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排序方式: 共有7991条查询结果,搜索用时 15 毫秒
41.
Skinner J Mee TJ Blackwell RP Maslanyj MP Simpson J Allen SG Day NE Cheng KK Gilman E Williams D Cartwright R Craft A Birch JM Eden OB McKinney PA Deacon J Peto J Beral V Roman E Elwood P Alexander FE Mott M Chilvers CE Muir K Doll R Taylor CM Greaves M Goodhead D Fry FA Adams G Law G;United Kingdom Childhood Cancer Study Investigators 《British journal of cancer》2002,87(11):1257-1266
The United Kingdom Childhood Cancer Study, a population-based case-control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0-14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure >/=20 V m(-1) to those in a reference category of exposure <10 V m(-1), odds ratios of 1.31 (95% confidence interval 0.68-2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73-2.39) for total leukaemia, 2.12 (95% confidence interval 0.78-5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77-2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49-1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56-1.54) for total leukaemia, 1.43 (95% confidence interval 0.68-3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59-1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m(-1) were close to unity for all disease categories, never differing significantly from one. 相似文献
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Although the chromosome 18 alpha-satellite probe is considered to have a very low polymorphism rate, the routine use of this probe in prenatal diagnosis revealed rare variants in size and copy number of these sequences. A polymorphic signal was detected in preimplantation genetic diagnosis (PGD) for aneuploidy, in a patient with repeated early miscarriages. A third small signal of chromosome 18 alpha-satellite probe was observed in two of four evaluated embryos. Hybridization to the woman's metaphasic lymphocytes revealed that the small signal was localized in the pericentromeric region of chromosome 1. Reanalysis of blastomeres with telomeric probes for chromosome 18q confirmed the presence of only two copies of chromosome 18. Options for verifying PGD analysis results, to prevent misdiagnosis in cases of suspected polymorphism, are discussed. Although some authors speculate about a possible role of heterochromatin polymorphism in infertility, this rare polymorphism of 18 alpha-satellite sequences is in itself probably a normal variant. This is the third report of a cross-hybridization of the chromosome 18 alpha-satellite probe and the first report of the localization of the polymorphic 18 alpha-satellite signal to chromosome 1. 相似文献
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STUDY OBJECTIVE: To examine transvaginal hydrolaparoscopy (THL) practices in French tertiary care centers. DESIGN: Prospective longitudinal study (Canadian Task Force classification III). SETTING: University hospital in France. PARTICIPANTS: Gynecology and obstetrics departments of all 48 French teaching hospitals. INTERVENTIONS: Practice of THL using a 8-item questionnaire. MEASUREMENTS AND MAIN RESULTS: Main outcome measure was practice, indications, and complications of THL in French tertiary care centers. Between October 2005 and March 2006, the departments were sent an 8-item questionnaire on the use of diagnostic and operative THL. In all, 38 (79%) hospitals completed the questionnaire. THL was or is still used in 20 (53%) departments. The main reason given by the 18 departments that never used THL was that it was "less informative than laparoscopy." Only 8 (40%) of 20 departments with experience of THL continued to use the procedure routinely. The main reason given for abandoning THL was its limited operative potential. Among the 8 departments that continued to use THL, 6 used operative THL (mainly for ovarian drilling). Among the 30 departments that answered the item on the likely future place of THL, only 6 (20%) considered that THL would continue to be performed. CONCLUSION: Few French teaching hospitals routinely use THL. Further data on THL, and especially its cost effectiveness, are needed to clarify its place to evaluate female fertility. 相似文献
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Dominika Dudek Rafał Jaeschke Marcin Siwek Grzegorz Mączka Roman Topór-Mądry Janusz Rybakowski 《Psychiatry research》2014
The goals of this study have been to determine the prevalence of the bipolar spectrum features in the population of women with postpartum depression (PPD) symptoms, as well as to analyze the personality differences between putative ‘unipolar’ and ‘bipolar’ PPD subjects. The sample enrolled into the cross-sectional study consisted of 344 women at 6–12 weeks postpartum. The authors used the Edinburgh Postnatal Depression Scale (EPDS; cut-off score: 13 pts.) for the assessment of the PPD symptoms, the Mood Disorder Questionnaire (MDQ; cut-off scores: 7 or 8 pts.) for diagnosing the bipolar features, and the NEO-Five Factor Inventory (NEO-FFI) for the assessment of personality traits. The EPDS-positive subjects were more likely to score positively on the MDQ, as compared to the EPDS-negative ones. The EPDS-positive subjects who also scored ≥8 pts. on the MDQ were characterized by higher index of neuroticism, as compared to those who scored positively on the EPDS only. The results suggest that the presence of PPD symptoms is related to significantly higher scores of bipolarity and neuroticism. The more robust trait of neuroticism might be a marker of the ‘bipolar’ PPD, as compared to the ‘unipolar’ form of the disorder. 相似文献
48.
Gunasekaran Murali Sallal Rashid Abid Mugahed Amran Nikolai Ivanovich Vatin Roman Fediuk 《Materials》2022,15(9)
In recent years, prepacked aggregate fibrous concrete (PAFC) is a new composite that has earned immense popularity and attracted researchers globally. The preparation procedure consists of two steps: the coarse aggregate is initially piled into a mold to create a natural skeleton and then filled with flowable grout. In this instance, the skeleton was completely filled with grout and bonded into an integrated body due to cement hydration, yielding a solid concrete material. In this research, experimental tests were performed to introduce five simple alterations to the ACI 544 drop weight impact test setup, intending to decrease result dispersion. The first alteration was replacing the steel ball with a steel bar to apply a line impact instead of a single point impact. The second and third introduced line and cross notched specimens at the specimen’s top surface and the load applied through a steel plate of cross knife-like or line load types. These modifications distributed impact load over a broader area and decrease dispersion of results. The fourth and fifth were bedding with sand and coarse aggregate as an alternate to the solid base plate. One-hundred-and-eight cylindrical specimens were prepared and tested in 12 groups to evaluate the suggested alteration methods. Steel and polypropylene fibers were utilized with a dosage of 2.4% to produce PAFC. The findings indicated that the line notched specimens and sand bedding significantly decreased the coefficient of variation (COV) of the test results suggesting some alterations. Using a cross-line notched specimen and line of impact with coarse bedding also effectively reduced COV for all mixtures. 相似文献
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