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1.
Sixteen clinical Vibrio cholerae O1 strains from four different countries were selected for comparison by traditional ribotyping and an automated RiboPrinter system for identification and discrimination purposes. Automated ribotyping, which routinely uses the restriction enzyme EcoRI for typing all bacterial species, produced only five different ribotypes compared with 10 different EcoRI ribotypes obtained by the traditional method. Traditional and automated ribotyping using the restriction enzyme BglI, which is recommended for the ribotyping of V. cholerae, produced 10 and seven different ribotypes, respectively. The lower discrimination shown by the RiboPrinter system was caused mainly by an inability to differentiate closely located fragments due to a lower resolution and electrophoresis conditions, a parameter which cannot be changed in the automated system. The RiboPrinter system includes a database for bacterial identification. However, none of the V. cholerae O1 strains studied showed EcoRI ribotype patterns which matched any of the patterns included in the database. In conclusion, the existing RiboPrinter system is not adequate for taxonomic identification and classification of V. cholerae O1.  相似文献   

2.
Conventional grids with high grid ratios are not ideal for use in bedside radiography because of the difficulty in maintaining the required alignment. To address this issue, the potential usefulness of a combination system that employs removal processing software for scattered radiation and a conventional grid with a low grid ratio (3:1) for an indirect-conversion-type flat-panel detector system was evaluated by measuring image quality and observer performance. The hypothetical grid ratios for the software were 2:1, 3:1, 6:1, 8:1, and 10:1. The scatter fraction of the combination system was lower than that of the software alone. Significant improvement was observed in the effect of scattered radiation removal up to a hypothetical software grid ratio of 6:1. However, the Wiener spectrum increased (radiographic noise degraded) with an increase in the hypothetical grid ratio. The contrast ratios of the combination system were improved compared to those of the software alone for anthropomorphic chest radiographs. An observer test was also conducted using the contrast-detail phantom. The combination system indicated higher low-contrast detectability compared to the software alone, although there were no statistical differences between the hypothetical grid ratios of 6:1, 8:1, and 10:1 in all combinations of the software alone and the combination system. We concluded that a combination system with software that uses a hypothetical grid ratio of 6:1 or more and a 3:1 conventional grid would be more useful for reducing the scattered radiation component compared to the software alone with a hypothetical higher grid ratio for thicker objects.  相似文献   

3.
Reverse-phase supports for the separation of peptides and proteins are compared in two high-performance liquid chromatographic systems. One uses a trifluoroacetic acid-acetonitrile solvent system with a 206-nm detector, and the other uses pyridine-formate or pyridine-acetate and 1-propanol with a postcolumn fluorescence detector. Each system was examined with RP8, RP18, and alkylphenyl supports. In most applications, the trifluoroacetic acid-acetonitrile solvent system used in conjunction with an alkylphenyl column performed best. The use of this system for the preparation of low-microgram amounts of samples for microsequence analysis is illustrated.  相似文献   

4.
A novel system for scintimammography has been developed, which has high spatial resolution, good sensitivity, better energy resolution, and lower cost than conventional systems. In addition, the system incorporates the potential to provide additional information and functionality beyond imaging, including x,y and z lesion location, integration with a stereotatic biopsy system and images both breasts at the same time. Methods: The system uses sheet NaI (Tl) crystals, PM Tubes, and slant hole collimators allowing complete separation of the breast from the chest wall while remaining in contact with the breast at all depths. The physical characteristics are presented, with images and compared with other systems. Results: The limit of lesion detectability in terms lesion size, depth and contrast has been investigated and compared with a current conventional system. Using accepted patient dose data, the anticipated radiopharmaceutical activity related to the lesion size is used for imaging tests and provides a measure of expected of lesion detectability. Conclusion: Large area, sheet NaI (Tl) detector systems with slant hole collimators are capable of imaging features of below 5mm size at both surface and at clinical depths with the amount of activity expected in lesions of this size with patient administered doses in the clinically acceptable range.  相似文献   

5.
Four different neural network algorithms, binary adaptive resonance theory (ART1), self-organizing map, learning vector quantization and back-propagation, were compared in the diagnosis of acute appendicitis with different parameter groups. The results show that supervised learning algorithms learning vector quantization and back-propagation were better than unsupervised algorithms in this medical decision making problem. The best results were obtained with the learning vector quantization. The self-organizing map algorithm showed good specificity, but this was in conjunction with lower sensitivity. The best parameter group was found to be the clinical signs. It seems beneficial to design a decision support system which uses these methods in the decision making process.  相似文献   

6.
The capacity of human foetal lymphocytes to respond to PHA and to form E-rosettes have been compared with data from adult individuals. For this purpose a microculture system that uses whole blood and avoids the problems of lymphocyte separation, has been developed. Foetal lymphocytes reached optimal stimulation with lower dosis of PHA (31,2 microgram/ml) as compared with adult cells (125-252 microgram/ml). However their quantitative response (measured by 14C-thymidine uptake) was equal in both groups. In addition, peripheral T cells (E-rosetting cells) reached values of 36.47 +/- 9% in newborn and 49.6 +/- 10% in normal adult controls. These results are discussed as to the status and development of cellular inmunity in human foetus.  相似文献   

7.
Caiçaras are inhabitants of the Atlantic Forest coast in SE Brazil. We studied the uses of plants by five Caiçara communities and compared medicinal plant citations by informants in coastal and island communities. We use diversity indices to evaluate the use of plants and to compare communities. There is a high diversity of plants used in the Atlantic Forest coasts: we found 276 species used for food, medicine and construction. Caiçaras rely on folk medicine, and medicinal plants were especially cited in interviews. Following predictions of island biogeography theory, we found a lower diversity of medicinal plants cited in islands compared to continental communities.  相似文献   

8.
Cold adaptation of microorganisms   总被引:11,自引:0,他引:11  
Psychrophilic and psychrotrophic microorganisms are important in global ecology as a large proportion of our planet is cold (below 5 degrees C); they are responsible for the spoilage of chilled food and they also have potential uses in low-temperature biotechnological processes. Psychrophiles and psychrotrophs are both capable of growing at or close to zero, but the optimum and upper temperature limits for growth are lower for psychrophiles compared with psychrotrophs. Psychrophiles are more often isolated from permanently cold habitats, whereas psychrotrophs tend to dominate those environments that undergo thermal fluctuations. The molecular basis of psychrophily is reviewed in terms of biochemical mechanisms. The lower growth temperature limit is fixed by the freezing properties of dilute aqueous solutions inside and outside the cell. In contrast, the ability of psychrophiles and psychrotrophs to grow at low, but not moderate, temperatures depends on adaptive changes in cellular proteins and lipids. Changes in proteins are genotypic, and are related to the properties of enzymes and translation systems, whereas changes in lipids are genotypic or phenotypic and are important in regulating membrane fluidity and permeability. The ability to adapt their solute uptake systems through membrane lipid modulation may distinguish psychrophiles from psychrotrophs. The upper growth temperature limit can result from the inactivation of a single enzyme type or system, including protein synthesis or energy generation.  相似文献   

9.
Immunostimulating complexes (ISCOMs) are unique, multimolecular structures formed by encapsulating antigens, lipids, and triterpene saponins of plant origin, and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants collected in Kazakhstan, with antigens from the poultry coccidian parasite Eimeria tenella, were evaluated for their potential use in developing a vaccine for control of avian coccidiosis. Saponins isolated from the plants Aesculus hippocastanum and Glycyrrhiza glabra were partially purified by HPLC. The saponin fractions obtained from HPLC were evaluated for toxicity in chickens and chicken embryos. The HPLC saponin fractions with the least toxicity, compared to a commercial saponin Quil A, were used to assemble ISCOMs. When chicks were immunized with ISCOMs prepared with saponins from Kazakhstan plants and E. tenella antigens, and then challenged with E. tenella oocysts, significant protection was conveyed compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used, with low toxicity, for preparation of highly immunogenic coccidia vaccine.  相似文献   

10.
Chen S 《Proteomics》2006,6(1):16-25
Current protein identification techniques are largely based on MALDI-TOF mass fingerprinting and LC-ESI MS/MS sequence tag analysis. Here we describe an improved method for rapid protein identification that uses direct infusion nanoelectrospray quadrupole time-of-flight (nanoESI QTOF) MS. Protein digests were analyzed without LC separation using nanoESI on a QSTAR XL MS/MS system in information dependent data acquisition mode. The protein identification conditions and parameters were extensively evaluated with in-solution and in-gel digested protein samples. Rapid identification of proteins was achieved and compared directly to the results obtained on the same samples using nanoflow HPLC-MS/MS on the QSTAR system. The increased throughput, reproducibility, the high data quality, and the ease of use make the direct infusion system an efficient and affordable technique for protein identification analysis.  相似文献   

11.
Algae are the promising feedstock of biofuel. The screening of competent species and proper fertilizer supply is of the most important tasks. To accelerate this rather slow and laborious step, we developed an integrated high‐throughput digital microfluidic (DMF) system that uses a discrete droplet to serve as a microbioreactor, encapsulating microalgal cells. On the basis of fundamental understanding of various droplet hydrodynamics induced by the existence of different sorts of ions and biological species, incorporation of capacitance‐based position estimator, electrode‐saving‐based compensation, and deterministic splitting approach, was performed to optimize the DMF bioreactor. Thus, it enables all processes (e.g., nutrient gradient generation, algae culturing, and analyzing of growth and lipid accumulation) occurring automatically on‐chip especially in a high‐fidelity way. The ability of the system to compare different microalgal strains on‐chip was investigated. Also, the Chlorella sp. were stressed by various conditions and then growth and oil accumulation were analyzed and compared, which demonstrated its potential as a powerful tool to investigate microalgal lipid accumulation at significantly lower laborites and reduced time.  相似文献   

12.
A system has been developed to identify the samples obtained from Apollo spacecraft which uses a computer to process laboratory test results. This system is described in detail. The results of using the system with the available data are presented compared with conventional laboratory identifications. As a result of the performance with these comparisons, the system has been incorporated into NASA's Planetary Quarantine Lunar Information System for routine use.This work was conducted under Contracts W-12,853 and W-13,062, Bioscience Division, Office of Space Science and Applications, NASA Headquarters, Washington, D.C.  相似文献   

13.
Despite the many studies on eight-legged animals and the importance of their mechanics of terrestrial locomotion, the mechanical energy of crabs in voluntary locomotion on uneven, unpredictable terrain surfaces has received little attention thus far. In this paper, motion video images of Chinese mitten crab (Eriocheir sinensis Milne-Edwards) locomotion on five types of terrains were recorded using a high-speed three-dimensional (3D) recording video system. The typical variables of locomotion such as gait patterns, duty factor, mechanical energy of the mass center, mass-specific rate of the total mechanical power of the mass center, and percentage recovery, were analyzed. Results show that the Chinese mitten crab uses random gaits instead of the alternating tetrapod gait with the increasing terrain roughness. The duty factors of the rows of the leading legs are greater for all terrains than those of the rows of the trailing legs. On smooth terrain, the duty factors of the rows of the trailing legs are greater than that on rough terrains. Kinematic measurements and calculations reveal that similar to mammals, birds, and arthropods, the Chinese mitten crab uses two fundamental gaits to save mechanical energy: the inverted pendulum gait and the bouncing gait. The bouncing gait is the main pattern of mechanical energy conservation. The low probability of injury and energy expenditure due to adaptations to various terrains induce the Chinese mitten crab to modify the mass-specific rate of the total mechanical power of the mass center. The statistical results of percentage recovery also reveal that the Chinese mitten crab has lower energy recovery efficiency over rough terrains compared with smooth terrains.  相似文献   

14.
This study reports on the carbon, water, and energy footprints of tomatoes grown in a greenhouse in Northern Italy and two possible future variations of heating and carbon dioxide (CO2) fertilization on the current setup. The heat supply in place, consisting of natural gas (NG) and canola oil combustion, is compared to cogeneration and incineration of municipal solid waste for heating and CO2 from industrial exhaust for fertilization. As a benchmark, the current system is also compared to a conventional system, in which heat is delivered solely based on NG. Each kilogram (kg) of fresh tomatoes (“Cuore di Bue” variety) produced in the current greenhouse emits 2.28 kg CO2 equivalents (eq) and uses 95.5 megajoules (MJ) eq energy and 122 liters (L) of water. Relative to the system in place, the carbon footprint (CF) is 57.5% and 18% higher with conventional NG heating and cogeneration and is 40% lower with waste valorization. Further, 33%, 55%, and 63% less energy and 9%, 96%, and 14% less water are used in the conventional, cogeneration, and waste valorization scenarios, respectively. This confirms that there are multiple strategies to reduce the impact of the tomato production under consideration.  相似文献   

15.
Errors and imprecisions in distance restraints derived from NOESY peak volumes are usually accounted for by generous lower and upper bounds on the distances. In this paper, we propose a new form of distance restraints, replacing the subjective bounds by a potential function obtained from the error distribution of the distances. We derived the shape of the potential from molecular dynamics calculations and by comparison of NMR data with X-ray crystal structures. We used complete cross-validation to derive the optimal weight for the data in the calculation. In a model system with synthetic restraints, the accuracy of the structures improved significantly compared to calculations with the usual form of restraints. For experimental data sets, the structures systematically approach the X-ray crystal structures of the same protein. Also standard quality indicators improve compared to standard calculations. The results did not depend critically on the exact shape of the potential. The new approach is less subjective and uses fewer assumptions in the interpretation of NOESY peak volumes as distance restraints than the usual approach. Figures of merit for the structures, such as the RMS difference from the average structure or the RMS difference from the data, are therefore less biased and more meaningful measures of structure quality than with the usual form of restraints.  相似文献   

16.
This paper describes a new, simple, quantitative technique for evaluating the relative usefulness of plants to people. The technique is then compared to the quantitative approaches in ethnobotany that have been developed recently. Our technique is used to calculate the importance of over 600 species of woody plants to non-indigenous mestizo people in Tambopata, Amazonian Peru. Two general classes of hypotheses are formulated and tested statistically, concerning (1) the relative importance of different species, and (2) the importance of different families. The plant families are compared with respect to all uses, and with respect to five broad groups of uses. Palms, Annonaceae, and Lauraceae were found to be the most useful woody plant families. On average, the 20 largest woody plant families are most important to mestizos for subsistence construction materials, followed in descending order by commercial, edible, technological, and medicinal uses.  相似文献   

17.
Next-generation manufacturing (NGM) has evolved over the past decade to a point where large biopharmaceutical organizations are making large investments in the technology and considering implementation in clinical and commercial processes. There are many well-considered reasons to implement NGM. For the most part, organizations will not fund NGM unless the implementation benefits the funding organization by providing reduced costs, reduced time, or additional needed capabilities. Productivity improvements gained from continuous purification are shown in this work, which used a new system that fully integrates and automates several downstream unit operations of a biopharmaceutical process to provide flexibility and easy implementation of NGM. The equipment and automation needed to support NGM can be complicated and expensive. Biopharmaceutical Process Development considered two options as follows: (1) design its own NGM system or (2) buy a prebuilt system. PAK BioSolutions offers a turn-key automated and integrated system that can operate up to four continuous purification stages simultaneously, while maintaining a small footprint in the manufacturing plant. The system provides significant cost benefits (~10× lower) compared with the alternative—integration of many different pieces of equipment through a Distributed Control System that would require significant engineering time for design, automation, and integration. Integrated and Continuous Biomanufacturing can lead to significant reductions in facility size, reduced manufacturing costs, and enhanced product quality when compared with the traditional batch mode of operation. The system uses new automation strategies that robustly link unit operations. We present the optimized process fit, sterility and bioburden control strategy, and automation features (such as pH feedback control and in-line detergent addition), which enabled continuous operation of a 14-day end-to-end monoclonal antibody purification process at the clinical manufacturing scale.  相似文献   

18.
19.
While there is literature on excess winter mortality, there are few studies examining the evolution of its trend which may be changing in parallel with global warming. This study aimed to examine the trend in the excess mortality in winter as compared to summer among the older population in a sub-tropical city and to explore its association with extreme weather. We used a retrospective study based on the registered deaths among the older population in Hong Kong during 1976-2010. An Excess Mortality for Winter versus Summer (EMWS) Index was used to quantify the excess number of deaths in winter compared to summer. Multiple linear regressions were used to analyze the trends and its association with extreme weather. Overall, the EMWS Index for ischemic heart disease, cerebrovascular diseases, chronic lower respiratory diseases, pneumonia, and other causes were 43.0%, 34.2%, 42.7%, 23.4% and 17.6%, respectively. Significant decline was observed in the EMWS Index for chronic lower respiratory diseases and other causes. The trend in the index for cerebrovascular diseases depended on the age group, with older groups showing a decline but younger groups not showing any trend. Meteorological variables, in terms of extreme weather, were associated with the trends in the EMWS Index. We concluded that shrinking excess winter mortality from cerebrovascular diseases and chronic lower respiratory diseases was found in a sub-tropical city. These trends were associated with extreme weather, which coincided with global warming.  相似文献   

20.
Summary Three improved versions of the gradient-enhanced HMQC experiment are presented which yield phase-sensitive spectra with increased sensitivity compared to the recently described field-gradient HMQC schemes. The first method uses a complex linear back-prediction in order to generate the FIDs at the t1=0. With this approach, refocusing pulses on the heteronucleus are not necessary. The sequence is especially useful for larger proteins with short relaxation times for the coherences that evolve during t1. In the other two methods lower and shorter gradient pulses or asymmetric gradients are used to optimize sensitivity.  相似文献   

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