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61.
In order to obtain evidence for the existence of psychrophilic methanogenic communities in sediments of deep lakes that are low-temperature environments (4 to 5 degrees C), slurries were first incubated at temperatures between 4 and 60 degrees C for several weeks, at which time they were amended, or not, with an additional substrate, such as cellulose, butyrate, propionate, acetate, or hydrogen, and further incubated at 6 degrees C. Initial methane production rates were highest in slurries preincubated at temperatures between 4 and 15 degrees C, with maximal rates in slurries kept at 6 degrees C. Hydrogen-amended cultures were the only exceptions, with the highest methane production rates at 6 degrees C after preincubation at 30 degrees C.  相似文献   
62.
This study shows how a probabilistic microstructural model for fibrous connective tissue behavior can be used to objectively describe soft tissue low-load behavior. More specifically, methods to determine tissue reference length and the transition from the strain-stiffening "toe-region" to the more linear region of the stress-strain curve of fibrous connective tissues are presented. According to a microstructural model for uniaxially loaded collagenous tissues, increasingly more fibers are recruited and bear load with increased tissue elongation. Fiber recruitment is represented statistically according to a Weibull probability density function (PDF). The Weibull PDF location parameter in this formulation corresponds to the stretch at which the first fibers begin to bear load and provides a convenient method of determining reference length. The toe-to-linear region transition is defined by utilizing the Weibull cumulative distribution function (CDF) which relates the fraction of loaded fibers to the tissue elongation. These techniques are illustrated using representative tendon and ligament data from the literature, and are shown to be applicable retrospectively to data from specimens that are not heavily preloaded. The reference length resulting from this technique provides an objective datum from which to calculate stretch, strain, and tangent modulus, while the Weibull CDF provides an objective parameter with which to characterize the limits of low-load behavior.  相似文献   
63.
64.
A clinical trial of retroviral-mediated transfer of the adenosine deaminase (ADA) gene into umbilical cord blood CD34(+) cells was started in 1993. ADA-containing peripheral blood mononuclear cells (PBMCs) have persisted in patients from this trial, with T lymphocytes showing the highest prevalence of gene marking. To gain a greater understanding of the nature and number of the transduced cells that were engrafted, we used linear amplification-mediated PCR (LAM-PCR) to identify clonal vector proviral integrants. In one patient, a single vector integrant was predominant in T lymphocytes at a stable level over most of the eight-year time span analyzed and was also detected in some myeloid samples. T-cell clones with the predominant integrant, isolated after eight years, showed multiple patterns of T-cell receptor (TCR) gene rearrangement, indicating that a single pre-thymic stem or progenitor cell served as the source of the majority of the gene-marked cells over an extended period of time. It is important to distinguish the stable pattern of monoclonal gene marking that we observed here from the progressive increase of a T-cell clone with monoclonal gene marking that results from leukemic transformation, as observed in two subjects in a clinical trial of gene therapy for X-linked severe combined immunodeficiency (SCID).  相似文献   
65.
Pietsch M  König WA  Joulain D 《Chirality》2003,15(9):794-798
(-)-2,6-Dimethyl-10-(p-tolyl)-2,6(E)-undecadiene (1) is a major constituent in the essential oil of Cistus monspeliensis, an aromatic shrub common in Mediterranian countries. 1 was isolated by column chromatography, subjected to ozonolyses, and the absolute configuration was determined by enantioselective gas chromatographic correlation with the ozonolysis product of the sesquiterpene hydrocarbon ar-curcumene with known absolute configuration.  相似文献   
66.
Oligomers of the negatively-charged amino acids, glutamic acid, aspartic acid, and O-phospho-L-serine are adsorbed by hydroxylapatite and illite with affinities that increase with oligomer length. In the case of oligo-glutamic acids adsorbed on hydroxylapatite, addition of an extra residue results in an approximately four-fold increase in the strength of adsorption. Oligomers much longer than the 7-mer are retained tenaciously by the mineral. Repeated incubation of short oligo-glutamic acids adsorbed on hydroxylapatite or illite with activated monomer leads to the accumulation of oligomers at least 45 units long. The corresponding reactions of aspartic acid and O-phospho-L-serine on hydroxylapatite are less effective in generating long oligomers, while illite fails to accumulate substantial amounts of long oligomers of aspartic acid or of O-phospho-L-serine.  相似文献   
67.
Partially amorphous La0.6Sr0.4CoO3‐δ (LSC) thin‐film cathodes are fabricated using pulsed laser deposition and are integrated in free‐standing micro‐solid oxide fuel cells (micro‐SOFC) with a 3YSZ electrolyte and a Pt anode. A low degree of crystallinity of the LSC layers is achieved by taking advantage of the miniaturization of the cells, which permits low‐temperature operation (300–450 °C). Thermomechanically stable micro‐SOFC are obtained with strongly buckled electrolyte membranes. The nanoporous columnar microstructure of the LSC layers provides a large surface area for oxygen incorporation and is also believed to reduce the amount of stress at the cathode/electrolyte interface. With a high rate of failure‐free micro‐SOFC membranes, it is possible to avoid gas cross‐over and open‐circuit voltages of 1.06 V are attained. First power densities as high as 200–262 mW cm?2 at 400–450 °C are achieved. The area‐specific resistance of the oxygen reduction reaction is lower than 0.3 Ω cm2 at 400 °C around the peak power density. These outstanding findings demonstrate that partially amorphous oxides are promising electrode candidates for the next‐generation of solid oxide fuel cells working at low‐temperatures.  相似文献   
68.

Purpose

This study examines the subjective acceptance during UHF-CMR in a cohort of healthy volunteers who underwent a cardiac MR examination at 7.0T.

Methods

Within a period of two-and-a-half years (January 2012 to June 2014) a total of 165 healthy volunteers (41 female, 124 male) without any known history of cardiac disease underwent UHF-CMR. For the assessment of the subjective acceptance a questionnaire was used to examine the participants experience prior, during and after the UHF-CMR examination. For this purpose, subjects were asked to respond to the questionnaire in an exit interview held immediately after the completion of the UHF-CMR examination under supervision of a study nurse to ensure accurate understanding of the questions. All questions were answered with “yes” or “no” including space for additional comments.

Results

Transient muscular contraction was documented in 12.7% of the questionnaires. Muscular contraction was reported to occur only during periods of scanning with the magnetic field gradients being rapidly switched. Dizziness during the study was reported by 12.7% of the subjects. Taste of metal was reported by 10.1% of the study population. Light flashes were reported by 3.6% of the entire cohort. 13% of the subjects reported side effects/observations which were not explicitly listed in the questionnaire but covered by the question about other side effects. No severe side effects as vomiting or syncope after scanning occurred. No increase in heart rate was observed during the UHF-CMR exam versus the baseline clinical examination.

Conclusions

This study adds to the literature by detailing the subjective acceptance of cardiovascular magnetic resonance imaging examinations at a magnetic field strength of 7.0T. Cardiac MR examinations at 7.0T are well tolerated by healthy subjects. Broader observational and multi-center studies including patient cohorts with cardiac diseases are required to gain further insights into the subjective acceptance of UHF-CMR examinations.  相似文献   
69.
The detection of West Nile virus (WNV) nucleic acid in a blood donation from Vienna, Austria, as well as in Culex pipiens pupae and egg rafts, sampled close to the donor’s residence, is reported. Complete genomic sequences of the human- and mosquito-derived viruses were established, genetically compared and phylogenetically analyzed. The viruses were not identical, but closely related to each other and to recent Czech and Italian isolates, indicating co-circulation of related WNV strains within a confined geographic area. The detection of WNV in a blood donation originating from an area with low WNV prevalence in humans (only three serologically diagnosed cases between 2008 and 2014) is surprising and emphasizes the importance of WNV nucleic acid testing of blood donations even in such areas, along with active mosquito surveillance programs.  相似文献   
70.
BackgroundPollen released by allergenic members of the botanically unrelated families of Asteraceae and Cupressaceae represent potent elicitors of respiratory allergies in regions where these plants are present. As main allergen sources the Asteraceae species ragweed and mugwort, as well as the Cupressaceae species, cypress, mountain cedar, and Japanese cedar have been identified. The major allergens of all species belong to the pectate lyase enzyme family. Thus, we thought to investigate cross-reactivity pattern as well as sensitization capacities of pectate lyase pollen allergens in cohorts from distinct geographic regions.MethodsThe clinically relevant pectate lyase pollen allergens Amb a 1, Art v 6, Cup a 1, Jun a 1, and Cry j 1 were purified from aqueous pollen extracts, and patients´ sensitization pattern of cohorts from Austria, Canada, Italy, and Japan were determined by IgE ELISA and cross-inhibition experiments. Moreover, we performed microarray experiments and established a mouse model of sensitization.ResultsIn ELISA and ELISA inhibition experiments specific sensitization pattern were discovered for each geographic region, which reflected the natural allergen exposure of the patients. We found significant cross-reactivity within Asteraceae and Cupressaceae pectate lyase pollen allergens, which was however limited between the orders. Animal experiments showed that immunization with Asteraceae allergens mainly induced antibodies reactive within the order, the same was observed for the Cupressaceae allergens. Cross-reactivity between orders was minimal. Moreover, Amb a 1, Art v 6, and Cry j 1 showed in general higher immunogenicity.ConclusionWe could cluster pectate lyase allergens in four categories, Amb a 1, Art v 6, Cup a 1/Jun a 1, and Cry j 1, respectively, at which each category has the potential to sensitize predisposed individuals. The sensitization pattern of different cohorts correlated with pollen exposure, which should be considered for future allergy diagnosis and therapy.  相似文献   
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