bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring patient's expectation and the perception of quality in LASIK services
Authors: Lin Deng-Juin , Sheu Ing-Cheau , Pai Jar-Yuan , Bair Alex , Hung Che-Yu , Yeh Yuan-Hung , Chou Ming-Jen
Published: July 2009

Background

LASIK is the use of excimer lasers to treat therapeutic and refractive visual disorders, ranging from superficial scars to nearsightedness (myopia), and from astigmatism to farsightedness (hyperopia). The purposes of this study are to checking the applicability and psychometric properties of the SERVQUAL on Lasik surgery population. Second, use SEM methods to investigate the loyalty, perceptions and expectations relationship on LASIK surgery.

Methods

The method with which this study was conducted was questionnaire development. A total of 463 consecutive patients, attending LASIK surgery affiliated with Chung Shan Medical University Eye Center, enrolled in this study. All participants were asked to complete revised SERVQUAL questionnaires. Student t test, correlation test, and ANOVA and factor analyses were used to identify the characters and factors of service quality. Paired t test were used to test the gap between expectation and perception scores and structural equation modeling was used to examine relationships among satisfaction components.

Results

The effective response rate was 97.3%. Validity was verified by several methods and internal reliability Cronbach's alpha was > 0.958. The results from patient's scores were very high with an overall score of 6.41(0.66), expectations at 6.68(0.47), and perceptions at 6.51(0.57). The gap between expectations and perceptions was significant, however, (t = 6.08). Furthermore, there were significant differences in the expectation scores among the different jobs. Also, the results showed that the higher the education of the patient, the lower their perception score (r = -0.10). The factor loading results of factor analysis showed 5 factors of the 22 items of the SERVQUAL model. The 5 factors of perception explained 72.94% of the total variance there; and on expectations it explained 77.12% of the total variance of satisfaction scores.

The goodness-of-fit summary, of structure equation modeling, showed trends in concept on expectations, perceptions, and loyalty.

Conclusion

The results of this research appear to show that the SERVQUAL instrument is a useful measurement tool in assessing and monitoring service quality in LASIK service, and enabling staff to identify where improvements are needed, from the patients' perspective. There were service quality gaps in the reliability, assurance, and empathy. This study suggested that physicians should increase their discussions with patients; which has, of course, already been proven to be an effective way to increase patient's satisfaction with medical care, regardless of the procedure received.
Addressing gaps in surgical skills training by means of low-cost simulation at Muhimbili University in Tanzania
Authors: Taché Stephanie , Mbembati Naboth , Marshall Nell , Tendick Frank , Mkony Charles , O'Sullivan Patricia
Published: July 2009

Background

Providing basic surgical and emergency care in rural settings is essential, particularly in Tanzania, where the mortality burden addressable by emergency and surgical interventions has been estimated at 40%. However, the shortages of teaching faculty and insufficient learning resources have hampered the traditionally intensive surgical training apprenticeships. The Muhimbili University of Health and Allied Sciences consequently has experienced suboptimal preparation for graduates practising surgery in the field and a drop in medical graduates willing to become surgeons. To address the decline in circumstances, the first step was to enhance technical skills in general surgery and emergency procedures for senior medical students by designing and implementing a surgical skills practicum using locally developed simulation models.

Methods

A two-day training course in nine different emergency procedures and surgical skills based on the Canadian Network for International Surgery curriculum was developed. Simulation models for the surgical skills were created with locally available materials. The curriculum was pilot-tested with a cohort of 60 senior medical students who had completed their surgery rotation at Muhimbili University. Two measures were used to evaluate surgical skill performance: Objective Structured Clinical Examinations and surveys of self-perceived performance administered pre- and post-training.

Results

Thirty-six students participated in the study. Prior to the training, no student was able to correctly perform a surgical hand tie, only one student was able to correctly perform adult intubation and three students were able to correctly scrub, gown and glove. Performance improved after training, demonstrated by Objective Structured Clinical Examination scores that rose from 6/30 to 15/30. Students perceived great benefit from practical skills training. The cost of the training using low-tech simulation was four United States dollars per student.

Conclusion

Simulation is valued to gain experience in practising surgical skills prior to working with patients. In the context of resource-limited settings, an additional benefit is that of learning skills not otherwise obtainable. Further testing of this approach will determine its applicability to other resource-limited settings seeking to develop skill-based surgical and emergency procedure apprenticeships. Additionally, skill sustainability and readiness for actual surgical and emergency experiences need to be assessed.
Evaluation of preoperative intra-aortic balloon pump in coronary patients with severe left ventricular dysfunction undergoing OPCAB surgery: early and mid-term outcomes
Authors: Qiu Zhibing , Chen Xin , Xu Ming , Jiang Yingshuo , Xiao Liqiong , Liu LeLe , Wang Liming
Published: July 2009

Background

The purpose of the present study was to evaluate the safety and the cost-effectiveness of using preoperative IABP as support compared with postoperative IABP treatment in coronary patients with severe left ventricular dysfunction (SLVD) who is undergoing off-pump coronary artery bypass surgery (OPCAB), including early outcomes, hospital mortality and morbidity, and mid-term follow-up outcomes.

Methods

Between March 2000 and December 2008, we prospectively and randomly studied the insertion of preoperative IABP in 115 (7.4%) and postoperative IABP in 106 (6.8%) of the 1560 consecutive patients. Group A is preoperative IABP therapy. Group B is postoperative IABP therapy.

Results

There was no significant difference in the number of grafts used between the two groups. Completeness of revascularization did not differ between the two groups. The statistically significant difference was hospital mortality (2.6% in group A vs. 3.8% in group B) (p < 0.05). And there was significant reduction in postoperative low cardiac output, malignant arrhythmia, acute renal failure and length of stay in ICU in group A, compared with group B (p < 0.05). In the two groups, six-, 12-, 24- and 48-month survival rates were similar. In the study the degree of improvement in angina and quality of life did not differ significantly between the two groups.

Conclusion

The use of preoperative IABP in SLVD patients undergoing OPCAB is of safety and effectiveness. The combined use of preoperative IABP and OPCAB allows complete revascularization in SLVD patients with an important reduction in operative mortality and excellent mid-term results.
An integration of complementary strategies for gene-expression analysis to reveal novel therapeutic opportunities for breast cancer
Authors: Bild Andrea H , Parker Joel S , Gustafson Adam M , Acharya Chaitanya R , Hoadley Katherine A , Anders Carey , Marcom P Kelly , Carey Lisa A , Potti Anil , Nevins Joseph R , Perou Charles M
Published: July 2009

Introduction

Perhaps the major challenge in developing more effective therapeutic strategies for the treatment of breast cancer patients is confronting the heterogeneity of the disease, recognizing that breast cancer is not one disease but multiple disorders with distinct underlying mechanisms. Gene-expression profiling studies have been used to dissect this complexity, and our previous studies identified a series of intrinsic subtypes of breast cancer that define distinct populations of patients with respect to survival. Additional work has also used signatures of oncogenic pathway deregulation to dissect breast cancer heterogeneity as well as to suggest therapeutic opportunities linked to pathway activation.

Methods

We used genomic analyses to identify relations between breast cancer subtypes, pathway deregulation, and drug sensitivity. For these studies, we use three independent breast cancer gene-expression data sets to measure an individual tumor phenotype. Correlation between pathway status and subtype are examined and linked to predictions for response to conventional chemotherapies.

Results

We reveal patterns of pathway activation characteristic of each molecular breast cancer subtype, including within the more aggressive subtypes in which novel therapeutic opportunities are critically needed. Whereas some oncogenic pathways have high correlations to breast cancer subtype (RAS, CTNNB1, p53, HER1), others have high variability of activity within a specific subtype (MYC, E2F3, SRC), reflecting biology independent of common clinical factors. Additionally, we combined these analyses with predictions of sensitivity to commonly used cytotoxic chemotherapies to provide additional opportunities for therapeutics specific to the intrinsic subtype that might be better aligned with the characteristics of the individual patient.

Conclusions

Genomic analyses can be used to dissect the heterogeneity of breast cancer. We use an integrated analysis of breast cancer that combines independent methods of genomic analyses to highlight the complexity of signaling pathways underlying different breast cancer phenotypes and to identify optimal therapeutic opportunities.
Prostate Cancer–Specific Mortality After Radical Prostatectomy for Patients Treated in the Prostate-Specific Antigen Era
Authors: Stephenson Andrew J. , Kattan Michael W. , Eastham James A. , Bianco Fernando J. , Yossepowitch Ofer , Vickers Andrew J. , Klein Eric A. , Wood David P. , Scardino Peter T.
Published: July 2009

Purpose

The long-term risk of prostate cancer–specific mortality (PCSM) after radical prostatectomy is poorly defined for patients treated in the era of widespread prostate-specific antigen (PSA) screening. Models that predict the risk of PCSM are needed for patient counseling and clinical trial design.

Methods

A multi-institutional cohort of 12,677 patients treated with radical prostatectomy between 1987 and 2005 was analyzed for the risk of PCSM. Patient clinical information and treatment outcome was modeled using Fine and Gray competing risk regression analysis to predict PCSM.

Results

Fifteen-year PCSM and all-cause mortality were 12% and 38%, respectively. The estimated PCSM ranged from 5% to 38% for patients in the lowest and highest quartiles of predicted risk of PSA-defined recurrence, based on a popular nomogram. Biopsy Gleason grade, PSA, and year of surgery were associated with PCSM. A nomogram predicting the 15-year risk of PCSM was developed, and the externally validated concordance index was 0.82. Neither preoperative PSA velocity nor body mass index improved the model's accuracy. Only 4% of contemporary patients had a predicted 15-year PCSM of greater than 5%.

Conclusion

Few patients will die from prostate cancer within 15 years of radical prostatectomy, despite the presence of adverse clinical features. This favorable prognosis may be related to the effectiveness of radical prostatectomy (with or without secondary therapy) or the low lethality of screen-detected cancers. Given the limited ability to identify contemporary patients at substantially elevated risk of PCSM on the basis of clinical features alone, the need for novel markers specifically associated with the biology of lethal prostate cancer is evident.
Phase I Dose Escalation Study of Telatinib, a Tyrosine Kinase Inhibitor of Vascular Endothelial Growth Factor Receptor 2 and 3, Platelet-Derived Growth Factor Receptor β, and c-Kit, in Patients With Advanced or Metastatic Solid Tumors
Authors: Eskens Ferry A.L.M. , Steeghs Neeltje , Verweij Jaap , Bloem Johan L. , Christensen Olaf , van Doorn Leni , Ouwerkerk Jan , de Jonge Maja J.A. , Nortier Johan W.R. , Kraetzschmar Joern , Rajagopalan Prabhu , Gelderblom Hans
Published: July 2009

Purpose

Telatinib (BAY 57-9352) is an orally available tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR) -2, VEGFR-3, platelet-derived growth factor receptor-β, and c-Kit. This phase I dose escalation study was conducted to evaluate the safety and tolerability of telatinib, with additional pharmacokinetic, pharmacodynamic, and efficacy assessments.

Patients and Methods

Patients with solid tumors refractory to standard therapies or with no standard therapy available were enrolled. Doses of continuously administered telatinib were escalated from 20 mg once daily to 1,500 mg twice daily.

Results

Fifty-three patients were enrolled. Most frequently observed drug-related adverse events were nausea (26.4%; grade ≥ 3, 0%) and hypertension (20.8%; grade 3, 11.3%; grade 4, 0%). Two dose-limiting toxicities were observed: one poorly controlled hypertension (600 mg twice daily), and one grade 2 weight loss, anorexia, and fatigue (1,500 mg twice daily). A formal maximum-tolerated dose was not reached. Telatinib was rapidly absorbed, with median time to peak concentration (tmax) lower than 3 hours after dose. A nearly dose-proportional increase in exposure was observed with substantial variability. Telatinib half-life averaged 5.5 hours. Biomarker analyses showed dose-dependent increase in VEGF levels and decrease in plasma soluble VEGFR-2 levels, with a plateau at 900 mg twice daily. A decrease in tumor blood flow (Ktrans and IAUC60) was observed with dynamic contrast-enhanced magnetic resonance imaging. Best tumor response was stable disease, observed in 50.9% of patients.

Conclusion

Telatinib was safe and well tolerated up to 1,500 mg twice daily. Based on pharmacodynamic and pharmacokinetic end points, telatinib 900 mg twice daily is the recommended dose for subsequent phase II studies.
Gene Expression Profiles of Tumor Biology Provide a Novel Approach to Prognosis and May Guide the Selection of Therapeutic Targets in Multiple Myeloma
Authors: Anguiano Ariel , Tuchman Sascha A. , Acharya Chaitanya , Salter Kelly , Gasparetto Cristina , Zhan Fenghuang , Dhodapkar Madhav , Nevins Joseph , Barlogie Bart , Shaughnessy John D. , Potti Anil
Published: July 2009

Purpose

Monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) comprise heterogeneous disorders with incompletely understood molecular defects and variable clinical features. We performed gene expression profiling (GEP) with microarray data to better dissect the molecular phenotypes and prognoses of these diseases.

Methods

Using gene expression and clinical data from 877 patients ranging from normal plasma cells (NPC) to relapsed MM (RMM), we applied gene expression signatures reflecting deregulation of oncogenic pathways and tumor microenvironment to highlight molecular changes that occur as NPCs transition to MM, create a high-risk MGUS gene signature, and subgroup International Staging System (ISS) stages into more prognostically accurate clusters of patients.

Results

Myc upregulation and increasing chromosomal instability (CIN) characterized the evolution from NPC to RMM (P < .0001 for both). Studies of MGUS revealed that some samples shared biologic features with RMM, which comprised the basis for a high-risk MGUS signature. Regarding MM, we subclassified ISS stages into clusters based on shared features of tumor biology. These clusters differentiated themselves based on predictions for prognosis (eg, in ISS stage I, one cluster was characterized by increased CIN and a poor prognosis).

Conclusion

GEP provides insight into the molecular defects underlying plasma cell dyscrasias that may explain their clinical heterogeneity. GEP also may also refine current prognostic and therapeutic models for MGUS and MM.
Trends in Mastectomy Rates at the Mayo Clinic Rochester: Effect of Surgical Year and Preoperative Magnetic Resonance Imaging
Authors: Katipamula Rajini , Degnim Amy C. , Hoskin Tanya , Boughey Judy C. , Loprinzi Charles , Grant Clive S. , Brandt Kathleen R. , Pruthi Sandhya , Chute Christopher G. , Olson Janet E. , Couch Fergus J. , Ingle James N. , Goetz Matthew P.
Published: July 2009

Purpose

Recent changes have occurred in the presurgical planning for breast cancer, including the introduction of preoperative breast magnetic resonance imaging (MRI). We sought to analyze the trends in mastectomy rates and the relationship to preoperative MRI and surgical year at Mayo Clinic, Rochester, MN.

Patients and Methods

We identified 5,405 patients who underwent surgery between 1997 and 2006. Patients undergoing MRI were identified from a prospective database. Trends in mastectomy rate and the association of MRI with surgery type were analyzed. Multiple logistic regression was used to assess the effect of surgery year and MRI on surgery type, while adjusting for potential confounding variables.

Results

Mastectomy rates differed significantly across time (P < .0001), and decreased from 45% in 1997% to 31% in 2003, followed by increasing rates for 2004 to 2006. The use of MRI increased from 10% in 2003% to 23% in 2006 (P < .0001). Patients with MRI were more likely to undergo mastectomy than those without MRI (54% v 36%; P < .0001). However, mastectomy rates increased from 2004 to 2006 predominantly among patients without MRI (29% in 2003% to 41% in 2006; P < .0001). In a multivariable model, both MRI (odds ratio [OR], 1.7; P < .0001) and surgical year (compared to 2003 OR: 1.4 for 2004, 1.8 for 2005, and 1.7 for 2006; P < .0001) were independent predictors of mastectomy.

Conclusion

After a steady decline, mastectomy rates have increased in recent years with both surgery year and MRI as significant predictors for type of surgery. Further studies are needed to evaluate the role of MRI and other factors influencing surgical planning.
Comparison of Power Between Randomized Discontinuation Design and Upfront Randomization Design on Progression-Free Survival
Authors: Fu Pingfu , Dowlati Afshin , Schluchter Mark
Published: July 2009

Purpose

Enrichment based on molecular characteristics has emerged as an important inclusion criterion in phase II trials of targeted anticancer agents. In this study, we evaluate a well-described method of population enrichment by tumor growth characteristics in the early development stage of targeted cytostatic agents.

Methods

For some solid tumors, such as pancreatic carcinoma, using a time-to-event end point (eg, time to disease progression) to evaluate the efficacy of a cytostatic agent in a phase II trial is more relevant than clinical response by Response Evaluation Criteria in Solid Tumors. In this setting, we compared the power of the randomized discontinuation and upfront randomization designs under two previously proposed tumor growth models for treatment effect when the end point is time-to-event.

Results

By selecting patients with more homogeneous tumor growth characteristics, the randomized discontinuation design is more efficient than the upfront randomization design when treatment benefit is restricted to slow-growing tumors. Under a model where only a subset of patients expressing the molecular target are sensitive to the agent, the randomized discontinuation design is more powerful than the upfront randomization design when the treatment effect is small; and vice versa when the treatment effect is moderate to large.

Conclusion

For selected targeted agents where a bioassay to select patients expressing the specific molecular target is not available, the randomized discontinuation design is a feasible alternative patient enrichment strategy in certain disease settings and provides a reasonable platform to evaluate drugs before phase III testing.
Safety and Immunological Efficacy of a DNA Vaccine Encoding Prostatic Acid Phosphatase in Patients With Stage D0 Prostate Cancer
Authors: McNeel Douglas G. , Dunphy Edward J. , Davies James G. , Frye Thomas P. , Johnson Laura E. , Staab Mary Jane , Horvath Dorothea L. , Straus Jane , Alberti Dona , Marnocha Rebecca , Liu Glenn , Eickhoff Jens C. , Wilding George
Published: July 2009

Purpose

Prostatic acid phosphatase (PAP) is a prostate tumor antigen. We have previously demonstrated that a DNA vaccine encoding PAP can elicit antigen-specific CD8+ T cells in rodents. We report here the results of a phase I/IIa trial conducted with a DNA vaccine encoding human PAP in patients with stage D0 prostate cancer.

Patients and Methods

Twenty-two patients were treated in a dose-escalation trial with 100 μg, 500 μg, or 1,500 μg plasmid DNA, coadministered intradermally with 200 μg granulocyte-macrophage colony-stimulating factor as a vaccine adjuvant, six times at 14-day intervals. All patients were observed for 1 year after treatment.

Results

No significant adverse events were observed. Three (14%) of 22 patients developed PAP-specific IFNγ-secreting CD8+ T-cells immediately after the treatment course, as determined by enzyme-linked immunospot. Nine (41%) of 22 patients developed PAP-specific CD4+ and/or CD8+ T-cell proliferation. Antibody responses to PAP were not detected. Overall, the prostate-specific antigen (PSA) doubling time was observed to increase from a median 6.5 months pretreatment to 8.5 months on-treatment (P = .033), and 9.3 months in the 1-year post-treatment period (P = .054).

Conclusion

The demonstration that a DNA vaccine encoding PAP is safe, elicits an antigen-specific T-cell response, and may be associated with an increased PSA doubling time suggests that a multi-institutional phase II trial designed to evaluate clinical efficacy is warranted.
Chronic Physical Effects and Health Care Utilization in Long-Term Ovarian Germ Cell Tumor Survivors: A Gynecologic Oncology Group Study
Authors: Matei Daniela , Miller Anna M. , Monahan Patrick , Gershenson David , Zhao Qianqian , Cella David , Champion Victoria L. , Williams Stephen D.
Published: July 2009

Purpose

This study compares late effects of treatment on physical well-being and utilization of health care resources between ovarian germ cell tumor (OGCT) survivors and age/race/education-matched controls.

Patients and Methods

Eligible patients had OGCT treated with surgery and chemotherapy and were disease-free for at least 2 years at time of enrollment. The matched control group was selected from acquaintances recommended by survivors. Symptoms and function were measured using previously validated scales. Health care utilization was assessed by questions regarding health insurance coverage and health services utilization.

Results

One hundred thirty-two survivors and 137 controls completed the study. Survivors were significantly more likely to report a diagnosis of hypertension (17% v 8%, P = .02), and marginally hypercholesterolemia (9.8% v 4.4%, P = .09), and hearing loss (5.3% v 1.5%, P = .09) compared with controls. There were no significant differences in the rates of self-reported arthritis, heart, pulmonary or kidney disease, diabetes, non-OGCT malignancies, anxiety, hearing loss, or eating disorders between groups. Among chronic functional problems, numbness, tinnitus, nausea elicited by reminders of chemotherapy (v general nausea triggers for controls), and Raynaud's symptoms were reported more frequently by survivors. Patients who received vincristine, dactinomycin, and cyclophosphamide in addition to cisplatin therapy had increased functional complaints, particularly numbness and nausea. Health care utilization was similar, but 15.9% of survivors reported being denied health insurance versus 4.4% of controls (P < .001).

Conclusion

Although a few sequelae of treatment persist, in general, OGCT survivors enjoy a healthy life comparable to that of controls.
Accelerated Approval of Cancer Drugs: Improved Access to Therapeutic Breakthroughs or Early Release of Unsafe and Ineffective Drugs?
Authors: Richey Elizabeth A. , Lyons E. Alison , Nebeker Jonathan R. , Shankaran Veena , McKoy June M. , Luu Thanh Ha , Nonzee Narissa , Trifilio Steven , Sartor Oliver , Benson Al B. , Carson Kenneth R. , Edwards Beatrice J. , Gilchrist-Scott Douglas , Kuzel Timothy M. , Raisch Dennis W. , Tallman Martin S. , West Dennis P. , Hirschfeld Steven , Grillo-Lopez Antonio J. , Bennett Charles L.
Published: July 2009

Purpose

Accelerated approval (AA) was initiated by the US Food and Drug Administration (FDA) to shorten development times of drugs for serious medical illnesses. Sponsors must confirm efficacy in postapproval trials. Confronted with several drugs that received AA on the basis of phase II trials and for which confirmatory trials were incomplete, FDA officials have encouraged sponsors to design AA applications on the basis of interim analyses of phase III trials.

Methods

We reviewed data on orphan drug status, development time, safety, and status of confirmatory trials of AAs and regular FDA approvals of new molecular entities (NMEs) for oncology indications since 1995.

Results

Median development times for AA NMEs (n = 19 drugs) and regular-approval oncology NMEs (n = 32 drugs) were 7.3 and 7.2 years, respectively. Phase III trials supported efficacy for 75% of regular-approval versus 26% of AA NMEs and for 73% of non–orphan versus 45% of orphan drug approvals. AA accounted for 78% of approvals for oncology NMEs between 2001 and 2003 but accounted for 32% in more recent years. Among AA NMEs, confirmatory trials were nine-fold less likely to be completed for orphan drug versus non–orphan drug indications. Postapproval, black box warnings were added to labels for four oncology NMEs (17%) that had received AA and for two oncology NMEs (9%) that had received regular approval.

Conclusion

AA oncology NMEs are safe and effective, although development times are not accelerated. A return to endorsing phase II trial designs for AA for oncology NMEs, particularly for orphan drug indications, may facilitate timely FDA approval of novel cancer drugs.
Prognostic Implications of NOTCH1 and FBXW7 Mutations in Adults With T-Cell Acute Lymphoblastic Leukemia Treated on the MRC UKALLXII/ECOG E2993 Protocol
Authors: Mansour Marc R. , Sulis Maria L. , Duke Veronique , Foroni Letizia , Jenkinson Sarah , Koo Kenneth , Allen Christopher G. , Gale Rosemary E. , Buck Georgina , Richards Sue , Paietta Elisabeth , Rowe Jacob M. , Tallman Martin S. , Goldstone Anthony H. , Ferrando Adolfo A. , Linch David C.
Published: July 2009

Purpose

Notch pathway activation by mutations in either NOTCH1 and/or FBXW7 is one of the most common molecular events in T-cell acute lymphoblastic leukemia (T-ALL) and, in pediatric disease, predicts for favorable outcome. Their prognostic significance in adult T-ALL is unclear. We sought to evaluate the outcome according to mutation status of patients with adult T-ALL treated on the United Kingdom Acute Lymphoblastic Leukaemia XII (UKALLXII)/Eastern Cooperative Oncology Group (ECOG) E2993 protocol.

Methods

NOTCH1 and FBXW7 were screened by a combination of denaturing high-performance liquid chromatography and sequencing in 88 adult patients with T-ALL treated on the UKALLXII/ECOG E2993 protocol and compared with clinical characteristics and outcome.

Results

NOTCH1 and FBXW7 mutations were common (60% and 18%, respectively) and were not associated with age or WBC count. NOTCH1 heterodimerization domain mutations were associated with FBXW7 mutations (P = .02), and NOTCH1 proline, glutamic acid, serine, threonine (PEST) rich domain and FBXW7 mutations were mutually exclusive. There were an equal number of high- and standard-risk patients in the NOTCH1 and FBXW7 mutated (MUT) groups. Patients wild type (WT) for both markers trended toward poorer event-free survival (EFS; MUT v WT, 51% v 27%, P = .10; hazard ratio, 0.6). Analysis by each marker individually was not significantly predictive of outcome (NOTCH1 MUT v WT, EFS 49% v 34%, P = .20; FBXW7 MUT v WT, EFS 53% v 41%, P.72).

Conclusion

NOTCH1 and FBXW7 mutant-positive patients do not fare sufficiently well to warrant an individualized treatment approach in future studies.
The collapse of thick-walled metal tubes with wide external grooves as controllable energy-dissipating devices
Authors: Salehghaffari S , Tajdari M , Mokhtarnezhad F
Published: July 2009

This article focuses on the experimental and theoretical investigation of the axial crushing behaviour of thick-walled tubes with a number of wide grooves, cut from their outer surface, under both static and dynamic loading. While this structure is subjected to axial loading, plastic deformation occurs within the space of each wide groove, and thick portions (grooveless areas) control and stabilize the collapsing of grooved thick-walled tubes. Therefore, the kinetic energy is dissipated by the plastic collapsing of the structure between grooves. In the present study, quasi-static compression tests of specimens with various geometric parameters are performed. Dynamic tests of some specimens using a drop hammer apparatus are also carried out to study the dynamic effects on the collapsing and energy absorption behaviour of the shock absorber. Numerical simulations of axial crushing of the shock absorber under both quasi-static and impact loading, using LS-DYNA finite-element explicit code, are also carried out in this article, and their results are verified with experimental findings. Based on experimental studies, an analysis with consideration of strain hardening effects to predict mean crushing load and energy absorption of the structure under axial compression is developed. Through the performed experimental, numerical, and analytical studies, major parameters in the design of the shock absorber are characterized and possible collapse modes of deformation during axial crushing of the structure are identified. In the present study, experimental and theoretical studies show that the introduced structure can be considered as an efficient energy-dissipating device since it provides favourable crashworthiness characteristics.
Heat transfer characteristics of a cylindrical porous radiant air heater under the influence of a two-dimensional axisymmetric radiative field
Authors: Keshtkar M M , Gandjalikhan Nassab S A , Nasr M R J
Published: July 2009

This work presents the heat transfer characteristics of a new type of porous radiant air heater (PRAH) that operates on the basis of an effective energy conversion method between flowing gas enthalpy and thermal radiation. In this system, four porous layers consisting of porous radiant burner (PRB), high-temperature (HT) section, first heat recovery section, and second heat recovery section are considered. These layers are separated from each other by three quartz glass walls. The PRB generates a large amount of thermal radiative energy, which is converted into gas enthalpy in heat recovery layers. In the HT section, the gas enthalpy of the exhaust flow from PRB converts into thermal radiation. At each layer, the gas and solid phases are considered in non-local thermal equilibrium and combustion in the PRB is modelled by considering a non-uniform heat generation zone. The homogeneous porous media, in addition to its convective heat exchange with the gas, may absorb, emit, and scatter thermal radiation. In order to determine the thermal characteristics of the proposed PRAH, a two-dimensional model is used to solve the governing equations for porous medium and gas flow and the discrete ordinates method is used to obtain the distribution of radiative heat flux in the porous media. Computational results show that this type of air heater has much higher efficiency than the conventional ones. In addition, it is clarified that the high optical thickness and low scattering coefficient for porous layers improve the heater efficiency. In order to validate the applied numerical method at the present analysis, the results are compared with some reported theoretical and experimental results by other investigators and good agreement is found.
Realization of transverse pure spin currents in a four-terminal double-quantum-dot Aharonov—Bohm interferometer
Authors: Gong W , Han Y , Wei G
Published: July 2009

Spin-dependent electron transport properties in a parallel double-dot structure with four terminals are investigated theoretically by means of the non-equilibrium Green function technique. By applying a local Rashba spin—orbit interaction on an individual quantum dot and introducing a finite bias between the longitudinal terminals, it is found that, in the presence of appropriate structure parameters, transverse pure spin currents without an accompanying charge current appear. Moreover, the flow direction of such spin currents can be inverted by altering the structure parameters, i.e. magnetic flux, bias voltage, and values of quantum-dot levels with respect to the zero point of energy.
A review of the microstructure and rheology of carbon nanotube suspensions
Authors: Ma A W K , Yearsley K M , Chinesta F , Mackley M R
Published: July 2009

The present review is concerned with the way that the incorporation of carbon nanotubes (CNTs) into a fluid matrix can modify the microstructure and rheology of the resulting suspensions. Some background to CNT manufacture and in particular methods of dispersing them into a suspension is presented for a range of different systems, where effective dispersion of CNTs remains a delicate and open issue. Steady shear, linear viscoelasticity, non-linear viscoelasticity and extensional responses are classified for a range of different CNT/matrix combinations together with their associated microstructure. The rheological modelling of certain CNT/matrix systems is reviewed, with particular attention given to the authors’ work on modelling CNT suspension behaviour using Fokker—Planck advection-diffusion modelling.
Processing of Drosophila endo-siRNAs depends on a specific Loquacious isoform
Authors: Zhou Rui , Czech Benjamin , Brennecke Julius , Sachidanandam Ravi , Wohlschlegel James A. , Perrimon Norbert , Hannon Gregory J.
Published: July 2009

Drosophila melanogaster expresses three classes of small RNAs, which are classified according to their mechanisms of biogenesis. MicroRNAs are ∼22–23 nucleotides (nt), ubiquitously expressed small RNAs that are sequentially processed from hairpin-like precursors by Drosha/Pasha and Dcr-1/Loquacious complexes. MicroRNAs usually associate with AGO1 and regulate the expression of protein-coding genes. Piwi-interacting RNAs (piRNAs) of ∼24–28 nt associate with Piwi-family proteins and can arise from single-stranded precursors. piRNAs function in transposon silencing and are mainly restricted to gonadal tissues. Endo-siRNAs are found in both germline and somatic tissues. These ∼21-nt RNAs are produced by a distinct Dicer, Dcr-2, and do not depend on Drosha/Pasha complexes. They predominantly bind to AGO2 and target both mobile elements and protein-coding genes. Surprisingly, a subset of endo-siRNAs strongly depend for their production on the dsRNA-binding protein Loquacious (Loqs), thought generally to be a partner for Dcr-1 and a cofactor for miRNA biogenesis. Endo-siRNA production depends on a specific Loqs isoform, Loqs-PD, which is distinct from the one, Loqs-PB, required for the production of microRNAs. Paralleling their roles in the biogenesis of distinct small RNA classes, Loqs-PD and Loqs-PB bind to different Dicer proteins, with Dcr-1/Loqs-PB complexes and Dcr-2/Loqs-PD complexes driving microRNA and endo-siRNA biogenesis, respectively.
Dyslexia and reasoning: The importance of visual processes
Authors: Bacon Alison M. , Handley Simon J.
Published: July 2009

Recent research has suggested that individuals with dyslexia rely on explicit visuospatial representations for syllogistic reasoning while most non‐dyslexics opt for an abstract verbal strategy. This paper investigates the role of visual processes in relational reasoning amongst dyslexic reasoners. Expt 1 presents written and verbal protocol evidence to suggest that reasoners with dyslexia generate detailed representations of relational properties and use these to make a visual comparison of objects. Non‐dyslexics use a linear array of objects to make a simple transitive inference. Expt 2 examined evidence for the visual‐impedance effect which suggests that visual information detracts from reasoning leading to longer latencies and reduced accuracy. While non‐dyslexics showed the impedance effects predicted, dyslexics showed only reduced accuracy on problems designed specifically to elicit imagery. Expt 3 presented problems with less semantically and visually rich content. The non‐dyslexic group again showed impedance effects, but dyslexics did not. Furthermore, in both studies, visual memory predicted reasoning accuracy for dyslexic participants, but not for non‐dyslexics, particularly on problems with highly visual content. The findings are discussed in terms of the importance of visual and semantic processes in reasoning for individuals with dyslexia, and we argue that these processes play a compensatory role, offsetting phonological and verbal memory deficits.
Cooperatism, social capital and regional development: the Mondragon experience
Authors: Lizarralde Iosu
Published: July 2009

This article discusses the importance of the principles of social capital within the Mondragon cooperative experience. It investigates the impact of social capital on the value creation and innovation capacity of the Mondragon group. It proposes to investigate how social capital fosters
collective action, participation and innovation to build dynamic communities and regional development. The article describes the development of the Mondragon cooperative movement around a four-pillared structure which includes training, research, enterprise promotion, and financial and social
support. The article also demonstrates that the success of the Mondragon experience is linked to factors such the setting up of networks of communication, trusting relationships, and exploration and exploitation of new situations.
Innovation in industrial cooperatives: special features and potential of the Mondragon model
Authors: Lopez Urko , Lopez Sain , Larraaga Iaki
Published: July 2009

Since its creation in 1956, the Mondragn Cooperative Experience has given rise to one of the largest industrial cooperatives in the world, known today as Mondragon Corporation. One of the main objectives of this group is to continue increasing its base of 103,731 jobs a figure created
in a context that is no longer local but has become global in reach. This article examines the case of Mondragon, analyzing the role played by innovation in its historical development, as well as the importance it still has in the design of a new industrial cooperative that is truly people-oriented,
but at the same time highly focussed on survival and growth. The article is divided into four main parts. First, Mondragon's innovation background is presented, through a discussion of the evolution, application and adaptation of innovation within the group, the structural and strategic elements
underlying innovation in Mondragon and the innovation issues being addressed by Mondragon companies. The second section examines the particularities determining Mondragon innovation activity and shaping its development, such as the group's internal innovation mechanisms and resources, as well
as the surrounding environment. The third part of the article is devoted to an evaluation of Mondragon innovation potential, its latent capacities and the challenges it must meet in stimulating further development. Finally, before drawing conclusions and presenting the outlook for the future,
a brief description is made of the individual results of certain Mondragon companies and the innovation strategies they have adopted, paying special attention to the case of Ulma Packaging, a cooperative that has chartered a clear path to growth based on innovation.
The Future of X-Ray Fluorescence Instrumentation
Authors: Kemp J. W.
Published: July 2009

In a rapidly moving field like X-ray fluorescence analysis, instrument manufacturers are hard-pressed to provide adequate instrumentation for commercial utilization of the latest techniques. Many components of the presently available instruments are performing adequately, but it takes little imagination to see that some other components will require considerable improvement before they will be completely satisfactory to the routine user. It is the author's intention here to review existing components and to point out needed improvements. Before discussing at length what is wrong with X-ray fluorescence instrumentation it is only fair to note that many instruments of this type are carrying out high-speed, quantitative analyses on a routine basis. All elements of atomic number greater than 11 can be analyzed for on a quantitative basis, and probably all elements with atomic number greater than 20 can be detected in the range of 1 to 10 ppm in an analytical time that is competitive with that of any other analytical technique. The precision of the X-ray technique is usually greater than that of any analytical technique available for calibrating the X-ray method. However, better precision is always being asked for.
Analytical Flame Photometry: New Developments
Authors: Gilbert Paul T.
Published: July 2009

The following topics are discussed: The current status of flame photometry; novel sources: hot flames (fluorine, perchloryl fluoride, cyanogen, carbon subnitride), special flames (ozone, atomic hydrogen, activated gases, spark-in-flame), discharges (spark-in-spray, Spectranal, discharge burner, electrodeless discharges, electronic torch, plasma jet, constricted arc, irradiated arc, etc.); atomic absorption analysis; topics in sample feeding and control: solid sparking, powder atomizers, centrifugal, ultrasonic, and electrostatic atomizers, controlled-flow pneumatic atomizers; novel methods of gas flow control; special mirrors for intensifying flame emission; high-resolution and multichannel flame spectrophotometers (Quantometers); interference wedges and filters; red-sensitive photodetectors, especially photomultipliers; flame spectrography; radioactive phosphor reference, special recording methods, oscillographic scanning, signal integration; new flame spectra of the elements: in oxyhydrogen (lithium, beryllium, magnesium, strontium, lanthanum, cerium, ytterbium, vanadium, iron, cobalt, nickel, boron, aluminum, indium, thallium, bismuth, tin), in air-hydrogen (zinc, bismuth), in oxycyanogen (chromium, magnesium, vanadium, molybdenum, tin, bismuth), and in a premixed oxyacetylene atomizer-burner (strontium, chromium); infrared flame spectra; some special applications: qualitative analysis, extraction methods, flame-photometric titration, indirect flame analysis (halides, sulfate, phosphate, aluminum, zirconium), lead in gasoline, boron, lithium, magnesium, the platinum metals, the rare earths, rubidium, cesium, sodium monitor, aerosol flame analysis, combustion analysis; special topics in interferences: dual atomizers, releasing agents, self-standardization.
The Unpaired Electron via Electron Paramagnetic Resonance Spectrometry
Authors: Sands R. H.
Published: July 2009

Of those forms of spectroscopy discussed in this symposium, Electron Paramagnetic Resonance (EPR) Spectrometry stands near the bottom in age. However, its significance makes it well worth discussing. Not only has it won acceptance as a powerful new tool in physics, chemistry and biology, but it has found application in the field of engineering for solid state amplifiers as well. Biophysics has been aided greatly by this new tool, and polymer and free radical chemistry have received a harvest of new data heretofore unavailable. The prospects offered by free radical and ion kinetics has spurred much fresh activity. In this light it is appropriate to discuss some of the unsolved problems. As with almost any form of spectroscopy, one does not have to look far to find problems which fall under this category—the chemist questions the structure of a given free radical, the physicist wishes to know the nature of the crystalline field, the biologist is interested in the structure of some metalloorganic or the nature of any free radical involved in metabolic processes. Not only is there not time to delineate all of the unsolved problems in EPR, there is not even sufficient time to discuss one of these problems in detail. For the sake of complementarity, however, problems in two different areas will be discussed—one related to instrumentation and the other to application.
Maser Applications and Traveling-Wave Techniques for Magnetic Resonance Spectroscopy
Authors: Siegman A. E.
Published: July 2009

The phenomena of electron paramagnetic resonance have recently found practical application in the solid-state maser, an extremely low-noise microwave amplifier using stimulated emission in a multi-level electron spin system subjected to a higher-frequency pumping signal. In order to obtain broadband amplifiers, the paramagnetic material is distributed along a low-group-velocity traveling-wave circuit in the most recent versions. The traveling-wave techniques developed for this application appear to have potential uses in experimental magnetic resonance spectroscopy as well. Proposals will be presented for some experiments using traveling-wave techniques which would not be possible with conventional resonant cavity techniques.
The Combination of Methods in the Analysis of Complex Hydrocarbon Systems
Authors: Coggeshall Norman D. , Hubis Walter
Published: July 2009

The last decade and a half has witnessed enormous strides in the technology of determining the composition of complex hydrocarbon systems. On the whole, the progress has been continuous and each year has seen important advances achieved and new areas penetrated. The complete problem is so vast that many techniques and many variations within techniques are employed. However, in looking back one can recognize three major landmarks of progress. These have been the advents of infrared spectroscopy, mass spectrometry, and, more recently, gas-liquid partition chromatography, respectively. It has been several years since the last of the major techniques came upon the scene. Nevertheless, the intense pace is continuing with significant progress in all important techniques in terms of instrumentation, a better understanding of the fundamental nature of the phenomena involved, and in empirical correlations. Parallel with this progress within techniques there has been a growing potential realizable by the combination of techniques for handling different aspects of major problems. The maximum utility of the different important techniques requires the services of professional specialists. The extensive utilization of various techniques on a teamwork approach to major problems therefore requires that a new degree of attention be applied to the segmentation of major problems and to effective technical coordination and communications. The vastness of the field of hydrocarbon analysis is a result of the thousands upon thousands of individual compounds that are inherently involved. It is well known that the number of possible isomers for any hydrocarbon class increases rapidly with the number of carbon atoms per molecule. This is displayed in Fig. 1, which gives the number of alkane isomers possible versus carbon number [11]. This extremely rapid rise effectively closes the door for comprehensive methods of analysis for specific compounds past the C7 or C8 range. The limitation is not so much a result of deficiencies in the techniques for resolving isomers as it is of the very high cost of synthesizing all the reference compounds. Another aspect is that a complete analysis of a C10 alkane cut, for example, involving information on each of the 75 isomers would not be very practical information to the process research or operations engineer. For other classes of hydrocarbons—olefins, for example— the number of possible isomers goes up even faster with carbon number.