bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct instruction vs. discovery: The long view
Authors: Dean Jr. David , Kuhn Deanna 
Published: December 2006

AbstractD. Klahr and M. Nigam (2004) make a case for the superiority of direct instruction over discovery learning in students' mastery of the control‐of‐variables strategy central to the scientific method. In the present work, we examine acquisition of this strategy among students of the same age as those studied by Klahr and Nigam, as well as follow central features of their design in directly comparing the two methods. In contrast to their design, however, we follow progress over an extended time period and a range of equivalent tasks. Three groups of 15 fourth‐grade students, of diverse socioeconomic background, were compared. One group engaged in 12 sessions over 10 weeks working on problems that required the control‐of‐variables strategy for effective solution. Another group engaged in the same activity, preceded by a session involving direct instruction on the control‐of‐variables strategy. A third group received only the initial direct instruction, without subsequent engagement and practice. In this longer term framework, direct instruction appears to be neither a necessary nor sufficient condition for robust acquisition or for maintenance over time. The patterns of attainment observed here point instead to a gradual and extended process of acquisition and consolidation. © 2006 Wiley Periodicals, Inc. Sci Ed 91:384–397, 2007
Comparison of CT‐ or ultrasound‐guided drainage with concomitant intravenous antibiotics vs. intravenous antibiotics alone in the management of tubo‐ovarian abscesses
Authors: Goharkhay N. , Verma U. , Maggiorotto F. 
Published: December 2006

AbstractObjectiveThe purpose of this study was to compare the outcome of treatment of tubo‐ovarian abscesses by imaging‐guided drainage and antibiotics vs. intravenous antibiotics alone.MethodsA retrospective chart review of all patients hospitalized with a diagnosis of tubo‐ovarian abscess was performed. Patients were categorized into two groups. The first group consisted of subjects treated with intravenous antibiotics alone. Patients in the second group had primary image‐guided drainage with concomitant intravenous antibiotics. Treatment failures in the primary antibiotics group underwent salvage drainage when feasible. The primary outcome of interest was complete response. Secondary outcomes included need for additional treatment, duration of resolution of fever, total length of hospital stay, and complication rates. We also evaluated the effectiveness of secondary drainage in patients who failed primary antibiotic therapy alone.ResultsA total of 58 patients were included in the study. Fifty patients were treated primarily with intravenous antibiotics; eight patients had primary drainage, which was guided by ultrasound in all cases. Complete response was noted in 29 (58%) patients treated with antibiotics alone. All eight (100%) patients in the primary drainage group responded to treatment. Of the 21 treatment failures with primary antibiotics, two underwent surgery and 19 (90.5%) had salvage drainage with either ultrasound or computed tomographic guidance; 18 of 19 salvage drainages led to complete recovery. Subjects in the primary drainage group required shorter hospital stays and showed more rapid resolution of fever. No significant morbidity was noted as a consequence of drainage procedures. A higher failure rate for secondary drainage was noted in older patients, those with larger tubo‐ovarian abscesses, and those with a history of pelvic inflammatory disease.ConclusionDrainage of tubo‐ovarian abscesses with concomitant intravenous antibiotics is an effective and safe treatment for the primary or secondary treatment of tubo‐ovarian abscesses. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Diffusion‐weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination in normal and pathological fetal kidneys
Authors: Chaumoitre K. , Colavolpe N. , Shojai R. , Sarran A. , D' Ercole C. , Panuel M. 
Published: December 2006

AbstractObjectivesTo assess the use of diffusion‐weighted magnetic resonance imaging (DW‐MRI) in the evaluation of the fetal kidney and to estimate age‐dependent changes in the apparent diffusion coefficient (ADC) of normal and pathological fetal kidneys.MethodsDW‐MRI was performed on a 1.5‐T machine at 23–38 gestational weeks in 51 pregnant women in whom the fetal kidneys were normal and in 10 whose fetuses had renal pathology (three with suspected nephropathy, three with renal tract dilatation, one with unilateral renal venous thrombosis, and three with twin–twin transfusion syndrome (TTTS)). The ADC was measured in an approximately 1‐cm2 region of interest within the renal parenchyma.ResultsADC values in normal renal parenchyma ranged from 1.1 to 1.8 10−3mm2s−1. There was no significant age‐dependent change in the ADC of normal kidneys. In cases of nephropathy, the ADC value was not always pathological but an ADC map could show abnormal findings. In cases of dilatation, the ADC value was difficult to determine when the dilatation was huge. In cases of TTTS, the ADC of the donor twin was higher than that of the recipient twin and the difference seemed to be related to the severity of the syndrome.ConclusionEvaluation of the ADC for fetal kidneys is feasible. Fetal measurement of the ADC value and ADC maps may be useful tools with which to explore the fetal kidney when used in conjunction with current methods. DW‐MR images, ADC value and ADC map seem to be useful in cases of suspected nephropathy (hyperechoic kidneys), dilated kidney and vascular pathology (renal venous thrombosis, TTTS). Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
First‐trimester combined screening for trisomy 21 in a predominantly Chinese population
Authors: Leung T. Y. , Chan L. W. , Leung T. N. , Fung T. Y. , Sahota D. S. , Spencer K. , Lau T. K. 
Published: December 2006

AbstractObjectiveTo examine the effectiveness of first‐trimester fetal trisomy 21 screening using a combination of maternal age, nuchal translucency thickness (NT) and maternal serum free beta‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A) levels in a predominantly Chinese population in Hong Kong.MethodsThis was a prospective study over a 1.5‐year period of 2990 women who underwent combined screening for trisomy 21 between 11 + 0 and 13 + 6 weeks of gestation in a university fetal medicine unit. NT was measured according to the criteria set by The Fetal Medicine Foundation (FMF), maternal serum free β‐hCG and PAPP‐A levels were measured, and the risk of trisomy 21 was calculated using The FMF's algorithm. Fetal karyotyping was advised when the risk was 1 : 300 or above. All subjects were followed up for pregnancy and fetal outcome.ResultsOf the 2990 women who underwent the screening program, 99% were Chinese. There were 57 twin pregnancies, giving a total of 3047 fetuses. Thirty‐one percent of the women were 35 years old or above. One hundred and eighty‐five (6.1%) fetuses were screen‐positive; this included 14 cases of trisomy 21 and 17 cases of other chromosomal abnormalities. The positive predictive value was 16.7%. Among the 2862 screen‐negative fetuses, only 18 (0.6%) cases had an unknown fetal outcome. There were no cases in which trisomy 21 was missed and the infant was liveborn.ConclusionFirst‐trimester combined screening for fetal trisomy 21 is highly effective among Chinese subjects. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Short cervix: is a follow‐up measurement useful?
Authors: Fox N. S. , Jean‐Pierre C. , Predanic M. , Chasen S. T. 
Published: December 2006

AbstractObjectiveTo study if a repeat cervical length (CL) measurement in the patient already diagnosed with a short cervix has any additional value in the prediction of preterm delivery.Study designThis was a retrospective study of singleton pregnancies with cervical lengths 1–25 mm at a gestational age of 16–28 weeks seen in our institution between 2002 and 2005. Patients who were managed expectantly and had a follow‐up CL measurement within 3 weeks were included. Delivery data were obtained from the patients' computerized medical records.ResultsSixty‐eight patients met the inclusion criteria. 37% of the patients had a shorter CL on the second measurement. These patients delivered at an earlier gestational age (36 + 4 vs. 38 + 2 weeks, P = 0.031) and were more likely to deliver at < 37 weeks (60% vs. 26%, P = 0.009). The change in the CL correlated with earlier gestational age at delivery and delivery at < 37 weeks.ConclusionIn patients diagnosed with a short cervix, follow‐up CL measurement is a strong predictor of preterm delivery. Greater change in the CL correlates with an earlier gestational age at delivery. In the patient diagnosed with a short cervix, a repeat measurement of CL gives additional predictive value. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Extraction of equivalent beam properties from blade models
Authors: Malcolm David J. , Laird Daniel L. 
Published: December 2006

AbstractA method is presented for extracting the equivalent beam properties from a finite element model of a wind turbine blade so that full aeroelastic models can be constructed more reliably. The method is based on applying unit loads at the tip of the blade and processing the resulting nodal displacements to generate the 6 × 6 stiffness matrices for the specified beam discretization. The finite element model can comprise shell and/or solid elements, but the use of shell elements with centroids offset from the surface has been shown to produce erroneous torsional stiffness values. The method includes all three‐dimensional effects such as shear and warping as well as flap–twist coupling, and these are demonstrated in a series of validation examples. The process will accommodate blades with curvature in one or both directions and has the added advantage of identifying the centre of mass, elastic centre, principal directions and shear centre. Published in 2006 by John Wiley &Sons, Ltd.
Mitochondrial DNA Mutations in Differentiated Thyroid Cancer with Respect to the Age Factor
Authors: Witte Jürgen , Lehmann Steffen , Wulfert Michael , Yang Quin , Röher Hans D. 
Published: December 2006

AbstractIntroductionIncreased numbers of mitochondria in differentiated thyroid cancer and, most strikingly, mutations in human mitochondrial DNA (mtDNA) in older people have led to speculation that mtDNA mutations might contribute to aging or accumulate in postmitotic tissues with age. Mutation analyses of mtDNA in papillary (PTCs) and follicular (FTCs) thyroid carcinomas have been limited to date. The significance and frequency of mtDNA mutations in PTC and FTC are therefore controversial, as is age dependence.MethodsWe analyzed eight sample pairs of PTC and six of FTC tissue with the corresponding normal thyroid tissue. DNA was extracted from frozen and formaldehyde‐fixed tissue using the QIAmp Tissue Kit. Sequence differences in the mtDNA between tumor and normal tissue were detected using appropriate polymerase chain reaction (PCR) products for heteroduplex analysis in a denaturing high performance liquid chromatography (HPLC) Wave System (Transgenomic). Mutations were confirmed and identified by sequencing the PCR products of conspicuous chromatograms. The samples were obtained from 346 patients with PTC and 105 patients with FTC. We analyzed the whole mitochondrial genome from seven PTC and three FTC tumors along with the corresponding normal thyroid tissue. 3/7 PTC samples showed two heteroplasmic mutations and one polymorphism; all 3 FTCs showed homoplasmic and/or heteroplasmic mutations.ResultsAll but one of these tumors are well documented in the mitochondrial database MITOMAP. MtDNA mutations were found in all three patients aged 45 years and older. There was no correlation, however, in this small group to clinical prognostic factors for recurrence and especially for survival in differentiated thyroid carcinomas, such as histology, tumor size, lymph node metastases, distant metastases, and gender, most likely because of the short follow‐up. While univariate analysis of the findings in the whole cohort of 346 patients with PTC suggested that age is a significant prognostic factor for survival (P= 0.0237) but not for recurrence (P= 0.65), this was not the case in the 105 patients with FTC.ConclusionsAlthough we found accumulation of mutations in two older patients with PTC and one patient with FTC (all three patients older than 45 years had mtDNA mutations), the low frequency of these mutations in the small group of 10 analyzed patients did not correlate with statistically validated clinical prognosticators for recurrence or survival, especially not with age. The low power of our data are therefore not able to support or refute the hypothesis that these mtDNA mutations are related to age‐dependent tumor progression in the thyroid or that they “may be involved in thyroid tumorigenesis.”
Assessment of Quality of Life after Laparoscopic Nissen Fundoplication in Patients with Gastroesophageal Reflux Disease
Authors: Balci Deniz , Turkcapar Ahmet G. 
Published: December 2006

AbstractBackgroundIn this study two different quality of life items are compared, and correlation of patient satisfaction with preoperative and postoperative symptoms after laparoscopic Nissen fundoplication (LNF) for chronic gastroesophageal reflux disease is evaluated.Materials and MethodsBetween December 2002 and December 2004, 60 patients with a diagnosis of chronic gastroesophageal reflux disease scheduled for laparoscopic Nissen fundoplication were recruited prospectively and volunteered to participate in this study. Patients underwent endoscopy, and their disease‐specific symptoms were scored on a scale. Quality of life was measured preoperatively and in the first and sixth postoperative months with two questionnaires: Short Form‐36 (SF 36) (preoperatively) and the Gastroesophageal Reflux Disease—Health‐Related Quality of Life (GERD‐HRQL) (postoperatively).ResultsIn more than 90% of the patients, typical symptoms (regurgitation and pyrozis) were controlled postoperatively (p < 0.001). In the first postoperative month, however, dysphagia (early dysphagia) was seen in 46 (76%) patients, whereas in the sixth postoperative month (late dysphagia) its incidence decreased to only 2 (3.3%) patients. Similarly, in the first postoperative month 42 (70%) patients had gas bloating, but the incidence of this symptom decreased to 26 (43.3%) patients by the sixth month (p = 0.01). The quality‐of‐life measurements obtained from both SF 36 and GERD‐HRQL showed that quality of life of the patients improved significantly in the related domain of each item after surgery (p < 0.001).ConclusionsLaparoscopic Nissen fundoplication is an effective operation that controls the typical symptoms and improves the quality of life of patients, but new‐onset symptoms affect postoperative well‐being. For closer evaluation of the benefits of the operation, we need new questionnaires that comprehensively evaluate the symptom spectrum of GERD both preoperatively and postoperatively.
Interleukin‐10 Gene Transfer: Prevention of Multiple Organ Injury in a Murine Cecal Ligation and Puncture Model of Sepsis
Authors: Kabay Burhan , Kocaefe Cetin , Baykal Atac , Özden Hilmi , Baycu Cengiz , Oner Zafer , Özgüç Meral , Sayek Iskender 
Published: December 2006

AbstractIntroductionThe aim of this study was to determine the effect of immunoregulatory cytokine interleukin‐10 (IL‐10) gene therapy on multiple organ injury (MOI) induced by a cecal ligation and puncture (CLP) model of sepsis in mice.MethodsMale Balb/c mice subjected to CLP were treated with either an hIL‐10‐carrying vector or an empty control vector. We assessed the degree of lung, liver, and kidney tissue destruction biochemically by measuring myeloperoxidase (MPO) and malondialdehyde (MDA) activity. Histologic assessments were based on neutrophil infiltration in lung and liver tissue. IL‐10 protein expression was examined immunohistochemically, and ultrastructural changes in the liver were studied by transmission electron microscopy. We analyzed the expression of tumor necrosis factor‐α (TNFα) mRNA by reverse transcription polymerase chain reaction 3, 8, and 24 hours after CLP in all organs.ResultsOrgan damage was significantly reduced by hIL‐10 gene transfer, which was associated at the tissue level with reduced MPO activity in the liver, lung, and kidney and decreased leukocyte sequestration and MDA formation in the lung. The liver MDA was not significantly higher in the hIL‐10 gene therapy group than in the controls and seemed not to be affected by hIL‐10 gene transfer. The reduced portal tract neutrophilic infiltration and preserved ultrastructure of the hepatocytes also showed that tissue function was not impaired. The lung and kidney TNFα mRNA expression was suppressed markedly in the hIL‐10 gene therapy group, but liver TNFα mRNA expression varied over time.ConclusionsThese findings showed that IL‐10 gene therapy significantly attenuated sepsis‐induced MOI.
Risk‐scoring Method for Prediction of 30‐Day Postoperative Outcome after Infrainguinal Surgical Revascularization for Critical Lower‐limb Ischemia: a Finnvasc Registry Study
Authors: Biancari Fausto , Salenius Juha‐Pekka , Heikkinen Maarit , Luther Michael , Ylönen Kari , Lepäntalo Mauri 
Published: December 2006

AbstractBackgroundThe aim of the present study was to develop a risk‐scoring method for prediction of immediate postoperative outcome after infrainguinal surgical revascularization for critical limb ischemia.MethodsThe Finnvasc registry included data on 3,925 infrainguinal surgical revascularization procedures. This database was randomly divided into a derivation and a validation data set of similar sizes.ResultsIn the overall series, 30‐day postoperative mortality and major amputation rates were 3.1% and 6.3%, respectively. The 30‐day postoperative mortality and/or limb‐loss rate was 9.2%. Diabetes, coronary artery disease, foot gangrene, and urgent operation were independent predictors of 30‐day postoperative mortality and/or major lower‐limb amputation. A risk score was developed by assigning 1 point each to the latter risk factors. In the derivation data set, the 30‐day postoperative mortality/amputation rates in patients with scores of 0, 1, 2, 3, and 4 were 7.7%, 6.4%, 11.1%, 20.4%, and 27.3%, respectively, (P < 0.0001); mortality rates were 1.3%, 2.3%, 4.1%, 7.7%, and 12.1%, respectively, (P < 0.0001); and major amputation rates were 6.4%, 4.3%, 7.1%, 12.7%, and 18.2%, respectively, (P < 0.0001). In the validation data set, the 30‐day postoperative mortality/amputation rates in patients with scores of 0, 1, 2, 3, and 4 were 4.8%, 7.5%, 10.1%, 15.9%, and 22.2%, respectively, (P < 0.0001); mortality rates were 0.7%, 2.3%, 4.2%, 5.5%, and 14.8%, respectively, (P < 0.0001); and major amputation rates were 4.6%, 5.3%, 6.4%, 11.0%, and 14.0%, respectively (P = 0.011).ConclusionsThis simple risk‐scoring method can be useful to stratify the immediate postoperative outcome of patients undergoing infrainguinal surgical revascularization for critical lower‐limb ischemia.
Ileosigmoidal Knotting in Children: A Review of 9 Cases
Authors: Atamanalp S. Selçuk , Ören Durkaya , Yildirgan M. İlhan , Başoğlu Mahmut , Aydinli Bülent , Öztürk Gürkan , Salman Bedii 
Published: December 2006

AbstractBackgroundThe purpose of this study was to review nine pediatric cases of ileosigmoidal knotting (ISK), which is an unusual form of intestinal obstruction common in adults, characterized by double‐loop obstruction.MethodsA retrospective analysis was designed to examine preoperative, operative, and postoperative findings of the nine children with ISK who were surgically treated in a university hospital throughout a 38.5‐year period..ResultsThe mean age was 10.6 years (range: 7–16 years). Seven patients (77.8 %) were male. The most common symptoms were abdominal pain, distention, obstipation, and vomiting, and the most common signs were abdominal tenderness and distention. The most common form was type 1A in 4 patients (44.4%) in whom the active ileum encircled the passive sigmoid colon in clockwise direction. There was a gangrene in both ileum and sigmoid colon in 7 patients (77.8%), one patient (11.1%) had gangrene in only the sigmoid colon, and the bowels were viable in 1 patient (11.1%). In the gangrenous cases, nonviable small bowel segments were resected, and anastomosis was performed, while gangrenous sigmoid colon was resected and Hartmann procedure or primary anastomosis was used. In the nongangrenous case, detorsion was performed and sigmoidopexy was added. One patient in this series (11.1%) died.ConclusionsIleosigmoidal knotting is a rare disease in children. Its preoperative diagnosis is not easy. It is generally misdiagnosed as an obstructive emergency. Aggressive preoperative resuscitation, effective and prompt surgery, and postoperative support are the basic principles of treatment. Although resection with primary anastomosis is advised in gangrenous cases, stomas may be lifesaving in unstable patients. In nongangrenous cases, definitive surgical procedures are generally used.
Is Esophageal Adenocarcinoma Occurring Late After Antireflux Surgery Due to Persistent Postoperative Reflux?
Authors: Lagergren Jesper , Viklund Pernilla 
Published: December 2006

AbstractBackgroundGastroesophageal reflux is the main risk factor for esophageal adenocarcinoma, but there is no strong support for a protective effect of antireflux surgery. We tested the hypothesis that esophageal adenocarcinoma that develops with long latency after antireflux surgery might be due to persistent postoperative reflux.MethodsA nationwide population‐based case‐control study in collaboration with 195 relevant Swedish hospital departments and tumor registries during the study period 1995–1997. Frequency‐matched control persons were randomly selected from the population register. All study participants were personally interviewed regarding background data, exposures, symptoms, conditions, diseases, surgery, and medications. Differences between cases and controls in the occurrence of daily, long‐standing antireflux medication 5 years or later after antireflux surgery were estimated using Fisher’s exact test.ResultsOne hundred and eighty‐nine out of 216 (88%) eligible cases of esophageal adenocarcinoma and 820 of 1,128 (73%) controls were prospectively enrolled. Seven (3.7%) patients and 8 controls had undergone antireflux surgery at least 5 years before the interview. All 7 case patients had Barrett’s mucosa. Four of the case patients had used postoperative antireflux medications continuously (mean duration 10.2 years), while none of the control persons reported such use (P = 0.026). There was no difference in mean body mass index between patients with and without postoperative reflux (P = 0.81). No differences between the patients and controls were found regarding age, sex, body mass index, or tobacco smoking status.ConclusionsEsophageal adenocarcinoma occurring late after antireflux surgery might at least partly be due to persistent postoperative reflux. Further research is required to establish the role of antireflux surgery in the etiology of this tumor.