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101.
Several samples of commercial grade honey collected from different parts of Tennessee during the summer of 1973 were analyzed for chlorinated hydrocarbon insecticide (CHI) residues. A Modified Mill's Procedure was used to cleanup the samples prior to gas Chromatographic analysis using electron capture (EC) detection. The presence of CHI residues was confirmed by analysis on three different columns of widely varying polarity. Most of the samples contained CHI residues at 0.01—0.30 parts per billion (ppb) level. Beeswax produced during the same season contained several times higher levels of the residue than the honey samples. Recoveries of CHI residues varied from 81–95 percent by the procedure employed.  相似文献   
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Successful reconstruction of the anterior cruciate ligament (ACL) depends on anatomic placement of a graft ligament substitute. This study examined the accuracy of a plain radiograph in determining femoral tunnel position during ACL reconstruction. Nine cadaveric distal femurs had six separate tunnels made in each specimen: 12:00 (high position), 1:30 (anatomic position), and 3:00 (low position) in the left femora and 12:00 (high), 10:30 (anatomic), and 9:00 (low) in the right femora. At each position on the clock face, two 9-mm tunnels were drilled, leaving 2 mm (correct) and 12 mm (incorrect) of posterior wall intact. With a radiopaque tunnel dilator in each tunnel, a true lateral radiograph, a 10 degree externally rotated lateral radiograph, and a 10 degree internally rotated lateral radiograph were obtained. All radiographs were analyzed for femoral tunnel placement in the anteroposterior plane with the four-quadrant method described by Harner et al and the ratio method described by Aglietti et al. Statistically significant differences could only be distinguished between anatomic (10:30), anterior (12-mm rim), and posterior (2-mm rim) positions. There were no statistically significant differences for any of the other positions when comparing true laterals to true laterals, true laterals to internal or external oblique views, or when comparing internal and external oblique views. A malpositioned anterior tunnel (12-mm rim posterior), which was "low" at 9:00 or "high" at 12:00 in the notch (malplaced), could not be distinguished reliably from an anatomically correct placed tunnel with a single-plane lateral radiograph.  相似文献   
104.
In a two-wave longitudinal study of third and sixth graders ( N = 617), we obtained self-reports of depression and peer, teacher, parent, and self-reports of competence in five domains: academic, social, attractiveness, conduct, and athletic. Competency evaluations by others predicted change in self-perceived competence over time for girls, but not for boys. Depression predicted change in self-perceived competence over time for boys but not for girls. Among girls, the relative importance of parent, teacher, and peer appraisals shifted from third to sixth grade. For both boys and girls, self-perceptions of competence predicted change in depression scores over time. Furthermore, self-perceived competencies mediated the relation between competency appraisals by others and children's self-reported depression. Results are interpreted in light of a competency-based model of child depression.  相似文献   
105.
AIM: To provide a simple method for assessing centile change based on the British 1990 growth reference. STATISTICAL METHOD: The change in SD score over a period of time has SD square root of 2(1-r), where r is the correlation between the first and second SD score. This leads to an SD score for centile change. DATA: Annual height measurements from 2 to 9 years for 318 children from the French longitudinal growth study. RESULTS: The correlations between heights at different ages are higher for shorter measurement intervals and at older ages. The chance of a child's height centile falling one centile band width is correspondingly smaller for shorter measurement intervals and at older ages. An increase in height measurement error reduces the correlations and dramatically increases the chances of centile crossing. CONCLUSIONS: Quantitative height monitoring based on centile change is provided for whole year periods between 2 and 9 years of age. Effective monitoring requires the measurement error to be as small as possible.  相似文献   
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Background.Extragonadal endodermal sinus tumors arising in the external genitalia represent an exceedingly rare malignancy in women. Six cases of endodermal sinus tumors of the vulva have been reported to date, with three cases failing to respond to conservative surgery and vincristine-based chemotherapy. We report a seventh case of vulvar endodermal sinus tumor that was treated with radical surgery and platinum-based chemotherapy.Case.RT is an 18-year-old female who presented with a vulvar mass that was diagnosed as endodermal sinus tumor at the time of biopsy. She was subsequently treated with modified radical vulvectomy and ipsilateral groin lymphadenectomy, followed by bleomycin, etoposide, and cisplatin chemotherapeutic regimen. She has since remained free of disease for 18 months as evidenced by serum α-fetoprotein and physical exam at 18 months.Conclusions.Vulvar endodermal sinus tumors represent a very small number of germ cell tumors in women. Based on the previous accounts, this disease appears to be more fatal than endodermal sinus tumor arising at other sites. These tumors also have a predilection for local metastasis. Due to the previous accounts, we chose to treat this patient with radical surgery and platinum-based chemotherapy. This treatment regimen has resulted in a disease-free state for 18 months.  相似文献   
108.
Objectives—To assess the level of cycle helmet wearing among young people in two counties in the South East of England in 1994, and to identify the factors associated with helmet wearing.  相似文献   
109.
A 2-min focal application of Polyethylene Glycol (PEG) to injured mammalian spinal cords can offer significant yet limited restoration of functional and structural integrity. However, longer application of PEG has not been tested in similar injuries. In this study, isolated spinal cord white matter strips from adult guinea pigs were subjected to a 25 min exposure of PEG (MW: 2000; 50% w/w), with or without prior compression. When applied in a continuous steam, PEG, with a delay of about 6 min, suppressed the compound action potential (CAP) amplitude to 64+/-4% of the pre-PEG level in uninjured cords and to 64+/-7% in compressed cord strips. Both recovered to 70+/-5% (uninjured) and 88+/-11% (compressed) of the pre-PEG level following wash. When PEG was applied in a pulsatile manner, no significant decrease of CAP amplitude was observed. In summary, our results show that focal continuous application of PEG has minimal toxicity if applied for less than 5 min. Pulsatile application could extend this duration to at least 25 min with no toxicity. This study could be useful in determining the optimal protocol for the use of PEG in both animal research and human spinal cord victims.  相似文献   
110.
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