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Waddington Lamont E Harbour VL Barry-Shaw J Renteria Diaz L Robinson B Stewart J Amir S 《Neuroscience》2007,144(2):402-411
Restricted feeding schedules (RF) in which daily access to food is limited to a few hours each day can entrain the rhythms of expression of circadian clock genes in the brain and periphery in rodents. The critical factors mediating the effect of RF on rhythms of clock gene expression are unknown. Previously, we demonstrated that daytime RF shifts the phase of expression of the clock protein, Period2 (PER2) in the oval nucleus of the bed nucleus of the stria terminalis in rats kept on a 12-h light/dark cycle, and restored the rhythm of PER2 expression in rats housed in constant light. We now report that RF also modifies the rhythms of PER2 expression in the central and basolateral nuclei of the amygdala and in the dentate gyrus, such that all three areas become synchronized, peaking 12 h after the time of food presentation. Daily limited access to sucrose or saccharine in freely fed rats or scheduled access to saline in sodium-deprived rats had no effect on these PER2 rhythms. Thus, it would appear that the rhythms of PER2 in limbic forebrain structures are sensitive to signals that arise from the alleviation of a negative metabolic state associated with scheduled feeding and that access to rewarding substances in the absence of food deprivation or metabolic challenges, per se, is not sufficient to alter the rhythms of PER2 expression in these regions. 相似文献
64.
The technical specifications and the operation of two atrial synchronous ventricular inhibited (ASVIP) pacemaker designs are described along with the results of clinical evaluation of these pacemakers in 30 patients. Clinical advantages of such pacemakers are contrasted with the performance of A-V sequential (DVI) and atrial synchronous (VAT) systems. 相似文献
65.
Jaime Eduardo Regis Anabel Renteria Samuel Ernesto Hall Md Sahid Hassan Cory Marquez Yirong Lin 《Materials》2021,14(16)
The growing demand for wearable devices, soft robotics, and tissue engineering in recent years has led to an increased effort in the field of soft materials. With the advent of personalized devices, the one-shape-fits-all manufacturing methods may soon no longer be the standard for the rapidly increasing market of soft devices. Recent findings have pushed technology and materials in the area of additive manufacturing (AM) as an alternative fabrication method for soft functional devices, taking geometrical designs and functionality to greater heights. For this reason, this review aims to highlights recent development and advances in AM processable soft materials with self-healing, shape memory, electronic, chromic or any combination of these functional properties. Furthermore, the influence of AM on the mechanical and physical properties on the functionality of these materials is expanded upon. Additionally, advances in soft devices in the fields of soft robotics, biomaterials, sensors, energy harvesters, and optoelectronics are discussed. Lastly, current challenges in AM for soft functional materials and future trends are discussed. 相似文献
66.
IB BOESEN 《Acta paediatrica (Oslo, Norway : 1992)》2003,92(12):1490-1490
67.
IB SEWERIN 《European journal of oral sciences》1981,89(1):97-101
Abstract— Twelve test cavities were filled with Adaptic Radiopaque by die author, varying the spatulation times from 5 s to 60 s at 5-s intervals but using the same mixing technique. Fillings spatulated for less than 20 s appeared inhornogeneous on radiographs. 2) Twenty-eight dentists produced 84 test fillings determining themselves their spatulation time and applying their own mixing technique. Spatulation times varied! froira 10 to 35 s. The fillings were radiographed under standardized conditions. Twenty-five were classified as radio graphically homogeneous, 35 as partly iniiomogeneous, and 24 as inhomogeneous. Short spatulation times were correlated with a high frequency ofinhomogeiieous fillings. Only 15% of fillings spatula ted for less than 30 s were radiographically homogeneous. The observed inhomogeneities imply a risk of false positive diagnoses of secondary carious lesions. 相似文献
68.
Abstract — The CEJ on radiographs is often used as a reference point in the assessment of alveolar bone loss. The aim of the present study was to test the stability of the radiographic CEJ ("RCEJ") in relation to the alveolar west under varying angulations of the central X-ray beam. In an experimental model four types of extracted teeth were radicrgraphed al 0° and 20° vertical angulation and at 15 horizontal angulations varying from a 17.5° mesial view to a 17.5° distal view. The buccal alveolar bone margin was simulated by a steel needle. RCEJ-"crest" distances were read at a × 10 magnification. Changing the vertical angutation from 0° to 20° reduced the RCEJ-"crest" distances far all tooth types (range ofaverage reduction 2.2–4.1 mm). HorizontaE angulations without concomitant vertical angularion had a significant effect but where without clinical significance. Horizontal anglslations in combination with a 20° vertical angulation bad a considerable influence; in a mesial view, mesial RCEJ-"crest" distances decreas-ed and distal ones increased, and vice wna in a distal view. The deviations from the true CEJ-crest distance demonstrated may be of clinical significance, and a critical attitude to alveolar bone loss measures on radiographs using the RCEJ as reference point is recommended. 相似文献
69.
V Swanson BA IB McIntosh BA MB chB KG Power MA MApp Sci PhD H Dobson FRCP FRCR 《International journal of clinical practice》1996,50(3):129-135
SUMMARY This study aimed to assess and compare the impact of letter of invitation, initial breast screening mammography, and subsequent recall procedures on the level of anxiety over breast problems. The survey of females undergoing routine breast screening procedures in a primary care setting is part of the first wave of a national breast screening programme in the UK. Women aged 50-64 registered with six general practices (n=2618) were invited by letter to attend for screening. Their self-perceived impact of receipt of invitation letter, attendance at initial screening, and recall, in terms of anxiety and concern about breast problems, was measured by a self-report questionnaire and the physical, emotional and social dysfunction subscales of the Psychological Consequences of Screening Mammography Questionnaire (PCQ). Overall, subjects' anxiety levels diminished between the receipt of their invitation letter and the completion of their screening examination. Subjects did not, however, respond to the letter of invitation and screening procedure in a homogeneous manner. In a sample of 1253, the letter of invitation reduced anxiety about breast problems in 39.7%, increased anxiety in 24.6%, and had no appreciable effect in 35.7%. In the 1280 who attended for breast screening, the examination procedure reduced anxiety about breast problems in 55.9%, increased anxiety in 12.8%, and had no appreciable effect in 31.3%. In a smaller sample (n=33) who completed questionnaires at recall, there were significant increases in PCQ-measured anxiety. Throughout the study, the PCQ was sensitive to change in anxiety over breast problems. We conclude that screening procedures can either increase or reduce anxiety about breast problems, or have no appreciable effect. Subjects' perception of the impact of receiving the letter of invitation and undergoing the screening examination procedure is related to previous levels of concern over breast problems. Conclusions about the psychological effect of breast screening cannot be drawn without consideration of the time and place of the baseline assessment. Participants in breast screening programmes therefore cannot be considered a homogeneous entity. Caution should be exercised when assessing the impact of screening procedures on entire populations as this approach might mask an important diversity of response. 相似文献
70.
IB Lamster JT Grbic RS Bucklan D Mitchell-Lewis HS Reynolds JJ Zambon 《Oral diseases》1997,3(Z1):S141-S148
A review of periodontal disease as a manifestation of HIV infection suggests a shift in emphasis over the past 5 years. Initially the focus was on newly described forms of periodontal disease (ie, HIV-associated gingivitis or linear gingival erythema (LGE); HIV-associated periodontitis or necrotizing ulcerative periodontitis (NUP)). While the clinical definition of LGE varies from study to study, an association between LGE and Candida infection has been described. Furthermore, the prevalence of NUP is quite low and this disorder is associated with severe immunosuppression. In contrast, the focus today is on the accelerated rate of chronic adult periodontitis occurring in seropositive patients. While the organisms that characterize adult periodontitis in seronegative individuals are present in subgingival plaque from seropositive individuals, reports suggest that atypical pathogens are also present (ie, Mycoplasma salivarium, Enterobacter cloacae). Recent studies from our laboratory have identified a novel strain of Clostridium isolated from the subgingival plaque of injecting drug users that has pathologic potential. This organism, however, was found in both seropositive and seronegative individuals in this cohort, suggesting an association with lifestyle rather than serostatus. In addition, data has been published examining the local host response in periodontitis in seropositive individuals. Distinctly elevated levels of IgG in gingival crevicular fluid (GCF) have been observed in seropositive patients. Furthermore, data from our laboratory examining inflammatory mediators in GCF (polymorphonuclear leukocyte lysosomal enzyme β-glucuronidase and the pro-inflammatory cytokine interleukin-1β) suggests an altered response in patients with HIV infection. The alteration manifests as the absence of the expected strong correlation between polymorphonuclear leukocyte activity in the gingival crevice and clinical measures of existing periodontal disease, as well as elevated levels of interleukin-1β in sites with deeper probing depths. Therefore, it can be concluded that the progression of periodontal disease in the presence of HIV infection is dependent upon the immunlogic competency of the host as well as the local inflammatory response to typical and atypical subgingival microorganisms. 相似文献