fault effects. This paper focuses on the difference of the ground motions on the hanging wall side between the footwall side of the fault at dam site considering the key factors, such as actual topography, the rupture process. For this purpose, 3-D ground motions are numerically simulated by the spectrum element method (SEM), which takes into account the physical mechanism of generation and propagation of seismic waves. With the SEM model of 548 million DOFs, excitation and propagation of seismic waves are simulated to compare the difference between the ground motion on the hanging wall side and that on the footwall side. Take Dagangshan region located in China as an example, several seismogenic finite faults with different dip angle are simulated to investigate the hanging wall effect. Furthermore, by comparing the ground motions of the receiving points, the influence of several factors on hanging wall effect is investigated, such as the dip of the fault and the fault type (strike slip fault or dip-slip fault). The peak acceleration on the hanging wall side is obviously larger than those on the footwall side, which numerically evidences the hanging wall effect. Besides, the simulation shows that only when the dip is less than 70° does the hanging wall effect deserve attention.

Kritik Mitos Tentang “Hang Tuah” Karya Amir Hamzah

Directory of Open Access Journals (Sweden)

Puji Santosa

2014-06-01

Full Text Available This study reveals the myth criticism on rhyme "Hang Tuah", an Amir Hamzah’s work expressing Malay myth. The Malay myth found in the rhyme "Hang Tuah" is placed as a meeting place of myth criticism study which includes (1 the structure of the text, (2 figure with its ideology, (3 setting presenting the myth, (4 type of myth, (5 method the poet displays the myth, and (6 the benefit or function of myth. The six elements of the review are expected to contribute in exposing and describing the element of mythology in modern Indonesian poetry and its relevance to the present situation. It is identified that Hang Tuah has an ideology of Malay heroism loyalty able to be a resource in national character building: willing to sacrifice and resilient in defending the country's sovereignty rights. The Malay heroic myth of Hang Tuah, delivered in the form of poetic ballads, adds to the classic aesthetic value. The present benefits of Hang Tuah myth, by his heroism in getting rid of European colonization, is certainly to boost the fighting spirit in defending the rights and dignity as an independent nation, free from occupation or colonialism.  This study reveals the myth criticism on rhyme "Hang Tuah", an Amir Hamzah’s work expressing Malay myth. The Malay myth found in the rhyme "Hang Tuah" is placed as a meeting place of myth criticism study which includes (1 the structure of the text, (2 figure with its ideology, (3 setting presenting the myth, (4 type of myth, (5 method the poet displays the myth, and (6 the benefit or function of myth. The six elements of the review are expected to contribute in exposing and describing the element of mythology in modern Indonesian poetry and its relevance to the present situation. It is identified that Hang Tuah has an ideology of Malay heroism loyalty able to be a resource in national character building: willing to sacrifice and resilient in defending the country's sovereignty rights. The Malay heroic myth of Hang

Mixture effects of benzene, toluene, ethylbenzene, and xylenes (BTEX) on lung carcinoma cells via a hanging drop air exposure system.

Science.gov (United States)

Liu, Faye F; Escher, Beate I; Were, Stephen; Duffy, Lesley; Ng, Jack C

2014-06-16

A recently developed hanging drop air exposure system for toxicity studies of volatile chemicals was applied to evaluate the cell viability of lung carcinoma A549 cells after 1 and 24 h of exposure to benzene, toluene, ethylbenzene, and xylenes (BTEX) as individual compounds and as mixtures of four or six components. The cellular chemical concentrations causing 50% reduction of cell viability (EC50) were calculated using a mass balance model and came to 17, 12, 11, 9, 4, and 4 mmol/kg cell dry weight for benzene, toluene, ethylbenzene, m-xylene, o-xylene, and p-xylene, respectively, after 1 h of exposure. The EC50 decreased by a factor of 4 after 24 h of exposure. All mixture effects were best described by the mixture toxicity model of concentration addition, which is valid for chemicals with the same mode of action. Good agreement with the model predictions was found for benzene, toluene, ethylbenzene, and m-xylene at four different representative fixed concentration ratios after 1 h of exposure, but lower agreement with mixture prediction was obtained after 24 h of exposure. A recreated car exhaust mixture, which involved the contribution of the more toxic p-xylene and o-xylene, yielded an acceptable, but lower quality, prediction as well.

Hanging off a bar

NARCIS (Netherlands)

Mueller, F.; Walmink, W.; Toprak, C.; Bongers, Bert; Graether, E.; Hoven, van den E.A.W.H.

2012-01-01

Exertion Games involve physical effort and as a result can facilitate physical health benefits. We present Hanging off a Bar, an action hero-inspired Exertion Game in which players hang off an exercise bar over a virtual river for as long as possible. Initial observations from three events with

Death by hanging: implications for prevention of an important method of youth suicide.

Science.gov (United States)

Kosky, R J; Dundas, P

2000-10-01

The aim of this study was to identify factors associated with deaths by hanging among young people in Queensland, Australia. An examination of coroner's reports for all deaths by hanging of people under 25 years of age that occurred in Queensland in the years 1995 and 1996. All cases were recorded as suicides. Most were males and a quarter were indigenous persons. Half the deaths occurred in regional or rural areas. Unemployment, the experience of personal loss, psychiatric illness and alcohol use were possible precipitating agents. Early warning signs were the onset of uncharacteristic behaviours and threats of suicide. The private nature of hanging means that there are rarely opportunities to prevent it in the period immediately before the fatal event. Earlier interventions will have to be considered. To prevent hanging as a means of suicide, we need to understand more about the difficulties experienced by some young men who are living in rural areas. We need more information about the cultural problems experienced by indigenous youths in their teenage years. Young people in the justice system may need personal support. There is a pressing need to determine if young people, especially in rural areas, have adequate access to the professional expertise needed to diagnose and treat mental disorders.

Ultrasonic defect-sizing using decibel drop methods. I

International Nuclear Information System (INIS)

Murphy, R.V.

1987-03-01

Results are reported of a study performed to investigate the accuracy and repeatability of various ultrasonic decibel (dB) drop sizing methods in determining the length, vertical extent and orientation of artificial and real weld flaws in thin steel sections. Seven artificial flaws and nine real weld flaws were examined; over 200 data plots were produced. The general findings are: a) length and vertical extent are assessed most accurately when using a 14 dB drop from the maximum indication amplitude; b) decibel drops less that 14 dB generally undersize flaws while decibel drops greater than 14 dB generally oversize flaws; c) flaws which are smaller than the width of the sound beam cannot be assessed accurately using dB drop methods; d) large flaws are assessed most accurately when the sound beam strikes the flaws at near normal incidence; e) the vertical extent and orientation of large flaws are plotted most accurately using the beam centre line method as opposed to the beam profile method; and, f) the limitations of dB-drop-sizing methods have considerable ramifications for CAN3-N285.4-M83 and ASME XI evaluation criteria

Surface Tension Guided Hanging-Drop: Producing Controllable 3D Spheroid of High-Passaged Human Dermal Papilla Cells and Forming Inductive Microtissues for Hair-Follicle Regeneration.

Science.gov (United States)

Lin, Bojie; Miao, Yong; Wang, Jin; Fan, Zhexiang; Du, Lijuan; Su, Yongsheng; Liu, Bingcheng; Hu, Zhiqi; Xing, Malcolm

2016-03-09

Human dermal papilla (DP) cells have been studied extensively when grown in the conventional monolayer. However, because of great deviation from the real in vivo three-dimensional (3D) environment, these two-dimensional (2D) grown cells tend to lose the hair-inducible capability during passaging. Hence, these 2D caused concerns have motivated the development of novel 3D culture techniques to produce cellular microtissues with suitable mimics. The hanging-drop approach is based on surface tension-based technique and the interaction between surface tension and gravity field that makes a convergence of liquid drops. This study used this technique in a converged drop to form cellular spheroids of dermal papilla cells. It leads to a controllable 3Dspheroid model for scalable fabrication of inductive DP microtissues. The optimal conditions for culturing high-passaged (P8) DP spheroids were determined first. Then, the morphological, histological and functional studies were performed. In addition, expressions of hair-inductive markers including alkaline phosphatase, α-smooth muscle actin and neural cell adhesion molecule were also analyzed by quantitative RT-PCR, immunostaining and immunoblotting. Finally, P8-DP microtissues were coimplanted with newborn mouse epidermal cells (EPCs) into nude mice. Our results indicated that the formation of 3D microtissues not only endowed P8-DP microtissues many similarities to primary DP, but also confer these microtissues an enhanced ability to induce hair-follicle (HF) neogenesis in vivo. This model provides a potential to elucidate the native biology of human DP, and also shows the promising for the controllable and scalable production of inductive DP cells applied in future follicle regeneration.

Hanging-induced burst suppression pattern in EEG

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Nilgun Cinar

2012-01-01

Full Text Available Lethal suspension (hanging is one of the most common methods of attempting suicide. Spinal fractures, cognitive and motor deficits as well as epileptic seizures can be detected after unsuccessful hanging attempts. Introduced here is the case of a 25-year-old man exemplifying the clinical observations stated hereafter, who was conveyed to our emergency room after having survived attempted suicide by hanging, with his post-anoxic burst-suppression electroencephalography (BS-EEG pattern and clinical diagnoses in the post-comatose stage. The patient′s state of consciousness was gradually improved over a period of time. His neuropsychiatric assessment proved that memory deficit, a slight lack of attention and minor executive dysfunction was observed a month after the patient was discharged. Although the BS-EEG pattern indicates severe brain dysfunction, it is a poor prognostic factor; rarely, patients survive with minor cognitive deficits and can perform their normal daily activities.

Numerical simulation of the effects of hanging sound absorbers on TABS cooling performance

DEFF Research Database (Denmark)

Rage, Nils; Kazanci, Ongun Berk; Olesen, Bjarne W.

2016-01-01

simulating a two-person office of 20 m2, with a typical cooling load of 42 W/m2. The results show that covering 60% of the ceiling surface with sound absorbers hanging at 300 mm from the ceiling active deck is expected to reduce the cooling capacity coefficient of TABS by 15.8%. This drops to 25......Recently there has been a considerable increase in the use of Thermally-Active Building Systems (TABS) in Europe as an energy-efficient and economical cooling and heating solution for buildings. However, this widespread solution requires large uncovered hard surfaces indoors, which can lead...... to a degradation of the room acoustic comfort. Therefore, challenges arise when this system has to be combined with acoustic requirements. Soffit-hanging sound absorbers embody a promising solution. This study focuses on quantifying their impact on the cooling performance of TABS, assessed by means of the cooling...

Common Cause Case Study: An Estimated Probability of Four Solid Rocket Booster Hold-Down Post Stud Hang-ups

Science.gov (United States)

Cross, Robert

2005-01-01

Until Solid Rocket Motor ignition, the Space Shuttle is mated to the Mobil Launch Platform in part via eight (8) Solid Rocket Booster (SRB) hold-down bolts. The bolts are fractured using redundant pyrotechnics, and are designed to drop through a hold-down post on the Mobile Launch Platform before the Space Shuttle begins movement. The Space Shuttle program has experienced numerous failures where a bolt has hung up. That is, it did not clear the hold-down post before liftoff and was caught by the SRBs. This places an additional structural load on the vehicle that was not included in the original certification requirements. The Space Shuttle is currently being certified to withstand the loads induced by up to three (3) of eight (8) SRB hold-down experiencing a "hang-up". The results of loads analyses performed for (4) stud hang-ups indicate that the internal vehicle loads exceed current structural certification limits at several locations. To determine the risk to the vehicle from four (4) stud hang-ups, the likelihood of the scenario occurring must first be evaluated. Prior to the analysis discussed in this paper, the likelihood of occurrence had been estimated assuming that the stud hang-ups were completely independent events. That is, it was assumed that no common causes or factors existed between the individual stud hang-up events. A review of the data associated with the hang-up events, showed that a common factor (timing skew) was present. This paper summarizes a revised likelihood evaluation performed for the four (4) stud hang-ups case considering that there are common factors associated with the stud hang-ups. The results show that explicitly (i.e. not using standard common cause methodologies such as beta factor or Multiple Greek Letter modeling) taking into account the common factor of timing skew results in an increase in the estimated likelihood of four (4) stud hang-ups of an order of magnitude over the independent failure case.

Electrochemical study of the interaction between dsDNA and copper(I) using carbon paste and hanging mercury drop electrode.

Science.gov (United States)

Stanić, Z; Girousi, S

2008-06-30

The interaction of copper(I) with double-stranded (ds) calf thymus DNA was studied in solution and at the electrode surface by means of transfer voltammetry using a carbon paste electrode (CPE) as working electrode in 0.2 M acetate buffer solution (pH 5.0). As a result of the interaction of Cu(I) between the base pairs of the dsDNA, the characteristic peaks of dsDNA, due to the oxidation of guanine and adenine, increased and after a certain concentration of Cu(I) a new peak at +1.37 V appeared, probably due to the formation of a purine-Cu(I) complex (dsDNA-Cu(I) complex). Accordingly, the interaction of copper(I) with calf thymus dsDNA was studied in solution as well as at the electrode surface using hanging mercury drop electrode (HMDE) by means of alternating current voltammetry (AC voltammetry) in 0.3 M NaCl and 50 mM sodium phosphate buffer (pH 8.5) as supporting electrolyte. Its interaction with DNA is shown to be time dependent. Significant changes in the characteristic peaks of dsDNA were observed after addition of higher concentration of Cu(I) to a solution containing dsDNA, as a result of the interaction between Cu(I) and dsDNA. All the experimental results indicate that Cu(I) can bind to DNA by electrostatic binding and form an association complex.

Gan-Hang tectonic belt and its geologic significance

International Nuclear Information System (INIS)

Deng Jiarui; Zhang Zhiping.

1989-01-01

Gan-Hang tectonic belt is predominantly controlled by Gan-Hang fracture zone. It is mainly composed of Yongfeng-Zhuji downwarping zone, Gan-Hang volcanic activity structural belt and Gan-Hang red basin downfaulted zone. Gan-Hang fracture zone is derived from evolution and development of Shaoxing-Jiangshan deep fracture. It is mainly composed of three deep and large fracture and Fuzhou-Yongfeng large fracture. The fracture zone is a long active belt, but in each active period the geologic structural patterns intensity, depth and forming time were not same. Gan-Hang tectonic belt possesses obvious inheritance. It has always maintained the character of the relative depression or low land since the Caledonian movement. This specific structural environment is favourable for uranium mineralization. At any rate, the formation of this uranium minerogenetic zone has been experiencing a long and complicated processes which were closely associated with long activity of Gan-Hang fracture zone

Homicidal hanging masquerading as suicide

DEFF Research Database (Denmark)

Leth, Peter Mygind; Charles, Annie Vesterby

1997-01-01

Homicidal hanging is rare and presents special problems for the forensic pathologist. We report a case of homicide by hanging masquerading as suicide, in which the forensic evidence was of crucial importance. The victim was a 61 years old man, who was found in his house suspended by a rope around...

Scaling during capillary thinning of particle-laden drops

Science.gov (United States)

Thete, Sumeet; Wagoner, Brayden; Basaran, Osman

2017-11-01

A fundamental understanding of drop formation is crucial in many applications such as ink-jet printing, microfluidic devices, and atomization. During drop formation, the about-to-form drop is connected to the fluid hanging from the nozzle via a thinning filament. Therefore, the physics of capillary thinning of filaments is key to understanding drop formation and has been thoroughly studied for pure Newtonian fluids using theory, simulations, and experiments. In some of the applications however, the forming drop and hence the thinning filament may contain solid particles. The thinning dynamics of such particle-laden filaments differs radically from that of particle-free filaments. Moreover, our understanding of filament thinning in the former case is poor compared to that in the latter case despite the growing interest in pinch-off of particle-laden filaments. In this work, we go beyond similar studies and experimentally explore the impact of solid particles on filament thinning by measuring both the radial and axial scalings in the neck region. The results are summarized in terms of a phase diagram of capillary thinning of particle-laden filaments.

Ultrasonic defect sizing using decibel drop methods. III

International Nuclear Information System (INIS)

Mills, C.; Goszczynski, J.; Mitchell, A.B.

1988-03-01

An earlier study on the use of ultrasonic decibel drop sizing methods for determining the length and vertical extent of flaws in welded steel sections was based on the scanning of machined flaws and fabrication flaws. The present study utilized the techniques developed to perform a similar study of the type of flaws expected to develop during service (e.g. fatigue cracks). The general findings are that: a) the use of decibel drops of less than 14 dB generally undersize the length of fatigue cracks; and b) the use of decibel drop methods to determine vertical extent is questionable

Kritik Mitos Tentang “Hang Tuah” Karya Amir Hamzah

OpenAIRE

Santosa, Puji

2014-01-01

This study reveals the myth criticism on rhyme "Hang Tuah", an Amir Hamzah’s work expressing Malay myth. The Malay myth found in the rhyme "Hang Tuah" is placed as a meeting place of myth criticism study which includes (1) the structure of the text, (2) figure with its ideology, (3) setting presenting the myth, (4) type of myth, (5) method the poet displays the myth, and (6) the benefit or function of myth. The six elements of the review are expected to contribute in exposing and describing t...

Suicidal hanging donors for lung transplantation

Science.gov (United States)

Ananiadou, Olga; Schmack, Bastian; Zych, Bartlomiej; Sabashnikov, Anton; Garcia-Saez, Diana; Mohite, Prashant; Weymann, Alexander; Mansur, Ashham; Zeriouh, Mohamed; Marczin, Nandor; De Robertis, Fabio; Simon, Andre Rüdiger; Popov, Aron-Frederik

2018-01-01

Abstract In the context of limited donor pool in cardiothoracic transplantation, utilization of organs from high risk donors, such as suicidal hanging donors, while ensuring safety, is under consideration. We sought to evaluate the outcomes of lung transplantations (LTx) that use organs from this group. Between January 2011 and December 2015, 265 LTx were performed at our center. Twenty-two recipients received lungs from donors after suicidal hanging (group 1). The remaining 243 transplantations were used as a control (group 2). Analysis of recipient and donor characteristics as well as outcomes was performed. No statistically significant difference was found in the donor characteristics between analyzed groups, except for higher incidence of cardiac arrest, younger age and smoking history of hanging donors (P donor cause of death is not associated with poor mid-term survival or chronic lung allograft dysfunction following transplantation. These results encourage assessment of lungs from hanging donors, and their consideration for transplantation. PMID:29620623

Efficient biotechnological approach for lentiviral transduction of induced pluripotent stem cells.

Science.gov (United States)

Zare, Mehrak; Soleimani, Masoud; Mohammadian, Mozhdeh; Akbarzadeh, Abolfazl; Havasi, Parvaneh; Zarghami, Nosratollah

2016-01-01

Induced pluripotent stem (iPS) cells are generated from differentiated adult somatic cells by reprogramming them. Unlimited self-renewal, and the potential to differentiate into any cell type, make iPS cells very promising candidates for basic and clinical research. Furthermore, iPS cells can be genetically manipulated for use as therapeutic tools. DNA can be introduced into iPS cells, using lentiviral vectors, which represent a helpful choice for efficient transduction and stable integration of transgenes. In this study, we compare two methods of lentiviral transduction of iPS cells, namely, the suspension method and the hanging drop method. In contrast to the conventional suspension method, in the hanging drop method, embryoid body (EB) formation and transduction occur concurrently. The iPS cells were cultured to form EBs, and then transduced with lentiviruses, using the conventional suspension method and the hanging drop method, to express miR-128 and green fluorescent protein (GFP). The number of transduced cells were assessed by fluorescent microscopy and flow cytometry. MTT assay and real-time PCR were performed to determine the cell viability and transgene expression, respectively. Morphologically, GFP+ cells were more detectable in the hanging drop method, and this finding was quantified by flow cytometric analysis. According to the results of the MTT assay, cell viability was considerably higher in the hanging drop method, and real-time PCR represented a higher relative expression of miR-128 in the iPS cells introduced with lentiviruses in drops. Altogether, it seems that lentiviral transduction of challenging iPS cells using the hanging drop method offers a suitable and sufficient strategy in their gene transfer, with less toxicity than the conventional suspension method.

SUICIDAL HANGING IN URBAN YOUTH : A PROSPECTIVE STUDY

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Bhola Kumar Singh

2015-02-01

Full Text Available BACKGROUND : Suicide is among the top three causes of death among youth worldwide. Hanging is among the most common modes of suicide. OBJECTIVES: The purpose of this prospective study is to determine the Suicidal hanging in urban youth and determine the prevalence of suicidal hanging in our community. METHODS : In this descriptive, prospective, cross sectional study, all patients who pres ented to the department of emergency medicine with suicidal hanging during this study period of 12 months from January 2010 - December 2011 in . were included. RESULTS : Total number of males in the study is 32 (64%, females in the study is 18(36%. Mean age of the you th was 22.50± 8.15(SD years, Male 18.50± 12.15(SD years, Females 20.50 ±5.25(SD years; predominantly the patients were in the age group of 22 - 26 years. Number of male smokers in the study was 26 (81.25% female smokers were 4(22.22%, number of m ale alcoholics were 27(84.37% whereas female alcoholics were 6(33.33%, number of patients with pallor in males were 16(50% whereas females with pallor were 12(66.66%, number of males with skin changes were 6(18.75% when compared to females who had 8(4 4.44% skin changes, number of males wit oedema were 4(12.5% and 6(33.33% of females had oedema, the mean weight among males were 48±8.34kgs when compared to females which was 42±6.56kgs. Most of the patients who attempted suicide had varied personality issues from mood disorders to psychosis. CONCLUSION : There is significant percentage of patients who attempt suicide by hanging

Media influenced imitative hanging: a report from West Bengal.

Science.gov (United States)

Chowdhury, A N; Brahma, A; Banerjee, S; Biswas, M K

2007-01-01

Media influences behaviour, especially of the young children and adolescents in various ways. The present study examined the media coverage of a judicial hanging and its immediate social effect. In a qualitative study the media coverage of a case of a judicial hanging was thoroughly discussed and the media influence, for over a period of ten weeks of the incident, in terms of suicide and copying of hanging among children, was collected and analysed. Eighteen cases were reported as an aftermath of this hanging: 1 suicide and 17 imitative hanging in children with 5 deaths. This report calls for attention that media should be cautious and responsible in presenting the news items that have potential social impact.

An analysis of pipe degradation shape using potential drop method

International Nuclear Information System (INIS)

Jegal, S.; Lee, S. H.

1999-01-01

The Potential Drop (PD) method, one of NDE (Non-Destructive Evaluation) method is used to analyze the thickness distribution of pipes degraded by FAC (Flow Accelerated Corrosion). A DCPD (Direct Current Potential Drop) system which can measure PD for direct current was made, and the specimens with line defects and cylinder type defects have been used for experiments to prove the theory of Potential Drop method and to find out the effects of each factors. The experiment to find out defect distributions has been performed and it is found that PD method can analyze almost correct position of defects

Sensitive detection of cyclophosphamide using DNA-modified carbon paste, pencil graphite and hanging mercury drop electrodes.

Science.gov (United States)

Palaska, P; Aritzoglou, E; Girousi, S

2007-05-15

The interaction of cyclophosphamide (CP) with calf thymus double-stranded DNA (dsDNA) and thermally denatured single-stranded DNA (ssDNA) immobilized at the carbon paste (CPE) and pencil graphite electrodes (PGE), was studied electrochemically based on oxidation signals of guanine and adenine using differential pulse voltammetry (DPV). As a result of the interaction of CP with DNA, the voltammetric signals of guanine and adenine increased in the case of dsDNA while a slight increase was observed in ssDNA. The effect of experimental parameters such as the interaction time between CP and DNA forms and the concentration of CP, were studied using DPV with CPE and PGE. Additionally, reproducibility and detection limits were determined using both electrodes. A comparison of the analytical performance between CPE and PGE was done. Our results showed that these two different DNA biosensors could be used for the sensitive, rapid and cost effective detection of CP itself as well as of CP-DNA interaction. Furthermore, the interaction of CP with dsDNA and ssDNA was studied in solution and at the electrode surface by means of alternating current voltammetry (ACV) in 0.3M NaCl and 50mM sodium phosphate buffer (pH 8.5) supporting electrolyte, using a hanging mercury drop electrode (HMDE) as working electrode. The conclusions of this study were mainly based on tensammetric peaks I (at -1.183V) and II (-1.419V) of DNA. This study involved the interaction of CP with surface-confined and solution phase DNA where experimental parameters, such as the concentration of CP and the interaction time, were studied. By increasing the concentration of CP, an increase of peak II was observed in both ds and ssDNA, while an increase of peak I was observed only in the case of dsDNA. An overall conclusion of the study using HMDE was that the interaction of CP with surface-confined DNA significantly differed from that with solution phase DNA. The increase of peaks I and II was lower in the case of

Approach for growth of high-quality and large protein crystals

Energy Technology Data Exchange (ETDEWEB)

Matsumura, Hiroyoshi, E-mail: matsumura@chem.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); JST (Japan); SOSHO Inc., Osaka 541-0053 (Japan); Sugiyama, Shigeru; Hirose, Mika; Kakinouchi, Keisuke; Maruyama, Mihoko; Murai, Ryota [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); JST (Japan); Adachi, Hiroaki; Takano, Kazufumi [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); JST (Japan); SOSHO Inc., Osaka 541-0053 (Japan); Murakami, Satoshi [JST (Japan); SOSHO Inc., Osaka 541-0053 (Japan); Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501 (Japan); Mori, Yusuke; Inoue, Tsuyoshi [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); JST (Japan); SOSHO Inc., Osaka 541-0053 (Japan)

2011-01-01

Three crystallization methods, including crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study, crystallization has been further evaluated in the presence of a semi-solid agarose gel by crystallizing additional proteins. A novel crystallization method combining TSSG and the large-scale hanging-drop method has also been developed. Three crystallization methods for growing large high-quality protein crystals, i.e. crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study the effectiveness of crystallization in the presence of a semi-solid agarose gel has been further evaluated by crystallizing additional proteins in the presence of 2.0% (w/v) agarose gel, resulting in complete gelification with high mechanical strength. In TSSG the seed crystals are hung by a seed holder protruding from the top of the growth vessel to prevent polycrystallization. In the large-scale hanging-drop method, a cut pipette tip was used to maintain large-scale droplets consisting of protein–precipitant solution. Here a novel crystallization method that combines TSSG and the large-scale hanging-drop method is reported. A large and single crystal of lysozyme was obtained by this method.

Ligature material in hanging deaths: The neglected area in forensic examination

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Vipul Namdeorao Ambade

2015-09-01

Full Text Available The hanging mark is the most relevant feature of hanging and its characteristics are well known in the literature. Most of the time, the ligature material is not available during autopsy examination in hanging. Hence, the features of the ligature material are not submitted to systematic analysis. However, the type and position of the knot plays an important role in the mechanism of death and autopsy findings in hanging. Out of the total hanging deaths, complete hanging was seen in 67.7% of the cases, but a typical hanging was noted in only 10.2% of the cases. The commonest type of ligature material used for ligation around the neck was nylon rope followed by odhni and jute rope. The fixed knot was noted in 64.6% of the cases and a running (slip in 21.3% of the cases. The commonest position of the knot was at nape of the neck, followed by the left side of the neck at mastoid process. The number of turns/loops of a ligature around the neck was one turn in 72.4% and two in 25.2% the hanging deaths. Most victims committed suicide by hanging in their homes, and the commonest ligature points were trees, flowed by beams and ceiling hook/fans.

Hanging Fatalities in Central Bangkok, Thailand: A 13-Year Retrospective Study

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Nattapong Tulapunt

2017-02-01

Full Text Available Hanging is violent asphyxial death. The objective of this study is to assess the data of hanging cases. A descriptive-retrospective study was conducted. We studied 244 hanging cases autopsied in Forensic Division, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand, between January 2001 and December 2013. The study included 197 men (80.7% and 47 women (19.2%. Their age ranged from 14 to 93 years. Most of these cases were incomplete hanging (83.6%. Features of hanging victims, such as tongue protrusion; congestion of face; petechial hemorrhage of face, conjunctiva, and internal organs; and neck injuries, significantly correlated with complete hanging. The predominant occupation of hanging victims was in the service industry (63.1%. Suicides usually occurred in private homes or apartments (84.8%. A suicide note was found in 6.1% of cases. The most common ligature material used was nylon rope, found in 61.1% of cases. The most underlying diseases of the victims in hanging cases were tuberculosis and human immunodeficiency virus infection, 9 cases each. Blood ethanol levels of 29 cases (11.8% were detected to be higher than 150 mg%. Methamphetamine and benzodiazepine were detected in 5.3% and 3.3% of cases, respectively. This study provides comprehensive baseline data of hanging cases in central Bangkok.

New Method Developed to Measure Contact Angles of a Sessile Drop

Science.gov (United States)

Chao, David F.; Zhang, Nengli

2002-01-01

The spreading of an evaporating liquid on a solid surface occurs in many practical processes and is of importance in a number of practical situations such as painting, textile dyeing, coating, gluing, and thermal engineering. Typical processes involving heat transfer where the contact angle plays an important role are film cooling, boiling, and the heat transfer through heat pipes. The biological phenomenon of cell spreading also is analogous to a drop spreading (ref. 1). In the study of spreading, the dynamic contact angle describes the interfacial properties on solid substrates and, therefore, has been studied by physicists and fluid mechanics investigators. The dynamic contact angle of a spreading nonvolatile liquid drop provides a simple tool in the study of the free-boundary problem, but the study of the spreading of a volatile liquid drop is of more practical interest because the evaporation of common liquids is inevitable in practical processes. The most common method to measure the contact angle, the contact radius, and the height of a sessile drop on a solid surface is to view the drop from its edge through an optical microscope. However, this method gives only local information in the view direction. Zhang and Yang (ref. 2) developed a laser shadowgraphy method to investigate the evaporation of sessile drop on a glass plate. As described here, Zhang and Chao (refs. 3 and 4) improved the method and suggested a new optical arrangement to measure the dynamic contact angle and the instant evaporation rate of a sessile drop with much higher accuracy (less than 1 percent). With this method, any fluid motion in the evaporating drop can be visualized through shadowgraphy without using a tracer, which often affects the field under investigation.

SUITABILITY OF CORNEAL TISSUE FOR TRANSPLANTATION PROCURED FROM HANGING CASES

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Rekha Gyanchand

2017-06-01

Full Text Available BACKGROUND Requirement of donor cornea is essential to target the corneal blind. The best method to procure such corneas is from any major hospitals, which has a mortuary facility. The eye donation with hanging as the cause of death is very common in a mortuary setup. Some factors that are concerning regarding corneas procured from death due to hanging is the prolonged exposure of the cornea at the time of death, the exact time of death is not known, most of the cadavers are refrigerated for investigations as these arrive at the mortuary usually at night. Due to these reasons, the corneal surgeons are hesitant to use corneas procured from death due to hanging for corneal transplantation. Analysing these corneas would contribute to a great extent to the donor cornea pool in providing sight to the corneal blind, especially as majority are young individuals who commit suicide by hanging. In this study, the donor corneas were analysed with regards to corneal epithelial defect, endothelial cell morphology and utilisation of these corneas for transplantation. The aim of the HCRP study is to analyse the effect of death due to hanging on donor cornea. 1. Corneal epithelial status. 2. Corneal endothelial cell morphology. 3. Utilisation of corneas for transplantation. MATERIALS AND METHODS Donor corneas from 22 donors who died due to hanging were procured from hospital mortuary. All the 44 corneas were transplanted. Various parameters like demography, death to enucleation time, cadaver preservation in cold storage, endothelial cell density and utilisation of cornea for transplantation were noted. Design- Retrospective study. Statistical Analysis- Descriptive statistics, Pearson and Spearman correlation and Chi-square test were used to test the hypotheses. RESULTS Out of the 44 corneas analysed, 75% of the donors were refrigerated as a part of medicolegal investigations protocol. The average DTP time was 12 hours in refrigerated group and 5 hours in non

CASE REPORT OF SUCCESSFUL RESUSCITATION OF A CASE O F SUICIDAL HANGING

OpenAIRE

Yanki D.

2013-01-01

ABSTRACT: In Sikkim, the rate of suicide has been on the rise since the last 10 years. Suicidal hanging as method of ending life is a major concern among school children. It is very rare that the victims are brought on time for successful resuscit ation in Sikkim. Suicide by hanging is probably the most easy way to go about taking one’s own life , as the means to do it are easily available and uncomplicated and, brutally efficient in most case s . This is a case ...

The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers

NARCIS (Netherlands)

Heeres, P.; Setiawan, R.; Krol, M.C.; Adema, E.H.

2009-01-01

This paper describes two new methods for the determination of NO2 in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO2. With standard colorimetrical analysis, the amount of

On-line method to identify control rod drops in Pressurized Water Reactors

International Nuclear Information System (INIS)

Souza, T.J.; Martinez, A.S.; Medeiros, J.A.C.C.; Palma, D.A.P.; Gonçalves, A.C.

2014-01-01

Highlights: • On-line method to identify control rod drops in PWR reactors. • Identification method based on the readings of the ex-core detector. • Recognition of the patterns in the ex-core detector responses. - Abstract: A control rod drop event in PWR reactors leads to an unsafe operating condition. It is important to quickly identify the rod to minimise undesirable effects in such a scenario. The goal of this work is to develop an online method to identify control rod drops in PWR reactors. The method entails the construction of a tool based on ex-core detector responses. It proposes to recognize patterns in the neutron ex-core detectors responses and thus to make an online identification of a control rod drop in the core during the reactor operation. The results of the study, as well as the behaviour of the detector responses demonstrated the feasibility of this method

D.R.O.P: The Durable Reconnaissance and Observation Platform

Science.gov (United States)

McKenzie, Clifford; Parness, Aaron

2011-01-01

Robots can provide a remote presence in areas that are either inaccessible or too dangerous for humans. However, robots are often limited by their ability to adapt to the terrain or resist environmental factors. The Durable Reconnaissance and Observation Platform (DROP) is a lightweight robot that addresses these challenges with the capability to survive falls from significant heights, carry a useable payload, and traverse a variety of surfaces, including climbing vertical surfaces like wood, stone, and concrete. DROP is manufactured using a combination of rapid prototyping and shape deposition manufacturing. It uses microspine technology to create a new wheel-like design for vertical climbing. To date, DROP has successfully engaged several vertical surfaces, hanging statically without assistance, and traversed horizontal surfaces at approximately 30 cm/s. Unassisted vertical climbing is capable on surfaces up to 85deg at a rate of approximately 25cm*s(sup -1). DROP can also survive falls from up to 3 meters and has the ability to be thrown off of and onto rooftops. Future efforts will focus on improving the microspine wheels, selecting more resilient materials, customizing the controls, and performing more rigorous and quantifiable testing.

Acute pulmonary emphysema in death by hanging: a morphometric digital study.

Science.gov (United States)

Castiglioni, Claudia; Baumann, Pia; Fracasso, Tony

2016-09-01

Acute pulmonary emphysema (APE) has been described in cases of mechanical asphyxia such as ligature or manual strangulation but not in cases of hanging. In this study, we wanted to verify by morphometric digital analysis of lung tissue whether APE occurs in death by hanging.We investigated 16 cases of hanging (eight complete, eight incomplete), 10 cases of freshwater drowning (positive control group), and 10 cases of acute external bleeding (negative control group). Tissue sections were obtained from each pulmonary lobe. For each slide, five fields were randomly selected. The area of every alveolar space was measured by image analysis software. The mean alveolar area (MAA) was calculated for each group.In incomplete hanging, MAA was significantly higher than that observed in complete hanging and similar to the one observed in freshwater drowning.APE in cases of incomplete hanging can be considered as a sign of vitality. The high number of conditions that can cause alveolar distension (that were excluded in this study) limits the applicability of this vital sign in the routine forensic practice.

The discovery and exploration of Hang Son Doong

Energy Technology Data Exchange (ETDEWEB)

Limbert, H.; Limbert, D.; Hieu, N.; Phai, V. V.; Kinh Bac, D.; Phuong, T. H.; Granger, D.

2016-08-01

Hang Son Doong is located in the Phong Nha Ke Bang Limestone Massif in Quang Binh Province, Central Vietnam. Cave exploration by British cavers has been continuous in this area since 1990. Hang Son Doong is part of the Phong Nha Cave system which runs from the southern end of the National Park near the Lao border to the final resurgence at Phong Nha Cave. (Author)

Etiology and Use of the “Hanging Drop” Technique: A Review

Science.gov (United States)

Todorov, Ludmil; VadeBoncouer, Timothy

2014-01-01

Background. The hanging drop (HD) technique presumably relies on the presence of subatmospheric epidural pressure. It is not clear whether this negative pressure is intrinsic or an artifact and how it is affected by body position. There are few data to indicate how often HD is currently being used. Methods. We identified studies that measured subatmospheric pressures and looked at the effect of the sitting position. We also looked at the technique used for cervical and thoracic epidural anesthesia in the last 10 years. Results. Intrinsic subatmospheric pressures were measured in the thoracic and cervical spine. Three trials studied the effect of body position, indicating a higher incidence of subatmospheric pressures when sitting. The results show lower epidural pressure (−10.7 mmHg) with the sitting position. 28.8% of trials of cervical and thoracic epidural anesthesia that documented the technique used, utilized the HD technique. When adjusting for possible bias, the rate of HD use can be as low as 11.7%. Conclusions. Intrinsic negative pressure might be present in the cervical and thoracic epidural space. This effect is more pronounced when sitting. This position might be preferable when using HD. Future studies are needed to compare it with the loss of resistance technique. PMID:24839558

Etiology and Use of the “Hanging Drop” Technique: A Review

Directory of Open Access Journals (Sweden)

Ludmil Todorov

2014-01-01

Full Text Available Background. The hanging drop (HD technique presumably relies on the presence of subatmospheric epidural pressure. It is not clear whether this negative pressure is intrinsic or an artifact and how it is affected by body position. There are few data to indicate how often HD is currently being used. Methods. We identified studies that measured subatmospheric pressures and looked at the effect of the sitting position. We also looked at the technique used for cervical and thoracic epidural anesthesia in the last 10 years. Results. Intrinsic subatmospheric pressures were measured in the thoracic and cervical spine. Three trials studied the effect of body position, indicating a higher incidence of subatmospheric pressures when sitting. The results show lower epidural pressure (−10.7 mmHg with the sitting position. 28.8% of trials of cervical and thoracic epidural anesthesia that documented the technique used, utilized the HD technique. When adjusting for possible bias, the rate of HD use can be as low as 11.7%. Conclusions. Intrinsic negative pressure might be present in the cervical and thoracic epidural space. This effect is more pronounced when sitting. This position might be preferable when using HD. Future studies are needed to compare it with the loss of resistance technique.

Craniocervical injuries in judicial hangings: an anthropologic analysis of six cases.

Science.gov (United States)

Spence, M W; Shkrum, M J; Ariss, A; Regan, J

1999-12-01

Restoration projects and archaeologic excavations in two Canadian prisons resulted in the recovery of the skeletons of six felons executed by judicial hanging. Damage inflicted by hanging on various skeletal elements was observed. Among the injuries seen were fractures of the hyoid cornua, styloid processes, occipital bones, and cervical vertebral bodies (C2) and transverse processes (C1, C2, C3, and C5). Despite the general uniformity of the hanging technique, which involved a subaural knot, the trauma to the skeletal elements and the cause of death varied among individuals. Although some of this variation was probably due to minor differences in hanging practices, individual anatomic peculiarities of the victims likely also contributed.

A highly accurate boundary integral equation method for surfactant-laden drops in 3D

Science.gov (United States)

Sorgentone, Chiara; Tornberg, Anna-Karin

2018-05-01

The presence of surfactants alters the dynamics of viscous drops immersed in an ambient viscous fluid. This is specifically true at small scales, such as in applications of droplet based microfluidics, where the interface dynamics become of increased importance. At such small scales, viscous forces dominate and inertial effects are often negligible. Considering Stokes flow, a numerical method based on a boundary integral formulation is presented for simulating 3D drops covered by an insoluble surfactant. The method is able to simulate drops with different viscosities and close interactions, automatically controlling the time step size and maintaining high accuracy also when substantial drop deformation appears. To achieve this, the drop surfaces as well as the surfactant concentration on each surface are represented by spherical harmonics expansions. A novel reparameterization method is introduced to ensure a high-quality representation of the drops also under deformation, specialized quadrature methods for singular and nearly singular integrals that appear in the formulation are evoked and the adaptive time stepping scheme for the coupled drop and surfactant evolution is designed with a preconditioned implicit treatment of the surfactant diffusion.

Behaviour and quantification studies of terbacil and lenacil in environmental samples using cyclic and adsorptive stripping voltammetry at hanging mercury drop electrode.

Science.gov (United States)

Thriveni, T; Rajesh Kumar, J; Sujatha, D; Sreedhar, N Y

2007-05-01

The cyclic voltammograms of terbacil and lenacil at the hanging mercury drop electrode showed a single well defined four electron irreversible peak in universal buffer of pH 4.0 for both compounds. The peak potentials were shifted to more negative values on the increase of pH of the medium, implying the involvement of protons in the electrode reaction and that the proton transfer reaction precedes the proper electrode process. The four electron single peak may be attributed to the simultaneous reduction of carbonyl groups present in 2 and 4 in pyrimidine ring of terbacil and lenacil to the corresponding hydroxy derivative. Based on the interfacial adsorptive character of the terbacil and lenacil onto the mercury electrode surface, a simple sensitive and low cost differential pulse adsorptive stripping voltammetric procedure was optimized for the analysis of terbacil and lenacil. The optimal operational conditions of the proposed procedure were accumulation potential E (acc) = -0.4 V, accumulation time t (acc) = 80 s, scan rate = 40 mV s(-1), pulse amplitude = 25 mV using a universal buffer pH 4.0 as a supporting electrolyte. The linear concentration range was found to be 1.5 x 10(-5) to 1.2 x 10(-9) mol/l and 1.5 x 10(-5) to 2.5 x 10(-8) mol/l with the lower detection limit of 1.22 x 10(-9) and 2.0 x 10(-8) mol/l. The correlation coefficient and relative standard deviation values are found to be 0.942, 0.996, 1.64% and 1.23%, respectively, for 10 replicants. The procedure was successfully applied for determination of terbacil and lenacil in formulations, mixed formulations, environmental samples such as fruit samples and spiked water samples.

Drop Test Using Finite Element Method for Transport Package of Radioactive Material

International Nuclear Information System (INIS)

Xu Xiaoxiao; Zhao Bing; Zhang Jiangang; Li Gouqiang; Wang Xuexin; Tang Rongyao

2010-01-01

Mechanical test for transport package of radioactive material is one of the important tests for demonstrating package structure design. Drop test of package is a kind of destructive test. It is a common method of adopting the pre-analysis to determine drop orientation.Mechanical test of a sealed source package was calculated with finite element method (FEM) software. Based on the analysis of the calculation results, some values were obtained such as the stress, strain, acceleration and the drop orientation which causes the most severe damage, and the calculation results were compared with the results of test. (authors)

Thermodynamics of adsorption of dithiocarbamates at the hanging mercury drop.

Science.gov (United States)

Giannakopoulos, Evangelos; Deligiannakis, Yiannis

2007-02-27

Two dimethyldithiocarbamate (DMDTC) pesticides, thiram and ziram, are adsorbed onto a Hg drop via an entropically driven process. The adsorption isotherms are described by the Frumkin equation. For both molecules, the adsorption is characterized by a nonlinear pseudosigmoid temperature dependence of the Gibbs free energy. For the temperature range of 273-313 K, DeltaGADS varies between -43.4 and -56.71 kJ/mol for thiram and -42.60 and -55.67 kJ/mol for ziram. This variation of DeltaGADS reveals that the adsorption strength is increased at higher temperatures. During the adsorption of either molecule, strong lateral interactions are developed between neighboring adsorbates, which are severely weakened as the temperature increases. A unified reaction scheme is suggested for both ziram and thiram that predicts the formation and adsorption of a surface complex, (DMDTC)2Hg. In the case of thiram, two DMDTC molecules are formed by the cleavage of the disulfide S-S bond near the Hg electrode. The thermodynamic and structural parameters reveal that there are two limiting thermodynamic regimes for the adsorbed (DMDTC)2Hg species that originate from two limiting adsorption conformations of the adsorbates on the Hg surface. A transition occurs between these two conformations at temperatures in the region of 285-295 K. This transition is accompanied by large entropic and enthalpic changes.

Sistem Informasi Akademik pada SMA Swasta Hang Tuah Belawan

OpenAIRE

Syarifuddin, Ruisya

2015-01-01

Perancangan Sistem Informasi Akademik pada SMA Swasta Hang Tuah Belawan ini bertujuan untuk mempermudah proses pencarian atau searching data dan informasi untuk seluruh Siswa SMA Swasta Hang Tuah Belawan yang mengalami kesulitan dalam memperoleh data mengenai masalah Akademik tersebut. Faasilitas yang terdapat dalam aplikasi ini berupa penyediaan data dan informasi mengenai beritaberita terbaru, profil agenda kegiatan, dan data-data yang berguna untuk kelangsungan belajar si...

Cells on Gels: Cell Behavior at the Air-Gel Interface

Science.gov (United States)

O'Bryan, Christopher; Hormel, Tristan; Bhattacharjee, Tapomoy; Sawyer, W.; Angelini, Thomas

Numerous different types of cells are often grown at air-liquid interfaces. For example, a common way to create cell spheroids is to disperse cells in a droplet of liquid media that hangs from the lid of a culture dish - the ``hanging drop'' method. Some types of epithelial cells form monolayers at the bottom of hanging drops, instead of spheroids. Corneal epithelial cells stratify and exhibit a tissue-like phenotype when attached to liquid permeable culture surfaces positioned at the air-liquid media interface (air-lifted culture). These widely used culture methods make experimentation challenging - imaging through hanging drops and air-lifted culture dishes is prohibitive. However, similar results may be achieved by culturing cells on hydrogel surfaces at the air-gel interface. In this talk we will describe a method for culturing cells at air-gel interfaces. We seed human corneal epithelial cells (hTCEpi) onto the surfaces of hydrogel networks and jammed microgels, exposed to air. Preliminary observations of cell behavior at the air-gel interface will be presented.

First drop dissimilarity in drop-on-demand inkjet devices

International Nuclear Information System (INIS)

Famili, Amin; Palkar, Saurabh A.; Baldy, William J. Jr.

2011-01-01

As inkjet printing technology is increasingly applied in a broader array of applications, careful characterization of its method of use is critical due to its inherent sensitivity. A common operational mode in inkjet technology known as drop-on-demand ejection is used as a way to deliver a controlled quantity of material to a precise location on a target. This method of operation allows ejection of individual or a sequence (burst) of drops based on a timed trigger event. This work presents an examination of sequences of drops as they are ejected, indicating a number of phenomena that must be considered when designing a drop-on-demand inkjet system. These phenomena appear to be driven by differences between the first ejected drop in a burst and those that follow it and result in a break-down of the linear relationship expected between driving amplitude and drop mass. This first drop, as quantified by high-speed videography and subsequent image analysis, can be different in morphology, trajectory, velocity, and volume from subsequent drops within a burst. These findings were confirmed orthogonally by both volume and mass measurement techniques which allowed quantitation down to single drops.

Hanging Out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence

Science.gov (United States)

Siennick, Sonja E.; Osgood, D. Wayne

2012-01-01

Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out most with their most available friends and their most generally similar friends, not with their most at-risk or similarly at-risk friends. These findings vary little by gender and wave. Together, the findings suggest that the risks of hanging out stem from the nature of hanging out as an activity, not the nature of adolescents’ companions, and that hanging out is a context for friends’ mutual reinforcement of pre-existing characteristics. PMID:23204811

Hanging Out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence.

Science.gov (United States)

Siennick, Sonja E; Osgood, D Wayne

2012-12-01

Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out most with their most available friends and their most generally similar friends, not with their most at-risk or similarly at-risk friends. These findings vary little by gender and wave. Together, the findings suggest that the risks of hanging out stem from the nature of hanging out as an activity, not the nature of adolescents' companions, and that hanging out is a context for friends' mutual reinforcement of pre-existing characteristics.

A drop penetration method to measure powder blend wettability.

Science.gov (United States)

Wang, Yifan; Liu, Zhanjie; Muzzio, Fernando; Drazer, German; Callegari, Gerardo

2018-03-01

Water wettability of pharmaceutical blends affects important quality attributes of final products. We investigate the wetting properties of a pharmaceutical blend lubricated with Magnesium Stearate (MgSt) as a function of the mechanical shear strain applied to the blend. We measure the penetration dynamics of sessile drops deposited on slightly compressed powder beds. We consider a blend composed of 9% Acetaminophen 90% Lactose and 1% MgSt by weight. Comparing the penetration time of water and a reference liquid Polydimethylsiloxane (silicon oil) we obtain an effective cosine of the contact angle with water, based on a recently developed drop penetration method. We repeat the experiments for blends exposed to increasing levels of shear strain and demonstrate a significant decrease in water wettability (decrease in the cosine of the contact angle). The results are consistent with the development of a hydrophobic film coating the powder particles as a result of the increased shear strain. Finally, we show that, as expected dissolution times increase with the level of shear strain. Therefore, the proposed drop penetration method could be used to directly assess the state of lubrication of a pharmaceutical blend and act as a quality control on powder blend attributes before the blend is tableted. Copyright © 2017 Elsevier B.V. All rights reserved.

The epidemiology of injury in hang-gliding and paragliding.

Science.gov (United States)

Rekand, Tiina

2012-01-01

Para- and hang-gliding are modern air sports that developed in the 20th century. Performers should possess technical skills and manage certified equipment for successful flight. Injuries may happen during the take-off, flight and landing. PubMed was searched using the search terms 'paragliding' and/or 'hang-gliding'. The reference lists of articles identified in the search strategy were also searched for relevant articles. The most common injuries are fractures, dislocations or sprains in the extremities, followed by spinal and head traumas. Multiple injuries after accidents are common. Collision with electrical wires may cause burn injuries. Fatal outcomes are caused by brain injuries, spinal cord injuries at the cervical level or aorta rupture. Accidents happen because of risk-taking behavior, lack of education or use of self-modified equipment. Observational studies have suggested the need for protection of the head, trunk and lower extremities. The measures proposed are often based on conclusions of observational studies and not proven through randomized studies. Better education along with focusing on possible risk factors will probably diminish the risks of hang- and paragliding. Large denominator-based case series, case-control and population-based studies are needed for assessment of the risks of hang- and paragliding. Copyright © 2012 S. Karger AG, Basel.

Realization methodology for optimal design of steel structures conveyors with hanging belt

Directory of Open Access Journals (Sweden)

Boslovyak P.V.

2016-03-01

Full Text Available Presents the results of optimum design of metal structures of the fixed conveyor with hanging belt. The analysis results optimum design of steel structures of stationary conveyor with hanging belt.

Linkage between canopy water storage and drop size distributions of leaf drips

Science.gov (United States)

Nanko, Kazuki; Watanabe, Ai; Hotta, Norifumi; Suzuki, Masakazu

2013-04-01

Differences in drop size distribution (DSD) of leaf drips among tree species have been estimated and physically interpreted to clarify the leaf drip generation process. Leaf drip generation experiments for nine species were conducted in an indoor location without foliage vibration using an automatic mist spray. Broad-leaved species produced a similar DSD among species whose leaves had a matte surface and a second similar DSD among species whose leaves had a coated surface. The matte broad leaves produced a larger and wider range of DSDs than the coated broad leaves. Coated coniferous needles had a wider range of DSDs than the coated broad leaves and different DSDs were observed for different species. The species with shorter dense needles generated a larger DSD. The leaf drip diameter was calculated through the estimation of a state of equilibrium of a hanging drop on the leaves based on physical theory. The calculations indicated that the maximum diameter of leaf drips was determined by the contact angle, and the range of DSDs was determined by the variation in contact length and the contact diameter at the hanging points. The results revealed that leaf drip DSD changed due to variations in leaf hydrophobicity, leaf roughness, leaf geometry and leaf inclination among the different tree species. This study allows the modelization of throughfall DSD. Furthermore, it indicates the possibility of interpreting canopy water processes from canopy water storage to drainage through the contact angle and leaf drip DSD. The part of this study is published in Nanko et al. (2013, Agric. Forest. Meteorol. 169, 74-84).

Electrochemical methods for monitoring of environmental carcinogens.

Science.gov (United States)

Barek, J; Cvacka, J; Muck, A; Quaiserová, V; Zima, J

2001-04-01

The use of modern electroanalytical techniques, namely differential pulse polarography, differential pulse voltammetry on hanging mercury drop electrode or carbon paste electrode, adsorptive stripping voltammetry and high performance liquid chromatography with electrochemical detection for the determination of trace amounts of carcinogenic N-nitroso compounds, azo compounds, heterocyclic compounds, nitrated polycyclic aromatic hydrocarbons and aromatic and heterocyclic amines is discussed. Scope and limitations of these methods are described and some practical applications based on their combination with liquid-liquid or solid phase extraction are given.

Distribution of hanging garden vegetation associations on the Colorado Plateau, USA

Science.gov (United States)

James F. Fowler; N. L. Stanton; Ronald L. Hartman

2007-01-01

Hanging gardens are island-like habitats dominated by mesophytic-hydrophytic plant communities, growing on seeps on the xeric canyon walls of the Colorado Plateau in the American West. We measured the abundance of species and physical microhabitat characteristics of 73 individual hanging gardens during the growing seasons of 1991-1993. Cluster analysis of a simplified...

Comparative analysis of tumor spheroid generation techniques for differential in vitro drug toxicity

Science.gov (United States)

Raghavan, Shreya; Rowley, Katelyn R.; Mehta, Geeta

2016-01-01

Multicellular tumor spheroids are powerful in vitro models to perform preclinical chemosensitivity assays. We compare different methodologies to generate tumor spheroids in terms of resultant spheroid morphology, cellular arrangement and chemosensitivity. We used two cancer cell lines (MCF7 and OVCAR8) to generate spheroids using i) hanging drop array plates; ii) liquid overlay on ultra-low attachment plates; iii) liquid overlay on ultra-low attachment plates with rotating mixing (nutator plates). Analysis of spheroid morphometry indicated that cellular compaction was increased in spheroids generated on nutator and hanging drop array plates. Collagen staining also indicated higher compaction and remodeling in tumor spheroids on nutator and hanging drop arrays compared to conventional liquid overlay. Consequently, spheroids generated on nutator or hanging drop plates had increased chemoresistance to cisplatin treatment (20-60% viability) compared to spheroids on ultra low attachment plates (10-20% viability). Lastly, we used a mathematical model to demonstrate minimal changes in oxygen and cisplatin diffusion within experimentally generated spheroids. Our results demonstrate that in vitro methods of tumor spheroid generation result in varied cellular arrangement and chemosensitivity. PMID:26918944

Transformation of atmospheric components near a spark discharge at the anode polarization of a metallic electrode hanging over a solution

Science.gov (United States)

Orlov, A. M.; Yavtushenko, I. O.; Bodnarskii, D. S.

2013-03-01

The variation of the pressure of a gas phase activated by spark discharges between an aqueous electrolyte solution (liquid cathode) and a metallic electrode (anode) hanging over the solution is studied. A mathematical model of the proceeding reaction kinetics is constructed, and the variation of the partial pressures of all initial and produced components in the gas phase is calculated. Both the Faraday and non-Faraday mechanisms of gas component production from water are confirmed. It is found that a large overhanging drop responsible for additional supply of simultaneously produced H2 and O2 molecules forms rapidly at the end face of the anodically polarized electrode.

Hanging out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence

Science.gov (United States)

Siennick, Sonja E.; Osgood, D. Wayne

2012-01-01

Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out…

A case of the CT scanning of a suicidal hanging brain

International Nuclear Information System (INIS)

Kawamata, Masaharu; Murooka, Hiroshi; Tanabe, Yasuhiko.

1988-01-01

A CT scanning of a case of hanging brain is reported. A 63-year-old man, who had been maintained with Aspirin (30 mg every morning) for cerebral infarction, attempted suicide by hanging, but failed. Several hours later, he was admitted because of consciousness disturbance and so was examined by means of CT scanning. Plain CT scanning showed symmetrical multiple intracerebral hemorrhages. Hemorrhages were found in the subcortical region of the bilateral temporal lobes and in the subependymal region near the foramen of Monro or in the choroidal plexus. We speculated that these hemorrhages may be caused by the congestion of the intracranial venous system caused by squeezing both internal jugular veins by hanging. Past angiograms (1981) for cerebral infarction revealed neither AVM nor angioma. (author)

HangOut: generating clean PSI-BLAST profiles for domains with long insertions.

Science.gov (United States)

Kim, Bong-Hyun; Cong, Qian; Grishin, Nick V

2010-06-15

Profile-based similarity search is an essential step in structure-function studies of proteins. However, inclusion of non-homologous sequence segments into a profile causes its corruption and results in false positives. Profile corruption is common in multidomain proteins, and single domains with long insertions are a significant source of errors. We developed a procedure (HangOut) that, for a single domain with specified insertion position, cleans erroneously extended PSI-BLAST alignments to generate better profiles. HangOut is implemented in Python 2.3 and runs on all Unix-compatible platforms. The source code is available under the GNU GPL license at http://prodata.swmed.edu/HangOut/. Supplementary data are available at Bioinformatics online.

Neurological outcomes following suicidal hanging: A prospective study of 101 patients

Directory of Open Access Journals (Sweden)

Mohammed Turab Jawaid

2017-01-01

Full Text Available Context: Survivors of suicidal hanging can have variable neurological outcomes – from complete recovery to irreversible brain damage. Literature on the neurological outcomes in these patients is confined to retrospective studies and case series. Hence, this prospective study was carried out. Aims: The aim is to study the neurological outcomes in suicidal hanging. Settings and Design: This was a prospective observational study carried out from July 2014 to July 2016. Subjects and Methods: Consecutive patients admitted to the emergency and medicine wards were included in the study. Details of the clinical and radiological findings, course in hospital and at 1 month postdischarge were analyzed. Statistical Analysis Used: Statistical analysis was performed using IBM SPSS advanced statistics 20.0 (SPSS Inc., Chicago, USA. Univariate analysis was performed using Chi-square test for significance and Odd's ratio was calculated. Results: Of the 101 patients, 6 died and 4 had residual neuro deficits. Cervical spine injury was seen in 3 patients. Interestingly, 39 patients could not remember the act of hanging (retrograde amnesia. Hypotension, pulmonary edema, Glasgow coma scale (GCS score <8 at admission, need for mechanical ventilation, and cerebral edema on plain computed tomography were more in those with amnesia as compared to those with normal memory and these findings were statistically significant. Conclusions: Majority of patients recovered without any sequelae. Routine imaging of cervical spine may not be warranted in all patients, even in those with poor GCS. Retrograde amnesia might be more common than previously believed and further studies are needed to analyze this peculiar feature.

Modern Electrochemical Methods for Monitoring of Chemical Carcinogens

Directory of Open Access Journals (Sweden)

J. Zima

2005-04-01

Full Text Available This contribution is based on our presentation at the 1st International Symposiumon Sensor Science, Paris, 16-20 June 2003. It presents recent results regarding theelectrochemical determination of submicromolar and nanomolar concentrations of variouscarcinogenic substances (nitrated polycyclic aromatic hydrocarbons, heterocycliccompounds, azo compounds, aromatic amino compounds, etc. using both traditional(classical dropping mercury electrode, static mercury drop electrode, hanging mercury dropelectrode and non-traditional types of electrodes (solid amalgam electrodes, carbon pasteelectrodes, platinum tubular electrodes.

Determination of deuterium concentration by falling drop method

International Nuclear Information System (INIS)

Kawai, Hiroshi; Morishima, Hiroshige; Koga, Taeko; Niwa, Takeo; Fujii, Takashi.

1976-01-01

Falling drop method for determination of deuterium concentration in water sample was studied. The principle is the same as that developed by Kirshenbaum, I. in 1932. One drop of water sample falls down through a column filled with o-fluorotoluene at temperature of nearly 25 0 C. The falling time is, instead of using a stop-watch, measured with two light pulses led to a photomultiplier with mirrors, which make two pulse marks on moving chart paper. Distance between the two pulse marks is proportional to falling time. Instead of water filled double chambers of constant temperature equipped with heaters, thermostats and propellers for stirring, the column is dipped in circulating water supplied from a ''Thermoelectric'' made by ''Sharp'' company, which can circulate constant temperature water cooled or heated with thermoelements. Variation of the temperature is about 0.01 0 C. The range of deuterium concentration in our case was 20 -- 60D%. Sensitivity increased as the medium temperature decreased and as deuterium concentration of water sample increased. (auth.)

A mix-and-read drop-based in vitro two-hybrid method for screening high-affinity peptide binders

Science.gov (United States)

Cui, Naiwen; Zhang, Huidan; Schneider, Nils; Tao, Ye; Asahara, Haruichi; Sun, Zhiyi; Cai, Yamei; Koehler, Stephan A.; de Greef, Tom F. A.; Abbaspourrad, Alireza; Weitz, David A.; Chong, Shaorong

2016-01-01

Drop-based microfluidics have recently become a novel tool by providing a stable linkage between phenotype and genotype for high throughput screening. However, use of drop-based microfluidics for screening high-affinity peptide binders has not been demonstrated due to the lack of a sensitive functional assay that can detect single DNA molecules in drops. To address this sensitivity issue, we introduced in vitro two-hybrid system (IVT2H) into microfluidic drops and developed a streamlined mix-and-read drop-IVT2H method to screen a random DNA library. Drop-IVT2H was based on the correlation between the binding affinity of two interacting protein domains and transcriptional activation of a fluorescent reporter. A DNA library encoding potential peptide binders was encapsulated with IVT2H such that single DNA molecules were distributed in individual drops. We validated drop-IVT2H by screening a three-random-residue library derived from a high-affinity MDM2 inhibitor PMI. The current drop-IVT2H platform is ideally suited for affinity screening of small-to-medium-sized libraries (103–106). It can obtain hits within a single day while consuming minimal amounts of reagents. Drop-IVT2H simplifies and accelerates the drop-based microfluidics workflow for screening random DNA libraries, and represents a novel alternative method for protein engineering and in vitro directed protein evolution. PMID:26940078

Improved algorithm based on equivalent enthalpy drop method of pressurized water reactor nuclear steam turbine

International Nuclear Information System (INIS)

Wang Hu; Qi Guangcai; Li Shaohua; Li Changjian

2011-01-01

Because it is difficulty to accurately determine the extraction steam turbine enthalpy and the exhaust enthalpy, the calculated result from the conventional equivalent enthalpy drop method of PWR nuclear steam turbine is not accurate. This paper presents the improved algorithm on the equivalent enthalpy drop method of PWR nuclear steam turbine to solve this problem and takes the secondary circuit thermal system calculation of 1000 MW PWR as an example. The results show that, comparing with the design value, the error of actual thermal efficiency of the steam turbine cycle obtained by the improved algorithm is within the allowable range. Since the improved method is based on the isentropic expansion process, the extraction steam turbine enthalpy and the exhaust enthalpy can be determined accurately, which is more reasonable and accurate compared to the traditional equivalent enthalpy drop method. (authors)

Controlling charge on levitating drops.

Science.gov (United States)

Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

2007-08-01

Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation.

Sistem Informasi Akademik pada SMA Hang Tuah Belawan

OpenAIRE

Tanjung, Dini Syahroni

2015-01-01

Informasi yang disampaikan oleh SMA HANG TUAH BELAWAN selama ini disebarkan melalui brosur dan cara yang seperti itu kurang efektif. Oleh karena itu dibuatlah sistem informasi akademik ini agar penyampaian informasinya lebih efektif dan efisien. 092406181

The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers.

Science.gov (United States)

Heeres, Paul; Setiawan, Rineksa; Krol, Maarten Cornelis; Adema, Eduard Hilbrand

2009-12-01

This paper describes two new methods for the determination of NO(2) in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO(2). With standard colorimetrical analysis, the amount of NO(2) on the filters is determined. The second method is performed with fritted bubblers filled with Saltzman reagent, where, with a special procedure the absorption efficiencies of the bubblers are determined using ambient air, without the use of standard gases and electronic analytical instruments. The results of the bubblers are used to calibrate the free hanging filters. The two methods were applied simultaneously in the city of Yogyakarta, Indonesia. The methods are inexpensive and very well suited for use in low-budget situations. A characteristic of the free filter is the Sampling Volume, SV. This is the ratio of the amount of NO(2) on the filter and the ambient concentration. With the filter used in this study, the amount of triethanolamine and exposure time, the SV is 0.0166 m(3). The sampling rate (SR) of the filter, 4.6 cm(3)/s, is high. Hourly averaged measurements are performed for 15 hours per day in four busy streets. The measured amounts of NO(2) on the filters varied between 0.57 and 2.02 microg NO(2), at ambient air concentrations of 32 to 141 microg/m(3) NO(2). During the experiments the wind velocity was between 0.2 and 2.0 m/s, the relative humidity between 24 and 83 % and the temperature between 295 K and 311 K. These variations in weather conditions have no influence on the uptake of NO(2).

29 CFR 1926.907 - Use of safety fuse.

Science.gov (United States)

2010-07-01

... way shall be forbidden. (b) The hanging of a fuse on nails or other projections which will cause a...-called “drop fuse” method of dropping or pushing a primer or any explosive with a lighted fuse attached...

High-throughput method for optimum solubility screening for homogeneity and crystallization of proteins

Science.gov (United States)

Kim, Sung-Hou [Moraga, CA; Kim, Rosalind [Moraga, CA; Jancarik, Jamila [Walnut Creek, CA

2012-01-31

An optimum solubility screen in which a panel of buffers and many additives are provided in order to obtain the most homogeneous and monodisperse protein condition for protein crystallization. The present methods are useful for proteins that aggregate and cannot be concentrated prior to setting up crystallization screens. A high-throughput method using the hanging-drop method and vapor diffusion equilibrium and a panel of twenty-four buffers is further provided. Using the present methods, 14 poorly behaving proteins have been screened, resulting in 11 of the proteins having highly improved dynamic light scattering results allowing concentration of the proteins, and 9 were crystallized.

Calculation method for control rod dropping time in reactor

International Nuclear Information System (INIS)

Nogami, Takeki; Kato, Yoshifumi; Ishino, Jun-ichi; Doi, Isamu.

1996-01-01

If a control rod starts dropping, the dropping speed is rapidly increased, then settled substantially constant, rapidly decreased when it reaches a dash pot. A second detection signal generated by removing an AC component from a first detection signal is differentiated twice. The time when the maximum value among the twice differentiated values is generated is determined as a time when the control rods starts dropping. The time when minimum value among the twice differentiated values is generated is determined as a time when the control rod reaches the dash pot of the reactor. The measuring time within a range from the time when the control rod starts dropping to the time when the control rod reaches the dash pot of the reactor is determined. As a result, processing for the calculation of the dropping start time and dash pot reaching time of the control rod can be automatized. Further, it is suffice to conduct differentiation twice till the reaching time, which can facilitate the processing thereby enabling to determine a reliable time range. (N.H.)

Wireless Orbiter Hang-Angle Inclinometer System

Science.gov (United States)

Lucena, Angel; Perotti, Jose; Green, Eric; Byon, Jonathan; Burns, Bradley; Mata, Carlos; Randazzo, John; Blalock, Norman

2011-01-01

A document describes a system to reliably gather the hang-angle inclination of the orbiter. The system comprises a wireless handheld master station (which contains the main station software) and a wireless remote station (which contains the inclinometer sensors, the RF transceivers, and the remote station software). The remote station is designed to provide redundancy to the system. It includes two RF transceivers, two power-management boards, and four inclinometer sensors.

RODDRP - A FORTRAN program for use in control rod calibration by the rod drop method

International Nuclear Information System (INIS)

Wilson, W.E.

1972-01-01

The different methods to measure reactivity which are applicable to control rod calibration are discussed. They include: 1) the positive period method, 2) the rod drop method, 3) the source-jerk method, 4) the rod oscillation method, and 5) the pulsed neutron method. The instrument setup used at WSU for rod drop measurements is presented. To speed up the analysis of power fall-off trace, a FORTRAN IV program called RODDRP was written to simultaneously solve the in-hour equation and relative neutron flux. The procedure for calculating the worth of the rod that produced the power trace is given. The reactivity for each time relative flux point is obtained. Conclusions about the status of the equipment are made

Simulation of hanging dams downstream of Ossauskoski power plant

Energy Technology Data Exchange (ETDEWEB)

Aaltonen, J.; Huokuna, M. [Finnish Environment Inst., Helsinki (Finland); Severinkangas, K.; Talvensaari, M. [Kemijoki Oy, Rovaniemi (Finland)

2008-07-01

Sixteen power plants have been constructed along Finland's Kemijoki River for hydroelectric power production. The Ossauskoski facility has recently undergone major renovations and upgrade, making it the sixth largest hydroelectric power plant in Finland, with a new capacity of 124 MW and an annual energy output of 501 GWh. The increase in power output and discharge may cause changes in ice conditions downstream of the power plant. The section of the river is already subjected to frazil ice problems and hanging dam formation. Discharges and adverse effects of frazil ice phenomena are likely to increase due to climate change, resulting in harm for hydropower production and the environment, particularly in flow regulated rivers where winter discharges are higher than natural discharges. As such, a study was launched to investigate a dredge plan suggested by by the electric utility Kemijoki Oy. The project involved mapping the river bed topography to identify the location and extent of hanging dams. A sounding device and ground penetrating radar was used to find the thaw regions in the ice cover. The JJT numerical river ice model was effectively used to study the effect of hanging dams on water levels. However, the ice bridging phenomena was not modelled in a reliable way by the JJT model and will be modelled in the future using the CRISSP2D numerical model. 5 refs., 11 figs.

Hanging-wall deformation above a normal fault: sequential limit analyses

Science.gov (United States)

Yuan, Xiaoping; Leroy, Yves M.; Maillot, Bertrand

2015-04-01

The deformation in the hanging wall above a segmented normal fault is analysed with the sequential limit analysis (SLA). The method combines some predictions on the dip and position of the active fault and axial surface, with geometrical evolution à la Suppe (Groshong, 1989). Two problems are considered. The first followed the prototype proposed by Patton (2005) with a pre-defined convex, segmented fault. The orientation of the upper segment of the normal fault is an unknown in the second problem. The loading in both problems consists of the retreat of the back wall and the sedimentation. This sedimentation starts from the lowest point of the topography and acts at the rate rs relative to the wall retreat rate. For the first problem, the normal fault either has a zero friction or a friction value set to 25o or 30o to fit the experimental results (Patton, 2005). In the zero friction case, a hanging wall anticline develops much like in the experiments. In the 25o friction case, slip on the upper segment is accompanied by rotation of the axial plane producing a broad shear zone rooted at the fault bend. The same observation is made in the 30o case, but without slip on the upper segment. Experimental outcomes show a behaviour in between these two latter cases. For the second problem, mechanics predicts a concave fault bend with an upper segment dip decreasing during extension. The axial surface rooting at the normal fault bend sees its dips increasing during extension resulting in a curved roll-over. Softening on the normal fault leads to a stepwise rotation responsible for strain partitioning into small blocks in the hanging wall. The rotation is due to the subsidence of the topography above the hanging wall. Sedimentation in the lowest region thus reduces the rotations. Note that these rotations predicted by mechanics are not accounted for in most geometrical approaches (Xiao and Suppe, 1992) and are observed in sand box experiments (Egholm et al., 2007, referring

Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

International Nuclear Information System (INIS)

Souza, C. S.; Ferreira, L. C. S.; Thomas, L.; Barbosa, J. A. R. G.; Balan, A.

2009-01-01

The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6 1 22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 Å, and contained two molecules in the asymetric unit. It diffracted to 2.24 Å resolution

Application of the DC potential drop and the partial unloading methods to fracture mechanics tests

International Nuclear Information System (INIS)

Heerens, J.; Schwalbe, K.H.; Hellmann, D.; Knaack, J.; Mueller-Roos, J.

1985-01-01

The ability of the DC potential drop method and the partial unloading technique to measure crack growth and to detect initation of crack growth has been investigated using a number of steels and aluminium alloys. It was found that within the range of parameters investigated both of these methods can be recommended for the determination of the R-curve; however, since at small amounts of crack growth the DC potential drop method gave more consistent results it is therefore considered to be superior. The initation values J(0) of J determined by fractography were compared with J(Ic) as obtained by current practice. It was found that J(Ic) is poorly related to initation or to specific amount of crack growth. A modification of the J(Ic) procedure is proposed. Two contacting arrangements of the DC potential drop method were checked for initation detection: one indicates initation by a potential minimum (related to a J value J(min)), the other by the intersection of the R-curve with the blunting line (related to a J value J(int)). (orig.) [de

Implementasi Kebijakan Kawasan Tanpa Rokok (KTR) pada Mahasiswa di Lingkungan Sekolah Tinggi Ilmu Kesehatan Hang Tuah Pekanbaru

OpenAIRE

Reno Renaldi

2014-01-01

Sekolah Tinggi Ilmu Kesehatan (STIKes) Hang Tuah Pekanbaru sebagai tempat pelaksanaan proses belajar mengajar bagi mahasiswa sekaligus tempat kerja bagi karyawannya,  yang mana seyogyanya tempat tersebut menjadi tempat Kawasan Tanpa Rokok berdasarkan Undang-undang kesehatan.Oleh karena itu sejak tahun2011STIKes Hang Tuah telah mengeluarkan kebijakan dalam bentuk surat edaran dengan nomor surat No/09/STIKes-HTP/IX/2011/289/mengenai Kawasan Tanpa Rokok di lingkungan STIKes Hang Tuah Pekanbaru.P...

SU-F-T-75: Dosimetry Considerations in the Use of Hanging-Eye Block for Lesions of the Conjunctiva

Energy Technology Data Exchange (ETDEWEB)

Grelewicz, Z; Lee, B; Cutright, D; Kang, Z; Gopalakrishnan, M; Sathiaseelan, V; Zhang, H [Northwestern Memorial Hospital, Chicago, IL (United States)

2016-06-15

Purpose: Superficial lesions in the conjunctiva are frequently treated with en face electrons, using a hanging block to spare dose to the lens of the eye. Dose to the tumor and lens depend on the design and setup of the block and supporting apparatus. We performed in phantom measurements in order to characterize the dose sparing effects of the block as well as the under-dosing effect under the supporting apparatus for 6 MeV treatment. Methods: The commercial hanging block studied uses a 1.2 cm diameter tungsten cylinder supported by a 3 mm diameter acrylic rod. Point dose measurements under the hanging block, under an unblocked part of the field, and under the acrylic rod were performed using MOSFET detectors. In addition, EBT3 film was used for both PDD and profile measurements at a depth in phantom of 3 mm for both 105 and 103 cm SSD. Results: MOSFET measurements reported a dose reduction of 95% under the tungsten block when using an SSD of 103 cm, and 86% when using an SSD of 105 cm at a depth in phantom of 3 mm. Film measurements showed that the area under the acrylic rod may be under-dosed by as much as 30% when using 103 SSD. MOSFET measurements confirmed that when using an SSD of 103 cm, the area under the acrylic rod is under-dosed by up to 30% at 3mm depth, compared to the unblocked part of the field. Conclusion: The effectiveness of the commercial hanging block apparatus depends on setup, with 95% lens sparing possible with an SSD of 103 cm. This short SSD is necessary for sharp penumbra. At this SSD, substantial under-dosing under the acrylic support rod is possible. This must be mitigated with either feathering, or using an alternative method of support for the tungsten block.

An improved potential drop method for measuring and monitoring defects in metallic structures

International Nuclear Information System (INIS)

Oppermann, W.; Keller, H.P.

1993-01-01

In the developed form described the direct current potential drop method is a reliable and relatively accurate procedure for the measuring and surveillance of surface cracks in metallic materials. There are also significant possibilities in practice of surveying cracks on the inaccessible side of the structure. The basis for the improvement in accuracy, in particular for short cracks, is firstly an improved measuring technique and secondly calibration curves determined using an electrolytic tank. Practical experience gained in conventional plants is to date positive. The opportunity exists of benefitting from the advantages that would be brought about by an increased use of the potential drop method in plant surveillance. In nuclear plants specifically this would achieve a reduction in the testing personnel's exposure to radiation. (orig.)

Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction

International Nuclear Information System (INIS)

Yang Fangwen; Liu Rui; Tan Zhiqiang; Wen Xiaodong; Zheng Chengbin; Lv Yi

2010-01-01

An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl 4 (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I 0 and I i ) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L -1 , with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L -1 . The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water).

Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction.

Science.gov (United States)

Yang, Fangwen; Liu, Rui; Tan, Zhiqiang; Wen, Xiaodong; Zheng, Chengbin; Lv, Yi

2010-11-15

An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl(4) (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I(0) and I(i)) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L(-1), with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L(-1). The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water). Copyright © 2010 Elsevier B.V. All rights reserved.

Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

OpenAIRE

Li Yuting; Gan Fangji; Wan Zhengjun; Liao Junbi; Li Wenqiang

2015-01-01

Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of s...

Liver hanging maneuver for right hemiliver in situ donation – anatomical considerations

OpenAIRE

Trotovšek, B.; Gadžijev, E.M.; Ravnik, D.; Hribernik, M.

2006-01-01

Background. An anatomical study was carried out to evaluate the safety of the liver hanging maneuver for the right hemiliver in living donor and in situ splitting transplantation. During this procedure a 4–6 cm blind dissection is performed between the inferior vena cava and the liver. Short subhepatic veins entering the inferior vena cava from segments 1 and 9 could be torn with consequent hemorrhage. Materials and methods. One hundred corrosive casts of livers were evaluated to establish th...

Anatomical basis of the liver hanging maneuver.

Science.gov (United States)

Trotovsek, Blaz; Belghiti, Jacques; Gadzijev, Eldar M; Ravnik, Dean; Hribernik, Marija

2005-01-01

The anterior approach to right hepatectomy using the liver hanging maneuver without liver mobilization claims to be anatomically evaluated. During this procedure a 4 to 6-cm blind dissection between the inferior vena cava and the liver is performed. Short subhepatic veins, entering the inferior vena cava could be torn and a hemorrhage, difficult to control, could occur. On 100 corrosive casts of livers the anterior surface of the inferior vena cava was studied to evaluate the position, diameter and draining area of short subhepatic veins and inferior right hepatic vein. The width of the narrowest point on the planned route of blind dissection was determined. The average value of the narrowest point on the planned route of blind dissection was 8.7+/-2.3mm (range 2-15mm). The ideal angle of dissection being 0 degrees was found in 93% of cases. In 7% we found the angle of 5 degrees toward the right border of inferior vena cava to be the better choice. Our results show that liver hanging maneuver is a safe procedure. With the dissection in the proposed route the risk of disrupting short subhepatic veins is low (7%).

Differentiation of mouse embryonic stem cells into cardiomyocytes via the hanging-drop and mass culture methods.

Science.gov (United States)

Fuegemann, Christopher J; Samraj, Ajoy K; Walsh, Stuart; Fleischmann, Bernd K; Jovinge, Stefan; Breitbach, Martin

2010-12-01

Herein, we describe two protocols for the in vitro differentiation of mouse embryonic stem cells (mESCs) into cardiomyocytes. mESCs are pluripotent and can be differentiated into cells of all three germ layers, including cardiomyocytes. The methods described here facilitate the differentiation of mESCs into the different cardiac subtypes (atrial-, ventricular-, nodal-like cells). The duration of cell culture determines whether preferentially early- or late-developmental stage cardiomyocytes can be obtained preferentially. This approach allows the investigation of cardiomyocyte development and differentiation in vitro, and also allows for the enrichment and isolation of physiologically intact cardiomyocytes for transplantation purposes. © 2010 by John Wiley & Sons, Inc.

A novel fabrication technique for free-hanging homogeneous polymeric cantilever waveguides

International Nuclear Information System (INIS)

Nordström, Maria; Hübner, Jörg; Boisen, Anja; Calleja, Montserrat

2008-01-01

We present a novel bonding technique developed for the fabrication of a cantilever-based biosensing system with integrated optical read-out. The read-out mechanism is based on single-mode waveguides fabricated monolithically in SU-8. For optimal operation of the read-out mode, the cantilever waveguides should be homogenous and this bonding technique ensures free-hanging cantilevers that are surrounded by the same material for bottom and top claddings. The bonding step is necessary because SU-8 is a negative resist where free-hanging structures cannot be fabricated directly. This paper gives details on the processing aspects and the parameters of the fabrication steps

Perilaku Seks Pranikah pada Mahasiswa STIKes Hang Tuah Pekanbaru

Directory of Open Access Journals (Sweden)

Novita Rany

2012-11-01

Full Text Available Hasil penelitian PKBI (Persatuan Keluarga Berencana Indonesia – Riau tahun 2009 bahwa 38,75 % pria sudah melakukan hubungan seks pranikah sedangkan wanita 16,98 %. Penelitian ini menggunakan metode kualitatif. Subjek penelitian adalah mahasiswa STIKes Hang Tuah Pekanbaru, informan kunci merupakan dosen bagian kemahasiswaan, orang tua, ibu kos dan teman dekat. Dari penelitian ini diperoleh bahwa Perilaku seksual dibagi kedalam yang tidak berisiko (mulai dari ngobrol dan pegangan tangan saja, dan yang berisiko (dari ciuman sampai dengan berhubungan intim. Dari hasil penelitian diketahui 7 informan yang berisiko dan 9 lainnya tidak berisiko. Hampir separuh (7 dari 16 informan berperilaku seksual yang berisiko dan beberapa diantaranya pernah melakukan hubungan seksual pra nikah. Ada kecenderungan hubungan antara pengetahuan, sikap, persepsi, teman sebaya dan peran keluarga dalam mengawasi pergaulan anaknya terhadap perilaku seks berisiko. Saran bagi STIKes Hang Tuah dan Dinas Kesehatan agar dapat memasukan pendidikan seks kedalam kurikulum

Death by hanging while watching violent pornographic videos on the Internet - suicide or accidental autoerotic death?

Science.gov (United States)

Vennemann, B; Pollak, S

2006-03-01

In deaths by hanging, it may sometimes be difficult to differentiate between autoerotic accident and suicide. Our report deals with a 30-year-old man who was found hanged in the living room of his flat. The deceased was wearing headphones connected to a PC. Within the deceased's view was a computer screen showing the last picture of a video file downloaded from the Internet with the head of an unclothed, allegedly hanged female. The deceased's left hand was inside his trousers in the genital region. The autopsy did not only show findings typical for hanging, but also advanced sarcoidosis, which was known to the victim. Although this basic illness could have been a possible motive for suicide, the circumstances in the presented case pointed more in the direction of an accidental autoerotic death. As far as we know, this is the first description of a death during autoerotic activity in which sexual stimulation was achieved by watching a video file downloaded from the Internet.

Expression, purification, crystallization and preliminary X-ray studies of the Ebola VP35 interferon inhibitory domain

International Nuclear Information System (INIS)

Leung, Daisy W.; Ginder, Nathaniel D.; Nix, Jay C.; Basler, Christopher F.; Honzatko, Richard B.; Amarasinghe, Gaya K.

2009-01-01

Native and selenomethionine-labeled crystals of Ebola VP35 interferon inhibitory domain were obtained by the hanging-drop vapor-diffusion method. Ebola VP35 is a multifunctional protein that is important for host immune suppression and pathogenesis. VP35 contains an N-terminal oligomerization domain and a C-terminal interferon inhibitory domain (IID). Mutations within the VP35 IID result in loss of host immune suppression. Here, efforts to crystallize recombinantly overexpressed VP35 IID that was purified from Escherichia coli are described. Native and selenomethionine-labeled crystals belonging to the orthorhombic space group P2 1 2 1 2 1 were obtained by the hanging-drop vapor-diffusion method and diffraction data were collected at the ALS synchrotron

Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

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Li Yuting

2015-10-01

Full Text Available Potential drop techniques are of two types: the direct current potential drop (DCPD technique and alternating current potential drop (ACPD technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

Science.gov (United States)

Li, Yuting; Gan, Fangji; Wan, Zhengjun; Liao, Junbi; Li, Wenqiang

2015-10-01

Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

Rapid detection of atrazine and metolachlor in farm soils: gas chromatography-mass spectrometry-based analysis using the bubble-in-drop single drop microextraction enrichment method.

Science.gov (United States)

Williams, D Bradley G; George, Mosotho J; Marjanovic, Ljiljana

2014-08-06

Tracking of metolachlor and atrazine herbicides in agricultural soils, from spraying through to harvest, was conducted using our recently reported "bubble-in-drop single-drop microextraction" method. The method showed good linearity (R(2) = 0.999 and 0.999) in the concentration range of 0.01-1.0 ng/mL with LOD values of 0.01 and 0.02 ng/mL for atrazine and metolachlor, respectively. Sonication methods were poor at releasing these herbicides from the soil matrixes, while hot water extraction readily liberated them, providing an efficient accessible alternative to sonication techniques. Good recoveries of 97% and 105% were shown for atrazine and metolachlor, respectively, from the soil. The spiking protocol was also investigated, resulting in a traceless spiking method. We demonstrate a very sensitive technique by which to assess, for example, the length of residence of pesticides in given soils and thus risk of exposure.

Animations, games, and virtual reality for the Jing-Hang Grand Canal.

Science.gov (United States)

Chen, Wenzhi; Zhang, Mingmin; Pan, Zhigeng; Liu, Gengdai; Shen, Huaqing; Chen, Shengnan; Liu, Yong

2010-01-01

Digital heritage, an effective method to preserve and present natural and cultural heritage, is engaging many heritage preservation specialists and computer scientists. In particular, computer graphics researchers have become involved, and digital heritage has employed many CG techniques. For example, Daniel Pletinckx and his colleagues employed VR in a real museum at Ename, Belgium, and Zhigeng Pan and his colleagues applied it to construct a virtual Olympics museum. Soo-Chang Pei and his colleagues focused on restoring ancient Chinese paintings. Here, we describe how we've applied animations, computer games, and VR to China's famous Jing-Hang Grand Canal.

Ingestion of safety razor blade and delayed hanging in a complex suicide.

Science.gov (United States)

Chauhan, Mohit Singh; Behera, C; Naagar, Sunil; Sreenivas, M

2016-12-01

Ingestion of a foreign body is mostly accidental in children and intentional in prisoners to achieve hospitalization; however, use of this method of suicide is rare. We report a case where the victim first ingested a safety razor blade, but failed to die and then hanged himself, but failed again and finally succumbed to the complications on the sixth day. He had also attempted suicide by inflicting multiple incised wounds on his neck four days before the safety blade ingestion, but none were fatal. © The Author(s) 2016.

A new method for the compensation of ohmic drop in galvanic cells

NARCIS (Netherlands)

Kooijman, D.J.; Sluyters, J.H.

Generally the ohmic potential drop in a galvanic cell that occurs if a rectangular pulse is led through the cell, is compensated by means of a well-known bridge circuit. A better method making use of a phase reverter is described and its features are discussed. Exchange current densities up to 1200

Effects of fullerol on the osteogenic differentiation of adipose-derived mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Yan-ting TANG

2016-09-01

Full Text Available Objective 　To investigate the effect of fullerol on the osteogenic differentiation of rat adipose-derived mesenchymal stem cells (rADSCs based on hanging drop culture. Methods 　rADSC spheres were formed by hanging drop culture for 3 days, then the spheres were dissociated to single cell by trypsin (called rADSC sphere-derived cells. The rADSC sphere-derived cells were cultured in 2-D adherent cell cultures for 24 hours, then the ordinary culture medium was replaced by osteogenic induction medium (osteogenic medium, OM. OM without fullerol served as control group (CM; OM with 1.0μmol/L fullerol was used as the experimental group (OM+Ful1.0μmol/L. Two groups were induced to differentiation for 14d and 21d, using two methods of alizarin red staining and quantitative real-time PCR (qPCR to detecte the ability of rADSC sphere-derived cells differentiating into osteoblasts. Results 　rADSCs could form a uniform size microspheres structure through hanging drop culture for 3 days; rADSC sphere-derived cells were obtained by dissipation of trypsin. Compared with OM group, OM+Ful1.0μmol/L can make rADSC sphere-derived cells form more mineralized calcium nodules, and enhance the expression of the relevant osteogenic gene Runx2, OCN and ColI. Conclusion 　Fullerol can significantly enhance the osteogenic differentiation of rADSCs based on hanging drop culture, and it is helpful to improve the efficiency of osteogenic induction of rADSCs. DOI: 10.11855/j.issn.0577-7402.2016.08.03

Purification, crystallization and preliminary crystallographic analysis of biotin protein ligase from Staphylococcus aureus

International Nuclear Information System (INIS)

Pendini, Nicole R.; Polyak, Steve W.; Booker, Grant W.; Wallace, John C.; Wilce, Matthew C. J.

2008-01-01

The biotin protein ligase from S. aureus has been overexpressed in E. coli, purified, crystallized by the hanging-drop vapour-diffusion method and analysed using X-ray diffraction. Biotin protein ligase from Staphylococcus aureus catalyses the biotinylation of acetyl-CoA carboxylase and pyruvate carboxylase. Recombinant biotin protein ligase from S. aureus has been cloned, expressed and purified. Crystals were grown using the hanging-drop vapour-diffusion method using PEG 8000 as the precipitant at 295 K. X-ray diffraction data were collected to 2.3 Å resolution from crystals using synchrotron X-ray radiation at 100 K. The diffraction was consistent with the tetragonal space group P4 2 2 1 2, with unit-cell parameters a = b = 93.665, c = 131.95

Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

Energy Technology Data Exchange (ETDEWEB)

Zhao, Minglian; Li, Zhenguo; Zheng, Wei; Lou, Zhiyong [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Chen, Guo-Qiang, E-mail: chengq@stu.edu.cn [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong (China)

2006-08-01

The phasin PhaP{sub Ah} from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaP{sub Ah} from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å.

A direct current potential drop method for evaluating oxide film thickness formed in high-temperature water

International Nuclear Information System (INIS)

Anzai, Hideya; Ishibashi, Ryo; Saka, Masumi

2016-01-01

To establish an evaluation technique for oxide film thickness in-situ, the applicability of a four-point-probe direct current potential drop method is discussed in this study. Several samples of JIS SUS316L stainless steel with different oxide film thickness were prepared after immersing them in oxygenated pure water at 288°C for different periods. The oxide film thickness was measured by cross sectional observation using a transmission electron microscope. Potential drop on the oxide surface was measured every second during an acquisition period of about 20 s while a constant current was being injected into the sample simultaneously. This kind of measurement was repeatedly carried out at several arbitrary contact positions on the surface of the same sample. The measurement results showed that the potential drop slightly changed during the acquisition period and the tendency varied at the different contact positions. Multiple measurements at different contact positions revealed that the tendency could be categorized into two general types: the decreasing potential drop and the increasing potential drop, defined by the overall trend of the potential drop during the acquisition time. It was found that the ratio of contact positions with a decreasing potential drop tendency to all the contact positions of measurement tended to increase as applied current increased. This tendency depended on the oxide film thickness. The threshold value of applied current was found to correlate well with the oxide film thickness when the occurrence rate of decreasing potential drop ranged from 70 to 90% showing the best correlation at 70%. (author)

Water resources and effects of potential surface coal mining on dissolved solids in Hanging Woman Creek basin, southeastern Montana

Science.gov (United States)

Cannon, M.R.

1989-01-01

Groundwater resources of the Hanging Woman Creek basin, Montana include Holocene and Pleistocene alluvial aquifers and sandstone , coal, and clinker aquifers in the Paleocene Fort Union Formation. Surface water resources are composed of Hanging Woman Creek, its tributaries, and small stock ponds. Dissolved-solids concentrations in groundwater ranged from 200 to 11,00 mg/L. Generally, concentrations were largest in alluvial aquifers and smallest in clinker aquifers. Near its mouth, Hanging Woman Creek had a median concentration of about 1,800 mg/L. Mining of the 20-foot to 35-foot-thick Anderson coal bed and 3-foot to 16-foot thick Dietz coal bed could increase dissolved-solids concentrations in shallow aquifers and in Hanging Woman Creek because of leaching of soluble minerals from mine spoils. Analysis of saturated-paste extracts from 158 overburden samples indicated that water moving through mine spoils would have a median increase in dissolved-solids concentration of about 3,700 mg/L, resulting in an additional dissolved-solids load to Hanging Woman Creek of about 3.0 tons/day. Hanging Woman Creek near Birney could have an annual post-mining dissolved-solids load of 3,415 tons at median discharge, a 47% increase from pre-mining conditions load. Post-mining concentrations of dissolved solids, at median discharge, could range from 2,380 mg/L in March to 3,940 mg/L in August, compared to mean pre-mining concentrations that ranged from 1,700 mg/L in July, November, and December to 2,060 mg/L in May. Post-mining concentrations and loads in Hanging Woman Creek would be smaller if a smaller area were mined. (USGS)

Unusual planned complex suicide committed with a muzzle-loading pistol in combination with subsequent hanging.

Science.gov (United States)

Ondruschka, Benjamin; Morgenthal, Sylvia; Dreβler, Jan; Bayer, Ronny

2016-11-01

In Germany, suicides by firearms are not very common in contrast to deaths by hanging and intoxications. The use of historical muzzle-loading firearms in the context of suicides is a rarity. Contact shots from muzzle loaders cause an unusual wound morphology with extensive soot soiling. We report the case of a 59-year-old man, who committed a planned complex suicide by shooting into his mouth with a replica percussion gun in combination with hanging. The gunshot injury showed strong explosive effects in the oral cavity with fractures of the facial bones and the skull associated with cerebral evisceration (so-called Krönlein shot). Due to the special constellation of the case with hanging immediately after the shot, external bleeding from the head injuries was only moderate. Therefore, the head injuries could be assessed and partially reconstructed already at the scene.

A tree branch instead of a ligature: an unusual accidental hanging.

Science.gov (United States)

Vadysinghe, Amal Nishantha; Sivasubramanium, Murugupillai; Jayasooriya, Rankothge Pemasiri

2017-12-01

A unique case of accidental hanging due to compression of the neck of an adult by the branches of a coffee tree is reported. The decedent was a 42-year-old male who was found dead in a semi prone position on a slope. His neck was lodged in a wedge formed by two branches of a coffee tree, with his legs angled downwards on the slope. Autopsy revealed two friction abrasions located horizontally on either side of the front of the neck, just above the larynx. The findings were compatible with compression of the neck by the branches of the tree, with the body weight of the decedent contributing to compression. Subsequent complete autopsy examination confirmed the cause of death as hanging. Following an inquest the death was ruled to be accidental.

Drop weight impact measurements of HE sensitivity: modified detection methods

International Nuclear Information System (INIS)

Preston, D N; Brown, G W; Tappan, B C; Oshwald, D M; Koby, J R; Schoonover, M L

2014-01-01

High explosives small-scale sensitivity testing has been a hallmark of safety screening since WWII. Sensitivity testing was once crude and simple; broom sticks were used to scrape explosives on the floor while experimenters would look, listen, and smell for signs of a reaction. Since then, a wide variety of testing apparatus have been developed to explore the effects of different stimuli on explosives. In concert with the development of the machines themselves, the reaction detection methods have also evolved. This paper's focus is on the Los Alamos National Laboratory's (LANL) drop weight impact machine and reaction detection methods. A critical evaluation of results is presented with cautionary examples of false positives that can occur with non-explosive materials.

Preparation of magnesium hydroxide nanoflowers from boron mud via anti-drop precipitation method

Energy Technology Data Exchange (ETDEWEB)

Ma, Xi [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China); Ma, Hongwen, E-mail: mahw@cugb.edu.cn [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Xiaoqian [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Zhouqing [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China)

2014-08-15

Highlights: • We use the anti-drop precipitation method for synthesis of magnesium hydroxide. • Boron mud which is solid waste from a borax factory is used as the magnesium source. • The magnesium hydroxide nanoflowers are prepared in a short time. • The as-prepared magnesium hydroxide can be used as an effective flame retardant. - Abstract: Using boron mud as the starting material, the flower-like magnesium hydroxide (MH) has been successfully prepared via anti-drop precipitation method. The effect of NH{sub 3}·H{sub 2}O concentration, aging time, and surfactant on the morphology of MH was investigated. The optimum precipitation conditions are dropping MgSO{sub 4} solution in 5% NH{sub 3}·H{sub 2}O solution, with 3% polyethylene glycol as surfactant, aging for 30 min. XRD, SEM, FI-IR, and TG/DTA have been employed to characterize the as-prepared samples. XRD reveals that MH with high purity has the brucite structure. SEM images show that the flower-like MH exists in the form of mono-disperse well uniform spherical aggregation with diameter of 3–5 μm. TG/DTA shows a total percentage of weight loss 33.6% with a well-defined endothermic peak near 381.3 °C corresponding to the decomposition of MH. Furthermore, it reports that the extremely fast primary nucleation is of significance for crystal growth of MH.

Coalescence collision of liquid drops I: Off-center collisions of equal-size drops

Directory of Open Access Journals (Sweden)

Alejandro Acevedo-Malavé

2011-09-01

Full Text Available The Smoothed Particle Hydrodynamics method (SPH is used here to model off-center collisions of equal-size liquid drops in a three-dimensional space. In this study the Weber number is calculated for several conditions of the droplets dynamics and the velocity vector fields formed inside the drops during the collision process are shown. For the permanent coalescence the evolution of the kinetic and internal energy is shown and also the approaching to equilibrium of the resulting drop. Depending of the Weber number three possible outcomes for the collision of droplets is obtained: permanent coalescence, flocculation and fragmentation. The fragmentation phenomena are modeled and the formation of small satellite drops can be seen. The ligament that is formed follows the “end pinching” mechanism and it is transformed into a flat structure.

Flat-ramp vs. convex-concave thrust geometries in a deformable hanging wall: new insights from analogue modeling experiments

Science.gov (United States)

Almeida, Pedro; Tomas, Ricardo; Rosas, Filipe; Duarte, Joao; Terrinha, Pedro

2015-04-01

Different modes of strain accommodation affecting a deformable hanging-wall in a flat-ramp-flat thrust system were previously addressed through several (sandbox) analog modeling studies, focusing on the influence of different variables, such as: a) thrust ramp dip angle and friction (Bonini et al, 2000); b) prescribed thickness of the hanging-wall (Koy and Maillot, 2007); and c) sin-thrust erosion (compensating for topographic thrust edification, e.g. Persson and Sokoutis, 2002). In the present work we reproduce the same experimental procedure to investigate the influence of two different parameters on hanging-wall deformation: 1) the geometry of the thrusting surface; and 2) the absence of a velocity discontinuity (VD) that is always present in previous similar analogue modeling studies. Considering the first variable we use two end member ramp geometries, flat-ramp-flat and convex-concave, to understand the control exerted by the abrupt ramp edges in the hanging-wall stress-strain distribution, comparing the obtain results with the situation in which such edge singularities are absent (convex-concave thrust ramp). Considering the second investigated parameter, our motivation was the recognition that the VD found in the different analogue modeling settings simply does not exist in nature, despite the fact that it has a major influence on strain accommodation in the deformable hanging-wall. We thus eliminate such apparatus artifact from our models and compare the obtained results with the previous ones. Our preliminary results suggest that both investigated variables play a non-negligible role on the structural style characterizing the hanging-wall deformation of convergent tectonic settings were such thrust-ramp systems were recognized. Acknowledgments This work was sponsored by the Fundação para a Ciência e a Tecnologia (FCT) through project MODELINK EXPL/GEO-GEO/0714/2013. Pedro Almeida wants to thank to FCT for the Ph.D. grant (SFRH/BD/52556/2014) under the

Crystallization and preliminary X-ray characterization of a PaaX-like protein from Sulfolobus solfataricus P2

International Nuclear Information System (INIS)

Cao, Yi; Lou, Zhiyong; Sun, Yuna; Xue, Fei; Feng, Changzeng; Gong, Xiaocui; Yang, Dongmei; Bartlam, Mark; Meng, Zhaohui; Zhang, Keqin

2009-01-01

In this study, the PaaX-like protein from the hyperthermophilic archaeon Sulfolobus solfataricus P2 was successfully crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. PaaX is a global regulator of the phenylacetyl-coenzyme A catabolon that adjusts the expression of different operons to that of the paa-encoded central pathway. In this study, the PaaX-like protein from the hyperthermophilic archaeon Sulfolobus solfataricus P2 was successfully crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. Diffraction data were obtained to a resolution of 3.0 Å using synchrotron radiation at the Photon Factory. The crystal belonged to space group P321, with unit-cell parameters a = 86.4, b = 86.4, c = 105.5 Å

Investigation into spatial distribution of macroelements in dried drops of albumins and proteins by the methods of atomic-emission multichannel spectrometry

International Nuclear Information System (INIS)

Chin', N.Kh.; Zazhogin, A.P.; Bulojchik, Zh.I.; Tanin, A.L.; Pashkovskaya, I.D.; Nechipurenko, N.I.

2011-01-01

Based on local analysis of the line intensities of Al, Ca, Mg, and Zn in spectra for the samples of dried drops of egg albumin, the possibility for estimation of the spatial elemental distribution by the drop diameter was demonstrated using the atomic-emission multichannel spectrometry method. It was found that with an increase in the concentration of the elements with a high diffusion coefficient (Ca) diffusion counteracts their carry-over to the boundary of evaporating drops, simultaneously displacing the salts of other elements (Al, Fe, Zn) to the drop periphery. This work shows that excitation of the analyzed surface of a dried protein drop by double laser pulses enables a semi-quantitative estimation of the distribution of essential elements by the drop radius. Such investigations look very promising in search for markers of various diseases and in the development of methods revealing the pathological processes at the preclinical stage, making it possible to look for the causes of the elemental unbalance, to realize a targeted selection of preparations and active additives, to correct the treatment course. (authors)

Application of Proteomics to the Study of Pollination Drops

Directory of Open Access Journals (Sweden)

Natalie Prior

2013-04-01

Full Text Available Premise of the study: Pollination drops are a formative component in gymnosperm pollen-ovule interactions. Proteomics offers a direct method for the discovery of proteins associated with this early stage of sexual reproduction. Methods: Pollination drops were sampled from eight gymnosperm species: Chamaecyparis lawsoniana (Port Orford cedar, Ephedra monosperma, Ginkgo biloba, Juniperus oxycedrus (prickly juniper, Larix ×marschlinsii, Pseudotsuga menziesii (Douglas-fir, Taxus ×media, and Welwitschia mirabilis. Drops were collected by micropipette using techniques focused on preventing sample contamination. Drop proteins were separated using both gel and gel-free methods. Tandem mass spectrometric methods were used including a triple quadrupole and an Orbitrap. Results: Proteins are present in all pollination drops. Consistency in the protein complement over time was shown in L. ×marschlinsii. Representative mass spectra from W. mirabilis chitinase peptide and E. monosperma serine carboxypeptidase peptide demonstrated high quality results. We provide a summary of gymnosperm pollination drop proteins that have been discovered to date via proteomics. Discussion: Using proteomic methods, a dozen classes of proteins have been identified to date. Proteomics presents a way forward in deepening our understanding of the biological function of pollination drops.

A method to determine the dampening system of control rod drop mechanism for PWR reactors

International Nuclear Information System (INIS)

Trindade, C.E.; Mattos, J.R.L. de; Perrotta, J.A.

1988-08-01

A method to determine the Control Assembly damping drop system (dashpot/guide tube) was developed. It's presented a theoretical model, an experimental device and the procedures to determine this system, which is used in PWR reactors. (author) [pt

A boundary integral method for two-dimensional (non)-Newtonian drops in slow viscous flow

NARCIS (Netherlands)

Toose, E.M.; Geurts, B.J.; Kuerten, J.G.M.

1995-01-01

A boundary integral method for the simulation of the time-dependent deformation of Newtonian or non-Newtonian drops suspended in a Newtonian fluid is developed. The boundary integral formulation for Stokes flow is used and the non-Newtonian stress is treated as a source term which yields an extra

CONSTOR registered V/TC drop tests. Pre-test analysis by finite element method

International Nuclear Information System (INIS)

Voelzer, W.; Koenig, S.; Klein, K.; Tso, C.F.; Owen, S.; Monk, C.

2004-01-01

The CONSTOR registered family of steel-concrete-steel sandwich cask designs have been developed to fulfil both the internationally valid IAEA criteria for transportation and the requirements for long-term intermediate storage in the US and various European countries. A comprehensive drop testing programme using a full-scale prototype test cask (CONSTOR registered V/TC) has been developed as part of the application for a transport license in both Germany and the US. The drop tests using the full-scale cask will be performed by BAM at test facilities in Horstwalde. The tests will include five different 9m drops onto flat unyielding targets and seven different 1m drops onto a punch. The first drop test, a 9m side drop, will be performed during PATRAM 2004. The other drop tests will take place during the following year. The development of the cask design and the formulation of the drop test programme has been supported by an extensive series of finite element analyses. The objectives of the finite element analyses were; to provide an intermediate step in demonstrating the performance of the CONSTOR registered in fulfilling the requirements of 10 CFR 71 and the IAEA transport regulations. To justify the selection of drop tests. To predict the performance of V/TC during the drop tests. To estimate the strain and acceleration time histories at measuring points on the test cask and to aid in the setting up of the test instrumentation. To develop an analysis model that can be used in future safety analyses for transport and storage license applications and which can confidently be used to demonstrate the performance of the package. This paper presents an overview of the analyses performed, including a summary of all the different drop orientations that were considered. The major assumptions employed during the analyses are also discussed, as are the specifics of the modelling techniques that were employed. At the end of the paper, the key results obtained from the analyses

Density Measurement of Liquid Ni-Ta Alloys by a Modified Sessile Drop Method

Institute of Scientific and Technical Information of China (English)

FANG Liang; XIAO Feng; TAO Zainan; Kusuhiro Mukai

2005-01-01

The density of liquid Ni-Ta alloys was measured by using a modified sessile drop method. It is found that the density of the liquid Ni-Ta alloys decreases with the increasing temperature, but increases with the increase of tantalum concentration in the alloys. The molar volume of liquid Ni-Ta binary alloys increases with the increase of temperature and tantalum concentration.

Prognosis at 6 and 12months after self-attempted hanging.

Science.gov (United States)

Gantois, Guillaume; Parmentier-Decrucq, Erika; Duburcq, Thibault; Favory, Raphaël; Mathieu, Daniel; Poissy, Julien

2017-11-01

Patients surviving a self-attempted hanging have a total neurological recovery in 57-77% of cases at hospital discharge, but no long-term data are available. In this observational study, all patients hospitalized post-self-attempted hanging in the intensive care unit (ICU) in a 5-year period were included. Neurological evaluations at 6 and 12months were performed according to Cerebral Performance Category (CPC) scores. Factors associated with neurological recovery were determined by comparing CPC2+3+4 (bad recovery) vs. CPC1 (good recovery). Of 231 patients included, 104 (47%) were found to have cardiac arrest (CA). Ninety-five (41%) patients died in the ICU: 93 (89%) in the CA group and 2 (1.6%) in the group without CA. Neurological evaluations at 6 and 12months were obtained in 97 of the 136 surviving patients. At 6months, in the CA group (n=9), the CPC score was 1 for 6 patients, 2 for 2, and 4 for 1 patient. In the group without CA (n=88), 79 patients had normal neurological status at 6months and 78 at 12months. Among these patients, 96% returned home, 77% returned to work, 16 (18%) patients re-attempted suicide within the year. Risk factors of neurological sequelae at 6months were a CA at the hanging site (P=0.045), an elevated diastolic blood pressure (87 vs. 70 mm Hg; P=0.04), a lower initial Glasgow score (4 vs. 5; P=0.04), and an elevated blood glucose level (139 vs. 113 mg/dL; Pgood neurological outcome. The rate of suicidal recidivism is particularly important, which justifies joint work with psychiatrists. Copyright © 2017 Elsevier Inc. All rights reserved.

Standard test method for drop-weight tear tests of ferritic steels

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This test method covers drop-weight tear tests (DWTT) on ferritic steels with thicknesses between 3.18 and 19.1 mm. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

Science.gov (United States)

Shrivas, Kamlesh; Wu, Hui-Fen

2007-11-02

A simple and rapid sample cleanup and preconcentration method for the quantitative determination of caffeine in one drop of beverages and foods by gas chromatography/mass spectrometry (GC/MS) has been proposed using drop-to-drop solvent microextraction (DDSME). The best optimum experimental conditions for DDSME were: chloroform as the extraction solvent, 5 min extraction time, 0.5 microL exposure volume of the extraction phase and no salt addition at room temperature. The optimized methodology exhibited good linearity between 0.05 and 5.0 microg/mL with correlation coefficient of 0.980. The relative standard deviation (RSD) and limits of detection (LOD) of the DDSME/GC/MS method were 4.4% and 4.0 ng/mL, respectively. Relative recovery of caffeine in beverages and foods were found to be 96.6-101%, which showing good reliability of this method. This DDSME excludes the major disadvantages of conventional method of caffeine extraction, like large amount of organic solvent and sample consumption and long sample pre-treatment process. So, this approach proves that the DDSME/GC/MS technique can be applied as a simple, fast and feasible diagnosis tool for environmental, food and biological application for extremely small amount of real sample analysis.

Gender differences in suicide methods.

Science.gov (United States)

Callanan, Valerie J; Davis, Mark S

2012-06-01

Gender differences in suicide completion rates have been attributed to the differences in lethality of suicide methods chosen by men and women, but few empirical studies have investigated factors other than demographic characteristics that might explain this differential. Data from the 621 suicides in Summit County, Ohio during 1997-2006 were disaggregated by gender to compare known correlates of suicide risk on three methods of suicide-firearm, hanging and drug poisoning. Compared to women, men who completed suicide with firearms were more likely to be married and committed the act at home. Unmarried men were likelier to hang themselves than married men, but unmarried women were less likely to hang themselves than married women. Men with a history of depression were more likely to suicide by hanging, but women with depression were half as likely to hang themselves compared to the women without a history of depression. Men with a history of substance abuse were more likely to suicide by poisoning than men without such history, but substance abuse history had no influence on women's use of poisoning to suicide. For both sexes, the odds of suicide by poisoning were significantly higher for those on psychiatric medications.

A Novel Method for Measuring In-Shoe Navicular Drop during Gait

Directory of Open Access Journals (Sweden)

Henrik Karstoft

2012-08-01

Full Text Available Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user.

Spent Nuclear Fuel (SNF) Bounding Drop Support Calculations

International Nuclear Information System (INIS)

CHENAULT, D.M.

1999-01-01

This report evaluates different drop heights, concrete and other impact media to which the transport package and/or the MCO is dropped. A prediction method is derived for estimating the resultant impact factor for determining the bounding drop case for the SNF Project

Optimization of the formation of embedded multicellular spheroids of MCF-7 cells: How to reliably produce a biomimetic 3D model.

Science.gov (United States)

Zhang, Wenli; Li, Caibin; Baguley, Bruce C; Zhou, Fang; Zhou, Weisai; Shaw, John P; Wang, Zhen; Wu, Zimei; Liu, Jianping

2016-12-15

To obtain a multicellular MCF-7 spheroid model to mimic the three-dimensional (3D) of tumors, the microwell liquid overlay (A) and hanging-drop/agar (B) methods were first compared for their technical parameters. Then a method for embedding spheroids within collagen was optimized. For method A, centrifugation assisted cells form irregular aggregates but not spheroids. For method B, an extended sedimentation period of over 24 h for cell suspensions and increased viscosity of the culture medium using methylcellulose were necessary to harvest a dense and regular cell spheroid. When the number was less than 5000 cells/drop, embedded spheroids showed no tight cores and higher viability than the unembedded. However, above 5000 cells/drop, cellular viability of embedded spheroids was not significantly different from unembedded spheroids and cells invading through the collagen were in a sun-burst pattern with tight cores. Propidium Iodide staining indicated that spheroids had necrotic cores. The doxorubicin cytotoxicity demonstrated that spheroids were less susceptible to DOX than their monolayer cells. A reliable and reproducible method for embedding spheroids using the hanging-drop/agarose method within collagen is described herein. The cell culture model can be used to guide experimental manipulation of 3D cell cultures and to evaluate anticancer drug efficacy. Copyright © 2016 Elsevier Inc. All rights reserved.

Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping

NARCIS (Netherlands)

Bobbert, M F; Huijing, P A; van Ingen Schenau, G J

In the literature, athletes preparing for explosive activities are recommended to include drop jumping in their training programs. For the execution of drop jumps, different techniques and different dropping heights can be used. This study was designed to investigate for the performance of bounce

Suicidal hanging donors for lung transplantation: Is this chapter still closed? Midterm experience from a single center in United Kingdom.

Science.gov (United States)

Ananiadou, Olga; Schmack, Bastian; Zych, Bartlomiej; Sabashnikov, Anton; Garcia-Saez, Diana; Mohite, Prashant; Weymann, Alexander; Mansur, Ashham; Zeriouh, Mohamed; Marczin, Nandor; De Robertis, Fabio; Simon, Andre Rüdiger; Popov, Aron-Frederik

2018-04-01

In the context of limited donor pool in cardiothoracic transplantation, utilization of organs from high risk donors, such as suicidal hanging donors, while ensuring safety, is under consideration. We sought to evaluate the outcomes of lung transplantations (LTx) that use organs from this group.Between January 2011 and December 2015, 265 LTx were performed at our center. Twenty-two recipients received lungs from donors after suicidal hanging (group 1). The remaining 243 transplantations were used as a control (group 2). Analysis of recipient and donor characteristics as well as outcomes was performed.No statistically significant difference was found in the donor characteristics between analyzed groups, except for higher incidence of cardiac arrest, younger age and smoking history of hanging donors (P donor cause of death is not associated with poor mid-term survival or chronic lung allograft dysfunction following transplantation. These results encourage assessment of lungs from hanging donors, and their consideration for transplantation.

Optimal Protection of Reactor Hall Under Nuclear Fuel Container Drop Using Simulation Methods

Directory of Open Access Journals (Sweden)

Králik Juraj

2014-12-01

Full Text Available This paper presents of the optimal design of the damping devices cover of reactor hall under impact of nuclear fuel container drop of type TK C30. The finite element idealization of nuclear power plant structure is used in software ANSYS. The steel pipe damper system is proposed for dissipation of the kinetic energy of the container free fall in comparison with the experimental results. The probabilistic and sensitivity analysis of the damping devices was considered on the base of the simulation methods in program AntHill using the Monte Carlo method.

Crystallization and preliminary crystallographic analysis of recombinant immunoglobulin G-binding protein from Streptococcus suis

Energy Technology Data Exchange (ETDEWEB)

Khan, Abdul Hamid; Chu, Fuliang; Feng, Youjun; Zhang, Qinagmin [Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Qi, Jianxun [Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Gao, George Fu, E-mail: gaof@im.ac.cn [Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China)

2008-08-01

Crystallization of recombinant IgG-binding protein expressed in Escherichia coli using the hanging-drop vapour-diffusion method is described. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 Å. Streptococcus suis, an important zoonotic pathogen, expresses immunoglobulin G-binding protein, which is thought to be helpful to the organism in eluding the host defence system. Recombinant IgG-binding protein expressed in Escherichia coli has been crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 Å and one molecule in the asymmetric unit. Diffraction data were collected to 2.60 Å resolution.

Importance of tissue biopsy in suicidal hanging deaths

Directory of Open Access Journals (Sweden)

Manal S. Bamousa

2015-12-01

The total number of cases was 62; 85.5% of the deceased were males, while 15% were females. The majority of cases (53% were among the age group of 20–30 years. Hemorrhage of the sternocleidomastoid muscle and carotid intimal tear were both found in 90% of cases. Thyroid congestion was detected in 91%, and Hashimoto’s thyroiditis was diagnosed in 2% of studied cases. The study discusses the importance of biopsy examination in hanging deaths and compares its results with other similar previous studies.

Interphase transfer kinetics of uranium using the drop method, Lewis cell, and Kenics mixer

International Nuclear Information System (INIS)

Horner, D.E.; Mailen, J.C.; Thiel, S.W.; Scott, T.C.; Yates, R.G.

1979-05-01

The rate constants for the interphase transfer of uranium between 3.5 M HNO 3 and tributyl phosphate (TBP) - normal hydrocarbon diluent solutions have been measured using the single drop method, Lewis cell method, and a Kenics mixer - centrifugal separator. Rate constants obtained by all methods were the same within experimental error. The variables studied that affect the rate constants include the TBP concentration, the acidity and total neutral nitrate concentrations of the aqueous phase, and temperature. Results of these tests indicate that the rate controlling mechanism is chemical reaction at the interface

Sensitive voltammetric method for determination of herbicide triasulfuron using silver solid amalgam electrode

Czech Academy of Sciences Publication Activity Database

Bandžuchová, L.; Šelešovská, R.; Navrátil, Tomáš; Chýlková, J.

2013-01-01

Roč. 113, DEC 2013 (2013), s. 1-8 ISSN 0013-4686 R&D Projects: GA ČR(CZ) GAP208/12/1645 Grant - others:GA MŠk(CZ) CZ.1.07/2.3.00/30.0021 Institutional support: RVO:61388955 Keywords : Triasulfuron * Hanging mercury drop electrode * Mercury meniscus modified silver solid amalgam electrode Subject RIV: CG - Electrochemistry Impact factor: 4.086, year: 2013

Calculation of drop course of control rod assembly in PWR

International Nuclear Information System (INIS)

Zhou Xiaojia; Mao Fei; Min Peng; Lin Shaoxuan

2013-01-01

The validation of control rod drop performance is an important part of safety analysis of nuclear power plant. Development of computer code for calculating control rod drop course will be useful for validating and improving the design of control rod drive line. Based on structural features of the drive line, the driving force on moving assembly was analyzed and decomposed, the transient value of each component of the driving force was calculated by choosing either theoretical method or numerical method, and the simulation code for calculating rod cluster control assembly (RCCA) drop course by time step increase was achieved. The analysis results of control rod assembly drop course calculated by theoretical model and numerical method were validated by comparing with RCCA drop test data of Qinshan Phase Ⅱ 600 MW PWR. It is shown that the developed RCCA drop course calculation code is suitable for RCCA in PWR and can correctly simulate the drop course and the stress of RCCA. (authors)

Parametric resonance in acoustically levitated water drops

International Nuclear Information System (INIS)

Shen, C.L.; Xie, W.J.; Wei, B.

2010-01-01

Liquid drops can be suspended in air with acoustic levitation method. When the sound pressure is periodically modulated, the levitated drop is usually forced into an axisymmetric oscillation. However, a transition from axisymmetric oscillation into sectorial oscillation occurs when the modulation frequency approaches some specific values. The frequency of the sectorial oscillation is almost exactly half of the modulation frequency. It is demonstrated that this transition is induced by the parametric resonance of levitated drop. The natural frequency of sectorial oscillation is found to decrease with the increase of drop distortion extent.

Parametric resonance in acoustically levitated water drops

Energy Technology Data Exchange (ETDEWEB)

Shen, C.L.; Xie, W.J. [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China); Wei, B., E-mail: bbwei@nwpu.edu.c [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

2010-05-10

Liquid drops can be suspended in air with acoustic levitation method. When the sound pressure is periodically modulated, the levitated drop is usually forced into an axisymmetric oscillation. However, a transition from axisymmetric oscillation into sectorial oscillation occurs when the modulation frequency approaches some specific values. The frequency of the sectorial oscillation is almost exactly half of the modulation frequency. It is demonstrated that this transition is induced by the parametric resonance of levitated drop. The natural frequency of sectorial oscillation is found to decrease with the increase of drop distortion extent.

Crystallization and preliminary X-ray diffraction studies of the pneumococcal teichoic acid phosphorylcholine esterase Pce

Energy Technology Data Exchange (ETDEWEB)

Lagartera, Laura; González, Ana; Stelter, Meike; García, Pedro; Kahn, Richard; Menéndez, Margarita; Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es

2005-02-01

The modular choline-binding protein Pce, the phosphorylcholine esterase from S. pneumoniae, has been crystallized by the hanging-drop vapour-diffusion method. A SAD data set from a derivative with a gadolinium complex has been collected to 2.7 Å resolution.

Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

Energy Technology Data Exchange (ETDEWEB)

Endo, Masayuki, E-mail: masay010@yahoo.co.jp; Kaminou, Toshio, E-mail: kaminout@med.tottori-u.ac.jp; Ohuchi, Yasufumi, E-mail: oyasu@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Sugiura, Kimihiko, E-mail: kimihikosugiura@gmail.com [Yonago Medical Center, Department of Radiology (Japan); Yata, Shinsaku, E-mail: yata-s@med.tottori-u.ac.jp; Adachi, Akira, E-mail: july1st@med.tottori-u.ac.jp; Kawai, Tsuyoshi, E-mail: prgr-xxio@kuc.biglobe.ne.jp; Takasugi, Syohei, E-mail: stakasugi@med.tottori-u.ac.jp; Yamamoto, Shuichi, E-mail: yamamotoshu@med.tottori-u.ac.jp; Matsumoto, Kensuke, E-mail: matsumoto-k@v103.vaio.ne.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Hashimoto, Masayuki, E-mail: hashimotom@pref.tottori.jp [Tottori Prefectural Kosei Hospital, Department of Radiology (Japan); Ihaya, Takashi, E-mail: iahaya@orange.ocn.ne.jp [Sanin Rosai Hospital, Department of Radiology (Japan); Ogawa, Toshihide, E-mail: ogawa@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan)

2012-10-15

Purpose: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. Methods: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. Results: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. Conclusions: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

International Nuclear Information System (INIS)

Endo, Masayuki; Kaminou, Toshio; Ohuchi, Yasufumi; Sugiura, Kimihiko; Yata, Shinsaku; Adachi, Akira; Kawai, Tsuyoshi; Takasugi, Syohei; Yamamoto, Shuichi; Matsumoto, Kensuke; Hashimoto, Masayuki; Ihaya, Takashi; Ogawa, Toshihide

2012-01-01

Purpose: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. Methods: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. Results: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. Conclusions: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

Electrowetting-on-dielectrics for manipulation of oil drops and gas bubbles in aqueous-shell compound drops.

Science.gov (United States)

Li, Jiang; Wang, Yixuan; Chen, Haosheng; Wan, Jiandi

2014-11-21

We present the manipulation of oil, organic and gaseous chemicals by electrowetting-on-dielectric (EWOD) technology using aqueous-shell compound drops. We demonstrate that the transport and coalescence of viscous oil drops, the reaction of bromine with styrene in benzene solution, and the reaction of red blood cells with carbon monoxide bubbles can be accomplished using this method.

Foraging of the Indian Short-nosed Fruit Bat Cynopterus sphinx on banana in shops and on the pieces dropped by monkeys at a temple

Directory of Open Access Journals (Sweden)

A. Rathinakumar

2016-11-01

Full Text Available The Indian Short-nosed Fruit Bat Cynopterus sphinx fed on the pieces of banana fruit that were dropped by monkeys on the tower of a temple and in nearby shops.  The monkeys obtained fruits from devotees and shop owners.  The peak number of bat visits occurred during pre- and post- midnight hours at the tower and shops, respectively, coinciding with the lights off situation and reduced human disturbance.  The bats landed on bunches of ripe bananas hanging in the front of shops.  The number of bat landings on the tower was greater than that in the shops.  The overall number of bat visits were higher during October when compared to other periods of the year.  This may be due to the occurrence of more festivals during October.  Our study is an example of opportunistic feeding, in which banana pieces dropped while monkeys were feeding on them were eaten by the bats.

Drop Testing Representative Multi-Canister Overpacks

Energy Technology Data Exchange (ETDEWEB)

Snow, Spencer D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Morton, Dana K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-06-01

The objective of the work reported herein was to determine the ability of the Multi- Canister Overpack (MCO) canister design to maintain its containment boundary after an accidental drop event. Two test MCO canisters were assembled at Hanford, prepared for testing at the Idaho National Engineering and Environmental Laboratory (INEEL), drop tested at Sandia National Laboratories, and evaluated back at the INEEL. In addition to the actual testing efforts, finite element plastic analysis techniques were used to make both pre-test and post-test predictions of the test MCOs structural deformations. The completed effort has demonstrated that the canister design is capable of maintaining a 50 psig pressure boundary after drop testing. Based on helium leak testing methods, one test MCO was determined to have a leakage rate not greater than 1x10^-5 std cc/sec (prior internal helium presence prevented a more rigorous test) and the remaining test MCO had a measured leakage rate less than 1x10^-7 std cc/sec (i.e., a leaktight containment) after the drop test. The effort has also demonstrated the capability of finite element methods using plastic analysis techniques to accurately predict the structural deformations of canisters subjected to an accidental drop event.

High-precision drop shape analysis on inclining flat surfaces: introduction and comparison of this special method with commercial contact angle analysis.

Science.gov (United States)

Schmitt, Michael; Heib, Florian

2013-10-07

Drop shape analysis is one of the most important and frequently used methods to characterise surfaces in the scientific and industrial communities. An especially large number of studies, which use contact angle measurements to analyse surfaces, are characterised by incorrect or misdirected conclusions such as the determination of surface energies from poorly performed contact angle determinations. In particular, the characterisation of surfaces, which leads to correlations between the contact angle and other effects, must be critically validated for some publications. A large number of works exist concerning the theoretical and thermodynamic aspects of two- and tri-phase boundaries. The linkage between theory and experiment is generally performed by an axisymmetric drop shape analysis, that is, simulations of the theoretical drop profiles by numerical integration onto a number of points of the drop meniscus (approximately 20). These methods work very well for axisymmetric profiles such as those obtained by pendant drop measurements, but in the case of a sessile drop onto real surfaces, additional unknown and misunderstood effects on the dependence of the surface must be considered. We present a special experimental and practical investigation as another way to transition from experiment to theory. This procedure was developed to be especially sensitive to small variations in the dependence of the dynamic contact angle on the surface; as a result, this procedure will allow the properties of the surface to be monitored with a higher precession and sensitivity. In this context, water drops onto a 111 silicon wafer are dynamically measured by video recording and by inclining the surface, which results in a sequence of non-axisymmetric drops. The drop profiles are analysed by commercial software and by the developed and presented high-precision drop shape analysis. In addition to the enhanced sensitivity for contact angle determination, this analysis technique, in

[A homicidal strangulation by ligature, disguised as a suicidal hanging].

Science.gov (United States)

Ueno, Y; Fukunaga, T; Nakagawa, K; Imabayashi, T; Fujiwara, S; Adachi, J; Mizoi, Y

1989-02-01

A naked 38-year-old woman was found dead, lying beside a bed in a guest room of a hotel. A cotton cord was looped around her neck, with one end tied to a bedpost. Thus it seemed that she had hanged herself in a lying position. Yet, certain suspicious factors gave rise to doubts. The hair and a necklace were intertwined with the cord and a man that had been staying in the same room had fled. On the postmortem examination, marked congestion and many petechial haemorrhages were seen in the face and the upper area of the neck, also in conjunctiva. A light-brown and highly dry ligature mark, about one centimeter in width, was found on the neck. The mark, crossing the front of the neck, was clearly evident from the back to the right side of the neck. The lower borders of the congestion and petechial haemorrhages in the face and neck were located 1 or 2 centimeters above the ligature mark. On the left side of the neck, another pale ligature mark with slight subcutaneous haemorrhages was seen between the dry mark and the lower border of the congested part of the neck. A similar ligature mark also was found on the back of the neck. On internal examination, congestion of the cervical lymph nodes and haemorrhages in the cervical muscles were recognized in the areas of the cutaneous congestion. These findings supported suspicions that the dry ligature mark had been caused by hanging after her death, and that the light ligature mark with slight subcutaneous haemorrhages on the left side and back of the neck had been caused by strangulation, which had brought on the victim's death. Therefore, it was decided that her death had been disguised as a suicidal hanging, after she had been strangled by ligature. A week later, her former husband was arrested and confessed his crime.

Liver hanging maneuver for right hemiliver in situ donation--anatomical considerations.

Science.gov (United States)

Trotovsek, B; Gadzijev, E M; Ravnik, D; Hribernik, M

2006-01-01

An anatomical study was carried out to evaluate the safety of the liver hanging maneuver for the right hemiliver in living donor and in situ splitting transplantation. During this procedure a 4-6 cm blind dissection is performed between the inferior vena cava and the liver. Short subhepatic veins entering the inferior vena cava from segments 1 and 9 could be torn with consequent hemorrhage. One hundred corrosive casts of livers were evaluated to establish the position and diameter of short subhepatic veins and the inferior right hepatic vein. The average distance from the right border of the inferior vena cava to the opening of segment 1 veins was 16.7+/-3.4 mm and to the entrance of segment 9 veins was 5.0+/-0.5 mm. The width of the narrowest point on the route of blind dissection was determined, with the average value being 8.7+/-2.3 mm (range 2-15 mm). The results show that the liver hanging maneuver is a safe procedure. A proposed route of dissection minimizes the risk of disrupting short subhepatic veins (7%).

THE BEHAVIOURAL REACTION OF WEANERS TO HANGING TOYS: WOODEN BALL AND AROMATIZED WOODEN BALL – WAY TO REDUCE AGGRESSION AFTER MIXING

Directory of Open Access Journals (Sweden)

Jacek NOWICKI

2008-05-01

Full Text Available The behaviour of weaners after mixing housed in pens equipped with hanging wooden ball, aromatized with vanilla fluid hanging wooden ball and without enrichment was evaluated. It was found that both enrichments reduced aggression, however the most interesting for weaners was the aromatized wooden ball.

Determination of lead element trace in some Syrian cigarettes and Its mixtures using voltammetric method on HMDE

International Nuclear Information System (INIS)

Nasser, H.; Kabass, H.

2010-01-01

This study aims for estimating of trace for these elements in various brands of Syrian Cigarettes and its mixtures, by using voltammetric method (HMDE) hanging mercury drop elec trod. This method is first used to determined Syrian Cigarettes brand and its mixtures, during this study it was found that we can use it easily with low commission, high sensitivity and accurate results comparing with others studies. We prepare the samples by using reference methods. The samples were collected during two times in one year from the same kinds of samples. We noticed that the high concentrations was (3.795μg/g) in Gitanes samples, and the low concentrations in shame samples was (0.37 μg/g). This study refers that there is different concentrations of lead element in this samples.(author)

Direct immersion single drop micro-extraction method for multi-class pesticides analysis in mango using GC-MS.

Science.gov (United States)

Pano-Farias, Norma S; Ceballos-Magaña, Silvia G; Muñiz-Valencia, Roberto; Jurado, Jose M; Alcázar, Ángela; Aguayo-Villarreal, Ismael A

2017-12-15

Due the negative effects of pesticides on environment and human health, more efficient and environmentally friendly methods are needed. In this sense, a simple, fast, free from memory effects and economical direct-immersion single drop micro-extraction (SDME) method and GC-MS for multi-class pesticides determination in mango samples was developed. Sample pre-treatment using ultrasound-assisted solvent extraction and factors affecting the SDME procedure (extractant solvent, drop volume, stirring rate, ionic strength, time, pH and temperature) were optimized using factorial experimental design. This method presented high sensitive (LOD: 0.14-169.20μgkg -1 ), acceptable precision (RSD: 0.7-19.1%), satisfactory recovery (69-119%) and high enrichment factors (20-722). Several obtained LOQs are below the MRLs established by the European Commission; therefore, the method could be applied for pesticides determination in routing analysis and custom laboratories. Moreover, this method has shown to be suitable for determination of some of the studied pesticides in lime, melon, papaya, banana, tomato, and lettuce. Copyright © 2017 Elsevier Ltd. All rights reserved.

Obtaining of lysozyme spherulitic forms at ambient temperature using pyrrolidinium octanoat as ionic liquid additive

Directory of Open Access Journals (Sweden)

Claudia Simona ŞTEFAN

2012-12-01

Full Text Available Pyrrolidinium octanoate carboxylate (Py+CnH2n+1COO-; PyO in abbreviation was used as additive for advanced crystallization of Lysozyme protein, to investigate the impact of protic ionic liquid on the protein crystal morphology. The ionic liquid was synthesized by acidic-base Brönsted neutralization, and its purity was checked by HPLC. The protein crystallization was made through the method of vapour diffusion with hanging drops. Crystallization experiments of Lysozyme with the addition of PyO were performed at 0.4 M PyO and respectively 1.6 M. The morphological of spherulitic forms of Lysozyme in aqueous solutions of PyO protic ionic liquid was investigated by optical microscopy after trials were incubated at ambient temperature (18-20°C, in various growth periods (3 days and 1 week. Hanging-drop vapour diffusion crystallization experiments with the addition of 0.4 M of PyO show that Lysozyme crystallized in type I spherulitic form. This is assumed to be a result of heterogeneous nucleation, with thin needles radially growing outwardfrom a more or less spherical particle. Hanging-drop vapour diffusioncrystallization experiments revealed that the addition of 1.6 M of PyO led to a second type of spherulitic form of the Lysozyme.

Eye-Drops for Activation of DREADDs

Directory of Open Access Journals (Sweden)

William T. Keenan

2017-11-01

Full Text Available Designer Receptors Exclusively Activated by Designer Drugs (DREADDs are an important tool for modulating and understanding neural circuits. Depending on the DREADD system used, DREADD-targeted neurons can be activated or repressed in vivo following a dose of the DREADD agonist clozapine-N-oxide (CNO. Because DREADD experiments often involve behavioral assays, the method of CNO delivery is important. Currently, the most common delivery method is intraperitoneal (IP injection. IP injection is both a fast and reliable technique, but it is painful and stressful particularly when many injections are required. We sought an alternative CNO delivery paradigm, which would retain the speed and reliability of IP injections without being as invasive. Here, we show that CNO can be effectively delivered topically via eye-drops. Eye-drops robustly activated DREADD-expressing neurons in the brain and peripheral tissues and does so at the same dosages as IP injection. Eye-drops provide an easier, less invasive and less stressful method for activating DREADDs in vivo.

A three-dimensional in vitro HepG2 cells liver spheroid model for genotoxicity studies.

Science.gov (United States)

Shah, Ume-Kulsoom; Mallia, Jefferson de Oliveira; Singh, Neenu; Chapman, Katherine E; Doak, Shareen H; Jenkins, Gareth J S

2018-01-01

The liver's role in metabolism of chemicals makes it an appropriate tissue for toxicity testing. Current testing protocols, such as animal testing and two-dimensional liver cell systems, offer limited resemblance to in vivo liver cell behaviour, in terms of gene expression profiles and metabolic competence; thus, they do not always accurately predict human toxicology. In vitro three-dimensional liver cell models offer an attractive alternative. This study reports on the development of a 3D liver model, using HepG2 cells, by a hanging-drop technique, with a focus on evaluating spheroid growth characteristics and suitability for genotoxicity testing. The cytokinesis-blocked micronucleus assay protocol was adapted to enable micronucleus (MN) detection in the 3D spheroid models. This involved evaluating the difference between hanging vs non-hanging drop positions for dosing of the test agents and comparison of automated Metafer scoring with manual scoring for MN detection in HepG2 spheroids. The initial seeding density, used for all experiments, was 5000 cells/20 μl drop hanging spheroids, harvested on day 4, with >75% cell viability. Albumin secretion (7.8 g/l) and both CYP1A1 and CYP1A2 gene expression were highest in the 3D environment at day 4. Exposure to metabolically activated genotoxicants for 24 h resulted in a 6-fold increase in CYP1A1 enzyme activity (3 μM B[a]P) and a 30-fold increase in CYP1A2 enzyme activity (5 μM PhIP) in 3D hanging spheroids. MN inductions in response to B[a]P or PhIP were 2-fold and 3-fold, respectively, and were greater in 3D hanging spheroids than in 2D format, showing that hanging spheroids are more sensitive to genotoxic agents. HepG2 hanging-drop spheroids are an exciting new alternative system for genotoxicity studies, due to their improved structural and physiological properties, relative to 2D cultures. Copyright © 2017 Elsevier B.V. All rights reserved.

Crystallization and preliminary X-ray analysis of human S100A13

International Nuclear Information System (INIS)

Imai, Fabiana Lica; Nagata, Koji; Yonezawa, Naoto; Yu, Jinyan; Ito, Eriko; Kanai, Saeko; Tanokura, Masaru; Nakano, Minoru

2006-01-01

Human S100A13 protein was cloned, expressed, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals obtained belonged to space group P2 1 2 1 2 1 and diffracted to a resolution of 1.8 Å. S100A13 is a member of the S100 family of EF-hand-containing calcium-binding proteins and plays an important role in the secretion of fibroblast growth factor-1 and interleukin 1α, two pro-angiogenic factors released by the endoplasmic reticulum/Golgi-independent non-classical secretory pathway. Human S100A13 was heterologously expressed in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.8 Å resolution and the space group was assigned as primitive orthorhombic P2 1 2 1 2 1

Crystallization and preliminary X-ray diffraction studies of FAD synthetase from Corynebacterium ammoniagenes

International Nuclear Information System (INIS)

Herguedas, Beatriz; Martínez-Júlvez, Marta; Frago, Susana; Medina, Milagros; Hermoso, Juan A.

2009-01-01

Native and selenomethionine-labelled FAD synthetase from C. ammoniagenes have been crystallized by the hanging-drop vapour-diffusion method. A MAD data set for SeMet-labelled FAD synthetase was collected to 2.42 Å resolution, while data sets were collected to 1.95 Å resolution for the native crystals. FAD synthetase from Corynebacterium ammoniagenes (CaFADS), a prokaryotic bifunctional enzyme that catalyses the phosphorylation of riboflavin as well as the adenylylation of FMN, has been crystallized using the hanging-drop vapour-diffusion method at 277 K. Diffraction-quality cubic crystals of native and selenomethionine-labelled (SeMet-CaFADS) protein belonged to the cubic space group P2 1 3, with unit-cell parameters a = b = c = 133.47 Å and a = b = c = 133.40 Å, respectively. Data sets for native and SeMet-containing crystals were collected to 1.95 and 2.42 Å resolution, respectively

An evaluation of prediction methods for frictional pressure drop of Two-phase flow in mini-channels

International Nuclear Information System (INIS)

Sun Licheng; Yan Changqi; Sun Zhongning

2010-01-01

2092 pieces of data for frictional pressure drop of two-phase flow were collected from 18 published papers of which the working fluids include R123, R134a, R22, R236ea, R245fa, R404a, R407C, R410a, R507, CO2, water and air. The hydraulic diameter ranges from 0.506 to 12 mm; Re l from 10 to 37000, and Re g from 3 to 4 x 10 5 . 11 correlations and models for calculating the frictional pressure drop of two-phase flow were evaluated based on these data. The results show that the accuracy of the Lockhart-Martinelli method, Mishima and Hibiki correlation, Zhang and Mishima correlation and Lee and Mudawar correlation in the laminar region is very close to each other, while the Muller-Steinhagen and Heck correlation is the best among the evaluated correlations in the turbulent region. New correlation based on Chishom method was proposed, which is better than other methods in both laminar region and turbulent region. (authors)

Evaluation of a hanging core support concept for LMR application

International Nuclear Information System (INIS)

Burelbach, J.P.; Cha, B.K.; Huebotter, P.R.; Kann, W.J.; Pan, Y.C.; Saiveau, J.G.; Seidensticker, R.W.; Wu, T.S.

1985-01-01

The paper describes an innovative design concept for a liquid metal reactor (LMR) core support structure (CSS). A hanging core support structure is described and analyzed. The design offers inherent safety features, constructability advantages, and potential cost reductions. Some safety considerations are examined which include the in-service inspection (ISI), the backup support system and the structural behavior in a hypothetical case of a broken beam in the core support structure

Electrohydrodynamics of a viscous drop with inertia.

Science.gov (United States)

Nganguia, H; Young, Y-N; Layton, A T; Lai, M-C; Hu, W-F

2016-05-01

Most of the existing numerical and theoretical investigations on the electrohydrodynamics of a viscous drop have focused on the creeping Stokes flow regime, where nonlinear inertia effects are neglected. In this work we study the inertia effects on the electrodeformation of a viscous drop under a DC electric field using a novel second-order immersed interface method. The inertia effects are quantified by the Ohnesorge number Oh, and the electric field is characterized by an electric capillary number Ca_{E}. Below the critical Ca_{E}, small to moderate electric field strength gives rise to steady equilibrium drop shapes. We found that, at a fixed Ca_{E}, inertia effects induce larger deformation for an oblate drop than a prolate drop, consistent with previous results in the literature. Moreover, our simulations results indicate that inertia effects on the equilibrium drop deformation are dictated by the direction of normal electric stress on the drop interface: Larger drop deformation is found when the normal electric stress points outward, and smaller drop deformation is found otherwise. To our knowledge, such inertia effects on the equilibrium drop deformation has not been reported in the literature. Above the critical Ca_{E}, no steady equilibrium drop deformation can be found, and often the drop breaks up into a number of daughter droplets. In particular, our Navier-Stokes simulations show that, for the parameters we use, (1) daughter droplets are larger in the presence of inertia, (2) the drop deformation evolves more rapidly compared to creeping flow, and (3) complex distribution of electric stresses for drops with inertia effects. Our results suggest that normal electric pressure may be a useful tool in predicting drop pinch-off in oblate deformations.

Dynamic fracture testing of ferritic steels using direct current potential drop method

International Nuclear Information System (INIS)

Oh, Y. J.; Kim, J. H.; Hwang, I. S.; Park, Y. W.

2000-01-01

To apply leak-before-break (LBB) concept to nuclear pipes, the dynamic strain aging of low carbon steel materials has to be considered. For this goal, the J-R tests are needed over a range of temperatures and loading rates, including rapid dynamic loading conditions. In dynamic J-R tests, the unloading compliance method can not be applied and usually the direct current potential drop (DCPD) method has been used. But, even the DCPD method was known to have the problem in defining the crack initiation point due to a potential peak arising in early part of loading of ferromagnetic materials. In this study, potential peaks characteristics were investigated for SA106Gr.C piping steels, and the definition of crack initiation point was made by back tracking from final physical crack length, and it was proposed that this technique could be applied to DCPD method in dynamic loading J-R test

Crystallization and preliminary X-ray analysis of Streptococcus mutans dextran glucosidase

Energy Technology Data Exchange (ETDEWEB)

Saburi, Wataru; Hondoh, Hironori, E-mail: hondoh@abs.agr.hokudai.ac.jp [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan); Unno, Hideaki [Faculty of Engineering, Nagasaki University, Bunkyo-machi, Nagasaki 852-8521 (Japan); Okuyama, Masayuki; Mori, Haruhide [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan); Nakada, Toshitaka [Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Matsuura, Yoshiki [Institute for Protein Research, Osaka University, Suita, Osaka 565-0871 (Japan); Kimura, Atsuo [Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589 (Japan)

2007-09-01

Dextran glucosidase from S. mutans was crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.2 Å resolution. Dextran glucosidase from Streptococcus mutans is an exo-hydrolase that acts on the nonreducing terminal α-1,6-glucosidic linkage of oligosaccharides and dextran with a high degree of transglucosylation. Based on amino-acid sequence similarity, this enzyme is classified into glycoside hydrolase family 13. Recombinant dextran glucosidase was purified and crystallized by the hanging-drop vapour-diffusion technique using polyethylene glycol 6000 as a precipitant. The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 72.72, b = 86.47, c = 104.30 Å. A native data set was collected to 2.2 Å resolution from a single crystal.

Crystallization and preliminary X-ray analysis of Streptococcus mutans dextran glucosidase

International Nuclear Information System (INIS)

Saburi, Wataru; Hondoh, Hironori; Unno, Hideaki; Okuyama, Masayuki; Mori, Haruhide; Nakada, Toshitaka; Matsuura, Yoshiki; Kimura, Atsuo

2007-01-01

Dextran glucosidase from S. mutans was crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.2 Å resolution. Dextran glucosidase from Streptococcus mutans is an exo-hydrolase that acts on the nonreducing terminal α-1,6-glucosidic linkage of oligosaccharides and dextran with a high degree of transglucosylation. Based on amino-acid sequence similarity, this enzyme is classified into glycoside hydrolase family 13. Recombinant dextran glucosidase was purified and crystallized by the hanging-drop vapour-diffusion technique using polyethylene glycol 6000 as a precipitant. The crystals belong to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 72.72, b = 86.47, c = 104.30 Å. A native data set was collected to 2.2 Å resolution from a single crystal

Drop Impact Dynamics with Sessile Drops and Geometries: Spreading, Jetting, and Fragmentation

Science.gov (United States)

Tilger, Christopher F.

The tendency of surface tension to cause small parcels of fluid to form into drops allows convenient packaging, transport, dispersal of liquid phase matter. Liquid drop impacts with solids, liquids, and other drops have realized and additional future applications in biological, manufacturing, heat transfer, and combustion systems. Experiments were conducted to investigate the dynamics of multiple drop collisions, rather than the most-studied phenomenon of single drop impacts. Additional drop impacts were performed on rigid hemispheres representing sessile drops, angled substrates, and into the vertex of two tilted surfaces arranged into a vee shape. A qualitative inspection of drop-sessile drop impacts shows distinct post-impact shapes depending on the offset distance between the drops. At intermediate offset distances, distinct jets issue from the overlap region between the two drops projected areas. These jets are observed to reach their maximum extent at a critical offset distance ratio, epsilon epsilon ˜ 0.75-0.80, with substrate contact angle and W e having a lesser effect. Capillary waves that traverse the sessile drop after collision cause a lower aspect ratio liquid column to emanate from the sessile drop opposite the impact. In order to better understand the jetting phenomenon seen in the offset drop-sessile drop impacts, simpler solid geometries are investigated that elicit a similar behavior. Solid hemispheres do not show the singular jetting observed in the fluidic case, however, a simple vee formed by two intersection planar substrates do jet in a similar fashion to the fluidic case. A geometric model with partnered experiments is developed to describe the bisymmetric spread of an impacting drop on an angled substrate. This geometric model is used to guide a time of arrival based model for various features of the drop impact, which is used to predict jetting in various vee channel experiments.

Crystallization and preliminary crystallographic data of the PAS domain of the NifL protein from Azotobacter vinelandii.

NARCIS (Netherlands)

Hefti, M.H.; Hendle, J.; Enroth, C.; Vervoort, J.J.M.; Tucker, P.A.

2001-01-01

The Azotobacter vinelandii NifL protein is a redox-sensing flavoprotein which inhibits the activity of the nitrogen-specific transcriptional activator NifA. The N-terminal PAS domain has been overexpressed in Escherichia coli and crystallized by the hanging-drop vapour-diffusion method. The crystal

Purification, crystallization and preliminary X-ray diffraction analysis of an oomycete-derived Nep1-like protein

NARCIS (Netherlands)

Luberacki, B.; Weyand, M.; Seitz, H.U.; Koch, W.; Oecking, C.; Ottmann, C.

2008-01-01

The elicitor protein Nep1-like protein from the plant pathogen Pythium aphanidermatum was purified and crystallized using the hanging-drop vapour-diffusion method. A native data set was collected to 1.35 angstrom resolution at 100 K using synchrotron radiation. Since selenomethionine-labelled

Crystallization of Enzyme IIB of the Cellobiose-specific Phosphotransferase System of Escherichia coli

NARCIS (Netherlands)

van Montfort, Robert; Pijning, Tjaard; Kalk, Kornelis; Schuurman-Wolters, Gea K.; Reizer, Jonathan; Safer Jr., Milton H.; Robillard, George; Dijkstra, Bauke W.

1994-01-01

Crystals of enzyme IIB of the cellobiose-specific phosphotransferase system have been obtained from 15% polyethylene glycol 4000 using both streak-seeding and macroseeding techniques at 4°. Crystals were grown with the hanging drop method of vapour diffusion. Addition of 2-propanol and

Crystallization and quaternary structure analysis of an Lrp-like regulatory protein from the hyperthermophile Pyrococcus furiosus

NARCIS (Netherlands)

Sedelnikova, S.E.; Smits, S.H.J.; Leonard, P.M.; Brinkman, A.B.; Oost, van der J.; Rafferty, J.B.

2001-01-01

The LrpA transcriptional regulator from Pyrococcus furiosus, a member of the leucine-responsive regulatory protein (Lrp) family, has been crystallized by the hanging-drop method of vapour diffusion using ammonium sulfate as the precipitant. The crystals belong to the tetragonal system and are in

Effect of loose spring skirt mounting position on vibration damping in a multi segment hanging cantilever

International Nuclear Information System (INIS)

Nazeer, M.M.; Khan, A.F.; Shah, R.H; Afzal, M.; Ahmed, N.

2001-01-01

The loose spring skirt clearance is the major factor effecting the damping and amplitude control of randomly excited vibrations in a vertically hanging cantilever. However, the spring's mounting position also has an important role to play. In this work, the results of computational model as well as that of experimental set-up for various spring mounting positions having optimum annular clearance between skirted member and the skirt are presented and their vibration damping response is analyzed. It is observed that lower is the mounting position, the better is the damping and its maximum value is attained when the bottom end of spring skirt and the hanging cantilever are mutually flushed. (author)

Design of 3D printed insert for hanging culture of Caco-2 cells

International Nuclear Information System (INIS)

Shen, Chong; Meng, Qin; Zhang, Guoliang

2015-01-01

A Caco-2 cell culture on Transwell, an alternative testing to animal or human testing used in evaluating drug intestinal permeability, incorrectly estimated the absorption of actively transported drugs due to the low expression of membrane transporters. Similarly, three-dimensional (3D) cultures of Caco-2 cells, which have been recommended to be more physiological relevant, were not superior to the Transwell culture in either accuracy or convenience in drug permeability testing. Using rapid 3D printing prototyping techniques, this study proposed a hanging culture of Caco-2 cells that performed with high accuracy in predicting drug permeability in humans. As found, hanging cultured Caco-2 cells formed a confluent monolayer and maintained high cell viability on the 3D printed insert. Compared with the normal culture on Transwell, the Caco-2 cells on the 3D printed insert presented ∼30–100% higher brush border enzyme activity and ∼2–7 folds higher activity of P-glycoprotein/multidrug resistance-associated protein 2 during 21 days of incubation. For the eight membrane transporter substrates, the predictive curve of the 3D printing culture exhibited better linearity (R 2  = 0.92) to the human oral adsorption than that of the Transwell culture (R 2  = 0.84), indicating better prediction by the 3D printing culture. In this regard, the 3D printed insert for hanging culture could be potentially developed as a convenient and low-cost tool for testing drug oral absorption. (paper)

Surgical results of the slipped medial rectus muscle after hang back recession surgery

Directory of Open Access Journals (Sweden)

Yasar Duranoglu

2014-12-01

Full Text Available AIM:To analyze the surgical results of a slipped medial rectus muscle (MRM after hang back recession surgery for esotropia.METHODS:Twenty-one patients who underwent re-exploration for diagnosed slipped muscle after hang back recession surgery were included in this retrospective study. Dynamic magnetic resonance imaging was performed to identify the location of the slipped muscle. Ocular motility was evaluated with assessment with prism and cover test in gaze at cardinal positions. The operations were performed by the same consultant. Intraoperative forced duction test was performed under general anesthesia. The empty sheath of the slipped MRM was resected and the muscle was advanced to the original insertion site in all patients.RESULTS:The average age of 21 patients who hadconsecutive exotropia with a slipped MRM at the time of presentation was 17.4±5.4y (5-50y. The average duration between the first operation and the diagnosis of the slipped muscle was 25mo (12 to 36mo. The mean follow up after the corrective surgery was 28mo. The mean preoperative adduction limitation in the field of action of the slipped muscle was -2.26 (ranging from -1 to -4. All patients had full adduction postoperatively.CONCLUSION:The diagnosis of the slipped muscle should be confirmed during the strabismus surgery. The slipped muscle may be caused due to insufficient suture and excessive rubbing of the eye. When divergent strabismus is observed after the recession of the MRM, a slipped muscle should be considered in the differential diagnosis.

Drop size measurements in Venturi scrubbers

Energy Technology Data Exchange (ETDEWEB)

Fernandez Alonso, D.; Azzopardi, B.J. [Nottingham Univ. (United Kingdom). Dept. of Chemical Engineering; Goncalves, J.A.S.; Coury, J.R. [Universidade Federal de Sao Carlos (Brazil). Departamento de Engenharia Quimica

2001-07-01

Venturi scrubbers are high efficiency gas cleaners in which suspended particles are removed from gas streams by drops formed by liquid atomisation, usually in the Venturi throat. The size of the drops formed are of fundamental importance to the performance of the equipment, both in terms of pressure drop and dust removal efficiency. In this study, drop sizes in a cylindrical laboratory-scale Venturi scrubber were measured using a laser diffraction technique. Gas velocity and liquid to gas ratios varied from 50 to 90 m/s and 0.5 to 2.0 1/m{sup 3}, respectively. Water was injected using two different arrangements: either as jets in the throat or as a film just upstream of the convergence. Drop size measurements were performed at three positions in the case of jet injection: two located along the throat, and the last one at the end of the diffuser. The present data shows that the Sauter mean diameter of the spray can be well correlated by the equation of Boll et al. (J. Air Pollut. Control Assoc. 24 (1974) 932). Drop size distributions are satisfactorily represented by a Rosin-Rammler function. This paper also provides a simple method for calculating the parameters of the Rosin-Rammler function. As a result of this work, drop sizes in Venturi scrubbers can be estimated with much higher accuracy. (Author)

Thermocapillary reorientation of Janus drops

Science.gov (United States)

Rosales, Rodolfo; Saenz, Pedro

2017-11-01

Janus drops, named after the Ancient Roman two-faced god, are liquid drops formed from two immiscible fluids. Experimental observations indicate that a Janus drop may re-orientate in response to an applied external thermal gradient due to the Marangoni effect. Depending on the angle between the interior interface and the direction of the temperature gradient, disparities in the physical properties of the constituent liquids may lead to asymmetries in the thermocapillary flow. As a result, the drop will move along a curved path until a torque-free configuration is achieved, point after which it will continue on a straight trajectory. Here, we present the results of a theoretical investigation of this realignment phenomenon in the Stokes regime and in the limit of non-deformable interfaces. A 3D semi-analytical method in terms of polar spherical harmonics is developed to characterize and rationalize the hydrodynamic response (forces and torques), flow (velocity and temperature distribution) and trajectory of a Janus drop moving during the temperature-driven reorientation process. Furthermore, we discuss how this phenomenon may be exploited to develop dynamically reconfigurable micro-lenses. This work was partially supported by the US National Science Foundation through Grants DMS-1614043 and DMS-1719637.

Drop Jumping as a Training Method for Jumping Ability

NARCIS (Netherlands)

Bobbert, Maarten F.

1990-01-01

Vertical jumping ability is of importance for good performance in sports such as basketball and volleyball. Coaches are in need of exercises that consume only little time and still help to improve their players’ jumping ability, without involving a high risk of injury. Drop jumping is assumed to

Arbitrary-Level Hanging Nodes and Automatic Adaptivity in the hp-FEM

Czech Academy of Sciences Publication Activity Database

Šolín, Pavel; Červený, Jakub; Doležel, Ivo

2008-01-01

Roč. 77, č. 1 (2008), s. 117-132 ISSN 0378-4754 R&D Projects: GA ČR(CZ) GA102/07/0496; GA ČR GA102/05/0629; GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : constrained approximation * hanging nodes * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.930, year: 2008

Toxicology findings in cases of hanging in the City and County of San Francisco over the 3-year period from 2011 to 2013.

Science.gov (United States)

San Nicolas, A C; Lemos, N P

2015-10-01

In postmortem cases where the cause of death is hanging, toxicological analyses may be considered unnecessary by some medical examiners, toxicologists, and other persons involved in medico-legal investigations because the cause of death seems "obvious." To ascertain if toxicological analyses are necessary when the cause of death is hanging, all 102 hanging cases (25 females; 77 males) from 2011 to 2013 that came under the jurisdiction of the San Francisco Office of the Chief Medical Examiner were examined from a total of 3912 sudden, unexpected, or violent death cases in the same period. Suicide was the manner of death in 99 of these cases, with two accidental and one undetermined death. The average age of decedents was 43.9 years (median 41), the youngest was an 11-year old male and the oldest was an 86-year old female. Of the 102 cases, 33 had negative toxicology while 69 cases had at least one positive toxicology result. Females were equally likely to have negative or positive results (12 and 13 cases respectively), but males were 37.5% more likely to have positive toxicology (n=56) rather than negative toxicology (n=21). For females, alcohol, mirtazapine, venlafaxine, and trazodone were the top psychoactive substances in peripheral blood while THC, cocaine, hydrocodone, bupropion, olanzapine, doxylamine, quetiapine and dextromethorphan were also reported. For males, alcohol, THC, cocaine, amphetamine, methamphetamine, bupropion, and diphenhydramine were the top psychoactive substances in blood, but several other drugs were also found in individual cases. Our study of hanging cases over a 3-year period support the idea that complete postmortem toxicology investigation of hangings should be performed, even when the "obvious" cause of death is asphyxia due to hanging. Many of these cases involved psychoactive substances (most often alcohol and cannabis), and having such knowledge provides a better understanding of the circumstances surrounding the decedent's death

Crystallization and preliminary X-ray analysis of human S100A13

Energy Technology Data Exchange (ETDEWEB)

Imai, Fabiana Lica [Department of Chemistry, Faculty of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Nagata, Koji [Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Yonezawa, Naoto [Department of Chemistry, Faculty of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yu, Jinyan; Ito, Eriko; Kanai, Saeko [Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Tanokura, Masaru [Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Nakano, Minoru, E-mail: mnakano@faculty.chiba-u.jp [Department of Chemistry, Faculty of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan)

2006-11-01

Human S100A13 protein was cloned, expressed, purified and crystallized by the hanging-drop vapour-diffusion method. The crystals obtained belonged to space group P2{sub 1}2{sub 1}2{sub 1} and diffracted to a resolution of 1.8 Å. S100A13 is a member of the S100 family of EF-hand-containing calcium-binding proteins and plays an important role in the secretion of fibroblast growth factor-1 and interleukin 1α, two pro-angiogenic factors released by the endoplasmic reticulum/Golgi-independent non-classical secretory pathway. Human S100A13 was heterologously expressed in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.8 Å resolution and the space group was assigned as primitive orthorhombic P2{sub 1}2{sub 1}2{sub 1}.

Crystallization and preliminary X-ray analysis of cecropin B from Bombyx mori

International Nuclear Information System (INIS)

Liu, Zhongyuan; Zhou, Qiangjun; Mao, Xinfang; Zheng, Xiangdong; Guo, Jiubiao; Zhang, Fuchun; Wen, Tingyi; Pang, Hai

2010-01-01

Cecropin B derived from the hemolymph of Bombyx mori has been crystallized by the hanging-drop vapour-diffusion method. The crystal diffracted to 1.43 Å resolution using X-ray radiation. Cecropin B is a 37-residue cationic antimicrobial peptide derived from the haemolymph of Bombyx mori. The precise mechanism by which cecropins exert their antimicrobial and cytolytic activities is not well understood. Crystals of cecropin B were obtained by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitant at 289 K. The crystal diffracted to 1.43 Å resolution using X-ray radiation and belonged to the orthorhombic space group P1, with unit-cell parameters a = 15.08, b = 22.75, c = 30.20 Å, α = 96.9, β = 103.1, γ = 96.5°. The asymmetric unit contained only one molecule of cecropin B, with a calculated Matthews coefficient of 2.48 Å 3 Da −1 and a solvent content of 50.4%

Over a century of neuron culture: from the hanging drop to microfluidic devices.

Science.gov (United States)

Millet, Larry J; Gillette, Martha U

2012-12-01

The brain is the most intricate, energetically active, and plastic organ in the body. These features extend to its cellular elements, the neurons and glia. Understanding neurons, or nerve cells, at the cellular and molecular levels is the cornerstone of modern neuroscience. The complexities of neuron structure and function require unusual methods of culture to determine how aberrations in or between cells give rise to brain dysfunction and disease. Here we review the methods that have emerged over the past century for culturing neurons in vitro, from the landmark finding by Harrison (1910) - that neurons can be cultured outside the body - to studies utilizing culture vessels, micro-islands, Campenot and brain slice chambers, and microfluidic technologies. We conclude with future prospects for neuronal culture and considerations for advancement. We anticipate that continued innovation in culture methods will enhance design capabilities for temporal control of media and reagents (chemotemporal control) within sub-cellular environments of three-dimensional fluidic spaces (microfluidic devices) and materials (e.g., hydrogels). They will enable new insights into the complexities of neuronal development and pathology.

Purification, crystallization and preliminary X-ray diffraction of the G3BP1 NTF2-like domain

DEFF Research Database (Denmark)

Vognsen, Tina; Möller, Ingvar Rúnar; Kristensen, Ole

2011-01-01

The nuclear transport factor 2-like (NTF2-like) domain of human G3BP1 was subcloned, overexpressed in Escherichia coli and purified. Crystals were obtained using the hanging-drop vapour-diffusion method. Diffraction data were collected to 3.6 Å resolution using synchrotron radiation. The crystals...

The learning machine in quantitative chemical analysis : Part I. Anodic Stripping Voltammetry of Cadmium, Lead and Thallium

NARCIS (Netherlands)

Bos, M.; Jasink, G.

1978-01-01

The linear learning machine method was applied to the determination of cadmium, lead and thallium down to 10-8 M by anodic stripping voltammetry at a hanging mercury drop electrode. With a total of three trained multicategory classifiers, concentrations of Cd, Pb and Tl could be predicted with an

Heterologous expression, purification, crystallization and preliminary X-ray analysis of raucaffricine glucosidase, a plant enzyme specifically involved in Rauvolfia alkaloid biosynthesis

Energy Technology Data Exchange (ETDEWEB)

Ruppert, Martin [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Panjikar, Santosh [European Molecular Biology Laboratory Hamburg, Outstation Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Barleben, Leif [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Stöckigt, Joachim [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); College of Pharmaceutical Sciences, Zhejiang University, 353 Yan An Road, 310031 Hangzhou (China)

2006-03-01

Raucaffricine glucosidase, an enzyme involved in the biosynthesis of monoterpenoid indole alkaloids in the plant Rauvolfia serpentina, was crystallized by the hanging-drop vapour-diffusion method using PEG4000 as precipitant. The crystals diffract to 2.3 Å resolution and belong to space group I222. Raucaffricine glucosidase (RG) is an enzyme that is specifically involved in the biosynthesis of indole alkaloids from the plant Rauvolfia serpentina. After heterologous expression in Escherichia coli cells, crystals of RG were obtained by the hanging-drop vapour-diffusion technique at 293 K with 0.3 M ammonium sulfate, 0.1 M sodium acetate pH 4.6 buffer and 11% PEG 4000 as precipitant. Crystals belong to space group I222 and diffract to 2.30 Å, with unit-cell parameters a = 102.8, b = 127.3, c = 215.8 Å.

Heterologous expression, purification, crystallization and preliminary X-ray analysis of raucaffricine glucosidase, a plant enzyme specifically involved in Rauvolfia alkaloid biosynthesis

International Nuclear Information System (INIS)

Ruppert, Martin; Panjikar, Santosh; Barleben, Leif; Stöckigt, Joachim

2006-01-01

Raucaffricine glucosidase, an enzyme involved in the biosynthesis of monoterpenoid indole alkaloids in the plant Rauvolfia serpentina, was crystallized by the hanging-drop vapour-diffusion method using PEG4000 as precipitant. The crystals diffract to 2.3 Å resolution and belong to space group I222. Raucaffricine glucosidase (RG) is an enzyme that is specifically involved in the biosynthesis of indole alkaloids from the plant Rauvolfia serpentina. After heterologous expression in Escherichia coli cells, crystals of RG were obtained by the hanging-drop vapour-diffusion technique at 293 K with 0.3 M ammonium sulfate, 0.1 M sodium acetate pH 4.6 buffer and 11% PEG 4000 as precipitant. Crystals belong to space group I222 and diffract to 2.30 Å, with unit-cell parameters a = 102.8, b = 127.3, c = 215.8 Å

Application of the potential-drop method to measurements of hydrogen-induced sub-critical crack growth in zirconium-2.5 wt% niobium

International Nuclear Information System (INIS)

Simpson, L.A.; Clarke, C.F.

1977-10-01

Adaptation of the potential-drop method of crack-following to the problem of hydrogen-induced sub-critical crack growth in Zr-2.5% Nb is described. Reasons for non-linearity in the calibration of crack extension against potential drop in compact tension specimens are discussed. It is shown that despite non-linearities, careful comparison of fractographic features with the potential-drop record can lead to a continuous plot of crack velocity against time or stress intensity factor. Procedures for correcting data through temperature and load changes are also described. The application of the technique to studies of the mechanism of hydrogen crack growth is illustrated with several examples. (author)

Human serum albumin crystals and method of preparation

Science.gov (United States)

Carter, Daniel C. (Inventor)

1989-01-01

Human serum albumin (HSA) crystals are provided in the form of tetragonal plates having the space groups P42(sub 1)2, the crystals being grown to sizes in excess of 0.5 mm in two dimensions and a thickness of 0.1 mm. Growth of the crystals is carried out by a hanging drop method wherein a precipitant solution containing polyethylene glycol (PEG) and a phosphate buffer is mixed with an HSA solution, and a droplet of mixed solution is suspended over a well of precipitant solution. Crystals grow to the desired size in 3 to 7 days. Concentration of reagents, pH and other parameters are controlled within prescribed limits. The resulting crystals exhibit a size and quality such as to allow performance of x ray diffraction studies and enable the conduct of drug binding studies as well as genetic engineering studies.

Drop shape analysis for determination of dynamic contact angles by double sided elliptical fitting method

DEFF Research Database (Denmark)

Andersen, Nis Korsgaard; Taboryski, Rafael J.

2017-01-01

Contact angle measurements are a fast and simple way to measure surface properties and is therefore widely used to measure surface energy and quantify wetting of a solid surface by a liquid substance. In common praxis contact angle measurements are done with sessile drops on a horizontal surface...... fitted to a drop profile derived from the Young-Laplace equation. When measuring the wetting behaviour by tilting experiments this is not possible since it involves moving drops that are not in equilibrium. Here we present a fitting technique capable of determining the contact angle of asymmetric drops...

Measurement of the Mass of an Object Hanging from a Spring--Revisited

Science.gov (United States)

Serafin, Kamil; Oracz, Joanna; Grzybowski, Marcin; Koperski, Maciej; Sznajder, Pawel; Zinkiewicz, Lukasz; Wasylczyk, Piotr

2012-01-01

In an open competition, students were to determine the mass of a metal cylinder hanging on a spring inside a transparent enclosure. With the time for experiments limited to 24 h due to the unexpectedly large number of participants, a few surprisingly accurate results were submitted, the best of them differing by no more than 0.5% from the true…

Self-Renewal and CSCs In Vitro Enrichment: Growth as Floating Spheres

Science.gov (United States)

Mehta, Pooja; Novak, Caymen; Raghavan, Shreya; Ward, Maria; Mehta, Geeta

2018-01-01

Cancer stem cells (CSC) are a vital component to the progression and reoccurrence of cancers, making them a primary target of study for both fundamental understanding of cancer biology and the development of effective and targeted treatments. CSCs reside in a complex 3D microenvironment, and the 3D spheroids are an indispensable tool in tumor biology due to their 3D structure and replication of the tumor microenvironment. Within this chapter the methodology for CSC isolation, suspension culture in hanging drop model, and characterization assays for CSC are described. First, the methodology for identifying and isolating CSCs from patient tumors, ascites, or cancer cell lines is described through the use of FACS analysis. Next, a detailed description of 3D hanging drop model for generating CSC spheroids is provided, followed by maintenance and monitoring techniques for extended 3D culture. Analysis methods are described for the quantification of CSC spheroid proliferation and viability tracking, throughout culture by on-plate alamarBlue fluorescence. Additional viability assays are described utilizing confocal microscopy with Live/Dead Viability/Cytotoxicity Kit. The characterization of CSCs populations within spheroids is described through FACS analysis. Further, an immunohistochemistry procedure is described for cell-cell and cell-matrix interaction assessment. Finally, several notes and tips for successful experiments with 3D CSC spheroids on the hanging drop model are provided. These methods are not only applicable to CSCs within a variety of tumor cell types, for not only understanding the fundamental tumor biology, but also for drug screening and development of preclinical chemotherapeutic strategies. PMID:28986887

The effect of dropping impact on bruising pomegranate fruit

Directory of Open Access Journals (Sweden)

M Mohammad Shafie

2016-04-01

Full Text Available Introduction: The pomegranate journey from orchard to supermarket is very complex and pomegranates are subjected to the variety of static and dynamic loads that could result in this damage and bruise occurring. Bruise area and bruise volume are the most important parameters to evaluate fruit damage occurred in harvest and postharvest stages. The bruising is defined as damage to fruit flesh usually with no abrasion of the peel. The two different types of dynamic loading which can physically cause fruit bruising are impact and vibration. The impact and vibration loadings may occur during picking or sorting as the pomegranates are dropped into storage bins and during transportation. The focus of this work was on the impact loading as this appeared to be the most prevalent. In view of the limitations of conventional testing methods (ASTM D3332 Standard Test Methods for Mechanical Shock Fragility of Products, the method and procedure for determining dropping bruise boundary of fruit were also established by adapting free-fall dropping tests. Materials and Methods: After the ‘Malas-e-Saveh’ pomegranates had been selected, they were numbered, and the weight and dimension of each sample were measured and recorded. Firmness in cheek region of each fruit was also measured. Fruit firmness was determined by measuring the maximum force during perforating the sample to a depth of 10 mm at a velocity of 100 mm min-1 with an 8 mm diameter cylindrical penetrometer mounted onto a STM-5 Universal Testing Machine (SANTAM, Design CO. LTD., England. Free-fall dropping tests with a series of drop heights (6, 7, 10, 15, 30 and 60 cm were conducted on fresh ‘Malas-e-Saveh’ pomegranates. Three samples were used for each dropping height, and each sample was subjected to impact on two different positions. Before the test was started, it was necessary to control the sample's drop position. The cheek of sample was placed on the fruit holder. An aluminum plate mounted

Drop performance test and evaluation for HANARO shutoff units

International Nuclear Information System (INIS)

Jung, Y. H.; Cho, Y. K.; Lee, J. H.; Choi, Y. S.; Woo, J. S.

2004-01-01

The function of the shutoff units of the HANARO is to rapidly insert the shutoff rod into the reactor core for safe shutdown of reactor. This paper describes drop performance test and evaluation for a shutoff unit for the technical verification of lifetime extension and localization of the HANARO shutoff units. We have performed preliminary drop performance tests for a shutoff unit at 1/2-core test loop and analyzed through the comparison with the test results performed during design verification test and the results of the periodic performance test in HANARO. It shows that the results of the local fabrication, installation and alignment for the shutoff unit meet the basic performance requirements, Furthermore, the performance evaluation method of the periodic drop test of the HANARO shutoff units is a conservative method comparing with the real drop time

[Optimize dropping process of Ginkgo biloba dropping pills by using design space approach].

Science.gov (United States)

Shen, Ji-Chen; Wang, Qing-Qing; Chen, An; Pan, Fang-Lai; Gong, Xing-Chu; Qu, Hai-Bin

2017-07-01

In this paper, a design space approach was applied to optimize the dropping process of Ginkgo biloba dropping pills. Firstly, potential critical process parameters and potential process critical quality attributes were determined through literature research and pre-experiments. Secondly, experiments were carried out according to Box-Behnken design. Then the critical process parameters and critical quality attributes were determined based on the experimental results. Thirdly, second-order polynomial models were used to describe the quantitative relationships between critical process parameters and critical quality attributes. Finally, a probability-based design space was calculated and verified. The verification results showed that efficient production of Ginkgo biloba dropping pills can be guaranteed by operating within the design space parameters. The recommended operation ranges for the critical dropping process parameters of Ginkgo biloba dropping pills were as follows: dropping distance of 5.5-6.7 cm, and dropping speed of 59-60 drops per minute, providing a reference for industrial production of Ginkgo biloba dropping pills. Copyright© by the Chinese Pharmaceutical Association.

Lambda-dropping

DEFF Research Database (Denmark)

Danvy, Olivier; Schultz, Ulrik Pagh

1997-01-01

Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

Development of new testing methods for the numerical load analysis for the drop test of steel sheet containers for the final repository Konrad

International Nuclear Information System (INIS)

Protz, C.; Voelzke, H.; Zencker, U.; Hagenow, P.; Gruenewald, H.

2011-01-01

The qualification of steel sheet containers as intermediate-level waste container for the final repository is performed by the BAM (Bundeasmt fuer Materialpruefung) according to the BfS (Bundesamt fuer Strahlenschutz) requirements. The testing requirements include the stacking pressure tests, lifting tests, drop tests thermal tests (fire resistance) and tightness tests. Besides the verification using model or prototype tests and transferability considerations numerical safety analyses may be performed alternatively. The authors describe the internal BAM research project ConDrop aimed to develop extended testing methods for the drop test of steel sheet containers for the final repository Konrad using numerical load analyses. A finite element model was developed using The FE software LS-PrePost 3.0 and ANSYS 12.0 and the software FE-Code LS-DYNA for the simulation of the drop test (5 m height). The results were verified by experimental data from instrumented drop tests. The container preserves its integrity after the drop test, plastic deformation occurred at the bottom plate, the side walls, the cask cover and the lateral uprights.

An autopsy study of death due to Suicidal Hanging – 264 cases

Directory of Open Access Journals (Sweden)

Dinesh Rao

2016-09-01

Full Text Available The present study was carried out between 2010 and 2013, a total of 7968 Autopsies were conducted of which 3.31% (n – 264 cases were deaths due to hanging. The most preferred ligature materials were Stole (n – 79 and Bed spread/Sari (n – 68. In 88% of the cases, hanging was complete. Females (n – 136 and males (n – 128 were equally affected. The major age group involved in both the sexes was of 31–40 years, contributing to 50.76% (n – 136 of the self suspension. In 80.58% (n – 213 of the incidents, ligature mark showed discontinuity (incomplete. A Slip type of knot was used in majority of the noose, contributing to 97.73% (n – 258 of the suspensions. In 87.88% (n – 232 of hanging an oblique shaped ligature mark was noticed. The horizontal and near oblique ligature marks were seen only in cases of partial suspension. In 95.45% (n – 252 of the cases, the ligature mark showed blackening of the skin (friction burn. Only 4.54% (n – 12 showed intact skin. The outer layer of the skin over the ligature mark showed displacement in majority of the cases. Married victims contributed to 70.45% of cases. Domestic issues were the commonest reason (n – 82 for self suspension, of which female (n – 68 formed the majority of victims. In 70.83% (n – 187 of cases damage to neck muscle fibers and hemorrhage at the Sternal end of the Sternocleidomastoid muscle were present. In 85.61% (n – 226 of cases the cervical vertebra was intact. In 52.27% (n – 138 of the cases the internal carotid artery showed transverse tear. In 99.42% (n – 248 cases the thyroid cartilage was found intact. The hyoid bone was damaged in 6.06% (n – 16 of the victims. Majority of the victims, 59.09% (n – 156 belonged to low socioeconomic class.

Bubble and Drop Nonlinear Dynamics (BDND)

Science.gov (United States)

Trinh, E. H.; Leal, L. Gary; Thomas, D. A.; Crouch, R. K.

1998-01-01

Free drops and bubbles are weakly nonlinear mechanical systems that are relatively simple to characterize experimentally in 1-G as well as in microgravity. The understanding of the details of their motion contributes to the fundamental study of nonlinear phenomena and to the measurement of the thermophysical properties of freely levitated melts. The goal of this Glovebox-based experimental investigation is the low-gravity assessment of the capabilities of a modular apparatus based on ultrasonic resonators and on the pseudo- extinction optical method. The required experimental task is the accurate measurements of the large-amplitude dynamics of free drops and bubbles in the absence of large biasing influences such as gravity and levitation fields. A single-axis levitator used for the positioning of drops in air, and an ultrasonic water-filled resonator for the trapping of air bubbles have been evaluated in low-gravity and in 1-G. The basic feasibility of drop positioning and shape oscillations measurements has been verified by using a laptop-interfaced automated data acquisition and the optical extinction technique. The major purpose of the investigation was to identify the salient technical issues associated with the development of a full-scale Microgravity experiment on single drop and bubble dynamics.

Searching for new features of intravitality of hanging based on macro- and microscopic evaluation of the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone

Directory of Open Access Journals (Sweden)

Łukasz Szleszkowski

2016-03-01

Full Text Available Aim of the study : Assessment of the usefulness of intravital lesions in the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone in medico-legal evaluation of death by hanging. Material and methods: The study material was obtained from the bodies of 35 people who died by hanging. The control group comprised specimens collected from 30 people who died of non-traumatic causes. The structures under study were examined macro- and microscopically. The basic change which could be recognized as a marker of intravitality of hanging was the presence of a macroscopically extensive blotchy area of abundant ecchymosis in the proximal muscle attachment, similar to that found in the distal attachment, and the presence of abundant diffuse intraosseous ecchymoses in the mastoid process. Results: None of the cases revealed any ecchymoses in the proximal attachment of the muscle that would be similar to those present in the distal attachment. Discolourations within the mastoid processes, macroscopically suggestive of extensive intraosseous effusions arising from the mechanism of stretching, were not confirmed by microscopic evaluation and occurred at the same frequency as in the control group. Limitations of the study were related to the method which involved sample collection by means of bone chisels, decalcification and preparation of specimens, which had an effect, for example, on the measurable evaluation of the degree of congestion. Conclusions : The study has failed to provide convincing and unambiguous data on the usefulness of examining mastoid processes and proximal attachments of the sternocleidomastoid muscles during autopsy to determine the presence of intravitality features of hanging. A description of research methodology and its associated difficulties, e.g. with the interpretation of results, can also be useful for the planning of similar studies by other researchers.

An Efficient Estimation Method for Reducing the Axial Intensity Drop in Circular Cone-Beam CT

Directory of Open Access Journals (Sweden)

Lei Zhu

2008-01-01

Full Text Available Reconstruction algorithms for circular cone-beam (CB scans have been extensively studied in the literature. Since insufficient data are measured, an exact reconstruction is impossible for such a geometry. If the reconstruction algorithm assumes zeros for the missing data, such as the standard FDK algorithm, a major type of resulting CB artifacts is the intensity drop along the axial direction. Many algorithms have been proposed to improve image quality when faced with this problem of data missing; however, development of an effective and computationally efficient algorithm remains a major challenge. In this work, we propose a novel method for estimating the unmeasured data and reducing the intensity drop artifacts. Each CB projection is analyzed in the Radon space via Grangeat's first derivative. Assuming the CB projection is taken from a parallel beam geometry, we extract those data that reside in the unmeasured region of the Radon space. These data are then used as in a parallel beam geometry to calculate a correction term, which is added together with Hu’s correction term to the FDK result to form a final reconstruction. More approximations are then made on the calculation of the additional term, and the final formula is implemented very efficiently. The algorithm performance is evaluated using computer simulations on analytical phantoms. The reconstruction comparison with results using other existing algorithms shows that the proposed algorithm achieves a superior performance on the reduction of axial intensity drop artifacts with a high computation efficiency.

Many Drops Interactions I: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

Directory of Open Access Journals (Sweden)

Alejandro Acevedo-Malavé

2012-06-01

Full Text Available Smoothed Particle Hydrodynamics (SPH is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. In this study, the SPH method is applied to simulate the hydrodynamics interaction of many drops, showing some settings for the coalescence, fragmentation and flocculation problem of equally sized liquid drops in three-dimensional spaces. For small velocities the drops interact only through their deformed surfaces and the flocculation of the droplets arises. This result is very different if the collision velocity is large enough for the fragmentation of droplets takes place. We observe that for velocities around 15 mm/ms the coalescence of droplets occurs. The velocity vector fields formed inside the drops during the collision process are shown.

Crystallization of the A-Domain of the Mannitol Transport Protein Enzyme IImtl

NARCIS (Netherlands)

Lammers, Leidy A.; Dijkstra, Bauke W.; Weeghel, Rob P. van; Pas, Hendri H.; Robillard, George T.

1992-01-01

The A-domain of the mannitol transport protein enzyme IImtl from Escherichia coli (relative molecular mass 16,300) was crystallized, both at room temperature and 4°C, from 40% polyethylene glycol 6000 (pH 8.5 to 9.0) using the hanging-drop method of vapour diffusion. The crystals have the monoclinic

Crystallization and Preliminary Crystallographic Characterization of Endo-polygalacturonase II from Aspergillus niger

NARCIS (Netherlands)

Schröter, K.-H.; Arkema, A.; Kester, H.C.M.; Visser, J.; Dijkstra, B.W.

1994-01-01

The endo-polygalacturonase II from Aspergillus niger has been crystallized from an ammonium sulfate solution by the hanging drop method. The crystals belong to the monoclinic space group P2(1), with cell dimensions a = 60.6 Angstrom, b = 152.6 Angstrom, c = 74.0 Angstrom and beta = 91.2 degrees with

Tetrazolium chloride as an indicator of pine pollen germinability

Science.gov (United States)

Stanton A. Cook; Robert G. Stanley

1960-01-01

Controlled pollination in forest tree breeding requires pollen of known germination capacity. Methods of determining pollen viability include germination in a hanging drop, in a moist atmosphere, on agar gel, or in a sugar solution (DUFFIELD, 1954; DILLON et al., 1957). Errors commonly arise in the application of these techniques because maximum...

DEEP HANGING WALL TRAPS-THE REMAINING PROMISSING TARGETS FOR OIL EXPLORATION IN THE NIGER DELTA

International Nuclear Information System (INIS)

Oton, S.W

2004-01-01

It is well known that the most dominant types of Hydrocarbon types found in the petroliferous Niger Delta are the classical rollover anticlinical traps 'I of oil exploration in the delta, these easy-to-find rollover structures are getting exhausted. They are most numerous at shallow depths in the younger delta front sedimentary sequence. Generally, during this primary oil exploration stage, oil and gas exploration have been concentrated in the shallow depths where they are easy to reach, easy to explore and easy to produce. This means that the present and future exploration campaigns in the Niger Delta should be directed towards other types of hydrocarbon trapping mechanisms that have been mapped in the delta. Many exploration models have been used and oil has been found in at least nine types of traps in the Niger Delta. The contrary (or anitithetic) fault model was used at the close of the last century. This model is so called because the controlling antithetic fault has a regional dip contrary to the structure-building growth fault with which it is associated. These faults, which are widespread in the Niger Delta, are easy to map especially on the Petro geological model. In this period, several promising hydrocarbon accumulations trapped against antithetic faults were discovered and tested. These hydrocarbon targets also seem fully explored and exhausted now. Recently, from modern high resolution 2-D and 3-D seismic data a lot of good prospects have been mapped and drilled in the deep horizon. In the last few years, a lot of unexplored oil have been discovered and tested in the deep horizons. They are mostly in hanging wall traps, at depth below 4,000 meters. This shows that most of the remaining undiscovered hydrocarbons in the Niger Delta may well be in these deep hanging wall traps between 4,000 and close to 5,600 meters. A definite search for deep-seated hanging wall traps is therefore recommended in a bid to find more new reservoirs and thereby increase the

Ballistic Jumping Drops on Superhydrophobic Surfaces via Electrostatic Manipulation.

Science.gov (United States)

Li, Ning; Wu, Lei; Yu, Cunlong; Dai, Haoyu; Wang, Ting; Dong, Zhichao; Jiang, Lei

2018-02-01

The ballistic ejection of liquid drops by electrostatic manipulating has both fundamental and practical implications, from raindrops in thunderclouds to self-cleaning, anti-icing, condensation, and heat transfer enhancements. In this paper, the ballistic jumping behavior of liquid drops from a superhydrophobic surface is investigated. Powered by the repulsion of the same kind of charges, water drops can jump from the surface. The electrostatic acting time for the jumping of a microliter supercooled drop only takes several milliseconds, even shorter than the time for icing. In addition, one can control the ballistic jumping direction precisely by the relative position above the electrostatic field. The approach offers a facile method that can be used to manipulate the ballistic drop jumping via an electrostatic field, opening the possibility of energy efficient drop detaching techniques in various applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystallization and preliminary X-ray analysis of a bifunctional catalase-phenol oxidase from Scytalidium thermophilum

International Nuclear Information System (INIS)

Sutay Kocabas, Didem; Pearson, Arwen R.; Phillips, Simon E. V.; Bakir, Ufuk; Ogel, Zumrut B.; McPherson, Michael J.; Trinh, Chi H.

2009-01-01

The bifunctional enzyme catalase-phenol oxidase from S. thermophilum was crystallized by the hanging-drop vapour-diffusion method in space group P2 1 and diffraction data were collected to 2.8 Å resolution. Catalase-phenol oxidase from Scytalidium thermophilum is a bifunctional enzyme: its major activity is the catalase-mediated decomposition of hydrogen peroxide, but it also catalyzes phenol oxidation. To understand the structural basis of this dual functionality, the enzyme, which has been shown to be a tetramer in solution, has been purified by anion-exchange and gel-filtration chromatography and has been crystallized using the hanging-drop vapour-diffusion technique. Streak-seeding was used to obtain larger crystals suitable for X-ray analysis. Diffraction data were collected to 2.8 Å resolution at the Daresbury Synchrotron Radiation Source. The crystals belonged to space group P2 1 and contained one tetramer per asymmetric unit

Measurement of the mass of an object hanging from a spring—revisited

International Nuclear Information System (INIS)

Serafin, Kamil; Oracz, Joanna; Grzybowski, Marcin; Koperski, Maciej; Sznajder, Paweł; Zinkiewicz, Łukasz; Wasylczyk, Piotr

2012-01-01

In an open competition, students were to determine the mass of a metal cylinder hanging on a spring inside a transparent enclosure. With the time for experiments limited to 24 h due to the unexpectedly large number of participants, a few surprisingly accurate results were submitted, the best of them differing by no more than 0.5% from the true value with a relative uncertainty of less than 1%.

Building micro-soccer-balls with evaporating colloidal fakir drops

Science.gov (United States)

Gelderblom, Hanneke; Marín, Álvaro G.; Susarrey-Arce, Arturo; van Housselt, Arie; Lefferts, Leon; Gardeniers, Han; Lohse, Detlef; Snoeijer, Jacco H.

2013-11-01

Drop evaporation can be used to self-assemble particles into three-dimensional microstructures on a scale where direct manipulation is impossible. We present a unique method to create highly-ordered colloidal microstructures in which we can control the amount of particles and their packing fraction. To this end, we evaporate colloidal dispersion drops from a special type of superhydrophobic microstructured surface, on which the drop remains in Cassie-Baxter state during the entire evaporative process. The remainders of the drop consist of a massive spherical cluster of the microspheres, with diameters ranging from a few tens up to several hundreds of microns. We present scaling arguments to show how the final particle packing fraction of these balls depends on the drop evaporation dynamics, particle size, and number of particles in the system.

Green chemistry and nanofabrication in a levitated Leidenfrost drop

Science.gov (United States)

Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

2013-10-01

Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

The Drop Tower Bremen -Experiment Operation

Science.gov (United States)

Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

On-line mass spectrometry system for measurements at single-crystal electrodes in hanging meniscus configuration

NARCIS (Netherlands)

Wonders, A.H.; Housmans, T.H.M.; Rosca, V.; Koper, M.T.M.

2006-01-01

We present the construction and some first applications of an On-line electrochemical mass spectrometry system for detecting volatile products formed during electrochemical reactions at a single-crystal electrode in hanging meniscus configuration. The system is based on a small inlet tip made of

Extending total parenteral nutrition hang time in the neonatal intensive care unit: is it safe and cost effective?

Science.gov (United States)

Balegar V, Kiran Kumar; Azeem, Mohammad Irfan; Spence, Kaye; Badawi, Nadia

2013-01-01

To investigate the effects of prolonging hang time of total parenteral nutrition (TPN) fluid on central line-associated blood stream infection (CLABSI), TPN-related cost and nursing workload. A before-after observational study comparing the practice of hanging TPN bags for 48 h (6 February 2009-5 February 2010) versus 24 h (6 February 2008-5 February 2009) in a tertiary neonatal intensive care unit was conducted. The main outcome measures were CLABSI, TPN-related expenses and nursing workload. One hundred thirty-six infants received 24-h TPN bags and 124 received 48-h TPN bags. Median (inter-quartile range) gestation (37 weeks (33,39) vs. 36 weeks (33,39)), mean (±standard deviation) admission weight of 2442 g (±101) versus 2476 g (±104) and TPN duration (9.7 days (±12.7) vs. 9.9 days (±13.4)) were similar (P > 0.05) between the 24- and 48-h TPN groups. There was no increase in CLABSI with longer hang time (0.8 vs. 0.4 per 1000 line days in the 24-h vs. 48-h group; P < 0.05). Annual cost saving using 48-h TPN was AUD 97,603.00. By using 48-h TPN, 68.3% of nurses indicated that their workload decreased and 80.5% indicated that time spent changing TPN reduced. Extending TPN hang time from 24 to 48 h did not alter CLABSI rate and was associated with a reduced TPN-related cost and perceived nursing workload. Larger randomised controlled trials are needed to more clearly delineate these effects. © 2012 The Authors. Journal of Paediatrics and Child Health © 2012 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Dynamics of deforming drops

OpenAIRE

Bouwhuis, W.

2015-01-01

Liquid drops play a dominant role in numerous industrial applications, such as spray coating, spray painting, inkjet printing, lithography processes, and spraying/sprinkling in agriculture or gardening. In all of these examples, the generation, flight, impact, and spreading of drops are separate stages of the corresponding industrial processes, which are all thoroughly studied for many years. This thesis focuses on drop dynamics, impact phenomena, Leidenfrost drops, and pouring flows. Based o...

Scanning drop sensor

Energy Technology Data Exchange (ETDEWEB)

Jin, Jian; Xiang, Chengxiang; Gregoire, John

2017-05-09

Electrochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

Crystallization and preliminary X-ray analysis of ZHE1, a hatching enzyme from the zebrafish Danio rerio

International Nuclear Information System (INIS)

Okada, Akitoshi; Nagata, Koji; Sano, Kaori; Yasumasu, Shigeki; Kubota, Keiko; Ohtsuka, Jun; Iuchi, Ichiro; Tanokura, Masaru

2009-01-01

The hatching enzyme of zebrafish, ZHE1, was expressed, purified and crystallized using the hanging-drop vapour-diffusion method. The crystal belonged to space group P2 1 2 1 2 1 and diffracted X-rays to a resolution of 1.14 Å. The hatching enzyme of the zebrafish, ZHE1 (29.3 kDa), is a zinc metalloprotease that catalyzes digestion of the egg envelope (chorion). ZHE1 was heterologously expressed in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. Two diffraction data sets with resolution ranges 50.0–1.80 and 50.0–1.14 Å were independently collected from two crystals and were merged to give a highly complete data set over the full resolution range 50.0–1.14 Å. The space group was assigned as primitive orthorhombic P2 1 2 1 2 1 , with unit-cell parameters a = 32.9, b = 62.5, c = 87.4 Å. The crystal contained one ZHE1 molecule in the asymmetric unit

Crystallization and preliminary X-ray crystallographic analysis of BxlA, an intracellular β-d-xylosidase from Streptomyces thermoviolaceus OPC-520

International Nuclear Information System (INIS)

Morioka, Hideaki; Miki, Yasuhiro; Saito, Kei; Tomoo, Koji; Ishida, Toshimasa; Hasegawa, Tomokazu; Yamano, Akihito; Takada, Chiaki; Miyamoto, Katsushiro; Tsujibo, Hiroshi

2010-01-01

BxlA from Streptomyces thermoviolaceus OPC-520 (molecular weight 82 kDa) was crystallized by the hanging-drop vapour-diffusion method at 289 K. BxlA from Streptomyces thermoviolaceus OPC-520, together with the extracellular BxlE and the integral membrane proteins BxlF and BxlG, constitutes a xylanolytic system that participates in the intracellular transport of xylan-degradation products and the production of xylose. To elucidate the mechanism of the hydrolytic degradation of xylooligosaccharides to xylose at the atomic level, X-ray structural analysis of BxlA was attempted. The recombinant BxlA protein (molecular weight 82 kDa) was crystallized by the hanging-drop vapour-diffusion method at 289 K. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 142.2, b = 129.5, c = 101.4 Å, β = 119.8°, and contained two molecules per asymmetric unit (V M = 2.47 Å 3 Da −1 ). Diffraction data were collected to a resolution to 2.50 Å and provided a data set with an overall R merge of 8.3%

Crystallization and preliminary X-ray diffraction studies of choline-binding protein F from Streptococcus pneumoniae

Energy Technology Data Exchange (ETDEWEB)

Molina, Rafael [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); González, Ana; Moscoso, Miriam; García, Pedro [Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Stelter, Meike; Kahn, Richard [Institut de Biologie Structurale J.-P. Ebel CEA CNRS UJF, Laboratoire de Cristallographie Macromoléculaire, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 1 (France); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

2007-09-01

The modular choline-binding protein F (CbpF) from S. pneumoniae has been crystallized by the hanging-drop vapour-diffusion method. A SAD data set from a gadolinium-complex derivative has been collected to 2.1 Å resolution. Choline-binding protein F (CbpF) is a modular protein that is bound to the pneumococcal cell wall through noncovalent interactions with choline moieties of the bacterial teichoic and lipoteichoic acids. Despite being one of the more abundant proteins on the surface, along with the murein hydrolases LytA, LytB, LytC and Pce, its function is still unknown. CbpF has been crystallized using the hanging-drop vapour-diffusion method at 291 K. Diffraction-quality orthorhombic crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 49.13, b = 114.94, c = 75.69 Å. A SAD data set from a Gd-HPDO3A-derivatized CbpF crystal was collected to 2.1 Å resolution at the gadolinium L{sub III} absorption edge using synchrotron radiation.

Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

Energy Technology Data Exchange (ETDEWEB)

Pérez-Dorado, Inmaculada [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Bortolotti, Ana; Cortez, Néstor [Instituto de Biología Molecular y Celular de Rosario (Universidad Nacional de Rosario y CONICET), Suipacha 531, S2002LRK Rosario (Argentina); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

2008-05-01

The flavodoxin NifF from R. capsulatus, a candidate for nitrogenase reduction during nitrogen fixation, has been crystallized using the hanging-drop vapour-diffusion method. Preliminary X-ray data processing at 2.17 Å resolution allowed determination of the crystal system and unit-cell parameters. Flavodoxins are small electron-transfer proteins that contain one molecule of noncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF from the photosynthetic bacterium Rhodobacter capsulatus is reduced by one electron from ferredoxin/flavodoxin:NADP(H) reductase and was postulated to be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressed in Escherichia coli, purified and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 66.49, c = 121.32 Å. X-ray data sets have been collected to 2.17 Å resolution.

Crystallization and preliminary X-ray diffraction studies of choline-binding protein F from Streptococcus pneumoniae

International Nuclear Information System (INIS)

Molina, Rafael; González, Ana; Moscoso, Miriam; García, Pedro; Stelter, Meike; Kahn, Richard; Hermoso, Juan A.

2007-01-01

The modular choline-binding protein F (CbpF) from S. pneumoniae has been crystallized by the hanging-drop vapour-diffusion method. A SAD data set from a gadolinium-complex derivative has been collected to 2.1 Å resolution. Choline-binding protein F (CbpF) is a modular protein that is bound to the pneumococcal cell wall through noncovalent interactions with choline moieties of the bacterial teichoic and lipoteichoic acids. Despite being one of the more abundant proteins on the surface, along with the murein hydrolases LytA, LytB, LytC and Pce, its function is still unknown. CbpF has been crystallized using the hanging-drop vapour-diffusion method at 291 K. Diffraction-quality orthorhombic crystals belong to space group P2 1 2 1 2, with unit-cell parameters a = 49.13, b = 114.94, c = 75.69 Å. A SAD data set from a Gd-HPDO3A-derivatized CbpF crystal was collected to 2.1 Å resolution at the gadolinium L III absorption edge using synchrotron radiation

Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

International Nuclear Information System (INIS)

Pérez-Dorado, Inmaculada; Bortolotti, Ana; Cortez, Néstor; Hermoso, Juan A.

2008-01-01

The flavodoxin NifF from R. capsulatus, a candidate for nitrogenase reduction during nitrogen fixation, has been crystallized using the hanging-drop vapour-diffusion method. Preliminary X-ray data processing at 2.17 Å resolution allowed determination of the crystal system and unit-cell parameters. Flavodoxins are small electron-transfer proteins that contain one molecule of noncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF from the photosynthetic bacterium Rhodobacter capsulatus is reduced by one electron from ferredoxin/flavodoxin:NADP(H) reductase and was postulated to be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressed in Escherichia coli, purified and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal space group P4 1 2 1 2, with unit-cell parameters a = b = 66.49, c = 121.32 Å. X-ray data sets have been collected to 2.17 Å resolution

Purification, crystallization and preliminary X-ray analysis of 3-hydroxy-3-methylglutaryl-coenzyme A reductase of Streptococcus pneumoniae

International Nuclear Information System (INIS)

Zhang, Liping; Feng, Lingling; Zhou, Li; Gui, Jie; Wan, Jian; Hu, Xiaopeng

2010-01-01

3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase of Streptococcus pneumoniae has been cloned, overexpressed and purified to homogeneity using Ni–NTA affinity chromatography. Crystals were obtained using the hanging-drop vapour-diffusion method. Class II 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductases are potential targets for novel antibiotic development. In order to obtain a precise structural model for use in virtual screening and inhibitor design, HMG-CoA reductase of Streptococcus pneumoniae was cloned, overexpressed and purified to homogeneity using Ni–NTA affinity chromatography. Crystals were obtained using the hanging-drop vapour-diffusion method. A complete data set was collected from a single frozen crystal on a home X-ray source. The crystal diffracted to 2.3 Å resolution and belonged to the orthorhombic space group C222 1 , with unit-cell parameters a = 773.4836, b = 90.3055, c = 160.5592 Å, α = β = γ = 90°. Assuming the presence of two molecules in the asymmetric unit, the solvent content was estimated to be 54.1% (V M = 2.68 Å 3 Da −1 )

Formation and evolution of mesozoic volcanic basins in Gan-Hang tectonic belt

International Nuclear Information System (INIS)

Zhang Xingpu

1999-01-01

The author mainly discusses the principle model for the formation and the evolution of Mesozoic volcanic basins in the Gan-Hang Tectonic Belt, and describes the distinct evolution features between the internal and external sites of volcanic basins, the natural relation between the down-warped, down-faulted, collapse volcanic basins and volcanic domes, the relationship between the formation of inter layered fractured zones of the volcanic cover and the evolution of volcanic basins

Drop-out from a psychodynamic group psychotherapy outpatient unit.

Science.gov (United States)

Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

2014-11-01

BACKGROUND. Drop-out from psychotherapy is common and represents a considerable problem in clinical practice and research. Aim. To explore pre-treatment predictors of early and late drop-out from psychodynamic group therapy in a public outpatient unit for non-psychotic disorders in Denmark. Methods. Naturalistic design including 329 patients, the majority with mood, neurotic and personality disorders referred to 39-session group therapy. Predictors were socio-demographic and clinical variables, self-reported symptoms (Symptom Check List-90-Revised) and personality style (Millon Clinical Multiaxial Inventory-II). Drop-out was classified into early and late premature termination excluding patients who dropped out for external reasons. Results. Drop-out comprised 20.6% (68 patients) of the sample. Logistic regression revealed social functioning, vocational training, alcohol problems and antisocial behavior to be related to drop-out. However, early drop-outs had prominent agoraphobic symptoms, lower interpersonal sensitivity and compulsive personality features, and late drop-outs cognitive and somatic anxiety symptoms and antisocial personality features. Clinical and psychological variables accounted for the major part of variance in predictions of drop-out, which ranged from 15.6% to 19.5% (Nagelkerke Pseudo R-Square). Conclusion. Social functioning was consistently associated with drop-out, but personality characteristics and anxiety symptoms differentiated between early and late drop-out. Failure to discriminate between stages of premature termination may explain some of the inconsistencies in the drop-out literature. Clinical implications. Before selection of patients to time-limited psychodynamic groups, self-reported symptoms should be thoroughly considered. Patients with agoraphobic symptoms should be offered alternative treatment. Awareness of and motivation to work with interpersonal issues may be essential for compliance with group therapy.

Reducing Variability in Stress Drop with Root-Mean Acceleration

Science.gov (United States)

Crempien, J.; Archuleta, R. J.

2012-12-01

Stress drop is a fundamental property of the earthquake source. For a given tectonic region stress drop is assumed to be constant allowing for the scaling of earthquake spectra. However, the variability of the stress drop, either for worldwide catalogs or regional catalogs, is quite large. The variability around the median value is on the order of 1.5 in log10 units. One question that continues to pervade the analysis of stress drop is whether this variability is an inherent characteristic of the Earth or is an artifact of the determination of stress drop via the use of the spectral analysis. It is simple to see that the stress drop determined by seismic moment times corner frequency cubed that errors in the corner frequency will strongly influence the variability in the stress drop. To avoid this strong dependence on corner frequency cubed, we have examined the determination of stress drop based on the approach proposed by Hanks (1979), namely using the root-mean-square acceleration. The stress drop determined using rms acceleration may be advantageous because the stress drop is only affected by the square root of the corner frequency. To test this approach we have determined stress drops for the 2000 Tottori earthquake and its aftershocks. We use both the classic method of fitting to a spectrum as well as using rms acceleration. For a preliminary analysis of eight aftershocks and the mainshock we find that the variability in stress drop is reduced by about a factor of two. This approach needs more careful analysis of more events, which will be shown at the meeting.

Detrended cross-correlation analysis on RMB exchange rate and Hang Seng China Enterprises Index

Science.gov (United States)

Ruan, Qingsong; Yang, Bingchan; Ma, Guofeng

2017-02-01

In this paper, we investigate the cross-correlations between the Hang Seng China Enterprises Index and RMB exchange markets on the basis of a cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). MF-DCCA has, at best, serious limitations for most of the signals describing complex natural processes and often indicates multifractal cross-correlations when there are none. In order to prevent these false multifractal cross-correlations, we apply MFCCA to verify the cross-correlations. Qualitatively, we find that the return series of the Hang Seng China Enterprises Index and RMB exchange markets were, overall, significantly cross-correlated based on the statistical analysis. Quantitatively, we find that the cross-correlations between the stock index and RMB exchange markets were strongly multifractal, and the multifractal degree of the onshore RMB exchange markets was somewhat larger than the offshore RMB exchange markets. Moreover, we use the absolute return series to investigate and confirm the fact of multifractality. The results from the rolling windows show that the short-term cross-correlations between volatility series remain high.

Scanning drop sensor

Energy Technology Data Exchange (ETDEWEB)

Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Shinde, Aniketa A.; Guevarra, Dan W.; Jones, Ryan J.; Marcin, Martin R.; Mitrovic, Slobodan

2017-05-09

Electrochemical or electrochemical and photochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

Flutter instability of freely hanging articulated pipes conveying fluid

Science.gov (United States)

Schouveiler, Lionel; Chermette, Félix

2018-03-01

We experimentally investigate the stability of freely hanging articulated pipes made of rigid segments connected by flexible joints and with their displacements constrained in a vertical plane. When the velocity of the fluid conveyed by the pipe is increased, flutter-type instability occurs above a critical value. The critical velocity and the characteristics of the flutter modes (frequency, amplitude, and shape) are determined as a function of the number n of segments into the pipe which is varied from 2 to 5. Experimental results are compared to predictions from linear stability analysis extending previous studies by taking into account damping due to the dissipation in the joints. Qualitative agreement is found and the limits of the analysis are discussed.

Validation of a chromatographic method for quantitation of 50 μg/mL Latanoprost in a Cuban eye drops

International Nuclear Information System (INIS)

Garcia Penna, Caridad Margarita; Martinez Espinosa, Vivian; Gonzalez Cortezon, Ania

2012-01-01

Latanoprost is indicated to treat high intraocular pressure in patients suffering from ocular hypertension or from open angle glaucoma. To develop and to validate a high performance liquid chromatography-based analytical method for quality control of 50 μg/mL Latanoprost eye drops

Hanging out at the airport: Unusual upside-down perching behavior by Eurasian Jackdaws (Corvus monedula) in a human-dominated environment

Science.gov (United States)

Katzner, Todd E.

2016-01-01

Animals occupying human-dominated environments show the capacity for behavioral flexibility. Corvids are among the most intelligent synanthropic bird species. During a layover at Schipol Airport in Amsterdam, Netherlands, I photographically documented Eurasian Jackdaws (Corvus monedula) perching upside down from a building cornice. In contrast to other reports of hanging birds, these jackdaws did not forage or play while upside down and appeared to use the perching spot to observe their surroundings. Although Corvids and Psittacines are known to hang upside down, especially in captive situations, such behaviors are rarely documented in the wild, and never before in association with human-built structures.

Hydraulic Behavior in The Downflow Hanging Sponge Bioreactor

Directory of Open Access Journals (Sweden)

Izarul Machdar

2016-12-01

Full Text Available Performance efficiency in a Downflow Hanging Sponge (DHS bioreactor is associated with the amount of time that a wastewater remains in the bioreactor. The bioreactor is considered as a plug flow reactor and its hydraulic residence time (HRT depends on the void volume of packing material and the flow rate. In this study, hydraulic behavior of DHS bioreactor was investigated by using tracer method. Two types of sponge module covers, cylindrical plastic frame (module-1 and plastic hair roller (module-2, were investigated and compared. A concentrated NaCl solution used as an inert tracer and input as a pulse at the inlet of DHS bioreactor. Analysis of the residence time distribution (RTD curves provided interpretation of the index distribution or holdup water (active volume, the degree of short-circuiting, number of tanks in series (the plug flow characteristic, and the dispersion number. It was found that the actual HRT was primarily shorter than theoretical HRT of each test. Holdup water of the DHS bioreactor ranged from 60% to 97% and 36% to 60% of module-1 and module-2, respectively. Eventhough module-1 has higher effective volume than module-2, result showed that the dispersion numbers of the two modules were not significant difference. Furthermore, N-values were found larger at a higher flow rate. It was concluded that a DHS bioreactor design should incorporated a combination of water distributor system, higher loading rate at startup process to generate a hydraulic behavior closer to an ideal plug flow.ABSTRAKEfisiensi unjuk kerja bioreactor Downflow Hanging Sponge (DHS berkaitan dengan lamanya waktu tinggal limbah berada di dalam bioreaktor tersebut. Bioreaktor DHS dianggap sebagai seuatu reaktor aliran sumbat (plug flow dimana waktu tinggal hidraulik (HRT tergantung pada volume pori material isian dan laju alir. Dua jenis modul digunakan dalam penelitian ini, yang diberi nama dengan module-1 dan module-2 untuk melihat pengaruh jenis modul

Practical measurement of silicon in low alloy steels by differential pulse stripping voltammetry

International Nuclear Information System (INIS)

Rahier, A.; Lunardi, S.; Triki, C.

2005-01-01

A sensitive differential pulse anodic stripping voltammetry has been adapted to allow the determination of Si in low-alloy steels using a hanging mercury drop electrode. The method has been qualified using certified ASTM standards and is now running in routine. The present report describes the experimental details, thereby allowing the reader to carry out the measurements precisely. (author)

Pressure drop in contraction flow

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz

This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find...

First Electrochemical Method of Nitrothal-Isopropyl Determination in Water Samples

Directory of Open Access Journals (Sweden)

Dariusz Guziejewski

2016-01-01

Full Text Available The aim of the research was the use of square wave adsorptive stripping voltammetry (SWAdSV in conjunction with a hanging mercury drop electrode (HMDE for the determination of nitrothal-isopropyl. It was found that optimal SW technique parameters were frequency, 200 Hz; amplitude, 50 mV; and step potential, 5 mV. Accumulation time and potential were studied to select the optimal conditions in adsorptive stripping voltammetry: 45 s at 0.0 V, respectively. The calibration curve (SWSV was linear in the nitrothal-isopropyl concentration range from 2.0 × 10−7 to 2.0 × 10−6 mol L−1 with detection limit of 3.46 × 10−8 mol L−1. The repeatability of the method was determined at a nitrothal-isopropyl concentration level equal to 6.0 × 10−7 mol L−1 and expressed as RSD = 5.5% (n=6. The proposed method was successfully validated by studying the recovery of nitrothal-isopropyl in spiked environmental samples.

Differentiating Mouse Embryonic Stem Cells into Embryoid Bodies by Hanging-Drop Cultures.

Science.gov (United States)

Behringer, Richard; Gertsenstein, Marina; Nagy, Kristina Vintersten; Nagy, Andras

2016-12-01

Embryonic stem (ES) cells can develop into many types of differentiated tissues if they are placed into a differentiating environment. This can occur in vivo when the ES cells are injected into or aggregated with an embryo, or in vitro if their culture conditions are modified to induce differentiation. There are an increasing number of differentiating culture conditions that can bias the differentiation of ES cells into desired cell types. Determining the mechanisms that control ES cell differentiation into therapeutically important cell types is a quickly growing area of research. Knowledge gained from these studies may eventually lead to the use of stem cells to repair specific damaged tissues. Many times ES cell differentiation proceeds through an intermediate stage called the embryoid body (EB). EBs are round structures composed of ES cells that have undergone some of the initial stages of differentiation. EBs can then be manipulated further to generate more specific cell types. This protocol describes a method to differentiate ES cells into EBs. It produces EBs of comparable size. This aspect is important because the differentiation processes taking place inside an EB are influenced by its size. © 2016 Cold Spring Harbor Laboratory Press.

Overexpression, purification, characterization and preliminary crystallographic study of phosphoglycolate phosphatase from Shigella flexneri 2a strain 301

International Nuclear Information System (INIS)

Liu, Heli; Zhou, Huina; Zhu, Deyu; Bi, Ruchang

2008-01-01

Recombinant phosphoglycolate phosphatase from S. flexneri was overexpressed, purified, characterized and crystallized using the hanging-drop vapour-diffusion method. SeMet-labelled protein was also prepared and was crystallized for phase determination using the MAD technique. Phosphoglycolate phosphatase has a salvage function in the metabolism of the 2-phosphoglycolate formed during bacterial DNA repair. In order to better understand its dimerization behaviour, the influence of metal ions on its activity and its catalytic mechanism at the molecular level, recombinant phosphoglycolate phosphatase from Shigella flexneri was overexpressed, purified, characterized and crystallized by the hanging-drop vapour-diffusion method at 291 K using polyethylene glycol 3500 as a precipitant and zinc acetate as an additive. The crystals belonged to space group R3, with unit-cell parameters a = 88.1, b = 88.1, c = 259.2 Å, corresponding to the presence of two molecules in the asymmetric unit. SeMet-labelled protein was also prepared and crystallized for use in phase determination. Initial structure determination using the multiwavelength anomalous dispersion (MAD) method clearly revealed that SfPGPase bears an α-helical cap domain that differs from that of a previously reported orthologue

Effect of rb-bFGF eye drops and hydroxyl indican eye drops on tear film stability and dry eye symptoms after age-related cataract surgery

Directory of Open Access Journals (Sweden)

Jing Chen

2017-10-01

Full Text Available AIM: To compare and analyze the effect of recombinant bovine basic fibroblast growth factor(bFGFeye drops and hydroxyl indican eye drops on the tear film stability and dry eye symptoms after age-related cataract surgery. METHODS: A total of 115 patients(115 affected eyeswith dry eyes after age-related cataract surgery were divided into the bFGF group, the hydroxyl indican group and the blank control group by the random number table method. The blank control group was only given routine anti-inflammatory treatment, and on the basis, the bFGF group and the hydroxyl indican group were treated with bFGF eye drops and hydroxyl indican eye drops respectively. The clinical efficacy, adverse reactions, changes in scores of dry eye symptoms, Schirmer test(SⅠt, tear film break-up time(BUTand corneal fluorescein staining(CFSscores at different time points were compared among the three groups. RESULTS: The total markedly effective rates in the bFGF group(89.5%was higher than that in the hydroxyl indican group(70.3%or the blank control group(47.5%(PPPCONCLUSION: The tear film is unstable in early stage after age-related cataract surgery, and there are dry eye symptoms. The intervention with bFGF eye drops and hydroxyl indican eye drops can effectively restore the tear film stability and significantly relieve dry eye symptoms, and the effect of bFGF eye drops is more significant.

Cathodic adsorptive stripping voltammetry of an anti-emetic agent Granisetron in pharmaceutical formulation and biological matrix

Directory of Open Access Journals (Sweden)

Rajeev Jain

2012-12-01

Full Text Available Granisetron showed one well-defined reduction peak at Hanging Mercury Drop Electrode (HMDE in the potential range from −1.3 to −1.5 V due to reduction of C=N bond. Solid-phase extraction technique was employed for extraction of Granisetron from spiked human plasma. Granisetron showed peak current enhancement of 4.45% at square-wave voltammetry and 5.33% at cyclic voltammetry as compared with the non stripping techniques. The proposed voltammetric method allowed quantification of Granisetron in pharmaceutical formulation over the target concentration range of 50–200 ng/mL with detection limit 13.63 ng/mL, whereas in human plasma 50–225 ng/mL with detection limit 11.75 ng/mL. Keywords: Granisetron, Human plasma, Solid-phase extraction, Pharmaceutical formulation, Voltammetry, Hanging mercury drop electrode

29 CFR Appendix B to Subpart I of... - General Testing Conditions and Additional Guidelines for Personal Fall Protection Systems (Non...

Science.gov (United States)

2010-07-01

..., to its hanging location (6 feet (1.83 m) below the anchorage). The test weight should fall without... belts, the complete belt should withstand a drop test consisting of a 250 pound (113.4 kg) weight.... One belt terminal should be attached to a rigid anchor and the other terminal should hang free. The...

Rehabilitation approaches to dysphagia that was developed for a patient who attempted to commit suicide by hanging: a case report.

Science.gov (United States)

Kii, Y; Mizuma, M

2014-04-01

We report our experience with a case of attempted suicidal hanging presenting with dysphagia, in which rehabilitation approaches resulted in improvement. A 36-year-old man was discovered collapsed at home. From the finding of a broken cord nearby, attempted suicide by hanging was suspected. He was transported to hospital after 40 minutes, and regained consciousness after emergency treatment. There were no noteworthy findings on brain magnetic resonance imaging, cervical spine computed tomography, or vocal cord examination. There were no noteworthy psychiatric disorders or cognitive abnormalities. On hospital day 10, he showed signs of dysphagia. Videofluoroscopic examination of swallowing revealed piriform sinuses residue and aspiration after ingestion of jelly in any posture. Rehabilitation approaches were started based on the diagnosis of dysphagia due to impaired transit through the piriform sinuses. The patient achieved independent oral intake by 40 days after the injury. In this case, dysphagia was considered attributable to compression of the vagus nerves running along the lateral aspects of the neck by the cord used in the hanging. If compression is brief, full functional recovery can be expected. Implementation of rehabilitation approaches is also important in this situation.

Toxicologic Laboratory Findings in Cases Reported with Hanging Death: a Two-Year Retrospective Study in Northeast Iran

Directory of Open Access Journals (Sweden)

Mohammad Ranjbar

2013-09-01

How to cite this article: Ranjbar R, Liaghat AR, Ranjbar A, Mohabbati H. Toxicologic Laboratory Findings in Cases Reported with Hanging Death: a Two-Year Retrospective Study in Northeast Iran. Asia Pac J Med Toxicol 2013;2:92-5.

Characterizing Ductile Damage and Failure: Application of the Direct Current Potential Drop Method to Uncracked Tensile Specimens

OpenAIRE

Brinnel, V.; Döbereiner, B.; Münstermann, Sebastian

2014-01-01

Modern high-strength steels exhibit excellent ductility properties but their application is hindered by traditional design rules. A characterization of necessary safety margins for the ductile failure of these steels is therefore required. Direct observation of ductile damage within tests is currently not possible, only limited measurements can be made with synchrotron or X-ray radiation facilities. The direct current potential drop (DCPD) method can determine ductile crack propagation with l...

Complex dynamic behaviors of oriented percolation-based financial time series and Hang Seng index

International Nuclear Information System (INIS)

Niu, Hongli; Wang, Jun

2013-01-01

Highlights: • We develop a financial time series model by two-dimensional oriented percolation system. • We investigate the statistical behaviors of returns for HSI and the financial model by chaos-exploring methods. • We forecast the phase point of reconstructed phase space by RBF neural network. -- Abstract: We develop a financial price model by the two-dimensional oriented (directed) percolation system. The oriented percolation model is a directed variant of ordinary (isotropic) percolation, and it is applied to describe the fluctuations of stock prices. In this work, we assume that the price fluctuations result from the participants’ investment attitudes toward the market, and we investigate the information spreading among the traders and the corresponding effect on the price fluctuations. We study the complex dynamic behaviors of return time series of the model by using the multiaspect chaos-exploring methods. And we also explore the corresponding behaviors of the actual market index (Hang Seng Index) for comparison. Further, we introduce the radial basic function (RBF) neural network to train and forecast the phase point of reconstructed phase space

Annual Occurrence of Meteorite-Dropping Fireballs

Science.gov (United States)

Konovalova, Natalia; Jopek, Tadeusz J.

2016-07-01

The event of Chelyabinsk meteorite has brought about change the earlier opinion about limits of the sizes of potentially dangerous asteroidal fragments that crossed the Earth's orbit and irrupted in the Earth's atmosphere making the brightest fireball. The observations of the fireballs by fireball networks allows to get the more precise data on atmospheric trajectories and coordinates of predicted landing place of the meteorite. For the reason to search the periods of fireball activity is built the annual distribution of the numbers of meteorites with the known fall dates and of the meteorite-dropping fireballs versus the solar longitude. The resulting profile of the annual activity of meteorites and meteorite-dropping fireballs shows several periods of increased activity in the course of the year. The analysis of the atmospheric trajectories and physical properties of sporadic meteorite-dropping fireballs observed in Tajikistan by instrumental methods in the summer‒autumn periods of increased fireballs activity has been made. As a result the structural strength, the bulk density and terminal mass of the studied fireballs that can survive in the Earth atmosphere and became meteorites was obtained. From the photographic IAU MDC_2003 meteor database and published sources based on the orbit proximity as determined by D-criterion of Southworth and Hawkins the fireballs that could be the members of group of meteorite-dropping fireballs, was found. Among the near Earth's objects (NEOs) the searching for parent bodies for meteorite-dropping fireballs was made and the evolution of orbits of these objects in the past on a long interval of time was investigated.

TRICHOMONAS URETHRITIS IN MALES

Science.gov (United States)

Le Duc, Ector

1955-01-01

Trichomonas urethritis in the male should be suspected in all chronic cases of urethritis. The diagnosis is easily established by the hanging-drop method of examining the urethral discharge, or the first-glass urine specimen. Curative treatment is readily accomplished by the use of urethral instillations of Carbarsone suspension using 1 capsule of Carbarsone per ounce of distilled water. PMID:13270111

Potential drop crack measurement systems for CANDU components

Energy Technology Data Exchange (ETDEWEB)

Sahney, R [Carleton Univ., Ottawa, ON (Canada)

1994-12-31

A project to develop an automated crack measurement system for CANDU pressure tube burst testing is currently underway. The system will utilize either Direct Current Potential Drop (DCPD) or Alternating Current Potential Drop (ACPD) techniques for crack measurement. The preliminary stage of the project involves testing and comparison of both ACPD and DCPD methods on a Zr - 2.5% Nb alloy plate with saw cuts (used to simulate cracks). Preliminary results show that both ACPD and DCPD techniques are capable of detecting cracks; further testing is in progress to determine the ability of each of the two systems to make accurate crack depth measurements. This paper will describe the two potential drop techniques and will present test results from the experimental program. (author). 10 refs., 7 figs.

Efficacy of atropine and anisodamine eye drops for adolescent pseudomyopia

OpenAIRE

Hui-Jie Wang

2017-01-01

AIM:To investigate the effect and local influence of atropine and anisodamine eye drops on adolescent pseudomyopia. METHODS:Totally 110 cases of juvenile pseudomyopia were randomly divided into two groups, the control group was given 10g/L atropine sulfate eye gel, and the observation group was treated with 5g/L raceanisodamine eye drops. The efficacy of two methods, the changes of axial length and intraocular pressure before and after treatment, and the incidence of adverse reactions were co...

Vibration-Induced Climbing of Drops

Science.gov (United States)

Brunet, P.; Eggers, J.; Deegan, R. D.

2007-10-01

We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

Comparação entre o método da gota pendente e o método da gota girante para medida da tensão interfacial entre polímeros Comparison between the pendant drop and spinning drop method to measure interfacial tension between polymers

Directory of Open Access Journals (Sweden)

Nicole R. Demarquette

1997-09-01

Full Text Available Dois instrumentos, um deles baseado no princípio da gota pendente e o outro baseado no método da gota girante, para medir a tensão interfacial entre polímeros, são apresentados e comparados aqui. Com ambos instrumentos foi possível visualizar a gota de polímero "on line". Os instrumentos mostraram-se complementares quanto às suas áreas de aplicação. O método da gota pendente deve ser usado quando as quantidades de polímero são limitadas ou quando o polímero mais denso é opaco. O método da gota girante deve ser usado quando a degradação térmica pode ser um problema ou quando o polímero menos denso é opaco.In this paper two apparatuses, one based on the principle of the pendant drop method and one based on the principle of the spinning drop are presented and compared. With both apparatuses it was possible to view the drop in real time and calculate the interfacial tension on-line. The two equipments were shown to be complementary in their use. The pendant drop method should be used when there are limited quantities of polymer and/or the denser polymer is opaque. The spinning drop method should be used when thermal degradation could be a problem and/or when the lighter polymer is opaque.

Study for identification of control rod drops in PWR reactors at any burnup step

International Nuclear Information System (INIS)

Souza, Thiago J.; Martinez, Aquilino S.; Medeiros, Jose A.C.C.; Goncalves, Alessandro C.

2013-01-01

The control rod drop event in PWR reactors induces an unsafe operating condition. Therefore, in a scenario of a control rod drop is important to quickly identify the rod to minimize undesirable effects. The objective of this work is to develop an on-line method for identification of control rod drop in PWR reactors. The method consists on the construction of a tool that is based on the ex-core detector responses. Therefore, it is proposed to recognize patterns in the neutron ex-core detectors responses and thus to identify on-line a control rod drop in the core during the reactor operation. The results of the study, as well as the behavior of the detector responses, demonstrated the feasibility of this method. (author)

Study for identification of control rod drops in PWR reactors at any burnup step

Energy Technology Data Exchange (ETDEWEB)

Souza, Thiago J.; Martinez, Aquilino S.; Medeiros, Jose A.C.C.; Goncalves, Alessandro C., E-mail: tsouza@nuclear.ufrj.br, E-mail: aquilino@lmp.ufrj.br, E-mail: canedo@lmp.ufrj.br, E-mail: alessandro@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Palma, Daniel A.P., E-mail: dapalma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

2013-07-01

The control rod drop event in PWR reactors induces an unsafe operating condition. Therefore, in a scenario of a control rod drop is important to quickly identify the rod to minimize undesirable effects. The objective of this work is to develop an on-line method for identification of control rod drop in PWR reactors. The method consists on the construction of a tool that is based on the ex-core detector responses. Therefore, it is proposed to recognize patterns in the neutron ex-core detectors responses and thus to identify on-line a control rod drop in the core during the reactor operation. The results of the study, as well as the behavior of the detector responses, demonstrated the feasibility of this method. (author)

TREATMENT OF METHANOLIC WASTEWATER BY ANAEROBIC DOWN-FLOW HANGING SPONGE (ANDHS) REACTOR AND UASB REACTOR

Science.gov (United States)

Sumino, Haruhiko; Wada, Keiji; Syutsubo, Kazuaki; Yamaguchi, Takashi; Harada, Hideki; Ohashi, Akiyoshi

Anaerobic down-flow hanging sponge (AnDHS) reactor and UASB reactor were operated at 30℃ for over 400 days in order to investigate the process performance and the sludge characteristics of treating methanolic wastewater (2 gCOD/L). The settings OLR of AnDHS reactor and of UASB reactor were 5.0 -10.0 kgCOD/m3/d and 5.0 kgCOD/m3/d. The average of the COD removal demonstrated by both reactors were over 90% throughout the experiment. From the results of methane producing activities and the PCR-DGGE method, most methanol was directly converted to methane in both reactors. The conversion was carried out by different methanogens: one closely related to Methanomethylovorans hollandica in the AnDHS retainted sludge and the other closely related to Methanosarcinaceae and Metanosarciales in the UASB retainted sludge.

Drop Tower Physics

Science.gov (United States)

Dittrich, William A.

2014-01-01

The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

A two-phase pressure drop calculation code based on a new method with a correlation factor obtained from an assessment of existing correlations

International Nuclear Information System (INIS)

Chun, Moon Hyun; Oh, Jae Guen

1989-01-01

Ten methods of the total two-phase pressure drop prediction based on five existing models and correlations have been examined for their accuracy and applicability to pressurized water reactor conditions. These methods were tested against 209 experimental data of local and bulk boiling conditions: Each correlations were evaluated for different ranges of pressure, mass velocity and quality, and best performing models were identified for each data subsets. A computer code entitled 'K-TWOPD' has been developed to calculate the total two phase pressure drop using the best performing existing correlations for a specific property range and a correction factor to compensate for the predicted error of the selected correlations. Assessment of this code shows that the present method fits all the available data within ±11% at a 95% confidence level compared with ± 25% for the existing correlations. (Author)

Searching for new features of intravitality of hanging based on macro- and microscopic evaluation of the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone.

Science.gov (United States)

Szleszkowski, Ł; Hałoń, A; Thannhäuser, A; Jurek, T

2015-01-01

Assessment of the usefulness of intravital lesions in the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone in medico-legal evaluation of death by hanging. The study material was obtained from the bodies of 35 people who died by hanging. The control group comprised specimens collected from 30 people who died of non-traumatic causes. The structures under study were examined macro- and microscopically. The basic change which could be recognized as a marker of intravitality of hanging was the presence of a macroscopically extensive blotchy area of abundant ecchymosis in the proximal muscle attachment, similar to that found in the distal attachment, and the presence of abundant diffuse intraosseous ecchymoses in the mastoid process. None of the cases revealed any ecchymoses in the proximal attachment of the muscle that would be similar to those present in the distal attachment. Discolourations within the mastoid processes, macroscopically suggestive of extensive intraosseous effusions arising from the mechanism of stretching, were not confirmed by microscopic evaluation and occurred at the same frequency as in the control group. Limitations of the study were related to the method which involved sample collection by means of bone chisels, decalcification and preparation of specimens, which had an effect, for example, on the measurable evaluation of the degree of congestion. The study has failed to provide convincing and unambiguous data on the usefulness of examining mastoid processes and proximal attachments of the sternocleidomastoid muscles during autopsy to determine the presence of intravitality features of hanging. A description of research methodology and its associated difficulties, e.g. with the interpretation of results, can also be useful for the planning of similar studies by other researchers.

Drop "impact" on an airfoil surface.

Science.gov (United States)

Wu, Zhenlong

2018-05-17

Drop impact on an airfoil surface takes place in drop-laden two-phase flow conditions such as rain and icing, which are encountered by wind turbines or airplanes. This phenomenon is characterized by complex nonlinear interactions that manifest rich flow physics and pose unique modeling challenges. In this article, the state of the art of the research about drop impact on airfoil surface in the natural drop-laden two-phase flow environment is presented. The potential flow physics, hazards, characteristic parameters, droplet trajectory calculation, drop impact dynamics and effects are discussed. The most key points in establishing the governing equations for a drop-laden flow lie in the modeling of raindrop splash and water film. The various factors affecting the drop impact dynamics and the effects of drop impact on airfoil aerodynamic performance are summarized. Finally, the principle challenges and future research directions in the field as well as some promising measures to deal with the adverse effects of drop-laden flows on airfoil performance are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

Dropped fuel damage prediction techniques and the DROPFU code

International Nuclear Information System (INIS)

Mottershead, K.J.; Beardsmore, D.W.; Money, G.

1995-01-01

During refuelling, and fuel handling, at UK Advanced Gas Cooled Reactor (AGR) stations it is recognised that the accidental dropping of fuel is a possibility. This can result in dropping individual fuel elements, a complete fuel stringer, or a whole assembly. The techniques for assessing potential damage have been developed over a number of years. This paper describes how damage prediction techniques have subsequently evolved to meet changing needs. These have been due to later fuel designs and the need to consider drops in facilities outside the reactor. The paper begins by briefly describing AGR fuel and possible dropped fuel scenarios. This is followed by a brief summary of the damage mechanisms and the assessment procedure as it was first developed. The paper then describes the additional test work carried out, followed by the detailed numerical modelling. Finally, the paper describes the extensions to the practical assessment methods. (author)

Crystallization and preliminary X-ray diffraction analysis of rat protein tyrosine phosphatase η

Energy Technology Data Exchange (ETDEWEB)

Matozo, Huita C.; Nascimento, Alessandro S.; Santos, Maria A. M. [Instituto de Física de São Carlos, Departamento de Física e Informática, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, CEP 13566-590 São Carlos, SP (Brazil); Iuliano, Rodolfo [Dipartimento di Medicina Sperimentale e Clinica, Facoltà di Medicina e Chirurgia, Università di Catanzaro, 88100 Catanzaro (Italy); Fusco, Alfredo [Dipartimento di Biologia e Patologia Cellulare e Molecolare, c/o Instituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facolta di Medicina e Chirurgia, Università degli Studi di Napoli ‘Federico II’, Via Pansini 5, 80131 Naples (Italy); NOGEC (Naples Oncogenomocs Center)-CEINGE, Biotecnologie Avanzate, Via Comunale Margherita 482, 80145 Naples (Italy); Polikarpov, Igor, E-mail: ipolikarpov@if.sc.usp.br [Instituto de Física de São Carlos, Departamento de Física e Informática, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, CEP 13566-590 São Carlos, SP (Brazil); Laboratório Nacional de Luz Síncrotron, Campinas, SP (Brazil)

2006-09-01

In this study, the catalytic domain of rat protein tyrosine phosphatase η was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. The rat protein tyrosine phosphatase η (rPTPη) is a cysteine-dependent phosphatase which hydrolyzes phosphoester bonds in proteins and other molecules. rPTPη and its human homologue DEP-1 are involved in neoplastic transformations. Thus, expression of the protein is reduced in all oncogene-transformed thyroid cell lines and is absent in highly malignant thyroid cells. Moreover, consistent with the suggested tumour suppression role of PTPη, inhibition of the tumorigenic process occurs after its exogenous reconstitution, suggesting that PTPη might be important for gene therapy of cancers. In this study, the catalytic domain of rPTPη was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. Diffraction data were collected to 1.87 Å resolution. The crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.46, b = 63.07, c = 111.64 Å, and contains one molecule per asymmetric unit.

Crystallization and preliminary X-ray diffraction analysis of prephenate dehydratase from Mycobacterium tuberculosis H37Rv

Energy Technology Data Exchange (ETDEWEB)

Vivan, Ana Luiza [Programa de Pós Graduação em Genética e Biologia Molecular, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Centro de Pesquisa em Biologia Molecular e Funcional, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul-PUCRS, Av. Ipiranga, 6681 Prédio 92A-TECNOPUC-Partenon, CEP 90619-900, Porto Alegre, RS (Brazil); Dias, Márcio Vinícius Bertacini [Programa de Pós Graduação em Biofísica Molecular, Departamento de Física, IBILCE/UNESP, São José do Rio Preto, SP, 15054-000 (Brazil); Schneider, Cristopher Z. [Programa de Pós Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Centro de Pesquisa em Biologia Molecular e Funcional, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul-PUCRS, Av. Ipiranga, 6681 Prédio 92A-TECNOPUC-Partenon, CEP 90619-900, Porto Alegre, RS (Brazil); Azevedo, Walter Filgueira Jr de; Basso, Luiz Augusto, E-mail: luiz.basso@pucrs.br; Santos, Diógenes Santiago, E-mail: luiz.basso@pucrs.br [Centro de Pesquisa em Biologia Molecular e Funcional, Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul-PUCRS, Av. Ipiranga, 6681 Prédio 92A-TECNOPUC-Partenon, CEP 90619-900, Porto Alegre, RS (Brazil); Programa de Pós Graduação em Genética e Biologia Molecular, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

2006-04-01

The M. tuberculosis prephenate dehydratase was cloned, expressed, purified, crystallized by the hanging-drop vapour-diffusion method, and a complete data set collected to 3.2 Å resolution using synchrotron radiation. These results should pave the way for the three-dimensional structure determination of the enzyme and provide a framework on which to base the rational design of chemotherapeutic agents to treat tuberculosis. Tuberculosis remains the leading cause of mortality arising from a bacterial pathogen (Mycobacterium tuberculosis). There is an urgent need for the development of new antimycobacterial agents. The aromatic amino-acid pathway is essential for the survival of this pathogen and represents a target for structure-based drug design. Accordingly, the M. tuberculosis prephenate dehydratase has been cloned, expressed, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 400 as a precipitant. The crystal belongs to the orthorhombic space group I222 or I2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 98.26, b = 133.22, c = 225.01 Å, and contains four molecules in the asymmetric unit. A complete data set was collected to 3.2 Å resolution using a synchrotron-radiation source.

Purification and crystallization of Kokobera virus helicase

International Nuclear Information System (INIS)

De Colibus, Luigi; Speroni, Silvia; Coutard, Bruno; Forrester, Naomi L.; Gould, Ernest; Canard, Bruno; Mattevi, Andrea

2007-01-01

Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method and exhibit a diffraction limit of 2.3 Å. Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. The flavivirus genus is characterized by a positive-sense single-stranded RNA genome. The unique open reading frame of the viral RNA is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the NS3 gene that encodes a C-terminal helicase domain consisting of 431 amino acids. Helicase inhibitors are potential antiviral drugs as the helicase is essential to viral replication. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method. The crystals belong to space group P3 1 21 (or P3 2 21), with unit-cell parameters a = 88.6, c = 138.6 Å, and exhibit a diffraction limit of 2.3 Å

Crystallization and X-ray analysis of the salmon-egg lectin SEL24K

Energy Technology Data Exchange (ETDEWEB)

Murata, Kenji [Department of Animal Science, University of California, Davis 95616 (United States); Fisher, Andrew J. [Department of Chemistry, University of California, Davis 95616 (United States); Hedrick, Jerry L., E-mail: jlhedrick@ucdavis.edu [Department of Animal Science, University of California, Davis 95616 (United States)

2007-05-01

The 24 kDa egg lectin of Chinook salmon (Oncorhynchus tshawytscha) was purified by affinity chromatography from salmon eggs and crystallized by the hanging-drop vapor-diffusion method using 15/4 EO/OH (pentaerythritol ethoxylate) as a precipitant. The 24 kDa egg lectin of Chinook salmon (Oncorhynchus tshawytscha) is released from the egg during the cortical reaction. The lectin functions in blocking polyspermy during the fertilization process. The egg lectin was purified by affinity chromatography from salmon eggs and crystallized by the hanging-drop vapor-diffusion method using 15/4 EO/OH (pentaerythritol ethoxylate) as a precipitant. The crystal diffracted synchrotron-radiation X-rays to 1.63 Å resolution. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 93.0, b = 73.6, c = 113.6 Å, α = 90, β = 92.82, γ = 90°. The crystal is likely to contain eight molecules in the asymmetric unit (V{sub M} = 2.3 Å{sup 3} Da{sup −1}), corresponding to a solvent content of 45.5%. A self-rotation function suggests an arrangement with 222 point symmetry within the asymmetric unit.

Transplantation of co-aggregates of Sertoli cells and islet cells into liver without immunosuppression.

Science.gov (United States)

Takemoto, Naohiro; Liu, Xibao; Takii, Kento; Teramura, Yuji; Iwata, Hiroo

2014-02-15

Transplantation of islets of Langerhans (islets) was used to treat insulin-dependent diabetes mellitus. However, islet grafts must be maintained by administration of immunosuppressive drugs, which can lead to complications in the long term. An approach that avoids immunosuppressive drug use is desirable. Co-aggregates of Sertoli cells and islet cells from BALB/c mice that were prepared by the hanging drop method were transplanted into C57BL/6 mouse liver through the portal vein as in human clinical islet transplantation. The core part of the aggregates contained mainly Sertoli cells, and these cells were surrounded by islet cells. The co-aggregates retained the functions of both Sertoli and islet cells. When 800 co-aggregates were transplanted into seven C57BL/6 mice via the portal vein, six of seven recipient mice demonstrated quasi-normoglycemia for more than 100 days. The hanging drop method is suitable for preparing aggregates of Sertoli and islet cells for transplantation. Notably, transplantation of these allogeneic co-aggregates into mice with chemically induced diabetes via the portal vein resulted in long-term graft survival without systemic immunosuppression.

Crystallization and preliminary X-ray diffraction analysis of rat protein tyrosine phosphatase η

International Nuclear Information System (INIS)

Matozo, Huita C.; Nascimento, Alessandro S.; Santos, Maria A. M.; Iuliano, Rodolfo; Fusco, Alfredo; Polikarpov, Igor

2006-01-01

In this study, the catalytic domain of rat protein tyrosine phosphatase η was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. The rat protein tyrosine phosphatase η (rPTPη) is a cysteine-dependent phosphatase which hydrolyzes phosphoester bonds in proteins and other molecules. rPTPη and its human homologue DEP-1 are involved in neoplastic transformations. Thus, expression of the protein is reduced in all oncogene-transformed thyroid cell lines and is absent in highly malignant thyroid cells. Moreover, consistent with the suggested tumour suppression role of PTPη, inhibition of the tumorigenic process occurs after its exogenous reconstitution, suggesting that PTPη might be important for gene therapy of cancers. In this study, the catalytic domain of rPTPη was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. Diffraction data were collected to 1.87 Å resolution. The crystal belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 46.46, b = 63.07, c = 111.64 Å, and contains one molecule per asymmetric unit

Crystallization and preliminary crystallographic analysis of orotidine 5′-monophosphate decarboxylase from the human malaria parasite Plasmodium falciparum

International Nuclear Information System (INIS)

Krungkrai, Sudaratana R.; Tokuoka, Keiji; Kusakari, Yukiko; Inoue, Tsuyoshi; Adachi, Hiroaki; Matsumura, Hiroyoshi; Takano, Kazufumi; Murakami, Satoshi; Mori, Yusuke; Kai, Yasushi; Krungkrai, Jerapan; Horii, Toshihiro

2006-01-01

Orotidine 5′-monophosphate decarboxylase of human malaria parasite P. falciparum was crystallized by the seeding method in a hanging drop using PEG 3000 as a precipitant. A complete set of diffraction data from a native crystal was collected to 2.7 Å resolution at 100 K using synchrotron radiation. Orotidine 5′-monophosphate (OMP) decarboxylase (OMPDC; EC 4.1.1.23) catalyzes the final step in the de novo synthesis of uridine 5′-monophosphate (UMP) and defects in the enzyme are lethal in the malaria parasite Plasmodium falciparum. Active recombinant P. falciparum OMPDC (PfOMPDC) was crystallized by the seeding method in a hanging drop using PEG 3000 as a precipitant. A complete set of diffraction data from a native crystal was collected to 2.7 Å resolution at 100 K using synchrotron radiation at the Swiss Light Source. The crystal exhibits trigonal symmetry (space group R3), with hexagonal unit-cell parameters a = b = 201.81, c = 44.03 Å. With a dimer in the asymmetric unit, the solvent content is 46% (V M = 2.3 Å 3 Da −1 )

Purification and crystallization of Kokobera virus helicase

Energy Technology Data Exchange (ETDEWEB)

De Colibus, Luigi; Speroni, Silvia [Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia (Italy); Coutard, Bruno [Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS et Université Aix-Marseille I et II, ESIL, Campus de Luminy, 13288 Marseille CEDEX 09 (France); Forrester, Naomi L.; Gould, Ernest [Centre for Ecology and Hydrology (formerly Institute of Virology), Mansfield Road, Oxford OX1 3SR (United Kingdom); Canard, Bruno [Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS et Université Aix-Marseille I et II, ESIL, Campus de Luminy, 13288 Marseille CEDEX 09 (France); Mattevi, Andrea, E-mail: mattevi@ipvgen.unipv.it [Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia (Italy)

2007-03-01

Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method and exhibit a diffraction limit of 2.3 Å. Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. The flavivirus genus is characterized by a positive-sense single-stranded RNA genome. The unique open reading frame of the viral RNA is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the NS3 gene that encodes a C-terminal helicase domain consisting of 431 amino acids. Helicase inhibitors are potential antiviral drugs as the helicase is essential to viral replication. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method. The crystals belong to space group P3{sub 1}21 (or P3{sub 2}21), with unit-cell parameters a = 88.6, c = 138.6 Å, and exhibit a diffraction limit of 2.3 Å.

Crystallization and preliminary X-ray diffraction analysis of prephenate dehydratase from Mycobacterium tuberculosis H37Rv

International Nuclear Information System (INIS)

Vivan, Ana Luiza; Dias, Márcio Vinícius Bertacini; Schneider, Cristopher Z.; Azevedo, Walter Filgueira Jr de; Basso, Luiz Augusto; Santos, Diógenes Santiago

2006-01-01

The M. tuberculosis prephenate dehydratase was cloned, expressed, purified, crystallized by the hanging-drop vapour-diffusion method, and a complete data set collected to 3.2 Å resolution using synchrotron radiation. These results should pave the way for the three-dimensional structure determination of the enzyme and provide a framework on which to base the rational design of chemotherapeutic agents to treat tuberculosis. Tuberculosis remains the leading cause of mortality arising from a bacterial pathogen (Mycobacterium tuberculosis). There is an urgent need for the development of new antimycobacterial agents. The aromatic amino-acid pathway is essential for the survival of this pathogen and represents a target for structure-based drug design. Accordingly, the M. tuberculosis prephenate dehydratase has been cloned, expressed, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 400 as a precipitant. The crystal belongs to the orthorhombic space group I222 or I2 1 2 1 2 1 , with unit-cell parameters a = 98.26, b = 133.22, c = 225.01 Å, and contains four molecules in the asymmetric unit. A complete data set was collected to 3.2 Å resolution using a synchrotron-radiation source

Cloning, overexpression, purification, crystallization and preliminary X-ray analysis of 3-ketosteroid Δ4-(5α)-dehydrogenase from Rhodococcus jostii RHA1

International Nuclear Information System (INIS)

Oosterwijk, Niels van; Knol, Jan; Dijkhuizen, Lubbert; Geize, Robert van der; Dijkstra, Bauke W.

2011-01-01

The gene for 3-ketosteroid Δ 4 -(5α)-dehydrogenase from R. jostii RHA1 was cloned and overexpressed in E. coli and the protein product was purified and crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group C222 1 and diffraction data were collected to a resolution of 1.6 Å. 3-Ketosteroid dehydrogenases are flavoproteins which play key roles in steroid ring degradation. The enzymes are abundantly present in actinobacteria, including the catabolic powerhouse Rhodococcus jostii and the pathogenic species R. equi and Mycobacterium tuberculosis. The gene for 3-ketosteroid Δ 4 -(5α)-dehydrogenase [Δ 4 -(5α)-KSTD] from R. jostii RHA1 was cloned and overexpressed in Escherichia coli. His-tagged Δ 4 -(5α)-KSTD enzyme was purified by Ni 2+ –NTA affinity chromatography, anion-exchange chromatography and size-exclusion chromatography and was crystallized using the hanging-drop vapour-diffusion method. Seeding greatly improved the number of crystals obtained. The crystals belonged to space group C222 1 , with unit-cell parameters a = 99.2, b = 114.3, c = 110.2 Å. Data were collected to a resolution of 1.6 Å

Miniaturized and green method for determination of chemical oxygen demand using UV-induced oxidation with hydrogen peroxide and single drop microextraction

International Nuclear Information System (INIS)

Akhoundzadeh, Jeyran; Chamsaz, Mahmoud; Costas, Marta; Lavilla, Isela; Bendicho, Carlos

2013-01-01

We report on a green method for the determination of low levels of chemical oxygen demand. It is based on the combination of (a) UV-induced oxidation with hydrogen peroxide, (b) headspace single-drop microextraction with in-drop precipitation, and (c) micro-turbidimetry. The generation of CO 2 after photolytic oxidation followed by its sequestration onto a microdrop of barium hydroxide gives rise to a precipitate of barium carbonate which is quantified by turbidimetry. UV-light induced oxidation was studied in the absence and presence of H 2 O 2 , ultrasound, and ferrous ion. Determinations of chemical oxygen demand were performed using potassium hydrogen phthalate as a model compound. The optimized method gives a calibration curve that is linear between 3.4 and 20 mg L −1 oxygen. The detection limit was 1.2 mg L −1 of oxygen, and the repeatability (as relative standard deviation) was around 5 %. The method was successfully applied to the determination of chemical oxygen demand in different natural waters and a synthetic wastewater. (author)

Ultrasonic characterization of single drops of liquids

Energy Technology Data Exchange (ETDEWEB)

Sinha, Dipen N. (Los Alamos, NM)

1998-01-01

Ultrasonic characterization of single drops of liquids. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities.

Ultrasonic characterization of single drops of liquids

Energy Technology Data Exchange (ETDEWEB)

Sinha, D.N.

1998-04-14

Ultrasonic characterization of single drops of liquids is disclosed. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities. 5 figs.

Network-based H.264/AVC whole frame loss visibility model and frame dropping methods.

Science.gov (United States)

Chang, Yueh-Lun; Lin, Ting-Lan; Cosman, Pamela C

2012-08-01

We examine the visual effect of whole frame loss by different decoders. Whole frame losses are introduced in H.264/AVC compressed videos which are then decoded by two different decoders with different common concealment effects: frame copy and frame interpolation. The videos are seen by human observers who respond to each glitch they spot. We found that about 39% of whole frame losses of B frames are not observed by any of the subjects, and over 58% of the B frame losses are observed by 20% or fewer of the subjects. Using simple predictive features which can be calculated inside a network node with no access to the original video and no pixel level reconstruction of the frame, we developed models which can predict the visibility of whole B frame losses. The models are then used in a router to predict the visual impact of a frame loss and perform intelligent frame dropping to relieve network congestion. Dropping frames based on their visual scores proves superior to random dropping of B frames.

Vortex flow in acoustically levitated drops

Energy Technology Data Exchange (ETDEWEB)

Yan, Z.L.; Xie, W.J. [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China); Wei, B., E-mail: bbwei@nwpu.edu.cn [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

2011-08-29

The internal flow of acoustically levitated water drops is investigated experimentally. This study reveals a kind of vortex flow which rotates in the meridional plane of the levitated drop. The magnitude of fluid velocity is nearly vanishing at the drop center, whereas it increases toward the free surface of a levitated drop until the maximum value of about 80 mm/s. A transition of streamline shapes from concentric circles to ellipses takes place at the distance of about 1.2 mm from the drop center. The fluid velocity distribution is plotted as a function of polar angle for seven characteristic streamlines. -- Highlights: → We experimentally observe the internal flow of acoustically levitated water drops. → We present a fascinating structure of vortex flow inside the levitated water drop. → This vortex flow rotates around the drop center in the meridional plane. → Velocity distribution information of this vortex flow is quantitatively analyzed.

Vortex flow in acoustically levitated drops

International Nuclear Information System (INIS)

Yan, Z.L.; Xie, W.J.; Wei, B.

2011-01-01

The internal flow of acoustically levitated water drops is investigated experimentally. This study reveals a kind of vortex flow which rotates in the meridional plane of the levitated drop. The magnitude of fluid velocity is nearly vanishing at the drop center, whereas it increases toward the free surface of a levitated drop until the maximum value of about 80 mm/s. A transition of streamline shapes from concentric circles to ellipses takes place at the distance of about 1.2 mm from the drop center. The fluid velocity distribution is plotted as a function of polar angle for seven characteristic streamlines. -- Highlights: → We experimentally observe the internal flow of acoustically levitated water drops. → We present a fascinating structure of vortex flow inside the levitated water drop. → This vortex flow rotates around the drop center in the meridional plane. → Velocity distribution information of this vortex flow is quantitatively analyzed.

Density of Liquid Ni-Mo Alloys Measured by a Modified Sessile Drop Method

Institute of Scientific and Technical Information of China (English)

Liang FANG; Zushu LI; ZaiNan TAO; Feng XIAO

2004-01-01

The density of liquid binary Ni-Mo alloys with molybdenum concentration from 0 to 20% (mass fraction) was measured by a modified sessile drop method. It has been found that the density of the liquid Ni-Mo alloys decreases with increasing temperature, but increases with the increase of molybdenum concentration in the alloys. The molar volume of liquid Ni-Mo binary alloys increases with the increase of temperature and molybdenum concentration. The partial molar volume of molybdenum in Ni-Mo binary alloy has been approximately calculated as [13.18 - 2.65 × 10-3T + (-47.94 + 3.10 × 10-2T) × 10-2XMo] × 10-6m3·mol-1. The molar volume of Ni-Mo alloy determined in the present work shows a negative deviation from the ideal linear mixing molar volume.

A new method to predict the epidemiology of fungal keratitis by monitoring the sales distribution of antifungal eye drops in Brazil.

Directory of Open Access Journals (Sweden)

Marlon Moraes Ibrahim

Full Text Available PURPOSE: Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. METHODS: Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. RESULTS: A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01. A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01. CONCLUSIONS: Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier, when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.

A New Method to Predict the Epidemiology of Fungal Keratitis by Monitoring the Sales Distribution of Antifungal Eye Drops in Brazil

Science.gov (United States)

Ibrahim, Marlon Moraes; de Angelis, Rafael; Lima, Acacio Souza; Viana de Carvalho, Glauco Dreyer; Ibrahim, Fuad Moraes; Malki, Leonardo Tannus; de Paula Bichuete, Marina; de Paula Martins, Wellington; Rocha, Eduardo Melani

2012-01-01

Purpose Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil. Methods Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008. Results A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01). Conclusions Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects. PMID:22457787

Evaluating Eye Drop Instillation Technique and Its Determinants in Glaucoma Patients

Directory of Open Access Journals (Sweden)

Xinbo Gao

2018-01-01

Full Text Available Aim. To evaluate eye drop instillation technique and to explore its determinants in glaucoma patients. Methods. One hundred and thirteen patients diagnosed with glaucoma and self-administering topical antiglaucoma eye drops for at least 1 month were evaluated. All patients instilled artificial tear solution in one eye as they would do at home. The whole process was evaluated by two study staff. A comprehensive score system associated with eye drop instillation techniques was used to quantify the instillation technique and explore its determinants such as demographic and clinical characteristics. Results. Half of the patients (48.67% finished the administration of eye drop on first attempt.1.7 eye drops were squeezed out on average. 43 patients (37.17% got contact with ocular surface or adnexa. Only 19.7% patients had eye drop instillation techniques being defined as well. 11 patients (9.7% had prior instruction regarding using eye drops, while only 4 patients knew to occlude the tear duct by pressing the dacryocyst area. Older age and worse visual acuity were found to be independent risk factors for worse instillation technique. Conclusions. Eye drop instillation technique in glaucoma patients deserves great attention from eye care practitioners during their lifelong follow-up, especially those aged older and have worse visual acuity.

From Green Aerogels to Porous Graphite by Emulsion Gelation of Acrylonitrile

Science.gov (United States)

2012-01-01

interparticle covalent bridging in the mechanical properties of aerogels,30 we have opted for a bottom-up process, whereas PAN aerogels are...series that employs the hanging pendant drop method, and data were analyzed using the Young−Laplace equation through the instrument software. Elemental...that the layer of the surfactant prevents intimate contact and efficient covalent bridging between the skeletal nanoparticles. Overall, our ability to

Optimization of a single-drop microextraction method for multielemental determination by electrothermal vaporization inductively coupled plasma mass spectrometry following in situ vapor generation

International Nuclear Information System (INIS)

Gil, Sandra; Loos-Vollebregt, Margaretha T.C. de; Bendicho, Carlos

2009-01-01

A headspace single-drop microextraction (HS-SDME) method has been developed in combination with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the simultaneous determination of As, Sb, Bi, Pb, Sn and Hg in aqueous solutions. Vapor generation is carried out in a 40 mL volume closed-vial containing a solution with the target analytes in hydrochloric acid and potassium ferricyanide medium. Hydrides (As, Sb, Bi, Pb, Sn) and Hg vapor are trapped onto an aqueous single drop (3 μL volume) containing Pd(II), followed by the subsequent injection in the ETV. Experimental variables such as medium composition, sodium tetrahydroborate (III) volume and concentration, stirring rate, extraction time, sample volume, ascorbic acid concentration and palladium amount in the drop were fully optimized. The limits of detection (LOD) (3σ criterion) of the proposed method for As, Sb, Bi, Pb, Sn and Hg were 0.2, 0.04, 0.01, 0.07, 0.09 and 0.8 μg/L, respectively. Enrichment factors of 9, 85, 138, 130, 37 and 72 for As, Sb, Bi, Pb, Sn and Hg, respectively, were achieved in 210 s. The relative standard deviations (N = 5) ranged from 4 to 8%. The proposed HS-SDME-ETV-ICP-MS method has been applied for the determination of As, Sb, Bi, Pb, Sn and Hg in NWRI TM-28.3 certified reference material.

Origin and dynamics of vortex rings in drop splashing.

Science.gov (United States)

Lee, Ji San; Park, Su Ji; Lee, Jun Ho; Weon, Byung Mook; Fezzaa, Kamel; Je, Jung Ho

2015-09-04

A vortex is a flow phenomenon that is very commonly observed in nature. More than a century, a vortex ring that forms during drop splashing has caught the attention of many scientists due to its importance in understanding fluid mixing and mass transport processes. However, the origin of the vortices and their dynamics remain unclear, mostly due to the lack of appropriate visualization methods. Here, with ultrafast X-ray phase-contrast imaging, we show that the formation of vortex rings originates from the energy transfer by capillary waves generated at the moment of the drop impact. Interestingly, we find a row of vortex rings along the drop wall, as demonstrated by a phase diagram established here, with different power-law dependencies of the angular velocities on the Reynolds number. These results provide important insight that allows understanding and modelling any type of vortex rings in nature, beyond just vortex rings during drop splashing.

Crystallization and preliminary X-ray analysis of a decameric form of cytosolic thioredoxin peroxidase 1 (Tsa1), C47S mutant, from Saccharomyces cerevisiae

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Marcos Antonio de, E-mail: scaff@lnls.br; Genu, Victor; Discola, Karen Fulan; Alves, Simone Vidigal; Netto, Luis Eduardo Soares [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo-SP (Brazil); Guimarães, Beatriz Gomes, E-mail: scaff@lnls.br [Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, 13084-971 Campinas-SP (Brazil); Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo-SP (Brazil)

2007-08-01

A recombinant mutant (C47S) of cytosolic thioredoxin peroxidase 1 from S. cerevisiae was expressed, purified and crystallized by the hanging-drop vapour-diffusion method from protein previously treated with 1,4-dithiothreitol. The crystals belong to the monoclinic space group C2 and diffraction data were collected to 2.8 Å resolution using a synchrotron-radiation source. Saccharomyces cerevisiae cytosolic thioredoxin peroxidase 1 (cTPxI or Tsa1) is a bifunctional enzyme with protective roles in cellular defence against oxidative and thermal stress that exhibits both peroxidase and chaperone activities. Protein overoxidation and/or high temperatures induce great changes in its quaternary structure and lead to its assembly into large complexes that possess chaperone activity. A recombinant mutant of Tsa1 from S. cerevisiae, with Cys47 substituted by serine, was overexpressed in Escherichia coli as a His{sub 6}-tagged fusion protein and purified by nickel-affinity chromatography. Crystals were obtained from protein previously treated with 1,4-dithiothreitol by the hanging-drop vapour-diffusion method using PEG 3000 as precipitant and sodium fluoride as an additive. Diffraction data were collected to 2.8 Å resolution using a synchrotron-radiation source. The crystal structure was solved by molecular-replacement methods and structure refinement is currently in progress.

"Self-Shaping" of Multicomponent Drops.

Science.gov (United States)

Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

2017-06-13

In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

Mouse-induced pluripotent stem cells differentiate into odontoblast-like cells with induction of altered adhesive and migratory phenotype of integrin.

Directory of Open Access Journals (Sweden)

Nobuaki Ozeki

Full Text Available Methods for differentiating induced pluripotent stem (iPS cells into odontoblasts generally require epithelial-mesenchymal interactions. Here, we sought to characterize the cells produced by a 'hanging drop' technique for differentiating mouse iPS cells into odontoblast-like cells that requires no such interaction. Cells were cultured by the hanging drop method on a collagen type-I (Col-I scaffold (CS combined with bone morphogenetic protein (BMP-4 (CS/BMP-4 without an epithelial-mesenchymal interaction. We evaluated the expression of odontoblast-related mRNA and protein, and the proliferation rate of these cells using reverse-transcription polymerase chain reaction, immunofluorescence staining, and BrdU cell proliferation enzyme-linked immunosorbent assay, respectively. The differentiated cells strongly expressed the mRNA for dentin sialophosphoprotein (DSPP and dentin matrix protein-1 (Dmp-1, which are markers of mature odontoblasts. Osteopontin and osteocalcin were not expressed in the differentiated cells, demonstrating that the differentiated iPS cells bore little resemblance to osteoblasts. Instead, they acquired odontoblast-specific properties, including the adoption of an odontoblastic phenotype, typified by high alkaline phosphatase (ALP activity and calcification capacity. The cell-surface expression of proteins such as integrins α2, α6, αV and αVβ3 was rapidly up-regulated. Interestingly, antibodies and siRNAs against integrin α2 suppressed the expression of DSPP and Dmp-1, reduced the activity of ALP and blocked calcification, suggesting that integrin α2 in iPS cells mediates their differentiation into odontoblast-like cells. The adhesion of these cells to fibronectin and Col-I, and their migration on these substrata, was significantly increased following differentiation into odontoblast-like cells. Thus, we have demonstrated that integrin α2 is involved in the differentiation of mouse iPS cells into odontoblast-like cells

Toxicological findings in two planned complex suicide cases: ingestion of petroleum distillates and subsequent hanging.

Science.gov (United States)

Martínez, María Antonia; Ballesteros, Salomé

2009-01-01

This paper describes two fatal cases of planned complex suicide by two male individuals, 86 and 51 years old, involving ingestion of petroleum distillates and hanging. Remarkable internal findings during autopsy of both cases included the intense odor of petroleum distillates that alerted authorities to the suspicion of ingestion. The initial toxicological screening and quantitation of these compounds were performed by gas chromatography with flame-ionization detection, and confirmation was performed using gas chromatography-mass spectrometry in total ion chromatogram mode after liquid-liquid extraction of biological samples following a previously published analytical method. In Case 1, diesel fuel No. 2 concentrations were distillates when there is a suspicion of ingestion of these products due to the odor observed at the scene of death and/or during autopsy. The results of these toxicological investigations can help to determine the manner of death and the medicolegal interpretation.

The development of crack measurement system using the direct current potential drop method for use in the hot cell

International Nuclear Information System (INIS)

Kim, Do-Sik; Ahn, Sang-Bok; Lee, Key-Soon; Kim, Yong-Suk; Kwon, Sang-Chul

1999-01-01

The crack length measurement system using the direct current potential drop (DCPD) method was developed for the detection of crack growth initiation and subsequent crack growth. The experimental precautions and data processing procedure required for its application were also described find discussed. The system presented herein was specially built for use in fracture toughness testing of unirradiated or irradiated pressure tube materials from nuclear reactor. The application of this system for fracture toughness determination was illustrated from the test of curved compact tension specimens removed from CANDU reactor pressure tubes. The crack extension was monitored using the DCPD method. It is found that the changes of the potential drop and the changes of the crack length have a linear relationship. The final crack front was marked by heat-tinting after the test and the specimen broken open for determination of the initial and final physical crack length. The physical crack lengths, obtained by the 9-point average method described in ASTM E1737-96 on heat-tinted fracture surface, were used to calibrate the DCPD method for each test on an individual basis by matching the change in voltage to the crack extension. It is found that this system can be recommended for determination of the J-integral resistance (J-R) curve of unirradiated or irradiation materials in the hot cell, especially when testing at elevated temperature and in the environment chamber or furnace. (author)

SU-E-T-556: Monte Carlo Generated Dose Distributions for Orbital Irradiation Using a Single Anterior-Posterior Electron Beam and a Hanging Lens Shield

International Nuclear Information System (INIS)

Duwel, D; Lamba, M; Elson, H; Kumar, N

2015-01-01

Purpose: Various cancers of the eye are successfully treated with radiotherapy utilizing one anterior-posterior (A/P) beam that encompasses the entire content of the orbit. In such cases, a hanging lens shield can be used to spare dose to the radiosensitive lens of the eye to prevent cataracts. Methods: This research focused on Monte Carlo characterization of dose distributions resulting from a single A-P field to the orbit with a hanging shield in place. Monte Carlo codes were developed which calculated dose distributions for various electron radiation energies, hanging lens shield radii, shield heights above the eye, and beam spoiler configurations. Film dosimetry was used to benchmark the coding to ensure it was calculating relative dose accurately. Results: The Monte Carlo dose calculations indicated that lateral and depth dose profiles are insensitive to changes in shield height and electron beam energy. Dose deposition was sensitive to shield radius and beam spoiler composition and height above the eye. Conclusion: The use of a single A/P electron beam to treat cancers of the eye while maintaining adequate lens sparing is feasible. Shield radius should be customized to have the same radius as the patient’s lens. A beam spoiler should be used if it is desired to substantially dose the eye tissues lying posterior to the lens in the shadow of the lens shield. The compromise between lens sparing and dose to diseased tissues surrounding the lens can be modulated by varying the beam spoiler thickness, spoiler material composition, and spoiler height above the eye. The sparing ratio is a metric that can be used to evaluate the compromise between lens sparing and dose to surrounding tissues. The higher the ratio, the more dose received by the tissues immediately posterior to the lens relative to the dose received by the lens

49 CFR 178.965 - Drop test.

Science.gov (United States)

2010-10-01

... Large Packaging design types and performed periodically as specified in § 178.955(e) of this subpart. (b... § 178.960(d). (d) Test method. (1) Samples of all Large Packaging design types must be dropped onto a... be restored to the upright position for observation. (2) Large Packaging design types with a capacity...

Development and validation of Ketorolac Tromethamine in eye drop formulation by RP-HPLC method

Directory of Open Access Journals (Sweden)

G. Sunil

2017-02-01

Full Text Available A simple, precise and accurate method was developed and validated for analysis of Ketorolac Tromethamine in eye drop formulation. An isocratic HPLC analysis was performed on Kromosil C18 column (150 cm × 4.6 mm × 5 μm. The compound was separated with the mixture of methanol and ammonium dihydrogen phosphate buffer in the ratio of 55:45 V/V, pH 3.0 was adjusted with O-phosphoric acid as the mobile phase at flow of 1.5 mL min−1. UV detection was performed at 314 nm using photo diode array detection. The retention time was found to be 6.01 min. The system suitability parameters such as theoretical plate count, tailing and percentage RSD between six standard injections were within the limit. The method was validated according to ICH guidelines. Calibrations were linear over the concentration range of 50–150 μg mL−1 as indicated by correlation coefficient (r of 0.999. The robustness of the method was evaluated by deliberately altering the chromatographic conditions. The developed method can be applicable for routine quantitative analysis.

Dynamics of deforming drops

NARCIS (Netherlands)

Bouwhuis, W.

2015-01-01

Liquid drops play a dominant role in numerous industrial applications, such as spray coating, spray painting, inkjet printing, lithography processes, and spraying/sprinkling in agriculture or gardening. In all of these examples, the generation, flight, impact, and spreading of drops are separate

Electrohydrodynamics of drops in strong electric fields: Simulations and theory

Science.gov (United States)

Saintillan, David; Das, Debasish

2016-11-01

Weakly conducting dielectric liquid drops suspended in another dielectric liquid exhibit a wide range of dynamical behaviors when subject to an applied uniform electric field contingent on field strength and material properties. These phenomena are best described by the much celebrated Maylor-Taylor leaky dielectric model that hypothesizes charge accumulation on the drop-fluid interface and prescribes a balance between charge relaxation, the jump in Ohmic currents and charge convection by the interfacial fluid flow. Most previous numerical simulations based on this model have either neglected interfacial charge convection or restricted themselves to axisymmetric drops. In this work, we develop a three-dimensional boundary element method for the complete leaky dielectric model to systematically study the deformation and dynamics of liquid drops in electric fields. The inclusion of charge convection in our simulation permits us to investigate drops in the Quincke regime, in which experiments have demonstrated symmetry-breaking bifurcations leading to steady electrorotation. Our simulation results show excellent agreement with existing experimental data and small deformation theories. ACSPRF Grant 53240-ND9.

Semisupervised Community Detection by Voltage Drops

Directory of Open Access Journals (Sweden)

Min Ji

2016-01-01

Full Text Available Many applications show that semisupervised community detection is one of the important topics and has attracted considerable attention in the study of complex network. In this paper, based on notion of voltage drops and discrete potential theory, a simple and fast semisupervised community detection algorithm is proposed. The label propagation through discrete potential transmission is accomplished by using voltage drops. The complexity of the proposal is OV+E for the sparse network with V vertices and E edges. The obtained voltage value of a vertex can be reflected clearly in the relationship between the vertex and community. The experimental results on four real networks and three benchmarks indicate that the proposed algorithm is effective and flexible. Furthermore, this algorithm is easily applied to graph-based machine learning methods.

A Downflow Hanging Sponge (DHS) reactor for faecal coliform removal from an Upflow Anaerobic Sludge Bed (UASB) effluent

NARCIS (Netherlands)

Yaya Beas, R.E.; Kujawa-Roeleveld, K.; Lier, van J.B.; Zeeman, G.

2015-01-01

This research was conducted to study the faecal coliforms removal capacity of Downflow Hanging Sponge (DHS) reactors as a post-treatment for an Upflow Anaerobic Sludge Blanket (UASB) reactor. Three long-term continuous lab-scale DHS reactors i.e. a reactor with cube type sponges without

Evaluation of the impact behavior of the contents of reprocessing radioactive waste shipping cask subjected to drop impact

International Nuclear Information System (INIS)

Shirai, K.; Ito, C.; Funahashi, M.

1993-01-01

In this study, to investigate the impact response characteristics of the contents in the cask precisely, we performed the laboratory-scale drop tests, and on the basis of the test results, we proposed the construction of the spring-mass model and confirmed the accuracy of the proposed drop analysis method by comparison with drop test using a full-scale cask for high level wastes. Following the results of the drop tests and analysis, the outline of the contents and results is summarized below. 1) The drop tests onto the unyielding surface using a scale model containing several contents were performed and the effect of the interaction between the contents and the cask body on the impact response experimentally. 2) The above interaction can be characterized by the gap between the contents and the cask body caused by the release of the gravitational force at the moment the drop started. So, we proposed the analysis method for considering gap using spring-mass model by comparing the laboratory-scale drop test results. 3) We applied the proposed analysis method to a drop test using a full-scale cask for high level wastes, and it was found that this method seems to be good and convenient enough to evaluate the impact behavior of the contents in a transport cask subjected to drop impact. (J.P.N.)

Estimating drizzle drop size and precipitation rate using two-colour lidar measurements

Directory of Open Access Journals (Sweden)

C. D. Westbrook

2010-06-01

Full Text Available A method to estimate the size and liquid water content of drizzle drops using lidar measurements at two wavelengths is described. The method exploits the differential absorption of infrared light by liquid water at 905 nm and 1.5 μm, which leads to a different backscatter cross section for water drops larger than ≈50 μm. The ratio of backscatter measured from drizzle samples below cloud base at these two wavelengths (the colour ratio provides a measure of the median volume drop diameter D₀. This is a strong effect: for D₀=200 μm, a colour ratio of ≈6 dB is predicted. Once D₀ is known, the measured backscatter at 905 nm can be used to calculate the liquid water content (LWC and other moments of the drizzle drop distribution.

The method is applied to observations of drizzle falling from stratocumulus and stratus clouds. High resolution (32 s, 36 m profiles of D₀, LWC and precipitation rate R are derived. The main sources of error in the technique are the need to assume a value for the dispersion parameter μ in the drop size spectrum (leading to at most a 35% error in R and the influence of aerosol returns on the retrieval (≈10% error in R for the cases considered here. Radar reflectivities are also computed from the lidar data, and compared to independent measurements from a colocated cloud radar, offering independent validation of the derived drop size distributions.

Verkapselungseinreichtung und -verfahren zur Verkapselung einer Probe in einer Polymerkapsel

OpenAIRE

Zimmermann, Heiko; Neubauer, Julia

2015-01-01

Source: WO15010763A1 [EN] The invention relates to an encapsulating device (100), which is designed to encapsulate a sample (1, 2) in a polymer capsule, comprising a drop generator (10), which is designed to provide a drop (3) of a suspension, which drop contains the sample (1), and a cross-linking device (20), which is designed to polymerize the drop (3), wherein the drop generator (10) has a retaining device (11), which is designed to accommodate the drop (3) in a hanging state, and the cro...

Estimation of pressure drop in gasket plate heat exchangers

Directory of Open Access Journals (Sweden)

Neagu Anisoara Arleziana

2016-06-01

Full Text Available In this paper, we present comparatively different methods of pressure drop calculation in the gasket plate heat exchangers (PHEs, using correlations recommended in literature on industrial data collected from a vegetable oil refinery. The goal of this study was to compare the results obtained with these correlations, in order to choose one or two for practical purpose of pumping power calculations. We concluded that pressure drop values calculated with Mulley relationship and Buonopane & Troupe correlation were close and also Bond’s equation gave results pretty close to these but the pressure drop is slightly underestimated. Kumar correlation gave results far from all the others and its application will lead to oversize. In conclusion, for further calculations we will chose either the Mulley relationship or the Buonopane & Troupe correlation.

Crystallization and preliminary X-ray crystallographic study of the extracellular domain of the 4-1BB ligand, a member of the TNF family

Energy Technology Data Exchange (ETDEWEB)

Byun, Jung-Sue; Kim, Dong-Uk [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of); Ahn, Byungchan; Kwon, Byoung Se [Immunomodulation Research Center, Ulsan University, Ulsan 680-749 (Korea, Republic of); Cho, Hyun-Soo, E-mail: hscho8@yonsei.ac.kr [Department of Biology, Yonsei University, Seoul 120-749 (Korea, Republic of)

2006-01-01

The extracellular domain of the 4-1BB ligand fused with glutathione-S-transferase was expressed in Escherichia coli (Origami) and purified by using affinity and ion-exchange column chromatographic methods. Crystals of the 4-1BB ligand were obtained at 290 K by the hanging-drop vapour-diffusion method. The 4-1BB ligand, a member of the tumour necrosis factor (TNF) family, is an important co-stimulatory molecule that plays a key role in the clonal expansion and survival of CD8+ T cells. Signalling through binding of the 4-1BB ligand and 4-1BB has been reported to enhance CD8+ T-cell expansion and protect activated CD8+ T cells from death. The 4-1BB ligand is an integral protein expressed on activated antigen-presenting cells. The extracellular domain of the 4-1BB ligand fused with glutathione-S-transferase was expressed in Escherichia coli (Origami) and purified by using affinity and ion-exchange column chromatographic methods. Crystals of the 4-1BB ligand were obtained at 290 K by the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from these crystals to 2.8 Å resolution and the crystals belong to space group C2, with unit-cell parameters a = 114.6, b = 73.8, c = 118.50 Å, β = 115.5°.

Crystallization and preliminary X-ray crystallographic study of the extracellular domain of the 4-1BB ligand, a member of the TNF family

International Nuclear Information System (INIS)

Byun, Jung-Sue; Kim, Dong-Uk; Ahn, Byungchan; Kwon, Byoung Se; Cho, Hyun-Soo

2005-01-01

The extracellular domain of the 4-1BB ligand fused with glutathione-S-transferase was expressed in Escherichia coli (Origami) and purified by using affinity and ion-exchange column chromatographic methods. Crystals of the 4-1BB ligand were obtained at 290 K by the hanging-drop vapour-diffusion method. The 4-1BB ligand, a member of the tumour necrosis factor (TNF) family, is an important co-stimulatory molecule that plays a key role in the clonal expansion and survival of CD8+ T cells. Signalling through binding of the 4-1BB ligand and 4-1BB has been reported to enhance CD8+ T-cell expansion and protect activated CD8+ T cells from death. The 4-1BB ligand is an integral protein expressed on activated antigen-presenting cells. The extracellular domain of the 4-1BB ligand fused with glutathione-S-transferase was expressed in Escherichia coli (Origami) and purified by using affinity and ion-exchange column chromatographic methods. Crystals of the 4-1BB ligand were obtained at 290 K by the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from these crystals to 2.8 Å resolution and the crystals belong to space group C2, with unit-cell parameters a = 114.6, b = 73.8, c = 118.50 Å, β = 115.5°

Understanding water equilibration fundamentals as a step for rational protein crystallization.

Directory of Open Access Journals (Sweden)

Pedro M Martins

Full Text Available BACKGROUND: Vapor diffusion is the most widely used technique for protein crystallization and the rate of water evaporation plays a key role on the quality of the crystals. Attempts have been made in the past to solve the mass transfer problem governing the evaporation process, either analytically or by employing numerical methods. Despite these efforts, the methods used for protein crystallization remain based on trial and error techniques rather than on fundamental principles. METHODOLOGY/PRINCIPAL FINDINGS: Here we present a new theoretical model which describes the hanging drop method as a function of the different variables that are known to influence the evaporation process. The model is extensively tested against experimental data published by other authors and considering different crystallizing conditions. Aspects responsible for the discrepancies between the existing theories and the measured evaporation kinetics are especially discussed; they include the characterization of vapor-liquid equilibrium, the role of mass transfer within the evaporating droplet, and the influence of the droplet-reservoir distance. CONCLUSIONS/SIGNIFICANCE: The validation tests show that the proposed model can be used to predict the water evaporation rates under a wide range of experimental conditions used in the hanging drop vapor-diffusion method, with no parameter fitting or computational requirements. This model combined with protein solubility data is expected to become a useful tool for a priori screening of crystallization conditions.

Increased medial foot loading during drop jump in subjects with patellofemoral pain

DEFF Research Database (Denmark)

Rathleff, Michael S; Richter, Camilla; Brushøj, Christoffer

2014-01-01

PURPOSE: To compare medial-to-lateral plantar forces during drop jump and single leg squat in individuals with and without patellofemoral pain. METHODS: This cross-sectional study compared 23 young adults with patellofemoral pain to 20 age- and sex-matched controls without knee pain. The plantar...... pressure distribution was collected during drop jump and single leg squat using pressure-sensitive Pedar insoles, inserted into a standard flat shoe. The primary outcome was the medial-to-lateral force, quantified as the peak force under the medial forefoot as the percentage of force under the total...... forefoot during drop jump. Secondary outcomes included peak medial-to-lateral force during single leg squat and mean forces during drop jump and single leg squat. RESULTS: The primary outcome showed that individuals with patellofemoral pain had a 22 % higher medial-to-lateral peak force during drop jump...

Turbulence, bubbles and drops

NARCIS (Netherlands)

van der Veen, Roeland

2016-01-01

In this thesis, several questions related to drop impact and Taylor-Couette turbulence are answered. The deformation of a drop just before impact can cause a bubble to be entrapped. For many applications, such as inkjet printing, it is crucial to control the size of this entrapped bubble. To study

Mode-routed fiber-optic add-drop filter

Science.gov (United States)

Moslehi, Behzad (Inventor); Black, Richard James (Inventor); Shaw, Herbert John (Inventor)

2000-01-01

New elements mode-converting two-mode grating and mode-filtering two-mode coupler are disclosed and used as elements in a system for communications, add-drop filtering, and strain sensing. Methods of fabrication for these new two-mode gratings and mode-filtering two-mode couplers are also disclosed.

Standard test method for conducting drop-weight test to determine nil-ductility transition temperature of ferritic steels

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 This test method covers the determination of the nil-ductility transition (NDT) temperature of ferritic steels, 5/8 in. (15.9 mm) and thicker. 1.2 This test method may be used whenever the inquiry, contract, order, or specification states that the steels are subject to fracture toughness requirements as determined by the drop-weight test. 1.3 The values stated in inch-pound units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Life cycle and population growth rate of Caenorhabditis elegans studied by a new method.

Science.gov (United States)

Muschiol, Daniel; Schroeder, Fabian; Traunspurger, Walter

2009-05-16

The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, age-specific fecundity/mortality, total reproduction, mean and maximum lifespan, and intrinsic population growth rates. However, we found that in life-cycle experiments care is needed regarding protocol design. Here, we test a recently developed method that overcomes some problems associated with traditional cultivation techniques. In this fast and yet precise approach, single individuals are maintained within hanging drops of semi-fluid culture medium, allowing the simultaneous investigation of various life-history traits at any desired degree of accuracy. Here, the life cycles of wild-type C. elegans strains N2 (Bristol, UK) and MY6 (Münster, Germany) were compared at 20 degrees C with 5 x 10(9) Escherichia coli ml-1 as food source. High-resolution life tables and fecundity schedules of the two strains are presented. Though isolated 700 km and 60 years apart from each other, the two strains barely differed in life-cycle parameters. For strain N2 (n = 69), the intrinsic rate of natural increase (r m d(-1)), calculated according to the Lotka equation, was 1.375, the net reproductive rate (R 0) 291, the mean generation time (T) 90 h, and the minimum generation time (T min) 73.0 h. The corresponding values for strain MY6 (n = 72) were r m = 1.460, R0 = 289, T = 84 h, and T min = 67.3 h. Peak egg-laying rates in both strains exceeded 140 eggs d(-1). Juvenile and early adulthood mortality was negligible. Strain N2 lived, on average, for 16.7 d, while strain MY6 died 2 days earlier; however

Life cycle and population growth rate of Caenorhabditis elegans studied by a new method

Directory of Open Access Journals (Sweden)

Schroeder Fabian

2009-05-01

Full Text Available Abstract Background The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, age-specific fecundity/mortality, total reproduction, mean and maximum lifespan, and intrinsic population growth rates. However, we found that in life-cycle experiments care is needed regarding protocol design. Here, we test a recently developed method that overcomes some problems associated with traditional cultivation techniques. In this fast and yet precise approach, single individuals are maintained within hanging drops of semi-fluid culture medium, allowing the simultaneous investigation of various life-history traits at any desired degree of accuracy. Here, the life cycles of wild-type C. elegans strains N2 (Bristol, UK and MY6 (Münster, Germany were compared at 20°C with 5 × 109 Escherichia coli ml-1 as food source. Results High-resolution life tables and fecundity schedules of the two strains are presented. Though isolated 700 km and 60 years apart from each other, the two strains barely differed in life-cycle parameters. For strain N2 (n = 69, the intrinsic rate of natural increase (rmd-1, calculated according to the Lotka equation, was 1.375, the net reproductive rate (R0 291, the mean generation time (T 90 h, and the minimum generation time (Tmin 73.0 h. The corresponding values for strain MY6 (n = 72 were rm = 1.460, R0 = 289, T = 84 h, and Tmin = 67.3 h. Peak egg-laying rates in both strains exceeded 140 eggs d-1. Juvenile and early adulthood mortality was negligible. Strain N2 lived, on average, for 16.7 d, while strain MY6 died 2 days

All-Optical Regenerative OTDM Add/Drop Multiplexing at 40 Gbit/s using Monolithic InP Mach-Zehnder Interferometer

DEFF Research Database (Denmark)

Buxens, Alvaro A.; Clausen, Anders; Poulsen, Henrik Nørskov

2000-01-01

We report a novel method for simultaneous add-drop multiplexing in OTDM systems which includes regenerative capabilities and perfect clearing of the drop channel time slot. The principle has been demonstrated at 40 Gb/s showing an excellent performance.......We report a novel method for simultaneous add-drop multiplexing in OTDM systems which includes regenerative capabilities and perfect clearing of the drop channel time slot. The principle has been demonstrated at 40 Gb/s showing an excellent performance....

Electrochemical noise measurements techniques and the reversing dc potential drop method applied to stress corrosion essays

International Nuclear Information System (INIS)

Aly, Omar Fernandes; Andrade, Arnaldo Paes de; MattarNeto, Miguel; Aoki, Idalina Vieira

2002-01-01

This paper aims to collect information and to discuss the electrochemical noise measurements and the reversing dc potential drop method, applied to stress corrosion essays that can be used to evaluate the nucleation and the increase of stress corrosion cracking in Alloy 600 and/or Alloy 182 specimens from Angra I Nuclear Power Plant. Therefore we will pretend to establish a standard procedure to essays to be realized on the new autoclave equipment on the Laboratorio de Eletroquimica e Corrosao do Departamento de Engenharia Quimica da Escola Politecnica da Universidade de Sao Paulo - Electrochemical and Corrosion Laboratory of the Chemical Engineering Department of Polytechnical School of Sao Paulo University, Brazil. (author)

Dispersion of silver particles in aqueous solutions visualized by polarography/voltammetry

Czech Academy of Sciences Publication Activity Database

Korshunov, A.; Heyrovský, Michael

2009-01-01

Roč. 54, č. 26 (2009), s. 6264-6268 ISSN 0013-4686 R&D Projects: GA AV ČR IAA400400806 Institutional research plan: CEZ:AV0Z40400503 Keywords : silver ions * silver particles * drop ping mercury electrode * hanging mercury drop electrode Subject RIV: CG - Electrochemistry Impact factor: 3.325, year: 2009

Drop impact splashing and air entrapment

KAUST Repository

Thoraval, Marie-Jean

2013-03-01

Drop impact is a canonical problem in fluid mechanics, with numerous applications in industrial as well as natural phenomena. The extremely simple initial configuration of the experiment can produce a very large variety of fast and complex dynamics. Scientific progress was made in parallel with major improvements in imaging and computational technologies. Most recently, high-speed imaging video cameras have opened the exploration of new phenomena occurring at the micro-second scale, and parallel computing allowed realistic direct numerical simulations of drop impacts. We combine these tools to bring a new understanding of two fundamental aspects of drop impacts: splashing and air entrapment. The early dynamics of a drop impacting on a liquid pool at high velocity produces an ejecta sheet, emerging horizontally in the neck between the drop and the pool. We show how the interaction of this thin liquid sheet with the air, the drop or the pool, can produce micro-droplets and bubble rings. Then we detail how the breakup of the air film stretched between the drop and the pool for lower impact velocities can produce a myriad of micro-bubbles.

Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production.

Science.gov (United States)

Pirone-Davies, Cary; Prior, Natalie; von Aderkas, Patrick; Smith, Derek; Hardie, Darryl; Friedman, William E; Mathews, Sarah

2016-05-01

Many gymnosperms produce an ovular secretion, the pollination drop, during reproduction. The drops serve as a landing site for pollen, but also contain a suite of ions and organic compounds, including proteins, that suggests diverse roles for the drop during pollination. Proteins in the drops of species of Chamaecyparis, Juniperus, Taxus, Pseudotsuga, Ephedra and Welwitschia are thought to function in the conversion of sugars, defence against pathogens, and pollen growth and development. To better understand gymnosperm pollination biology, the pollination drop proteomes of pollination drops from two species of Cephalotaxus have been characterized and an ovular transcriptome for C. sinensis has been assembled. Mass spectrometry was used to identify proteins in the pollination drops of Cephalotaxus sinensis and C. koreana RNA-sequencing (RNA-Seq) was employed to assemble a transcriptome and identify transcripts present in the ovules of C. sinensis at the time of pollination drop production. About 30 proteins were detected in the pollination drops of both species. Many of these have been detected in the drops of other gymnosperms and probably function in defence, polysaccharide metabolism and pollen tube growth. Other proteins appear to be unique to Cephalotaxus, and their putative functions include starch and callose degradation, among others. Together, the proteins appear either to have been secreted into the drop or to occur there due to breakdown of ovular cells during drop production. Ovular transcripts represent a wide range of gene ontology categories, and some may be involved in drop formation, ovule development and pollen-ovule interactions. The proteome of Cephalotaxus pollination drops shares a number of components with those of other conifers and gnetophytes, including proteins for defence such as chitinases and for carbohydrate modification such as β-galactosidase. Proteins likely to be of intracellular origin, however, form a larger component of drops

Correction of Pressure Drop in Steam and Water System in Performance Test of Boiler

Science.gov (United States)

Liu, Jinglong; Zhao, Xianqiao; Hou, Fanjun; Wu, Xiaowu; Wang, Feng; Hu, Zhihong; Yang, Xinsen

2018-01-01

Steam and water pressure drop is one of the most important characteristics in the boiler performance test. As the measuring points are not in the guaranteed position and the test condition fluctuation exsits, the pressure drop test of steam and water system has the deviation of measuring point position and the deviation of test running parameter. In order to get accurate pressure drop of steam and water system, the corresponding correction should be carried out. This paper introduces the correction method of steam and water pressure drop in boiler performance test.

Effect of textured eye drop bottles on the photostability of pranoprofen 0.1% ophthalmic solution.

Science.gov (United States)

Iwatsuka, Kinya; Inada, Katsuhiro; Ueoka, Hiroki; Otsuka, Tadashi; Maeda, Masaki; Yamaguchi, Masazumi; Yasueda, Shin-ichi

2015-01-01

Ophthalmic solutions are usually filled in a plastic bottle due to its durability and disposability. In Japan, photostability is one of the concerns for the quality control because an eye drop bottle must be a transparent container. The present work studied the effect of textured eye drop bottles on its light blocking to improve the photostability of ophthalmic solutions. We investigated the photostability of Pranoprofen ophthalmic solution filled in a variety of textured eye drop bottles. Pranoprofen content was analyzed by high-performance liquid chromatography and surface structure of textured eye drop bottles was evaluated by transmittance, calculated average roughness (Ra) and haze intensity. We observed that eye drop bottle which had greater than Ra value of 1.0 µm and haze intensity 62% clearly showed photostability improvement. This report is the first one which shows that photostability of ophthalmic solution is improved by using textured eye drop bottle. Moreover, this approach is a simple and effective method to improve the photostability. This method is available for not only various ophthalmic applications but also other liquid pharmaceuticals or food products.

Langevin modelling of high-frequency Hang-Seng index data

Science.gov (United States)

Tang, Lei-Han

2003-06-01

Accurate statistical characterization of financial time series, such as compound stock indices, foreign currency exchange rates, etc., is fundamental to investment risk management, pricing of derivative products and financial decision making. Traditionally, such data were analyzed and modeled from a purely statistics point of view, with little concern on the specifics of financial markets. Increasingly, however, attention has been paid to the underlying economic forces and the collective behavior of investors. Here we summarize a novel approach to the statistical modeling of a major stock index (the Hang Seng index). Based on mathematical results previously derived in the fluid turbulence literature, we show that a Langevin equation with a variable noise amplitude correctly reproduces the ubiquitous fat tails in the probability distribution of intra-day price moves. The form of the Langevin equation suggests that, despite the extremely complex nature of financial concerns and investment strategies at the individual's level, there exist simple universal rules governing the high-frequency price move in a stock market.

MHD pressure drop in ducts with imperfectly insulating coatings

International Nuclear Information System (INIS)

Malang, S.; Buehler, L.

1994-08-01

Liquid metal cooled blankets in fusion tokamak's are feasible only with electrically insulating coatings at the coolant channel walls. The requirements of such coatings are investigated and a simple analytical model is developed to determine the influence of imperfections in the coatings on the magneto-hydrodynamic pressure drop. This model is compared with the results of a 3D-MHD code based on the core flow approach. Both methods are in good agreement as long as the imperfections do not increase the pressure drop by more than 20%. The analytical model over-estimates the pressure drop for values larger than 20%. The importance of self-healing of coatings in case of cracking or flaking is quantified and an equation for the equilibrium conditions between the generation of imperfection and the healing of such spots is provided

CANFLEX fuel bundle junction pressure drop

International Nuclear Information System (INIS)

Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

1996-11-01

This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs

CANFLEX fuel bundle junction pressure drop

Energy Technology Data Exchange (ETDEWEB)

Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

1996-11-01

This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs.

49 CFR 178.603 - Drop test.

Science.gov (United States)

2010-10-01

... used for the hydrostatic pressure or stacking test. Exceptions for the number of steel and aluminum..., non-resilient, flat and horizontal surface. (e) Drop height. Drop heights, measured as the vertical... than flat drops, the center of gravity of the test packaging must be vertically over the point of...

Simplified analytical solutions for free drops during NCT for radioactive material packagings

International Nuclear Information System (INIS)

Gupta, N.K.

1997-01-01

To ensure structural integrity during normal conditions of transport (NCT), Federal regulations in 10CFR71.71 require that the nuclear material package designs be evaluated for the effects of free drops. The vessel stress acceptance criteria for these drops are given in Regulatory Guide 7.6 and ASME Section III Code. During initial phases of the package design, the effects of the NCT free drops can be evaluated by simplified analytical solutions which will ensure that the safety margins specified in R. G. 7.6 are met. These safety margins can be verified during the final stages of the package design with dynamic analyses using finite element methods. This paper calculates the maximum impact open-quotes gclose quotes loading on the vessels using single degree of freedom models for different drop orientations. Only end, bottom, and corner drops are analyzed for cylindrical packages or packages with cylindrical ends

Prediction of drop time and impact velocity of rod cluster control assembly

International Nuclear Information System (INIS)

Choi, Kee Sung; Yim, Jeong Sik; Kim, Il Kon; Kim, Kyu Tae

1992-01-01

This paper deals with the drop modelling of rod cluster control assembly(RCCA) and the prediction of drop time and impact velocity of RCCA at scram event. On the scram, RCCA, dropping into the guide thimble of fuel assembly by the gravity, is subject to retarding forces such as hydraulic resistance, mechanical friction and buoyancy. Considering these retarding forces RCCA dynamic equation is derived and computerized it to solve the equation in conjunction with fluid equation which is coupled with the motion of the RCCA. Because the equation is nonlinear, coupled with fluid equations, the program is written in FORTRAN using numerical method in order to calculate the drop distance and velocity with time increment. To verify the program, its results are compared with those of other fuel vendors. Predicting identical tendency as other fuel vendors and the deviation is insignificant in values this program is expected to be used for predicting the drop time and impact velocity of RCCA when the parameters affecting the control rod drop time and impact velocity changes are occurred

The Measurement of the Surface Energy of Solids by Sessile Drop Accelerometry

Science.gov (United States)

Calvimontes, Alfredo

2018-05-01

A new physical method, the sessile drop accelerometry (SDACC) for the study and measurement of the interfacial energies of solid-liquid-gas systems, is tested and discussed in this study. The laboratory instrument and technique—a combination of a drop shape analyzer with high-speed camera and a laboratory drop tower- and the evaluation algorithms, were designed to calculate the interfacial energies as a function of the geometrical changes of a sessile droplet shape due to the effect of "switching off" gravity during the experiment. The method bases on Thermodynamics of Interfaces and differs from the conventional approach of the two hundred-years-old Young's equation in that it assumes a thermodynamic equilibrium between interfaces, rather than a balance of tensions on a point of the solid-liquid-gas contour line. A comparison of the mathematical model that supports the method with the widely accepted Young`s equation is discussed in detail in this study. The method opens new possibilities to develop surface characterization procedures by submitting the solid-liquid-system to artificial generated and uniform force fields.

Different cellular effects of four anti-inflammatory eye drops on human corneal epithelial cells: independent in active components

OpenAIRE

Qu, Mingli; Wang, Yao; Yang, Lingling; Zhou, Qingjun

2011-01-01

Purpose To evaluate and compare the cellular effects of four commercially available anti-inflammatory eye drops and their active components on human corneal epithelial cells (HCECs) in vitro. Methods The cellular effects of four eye drops (Bromfenac Sodium Hydrate Eye Drops, Pranoprofen Eye Drops, Diclofenac Sodium Eye Drops, and Tobramycin & Dex Eye Drops) and their corresponding active components were evaluated in an HCEC line with five in vitro assays. Cell proliferation and migration were...

Adhesion of bubbles and drops to solid surfaces, and anisotropic surface tensions studied by capillary meniscus dynamometry.

Science.gov (United States)

Danov, Krassimir D; Stanimirova, Rumyana D; Kralchevsky, Peter A; Marinova, Krastanka G; Stoyanov, Simeon D; Blijdenstein, Theodorus B J; Cox, Andrew R; Pelan, Eddie G

2016-07-01

Here, we review the principle and applications of two recently developed methods: the capillary meniscus dynamometry (CMD) for measuring the surface tension of bubbles/drops, and the capillary bridge dynamometry (CBD) for quantifying the bubble/drop adhesion to solid surfaces. Both methods are based on a new data analysis protocol, which allows one to decouple the two components of non-isotropic surface tension. For an axisymmetric non-fluid interface (e.g. bubble or drop covered by a protein adsorption layer with shear elasticity), the CMD determines the two different components of the anisotropic surface tension, σs and σφ, which are acting along the "meridians" and "parallels", and vary throughout the interface. The method uses data for the instantaneous bubble (drop) profile and capillary pressure, but the procedure for data processing is essentially different from that of the conventional drop shape analysis (DSA) method. In the case of bubble or drop pressed against a substrate, which forms a capillary bridge, the CBD method allows one to determine also the capillary-bridge force for both isotropic (fluid) and anisotropic (solidified) adsorption layers. The experiments on bubble (drop) detachment from the substrate show the existence of a maximal pulling force, Fmax, that can be resisted by an adherent fluid particle. Fmax can be used to quantify the strength of adhesion of bubbles and drops to solid surfaces. Its value is determined by a competition of attractive transversal tension and repulsive disjoining pressure forces. The greatest Fmax values have been measured for bubbles adherent to glass substrates in pea-protein solutions. The bubble/wall adhesion is lower in solutions containing the protein HFBII hydrophobin, which could be explained with the effect of sandwiched protein aggregates. The applicability of the CBD method to emulsion systems is illustrated by experiments with soybean-oil drops adherent to hydrophilic and hydrophobic substrates in

Liquid-gas mass transfer at drop structures

DEFF Research Database (Denmark)

Matias, Natércia; Nielsen, Asbjørn Haaning; Vollertsen, Jes

2017-01-01

-water mass transfer, little is known about hydrogen sulfide emission under highly turbulent conditions (e.g., drop structures, hydraulic jumps). In this study, experimental work was carried out to analyze the influence of characteristics of drops on reaeration. Physical models were built, mimicking typical...... sewer drop structures and allowing different types of drops, drop heights, tailwater depths and flow rates. In total, 125 tests were performed. Based on their results, empirical expressions translating the relationship between the mass transfer of oxygen and physical parameters of drop structures were...... established. Then, by applying the two-film theory with two-reference substances, the relation to hydrogen sulfide release was defined. The experiments confirmed that the choice of the type of drop structure is critical to determine the uptake/emission rates. By quantifying the air-water mass transfer rates...

A device for pre-separating water-drops in a two-phase flow

International Nuclear Information System (INIS)

Andro, Jean; Peyrelongue, J.-P.

1974-01-01

The invention relates to the mechanical pre-separation of water-drops in suspension in a flow of saturated steam. To this end, the method comprises the steps of carrying out rough separations by directing the flow towards curved surfaces adapted to deflect that flow and to project the drops onto said surfaces, sucking the film formed by the water-drops displaced by centrifugal force on the outer periphery of said surfaces, directing the steam separated from the water-drops onto five separators so as to extract dry steam and discharging the water provided by the sucking of said surfaces and the five separators. The invention applies to the drying of steam issuing from the high-pressure bodies of nuclear steam-turbines [fr

Drop weight impact strength measurement method for porous concrete using laser doppler velocimetry

NARCIS (Netherlands)

Agar-Ozbek, A.S.; Weerheijm, J.; Schlangen, E.; Breugel, K. van

2012-01-01

In this study, an experimental configuration that reveals the dynamic response of porous concretes in a drop weight impact test was introduced. Through the measurement of particle velocity at the interface, between the impactor and the concrete target, the dynamic response was obtained in an easily

Nonlinear oscillations of inviscid free drops

Science.gov (United States)

Patzek, T. W.; Benner, R. E., Jr.; Basaran, O. A.; Scriven, L. E.

1991-01-01

The present analysis of free liquid drops' inviscid oscillations proceeds through solution of Bernoulli's equation to obtain the free surface shape and of Laplace's equation for the velocity potential field. Results thus obtained encompass drop-shape sequences, pressure distributions, particle paths, and the temporal evolution of kinetic and surface energies; accuracy is verified by the near-constant drop volume and total energy, as well as the diminutiveness of mass and momentum fluxes across drop surfaces. Further insight into the nature of oscillations is provided by Fourier power spectrum analyses of mode interactions and frequency shifts.

Crystallization and preliminary X-ray diffraction analysis of central structure domains from mumps virus F protein

International Nuclear Information System (INIS)

Liu, Yueyong; Xu, Yanhui; Zhu, Jieqing; Qiu, Bingsheng; Rao, Zihe; Gao, George F.; Tien, Po

2005-01-01

Single crystals of the central structure domains from mumps virus F protein have been obtained by the hanging-drop vapour-diffusion method. A diffraction data set has been collected to 2.2 Å resolution. Fusion of members of the Paramyxoviridae family involves two glycoproteins: the attachment protein and the fusion protein. Changes in the fusion-protein conformation were caused by binding of the attachment protein to the cellular receptor. In the membrane-fusion process, two highly conserved heptad-repeat (HR) regions, HR1 and HR2, are believed to form a stable six-helix coiled-coil bundle. However, no crystal structure has yet been determined for this state in the mumps virus (MuV, a member of the Paramyxoviridae family). In this study, a single-chain protein consisting of two HR regions connected by a flexible amino-acid linker (named 2-Helix) was expressed, purified and crystallized by the hanging-drop vapour-diffusion method. A complete X-ray data set was obtained in-house to 2.2 Å resolution from a single crystal. The crystal belongs to space group C2, with unit-cell parameters a = 161.2, b = 60.8, c = 40.1 Å, β = 98.4°. The crystal structure will help in understanding the molecular mechanism of Paramyxoviridae family membrane fusion

Preliminary X-ray crystallographic studies of Bacillus subtilis SpeA protein

International Nuclear Information System (INIS)

Liu, Xiao-Yan; Lei, Jian; Liu, Xiang; Su, Xiao-Dong; Li, Lanfen

2009-01-01

In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme the speA gene was amplified from B. subtilis genomic DNA and cloned. The enzyme was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 298 K. The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme in polyamine metabolism in B. subtilis. In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme, the speA gene was amplified from B. subtilis genomic DNA and cloned into the expression vector pET-28a(+). SpeA was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 289 K. The best crystal diffracted to 2.0 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 86.4, b = 63.3 c = 103.3 Å, β = 113.9°

Cloning, overexpression, purification, crystallization and preliminary X-ray analysis of 3-ketosteroid Δ{sup 4}-(5α)-dehydrogenase from Rhodococcus jostii RHA1

Energy Technology Data Exchange (ETDEWEB)

Oosterwijk, Niels van; Knol, Jan; Dijkhuizen, Lubbert; Geize, Robert van der; Dijkstra, Bauke W., E-mail: b.w.dijkstra@rug.nl [University of Groningen, Nijenborgh 7, 9747 AG Groningen (Netherlands)

2011-10-01

The gene for 3-ketosteroid Δ{sup 4}-(5α)-dehydrogenase from R. jostii RHA1 was cloned and overexpressed in E. coli and the protein product was purified and crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group C222{sub 1} and diffraction data were collected to a resolution of 1.6 Å. 3-Ketosteroid dehydrogenases are flavoproteins which play key roles in steroid ring degradation. The enzymes are abundantly present in actinobacteria, including the catabolic powerhouse Rhodococcus jostii and the pathogenic species R. equi and Mycobacterium tuberculosis. The gene for 3-ketosteroid Δ{sup 4}-(5α)-dehydrogenase [Δ{sup 4}-(5α)-KSTD] from R. jostii RHA1 was cloned and overexpressed in Escherichia coli. His-tagged Δ{sup 4}-(5α)-KSTD enzyme was purified by Ni{sup 2+}–NTA affinity chromatography, anion-exchange chromatography and size-exclusion chromatography and was crystallized using the hanging-drop vapour-diffusion method. Seeding greatly improved the number of crystals obtained. The crystals belonged to space group C222{sub 1}, with unit-cell parameters a = 99.2, b = 114.3, c = 110.2 Å. Data were collected to a resolution of 1.6 Å.

Crystallization, optimization and preliminary X-ray characterization of a metal-dependent PI-PLC from Streptomyces antibioticus

International Nuclear Information System (INIS)

Jackson, Michael R.; Selby, Thomas L.

2012-01-01

Crystallization and diffraction analysis of a Ca 2+ -dependent PI-PLC from Streptomyces is reported. Optimization of crystals was completed using a drop-pinning technique and heavy-atom soaks to achieve high-quality diffraction to 1.23 Å. A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) from Streptomyces antibioticus has been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space group P222, with unit-cell parameters a = 41.26, b = 51.86, c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution

Total Site Heat Integration Considering Pressure Drops

Directory of Open Access Journals (Sweden)

Kew Hong Chew

2015-02-01

Full Text Available Pressure drop is an important consideration in Total Site Heat Integration (TSHI. This is due to the typically large distances between the different plants and the flow across plant elevations and equipment, including heat exchangers. Failure to consider pressure drop during utility targeting and heat exchanger network (HEN synthesis may, at best, lead to optimistic energy targets, and at worst, an inoperable system if the pumps or compressors cannot overcome the actual pressure drop. Most studies have addressed the pressure drop factor in terms of pumping cost, forbidden matches or allowable pressure drop constraints in the optimisation of HEN. This study looks at the implication of pressure drop in the context of a Total Site. The graphical Pinch-based TSHI methodology is extended to consider the pressure drop factor during the minimum energy requirement (MER targeting stage. The improved methodology provides a more realistic estimation of the MER targets and valuable insights for the implementation of the TSHI design. In the case study, when pressure drop in the steam distribution networks is considered, the heating and cooling duties increase by 14.5% and 4.5%.

Rain drop size densities over land and over sea

Science.gov (United States)

Bumke, Karl

2010-05-01

A detailed knowledge of rain drop size densities is an essential presumption with respect to remote sensing of precipitation. Since maritime and continental aerosol is significantly different yielding to differences in cloud drop size densities, maritime and continental rain drop size densities may be different, too. In fact only a little is known about differences in rain drop size densities between land and sea due to a lack of suitable data over the sea. To fill in this gap measurements were performed during the recent 10 years at different locations in Germany and on board of research vessels over the Baltic Sea, the North Sea, Atlantic, Indian, and Pacific Ocean. Measurements were done by using an optical disdrometer (ODM 470, Großklaus et al., 1998), which is designed especially to perform precipitation measurements on moving ships and under high wind speeds. Temporal resolution of measurements is generally 1 minute, total number of time series is about 220000. To investigate differences in drop size densities over land and over sea measurements have been divided into four classes on the basis of prevailing continental or maritime influence: land measurements, coastal measurements, measurements in areas of semi-enclosed seas, and open sea measurements. In general differences in drop size densities are small between different areas. A Kolmogoroff Smirnoff test does not give any significant difference between drop size densities over land, coastal areas, semi-enclosed, and open seas at an error rate of 5%. Thus, it can be concluded that there are no systematic differences between maritime and continental drop size densities. The best fit of drop size densities is an exponential decay curve, N(D ) = 6510m -3mm -1mm0.14h- 0.14×R-0.14×exp(- 4.4mm0.25h-0.25×R- 0.25×D mm -1), it is estimated by using the method of least squares. N(D) is the drop size density normalized by the resolution of the optical disdrometer, D the diameter of rain drops in mm, and R the

Analysis of preparation of Chinese traditional medicine based on the fiber fingerprint drop trace

Science.gov (United States)

Zhang, Zhilin; Wang, Jialu; Sun, Weimin; Yan, Qi

2010-11-01

The purpose of the fiber micro-drop analyzing technique is to measure the characteristics of liquids using optical methods. The fiber fingerprint drop trace (FFDT) is a curve of light intensity vs. time. This curve indicates the forming, growing and dripping processes of the liquid drops. A pair of fibers was used to monitor the dripping process. The FFDTs are acquired and analyzed by a computer. Different liquid samples of many kinds of preparation of Chinese traditional medicines were tested by using the fiber micro-drop sensor in the experiments. The FFDTs of preparation of Chinese traditional medicines with different concentrations were analyzed in different ways. Considering the characters of the FFDTs, a novel method is proposed to measure the different preparation of Chinese traditional medicines and its concentration based on the corresponding relationship of FFDTs and the physical and chemical parameters of the liquids.

Liquid drop parameters for hot nuclei

International Nuclear Information System (INIS)

Guet, C.; Strumberger, E.; Brack, M.

1988-01-01

Using the semiclassical extended Thomas-FERMI (ETF) density variational method, we derived selfconsistently the liquid drop model (LDM) coefficients for the free energy of hot nuclear systems from a realistic effective interaction (Skyrme SkM*). We expand the temperature (T) dependence of these coefficients up to the second order in T and test their application to the calculation of the fission barriers of the nuclei 208 Pb and 240 Pu

Effect of rb-bFGF eye drops and hydroxyl indican eye drops on tear film stability and dry eye symptoms after age-related cataract surgery

Directory of Open Access Journals (Sweden)

Yu Ling

2018-01-01

Full Text Available AIM: To investigate the effect of recombinant bovine basic fibroblast growth factor(rb-bFGFeye drops and hydroxyl indican eye drops on tear film stability and dry eye symptoms after age-related cataract surgery. METHODS: Totally 80 patients with 80 affected eyes undergoing age-related cataract surgery in our hospital from January 2015 to October 2016 were selected as study subjects, and they were randomly divided into control group and experimental group with 40 patients(40 affected eyesin each group. The two groups were treated with hydroxyl indican eye drops and rb-bFGF eye drops, respectively. The clinical curative effect, inflammation related factors \\〖interleukin 6(IL-6, tumor necrosis factor α(TNF-α\\〗, Schirmer test(SⅠt, break-up time(BUTof tear film, corneal sodium fluorescein staining(FLand scores of dry eye symptoms in the two groups were observed. RESULTS: The total treatment effective rate of experimental group after treatment was significantly higher than that of the control group(90.0% vs 72.5%; χ2=4.021, PP>0.05. After treatment, IL-6, TNF-α, SⅠt, FL score and scores of dry eye symptoms in two groups significantly decreased while BUT significantly increased(PPCONCLUSION: In the treatment of patients after age-related cataract after surgery, rb-bFGF eye drops has more advantages over hydroxyl indican eye drops in regulating the expression of inflammatory factors, improving the tear film stability and relieving dry eye symptoms.

“just hanging out with you in my back yard”: Mark Zuckerberg and Mediated Paternalism

OpenAIRE

Little Ben; Winch Alison

2018-01-01

In a video that showcases a new Facebook feature, Mark Zuckerberg chats to his users, telling them that he’s “just hanging out with you in my backyard.” In this video-which is on his Facebook page-Zuckerberg discloses the domestic space of his backyard, revealing his interaction with family and friends. Depicted hosting a barbeque while watching the electoral debate, Zuckerberg performs an affective white postfeminist paternity (Hamad, 2014) by talking about hunting, eating meat, and being a ...

Sepsis from dropped clips at laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Hussain, Sarwat

2001-01-01

We report seven patients in whom five dropped surgical clips and two gallstones were visualized in the peritoneal cavity, on radiological studies. In two, subphrenic abscesses and empyemas developed as a result of dropped clips into the peritoneal cavity during or following laparoscopic cholecystectomy. In one of these two, a clip was removed surgically from the site of an abscess. In two other patients dropped gallstones, and in three, dropped clips led to no complications. These were seen incidentally on studies done for other indications. Abdominal abscess secondary to dropped gallstones is a well-recognized complication of laparoscopic cholecystectomy (LC). We conclude that even though dropped surgical clips usually do not cause problems, they should be considered as a risk additional to other well-known causes of post-LC abdominal sepsis

Emotional Competence and Drop-Out Rates in Higher Education

Science.gov (United States)

Kingston, Emma

2008-01-01

Purpose: The purpose of this paper is to compare the emotional competence of first year undergraduates enrolled on a high or low drop-out rate (HDR and LDR, respectively) course, at a newly established university within the UK. Design/methodology/approach: A mixed methods approach using both quantitative and qualitative data collection methods was…

Micro-splashing by drop impacts

KAUST Repository

Thoroddsen, Sigurdur T; Takehara, Kohsei; Etoh, Takeharugoji

2012-01-01

We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

Micro-splashing by drop impacts

KAUST Repository

Thoroddsen, Sigurdur T.

2012-07-18

We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

Pressure drop in ET-RR-1

International Nuclear Information System (INIS)

Khattab, M.; Mina, A.R.

1990-01-01

Measurements of pressure drop through a bundle comprising 16 rods and their lower arrangement grid as well as orifices similar to those of ET-RR-1 core have been done. Experiments are carried out under adiabatic turbulent flow conditions at about 35 degree C. Bundle Reynolds number range is 4 x 10 -2 x 10. Orifices of diameters 4.5, 3.25 or 2.5 cm. are mounted underneath the bundle. The bundle and lower grid pressure drop coefficients are 3.75 and 1.8 respectively. Orifices pressure drop coefficients are 2.65, 19.67 and 53.55 respectively. The ratio of bundle pressure drop to that of 4.5 cm. Orifice diameter is 1.415. The pressure drop coefficients are utilizer to calculate flow through bundles. The flow rate per bundle is 39.1, 20.4 or 13.1 m 3 /hr. Depending on orifice diameter

Controls on fault zone structure and brittle fracturing in the foliated hanging wall of the Alpine Fault

Science.gov (United States)

Williams, Jack N.; Toy, Virginia G.; Massiot, Cécile; McNamara, David D.; Smith, Steven A. F.; Mills, Steven

2018-04-01

Three datasets are used to quantify fracture density, orientation, and fill in the foliated hanging wall of the Alpine Fault: (1) X-ray computed tomography (CT) images of drill core collected within 25 m of its principal slip zones (PSZs) during the first phase of the Deep Fault Drilling Project that were reoriented with respect to borehole televiewer images, (2) field measurements from creek sections up to 500 m from the PSZs, and (3) CT images of oriented drill core collected during the Amethyst Hydro Project at distances of ˜ 0.7-2 km from the PSZs. Results show that within 160 m of the PSZs in foliated cataclasites and ultramylonites, gouge-filled fractures exhibit a wide range of orientations. At these distances, fractures are interpreted to have formed at relatively high confining pressures and/or in rocks that had a weak mechanical anisotropy. Conversely, at distances greater than 160 m from the PSZs, fractures are typically open and subparallel to the mylonitic or schistose foliation, implying that fracturing occurred at low confining pressures and/or in rocks that were mechanically anisotropic. Fracture density is similar across the ˜ 500 m width of the field transects. By combining our datasets with measurements of permeability and seismic velocity around the Alpine Fault, we further develop the hierarchical model for hanging-wall damage structure that was proposed by Townend et al. (2017). The wider zone of foliation-parallel fractures represents an outer damage zone that forms at shallow depths. The distinct inner damage zone. This zone is interpreted to extend towards the base of the seismogenic crust given that its width is comparable to (1) the Alpine Fault low-velocity zone detected by fault zone guided waves and (2) damage zones reported from other exhumed large-displacement faults. In summary, a narrow zone of fracturing at the base of the Alpine Fault's hanging-wall seismogenic crust is anticipated to widen at shallow depths, which is

Enhanced intelligent water drops algorithm for multi-depot vehicle routing problem.

Science.gov (United States)

Ezugwu, Absalom E; Akutsah, Francis; Olusanya, Micheal O; Adewumi, Aderemi O

2018-01-01

The intelligent water drop algorithm is a swarm-based metaheuristic algorithm, inspired by the characteristics of water drops in the river and the environmental changes resulting from the action of the flowing river. Since its appearance as an alternative stochastic optimization method, the algorithm has found applications in solving a wide range of combinatorial and functional optimization problems. This paper presents an improved intelligent water drop algorithm for solving multi-depot vehicle routing problems. A simulated annealing algorithm was introduced into the proposed algorithm as a local search metaheuristic to prevent the intelligent water drop algorithm from getting trapped into local minima and also improve its solution quality. In addition, some of the potential problematic issues associated with using simulated annealing that include high computational runtime and exponential calculation of the probability of acceptance criteria, are investigated. The exponential calculation of the probability of acceptance criteria for the simulated annealing based techniques is computationally expensive. Therefore, in order to maximize the performance of the intelligent water drop algorithm using simulated annealing, a better way of calculating the probability of acceptance criteria is considered. The performance of the proposed hybrid algorithm is evaluated by using 33 standard test problems, with the results obtained compared with the solutions offered by four well-known techniques from the subject literature. Experimental results and statistical tests show that the new method possesses outstanding performance in terms of solution quality and runtime consumed. In addition, the proposed algorithm is suitable for solving large-scale problems.

Contact angle of copper-bearing shales using the sessile drop and captive bubble methods in the presence of selected frothers

Directory of Open Access Journals (Sweden)

Danuta Szyszka

2016-01-01

Full Text Available This paper describes the measurement of contact angle of copper-bearing shales. The values of advancing and receding contact angles were determined using the sessile drop and captive bubble methods in the presence of aqueous solutions of acetal and pyridine and distilled water. Both methods demonstrated that the tested substances had only minor impact on the surface hydrophobicity of copper-bearing shales expressed by contact angle. The tests carried out proved that neither acetal nor pyridine may be classified to the collecting reagents because none of them improves hydrophobicity of copper-bearing shales. These reagents are only flotation frothers.

Drop trampoline

Science.gov (United States)

Chantelot, Pierre; Coux, Martin; Clanet, Christophe; Quere, David

2017-11-01

Superhydrophobic substrates inspired from the lotus leaf have the ability to reflect impacting water drops. They do so very efficiently and contact lasts typically 10 ms for millimetric droplets. Yet unlike a lotus leaf most synthetic substrates are rigid. Focusing on the interplay between substrate flexibility and liquid repellency might allow us to understand the dynamic properties of natural surfaces. We perform liquid marbles impacts at velocity V onto thin ( 0.01 mm) stretched circular PDMS membranes. We obtain contact time reductions of up to 70%. The bouncing mechanism is drastically modified compared to that on a rigid substrate: the marble leaves the substrate while it is still spread in a disk shape as it is kicked upwards by the membrane. We show that the bouncing is controlled by an interplay between the dynamics of the drop and the membrane.

Drop Spreading with Random Viscosity

Science.gov (United States)

Xu, Feng; Jensen, Oliver

2016-11-01

Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

On the equilibrium contact angle of sessile liquid drops from molecular dynamics simulations.

Science.gov (United States)

Ravipati, Srikanth; Aymard, Benjamin; Kalliadasis, Serafim; Galindo, Amparo

2018-04-28

We present a new methodology to estimate the contact angles of sessile drops from molecular simulations by using the Gaussian convolution method of Willard and Chandler [J. Phys. Chem. B 114, 1954-1958 (2010)] to calculate the coarse-grained density from atomic coordinates. The iso-density contour with average coarse-grained density value equal to half of the bulk liquid density is identified as the average liquid-vapor (LV) interface. Angles between the unit normal vectors to the average LV interface and unit normal vector to the solid surface, as a function of the distance normal to the solid surface, are calculated. The cosines of these angles are extrapolated to the three-phase contact line to estimate the sessile drop contact angle. The proposed methodology, which is relatively easy to implement, is systematically applied to three systems: (i) a Lennard-Jones (LJ) drop on a featureless LJ 9-3 surface; (ii) an SPC/E water drop on a featureless LJ 9-3 surface; and (iii) an SPC/E water drop on a graphite surface. The sessile drop contact angles estimated with our methodology for the first two systems are shown to be in good agreement with the angles predicted from Young's equation. The interfacial tensions required for this equation are computed by employing the test-area perturbation method for the corresponding planar interfaces. Our findings suggest that the widely adopted spherical-cap approximation should be used with caution, as it could take a long time for a sessile drop to relax to a spherical shape, of the order of 100 ns, especially for water molecules initiated in a lattice configuration on a solid surface. But even though a water drop can take a long time to reach the spherical shape, we find that the contact angle is well established much faster and the drop evolves toward the spherical shape following a constant-contact-angle relaxation dynamics. Making use of this observation, our methodology allows a good estimation of the sessile drop contact

Hyperbolic umbilic caustics from oblate water drops with tilted illumination: Observations

Science.gov (United States)

Jobe, Oli; Thiessen, David B.; Marston, Philip L.

2017-11-01

Various groups have reported observations of hyperbolic umbilic diffraction catastrophe patterns in the far-field scattering by oblate acoustically levitated drops with symmetric illumination. In observations of that type the drop's symmetry axis is vertical and the illuminating light beam (typically an expanded laser beam) travels horizontally. In the research summarized here, scattering patterns in the primary rainbow region and drop measurements were recorded with vertically tilted laser beam illumination having a grazing angle as large as 4 degrees. The findings from these observations may be summarized as follows: (a) It remains possible to adjust the drop aspect ratio (diameter/height) = D/H so as to produce a V-shaped hyperbolic umbilic focal section (HUFS) in the far-field scattering. (b) The shift in the required D/H was typically an increase of less than 1% and was quadratic in the tilt. (c) The apex of the V-shaped HUFS was shifted vertically by an amount proportional to the tilt with a coefficient close to unity. The levitated drops had negligible up-down asymmetry. Our method of investigation should be useful for other generalized rainbows with tilted illumination.

Muscle activity and spine load during anterior chain whole body linkage exercises: the body saw, hanging leg raise and walkout from a push-up.

Science.gov (United States)

McGill, Stuart; Andersen, Jordan; Cannon, Jordan

2015-01-01

This study examined anterior chain whole body linkage exercises, namely the body saw, hanging leg raise and walkout from a push-up. Investigation of these exercises focused on which particular muscles were challenged and the magnitude of the resulting spine load. Fourteen males performed the exercises while muscle activity, external force and 3D body segment motion were recorded. A sophisticated and anatomically detailed 3D model used muscle activity and body segment kinematics to estimate muscle force, and thus sensitivity to each individual's choice of motor control for each task. Gradations of muscle activity and spine load characteristics were observed across tasks. On average, the hanging straight leg raise created approximately 3000 N of spine compression while the body saw created less than 2500 N. The hanging straight leg raise created the highest challenge to the abdominal wall (>130% MVC in rectus abdominis, 88% MVC in external oblique). The body saw resulted in almost 140% MVC activation of the serratus anterior. All other exercises produced substantial abdominal challenge, although the body saw did so in the most spine conserving way. These findings, along with consideration of an individual's injury history, training goals and current fitness level, should assist in exercise choice and programme design.

Liquid-metal pin-fin pressure drop by correlation in cross flow

International Nuclear Information System (INIS)

Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

1994-01-01

The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

Adhesion of bubbles and drops to solid surfaces, and anisotropic surface tensions studied by capillary meniscus dynamometry

NARCIS (Netherlands)

Danov, Krassimir D.; Stanimirova, Rumyana D.; Kralchevsky, Peter A.; Marinova, Krastanka G.; Stoyanov, Simeon D.; Blijdenstein, Theodorus B.J.; Cox, Andrew R.; Pelan, Eddie G.

2016-01-01

Here, we review the principle and applications of two recently developed methods: the capillary meniscus dynamometry (CMD) for measuring the surface tension of bubbles/drops, and the capillary bridge dynamometry (CBD) for quantifying the bubble/drop adhesion to solid surfaces. Both methods are

CPAS Preflight Drop Test Analysis Process

Science.gov (United States)

Englert, Megan E.; Bledsoe, Kristin J.; Romero, Leah M.

2015-01-01