Alterations in physical state of silver nanoparticles exposed to synthetic human stomach fluid

International Nuclear Information System (INIS)

Rogers, Kim R.; Bradham, Karen; Tolaymat, Thabet; Thomas, David J.; Hartmann, Thomas; Ma, Longzhou; Williams, Alan

2012-01-01

The bioavailability of ingested silver nanoparticles (AgNPs) depends in large part on initial particle size, shape and surface coating, properties which will influence aggregation, solubility and chemical composition during transit of the gastrointestinal tract. Citrate-stabilized AgNPs were exposed to synthetic human stomach fluid (SSF) (pH 1.5) and changes in size, shape, zeta potential, hydrodynamic diameter and chemical composition were determined during a 1 h exposure period using Surface Plasmon Resonance (SPR), High Resolution Transmission Electron Microscopy/Energy Dispersive X-ray Spectroscopy (TEM/EDS), Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD) combined with Rietveld analysis. Exposure of AgNPs to SSF produced a rapid decrease in the SPR peak at 414 nm and the appearance of a broad absorbance peak in the near infrared (NIR) spectral region. During exposure to SSF, changes in zeta potential, aggregation and morphology of the particles were also observed as well as production of silver chloride which appeared physically associated with particle aggregates. - Highlights: ► Citrate-stabilized AgNPs were exposed to synthetic human stomach fluid (pH 1.5). ► Particle changes in chemical composition, zeta potential, aggregation and morphology were observed. ► Silver chloride appeared to be physically associated with the particle aggregates.

Alterations in physical state of silver nanoparticles exposed to synthetic human stomach fluid

Energy Technology Data Exchange (ETDEWEB)

Rogers, Kim R., E-mail: rogers.kim@epa.gov [U.S. Environmental Protection Agency, Las Vegas, NV (United States); Bradham, Karen [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Tolaymat, Thabet [U.S. Environmental Protection Agency, Cincinnati, OH (United States); Thomas, David J. [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Hartmann, Thomas; Ma, Longzhou [University of Nevada, Harry Reid Center for Environmental Studies, Las Vegas, NV (United States); Williams, Alan [U.S. Environmental Protection Agency, Las Vegas, NV (United States)

2012-03-15

The bioavailability of ingested silver nanoparticles (AgNPs) depends in large part on initial particle size, shape and surface coating, properties which will influence aggregation, solubility and chemical composition during transit of the gastrointestinal tract. Citrate-stabilized AgNPs were exposed to synthetic human stomach fluid (SSF) (pH 1.5) and changes in size, shape, zeta potential, hydrodynamic diameter and chemical composition were determined during a 1 h exposure period using Surface Plasmon Resonance (SPR), High Resolution Transmission Electron Microscopy/Energy Dispersive X-ray Spectroscopy (TEM/EDS), Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD) combined with Rietveld analysis. Exposure of AgNPs to SSF produced a rapid decrease in the SPR peak at 414 nm and the appearance of a broad absorbance peak in the near infrared (NIR) spectral region. During exposure to SSF, changes in zeta potential, aggregation and morphology of the particles were also observed as well as production of silver chloride which appeared physically associated with particle aggregates. - Highlights: Black-Right-Pointing-Pointer Citrate-stabilized AgNPs were exposed to synthetic human stomach fluid (pH 1.5). Black-Right-Pointing-Pointer Particle changes in chemical composition, zeta potential, aggregation and morphology were observed. Black-Right-Pointing-Pointer Silver chloride appeared to be physically associated with the particle aggregates.

Spectrophotometric Quantification of Toxicologically Relevant Concentrations of Chromium(VI in Cosmetic Pigments and Eyeshadow Using Synthetic Lachrymal Fluid Extraction

Directory of Open Access Journals (Sweden)

Sarah Wurster

2012-01-01

Full Text Available Chromium(VI salts are possible contaminants of the chromium(III pigments used as colorants in eyeshadow preparations. The use of products containing these contaminants poses acute risks for sensitization and contact allergies. Chromium(VI compounds are also classified as carcinogenic to humans (IARC group 1. An analytical method to analyse trace levels of chromium(VI in eyeshadow was developed in this study. The method is based on an extraction of the chromium(VI from the sample using a maximum extraction with alkali and additionally with synthetic lachrymal fluid to simulate physiological conditions. Following derivatization with 1,5-diphenylcarbazide, the extracted chromium(VI is then quantified by spectrophotometry (540 nm. Validation tests indicated a method standard deviation (inter- and intraday of 8.7% and a linear range up to 25 mg/kg. The average recovery was 107.9%, and the detection limit was 2.7 mg/kg. The applicability of the procedure was confirmed by the analysis of pigments and authentic eyeshadow matrices.

Changes in silver nanoparticles exposed to human synthetic stomach fluid: Effects of particle size and surface chemistry

International Nuclear Information System (INIS)

Mwilu, Samuel K.; El Badawy, Amro M.; Bradham, Karen; Nelson, Clay; Thomas, David; Scheckel, Kirk G.; Tolaymat, Thabet; Ma, Longzhou; Rogers, Kim R.

2013-01-01

The significant rise in consumer products and applications utilizing the antibacterial properties of silver nanoparticles (AgNPs) has increased the possibility of human exposure. The mobility and bioavailability of AgNPs through the ingestion pathway will depend, in part, on properties such as particle size and the surface chemistries that will influence their physical and chemical reactivities during transit through the gastrointestinal tract. This study investigates the interactions between synthetic stomach fluid and AgNPs of different sizes and with different capping agents. Changes in morphology, size and chemical composition were determined during a 30 min exposure to synthetic human stomach fluid (SSF) using Absorbance Spectroscopy, High Resolution Transmission Electron and Scanning Electron Microscopy (TEM/SEM), Dynamic Light Scattering (DLS), and Nanoparticle Tracking Analysis (NTA). AgNPs exposed to SSF were found to aggregate significantly and also released ionic silver which physically associated with the particle aggregates as silver chloride. Generally, the smaller sized AgNPs (< 10 nm) showed higher rates of aggregation and physical transformation than larger particles (75 nm). Polyvinylpyrrolidone (pvp)-stabilized AgNPs prepared in house behaved differently in SSF than particles obtained from a commercial source despite having similar surface coating and size distribution characteristics. - Highlights: ► Interactions between synthetic stomach fluid (SSF) and silver nanoparticles (AgNPs) are described. ► AgNPs exposed to SSF aggregate and silver chloride are associated with the particle aggregates. ► Smaller AgNPs (< 10 nm) showed higher rates of aggregation and transformation than larger particles (75 nm). ► Polyvinylpyrrolidone-stabilized AgNPs obtained from different sources aggregated at different rates when exposed to SSF

Effects of Weightlessness on Human Fluid and Electrolyte Physiology

Science.gov (United States)

Leach, Carolyn S.; Johnson, Philip C., Jr.

1991-01-01

The changes that occur in human fluid and electrolyte physiology during the acute and adaptive phases of adaptation to spaceflight are summarized. A number of questions remain to be answered. At a time when plasma volume and extracellular fluid volume are contracted and salt and water intake is unrestricted. ADH does not correct the volume deficit and serum sodium decreases. Change in secretion or activity of a natriuretic factor during spaceflight is one possible explanation. Recent identification of a polypeptide hormone produced in cardiac muscle cells which is natiuretic, is hypotensive, and has an inhibitory effect on renin and aldosterone secretion has renewed interest in the role of a natriuretic factor. The role of this atrial natriuretic factor (ANF) in both long- and short-term variation in extracellular volumes and in the inability of the kidney to bring about an escape from the sodium-retaining state accompanying chronic cardiac dysfunction makes it reasonable to look for a role of ANF in the regulation of sodium during exposure to microgravity. Prostaglandin-E is another hormone that may antagonize the action of ADH. Assays of these hormones will be performed on samples from crew members in the future.

Removal of zearalenone toxin from synthetics gastric and body fluids using talc and diatomite: a batch kinetic study.

Science.gov (United States)

Sprynskyy, Myroslav; Gadzała-Kopciuch, Renata; Nowak, Karolina; Buszewski, Bogusław

2012-06-01

Adsorption kinetics of zearalenone (ZEA) toxin from synthetic gastric fluid (SGF) and synthetic body fluid (SBF) by talc and diatomite was studied in the batch experiments. Chemical composition, morphology and structure of the used adsorbents were examined by scanning electron microscopy, FTIR spectroscopy and low-temperature nitrogen adsorption/desorption method. High performance liquid chromatography (HPLC) method was used for ZEA determining. The study results showed that ZEA is more effectively adsorbed on the talc (73% and 54% from SGF and SBF respectively). The efficiency on the diatomite was lower (53% and 42% from SGF and SBF respectively). The first order kinetics model was applied to describe the adsorption process. Rate of the ZEA adsorption from SGF is very rapid initially with about 95% of amount of the toxin adsorbed during first 5 min, while ZEA is adsorbed from SBF in two steps. The values of determined Gibbs free energy of adsorption (from -13 to -17 kJ/mol) indicated that adsorption of ZEA toxin by the both adsorbents are spontaneous and exothermic. Copyright © 2012 Elsevier B.V. All rights reserved.

Experience with synthetic fluorinated fluid lubricants

Science.gov (United States)

Conley, Peter L.; Bohner, John J.

1990-01-01

Since the late 1970's, the wet lubricant of choice for space mechanisms has been one of the family of synthetic perfluoro polyalkylether (PFPE) compounds, namely Fomblin Z-25 (Bray-815Z) or DuPont's Krytox 143xx series. While offering the advantages of extremely low vapor pressures and wide temperature ranges, these oils and derived greases have a complex chemistry compared to the more familiar natural and synthetic hydrocarbons. Many aerospace companies have conducted test programs to characterize the behavior of these compounds in a space environment, resulting in a large body of hard knowledge as well as considerable space lore concerning the suitability of the lubricants for particular applications and techniques for successful application. The facts are summarized and a few myths about the compounds are dispelled, and some performance guidelines for the mechanism design engineer are provided.

Metabolism and toxicological analysis of synthetic cannabinoids in biological fluids and tissues.

Science.gov (United States)

Presley, B C; Gurney, S M R; Scott, K S; Kacinko, S L; Logan, B K

2016-07-01

Synthetic cannabinoids, which began proliferating in the United States in 2009, have gone through numerous iterations of modification to their chemical structures. More recent generations of compounds have been associated with significant adverse outcomes following use, including cognitive and psychomotor impairment, seizures, psychosis, tissue injury and death. These effects increase the urgency for forensic and public health laboratories to develop methods for the detection and identification of novel substances, and apply these to the determination of their metabolism and disposition in biological samples. This comprehensive review describes the history of the appearance of the drugs in the United States, discusses the naming conventions emerging to designate new structures, and describes the most prominent new compounds linked to the adverse effects now associated with their use. We review in depth the metabolic pathways that have been elucidated for the major members of each of the prevalent synthetic cannabinoid drug subclasses, the enzyme systems responsible for their metabolism, and the use of in silico approaches to assist in predicting and identifying the metabolites of novel compounds and drug subclasses that will continue to appear. Finally, we review and critique analytical methods applied to the detection of the drugs and their metabolites, including immunoassay screening, and liquid chromatography mass spectrometry confirmatory techniques applied to urine, serum, whole blood, oral fluid, hair, and tissues. Copyright © 2016 Central Police University.

Estimation of the physiological mechanical conditioning in vascular tissue engineering by a predictive fluid-structure interaction approach.

Science.gov (United States)

Tresoldi, Claudia; Bianchi, Elena; Pellegata, Alessandro Filippo; Dubini, Gabriele; Mantero, Sara

2017-08-01

The in vitro replication of physiological mechanical conditioning through bioreactors plays a crucial role in the development of functional Small-Caliber Tissue-Engineered Blood Vessels. An in silico scaffold-specific model under pulsatile perfusion provided by a bioreactor was implemented using a fluid-structure interaction (FSI) approach for viscoelastic tubular scaffolds (e.g. decellularized swine arteries, DSA). Results of working pressures, circumferential deformations, and wall shear stress on DSA fell within the desired physiological range and indicated the ability of this model to correctly predict the mechanical conditioning acting on the cells-scaffold system. Consequently, the FSI model allowed us to a priori define the stimulation pattern, driving in vitro physiological maturation of scaffolds, especially with viscoelastic properties.

Radioimmunoasay of calcitonin in plasma and cerebro-spinal fluid

International Nuclear Information System (INIS)

Cecchettin, M.; Comberti, E.; Quinzanini, M.; Albertini, A.; Tarquini, B.

1985-01-01

An acceptable radioimmunoassay of calcitonin (CT) in man requires a highly purified antigen that can be labelled without loss of immunoreactivity. Radiolabelled synthetic CT showed an additional large peak of radiopeptides with high molecular weight. Therefore, a standard electrofocussing experiment was performed. Standards exhibiting an atypical behaviour after radioiodination showed a pI different from synthetic human monomer. CT electrophoretogram shows a larger component at pI 7.9 and two smaller contaminations at pI 8.6. Besides, the antisera available for CT assay are considered in healthy subjects. 0H 2 and COOH assays give non-homogeneous results. A CT assay in cerebrospinal fluid is performed. The direct assay was unable to detect significant correlation between serum and cerebrospinal levels both in physiological and pathological conditions. Finally, the quality control of the CT assay is discussed. (Auth./G.J.P.)

Effect of a synthetic drilling fluid (IPAR) on antioxidant enzymes and peroxisome proliferation in the American lobster, Homarsus americanus

International Nuclear Information System (INIS)

Hamoutene, D.; Payne, J.F.; Andrews, C.; Wells, J.; Guiney, J.

2004-01-01

The acute, sublethal toxicity of a synthetic paraffinic drilling fluid (IPAR) was examined in this study which exposed 2 sets of 14 lobsters to the substance. Synthetic-based muds (SBMs) make up the fluid component of drilling muds along with water-based muds (WBMs) and oil-based muds (OBMs). Although SBMs are proposed to replace OBMs, little is known about their environmental impact. IPAR, an ultra-pure isoalkane with no aromatics or sulphur compounds, is currently used in the Newfoundland offshore. This study examined the effect of IPAR on benthic crustacean because most of the wastes discharged from drilling platforms sediment quickly and the impact is greatest on benthic animals. The lobsters were injected with 1 mL of IPAR every 3 days, to a maximum of 5 mL. They were also exposed to very high levels of the fluid, which would not be expected under field conditions. Different aspects of lipid and protein metabolism were monitored along with the effect of IPAR on peroxisome proliferations and various serum and organ enzymes. The study showed that even at the high dose administered to the lobsters, the isoalkane mixture had no influence on peroxisome proliferation. Increased amounts of protein was found in claw muscles, but no increase was observed in gills, hepatopancreas or heart, suggesting no adverse impact of IPAR. A slight increase was also noted in serum aminotransferases. The study results are in agreement with the hypothesis that IPAR has little or no ecotoxicological potential. 32 refs., 3 tabs., 2 figs

Effect of a synthetic drilling fluid (IPAR) on antioxidant enzymes and peroxisome proliferation in the American lobster, Homarsus americanus

Energy Technology Data Exchange (ETDEWEB)

Hamoutene, D.; Payne, J.F.; Andrews, C.; Wells, J.; Guiney, J.

2004-07-01

The acute, sublethal toxicity of a synthetic paraffinic drilling fluid (IPAR) was examined in this study which exposed 2 sets of 14 lobsters to the substance. Synthetic-based muds (SBMs) make up the fluid component of drilling muds along with water-based muds (WBMs) and oil-based muds (OBMs). Although SBMs are proposed to replace OBMs, little is known about their environmental impact. IPAR, an ultra-pure isoalkane with no aromatics or sulphur compounds, is currently used in the Newfoundland offshore. This study examined the effect of IPAR on benthic crustacean because most of the wastes discharged from drilling platforms sediment quickly and the impact is greatest on benthic animals. The lobsters were injected with 1 mL of IPAR every 3 days, to a maximum of 5 mL. They were also exposed to very high levels of the fluid, which would not be expected under field conditions. Different aspects of lipid and protein metabolism were monitored along with the effect of IPAR on peroxisome proliferations and various serum and organ enzymes. The study showed that even at the high dose administered to the lobsters, the isoalkane mixture had no influence on peroxisome proliferation. Increased amounts of protein was found in claw muscles, but no increase was observed in gills, hepatopancreas or heart, suggesting no adverse impact of IPAR. A slight increase was also noted in serum aminotransferases. The study results are in agreement with the hypothesis that IPAR has little or no ecotoxicological potential. 32 refs., 3 tabs., 2 figs.

Implementation of physiological fluids to provide insight into the characterization, fate, and biological interactions of silver nanoparticles

Science.gov (United States)

Breitner, Emily K.; Burns, Katherine E.; Hussain, Saber M.; Comfort, Kristen K.

2018-06-01

Silver nanoparticles (AgNPs) are being increasingly utilized in consumer and medical applications. However, there remains conflicting reports on their safety, which are evaluated through a combination of in vitro and in vivo exposure models. These discrepancies may arise, in part, due to the inherent differences between cell-based and animal systems. It is well established that nanotoxicological effects are highly dependent on the unique physicochemical properties and behavior of the particle set, including size, surface chemistry, agglomeration, and ionic dissolution. However, recent studies have identified that these properties vary as a function of exposure environment; providing a rationale for the contradictory results between in vitro and in vivo assessments. Artificial physiological fluids are emerging as a powerful tool as they allow for the characterization of NPs in an environment which they would likely encounter in vivo, in addition to having the experimental advantages of flexibility and consistency. Here, we demonstrated that the utilization of artificial fluids provided a mechanism to assess AgNP behavior and induced bioresponses in environments that they would likely encounter in vivo. AgNPs were introduced within an alveolar-based exposure model, which included alveolar epithelial (A549) cells incubated within artificial alveolar fluid (AF). Additionally, the particles underwent extensive characterization within both AF and lysosomal fluid, which the AgNPs would encounter following cellular internalization. Following incubation in physiological environments AgNP properties were significantly modified versus a traditional media environment, including alterations to both extent of agglomeration and rate of ionic dissolution. Moreover, when A549s were exposed to AgNPs in AF, the cells displayed lower cytotoxicity and stress rates, corresponding to a fluid-dependent drop in silver ion production. This work highlights the need for enhanced in vitro

Seminal Fluid-Mediated Inflammation in Physiology and Pathology of the Female Reproductive Tract

Directory of Open Access Journals (Sweden)

Anthonio O. Adefuye

2016-01-01

Full Text Available Inflammation is a multifaceted process involving a host of resident and recruited immune cells that eliminate the insult or injury and initiate tissue repair. In the female reproductive tract (FMRT, inflammation-mediated alterations in epithelial, vascular, and immune functions are important components of complex physiological processes and many local and systemic pathologies. It is well established that intracoital and postcoital function of seminal fluid (SF goes beyond nutritive support for the spermatozoa cells. SF, in particular, the inflammatory bioactive lipids, and prostaglandins present in vast quantities in SF, have a role in localized immune modulation and regulation of pathways that can exacerbate inflammation in the FMRT. In sexually active women SF-mediated inflammation has been implicated in physiologic processes such as ovulation, implantation, and parturition while also enhancing tumorigenesis and susceptibility to infection. This review highlights the molecular mechanism by which SF regulates inflammatory pathways in the FMRT and how alterations in these pathways contribute to physiology and pathology of the female reproductive function. In addition, based on findings from TaqMan® 96-Well Plate Arrays, on neoplastic cervical cells treated with SF, we discuss new findings on the role of SF as a potent driver of inflammatory and tumorigenic pathways in the cervix.

Personalised fluid resuscitation in the ICU: still a fluid concept?

Science.gov (United States)

van Haren, Frank

2017-12-28

The administration of intravenous fluid to critically ill patients is one of the most common, but also one of the most fiercely debated, interventions in intensive care medicine. Even though many thousands of patients have been enrolled in large trials of alternative fluid strategies, consensus remains elusive and practice is widely variable. Critically ill patients are significantly heterogeneous, making a one size fits all approach unlikely to be successful.New data from basic, animal, and clinical research suggest that fluid resuscitation could be associated with significant harm. There are several important limitations and concerns regarding fluid bolus therapy as it is currently being used in clinical practice. These include, but are not limited to: the lack of an agreed definition; limited and short-lived physiological effects; no evidence of an effect on relevant patient outcomes; and the potential to contribute to fluid overload, specifically when fluid responsiveness is not assessed and when targets and safety limits are not used.Fluid administration in critically ill patients requires clinicians to integrate abnormal physiological parameters into a clinical decision-making model that also incorporates the likely diagnosis and the likely risk or benefit in the specific patient's context. Personalised fluid resuscitation requires careful attention to the mnemonic CIT TAIT: context, indication, targets, timing, amount of fluid, infusion strategy, and type of fluid.The research agenda should focus on experimental and clinical studies to: improve our understanding of the physiological effects of fluid infusion, e.g. on the glycocalyx; evaluate new types of fluids; evaluate novel fluid minimisation protocols; study the effects of a no-fluid strategy for selected patients and scenarios; and compare fluid therapy with other interventions. The adaptive platform trial design may provide us with the tools to evaluate these types of interventions in the intrinsically

Performance Comparison and Selection of Transformer Fluid

Directory of Open Access Journals (Sweden)

Lu Yang

2016-01-01

Full Text Available Transformer fluid directly affects the working state of the components and the cooling efficiency of transformer. There are three kinds of transformer fluid used for electric locomotive, EMU and suburban rail vehicles: mineral oil, silicone liquid and synthetic ester based insulating oil. In this paper, the three kinds of oil are compared from the fire safety, environmental protection, reliability and low maintenance. It provides a strong basis for the selection of transformer fluid. By comprehensive analysis, synthetic ester based insulating oil can completely replace mineral oil and silicone liquid. With rail transport safety and environmental protection standards improving, synthetic ester based insulating oil will be the best choice for transformer.

Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids

International Nuclear Information System (INIS)

Tang, Qian; Li, Zai-yong; Wei, Yu-bo; Yang, Xia; Liu, Lan-tao; Gong, Cheng-bin; Ma, Xue-bing; Lam, Michael Hon-wah; Chow, Cheuk-fai

2016-01-01

A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22 × 10"−"5 M in aqueous NaH_2PO_4 buffer at pH = 7.0 and a maximal adsorption capacity of 1.45 μmol g"−"1. Upon alternate irradiation at 365 and 440 nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid. - Highlights: • Novel surface molecularly imprinted polymer on ZnO nanorods was synthesized. • ZnO-SMIP showed good selectivity toward uric acid in physiological fluids. • ZnO-SMIP displayed good photoresponsive properties.

Photoresponsive surface molecularly imprinted polymer on ZnO nanorods for uric acid detection in physiological fluids

Energy Technology Data Exchange (ETDEWEB)

Tang, Qian [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Department of Science and Environmental Studies, The Hong Kong Institute of Education (Hong Kong); Li, Zai-yong; Wei, Yu-bo; Yang, Xia; Liu, Lan-tao [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Gong, Cheng-bin, E-mail: gongcbtq@swu.edu.cn [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Ma, Xue-bing [The Key Laboratory of Applied Chemistry of Chongqing Municipality, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Lam, Michael Hon-wah [Department of Biology and Chemistry, City University of Hong Kong (Hong Kong); Chow, Cheuk-fai, E-mail: cfchow@ied.edu.hk [Department of Science and Environmental Studies, The Hong Kong Institute of Education (Hong Kong)

2016-09-01

A photoresponsive surface molecularly imprinted polymer for uric acid in physiological fluids was fabricated through a facile and effective method using bio-safe and biocompatible ZnO nanorods as a support. The strategy was carried out by introducing double bonds on the surface of the ZnO nanorods with 3-methacryloxypropyltrimethoxysilane. The surface molecularly imprinted polymer on ZnO nanorods was then prepared by surface polymerization using uric acid as template, water-soluble 5-[(4-(methacryloyloxy)phenyl)diazenyl]isophthalic acid as functional monomer, and triethanolamine trimethacryl ester as cross-linker. The surface molecularly imprinted polymer on ZnO nanorods showed good photoresponsive properties, high recognition ability, and fast binding kinetics toward uric acid, with a dissociation constant of 3.22 × 10{sup −5} M in aqueous NaH{sub 2}PO{sub 4} buffer at pH = 7.0 and a maximal adsorption capacity of 1.45 μmol g{sup −1}. Upon alternate irradiation at 365 and 440 nm, the surface molecularly imprinted polymer on ZnO nanorods can quantitatively uptake and release uric acid. - Highlights: • Novel surface molecularly imprinted polymer on ZnO nanorods was synthesized. • ZnO-SMIP showed good selectivity toward uric acid in physiological fluids. • ZnO-SMIP displayed good photoresponsive properties.

Particulate metal bioaccessibility in physiological fluids and cell culture media: Toxicological perspectives.

Science.gov (United States)

Leclercq, Bérénice; Alleman, Laurent Yves; Perdrix, Esperanza; Riffault, Véronique; Happillon, Mélanie; Strecker, Alain; Lo-Guidice, Jean-Marc; Garçon, Guillaume; Coddeville, Patrice

2017-07-01

According to the literature, tiny amounts of transition metals in airborne fine particles (PM 2.5 ) may induce proinflammatory cell response through reactive oxygen species production. The solubility of particle-bound metals in physiological fluids, i.e. the metal bioaccessibility is driven by factors such as the solution chemical composition, the contact time with the particles, and the solid-to-liquid phase ratio (S/L). In this work, PM 2.5 -bound metal bioaccessibility was assessed in various physiological-like solutions including cell culture media in order to evidence the potential impact on normal human bronchial epithelial cells (NHBE) when studying the cytotoxicity and inflammatory responses of PM 2.5 towards the target bronchial compartment. Different fluids (H 2 O, PBS, LHC-9 culture medium, Gamble and human respiratory mucus collected from COPD patients), various S/L conditions (from 1/6000 to 1/100,000) and exposure times (6, 24 and 72h) were tested on urban PM 2.5 samples. In addition, metals' total, soluble and insoluble fractions from PM 2.5 in LHC-9 were deposited on NHBE cells (BEAS-2B) to measure their cytotoxicity and inflammatory potential (i.e., G6PDH activity, secretion of IL-6 and IL-8). The bioaccessibility is solution-dependent. A higher salinity or organic content may increase or inhibit the bioaccessibiliy according to the element, as observed in the complex mucus matrix. Decreasing the S/L ratio also affect the bioaccessibility depending on the solution tested while the exposure time appears less critical. The LHC-9 culture medium appears to be a good physiological proxy as it induces metal bioaccessibilities close to the mucus values and is little affected by S/L ratios or exposure time. Only the insoluble fraction can be linked to the PM 2.5 -induced cytotoxicity. By contrast, both soluble and insoluble fractions can be related to the secretion of cytokines. The metal bioaccessibility in LHC-9 of the total, soluble, and insoluble

Beneficial effects of intermittent fluid pressure of low physiological magnitude on cartilage and inflammation in osteoarthritis. An in vitro study

NARCIS (Netherlands)

van Valburg, A. A.; van Roy, H. L.; Lafeber, F. P.; Bijlsma, J. W.

1998-01-01

To investigate the in vitro effects of low physiological levels of intermittent fluid pressure (0-13 kPa; 0.33 Hz), in the absence of mechanical stress, on articular cartilage, inflammatory cells, and on the combination of these components, present in the osteoarthritic (OA) joint. Normal and OA

Biological activity and toxicitiy of imported and synthetic metal ...

African Journals Online (AJOL)

... of green alga Scendesmus obliquus. The toxicity of surfactants to Scendesmus obliquus are arranged in the order: imported fluid > Synthetic fluid > S+ D > I+A> S+B> I+ C> I+B > I+D > I+D >S+A > I+4. These results prove that, the toxicity of fluids depends on its chemical structure. Egyptian Journal of Biotechnology Vol.

Synthetic lubricants based on copolymers of n-butyl methacrylate and α-olefins

Directory of Open Access Journals (Sweden)

Đakov Tatjana A.

2002-01-01

Full Text Available Synthetic fluids obtained by the copolymerization of α -olefins with alkyl esters of unsaturated carboxylic acids have a unique combination of properties of non-polar poly-a-olefins (PAOs and polar esters in a single molecule. These compounds are characterized by superior thermal, oxidative and hydrolytic stability, miscibility with mineral and synthetic base oils solubility of additives and neutral elastomer behavior. Depending on the molar masses and comonomer ratios in the copolymer molecule, synthetic fluids with a wide range of properties are obtained. These compounds are valuable components in lubricating oil formulations for different applications.

Exploration of the phase diagram of liquid water in the low-temperature metastable region using synthetic fluid inclusions

DEFF Research Database (Denmark)

Qiu, Chen; Krüger, Yves; Wilke, Max

2016-01-01

water with a density of 0.921 kg/m3 remains in a homogeneous state during cooling down to the temperaure of −30.5 °C, where it is transformed into ice whose density corresponds to zero pressure. iii) ice melting. Ice melting temperatures of up to 6.8 °C were measured in absence of the vapour bubble, i......We present new experimental data of the low-temperature metastable region of liquid water derived from high-density synthetic fluid inclusions (996−916 kg/m3) in quartz. Microthermometric measurements include: i) Prograde (upon heating) and retrograde (upon cooling) liquid-vapour homogenisation. We...

Experimental study and calculations of the near critical behavior of a synthetic fluid in nitrogen injection

International Nuclear Information System (INIS)

Coronado Parra, Carlos Alberto; Escobar Remolina, Juan Carlos M

2005-01-01

In recent years, the use of nitrogen has increased as gas injection to recover oil fluids near the critical point. The behavior of hydrocarbon mixture phases in the critical region shows very interesting complex phenomena when facing a recovery project with nitrogen. Therefore, it is important to have experimental information of the PVTx thermodynamic variable, often scarce, for this type of critical phenomena. This paper reports the experimental measures of the volumetric behavior and phases of synthetic fluid in a nitrogen injection process. The experiment was performed at laboratory scale, and it obtained variations on the saturation pressure, gas oil ratio, density and composition of the hydrocarbon phase when nitrogen was injected at molars of 10,20,30 and 40% on different volumetric portions of the mother sample. In addition, the data obtained experimentally was used to demonstrate the capacity of tune to compositional models. The data provided represents a valuable contribution to the understanding of phenomena associated with retrograde and near critical regions, as well as their use in tuning and developing more elaborate models such as Cubic Equations of State (EOS). It is worth highlighting the importance of this data in the potential processes of nitrogen, CO 2 , and lean gas injection, which require knowledge of the gas-oil ratio, saturation pressures, density and composition of the fluid in current production. The identification of the phenomena shown, represent a potential application to the modeling of displacements and maintaining the pressure in the improved recovery when scaling up the laboratory data to the field / reservoir conditions

Synthetics, mineral oils, and bio-based lubricants chemistry and technology

CERN Document Server

Rudnick, Leslie R

2005-01-01

As the field of tribology has evolved, the lubrication industry is also progressing at an extraordinary rate. Updating the author's bestselling publication, Synthetic Lubricants and High-Performance Functional Fluids, this book features the contributions of over 60 specialists, ten new chapters, and a new title to reflect the evolving nature of the field: Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology. The book contains chapters on all major lubricant fluids used in a wide range of applications. For each type of lubricant, the authors discuss the historical develo

Liquid chromatography tandem mass spectrometry determination of selected synthetic cathinones and two piperazines in oral fluid. Cross reactivity study with an on-site immunoassay device.

Science.gov (United States)

de Castro, Ana; Lendoiro, Elena; Fernández-Vega, Hadriana; Steinmeyer, Stefan; López-Rivadulla, Manuel; Cruz, Angelines

2014-12-29

Since the past few years, several synthetic cathinones and piperazines have been introduced into the drug market to substitute illegal stimulant drugs such as amphetamine and derivatives or cocaine due to their unregulated situation. These emerging drugs are not usually included in routine toxicological analysis. We developed and validated a LC-MS/MS method for the determination of methedrone, methylone, mephedrone, 3,4-methylenedioxypyrovalerone (MDPV), fluoromethcathinone, fluoromethamphetamine, 1-(3-chlorophenyl)piperazine (mCPP) and 3-trifluoromethylphenylpiperazine (TFMPP) in oral fluid. Sample extraction was performed using Strata X cartridges. Chromatographic separation was achieved in 10min using an Atlantis(®) T3 column (100mm×2.1mm, 3μm), and formic acid 0.1% and acetonitrile as mobile phase. The method was satisfactorily validated, including selectivity, linearity (0.2-0.5 to 200ng/mL), limits of detection (0.025-0.1ng/mL) and quantification (0.2-0.5ng/mL), imprecision and accuracy in neat oral fluid (%CV=0.0-12.7% and 84.8-103.6% of target concentration, respectively) and in oral fluid mixed with Quantisal™ buffer (%CV=7.2-10.3% and 80.2-106.5% of target concentration, respectively), matrix effect in neat oral fluid (-11.6 to 399.7%) and in oral fluid with Quantisal™ buffer (-69.9 to 131.2%), extraction recovery (87.9-134.3%) and recovery from the Quantisal™ (79.6-107.7%), dilution integrity (75-99% of target concentration) and stability at different conditions (-14.8 to 30.8% loss). In addition, cross reactivity produced by the studied synthetic cathinones in oral fluid using the Dräger DrugTest 5000 was assessed. All the analytes produced a methamphetamine positive result at high concentrations (100 or 10μg/mL), and fluoromethamphetamine also at low concentration (0.075μg/mL). Copyright © 2014 Elsevier B.V. All rights reserved.

Physiology for engineers applying engineering methods to physiological systems

CERN Document Server

Chappell, Michael

2016-01-01

This book provides an introduction to qualitative and quantitative aspects of human physiology. It looks at biological and physiological processes and phenomena, including a selection of mathematical models, showing how physiological problems can be mathematically formulated and studied. It also illustrates how a wide range of engineering and physics topics, including electronics, fluid dynamics, solid mechanics and control theory can be used to describe and understand physiological processes and systems. Throughout the text there are introductions to measuring and quantifying physiological processes using both signal and imaging technologies. Physiology for Engineers describes the basic structure and models of cellular systems, the structure and function of the cardiovascular system, the electrical and mechanical activity of the heart and provides an overview of the structure and function of the respiratory and nervous systems. It also includes an introduction to the basic concepts and applications of reacti...

Optimal composition of fluid-replacement beverages.

Science.gov (United States)

Baker, Lindsay B; Jeukendrup, Asker E

2014-04-01

The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.

Electro-osmotically actuated oscillatory flow of a physiological fluid on a porous microchannel subject to an external AC electric field having dissimilar frequencies

Science.gov (United States)

Misra, Jagadis C.; Chandra, Sukumar

2014-04-01

Electro-osmotic flow of a physiological fluid with prominent micropolar characteristics, flowing over a microchannel has been analyzed for a situation, where the system is subject to the action of an external AC electric field. In order to account for the rotation of the micro-particles suspended in the physiological fluid, the fluid has been treated as a micropolar fluid. The microchannel is considered to be bounded by two porous plates executing oscillatory motion. Such motion of the plates will normally induce oscillatory flow of the fluid. The governing equations of the fluid include a second-order partial differential equation depicting Gauss's law of electrical charge distributions and two other partial differential equations of second order that arise out of the laws of conservation of linear and angular momenta. These equations have been solved under the sole influence of electrokinetic forces, by using appropriate boundary conditions. This enabled us to determine explicit analytical expressions for the electro-osmotic velocity of the fluid and the microrotation of the suspended micro-particles. These expressions have been used to obtain numerical estimates of important physical variables associated with the oscillatory electro-osmotic flow of a blood sample inside a micro-bio-fluidic device. The numerical results presented in graphical form clearly indicate that the formation of an electrical double layer near the vicinity of the wall causes linear momentum to reduce. In contrast, the angular momentum increases with the enhancement of microrotation of the suspended microparticles. The study will find important applications in the validation of results of further experimental and numerical models pertaining to flow in micro-bio-fluidic devices. It will also be useful in the improvement of the design and construction of various micro-bio-fluidic devices.

Physiologic effects of intravenous fluid administration in healthy volunteers

DEFF Research Database (Denmark)

Holte, Kathrine; Jensen, Peter; Kehlet, Henrik

2003-01-01

, infusion of the fluid over 3 h in the morning, and additionally 24-h hospitalization under standardized conditions. Primary outcome assessments were pulmonary function (spirometry), exercise capacity (submaximal treadmill test), balance function (BalanceMaster), and weight. Infusion of 40 mL/kg of lactated...... by fluid administration. These findings may serve as a basis for clinical studies applying the same type of fluid in different amounts to determine the optimal amount of perioperative fluid in various surgical procedures. IMPLICATIONS: Infusion of 40 mL/kg of lactated Ringer's solution in volunteers led...

Axisymmetric Synthetic Jet Actuators with Large Streamwise Dimensions

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Trávníček, Zdeněk

2013-01-01

Roč. 51, č. 12 (2013), s. 2862-2877 ISSN 0001-1452 R&D Projects: GA ČR GPP101/12/P556; GA ČR(CZ) GCP101/11/J019 Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * resonance frequency Subject RIV: BK - Fluid Dynamics Impact factor: 1.165, year: 2013 http://arc.aiaa.org/doi/abs/10.2514/1.J052504

Differential physiological and behavioral cues observed in individuals smoking botanical marijuana versus synthetic cannabinoid drugs.

Science.gov (United States)

Chase, Peter B; Hawkins, Jeff; Mosier, Jarrod; Jimenez, Ernest; Boesen, Keith; Logan, Barry K; Walter, Frank G

2016-01-01

Synthetic cannabinoid use has increased in many states, and medicinal and/or recreational marijuana use has been legalized in some states. These changes present challenges to law enforcement drug recognition experts (DREs) who determine whether drivers are impaired by synthetic cannabinoids or marijuana, as well as to clinical toxicologists who care for patients with complications from synthetic cannabinoids and marijuana. Our goal was to compare what effects synthetic cannabinoids and marijuana had on performance and behavior, including driving impairment, by reviewing records generated by law enforcement DREs who evaluated motorists arrested for impaired driving. Data were from a retrospective, convenience sample of de-identified arrest reports from impaired drivers suspected of using synthetic cannabinoids (n = 100) or marijuana (n = 33). Inclusion criteria were arrested drivers who admitted to using either synthetic cannabinoids or marijuana, or who possessed either synthetic cannabinoids or marijuana; who also had a DRE evaluation at the scene; and whose blood screens were negative for alcohol and other drugs. Exclusion criteria were impaired drivers arrested with other intoxicants found in their drug or alcohol blood screens. Blood samples were analyzed for 20 popular synthetic cannabinoids by using liquid chromatography-tandem mass spectrometry. Delta-9-tetrahydrocannabinol (THC) and THC-COOH were quantified by gas chromatography-mass spectrometry. Statistical significance was determined by using Fisher's exact test or Student's t-test, where appropriate, to compare the frequency of characteristics of those in the synthetic cannabinoid group versus those in the marijuana group. 16 synthetic cannabinoid and 25 marijuana records met selection criteria; the drivers of these records were arrested for moving violations. Median age for the synthetic cannabinoid group (n = 16, 15 males) was 20 years (IQR 19-23 years). Median age for the marijuana group (n = 25, 21

High-water-base hydraulic fluid-irradiation experiments

International Nuclear Information System (INIS)

Bradley, E.C.; Meacham, S.A.

1981-10-01

A remote system for shearing spent nuclear fuel assemblies is being designed under the direction of the Consolidated Fuel Reprocessing Program (CFRP). The design incorporates a dual hydraulic fluid actuation system in which only one of the fluids, a high-water-base (HWBF), would be exposed to ionizing radiation and radioactive contamination. A commercially available synthetic, solution-type HWBF was selected as the reference. Single-sample irradiation experiments were conducted with three commercial fluids over a range of irradiation exposures. The physical and chemical properties of the irradiated HWBFs were analyzed and compared with unirradiated samples. In general, the results of the analyses showed increasing degradation of fluid properties with increasing irradiation dose. The results also indicated that a synthetic solution-type HWBF would perform satisfactorily in the remote shear system where irradiation doses up to 10 6 Gy (10 8 rad) are expected

High-water-base hydraulic fluid-irradiation experiments

Energy Technology Data Exchange (ETDEWEB)

Bradley, E.C.; Meacham, S.A.

1981-10-01

A remote system for shearing spent nuclear fuel assemblies is being designed under the direction of the Consolidated Fuel Reprocessing Program (CFRP). The design incorporates a dual hydraulic fluid actuation system in which only one of the fluids, a high-water-base (HWBF), would be exposed to ionizing radiation and radioactive contamination. A commercially available synthetic, solution-type HWBF was selected as the reference. Single-sample irradiation experiments were conducted with three commercial fluids over a range of irradiation exposures. The physical and chemical properties of the irradiated HWBFs were analyzed and compared with unirradiated samples. In general, the results of the analyses showed increasing degradation of fluid properties with increasing irradiation dose. The results also indicated that a synthetic solution-type HWBF would perform satisfactorily in the remote shear system where irradiation doses up to 10/sup 6/ Gy (10/sup 8/ rad) are expected.

Coupled in silico platform: Computational fluid dynamics (CFD) and physiologically-based pharmacokinetic (PBPK) modelling.

Science.gov (United States)

Vulović, Aleksandra; Šušteršič, Tijana; Cvijić, Sandra; Ibrić, Svetlana; Filipović, Nenad

2018-02-15

One of the critical components of the respiratory drug delivery is the manner in which the inhaled aerosol is deposited in respiratory tract compartments. Depending on formulation properties, device characteristics and breathing pattern, only a certain fraction of the dose will reach the target site in the lungs, while the rest of the drug will deposit in the inhalation device or in the mouth-throat region. The aim of this study was to link the Computational fluid dynamics (CFD) with physiologically-based pharmacokinetic (PBPK) modelling in order to predict aerolisolization of different dry powder formulations, and estimate concomitant in vivo deposition and absorption of amiloride hydrochloride. Drug physicochemical properties were experimentally determined and used as inputs for the CFD simulations of particle flow in the generated 3D geometric model of Aerolizer® dry powder inhaler (DPI). CFD simulations were used to simulate air flow through Aerolizer® inhaler and Discrete Phase Method (DPM) was used to simulate aerosol particles deposition within the fluid domain. The simulated values for the percent emitted dose were comparable to the values obtained using Andersen cascade impactor (ACI). However, CFD predictions indicated that aerosolized DPI have smaller particle size and narrower size distribution than assumed based on ACI measurements. Comparison with the literature in vivo data revealed that the constructed drug-specific PBPK model was able to capture amiloride absorption pattern following oral and inhalation administration. The PBPK simulation results, based on the CFD generated particle distribution data as input, illustrated the influence of formulation properties on the expected drug plasma concentration profiles. The model also predicted the influence of potential changes in physiological parameters on the extent of inhaled amiloride absorption. Overall, this study demonstrated the potential of the combined CFD-PBPK approach to model inhaled drug

Synthetic biology meets tissue engineering.

Science.gov (United States)

Davies, Jamie A; Cachat, Elise

2016-06-15

Classical tissue engineering is aimed mainly at producing anatomically and physiologically realistic replacements for normal human tissues. It is done either by encouraging cellular colonization of manufactured matrices or cellular recolonization of decellularized natural extracellular matrices from donor organs, or by allowing cells to self-organize into organs as they do during fetal life. For repair of normal bodies, this will be adequate but there are reasons for making unusual, non-evolved tissues (repair of unusual bodies, interface to electromechanical prostheses, incorporating living cells into life-support machines). Synthetic biology is aimed mainly at engineering cells so that they can perform custom functions: applying synthetic biological approaches to tissue engineering may be one way of engineering custom structures. In this article, we outline the 'embryological cycle' of patterning, differentiation and morphogenesis and review progress that has been made in constructing synthetic biological systems to reproduce these processes in new ways. The state-of-the-art remains a long way from making truly synthetic tissues, but there are now at least foundations for future work. © 2016 Authors; published by Portland Press Limited.

Impinging jet-based fluidic diodes for hybrid synthetic jet actuators

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Broučková, Zuzana; Trávníček, Zdeněk

2015-01-01

Roč. 18, č. 3 (2015), s. 449-458 ISSN 1343-8875 R&D Projects: GA ČR GPP101/12/P556 Institutional support: RVO:61388998 Keywords : synthetic jet * hybrid synthetic jet * volumetric efficiency Subject RIV: BK - Fluid Dynamics Impact factor: 0.720, year: 2015 http://link.springer.com/article/10.1007%2Fs12650-014-0251-0

Chromatin regulation at the frontier of synthetic biology

Science.gov (United States)

Keung, Albert J.; Joung, J. Keith; Khalil, Ahmad S.; Collins, James J.

2016-01-01

As synthetic biology approaches are extended to diverse applications throughout medicine, biotechnology and basic biological research, there is an increasing need to engineer yeast, plant and mammalian cells. Eukaryotic genomes are regulated by the diverse biochemical and biophysical states of chromatin, which brings distinct challenges, as well as opportunities, over applications in bacteria. Recent synthetic approaches, including `epigenome editing', have allowed the direct and functional dissection of many aspects of physiological chromatin regulation. These studies lay the foundation for biomedical and biotechnological engineering applications that could take advantage of the unique combinatorial and spatiotemporal layers of chromatin regulation to create synthetic systems of unprecedented sophistication. PMID:25668787

The use of physiological solutions or media in calcium phosphate synthesis and processing.

Science.gov (United States)

Tas, A Cuneyt

2014-05-01

This review examined the literature to spot uses, if any, of physiological solutions/media for the in situ synthesis of calcium phosphates (CaP) under processing conditions (i.e. temperature, pH, concentration of inorganic ions present in media) mimicking those prevalent in the human hard tissue environments. There happens to be a variety of aqueous solutions or media developed for different purposes; sometimes they have been named as physiological saline, isotonic solution, cell culture solution, metastable CaP solution, supersaturated calcification solution, simulated body fluid or even dialysate solution (for dialysis patients). Most of the time such solutions were not used as the aqueous medium to perform the biomimetic synthesis of calcium phosphates, and their use was usually limited to the in vitro testing of synthetic biomaterials. This review illustrates that only a limited number of research studies used physiological solutions or media such as Earle's balanced salt solution, Bachra et al. solutions or Tris-buffered simulated body fluid solution containing 27mM HCO3(-) for synthesizing CaP, and these studies have consistently reported the formation of X-ray-amorphous CaP nanopowders instead of Ap-CaP or stoichiometric hydroxyapatite (HA, Ca10(PO4)6(OH)2) at 37°C and pH 7.4. By relying on the published articles, this review highlights the significance of the use of aqueous solutions containing 0.8-1.5 mMMg(2+), 22-27mM HCO3(-), 142-145mM Na(+), 5-5.8mM K(+), 103-133mM Cl(-), 1.8-3.75mM Ca(2+), and 0.8-1.67mM HPO4(2-), which essentially mimic the composition and the overall ionic strength of the human extracellular fluid (ECF), in forming the nanospheres of X-ray-amorphous CaP. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Induction of interleukin 1 by synthetic and naturally occurring muramyl peptides.

Science.gov (United States)

Dinarello, C A; Krueger, J M

1986-10-01

Like bacterial lipopolysaccharides (endotoxins), synthetic muramyl peptides (MPs) are thought to exert many of their biological effects by inducing the production of various mediators from host cells. Both synthetic muramyl dipeptide (MDP) and naturally occurring sleep factor (SF), which contains an MP structure, stimulate human monocytes to produce interleukin 1 (IL 1). IL 1 is a family of unique polypeptides that mediate a variety of host defense functions and possess several biological properties, many of which are shared with MPs. Endotoxins are potent inducers of IL 1, but polymyxin B, which blocks endotoxin's biological activities, has no effect on MP-induced IL 1 production. SF purified from human urine and SF isolated from the peritoneal fluid of patients undergoing chronic ambulatory peritoneal dialysis (CAPD) induce IL 1 when incubated with human mononuclear cells in vitro. SF from urine or CAPD fluid induces IL 1 production in the picrogram per milliliter range whereas synthetic MDP requires microgram per milliliter concentrations. Thus, both synthetic and naturally occurring MPs exert their biological effects, in part, by inducing IL 1.

Feasibility of a tetracycline-binding method for detecting synovial fluid basic calcium phosphate crystals.

Science.gov (United States)

Rosenthal, Ann K; Fahey, Mark; Gohr, Claudia; Burner, Todd; Konon, Irina; Daft, Laureen; Mattson, Eric; Hirschmugl, Carol; Ryan, Lawrence M; Simkin, Peter

2008-10-01

Basic calcium phosphate (BCP) crystals are common components of osteoarthritis (OA) synovial fluid. Progress in understanding the role of these bioactive particles in clinical OA has been hampered by difficulties in their identification. Tetracyclines stain calcium phosphate mineral in bone. The aim of this study was to investigate whether tetracycline staining might be an additional or alternative method for identifying BCP crystals in synovial fluid. A drop of oxytetracycline was mixed with a drop of fluid containing synthetic or native BCP, calcium pyrophosphate dihydrate (CPPD), or monosodium urate (MSU) crystals and placed on a microscope slide. Stained and unstained crystals were examined by light microscopy, with and without a portable broad-spectrum ultraviolet (UV) pen light. A small set of characterized synovial fluid samples were compared by staining with alizarin red S and oxytetracycline. Synthetic BCP crystals in synovial fluid were quantified fluorimetrically using oxytetracycline. After oxytetracycline staining, synthetic and native BCP crystals appeared as fluorescent amorphous aggregates under UV light. Oxytetracycline did not stain CPPD or MSU crystals or other particulates. Oxytetracycline staining had fewer false-positive test results than did alizarin red S staining and could provide estimates of the quantities of synthetic BCP crystals in synovial fluid. With further validation, oxytetracycline staining may prove to be a useful adjunct or alternative to currently available methods for identifying BCP crystals in synovial fluid.

Push-out bond strength of bioceramic materials in a synthetic tissue fluid.

Directory of Open Access Journals (Sweden)

Noushin Shokouhinejad

2013-12-01

Full Text Available This study compared the push-out bond strength of EndoSequence Root Repair Material (ERRM and Bioaggregate (BA, new bioceramic materials, to that of mineral trioxide aggregate (MTA after incubation in phosphate-buffered saline (PBS, a synthetic tissue fluid, for either 1 week or 2 months.One-hundred and twenty root sections were filled with ProRoot MTA, BA, or ERRM. Each tested material was then randomly divided into two subgroups (n = 20: root sections were immersed in PBS for 1 week or 2 months. The bond strengths were measured using a universal testing machine. After that, the failure modes were examined with stereomicroscopy and scanning electron microscopy (SEM. The push-out data and failure mode categories were analyzed by two-way ANOVA and chi-square tests, respectively.The bond strength of ERRM was significantly higher than that of BA and MTA at both incubation periods. No significant difference was found between the bond strength of MTA and BA at either 1 week or 2 months. Increasing the incubation time to 2 months resulted in a significant increase in bond strength of all the materials. The failure mode was mainly mixed for MTA and BA, but cohesive for ERRM at both incubation periods.ERRM had significantly higher bond strength to root canal walls compared to MTA and BA. Increasing the incubation time significantly improved the bond strength and bioactive reaction products of all materials.

SYNTHETIC JET APPLIED TO DETECT POTENTIAL TERRORISTS

Czech Academy of Sciences Publication Activity Database

Tesař, Václav; Peszyński, K.

2010-01-01

Roč. 5, č. 3 (2010), s. 229-234 ISSN 1231-3998 R&D Projects: GA AV ČR IAA200760705; GA ČR GA101/07/1499 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jets * annular jets * terrorism Subject RIV: BK - Fluid Dynamics

Protein Analysis in Human Cerebrospinal Fluid: Physiological Aspects, Current Progress and Future Challenges

Directory of Open Access Journals (Sweden)

Andreas F. Hühmer

2006-01-01

Full Text Available The introduction of lumbar puncture into clinical medicine over 100 years ago marks the beginning of the study of central nervous system diseases using the human cerebrospinal fluid (CSF. Ever since, CSF has been analyzed extensively to elucidate the physiological and biochemical bases of neurological disease. The proximity of CSF to the brain makes it a good target for studying the pathophysiology of brain functions, but the barrier function of the CSF also impedes its diagnostic value. Today, measurements to determine alterations in the composition of CSF are central in the differential diagnosis of specific diseases of the central nervous system (CNS. In particular, the analysis of the CSF protein composition provides crucial information in the diagnosis of CNS diseases. This enables the assessment of the physiology of the blood-CSF barrier and of the immunology of intrathecial responses. Besides those routine measurements, protein compositional studies of CSF have been extended recently to many other proteins in the expectation that comprehensive analysis of lower abundance CSF proteins will lead to the discovery of new disease markers. Disease marker discovery by molecular profiling of the CSF tissue has the enormous potential of providing many new disease relevant molecules. New developments in protein profiling techniques hold promise for the discovery and validation of relevant disease markers. In this review, we summarize the current efforts and progress in CSF protein profiling measurements using conventional and current protein analysis tools. We also discuss necessary development in methodology in order to have the highest impact on the study of the molecular composition of CSF proteins.

Performance of the mineral blended ester oil-based drilling fluid systems

Energy Technology Data Exchange (ETDEWEB)

Ismail, A.R.; Kamis, A.; Foo, K.S. [University Teknologi (Malaysia)

2001-06-01

A study was conducted in which the properties of ester oil-based drilling fluid systems were examined using a blended mixture of ester and synthetic mineral oil. Biodegradable invert emulsion ester-based fluids are preferred over mineral oil-based drilling fluids for environmental reasons, but they tend to cause alkaline hydrolysis resulting in solidification of the drilling fluid systems. The drilling fluid examined here consisted of Malaysian palm oil ester derivatives (methyl laureate ester or isopropyl laureate ester) blended with commercially available synthetic mineral oil. This mineral oil was added to reduce the problem of alkaline hydrolysis. This mixture, however, was found to be unstable and could not solve the problem at high temperature. The isopropyl laureate and mineral oil blended system was more stable towards the hydrolysis process up to 250 degrees F. In order to enhance the performance of an invert emulsion drilling fluid system, it was recommended that brine water content of the fluid system be lowered. 3 refs., 2 figs.

Quasi-Similarity Model of Synthetic Jets

Czech Academy of Sciences Publication Activity Database

Tesař, Václav; Kordík, Jozef

2009-01-01

Roč. 149, č. 2 (2009), s. 255-265 ISSN 0924-4247 R&D Projects: GA AV ČR IAA200760705; GA ČR GA101/07/1499 Institutional research plan: CEZ:AV0Z20760514 Keywords : jets * synthetic jets * similarity solution Subject RIV: BK - Fluid Dynamics Impact factor: 1.674, year: 2009 http://www.sciencedirect.com

Rheological properties of PHPA polymer support fluids

OpenAIRE

Lam, Carlos; Martin, P J; Jefferis, S A

2015-01-01

Synthetic polymer fluids are becoming a popular replacement for bentonite slurries to support excavations for deep foundation elements. However, the rheological properties of the polymer fluids used in excavation support have not been studied in detail, and there is currently confusion about the choice of mathematical models for this type of fluid. To advance the current state of knowledge, a laboratory study has been performed to investigate the steady-shear viscosity and transient viscoelas...

Reproductive Fecundity of Iraqi Awassi Ewes Immunized against Synthetic Inhibin-α Subunit or Steroid-Free Bovine Follicular Fluid.

Science.gov (United States)

Al-Saaidi, Jabbar Abbas Ahmed; Khudair, Khalisa Khadim; Al-Kafaji, Sura Safe Aubaes

2018-03-02

The present study was conducted to investigate the impacts of active and passive immunization against synthetic inhibin and steroid-free bovine follicular fluid, respectively, on reproductive fecundity out of breeding season in Iraqi Awassi ewes. Follicular fluid was aspired from mature bovine follicles, treated with activated charcoal, and used for immunization of male rabbits for obtaining steroid free bovine follicular fluid (SFBFF) antiserum. Forty non-pregnant Awassi ewes were allocated into 4 groups (n = 10 each). At day 38 of experiment, ewes were treated with intra-vaginal MPA sponge (60 mg for 12 days). Ewes were treated at 0, 28, and 50 days with 4, 2 and 2 ml of normal saline (control; C-ve), 400, 200 and 200 µl of ovalbumine (C+ve), 400, 200 and 200 µl of inhibin (SI group), and 4 ml of normal saline at 0 day, and 4ml and 2ml of SFBFF antiserum, at 28, and 50 days (AI group). After mating with Awassi rams, pregnancy and embryo number were diagnosed using ultrasonography. Blood samples were collected at 30, 60, 90, and 120 days of pregnancy, for assessment of estradiol-17β (E2) and progesterone (P4) levels. After parturition, numbers of delivered lambs were recorded. The results revealed significant increase of P4 and significant decrease of E2 levels in SI and AI pregnant ewes than controls at 30, 60 and 90 day. Newborn number increased significantly in SI and AI treated than control ewes. Active or passive immunization against endogenous inhibin could augment reproductive fecundity out of breeding season in Iraqi Awassi ewes.

Novel methods for evaluation of the Reynolds number of synthetic jets

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Broučková, Zuzana; Vít, T.; Pavelka, Miroslav; Trávníček, Zdeněk

2014-01-01

Roč. 55, č. 6 (2014), 1757_1-1757_16 ISSN 0723-4864 R&D Projects: GA ČR GPP101/12/P556 Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * Reynolds number Subject RIV: BK - Fluid Dynamics Impact factor: 1.670, year: 2014 http://link.springer.com/article/10.1007%2Fs00348-014-1757-x

Information Theory Analysis of Cascading Process in a Synthetic Model of Fluid Turbulence

Directory of Open Access Journals (Sweden)

Massimo Materassi

2014-02-01

Full Text Available The use of transfer entropy has proven to be helpful in detecting which is the verse of dynamical driving in the interaction of two processes, X and Y . In this paper, we present a different normalization for the transfer entropy, which is capable of better detecting the information transfer direction. This new normalized transfer entropy is applied to the detection of the verse of energy flux transfer in a synthetic model of fluid turbulence, namely the Gledzer–Ohkitana–Yamada shell model. Indeed, this is a fully well-known model able to model the fully developed turbulence in the Fourier space, which is characterized by an energy cascade towards the small scales (large wavenumbers k, so that the application of the information-theory analysis to its outcome tests the reliability of the analysis tool rather than exploring the model physics. As a result, the presence of a direct cascade along the scales in the shell model and the locality of the interactions in the space of wavenumbers come out as expected, indicating the validity of this data analysis tool. In this context, the use of a normalized version of transfer entropy, able to account for the difference of the intrinsic randomness of the interacting processes, appears to perform better, being able to discriminate the wrong conclusions to which the “traditional” transfer entropy would drive.

Transition in synthetic jets

Czech Academy of Sciences Publication Activity Database

Tesař, Václav; Kordík, Jozef

2012-01-01

Roč. 187, NOV 2012 (2012), s. 105-117 ISSN 0924-4247 R&D Projects: GA TA ČR(CZ) TA02020795; GA ČR(CZ) GPP101/12/P556; GA ČR(CZ) GCP101/11/J019 Institutional research plan: CEZ:AV0Z20760514 Keywords : turbulence * synthetic jet * transition * velocity spectra Subject RIV: BK - Fluid Dynamics Impact factor: 1.841, year: 2012 http://www. science direct.com/ science /article/pii/S0924424712005031

Lack of effect of synthetic human gastric inhibitory polypeptide and glucagon-like peptide 1 [7-36 amide] infused at near-physiological concentrations on pentagastrin-stimulated gastric acid secretion in normal human subjects

DEFF Research Database (Denmark)

Nauck, M A; Bartels, E; Orskov, C

1992-01-01

-stimulated (0.1 micrograms/kg/h from -90 to 120 min) gastric volume, acid and chloride output, on separate occasions, synthetic human GIP (1 pmol/kg/min) and/or GLP-1 [7-36 amide] (0.3 pmol/kg/min) or placebo (0.9% NaCl with 1% albumin) were infused intravenously (from -30 to 120 min) in 9 healthy volunteers...... secretion). In conclusion, (penta)gastrin-stimulated gastric acid secretion is not inhibited by physiological circulating concentrations of GIP or GLP-1 [7-36 amide]. Therefore, the insulinotropic action of these intestinal hormones is physiologically more important than their possible role...

Synthetic-based fluid replacement: excellent drilling efficiency and imaging evaluation achieved with inhibitive water-based fluid

Energy Technology Data Exchange (ETDEWEB)

Mendonca, Ricardo; Fernandez, Jovan Andrade [PETROBRAS, Rio de Janeiro, RJ (Brazil); Anderson, Tom; Loureiro, Mario; Pereira, Alex; Shah, Fayyaz [Halliburton Baroid, Aracaju, SE (Brazil)

2004-07-01

The highly reactive Calumbi shale is encountered in wells drilled by PETROBRAS in the Sergipe area. Normally an invert emulsion fluid would be used. However, the ability to run high resolution imaging logs was crucial to determining the potential of the offshore Sergipe fields, and these tools work best in water-based fluids. PETROBRAS selected a new high performance water-based fluid (WBF) to drill the Poco 3-GA-73-SES well. The fluid selection was based on the results of X-ray diffraction, dispersion/erosion and linear swell meter testing of Calumbi formation samples. The new WBF incorporates a unique polymer chemistry that can provide shale inhibition very similar to that achieved with an invert emulsion fluid, without sacrificing drilling performance. The polymeric additives can effectively flocculate and encapsulate colloidal drill solids so that they can be easily removed mechanically. The polymers also help prevent hole erosion and bit balling. After the high-performance WBF was used, the following results were obtained on the Poco 3- GA-73-SES well: 805 m drilled in 65 hr (12.65 m/hr) in a single bit run; trips completed with minimal use of the pumps or back reaming, considered exceptional for a WBF while drilling the Calumbi shale; imaging logs run successfully with no delays or obstructions while tripping or logging; the average hole diameter was 8.63-in. per the caliper log for the 8 1/2-in. section; no accretion on the bit or drill string observed; no flow line plugging or shaker screen blinding. (author)

EXPERIMENTS WITH SYNTHETIC JET FOR DETECTING POTENTIAL TERRORISTS

Czech Academy of Sciences Publication Activity Database

Tesař, Václav; Peszyński, K.

2010-01-01

Roč. 5, č. 3 (2010), s. 221-227 ISSN 1231-3998 R&D Projects: GA AV ČR IAA200760705; GA ČR GA101/07/1499 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jets * annular jets * terrorism Subject RIV: BK - Fluid Dynamics

The assessment of cold atmospheric plasma treatment of DNA in synthetic models of tissue fluid, tissue and cells

Science.gov (United States)

Szili, Endre J.; Gaur, Nishtha; Hong, Sung-Ha; Kurita, Hirofumi; Oh, Jun-Seok; Ito, Masafumi; Mizuno, Akira; Hatta, Akimitsu; Cowin, Allison J.; Graves, David B.; Short, Robert D.

2017-07-01

There is a growing literature database that demonstrates the therapeutic potential of cold atmospheric plasma (herein referred to as plasma). Given the breadth of proposed applications (e.g. from teeth whitening to cancer therapy) and vast gamut of plasma devices being researched, it is timely to consider plasma interactions with specific components of the cell in more detail. Plasma can produce highly reactive oxygen and nitrogen species (RONS) such as the hydroxyl radical (OH•), peroxynitrite (ONOO-) and superoxide (\\text{O}2- ) that would readily modify essential biomolecules such as DNA. These modifications could in principle drive a wide range of biological processes. Against this possibility, the reported therapeutic action of plasmas are not underpinned by a particularly deep knowledge of the potential plasma-tissue, -cell or -biomolecule interactions. In this study, we aim to partly address this issue by developing simple models to study plasma interactions with DNA, in the form of DNA-strand breaks. This is carried out using synthetic models of tissue fluid, tissue and cells. We argue that this approach makes experimentation simpler, more cost-effective and faster than compared to working with real biological materials and cells. Herein, a helium plasma jet source was utilised for these experiments. We show that the plasma jet readily induced DNA-strand breaks in the tissue fluid model and in the cell model, surprisingly without any significant poration or rupture of the phospholipid membrane. In the plasma jet treatment of the tissue model, DNA-strand breaks were detected in the tissue mass after pro-longed treatment (on the time-scale of minutes) with no DNA-strand breaks being detected in the tissue fluid model underneath the tissue model. These data are discussed in the context of the therapeutic potential of plasma.

Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia.

Science.gov (United States)

Saraghi, Mana

2015-01-01

Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.

The physiology of the normal human breast: an exploratory study.

Science.gov (United States)

Mills, Dixie; Gordon, Eva J; Casano, Ashley; Lahti, Sarah Michelle; Nguyen, Tinh; Preston, Alex; Tondre, Julie; Wu, Kuan; Yanase, Tiffany; Chan, Henry; Chia, David; Esfandiari, Mahtash; Himmel, Tiffany; Love, Susan M

2011-12-01

The physiology of the nonlactating human breast likely plays a key role in factors that contribute to the etiology of breast cancer and other breast conditions. Although there has been extensive research into the physiology of lactation, few reports explore the physiology of the resting mammary gland, including mechanisms by which compounds such as hormones, drugs, and potential carcinogens enter the breast ducts. The purpose of this study was to explore transport of exogenous drugs into ductal fluid in nonlactating women and determine if their concentrations in the fluid are similar to those observed in the breast milk of lactating women. We selected two compounds that have been well characterized during lactation, caffeine and cimetidine. Caffeine passively diffuses into breast milk, but cimetidine is actively transported and concentrated in breast milk. After ingestion of caffeine and cimetidine, 14 nonlactating subjects had blood drawn and underwent ductal lavage at five time points over 12 h to measure drug levels in the fluid and blood. The concentrations of both caffeine and cimetidine in lavage fluid were substantially less than those observed in breast milk. Our results support recent evidence that the cimetidine transporter is not expressed in the nonlactating mammary gland, and highlight intriguing differences in the physiology and molecular transport of the lactating and nonlactating breast. The findings of this exploratory study warrant further exploration into the physiology of the nonlactating mammary gland to elucidate factors involved in disease initiation and progression.

Optimization of T2-weighted imaging for shoulder magnetic resonance arthrography by synthetic magnetic resonance imaging.

Science.gov (United States)

Lee, Seung Hyun; Lee, Young Han; Hahn, Seok; Yang, Jaemoon; Song, Ho-Taek; Suh, Jin-Suck

2017-01-01

Background Synthetic magnetic resonance imaging (MRI) allows reformatting of various synthetic images by adjustment of scanning parameters such as repetition time (TR) and echo time (TE). Optimized MR images can be reformatted from T1, T2, and proton density (PD) values to achieve maximum tissue contrast between joint fluid and adjacent soft tissue. Purpose To demonstrate the method for optimization of TR and TE by synthetic MRI and to validate the optimized images by comparison with conventional shoulder MR arthrography (MRA) images. Material and Methods Thirty-seven shoulder MRA images acquired by synthetic MRI were retrospectively evaluated for PD, T1, and T2 values at the joint fluid and glenoid labrum. Differences in signal intensity between the fluid and labrum were observed between TR of 500-6000 ms and TE of 80-300 ms in T2-weighted (T2W) images. Conventional T2W and synthetic images were analyzed for diagnostic agreement of supraspinatus tendon abnormalities (kappa statistics) and image quality scores (one-way analysis of variance with post-hoc analysis). Results Optimized mean values of TR and TE were 2724.7 ± 1634.7 and 80.1 ± 0.4, respectively. Diagnostic agreement for supraspinatus tendon abnormalities between conventional and synthetic MR images was excellent (κ = 0.882). The mean image quality score of the joint space in optimized synthetic images was significantly higher compared with those in conventional and synthetic images (2.861 ± 0.351 vs. 2.556 ± 0.607 vs. 2.750 ± 0.439; P optimized TR and TE for shoulder MRA enables optimization of soft-tissue contrast.

Reward-based hypertension control by a synthetic brain-dopamine interface.

Science.gov (United States)

Rössger, Katrin; Charpin-El Hamri, Ghislaine; Fussenegger, Martin

2013-11-05

Synthetic biology has significantly advanced the design of synthetic trigger-controlled devices that can reprogram mammalian cells to interface with complex metabolic activities. In the brain, the neurotransmitter dopamine coordinates communication with target neurons via a set of dopamine receptors that control behavior associated with reward-driven learning. This dopamine transmission has recently been suggested to increase central sympathetic outflow, resulting in plasma dopamine levels that correlate with corresponding brain activities. By functionally rewiring the human dopamine receptor D1 (DRD1) via the second messenger cyclic adenosine monophosphate (cAMP) to synthetic promoters containing cAMP response element-binding protein 1(CREB1)-specific cAMP-responsive operator modules, we have designed a synthetic dopamine-sensitive transcription controller that reversibly fine-tunes specific target gene expression at physiologically relevant brain-derived plasma dopamine levels. Following implantation of circuit-transgenic human cell lines insulated by semipermeable immunoprotective microcontainers into mice, the designer device interfaced with dopamine-specific brain activities and produced a systemic expression response when the animal's reward system was stimulated by food, sexual arousal, or addictive drugs. Reward-triggered brain activities were able to remotely program peripheral therapeutic implants to produce sufficient amounts of the atrial natriuretic peptide, which reduced the blood pressure of hypertensive mice to the normal physiologic range. Seamless control of therapeutic transgenes by subconscious behavior may provide opportunities for treatment strategies of the future.

Mathematical physiology

CERN Document Server

Sneyd, James

2009-01-01

There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...

Cutting fluids and clean technologies; Los fluidos de corte y las tecnologias limpias (III)

Energy Technology Data Exchange (ETDEWEB)

Terradillos, J.; Arnaiz, A.

2003-07-01

Metalworking fluids are an essential constituent of manufacturing and represent an important part of machining cost and disposal charges. Practically all cutting fluids currently in use fall into four categories: straight oils, soluble oils, semi-synthetic fluids and synthetic oils. The composition of these fluids depends on the machining requirements and primary functions include improving tool life, reducing thermal deformation of parts and improving surface finish and flushing away chips from the cutting zone. To maintain cutting fluid quality in the long term and, at the same time, reduce its environmental impact, three strategies could be followed: Prevention, Minimization and Evaluation, Related to prevention, different approaches exist for reducing the impact of cutting fluids. They include dry cutting, machining using a minimum quantity of lubricant (MQL) and developing environmental friendly acceptable formulations or refrigerant gases. (Author)

Changes in D-aspartic acid and D-glutamic acid levels in the tissues and physiological fluids of mice with various D-aspartate oxidase activities.

Science.gov (United States)

Han, Hai; Miyoshi, Yurika; Koga, Reiko; Mita, Masashi; Konno, Ryuichi; Hamase, Kenji

2015-12-10

D-Aspartic acid (D-Asp) and D-glutamic acid (D-Glu) are currently paid attention as modulators of neuronal transmission and hormonal secretion. These two D-amino acids are metabolized only by D-aspartate oxidase (DDO) in mammals. Therefore, in order to design and develop new drugs controlling the D-Asp and D-Glu amounts via regulation of the DDO activities, changes in these acidic D-amino acid amounts in various tissues are expected to be clarified in model animals having various DDO activities. In the present study, the amounts of Asp and Glu enantiomers in 6 brain tissues, 11 peripheral tissues and 2 physiological fluids of DDO(+/+), DDO(+/-) and DDO(-/-) mice were determined using a sensitive and selective two-dimensional HPLC system. As a result, the amounts of D-Asp were drastically increased with the decrease in the DDO activity in all the tested tissues and physiological fluids. On the other hand, the amounts of D-Glu were almost the same among the 3 strains of mice. The present results are useful for designing new drug candidates, such as DDO inhibitors, and further studies are expected. Copyright © 2015 Elsevier B.V. All rights reserved.

Usefulness of in-house real time PCR for HBV DNA quantification in serum and oral fluid samples.

Science.gov (United States)

Portilho, Moyra Machado; Mendonça, Ana Carolina da Fonseca; Bezerra, Cristianne Sousa; do Espirito-Santo, Márcia Paschoal; de Paula, Vanessa Salete; Nabuco, Leticia Cancella; Villela-Nogueira, Cristiane Alves; Lewis-Ximenez, Lia Laura; Lampe, Elisabeth; Villar, Livia Melo

2018-06-01

For quantification of hepatitis B virus DNA (HBV DNA), commercial assays are used with serum or plasma samples, but oral fluid samples could be an alternative for HBV diagnosis due to ease of collection. This study aims to develop in-house real time PCR using synthetic curve for HBV DNA quantification for serum and oral fluid samples. Samples were collected from 103 individuals (55 HBsAg reactive and HBV DNA reactive by commercial assay and 48 without HBV markers) and submitted to two in-house real time PCR assays for HBV pre-S/S region with different standard curves: qPCR plasmidial and qPCR synthetic. A total of 27 serum samples were HBV DNA positive by qPCR plasmidial and 40 with qPCR synthetic (72% and 85% of concordance, respectively). Quantitative PCR synthetic presented efficiency of 99% and sensitivity of 2log10 copies/mL. Among oral fluid samples, five and ten were detected using qPCR plasmidial and synthetic, respectively. This study demonstrated that qPCR synthetic using serum samples could be used as alternative for HBV DNA quantification due to its sensitivity. In addition, it was possible to quantify HBV DNA in oral fluid samples suggesting the potential of this specimen for molecular diagnosis of HBV. Copyright © 2018 Elsevier B.V. All rights reserved.

Cfd modeling of a synthetic jet actuator

International Nuclear Information System (INIS)

Dghim, Marouane; Ben Chiekh, Maher; Ben Nasrallah, Sassi

2009-01-01

Synthetic jet actuators show good promise as an enabling technology for innovative boundary layer flow control applied to external surfaces, like airplane wings, and to internal flows, like those occurring in a curved engine inlet. The appealing characteristics of a synthetic jet are zero-net-mass flux operation and an efficient control effect that takes advantages of unsteady fluid phenomena. The formation of a synthetic jet in a quiescent external air flow is only beginning to be understood and a rational understanding of these devices is necessary before they can be applied to the control of flows outside of the laboratory. The synthetic jet flow generated by a planar orifice is investigated here using computational approach. Computations of the 2D synthetic jet are performed with unsteady RANS modeled with the Realizable κ - ε turbulence model available in FLUENT environment. In this present work, the ability of the first order turbulence model, employed in our computations, to model the formation of the counter-rotating-vortex pair (CVP) that appears in the flow-field was investigated. Computational results were in good agreement with experimental measurements. The effectiveness of such control actuator was tested on separated boundary layer. Preliminary investigation were presented and discussed

Comparison of double-acting and single-acting synthetic jets

Czech Academy of Sciences Publication Activity Database

Hsu, S.S.; Trávníček, Zdeněk; Chou, C.-C.; Chen, C. C.; Wang, A. B.

2013-01-01

Roč. 203, December (2013), s. 291-299 ISSN 0924-4247 Institutional support: RVO:61388998 Keywords : synthetic jet * double-acting & single acting machines * PIV Subject RIV: BK - Fluid Dynamics Impact factor: 1.943, year: 2013 http://dx.doi.org/10.1016/j.sna.2013.09.005

Hydrogen speciation in synthetic quartz

Science.gov (United States)

Aines, R.D.; Kirby, S.H.; Rossman, G.R.

1984-01-01

The dominant hydrogen impurity in synthetic quartz is molecular H2O. H-OH groups also occur, but there is no direct evidence for the hydrolysis of Si-O-Si bonds to yield Si-OH HO-Si groups. Molecular H2O concentrations in the synthetic quartz crystals studied range from less than 10 to 3,300 ppm (H/Si), and decrease smoothly by up to an order of magnitude with distance away from the seed. OH- concentrations range from 96 to 715 ppm, and rise smoothly with distance away from the seed by up to a factor of three. The observed OH- is probably all associated with cationic impurities, as in natural quartz. Molecular H2O is the dominant initial hydrogen impurity in weak quartz. The hydrolytic weakening of quartz may be caused by the transformation H2O + Si-O-Si ??? 2SiOH, but this may be a transitory change with the SiOH groups recombining to form H2O, and the average SiOH concentration remaining very low. Synthetic quartz is strengthened when the H2O is accumulated into fluid inclusions and cannot react with the quartz framework. ?? 1984 Springer-Verlag.

The impact of environmental regulations on drilling fluid technology

International Nuclear Information System (INIS)

Clark, R.K.

1994-01-01

A multitude of new drilling fluid products, systems, and treatment processes have been developed in recent years in response to increasingly stringent environmental regulations. Many fluid additives and systems that once played a major role in the drilling industry are little used today or are no longer available. New water-base mud systems are approaching the performance levels typical of conventional oil-base muds, levels largely achieved by the new synthetic-base fluids. However, these new drilling fluids do not have the adverse environmental impact associated with oil-base systems when waste fluids and cuttings are discarded. 65 refs., 3 tabs

Quantitative analysis of abused drugs in physiological fluids by gas chromatography/chemical ionization mass spectrometry

International Nuclear Information System (INIS)

Foltz, R.L.

1978-01-01

Methods have been developed for quantitative analysis of commonly abused drugs in physiological fluids using gas chromatography/chemical ionization mass spectrometry. The methods are being evaluated in volunteer analytical and toxicological laboratories, and analytical manuals describing the methods are being prepared. The specific drug and metabolites included in this program are: Δ 9 -tetrahydrocannabinol, methadone, phencyclidine, methaqualone, morphine, amphetamine, methamphetamine, mescaline, 2,5-dimethoxy-4-methyl amphetamine, cocaine, benzoylecgonine, diazepam, and N-desmethyldiazepam. The current analytical methods utilize relatively conventional instrumentation and procedures, and are capable of measuring drug concentrations as low as 1 ng/ml. Various newer techniques such as sample clean-up by high performance liquid chromatography, separation by glass capillary chromatography, and ionization by negative ion chemical ionization are being investigated with respect to their potential for achieving higher sensitivity and specificity, as well as their ability to facilitate simultaneous analysis of more than one drug and metabolite. (Auth.)

Acute Toxicity of a Recently Identified Phenol-based Synthetic ...

African Journals Online (AJOL)

This paper reports on the acute toxicity of a new phenol based synthetic tsetse fly repellent recently identified at the International Centre for Insect Physiology and Ecology (patent No. ... The repellent can be classified as being highly toxic with central nervous system (CNS) involvement and a mild skin and eye irritant.

Maximization of integral outlet quantities of an axisymmetric synthetic jet actuator based on a loudspeaker

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Trávníček, Zdeněk

2016-01-01

Roč. 114, March (2016), č. článku 02152. ISSN 2101-6275. [International Conference on Experimental Fluid Mechanics /10./. Praha, 17.11.2015-20.11.2015] R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * resonance Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts

Fluid and Electrolyte Disturbances in Critically Ill Patients

OpenAIRE

Lee, Jay Wook

2010-01-01

Disturbances in fluid and electrolytes are among the most common clinical problems encountered in the intensive care unit (ICU). Recent studies have reported that fluid and electrolyte imbalances are associated with increased morbidity and mortality among critically ill patients. To provide optimal care, health care providers should be familiar with the principles and practice of fluid and electrolyte physiology and pathophysiology. Fluid resuscitation should be aimed at restoration of normal...

Configurations of Fluidic Actuators for Generation of Hybrid-Synthetic Jets

Czech Academy of Sciences Publication Activity Database

Tesař, Václav

2007-01-01

Roč. 138, - (2007), s. 213-220 ISSN 0924-4247 R&D Projects: GA ČR GA101/07/1499 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jets * fluidics * fluidic alternators Subject RIV: BK - Fluid Dynamics Impact factor: 1.348, year: 2007

Studies on the physiology and endocrinology of reproduction of Helisoma duryi (Mollusca: Pulmonata)

Energy Technology Data Exchange (ETDEWEB)

Miksys, S.L.

1987-01-01

Helisoma duryi is a hermaphroditic, freshwater, pulmonate snail native to North America. It has been proposed as a biological control agent against snail intermediate hosts of Schistosoma sp., a parasitic trematode in man. Very little is known of the physiology and endocrinology of reproduction of H. duryi. This thesis investigates vitello-genesis, endocrine control of the synthesis of albumen, a nutrient-rich fluid catabolized by developing embryos, and the possible endocrine role of the gonad. Light and electron microscopy, chemical extraction, energy dispersive X-ray analysis, and radioimmunoassay are used to identify the yolk protein ferritin. It is proposed that ferritin synthesis, and its circulating levels, are regulated, probably indirectly, by a gonadal factor released into the blood. The rate of synthesis of albumen polysaccharides can be monitored in vitro by providing albumen gland explants with the precursor /sup 14/C-glucose and measuring /sup 14/C-polysaccharide produced. The basal synthetic activity of the gland reflects the reproductive activity of the snail.

Ultrahigh performance supercritical fluid chromatography of lipophilic compounds with application to synthetic and commercial biodiesel.

Science.gov (United States)

Ashraf-Khorassani, M; Yang, J; Rainville, P; Jones, M D; Fountain, K J; Isaac, G; Taylor, L T

2015-03-01

Ultrahigh performance supercritical fluid chromatography (UHPSFC) in combination with sub-2μm particles and either diode array ultraviolet (UV), evaporative light scattering, (ELSD), or mass spectrometric (MS) detection has been shown to be a valuable technique for the determination of acylglycerols in soybean, corn, sesame, and tobacco seed oils. Excellent resolution on an un-endcapped single C18 column (3.0mm×150mm) with a mobile phase gradient of acetonitrile and carbon dioxide in as little as 10min served greatly as an improvement on first generation packed column SFC instrumentation. Unlike high resolution gas chromatography and high performance liquid chromatography with mass spectrometric detection, UHPSFC/MS was determined to be a superior analytical tool for both separation and detection of mono-, di-, and tri-acylglycerols as well as free glycerol itself in biodiesel without derivatization. Baseline separation of residual tri-, di-, and mono-acylglycerols alongside glycerol at 0.05% (w/w) was easily obtained employing packed column SFC. The new analytical methodology was applied to both commercial B100 biodiesel (i.e. fatty acid methyl esters) derived from vegetable oil and to an "in-house" synthetic biodiesel (i.e. fatty acid ethyl esters) derived from tobacco seed oil and ethanol both before and after purification via column chromatography on bare silica. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthetic model for Doppler broadening of neutron absorption resonances in molecular fluids

Energy Technology Data Exchange (ETDEWEB)

Villanueva, Alejandro J., E-mail: villanueva@cab.cnea.gov.a [Comision Nacional de Energia Atomica, Centro Atomico Bariloche and Instituto Balseiro, 8400 S.C. de Bariloche (RN) (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina); Granada, J.R. [Comision Nacional de Energia Atomica, Centro Atomico Bariloche and Instituto Balseiro, 8400 S.C. de Bariloche (RN) (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina)

2010-08-15

A general and systematic approach expressed in modern language, accounting for molecular motion effects on Doppler Broadening of Neutron Absorption Resonances (DBNAR) is given the form of a new model. It relies on well validated hypothesis: The separability of atomic from nuclear degrees of freedom, the use of the Van Hove scattering formalism and the fact that a conceptually identical approach produced experimentally proved predictions when applied to DBNAR in solid systems. We treat the molecular internal degrees of freedom approximately as harmonic oscillators. As a second contribution of this work, a synthetic model is presented in order to make the more complete model mentioned above suitable for neutron calculation codes. This second synthetic model reduces to the exact expressions of the complete model in the low and high neutron energy regimes and provides a plausible transition in between. Numerical results are presented for a general hypothetical case to show its strengths and limitations. Also, both models are applied to a real case of the {sup 238}U 6.674 eV resonant effective broadened absorption cross-section in UF6 (uranium hexafluoride). A direct experimental validation of our models is still necessary for which a special high resolution neutron transmission experiment ought to be devised at low temperatures and pressures on a gaseous system. It is showed how the synthetic model can be used to make thermometric predictions in an improved fashion in comparison to the effective temperature gas model at low temperatures.

Corrosion behavior of AZ91 magnesium alloy treated by plasma immersion ion implantation and deposition in artificial physiological fluids

International Nuclear Information System (INIS)

Liu Chenglong; Xin Yunchang; Tian Xiubo; Chu, Paul K.

2007-01-01

Due to the good biocompatibility and tensile yield strength, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to investigate the corrosion behavior of surgical AZ91 magnesium alloy treated by aluminum, zirconium, and titanium plasma immersion ion implantation and deposition (PIII and D) at 10 kV in artificial physiological fluids. The surface layers show a characteristic intermixed layer and the outer surface are mainly composed of aluminum, zirconium or titanium oxide with a lesser amount of magnesium oxide. Comparing the three sets of samples, aluminum PIII and D significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP

A synthetic multifunctional mammalian pH sensor and CO2 transgene-control device.

Science.gov (United States)

Ausländer, David; Ausländer, Simon; Charpin-El Hamri, Ghislaine; Sedlmayer, Ferdinand; Müller, Marius; Frey, Olivier; Hierlemann, Andreas; Stelling, Jörg; Fussenegger, Martin

2014-08-07

All metabolic activities operate within a narrow pH range that is controlled by the CO2-bicarbonate buffering system. We hypothesized that pH could serve as surrogate signal to monitor and respond to the physiological state. By functionally rewiring the human proton-activated cell-surface receptor TDAG8 to chimeric promoters, we created a synthetic signaling cascade that precisely monitors extracellular pH within the physiological range. The synthetic pH sensor could be adjusted by organic acids as well as gaseous CO2 that shifts the CO2-bicarbonate balance toward hydrogen ions. This enabled the design of gas-programmable logic gates, provided remote control of cellular behavior inside microfluidic devices, and allowed for CO2-triggered production of biopharmaceuticals in standard bioreactors. When implanting cells containing the synthetic pH sensor linked to production of insulin into type 1 diabetic mice developing diabetic ketoacidosis, the prosthetic network automatically scored acidic pH and coordinated an insulin expression response that corrected ketoacidosis. Copyright © 2014 Elsevier Inc. All rights reserved.

Delineating the Impact of Weightlessness on Human Physiology Using Computational Models

Science.gov (United States)

Kassemi, Mohammad

2015-01-01

Microgravity environment has profound effects on several important human physiological systems. The impact of weightlessness is usually indirect as mediated by changes in the biological fluid flow and transport and alterations in the deformation and stress fields of the compliant tissues. In this context, Fluid-Structural and Fluid-Solid Interaction models provide a valuable tool in delineating the physical origins of the physiological changes so that systematic countermeasures can be devised to reduce their adverse effects. In this presentation, impact of gravity on three human physiological systems will be considered. The first case involves prediction of cardiac shape change and altered stress distributions in weightlessness. The second, presents a fluid-structural-interaction (FSI) analysis and assessment of the vestibular system and explores the reasons behind the unexpected microgravity caloric stimulation test results performed aboard the Skylab. The last case investigates renal stone development in microgravity and the possible impact of re-entry into partial gravity on the development and transport of nucleating, growing, and agglomerating renal calculi in the nephron. Finally, the need for model validation and verification and application of the FSI models to assess the effects of Artificial Gravity (AG) are also briefly discussed.

[Arterial pressure curve and fluid status].

Science.gov (United States)

Pestel, G; Fukui, K

2009-04-01

Fluid optimization is a major contributor to improved outcome in patients. Unfortunately, anesthesiologists are often in doubt whether an additional fluid bolus will improve the hemodynamics of the patient or not as excess fluid may even jeopardize the condition. This article discusses physiological concepts of liberal versus restrictive fluid management followed by a discussion on the respective capabilities of various monitors to predict fluid responsiveness. The parameter difference in pulse pressure (dPP), derived from heart-lung interaction in mechanically ventilated patients is discussed in detail. The dPP cutoff value of 13% to predict fluid responsiveness is presented together with several assessment techniques of dPP. Finally, confounding variables on dPP measurements, such as ventilation parameters, pneumoperitoneum and use of norepinephrine are also mentioned.

Using lame's petrophysical parameters for fluid detection and ...

African Journals Online (AJOL)

AVO synthetic gather models were created using various gas/brine/oil ... a quantitative extraction of rock properties to clearly determine lithology and fluids. ... an improved separation of high porosity sands from shale was also achieved using ...

Fluid mechanics in the perivascular space.

Science.gov (United States)

Wang, Peng; Olbricht, William L

2011-04-07

Perivascular space (PVS) within the brain is an important pathway for interstitial fluid (ISF) and solute transport. Fluid flowing in the PVS can affect these transport processes and has significant impacts on physiology. In this paper, we carry out a theoretical analysis to investigate the fluid mechanics in the PVS. With certain assumptions and approximations, we are able to find an analytical solution to the problem. We discuss the physical meanings of the solution and particularly examine the consequences of the induced fluid flow in the context of convection-enhanced delivery (CED). We conclude that peristaltic motions of the blood vessel walls can facilitate fluid and solute transport in the PVS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Predicting and measuring fluid responsiveness with echocardiography

Directory of Open Access Journals (Sweden)

Ashley Miller

2016-06-01

Full Text Available Echocardiography is ideally suited to guide fluid resuscitation in critically ill patients. It can be used to assess fluid responsiveness by looking at the left ventricle, aortic outflow, inferior vena cava and right ventricle. Static measurements and dynamic variables based on heart–lung interactions all combine to predict and measure fluid responsiveness and assess response to intravenous fluid esuscitation. Thorough knowledge of these variables, the physiology behind them and the pitfalls in their use allows the echocardiographer to confidently assess these patients and in combination with clinical judgement manage them appropriately.

Rewiring protein synthesis: From natural to synthetic amino acids.

Science.gov (United States)

Fan, Yongqiang; Evans, Christopher R; Ling, Jiqiang

2017-11-01

The protein synthesis machinery uses 22 natural amino acids as building blocks that faithfully decode the genetic information. Such fidelity is controlled at multiple steps and can be compromised in nature and in the laboratory to rewire protein synthesis with natural and synthetic amino acids. This review summarizes the major quality control mechanisms during protein synthesis, including aminoacyl-tRNA synthetases, elongation factors, and the ribosome. We will discuss evolution and engineering of such components that allow incorporation of natural and synthetic amino acids at positions that deviate from the standard genetic code. The protein synthesis machinery is highly selective, yet not fixed, for the correct amino acids that match the mRNA codons. Ambiguous translation of a codon with multiple amino acids or complete reassignment of a codon with a synthetic amino acid diversifies the proteome. Expanding the genetic code with synthetic amino acids through rewiring protein synthesis has broad applications in synthetic biology and chemical biology. Biochemical, structural, and genetic studies of the translational quality control mechanisms are not only crucial to understand the physiological role of translational fidelity and evolution of the genetic code, but also enable us to better design biological parts to expand the proteomes of synthetic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

PIXE analysis of cerebrospinal fluid before and after brain transplantation

International Nuclear Information System (INIS)

Ma Xinpei; Wang Junke.

1992-01-01

Considering methodology of PIXE quantitative analysis based on Inner-standard, we provide a simple and convenient method to measure the elemental relative sensitivity curve. The concentrations of 16 various elements in cerebrospinal fluid samples before and after brain transplantation have been investigated and compared with those of normal person's and transplanted tissues. The experimental results show that the brain transplantation results in apparently curative effects in compensating and regulating the element concentrations in cerebrospinal fluid and improvement of elemental physiological metabolism. It illustrates that the appropriate concentrations of trace elements in cerebrospinal fluid play an undoubtedly important role in keeping the normal physiological function of brain and central nervous system. (author)

Influence of Population Variation of Physiological Parameters in Computational Models of Space Physiology

Science.gov (United States)

Myers, J. G.; Feola, A.; Werner, C.; Nelson, E. S.; Raykin, J.; Samuels, B.; Ethier, C. R.

2016-01-01

The earliest manifestations of Visual Impairment and Intracranial Pressure (VIIP) syndrome become evident after months of spaceflight and include a variety of ophthalmic changes, including posterior globe flattening and distension of the optic nerve sheath. Prevailing evidence links the occurrence of VIIP to the cephalic fluid shift induced by microgravity and the subsequent pressure changes around the optic nerve and eye. Deducing the etiology of VIIP is challenging due to the wide range of physiological parameters that may be influenced by spaceflight and are required to address a realistic spectrum of physiological responses. Here, we report on the application of an efficient approach to interrogating physiological parameter space through computational modeling. Specifically, we assess the influence of uncertainty in input parameters for two models of VIIP syndrome: a lumped-parameter model (LPM) of the cardiovascular and central nervous systems, and a finite-element model (FEM) of the posterior eye, optic nerve head (ONH) and optic nerve sheath. Methods: To investigate the parameter space in each model, we employed Latin hypercube sampling partial rank correlation coefficient (LHSPRCC) strategies. LHS techniques outperform Monte Carlo approaches by enforcing efficient sampling across the entire range of all parameters. The PRCC method estimates the sensitivity of model outputs to these parameters while adjusting for the linear effects of all other inputs. The LPM analysis addressed uncertainties in 42 physiological parameters, such as initial compartmental volume and nominal compartment percentage of total cardiac output in the supine state, while the FEM evaluated the effects on biomechanical strain from uncertainties in 23 material and pressure parameters for the ocular anatomy. Results and Conclusion: The LPM analysis identified several key factors including high sensitivity to the initial fluid distribution. The FEM study found that intraocular pressure and

Natural and synthetic biomaterials for controlled drug delivery.

Science.gov (United States)

Kim, Jang Kyoung; Kim, Hyung Jin; Chung, Jee-Young; Lee, Jong-Hwan; Young, Seok-Beom; Kim, Yong-Hee

2014-01-01

A wide variety of delivery systems have been developed and many products based on the drug delivery technology are commercially available. The development of controlled-release technologies accelerated new dosage form design by altering pharmacokinetic and pharmacodynamics profiles of given drugs, resulting in improved efficacy and safety. Various natural or synthetic polymers have been applied to make matrix, reservoir or implant forms due to the characteristics of polymers, especially ease of control for modifications of biocompatibility, biodegradation, porosity, charge, mechanical strength and hydrophobicity/hydrophilicity. Hydrogel is a hydrophilic, polymeric network capable of imbibing large amount of water and biological fluids. This review article introduces various applications of natural and synthetic polymer-based hydrogels from pharmaceutical, biomedical and bioengineering points of view.

Image quality at synthetic brain magnetic resonance imaging in children

Energy Technology Data Exchange (ETDEWEB)

Lee, So Mi; Cho, Seung Hyun; Kim, Won Hwa; Kim, Hye Jung [Kyungpook National University Hospital, Department of Radiology, Daegu (Korea, Republic of); Choi, Young Hun; Cheon, Jung-Eun; Kim, In-One [Seoul National University College of Medicine, Department of Radiology and Institute of Radiation Medicine, Seoul (Korea, Republic of); Cho, Hyun-Hae [Ewha Womans University Mokdong Hospital, Department of Radiology, Seoul (Korea, Republic of); You, Sun-Kyoung [Chungnam National University Hospital, Department of Radiology, Daejeon (Korea, Republic of); Park, Sook-Hyun [Kyungpook National University Hospital, Department of Pediatrics, Daegu (Korea, Republic of); Hwang, Moon Jung [GE Healthcare, MR Applications and Workflow, Seoul (Korea, Republic of)

2017-11-15

The clinical application of the multi-echo, multi-delay technique of synthetic magnetic resonance imaging (MRI) generates multiple sequences in a single acquisition but has mainly been used in adults. To evaluate the image quality of synthetic brain MR in children compared with that of conventional images. Twenty-nine children (median age: 6 years, range: 0-16 years) underwent synthetic and conventional imaging. Synthetic (T2-weighted, T1-weighted and fluid-attenuated inversion recovery [FLAIR]) images with settings matching those of the conventional images were generated. The overall image quality, gray/white matter differentiation, lesion conspicuity and image degradations were rated on a 5-point scale. The relative contrasts were assessed quantitatively and acquisition times for the two imaging techniques were compared. Synthetic images were inferior due to more pronounced image degradations; however, there were no significant differences for T1- and T2-weighted images in children <2 years old. The quality of T1- and T2-weighted images were within the diagnostically acceptable range. FLAIR images showed greatly reduced quality. Gray/white matter differentiation was comparable or better in synthetic T1- and T2-weighted images, but poorer in FLAIR images. There was no effect on lesion conspicuity. Synthetic images had equal or greater relative contrast. Acquisition time was approximately two-thirds of that for conventional sequences. Synthetic T1- and T2-weighted images were diagnostically acceptable, but synthetic FLAIR images were not. Lesion conspicuity and gray/white matter differentiation were comparable to conventional MRI. (orig.)

Clinical validation of synthetic brain MRI in children: initial experience

Energy Technology Data Exchange (ETDEWEB)

West, Hollie; Leach, James L.; Jones, Blaise V.; Care, Marguerite; Radhakrishnan, Rupa; Merrow, Arnold C.; Alvarado, Enrique; Serai, Suraj D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

2017-01-15

The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted. (orig.)

Clinical validation of synthetic brain MRI in children: initial experience

International Nuclear Information System (INIS)

West, Hollie; Leach, James L.; Jones, Blaise V.; Care, Marguerite; Radhakrishnan, Rupa; Merrow, Arnold C.; Alvarado, Enrique; Serai, Suraj D.

2017-01-01

The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted. (orig.)

[Physiology in Relation to Anesthesia Practice: Preface and Comments].

Science.gov (United States)

Yamada, Yoshitsugu

2016-05-01

It has been long recognized that anesthesia practice is profoundly based in physiology. With the advance of the technology of imaging, measurement and information, a serious gap has emerged between anesthesia mainly handling gross systemic parameters and molecular physiology. One of the main reasons is the lack of establishment of integration approach. This special series of reviews deals with systems physiology covering respiratory, cardiovascular, and nervous systems. It also includes metabolism, and fluid, acid-base, and electrolyte balance. Each review focuses on several physiological concepts in each area, explaining current understanding and limits of the concepts based on the new findings. They reaffirm the importance of applying physiological inference in anesthesia practice and underscore the needs of advancement of systems physiology.

7 CFR 2902.20 - Fluid-filled transformers.

Science.gov (United States)

2010-01-01

... transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non... transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... 7 Agriculture 15 2010-01-01 2010-01-01 false Fluid-filled transformers. 2902.20 Section 2902.20...

THERMOREGULATION IN CHILDREN: EXERCISE, HEAT STRESS & FLUID BALANCE

Directory of Open Access Journals (Sweden)

Shawnda A. Morrison

2014-12-01

Full Text Available This review focuses on the specific physiological strategies of thermoregulation in children, a brief literary update relating exercise to heat stress in girls and boys as well as a discussion on fluid balance strategies for children who are performing exercise in the heat. Both sport performance and thermoregulation can be affected by the body’s water and electrolyte content. The recommendations for pre-pubertal fluid intake have been generalized from adult literature, including a limited concession for the physiological differences between adults and children. Considering these body fluid shifts, carbohydrate-electrolyte drinks are thought to be an essential tool in combating dehydration as a result of active hyperthermia (i.e. exercise, thus we examine current hydration practices in exercising children. Finally, this review summarizes research which examines the relationship between cognition and hypohydration on young athletes’ performance.

Comparing human peritoneal fluid and phosphate-buffered saline for drug delivery: do we need bio-relevant media?

Science.gov (United States)

Bhusal, Prabhat; Rahiri, Jamie Lee; Sua, Bruce; McDonald, Jessica E; Bansal, Mahima; Hanning, Sara; Sharma, Manisha; Chandramouli, Kaushik; Harrison, Jeff; Procter, Georgina; Andrews, Gavin; Jones, David S; Hill, Andrew G; Svirskis, Darren

2018-06-01

An understanding of biological fluids at the site of administration is important to predict the fate of drug delivery systems in vivo. Little is known about peritoneal fluid; therefore, we have investigated this biological fluid and compared it to phosphate-buffered saline, a synthetic media commonly used for in vitro evaluation of intraperitoneal drug delivery systems. Human peritoneal fluid samples were analysed for electrolyte, protein and lipid levels. In addition, physicochemical properties were measured alongside rheological parameters. Significant inter-patient variations were observed with regard to pH (p < 0.001), buffer capacity (p < 0.05), osmolality (p < 0.001) and surface tension (p < 0.05). All the investigated physicochemical properties of peritoneal fluid differed from phosphate-buffered saline (p < 0.001). Rheological examination of peritoneal fluid demonstrated non-Newtonian shear thinning behaviour and predominantly exhibited the characteristics of an entangled network. Inter-patient and inter-day variability in the viscosity of peritoneal fluid was observed. The solubility of the local anaesthetic lidocaine in peritoneal fluid was significantly higher (p < 0.05) when compared to phosphate-buffered saline. Interestingly, the dissolution rate of lidocaine was not significantly different between the synthetic and biological media. Importantly, and with relevance to intraperitoneal drug delivery systems, the sustained release of lidocaine from a thermosensitive gel formulation occurred at a significantly faster rate into peritoneal fluid. Collectively, these data demonstrate the variation between commonly used synthetic media and human peritoneal fluid. The differences in drug release rates observed illustrate the need for bio-relevant media, which ultimately would improve in vitro-in vivo correlation.

Physiology Of Prolonged Bed Rest

Science.gov (United States)

Greenleaf, John E.

1991-01-01

Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

The Next Generation of Synthetic Biology Chassis: Moving Synthetic Biology from the Laboratory to the Field.

Science.gov (United States)

Adams, Bryn L

2016-12-16

Escherichia coli (E. coli) has played a pivotal role in the development of genetics and molecular biology as scientific fields. It is therefore not surprising that synthetic biology (SB) was built upon E. coli and continues to dominate the field. However, scientific capabilities have advanced from simple gene mutations to the insertion of rationally designed, complex synthetic circuits and creation of entirely synthetic genomes. The point is rapidly approaching where E. coli is no longer an adequate host for the increasingly sophisticated genetic designs of SB. It is time to develop the next generation of SB chassis; robust organisms that can provide the advanced physiology novel synthetic circuits will require to move SB from the laboratory into fieldable technologies. This can be accomplished by developing chassis-specific genetic toolkits that are as extensive as those for E. coli. However, the holy grail of SB would be the development of a universal toolkit that can be ported into any chassis. This viewpoint article underscores the need for new bacterial chassis, as well as discusses some of the important considerations in their selection. It also highlights a few examples of robust, tractable bacterial species that can meet the demands of tomorrow's state-of-the-art in SB. Significant advances have been made in the first 15 years since this field has emerged. However, the advances over the next 15 years will occur not in laboratory organisms, but in fieldable species where the potential of SB can be fully realized in game changing technology.

Supercritical fluid regeneration of adsorbents

Science.gov (United States)

Defilippi, R. P.; Robey, R. J.

1983-05-01

The results of a program to perform studies supercritical (fluid) carbon dioxide (SCF CO2) regeneration of adsorbents, using samples of industrial wastewaters from manufacturing pesticides and synthetic solution, and to estimate the economics of the specific wastewater treatment regenerations, based on test data are given. Processing costs for regenerating granular activated carbon GAC) for treating industrial wastewaters depend on stream properties and regeneration throughput.

Induction of Fish Biomarkers by Synthetic-Based Drilling Muds

Science.gov (United States)

Gagnon, Marthe Monique; Bakhtyar, Sajida

2013-01-01

The study investigated the effects of chronic exposure of pink snapper (Pagrus auratus Forster), to synthetic based drilling muds (SBMs). Fish were exposed to three mud systems comprised of three different types of synthetic based fluids (SBFs): an ester (E), an isomerized olefin (IO) and linear alpha olefin (LAO). Condition factor (CF), liver somatic index (LSI), hepatic detoxification (EROD activity), biliary metabolites, DNA damage and stress proteins (HSP-70) were determined. Exposure to E caused biologically significant effects by increasing CF and LSI, and triggered biliary metabolite accumulation. While ester-based SBFs have a rapid biodegradation rate in the environment, they caused the most pronounced effects on fish health. IO induced EROD activity and biliary metabolites and LAO induced EROD activity and stress protein levels. The results demonstrate that while acute toxicity of SBMs is generally low, chronic exposure to weathering cutting piles has the potential to affect fish health. The study illustrates the advantages of the Western Australian government case-by-case approach to drilling fluid management, and highlights the importance of considering the receiving environment in the selection of SBMs. PMID:23894492

Time-Mean Structure of Axisymmetric Synthetic Jets

Czech Academy of Sciences Publication Activity Database

Tesař, Václav; Kordík, Jozef

2010-01-01

Roč. 161, 1-2 (2010), s. 217-224 ISSN 0924-4247 R&D Projects: GA ČR GA101/07/1499; GA AV ČR IAA200760705 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * similarity solution * fluid flow Subject RIV: BK - Fluid Dynamics Impact factor: 1.933, year: 2010 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THG-50B49R5-1&_user=640952&_coverDate=06%2F30%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1401478319&_rerunOrigin=scholar. google &_acct=C000034318&_version=1&_urlVersion=0&_userid=640952&md5=9c1ee293f204acab661943a9c5be6438

Synthetic biology, inspired by synthetic chemistry.

Science.gov (United States)

Malinova, V; Nallani, M; Meier, W P; Sinner, E K

2012-07-16

The topic synthetic biology appears still as an 'empty basket to be filled'. However, there is already plenty of claims and visions, as well as convincing research strategies about the theme of synthetic biology. First of all, synthetic biology seems to be about the engineering of biology - about bottom-up and top-down approaches, compromising complexity versus stability of artificial architectures, relevant in biology. Synthetic biology accounts for heterogeneous approaches towards minimal and even artificial life, the engineering of biochemical pathways on the organismic level, the modelling of molecular processes and finally, the combination of synthetic with nature-derived materials and architectural concepts, such as a cellular membrane. Still, synthetic biology is a discipline, which embraces interdisciplinary attempts in order to have a profound, scientific base to enable the re-design of nature and to compose architectures and processes with man-made matter. We like to give an overview about the developments in the field of synthetic biology, regarding polymer-based analogs of cellular membranes and what questions can be answered by applying synthetic polymer science towards the smallest unit in life, namely a cell. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

LABILE IRON IN CELLS AND BODY FLUIDS . Physiology, Pathology and Pharmacology

Directory of Open Access Journals (Sweden)

Zvi Ioav Cabantchik

2014-03-01

Full Text Available In living systems iron appears predominantly associated with proteins, but can also be detected in forms referred as labile iron, which denotes the combined redox properties of iron and its amenability to exchange between ligands, including chelators. The labile cell iron (LCI composition varies with metal concentration and substances with chelating groups but also with pH and the redox potential. Although physiologically in the lower µM range, LCI plays a key role in cell iron economy as cross-roads of metabolic pathways. LCI levels are continually regulated by an iron-responsive machinery that balances iron uptake versus deposition into ferritin. However, LCI rises aberrantly in some cell types due to faulty cell utilization pathways or infiltration by pathological iron forms that are found in hemosiderotic plasma. As LCI attains pathological levels, it can catalyze reactive O species (ROS formation that, at particular threshold, can surpass cellular anti-oxidant capacities and seriously damage its constituents. While in normal plasma and interstitial fluids, virtually all iron is securely carried by circulating transferrin (that renders iron essentially non-labile, in systemic iron overload (IO, the total plasma iron binding capacity is often surpassed by a massive iron influx from hyperabsorptive gut or from erythrocyte overburdened spleen and/or liver. As plasma transferrin approaches iron saturation, labile plasma iron (LPI emerges in forms that can infiltrate cells by unregulated routes and raise LCI to toxic levels. Despite the limited knowledge available on LPI speciation in different types and degrees of iron overload, LPI measurements can be and are in fact used for identifying systemic IO and for initiating/adjusting chelation regimens to attain full-day LPI protection. A recent application of labile iron assay is the detection of labile components in iv iron formulations per se as well as in plasma (LPI following parenteral iron

Time-frequency analysis of submerged synthetic jet

Science.gov (United States)

Kumar, Abhay; Saha, Arun K.; Panigrahi, P. K.

2017-12-01

The coherent structures transport the finite body of fluid mass through rolling which plays an important role in heat transfer, boundary layer control, mixing, cooling, propulsion and other engineering applications. A synthetic jet in the form of a train of vortex rings having coherent structures of different length scales is expected to be useful in these applications. The propagation and sustainability of these coherent structures (vortex rings) in downstream direction characterize the performance of synthetic jet. In the present study, the velocity signal acquired using the S-type hot-film probe along the synthetic jet centerline has been taken for the spectral analysis. One circular and three rectangular orifices of aspect ratio 1, 2 and 4 actuating at 1, 6 and 18 Hz frequency have been used for creating different synthetic jets. The laser induced fluorescence images are used to study the flow structures qualitatively and help in explaining the velocity signal for detection of coherent structures. The study depicts four regions as vortex rollup and suction region (X/D h ≤ 3), steadily translating region (X/D h ≤ 3-8), vortex breakup region (X/Dh ≤ 4-8) and dissipation of small-scale vortices (X/D h ≤ 8-15). The presence of coherent structures localized in physical and temporal domain is analyzed for the characterization of synthetic jet. Due to pulsatile nature of synthetic jet, analysis of velocity time trace or signal in time, frequency and combined time-frequency domain assist in characterizing the signatures of coherent structures. It has been observed that the maximum energy is in the first harmonic of actuation frequency, which decreases slowly in downstream direction at 6 Hz compared to 1 and 18 Hz of actuation.

Hydrothermal diamond-anvil cell: Application to studies of geologic fluids

Science.gov (United States)

Chou, I.-Ming

2003-01-01

The hydrothermal diamond-anvil cell (HDAC) was designed to simulate the geologic conditions of crustal processes in the presence of water or other fluids. The HDAC has been used to apply external pressure to both synthetic and natural fluid inclusions in quartz to minimize problems caused by stretching or decrepitation of inclusions during microthermometric analysis. When the HDAC is loaded with a fluid sample, it can be considered as a large synthetic fluid inclusion and therefore, can be used to study the PVTX properties as well as phase relations of the sample fluid. Because the HDAC has a wide measurement pressure-temperature range and also allows in-situ optical observations, it has been used to study critical phenomena of various chemical systems, such as the geologically important hydrous silicate melts. It is possible, when the HDAC is combined with synchrotron X-ray sources, to obtain basic information on speciation and structure of metal including rare-earth elements (REE) complexes in hydrothermal solutions as revealed by X-ray absorption fine structure (XAFS) spectra. Recent modifications of the HDAC minimize the loss of intensity of X-rays due to scattering and absorption by the diamonds. These modifications are especially important for studying elements with absorption edges below 10 keV and therefore particularly valuable for our understanding of transport and deposition of first-row transition elements and REE in hydrothermal environments.

Protein profiling of cerebrospinal fluid

DEFF Research Database (Denmark)

Simonsen, Anja H

2012-01-01

The cerebrospinal fluid (CSF) perfuses the brain and spinal cord. CSF contains proteins and peptides important for brain physiology and potentially also relevant for brain pathology. Hence, CSF is the perfect source to search for new biomarkers to improve diagnosis of neurological diseases as well...

Simultaneous determination of moxifloxacin and ofloxacin in physiological fluids using high performance liquid chromatography with ultraviolet detection.

Science.gov (United States)

Khan, Fahim Ullah; Nasir, Fazli; Iqbal, Zafar; Khan, Ismail; Shahbaz, Naila; Hassan, Muhammad; Ullah, Farhad

2016-04-01

A novel, sensitive and validated RP-HPLC-UV method was developed for simultaneous determination of moxifloxacin and ofloxacin using timolol maleate as internal standard in physiological fluids. Different experimental parameters were optimized and validated according to international guidelines. Complete separation of the analytes was achieved with Kromasil 100-5C18 analytical column (250mm×4.6mm×5μm), methanol and 0.05% trifloroacetic acid (TFA) (38:62v/v) were used as mobile phase, pumped at flow rate of 1.1ml/min in isocratic phase, column oven temperature maintained at 45°C and detection wavelength of 290nm. Protein precipitation method was applied to extract the drugs from human plasma and bovine aqueous humor samples using methanol as precipitating solvent. This method is linear in concentration range of 0.018-100μg/ml for moxifloxacin and 0.014-20μg/ml for ofloxacin. The recoveries of the method were 97.52 and 97.39% in human plasma for MX and OFN respectively, while in aqueous humor 94.48% for MX. The LOD values in plasma were found to be 10.0 and 8.00ng/ml for MX and OFN respectively, while their respective LOQ values were 18.0 and 14ng/ml. In aqueous humor the LOD and LOQ for MX were 16.0 and 24ng/ml respectively. In future, this method will be used to study the pharmacokinetic profile of moxifloxacin and ofloxacin in biological fluids and pharmaceutical products. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of synthetic zeolites as oral delivery vehicle for anti-inflammatory drugs

Directory of Open Access Journals (Sweden)

Elham Khodaverdi

2014-05-01

Full Text Available Objective(s: In this research, zeolite X and zeolite Y were used as vehicle to prepare intestine targeted oral delivery systems of indomethacin and ibuprofen. Materials and Methods: A soaking procedure was implemented to encapsulate indomethacin or ibuprofen within synthetic zeolites. Gravimetric methods and IR spectra of prepared formulations were used to assess drug loading efficiencies into zeolite structures. Scanning Electron Microscopy (SEM was also utilized to determine morphologies changes in synthetic zeolites after drug loading. At the next stage, dissolution studies were used to predict the in vivo performance of prepared formulations at HCl 0.1 N and PBS pH 6.5 as simulated gastric fluid (SGF and simulated intestine fluid (SIF, respectively. Results: Drug loadings of prepared formulations was determined between 24-26 % w/w. Dissolution tests at SGF were shown that zeolites could retain acidic model drugs in their porous structures and can be able to limit their release into the stomach. On the other hand, all prepared formulations completely released model drugs during 3 hr in simulated intestine fluid. Conclusion: Obtained results indicated zeolites could potentially be able to release indomethacin and ibuprofen in a sustained and controlled manner and reduced adverse effects commonly accompanying oral administrations of NSAIDs.

Numerical study of circular synthetic jets at low Reynolds numbers

International Nuclear Information System (INIS)

Xia, Qingfeng; Lei, Shenghui; Ma, Jieyan; Zhong, Shan

2014-01-01

Highlights: • Parameter maps depicting different flow regimes of synthetic jets are produced. • Boundaries separating these regimes are defined using quantitative criteria. • The Reynolds number is most appropriate for classifying different flow regimes. • A use of high suction cycle factors enhances the effectiveness of synthetic jets. - Abstract: In this paper, the flow patterns of circular synthetic jets issuing into a quiescent flow at low Reynolds numbers are studied numerically. The results confirm the presence of the three jet flow regimes, i.e. no jet formation, jet flow without rollup and jet flow with rollup reported in the literature. The boundaries of the different jet flow regimes are determined by tracking the structures produced by the synthetic jets in the near field of the jet orifice over several actuation cycles and examining the cycle-averaged streamwise velocity profiles along the jet central axis. When the Stokes number is above a certain threshold value appropriate for the corresponding flow regime, a good correlation between the flow patterns and the jet Reynolds number defined using the jet orifice diameter, Re Do , is also found. Furthermore, the flow structures of synthetic jets with different suction duty cycle factors are compared. The use of a high suction duty cycle factor strengthens the synthetic jet resulting in a greater penetration depth into the surrounding fluid. Overall, the finding from this study enables the flow regimes, in which a synthetic jet actuator with a circular orifice operates, to be determined. It also provides a way of designing more effective synthetic jet actuators for enhancing mass and momentum transfer at very low Reynolds numbers

Mathematical modeling of fluid and solute transport in peritoneal dialysis

OpenAIRE

Waniewski, Jacek

2001-01-01

Optimization of peritoneal dialysis schedule and dialysis fluid composition needs, among others, methods for quantitative assessment of fluid and solute transport. Furthermore, an integrative quantitative description of physiological processes within the tissue, which contribute to the net transfer of fluid and solutes, is necessary for interpretation of the data and for predictions of the outcome of possible intervention into the peritoneal transport system. The current pro...

Synthesis of high-temperature viscosity stabilizer used in drilling fluid

Science.gov (United States)

Zhang, Yanna; Luo, Huaidong; Shi, Libao; Huang, Hongjun

2018-02-01

Abstract For a well performance drilling fluid, when it operates in deep wells under high temperature, the most important property required is the thermal stability. The drilling fluid properties under high temperature can be controlled by proper selection of viscosity stabilizer, which can capture oxygen to protect polymer agent in the drilling fluid. In this paper a viscosity stabilizer PB-854 is described, which was synthesized by 4-phenoxybutyl bromide, paraformaldehyde, and phloroglucinol using etherification method and condensation reaction. We studied the effect of catalyst dosage, temperature, time, and stirring rate on the synthetic yield. Under this condition: molar ratio of 2-tert-Butylphenol, paraformaldehyde and phloroglucinol of 2:1:2.5, reacting temperature of 100 °C, stirring rate of 100 r min-1, and mass content of catalyst of 15 %, char yield of 5-bromine-3-tert-butyl salicylaldehyde reached 86 %. Under this condition: molar ratio of 5-bromine-3-tert-butyl salicylaldehyde and phloroglucinol of 4, reacting temperature of 60 °C, reacting time of 30 min, volume content of sulphuric acid of 80 %, char yield of the target product viscosity stabilizer PB-854 is 86%. Finally, in this paper, infrared spectroscopy is adopted to analyse the structure of the synthetic product PB-854.The improvement in the stability of drilling fluid was further shown after adding the viscosity stabilizer in the common polymer drilling fluid under high temperature conditions of 120 °C ˜ 180 °C. The results show significant change in terms of fluid stability in the presence of this new stabilizer as it provides better stability.

Intraoperative fluid therapy in neonates

African Journals Online (AJOL)

Differences from adults and children in physiology and anatomy of neonates inform our ... is based on energy expenditure indexed to bodyweight.2 Energy ... fragile and poorly keratinised.5 ... neonates means that very conservative fluid regimes in neonates ..... I make an estimation of insensible loss from the skin, viscera,.

Pulse Packet Stochastic Model for Gastric Emptying in the Fasted State: A Physiological Approach.

Science.gov (United States)

Talattof, Arjang; Amidon, Gordon L

2018-03-05

Fasted-state gastrointestinal (GI) fluid transit is typically represented as a first-order, deterministic process (averaged and viewed as a continuous approximation). It is, however, most likely a discrete process involving fluid packets interrupted by variable time periods of little to no fluid emptying. In this report we present a physiologically based pulsed-packet gastric fluid emptying model and evaluate it with respect to recent gastrointestinal fluid volume emptying results, published gastric emptying of various dosage forms, and gastric fluid emptying as a function of GI motility. We develop the mathematical model for gastric emptying of discrete volumes emptied during intermittent pulse times of variable lengths, defined as a function of gastric motility utilizing a Poisson point process with motility-dependent intensity. We compare the simulations with observed gastric emptying results. The discrete pulse-packet gastric volumetric emptying model is a more physiologically realistic mathematical model for gastric emptying and it accounts well for the average observed emptying rates and, importantly, encompasses the variability of of observed volume and dosage form emptying rates.

Stress assessment in piping under synthetic thermal loads emulating turbulent fluid mixing

Energy Technology Data Exchange (ETDEWEB)

Costa Garrido, Oriol, E-mail: oriol.costa@ijs.si; El Shawish, Samir, E-mail: samir.elshawish@ijs.si; Cizelj, Leon, E-mail: leon.cizelj@ijs.si

2015-03-15

Highlights: • Generation of complex space-continuous and time-dependent temperature fields. • 1D and 3D thermo-mechanical analyses of pipes under complex surface thermal loads. • Surface temperatures and stress fluctuations are highly linearly correlated. • 1D and 3D results agree for a wide range of Fourier and Biot numbers. • Global thermo-mechanical loading promotes non-equibiaxial stress state. - Abstract: Thermal fatigue assessment of pipes due to turbulent fluid mixing in T-junctions is a rather difficult task because of the existing uncertainties and variability of induced thermal stresses. In these cases, thermal stresses arise on three-dimensional pipe structures due to complex thermal loads, known as thermal striping, acting at the fluid-wall interface. A recently developed approach for the generation of space-continuous and time-dependent temperature fields has been employed in this paper to reproduce fluid temperature fields of a case study from the literature. The paper aims to deliver a detailed study of the three-dimensional structural response of piping under the complex thermal loads arising in fluid mixing in T-junctions. Results of three-dimensional thermo-mechanical analyses show that fluctuations of surface temperatures and stresses are highly linearly correlated. Also, surface stress fluctuations, in axial and hoop directions, are almost equi-biaxial. These findings, representative on cross sections away from system boundaries, are moreover supported by the sensitivity analysis of Fourier and Biot numbers and by the comparison with standard one-dimensional analyses. Agreement between one- and three-dimensional results is found for a wide range of studied parameters. The study also comprises the effects of global thermo-mechanical loading on the surface stress state. Implemented mechanical boundary conditions develop more realistic overall system deformation and promote non-equibiaxial stresses.

Performance of synthetic jet actuators based on hybrid and double-acting principles

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Tesař, Václav; Kordík, Jozef

2008-01-01

Roč. 11, č. 3 (2008), s. 221-229 ISSN 1343-8875 R&D Projects: GA ČR GA101/07/1499; GA AV ČR(CZ) IAA200760801 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * impinging jet * actuator Subject RIV: BK - Fluid Dynamics Impact factor: 0.943, year: 2008

The predominant effect of stroke length on velocity profiles at the exit of axisymmetric synthetic jet actuators

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Trávníček, Zdeněk; Timchenko, V.; Ismail, N.A.

2017-01-01

Roč. 66, August (2017), s. 197-208 ISSN 0142-727X R&D Projects: GA ČR(CZ) GA16-16596S Institutional support: RVO:61388998 Keywords : synthetic jet * stroke length * reynolds number Subject RIV: BK - Fluid Dynamics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.873, year: 2016 http://www.sciencedirect.com/science/article/pii/S0142727X17300073

The mobility of U and Th in subduction zone fluids: an indicator of oxygen fugacity and fluid salinity

Science.gov (United States)

Bali, Enikő; Audétat, Andreas; Keppler, Hans

2011-04-01

The solubility of U and Th in aqueous solutions at P-T-conditions relevant for subduction zones was studied by trapping uraninite or thorite saturated fluids as synthetic fluid inclusions in quartz and analyzing their composition by Laser Ablation-ICPMS. Uranium is virtually insoluble in aqueous fluids at Fe-FeO buffer conditions, whereas its solubility increases both with oxygen fugacity and with salinity to 960 ppm at 26.1 kbar, Re-ReO2 buffer conditions and 14.1 wt% NaCl in the fluid. At 26.1 kbar and 800°C, uranium solubility can be reproduced by the equation: log {{U}} = 2.681 + 0.1433log f{{O}}2 + 0.594{{Cl,}} where fO2 is the oxygen fugacity, and Cl is the chlorine content of the fluid in molality. In contrast, Th solubility is generally low (uranium increases strongly both with oxygen fugacity and with salinity. We show that reducing or NaCl-free fluids cannot produce primitive arc magmas with U/Th ratio higher than MORB. However, the dissolution of several wt% of oxidized, saline fluids in arc melts can produce U/Th ratios several times higher than in MORB. We suggest that observed U/Th ratios in arc magmas provide tight constraints on both the salinity and the oxidation state of subduction zone fluids.

In vitro culture of mouse embryos amniotic fluid ID human

African Journals Online (AJOL)

1989-07-15

Jul 15, 1989 ... Because human amniotic fluid is a physiological, balanced ultrafiltrate, it has been considered as an inexpensive alternative culture medium in. IVF. A study of the development of mouse embryos in human amniotic fluid was undertaken to assess the suitability of this as an optional culture medium in human ...

Optimal diameter of nozzles of synthetic jet actuators based on electrodynamic transducers

Czech Academy of Sciences Publication Activity Database

Kordík, Jozef; Trávníček, Zdeněk

2017-01-01

Roč. 86, September (2017), s. 281-294 ISSN 0894-1777 R&D Projects: GA ČR(CZ) GA16-16596S Institutional support: RVO:61388998 Keywords : synthetic jet * volumetric flux * momentum flux Subject RIV: BK - Fluid Dynamics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.830, year: 2016 http://ac.els-cdn.com/S0894177717300742/1-s2.0-S0894177717300742-main.pdf?_tid=6ea733c0-355f-11e7-b903-00000aab0f27&acdnat=1494407145_e51e007a0043b8f660576ad000820efd

The Study Of Metalworking Fluids Biodegradability By Indirect Measurement Of Bacterial Inoculum Respiration

Directory of Open Access Journals (Sweden)

Gerulová Kristína

2015-06-01

Full Text Available An apparatus for measuring biodegradability of metalworking fluids (MWFs was constructed according to (1, based on the Zahn-Wellens test which enables a continuous determination of CO2 production by the change in conductivity of absorption solution. Results obtained from the testing of 8 different MWFs by this modified method were compared to those obtained in standardized OECD 302 B. The comparison showed better description of bacterial inoculum activity in tested solution; lag phase was easy to indicate. Tested emulsion achieved the level of primary degradability 39.7 – 40.8 %, and semi-synthetics 19.1 – 43.5%. The samples of synthetics where the degradation level reached 43.9 - 58.6 % were identified as the most degradable metalworking fluids.

Formation Criterion for Axisymmetric Synthetic Jets at High Stokes Numbers

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Broučková, Zuzana; Kordík, Jozef

2012-01-01

Roč. 50, č. 9 (2012), s. 2012-2017 ISSN 0001-1452 R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GCP101/11/J019 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * power spectral density * hot-wire anemometry Subject RIV: BK - Fluid Dynamics Impact factor: 1.080, year: 2012 http://arc.aiaa.org/doi/abs/10.2514/1.J051649

The Effect of Loading Rate on Hydraulic Fracturing in Synthetic Granite - a Discrete Element Study

Science.gov (United States)

Tomac, I.; Gutierrez, M.

2015-12-01

Hydraulic fracture initiation and propagation from a borehole in hard synthetic rock is modeled using the two dimensional Discrete Element Method (DEM). DEM uses previously established procedure for modeling the strength and deformation parameters of quasi-brittle rocks with the Bonded Particle Model (Itasca, 2004). A series of simulations of laboratory tests on granite in DEM serve as a reference for synthetic rock behavior. Fracturing is enabled by breaking parallel bonds between DEM particles as a result of the local stress state. Subsequent bond breakage induces fracture propagation during a time-stepping procedure. Hydraulic fracturing occurs when pressurized fluid induces hoop stresses around the wellbore which cause rock fracturing and serves for geo-reservoir permeability enhancement in oil, gas and geothermal industries. In DEM, a network of fluid pipes and reservoirs is used for mathematical calculation of fluid flow through narrow channels between DEM particles, where the hydro-mechanical coupling is fully enabled. The fluid flow calculation is superimposed with DEM stress-strain calculation at each time step. As a result, the fluid pressures during borehole pressurization in hydraulic fracturing, as well as, during the fracture propagation from the borehole, can be simulated. The objective of this study is to investigate numerically a hypothesis that fluid pressurization rate, or the fluid flow rate, influences upon character, shape and velocity of fracture propagation in rock. The second objective is to better understand and define constraints which are important for successful fracture propagation in quasi-brittle rock from the perspective of flow rate, fluid density, viscosity and compressibility relative to the rock physical properties. Results from this study indicate that not only too high fluid flow rates cause fracture arrest and multiple fracture branching from the borehole, but also that the relative compressibility of fracturing fluid and

Natural - synthetic - artificial!

DEFF Research Database (Denmark)

Nielsen, Peter E

2010-01-01

The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

Analysis of I-Br-Cl in single fluid inclusions by LA-ICP-MS

Science.gov (United States)

Giehl, C.; Fusswinkel, T.; Beermann, O.; Garbe-Schönberg, D.; Scholten, L.; Wagner, T.

2017-12-01

Halogens are excellent tracers of hydrothermal fluid sources and in-situ LA-ICP-MS analysis of Cl and Br in single fluid inclusions has provided fundamentally new insight into hydrothermal fluid flow and ore formation. There is mounting evidence that enrichment and depletion of Br relative to Cl may be caused by a number of processes beyond seawater evaporation and halite dissolution which cannot be discriminated on the basis of Br/Cl ratios alone. Expanding the analytical capabilities of fluid inclusion LA-ICP-MS analysis to include iodine would allow to discern between selective and coupled enrichment processes of Cl, Br and I, even in geologically complex samples that are inaccessible to bulk extraction techniques. We present iodine concentration data determined by LA-ICP-MS analysis of synthetic fluid inclusions, using the Sca17 scapolite reference material for external standardization (Seo et al., 2011). Iodine concentrations in Sca17 were determined using the Durango apatite standard. Four starting solutions containing I (0.3, 1.5, 27, 78 µg/g), Br (941, 1403, 2868, 4275 µg/g), Na (30.7, 94.7 mg/g), and Cl (50, 137 mg/g) (analyzed by ICP-OES and ICP-MS at CAU Kiel) were prepared by dissolving reagent grade chemical powders in ultra-pure water. Spherical inclusions (up to 40 µm) were synthesized from the starting solutions in pre-cracked, HF-treated synthetic quartz crystals which were placed in gold capsules and equilibrated at 600°C, 100/200 MPa in cold seal pressure vessels. Fluid inclusion LA-ICP-MS analysis (University of Helsinki) yielded average I concentrations in excellent agreement with the starting solutions (27.3 µg/g ± 14 %RSD for the 27 µg/g solution and 77.6 µg/g ± 8.3 %RSD for the 78 µg/g solution). Average Br and I concentrations deviate less than 10 % from solution concentration values. For the low I concentration solutions, the synthetic inclusions were too small to detect I. Thus, given suitable standard materials and sufficient

Thoracentesis-reverting cardiac tamponade physiology in a patient with myxedema coma and large pleural effusion.

Science.gov (United States)

Werlang, Monia E; Pimentel, Mario R; Diaz-Gomez, Jose L

2017-07-01

A large pleural effusion causing cardiac tamponade physiology and severe hemodynamic compromise is an uncommon event. We report a case of a 53-year-old woman with severe hypothyroidism presenting with myxedema coma and refractory shock. Her hemodynamic status failed to respond to fluid resuscitation and vasopressors. A transthoracic echocardiogram and chest radiograph demonstrated a pericardial fluid accumulation associated with a large left-sided pleural effusion. Thoracostomy tube insertion resulted in prompt improvement of the patient's hemodynamic status. Our finding demonstrates that a large pleural effusion may play an important role in cardiac tamponade physiology.

Physiological Characteristics of Some Monoamine Metabolites in Cat Cerebrospinal Fluid

OpenAIRE

Orešković, Darko; Sanković, Mauricio; Fröbea, Ana; Klarica, Marijan

1995-01-01

The concentrations of main metabolites of serotonin and dopamine, 5-hydroxyindoleacetic acid and homovanillic acid, respectively, were measured in cisternal cerebrospinal fluid of cats by high performance liquid chromatography with an electrochemical detector. Higher concentrations of homovanillic acid and a wide interindividual oscillation for both parameters have been found. However, samples collected at four different time intervals showed stabile intraindividual concentrations of the m...

Computer simulation studies in fluid and calcium regulation and orthostatic intolerance

Science.gov (United States)

1985-01-01

The systems analysis approach to physiological research uses mathematical models and computer simulation. Major areas of concern during prolonged space flight discussed include fluid and blood volume regulation; cardiovascular response during shuttle reentry; countermeasures for orthostatic intolerance; and calcium regulation and bone atrophy. Potential contributions of physiologic math models to future flight experiments are examined.

Plant synthetic biology.

Science.gov (United States)

Liu, Wusheng; Stewart, C Neal

2015-05-01

Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Seafloor monitoring for synthetic-based mud discharged in the Western Gulf of Mexico

International Nuclear Information System (INIS)

Candler, J.E.; Hoskin, S.; Churan, M.

1995-01-01

Synthetic-based muds have been used to simultaneously improve drilling and environmental performance. The fate and effects of synthetic-based mud discharges in the marine environment have been issues of concern with the drilling industry and governmental agencies. Most of the environmental data on synthetic-based muds have been generated under laboratory conditions. This study uses field-collected data to investigate, the fate and effects of a polyalphaolefin synthetic-based drilling fluid. The first well drilled in the Gulf of Mexico using synthetic-based mud was completed in June 1992. Approximately 441 bbl of cuttings and 354 bbl of synthetic-based mud were discharged over a 9-day period. Three sampling trips have been made to the discharge location to collect sediment samples for chemical and biological analysis over a 2-year period. The sediment samples were analyzed for content of organic compounds and barium. On the third trip, infaunal samples were also taken. Information collected from the chemical and biological analysis is documented and compared to similar field studies performed on oil-based and water-based muds. Sampling techniques and analytical protocols are described to facilitate future studies. Two years after discharges of synthetic-based cuttings were completed, an area within 50 m of the discharge point continued to exhibit alterations in the benthic community not normally associated with water-based mud discharges. However, the study indicates that polyalphaolefin synthetic-based mud exhibits significant improvements over oil-based mud in terms of removal of organic contamination and minimization of adverse effects on the benthic community

Effect of drilling fluids on permeability of uranium sandstone. Report of Investigations/1984

International Nuclear Information System (INIS)

Ahlness, J.K.; Johnson, D.I.; Tweeton, D.R.

1984-01-01

The Bureau of Mines conducted laboratory and field experiments to determine the amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simulated drill cuttings added to represent field use. The least permeability reduction was obtained from a multi-polymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells

Plant synthetic biology: a new platform for industrial biotechnology.

Science.gov (United States)

Fesenko, Elena; Edwards, Robert

2014-05-01

Thirty years after the production of the first generation of genetically modified plants we are now set to move into a new era of recombinant crop technology through the application of synthetic biology to engineer new and complex input and output traits. The use of synthetic biology technologies will represent more than incremental additions of transgenes, but rather the directed design of completely new metabolic pathways, physiological traits, and developmental control strategies. The need to enhance our ability to improve crops through new engineering capability is now increasingly pressing as we turn to plants not just for food, but as a source of renewable feedstocks for industry. These accelerating and diversifying demands for new output traits coincide with a need to reduce inputs and improve agricultural sustainability. Faced with such challenges, existing technologies will need to be supplemented with new and far-more-directed approaches to turn valuable resources more efficiently into usable agricultural products. While these objectives are challenging enough, the use of synthetic biology in crop improvement will face public acceptance issues as a legacy of genetically modified technologies in many countries. Here we review some of the potential benefits of adopting synthetic biology approaches in improving plant input and output traits for their use as industrial chemical feedstocks, as linked to the rapidly developing biorefining industry. Several promising technologies and biotechnological targets are identified along with some of the key regulatory and societal challenges in the safe and acceptable introduction of such technology.

Neural Control Mechanisms and Body Fluid Homeostasis

Science.gov (United States)

Johnson, Alan Kim

1998-01-01

The goal of the proposed research was to study the nature of afferent signals to the brain that reflect the status of body fluid balance and to investigate the central neural mechanisms that process this information for the activation of response systems which restore body fluid homeostasis. That is, in the face of loss of fluids from intracellular or extracellular fluid compartments, animals seek and ingest water and ionic solutions (particularly Na(+) solutions) to restore the intracellular and extracellular spaces. Over recent years, our laboratory has generated a substantial body of information indicating that: (1) a fall in systemic arterial pressure facilitates the ingestion of rehydrating solutions and (2) that the actions of brain amine systems (e.g., norepinephrine; serotonin) are critical for precise correction of fluid losses. Because both acute and chronic dehydration are associated with physiological stresses, such as exercise and sustained exposure to microgravity, the present research will aid in achieving a better understanding of how vital information is handled by the nervous system for maintenance of the body's fluid matrix which is critical for health and well-being.

Synthetic Cannabinoids

Directory of Open Access Journals (Sweden)

Aslihan Okan Ibiloglu

2017-09-01

Full Text Available Synthetic cannabinoids which is a subgroup of cannabinoids are commonly used for recreational drug use throughout the whole world. Although both marijuana and synthetic cannabinoids stimulate the same receptors, cannabinoid receptor 1 (CB1 and cannabinoid receptor 2 (CB2, studies have shown that synthetic cannabinoids are much more potent than marijuana. The longer use of synthetic cannabinoids can cause severe physical and psychological symptoms that might even result in death, similar to many known illicit drugs. Main treatment options mostly involve symptom management and supportive care. The aim of this article is to discuss clinical and pharmacological properties of the increasingly used synthetic cannabinoids. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2017; 9(3.000: 317-328

Heterogeneous porous media permeability field characterization from fluid displacement data; Integration de donnees de deplacements de fluides dans la caracterisation de milieux poreux heterogenes

Energy Technology Data Exchange (ETDEWEB)

Kretz, V.

2002-11-01

The prediction of oil recovery or pollutant dispersion requires an accurate knowledge of the permeability field distribution. Available data are usually measurements in well bores, and, since a few years, 4D-seismic data (seismic mappings repeated in time). Such measurements allow to evaluate fluids displacements fronts evolution. The purpose of the thesis is to evaluate the possibility to determinate permeability fields from fluid displacement measurements in heterogeneous porous media. At the laboratory scale, experimental studies are made on a model and on numerical simulations. The system uses blocks of granular materials whose individual geometries and permeabilities are controlled. The fluids displacements are detected with an acoustical. The key parameters of the study are the size and spatial correlation of the permeability heterogeneity distribution, and the influence of viscosity and gravity contrasts between the injected ant displaced fluid. Then the inverse problem - evaluating the permeability field from concentration fronts evolution - is approached. At the reservoir scale, the work will mainly be focused on the integration of 4D-seismic data into inversion programs on a 3D synthetic case. A particular importance will be given to the calculation of gradients, in order to obtain a complementary information about the sensitivity of data. The information provided by 4D-seismic data consists in maps showing the vertical average of oil saturation or the presence of gas. The purpose is to integrate this qualitative information in the inversion process and to evaluate the impact on the reservoir characterization. Comparative studies - with or without 4D-seismic data - will be realized on a synthetic case. (author)

Atomic force microscopy analysis of synthetic membranes applied in release studies

Energy Technology Data Exchange (ETDEWEB)

Olejnik, Anna, E-mail: annamar@amu.edu.pl; Nowak, Izabela

2015-11-15

Graphical abstract: - Highlights: • We compare eight synthetic membranes by atomic force microscopy. • We predict the behavior of membranes in the release experiments. • The polymeric synthetic membranes varied in shape and size. • We detect substructures in pores of cellulose esters and nylon membranes. • Substructures limit the release rate of active compound. - Abstract: Synthetic membranes are commonly used in drug release studies and are applied mostly in quality control. They contain pores through which the drug can be diffused directly into the receptor fluid. Investigation of synthetic membranes permits determination of their structure and characterization of their properties. We suggest that the preliminary characterization of the membranes can be relevant to the interpretation of the release results. The aim of this study was to compare eight synthetic membranes by using atomic force microscopy in order to predict and understand their behavior in the release experiments. The results proved that polytetrafluoroethylene membrane was not suitable for the release study of tetrapeptide due to its hydrophobic nature, thickness and the specific structure with high trapezoid shaped blocks. The additional substructures in pores of mixed cellulose esters and nylon membranes detected by AFM influenced the diffusion rate of the active compound. These findings indicate that the selection of the membrane for the release studies should be performed cautiously by taking into consideration the membrane properties and by analyzing them prior the experiment.

Atomic force microscopy analysis of synthetic membranes applied in release studies

International Nuclear Information System (INIS)

Olejnik, Anna; Nowak, Izabela

2015-01-01

Graphical abstract: - Highlights: • We compare eight synthetic membranes by atomic force microscopy. • We predict the behavior of membranes in the release experiments. • The polymeric synthetic membranes varied in shape and size. • We detect substructures in pores of cellulose esters and nylon membranes. • Substructures limit the release rate of active compound. - Abstract: Synthetic membranes are commonly used in drug release studies and are applied mostly in quality control. They contain pores through which the drug can be diffused directly into the receptor fluid. Investigation of synthetic membranes permits determination of their structure and characterization of their properties. We suggest that the preliminary characterization of the membranes can be relevant to the interpretation of the release results. The aim of this study was to compare eight synthetic membranes by using atomic force microscopy in order to predict and understand their behavior in the release experiments. The results proved that polytetrafluoroethylene membrane was not suitable for the release study of tetrapeptide due to its hydrophobic nature, thickness and the specific structure with high trapezoid shaped blocks. The additional substructures in pores of mixed cellulose esters and nylon membranes detected by AFM influenced the diffusion rate of the active compound. These findings indicate that the selection of the membrane for the release studies should be performed cautiously by taking into consideration the membrane properties and by analyzing them prior the experiment.

The effect of biomolecules on the behaviour of CoCrMo alloy in various simulated physiological solutions

International Nuclear Information System (INIS)

Milošev, Ingrid

2012-01-01

Highlights: ► The behaviour of CoCrMo alloy is investigated in four simulated physiological solutions. ► The effect of synovial fluid significantly differs from the effect of organic components hitherto studied. ► In the presence of organic components carbon and nitrogen containing species are formed. ► Composition, structure and thickness of surface layers were determined by XPS. - Abstract: CoCrMo orthopaedic alloy was oxidized potentiostatically in various simulated physiological solutions in order to reveal differences in the composition, thickness and structure of the surface layers formed as a function of solution composition. X-ray photoelectron spectroscopy, combined with angle-resolved measurements and depth profiling, was used for the purpose. The following simulated physiological solutions were used: (1) 0.9% NaCl, (2) simulated Hanks physiological solution containing various inorganic salts, (3) simulated Hanks physiological solution containing an aliquot of synovial fluid retrieved at a primary operation, and (4) minimum essential medium containing various inorganic salts, amino acids and vitamins. No significant differences between alloy treated in these solutions were observed after oxidation in the passive region; the oxide films are a few nanometres thick and, except in NaCl solution, contain a small amount of calcium phosphate. After oxidation at a potential in the transpassive range, however, the oxide thickness increases considerably due to incorporation of cobalt and molybdenum oxides. Further, the concentration of calcium phosphate increases. The layers formed in minimum essential medium and Hanks solution containing synovial fluid comprise nitrogen and carbon containing species. The addition of synovial fluid significantly affects the behaviour in Hanks solution.

Mechanisms controlling the volume of pleural fluid and extravascular lung water

Directory of Open Access Journals (Sweden)

G. Miserocchi

2009-12-01

Full Text Available Pleural and interstitial lung fluid volumes are strictly controlled and maintained at the minimum thanks to the ability of lymphatics to match the increase in filtration rate. In the pleural cavity, fluid accumulation is easily accommodated by retraction of lung and chest wall (high compliance of the pleural space; the increase of lymph flow per unit increase in pleural fluid volume is high due to the great extension of the parietal lymphatic. However, for the lung interstitium, the increase in lymph flow to match increased filtration does not need to be so great. In fact, increased filtration only causes a minor increase in extravascular water volume (<10% due to a marked increase in interstitial pulmonary pressure (low compliance of the extracellular matrix which, in turn, buffers further filtration. Accordingly, a less extended lymphatic network is needed. The efficiency of lymphatic control is achieved through a high lymphatic conductance in the pleural fluid and through a low interstitial compliance for the lung interstitium. Fluid volume in both compartments is so strictly controlled that it is difficult to detect initial deviations from the physiological state; thus, a great physiological advantage turns to be a disadvantage on a clinical basis as it prevents an early diagnosis of developing disease.

Synthetic Biology and Human Health: Potential Applications for Spaceflight

Science.gov (United States)

Karouia, Fathi; Carr, Christopher; Cai, Yizhi; Chen, Y.; Grenon, Marlene; Larios-Sanz, Maia; Jones, Jeffrey A.; Santos, Orlando

2011-01-01

Human space travelers experience a unique environment that affects homeostasis and physiologic adaptation. Spaceflight-related changes have been reported in the musculo-skeletal, cardiovascular, neurovestibular, endocrine, and immune systems. The spacecraft environment further subjects the traveler to noise and gravitational forces, as well as airborne chemical, microbiological contaminants, and radiation exposure. As humans prepare for longer duration missions effective countermeasures must be developed, verified, and implemented to ensure mission success. Over the past ten years, synthetic biology has opened new avenues for research and development in areas such as biological control, biomaterials, sustainable energy production, bioremediation, and biomedical therapies. The latter in particular is of great interest to the implementation of long-duration human spaceflight capabilities. This article discusses the effects of spaceflight on humans, and reviews current capabilities and potential needs associated with the health of the astronauts where synthetic biology could play an important role in the pursuit of space exploration.

[From synthetic biology to synthetic humankind].

Science.gov (United States)

Nouvel, Pascal

2015-01-01

In this paper, we propose an historical survey of the expression "synthetic biology" in order to identify its main philosophical components. The result of the analysis is then used to investigate the meaning of the notion of "synthetic man". It is shown that both notions share a common philosophical background that can be summed up by the short but meaningful assertion: "biology is technology". The analysis allows us to distinguish two notions that are often confused in transhumanist literature: the notion of synthetic man and the notion of renewed man. The consequences of this crucial distinction are discussed. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

The chronic toxicity of mineral oil-wet and synthetic liquid-wet cuttings on an estuarine fish, Fundulus grandis

International Nuclear Information System (INIS)

Jones, F.V.; Rushing, J.H.; Churan, M.A.

1991-01-01

One of the major factors concerning oil-wet cuttings discharges in the long-term effect on the aquatic environment. This paper investigates the survival and growth of the mud minnow, Fundulus grandis, when exposed to different concentrations of mineral oil-wet and synthetic liquid-wet cuttings in flow-through bioassay chambers. The test fluids were a low aromatic mineral oil-based mud (MOBM) and a synthetic liquid-based mud (SBM). Each test fluid was added to a container of dried water-based cuttings which contained minimum hydrocarbons. The fluid and cuttings were mixed to obtain the desired test concentrations. The study tested three concentrations (1%, 5%, and 8.4% by dry weight) of each fluid on the cuttings. Growth rates during the 3-day period were modest with fish in 1% MOBM losing weight. The highest percent growth rates were obtained with fish cultured in 5% SBM and the controls. However, overall growth was not significantly different between treatments. Mean growth did show a significant difference between controls and 5% SBM, and other treatments. The cuttings of the 5% and 8.4% concentrations of both treatments looked like paste. These pastes may have slowed the movement of organics off of the cuttings beds and affected biodegradability and growth rates. Cuttings in the controls and 1% concentrations stayed suspended in the water column longer when disturbed and looked more like loose gravel. Uptake of the MOBM occurred in the internal organs and tissue of fish. No such uptake was observed in the fish tissue with the SBM; a very low level of synthetic liquid was detected in one gut sample only. This may be the major reason for the variations noted in growth rates. Fish mortality during the study was related to the buildup of anaerobic conditions and insufficient aeration. Fish survival for the entire study was 94%

A new method for fluid input into a hybrid synthetic jet actuator

Directory of Open Access Journals (Sweden)

Kordík J.

2014-03-01

Full Text Available A new principle of flow rectification for hybrid synthetic jet actuators is introduced in this paper. As is well known, the flow rectification can be best accomplished by means of fluidic diodes. Novelty of the present study are fluidic diodes with two mutually opposed nozzles. Interaction between the periodic jet flows from the nozzles causes a difference between the blowing and suction strokes, resulting in a particularly efficient rectification effect. The distance between the nozzle exits as well as the oscillation frequency were the parameters, which were varied during hot-wire measurements. The combination of those parameters achieving the highest volumetric effciency was identified.

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

Science.gov (United States)

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses

Perspectives in Fluid Dynamics

Science.gov (United States)

Batchelor, G. K.; Moffatt, H. K.; Worster, M. G.

2002-12-01

With applications ranging from modelling the environment to automotive design and physiology to astrophysics, conventional textbooks cannot hope to give students much information on what topics in fluid dynamics are currently being researched, or how to choose between them. This book rectifies matters. It consists of eleven chapters that introduce and review different branches of the subject for graduate-level courses, or for specialists seeking introductions to other areas. Hb ISBN (2001): 0-521-78061-6

Magnetic nanofluids and magnetic composite fluids in rotating seal systems

International Nuclear Information System (INIS)

Borbath, T; Borbath, I; Boros, T; Bica, D; Vekas, L; Potencz, I

2010-01-01

Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

Modeling physiological resistance in bacterial biofilms.

Science.gov (United States)

Cogan, N G; Cortez, Ricardo; Fauci, Lisa

2005-07-01

A mathematical model of the action of antimicrobial agents on bacterial biofilms is presented. The model includes the fluid dynamics in and around the biofilm, advective and diffusive transport of two chemical constituents and the mechanism of physiological resistance. Although the mathematical model applies in three dimensions, we present two-dimensional simulations for arbitrary biofilm domains and various dosing strategies. The model allows the prediction of the spatial evolution of bacterial population and chemical constituents as well as different dosing strategies based on the fluid motion. We find that the interaction between the nutrient and the antimicrobial agent can reproduce survival curves which are comparable to other model predictions as well as experimental results. The model predicts that exposing the biofilm to low concentration doses of antimicrobial agent for longer time is more effective than short time dosing with high antimicrobial agent concentration. The effects of flow reversal and the roughness of the fluid/biofilm are also investigated. We find that reversing the flow increases the effectiveness of dosing. In addition, we show that overall survival decreases with increasing surface roughness.

Resistance of Listeria monocytogenes F2365 cells to synthetic gastric fluid is greater following growth on ready-to-eat deli turkey meat than in brain heart infusion broth.

Science.gov (United States)

Peterson, Luke D; Faith, Nancy G; Czuprynski, Charles J

2007-11-01

Ready-to-eat (RTE) deli meats have been categorized as high-risk foods for contraction of foodborne listeriosis. Several recent listeriosis outbreaks have been associated with the consumption of RTE deli turkey meat. In this study, we examined whether the growth of Listeria monocytogenes F2365 on commercially prepared RTE deli turkey meat causes listerial cells to become more resistant to inactivation by synthetic gastric fluid (SGF). Listerial cells grown on turkey meat to late logarithmic-early stationary phase were significantly more resistant to SGF at pH 7.0, 5.0, or 3.5 than listerial cells grown in brain heart infusion (BHI) broth. The pH was lower in the fluid in packages of turkey meat than in BHI broth (6.5 versus 7.5). However, listerial cells grown in BHI broth adjusted to a lower pH (6.0) did not exhibit enhanced resistance to SGF. The lesser resistance to SGF of listerial cells grown in BHI broth may be due, in part, to the presence of glucose (0.2%). This study indicates the environment presented by the growth of L. monocytogenes on deli turkey meat affects its ability to survive conditions it encounters in the gastrointestinal tract.

Fluid Shifts

Science.gov (United States)

Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.;

Comparison of the antioxidant effects of carnosic acid and synthetic antioxidants on tara seed oil.

Science.gov (United States)

Li, Zhan-Jun; Yang, Feng-Jian; Yang, Lei; Zu, Yuan-Gang

2018-04-04

In the present study, tara seed oil was obtained by supercritical fluid extraction and used to investigate the antioxidant strength of carnosic acid (CA) compared with conventional synthetic antioxidants. The antioxidants were added to the tara seed oil at 0.2 mg of antioxidant per gram of oil. The samples were then submitted to at 60 °C 15 days for an accelerated oxidation process, with samples taken regularly for analysis. After oxidation, the samples were analyzed to determine the peroxide value, thiobarbituric acid reactive substances, conjugated diene content, and free fatty acid content. CA was investigated at three purity levels (CA20, CA60, CA99), and compared with three synthetic antioxidants (butylatedhydroxyanisole, butylatedhydroxytoluene, and tert-butylhydroquinone). The oxidation indicators showed that CA was a strong antioxidant compared to the synthetic antioxidants. The antioxidant activities decreased in the order: tert-butylhydroquinone > CA99 > CA60 > CA20 > butylatedhydroxyanisole > butylatedhydroxytoluene. These results show that CA could be used to replace synthetic antioxidants in oil products, and should be safer for human consumption and the environment.

Release of Si from Silicon, a Ferrosilicon (FeSi) Alloy and a Synthetic Silicate Mineral in Simulated Biological Media

Science.gov (United States)

Herting, Gunilla; Jiang, Tao; Sjöstedt, Carin; Odnevall Wallinder, Inger

2014-01-01

Unique quantitative bioaccessibility data has been generated, and the influence of surface/material and test media characteristics on the elemental release process were assessed for silicon containing materials in specific synthetic body fluids at certain time periods at a fixed loading. The metal release test protocol, elaborated by the KTH team, has previously been used for classification, ranking, and screening of different alloys and metals. Time resolved elemental release of Si, Fe and Al from particles, sized less than 50 µm, of two grades of metallurgical silicon (high purity silicon, SiHG, low purity silicon, SiLG), an alloy (ferrosilicon, FeSi) and a mineral (aluminium silicate, AlSi) has been investigated in synthetic body fluids of varying pH, composition and complexation capacity, simple models of for example dermal contact and digestion scenarios. Individual methods for analysis of released Si (as silicic acid, Si(OH)4) in synthetic body fluids using GF-AAS were developed for each fluid including optimisation of solution pH and graphite furnace parameters. The release of Si from the two metallurgical silicon grades was strongly dependent on both pH and media composition with the highest release in pH neutral media. No similar effect was observed for the FeSi alloy or the aluminium silicate mineral. Surface adsorption of phosphate and lactic acid were believed to hinder the release of Si whereas the presence of citric acid enhanced the release as a result of surface complexation. An increased presence of Al and Fe in the material (low purity metalloid, alloy or mineral) resulted in a reduced release of Si in pH neutral media. The release of Si was enhanced for all materials with Al at their outermost surface in acetic media. PMID:25225879

Release of Si from silicon, a ferrosilicon (FeSi alloy and a synthetic silicate mineral in simulated biological media.

Directory of Open Access Journals (Sweden)

Gunilla Herting

Full Text Available Unique quantitative bioaccessibility data has been generated, and the influence of surface/material and test media characteristics on the elemental release process were assessed for silicon containing materials in specific synthetic body fluids at certain time periods at a fixed loading. The metal release test protocol, elaborated by the KTH team, has previously been used for classification, ranking, and screening of different alloys and metals. Time resolved elemental release of Si, Fe and Al from particles, sized less than 50 µm, of two grades of metallurgical silicon (high purity silicon, SiHG, low purity silicon, SiLG, an alloy (ferrosilicon, FeSi and a mineral (aluminium silicate, AlSi has been investigated in synthetic body fluids of varying pH, composition and complexation capacity, simple models of for example dermal contact and digestion scenarios. Individual methods for analysis of released Si (as silicic acid, Si(OH4 in synthetic body fluids using GF-AAS were developed for each fluid including optimisation of solution pH and graphite furnace parameters. The release of Si from the two metallurgical silicon grades was strongly dependent on both pH and media composition with the highest release in pH neutral media. No similar effect was observed for the FeSi alloy or the aluminium silicate mineral. Surface adsorption of phosphate and lactic acid were believed to hinder the release of Si whereas the presence of citric acid enhanced the release as a result of surface complexation. An increased presence of Al and Fe in the material (low purity metalloid, alloy or mineral resulted in a reduced release of Si in pH neutral media. The release of Si was enhanced for all materials with Al at their outermost surface in acetic media.

How can we probe the atom mass currents induced by synthetic gauge fields?

Science.gov (United States)

Paramekanti, Arun; Killi, Matthew; Trotzky, Stefan

2013-05-01

Ultracold atomic fermions and bosons in an optical lattice can have quantum ground states which support equilibrium currents in the presence of synthetic magnetic fields or spin orbit coupling. As a tool to uncover these mass currents, we propose using an anisotropic quantum quench of the optical lattice which dynamically converts the current patterns into measurable density patterns. Using analytical calculations and numerical simulations, we show that this scheme can probe diverse equilibrium bulk current patterns in Bose superfluids and Fermi fluids induced by synthetic magnetic fields, as well as detect the chiral edge currents in topological states of atomic matter such as quantum Hall and quantum spin Hall insulators. This work is supported by NSERC of Canada and the Canadian Institute for Advanced Research.

Renal renin secretion as regulator of body fluid homeostasis

DEFF Research Database (Denmark)

Damkjær, Mads; Isaksson, Gustaf L; Stubbe, Jane

2013-01-01

The renin-angiotensin system is essential for body fluid homeostasis and blood pressure regulation. This review focuses on the homeostatic regulation of the secretion of active renin in the kidney, primarily in humans. Under physiological conditions, renin secretion is determined mainly by sodium...

Mortality studies of metalworking fluid exposure in the automobile industry: VI. A case-control study of esophageal cancer.

Science.gov (United States)

Sullivan, P A; Eisen, E A; Woskie, S R; Kriebel, D; Wegman, D H; Hallock, M F; Hammond, S K; Tolbert, P E; Smith, T J; Monson, R R

1998-07-01

Results are reported from a nested case-control study of 60 esophageal cancer deaths among 46,384 automobile manufacturing workers potentially exposed to metalworking fluids (MWF) in machining and grinding operations. By using incidence-density sampling, controls were selected with a sampling ratio of 20:1 from among co-workers who remained at risk by the age of death of the case, matched on race, gender, plant, and year of birth. Conditional logistic regression was used to evaluate the risk associated with cumulative exposure (mg/m3-years) to each of three types of metalworking fluid (straight, soluble, and synthetic MWF), as well as with years of exposure to selected components of MWF, including nitrosamines, sulfur, biocides, and several metals. Esophageal cancer was found to be significantly associated with exposure to both soluble and synthetic MWF in grinding operations. The odds ratios (ORs) for grinding with soluble MWF were elevated at 2.5 or greater in all categories of cumulative exposure, although the exposure-response trend was statistically significant only when exposure was measured as duration. Those with 12 or more years exposure to soluble MWF in grinding operations experienced a 9.3-fold relative risk of esophageal cancer mortality (95% CI = 2.1-42.1). The OR for ever grinding with synthetic MWF was 4.1 (95% CI = 1.1-15.0). Elevated risk was also associated with two agents found in both synthetic and soluble fluids, nitrosamines, and biocides. For exposure to nitrosamines, the OR was 5.4 (95% CI = 1.5-19.9); for biocides the OR was 3.8 (95% CI = 0.8-18.9). However, because the same workers were exposed to grinding with synthetics, nitrosamines and biocides, it was not possible to separate the specific risks associated with these components.

Research into the Physiology of Cerebrospinal Fluid Reaches a New Horizon: Intimate Exchange between Cerebrospinal Fluid and Interstitial Fluid May Contribute to Maintenance of Homeostasis in the Central Nervous System.

Science.gov (United States)

Matsumae, Mitsunori; Sato, Osamu; Hirayama, Akihiro; Hayashi, Naokazu; Takizawa, Ken; Atsumi, Hideki; Sorimachi, Takatoshi

2016-07-15

Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.

Forensic applications of supercritical fluid chromatography - mass spectrometry.

Science.gov (United States)

Pauk, Volodymyr; Lemr, Karel

2018-06-01

Achievements of supercritical fluid chromatography with mass spectrometric detection made in the field of forensic science during the last decade are reviewed. The main topics include analysis of traditional drugs of abuse (e.g. cannabis, methamphetamine) as well as new psychoactive substances (synthetic cannabinoids, cathinones and phenethylamines), doping agents (anabolic steroids, stimulants, diuretics, analgesics etc.) and chemical warfare agents. Control of food authenticity, detection of adulteration and identification of toxic substances in food are also pointed out. Main aspects of an analytical workflow, such as sample preparation, separation and detection are discussed. A special attention is paid to the performance characteristics and validation parameters of supercritical fluid chromatography-mass spectrometric methods in comparison with other separation techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

Oxytocin-receptor-expressing neurons in the parabrachial nucleus regulate fluid intake.

Science.gov (United States)

Ryan, Philip J; Ross, Silvano I; Campos, Carlos A; Derkach, Victor A; Palmiter, Richard D

2017-12-01

Brain regions that regulate fluid satiation are not well characterized, yet are essential for understanding fluid homeostasis. We found that oxytocin-receptor-expressing neurons in the parabrachial nucleus of mice (Oxtr PBN neurons) are key regulators of fluid satiation. Chemogenetic activation of Oxtr PBN neurons robustly suppressed noncaloric fluid intake, but did not decrease food intake after fasting or salt intake following salt depletion; inactivation increased saline intake after dehydration and hypertonic saline injection. Under physiological conditions, Oxtr PBN neurons were activated by fluid satiation and hypertonic saline injection. Oxtr PBN neurons were directly innervated by oxytocin neurons in the paraventricular hypothalamus (Oxt PVH  neurons), which mildly attenuated fluid intake. Activation of neurons in the nucleus of the solitary tract substantially suppressed fluid intake and activated Oxtr PBN neurons. Our results suggest that Oxtr PBN neurons act as a key node in the fluid satiation neurocircuitry, which acts to decrease water and/or saline intake to prevent or attenuate hypervolemia and hypernatremia.

Development of a Physiologically-Based Pharmacokinetic Model of the Rat Central Nervous System

Directory of Open Access Journals (Sweden)

Raj K. Singh Badhan

2014-03-01

Full Text Available Central nervous system (CNS drug disposition is dictated by a drug’s physicochemical properties and its ability to permeate physiological barriers. The blood–brain barrier (BBB, blood-cerebrospinal fluid barrier and centrally located drug transporter proteins influence drug disposition within the central nervous system. Attainment of adequate brain-to-plasma and cerebrospinal fluid-to-plasma partitioning is important in determining the efficacy of centrally acting therapeutics. We have developed a physiologically-based pharmacokinetic model of the rat CNS which incorporates brain interstitial fluid (ISF, choroidal epithelial and total cerebrospinal fluid (CSF compartments and accurately predicts CNS pharmacokinetics. The model yielded reasonable predictions of unbound brain-to-plasma partition ratio (Kpuu,brain and CSF:plasma ratio (CSF:Plasmau using a series of in vitro permeability and unbound fraction parameters. When using in vitro permeability data obtained from L-mdr1a cells to estimate rat in vivo permeability, the model successfully predicted, to within 4-fold, Kpuu,brain and CSF:Plasmau for 81.5% of compounds simulated. The model presented allows for simultaneous simulation and analysis of both brain biophase and CSF to accurately predict CNS pharmacokinetics from preclinical drug parameters routinely available during discovery and development pathways.

Wavelet analysis of polarization maps of polycrystalline biological fluids networks

Science.gov (United States)

Ushenko, Y. A.

2011-12-01

The optical model of human joints synovial fluid is proposed. The statistic (statistic moments), correlation (autocorrelation function) and self-similar (Log-Log dependencies of power spectrum) structure of polarization two-dimensional distributions (polarization maps) of synovial fluid has been analyzed. It has been shown that differentiation of polarization maps of joint synovial fluid with different physiological state samples is expected of scale-discriminative analysis. To mark out of small-scale domain structure of synovial fluid polarization maps, the wavelet analysis has been used. The set of parameters, which characterize statistic, correlation and self-similar structure of wavelet coefficients' distributions of different scales of polarization domains for diagnostics and differentiation of polycrystalline network transformation connected with the pathological processes, has been determined.

Enhancement of synthetic jets by means of an integrated valve-less pump, Part II: Numerical and experimental studies

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Tesař, Václav; Wang, A.

2005-01-01

Roč. 125, č. 1 (2005), s. 50-58 ISSN 0924-4247 R&D Projects: GA AV ČR(CZ) KSK2076106 Institutional research plan: CEZ:AV0Z20760514 Keywords : periodic jets * synthetic jets Subject RIV: BK - Fluid Dynamics Impact factor: 1.363, year: 2005

Sequential bottom-up assembly of mechanically stabilized synthetic cells by microfluidics

Science.gov (United States)

Weiss, Marian; Frohnmayer, Johannes Patrick; Benk, Lucia Theresa; Haller, Barbara; Janiesch, Jan-Willi; Heitkamp, Thomas; Börsch, Michael; Lira, Rafael B.; Dimova, Rumiana; Lipowsky, Reinhard; Bodenschatz, Eberhard; Baret, Jean-Christophe; Vidakovic-Koch, Tanja; Sundmacher, Kai; Platzman, Ilia; Spatz, Joachim P.

2018-01-01

Compartments for the spatially and temporally controlled assembly of biological processes are essential towards cellular life. Synthetic mimics of cellular compartments based on lipid-based protocells lack the mechanical and chemical stability to allow their manipulation into a complex and fully functional synthetic cell. Here, we present a high-throughput microfluidic method to generate stable, defined sized liposomes termed `droplet-stabilized giant unilamellar vesicles (dsGUVs)’. The enhanced stability of dsGUVs enables the sequential loading of these compartments with biomolecules, namely purified transmembrane and cytoskeleton proteins by microfluidic pico-injection technology. This constitutes an experimental demonstration of a successful bottom-up assembly of a compartment with contents that would not self-assemble to full functionality when simply mixed together. Following assembly, the stabilizing oil phase and droplet shells are removed to release functional self-supporting protocells to an aqueous phase, enabling them to interact with physiologically relevant matrices.

The wettability modification of bio-grade stainless steel in contact with simulated physiological liquids by the means of laser irradiation

International Nuclear Information System (INIS)

Hao, L.; Lawrence, J.; Li, L.

2005-01-01

Early surface events that occur rapidly upon implantation of a biomaterial into biological fluids determine the subsequent response. These involve wetting by physiological liquids followed by adsorption of proteins and cells to the biomaterials surface. A CO 2 laser and high power diode laser (HPDL) were used to modify the surface properties of the material and thus manipulate the wettability of the material and its interaction with physiological liquids. The contact angles, θ, of selected test liquids including simulated physiological liquids shows that the wettability of the stainless steel improved after CO 2 and HPDL treatment. The determined adhesion work of stainless steel towards stimulated physiological fluid enhanced after laser treatment, implying better interaction with the biological liquids. It is demonstrated that the laser could be a novel and controllable technique for enhancing the biocompatibility of bio-grade stainless steel

Fluid Distribution in Synthetic Wet Halite Rocks : Inference from Measured Elastic Wave Velocity and Electrical Conductivity

Science.gov (United States)

Watanabe, T.; Kitano, M.

2011-12-01

Intercrystalline fluid can significantly affect rheological and transport properties of rocks. Its influences are strongly dependent on its distribution. The dihedral angle between solid and liquid phases has been widely accepted as a key parameter that controls solid-liquid textures. The liquid phase is not expected to be interconnected if the dihedral angle is larger than 60 degree. However, observations contradictory to dihedral angle values have been reported. Watanabe (2010) suggested the coexistence of grain boundary fluid with a positive dihedral angle. For good understanding of fluid distribution, it is thus critical to study the nature of grain boundary fluid. We have developed a high pressure and temperature apparatus for study of intercrystalline fluid distribution. It was specially designed for measurements of elastic wave velocities and electrical conductivity. The apparatus mainly consists of a conventional cold-seal vessel with an external heater. The pressure medium is silicon oil of the viscosity of 0.1 Pa s. The pressure and temperature can be controlled from 0 to 200 MPa and from 20 to 200 C, respectively. Dimensions of a sample are 9 mm in diameter, and 15 mm in length. Halite-water system is used as an analog for crustal rocks. The dihedral angle has been studied systematically at various pressure and temperature conditions [Lewis and Holness, 1996]. The dihedral angle is larger than 60 degree at lower pressure and temperature. It decreases to be smaller than 60 degree with increasing pressure and temperature. A sample is prepared by cold-pressing and annealing of wet NaCl powder. Optical examination has shown that synthesized samples are microstructurally homogeneous. Grains are polygonal and equidimensional with a mean diameter of 100 micrometer. Grain boundaries vary from straight to bowed and 120 degree triple junctions are common. Gas and fluid bearing inclusions are visible on the grain boundaries. There are spherical inclusions or

Physiological and biochemical principles underlying volume-targeted therapy--the "Lund concept".

Science.gov (United States)

Nordström, Carl-Henrik

2005-01-01

The optimal therapy of sustained increase in intracranial pressure (ICP) remains controversial. The volume-targeted therapy ("Lund concept") discussed in this article focuses on the physiological volume regulation of the intracranial compartments. The balance between effective transcapillary hydrostatic and osmotic pressures constitutes the driving force for transcapillary fluid exchange. The low permeability for sodium and chloride combined with the high crystalloid osmotic pressure (approximately 5700 mmHg) on both sides of the blood-brain barrier (BBB) counteracts fluid exchange across the intact BBB. Additionally, variations in systemic blood pressure generally are not transmitted to these capillaries because cerebral intracapillary hydrostatic pressure (and blood flow) is physio-logically tightly autoregulated. Under pathophysiological conditions, the BBB may be partially disrupted. Transcapillary water exchange is then determined by the differences in hydrostatic and colloid osmotic pressure between the intra- and extracapillary compartments. Pressure autoregulation of cerebral blood flow is likely to be impaired in these conditions. A high cerebral perfusion pressure accordingly increases intracapillary hydrostatic pressure and leads to increased intracerebral water content and an increase in ICP. The volume-targeted "Lund concept" has been evaluated in experimental and clinical studies to examine the physiological and biochemical (utilizing intracerebral microdialysis) effects, and the clinical experiences have been favorable.

Designing synthetic biology.

Science.gov (United States)

Agapakis, Christina M

2014-03-21

Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology.

Exacerbation of substrate toxicity by IPTG in Escherichia coli BL21(DE3) carrying a synthetic metabolic pathway.

Science.gov (United States)

Dvorak, Pavel; Chrast, Lukas; Nikel, Pablo I; Fedr, Radek; Soucek, Karel; Sedlackova, Miroslava; Chaloupkova, Radka; de Lorenzo, Víctor; Prokop, Zbynek; Damborsky, Jiri

2015-12-21

Heterologous expression systems based on promoters inducible with isopropyl-β-D-1-thiogalactopyranoside (IPTG), e.g., Escherichia coli BL21(DE3) and cognate LacI(Q)/P(lacUV5)-T7 vectors, are commonly used for production of recombinant proteins and metabolic pathways. The applicability of such cell factories is limited by the complex physiological burden imposed by overexpression of the exogenous genes during a bioprocess. This burden originates from a combination of stresses that may include competition for the expression machinery, side-reactions due to the activity of the recombinant proteins, or the toxicity of their substrates, products and intermediates. However, the physiological impact of IPTG-induced conditional expression on the recombinant host under such harsh conditions is often overlooked. The physiological responses to IPTG of the E. coli BL21(DE3) strain and three different recombinants carrying a synthetic metabolic pathway for biodegradation of the toxic anthropogenic pollutant 1,2,3-trichloropropane (TCP) were investigated using plating, flow cytometry, and electron microscopy. Collected data revealed unexpected negative synergistic effect of inducer of the expression system and toxic substrate resulting in pronounced physiological stress. Replacing IPTG with the natural sugar effector lactose greatly reduced such stress, demonstrating that the effect was due to the original inducer's chemical properties. IPTG is not an innocuous inducer; instead, it exacerbates the toxicity of haloalkane substrate and causes appreciable damage to the E. coli BL21(DE3) host, which is already bearing a metabolic burden due to its content of plasmids carrying the genes of the synthetic metabolic pathway. The concentration of IPTG can be effectively tuned to mitigate this negative effect. Importantly, we show that induction with lactose, the natural inducer of P lac , dramatically lightens the burden without reducing the efficiency of the synthetic TCP degradation

Proteomic Assessment of Fluid Shifts and Association with Visual Impairment and Intracranial Pressure in Twin Astronauts

Science.gov (United States)

Rana, Brinda K.; Stenger, Michael B.; Lee, Stuart M. C.; Macias, Brandon R.; Siamwala, Jamila; Piening, Brian Donald; Hook, Vivian; Ebert, Doug; Patel, Hemal; Smith, Scott;

Fluid management in acute kidney injury

DEFF Research Database (Denmark)

Perner, Anders; Prowle, John; Joannidis, Michael

2017-01-01

Acute kidney injury (AKI) and fluids are closely linked through oliguria, which is a marker of the former and a trigger for administration of the latter. Recent progress in this field has challenged the physiological and clinical rational of using oliguria as a trigger for the administration...... of crystalloids and colloids on kidney function and the effect of various resuscitation and de-resuscitation strategies on the course and outcome of AKI....

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

Directory of Open Access Journals (Sweden)

Brianna Larsen

Full Text Available This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36 were matched and allocated to either the CON (19°C or HOT (33°C condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc, and skin temperature (Tsk were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of

Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

Science.gov (United States)

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological

Fluid therapy in neurotrauma: basic and clinical concepts

Directory of Open Access Journals (Sweden)

Hernando Raphael Alvis-Miranda

2014-01-01

Full Text Available The patient with head trauma is a challenge for the emergency physician and for the neurosurgeon. Currently traumatic brain injury constitutes a public health problem. Knowledge of the various therapeutic strategies to provide support in the prehospital and perioperative are essential for optimal care. Rapid infusion of large volumes of crystalloids to restore blood volume and blood pressure quickly is now the standard treatment for patients with combined TBI and HS The fluid in patients with brain and especially in the carrier of brain injury is a critical topic; we present a review of the literature about the history, physiology of current fluid preparations, and a discussion regard the use of fluid therapy in traumatic brain injury and decompressive craniectomy.http://dx.doi.org/10.7175/rhc.v5i1.636

Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

International Nuclear Information System (INIS)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan; Ondra, Peter; Válka, Ivo; Ševčík, Juraj; Chrastina, Jan; Maier, Vítězslav

2015-01-01

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry

Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

Energy Technology Data Exchange (ETDEWEB)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Ondra, Peter; Válka, Ivo [Department of Forensic Medicine and Medical Law Faculty Hospital, Hněvotínská 3, Olomouc CZ-77146 (Czech Republic); Ševčík, Juraj [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Chrastina, Jan [Institute of Special Education Studies, Faculty of Education, Palacký University, Žižkovo náměsti 5, Olomouc CZ-77146 (Czech Republic); Maier, Vítězslav, E-mail: vitezslav.maier@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic)

2015-05-18

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry.

Modern embalming, circulation of fluids, and the voyage through the human arterial system: Carl L. Barnes and the culture of immortality in America.

Science.gov (United States)

Podgorny, Irina

2011-01-01

By considering the work of American embalmer, lawyer, and physician Carl Lewis Barnes (1872-1927), this paper analyzes the emergence of modern embalming in America. Barnes experimented with and exhibited the techniques by which embalming fluids travelled into the most remote cavities of the human body. In this sense, modem embalmers based their skills and methods on experimental medicine, turning the anatomy of blood vessels, physiology of circulation, and composition of blood into a circuit that allowed embalming fluids to move throughout the corpse. Embalmers in the late 19th century took ownership of the laws of hydrodynamics and the physiology of blood circulation to market their fluids and equipment, thus playing the role of physiologists of death, performing and demonstrating physiological experiments with dead bodies.

Fluid loading and norepinephrine infusion mask the left ventricular preload decrease induced by pleural effusion

DEFF Research Database (Denmark)

Wemmelund, Kristian Borup; Ringgård, Viktor Kromann; Vistisen, Simon Tilma

2017-01-01

BACKGROUND: Pleural effusion (PLE) may lead to low blood pressure and reduced cardiac output. Low blood pressure and reduced cardiac output are often treated with fluid loading and vasopressors. This study aimed to determine the impact of fluid loading and norepinephrine infusion on physiologic d...... global haemodynamic parameters. Inferior vena cava distensibility remained unchanged. The haemodynamic significance of PLE may be underestimated during fluid or norepinephrine administration, potentially masking the presence of PLE....

Quantitative measurement of XLR11 and UR-144 in oral fluid by LC-MS-MS.

Science.gov (United States)

Amaratunga, Piyadarsha; Thomas, Christopher; Lemberg, Bridget Lorenz; Lemberg, Dave

2014-01-01

Availability and consumption of synthetic cannabinoids have risen recently in the USA and Europe. These drugs have adverse effects, including acute psychosis and bizarre behavior. In 2012, the United States Drug Enforcement Agency permanently banned five of the synthetic cannabinoids and in 2013, temporarily added XLR11, UR-144 and AKB48 to Schedule I of the Controlled Substances Act. As synthetic cannabinoid strains are added to the Schedule I list, new strains are being introduced into the market. XLR11 and UR-144 are two of the most recent additions to the synthetic cannabinoid drug class. To test collected oral fluid samples for XLR11 and UR-144, we developed a bioanalytical method that initially purifies the sample with solid-phase extraction and then quantitatively identifies the drugs with ultra-high-performance liquid chromatography-tandem mass spectrometry. The method was validated according to United States Food and Drug Administration guidelines and Scientific Working Group for Forensic Toxicology guidelines and the validation data showed that the method is an accurate, precise, robust and efficient method suited for high-throughput toxicological screening applications. We tested human subject samples with the developed method and found the presence of parent drugs (XLR11 and UR-144), their metabolites and their pyrolysis products in oral fluid. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mud-filtrate correction of sonic logs by fluid substitution

DEFF Research Database (Denmark)

Sørensen, Morten Kanne

structures. Making reliable discoveries in challenging conditions requires an increasing level of detail in seismic interpretation. Advanced seismic processing as Amplitude-Versus-Offset (AVO) analysis, have become commonplace in seismic interpretation. These techniques involves comparison with synthetic...... of wetting phase saturation, and the clay content. When the water saturation is at the irreducible water saturation or higher only the effect of clay on the elastic velocities have a differential effect on the elastic velocities. Mixed saturations are fluid substituted using effective fluid moduli formulated...... as a set of bounds by Mavko and Mukerji (1998). Ultrasonic velocity data from the literature shows that these bounds applies most accurately to sandstones with a simple pore-space, as reflected in a high permeability and low clay fraction....

Proteomic analysis of Bombyx mori molting fluid: Insights into the molting process.

Science.gov (United States)

Liu, Hua-Wei; Wang, Luo-Ling; Tang, Xin; Dong, Zhao-Ming; Guo, Peng-Chao; Zhao, Dong-Chao; Xia, Qing-You; Zhao, Ping

2018-02-20

Molting is an essential biological process occurring multiple times throughout the life cycle of most Ecdysozoa. Molting fluids accumulate and function in the exuvial space during the molting process. In this study, we used liquid chromatography-tandem mass spectrometry to investigate the molting fluids to analyze the molecular mechanisms of molting in the silkworm, Bombyx mori. In total, 375 proteins were identified in molting fluids from the silkworm at 14-16h before pupation and eclosion, including 12 chitin metabolism-related enzymes, 35 serine proteases, 15 peptidases, and 38 protease inhibitors. Gene ontology analysis indicated that "catalytic" constitutes the most enriched function in the molting fluid. Gene expression patterns and bioinformatic analyses suggested that numerous enzymes are involved in the degradation of cuticle proteins and chitin. Protein-protein interaction network and activity analyses showed that protease inhibitors are involved in the regulation of multiple pathways in molting fluid. Additionally, many immune-related proteins may be involved in the immune defense during molting. These results provide a comprehensive proteomic insight into proteolytic enzymes and protease inhibitors in molting fluid, and will likely improve the current understanding of physiological processes in insect molting. Insect molting constitutes a dynamic physiological process. To better understand this process, we used LC-MS/MS to investigate the proteome of silkworm molting fluids and identified key proteins involved in silkworm molting. The biological processes of the old cuticle degradation pathway and immune defense response were analyzed in the proteome of silkworm molting fluid. We report that protease inhibitors serve as key factors in the regulation of the molting process. The proteomic results provide new insight into biological molting processes in insects. Copyright © 2017 Elsevier B.V. All rights reserved.

Perilymph composition in scala tympani of the cochlea: influence of cerebrospinal fluid.

Science.gov (United States)

Hara, A; Salt, A N; Thalmann, R

1989-11-01

A commonly used technique to obtain cochlear perilymph for analysis has been the aspiration of samples through the round window membrane. The present study has investigated the influence of the volume withdrawn on sample composition in the guinea pig. Samples of less than 200 nl in volume taken through the round window showed relatively high glycine content, comparable to the level found in samples taken from scala vestibuli. If larger volumes are withdrawn, lower glycine levels are observed. This is consistent with cerebrospinal fluid (having a low glycine content) being drawn into scala tympani through the cochlear aqueduct and contaminating the sample. The existence of a concentration difference for glycine between scala tympani perilymph and cerebrospinal fluid suggests the physiologic communication across the cochlear aqueduct is relatively small in this species. The observation of considerable exchange between cerebrospinal fluid and perilymph, as reported in some studies, is more likely to be an artifact of the experimental procedures, rather than of physiologic significance. Alternative sampling procedures have been evaluated which allow larger volumes of uncontaminated scala tympani perilymph to be collected.

Applying Tiab’s direct synthesis technique to dilatant non-Newtonian/Newtonian fluids

Directory of Open Access Journals (Sweden)

Javier Andrés Martínez

2011-09-01

Full Text Available Non-Newtonian fluids, such as polymer solutions, have been used by the oil industry for many years as fracturing agents and drilling mud. These solutions, which normally include thickened water and jelled fluids, are injected into the formation to enhanced oil recovery by improving sweep efficiency. It is worth noting that some heavy oils behave non-Newtonianly. Non-Newtonian fluids do not have direct proportionality between applied shear stress and shear rate and viscosity varies with shear rate depending on whether the fluid is either pseudoplastic or dilatant. Viscosity decreases as shear rate increases for the former whilst the reverse takes place for dilatants. Mathematical models of conventional fluids thus fail when applied to non-Newtonian fluids. The pressure derivative curve is introduced in this descriptive work for a dilatant fluid and its pattern was observed. Tiab’s direct synthesis (TDS methodology was used as a tool for interpreting pressure transient data to estimate effective permeability, skin factors and non-Newtonian bank radius. The methodology was successfully verified by its application to synthetic examples. Also, comparing it to pseudoplastic behavior, it was found that the radial flow regime in the Newtonian zone of dilatant fluids took longer to form regarding both the flow behavior index and consistency factor.

Intracellular production of hydrogels and synthetic RNA granules by multivalent molecular interactions

Science.gov (United States)

Nakamura, Hideki; Lee, Albert A.; Afshar, Ali Sobhi; Watanabe, Shigeki; Rho, Elmer; Razavi, Shiva; Suarez, Allister; Lin, Yu-Chun; Tanigawa, Makoto; Huang, Brian; Derose, Robert; Bobb, Diana; Hong, William; Gabelli, Sandra B.; Goutsias, John; Inoue, Takanari

2018-01-01

Some protein components of intracellular non-membrane-bound entities, such as RNA granules, are known to form hydrogels in vitro. The physico-chemical properties and functional role of these intracellular hydrogels are difficult to study, primarily due to technical challenges in probing these materials in situ. Here, we present iPOLYMER, a strategy for a rapid induction of protein-based hydrogels inside living cells that explores the chemically inducible dimerization paradigm. Biochemical and biophysical characterizations aided by computational modelling show that the polymer network formed in the cytosol resembles a physiological hydrogel-like entity that acts as a size-dependent molecular sieve. We functionalize these polymers with RNA-binding motifs that sequester polyadenine-containing nucleotides to synthetically mimic RNA granules. These results show that iPOLYMER can be used to synthetically reconstitute the nucleation of biologically functional entities, including RNA granules in intact cells.

Physiology of bile secretion.

Science.gov (United States)

Esteller, Alejandro

2008-10-07

The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

Freedom and Responsibility in Synthetic Genomics: The Synthetic Yeast Project

OpenAIRE

Sliva, Anna; Yang, Huanming; Boeke, Jef D.; Mathews, Debra J. H.

2015-01-01

First introduced in 2011, the Synthetic Yeast Genome (Sc2.0) Project is a large international synthetic genomics project that will culminate in the first eukaryotic cell (Saccharomyces cerevisiae) with a fully synthetic genome. With collaborators from across the globe and from a range of institutions spanning from do-it-yourself biology (DIYbio) to commercial enterprises, it is important that all scientists working on this project are cognizant of the ethical and policy issues associated with...

Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

Science.gov (United States)

Watanabe, Shoji

2008-01-01

This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory.

Physiological effects of some synthetic food colouring additives on rats.

Science.gov (United States)

Aboel-Zahab, H; el-Khyat, Z; Sidhom, G; Awadallah, R; Abdel-al, W; Mahdy, K

1997-11-01

Three different synthetic chocolate colourant agents (A, B and C) were administered to healthy adult male albino rats for 30 and 60 day periods to evaluate their effects on body weight, blood picture, liver and kidney functions, blood glucose, serum and liver lipids, liver nucleic acids (DNA and RNA), thyroid hormones (T3 and T4) and growth hormone. In addition, histopathological examinations of liver, kidney and stomach sections were studied. These parameters were also investigated 30 days after colourant stoppage (post effect). Ingestion of colourant C (brown HT and indigocarmine) significantly decreased rat body weight, serum cholesterol and HDL-cholesterol fraction, while, T4 hormone, liver RNA content, liver enzymes (S. GOT, S. GPT and alkaline phosphatase), total protein and globulin fractions were significantly elevated. Significant increases were observed in serum total lipids, cholesterol, triglycerides, total protein, globulin and serum transaminases in rats whose diets were supplemented with chocolate colours A and B (sunset yellow, tartrazine, carmoisine and brilliant blue in varying concentrations). Haematological investigations demonstrated selective neutropenia and lymphocytosis with no significant alterations of total white blood cell counts in all rat groups, while haemoglobin concentrations and red blood cell counts were significantly decreased in the rats who were administered food additives A and B. Eosinophilia was noted in rats fed on colourant A only. No changes were recorded for blood glucose, growth hormone and kidney function tests. Histopathological studies showed brown pigment deposition in the portal tracts and Van Küpffer cells of the liver as well as in the interstitial tissue and renal tubular cells of the kidney mainly induced by colourant A. Congested blood vessels and areas of haemorrhage in both liver and renal sections were revealed in those rats who were given colourants B and C. There were no-untoward-effects recorded in the

Assessing Acid-Base Status: Physiologic Versus Physicochemical Approach.

Science.gov (United States)

Adrogué, Horacio J; Madias, Nicolaos E

2016-11-01

The physiologic approach has long been used in assessing acid-base status. This approach considers acids as hydrogen ion donors and bases as hydrogen ion acceptors and the acid-base status of the organism as reflecting the interaction of net hydrogen ion balance with body buffers. In the physiologic approach, the carbonic acid/bicarbonate buffer pair is used for assessing acid-base status and blood pH is determined by carbonic acid (ie, Paco 2 ) and serum bicarbonate levels. More recently, the physicochemical approach was introduced, which has gained popularity, particularly among intensivists and anesthesiologists. This approach posits that the acid-base status of body fluids is determined by changes in the dissociation of water that are driven by the interplay of 3 independent variables: the sum of strong (fully dissociated) cation concentrations minus the sum of strong anion concentrations (strong ion difference); the total concentration of weak acids; and Paco 2 . These 3 independent variables mechanistically determine both hydrogen ion concentration and bicarbonate concentration of body fluids, which are considered as dependent variables. Our experience indicates that the average practitioner is familiar with only one of these approaches and knows very little, if any, about the other approach. In the present Acid-Base and Electrolyte Teaching Case, we attempt to bridge this knowledge gap by contrasting the physiologic and physicochemical approaches to assessing acid-base status. We first outline the essential features, advantages, and limitations of each of the 2 approaches and then apply each approach to the same patient presentation. We conclude with our view about the optimal approach. Copyright © 2016 National Kidney Foundation, Inc. All rights reserved.

In vitro and in vivo physiology of low nanomolar concentrations of Zn2+ in artificial cerebrospinal fluid.

Science.gov (United States)

Tamano, Haruna; Nishio, Ryusuke; Shakushi, Yukina; Sasaki, Miku; Koike, Yuta; Osawa, Misa; Takeda, Atsushi

2017-02-17

Artificial cerebrospinal fluid (ACSF), i.e., brain extracellular medium, which includes Ca 2+ and Mg 2+ , but not other divalent cations such as Zn 2+ , has been used for in vitro and in vivo experiments. The present study deals with the physiological significance of extracellular Zn 2+ in ACSF. Spontaneous presynaptic activity is suppressed in the stratum lucidum of brain slices from young rats bathed in ACSF containing 10 nM ZnCl 2 , indicating that extracellular Zn 2+ modifies hippocampal presynaptic activity. To examine the in vivo action of 10 nM ZnCl 2 on long-term potentiation (LTP), the recording region was perfused using a recording electrode attached to a microdialysis probe. The magnitude of LTP was not modified in young rats by perfusion with ACSF containing 10 nM ZnCl 2 , compared to perfusion with ACSF without Zn 2+ , but attenuated by perfusion with ACSF containing 100 nM ZnCl 2 . Interestingly, the magnitude of LTP was not modified in aged rats even by perfusion with ACSF containing 100 nM ZnCl 2 , but enhanced by perfusion with ACSF containing 10 mM CaEDTA, an extracellular Zn 2+ chelator. The present study indicates that the basal levels of extracellular Zn 2+ , which are in the range of low nanomolar concentrations, are critical for synaptic activity and perhaps increased age-dependently.

Hydration status and physiological workload of UAE construction workers: A prospective longitudinal observational study

Directory of Open Access Journals (Sweden)

Schneider John

2008-09-01

Full Text Available Abstract Background The objective of the study was to investigate the physiological responses of construction workers labouring in thermally stressful environments in the UAE using Thermal Work Limit (TWL as a method of environmental risk assessment. Methods The study was undertaken in May 2006. Aural temperature, fluid intake, and urine specific gravity were recorded and continuous heart rate monitoring was used to assess fatigue. Subjects were monitored over 3 consecutive shifts. TWL and WBGT were used to assess the thermal stress. Results Most subjects commenced work euhydrated and maintained this status over a 12-hour shift. The average fluid intake was 5.44 L. There were no changes in core temperature or average heart rate between day 1 and day 3, nor between shift start and finish, despite substantial changes in thermal stress. The results obtained indicated that the workers were not physiologically challenged despite fluctuating harsh environmental conditions. Core body temperatures were not elevated suggesting satisfactory thermoregulation. Conclusion The data demonstrate that people can work, without adverse physiological effects, in hot conditions if they are provided with the appropriate fluids and are allowed to self-pace. The findings suggested that workers will self-pace according to the conditions. The data also demonstrated that the use of WBGT (a widely used risk assessment tool as a thermal index is inappropriate for use in Gulf conditions, however TWL was found to be a valuable tool in assessing thermal stress.

Characterization of Thermal Stability of Synthetic and Semi-Synthetic Engine Oils

Directory of Open Access Journals (Sweden)

Anand Kumar Tripathi

2015-03-01

Full Text Available Engine oils undergo oxidative degradation and wears out during service. Hence it is important to characterize ageing of engine oils at different simulated conditions to evaluate the performance of existing oils and also design new formulations. This work focuses on characterizing the thermo-oxidative degradation of synthetic and semi-synthetic engine oils aged at 120, 149 and 200 °C. Apparent activation energy of decomposition of aged oils evaluated using the isoconversional Kissinger-Akahira-Sunose technique was used as a thermal stability marker. The temporal variation of stability at different ageing temperatures was corroborated with kinematic viscosity, oxidation, sulfation and nitration indices, total base number, antiwear additive content and molecular structure of the organic species present in the oils. At the lowest temperature employed, synthetic oil underwent higher rate of oxidation, while semi-synthetic oil was stable for longer time periods. At higher temperatures, the initial rate of change of average apparent activation energy of synthetic oil correlated well with a similar variation in oxidation number. A mixture of long chain linear, branched, and cyclic hydrocarbons were observed when semi-synthetic oil was degraded at higher temperatures.

The Role of Interstitial Fluid Pressurization in Articular Cartilage Lubrication

Science.gov (United States)

Ateshian, Gerard A.

2009-01-01

Over the last two decades, considerable progress has been reported in the field of cartilage mechanics that impacts our understanding of the role of interstitial fluid pressurization on cartilage lubrication. Theoretical and experimental studies have demonstrated that the interstitial fluid of cartilage pressurizes considerably under loading, potentially supporting most of the applied load under various transient or steady-state conditions. The fraction of the total load supported by fluid pressurization has been called the fluid load support. Experimental studies have demonstrated that the friction coefficient of cartilage correlates negatively with this variable, achieving remarkably low values when the fluid load support is greatest. A theoretical framework that embodies this relationship has been validated against experiments, predicting and explaining various outcomes, and demonstrating that a low friction coefficient can be maintained for prolonged loading durations under normal physiological function. This paper reviews salient aspects of this topic, as well as its implications for improving our understanding of boundary lubrication by molecular species in synovial fluid and the cartilage superficial zone. Effects of cartilage degeneration on its frictional response are also reviewed. PMID:19464689

Fluid flow and convective transport of solutes within the intervertebral disc.

Science.gov (United States)

Ferguson, Stephen J; Ito, Keita; Nolte, Lutz P

2004-02-01

Previous experimental and analytical studies of solute transport in the intervertebral disc have demonstrated that for small molecules diffusive transport alone fulfils the nutritional needs of disc cells. It has been often suggested that fluid flow into and within the disc may enhance the transport of larger molecules. The goal of the study was to predict the influence of load-induced interstitial fluid flow on mass transport in the intervertebral disc. An iterative procedure was used to predict the convective transport of physiologically relevant molecules within the disc. An axisymmetric, poroelastic finite-element structural model of the disc was developed. The diurnal loading was divided into discrete time steps. At each time step, the fluid flow within the disc due to compression or swelling was calculated. A sequentially coupled diffusion/convection model was then employed to calculate solute transport, with a constant concentration of solute being provided at the vascularised endplates and outer annulus. Loading was simulated for a complete diurnal cycle, and the relative convective and diffusive transport was compared for solutes with molecular weights ranging from 400 Da to 40 kDa. Consistent with previous studies, fluid flow did not enhance the transport of low-weight solutes. During swelling, interstitial fluid flow increased the unidirectional penetration of large solutes by approximately 100%. Due to the bi-directional temporal nature of disc loading, however, the net effect of convective transport over a full diurnal cycle was more limited (30% increase). Further study is required to determine the significance of large solutes and the timing of their delivery for disc physiology.

Towards a synthetic osteo-odonto-keratoprosthesis.

Science.gov (United States)

Viitala, Reeta; Franklin, Valerie; Green, David; Liu, Christopher; Lloyd, Andrew; Tighe, Brian

2009-01-01

Osteo-odonto-keratoprostheses (OOKP) is a unique form of keratoprosthesis involving surgical removal of a tooth root and surrounding bone from the patient which are then used to construct an osteo-odonto lamina into which an optical cylinder is cemented. The OOKP procedure is successful and capable of withstanding the very hostile ocular environments found in severe Stevens-Johnson syndrome, pemphigoid, chemical burns, trachoma and multiple corneal graft failure. The existing procedure is complex and time consuming in terms of operative time, and additionally involves sacrifice of the oral structures. This paper discusses the rational search for a "synthetic" analogue of the dental lamina, capable of mimicking those features of the natural system that are responsible for the success of OOKP. In this study the degradation of selected commercial and natural bioceramics was tested in vitro using a purpose-designed resorption assay. Degradation rate was compared with tooth and bone, which are currently used in OOKP lamina. At normal physiological pH the degradation of bioceramics was equivalent to tooth and bone; however, at pH 6.5-5.0, associated with infectious and inflamed tissues, the bioceramics degrade more rapidly. At lower pH the degradation rate decreased in the following order: calcium carbonate corals>biphasic calcium phosphates>hydroxyapatite. Porosity did not significantly influence these degradation rates. Such degradation is likely to compromise the stability and viability of the synthetic OOKP. Consequently more chemically stable materials are required that are optimized for the surrounding ocular environment.

[Clinical aspect of recent progress in phosphate metabolism. Distribution of phosphorus and its physiological roles in the body: the form, distribution, and physiological function].

Science.gov (United States)

Yano, Shozo; Sugimoto, Toshitsugu

2009-06-01

Phosphorus plays pivotal roles in the survival such as the cellular structure, genomic information, energy metabolism, and cell signaling. Total amount of phosphorus is 500-700 g in human, most of which is stored in the bone in an insoluble form of calcium salt. About 15% of phosphorus is located in the cell membrane and the intracellular fluid in the soft tissues in a form of organic phosphate. Only 0.1% is present in the extracellular fluid. This phosphate pool plays a role in the dynamic equilibrium through the gut, kidney, bone and other tissues. Most of inorganic phosphates in the extracellular fluid are present in a form of ions such as H2PO4- and HPO(4)2-, and the concentration of phosphatic acids is about 1.2 mM. The form, distribution, and physiological function of phosphorus in the body are summarized in this review.

Synthetic torpor: A method for safely and practically transporting experimental animals aboard spaceflight missions to deep space

Science.gov (United States)

Griko, Yuri; Regan, Matthew D.

2018-02-01

Animal research aboard the Space Shuttle and International Space Station has provided vital information on the physiological, cellular, and molecular effects of spaceflight. The relevance of this information to human spaceflight is enhanced when it is coupled with information gleaned from human-based research. As NASA and other space agencies initiate plans for human exploration missions beyond low Earth orbit (LEO), incorporating animal research into these missions is vitally important to understanding the biological impacts of deep space. However, new technologies will be required to integrate experimental animals into spacecraft design and transport them beyond LEO in a safe and practical way. In this communication, we propose the use of metabolic control technologies to reversibly depress the metabolic rates of experimental animals while in transit aboard the spacecraft. Compared to holding experimental animals in active metabolic states, the advantages of artificially inducing regulated, depressed metabolic states (called synthetic torpor) include significantly reduced mass, volume, and power requirements within the spacecraft owing to reduced life support requirements, and mitigated radiation- and microgravity-induced negative health effects on the animals owing to intrinsic physiological properties of torpor. In addition to directly benefitting animal research, synthetic torpor-inducing systems will also serve as test beds for systems that may eventually hold human crewmembers in similar metabolic states on long-duration missions. The technologies for inducing synthetic torpor, which we discuss, are at relatively early stages of development, but there is ample evidence to show that this is a viable idea and one with very real benefits to spaceflight programs. The increasingly ambitious goals of world's many spaceflight programs will be most quickly and safely achieved with the help of animal research systems transported beyond LEO; synthetic torpor may

Freedom and Responsibility in Synthetic Genomics: The Synthetic Yeast Project.

Science.gov (United States)

Sliva, Anna; Yang, Huanming; Boeke, Jef D; Mathews, Debra J H

2015-08-01

First introduced in 2011, the Synthetic Yeast Genome (Sc2.0) PROJECT is a large international synthetic genomics project that will culminate in the first eukaryotic cell (Saccharomyces cerevisiae) with a fully synthetic genome. With collaborators from across the globe and from a range of institutions spanning from do-it-yourself biology (DIYbio) to commercial enterprises, it is important that all scientists working on this project are cognizant of the ethical and policy issues associated with this field of research and operate under a common set of principles. In this commentary, we survey the current ethics and regulatory landscape of synthetic biology and present the Sc2.0 Statement of Ethics and Governance to which all members of the project adhere. This statement focuses on four aspects of the Sc2.0 PROJECT: societal benefit, intellectual property, safety, and self-governance. We propose that such project-level agreements are an important, valuable, and flexible model of self-regulation for similar global, large-scale synthetic biology projects in order to maximize the benefits and minimize potential harms. Copyright © 2015 by the Genetics Society of America.

Heat and mass transfer caused by a laminar channel flow equipped with a synthetic jet array

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Dančová, Petra; Kordík, Jozef; Vít, Tomáš; Pavelka, Miroslav

2011-01-01

Roč. 2, č. 4 (2011), 041006-041006 ISSN 1948-5085 R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GA101/09/1959 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * flow control * naphthalene sublimation Subject RIV: BK - Fluid Dynamics http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JTSEBV000002000004041006000001&idtype=cvips&gifs=yes

Targeted genome regulation via synthetic programmable transcriptional regulators

KAUST Repository

Piatek, Agnieszka Anna

2016-04-19

Regulation of gene transcription controls cellular functions and coordinates responses to developmental, physiological and environmental cues. Precise and efficient molecular tools are needed to characterize the functions of single and multiple genes in linear and interacting pathways in a native context. Modular DNA-binding domains from zinc fingers (ZFs) and transcriptional activator-like proteins (TALE) are amenable to bioengineering to bind DNA target sequences of interest. As a result, ZF and TALE proteins were used to develop synthetic programmable transcription factors. However, these systems are limited by the requirement to re-engineer proteins for each new target sequence. The clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR associated 9 (Cas9) genome editing tool was recently repurposed for targeted transcriptional regulation by inactivation of the nuclease activity of Cas9. Due to the facile engineering, simplicity, precision and amenability to library construction, the CRISPR/Cas9 system is poised to revolutionize the functional genomics field across diverse eukaryotic species. In this review, we discuss the development of synthetic customizable transcriptional regulators and provide insights into their current and potential applications, with special emphasis on plant systems, in characterization of gene functions, elucidation of molecular mechanisms and their biotechnological applications. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Fast Virtual Fractional Flow Reserve Based Upon Steady-State Computational Fluid Dynamics Analysis

Directory of Open Access Journals (Sweden)

Paul D. Morris, PhD

2017-08-01

Full Text Available Fractional flow reserve (FFR-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel “pseudotransient” analysis protocol for computing virtual fractional flow reserve (vFFR based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis. Sensitivity analysis demonstrated that physiological lesion significance was influenced less by coronary or lesion anatomy (33% and more by microvascular physiology (59%. If coronary microvascular resistance can be estimated, vFFR can be accurately computed in less time than it takes to make invasive measurements.

Liberal Versus Restrictive Fluid Management in Knee Arthroplasty: A Randomized, Double-Blind Study

DEFF Research Database (Denmark)

Holte, Kathrine; Kristensen, Billy Bjarne; Valentiner, Lotte

2007-01-01

BACKGROUND: There are few data describing the relationship between amount of perioperative fluid and organ function. In this study we investigated the effects of two levels of intravascular fluid administration ("liberal" versus "restrictive") in knee arthroplasty on physiological recovery...... with a standardized volume of colloid. All other aspects of perioperative management (including anesthesia, preoperative fluid status, and postoperative management) were standardized. Primary outcome variables included pulmonary function (spirometry), exercise capacity ("timed up and go" test), coagulation...... as the primary outcome variable. METHODS: In a double-blind study, 48 ASA I-III patients undergoing fast-track elective knee arthroplasty were randomized to restrictive or liberal perioperative intravascular fluid administration. Patients received a fixed rate infusion of Ringer's lactate solution...

Rewiring cells: synthetic biology as a tool to interrogate the organizational principles of living systems.

Science.gov (United States)

Bashor, Caleb J; Horwitz, Andrew A; Peisajovich, Sergio G; Lim, Wendell A

2010-01-01

The living cell is an incredibly complex entity, and the goal of predictively and quantitatively understanding its function is one of the next great challenges in biology. Much of what we know about the cell concerns its constituent parts, but to a great extent we have yet to decode how these parts are organized to yield complex physiological function. Classically, we have learned about the organization of cellular networks by disrupting them through genetic or chemical means. The emerging discipline of synthetic biology offers an additional, powerful approach to study systems. By rearranging the parts that comprise existing networks, we can gain valuable insight into the hierarchical logic of the networks and identify the modular building blocks that evolution uses to generate innovative function. In addition, by building minimal toy networks, one can systematically explore the relationship between network structure and function. Here, we outline recent work that uses synthetic biology approaches to investigate the organization and function of cellular networks, and describe a vision for a synthetic biology toolkit that could be used to interrogate the design principles of diverse systems.

Pathophysiology and clinical implications of peroperative fluid management in elective surgery

DEFF Research Database (Denmark)

Holte, Kathrine

2010-01-01

amounts of fluid caused adverse physiologic effects in healthy volunteers indicates that addition of the surgical trauma per se increases fluid requirements. Volume kinetic analysis applied 4 hours postoperatively was not able to detect the presence of either overhydration or hypovolemia regardless...... mobilization. In major (colonic) surgery with a standardized multimodal rehabilitation regimen, over-all functional recovery was not affected with a "liberal" ( approximately 5 liters) vs. "restrictive" 1.5 liter crystalloid-based regimen, however based on three anastomotic leakages in the "restrictive" group...

Utilisation of transparent synthetic soil surrogates in geotechnical physical models: A review

Directory of Open Access Journals (Sweden)

Abideen Adekunle Ganiyu

2016-08-01

Full Text Available Efforts to obtain non-intrusive measurement of deformations and spatial flow within soil mass prior to the advent of transparent soils have perceptible limitations. The transparent soil is a two-phase medium composed of both the synthetic aggregate and fluid components of identical refractive indices aiming at attaining transparency of the resulting soil. The transparency facilitates real life visualisation of soil continuum in physical models. When applied in conjunction with advanced photogrammetry and image processing techniques, transparent soils enable the quantification of the spatial deformation, displacement and multi-phase flow in physical model tests. Transparent synthetic soils have been successfully employed in geotechnical model tests as soil surrogates based on the testing results of their geotechnical properties which replicate those of natural soils. This paper presents a review on transparent synthetic soils and their numerous applications in geotechnical physical models. The properties of the aggregate materials are outlined and the features of the various transparent clays and sands available in the literature are described. The merits of transparent soil are highlighted and the need to amplify its application in geotechnical physical model researches is emphasised. This paper will serve as a concise compendium on the subject of transparent soils for future researchers in this field.

Clearance from cerebrospinal fluid of intrathecally administered beta-endorphin in monkeys

International Nuclear Information System (INIS)

Lee, V.C.; Burns, R.S.; Dubois, M.; Cohen, M.R.

1984-01-01

Five adult male monkeys (Macaca mulatta) weighing 7.1-9.9 kg were given synthetic human beta-endorphin (800 micrograms) and [ 14 C]methoxy-inulin (50 microCi) in 400 microliters of normal saline intrathecally. Serial samples of cerebrospinal fluid were drawn through a previously positioned indwelling spinal catheter and were assayed for concentrations of beta-endorphin (determined by radioimmunoassay) and inulin (determined by liquid scintillation counter). Spinal fluid concentrations of beta-endorphin and inulin peaked and declined in a parallel manner. The clearance ratio (calculated from the reciprocal of the ratio of the areas under the respective curves of elimination of the two species) remained remarkably similar from animal to animal, giving a mean value of 1.060 +/- 0.090 (SEM). This ratio, being near unity, suggests that beta-endorphin is eliminated from spinal fluid in a fashion similar to that of inulin, which is removed exclusively by bulk absorption

Synthesis and characterization of low cost magnetorheological (MR) fluids

Science.gov (United States)

Sukhwani, V. K.; Hirani, H.

2007-04-01

Magnetorheological fluids have great potential for engineering applications due to their variable rheological behavior. These fluids find applications in dampers, brakes, shock absorbers, and engine mounts. However their relatively high cost (approximately US600 per liter) limits their wide usage. Most commonly used magnetic material "Carbonyl iron" cost more than 90% of the MR fluid cost. Therefore for commercial viability of these fluids there is need of alternative economical magnetic material. In the present work synthesis of MR fluid has been attempted with objective to produce low cost MR fluid with high sedimentation stability and greater yield stress. In order to reduce the cost, economical electrolytic Iron powder (US 10 per Kg) has been used. Iron powder of relatively larger size (300 Mesh) has been ball milled to reduce their size to few microns (1 to 10 microns). Three different compositions have been prepared and compared for MR effect produced and stability. All have same base fluid (Synthetic oil) and same magnetic phase i.e. Iron particles but they have different additives. First preparation involves organic additives Polydimethylsiloxane (PDMS) and Stearic acid. Other two preparations involve use of two environmental friendly low-priced green additives guar gum (US 2 per Kg) and xanthan gum (US 12 per Kg) respectively. Magnetic properties of Iron particles have been measured by Vibrating Sample Magnetometer (VSM). Morphology of Iron particles and additives guar gum and xanthan gum has been examined by Scanning Electron Microscopy (SEM) and Particles Size Distribution (PSD) has been determined using Particle size analyzer. Microscopic images of particles, MH plots and stability of synthesized MR fluids have been reported. The prepared low cost MR fluids showed promising performance and can be effectively used for engineering applications demanding controllability in operations.

Regulation of body fluid and salt homeostasis--from observations in space to new concepts on Earth.

Science.gov (United States)

Gerzer, R; Heer, M

2005-08-01

The present manuscript summarizes recent discoveries that were made by studying salt and fluid homeostasis in weightlessness. These data indicate that 1. atrial natriuretic peptide appears not to play an important role in natriuresis in physiology, 2. the distribution of body fluids appears to be tightly coupled with hunger and thirst regulation, 3. intrathoracic pressure may be an important co-regulator of body fluid homeostasis, 4. a so far unknown low-affinity, high capacity osmotically inactive sodium storage mechanism appears to be present in humans that is acting through sodium/hydrogen exchange on glycosaminoglycans and might explain the pathophysiology, e.g., of salt sensitive hypertension. The surprising and unexpected data underline that weightlessness is an excellent tool to investigate the physiology of our human body: If we knew it, we should be able to predict changes that occur when gravity is absent. But, as data from space demonstrate, we do not.

Fluid viscosity affects the fragmentation and inertial cavitation threshold of lipid encapsulated microbubbles

Science.gov (United States)

Helfield, Brandon; Black, John J.; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S.

2015-01-01

Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (~4 cP). In this study, ultra-high speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25 – 2 MPa). The propensity for individual microbubble (n=220) fragmentation was shown to significantly decrease in 4 cP fluid as compared to 1 cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4 cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g. ultraharmonic) with increasing pressure as compared to 1 cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. PMID:26674676

The radioimmunoassay of biologically active compounds in parotid fluid and plasma

International Nuclear Information System (INIS)

Walker, R.F.; Read, G.F.; Riad-Fahmy, D.

1978-01-01

Parotid fluid collection is a simple stress-free procedure. The potential value of parotid fluid estimations of clomipramine, a tricyclic antidepressant, d-norgestrel, a synthetic contraceptive steroid and cortisol have been evaluated for assessment of clinical status and patient compliance. These compounds circulate bound largely to plasma proteins. Their concentration in parotid fluid, which reflects the non-protein bound fraction, is low but assay sensitivity (10, 1 and 30 pg/tube respectively) is adequate. Excellent agreement (r>0.9) was observed when parotid fluid samples were assayed with and without chromatographic purification. Clomipramine levels following oral dosage (150 mg) rose steadily to a maximum in plasma but showed wide fluctuations in parotid fluid. Clomipramine therapy can only be assessed by plasma assays, but patient compliance may be checked by parotid fluid concentrations. Following an oral dose of d-norgestrel (0.3 mg), parotid fluid levels rose steadily to a maximum but plasma response was biphasic making correlation impossible. The sensitivity and high throughput of the d-norgestrel methodology suggests its use in evaluating patient compliance in large-scale fertility control programmes. Changes in circulating cortisol concentrations were rapidly and accurately reflected in parotid fluid in normal volunteers. Parotid fluid cortisol showed a marked diurnal rhythm, suppression to low levels after dexamethasone, and elevation following Synacthen. Low levels after Synacthen stimulation in a patient with secondary adrenal atrophy and constant high levels in Cushingoid patients indicate that parotid fluid cortisol levels could be used for accurate adrenocortical evaluation. The value in rapid screening procedures is stressed since the assay can be performed directly on only 10 μl of parotid fluid. (author)

Biocompatibility and corrosion behavior of the shape memory NiTi alloy in the physiological environments simulated with body fluids for medical applications

International Nuclear Information System (INIS)

Khalil-Allafi, Jafar; Amin-Ahmadi, Behnam; Zare, Mehrnoush

2010-01-01

Due to unique properties of NiTi shape memory alloys such as high corrosion resistance, biocompatibility, super elasticity and shape memory behavior, NiTi shape memory alloys are suitable materials for medical applications. Although TiO 2 passive layer in these alloys can prevent releasing of nickel to the environment, high nickel content and stability of passive layer in these alloys are very debatable subjects. In this study a NiTi shape memory alloy with nominal composition of 50.7 atom% Ni was investigated by corrosion tests. Electrochemical tests were performed in two physiological environments of Ringer solution and NaCl 0.9% solution. Results indicate that the breakdown potential of the NiTi alloy in NaCl 0.9% solution is higher than that in Ringer solution. The results of Scanning Electron Microscope (SEM) reveal that low pitting corrosion occurred in Ringer solution compared with NaCl solution at potentiostatic tests. The pH value of the solutions increases after the electrochemical tests. The existence of hydride products in the X-ray diffraction analysis confirms the decrease of the concentration of hydrogen ion in solutions. Topographical evaluations show that corrosion products are nearly same in all samples. The biocompatibility tests were performed by reaction of mouse fibroblast cells (L929). The growth and development of cells for different times were measured by numbering the cells or statistics investigations. The figures of cells for different times showed natural growth of cells. The different of the cell numbers between the test specimen and control specimen was negligible; therefore it may be concluded that the NiTi shape memory alloy is not toxic in the physiological environments simulated with body fluids.

Synthetic environments

Science.gov (United States)

Lukes, George E.; Cain, Joel M.

1996-02-01

The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

Fluid and electrolyte disturbances in critically ill patients.

Science.gov (United States)

Lee, Jay Wook

2010-12-01

Disturbances in fluid and electrolytes are among the most common clinical problems encountered in the intensive care unit (ICU). Recent studies have reported that fluid and electrolyte imbalances are associated with increased morbidity and mortality among critically ill patients. To provide optimal care, health care providers should be familiar with the principles and practice of fluid and electrolyte physiology and pathophysiology. Fluid resuscitation should be aimed at restoration of normal hemodynamics and tissue perfusion. Early goal-directed therapy has been shown to be effective in patients with severe sepsis or septic shock. On the other hand, liberal fluid administration is associated with adverse outcomes such as prolonged stay in the ICU, higher cost of care, and increased mortality. Development of hyponatremia in critically ill patients is associated with disturbances in the renal mechanism of urinary dilution. Removal of nonosmotic stimuli for vasopressin secretion, judicious use of hypertonic saline, and close monitoring of plasma and urine electrolytes are essential components of therapy. Hypernatremia is associated with cellular dehydration and central nervous system damage. Water deficit should be corrected with hypotonic fluid, and ongoing water loss should be taken into account. Cardiac manifestations should be identified and treated before initiating stepwise diagnostic evaluation of dyskalemias. Divalent ion deficiencies such as hypocalcemia, hypomagnesemia and hypophosphatemia should be identified and corrected, since they are associated with increased adverse events among critically ill patients.

Physiologically-based pharmacokinetic model of vaginally administered dapivirine ring and film formulations.

Science.gov (United States)

Kay, Katherine; Shah, Dhaval K; Rohan, Lisa; Bies, Robert

2018-05-01

A physiologically-based pharmacokinetic (PBPK) model of the vaginal space was developed with the aim of predicting concentrations in the vaginal and cervical space. These predictions can be used to optimize the probability of success of vaginally administered dapivirine (DPV) for HIV prevention. We focus on vaginal delivery using either a ring or film. A PBPK model describing the physiological structure of the vaginal tissue and fluid was defined mathematically and implemented in MATLAB. Literature reviews provided estimates for relevant physiological and physiochemical parameters. Drug concentration-time profiles were simulated in luminal fluids, vaginal tissue and plasma after administration of ring or film. Patient data were extracted from published clinical trials and used to test model predictions. The DPV ring simulations tested the two dosing regimens and predicted PK profiles and area under the curve of luminal fluids (29 079 and 33 067 mg h l -1 in groups A and B, respectively) and plasma (0.177 and 0.211 mg h l -1 ) closely matched those reported (within one standard deviation). While the DPV film study reported drug concentration at only one time point per patient, our simulated profiles pass through reported concentration range. HIV is a major public health issue and vaginal microbicides have the potential to provide a crucial, female-controlled option for protection. The PBPK model successfully simulated realistic representations of drug PK. It provides a reliable, inexpensive and accessible platform where potential effectiveness of new compounds and the robustness of treatment modalities for pre-exposure prophylaxis can be evaluated. © 2018 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

The 1H NMR profile of healthy dog cerebrospinal fluid.

Directory of Open Access Journals (Sweden)

Mihai Musteata

Full Text Available The availability of data for reference values in cerebrospinal fluid for healthy humans is limited due to obvious practical and ethical issues. The variability of reported values for metabolites in human cerebrospinal fluid is quite large. Dogs present great similarities with humans, including in cases of central nervous system pathologies. The paper presents the first study on healthy dog cerebrospinal fluid metabolomic profile using (1H NMR spectroscopy. A number of 13 metabolites have been identified and quantified from cerebrospinal fluid collected from a group of 10 mix breed healthy dogs. The biological variability as resulting from the relative standard deviation of the physiological concentrations of the identified metabolites had a mean of 18.20% (range between 9.3% and 44.8%. The reported concentrations for metabolites may be used as normal reference values. The homogeneity of the obtained results and the low biologic variability show that the (1H NMR analysis of the dog's cerebrospinal fluid is reliable in designing and interpreting clinical and therapeutic trials in dogs with central nervous system pathologies.

Dopamine in human follicular fluid is associated with cellular uptake and metabolism-dependent generation of reactive oxygen species in granulosa cells: implications for physiology and pathology.

Science.gov (United States)

Saller, S; Kunz, L; Berg, D; Berg, U; Lara, H; Urra, J; Hecht, S; Pavlik, R; Thaler, C J; Mayerhofer, A

2014-03-01

Is the neurotransmitter dopamine (DA) in the human ovary involved in the generation of reactive oxygen species (ROS)? Human ovarian follicular fluid contains DA, which causes the generation of ROS in cultured human granulosa cells (GCs), and alterations of DA levels in follicular fluid and DA uptake/metabolism in GCs in patients with polycystic ovary syndrome (PCOS) are linked to increased levels of ROS. DA is an important neurotransmitter in the brain, and the metabolism of DA results in the generation of ROS. DA was detected in human ovarian homogenates, but whether it is present in follicular fluid and plays a role in the follicle is not known. We used human follicular fluid from patients undergoing in vitro fertilization (IVF), GCs from patients with or without PCOS and also employed mathematical modeling to investigate the presence of DA and its effects on ROS. DA in follicular fluid and GCs was determined by enzyme-linked immunosorbent assay. GC viability, apoptosis and generation of ROS were monitored in GCs upon addition of DA. Inhibitors of DA uptake and metabolism, an antioxidant and DA receptor agonists, were used to study cellular uptake and the mechanism of DA-induced ROS generation. Human GCs were examined for the presence and abundance of transcripts of the DA transporter (DAT; SLC6A3), the DA-metabolizing enzymes monoamine oxidases A/B (MAO-A/B) and catechol-O-methyltransferase and the vesicular monoamine transporter. A computational model was developed to describe and predict DA-induced ROS generation in human GCs. We found DA in follicular fluid of ovulatory follicles of the human ovary and in GCs. DAT and MAO-A/B, which are expressed by GCs, are prerequisites for a DA receptor-independent generation of ROS in GCs. Blockers of DAT and MAO-A/B, as well as an antioxidant, prevented the generation of ROS (P human follicular compartment, functions of DA could only be studied in IVF-derived GCs, which can be viewed as a cellular model for the

Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy.

Science.gov (United States)

Woodcock, T E; Woodcock, T M

2012-03-01

I.V. fluid therapy does not result in the extracellular volume distribution expected from Starling's original model of semi-permeable capillaries subject to hydrostatic and oncotic pressure gradients within the extracellular fluid. Fluid therapy to support the circulation relies on applying a physiological paradigm that better explains clinical and research observations. The revised Starling equation based on recent research considers the contributions of the endothelial glycocalyx layer (EGL), the endothelial basement membrane, and the extracellular matrix. The characteristics of capillaries in various tissues are reviewed and some clinical corollaries considered. The oncotic pressure difference across the EGL opposes, but does not reverse, the filtration rate (the 'no absorption' rule) and is an important feature of the revised paradigm and highlights the limitations of attempting to prevent or treat oedema by transfusing colloids. Filtered fluid returns to the circulation as lymph. The EGL excludes larger molecules and occupies a substantial volume of the intravascular space and therefore requires a new interpretation of dilution studies of blood volume and the speculation that protection or restoration of the EGL might be an important therapeutic goal. An explanation for the phenomenon of context sensitivity of fluid volume kinetics is offered, and the proposal that crystalloid resuscitation from low capillary pressures is rational. Any potential advantage of plasma or plasma substitutes over crystalloids for volume expansion only manifests itself at higher capillary pressures.

Opportunities in plant synthetic biology.

Science.gov (United States)

Cook, Charis; Martin, Lisa; Bastow, Ruth

2014-05-01

Synthetic biology is an emerging field uniting scientists from all disciplines with the aim of designing or re-designing biological processes. Initially, synthetic biology breakthroughs came from microbiology, chemistry, physics, computer science, materials science, mathematics, and engineering disciplines. A transition to multicellular systems is the next logical step for synthetic biologists and plants will provide an ideal platform for this new phase of research. This meeting report highlights some of the exciting plant synthetic biology projects, and tools and resources, presented and discussed at the 2013 GARNet workshop on plant synthetic biology.

From noise to synthetic nucleoli: can synthetic biology achieve new insights?

Science.gov (United States)

Ciechonska, Marta; Grob, Alice; Isalan, Mark

2016-04-18

Synthetic biology aims to re-organise and control biological components to make functional devices. Along the way, the iterative process of designing and testing gene circuits has the potential to yield many insights into the functioning of the underlying chassis of cells. Thus, synthetic biology is converging with disciplines such as systems biology and even classical cell biology, to give a new level of predictability to gene expression, cell metabolism and cellular signalling networks. This review gives an overview of the contributions that synthetic biology has made in understanding gene expression, in terms of cell heterogeneity (noise), the coupling of growth and energy usage to expression, and spatiotemporal considerations. We mainly compare progress in bacterial and mammalian systems, which have some of the most-developed engineering frameworks. Overall, one view of synthetic biology can be neatly summarised as "creating in order to understand."

Clearance from cerebrospinal fluid of intrathecally administered beta-endorphin in monkeys

Energy Technology Data Exchange (ETDEWEB)

Lee, V.C.; Burns, R.S.; Dubois, M.; Cohen, M.R.

1984-05-01

Five adult male monkeys (Macaca mulatta) weighing 7.1-9.9 kg were given synthetic human beta-endorphin (800 micrograms) and (/sup 14/C)methoxy-inulin (50 microCi) in 400 microliters of normal saline intrathecally. Serial samples of cerebrospinal fluid were drawn through a previously positioned indwelling spinal catheter and were assayed for concentrations of beta-endorphin (determined by radioimmunoassay) and inulin (determined by liquid scintillation counter). Spinal fluid concentrations of beta-endorphin and inulin peaked and declined in a parallel manner. The clearance ratio (calculated from the reciprocal of the ratio of the areas under the respective curves of elimination of the two species) remained remarkably similar from animal to animal, giving a mean value of 1.060 +/- 0.090 (SEM). This ratio, being near unity, suggests that beta-endorphin is eliminated from spinal fluid in a fashion similar to that of inulin, which is removed exclusively by bulk absorption.

Computer-aided biochemical programming of synthetic microreactors as diagnostic devices.

Science.gov (United States)

Courbet, Alexis; Amar, Patrick; Fages, François; Renard, Eric; Molina, Franck

2018-04-26

Biological systems have evolved efficient sensing and decision-making mechanisms to maximize fitness in changing molecular environments. Synthetic biologists have exploited these capabilities to engineer control on information and energy processing in living cells. While engineered organisms pose important technological and ethical challenges, de novo assembly of non-living biomolecular devices could offer promising avenues toward various real-world applications. However, assembling biochemical parts into functional information processing systems has remained challenging due to extensive multidimensional parameter spaces that must be sampled comprehensively in order to identify robust, specification compliant molecular implementations. We introduce a systematic methodology based on automated computational design and microfluidics enabling the programming of synthetic cell-like microreactors embedding biochemical logic circuits, or protosensors , to perform accurate biosensing and biocomputing operations in vitro according to temporal logic specifications. We show that proof-of-concept protosensors integrating diagnostic algorithms detect specific patterns of biomarkers in human clinical samples. Protosensors may enable novel approaches to medicine and represent a step toward autonomous micromachines capable of precise interfacing of human physiology or other complex biological environments, ecosystems, or industrial bioprocesses. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

The Study Into Potential Enhacement Of Metalworking Fluids Biodegradability By The Application Of O3/UV

Directory of Open Access Journals (Sweden)

Gerulová Kristína

2015-06-01

Full Text Available The increase in mineralization and biodegradability of MWFs by ozone/ultraviolet in comparison with ozone were investigated. Studied were two similar synthetic fluids pre-treated by the combination of the O3/UV advanced oxidative method. Expectations that the pre-treatment could enhance biodegradability of the metalworking fluid were not confirmed. The combined oxidation process at the defined conditions resulted in 1-35 % decrease of the achieved primary degradation level. Samples were prepared from real concentrates and diluted to approximately 350 mg/L of TOC.

A living foundry for Synthetic Biological Materials: A synthetic biology roadmap to new advanced materials

Directory of Open Access Journals (Sweden)

Rosalind A. Le Feuvre

2018-06-01

Full Text Available Society is on the cusp of harnessing recent advances in synthetic biology to discover new bio-based products and routes to their affordable and sustainable manufacture. This is no more evident than in the discovery and manufacture of Synthetic Biological Materials, where synthetic biology has the capacity to usher in a new Materials from Biology era that will revolutionise the discovery and manufacture of innovative synthetic biological materials. These will encompass novel, smart, functionalised and hybrid materials for diverse applications whose discovery and routes to bio-production will be stimulated by the fusion of new technologies positioned across physical, digital and biological spheres. This article, which developed from an international workshop held in Manchester, United Kingdom, in 2017 [1], sets out to identify opportunities in the new materials from biology era. It considers requirements, early understanding and foresight of the challenges faced in delivering a Discovery to Manufacturing Pipeline for synthetic biological materials using synthetic biology approaches. This challenge spans the complete production cycle from intelligent and predictive design, fabrication, evaluation and production of synthetic biological materials to new ways of bringing these products to market. Pathway opportunities are identified that will help foster expertise sharing and infrastructure development to accelerate the delivery of a new generation of synthetic biological materials and the leveraging of existing investments in synthetic biology and advanced materials research to achieve this goal. Keywords: Synthetic biology, Materials, Biological materials, Biomaterials, Advanced materials

Synthetic biology and metabolic engineering.

Science.gov (United States)

Stephanopoulos, Gregory

2012-11-16

Metabolic engineering emerged 20 years ago as the discipline occupied with the directed modification of metabolic pathways for the microbial synthesis of various products. As such, it deals with the engineering (design, construction, and optimization) of native as well as non-natural routes of product synthesis, aided in this task by the availability of synthetic DNA, the core enabling technology of synthetic biology. The two fields, however, only partially overlap in their interest in pathway engineering. While fabrication of biobricks, synthetic cells, genetic circuits, and nonlinear cell dynamics, along with pathway engineering, have occupied researchers in the field of synthetic biology, the sum total of these areas does not constitute a coherent definition of synthetic biology with a distinct intellectual foundation and well-defined areas of application. This paper reviews the origins of the two fields and advances two distinct paradigms for each of them: that of unit operations for metabolic engineering and electronic circuits for synthetic biology. In this context, metabolic engineering is about engineering cell factories for the biological manufacturing of chemical and pharmaceutical products, whereas the main focus of synthetic biology is fundamental biological research facilitated by the use of synthetic DNA and genetic circuits.

Computational Re-design of Synthetic Genetic Oscillators for Independent Amplitude and Frequency Modulation.

Science.gov (United States)

Tomazou, Marios; Barahona, Mauricio; Polizzi, Karen M; Stan, Guy-Bart

2018-04-25

To perform well in biotechnology applications, synthetic genetic oscillators must be engineered to allow independent modulation of amplitude and period. This need is currently unmet. Here, we demonstrate computationally how two classic genetic oscillators, the dual-feedback oscillator and the repressilator, can be re-designed to provide independent control of amplitude and period and improve tunability-that is, a broad dynamic range of periods and amplitudes accessible through the input "dials." Our approach decouples frequency and amplitude modulation by incorporating an orthogonal "sink module" where the key molecular species are channeled for enzymatic degradation. This sink module maintains fast oscillation cycles while alleviating the translational coupling between the oscillator's transcription factors and output. We characterize the behavior of our re-designed oscillators over a broad range of physiologically reasonable parameters, explain why this facilitates broader function and control, and provide general design principles for building synthetic genetic oscillators that are more precisely controllable. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Use and practice of achiral and chiral supercritical fluid chromatography in pharmaceutical analysis and purification.

Science.gov (United States)

Lemasson, Elise; Bertin, Sophie; West, Caroline

2016-01-01

The interest of pharmaceutical companies for complementary high-performance chromatographic tools to assess a product's purity or enhance this purity is on the rise. The high-throughput capability and economic benefits of supercritical fluid chromatography, but also the "green" aspect of CO2 as the principal solvent, render supercritical fluid chromatography very attractive for a wide range of pharmaceutical applications. The recent reintroduction of new robust instruments dedicated to supercritical fluid chromatography and the progress in stationary phase technology have also greatly benefited supercritical fluid chromatography. Additionally, it was shown several times that supercritical fluid chromatography could be orthogonal to reversed-phase high-performance liquid chromatography and could efficiently compete with it. Supercritical fluid chromatography is an adequate tool for small molecules of pharmaceutical interest: synthetic intermediates, active pharmaceutical ingredients, impurities, or degradation products. In this review, we first discuss about general chromatographic conditions for supercritical fluid chromatography analysis to better suit compounds of pharmaceutical interest. We also discuss about the use of achiral and chiral supercritical fluid chromatography for analytical purposes and the recent applications in these areas. The use of preparative supercritical fluid chromatography by pharmaceutical companies is also covered. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pathophysiology and clinical implications of peroperative fluid management in elective surgery

DEFF Research Database (Denmark)

Holte, Kathrine

2010-01-01

The purpose of this thesis was to describe pathophysiological aspects of perioperative fluid administration and create a rational background for future, clinical outcome studies. In laparoscopic cholecystectomy, we have found "liberal" crystalloid administration ( approximately 3 liters) to improve....... Based on the current evidence, administration of liters intravenous fluid without specific indication in major surgical procedures should be avoided, while administration of liters in patients with anastomoses may not be recommended, an issue needing clarification in large-scale clinical studies...... perioperative physiology and clinical outcome, which has implication for fluid management in other laparoscopic procedures such as laparoscopic fundoplication, laparoscopic repair of ventral hernia, hysterectomy etc., where 2-3 liters crystalloid should be administered based on the present evidence. That equal...

Synthetic biological networks

International Nuclear Information System (INIS)

Archer, Eric; Süel, Gürol M

2013-01-01

Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. (review article)

Gallium-67 activity in bronchoalveolar lavage fluid in sarcoidosis

International Nuclear Information System (INIS)

Trauth, H.A.; Heimes, K.; Schubotz, R.; von Wichert, P.

1986-01-01

Roentgenograms and gallium-67 scans and gallium-67 counts of BAL fluid samples, together with differential cell counts, have proved to be useful in assessing activity and lung involvement in sarcoidosis. In active pulmonary sarcoidosis gallium-67 scans are usually positive. Quantitation of gallium-67 uptake in lung scans, however, may be difficult. Because gallium-67 uptake and cell counts in BAL fluid may be correlated, we set out to investigate gallium-67 activity in BAL fluid recovered from patient of different groups. Sixteen patients with recently diagnosed and untreated sarcoidosis, nine patients with healthy lungs, and five patients with CFA were studied. Gallium-67 uptake of the lung, gallium-67 activity in the lavage fluid, SACE and LACE levels, and alpha 1-AT activity were measured. Significantly more gallium-67 activity was found in BAL fluid from sarcoidosis patients than in that from CFA patients (alpha = .001) or patients with healthy lungs (alpha = .001). Gallium-67 activity in BAL fluid could be well correlated with the number of lymphocytes in BAL fluid, but poorly with the number of macrophages. Subjects with increased levels of SACE or serum alpha 1-AT showed higher lavage gallium-67 activity than did normals, but no correlation could be established. High gallium-67 activity in lavage fluid may be correlated with acute sarcoidosis or physiological deterioration; low activity denotes change for the better. The results show that gallium-67 counts in BAL fluid reflects the intensity of gallium-67 uptake and thus of activity of pulmonary sarcoidosis

The study of crosslinked fluid leakoff in hydraulic fracturing physical simulations

Energy Technology Data Exchange (ETDEWEB)

Grothe, Vinicius Perrud; Ribeiro, Paulo Roberto [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Petroleo; Sousa, Jose Luiz Antunes de Oliveira e [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia. Dept. de Estruturas; Fernandes, Paulo Dore [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2000-07-01

The fluid loss plays an important role in the design and execution of hydraulic fracturing treatments. The main objectives of this work were: the study of the fluid loss associated with the propagation of hydraulic fractures generated at laboratory; and the comparison of two distinct methods for estimating leakoff coefficients - Nolte analysis and the filtrate volume vs. square root of time plot. Synthetic rock samples were used as well as crosslinked hydroxypropyl guar (HPG) fluids in different polymer concentrations. The physical simulations comprised the confinement of (0.1 x 0.1 x 0.1) m{sup 3} rock samples in a load cell for the application of an in situ stress field. Different flow rates were employed in order to investigate shear effects on the overall leakoff coefficient. Horizontal radial fractures were hydraulically induced with approximate diameters, what was accomplished by controlling the injection time. Leakoff coefficients determined by means of the pressure decline analysis were compared to coefficients obtained from static filtration tests, considering similar experimental conditions. The research results indicated that the physical simulation of hydraulic fracturing may be regarded as an useful tool for evaluating the effectiveness of fracturing fluids and that it can supply reliable estimates of fluid loss coefficients. (author)

Biological properties of extracellular vesicles and their physiological functions

Directory of Open Access Journals (Sweden)

María Yáñez-Mó

2015-05-01

Full Text Available In the past decade, extracellular vesicles (EVs have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system.

Biological properties of extracellular vesicles and their physiological functions

Science.gov (United States)

Yáñez-Mó, María; Siljander, Pia R.-M.; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E.; Buzas, Edit I.; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Silva, Anabela Cordeiro-da; Fais, Stefano; Falcon-Perez, Juan M.; Ghobrial, Irene M.; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H. H.; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Hoen, Esther N.M. Nolte-‘t; Nyman, Tuula A.; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; del Portillo, Hernando A.; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N.; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G.; Vasconcelos, M. Helena; Wauben, Marca H. M.; De Wever, Olivier

2015-01-01

In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system. PMID:25979354

Synthetic Cannabis Overdose and Withdrawal in a Young Adult: A Case Report, Commentary on Regulation, and Review of the Literature.

Science.gov (United States)

Samaan, John; Ferrer, Gerardo F; Akinyemi, Boye; Junquera, Patricia; Oms, Juan; Dumenigo, Rhaisa

2016-01-01

Introduction . Marijuana has been used for its psychotropic effects including enhanced relaxation and perceptual alterations. However, the use of synthetic marijuana (SM) leads to more frequent and drastic side effects than the typical use of regular marijuana, owing to the fact that SM has a shorter duration and an earlier peak of action. Despite all the potential adverse health effects associated with SM use, current health policies on SM are very limited. It is believed that the popularity of SM has increased, due to its easy accessibility in the US and lack of detection in typical urine drug screens for THC. Case Report . One case presented is of a young adult patient, with histories of recurrent synthetic cannabis and recreational cannabis use, who had developed drastic physiological and psychiatric symptoms, including the development of acute-onset psychosis. Conclusion/Discussion . This case, as many others nationwide, exemplifies the impact of synthetic cannabinoid use and abuse in adolescents. Side effects and adverse health consequences of synthetic cannabinoid use warrant stricter regulations and policies in order to decrease psychiatric hospital admissions and associated healthcare costs.

The characterization of the Ca–K geopolymer/solidified fluid fly-ash interlayer

Czech Academy of Sciences Publication Activity Database

Perná, Ivana; Šupová, Monika; Hanzlíček, Tomáš

2017-01-01

Roč. 61, č. 1 (2017), s. 26-33 ISSN 0862-5468 Institutional support: RVO:67985891 Keywords : fluid fly ash * blast-furnace slag * geopolymer * interlayer * recycling Subject RIV: DM - Solid Waste and Recycling OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 0.439, year: 2016 https://www.irsm.cas.cz/materialy/cs_content/2016_doi/Perna_CS_2016_0056.pdf

Starting physiology: bioelectrogenesis.

Science.gov (United States)

Baptista, Vander

2015-12-01

From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The topic of bioelectrogenesis encompasses multidisciplinary concepts, involves several mechanisms, and is a dynamic process, i.e., it never turns off during the lifetime of the cell. Therefore, to improve the transmission and acquisition of knowledge in this field, I present an alternative didactic model. The design of the model assumes that it is possible to build, in a series of sequential steps, an assembly of proteins within the membrane of an isolated cell in a simulated electrophysiology experiment. Initially, no proteins are inserted in the membrane and the cell is at a baseline energy state; the extracellular and intracellular fluids are at thermodynamic equilibrium. Students are guided through a sequence of four steps that add key membrane transport proteins to the model cell. The model is simple at the start and becomes progressively more complex, finally producing transmembrane chemical and electrical gradients. I believe that this didactic approach helps instructors with a more efficient tool for the teaching of the mechanisms of resting membrane potential while helping students avoid common difficulties that may be encountered when learning this topic. Copyright © 2015 The American Physiological Society.

Drosophila melanogaster seminal fluid can protect the sperm of other males

DEFF Research Database (Denmark)

Holman, Luke

2009-01-01

a different male. This study therefore provides strong evidence that seminal fluid does not kill rival sperm, and instead can actually protect them. This study also tested whether chemicals in the female reproductive tract harm sperm as in another Drosophila species, but found no evidence of this. # 3...... physiology. # 2. Seminal fluid is well-studied in Drosophila melanogaster, a species in which it has been suggested to 'incapacitate' the sperm of rival males (e.g. by killing them) and thereby provide an advantage in sperm competition. This hypothesis has been tested several times over many years......, but different studies have yielded conflicting conclusions. Here, I use fluorescent staining to directly measure the effects of D. melanogaster seminal fluid on the survival of sperm from the same male or from a rival. The results suggest that seminal fluid improves sperm survival, even if the sperm are from...

A living foundry for Synthetic Biological Materials: A synthetic biology roadmap to new advanced materials.

Science.gov (United States)

Le Feuvre, Rosalind A; Scrutton, Nigel S

2018-06-01

Society is on the cusp of harnessing recent advances in synthetic biology to discover new bio-based products and routes to their affordable and sustainable manufacture. This is no more evident than in the discovery and manufacture of Synthetic Biological Materials , where synthetic biology has the capacity to usher in a new Materials from Biology era that will revolutionise the discovery and manufacture of innovative synthetic biological materials. These will encompass novel, smart, functionalised and hybrid materials for diverse applications whose discovery and routes to bio-production will be stimulated by the fusion of new technologies positioned across physical, digital and biological spheres. This article, which developed from an international workshop held in Manchester, United Kingdom, in 2017 [1], sets out to identify opportunities in the new materials from biology era. It considers requirements, early understanding and foresight of the challenges faced in delivering a Discovery to Manufacturing Pipeline for synthetic biological materials using synthetic biology approaches. This challenge spans the complete production cycle from intelligent and predictive design, fabrication, evaluation and production of synthetic biological materials to new ways of bringing these products to market. Pathway opportunities are identified that will help foster expertise sharing and infrastructure development to accelerate the delivery of a new generation of synthetic biological materials and the leveraging of existing investments in synthetic biology and advanced materials research to achieve this goal.

Synthetic and Bio-Artificial Tactile Sensing: A Review

Directory of Open Access Journals (Sweden)

Maria Chiara Carrozza

2013-01-01

Full Text Available This paper reviews the state of the art of artificial tactile sensing, with a particular focus on bio-hybrid and fully-biological approaches. To this aim, the study of physiology of the human sense of touch and of the coding mechanisms of tactile information is a significant starting point, which is briefly explored in this review. Then, the progress towards the development of an artificial sense of touch are investigated. Artificial tactile sensing is analysed with respect to the possible approaches to fabricate the outer interface layer: synthetic skin versus bio-artificial skin. With particular respect to the synthetic skin approach, a brief overview is provided on various technologies and transduction principles that can be integrated beneath the skin layer. Then, the main focus moves to approaches characterized by the use of bio-artificial skin as an outer layer of the artificial sensory system. Within this design solution for the skin, bio-hybrid and fully-biological tactile sensing systems are thoroughly presented: while significant results have been reported for the development of tissue engineered skins, the development of mechanotransduction units and their integration is a recent trend that is still lagging behind, therefore requiring research efforts and investments. In the last part of the paper, application domains and perspectives of the reviewed tactile sensing technologies are discussed.

Effects of Turbulence on Settling Velocities of Synthetic and Natural Particles

Science.gov (United States)

Jacobs, C.; Jendrassak, M.; Gurka, R.; Hackett, E. E.

2014-12-01

For large-scale sediment transport predictions, an important parameter is the settling or terminal velocity of particles because it plays a key role in determining the concentration of sediment particles within the water column as well as the deposition rate of particles onto the seabed. The settling velocity of particles is influenced by the fluid dynamic environment as well as attributes of the particle, such as its size, shape, and density. This laboratory study examines the effects of turbulence, generated by an oscillating grid, on both synthetic and natural particles for a range of flow conditions. Because synthetic particles are spherical, they serve as a reference for the natural particles that are irregular in shape. Particle image velocimetry (PIV) and high-speed imaging systems were used simultaneously to study the interaction between the fluid mechanics and sediment particles' dynamics in a tank. The particles' dynamics were analyzed using a custom two-dimensional tracking algorithm used to obtain distributions of the particle's velocity and acceleration. Turbulence properties, such as root-mean-square turbulent velocity and vorticity, were calculated from the PIV data. Results are classified by Stokes number, which was based-on the integral scale deduced from the auto-correlation function of velocity. We find particles with large Stokes numbers are unaffected by the turbulence, while particles with small Stokes numbers primarily show an increase in settling velocity in comparison to stagnant flow. The results also show an inverse relationship between Stokes number and standard deviation of the settling velocity. This research enables a better understanding of the interdependence between particles and turbulent flow, which can be used to improve parameterizations in large-scale sediment transport models.

Hip chondrolabral mechanics during activities of daily living: Role of the labrum and interstitial fluid pressurization.

Science.gov (United States)

Todd, Jocelyn N; Maak, Travis G; Ateshian, Gerard A; Maas, Steve A; Weiss, Jeffrey A

2018-03-01

Osteoarthritis of the hip can result from mechanical factors, which can be studied using finite element (FE) analysis. FE studies of the hip often assume there is no significant loss of fluid pressurization in the articular cartilage during simulated activities and approximate the material as incompressible and elastic. This study examined the conditions under which interstitial fluid load support remains sustained during physiological motions, as well as the role of the labrum in maintaining fluid load support and the effect of its presence on the solid phase of the surrounding cartilage. We found that dynamic motions of gait and squatting maintained consistent fluid load support between cycles, while static single-leg stance experienced slight fluid depressurization with significant reduction of solid phase stress and strain. Presence of the labrum did not significantly influence fluid load support within the articular cartilage, but prevented deformation at the cartilage edge, leading to lower stress and strain conditions in the cartilage. A morphologically accurate representation of collagen fibril orientation through the thickness of the articular cartilage was not necessary to predict fluid load support. However, comparison with simplified fibril reinforcement underscored the physiological importance. The results of this study demonstrate that an elastic incompressible material approximation is reasonable for modeling a limited number of cyclic motions of gait and squatting without significant loss of accuracy, but is not appropriate for static motions or numerous repeated motions. Additionally, effects seen from removal of the labrum motivate evaluation of labral reattachment strategies in the context of labral repair. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthetic biology and occupational risk.

Science.gov (United States)

Howard, John; Murashov, Vladimir; Schulte, Paul

2017-03-01

Synthetic biology is an emerging interdisciplinary field of biotechnology that involves applying the principles of engineering and chemical design to biological systems. Biosafety professionals have done an excellent job in addressing research laboratory safety as synthetic biology and gene editing have emerged from the larger field of biotechnology. Despite these efforts, risks posed by synthetic biology are of increasing concern as research procedures scale up to industrial processes in the larger bioeconomy. A greater number and variety of workers will be exposed to commercial synthetic biology risks in the future, including risks to a variety of workers from the use of lentiviral vectors as gene transfer devices. There is a need to review and enhance current protection measures in the field of synthetic biology, whether in experimental laboratories where new advances are being researched, in health care settings where treatments using viral vectors as gene delivery systems are increasingly being used, or in the industrial bioeconomy. Enhanced worker protection measures should include increased injury and illness surveillance of the synthetic biology workforce; proactive risk assessment and management of synthetic biology products; research on the relative effectiveness of extrinsic and intrinsic biocontainment methods; specific safety guidance for synthetic biology industrial processes; determination of appropriate medical mitigation measures for lentiviral vector exposure incidents; and greater awareness and involvement in synthetic biology safety by the general occupational safety and health community as well as by government occupational safety and health research and regulatory agencies.

Synthetic Biology and Personalized Medicine

Science.gov (United States)

Jain, K.K.

2013-01-01

Synthetic biology, application of synthetic chemistry to biology, is a broad term that covers the engineering of biological systems with structures and functions not found in nature to process information, manipulate chemicals, produce energy, maintain cell environment and enhance human health. Synthetic biology devices contribute not only to improve our understanding of disease mechanisms, but also provide novel diagnostic tools. Methods based on synthetic biology enable the design of novel strategies for the treatment of cancer, immune diseases metabolic disorders and infectious diseases as well as the production of cheap drugs. The potential of synthetic genome, using an expanded genetic code that is designed for specific drug synthesis as well as delivery and activation of the drug in vivo by a pathological signal, was already pointed out during a lecture delivered at Kuwait University in 2005. Of two approaches to synthetic biology, top-down and bottom-up, the latter is more relevant to the development of personalized medicines as it provides more flexibility in constructing a partially synthetic cell from basic building blocks for a desired task. PMID:22907209

Tracking the emergence of synthetic biology.

Science.gov (United States)

Shapira, Philip; Kwon, Seokbeom; Youtie, Jan

2017-01-01

Synthetic biology is an emerging domain that combines biological and engineering concepts and which has seen rapid growth in research, innovation, and policy interest in recent years. This paper contributes to efforts to delineate this emerging domain by presenting a newly constructed bibliometric definition of synthetic biology. Our approach is dimensioned from a core set of papers in synthetic biology, using procedures to obtain benchmark synthetic biology publication records, extract keywords from these benchmark records, and refine the keywords, supplemented with articles published in dedicated synthetic biology journals. We compare our search strategy with other recent bibliometric approaches to define synthetic biology, using a common source of publication data for the period from 2000 to 2015. The paper details the rapid growth and international spread of research in synthetic biology in recent years, demonstrates that diverse research disciplines are contributing to the multidisciplinary development of synthetic biology research, and visualizes this by profiling synthetic biology research on the map of science. We further show the roles of a relatively concentrated set of research sponsors in funding the growth and trajectories of synthetic biology. In addition to discussing these analyses, the paper notes limitations and suggests lines for further work.

Space Physiology within an Exercise Physiology Curriculum

Science.gov (United States)

Carter, Jason R.; West, John B.

2013-01-01

Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

A noninvasive method to study regulation of extracellular fluid volume in rats using nuclear magnetic resonance

Data.gov (United States)

U.S. Environmental Protection Agency — NMR fluid measurements of commonly used rat strains when subjected to SQ normotonic or hypertonic salines, as well as physiologic comparisons to sedentary and...

Printability of Synthetic Papers by Electrophotography

Directory of Open Access Journals (Sweden)

Rozália Szentgyörgyvölgyi

2010-04-01

Full Text Available This paper deals with the printability of synthetic papers by the electrophotography technique. Prints of cmyk colour fields from 20% to 100% raster tone values were printed on three types of synthetic papers (one film synthetic paper and two fiber synthetic papers. The investigation of the appearance included densitometric measurement of the cmyk prints. The results have shown differences in the optical density and optical tone value between cmyk prints made on various synthetic papers. The highest optical density and the increase of the optical tone value were observed on the film synthetic paper, where cmyk prints were more saturated. The highest abrasion resistance of cmyk prints was obtained from the fibre synthetic paper.

GIP-(3-42) does not antagonize insulinotropic effects of GIP at physiological concentrations

DEFF Research Database (Denmark)

Deacon, Carolyn F; Plamboeck, Astrid; Rosenkilde, Mette M

2006-01-01

Glucose-dependent insulinotropic polypeptide [GIP-(1-42)] is degraded by dipeptidyl peptidase IV (DPP IV), forming GIP-(3-42). In mice, high concentrations of synthetic GIP-(3-42) may function as a GIP receptor antagonist, but it is unclear whether this occurs at physiological concentrations...... GIP, GIP-(3-42) behaved as a weak antagonist (IC(50), 92 and 731 nM for inhibition of cAMP accumulation elicited by 10 pM and 1 nM native GIP, respectively). In the isolated perfused rat pancreas, GIP-(3-42) alone had no effect on insulin output and only reduced the response to GIP (1 nM) when......-42) can weakly antagonize cAMP accumulation and insulin output in vitro, it does not behave as a physiological antagonist in vivo....

Fluid Viscosity Affects the Fragmentation and Inertial Cavitation Threshold of Lipid-Encapsulated Microbubbles.

Science.gov (United States)

Helfield, Brandon; Black, John J; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S

2016-03-01

Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (∼4 cP). In this study, ultrahigh-speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25-2 MPa). The propensity for individual microbubble (n = 220) fragmentation was found to significantly decrease in 4-cP fluid compared with 1-cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4-cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g., ultraharmonic) with increasing pressure, compared with those in 1-cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

Directory of Open Access Journals (Sweden)

Robinson RA

2013-05-01

Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

Epithelial Fluid Transport is Due to Electro-osmosis (80%), Plus Osmosis (20%).

Science.gov (United States)

Fischbarg, Jorge; Hernandez, Julio A; Rubashkin, Andrey A; Iserovich, Pavel; Cacace, Veronica I; Kusnier, Carlos F

2017-06-01

Epithelial fluid transport, an important physiological process shrouded in a long-standing enigma, may finally be moving closer to a solution. We propose that, for the corneal endothelium, relative proportions for the driving forces for fluid transport are 80% of paracellular electro-osmosis, and 20% classical transcellular osmosis. These operate in a cyclical process with a period of 9.2 s, which is dictated by the decrease and exhaustion of cellular Na + . Paracellular electro-osmosis is sketched here, and partially discussed as much as the subject still allows; transcellular osmosis is presented at length.

Evolvable synthetic neural system

Science.gov (United States)

Curtis, Steven A. (Inventor)

2009-01-01

An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

Fluid resuscitation for major burn patients with the TMMU protocol.

Science.gov (United States)

Luo, Gaoxing; Peng, Yizhi; Yuan, Zhiqiang; Cheng, Wenguang; Wu, Jun; Tang, Jin; Huang, Yuesheng; Fitzgerald, Mark

2009-12-01

Fluid resuscitation is one of the critical treatments for the major burn patient in the early phases after injury. We evaluated the practice of fluid resuscitation for severely burned patients with the Third Military Medical University (TMMU) protocol, which is most widely used in many regions of China. Patients with major burns (>30% total body surface area (TBSA)) presenting to Southwest Hospital, Third Military Medical University, between January 2005 and October 2007, were included in this study. Fluid resuscitation was initiated by the TMMU protocol. A total of 71 patients were (46 adults and 25 children) included in this study. All patients survived the first 48 h after injury smoothly and none developed abdominal compartment syndrome or other recognised complications associated with fluid resuscitation. The average quantity of fluid infused was 3.3-61.33% more than that calculated based on the TMMU protocol in both adult and paediatric groups. The average urine output during the first 24h after injury was about 1.2 ml per kg body weight per hour in the two groups, but reached 1.2 ml and 1.7 ml during the second 24h in adult and pediatric groups, respectively. This study indicates that the TMMU protocol for fluid resuscitation is a feasible option for burn patients. Individualised resuscitation - guided by the physiological response to fluid administration - is still important as in other protocols.

Mechanisms underlying the volume regulation of interstitial fluid by capillaries: a simulation study

Directory of Open Access Journals (Sweden)

Yukiko Himeno

2016-03-01

Conclusion: Mathematical analyses revealed that the system of the capillary is stable near the equilibrium point at steady state and normal physiological capillary pressure. The time course of the tissue-volume change was determined by two kinetic mechanisms: rapid fluid exchange and slow protein fluxes.

The treatment and eradication of sheep lice and ked with cyhalothrin--a new synthetic pyrethroid.

Science.gov (United States)

Rundle, J C; Forsyth, B A

1984-12-01

A new synthetic pyrethroid, cyhalothrin, has been evaluated as both a sheep dip and a jetting fluid for the control of body lice (Damalinia ovis), face lice (Linognathus ovillus), foot lice (Linognathus pedalis) and the sheep ked (Melophagus ovinus). A dip wash concentration of 1.25 ppm cyhalothrin eradicated D. ovis from sheep. A jetting fluid at a concentration of 20 ppm also eradicated D. ovis. In the field cyhalothrin was evaluated at 20 ppm as a dip wash and at 50 ppm as a jetting fluid. These field trials confirmed the ability of cyhalothrin to eradicate D. ovis from short and long-woolled sheep. The sucking lice, L. ovillus and L. pedalis, were also found to be very susceptible to cyhalothrin at a dip wash concentration of 20 ppm, but it was necessary to treat the predilection sites infested by these parasites twice within a 3-week period to achieve their eradication. Sheep ked (M. ovinus) were eradicated from an infected flock of sheep after plunge dipping in cyhalothrin at 20 ppm.

Synthetic Cathinones ("Bath Salts")

Science.gov (United States)

... Alcohol Club Drugs Cocaine Fentanyl Hallucinogens Inhalants Heroin Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Over-the-Counter Medicines Prescription Medicines Steroids (Anabolic) Synthetic Cannabinoids (K2/Spice) Synthetic Cathinones (Bath Salts) Tobacco/ ...

A PLIF and PIV study of liquid mixing enhanced by a lateral synthetic jet pair

International Nuclear Information System (INIS)

Xia Qingfeng; Zhong Shan

2012-01-01

Highlights: ► Enhancement of mixing between two water streams in a planar channel by means of a lateral synthetic jet pair is studied using PLIF and PIV. ► The excellent mixing observed is largely caused by a strong interaction between the opposing vortex pairs produced by the lateral synthetic jets. ► The synthetic jet operating conditions, at which a nearly homogenous mixing is achieved, are also identified and they are expressed in terms of a functional relationship. - Abstract: In this paper, enhancement of mixing between two water streams of the same flow rate in a planar channel by means of a lateral synthetic jet pair is studied at a net flow Reynolds number of 83 using PLIF and PIV. The synthetic jet pair is operated 180° out-of-phase at a range of actuation frequencies and displacements, with the latter being characterized by the dimensionless stroke length. The extent of mixing is evaluated using PLIF data at a location further downstream in the mixing channel. It is found that at a fixed actuation frequency a higher dimensionless stroke length produces a better mixing, and as the actuation frequency increases a lower dimensionless stroke length is required to achieve a given mixing degree. At a sufficiently high frequency or dimensionless stroke length, a nearly homogenous mixing with a mixing degree greater than 0.9 can be obtained. A functional relationship between actuation frequency and dimensionless stroke length is also obtained by best fitting the experimental data, which can be used for selecting the synthetic jet operating conditions to ensure a good mixing. Furthermore, both PLIF and PIV results show that each synthetic jet actuation cycle produce two opposing vortex pairs, which play an important role in prompting mixing between the two fluid streams. The excellent mixing obtained at a high frequency or a high dimensionless stroke length is found to be largely caused by a strong interaction between these opposing vortex pairs.

Note: A micro-perfusion system for use during real-time physiological studies under high pressure

Science.gov (United States)

Maltas, Jeff; Long, Zac; Huff, Alison; Maloney, Ryan; Ryan, Jordan; Urayama, Paul

2014-10-01

We construct a micro-perfusion system using piston screw pump generators for use during real-time, high-pressure physiological studies. Perfusion is achieved using two generators, with one generator being compressed while the other is retracted, thus maintaining pressurization while producing fluid flow. We demonstrate control over perfusion rates in the 10-μl/s range and the ability to change between fluid reservoirs at up to 50 MPa. We validate the screw-pump approach by monitoring the cyanide-induced response of UV-excited autofluorescence from Saccharomyces cerevisiae under pressurization.

Tartrazine induced changes in physiological and biochemical parameters in Swiss albino mice, Mus musculus

OpenAIRE

Arefin, Sayema; Hossain, Mohammad Salim; Akter Neshe, Shamme; Rashid, Md. Mamun Or; Amin, Mohammad Tohidul; Hussain, Md. Saddam

2017-01-01

Now-a-days synthetic food dyes are being used most commonly as food colorant in confectionaries, drugs and cosmetics. Present study was designed to evaluate the toxic effect of tartrazine, a widely used azo dye, on Swiss Albino mice. Experimental animals were treated with tested dye at a dose level 200mg/kg & 400mg/kg body weight along with normal diet. Various physiological and biochemical parameters were assessed to study the toxic effect of tartrazine. Our study rev...

Non-Newtonian fluid structure interaction in flexible biomimetic microchannels

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Kiran, M.; Dasgupta, Sunando; Chakraborty, Suman

2017-11-01

To investigate the complex fluid structure interactions in a physiologically relevant microchannel with deformable wall and non-Newtonian fluid that flows within it, we fabricated cylindrical microchannels of various softness out of PDMS. Experiments to measure the transient pressure drop across the channel were carried out with high sampling frequencies to capture the intricate flow physics. In particular, we showed that the waveforms varies greatly for each of the non-Newtonian and Newtonian cases for both non-deformable and deformable microchannels in terms of the peak amplitude, r.m.s amplitude and the crest factor. In addition, we carried out frequency sweep experiments to evaluate the frequency response of the system. We believe that these results will aid in the design of polymer based microfluidic phantoms for arterial FSI studies, and in particular for studying blood analog fluids in cylindrical microchannels as well as developing frequency specific Lab-on-chip systems for medical diagnostics.

Multi-solid model modified to predict paraffin in petroleum fluids at high temperatures and pressures

International Nuclear Information System (INIS)

Escobar Remolina, Juan Carlos M; Barrios Ortiz, Wilson; Santoyo Ramirez Gildardo

2009-01-01

A thermodynamic structure has been modified in order to calculate cloud point, fluidity and amount of precipitated wax under a wide range of temperature conditions, composition, and high pressures. The model is based on a combination of ideal solution concepts, fluid characterization, and formation of multiple solid phases using Cubic State Equations. The experimental data utilized for testing the prediction capacity and potentiality of a model exhibit different characteristics: continuous series synthetic systems of heavy alkanes, discontinuous series, and dead or living petroleum fluids with indefinite fractions such as C7+, C10+, C20+, and C30+. The samples were taken from the literature, petroleum fluids from the main Colombian reservoirs, and some samples of Bolivian fluids. Results presented in this paper show the minimum standard deviations between experimental data and data calculated with a model. This allows a progress in decision-making processes for flow assurance in reservoirs, wells, and surface facilities in the petroleum industry.

Molecular Imaging in Synthetic Biology, and Synthetic Biology in Molecular Imaging.

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Gilad, Assaf A; Shapiro, Mikhail G

2017-06-01

Biomedical synthetic biology is an emerging field in which cells are engineered at the genetic level to carry out novel functions with relevance to biomedical and industrial applications. This approach promises new treatments, imaging tools, and diagnostics for diseases ranging from gastrointestinal inflammatory syndromes to cancer, diabetes, and neurodegeneration. As these cellular technologies undergo pre-clinical and clinical development, it is becoming essential to monitor their location and function in vivo, necessitating appropriate molecular imaging strategies, and therefore, we have created an interest group within the World Molecular Imaging Society focusing on synthetic biology and reporter gene technologies. Here, we highlight recent advances in biomedical synthetic biology, including bacterial therapy, immunotherapy, and regenerative medicine. We then discuss emerging molecular imaging approaches to facilitate in vivo applications, focusing on reporter genes for noninvasive modalities such as magnetic resonance, ultrasound, photoacoustic imaging, bioluminescence, and radionuclear imaging. Because reporter genes can be incorporated directly into engineered genetic circuits, they are particularly well suited to imaging synthetic biological constructs, and developing them provides opportunities for creative molecular and genetic engineering.

New designer drugs (synthetic cannabinoids and synthetic cathinones): review of literature.

Science.gov (United States)

Cottencin, Olivier; Rolland, Benjamin; Karila, Laurent

2014-01-01

New designer drugs (synthetic cannabinoids and synthetic cathinones) are new "legal highs" that are sold online for recreational public or private use. Synthetic cannabinoids are psychoactive herbal and chemical products that mimic the effects of cannabis when used. These drugs are available on the Internet or in head shops as incense or air fresheners to circumvent the law. Cathinone is a naturally occurring beta-ketone amphetamine analog found in the leaves of the Catha edulis plant. Synthetic cathinones are phenylalkylamine derivatives that may possess amphetamine-like properties. These drugs are sold online as bath salts. Designer drugs are often labeled as "not for human consumption" to circumvent drug abuse legislation. The absence of legal risks, the ease of obtaining these drugs, the moderate cost, and the availability via the Internet are the main features that attract users, but the number of intoxicated people presenting with emergencies is increasing. There is evidence that negative health and social consequences may affect recreational and chronic users. The addictive potential of designer drugs is not negligible.

Current status of synthetic epikeratoplasty.

Science.gov (United States)

Thompson, K P; Hanna, K; Waring, G O; Gipson, I; Liu, Y; Gailitis, R P; Johnson-Wint, B; Green, K

1991-01-01

Many of the deficiencies with human tissue epikeratoplasty might be improved by the use of a suitable synthetic lenticule. Potential biomaterials for epikeratoplasty include collagen (types I, III, or IV), collagen-hydrogel copolymers, bioactive synthetics, and coated hydrogels. The biomaterial must be engineered to achieve strict specifications of optical clarity, support of epithelial migration and adhesion, permeability to solutes, and stability to corneal proteases. Attaching synthetic lenticules to the cornea without cutting Bowman's layer by adhesives, laser welding, or direct adhesion may also improve the efficacy of synthetic epikeratoplasty.

Tissue Harmonic Synthetic Aperture Imaging

DEFF Research Database (Denmark)

Rasmussen, Joachim

The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...

Life after the synthetic cell

DEFF Research Database (Denmark)

Rasmussen, Steen

2010-01-01

Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self-replicating ......Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self...

Estimation of Dry Fracture Weakness, Porosity, and Fluid Modulus Using Observable Seismic Reflection Data in a Gas-Bearing Reservoir

Science.gov (United States)

Chen, Huaizhen; Zhang, Guangzhi

2017-05-01

Fracture detection and fluid identification are important tasks for a fractured reservoir characterization. Our goal is to demonstrate a direct approach to utilize azimuthal seismic data to estimate fluid bulk modulus, porosity, and dry fracture weaknesses, which decreases the uncertainty of fluid identification. Combining Gassmann's (Vier. der Natur. Gesellschaft Zürich 96:1-23, 1951) equations and linear-slip model, we first establish new simplified expressions of stiffness parameters for a gas-bearing saturated fractured rock with low porosity and small fracture density, and then we derive a novel PP-wave reflection coefficient in terms of dry background rock properties (P-wave and S-wave moduli, and density), fracture (dry fracture weaknesses), porosity, and fluid (fluid bulk modulus). A Bayesian Markov chain Monte Carlo nonlinear inversion method is proposed to estimate fluid bulk modulus, porosity, and fracture weaknesses directly from azimuthal seismic data. The inversion method yields reasonable estimates in the case of synthetic data containing a moderate noise and stable results on real data.

Metformin is synthetically lethal with glucose withdrawal in cancer cells.

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Menendez, Javier A; Oliveras-Ferraros, Cristina; Cufí, Sílvia; Corominas-Faja, Bruna; Joven, Jorge; Martin-Castillo, Begoña; Vazquez-Martin, Alejandro

2012-08-01

Glucose deprivation is a distinctive feature of the tumor microecosystem caused by the imbalance between poor supply and an extraordinarily high consumption rate. The metabolic reprogramming from mitochondrial respiration to aerobic glycolysis in cancer cells (the "Warburg effect") is linked to oncogenic transformation in a manner that frequently implies the inactivation of metabolic checkpoints such as the energy rheostat AMP-activated protein kinase (AMPK). Because the concept of synthetic lethality in oncology can be applied not only to genetic and epigenetic intrinsic differences between normal and cancer cells but also to extrinsic ones such as altered microenvironment, we recently hypothesized that stress-energy mimickers such as the AMPK agonist metformin should produce metabolic synthetic lethality in a glucose-starved cell culture milieu imitating the adverse tumor growth conditions in vivo. Under standard high-glucose conditions, metformin supplementation mostly caused cell cycle arrest without signs of apoptotic cell death. Under glucose withdrawal stress, metformin supplementation circumvented the ability of oncogenes (e.g., HER2) to protect breast cancer cells from glucose-deprivation apoptosis. Significantly, representative cell models of breast cancer heterogeneity underwent massive apoptosis (by >90% in some cases) when glucose-starved cell cultures were supplemented with metformin. Our current findings may uncover crucial issues regarding the cell-autonomous metformin's anti-cancer actions: (1) The offently claimed clinically irrelevant, non-physiological concentrations needed to observe the metformin's anti-cancer effects in vitro merely underlie the artifactual interference of erroneous glucose-rich experimental conditions that poorly reflect glucose-starved in vivo conditions; (2) the preferential killing of cancer stem cells (CSC) by metformin may simply expose the best-case scenario for its synthetically lethal activity because an increased

Living GenoChemetics by hyphenating synthetic biology and synthetic chemistry in vivo.

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Sharma, Sunil V; Tong, Xiaoxue; Pubill-Ulldemolins, Cristina; Cartmell, Christopher; Bogosyan, Emma J A; Rackham, Emma J; Marelli, Enrico; Hamed, Refaat B; Goss, Rebecca J M

2017-08-09

Marrying synthetic biology with synthetic chemistry provides a powerful approach toward natural product diversification, combining the best of both worlds: expediency and synthetic capability of biogenic pathways and chemical diversity enabled by organic synthesis. Biosynthetic pathway engineering can be employed to insert a chemically orthogonal tag into a complex natural scaffold affording the possibility of site-selective modification without employing protecting group strategies. Here we show that, by installing a sufficiently reactive handle (e.g., a C-Br bond) and developing compatible mild aqueous chemistries, synchronous biosynthesis of the tagged metabolite and its subsequent chemical modification in living culture can be achieved. This approach can potentially enable many new applications: for example, assay of directed evolution of enzymes catalyzing halo-metabolite biosynthesis in living cells or generating and following the fate of tagged metabolites and biomolecules in living systems. We report synthetic biological access to new-to-nature bromo-metabolites and the concomitant biorthogonal cross-coupling of halo-metabolites in living cultures.Coupling synthetic biology and chemical reactions in cells is a challenging task. The authors engineer bacteria capable of generating bromo-metabolites, develop a mild Suzuki-Miyaura cross-coupling reaction compatible with cell growth and carry out the cross-coupling chemistry in live cell cultures.

Corrosion study of resorbable Ca60Mg15Zn25 bulk metallic glasses in physiological fluids

Directory of Open Access Journals (Sweden)

Rafał Babilas

2017-10-01

Full Text Available The corrosion activity of amorphous plates of Ca60Mg15Zn25 alloy was investigated. The biocompatible elements were selected for the alloy composition. The electrochemical corrosion and immersion tests were carried out in a multi-electrolyte fluid and Ringer's solution. Better corrosion behavior was observed for the samples tested in a multi-electrolyte fluid despite the active dissolution of Ca and Mg in Ringer's solution. The experimental results indicated that reducing concentration of NaCl from 8.6 g/dm3 for Ringer's solution to 5.75 g/dm3 caused the decrease of the corrosion rate. The volume of the hydrogen evolved after 480 min in Ringer's solution (40.1 ml/cm2 was higher in comparison with that obtained in a multi-electrolyte fluid (24.4 ml/cm2. The values of open-circuit potential (EOCP for the Ca60Mg15Zn25 glass after 1 h incubation in Ringer's solution and a multi-electrolyte fluid were determined to be −1553 and −1536 mV vs. a saturated calomel electrode (SCE. The electrochemical measurements indicated a shift of the corrosion current density (jcorr from 1062 μA/cm2 for the sample tested in Ringer's solution to 788 μA/cm2 for the specimen immersed in a multi-electrolyte fluid. The corrosion products analysis was conducted by using the X-ray photoelectron spectroscopy (XPS. The corrosion products were identified to be CaCO3, Mg(OH2, CaO, MgO and ZnO. The mechanism of corrosion process was proposed and described based on the microscopic observations. The X-ray diffraction and Fourier transform infrared spectroscopy (FTIR also indicated that Ca(OH2, CaCO3, Zn(OH2 and Ca(Zn(OH32·2H2O mainly formed on the surface of the studied alloy. Keywords: Ca-based metallic glasses, X-ray photoelectron spectroscopy, FTIR spectroscopy, X-ray diffraction, Corrosion resistance, Hydrogen evaluation

Upgrading oil sands bitumen with FLUID COKING and FLEXICOKING technologies

Energy Technology Data Exchange (ETDEWEB)

Kamienski, P.; Phillips, G. [ExxonMobil Research and Engineering Co., Fairfax, VA (United States); McKnight, C.; Rumball, B. [Syncrude Canada Ltd., Calgary, AB (Canada)

2009-07-01

This presentation described EMRE's Fluid Coking and Flexicoking technologies that are well suited for upgrading Alberta's heavy crudes and oil sands bitumen into pipelineable crudes or synthetic crudes, which can be further processed into transportation fuels. The Fluid Coking technology uses a fluidized bed reactor that thermally converts the heavy oils into light gases, liquids and coke. The metals and much of the sulphur are concentrated in the coke. Combustion of the coke provides process heat and the remaining coke is sold or stored on site for later recovery. Syncrude Canada currently operates 3 Fluid Coking units in northern Alberta. Flexicoking extends fluid coking by integrating air gasification to produce a carbon monoxide/hydrogen rich fuel gas that helps meet fuel and energy requirements of bitumen recovery and upgrading. The yields of light gas and liquids are similar to those of the Fluid Coking process. The partial combustion of coke provides the process heat for the thermal conversion and gasification steps. The remaining coke is gasified and desulphurized using Flexsorb technology. At present, there are 5 Flexicoking units in operation around the world. Interest in the technology is growing, particularly in locations with large demand for clean fuel or electricity. It is also suitable for steam assisted gravity drainage (SAGD) operations in Alberta. This presentation outlined the operating principles of the Flexicoking integrated gasification system and compared it with more expensive oxygen gasification processes. tabs., figs.

Hairy polyelectrolyte brushes-grafted thermosensitive microgels as artificial synovial fluid for simultaneous biomimetic lubrication and arthritis treatment.

Science.gov (United States)

Liu, Guoqiang; Liu, Zhilu; Li, Na; Wang, Xiaolong; Zhou, Feng; Liu, Weimin

2014-11-26

We report the fabrication of poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes grafted poly(N-isopropylacrylamide) (PNIPAAm) microgels and their potential as artificial synovial fluid for biomimetic aqueous lubrication and arthritis treatment. The negatively charged PSPMK brushes and thermosensitive PNIPAAm microgels play water-based hydration lubrication and temperature-triggered drug release, respectively. Under soft friction pairs, an ultralow coefficient of friction was achieved, while the hairy thermosensitive microgels showed a desirable temperature-triggered drugs release performance. Such a soft charged hairy microgel offers great possibility for designing intelligent synovial fluid. What is more, the combination of lubrication and drug loading capabilities enables the large clinical potential of novel soft hairy nanoparticles as synthetic joint lubricant fluid in arthritis treatment.

Na+ -K+ -2Cl- Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia.

Science.gov (United States)

Delpire, Eric; Gagnon, Kenneth B

2018-03-25

Two genes encode the Na + -K + -2Cl - cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na + , 1K + , and 2Cl - across the plasma membrane of cells. Na + -K + -2Cl - cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na + /K + pump. In many cells, NKCC1 accumulates Cl - above its electrochemical potential equilibrium, thereby facilitating Cl - channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca 2+ channels, leading to Ca 2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl - conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl - . In combination with the Na + /K + pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl - -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K + -driven fluid secretion in inner ear, and possibly in Na + -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na + /K + pump participates in reabsorbing 30% of the glomerular-filtered Na + . Overall, many critical physiological functions are maintained by the activity of the two Na + -K + -2Cl - cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

Altered vocal fold kinematics in synthetic self-oscillating models that employ adipose tissue as a lateral boundary condition.

Science.gov (United States)

Saidi, Hiba; Erath, Byron D.

2015-11-01

The vocal folds play a major role in human communication by initiating voiced sound production. During voiced speech, the vocal folds are set into sustained vibrations. Synthetic self-oscillating vocal fold models are regularly employed to gain insight into flow-structure interactions governing the phonation process. Commonly, a fixed boundary condition is applied to the lateral, anterior, and posterior sides of the synthetic vocal fold models. However, physiological observations reveal the presence of adipose tissue on the lateral surface between the thyroid cartilage and the vocal folds. The goal of this study is to investigate the influence of including this substrate layer of adipose tissue on the dynamics of phonation. For a more realistic representation of the human vocal folds, synthetic multi-layer vocal fold models have been fabricated and tested while including a soft lateral layer representative of adipose tissue. Phonation parameters have been collected and are compared to those of the standard vocal fold models. Results show that vocal fold kinematics are affected by adding the adipose tissue layer as a new boundary condition.

Ultra-fast magnetic resonance encephalography of physiological brain activity - Glymphatic pulsation mechanisms?

Science.gov (United States)

Kiviniemi, Vesa; Wang, Xindi; Korhonen, Vesa; Keinänen, Tuija; Tuovinen, Timo; Autio, Joonas; LeVan, Pierre; Keilholz, Shella; Zang, Yu-Feng; Hennig, Jürgen; Nedergaard, Maiken

2016-06-01

The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump cerebrospinal fluid from the peri-arterial spaces through the extracellular tissue into the peri-venous spaces facilitated by aquaporin water channels. Since cardiac pulses cannot be the sole mechanism of glymphatic propulsion, we searched for additional cerebrospinal fluid pulsations in the human brain with ultra-fast magnetic resonance encephalography. We detected three types of physiological mechanisms affecting cerebral cerebrospinal fluid pulsations: cardiac, respiratory, and very low frequency pulsations. The cardiac pulsations induce a negative magnetic resonance encephalography signal change in peri-arterial regions that extends centrifugally and covers the brain in ≈1 Hz cycles. The respiratory ≈0.3 Hz pulsations are centripetal periodical pulses that occur dominantly in peri-venous areas. The third type of pulsation was very low frequency (VLF 0.001-0.023 Hz) and low frequency (LF 0.023-0.73 Hz) waves that both propagate with unique spatiotemporal patterns. Our findings using critically sampled magnetic resonance encephalography open a new view into cerebral fluid dynamics. Since glymphatic system failure may precede protein accumulations in diseases such as Alzheimer's dementia, this methodological advance offers a novel approach to image brain fluid dynamics that potentially can enable early detection and intervention in neurodegenerative diseases. © The Author(s) 2015.

Creating biological nanomaterials using synthetic biology

International Nuclear Information System (INIS)

Rice, MaryJoe K; Ruder, Warren C

2014-01-01

Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

Creating biological nanomaterials using synthetic biology.

Science.gov (United States)

Rice, MaryJoe K; Ruder, Warren C

2014-02-01

Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

Synthetic Cannabis Overdose and Withdrawal in a Young Adult: A Case Report, Commentary on Regulation, and Review of the Literature

Directory of Open Access Journals (Sweden)

John Samaan

2016-01-01

Full Text Available Introduction. Marijuana has been used for its psychotropic effects including enhanced relaxation and perceptual alterations. However, the use of synthetic marijuana (SM leads to more frequent and drastic side effects than the typical use of regular marijuana, owing to the fact that SM has a shorter duration and an earlier peak of action. Despite all the potential adverse health effects associated with SM use, current health policies on SM are very limited. It is believed that the popularity of SM has increased, due to its easy accessibility in the US and lack of detection in typical urine drug screens for THC. Case Report. One case presented is of a young adult patient, with histories of recurrent synthetic cannabis and recreational cannabis use, who had developed drastic physiological and psychiatric symptoms, including the development of acute-onset psychosis. Conclusion/Discussion. This case, as many others nationwide, exemplifies the impact of synthetic cannabinoid use and abuse in adolescents. Side effects and adverse health consequences of synthetic cannabinoid use warrant stricter regulations and policies in order to decrease psychiatric hospital admissions and associated healthcare costs.

Potential environmental benefits from regulatory consideration of synthetic drilling muds

International Nuclear Information System (INIS)

Burke, C.J.; Veil, J.A.

1995-02-01

When drilling exploration and production wells for oil and gas, drillers use specialized drilling fluids, referred to as muds, to help maintain well control and to remove drill cuttings from the hole. Historically, either water-based muds (WBMs) or oil-based muds (OBMs) have been used for offshore wells. Recently, in response to US Environmental Protection Agency (EPA) regulations and drilling-waste discharge requirements imposed by North Sea nations, the drilling industry has developed several types of synthetic-based muds (SBMs) that combine the desirable operating qualities of OBMs with the lower toxicity and environmental impact qualities of WBMs. This report describes the operational, environmental, and economic features of all three types of muds and discusses potential EPA regulatory barriers to wider use of SBMs

Synthetic Defects for Vibrothermography

Science.gov (United States)

Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

2010-02-01

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

Wearable physiological systems and technologies for metabolic monitoring.

Science.gov (United States)

Gao, Wei; Brooks, George A; Klonoff, David C

2018-03-01

Wearable sensors allow continuous monitoring of metabolites for diabetes, sports medicine, exercise science, and physiology research. These sensors can continuously detect target analytes in skin interstitial fluid (ISF), tears, saliva, and sweat. In this review, we will summarize developments on wearable devices and their potential applications in research, clinical practice, and recreational and sporting activities. Sampling skin ISF can require insertion of a needle into the skin, whereas sweat, tears, and saliva can be sampled by devices worn outside the body. The most widely sampled metabolite from a wearable device is glucose in skin ISF for monitoring diabetes patients. Continuous ISF glucose monitoring allows estimation of the glucose concentration in blood without the pain, inconvenience, and blood waste of fingerstick capillary blood glucose testing. This tool is currently used by diabetes patients to provide information for dosing insulin and determining a diet and exercise plan. Similar technologies for measuring concentrations of other analytes in skin ISF could be used to monitor athletes, emergency responders, warfighters, and others in states of extreme physiological stress. Sweat is a potentially useful substrate for sampling analytes for metabolic monitoring during exercise. Lactate, sodium, potassium, and hydrogen ions can be measured in sweat. Tools for converting the concentrations of these analytes sampled from sweat, tears, and saliva into blood concentrations are being developed. As an understanding of the relationships between the concentrations of analytes in blood and easily sampled body fluid increases, then the benefits of new wearable devices for metabolic monitoring will also increase.

Synthetic biology: Emerging bioengineering in Indonesia

Science.gov (United States)

Suhandono, Sony

2017-05-01

The development of synthetic biology will shape the new era of science and technology. It is an emerging bioengineering technique involving genetic engineering which can alter the phenotype and behavior of the cell or the new product. Synthetic biology may produce biomaterials, drugs, vaccines, biosensors, and even a recombinant secondary metabolite used in herbal and complementary medicine, such as artemisinin, a malaria drug which is usually extracted from the plant Artemisia annua. The power of synthetic biology has encouraged scientists in Indonesia, and is still in early development. This paper also covers some research from an Indonesian research institute in synthetic biology such as observing the production of bio surfactants and the enhanced production of artemisinin using a transient expression system. Synthetic biology development in Indonesia may also be related to the iGEM competition, a large synthetic biology research competition which was attended by several universities in Indonesia. The application of synthetic biology for drug discovery will be discussed.

Biot Critical Frequency Applied to Description of Failure and Yield of Highly Porous Chalk with Different Pore Fluids

DEFF Research Database (Denmark)

Andreassen, Katrine Alling; Fabricius, Ida Lykke

2010-01-01

Injection of water into chalk hydrocarbon reservoirs has led to mechanical yield and failure. Laboratory experiments on chalk samples correspondingly show that the mechanical properties of porous chalk depend on pore fluid and temperature. In case of water-saturated samples, the concentration...... is controlled by solid-fluid friction. The reference frequency is thus a measure of this friction, and we propose that the fluid effect on mechanical properties of chalk may be the result of liquid-solid friction. We reviewed 622 published experiments on mechanical properties of porous chalk. The data include...... chalk samples that were tested at temperatures from 20 °C to 130 °C with the following pore fluids: fresh water, synthetic seawater, glycol, and oil of varying viscosity. The critical frequency is calculated for each experiment. For each specimen, we calculate the thickness to the slipping plane outside...

The Synthetic Biology Open Language (SBOL) provides a community standard for communicating designs in synthetic biology.

Science.gov (United States)

Galdzicki, Michal; Clancy, Kevin P; Oberortner, Ernst; Pocock, Matthew; Quinn, Jacqueline Y; Rodriguez, Cesar A; Roehner, Nicholas; Wilson, Mandy L; Adam, Laura; Anderson, J Christopher; Bartley, Bryan A; Beal, Jacob; Chandran, Deepak; Chen, Joanna; Densmore, Douglas; Endy, Drew; Grünberg, Raik; Hallinan, Jennifer; Hillson, Nathan J; Johnson, Jeffrey D; Kuchinsky, Allan; Lux, Matthew; Misirli, Goksel; Peccoud, Jean; Plahar, Hector A; Sirin, Evren; Stan, Guy-Bart; Villalobos, Alan; Wipat, Anil; Gennari, John H; Myers, Chris J; Sauro, Herbert M

2014-06-01

The re-use of previously validated designs is critical to the evolution of synthetic biology from a research discipline to an engineering practice. Here we describe the Synthetic Biology Open Language (SBOL), a proposed data standard for exchanging designs within the synthetic biology community. SBOL represents synthetic biology designs in a community-driven, formalized format for exchange between software tools, research groups and commercial service providers. The SBOL Developers Group has implemented SBOL as an XML/RDF serialization and provides software libraries and specification documentation to help developers implement SBOL in their own software. We describe early successes, including a demonstration of the utility of SBOL for information exchange between several different software tools and repositories from both academic and industrial partners. As a community-driven standard, SBOL will be updated as synthetic biology evolves to provide specific capabilities for different aspects of the synthetic biology workflow.

Structure measurements in a synthetic turbulent boundary layer

Science.gov (United States)

Arakeri, Jaywant H.

1987-09-01

Extensive hot-wire measurements have been made to determine the structure of the large eddy in a synthejc turbulent boundary layer on a flat-plate model. The experiments were carried out in a wind tunnel at a nominal free-stream velocity of 12 m/s. The synthetic turbulent boundary layer had a hexagonal pattern of eddies and a ratio of streamwise scale to spanwise scale of 3.2:1. The measured celerity of the large eddy was 84.2 percent of the free-stream velocity. There was some loss of coherence, but very little distortion, as the eddies moved downstream. Several mean properties of the synthetic boundary layer were found to agree quite well with the mean properties of a natural turbulent boundary layer at the same Reynolds number. The large eddy is composed of a pair of primary counter-rotating vortices about five [...] long in the streamwise direction and about one [...] apart in the spanwise direction, where [...] is the mean boundary-layer thickness. The sense of the primary pair is such as to pump fluid away from the wall in the region between the vortices. A secondary pair of counter-rotating streamwise vortices, having a sense opposite to that of the primary pair, is observed outside of and slightly downstream from the primary vortices. Both pairs of vortices extend across the full thickness of the boundary layer and are inclined at a shallow angle to the surface of the flat plate. The data show that the mean vorticity vectors are not tangential to the large-eddy vortices. In fact, the streamwise and normal vorticity components that signal the presence of the eddy are of the same order of magnitude. Definite signatures are obtained in terms of the mean skin-friction coefficient and the mean wake parameter averaged at constant phase. Velocities induced by the vortices are partly responsible for entrainment of irrotational fluid, for transport of momentum, for generation of Reynolds stresses, and for maintenance of streamwise and normal vorticity in the outer

Modeling single ventricle physiology: review of engineering tools to study first stage palliation of hypoplastic left heart syndrome.

Science.gov (United States)

Biglino, Giovanni; Giardini, Alessandro; Hsia, Tain-Yen; Figliola, Richard; Taylor, Andrew M; Schievano, Silvia

2013-10-30

First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic

A Canadian refiner's perspective of synthetic crudes

International Nuclear Information System (INIS)

Halford, T.L.; McIntosh, A.P.; Rasmussen

1997-01-01

Some of the factors affecting a refiner's choice of crude oil include refinery hardware, particularly gas oil crackers, products slate and product specifications, crude availability, relative crude price and crude quality. An overview of synthetic crude, the use of synthetic crude combined with other crudes and a comparison of synthetic crude with conventional crude oil was given. The two main users of synthetic crude are basically two groups of refiners, those large groups who use synthetic crude combined with other crudes, and a smaller group who run synthetic crude on specially designed units as a sole feed. The effects of changes in fuel legislation were reviewed. It was predicted that the changes will have a mixed impact on the value of synthetic crude, but low sulphur diesel regulations and gasoline sulphur regulations will make current synthetic crudes attractive. The big future change with a negative impact will be diesel cetane increases to reduce engine emissions. This will reduce synthetic crude attractiveness due to distillate yields and quality and high gas oil yields. Similarly, any legislation limiting aromatics in diesel fuel will also make synthetic crudes less attractive. Problems experienced by refiners with hardware dedicated to synthetic crude (salt, naphthenic acid, fouling, quality variations) were also reviewed. 3 tabs

Neonates with Bartter syndrome have enormous fluid and sodium requirements.

Science.gov (United States)

Azzi, Antonio; Chehade, Hassib; Deschênes, Georges

2015-07-01

Managing neonatal Bartter syndrome by achieving adequate weight gain is challenging. We assessed the correlation between weight gain in neonatal Bartter syndrome and the introduction of fluid and sodium supplementations and indomethacin during the first 4 weeks of life. Daily fluid and electrolytes requirements were analysed using linear regression and Spearman correlation coefficients. The weight gain coefficient was calculated as daily weight gain after physiological neonatal weight loss. We studied seven infants. The highest weight gain coefficients occurred between weeks two and four in the five neonates who either received prompt amounts of fluid (maximum 810 mL/kg/day) and sodium (maximum 70 mmol/kg/day) or were treated with indomethacin. For the two patients with the highest weight gain coefficient, water and sodium supplementations were decreased in weeks two to four leading to a significant negative Spearman correlation between weight gain and fluid supplements (r = -0.55 and -0.68) and weight gain and sodium supplementations (r = -0.96 and -0.72). The two patients with the lowest weight gain coefficient had positive Spearman correlation coefficients between weight gain and fluid and sodium supplementations. Infants with neonatal Bartter syndrome required rapid and enormous fluid and sodium supplementations or the early introduction of indomethacin treatment to achieve adequate weight gain during the early postnatal period. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Fluid and electrolyte homeostasis during spaceflight: Elucidation of mechanisms in a primate

Science.gov (United States)

Churchill, Susanne

1990-01-01

Although it is now well accepted that exposure to the hypogravic environment of space induces a shift of fluid from the lower extremities toward the upper body, the actual physiological responses to this central volume expansion have not been well characterized. Because it is likely that the fluid and electrolyte response to hypogravity plays a critical role in the development of Cardiovascular Deconditioning, elucidation of these mechanisms is of critical importance. The goal of flight experiment 223, scheduled to fly on SLS-2, is the definition of the basic renal, fluid and electrolyte response to spaceflight in four instrumented squirrel monkeys. The studies were those required to support the development of flight hardware and optimal inflight procedures, and to evaluate a ground-based model for weightlessness, lower body positive pressure (LBPP).

Investigating the recording and accuracy of fluid balance monitoring in critically ill patients

Directory of Open Access Journals (Sweden)

Annette Diacon

2014-11-01

Full Text Available Background. The accurate assessment of fluid balance data collected during physical assessment as well as during monitoring and record-keeping forms an essential part of the baseline patient information that guides medical and nursing interventions aimed at achieving physiological stability in patients. An informal audit of 24-hour fluid balance records in a local intensive care unit (ICU showed that seven out of ten fluid balance calculations were incorrect.Objective. To identify and describe current clinical nursing practice in fluid balance monitoring and measurement accuracy in ICUs, conducted as part of a broader study in partial fulfilment of a Master of Nursing degree.Methods. A quantitative approach utilising a descriptive, exploratory study design was applied. An audit of 103 ICU records was conducted to establish the current practices and accuracy in recording of fluid balance monitoring. Data were collected using a purpose-designed tool based on relevant literature and practice experience. Results. Of the original recorded fluid balance calculations, 79% deviated by more than 50 mL from the audited calculations. Further­more, a significant relationship was shown between inaccurate fluid balance calculation and administration of diuretics (p=0.01. Conclusion. The majority of fluid balance records were incorrectly calculated.

Finding Hope in Synthetic Biology.

Science.gov (United States)

Takala, Tuija

2017-04-01

For some, synthetic biology represents great hope in offering possible solutions to many of the world's biggest problems, from hunger to sustainable development. Others remain fearful of the harmful uses, such as bioweapons, that synthetic biology can lend itself to, and most hold that issues of biosafety are of utmost importance. In this article, I will evaluate these points of view and conclude that although the biggest promises of synthetic biology are unlikely to become reality, and the probability of accidents is fairly substantial, synthetic biology could still be seen to benefit humanity by enhancing our ethical understanding and by offering a boost to world economy.

Geo synthetic-reinforced Pavement systems

International Nuclear Information System (INIS)

Zornberg, J. G.

2014-01-01

Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

Mathematical model of renal elimination of fluid and small ions during hyper- and hypovolemic conditions.

Science.gov (United States)

Gyenge, Christina C; Bowen, Bruce D; Reed, Rolf K; Bert, Joel L

2003-02-01

This study is concerned with the formulation of a 'kidney module' linked to the plasma compartment of a larger mathematical model previously developed. Combined, these models can be used to predict, amongst other things, fluid and small ion excretion rates by the kidney; information that should prove useful in evaluating values and trends related to whole-body fluid balance for different clinical conditions to establish fluid administration protocols and for educational purposes. The renal module assumes first-order, negative-feedback responses of the kidney to changes in plasma volume and/or plasma sodium content from their normal physiological set points. Direct hormonal influences are not explicitly formulated in this empiric model. The model also considers that the renal excretion rates of small ions other than sodium are proportional to the excretion rate of sodium. As part of the model development two aspects are emphasized (1): the estimation of parameters related to the renal elimination of fluid and small ions, and (2) model validation via comparisons between the model predictions and selected experimental data. For validation, model predictions of the renal dynamics are compared with new experimental data for two cases: plasma overload resulting from external fluid infusion (e.g. infusions of iso-osmolar solutions and/or hypertonic/hyperoncotic saline solutions), and untreated hypo volemic conditions that result from the external loss of blood. The present study demonstrates that the empiric kidney module presented above can provide good short-term predictions with respect to all renal outputs considered here. Physiological implications of the model are also presented. Copyright Acta Anaesthesiologica Scandinavica 47 (2003)

Gastrin is not a physiological regulator of pancreatic exocrine secretion in the dog

International Nuclear Information System (INIS)

Koehler, E.; Beglinger, C.; Eysselein, V.; Groetzinger, U.; Gyr, K.

1987-01-01

The role of gastrin as a regulator of exocrine pancreatic secretion has not been proven adequately. In the present study the authors therefore compared the relative molar potencies of sulfated and unsulfated gastrin 17 with structurally related CCK peptides (synthetic CCK-8 and natural porcine CCK-33) in stimulating exocrine pancreatic secretion in conscious dogs. Dose response curves were constructed for pancreatic and gastric acid secretion. Plasma gastrin levels after exogenous gastrin 17-I and -II were compared with postprandial gastrin concentrations. The molar potency estimates calculated with synthetic CCK8 as standard for pancreatic protein secretion were natural porcine 50% pure CCK-33 1.60, gastrin 17-I 0.12, and gastrin 17-II 0.16. All four peptides induced a dose-dependent increase in pancreatic bicarbonate output. However, the blood concentrations needed to stimulate pancreatic secretion were above the postprandial gastrin levels. The data indicate that both gastrin 17 peptides are not physiological regulators of pancreatic enzyme secretion in dogs

Adropin – physiological and pathophysiological role

Directory of Open Access Journals (Sweden)

Natalia Marczuk

2016-09-01

Full Text Available Adropin is a peptide hormone that was discovered in 2008 by Kumar et al. This protein consists of 76 amino acids, and it was originally described as a secreted peptide, with residues 1-33 encoding a secretory signal peptide sequence. The amino acid sequence of this protein in humans, mice and rats is identical. While our knowledge of the exact physiological roles of this poorly understood peptide continues to evolve, recent data suggest a role in energy homeostasis and the control of glucose and fatty acid metabolism. This protein is encoded by the Enho gene, which is expressed primarily in the liver and the central nervous system. The regulation of adropin secretion is controversial. Adropin immunoreactivity has been reported by several laboratories in the circulation of humans, non-human primates and rodents. However, more recently it has been suggested that adropin is a membrane-bound protein that modulates cell-cell communication. Moreover, adropin has been detected in various tissues and body fluids, such as brain, cerebellum, liver, kidney, heart, pancreas, small intestine, endothelial cells, colostrum, cheese whey and milk. The protein level, as shown by previous research, changes in various physiological and pathophysiological conditions. Adropin is involved in carbohydrate-lipid metabolism, metabolic diseases, central nervous system function, endothelial function and cardiovascular disease. The knowledge of this interesting protein, its exact role and mechanism of action is insufficient. This article provides an overview of the existing literature about the role of adropin, both in physiological and pathophysiological conditions.

Mechanical properties of electrospun PCL scaffold under in vitro and accelerated degradation conditions

DEFF Research Database (Denmark)

Løvdal, Alexandra Liv Vest; Vange, Jakob; Nielsen, Lene Feldskov

2014-01-01

Within recent years, researchers have looked into using polycaprolactone (PCL) as a synthetic biodegradable scaffold for tissue engineering purposes. This study investigated the mechanical properties of an electrospun PCL, while being exposed to physiological fluids at 37C (in vitro conditions) w...... in buffer (pH 12). The accelerated study showed a linear decrease in both elastic modulus and yield stress as a function of degradation time....

Models for synthetic biology.

Science.gov (United States)

Kaznessis, Yiannis N

2007-11-06

Synthetic biological engineering is emerging from biology as a distinct discipline based on quantification. The technologies propelling synthetic biology are not new, nor is the concept of designing novel biological molecules. What is new is the emphasis on system behavior. The objective is the design and construction of new biological devices and systems to deliver useful applications. Numerous synthetic gene circuits have been created in the past decade, including bistable switches, oscillators, and logic gates, and possible applications abound, including biofuels, detectors for biochemical and chemical weapons, disease diagnosis, and gene therapies. More than fifty years after the discovery of the molecular structure of DNA, molecular biology is mature enough for real quantification that is useful for biological engineering applications, similar to the revolution in modeling in chemistry in the 1950s. With the excitement that synthetic biology is generating, the engineering and biological science communities appear remarkably willing to cross disciplinary boundaries toward a common goal.

Lower body negative pressure as a tool for research in aerospace physiology and military medicine

Science.gov (United States)

Convertino, V. A.

2001-01-01

Lower body negative pressure (LBNP) has been extensively used for decades in aerospace physiological research as a tool to investigate cardiovascular mechanisms that are associated with or underlie performance in aerospace and military environments. In comparison with clinical stand and tilt tests, LBNP represents a relatively safe methodology for inducing highly reproducible hemodynamic responses during exposure to footward fluid shifts similar to those experienced under orthostatic challenge. By maintaining an orthostatic challenge in a supine posture, removal of leg support (muscle pump) and head motion (vestibular stimuli) during LBNP provides the capability to isolate cardiovascular mechanisms that regulate blood pressure. LBNP can be used for physiological measurements, clinical diagnoses and investigational research comparisons of subject populations and alterations in physiological status. The applications of LBNP to the study of blood pressure regulation in spaceflight, groundbased simulations of low gravity, and hemorrhage have provided unique insights and understanding for development of countermeasures based on physiological mechanisms underlying the operational problems.

Modeling Fluid Flow in Faulted Basins

Directory of Open Access Journals (Sweden)

Faille I.

2014-07-01

Full Text Available This paper presents a basin simulator designed to better take faults into account, either as conduits or as barriers to fluid flow. It computes hydrocarbon generation, fluid flow and heat transfer on the 4D (space and time geometry obtained by 3D volume restoration. Contrary to classical basin simulators, this calculator does not require a structured mesh based on vertical pillars nor a multi-block structure associated to the fault network. The mesh follows the sediments during the evolution of the basin. It deforms continuously with respect to time to account for sedimentation, erosion, compaction and kinematic displacements. The simulation domain is structured in layers, in order to handle properly the corresponding heterogeneities and to follow the sedimentation processes (thickening of the layers. In each layer, the mesh is unstructured: it may include several types of cells such as tetrahedra, hexahedra, pyramid, prism, etc. However, a mesh composed mainly of hexahedra is preferred as they are well suited to the layered structure of the basin. Faults are handled as internal boundaries across which the mesh is non-matching. Different models are proposed for fault behavior such as impervious fault, flow across fault or conductive fault. The calculator is based on a cell centered Finite Volume discretisation, which ensures conservation of physical quantities (mass of fluid, heat at a discrete level and which accounts properly for heterogeneities. The numerical scheme handles the non matching meshes and guaranties appropriate connection of cells across faults. Results on a synthetic basin demonstrate the capabilities of this new simulator.

Corynebacterium glutamicum for Sustainable Bioproduction: From Metabolic Physiology to Systems Metabolic Engineering.

Science.gov (United States)

Becker, Judith; Gießelmann, Gideon; Hoffmann, Sarah Lisa; Wittmann, Christoph

Since its discovery 60 years ago, Corynebacterium glutamicum has evolved into a workhorse for industrial biotechnology. Traditionally well known for its remarkable capacity to produce amino acids, this Gram-positive soil bacterium, has become a flexible, efficient production platform for various bulk and fine chemicals, materials, and biofuels. The central turnstile of all these achievements is our excellent understanding of its metabolism and physiology. This knowledge base, together with innovative systems metabolic engineering concepts, which integrate systems and synthetic biology into strain engineering, has upgraded C. glutamicum into one of the most successful industrial microorganisms in the world.

Physiological system integrations with emphasis on the respiratory-cardiovascular system

Science.gov (United States)

Gallagher, R. R.

1975-01-01

The integration of two types of physiological system simulations is presented. The long term model is a circulatory system model which simulates long term blood flow variations and compartmental fluid shifts. The short term models simulate transient phenomena of the respiratory, thermoregulatory, and pulsatile cardiovascular systems as they respond to stimuli such as LBNP, exercise, and environmental gaseous variations. An overview of the interfacing approach is described. Descriptions of the variable interface for long term to short term and between the three short term models are given.

The emergence of Applied Physiology within the discipline of Physiology.

Science.gov (United States)

Tipton, Charles M

2016-08-01

Despite the availability and utilization of the physiology textbooks authored by Albrecht von Haller during the 18th century that heralded the modern age of physiology, not all physicians or physiologists were satisfied with its presentation, contents, or application to medicine. Initial reasons were fundamental disagreements between the "mechanists," represented by Boerhaave, Robinson, and von Haller, and the "vitalists," represented by the faculty and graduates of the Montpellier School of Medicine in France, notably, Bordeu and Barthez. Subsequently, objections originated from Europe, United Kingdom, and the United States in publications that focused not only on the teaching of physiology to medical and secondary students, but on the specific applications of the content of physiology to medicine, health, hygiene, pathology, and chronic diseases. At the turn of the 20th century, texts began to appear with applied physiology in their titles and in 1926, physician Samson Wright published a textbook entitled Applied Physiology that was intended for both medical students and the medical profession. Eleven years later, physicians Best and Taylor published The Physiological Basis of Medical Practice: A University of Toronto Texbook in Applied Physiology Although both sets of authors defined the connection between applied physiology and physiology, they failed to define the areas of physiology that were included within applied physiology. This was accomplished by the American Physiological Society (APS) Publications Committee in 1948 with the publication of the Journal of Appplied Physiology, that stated the word "applied" would broadly denote human physiology whereas the terms stress and environment would broadly include work, exercise, plus industrial, climatic and social factors. NIH established a study section (SS) devoted to applied physiology in 1964 which remained active until 2001 when it became amalgamated into other SSs. Before the end of the 20th century when

Electrical Conductivity Distributions in Discrete Fluid-Filled Fractures

Science.gov (United States)

James, S. C.; Ahmmed, B.; Knox, H. A.; Johnson, T.; Dunbar, J. A.

2017-12-01

It is commonly asserted that hydraulic fracturing enhances permeability by generating new fractures in the reservoir. Furthermore, it is assumed that in the fractured system predominant flow occurs in these newly formed and pre-existing fractures. Among the phenomenology that remains enigmatic are fluid distributions inside fractures. Therefore, determining fluid distribution and their associated temporal and spatial evolution in fractures is critical for safe and efficient hydraulic fracturing. Previous studies have used both forward modeling and inversion of electrical data to show that a geologic system consisting of fluid filled fractures has a conductivity distribution, where fractures act as electrically conductive bodies when the fluids are more conductive than the host material. We will use electrical inversion for estimating electrical conductivity distribution within multiple fractures from synthetic and measured data. Specifically, we will use data and well geometries from an experiment performed at Blue Canyon Dome in Socorro, NM, which was used as a study site for subsurface technology, engineering, and research (SubTER) funded by DOE. This project used a central borehole for energetically stimulating the system and four monitoring boreholes, emplaced in the cardinal directions. The electrical data taken during this project used 16 temporary electrodes deployed in the stimulation borehole and 64 permanent electrodes in the monitoring wells (16 each). We present results derived using E4D from scenarios with two discrete fractures, thereby discovering the electric potential response of both spatially and temporarily variant fluid distribution and the resolution of fluid and fracture boundaries. These two fractures have dimensions of 3m × 0.01m × 7m and are separated by 1m. These results can be used to develop stimulation and flow tests at the meso-scale that will be important for model validation. Sandia National Laboratories is a multi

Steroid hormones content and proteomic analysis of canine follicular fluid during the preovulatory period

Directory of Open Access Journals (Sweden)

Reynaud Karine

2010-11-01

Full Text Available Abstract Background Follicular fluid contains substances involved in follicle activity, cell differentiation and oocyte maturation. Studies of its components may contribute to better understanding of the mechanisms underlying follicular development and oocyte quality. The canine species is characterized by several ovarian activity features that are not extensively described such as preovulatory luteinization, oocyte ovulated at the GV stage (prophase 1 and poly-oocytic follicles. In this study, we examined the hypothesis that the preovulatory LH surge is associated with changes in steroid and protein content of canine follicular fluid prior to ovulation. Methods Follicular fluid samples were collected from canine ovaries during the preovulatory phase, before (pre-LH; n = 16 bitches and after (post-LH; n = 16 the LH surge. Blood was simultaneously collected. Steroids were assayed by radioimmunoassay and proteomic analyses were carried out by 2D-PAGE and mass spectrometry. Results The concentrations of 17beta-estradiol and progesterone at the pre-LH stage were 737.2 +/- 43.5 ng/ml and 2630.1 +/- 287.2 ng/ml in follicular fluid vs. 53 +/- 4.1 pg/ml and 3.9 +/- 0.3 ng/ml in plasma, respectively. At that stage, significant positive correlations between follicular size and intra-follicular steroid concentrations were recorded. After the LH peak, the intrafollicular concentration of 17beta-estradiol decreased significantly (48.3 +/- 4.4 ng/ml; p Proteomic analysis of canine follicular fluid identified 38 protein spots, corresponding to 21 proteins, some of which are known to play roles in the ovarian physiology. The comparison of 2D-PAGE patterns of follicular fluids from the pre- and post-LH stages demonstrated 3 differentially stained single spot or groups of spots. One of them was identified as complement factor B. A comparison of follicular fluid and plasma protein patterns demonstrated a group of 4 spots that were more concentrated in plasma than

Smolt physiology and endocrinology

Science.gov (United States)

McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

2013-01-01

Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

A study of unsteady physiological magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping.

Science.gov (United States)

Tripathi, Dharmendra; Bég, O Anwar

2012-08-01

Magnetohydrodynamic peristaltic flows arise in controlled magnetic drug targeting, hybrid haemodynamic pumps and biomagnetic phenomena interacting with the human digestive system. Motivated by the objective of improving an understanding of the complex fluid dynamics in such flows, we consider in the present article the transient magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping. Reynolds number is small enough and the wavelength to diameter ratio is large enough to negate inertial effects. Analytical solutions for temperature field, axial velocity, transverse velocity, pressure gradient, local wall shear stress, volume flowrate and averaged volume flowrate are obtained. The effects of the transverse magnetic field, Grashof number and thermal conductivity on the flow patterns induced by peristaltic waves (sinusoidal propagation along the length of channel) are studied using graphical plots. The present study identifies that greater pressure is required to propel the magneto-fluid by peristaltic pumping in comparison to a non-conducting Newtonian fluid, whereas, a lower pressure is required if heat transfer is effective. The analytical solutions further provide an important benchmark for future numerical simulations.

COMPARISON OF REACTIVITY OF SYNTHETIC AND BOVINE HYDROXYAPATITE IN VITRO UNDER DYNAMIC CONDITIONS

Directory of Open Access Journals (Sweden)

DIANA HORKAVCOVÁ

2014-03-01

Full Text Available Hydroxyapatite materials prepared by two methods: synthetic (HA–S and bovine (HA-B granules were exposed to a longterm in vitro test under dynamic conditions. Testing cells, filled up to one fourth (¼V of their volume with the tested material, were exposed to continuous flow of simulated body fluid (SBF for 56 days. The objective of the experiment was to determine whether reactivity of the biomaterials (hydroxyapatites, prepared by different methods but identical in terms of their chemical and phase composition, in SBF were comparable. Analyses of the solutions proved that both materials were highly reactive from the very beginning of interaction with SBF (significant decrease of Ca2+ and (PO43- concentrations in the leachate. SEM/EDS images have shown that the surface of bovine HA-B was covered with a new hydroxyapatite (HAp phase in the first two weeks of the test while synthetic HA–S was covered after two weeks of the immersion in SBF. At the end of the test, day 56, both materials were completely covered with well developed porous HAp phase in form of nano-plates. A calculation of the rate of HAp formation from the concentration of (PO43- ions in SBF leachates confirmed that all removed ions were consumed for the formation of the HAp phase throughout the entire testing time for bovine HA–B and only during the second half of the testing time for synthetic HA–S.

Meeting Report: Synthetic Biology Jamboree for Undergraduates

Science.gov (United States)

Campbell, A. Malcolm

2005-01-01

The field of synthetic biology (the name is derived from an analogy to synthetic chemistry) has recognized itself as a "field" only since about 2002. Synthetic biology has gotten some high-profile attention recently, but most people are not aware the field even exists. Synthetic biologists apply engineering principles to genomic circuits to…

21 CFR 73.1200 - Synthetic iron oxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Synthetic iron oxide. 73.1200 Section 73.1200 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any combination of synthetically prepared...

21 CFR 73.200 - Synthetic iron oxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Synthetic iron oxide. 73.200 Section 73.200 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.200 Synthetic iron oxide. (a) Identity. (1) The color additive synthetic iron oxide consists of any one or any combination of synthetically prepared...

21 CFR 172.888 - Synthetic petroleum wax.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic petroleum wax. 172.888 Section 172.888... CONSUMPTION Multipurpose Additives § 172.888 Synthetic petroleum wax. Synthetic petroleum wax may be safely used in or on foods in accordance with the following conditions: (a) Synthetic petroleum wax is a...

Modification of the protein corona–nanoparticle complex by physiological factors

Energy Technology Data Exchange (ETDEWEB)

Braun, Nicholas J.; DeBrosse, Madeleine C.; Hussain, Saber M. [Molecular Bioeffects Branch, Bioeffects Division, Human Effectiveness Directorate, 711 Human Performance Wing, Air Force Research Laboratory, Wright Patterson AFB, 2729 R. St, Bldg 837, Dayton, OH, 45433 (United States); Comfort, Kristen K., E-mail: kcomfort1@udayton.edu [Department of Chemical and Materials Engineering, University of Dayton, 524 Kettering Laboratories, 300 College Park, Dayton, OH 45469 (United States)

2016-07-01

Nanoparticle (NP) effects in a biological system are driven through the formation and structure of the protein corona–NP complex, which is dynamic by nature and dependent upon factors from both the local environment and NP physicochemical parameters. To date, considerable data has been gathered regarding the structure and behavior of the protein corona in blood, plasma, and traditional cell culture medium. However, there exists a knowledge gap pertaining to the protein corona in additional biological fluids and following incubation in a dynamic environment. Using 13 nm gold NPs (AuNPs), functionalized with either polyethylene glycol or tannic acid, we demonstrated that both particle characteristics and the associated protein corona were altered when exposed to artificial physiological fluids and under dynamic flow. Furthermore, the magnitude of observed behavioral shifts were dependent upon AuNP surface chemistry. Lastly, we revealed that exposure to interstitial fluid produced protein corona modifications, reshaping of the nano-cellular interface, modified AuNP dosimetry, and induction of previously unseen cytotoxicity. This study highlights the need to elucidate both NP and protein corona behavior in biologically representative environments in an effort to increase accurate interpretation of data and transfer of this knowledge to efficacy, behavior, and safety of nano-based applications. - Highlights: • Dynamic flow increased the size of the gold nanoparticle protein corona. • Exposure to biological fluids altered protein corona size and composition. • Interstitial fluid modified the nano-cellular interface and deposition efficiency. • Tannic acid coated nanoparticles induced toxicity in an interstitial environment.

Modification of the protein corona–nanoparticle complex by physiological factors

International Nuclear Information System (INIS)

Braun, Nicholas J.; DeBrosse, Madeleine C.; Hussain, Saber M.; Comfort, Kristen K.

2016-01-01

Nanoparticle (NP) effects in a biological system are driven through the formation and structure of the protein corona–NP complex, which is dynamic by nature and dependent upon factors from both the local environment and NP physicochemical parameters. To date, considerable data has been gathered regarding the structure and behavior of the protein corona in blood, plasma, and traditional cell culture medium. However, there exists a knowledge gap pertaining to the protein corona in additional biological fluids and following incubation in a dynamic environment. Using 13 nm gold NPs (AuNPs), functionalized with either polyethylene glycol or tannic acid, we demonstrated that both particle characteristics and the associated protein corona were altered when exposed to artificial physiological fluids and under dynamic flow. Furthermore, the magnitude of observed behavioral shifts were dependent upon AuNP surface chemistry. Lastly, we revealed that exposure to interstitial fluid produced protein corona modifications, reshaping of the nano-cellular interface, modified AuNP dosimetry, and induction of previously unseen cytotoxicity. This study highlights the need to elucidate both NP and protein corona behavior in biologically representative environments in an effort to increase accurate interpretation of data and transfer of this knowledge to efficacy, behavior, and safety of nano-based applications. - Highlights: • Dynamic flow increased the size of the gold nanoparticle protein corona. • Exposure to biological fluids altered protein corona size and composition. • Interstitial fluid modified the nano-cellular interface and deposition efficiency. • Tannic acid coated nanoparticles induced toxicity in an interstitial environment.

Regulation of tumor invasion by interstitial fluid flow

International Nuclear Information System (INIS)

Shieh, Adrian C; Swartz, Melody A

2011-01-01

The importance of the tumor microenvironment in cancer progression is undisputed, yet the significance of biophysical forces in the microenvironment remains poorly understood. Interstitial fluid flow is a nearly ubiquitous and physiologically relevant biophysical force that is elevated in tumors because of tumor-associated angiogenesis and lymphangiogenesis, as well as changes in the tumor stroma. Not only does it apply physical forces to cells directly, but interstitial flow also creates gradients of soluble signals in the tumor microenvironment, thus influencing cell behavior and modulating cell–cell interactions. In this paper, we highlight our current understanding of interstitial fluid flow in the context of the tumor, focusing on the physical changes that lead to elevated interstitial flow, how cells sense flow and how they respond to changes in interstitial flow. In particular, we emphasize that interstitial flow can directly promote tumor cell invasion through a mechanism known as autologous chemotaxis, and indirectly support tumor invasion via both biophysical and biochemical cues generated by stromal cells. Thus, interstitial fluid flow demonstrates how important biophysical factors are in cancer, both by modulating cell behavior and coupling biophysical and biochemical signals

Synthetic biology: programming cells for biomedical applications.

Science.gov (United States)

Hörner, Maximilian; Reischmann, Nadine; Weber, Wilfried

2012-01-01

The emerging field of synthetic biology is a novel biological discipline at the interface between traditional biology, chemistry, and engineering sciences. Synthetic biology aims at the rational design of complex synthetic biological devices and systems with desired properties by combining compatible, modular biological parts in a systematic manner. While the first engineered systems were mainly proof-of-principle studies to demonstrate the power of the modular engineering approach of synthetic biology, subsequent systems focus on applications in the health, environmental, and energy sectors. This review describes recent approaches for biomedical applications that were developed along the synthetic biology design hierarchy, at the level of individual parts, of devices, and of complex multicellular systems. It describes how synthetic biological parts can be used for the synthesis of drug-delivery tools, how synthetic biological devices can facilitate the discovery of novel drugs, and how multicellular synthetic ecosystems can give insight into population dynamics of parasites and hosts. These examples demonstrate how this new discipline could contribute to novel solutions in the biopharmaceutical industry.

Role of Synthetic and Dimensional Synthetic Organic Chemistry in Block Copolymer Micelle Nanosensor Engineering

DEFF Research Database (Denmark)

Ek, Pramod Kumar

This thesis investigated the role of amphiphilic triblock copolymer micelle nanomaterials in nanosensors, with emphasis on the synthesis of micelle particle sensors. The thesis is focused on the role of synthetic and dimensional synthetic organic chemistry in amphiphilic triblock core-shellcorona...

Origin of estradiol fatty acid esters in human ovarian follicular fluid.

Science.gov (United States)

Pahuja, S L; Kim, A H; Lee, G; Hochberg, R B

1995-03-01

The estradiol fatty acid esters are the most potent of the naturally occurring steroidal estrogens. These esters are present predominantly in fat, where they are sequestered until they are hydrolyzed by esterases. Thus they act as a preformed reservoir of estradiol. We have previously shown that ovarian follicular fluid from patients undergoing gonadotropin stimulation contains very high amounts of estradiol fatty acid esters (approximately 10(-7) M). The source of these esters is unknown. They can be formed by esterification of estradiol in the follicular fluid by lecithin:cholesterol acyltransferase (LCAT), or in the ovary by an acyl coenzyme A:acyltransferase. In order to determine which of these enzymatic processes is the source of the estradiol esters in the follicular fluid, we incubated [3H]estradiol with follicular fluid and cells isolated from human ovarian follicular fluid and characterized the fatty acid composition of the [3H]estradiol esters biosynthesized in each. In addition, we characterized the endogenous estradiol fatty acid esters in the follicular fluid and compared them to the biosynthetic esters. The fatty acid composition of the endogenous esters was different than those synthesized by the cellular acyl coenzyme A:acyltransferase, and the same as the esters synthesized by LCAT, demonstrating that the esters are produced in situ in the follicular fluid. Although the role of these estradiol esters in the ovary is not known, given their remarkable estrogenic potency it is highly probable that they have an important physiological role.

The tribological behaviour of different clearance MOM hip joints with lubricants of physiological viscosities.

Science.gov (United States)

Hu, X Q; Wood, R J K; Taylor, A; Tuke, M A

2011-11-01

Clearance is one of the most influential parameters on the tribological performance of metal-on-metal (MOM) hip joints and its selection is a subject of considerable debate. The objective of this paper is to study the lubrication behaviour of different clearances for MOM hip joints within the range of human physiological and pathological fluid viscosities. The frictional torques developed by MOM hip joints with a 50 mm diameter were measured for both virgin surfaces and during a wear simulator test. Joints were manufactured with three different diametral clearances: 20, 100, and 200 microm. The fluid used for the friction measurements which contained different ratios of 25 percent newborn calf serum and carboxymethyl cellulose (CMC) with the obtained viscosities values ranging from 0.001 to 0.71 Pa s. The obtained results indicate that the frictional torque for the 20 microm clearance joint remains high over the whole range of the viscosity values. The frictional torque of the 100 microm clearance joint was low for the very low viscosity (0.001 Pa s) lubricant, but increased with increasing viscosity value. The frictional torque of the 200 microm clearance joint was high at very low viscosity levels, however, it reduced with increasing viscosity. It is concluded that a smaller clearance level can enhance the formation of an elastohydrodynamic lubrication (EHL) film, but this is at the cost of preventing fluid recovery between the bearing surfaces during the unloaded phase of walking. Larger clearance bearings allow a better recovery of lubricant during the unloaded phase, which is necessary for higher viscosity lubricants. The selection of the clearance value should therefore consider both the formation of the EHL film and the fluid recovery as a function of the physiological viscosity in order to get an optimal tribological performance for MOM hip joints. The application of either 25 per cent bovine serum or water in existing in vitro tribological study should

Word selection affects perceptions of synthetic biology

Directory of Open Access Journals (Sweden)

Tonidandel Scott

2011-07-01

Full Text Available Abstract Members of the synthetic biology community have discussed the significance of word selection when describing synthetic biology to the general public. In particular, many leaders proposed the word "create" was laden with negative connotations. We found that word choice and framing does affect public perception of synthetic biology. In a controlled experiment, participants perceived synthetic biology more negatively when "create" was used to describe the field compared to "construct" (p = 0.008. Contrary to popular opinion among synthetic biologists, however, low religiosity individuals were more influenced negatively by the framing manipulation than high religiosity people. Our results suggest that synthetic biologists directly influence public perception of their field through avoidance of the word "create".

Fluid Circulation Determined in the Isolated Bovine Lens

Science.gov (United States)

Candia, Oscar A.; Mathias, Richard; Gerometta, Rosana

2012-01-01

Purpose. In 1997, a theoretical model was developed that predicted the existence of an internal, Na+-driven fluid circulation from the poles to the equator of the lens. In the present work, we demonstrate with a novel system that fluid movement can be measured across the polar and equatorial surface areas of isolated cow lenses. We have also determined the effects of ouabain and reduced bath [Na+]. Methods. Lenses were isolated in a chamber with three compartments separated by two thin O-rings. Each compartment, anterior (A), equatorial (E), and posterior (P), was connected to a vertical capillary graduated in 0.25 μL. Capillary levels were read every 15 minutes. The protocols consisted of 2 hours in either open circuit or short circuit. The effects of ouabain and low-Na+ solutions were determined under open circuit. Results. In 21 experiments, the E capillary increased at a mean rate of 0.060 μL/min while the A and P levels decreased at rates of 0.044 and 0.037 μL/min, respectively, closely accounting for the increase in E. The first-hour flows under short circuit were approximately 40% larger than those in open-circuit conditions. The first-hour flows were always larger than those during the second hour. Preincubation of lenses with either ouabain or low-[Na+] solutions resulted in reduced rates of fluid transport. When KCl was used to replace NaCl, a transitory stimulation of fluid transport occurred. Conclusions. These experiments support that a fluid circulation consistent with the 1997 model is physiologically active. PMID:22969071

Numerical Cerebrospinal System Modeling in Fluid-Structure Interaction.

Science.gov (United States)

Garnotel, Simon; Salmon, Stéphanie; Balédent, Olivier

2018-01-01

Cerebrospinal fluid (CSF) stroke volume in the aqueduct is widely used to evaluate CSF dynamics disorders. In a healthy population, aqueduct stroke volume represents around 10% of the spinal stroke volume while intracranial subarachnoid space stroke volume represents 90%. The amplitude of the CSF oscillations through the different compartments of the cerebrospinal system is a function of the geometry and the compliances of each compartment, but we suspect that it could also be impacted be the cardiac cycle frequency. To study this CSF distribution, we have developed a numerical model of the cerebrospinal system taking into account cerebral ventricles, intracranial subarachnoid spaces, spinal canal and brain tissue in fluid-structure interactions. A numerical fluid-structure interaction model is implemented using a finite-element method library to model the cerebrospinal system and its interaction with the brain based on fluid mechanics equations and linear elasticity equations coupled in a monolithic formulation. The model geometry, simplified in a first approach, is designed in accordance with realistic volume ratios of the different compartments: a thin tube is used to mimic the high flow resistance of the aqueduct. CSF velocity and pressure and brain displacements are obtained as simulation results, and CSF flow and stroke volume are calculated from these results. Simulation results show a significant variability of aqueduct stroke volume and intracranial subarachnoid space stroke volume in the physiological range of cardiac frequencies. Fluid-structure interactions are numerous in the cerebrospinal system and difficult to understand in the rigid skull. The presented model highlights significant variations of stroke volumes under cardiac frequency variations only.

Fluid migration through geo-membrane seams and through the interface between geo-membrane and geo-synthetic clay liner

International Nuclear Information System (INIS)

Barroso, M.

2005-03-01

Composite liners are used to limit the contamination migration from landfills. Their successful performance is closely related with the geo-membrane as it provides the primary barrier to diffusive and advective transport of contaminants. Critical issues on the performance of the geo-membranes are the seams between geo-membrane panels and the inevitable defects resulting, for instance, from inadequate installation activities. In landfills, where high density polyethylene geo-membranes are usually used, seams are typically made by the thermal-hot dual wedge method. A literature review on quality control of the seams showed that, in situ, fluid-tightness of seams is evaluated in qualitative terms (pass/failure criteria), despite their importance to ensure appropriate performance of the geo-membranes as barriers. In addition, a synthesis of studies on geo-membrane defects indicated that defects varying in density from 0.7 to 15.3 per hectare can be found in landfills. Defects represent preferential flow paths for leachate. Various authors have developed analytical solutions and empirical equations for predicting the flow rate through composite liners due to defects in the geo-membrane. The validity of these methods for composite liners comprising a geo-membrane over a geo-synthetic clay liner (GCL) over a compacted clay liner (CCL) has never been studied from an experimental point of view. To address the problem of fluid migration through the geo-membrane seams, an attempt is made to provide a test method, herein termed as 'gas permeation pouch test', for assessing the quality of the thermal-hot dual wedge seams. This test consists of pressurizing the air channel formed by the double seam with a gas to a specific pressure and, then, measuring the decrease in pressure over time. From the pressure decrease, both the gas permeation coefficients, in steady state conditions, and the time constant, in unsteady state conditions, can be estimated. Experiments were carried out

Estimating physiological skin parameters from hyperspectral signatures

Science.gov (United States)

Vyas, Saurabh; Banerjee, Amit; Burlina, Philippe

2013-05-01

We describe an approach for estimating human skin parameters, such as melanosome concentration, collagen concentration, oxygen saturation, and blood volume, using hyperspectral radiometric measurements (signatures) obtained from in vivo skin. We use a computational model based on Kubelka-Munk theory and the Fresnel equations. This model forward maps the skin parameters to a corresponding multiband reflectance spectra. Machine-learning-based regression is used to generate the inverse map, and hence estimate skin parameters from hyperspectral signatures. We test our methods using synthetic and in vivo skin signatures obtained in the visible through the short wave infrared domains from 24 patients of both genders and Caucasian, Asian, and African American ethnicities. Performance validation shows promising results: good agreement with the ground truth and well-established physiological precepts. These methods have potential use in the characterization of skin abnormalities and in minimally-invasive prescreening of malignant skin cancers.

Synthetic Biology for Specialty Chemicals.

Science.gov (United States)

Markham, Kelly A; Alper, Hal S

2015-01-01

In this review, we address recent advances in the field of synthetic biology and describe how those tools have been applied to produce a wide variety of chemicals in microorganisms. Here we classify the expansion of the synthetic biology toolbox into three different categories based on their primary function in strain engineering-for design, for construction, and for optimization. Next, focusing on recent years, we look at how chemicals have been produced using these new synthetic biology tools. Advances in producing fuels are briefly described, followed by a more thorough treatment of commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. Throughout this review, an emphasis is placed on how synthetic biology tools are applied to strain engineering. Finally, we discuss organism and host strain diversity and provide a future outlook in the field.

Mammalian synthetic biology: emerging medical applications.

Science.gov (United States)

Kis, Zoltán; Pereira, Hugo Sant'Ana; Homma, Takayuki; Pedrigi, Ryan M; Krams, Rob

2015-05-06

In this review, we discuss new emerging medical applications of the rapidly evolving field of mammalian synthetic biology. We start with simple mammalian synthetic biological components and move towards more complex and therapy-oriented gene circuits. A comprehensive list of ON-OFF switches, categorized into transcriptional, post-transcriptional, translational and post-translational, is presented in the first sections. Subsequently, Boolean logic gates, synthetic mammalian oscillators and toggle switches will be described. Several synthetic gene networks are further reviewed in the medical applications section, including cancer therapy gene circuits, immuno-regulatory networks, among others. The final sections focus on the applicability of synthetic gene networks to drug discovery, drug delivery, receptor-activating gene circuits and mammalian biomanufacturing processes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Fluid mechanics in fluids at rest.

Science.gov (United States)

Brenner, Howard

2012-07-01

Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

Protease-sensitive synthetic prions.

Directory of Open Access Journals (Sweden)

David W Colby

2010-01-01

Full Text Available Prions arise when the cellular prion protein (PrP(C undergoes a self-propagating conformational change; the resulting infectious conformer is designated PrP(Sc. Frequently, PrP(Sc is protease-resistant but protease-sensitive (s prions have been isolated in humans and other animals. We report here that protease-sensitive, synthetic prions were generated in vitro during polymerization of recombinant (rec PrP into amyloid fibers. In 22 independent experiments, recPrP amyloid preparations, but not recPrP monomers or oligomers, transmitted disease to transgenic mice (n = 164, denoted Tg9949 mice, that overexpress N-terminally truncated PrP. Tg9949 control mice (n = 174 did not spontaneously generate prions although they were prone to late-onset spontaneous neurological dysfunction. When synthetic prion isolates from infected Tg9949 mice were serially transmitted in the same line of mice, they exhibited sPrP(Sc and caused neurodegeneration. Interestingly, these protease-sensitive prions did not shorten the life span of Tg9949 mice despite causing extensive neurodegeneration. We inoculated three synthetic prion isolates into Tg4053 mice that overexpress full-length PrP; Tg4053 mice are not prone to developing spontaneous neurological dysfunction. The synthetic prion isolates caused disease in 600-750 days in Tg4053 mice, which exhibited sPrP(Sc. These novel synthetic prions demonstrate that conformational changes in wild-type PrP can produce mouse prions composed exclusively of sPrP(Sc.

Caffeine Inhibits Fluid Secretion by Interlobular Ducts From Guinea Pig Pancreas.

Science.gov (United States)

Mochimaru, Yuka; Yamamoto, Akiko; Nakakuki, Miyuki; Yamaguchi, Makoto; Taniguchi, Ituka; Ishiguro, Hiroshi

2017-04-01

Caffeine is contained in coffee, tea, and numerous beverages and foods. We examined the direct effects of caffeine on the physiological function of pancreatic duct cells by using interlobular duct segments isolated from guinea pig pancreas. The rate of fluid secretion was continuously measured by monitoring the luminal volume of isolated duct segments. Changes in intracellular Ca concentration ([Ca]i) were estimated by microfluorometry in ducts loaded with Fura-2. Both secretin-stimulated and acetylcholine (ACh)-stimulated fluid secretions were substantially and reversibly inhibited by relatively low concentrations of caffeine as low as 0.03 mM relevant to blood levels after ingestion of caffeine-containing beverages. Caffeine inhibited ACh-induced elevation of [Ca]i and secretin-induced fluctuation of [Ca]i. Caffeine abolished thapsigargin-induced intracellular Ca release but did not affect the entry of extracellular Ca. Caffeine (0.05 mM) abolished ethanol (1 mM)-induced fluid hypersecretion in secretin-stimulated pancreatic duct. Low concentrations of caffeine directly inhibit pancreatic ductal fluid secretion stimulated by secretin or ACh and also ethanol-induced fluid hypersecretion. The inhibition by caffeine seems to be mediated by the blockade of intracellular Ca mobilization. Daily intake of caffeine may reduce the volume of pancreatic juice secretion.

ADEQUATE UV EXPOSURES FOR HEALTHY LIFE: IN SITU MONITORING AND MODEL CALCULATION OF THE VITAMIN-D-SYNTHETIC CAPACITY OF SUNLIGHT

Directory of Open Access Journals (Sweden)

Irina Terenetskaya

2012-06-01

Full Text Available Vitamin D which is formed upon UV solar radiation in human skin is essential in many physiological functions. To estimate beneficial vitamin-D-synthetic capacity of sunlight a bio-equivalent UV dosimeter that is based on the same molecular photochemistry from which vitamin D is photosynthesized in human skin has been developed. The examples of an in situ monitoring of the vitamin-D-synthetic capacity of sunlight using an in vitro model of vitamin D synthesis are presented, and various operational principles of the UV biodosimeter are discussed. In addition, reliable algorithm is presented for direct calculation of previtamin D3 accumulation using the photoreaction mathematical model with solar UV spectra as input data. Critical dependence of previtamin D3 accumulation on cloudiness and aerosols is demonstrated.

Solution dynamics of synthetic and natural polyelectrolytes

Science.gov (United States)

Krause, Wendy E.

Polyelectrolytes are abundant in nature and essential to life, and used extensively in industry. This work discussed two polyelectrolytes: sodium poly(2-acrylamido-2-methylpropanesulfonate) (NaPAMS), synthetic polyelectrolyte, and sodium hyaluronate (NaHA), a glycosaminoglycan. Rheological data of NaPAMS solutions of variable chain length and concentration were reported. A strong dependence of viscosity eta on chain length: eta ˜ M2.4 was found. The comparison of the rheological data with two proposed scaling theories (Dobrynin 1995, Witten 1987) forces the conclusion that neither theory is correct. A possible interpretation of the viscosity data falling between the predictions of the two scaling theories is that some chain rigidity may persist beyond the correlation length. A sample model for the conductivity of semidilute polyelectrolytes with no added salt was presented. The model correctly describes the logarithmic decrease of specific conductance observed for many polyelectrolytes at low concentration (below ca. 10-2M), and is in good agreement with data from NaPAMS solutions. NaHA in phosphate buffered saline behaves as a typical polyelectrolyte in the high-salt limit, as Newtonian viscosities are observed over a wide range of shear rates. There is no evidence of intermolecular hydrogen bonding causing gel formation in NaHA solutions without protein present. The viscosity of 3 mg/mL NaHA was measured in the presence of the selected anti-inflammatory agents. Of the seven additives investigated only (D)-penicillamine significantly altered the rheology of HA. (D)-Penicillamine dramatically reduced the viscosity of HA, probably by disrupting intramolecular hydrogen bonding. The plasma proteins albumin and gamma-globulins bind to HA in solution to form a weak reversible gel. The rheology and osmotic pressure of the simple model for synovial fluid, consisting of 3mg/mL NaHA, 11 mg/mL albumin, and 7 mg/mL gamma-globulins in phosphate buffered saline, were studied

Synergistic Synthetic Biology: Units in Concert

Science.gov (United States)

Trosset, Jean-Yves; Carbonell, Pablo

2013-01-01

Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications. PMID:25022769

Synergistic Synthetic Biology: Units in Concert

International Nuclear Information System (INIS)

Trosset, Jean-Yves; Carbonell, Pablo

2013-01-01

Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications.

Fast Virtual Fractional Flow Reserve Based Upon Steady-State Computational Fluid Dynamics Analysis: Results From the VIRTU-Fast Study.

Science.gov (United States)

Morris, Paul D; Silva Soto, Daniel Alejandro; Feher, Jeroen F A; Rafiroiu, Dan; Lungu, Angela; Varma, Susheel; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

2017-08-01

Fractional flow reserve (FFR)-guided percutaneous intervention is superior to standard assessment but remains underused. The authors have developed a novel "pseudotransient" analysis protocol for computing virtual fractional flow reserve (vFFR) based upon angiographic images and steady-state computational fluid dynamics. This protocol generates vFFR results in 189 s (cf >24 h for transient analysis) using a desktop PC, with <1% error relative to that of full-transient computational fluid dynamics analysis. Sensitivity analysis demonstrated that physiological lesion significance was influenced less by coronary or lesion anatomy (33%) and more by microvascular physiology (59%). If coronary microvascular resistance can be estimated, vFFR can be accurately computed in less time than it takes to make invasive measurements.

Bioprinting synthetic self-assembling peptide hydrogels for biomedical applications

International Nuclear Information System (INIS)

Loo, Yihua; Hauser, Charlotte A E

2016-01-01

Three-dimensional (3D) bioprinting is a disruptive technology for creating organotypic constructs for high-throughput screening and regenerative medicine. One major challenge is the lack of suitable bioinks. Short synthetic self-assembling peptides are ideal candidates. Several classes of peptides self-assemble into nanofibrous hydrogels resembling the native extracellular matrix. This is a conducive microenvironment for maintaining cell survival and physiological function. Many peptides also demonstrate stimuli-responsive gelation and tuneable mechanical properties, which facilitates extrusion before dispensing and maintains the shape fidelity of the printed construct in aqueous media. The inherent biocompatibility and biodegradability bodes well for in vivo applications as implantable tissues and drug delivery matrices, while their short length and ease of functionalization facilitates synthesis and customization. By applying self-assembling peptide inks to bioprinting, the dynamic complexity of biological tissue can be recreated, thereby advancing current biomedical applications of peptide hydrogel scaffolds. (paper)

Learning from jellyfish: Fluid transport in muscular pumps at intermediate Reynolds numbers

Science.gov (United States)

Nawroth, Janna; Dabiri, John

2010-11-01

Biologically inspired hydrodynamic propulsion and maneuvering strategies promise the advancement of medical implants and minimally invasive clinical tools. We have chosen juvenile jellyfish as a model system for investigating fluid dynamics and morphological properties underlying fluid transport by a muscular pump at intermediate Reynolds numbers. Recently we have described how natural variations in viscous forces are balanced by changes in jellyfish body shape (phenotypic plasticity), to the effect of facilitating efficient body-fluid interaction. Complementing these studies in our live model organisms, we are also engaged in engineering an artificial jellyfish, that is, a jellyfish-inspired construct of a flexible plastic sheet actuated by a monolayer of rat cardiomyocytes. The main challenges here are (1) to derive a body shape and deformation suitable for effective fluid transport under physiological conditions, (2) to understand the mechanical properties of the muscular film and derive a design capable of the desired deformation, (3) to master the proper alignment and timely contraction of the muscle component needed to achieve the desired deformation, and (4) to evaluate the performance of the design.

Control theory meets synthetic biology.

Science.gov (United States)

Del Vecchio, Domitilla; Dy, Aaron J; Qian, Yili

2016-07-01

The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology. © 2016 The Author(s).

Synthetic biology, metaphors and responsibility.

Science.gov (United States)

McLeod, Carmen; Nerlich, Brigitte

2017-08-29

Metaphors are not just decorative rhetorical devices that make speech pretty. They are fundamental tools for thinking about the world and acting on the world. The language we use to make a better world matters; words matter; metaphors matter. Words have consequences - ethical, social and legal ones, as well as political and economic ones. They need to be used 'responsibly'. They also need to be studied carefully - this is what we want to do through this editorial and the related thematic collection. In the context of synthetic biology, natural and social scientists have become increasingly interested in metaphors, a wave of interest that we want to exploit and amplify. We want to build on emerging articles and books on synthetic biology, metaphors of life and the ethical and moral implications of such metaphors. This editorial provides a brief introduction to synthetic biology and responsible innovation, as well as a comprehensive review of literature on the social, cultural and ethical impacts of metaphor use in genomics and synthetic biology. Our aim is to stimulate an interdisciplinary and international discussion on the impact that metaphors can have on science, policy and publics in the context of synthetic biology.

Approaches to chemical synthetic biology.

Science.gov (United States)

Chiarabelli, Cristiano; Stano, Pasquale; Anella, Fabrizio; Carrara, Paolo; Luisi, Pier Luigi

2012-07-16

Synthetic biology is first represented in terms of two complementary aspects, the bio-engineering one, based on the genetic manipulation of extant microbial forms in order to obtain forms of life which do not exist in nature; and the chemical synthetic biology, an approach mostly based on chemical manipulation for the laboratory synthesis of biological structures that do not exist in nature. The paper is mostly devoted to shortly review chemical synthetic biology projects currently carried out in our laboratory. In particular, we describe: the minimal cell project, then the "Never Born Proteins" and lastly the Never Born RNAs. We describe and critically analyze the main results, emphasizing the possible relevance of chemical synthetic biology for the progress in basic science and biotechnology. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Bions: a family of biomimetic mineralo-organic complexes derived from biological fluids.

Directory of Open Access Journals (Sweden)

Cheng-Yeu Wu

Full Text Available Mineralo-organic nanoparticles form spontaneously in human body fluids when the concentrations of calcium and phosphate ions exceed saturation. We have shown previously that these mineralo-organic nanoparticles possess biomimetic properties and can reproduce the whole phenomenology of the so-called nanobacteria-mineralized entities initially described as the smallest microorganisms on earth. Here, we examine the possibility that various charged elements and ions may form mineral nanoparticles with similar properties in biological fluids. Remarkably, all the elements tested, including sodium, magnesium, aluminum, calcium, manganese, iron, cobalt, nickel, copper, zinc, strontium, and barium form mineralo-organic particles with bacteria-like morphologies and other complex shapes following precipitation with phosphate in body fluids. Upon formation, these mineralo-organic particles, which we term bions, invariably accumulate carbonate apatite during incubation in biological fluids; yet, the particles also incorporate additional elements and thus reflect the ionic milieu in which they form. Bions initially harbor an amorphous mineral phase that gradually converts to crystals in culture. Our results show that serum produces a dual inhibition-seeding effect on bion formation. Using a comprehensive proteomic analysis, we identify a wide range of proteins that bind to these mineral particles during incubation in medium containing serum. The two main binding proteins identified, albumin and fetuin-A, act as both inhibitors and seeders of bions in culture. Notably, bions possess several biomimetic properties, including the possibility to increase in size and number and to be sub-cultured in fresh culture medium. Based on these results, we propose that bions represent biological, mineralo-organic particles that may form in the body under both physiological and pathological homeostasis conditions. These mineralo-organic particles may be part of a

Individual Differences in the Temporal Profile of Cardiovascular Responses to Head Down Tilt and Orthostatic Stress with and Without Fluid Loading

Science.gov (United States)

Cowings, Patricia; Toscano, William; Kanis, Dionisios; Gebreyesus, Fiyore

2013-01-01

Susceptibility of healthy astronauts to orthostatic hypotension and presyncope is exacerbated upon return from spaceflight. Hypo-volemia is suspected to play an important role in cardiovascular deconditioning following exposure to spaceflight, which may lead to increased peripheral resistance, attenuated arterial baroreflex, and changes in cardiac function. The effect of altered gravity during space flight and planetary transition on human cardiovascular function is of critical importance to maintenance of astronaut health and safety. A promising countermeasure for post-flight orthostatic intolerance is fluid loading used to restore loss fluid volume by giving crew salt tablets and water prior to re-entry. Eight men and eight women will be tested during two, 6-hour exposures to 6o HDT: 1) fluid loading, 2) no fluid loading. Before and immediately after each HDT, subjects will perform a stand test to assess their orthostatic tolerance. Physiological measures (e.g., ECG, blood pressure, peripheral blood volume) will be continuously monitored while echocardiography measures are recorded at 30-minute intervals during HDT and stand tests. Preliminary results (N=4) clearly show individual differences in responses to this countermeasure and the time course of physiological changes induced by HDT.

Synthetic Aperture Sequential Beamforming

DEFF Research Database (Denmark)

Kortbek, Jacob; Jensen, Jørgen Arendt; Gammelmark, Kim Løkke

2008-01-01

A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective is to im......A synthetic aperture focusing (SAF) technique denoted Synthetic Aperture Sequential Beamforming (SASB) suitable for 2D and 3D imaging is presented. The technique differ from prior art of SAF in the sense that SAF is performed on pre-beamformed data contrary to channel data. The objective...... is to improve and obtain a more range independent lateral resolution compared to conventional dynamic receive focusing (DRF) without compromising frame rate. SASB is a two-stage procedure using two separate beamformers. First a set of Bmode image lines using a single focal point in both transmit and receive...... is stored. The second stage applies the focused image lines from the first stage as input data. The SASB method has been investigated using simulations in Field II and by off-line processing of data acquired with a commercial scanner. The performance of SASB with a static image object is compared with DRF...

Towards a synthetic chloroplast.

Directory of Open Access Journals (Sweden)

Christina M Agapakis

2011-04-01

Full Text Available The evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria, leading to the formation of mitochondria or chloroplasts, respectively. Engineered endosymbiotic relationships between different species of cells are a valuable tool for synthetic biology, where engineered pathways based on two species could take advantage of the unique abilities of each mutualistic partner.We explored the possibility of using the photosynthetic bacterium Synechococcus elongatus PCC 7942 as a platform for studying evolutionary dynamics and for designing two-species synthetic biological systems. We observed that the cyanobacteria were relatively harmless to eukaryotic host cells compared to Escherichia coli when injected into the embryos of zebrafish, Danio rerio, or taken up by mammalian macrophages. In addition, when engineered with invasin from Yersinia pestis and listeriolysin O from Listeria monocytogenes, S. elongatus was able to invade cultured mammalian cells and divide inside macrophages.Our results show that it is possible to engineer photosynthetic bacteria to invade the cytoplasm of mammalian cells for further engineering and applications in synthetic biology. Engineered invasive but non-pathogenic or immunogenic photosynthetic bacteria have great potential as synthetic biological devices.

Nasal Physiology

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... Caregivers Contact ARS HOME ANATOMY Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy Skull Base Anatomy Virtual Anatomy Disclosure ... Patient Education About this Website Font Size + - Home > ANATOMY > Nasal Physiology Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy ...

Fluorescence intensity and lifetime-based cyanide sensitive probes for physiological safeguard

International Nuclear Information System (INIS)

Badugu, Ramachandram; Lakowicz, Joseph R.; Geddes, Chris D.

2004-01-01

We characterize six new fluorescent probes that show both intensity and lifetime changes in the presence of free uncomplexed aqueous cyanide, allowing for fluorescence based cyanide sensing up to physiological safeguard levels, i.e. 2 to the anionic R-B - (CN) 3 form, a new cyanide binding mechanism which we have recently reported. The presence of an electron deficient quaternary heterocyclic nitrogen nucleus, and the electron rich cyanide bound form, provides for the intensity changes observed. We have determined the disassociation constants of the probes to be in the range ∼15-84 μM 3 . In addition we have synthesized control compounds which do not contain the boronic acid moiety, allowing for a rationale of the cyanide responses between the probe isomers to be made. The lifetime of the cyanide bound probes are significantly shorter than the free R-B(OH) 2 probe forms, providing for the opportunity of lifetime based cyanide sensing up to physiologically lethal levels. Finally, while fluorescent probes containing the boronic acid moiety have earned a well-deserved reputation for monosaccharide sensing, we show that strong bases such as CN - and OH - preferentially bind as compared to glucose, enabling the potential use of these probes for cyanide safeguard and determination in physiological fluids, especially given that physiologies do not experience any notable changes in pH

Numerical Simulation of Hemodynamic and Physiological Responses of Human Cardiovascular and Respiratory System under Drugs Administration

Czech Academy of Sciences Publication Activity Database

Převorovská, Světlana; Maršík, František

2004-01-01

Roč. 4, č. 4 (2004), s. 295-304 ISSN 1567-8822 R&D Projects: GA ČR(CZ) GA106/03/1073; GA ČR(CZ) GA106/03/0958 Institutional research plan: CEZ:AV0Z2076919 Keywords : human cardiovascular and respiratory system * baroreflex and chemoreflex control * physiologically based pharmacokinetic model Subject RIV: BK - Fluid Dynamics

Synthetic Biology: Advancing Biological Frontiers by Building Synthetic Systems

OpenAIRE

Chen, Yvonne Yu-Hsuan; Galloway, Kate E; Smolke, Christina D

2012-01-01

Advances in synthetic biology are contributing to diverse research areas, from basic biology to biomanufacturing and disease therapy. We discuss the theoretical foundation, applications, and potential of this emerging field.

Synthetic biology: an emerging engineering discipline.

Science.gov (United States)

Cheng, Allen A; Lu, Timothy K

2012-01-01

Over the past decade, synthetic biology has emerged as an engineering discipline for biological systems. Compared with other substrates, biology poses a unique set of engineering challenges resulting from an incomplete understanding of natural biological systems and tools for manipulating them. To address these challenges, synthetic biology is advancing from developing proof-of-concept designs to focusing on core platforms for rational and high-throughput biological engineering. These platforms span the entire biological design cycle, including DNA construction, parts libraries, computational design tools, and interfaces for manipulating and probing synthetic circuits. The development of these enabling technologies requires an engineering mindset to be applied to biology, with an emphasis on generalizable techniques in addition to application-specific designs. This review aims to discuss the progress and challenges in synthetic biology and to illustrate areas where synthetic biology may impact biomedical engineering and human health.

The characterization of exosomes from biological fluids of patients with different types of cancer

Science.gov (United States)

Yunusova, N. V.; Tamkovich, S. N.; Stakheeva, M. N.; Grigor'eva, A. A.; Somov, A. K.; Tugutova, E. A.; Kolomiets, L. A.; Molchanov, S. V.; Afanas'ev, S. G.; Kakurina, G. V.; Choinzonov, E. L.; Kondakova, I. V.

2017-09-01

Exosomes are extracellular membrane structures involved in many physiological and pathological processes including cancerogenesis and metastasis. The purpose of the study was to isolate, identify and analyze the total content of exosomes in biological fluids. The exosomes from the plasma and ascites samples of the patients with ovarian cancer, from the blood plasma of the patients with colorectal and head and neck squamous cell cancer as well as from the blood plasma of healthy donors were characterized using transmission electron microscopy and flow cytometry. The subpopulations of the exosomes in the biological fluids of the patients with different types of cancer were similar, but the protein concentrations of exosomes were different. In this paper we present the methodological approaches allowing us to obtain high quality exosome preparations from biological fluids.

Computational fluid dynamics analysis of a maglev centrifugal left ventricular assist device.

Science.gov (United States)

Burgreen, Greg W; Loree, Howard M; Bourque, Kevin; Dague, Charles; Poirier, Victor L; Farrar, David; Hampton, Edward; Wu, Z Jon; Gempp, Thomas M; Schöb, Reto

2004-10-01

The fluid dynamics of the Thoratec HeartMate III (Thoratec Corp., Pleasanton, CA, U.S.A.) left ventricular assist device are analyzed over a range of physiological operating conditions. The HeartMate III is a centrifugal flow pump with a magnetically suspended rotor. The complete pump was analyzed using computational fluid dynamics (CFD) analysis and experimental particle imaging flow visualization (PIFV). A comparison of CFD predictions to experimental imaging shows good agreement. Both CFD and experimental PIFV confirmed well-behaved flow fields in the main components of the HeartMate III pump: inlet, volute, and outlet. The HeartMate III is shown to exhibit clean flow features and good surface washing across its entire operating range.

Synthetic peptides for antibody production

NARCIS (Netherlands)

N.D. Zegers (Netty)

1995-01-01

textabstractSynthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps

Synthetic LDL as targeted drug delivery vehicle

Science.gov (United States)

Forte, Trudy M [Berkeley, CA; Nikanjam, Mina [Richmond, CA

2012-08-28

The present invention provides a synthetic LDL nanoparticle comprising a lipid moiety and a synthetic chimeric peptide so as to be capable of binding the LDL receptor. The synthetic LDL nanoparticle of the present invention is capable of incorporating and targeting therapeutics to cells expressing the LDL receptor for diseases associated with the expression of the LDL receptor such as central nervous system diseases. The invention further provides methods of using such synthetic LDL nanoparticles.

Programming languages for synthetic biology.

Science.gov (United States)

Umesh, P; Naveen, F; Rao, Chanchala Uma Maheswara; Nair, Achuthsankar S

2010-12-01

In the backdrop of accelerated efforts for creating synthetic organisms, the nature and scope of an ideal programming language for scripting synthetic organism in-silico has been receiving increasing attention. A few programming languages for synthetic biology capable of defining, constructing, networking, editing and delivering genome scale models of cellular processes have been recently attempted. All these represent important points in a spectrum of possibilities. This paper introduces Kera, a state of the art programming language for synthetic biology which is arguably ahead of similar languages or tools such as GEC, Antimony and GenoCAD. Kera is a full-fledged object oriented programming language which is tempered by biopart rule library named Samhita which captures the knowledge regarding the interaction of genome components and catalytic molecules. Prominent feature of the language are demonstrated through a toy example and the road map for the future development of Kera is also presented.

Multivalent Carbohydrate-Lectin Interactions: How Synthetic Chemistry Enables Insights into Nanometric Recognition

Directory of Open Access Journals (Sweden)

René Roy

2016-05-01

Full Text Available Glycan recognition by sugar receptors (lectins is intimately involved in many aspects of cell physiology. However, the factors explaining the exquisite selectivity of their functional pairing are not yet fully understood. Studies toward this aim will also help appraise the potential for lectin-directed drug design. With the network of adhesion/growth-regulatory galectins as therapeutic targets, the strategy to recruit synthetic chemistry to systematically elucidate structure-activity relationships is outlined, from monovalent compounds to glyco-clusters and glycodendrimers to biomimetic surfaces. The versatility of the synthetic procedures enables to take examining structural and spatial parameters, alone and in combination, to its limits, for example with the aim to produce inhibitors for distinct galectin(s that exhibit minimal reactivity to other members of this group. Shaping spatial architectures similar to glycoconjugate aggregates, microdomains or vesicles provides attractive tools to disclose the often still hidden significance of nanometric aspects of the different modes of lectin design (sequence divergence at the lectin site, differences of spatial type of lectin-site presentation. Of note, testing the effectors alone or in combination simulating (pathophysiological conditions, is sure to bring about new insights into the cooperation between lectins and the regulation of their activity.

Synthetic biology as red herring.

Science.gov (United States)

Preston, Beth

2013-12-01

It has become commonplace to say that with the advent of technologies like synthetic biology the line between artifacts and living organisms, policed by metaphysicians since antiquity, is beginning to blur. But that line began to blur 10,000 years ago when plants and animals were first domesticated; and has been thoroughly blurred at least since agriculture became the dominant human subsistence pattern many millennia ago. Synthetic biology is ultimately only a late and unexceptional offshoot of this prehistoric development. From this perspective, then, synthetic biology is a red herring, distracting us from more thorough philosophical consideration of the most truly revolutionary human practice-agriculture. In the first section of this paper I will make this case with regard to ontology, arguing that synthetic biology crosses no ontological lines that were not crossed already in the Neolithic. In the second section I will construct a parallel case with regard to cognition, arguing that synthetic biology as biological engineering represents no cognitive advance over what was required for domestication and the new agricultural subsistence pattern it grounds. In the final section I will make the case with regard to human existence, arguing that synthetic biology, even if wildly successful, is not in a position to cause significant existential change in what it is to be human over and above the massive existential change caused by the transition to agriculture. I conclude that a longer historical perspective casts new light on some important issues in philosophy of technology and environmental philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

US Competitiveness in Synthetic Biology.

Science.gov (United States)

Gronvall, Gigi Kwik

2015-01-01

Synthetic biology is an emerging technical field that aims to make biology easier to engineer; the field has applications in strategically important sectors for the US economy. While the United States currently leads in synthetic biology R&D, other nations are heavily investing in order to boost their economies, which will inevitably diminish the US leadership position. This outcome is not entirely negative--additional investments will expand markets--but it is critical that the US government take steps to remain competitive: There are applications from which the US population and economy may benefit; there are specific applications with importance for national defense; and US technical leadership will ensure that US experts have a leading role in synthetic biology governance, regulation, and oversight. Measures to increase competitiveness in S&T generally are broadly applicable for synthetic biology and should be pursued. However, the US government will also need to take action on fundamental issues that will affect the field's development, such as countering anti-GMO (genetically modified organism) sentiments and anti-GMO legislation. The United States should maintain its regulatory approach so that it is the product that is regulated, not the method used to create a product. At the same time, the United States needs to ensure that the regulatory framework is updated so that synthetic biology products do not fall into regulatory gaps. Finally, the United States needs to pay close attention to how synthetic biology applications may be governed internationally, such as through the Nagoya Protocol of the Convention on Biological Diversity, so that beneficial applications may be realized.

Synthetic Biology: Mapping the Scientific Landscape

Science.gov (United States)

Oldham, Paul; Hall, Stephen; Burton, Geoff

2012-01-01

This article uses data from Thomson Reuters Web of Science to map and analyse the scientific landscape for synthetic biology. The article draws on recent advances in data visualisation and analytics with the aim of informing upcoming international policy debates on the governance of synthetic biology by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) of the United Nations Convention on Biological Diversity. We use mapping techniques to identify how synthetic biology can best be understood and the range of institutions, researchers and funding agencies involved. Debates under the Convention are likely to focus on a possible moratorium on the field release of synthetic organisms, cells or genomes. Based on the empirical evidence we propose that guidance could be provided to funding agencies to respect the letter and spirit of the Convention on Biological Diversity in making research investments. Building on the recommendations of the United States Presidential Commission for the Study of Bioethical Issues we demonstrate that it is possible to promote independent and transparent monitoring of developments in synthetic biology using modern information tools. In particular, public and policy understanding and engagement with synthetic biology can be enhanced through the use of online interactive tools. As a step forward in this process we make existing data on the scientific literature on synthetic biology available in an online interactive workbook so that researchers, policy makers and civil society can explore the data and draw conclusions for themselves. PMID:22539946

Computer simulation of preflight blood volume reduction as a countermeasure to fluid shifts in space flight

Science.gov (United States)

Simanonok, K. E.; Srinivasan, R.; Charles, J. B.

1992-01-01

Fluid shifts in weightlessness may cause a central volume expansion, activating reflexes to reduce the blood volume. Computer simulation was used to test the hypothesis that preadaptation of the blood volume prior to exposure to weightlessness could counteract the central volume expansion due to fluid shifts and thereby attenuate the circulatory and renal responses resulting in large losses of fluid from body water compartments. The Guyton Model of Fluid, Electrolyte, and Circulatory Regulation was modified to simulate the six degree head down tilt that is frequently use as an experimental analog of weightlessness in bedrest studies. Simulation results show that preadaptation of the blood volume by a procedure resembling a blood donation immediately before head down bedrest is beneficial in damping the physiologic responses to fluid shifts and reducing body fluid losses. After ten hours of head down tilt, blood volume after preadaptation is higher than control for 20 to 30 days of bedrest. Preadaptation also produces potentially beneficial higher extracellular volume and total body water for 20 to 30 days of bedrest.

Synthetic peptides for antibody production

NARCIS (Netherlands)

Zegers, N.D.

1995-01-01

Synthetic peptides are useful tools for the generation of antibodies. The use of antibodies as specific reagents in inununochemical assays is widely applied. In this chapter, the application of synthetic peptides for the generation of antibodies is described. The different steps that lead to the

The Ethics of Synthetic Biology

DEFF Research Database (Denmark)

Christiansen, Andreas

The dissertation analyses and discusses a number of ethical issues that have been raised in connection with the development of synthetic biology. Synthetic biology is a set of new techniques for DNA-level design and construction of living beings with useful properties. The dissertation especially...

Content metamorphosis in synthetic holography

International Nuclear Information System (INIS)

Desbiens, Jacques

2013-01-01

A synthetic hologram is an optical system made of hundreds of images amalgamated in a structure of holographic cells. Each of these images represents a point of view on a three-dimensional space which makes us consider synthetic holography as a multiple points of view perspective system. In the composition of a computer graphics scene for a synthetic hologram, the field of view of the holographic image can be divided into several viewing zones. We can attribute these divisions to any object or image feature independently and operate different transformations on image content. In computer generated holography, we tend to consider content variations as a continuous animation much like a short movie. However, by composing sequential variations of image features in relation with spatial divisions, we can build new narrative forms distinct from linear cinematographic narration. When observers move freely and change their viewing positions, they travel from one field of view division to another. In synthetic holography, metamorphoses of image content are within the observer's path. In all imaging Medias, the transformation of image features in synchronisation with the observer's position is a rare occurrence. However, this is a predominant characteristic of synthetic holography. This paper describes some of my experimental works in the development of metamorphic holographic images.

Adding sleep restriction to the equation: impact on wildland firefighters' work performance and physiology in hot conditions.

Science.gov (United States)

Vincent, Grace E; Ferguson, Sally; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Aisbett, Brad

2018-04-06

To examine the effects of sleep restriction on firefighters' physical task performance, physical activity, and physiological and perceived exertion during simulated hot wildfire conditions. 31 firefighters were randomly allocated to either the hot (n = 18, HOT; 33 °C, 8-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Intermittent, self-paced work circuits of six firefighting tasks were performed for 3 days. Firefighters self-reported ratings of perceived exertion. Heart rate, core temperature, and physical activity were measured continuously. Fluids were consumed ad libitum, and all food and fluids consumed were recorded. Urine volume and urine specific gravity (USG) were analysed and sleep was assessed using polysomnography (PSG). There were no differences between the HOT and HOT + SR groups in firefighters' physical task performance, heart rate, core temperature, USG, or fluid intake. Ratings of perceived exertion were higher (p HOT + SR group for two of the six firefighting tasks. The HOT group spent approximately 7 min more undertaking moderate physical activity throughout the 2-h work circuits compared to the HOT + SR group. Two nights of sleep restriction did not influence firefighters' physical task performance or physiological responses during 3 days of simulated wildfire suppression. Further research is needed to explore firefighters' pacing strategies during real wildfire suppression.

Multiply-Imputed Synthetic Data: Advice to the Imputer

Directory of Open Access Journals (Sweden)

Loong Bronwyn

2017-12-01

Full Text Available Several statistical agencies have started to use multiply-imputed synthetic microdata to create public-use data in major surveys. The purpose of doing this is to protect the confidentiality of respondents’ identities and sensitive attributes, while allowing standard complete-data analyses of microdata. A key challenge, faced by advocates of synthetic data, is demonstrating that valid statistical inferences can be obtained from such synthetic data for non-confidential questions. Large discrepancies between observed-data and synthetic-data analytic results for such questions may arise because of uncongeniality; that is, differences in the types of inputs available to the imputer, who has access to the actual data, and to the analyst, who has access only to the synthetic data. Here, we discuss a simple, but possibly canonical, example of uncongeniality when using multiple imputation to create synthetic data, which specifically addresses the choices made by the imputer. An initial, unanticipated but not surprising, conclusion is that non-confidential design information used to impute synthetic data should be released with the confidential synthetic data to allow users of synthetic data to avoid possible grossly conservative inferences.

The use of cardiac output monitoring to guide the administration of intravenous fluid during hyperthermic intraperitoneal chemotherapy.

Science.gov (United States)

Thanigaimani, K; Mohamed, F; Cecil, T; Moran, B J; Bell, J

2013-12-01

The optimal strategy for intravenous (IV) fluid management during administration of hyperthermic intraperitoneal chemotherapy (HIPEC) is unclear. In this prospective study we describe the use of a LiDCOrapid™ (LiDCO, Cambridge, UK) cardiac output monitor to guide IV fluid management during cytoreductive surgery (CRS) with HIPEC. The aim of this study was to determine whether cardiac output monitoring will allow close maintenance of physiological parameters during the HIPEC phase. Twenty-five patients who underwent CRS combined with HIPEC were included in the study. Intra-operative IV fluid boluses were titrated using parameters measured by the LiDCOrapid™ monitor. Stroke volume variation was maintained below 10% with fluid boluses and mean arterial pressure was maintained within 20% of the baseline figure with vasopressors. There was no significant change in heart rate and cardiac output. The systemic vascular resistance dropped from an average of 966 dyn.s/cm-5 to 797 dyn s/cm(5) at 60 min during the HIPEC phase (P = 0.62) despite an increase in the dose of phenylepherine. The average total volume of fluid given was 748 ml in the first 30 min and 630 ml in the second 30 min with an average urine output of 307 and 445 ml, respectively. The change in lactate levels was not statistically or clinically significant. LiDCOrapid™ is an effective noninvasive tool for guiding fluid management in this population. It allows the anaesthesiologist to maintain tight control of essential physiological parameters during a phase of the procedure in which there is a risk of renal injury. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

Is synthetic biology mechanical biology?

Science.gov (United States)

Holm, Sune

2015-12-01

A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

Neuropeptide K is present in human cerebrospinal fluid

International Nuclear Information System (INIS)

Toresson, G.; de las Carreras, C.; Brodin, E.; Bertilsson, L.

1990-01-01

Neurokinin A-like immunoreactivity (NKA-LI) in human cerebrospinal fluid (CSF) was determined by radioimmuno assay (RIA) combined with high performance liquid chromatography (HPLC). The major immunoreactive component did not coelute with NKA, but coeluted with neuropeptide K (NPK), which contains the NKA sequence in its C-terminus. Trypsin treatment of this component from human CSF and of synthetic NPK, produced a substance which coeluted with NKA in the HPLC system. When the NKA-LI was oxidized with hydrogen peroxide and rechromatographed, the immunoreactivity coeluted with NPK sulfoxide. The results indicate that the main part of the NKA-LI in CSF is identical with NPK. The mean concentration of NPK measured in CSF from 6 healthy subjects by HPLC-RIA was 23 + 11 (SD) pmol/L

Automated microdialysis-based system for in situ microsampling and investigation of lead bioavailability in terrestrial environments under physiologically based extraction conditions.

Science.gov (United States)

Rosende, María; Magalhães, Luis M; Segundo, Marcela A; Miró, Manuel

2013-10-15

In situ automatic microdialysis sampling under batch-flow conditions is herein proposed for the first time for expedient assessment of the kinetics of lead bioaccessibility/bioavailability in contaminated and agricultural soils exploiting the harmonized physiologically based extraction test (UBM). Capitalized upon a concentric microdialysis probe immersed in synthetic gut fluids, the miniaturized flow system is harnessed for continuous monitoring of lead transfer across the permselective microdialysis membrane to mimic the diffusive transport of metal species through the epithelium of the stomach and of the small intestine. Besides, the addition of the UBM gastrointestinal fluid surrogates at a specified time frame is fully mechanized. Distinct microdialysis probe configurations and membranes types were investigated in detail to ensure passive sampling under steady-state dialytic conditions for lead. Using a 3-cm-long polysulfone membrane with averaged molecular weight cutoff of 30 kDa in a concentric probe and a perfusate flow rate of 2.0 μL min(-1), microdialysis relative recoveries in the gastric phase were close to 100%, thereby omitting the need for probe calibration. The automatic leaching method was validated in terms of bias in the analysis of four soils with different physicochemical properties and containing a wide range of lead content (16 ± 3 to 1216 ± 42 mg kg(-1)) using mass balance assessment as a quality control tool. No significant differences between the mass balance and the total lead concentration in the suite of analyzed soils were encountered (α = 0.05). Our finding that the extraction of soil-borne lead for merely one hour in the GI phase suffices for assessment of the bioavailable fraction as a result of the fast immobilization of lead species at near-neutral conditions would assist in providing risk assessment data from the UBM test on a short notice.

Effects of Stirring and Fluid Perfusion on the In Vitro Degradation of Calcium Phosphate Cement/PLGA Composites

NARCIS (Netherlands)

An, J.; Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Jansen, J.A.

2015-01-01

In vitro degradation rates of calcium phosphate bioceramics are investigated using a large variation of soaking protocols that do not all match the dynamic conditions of the perfused physiological environment. Therefore, we studied the effect of stirring and fluid perfusion on the in vitro

Synthetic cannabis and acute ischemic stroke.

Science.gov (United States)

Bernson-Leung, Miya E; Leung, Lester Y; Kumar, Sandeep

2014-01-01

An association between marijuana use and stroke has been previously reported. However, the health risks of newer synthetic cannabinoid compounds are less well known. We describe 2 cases that introduce a previously unreported association between synthetic cannabis use and ischemic stroke in young adults. A 22-year-old woman presented with dysarthria, left hemiplegia, and left hemianesthesia within hours of first use of synthetic cannabis. She was healthy and without identified stroke risk factors other than oral contraceptive use and a patent foramen ovale without venous thromboses. A 26-year-old woman presented with nonfluent aphasia, left facial droop, and left hemianesthesia approximately 12 hours after first use of synthetic cannabis. Her other stroke risk factors included migraine with aura, oral contraceptive use, smoking, and a family history of superficial thrombophlebitis. Both women were found to have acute, large-territory infarctions of the right middle cerebral artery. Our 2 cases had risk factors for ischemic stroke but were otherwise young and healthy and the onset of their deficits occurred within hours after first-time exposure to synthetic cannabis. Synthetic cannabis use is an important consideration in the investigation of stroke in young adults. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The Efficacy of Using Synthetic Vision Terrain-Textured Images to Improve Pilot Situation Awareness

Science.gov (United States)

Uenking, Michael D.; Hughes, Monica F.

2002-01-01

The General Aviation Element of the Aviation Safety Program's Synthetic Vision Systems (SVS) Project is developing technology to eliminate low visibility induced General Aviation (GA) accidents. SVS displays present computer generated 3-dimensional imagery of the surrounding terrain on the Primary Flight Display (PFD) to greatly enhance pilot's situation awareness (SA), reducing or eliminating Controlled Flight into Terrain, as well as Low-Visibility Loss of Control accidents. SVS-conducted research is facilitating development of display concepts that provide the pilot with an unobstructed view of the outside terrain, regardless of weather conditions and time of day. A critical component of SVS displays is the appropriate presentation of terrain to the pilot. An experimental study is being conducted at NASA Langley Research Center (LaRC) to explore and quantify the relationship between the realism of the terrain presentation and resulting enhancements of pilot SA and performance. Composed of complementary simulation and flight test efforts, Terrain Portrayal for Head-Down Displays (TP-HDD) experiments will help researchers evaluate critical terrain portrayal concepts. The experimental effort is to provide data to enable design trades that optimize SVS applications, as well as develop requirements and recommendations to facilitate the certification process. In this part of the experiment a fixed based flight simulator was equipped with various types of Head Down flight displays, ranging from conventional round dials (typical of most GA aircraft) to glass cockpit style PFD's. The variations of the PFD included an assortment of texturing and Digital Elevation Model (DEM) resolution combinations. A test matrix of 10 terrain display configurations (in addition to the baseline displays) were evaluated by 27 pilots of various backgrounds and experience levels. Qualitative (questionnaires) and quantitative (pilot performance and physiological) data were collected during

Obtaining of the antioxidants by supercritical fluid extraction

Directory of Open Access Journals (Sweden)

Babović Nada V.

2011-01-01

Full Text Available One of the important trends in the food industry today is demand for natural antioxidants from plant material. Synthetic antioxidants such as butylated hydroxytoluene (BHT, and butylated hydroxyanisole (BHA are now being replaced by the natural antioxidants because of theirs possible toxicity and as they may act as promoters of carcinogens. The natural antioxidants may show equivalent or higher antioxidant activity than the endogenous or the synthetic antioxidants. Thus, great effort is being devoted to the search for alternative and cheap sources of natural antioxidants, as well as to the development of efficient and selective extraction techniques. The supercritical fluid extraction (SFE with carbon dioxide is considered to be the most suitable method for producing natural antioxidants for the use in food industry. The supercritical extract does not contain residual organic solvents as in conventional extraction processes, which makes these products suitable for use in food, cosmetic and pharmaceutical industry. The recovery of antioxidants from plant sources involves many problematic aspects: choice of an adequate source (in terms of availability, cost, difference in phenolic content with variety and season; selection of the optimal recovery procedure (in terms of yield, simplicity, industrial application, cost; chemical analysis of extracts (for optimization purposes a fast colorimetric method is more preferable than a chromatographic one; evaluation of the antioxidant power (preferably by the different assay methods. The paper presents information about different operational methods for SFE of bioactive compounds from natural sources. It also includes the various reports on the antioxidant activity of the supercritical extracts from Lamiaceae herbs, in comparison with the activity of the synthetic antioxidants and the extracts from Lamiaceae herbs obtained by the conventional methods.

Lucas–Kanade fluid trajectories for time-resolved PIV

International Nuclear Information System (INIS)

Yegavian, Robin; Leclaire, Benjamin; Illoul, Cédric; Losfeld, Gilles; Champagnat, Frédéric

2016-01-01

We introduce a new method for estimating fluid trajectories in time-resolved PIV. It relies on a Lucas–Kanade paradigm and consists in a simple and direct extension of a two-frame estimation with FOLKI-PIV (Champagnat et al 2011 Exp. Fluids 50 1169–82). The so-called Lucas–Kanade Fluid Trajectories (LKFT) are assumed to be polynomial in time, and are found as the minimizer of a global functional, in which displacements are sought so as to match the intensities of a series of images pairs in the sequence, in the least-squares sense. All pairs involve the central image, similar to other recent time-resolved approaches (FTC (Lynch and Scarano 2013 Meas. Sci. Technol . 24 035305) and FTEE (Jeon et al 2014 Exp. Fluids 55 1–16)). As switching from a two-frame to a time-resolved objective simply amounts to adding terms in a functional, no significant additional algorithmic element is required. Similar to FOLKI-PIV the method is very well suited for GPU acceleration, which is an important feature as computational complexity increases with the image sequence size. Tests on synthetic data exhibiting peak-locking show that increasing the image sequence size strongly reduces both associated bias and random error, and that LKFT has a remaining total error comparable to that of FTEE on this case. Results on case B of the third PIV challenge (Stanislas et al 2008 Exp. Fluids 45 27–71) also show its ability to drastically reduce the error in situations with low signal-to-noise ratio. These results are finally confirmed on experimental images acquired in the near-field of a low Reynolds number jet. Strong reductions in peak-locking, spatial and temporal noise compared to two-frame estimation are also observed, on the displacement components themselves, as well as on spatial or temporal derivatives, such as vorticity and material acceleration. (paper)

Fluids in crustal deformation: Fluid flow, fluid-rock interactions, rheology, melting and resources

Science.gov (United States)

Lacombe, Olivier; Rolland, Yann

2016-11-01

Fluids exert a first-order control on the structural, petrological and rheological evolution of the continental crust. Fluids interact with rocks from the earliest stages of sedimentation and diagenesis in basins until these rocks are deformed and/or buried and metamorphosed in orogens, then possibly exhumed. Fluid-rock interactions lead to the evolution of rock physical properties and rock strength. Fractures and faults are preferred pathways for fluids, and in turn physical and chemical interactions between fluid flow and tectonic structures, such as fault zones, strongly influence the mechanical behaviour of the crust at different space and time scales. Fluid (over)pressure is associated with a variety of geological phenomena, such as seismic cycle in various P-T conditions, hydrofracturing (including formation of sub-horizontal, bedding-parallel veins), fault (re)activation or gravitational sliding of rocks, among others. Fluid (over)pressure is a governing factor for the evolution of permeability and porosity of rocks and controls the generation, maturation and migration of economic fluids like hydrocarbons or ore forming hydrothermal fluids, and is therefore a key parameter in reservoir studies and basin modeling. Fluids may also help the crust partially melt, and in turn the resulting melt may dramatically change the rheology of the crust.

New high-performance, water-based fluid benefits Santos basin operations with excellent inhibition and drilling efficiency

Energy Technology Data Exchange (ETDEWEB)

Anderson, Tom; West, Gary [Halliburton Baroid, Santos, SP (Brazil)

2004-07-01

For decades drilling fluids companies have been striving to create a water-based fluid (WBF) that yields performance similar to that of an invert emulsion in the areas of hole stability, rate of penetration (ROP) and lubricity. The HYDRO-GUARD system is a new highly inhibitive WBF that can yield drilling performance approaching that of an invert emulsion system. The new system uses a new combination of polymeric additives designed to inhibit reactive clays, minimize colloidal solids buildup, and produce a lubricious, gauge wellbore. This paper compares the field performance of the HYDRO-GUARD system on two recent Santos Basin wells drilled to over 5,000 m with the performance of synthetic-based fluids (SBF) used historically in the same area. Bottom hole temperatures (BHT) on these wells exceeded 315 deg F (157 deg C). Performance measures such as hole cleaning, penetration rates, hole stability, and torque and drag will be reviewed as well as general system benefits. (author)

Rice Physiology

Science.gov (United States)

P.A. Counce; Davidi R. Gealy; Shi-Jean Susana Sung

2002-01-01

Physiology occurs tn physical space through chemical reactions constrained by anatomy and morphology, yet guided by genetics. Physiology has been called the logic of life. Genes encode structural and fimcdonal proteins. These proteins are subsequently processed to produce enzymes that direct and govern the biomechanical processes involved in the physiology of the...

Arachnids secrete a fluid over their adhesive pads.

Directory of Open Access Journals (Sweden)

Anne M Peattie

Full Text Available BACKGROUND: Many arachnids possess adhesive pads on their feet that help them climb smooth surfaces and capture prey. Spider and gecko adhesives have converged on a branched, hairy structure, which theoretically allows them to adhere solely by dry (solid-solid intermolecular interactions. Indeed, the consensus in the literature is that spiders and their smooth-padded relatives, the solifugids, adhere without the aid of a secretion. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the adhesive contact zone of living spiders, solifugids and mites using interference reflection microscopy, which allows the detection of thin liquid films. Like insects, all the arachnids we studied left behind hydrophobic fluid footprints on glass (mean refractive index: 1.48-1.50; contact angle: 3.7-11.2°. Fluid was not always secreted continuously, suggesting that pads can function in both wet and dry modes. We measured the attachment forces of single adhesive setae from tarantulas (Grammostola rosea by attaching them to a bending beam with a known spring constant and filming the resulting deflection. Individual spider setae showed a lower static friction at rest (26%±2.8 SE of the peak friction than single gecko setae (Thecadactylus rapicauda; 96%±1.7 SE. This may be explained by the fact that spider setae continued to release fluid after isolation from the animal, lubricating the contact zone. SIGNIFICANCE: This finding implies that tarsal secretions occur within all major groups of terrestrial arthropods with adhesive pads. The presence of liquid in an adhesive contact zone has important consequences for attachment performance, improving adhesion to rough surfaces and introducing rate-dependent effects. Our results leave geckos and anoles as the only known representatives of truly dry adhesive pads in nature. Engineers seeking biological inspiration for synthetic adhesives should consider whether model species with fluid secretions are appropriate to their

Comparison of the extraction efficiencies of different leaching agents for reliable assessment of bio-accessible trace metal fractions in airborne particulate matter

OpenAIRE

Mukhtar A.; Limbeck A.

2013-01-01

In present study, an in-vitro physiologically based extraction test has been applied for extraction of bio-accessible trace metal fractions in airborne particulate matter (APM) samples collected from different urban sites in Austria and Pakistan using the leaching agents H2O, sodium chloride, ammonium acetate, ammonium citrate, synthetic gastric juice and artificial lung fluids. Obtained extracts were then measured using an ETV-ICP-OES procedure which allowed highly sensitive measurement of d...

Imaging with Synthetic Aperture Radar

CERN Document Server

Massonnet, Didier

2008-01-01

Describing a field that has been transformed by the recent availability of data from a new generation of space and airborne systems, the authors offer a synthetic geometrical approach to the description of synthetic aperture radar, one that addresses physicists, radar specialists, as well as experts in image processing.  

Coherent Raman scattering in high-pressure/high-temperature fluids: An overview

International Nuclear Information System (INIS)

Schmidt, S.C.; Moore, D.S.

1990-01-01

The present understanding of high-pressure/high-temperature dense-fluid behavior is derived almost exclusively from hydrodynamic and thermodynamic measurements. Such results average over the microscopic aspects of the materials and are, therefore, insufficient for a complete understanding of fluid behavior. At the present, dense-fluid models can be verified only to the extend that they agree with the macroscopic measurements. Recently, using stimulated Raman scattering, Raman induced Kerr effect scattering, and coherent anti-Stokes Raman scattering, we have been able to probe some of the microscopic phenomenology of these dense fluids. In this paper, we discuss primarily the use of CARS in conjunction with a two-stage light-gas gun to obtain vibrational spectra of shock-compressed liquid N 2 , O 2 , CO, their mixtures, CH 3 NO 2 , and N 2 O. These experimental spectra are compared to synthetic spectra calculated using a semiclassical model for CARS intensities and best fit vibrational frequencies, peak Raman susceptibilities, and Raman linewidths. For O 2 , the possibility of resonance enhancement from collision-induced absorption is addressed. Shifts in the vibrational frequencies reflect the influence of increased density and temperature on the intramolecular motion. The derived parameters suggest thermal equilibrium of the vibrational levels is established less than a few nanoseconds after shock passage. Vibrational temperatures are obtained that agree with those derived from equation-of-state calculations. Measured linewidths suggest that vibrational dephasing times have decreased to subpicosecond values at the highest shock pressures

Physiological parameters

International Nuclear Information System (INIS)

Natera, E.S.

1998-01-01

The physiological characteristics of man depend on the intake, metabolism and excretion of stable elements from food, water, and air. The physiological behavior of natural radionuclides and radionuclides from nuclear weapons testing and from the utilization of nuclear energy is believed to follow the pattern of stable elements. Hence information on the normal physiological processes occurring in the human body plays an important role in the assessment of the radiation dose received by man. Two important physiological parameters needed for internal dose determination are the pulmonary function and the water balance. In the Coordinated Research Programme on the characterization of Asian population, five participants submitted data on these physiological characteristics - China, India, Japan, Philippines and Viet Nam. During the CRP, data on other pertinent characteristics such as physical and dietary were simultaneously being collected. Hence, the information on the physiological characteristics alone, coming from the five participants were not complete and are probably not sufficient to establish standard values for the Reference Asian Man. Nonetheless, the data collected is a valuable contribution to this research programme

The effect of natural and synthetic fatty acids on membrane structure, microdomain organization, cellular functions and human health.

Science.gov (United States)

Ibarguren, Maitane; López, David J; Escribá, Pablo V

2014-06-01

This review deals with the effects of synthetic and natural fatty acids on the biophysical properties of membranes, and on their implication on cell function. Natural fatty acids are constituents of more complex lipids, like triacylglycerides or phospholipids, which are used by cells to store and obtain energy, as well as for structural purposes. Accordingly, natural and synthetic fatty acids may modify the structure of the lipid membrane, altering its microdomain organization and other physical properties, and provoking changes in cell signaling. Therefore, by modulating fatty acids it is possible to regulate the structure of the membrane, influencing the cell processes that are reliant on this structure and potentially reverting pathological cell dysfunctions that may provoke cancer, diabetes, hypertension, Alzheimer's and Parkinson's disease. The so-called Membrane Lipid Therapy offers a strategy to regulate the membrane composition through drug administration, potentially reverting pathological processes by re-adapting cell membrane structure. Certain fatty acids and their synthetic derivatives are described here that may potentially be used in such therapies, where the cell membrane itself can be considered as a target to combat disease. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

PVC membrane, coated-wire, and carbon-paste ion-selective electrodes for potentiometric determination of galantamine hydrobromide in physiological fluids.

Science.gov (United States)

Abdel-Haleem, Fatehy M; Saad, Mohamed; Barhoum, Ahmed; Bechelany, Mikhael; Rizk, Mahmoud S

2018-08-01

We report on highly-sensitive ion-selective electrodes (ISEs) for potentiometric determining of galantamine hydrobromide (GB) in physiological fluids. Galantamine hydrobromide (GB) was selected for this study due to its previous medical importance for treating Alzheimer's disease. Three different types of ISEs were investigated: PVC membrane electrode (PVCE), carbon-paste electrode (CPE), and coated-wire electrode (CWE). In the construction of these electrodes, galantaminium-reineckate (GR) ion-pair was used as a sensing species for GB in solutions. The modified carbon-paste electrode (MCPE) was prepared using graphene oxide (MCPE-GO) and sodium tetrakis (trifluoromethyl) phenyl borate (MCPE-STFPB) as ion-exchanger. The potentiometric modified CPEs (MCPE-GO and MCPE-STFPB) show an improved performance in term of Nernstian slope, selectivity, response time, and response stability compared to the unmodified CPE. The prepared electrodes PVCE, CWE, CPE, MCPE-GO and MCPE-STFPB show Nernstian slopes of 59.9, 59.5, 58.1, 58.3 and 57.0 mV/conc. decade, and detection limits of 5.0 × 10 -6 , 6.3 × 10 -6 , 8.0 × 10 -6 , 6.0 × 10 -6 and 8.0 × 10 -6  mol L -1 , respectively. The prepared ISEs also show high selectivity against cations (i.e. Na + , K + , NH 4 + , Ca 2+ , Al 3+ , Fe 3+ ), amino acids (i.e. glycine, L-alanine alanine), and sugars (i.e. fructose, glucose, maltose, lactose). The prepared ISEs are applicable for determining GB in spiked serums, urines, and pharmaceutical preparations, using a standard addition and a direct potentiometric method. The fast response time (<10 s), long lifetime (1-5 weeks), reversibility and stability of the measured signals facilitate the application of these sensors for routine analysis of the real samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Nepenthesin protease activity indicates digestive fluid dynamics in carnivorous nepenthes plants.

Directory of Open Access Journals (Sweden)

Franziska Buch

Full Text Available Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep. Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory.

Physiological parameters for oral delivery and in vitro testing.

Science.gov (United States)

Mudie, Deanna M; Amidon, Gordon L; Amidon, Gregory E

2010-10-04

Pharmaceutical solid oral dosage forms must undergo dissolution in the intestinal fluids of the gastrointestinal tract before they can be absorbed and reach the systemic circulation. Therefore, dissolution is a critical part of the drug-delivery process. The rate and extent of drug dissolution and absorption depend on the characteristics of the active ingredient as well as properties of the dosage form. Just as importantly, characteristics of the physiological environment such as buffer species, pH, bile salts, gastric emptying rate, intestinal motility, and hydrodynamics can significantly impact dissolution and absorption. While significant progress has been made since 1970 when the first compendial dissolution test was introduced (USP apparatus 1), current dissolution testing does not take full advantage of the extensive physiologic information that is available. For quality control purposes, where the question is one of lot-to-lot consistency in performance, using nonphysiologic test conditions that match drug and dosage form properties with practical dissolution media and apparatus may be appropriate. However, where in vitro-in vivo correlations are desired, it is logical to consider and utilize knowledge of the in vivo condition. This publication critically reviews the literature that is relevant to oral human drug delivery. Physiologically relevant information must serve as a basis for the design of dissolution test methods and systems that are more representative of the human condition. As in vitro methods advance in their physiological relevance, better in vitro-in vivo correlations will be possible. This will, in turn, lead to in vitro systems that can be utilized to more effectively design dosage forms that have improved and more consistent oral bioperformance.

[Treatment approaches for synthetic drug addiction].

Science.gov (United States)

Kobayashi, Ohji

2015-09-01

In Japan, synthetic drugs have emerged since late 2000s, and cases of emergency visits and fatal traffic accidents due to acute intoxication have rapidly increased. The synthetic drugs gained popularity mainly because they were cheap and thought to be "legal". The Japanese government restricted not only production and distribution, but also its possession and use in April 2014. As the synthetic drug dependent patients have better social profiles compared to methamphetamine abusers, this legal sanction may have triggered the decrease in the number of synthetic drug dependent patient visits observed at Kanagawa Psychiatric Center since July 2014. Treatment of the synthetic drug dependent patients should begin with empathic inquiry into the motives and positive psychological effects of the drug use. In the maintenance phase, training patients to trust others and express their hidden negative emotions through verbal communications is essential. The recovery is a process of understanding the relationship between psychological isolation and drug abuse, and gaining trust in others to cope with negative emotions that the patients inevitably would face in their subsequent lives.

[Synthetic biology and rearrangements of microbial genetic material].

Science.gov (United States)

Liang, Quan-Feng; Wang, Qian; Qi, Qing-Sheng

2011-10-01

As an emerging discipline, synthetic biology has shown great scientific values and application prospects. Although there have been many reviews of various aspects on synthetic biology over the last years, this article, for the first time, attempted to discuss the relationship and difference between microbial genetics and synthetic biology. We summarized the recent development of synthetic biology in rearranging microbial genetic materials, including synthesis, design and reduction of genetic materials, standardization of genetic parts and modularization of genetic circuits. The relationship between synthetic biology and microbial genetic engineering was also discussed in the paper.

A radioimmunoassay for the detection of diethylstilboestrol and related stilbenes in biological fluids

International Nuclear Information System (INIS)

Hallahan, Cornelius; McGarry, Yvonne; Collins, J.D.

1985-01-01

A radioimmunoassay for the measurement of the synthetic anabolic agent diethylstilboestrol (DES) is described. It is based on a commercially available antiserum and a tritiated derivative of DES. The method can detect low concentrations of residues (less than 0.5 ng/ml) in small samples (0.05 to 0.2 ml) of biological fluids. DES was measured in plasma, bile and urine obtained from a calf slaughtered 22 days after subcutaneous implantation of 24 mg DES. The assay described is suitable as a rapid screening procedure for identifying animals treated with stilbene substances. (author)

Synthetic Biology and the Translational Imperative.

Science.gov (United States)

Heidari Feidt, Raheleh; Ienca, Marcello; Elger, Bernice Simone; Folcher, Marc

2017-12-18

Advances at the interface between the biological sciences and engineering are giving rise to emerging research fields such as synthetic biology. Harnessing the potential of synthetic biology requires timely and adequate translation into clinical practice. However, the translational research enterprise is currently facing fundamental obstacles that slow down the transition of scientific discoveries from the laboratory to the patient bedside. These obstacles including scarce financial resources and deficiency of organizational and logistic settings are widely discussed as primary impediments to translational research. In addition, a number of socio-ethical considerations inherent in translational research need to be addressed. As the translational capacity of synthetic biology is tightly linked to its social acceptance and ethical approval, ethical limitations may-together with financial and organizational problems-be co-determinants of suboptimal translation. Therefore, an early assessment of such limitations will contribute to proactively favor successful translation and prevent the promising potential of synthetic biology from remaining under-expressed. Through the discussion of two case-specific inventions in synthetic biology and their associated ethical implications, we illustrate the socio-ethical challenges ahead in the process of implementing synthetic biology into clinical practice. Since reducing the translational lag is essential for delivering the benefits of basic biomedical research to society at large and promoting global health, we advocate a moral obligation to accelerating translational research: the "translational imperative."

Synthetic biology era: Improving antibiotic's world.

Science.gov (United States)

Guzmán-Trampe, Silvia; Ceapa, Corina D; Manzo-Ruiz, Monserrat; Sánchez, Sergio

2017-06-15

The emergence of antibiotic-resistant pathogen microorganisms is problematic in the context of the current spectrum of available medication. The poor specificity and the high toxicity of some available molecules have made imperative the search for new strategies to improve the specificity and to pursue the discovery of novel compounds with increased bioactivity. Using living cells as platforms, synthetic biology has counteracted this problem by offering novel pathways to create synthetic systems with improved and desired functions. Among many other biotechnological approaches, the advances in synthetic biology have made it possible to design and construct novel biological systems in order to look for new drugs with increased bioactivity. Advancements have also been made in the redesigning of RNA and DNA molecules in order to engineer antibiotic clusters for antibiotic overexpression. As for the production of these antibacterial compounds, yeasts and filamentous fungi as well as gene therapy are utilized to enhance protein solubility. Specific delivery is achieved by creating chimeras using plant genes into bacterial hosts. Some of these synthetic systems are currently in clinical trials, proving the proficiency of synthetic biology in terms of both pharmacological activities as well as an increase in the biosafety of treatments. It is possible that we may just be seeing the tip of the iceberg, and synthetic biology applications will overpass expectations beyond our present knowledge. Copyright © 2017. Published by Elsevier Inc.

Synthetic bedding and wheeze in childhood.

Science.gov (United States)

Ponsonby, Anne-Louise; Dwyer, Terence; Kemp, Andrew; Cochrane, Jennifer; Couper, David; Carmichael, Allan

2003-01-01

The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available. Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze. Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy. In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.

Transport characteristics of guanidino compounds at the blood-brain barrier and blood-cerebrospinal fluid barrier: relevance to neural disorders

Directory of Open Access Journals (Sweden)

Tachikawa Masanori

2011-02-01

Full Text Available Abstract Guanidino compounds (GCs, such as creatine, phosphocreatine, guanidinoacetic acid, creatinine, methylguanidine, guanidinosuccinic acid, γ-guanidinobutyric acid, β-guanidinopropionic acid, guanidinoethane sulfonic acid and α-guanidinoglutaric acid, are present in the mammalian brain. Although creatine and phosphocreatine play important roles in energy homeostasis in the brain, accumulation of GCs may induce epileptic discharges and convulsions. This review focuses on how physiologically important and/or neurotoxic GCs are distributed in the brain under physiological and pathological conditions. Transporters for GCs at the blood-brain barrier (BBB and the blood-cerebrospinal fluid (CSF barrier (BCSFB have emerged as substantial contributors to GCs distribution in the brain. Creatine transporter (CRT/solute carrier (SLC 6A8 expressed at the BBB regulates creatine concentration in the brain, and represents a major pathway for supply of creatine from the circulating blood to the brain. CRT may be a key factor facilitating blood-to-brain guanidinoacetate transport in patients deficient in S-adenosylmethionine:guanidinoacetate N-methyltransferase, the creatine biosynthetic enzyme, resulting in cerebral accumulation of guanidinoacetate. CRT, taurine transporter (TauT/SLC6A6 and organic cation transporter (OCT3/SLC22A3 expressed at the BCSFB are involved in guanidinoacetic acid or creatinine efflux transport from CSF. Interestingly, BBB efflux transport of GCs, including guanidinoacetate and creatinine, is negligible, though the BBB has a variety of efflux transport systems for synthetic precursors of GCs, such as amino acids and neurotransmitters. Instead, the BCSFB functions as a major cerebral clearance system for GCs. In conclusion, transport of GCs at the BBB and BCSFB appears to be the key determinant of the cerebral levels of GCs, and changes in the transport characteristics may cause the abnormal distribution of GCs in the brain seen

Synthetic biology analysed tools for discussion and evaluation

CERN Document Server

2016-01-01

Synthetic biology is a dynamic, young, ambitious, attractive, and heterogeneous scientific discipline. It is constantly developing and changing, which makes societal evaluation of this emerging new science a challenging task, prone to misunderstandings. Synthetic biology is difficult to capture, and confusion arises not only regarding which part of synthetic biology the discussion is about, but also with respect to the underlying concepts in use. This book offers a useful toolbox to approach this complex and fragmented field. It provides a biological access to the discussion using a 'layer' model that describes the connectivity of synthetic or semisynthetic organisms and cells to the realm of natural organisms derived by evolution. Instead of directly reviewing the field as a whole, firstly our book addresses the characteristic features of synthetic biology that are relevant to the societal discussion. Some of these features apply only to parts of synthetic biology, whereas others are relevant to synthetic bi...

Synthetic Sling Failure - Evaluations and Recommendations

Energy Technology Data Exchange (ETDEWEB)

Henderson, C. S. [Washington River Protection Solutions, Richland, WA (United States); Mackey, Thomas C. [Washington River Protection Solutions, Richland, WA (United States)

2009-10-26

The information and evaluations provided in this report were compiled to address the recurring problem of synthetic sling failure. As safety is the number one priority in all work aspects, a solution must be devised to prevent accidents from occurring. A total of thirteen cases regarding synthetic sling failure were evaluated in order to determine their causes, effects, and preventative measures. From the collected data, it was found that all cases in which the synthetic sling contacted the edge of its load resulted in sling failure. It is required that adequate synthetic sling protection devices be used to protect slings in any lift where the sling comes in direct contact with the edge or corner of its load. However, there are no consensus codes or standards stating the type, material, or purpose of the type of protective device used to protect the sling from being cut. Numerous industry standards and codes provide vague descriptions on how to protect synthetic slings. Without a clear, concise statement of how to protect synthetic slings, it is common for inadequate materials and sling protection devices to be used in an attempt to meet the intent of these requirements. The use of an inadequate sling protection device is the main cause of synthetic sling failure in all researched cases. Commercial sling protection devices come in many shapes and sizes, and have a variety of names, as well as advertised uses. 'Abrasion pads' and 'wear protectors' are two different names for products with the same intended purpose. There is no distinguishable way to determine the extent of sling protection which these devices will provide, or what specific scenarios they are made for. This creates room for error in a field where error is unacceptable. This report provides a recommended action for hoisting and rigging activities which require synthetic slings to contact a load, as well as recommended changes to industry standards which will benefit overall

Philosophy of Systems and Synthetic Biology

DEFF Research Database (Denmark)

Green, Sara

2017-01-01

This entry aims to clarify how systems and synthetic biology contribute to and extend discussions within philosophy of science. Unlike fields such as developmental biology or molecular biology, systems and synthetic biology are not easily demarcated by a focus on a specific subject area or level...... of organization. Rather, they are characterized by the development and application of mathematical, computational, and synthetic modeling strategies in response to complex problems and challenges within the life sciences. Proponents of systems and synthetic biology often stress the necessity of a perspective...... that goes beyond the scope of molecular biology and genetic engineering, respectively. With the emphasis on systems and interaction networks, the approaches explicitly engage in one of the oldest philosophical discussions on the relationship between parts and wholes, or between reductionism and holism...

Defining the Synthetic Biology Supply Chain.

Science.gov (United States)

Frazar, Sarah L; Hund, Gretchen E; Bonheyo, George T; Diggans, James; Bartholomew, Rachel A; Gehrig, Lindsey; Greaves, Mark

Several recent articles have described risks posed by synthetic biology and spurred vigorous discussion in the scientific, commercial, and government communities about how to best detect, prevent, regulate, and respond to these risks. The Pacific Northwest National Laboratory's (PNNL) deep experience working with dual-use technologies for the nuclear industry has shown that analysis of supply chains can reveal security vulnerabilities and ways to mitigate security risk without hindering beneficial research and commerce. In this article, a team of experts in synthetic biology, data analytics, and national security describe the overall supply chain surrounding synthetic biology to illustrate new insights about the effectiveness of current regulations, the possible need for different screening approaches, and new technical solutions that could help identify or mitigate risks in the synthetic biology supply chain.

Functional resistance of enamel and the phenomenon of transtegumental fluid transport

Directory of Open Access Journals (Sweden)

Okushko V.R. Okushko R.V. Ursan R.V.

2011-03-01

Full Text Available Current data related to transport of fluid through the covering tissue formations (skin, nail plate, dental enamel, gum valley are being analyzed. A supposition is made of transtegumental fluid transport (TFT as a general biological regularity which is specifically manifested in tissues of different functional purposes. Depending on the peculiarity of the organ, the tooth performs the TFT providing functional resistance of the enamel, whose level is clinically detected in the «test of enamel resistance» (TER used in modern research. The article draws attention to the reasonability of an in-depth study of the tooth physiology, where the central element is TFT. This phenomenon is of interest both from fundamental and highly practical standpoints. Identification of seasonal periods in the functional resistance decline makes it possible to get a distinct effect by means of concentrating prevention efforts on this. The TER sample, as well as other transtegumental fluid transport patterns, is to find place in the system of personalized predictive approach to caries diseases

Characterization of synthetic peptides by mass spectrometry

DEFF Research Database (Denmark)

Prabhala, Bala Krishna; Mirza, Osman Asghar; Højrup, Peter

2015-01-01

Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI......-TOF-MS and LC-MS of synthetic peptides....

A review of crosslinked fracturing fluids prepared with produced water

Directory of Open Access Journals (Sweden)

Leiming Li

2016-12-01

Full Text Available The rapidly increasing implementations of oilfield technologies such as horizontal wells and multistage hydraulic fracturing, particularly in unconventional formations, have expanded the need for fresh water in many oilfield locations. In the meantime, it is costly for services companies and operators to properly dispose large volumes of produced water, generated annually at about 21 billion barrels in the United States alone. The high operating costs in obtaining fresh water and dealing with produced water have motivated scientists and engineers, especially in recent years, to use produced water in place of fresh water to formulate well treatment fluids. The objective of this brief review is to provide a summary of the up-to-date technologies of reusing oilfield produced water in preparations of a series of crosslinked fluids implemented mainly in hydraulic fracturing operations. The crosslinked fluids formulated with produced water include borate- and metal-crosslinked guar and derivatized guar fluids, as well as other types of crosslinked fluid systems such as crosslinked synthetic polymer fluids and crosslinked derivatized cellulose fluids. The borate-crosslinked guar fluids have been successfully formulated with produced water and used in oilfield operations with bottomhole temperatures up to about 250 °F. The produced water sources involved showed total dissolved solids (TDS up to about 115,000 mg/L and hardness up to about 11,000 mg/L. The metal-crosslinked guar fluids prepared with produced water were successfully used in wells at bottomhole temperatures up to about 250 °F, with produced water TDS up to about 300,000 mg/L and hardness up to about 44,000 mg/L. The Zr-crosslinked carboxymethyl hydroxypropyl guar (CMHPG fluids have been successfully made with produced water and implemented in operations with bottomhole temperatures at about 250+ °F, with produced water TDS up to about 280,000 mg/L and hardness up to about 91,000�

Laboratory Investigation of Rheology and Infiltration Process of Non-Newtonian Fluids through Porous Media in a Non-Isothermal Flow Regime for Effective Remediation of Contaminants

Science.gov (United States)

Naseer, F.

2017-12-01

Contamination of soil and groundwater by adsorbent (persistent) contaminants have been a major concern. Mine tailings, Acid mine drainage, waste disposal areas, active or abandoned surface and underground mines are some major causes of soil and water contamination. It is need of the hour to develop cost effective and efficient remediation techniques for clean-up of soil and aquifers. The objective of this research is to study a methodology of using non-Newtonian fluids for effective remediation of adsorbent contaminants in porous media under non-isothermal flow regimes. The research comprises of three components. Since, non-Newtonian fluid rheology has not been well studied in cold temperatures, the first component of the objective is to expose a non-Newtonian fluid (Guar gum solution) to different temperatures ranging from 30 °C through -5 °C to understand the change in viscosity, shear strength and contact angle of the fluid. Study of the flow characteristic of non-Newtonian fluids in complex porous media has been limited. Hence, the second component of this study will focus on a comparison of flow characteristics of a Newtonian fluid, non-Newtonian fluid and a combination of both fluids in a glass-tube-bundle setup that will act as a synthetic porous media. The study of flow characteristics will also be done for different thermal regimes ranging from -5 °C to 30 °C. The third component of the research will be to compare the effectiveness Guar gum to remediate a surrogate adsorbed contaminant at a certain temperature from the synthetic porous media. Guar gum is biodegradable and hence it is benign to the environment. Through these experiments, the mobility and behavior of Guar gum under varying temperature ranges will be characterized and its effectiveness in removing contaminants from soils will be understood. The impact of temperature change on the fluid and flow stability in the porous medium will be examined in this research. Guar gum is good suspension

The emerging age of cell-free synthetic biology.

Science.gov (United States)

Smith, Mark Thomas; Wilding, Kristen M; Hunt, Jeremy M; Bennett, Anthony M; Bundy, Bradley C

2014-08-25

The engineering of and mastery over biological parts has catalyzed the emergence of synthetic biology. This field has grown exponentially in the past decade. As increasingly more applications of synthetic biology are pursued, more challenges are encountered, such as delivering genetic material into cells and optimizing genetic circuits in vivo. An in vitro or cell-free approach to synthetic biology simplifies and avoids many of the pitfalls of in vivo synthetic biology. In this review, we describe some of the innate features that make cell-free systems compelling platforms for synthetic biology and discuss emerging improvements of cell-free technologies. We also select and highlight recent and emerging applications of cell-free synthetic biology. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Connection Between Thermodynamics and Dynamics of Simple Fluids in Pores: Impact of Fluid-Fluid Interaction Range and Fluid-Solid Interaction Strength.

Science.gov (United States)

Krekelberg, William P; Siderius, Daniel W; Shen, Vincent K; Truskett, Thomas M; Errington, Jeffrey R

2017-08-03

Using molecular simulations, we investigate how the range of fluid-fluid (adsorbate-adsorbate) interactions and the strength of fluid-solid (adsorbate-adsorbent) interactions impact the strong connection between distinct adsorptive regimes and distinct self-diffusivity regimes reported in [Krekelberg, W. P.; Siderius, D. W.; Shen, V. K.; Truskett, T. M.; Errington, J. R. Langmuir 2013 , 29 , 14527-14535]. Although increasing the fluid-fluid interaction range changes both the thermodynamics and the dynamic properties of adsorbed fluids, the previously reported connection between adsorptive filling regimes and self-diffusivity regimes remains. Increasing the fluid-fluid interaction range leads to enhanced layering and decreased self-diffusivity in the multilayer-formation regime but has little effect on the properties within film-formation and pore-filling regimes. We also find that weakly attractive adsorbents, which do not display distinct multilayer formation, are hard-sphere-like at super- and subcritical temperatures. In this case, the self-diffusivity of the confined and bulk fluid has a nearly identical scaling-relationship with effective density.

Automated radiofrequency-based US measurement of common carotid intima-media thickness in RA patients treated with synthetic vs synthetic and biologic DMARDs.

Science.gov (United States)

Naredo, Esperanza; Möller, Ingrid; Corrales, Alfonso; Bong, David A; Cobo-Ibáñez, Tatiana; Corominas, Hector; Garcia-Vivar, Ma Luz; Macarrón, Pilar; Navio, Teresa; Richi, Patricia; Iagnocco, Annamaria; Garrido, Jesús; Martínez-Hernández, David

2013-02-01

To compare the carotid intima-media thickness (IMT) assessed with automated radiofrequency-based US in RA patients treated with synthetic vs synthetic and biologic DMARDs and controls. Ninety-four RA patients and 94 sex- and age-matched controls were prospectively recruited at seven centres. Cardiovascular (CV) risk factors and co-morbidities, RA characteristics and therapy were recorded. Common carotid artery (CCA)-IMT was assessed in RA patients and controls with automated radiofrequency-based US by the same investigator at each centre. Forty-five (47.9%) RA patients had been treated with synthetic DMARDs and 49 (52.1%) with synthetic and biologic DMARDs. There were no significant differences between the RA patients and controls in demographics, CV co-morbidities and CV disease. There were significantly more smokers among RA patients treated with synthetic and biologic DMARDs (P = 0.036). Disease duration and duration of CS and synthetic DMARD therapy was significantly longer in RA patients treated with synthetic and biologic DMARDs (P radiofrequency-based measurement of CCA-IMT can discriminate between RA patients treated with synthetic DMARDs vs RA patients treated with synthetic and biologic DMARDs.

The effects of consuming carbohydrate-electrolyte beverages on gastric emptying and fluid absorption during and following exercise.

Science.gov (United States)

Murray, R

1987-01-01

A variety of beverages formulated to provide fluid, carbohydrates, and electrolytes during and following exercise are commercially available. Such 'sport drinks' commonly contain 4 to 8% carbohydrate (as glucose, fructose, sucrose or maltodextrins) and small amounts of electrolytes (most often sodium, potassium, and chloride). The efficacy of consuming such beverages has been questioned primarily because of concern that beverage carbohydrate content may inhibit gastric emptying rate and fluid absorption during exercise, thereby jeopardizing physiological homeostasis and impairing exercise performance. Gastric motor activity, and consequently gastric emptying rate, is governed by neural and humoral feedback provided by receptors found in the gastric musculature and proximal small intestine. Gastric emptying rate may be influenced by a variety of factors including, but not limited to, the caloric content, volume, osmolality, temperature, and pH of the ingested fluid, diurnal and interindividual variation, metabolic state (rest/exercise), and the ambient temperature. The caloric content of the ingested fluid appears to be the most important variable governing gastric emptying rate, providing a mean caloric efflux from the stomach of 2.0 to 2.5 kcal/min for ingested fluid volumes less than 400 ml. At rest, gastric emptying is inhibited by solutions containing calories in a manner independent of the nutrient source (i.e. carbohydrate, fat or protein). Consequently, plain water is known to empty from the stomachs of resting subjects at rates faster than solutions containing calories. Gastric emptying is increasingly inhibited as the caloric content of the ingested fluid increases. During moderate exercise (less than 75% VO2max), gastric emptying occurs at a rate similar to that during rest; more intense exercise appears to inhibit gastric emptying. When fluids are consumed at regular intervals throughout prolonged exercise (greater than 2 hours), postexercise aspiration

Extended Near-Infrared Optoacoustic Spectrometry for Sensing Physiological Concentrations of Glucose

Directory of Open Access Journals (Sweden)

Ara Ghazaryan

2018-03-01

Full Text Available Glucose sensing is pursued extensively in biomedical research and clinical practice for assessment of the carbohydrate and fat metabolism as well as in the context of an array of disorders, including diabetes, morbid obesity, and cancer. Currently used methods for real-time glucose measurements are invasive and require access to body fluids, with novel tools and methods for non-invasive sensing of the glucose levels highly desired. In this study, we introduce a near-infrared (NIR optoacoustic spectrometer for sensing physiological concentrations of glucose within aqueous media and describe the glucose spectra within 850–1,900 nm and various concentration ranges. We apply the ratiometric and dictionary learning methods with a training set of data and validate their utility for glucose concentration measurements with optoacoustics in the probe dataset. We demonstrate the superior signal-to-noise ratio (factor of ~3.9 achieved with dictionary learning over the ratiometric approach across the wide glucose concentration range. Our data show a linear relationship between the optoacoustic signal intensity and physiological glucose concentration, in line with the results of optical spectroscopy. Thus, the feasibility of detecting physiological glucose concentrations using NIR optoacoustic spectroscopy is demonstrated, enabling the sensing glucose with ±10 mg/dl precision.

Calcium signalling in the acinar environment of the exocrine pancreas: physiology and pathophysiology

OpenAIRE

Gryshchenko, Oleksiy; Gerasimenko, Julia V.; Peng, Shuang; Gerasimenko, Oleg V.; Petersen, Ole Holger

2018-01-01

Physiological Ca2+ signals in pancreatic acinar cells control fluid and\\ud enzyme secretion, whereas excessive Ca2+ signals induced by pathological agents\\ud induce destructive processes leading to acute pancreatitis. Ca2+ signals in the periacinar\\ud stellate cells may also play a role in the development of acute pancreatitis. In\\ud this study, we have explored Ca2+ signalling in the different cell types to be found in\\ud the acinar environment of the pancreatic tissue. We have, for the firs...

The new vestibular stimuli: sound and vibration-anatomical, physiological and clinical evidence.

Science.gov (United States)

Curthoys, Ian S

2017-04-01

The classical view of the otoliths-as flat plates of fairly uniform receptors activated by linear acceleration dragging on otoconia and so deflecting the receptor hair bundles-has been replaced by new anatomical and physiological evidence which shows that the maculae are much more complex. There is anatomical spatial differentiation across the macula in terms of receptor types, hair bundle heights, stiffness and attachment to the overlying otolithic membrane. This anatomical spatial differentiation corresponds to the neural spatial differentiation of response dynamics from the receptors and afferents from different regions of the otolithic maculae. Specifically, receptors in a specialized band of cells, the striola, are predominantly type I receptors, with short, stiff hair bundles and looser attachment to the overlying otoconial membrane than extrastriolar receptors. At the striola the hair bundles project into holes in the otolithic membrane, allowing for fluid displacement to deflect the hair bundles and activate the cell. This review shows the anatomical and physiological evidence supporting the hypothesis that fluid displacement, generated by sound or vibration, deflects the short stiff hair bundles of type I receptors at the striola, resulting in neural activation of the irregular afferents innervating them. So these afferents are activated by sound or vibration and show phase-locking to individual cycles of the sound or vibration stimulus up to frequencies above 2000 Hz, underpinning the use of sound and vibration for clinical tests of vestibular function.

Nutrition and human physiological adaptations to space flight

Science.gov (United States)

Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

1993-01-01

Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

Robust synthetic biology design: stochastic game theory approach.

Science.gov (United States)

Chen, Bor-Sen; Chang, Chia-Hung; Lee, Hsiao-Ching

2009-07-15

Synthetic biology is to engineer artificial biological systems to investigate natural biological phenomena and for a variety of applications. However, the development of synthetic gene networks is still difficult and most newly created gene networks are non-functioning due to uncertain initial conditions and disturbances of extra-cellular environments on the host cell. At present, how to design a robust synthetic gene network to work properly under these uncertain factors is the most important topic of synthetic biology. A robust regulation design is proposed for a stochastic synthetic gene network to achieve the prescribed steady states under these uncertain factors from the minimax regulation perspective. This minimax regulation design problem can be transformed to an equivalent stochastic game problem. Since it is not easy to solve the robust regulation design problem of synthetic gene networks by non-linear stochastic game method directly, the Takagi-Sugeno (T-S) fuzzy model is proposed to approximate the non-linear synthetic gene network via the linear matrix inequality (LMI) technique through the Robust Control Toolbox in Matlab. Finally, an in silico example is given to illustrate the design procedure and to confirm the efficiency and efficacy of the proposed robust gene design method. http://www.ee.nthu.edu.tw/bschen/SyntheticBioDesign_supplement.pdf.

Numerical investigations on coupled heat transfer and synthetical performance of a pressurized volumetric receiver with MCRT–FVM method

International Nuclear Information System (INIS)

Cheng, Z.D.; He, Y.L.; Cui, F.Q.

2013-01-01

This paper presents an axisymmetric steady-state computational fluid dynamics model and further studies on the complex coupled heat transfer combined radiation–convection–conduction in the pressurized volumetric receiver (PVR), by combining the Finite Volume Method (FVM) and the Monte Carlo Ray-Trace (MCRT) method. Based on this, effects of geometric parameters of the compound parabolic concentrator (CPC) and properties of the porous absorber on synthetical characteristics and performance of the photo-thermal conversion process in the PVR are further analyzed and discussed detailedly. It is found that the solar flux density distributions are always very heterogeneous with large nonuniformities, and the variation trends of the corresponding temperature distributions are very similar to these but with much lower order of magnitude. The CPC shape determined by the CPC exit aperture has much larger effects on synthetical characteristics and performance of the PVR than that of the CPC entry aperture with a constant acceptance angle. And a suitable or optimal thickness of the porous absorber could be determined by examining where the drastic decreasing trends occur at the curves of variations of synthetical characteristics and performance with the porosity. - Highlights: ► An axisymmetric steady-state CFD model of PVR is presented with MCRT–FVM method. ► The complex coupled heat transfer and synthetical performance of the PVR are studied. ► The effects of geometric parameters and porous properties are analyzed and discussed. ► Solar flux and temperature in PVR are very heterogeneous with large nonuniformities. ► An optimal absorber thickness can be determined by examining the effects of porosity.

Synthetic biology of polyketide synthases

DEFF Research Database (Denmark)

Yuzawa, Satoshi; Backman, Tyler W.H.; Keasling, Jay D.

2018-01-01

). The modules are composed of enzymatic domains that share sequence and functional similarity across all known PKSs. We have used the nomenclature of synthetic biology to classify the enzymatic domains and modules as parts and devices, respectively, and have generated detailed lists of both. In addition, we...... realize the potential that synthetic biology approaches bring to this class of molecules....

Opportunities for Intervention Strategies for Weight Management: Global Actions on Fluid Intake Patterns

Directory of Open Access Journals (Sweden)

Max Lafontan

2015-01-01

Full Text Available Summary: Water is an essential nutrient for all physiological functions and particularly important for thermoregulation. About 60% of our body weight is made of water. Under standard conditions (18-20 °C and moderate activity, water balance is regulated within 0.2 % of body weight over a 24-hour period. Water requirement varies between individuals and according to environmental conditions. Concerning considerations related to obesity, the health impact of fluid intake is commonly overlooked. Fluid intake advices are missing in most of food pyramids offered to the public, and water requirements and hydration challenges remain often neglected. The purpose of this paper is to emphasize and discuss the role of water consumption in the context of other important public health measures for weight management. Attention will be focused on fluid intake patterns and hydration-related questions in the context of global interventions and/or physical activity programs settled in weight management protocols.

Opportunities for Intervention Strategies for Weight Management: Global Actions on Fluid Intake Patterns

Science.gov (United States)

Lafontan, Max; Visscher, Tommy L.S.; Farpour-Lambert, Nathalie; Yumuk, Volkan

2015-01-01

Water is an essential nutrient for all physiological functions and particularly important for thermoregulation. About 60% of our body weight is made of water. Under standard conditions (18-20 °C and moderate activity), water balance is regulated within 0.2 % of body weight over a 24-hour period. Water requirement varies between individuals and according to environmental conditions. Concerning considerations related to obesity, the health impact of fluid intake is commonly overlooked. Fluid intake advices are missing in most of food pyramids offered to the public, and water requirements and hydration challenges remain often neglected. The purpose of this paper is to emphasize and discuss the role of water consumption in the context of other important public health measures for weight management. Attention will be focused on fluid intake patterns and hydration-related questions in the context of global interventions and/or physical activity programs settled in weight management protocols. PMID:25765164

Computational fluid dynamics modelling in cardiovascular medicine.

Science.gov (United States)

Morris, Paul D; Narracott, Andrew; von Tengg-Kobligk, Hendrik; Silva Soto, Daniel Alejandro; Hsiao, Sarah; Lungu, Angela; Evans, Paul; Bressloff, Neil W; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

2016-01-01

This paper reviews the methods, benefits and challenges associated with the adoption and translation of computational fluid dynamics (CFD) modelling within cardiovascular medicine. CFD, a specialist area of mathematics and a branch of fluid mechanics, is used routinely in a diverse range of safety-critical engineering systems, which increasingly is being applied to the cardiovascular system. By facilitating rapid, economical, low-risk prototyping, CFD modelling has already revolutionised research and development of devices such as stents, valve prostheses, and ventricular assist devices. Combined with cardiovascular imaging, CFD simulation enables detailed characterisation of complex physiological pressure and flow fields and the computation of metrics which cannot be directly measured, for example, wall shear stress. CFD models are now being translated into clinical tools for physicians to use across the spectrum of coronary, valvular, congenital, myocardial and peripheral vascular diseases. CFD modelling is apposite for minimally-invasive patient assessment. Patient-specific (incorporating data unique to the individual) and multi-scale (combining models of different length- and time-scales) modelling enables individualised risk prediction and virtual treatment planning. This represents a significant departure from traditional dependence upon registry-based, population-averaged data. Model integration is progressively moving towards 'digital patient' or 'virtual physiological human' representations. When combined with population-scale numerical models, these models have the potential to reduce the cost, time and risk associated with clinical trials. The adoption of CFD modelling signals a new era in cardiovascular medicine. While potentially highly beneficial, a number of academic and commercial groups are addressing the associated methodological, regulatory, education- and service-related challenges. Published by the BMJ Publishing Group Limited. For permission

Mass Spectrometric Analysis of Synthetic Organic Pigments.

Science.gov (United States)

Sugaya, Naeko; Takahashi, Mitsuko; Sakurai, Katsumi; Tanaka, Nobuko; Okubo, Ichiro; Kawakami, Tsuyoshi

2018-04-18

Though synthetic organic colorants are used in various applications nowadays, there is the concern that impurities by-produced during the manufacturing and degradation products in some of these colorants are persistent organic pollutants and carcinogens. Thus, it is important to identify the synthetic organic colorants in various products, such as commercial paints, ink, cosmetics, food, textile, and plastics. Dyes, which are soluble in water and other solvents, could be analyzed by chromatographic methods. In contrast, it is difficult to analyze synthetic organic pigments by these methods because of their insolubility. This review is an overview of mass spectrometric analysis of synthetic organic pigments by various ionization methods. We highlight a recent study of textile samples by atmospheric pressure solid analysis probe MS. Furthermore, the mass spectral features of synthetic organic pigments and their separation from other components such as paint media and plasticizers are discussed.

Two-phase cooling fluids; Les fluides frigoporteurs diphasiques

Energy Technology Data Exchange (ETDEWEB)

Lallemand, A. [Institut National des Sciences Appliquees (INSA), 69 - Lyon (France)

1997-12-31

In the framework of the diminution of heat transfer fluid consumption, the concept of indirect refrigerating circuits, using cooling intermediate fluids, is reviewed and the fluids that are currently used in these systems are described. Two-phase cooling fluids advantages over single-phase fluids are presented with their thermophysical characteristics: solid fraction, two-phase mixture enthalpy, thermal and rheological properties, determination of heat and mass transfer characteristics, and cold storage through ice slurry

Computational Fluid and Particle Dynamics in the Human Respiratory System

CERN Document Server

Tu, Jiyuan; Ahmadi, Goodarz

2013-01-01

Traditional research methodologies in the human respiratory system have always been challenging due to their invasive nature. Recent advances in medical imaging and computational fluid dynamics (CFD) have accelerated this research. This book compiles and details recent advances in the modelling of the respiratory system for researchers, engineers, scientists, and health practitioners. It breaks down the complexities of this field and provides both students and scientists with an introduction and starting point to the physiology of the respiratory system, fluid dynamics and advanced CFD modeling tools. In addition to a brief introduction to the physics of the respiratory system and an overview of computational methods, the book contains best-practice guidelines for establishing high-quality computational models and simulations. Inspiration for new simulations can be gained through innovative case studies as well as hands-on practice using pre-made computational code. Last but not least, students and researcher...

Shock compression of synthetic opal

International Nuclear Information System (INIS)

Inoue, A; Okuno, M; Okudera, H; Mashimo, T; Omurzak, E; Katayama, S; Koyano, M

2010-01-01

Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO 4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO 2 glass. However, internal silanole groups still remain even at 38.1 GPa.

Super-Resolution for Synthetic Zooming

Directory of Open Access Journals (Sweden)

Li Xin

2006-01-01

Full Text Available Optical zooming is an important feature of imaging systems. In this paper, we investigate a low-cost signal processing alternative to optical zooming—synthetic zooming by super-resolution (SR techniques. Synthetic zooming is achieved by registering a sequence of low-resolution (LR images acquired at varying focal lengths and reconstructing the SR image at a larger focal length or increased spatial resolution. Under the assumptions of constant scene depth and zooming speed, we argue that the motion trajectories of all physical points are related to each other by a unique vanishing point and present a robust technique for estimating its D coordinate. Such a line-geometry-based registration is the foundation of SR for synthetic zooming. We address the issue of data inconsistency arising from the varying focal length of optical lens during the zooming process. To overcome the difficulty of data inconsistency, we propose a two-stage Delaunay-triangulation-based interpolation for fusing the LR image data. We also present a PDE-based nonlinear deblurring to accommodate the blindness and variation of sensor point spread functions. Simulation results with real-world images have verified the effectiveness of the proposed SR techniques for synthetic zooming.

Shock compression of synthetic opal

Science.gov (United States)

Inoue, A.; Okuno, M.; Okudera, H.; Mashimo, T.; Omurzak, E.; Katayama, S.; Koyano, M.

2010-03-01

Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO2 glass. However, internal silanole groups still remain even at 38.1 GPa.

Shock compression of synthetic opal

Energy Technology Data Exchange (ETDEWEB)

Inoue, A; Okuno, M; Okudera, H [Department of Earth Sciences, Kanazawa University Kanazawa, Ishikawa, 920-1192 (Japan); Mashimo, T; Omurzak, E [Shock Wave and Condensed Matter Research Center, Kumamoto University, Kumamoto, 860-8555 (Japan); Katayama, S; Koyano, M, E-mail: okuno@kenroku.kanazawa-u.ac.j [JAIST, Nomi, Ishikawa, 923-1297 (Japan)

2010-03-01

Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO{sub 4} tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO{sub 2} glass. However, internal silanole groups still remain even at 38.1 GPa.

Biological response to the synergistic effect of synthetic colour additives and gamma irradiation on rats

International Nuclear Information System (INIS)

Ashry, O.M.; Kafafy, Y.A.; Salama, S.F.

2007-01-01

This Study was conducted to determine the effect of the inevitable intake of synthetic colour additives in our everyday life and radiation exposure on the levels of some physiological parameters. Female rats were divided into: I- Control group. 2- Group administrated an azo dye mixture of tartrazine and brilliant blue orally for 2 weeks (100 mg/Kg body wt). 3- Group received gamma radiation of 5 Gy. 4- Animals received the dyes mixture for 2 weeks and irradiation. Rats were examined on the 1st, 3rd and 7th days post irradiation or dyes treatment followed by irradiation. Dyes treatment induced significant decreases in hemoglobin (Hb), hematocrit (Ht), red blood cells (RBCs), alkaline phosphatase (ALP) activity. Significant increases of plasma total proteins and albumin levels were recorded. No significant changes of alanine aminotransferase (ALT) activity, iron (Fe), cupper (Cu) and zinc (Zn) levels were noted. Irradiation induced significant decline in Hb, Ht, RBCs, Cu and Fe levels. Significant increases of glucose (7th day), uric acid (3rd and 7 days), total proteins (3rd day) levels, and ALT activity, while no changes were recorded in ALP, albumin or Zn levels. Dual treatment of irradiation and dyes aggravated the radiation-induced changes. Bearing in mind that safety concerns overweighed the approval of use of synthetic colors, the utilization of these colors in drug and food manufacturing should be limited to minimize the physiological disturbances and the risk concomitant to environmental oxidative stress. During the last decade, extensive studies on the use of colors in processed foods, drinks, drugs and cosmetics confirmed that they may act as xenobiotics (Guengerich, 1995). With the increasing awareness of possible health hazards associated with their use more attention has been focused on the biological

Viscous Flow with Large Fluid-Fluid Interface Displacement

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Hassager, Ole; Saasen, Arild

1998-01-01

The arbitrary Lagrange-Euler (ALE) kinematic description has been implemented in a 3D transient finite element program to simulate multiple fluid flows with fluid-fluid interface or surface displacements. The description of fluid interfaces includes variable interfacial tension, and the formulation...... is useful in the simulation of low and intermediate Reynolds number viscous flow. The displacement of two immiscible Newtonian fluids in a vertical (concentric and eccentric) annulus and a (vertical and inclined)tube is simulated....

The use of synthetic ligaments in the design of an enhanced stability total knee joint replacement.

Science.gov (United States)

Stokes, Michael D; Greene, Brendan C; Pietrykowski, Luke W; Gambon, Taylor M; Bales, Caroline E; DesJardins, John D

2018-03-01

Current total knee replacement designs work to address clinically desired knee stability and range of motion through a balance of retained anatomy and added implant geometry. However, simplified implant geometries such as bearing surfaces, posts, and cams are often used to replace complex ligamentous constraints that are sacrificed during most total knee replacement procedures. This article evaluates a novel total knee replacement design that incorporates synthetic ligaments to enhance the stability of the total knee replacement system. It was hypothesized that by incorporating artificial cruciate ligaments into a total knee replacement design at specific locations and lengths, the stability of the total knee replacement could be significantly altered while maintaining active ranges of motion. The ligament attachment mechanisms used in the design were evaluated using a tensile test, and determined to have a safety factor of three with respect to expected ligamentous loading in vivo. Following initial computational modeling of possible ligament orientations, a physical prototype was constructed to verify the function of the design by performing anterior/posterior drawer tests under physiologic load. Synthetic ligament configurations were found to increase total knee replacement stability up to 94% compared to the no-ligament case, while maintaining total knee replacement flexion range of motion between 0° and 120°, indicating that a total knee replacement that incorporates synthetic ligaments with calibrated location and lengths should be able to significantly enhance and control the kinematic performance of a total knee replacement system.

Transport of synthetic colloids through single saturated fractures: A literature review

International Nuclear Information System (INIS)

Reimus, P.W.

1995-07-01

Colloids having the same surface charge sign as the bulk of the geologic media in a groundwater system may be able to travel through the system faster than soluble species because they will follow fluid streamlines more closely and they should have less tendency to diffuse into pores or dead spaces in the media than soluble species. Synthetic colloids with uniform, controlled properties may be ideal for serving as open-quotes worst-caseclose quotes tracers that provide lower-bound estimates of contaminant travel times in hydrologic systems. This report discusses a review of the literature pertaining to colloid transport in single saturated natural fractures. After a brief background discussion to put the literature review in perspective, the phenomenon of colloid transport in saturated fractures is divided into three major topics, each of which is reviewed in detail: (1) saturated fluid flow through fractures; (2) colloid transport by convection, diffusion, and force fields; and (3) colloid interactions with surfaces. It is suggested that these phenomena be accounted for in colloid transport models by using (1) lubrication theory to describe water flow through fractures, (2) particle tracking methods to describe colloid transport in fractures, and (3) a kinetic boundary layer approximation to describe colloid interactions with fracture walls. These methods offer better computational efficiency and better experimental accessibility to model parameters than rigorously solving the complete governing equations

The influence of body position on cerebrospinal fluid pressure gradient and movement in cats with normal and impaired craniospinal communication.

Science.gov (United States)

Klarica, Marijan; Radoš, Milan; Erceg, Gorislav; Petošić, Antonio; Jurjević, Ivana; Orešković, Darko

2014-01-01

Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF) pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension.

The influence of body position on cerebrospinal fluid pressure gradient and movement in cats with normal and impaired craniospinal communication.

Directory of Open Access Journals (Sweden)

Marijan Klarica

Full Text Available Intracranial hypertension is a severe therapeutic problem, as there is insufficient knowledge about the physiology of cerebrospinal fluid (CSF pressure. In this paper a new CSF pressure regulation hypothesis is proposed. According to this hypothesis, the CSF pressure depends on the laws of fluid mechanics and on the anatomical characteristics inside the cranial and spinal space, and not, as is today generally believed, on CSF secretion, circulation and absorption. The volume and pressure changes in the newly developed CSF model, which by its anatomical dimensions and basic biophysical features imitates the craniospinal system in cats, are compared to those obtained on cats with and without the blockade of craniospinal communication in different body positions. During verticalization, a long-lasting occurrence of negative CSF pressure inside the cranium in animals with normal cranio-spinal communication was observed. CSF pressure gradients change depending on the body position, but those gradients do not enable unidirectional CSF circulation from the hypothetical site of secretion to the site of absorption in any of them. Thus, our results indicate the existence of new physiological/pathophysiological correlations between intracranial fluids, which opens up the possibility of new therapeutic approaches to intracranial hypertension.

Synthetic Rutile

International Nuclear Information System (INIS)

Burastero, J.

1975-01-01

This work is about the laboratory scale investigation of the conditions in the rutile synthetic production from one me nita in Aguas Dulces reservoir. The iron mineral is chlorinated and volatilized selectively leaving a residue enriched in titanium dioxide which can be used as a substitute of rutile mineral

Anisotropic evaluation of synthetic surgical meshes.

Science.gov (United States)

Saberski, E R; Orenstein, S B; Novitsky, Y W

2011-02-01

The material properties of meshes used in hernia repair contribute to the overall mechanical behavior of the repair. The anisotropic potential of synthetic meshes, representing a difference in material properties (e.g., elasticity) in different material axes, is not well defined to date. Haphazard orientation of anisotropic mesh material can contribute to inconsistent surgical outcomes. We aimed to characterize and compare anisotropic properties of commonly used synthetic meshes. Six different polypropylene (Trelex(®), ProLite™, Ultrapro™), polyester (Parietex™), and PTFE-based (Dualmesh(®), Infinit) synthetic meshes were selected. Longitudinal and transverse axes were defined for each mesh, and samples were cut in each axis orientation. Samples underwent uniaxial tensile testing, from which the elastic modulus (E) in each axis was determined. The degree of anisotropy (λ) was calculated as a logarithmic expression of the ratio between the elastic modulus in each axis. Five of six meshes displayed significant anisotropic behavior. Ultrapro™ and Infinit exhibited approximately 12- and 20-fold differences between perpendicular axes, respectively. Trelex(®), ProLite™, and Parietex™ were 2.3-2.4 times. Dualmesh(®) was the least anisotropic mesh, without marked difference between the axes. Anisotropy of synthetic meshes has been underappreciated. In this study, we found striking differences between elastic properties of perpendicular axes for most commonly used synthetic meshes. Indiscriminate orientation of anisotropic mesh may adversely affect hernia repairs. Proper labeling of all implants by manufacturers should be mandatory. Understanding the specific anisotropic behavior of synthetic meshes should allow surgeons to employ rational implant orientation to maximize outcomes of hernia repair.

Synthetic Lipoproteins as Carriers for Drug Delivery.

Science.gov (United States)

Huang, Gangliang; Liu, Yang; Huang, Hualiang

2016-01-01

Synthetic lipoprotein is an effective carrier of targeted delivery for drugs. It has the very small size, good biocompatibility, suitable half-life, and specific lipoprotein receptorbinding capacity. Compared with the traditional natural lipoprotein, synthetic lipoprotein not only retains the original biological characteristics and functions, but also exhibits the excellent characteristics in drug delivery. Herein, the advantages, development, applications, and prospect of synthetic lipoproteins as drug carriers were summarized.

Fluid transport due to nonlinear fluid-structure interaction

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard

1997-01-01

This work considers nonlinear fluid-structure interaction for a vibrating pipe containing fluid. Transverse pipe vibrations will force the fluid to move relative to the pipe creating unidirectional fluid flow towards the pipe end. The fluid flow induced affects the damping and the stiffness...... of the pipe. The behavior of the system in response to lateral resonant base excitation is analysed numerically and by the use of a perturbation method (multiple scales). Exciting the pipe in the fundamental mode of vibration seems to be most effective for transferring energy from the shaker to the fluid......, whereas higher modes of vibration can be used to transport fluid with pipe vibrations of smaller amplitude. The effect of the nonlinear geometrical terms is analysed and these terms are shown to affect the response for higher modes of vibration. Experimental investigations show good agreement...

Applications of cell-free protein synthesis in synthetic biology: Interfacing bio-machinery with synthetic environments.

Science.gov (United States)

Lee, Kyung-Ho; Kim, Dong-Myung

2013-11-01

Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell-free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell-based systems, cell-free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell-free protein synthesis is virtually free from the intrinsic constraints of cell-based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell-free protein synthesis can be combined with various man-made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell-free protein synthesis with various reaction devices and analytical platforms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydroxyl Radical Formation from HULIS and Fe(II) Interactions: Fulvic Acid-Fe(II) Complexes in Simulated and Human Lung Fluids

Science.gov (United States)

Gonzalez, D.

2017-12-01

Inhalation of fine particulate matter (PM2.5) has long been associated with adverse health outcomes. However, the causative agents and underlying mechanisms for these health effects have yet to be identified. One hypothesis is that PM2.5 deposited in the alveoli produce an excess of highly reactive radicals, leading to oxidative stress. The OH radical may be the most physiologically damaging, capable of oxidizing of lipids, proteins and DNA. Due to the variability and uncertainty in PM2.5 composition, the components that contribute to OH formation are not well understood. Soluble Fe is a component of PM2.5that produces OH under physiological conditions. Humic-like substances are water soluble organics found in biomass burning and tobacco smoke. Humic-like substances are capable of binding to Fe and enhancing OH formation, but this chemistry is not well understood. In this work, we use soil derived fulvic acid as a surrogate for Humic-like substances and investigate its effect on OH formation from Fe(II) under conditions relevant to the lungs. We use a fluorescent OH trapping probe, chemical kinetics and thermodynamic modeling to investigate OH formation from fulvic acid and Fe(II) dissolved in simulated and human lung fluids. In simulated lung fluid, we find that fulvic acid binds to Fe(II) and enhances the rate of key reactions that form OH. When fulvic acid is added to human lung fluids containing Fe(II), an enhancement of OH formation is observed. In human lung fluid, fulvic acid and metal binding proteins compete for Fe binding. These metal binding proteins are typically not found in simulated lung fluids. Results show that fulvic acid strongly binds Fe(II) and catalyzes key reactions that form OH in both simulated and human lung fluids. These results may help explain the role of Humic-like substances and Fe in oxidative stress and adverse health outcomes. Furthermore, we suggest that future studies employ simulated lung fluids containing metal binding proteins

Microfluidic Technologies for Synthetic Biology

Directory of Open Access Journals (Sweden)

Sung Kuk Lee

2011-06-01

Full Text Available Microfluidic technologies have shown powerful abilities for reducing cost, time, and labor, and at the same time, for increasing accuracy, throughput, and performance in the analysis of biological and biochemical samples compared with the conventional, macroscale instruments. Synthetic biology is an emerging field of biology and has drawn much attraction due to its potential to create novel, functional biological parts and systems for special purposes. Since it is believed that the development of synthetic biology can be accelerated through the use of microfluidic technology, in this review work we focus our discussion on the latest microfluidic technologies that can provide unprecedented means in synthetic biology for dynamic profiling of gene expression/regulation with high resolution, highly sensitive on-chip and off-chip detection of metabolites, and whole-cell analysis.

40 CFR 721.3627 - Branched synthetic fatty acid.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Branched synthetic fatty acid. 721... Substances § 721.3627 Branched synthetic fatty acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a branched synthetic fatty acid...

Dynamics of pleural fluid effusion and chylothorax in the fetus and newborn: role of the lymphatic system.

Science.gov (United States)

Bellini, C; Ergaz, Z; Boccardo, F; Bellini, T; Campisi, C C; Bonioli, E; Ramenghi, L A

2013-06-01

Pleural fluid effusion particularly chylothorax is a relatively rare occurrence in the newborn, but when it occurs it is often life-threatening. In this article, we describe and illustrate the morphologic features of the visceral and parietal pleura including pleural lymphatics and the physiology and pathophysiology of pleural fluid balance. The role and function of the lymphatic system in controlling the volume and composition of pleural liquid are detailed and a conceptual scheme presented. Finally, the crucial role of inadequate lymphatic drainage (either functional overload from an imbalance in Starling forces or mechanical insufficiency from lymphatic dysplasia) is emphasized.

Synthetic Sediments and Stochastic Groundwater Hydrology

Science.gov (United States)

Wilson, J. L.

2002-12-01

For over twenty years the groundwater community has pursued the somewhat elusive goal of describing the effects of aquifer heterogeneity on subsurface flow and chemical transport. While small perturbation stochastic moment methods have significantly advanced theoretical understanding, why is it that stochastic applications use instead simulations of flow and transport through multiple realizations of synthetic geology? Allan Gutjahr was a principle proponent of the Fast Fourier Transform method for the synthetic generation of aquifer properties and recently explored new, more geologically sound, synthetic methods based on multi-scale Markov random fields. Focusing on sedimentary aquifers, how has the state-of-the-art of synthetic generation changed and what new developments can be expected, for example, to deal with issues like conceptual model uncertainty, the differences between measurement and modeling scales, and subgrid scale variability? What will it take to get stochastic methods, whether based on moments, multiple realizations, or some other approach, into widespread application?

Fluid-fluid level on MR image: significance in Musculoskeletal diseases

Energy Technology Data Exchange (ETDEWEB)

Chung, Hye Won; Lee, Kyung Won [Seoul Naitonal University, Seoul (Korea, Republic of). Coll. of Medicine; Song, Chi Sung [Seoul City Boramae Hospital, Seoul (Korea, Republic of); Han, Sang Wook; Kang, Heung Sik [Seoul Naitonal University, Seoul (Korea, Republic of). Coll. of Medicine

1998-01-01

To evaluate the frequency, number and signal intensity of fluid-fluid levels of musculoskeletal diseases on MR images, and to determine the usefulness of this information for the differentiation of musculoskeletal diseases. MR images revealed fluid-fluid levels in the following diseases : giant cell tumor(6), telangiectatic osteosarcoma(4), aneurysmal bone cyst(3), synovial sarcoma(3), chondroblastoma(2), soft tissue tuberculous abscess(2), hematoma(2), hemangioma (1), neurilemmoma(1), metastasis(1), malignant fibrous histiocytoma(1), bursitis(1), pyogenic abscess(1), and epidermoid inclusion cyst(1). Fourteen benign tumors and ten malignant, three abscesses, and the epidermoid inclusion cyst showed only one fluid-fluid level in a unilocular cyst. On T1-weighted images, the signal intensities of fluid varied, but on T2-weighted images, superior layers were in most cases more hyperintense than inferior layers. Because fluid-fluid layers are a nonspecific finding, it is difficult to specifically diagnose each disease according to the number of fluid-fluid levels or signal intensity of fluid. In spite of the nonspecificity of fluid-fluid levels, they were frequently seen in cases of giant cell tumor, telangiectatic osteosarcoma, aneurysmal bone cycle, and synovial sarcoma. Nontumorous diseases such abscesses and hematomas also demonstrated this finding. (author). 11 refs., 1 tab., 4 figs.

Fluid-fluid level on MR image: significance in Musculoskeletal diseases

International Nuclear Information System (INIS)

Chung, Hye Won; Lee, Kyung Won; Han, Sang Wook; Kang, Heung Sik

1998-01-01

To evaluate the frequency, number and signal intensity of fluid-fluid levels of musculoskeletal diseases on MR images, and to determine the usefulness of this information for the differentiation of musculoskeletal diseases. MR images revealed fluid-fluid levels in the following diseases : giant cell tumor(6), telangiectatic osteosarcoma(4), aneurysmal bone cyst(3), synovial sarcoma(3), chondroblastoma(2), soft tissue tuberculous abscess(2), hematoma(2), hemangioma (1), neurilemmoma(1), metastasis(1), malignant fibrous histiocytoma(1), bursitis(1), pyogenic abscess(1), and epidermoid inclusion cyst(1). Fourteen benign tumors and ten malignant, three abscesses, and the epidermoid inclusion cyst showed only one fluid-fluid level in a unilocular cyst. On T1-weighted images, the signal intensities of fluid varied, but on T2-weighted images, superior layers were in most cases more hyperintense than inferior layers. Because fluid-fluid layers are a nonspecific finding, it is difficult to specifically diagnose each disease according to the number of fluid-fluid levels or signal intensity of fluid. In spite of the nonspecificity of fluid-fluid levels, they were frequently seen in cases of giant cell tumor, telangiectatic osteosarcoma, aneurysmal bone cycle, and synovial sarcoma. Nontumorous diseases such abscesses and hematomas also demonstrated this finding. (author). 11 refs., 1 tab., 4 figs

Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education.

Science.gov (United States)

Abram, Sean R; Hodnett, Benjamin L; Summers, Richard L; Coleman, Thomas G; Hester, Robert L

2007-06-01

We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop.

Behavioral responses and fluid regulation in male rats after combined dietary sodium deficiency and water deprivation.

Science.gov (United States)

Lucia, Kimberly J; Curtis, Kathleen S

2018-02-01

Most investigators use a single treatment such as water deprivation or dietary sodium deficiency to evaluate thirst or sodium appetite, which underlie behavioral responses to body fluid challenges. The goal of the present experiments was to assess the effects of combined treatments in driving behaviors. Therefore, we evaluated the effect of combined overnight water deprivation and dietary sodium deficiency on water intake and salt intake by adult male rats in 2-bottle (0.5M NaCl and water) tests. Overnight water deprivation alone increased water intake, and 10days of dietary sodium deficiency increased 0.5M NaCl intake, with a secondary increase in water intake. During combined water deprivation and dietary sodium deficiency, water intake was enhanced and 0.5M NaCl was reduced, but not eliminated, suggesting that physiologically relevant behavioral responses persist. Nonetheless, the pattern of fluid intake was altered by the combined treatments. We also assessed the effect of these behaviors on induced deficits in body sodium and fluid volume during combined treatments and found that, regardless of treatment, fluid ingestion partially repleted the induced deficits. Finally, we examined urine volume and sodium excretion during dietary sodium deficiency with or without overnight water deprivation and found that, whether or not rats were water deprived, and regardless of water consumption, sodium excretion was minimal. Thus, the combination of water deprivation and dietary sodium deficiency appears to arouse drives that stimulate compensatory behavioral responses. These behaviors, in conjunction with physiological adaptations to the treatments, underlie body sodium and volume repletion in the face of combined water deprivation and dietary sodium deficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

[Progress in synthetic biology of "973 Funding Program" in China].

Science.gov (United States)

Chen, Guoqiang; Wang, Ying

2015-06-01

This paper reviews progresses made in China from 2011 in areas of "Synthetic Biology" supported by State Basic Research 973 Program. Till the end of 2014, 9 "synthetic biology" projects have been initiated with emphasis on "microbial manufactures" with the 973 Funding Program. Combined with the very recent launch of one project on "mammalian cell synthetic biology" and another on "plant synthetic biology", Chinese "synthetic biology" research reflects its focus on "manufactures" while not giving up efforts on "synthetic biology" of complex systems.

Effect of the synthetic cannabinoid HU-210 on quorum sensing and on the production of quorum sensing-mediated virulence factors by Vibrio harveyi

OpenAIRE

Soni, Divya; Smoum, Reem; Breuer, Aviva; Mechoulam, Raphael; Steinberg, Doron

2015-01-01

Background Bacterial populations communicate through the cell density-dependent mechanism of quorum sensing (QS). Vibrio harveyi, one of the best studied model organisms for QS, was used to explore effects of the synthetic cannabinoid HU-210 on QS and different QS-regulated physiological processes in bacteria. Results Analysis of QS-regulated bioluminescence in wild-type and mutant strains of V. harveyi revealed that HU-210 affects the autoinducer-2 (AI-2) pathway, one of three known QS casca...

Finite element approach to study the behavior of fluid distribution in the dermal regions of human body due to thermal stress

Directory of Open Access Journals (Sweden)

M.A. Khanday

2015-10-01

Full Text Available The human body is a complex structure where the balance of mass and heat transport in all tissues is necessary for its normal functioning. The stabilities of intracellular and extracellular fluids are important physiological factors responsible for homoeostasis. To estimate the effects of thermal stress on the behavior of extracellular fluid concentration in human dermal regions, a mathematical model based on diffusion equation along with appropriate boundary conditions has been formulated. Atmospheric temperature, evaporation rate, moisture concentration and other factors affecting the fluid concentration were taken into account. The variational finite element approach has been employed to solve the model and the results were interpreted graphically.

Methods for preparing synthetic freshwaters.

Science.gov (United States)

Smith, E J; Davison, W; Hamilton-Taylor, J

2002-03-01

Synthetic solutions that emulate the major ion compositions of natural waters are useful in experiments aimed at understanding biogeochemical processes. Standard recipes exist for preparing synthetic analogues of seawater, with its relatively constant composition, but, due to the diversity of freshwaters, a range of compositions and recipes is required. Generic protocols are developed for preparing synthetic freshwaters of any desired composition. The major problems encountered in preparing hard and soft waters include dissolving sparingly soluble calcium carbonate, ensuring that the ionic components of each concentrated stock solution cannot form an insoluble salt and dealing with the supersaturation of calcium carbonate in many hard waters. For acidic waters the poor solubility of aluminium salts requires attention. These problems are overcome by preparing concentrated stock solutions according to carefully designed reaction paths that were tested using a combination of experiment and equilibrium modeling. These stock solutions must then be added in a prescribed order to prepare a final solution that is brought into equilibrium with the atmosphere. The example calculations for preparing hard, soft and acidic freshwater surrogates with major ion compositions the same as published analyses, are presented in a generalized fashion that should allow preparation of any synthetic freshwater according to its known analysis.

Reasons for Synthetic THC Use among College Students

Science.gov (United States)

Vidourek, Rebecca A.; King, Keith A.; Burbage, Michelle L.

2013-01-01

Synthetic THC, also known as fake marijuana, is used by college students in the United States. The present study examined reasons for recent synthetic THC use among college students (N = 339). Students completed a 3-page survey during regularly scheduled class times. Results indicated students reported using synthetic THC for curiosity, to get…

Role of various natural, synthetic and semi-synthetic polymers on drug release kinetics of losartan potassium oral controlled release tablets.

Science.gov (United States)

Jayasree, J; Sivaneswari, S; Hemalatha, G; Preethi, N; Mounika, B; Murthy, S Vasudeva

2014-10-01

The objective of the present work was to formulate and to characterize controlled release matrix tablets of losartan potassium in order to improve bioavailability and to minimize the frequency of administration and increase the patient compliance. Losartan potassium controlled release matrix tablets were prepared by direct compression technique by the use of different natural, synthetic and semisynthetic polymers such as gum copal, gum acacia, hydroxypropyl methyl cellulose K100 (HPMC K100), eudragit RL 100 and carboxy methyl ethyl cellulose (CMEC) individually and also in combination. Studies were carried out to study the influence of type of polymer on drug release rate. All the formulations were subjected to physiochemical characterization such as weight variation, hardness, thickness, friability, drug content, and swelling index. In vitro dissolution studies were carried out simulated gastric fluid (pH 1.2) for first 2 h and followed by simulated intestinal fluid (pH 6.8) up to 24 h, and obtained dissolution data were fitted to in vitro release kinetic equations in order to know the order of kinetics and mechanism of drug release. Results of physiochemical characterization of losartan potassium matrix tablets were within acceptable limits. Formulation containing HPMC K100 and CMEC achieved the desired drug release profile up to 24 h followed zero order kinetics, release pattern dominated by Korsmeyer - Peppas model and mechanism of drug release by nonfickian diffusion. The good correlation obtained from Hixson-Crowell model indicates that changes in surface area of the tablet also influences the drug release. Based on the results, losartan potassium controlled release matrix tablets prepared by employing HPMC K100 and CMEC can attain the desired drug release up to 24 h, which results in maintaining steady state concentration and improving bioavailability.

Defining the Synthetic Biology Supply Chain

Energy Technology Data Exchange (ETDEWEB)

Frazar, Sarah L.; Hund, Gretchen E.; Bonheyo, George T.; Diggans, James; Bartholomew, Rachel A.; Gehrig, Lindsey; Greaves, Mark

2017-08-01

In this article, a team of experts in synthetic biology, data analytics, and national security describe the overall supply chain surrounding synthetic biology. The team analyzes selected interactions within that network to better understand the risks raised by synthetic biology and identifies opportunities for risk mitigation. To introduce the concept, the article will briefly describe how an understanding of supply chains has been important in promoting nuclear nonproliferation objectives. The article concludes by assessing the structure and networks identified in the supply chains to reveal potential opportunities for future biodefense research and development; options for additional information exchange; and means to interdict, detect, or deter suspicious activity.

Patient-ventilator asynchrony affects pulse pressure variation prediction of fluid responsiveness.

Science.gov (United States)

Messina, Antonio; Colombo, Davide; Cammarota, Gianmaria; De Lucia, Marta; Cecconi, Maurizio; Antonelli, Massimo; Corte, Francesco Della; Navalesi, Paolo

2015-10-01

During partial ventilatory support, pulse pressure variation (PPV) fails to adequately predict fluid responsiveness. This prospective study aims to investigate whether patient-ventilator asynchrony affects PPV prediction of fluid responsiveness during pressure support ventilation (PSV). This is an observational physiological study evaluating the response to a 500-mL fluid challenge in 54 patients receiving PSV, 27 without (Synch) and 27 with asynchronies (Asynch), as assessed by visual inspection of ventilator waveforms by 2 skilled blinded physicians. The area under the curve was 0.71 (confidence interval, 0.57-0.83) for the overall population, 0.86 (confidence interval, 0.68-0.96) in the Synch group, and 0.53 (confidence interval, 0.33-0.73) in the Asynch group (P = .018). Sensitivity and specificity of PPV were 78% and 89% in the Synch group and 36% and 46% in the Asynch group. Logistic regression showed that the PPV prediction was influenced by patient-ventilator asynchrony (odds ratio, 8.8 [2.0-38.0]; P < .003). Of the 27 patients without asynchronies, 12 had a tidal volume greater than or equal to 8 mL/kg; in this subgroup, the rate of correct classification was 100%. Patient-ventilator asynchrony affects PPV performance during partial ventilatory support influencing its efficacy in predicting fluid responsiveness. Copyright © 2015 Elsevier Inc. All rights reserved.