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991.
Pedestrian injuries and vehicle type in Maryland, 1995-1999   总被引:2,自引:0,他引:2  
Pedestrian deaths constitute the second largest category of motor vehicle deaths in the US. The present study examined how pedestrian injury is associated with vehicle type, while controlling for vehicle weight and speed.Police, trauma registry, and autopsy data were linked for injured pedestrians. Logistic regression analyses were performed to control for vehicle weight and speed. Outcomes included pedestrian mortality, injury severity score, and injuries to specific body regions.Compared to conventional cars, pedestrians hit by sport utility vehicles and pick-up trucks were more likely to have higher injury severity scores (odds ratio=1.48; 95% confidence interval: 1.18-1.87) and to die (odds ratio=1.72; 95% confidence interval: 1.31-2.28). These relationships diminished when vehicle weight and speed were controlled for. At lower speeds, pedestrians struck by sport utility vehicles, pick-up trucks, and vans were approximately two times as likely to have traumatic brain, thoracic, and abdominal injuries; at higher speeds, there was no such association.The overall increased danger sport utility vehicles and pick-up trucks present to pedestrians may be explained by larger vehicle masses and faster speeds. At slower speeds being hit by sport utility vehicles, and pick-up trucks, and vans resulted in specific injuries, indicating that vehicle design may contribute to different injury patterns.  相似文献   
992.
The effect of cage size on spontaneous locomotor rhythms of laboratory mice was studied under simulated light-dark (12:12) cycles. On-line image analysis of bodily displacement yielded a locomotor signal over a period of 3 days. Continuous wavelet transform was applied to the signal, and ensemble averaging of eight mice revealed in the time-frequency plot bouts of increased motor activities. Notably, there were two bouts in the dark corresponding to ultradians of periods below 5 h: a first bout at the dark onset (at 0.6-1.0 cycle/h), and a second bout during the second half of the dark period (at 0.4-0.7 cycle/h). These increases of activity were more intense and distinct when the animals were kept inside the larger cage. Furthermore, the first bout disappeared when the animals were kept in the small cage for 3 days.  相似文献   
993.
Accumulation of cadmium was assessed by comparing 58 soil samples archived up to 50 years ago with present-day soils from the same sites. Mean levels of acid-extractable Cd have increased from 0.39 mg kg-1 to 0.85 mg kg-1 closely matching the amount of Cd applied in phosphate fertiliser. CaCl2-extractable Cd has increased from 0.02 mg kg-1 to 0.11 mg kg-1, a greater percentage increase than for acid-extractable Cd. This may be attributed to added Cd being more mobile than native Cd. Cadmium levels have increased in Allophanic Soils, Brown Soils, Gley Soils, Organic Soils, Oxidic Soils, Pallic Soils, Pumice Soils, and Hydrothermal Recent Soils but not in Fluvial Recent Soils, which appear to have a lower Cd retention capacity.  相似文献   
994.
The hamster cheek pouch is a much used but incompletely understood experimental model. In particular, the cheek pouch epithelial lipids, which are important for permeability barrier function as well as other aspects of epithelial biology, have not been completely characterized. In the present study, the complete lipid class composition has been determined by thin-layer chromatography in conjunction with photodensitometry. The major lipid classes were phospholipids, free sterols, and ceramides. Minor amounts of monohexosylceramides, sterol esters, fatty acids, and triglycerides were also present. Significant amounts of covalently bound omega-hydroxyceramide was also detected. Transmission electron micrographs reveal extensive, largely paired, lipid bilayers in the intercellular spaces of the stratum corneum.  相似文献   
995.
The complete Hox gene complement of the Japanese pufferfish has now been determined, together with the genomic organisation of all four Hox gene clusters. One of the many surprises is that this strange fish has lost an unusually large number of Hox genes.  相似文献   
996.
This paper describes the results of thermal stability studies of polybutadiene-coated zirconia reversed phases and application to fast HPLC separations at elevated temperatures and high flow rates. The thermal stability of the material was evaluated at temperatures up to 200 degrees C, and the rapid analyses of polyaromatic hydrocarbons and typical reversed-phase test mixtures were carried out at 100 degrees C and a flow rate of 5 mL/min. We found that the material is completely stable at 200 degrees C for at least 1300 column volumes. Analysis time can be decreased about 18-fold at high temperatures and flow rates without any significant loss in resolution relative to that at conventional temperatures and normal flow rates. For the separation of a five-component reversed-phase test mixture, the analysis time was only 50 s.  相似文献   
997.
Several formulations of poly(epsilon-caprolactone) (PCL), poly(lactic acid) (PLA), and poly(lactic-co-glycolic acid) (PLGA) nanocapsules containing phenylbutazone were prepared according to the interfacial deposition technique. These formulations differed in the type of polymer used to form the shell of the nanocapsules. Analysis of particle size distribution and encapsulation efficiency of the nanocapsules revealed that the type and molecular weight of polyester used were the main factors influencing these properties. PLA had the highest encapsulation efficiency with the best reproducibility. From in vitro release studies, a small amount of drug release was observed at pH 7.4. However, in the gastric medium, an important burst effect occurred and was highest with the PLGAs and lowest with PCL, suggesting that drug release from these systems is affected by the type of polymer and the environmental conditions. The two formulations of phenylbutazone-loaded nanocapsules should be evaluated based on PCL and PLA in vivo in order to determine to what extent they are able to reduce the local side effects of this drug.  相似文献   
998.
Chlorella sorokiniana has seven ammonium-inducible, chloroplastic NADP-specific glutamate dehydrogenase (NADP-GDH) isozymes composed of varying ratios of alpha- and beta-subunits. Southern blot and allele-specific PCR analyses indicate that the C. sorokiniana genome possesses a single 7178 bp nuclear NADP-GDH gene. cDNA cloning and sequencing, 5'-RACE-PCR analysis, and RNase protection analysis identified two NADP-GDH mRNAs that are identical with the exception of a 42 nt sequence located within the 5'-coding region of the longer mRNA. The 42 nt sequence, termed an auxon because it serves as an exon or intron, appears to undergo alternative splicing from the precursor mRNA by a process that is regulated by both nutritional and environmental signals. Depending upon whether the auxon is included or excluded in a mature mRNA, the gene can be considered to consist of 22 or 23 exons, respectively. The 2074 and 2116 nt mRNAs encode precursor proteins of 56,350 and 57,850 Da, respectively. The N-termini of the purified mature alpha- and beta-subunits were sequenced, identifying full-length subunits of 53,501 and 52,342 Da, respectively. The sequences of the subunits are identical except for an 11 amino acid extension at the N-terminus of the alpha-subunit. The alpha-subunit has an additional alpha-helical domain at its N-terminus compared with the beta-subunit. By correlating the abundances of the two mRNAs with the levels (and relative turnover rates) of the alpha- and beta-subunit antigens during induction in Chlorella, the larger mRNA is proposed to encode the larger subunit.  相似文献   
999.
Studies were carried out using DBA/2 mice on the relationship between the behavioral effects of antagonists of different types of 5-HT receptors and the level of activity of alpha 2-adrenoceptors. The 5-HT1c receptor antagonists mianserin (2 mg/kg) and cyproheptadine (2 mg/kg) and the 5-HT2 receptor antagonist ketanserin (3 mg/kg) had no effect on movement activity, while the 5-HT3 and 5-HT4 receptor antagonists zacopride (1 mg/kg) and ICS 205-930 (1 mg/kg) reduced movement behavior in intact animals. On a background of treatment with the alpha 2-adrenoceptor blocker yohimbine (0.5 mg/kg), mianserin, cyproheptadine, and ketanserin inhibited movement activity and significantly reduced the sensitivity of animals to audiogenic convulsions. These data indicate that administration of alpha 2-adrenoceptor antagonists increases the efficiency with which serotonin receptors regulate behavior.  相似文献   
1000.
Thirtysix patients with persistent gestational trophoblastic disease were analysed in The Clinic of Cancer of Female Reproductive System. Using transvaginal USG, the volume of pathological foci within myometrium, diametre of theca lutein ovarian cysts and uterus length before, during and after the treatment were registred. In order to check the effectiveness of USG examination in the monitoring of GTD treatment particular USG factors were compared with hCG level. On 28 patients (77.7%) in USG examination pathological changes in uterus and ovaries were seen. The relation between hCG level and tumor volume, uterus length and theca lutein ovarian cysts was stated. That proves the usefulness of transvaginal USG examination in the monitoring of treatment of patients with persistent gestational trophoblastic disease.  相似文献   
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