Showing papers on "Energy source published in 1998"

The complete genome of the hyperthermophilic bacterium Aquifex aeolicus

Abstract: Aquifex aeolicus was one of the earliest diverging, and is one of the most thermophilic, bacteria known. It can grow on hydrogen, oxygen, carbon dioxide, and mineral salts. The complex metabolic machinery needed for A. aeolicus to function as a chemolithoautotroph (an organism which uses an inorganic carbon source for biosynthesis and an inorganic chemical energy source) is encoded within a genome that is only one-third the size of the E. coli genome. Metabolic flexibility seems to be reduced as a result of the limited genome size. The use of oxygen (albeit at very low concentrations) as an electron acceptor is allowed by the presence of a complex respiratory apparatus. Although this organism grows at 95 degrees C, the extreme thermal limit of the Bacteria, only a few specific indications of thermophily are apparent from the genome. Here we describe the complete genome sequence of 1,551,335 base pairs of this evolutionarily and physiologically interesting organism.

Energy implications of future stabilization of atmospheric CO2 content

Abstract: The United Nations Framework Convention on Climate Change1 calls for “stabilization of greenhouse-gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system ” A standard baseline scenario2,3 that assumes no policy intervention to limit greenhouse-gas emissions has 10 TW (10 × 1012 watts) of carbon-emission-free power being produced by the year 2050, equivalent to the power provided by all today's energy sources combined Here we employ a carbon-cycle/energy model to estimate the carbon-emission-free power needed for various atmospheric CO2 stabilization scenarios We find that CO2 stabilization with continued economic growth will require innovative, cost-effective and carbon-emission-free technologies that can provide additional tens of terawatts of primary power in the coming decades, and certainly by the middle of the twenty-first century, even with sustained improvement in the economic productivity of primary energy At progressively lower atmospheric CO2-stabilization targets in the 750–350 ppmv range, implementing stabilization will become even more challenging because of the increasing demand for carbon-emission-free power The magnitude of the implied infrastructure transition suggests the need for massive investments in innovative energy research

The deep hot biosphere

Abstract: There are strong indications that microbial life is widespread at depth in the crust of the Earth, just as such life has been identified in numerous ocean vents. This life is not dependent on solar energy and photosynthesis for its primary energy supply, and it is essentially independent of the surface circumstances. Its energy supply comes from chemical sources, due to fluids that migrate upward from deeper levels in the Earth. In mass and volume it may be comparable with all surface life. Such microbial life may account for the presence of biological molecules in all carbonaceous materials in the outer crust, and the inference that these materials must have derived from biological deposits accumulated at the surface is therefore not necessarily valid. Subsurface life may be widespread among the planetary bodies of our solar system, since many of them have equally suitable conditions below, while having totally inhospitable surfaces. One may even speculate that such life may be widely disseminated in the universe, since planetary type bodies with similar subsurface conditions may be common as solitary objects in space, as well as in other solar-type systems.

Drug-releasing coatings for medical devices

Abstract: The invention is directed to medical devices having a drug-releasing coating and methods for making such coated devices. The coating permits timed or prolonged pharmacological activity on the surface of medical devices through a reservoir concept. Specifically, the coating comprises at least two layers: an outer layer containing at least one drug-ionic surfactant complex overlying a reservoir layer containing a polymer and the drug which is substantially free of an ionic surfactant. Upon exposure to body tissue of a medical device covered with such coating, the ionically bound drug in the outer layer is released into body fluid or tissue. Following release of such bound drug, the ionic surfactant binding sites in the outer layer are left vacant. To maintain the pharmacological activity after delivery of the ionically bound drug, additional amounts of the drug are embedded or incorporated in the reservoir layer in a manner which allows the drug, which is substantially free of ionic surfactants, to complex with the vacant binding sites of the ionic surfactant of the outer layer. As a result, the surface of the medical device is enriched with the drug to provide sustained pharmacological activity to prevent the adverse reaction due to the presence of the medical device. The invention is further directed to medical devices with stabilized drug-releasing coatings. The coatings are stabilized by exposure to a low energy, relatively non-penetrating energy source, e.g., gas plasma or an electron beam energy source.

Method for producing monocrystalline structures

Abstract: In the method for manufacturing monocrystalline structures, parts or workpieces of metallic super-alloys on substrates with a monocrystalline structure or monocrystalline structures, the surface of the substrate is melted with an energy beam of high energy density from an energy source. The material which is to be introduced into the monocrystalline structure is supplied to the melted region of the substrate. The supplied material is completely melted. The energy input with the energy beam is regulated and/or controlled in such a manner that the speed of solidification and the temperature gradient lie in the dendritic crystalline region in the GV diagram, outside the globulitic region.

Endogenous cellulases in animals: Isolation of β-1,4-endoglucanase genes from two species of plant-parasitic cyst nematodes

Abstract: β-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing β-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the cyst nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37–44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3′ end precluded the EGases from being of bacterial origin. Cyst nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation.

A hyperluminous galaxy at z = 2.8 found in a deep submillimetre survey

Abstract: We present a detailed study of SMM 02399–0136, a hyperluminous, active galaxy selected from a submm survey of the distant Universe. This galaxy is the brightest source in the fields of six rich, lensing clusters, with a total area of 0.01 deg2, that we have mapped with a sensitivity of ∼ 2 mJy beam−1 at 850 μm. We identify a compact optical counterpart with an apparent magnitude of B ∼ 23 and a low surface-brightness companion ∼ 3 arcsec away. Our spectroscopy shows that both components have the same redshift; z = 2.803 ± 0.003. The emission line widths, FWHM ≃ 1000–1500 km s−1, and line ratios, along with the compact morphology and high luminosity (MB ≃ −24.0) of the galaxy, indicate that SMM 02399–0136 contains a rare dust-embedded, narrow-line or type-2 active galactic nucleus (AGN). The source is gravitationally lensed by the foreground cluster, amplifying its apparent luminosity by a factor of 2.5, and our detailed lens model allows us to accurately correct for this. Taking the amplification into account, we estimate that SMM 02399–0136 is intrinsically a factor of five times more luminous than IRAS F 10214+4724. Its far-infrared (FIR) and Hα luminosities and low surface-brightness radio emission are indicative of an interaction-induced starburst, and the star formation rate (SFR) could be several thousand solar masses per year. This assumes that the starburst is the dominant source of energy, but we cannot yet determine reliably the relative contributions of the starburst and the buried AGN. A dust mass of 5–7 × 108 M⊙ is indicated by our data for a dust temperature of 40–50 K, independent of the dominant energy source. We estimate the possible space density of such luminous submm sources, and find that while a large population of these obscured sources could be detected in future wide-field submm surveys, they are unlikely to dominate the faint counts in this waveband. Galaxies such as SMM 02399–0136 and F 10214+4724 cannot easily be detected in conventional AGN/QSO surveys, and so estimates of the prevalence of AGN in the early Universe may require significant revision.

Glucose sensing and signaling by two glucose receptors in the yeast Saccharomyces cerevisiae

Abstract: How eukaryotic cells sense availability of glucose, their preferred carbon and energy source, is an important, unsolved problem. Bakers' yeast (Saccharomyces cerevisiae) uses two glucose transporter homologs, Snf3 and Rgt2, as glucose sensors that generate a signal for induction of expression of genes encoding hexose transporters (HXT genes). We present evidence that these proteins generate an intracellular glucose signal without transporting glucose. The Snf3 and Rgt2 glucose sensors contain unusually long C-terminal tails that are predicted to be in the cytoplasm. These tails appear to be the signaling domains of Snf3 and Rgt2 because they are necessary for glucose signaling by Snf3 and Rgt2, and transplantation of the C-terminal tail of Snf3 onto the Hxt1 and Hxt2 glucose transporters converts them into glucose sensors that can generate a signal for glucose-induced HXT gene expression. These results support the idea that yeast senses glucose using two modified glucose transporters that serve as glucose receptors.

Development, maintenance and role of riparian vegetation in the river landscape

Abstract: Summary 1. Riparian structure and function were considered from a longitudinal perspective in order to identify multiscale couplings with adjacent ecosystems and to identify research needs. 2. We characterized functional zones (with respect to vegetation development in association with various biogeochemical processes) within geomorphological settings using a delineation based upon erosional, transitional and depositional properties. 3. Vegetation dynamics within the riparian corridor are clearly influenced substantially by hydrological disturbance regimes. In turn, we suggest that vegetation productivity and diversity may widely influence riverine biogeochemical processes, especially as related to the consequences of changing redox conditions occurring from upstream to downstream. 4. However, surface and groundwater linkages are the predominant controls of landscape connectivity within riparian systems. 5. The importance of riparian zones as sources and sinks of matter and energy was examined in context of structural and functional attributes, such as sequestering or cycling of nutrients in sediments, retention of water in vegetation, and retention, diffusion or dispersal of biota. 6. The consequences of interactions between different communities (e.g. animals and plants, micro-organisms and plants) on biogeochemical processes are notably in need of research, especially with respect to control of landscape features. Multiscale approaches, coupling regional and local factors in all three spatial dimensions, are needed in order to understand more synthetically and to model biogeochemical and community processes within the river-riparian-upland landscape of catchments.

A cellulase gene of termite origin

Abstract: The traditional view of cellulose digestion in animals is that they cannot produce their own cellulase, and so rely on gut microorganisms to hydrolyse cellulose. A classic example of this symbiosis is that between phylogenetically lower termites and the unicellular organisms (protists) that colonize their hindguts: cellulose fermented to acetate by the protists can be used as an energy source by the termite1. There is evidence for the production of endogenous cellulase components by termites and other wood-feeding insects2; however, an unambiguous origin for such enzymes1 has not been established, to our knowledge, until now. Here we describe the first insect cellulase-endoding gene to be identified, RsEG, which encodes an endo-β-1,4-glucanase (EC 3.2.1.4) in the termite Reticulitermes speratus.

Polyunsaturated fatty acid regulation of gene expression.

Abstract: For the past three decades, polyunsaturated fatty acids (PUFA) have been recognized as important energy sources and membrane components. PUFA also play key roles in many cellular events, such as gene regulation. Most recently, research has focused on identifying the mechanisms by which PUFA modulate gene transcription, mRNA stability and cellular differentiation. It is the purpose of this review to examine the effects of PUFA on gene expression in lipogenic as well as other tissues. Because the (n-3) and (n-6) series of PUFA are intimately involved in gene regulation, they will be the focus of review. The effects of other fatty acid families on gene expression are reviewed elsewhere.

Energy delivery catheter and method for the use thereof

Abstract: A catheter comprising a flexible tube having a proximal portion and a distal end portion The proximal portion comprises a first or working lumen and a second lumen for a guidewire The distal end portion consists of a small-diameter flexible tube having a single lumen The catheter has a tapered transition portion interconnecting the proximal and distal portions, in which the first and second lumens have openings communicating internally of the catheter to the single lumen in the distal end portion Coupled to a proximal end of the catheter are means for inserting an ultrasound or optical fiber into the first lumen for transmitting energy from an energy source through the catheter to an emission end near the distal end of the catheter and means for inserting the guidewire through the second lumen The means for inserting are adapted to permit extension and retraction of the fiber and the guidewire in their respective lumens The distal end portion containing the single lumen is sized to a diameter suitable for introduction into small cranial vessels, with an outer diameter less than that of the proximal portion containing the first and second lumens This can be accomplished by sizing the distal end portion with an inner diameter of the single lumen just large enough to receive one of the guidewire and the fiber but not both

Method for treating annular fissures in intervertebral discs

Abstract: A percutaneous method of repairing a fissure in the annulus pulposus includes placing an energy source adjacent to the fissure and providing sufficient energy to the fissure to raise the temperature to at least about 45-70° C. and for a sufficient time to cause the collagen to weld. An intervertebral fissure also can be treated by placing a catheter with a lumen adjacent to the fissure and injecting sealant into the fissure via the catheter, thereby sealing the fissure. An intervertebral fissure additionally can be treated by providing a catheter having a distal end, a proximal end, a longitudinal axis, and an intradiscal section at the catheter's distal end on which there is at least one functional element. The next step is applying a force longitudinally to the proximal of the catheter which is sufficient to advance the intradiscal section through the nucleus pulposus and around an inner wall of an annulus fibrosus, but which force is insufficient to puncture the annulus fibrosus. Next the functional element is positioned at a selected location of the disc by advancing or retracting the catheter and optionally twisting the proximal end of the catheter. Then the functional unit treats the annular fissure. Optionally, there is an additional step of adding a substance to seal the fissure. An externally guidable intervertebral disc apparatus also is disclosed.

Lithium ion batteries : fundamentals and performance

Abstract: Rechargeable batteries with high energy density are in demand as energy sources for various purposes, such as handies, zero emission electric vehicles, or load levelling in electric power. Lithium batteries are the most promising to fulfill such needs because of their intrinsic discharge voltage with relatively light weight. This volume is an overview of the challenges facing the further development of lithium-ion batteries from the standpoint of both materials science and technology.

Improved electrosurgical hemostatic device including an anvil

Abstract: An electrosurgical instrument is provided for cauterization and/or welding of tissue of varying impedance, thickness and vascularity especially in the performance of endoscopic procedures. The instrument compresses the tissue between one pole of a bipolar energy source located on one interfacing surface, and a second interfacing surface applying pressure in a predetermined range wherein one of the interfacing surfaces is positioned on an anvil with a specified preload and spring rate. A second pole is located one of the two interfacing surfaces. In a preferred embodiment, the second pole is located on the same interfacing surface as the first pole and an insulator electrically isolates the two poles. A preferred application of the invention is in a cutting instrument wherein a hemostatic line is formed along a cut line using RFenergy.

Uninterruptible power supply with direction of DC electrical energy depending on predetermined ratio

Abstract: An uninterruptible power supply is disclosed in which the backup energy source is connected to the power supply of the protected computer by means of a bi-directional power converter. This converter operates without sensing circuitry, relays, or switches, operating continuously when a load is present in either charging or discharging the backup energy source. This uninterruptible power supply can be placed within the available space of a functioning standard computer power supply enclosure, and may be configured so that it may be replaced during normal computer operation (i.e. it is "hot swappable"). Methods are described to interface the uninterruptible power supply to the computer, providing mutual control and communication. The device may be also used to power devices requiring external DC power, which are commonly found in association with computer operations.

A system for determining the spatial position and orientation of a body

Abstract: A system for determining the spatial position and orientation of each of a plurality of bodies Each one of the bodies has at least three markers in a predetermined, relative geometric relationship The markers are adapted to emit energy in response to an activation signal and/or to reflect energy impinging upon such passive marker from an activatable energy source A common energy detector is provided for detecting the energy emitted by the active marker and the energy reflected by the passive marker A common processor is provided The processor has a memory The memory has stored therein the predetermined, relative geometric relation of the markers for each one of the bodies The processor compares the stored predetermined geometric relation of the markers for each of the bodies with the energy detected by the energy detector to identify the bodies emitting, or reflecting the detected energy With such an arrangement, a body can be tracked using a very simple sequence of operation in real-time with robust positive marker identification by taking advantage of a simple marker placement methodology Multiple bodies can thereby be tracked simultaneously

A theoretical comparison of energy sources--microwave, ultrasound and laser--for interstitial thermal therapy.

Abstract: A number of heating sources are available for minimally invasive thermal therapy of tumours. The purpose of this work was to compare, theoretically, the heating characteristics of interstitial microwave, laser and ultrasound sources in three tissue sites: breast, brain and liver. Using a numerical method, the heating patterns, temperature profiles and expected volumes of thermal damage were calculated during standard treatment times with the condition that tissue temperatures were not permitted to rise above 100 degrees C (to ensure tissue vaporization did not occur). Ideal spherical and cylindrical applicators (200 microm and 800 microm radii respectively) were modelled for each energy source to demonstrate the relative importance of geometry and energy attenuation in determining heating and thermal damage profiles. The theoretical model included the effects of the collapse of perfusion due to heating. Heating patterns were less dependent on the energy source when small spherical applicators were modelled than for larger cylindrical applicators due to the very rapid geometrical decrease in energy with distance for the spherical applicators. For larger cylindrical applicators, the energy source was of greater importance. In this case, the energy source with the lowest attenuation coefficient was predicted to produce the largest volume of thermally coagulated tissue, in each tissue site.

Insecticidal activity and biodegradation of the toxin from bacillus thuringiensis subsp. kurstaki bound to humic acids from soil

Abstract: The equilibrium adsorption and binding of the active toxin from Bacillus thuringiensis subsp kurstaki , toxic to lepidopteran larvae, to humic acids extracted from two forest and two cultivated soils, as well as the insecticidal activity and the biodegradation of the bound toxin, were studied From 75 to 85% of the toxin added was rapidly adsorbed to the humic acids at equilibrium, and adsorption to a constant amount of humic acids increased with the concentration of the toxin until a plateau was reached Differences in total acidity and in the content of phenolic groups of the humic acids appeared to be primarily responsible for differences in the amounts of toxin bound (45–80% of the adsorbed toxin) after extensive washing with distilled water The content of carboxyl groups and the degree of polymerization (E4/E6) did not appear to influence significantly the differential binding Bound humic acid–toxin complexes were toxic to larvae of the tobacco hornworm ( Manduca sexta ) The lethal concentration necessary to kill 50% of the larvae (LC 50 ) of the bound toxin was comparable with that of the free toxin, indicating that the binding of the toxin to humic acids did not affect its insecticidal activity The bound toxin did not support the growth of a mixed microbial culture from soil, although the free toxin was rapidly utilized as a carbon and energy source for growth, indicating that binding of the toxin to humic acids reduced its biodegradability The result of these studies indicate that the toxins from B thuringiensis introduced in transgenic plants and microbes could persist, accumulate, and remain insecticidal in soil as a result of binding to humic acids, as well as on clays, as previously described This persistence could pose a hazard to non-target organisms and enhance the selection of toxin-resistant target species

Differential Rotation and Turbulence in Extended HI Disks

Abstract: When present, extended disks of neutral hydrogen around spiral galaxies show a remarkably uniform velocity dispersion of approx 6 km/s. Since stellar winds and supernovae are largely absent in such regions, neither the magnitude nor the constancy of this number can be accounted for in the classical picture in which interstellar turbulence is driven by stellar energy sources. Here we suggest that magnetic fields with strengths of a few microgauss in these extended disks allow energy to be extracted from galactic differential rotation through MHD driven turbulence. The magnitude and constancy of the observed velocity dispersion may be understood if its value is Alfvenic. Moreover, by providing a simple explanation for a lower bound to the gaseous velocity fluctuations, MHD processes may account for the sharp outer edge to star formation in galaxy disks.

Instruments and methods employing thermal energy for the repair and replacement of cardiac valves

Abstract: The present invention is methods and devices for improving valve function in a heart. Particularly a device of the present invention comprises a an elongate member having a distal end and a proximal end, a thermal heating member fixed to the distal end of the elongate member, wherein the thermal heating member includes at least one thermal heating element adapted to supply thermal energy to a heart valve structure, and an energy source in communication with the thermal heating element. In use, a thermal heating device of the present invention is inserted into working space proximate the valve to be treated and is used to selectively contract the collagen fibers of the valve structure treated so as to improve the performance and functioning of the valve. Devices are disclosed suitable for use with a variety of access procedures on both beating and non-beating hearts, including: a minimally invasive surgical procedure, a sternotomy, a thoracotomy, an endovascular procedure, and endoscopic procedure, or a percutaneous procedure. Methods and devices are disclosed which are suitable for treatment of a chordae, leaflet, or annulus, as well as devices and methods for the replacement of heart valve with prosthetic valves.

Towards proalcool ii—a review of the brazilian bioethanol programme

Abstract: Since the creation of the National Alcohol Programme (NAP) in 1975, commonly known as “ProAlcool”, it has gone through a number of fluctuations reflecting Brazilian political, economic and energy priorities. In 1996–1997 over 175 Mt of sugarcane (65% of 270 Mt harvested) was converted to ethanol fuel. The ProAlcool started as a highly innovative programme, but in recent years has lost part of its technological zeal and in certain areas is becoming stagnant. This is due to a combination of reasons, e.g. unclear energy policy, high sugar prices in the international market and lower investment in ethanol production as a result of low international oil prices. A new impetus is needed to reflect changing economic and energy policy in Brazil. This paper reviews the implications for ProAlcool of the new economic policies and the possibilities for restructuring the programme to guarantee its survival as a pioneering and sustainable renewable energy source. This will bring new challenges, costs and opportunities to Brazilian society.

Distinct patterns of gene expression associated with development of fluconazole resistance in serial Candida albicans isolates from human immunodeficiency virus-infected patients with oropharyngeal candidiasis

Abstract: Resistance to fluconazole and other azole antifungal drugs has become an important clinical problem in the management of human immunodeficiency virus (HIV)-infected patients with recurrent oropharyngeal candidiasis (OPC) (17, 20). Recent advances in our understanding of the molecular mechanisms leading to azole resistance in Candida albicans, the main etiologic agent of OPC, suggest the multifactorial nature of resistance. Alterations in the target enzyme (lanosterol 14α-demethylase), including point mutations (10, 11, 22, 28, 32) and overexpression (31), lead to decreased susceptibilities to azole drugs. Increased efflux of drug, mediated by multidrug pumps belonging to two different families, the major facilitators and the ATP-binding cassette (ABC) transporters, also confers resistance to azole antifungal agents (1, 23–25, 29, 31). The genes coding for several ABC transporters in C. albicans have been identified, including several CDR genes (2, 16, 24, 25, 30). These ABC transporters, which have been associated with drug resistance in a variety of eukaryotic cells, include a membrane pore composed of transmembrane segments and two ATP-binding cassettes on the cytosolic side of the membrane, which provide the energy source for the pump (3, 7). The MDR1 gene (also called BENr) is the only gene coding for a major facilitator that has been identified in C. albicans so far (5), and its overexpression leads to fluconazole resistance exclusively among azole drugs (23, 25, 31). The major facilitators contain a transmembrane pore but use proton motive force as their energy source (12). In the present study, we have investigated the expression of C. albicans ERG11 (encoding lanosterol 14α-demethylase, formerly designated ERG16 [8, 9]), MDR1, and CDR genes in sequential clinical isolates obtained from HIV-infected patients with OPC in order to assess the distribution and frequency of various mechanisms responsible for the development of antifungal drug resistance and their clinical impact.

Concave probe for arthroscopic surgery

Abstract: Disclosed herein is a new arthroscopic probe with a concave distal tip which simultaneously constrains and cuts tissue. It is particularly adapted to cutting ligaments and tendons. Also disclosed is a thermal energy delivery apparatus which includes (a) a probe means with a distal end and a proximal end, wherein the distal end has a concave tip; (b) a first electrode means positioned at the distal end of the probe means, wherein the first electrode means is configured to deliver sufficient thermal energy to cut ligaments or tendons; and (c) a cabling means coupled to the proximal end of the probe means. In another embodiment of the invention a controller for controlling the delivery of energy and liquid to a surgical instrument with a temperature sensor is disclosed. The energy is supplied by an energy source and the liquid is supplied by a pump. The controller includes a temperature and a flow regulator. The temperature regulator is coupled to the energy source and coupled to the pump. The temperature regulator is responsive to a first temperature indication from the temperature sensor to determine that the first temperature indication exceeds a setpoint and to reduce an energy level from the energy source. The flow regulator is coupled to the pump and coupled to the temperature regulator. The flow regulator includes responsiveness to the first temperature indication to increase a flow of the liquid from the pump.

Surfactant-enhanced biodegradation of high molecular weight polycyclic aromatic hydrocarbons by stenotrophomonas maltophilia

Abstract: The objectives of this study were to isolate and evaluate microorganisms with the ability to degrade high molecular weight polycyclic aromatic hydrocarbons (PAHs) in the presence of synthetic surfactants. Stenotrophomonas maltophilia VUN 10,010, isolated from PAH-contaminated soil, utilized pyrene as a sole carbon and energy source and also degraded other high molecular weight PAHs containing up to seven benzene rings. Various synthetic surfactants were tested for their ability to improve the PAH degradation rate of strain VUN 10,010. Anionic and cationic surfactants were highly toxic to this strain, and the Tween series was used as a growth substrate. Five nonionic surfactants (Brij 35, Igepal CA-630, Triton X-100, Tergitol NP-10, and Tyloxapol) were not utilized by, and were less toxic to, strain VUN 10,010. MSR and log Km values were determined for fluoranthene, pyrene, and benzo[a]pyrene in the presence of these nonionic surfactants and their apparent solubility was increased by a minimum of 250-fold in the presence of 10 g L−1 of all surfactants. The rate of pyrene degradation by strain VUN 10,010 was enhanced by the addition of four of the nonionic surfactants (5–10 g L−1); however, 5 g L−1 Igepal CA-630 inhibited pyrene degradation and microbial growth. The specific growth rate of VUN 10,010 on pyrene was increased by 67% in the presence of 10 g L−1 Brij 35 or Tergitol NP-10. The addition of Brij 35 and Tergitol NP-10 to media containing a single high molecular weight PAH (four and five benzene rings) as the sole carbon source increased the maximum specific PAH degradation rate and decreased the lag period normally seen for PAH degradation. The addition of Tergitol NP-10 to VUN 10,010 cultures which contained a PAH mixture (three to seven benzene rings) substantially improved the overall degradation rate of each PAH and increased the specific growth rate of VUN 10,010 by 30%. Evaluation of the use of VUN 10,010 for degrading high molecular weight PAHs in leachates from surfactant-flushed, weathered, PAH-contaminated sites is warranted. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:482–494, 1998.

Electrosurgical hemostatic and stapling device

Abstract: An improved electrosurgical instrument is provided for cauterization and/or welding of tissue of varying impedances, thicknesses and vascularity especially in the performance of endoscopic procedures. The instrument compresses the tissue between one pole of a bipolar energy source located on one interfacing surface, and a second interfacing surface. A second pole is located on one of the two interfacing surfaces. In a preferred embodiment, the second pole is located on the same interfacing surface as the first pole and an insulator electrically isolates the two poles. A preferred application of the invention is in a cutting instrument wherein a hemostatic line is formed along a cut line using RF energy. The instrument makes use of staples and cartridges therefore.

Microbiology of a Nitrite-Oxidizing Bioreactor

Abstract: The microbiology of the biomass from a nitrite-oxidizing sequencing batch reactor (NOSBR) fed with an inorganic salts solution and nitrite as the sole energy source that had been operating for 6 months was investigated by microscopy, by culture-dependent methods, and by molecular biological methods, and the seed sludge that was used to inoculate the NOSBR was investigated by molecular biological methods. The NOSBR sludge comprised a complex and diverse microbial community containing gram-negative and gram-positive rods, cocci, and filaments. By culture-dependent methods (i.e., micromanipulation and sample dilution and spread plate inoculation), 16 heterotrophs (6 gram positive and 10 gram negative) were identified in the NOSBR sludge (RC), but no autotrophs were isolated. 16S ribosomal DNA clone libraries of the two microbial communities revealed that the seed sludge (GC) comprised a complex microbial community dominated by Proteobacteria (29% beta subclass; 18% gamma subclass) and high G+C gram-positive bacteria (10%). Three clones (4%) were closely related to the autotrophic nitrite-oxidizer Nitrospira moscoviensis. The NOSBR sludge was overwhelmingly dominated by bacteria closely related to N. moscoviensis (89%). Two clone sequences were similar to those of the genus Nitrobacter. Near-complete insert sequences of eight RC and one GC N. moscoviensis clone were determined and phylogenetically analyzed. This is the first report of the presence of bacteria from the Nitrospira phylum in wastewater treatment systems, and it is hypothesized that these bacteria are the unknown nitrite oxidizers in these processes.