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The kinesin motor proteins generate directional movement along microtubules and are involved in many vital processes, including cell division, in eukaryotes. The kinesin superfamily is characterized by a conserved motor domain of approximately 320 residues. Dimeric constructs of N and C class kinesins, with the motor domains at opposite ends of the heavy chain, move towards microtubule plus and minus ends, respectively. Their crystal structures differ mainly in the region linking the motor domain core to the alpha-helical coiled coil dimerization domain. Chimeric kinesins show that regions outside of the motor domain core determine the direction of movement and mutations in the linker region have a strong effect on motility. Recent work on chimeras and mutants is discussed in a structural context giving insights to possible molecular mechanisms of kinesin directionality and motility.  相似文献   
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In the present study, we analyzed the relationship between body mass, food and water intake, and behavioral activity in pregnant and lactating rat dams exposed to continuous, 1.5-g centrifugation for 32 days. The period of centrifugation spanned from Gestational day (G) 11 of the rats' 22-day pregnancy until Postnatal day (P) 21, the time of weaning.  相似文献   
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We report the design and evaluation of PCR primers 63f and 1387r for amplification of 16S rRNA genes from bacteria. Their specificity and efficacy were tested systematically with a variety of bacterial species and environmental samples. They were found to be more useful for 16S rRNA gene amplification in ecological and systematic studies than PCR amplimers that are currently more generally used.  相似文献   
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Two dimensional NMR spectra of porcine brain natriuretic peptide have been recorded at 400 MHz. Peak assignments have been made and the combined information from chemical shifts, coupling constants, temperature coefficients, exchange studies and nuclear Overhauser effects has been used to determine the conformation of pBNP in aqueous media. Overall the peptide appears to be conformationally averaged with the possibility of some restricted flexibility in localized regions. The conformation of porcine brain natriuretic peptide in water is compared to previous studies in d6-DMSO and to studies of atrial natriuretic peptide and some closely related analogues in H2O and d6-DMSO.  相似文献   
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Lower urinary tract symptoms (LUTS) including urinary frequency and nocturia are common in aging men. Recent studies have revealed a strong association of prostatic inflammation with LUTS. We developed an animal model of bacterial induced, isolated prostatic inflammation and examined the effect of prostatic inflammation on voiding behavior in adult C57BL/6J mice. Prostatic inflammation was induced by transurethral inoculation of uropathogenic E. coli—1677. Bacterial cystitis was prevented by continuous administration of nitrofurantoin. Hematoxylin and eosin (H&E) staining and bacterial culture were preformed to validate our animal model. Voiding behavior was examined by metabolic cage testing on post-instillation day 1 (PID 1), PID 4, PID 7 and PID 14 and both voiding frequency and volume per void were determined. Mice with prostatic inflammation showed significantly increased voiding frequency at PID 1, 7 and 14, and decreased volume per void at all time points, as compared to mice instilled with saline and receiving nitrofurantoin (NTF). Linked analysis of voiding frequency and voided volumes revealed an overwhelming preponderance of high frequency, low volume voiding in mice with prostatic inflammation. These observations suggest that prostatic inflammation may be causal for symptoms of urinary frequency and nocturia.  相似文献   
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