bluuebunny/crossref_metadata_2025 huggingface dataset:
Consequences of two naturally occurring missense mutations in the structure and function of Bruton agammaglobulinemia tyrosine kinase
Authors: Vargas‐Hernández Alexander , López‐Herrera Gabriela , Maravillas‐Montero José L. , Vences‐Catalán Felipe , Mogica‐Martínez Dolores , Rojo‐Domínguez Arturo , Espinosa‐Rosales Francisco J. , Santos‐Argumedo Leopoldo
Published: February 2012

Bruton agammaglobulinemia tyrosine kinase (BTK) is a key protein in the B‐cell receptor (BCR) signaling pathway and plays an essential role in the differentiation of B lymphocytes. X‐linked agammaglobulinemia (XLA) is a primary humoral immunodeficiency caused by mutations in the gene encoding BTK. Previously, we identified two novel variations, L111P and E605G, in BTK; these are localized within the pleckstrin homology and Src homology 1 domains, respectively. In the present study, we evaluated the potential effects of these variations on the structural conformation and the function of BTK. Using in silico methods, we found that the L111P and E650G variations are not located directly in protein–protein interfaces but close to them. They distorted the native structural conformation of the BTK protein, affecting not only its geometry and stability but also its ability for protein recognition and in consequence its functionality. To confirm the results of the in silico assays, WT BTK, L111P, and E650G variants were expressed in the BTK‐deficient DT40 cell line. The mutant proteins exhibited an absence of catalytic activity, aberrant redistribution after BCR‐crosslinking, and deficient intracellular calcium mobilization. This work demonstrates that L111 and E605 residues are fundamental for the activation and function of BTK. © 2012 IUBMB Life, 64(4): 346–353, 2012
A cellular delivery system fabricated with autologous BMSCs and collagen scaffold enhances angiogenesis and perfusion in ischemic hind limb
Authors: Wang Jinling , Cui Wugeng , Ye Jianhong , Ji Shufeng , Zhao Xiufeng , Zhan Linghui , Feng Jiachun , Zhang Zhigang , Zhao Yilin
Published: February 2012

Although therapeutic cellular angiogenesis is effective for chronic ischemia, the optimal mode of cellular administration is still under exploration. This study aimed to develop a cellular delivery system to enhance the perfusion and angiogenesis in the ischemic hind limb. Collagen scaffold (CS) was prepared, and for morphology and toxicity analysis, bone marrow‐derived mesenchymal stem cells (BMSCs) were isolated, expanded, filtrated, and seeded onto CS to construct BMSCs–CS. The ischemic hind limbs of rabbit models were implanted with autologous BMSCs–CS, CS, and autologous BMSCs; the untreated ischemic or normal animals were considered as the ischemic or normal control groups. Oxygen saturation parameters were regularly measured to determine the perfusion in the extremities. Histological examinations with hematoxylin and eosin immunostaining against von Willebrand factor and smooth muscle (SM) α‐actin were performed for capillary and mature vessel evaluation. CS was a multiporous structure without cytotoxicity. At several intervals, the oxygen saturation ratio (OSR) in normal control was the highest. The OSRs in BMSCs–CS and CS were higher than that in BMSCs and ischemic control (p< 0.05); the OSR in BMSCs–CS group was higher than that in CS at 6 and 8 weeks (p< 0.05). The capillaries in BMSCs–CS and CS were higher than that in CS, BMSCs, and the ischemic or normal control (p< 0.05). The mature vessels in BMSCs–CS were higher than that in CS, BMSCs, and the ischemic or normal control (p< 0.05). The autologous cellular delivery system proved to be an effective approach for improving higher ischemic hind limb perfusion and angiogenesis as opposed to cellular therapy alone. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Preparation and characterization of decellularized tendon slices for tendon tissue engineering
Authors: Ning Liang‐Ju , Zhang Yi , Chen Xiao‐He , Luo Jing‐Cong , Li Xiu‐Qun , Yang Zhi‐Ming , Qin Ting‐Wu
Published: February 2012

To develop a naturally derived tendon tissue engineering scaffold with the preservation of the native ultrastructure, tensile strength, and biochemical composition of the tendon extracellular matrix (ECM), decellularized tendon slices (DTSs) were prepared using repetitive freeze/thaw of the intact Achilles tendons, frozen section, and nuclease treatment. The DTSs were characterized in the native ultrastructure, mechanical properties, biochemical composition, and cytocompatibility. Histological examination and DNA quantification analysis confirmed that cells were completely removed from tendon tissue by repetitive freeze/thaw in combination with nuclease treatment 12 h. The intrinsic ultrastructure of tendon tissue was well preserved based on scanning electron microscopy examination. The tensile strength of the DTSs was retained 85.62% of native tendon slice. More than 93% of proteoglycans (fibromodulin, biglycan) and growth factors (TGF‐β1, IGF‐1, VEGF, and CTGF) inherent in tendon ECM were preserved in the DTSs according to ELISA analysis. Furthermore, the DTSs facilitated attachment and repopulation of NIH‐3T3 fibroblasts in vitro. Overall, the DTSs are sheet scaffolds with a combination of elemental mechanical strength and tendon ECM bioactive factors that may have many potential applications in tendon tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Reduced adenosine release from the aged mammalian heart
Authors: Fenton Richard A. , Dobson James G.
Published: February 2012

Adenosine (ADO) released in the heart results in enhanced coronary blood flow and reduced catecholamine release and myocardial responsiveness to adrenergic stimulation (anti‐adrenergic action). ADO release from the adrenergic‐stimulated aged heart is less than that from the young adult heart. Because adrenergic signaling in the aged heart is impaired, this study was conducted to determine if reduced ADO release from the aged heart results from this reduced adrenergic responsiveness. Hearts of 3–4 months (young adult) and 21–22 months (aged) Fischer‐344 rats were perfused with ADO deamination and re‐phosphorylation inhibited. Coronary effluent ADO levels were determined. Cellular‐free ADO levels with and without sodium acetate (NaAc)‐induced mitochondrial AMP synthesis were assessed using formed S‐adenosylhomocysteine (SAH) in L‐homocysteine thiolactone (L‐HC)‐treated hearts. The activities of SAH‐hydrolase were determined. Aged heart ADO release was 61% less than from young hearts. NaAc augmented young heart ADO release by 104%, while that of aged hearts remained unchanged. SAH synthesis was 51% and 56% lower in the aged heart in the absence and presence of NaAc, respectively, despite an 89% greater SAH hydrolase activity found in the aged hearts. Since synthesized AMP may be diverted to IMP and ultimately inosine by AMP deaminase, inosine release was determined. Aged heart inosine levels in the absence and presence of NaAc were 74% and 59% less than for the young hearts. It is concluded that a reduced mitochondrial AMP synthesis is in part responsible for the attenuation in ADO release from the adrenergic‐stimulated aged heart. J. Cell. Physiol. 227: 3709–3714, 2012. © 2012 Wiley Periodicals, Inc.
New insights on translational development of mesenchymal stromal cells for suppressor therapy
Authors: François Moïra , Galipeau Jacques
Published: February 2012

The discovery of the immunosuppressive properties of mesenchymal stromal cells (MSCs) has given new hope to patients suffering from autoimmune diseases as their lack of immunogenicity in addition to their immunosuppressive and regenerative properties makes them an ideal biological agent for the treatment of various disorders ranging from autoimmune diseases to tissue injury. The translational promises of a safer and more effective therapy has however suffered a setback with the recent release of the results from Phase III randomized clinical trial using MSCs for treatment of steroid refractory acute graft‐versus‐host disease (GvHD), which failed to meet its primary efficacy endpoint. In this review, we will address the current knowledge of the immunosuppressive mechanisms of MSCs from in vitro studies to animal models and then look upon the results obtained from human clinical trials in order to provide failure analysis of negative studies. We will conclude by proposing future directions which could help address this issue and allow rational development of MSCs as an effective and useful cell‐based immunotherapeutic. J. Cell. Physiol. 227: 3535–3538, 2012. © 2012 Wiley Periodicals, Inc.
“Out of sight, out of mind”: Housestaff perceptions of quality‐limiting factors in discharge care at teaching hospitals
Authors: Greysen S. Ryan , Schiliro Danise , Horwitz Leora I. , Curry Leslie , Bradley Elizabeth H.
Published: February 2012

BACKGROUND:

Improving hospital discharge has become a national priority for teaching hospitals, yet little is known about physician perspectives on factors limiting the quality of discharge care.

OBJECTIVES:

To describe the discharge process from the perspective of housestaff physicians, and to generate hypotheses about quality‐limiting factors and key strategies for improvement.

METHODS:

Qualitative study with in‐depth, in‐person interviews with a diverse sample of 29 internal medicine housestaff, in 2010–2011, at 2 separate internal medicine training programs, including 7 different hospitals. We used the constant comparative method of qualitative analysis to explore the experiences and perceptions of factors affecting the quality of discharge care.

RESULTS:

We identified 5 unifying themes describing factors perceived to limit the quality of discharge care: (1) competing priorities in the discharge process; (2) inadequate coordination within multidisciplinary discharge teams; (3) lack of standardization in discharge procedures; (4) poor patient and family communication; and (5) lack of postdischarge feedback and clinical responsibility.

CONCLUSIONS:

Quality‐limiting factors described by housestaff identified key processes for intervention. Establishment of clear standards for discharge procedures, including interdisciplinary teamwork, patient communication, and postdischarge continuity of care, may improve the quality of discharge care by housestaff at teaching hospitals. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
I can't get no job satisfaction: Meta‐analysis comparing permanent and contingent workers
Authors: Wilkin Christa L.
Published: February 2012

Scholars are concerned that contingent workers experience more adverse psychological job outcomes than permanent employees, but the empirical work on job satisfaction is mixed. The purpose of this study was to quantitatively summarize the potential mean differences in job satisfaction between contingent workers and permanent employees. Meta‐analytic results from 72 primary studies (N = 237 856) suggest that compared with permanent employees, contingent workers experience lower job satisfaction (d = −0.21); but when outlying primary studies are removed, the mean difference is small but significant (d = −0.06). Methodological artifacts explain small but significant differences in job satisfaction but do not account for much variance. Moderator analyses support previous findings that contingent workers are not a homogeneous group; some contingent workers (e.g., agency workers) experience lower job satisfaction than permanent employees, whereas the job satisfaction of other contingent workers (e.g., contractors) is similar to permanent employees. The findings have implications for increasing our understanding of job satisfaction by showing that job satisfaction appears to vary by employment type. Practical implications suggest that extending human resource practices to contingent workers may increase their job satisfaction, which has been shown to influence job performance, citizenship behaviors, and turnover. Copyright © 2012 John Wiley & Sons, Ltd.
Precipitation variations in Beijing during 1860–1897 AD revealed by daily weather records from the Weng Tong‐He Diary
Authors: Zhang Xue‐Zhen , Ge Quan‐Sheng , Fang Xiu‐Qi , Zheng Jing‐Yun , Fei Jie
Published: February 2012

Daily weather records from a historical private diary provide important data for studying historical climate change. We compiled daily weather records from the Weng Tong‐He Diary and counted the number of monthly precipitation days during 1860‐1897 AD for Beijing; then, using the number of monthly precipitation days, we reconstructed the seasonal precipitation using regression models relating the precipitation and precipitation days. The findings show that the monthly mean number of precipitation days for 1860‐1897 was greater than that for 1951‐2009 by about 1 d month−1 and that the summer (June to August, JJA) precipitation for 1860‐1897 was 471.8 mm greater than that for 1951‐2009 by about 15.5%. The JJA precipitation of 1860‐1897 had not only inter‐annual variations but also inter‐decadal variations that were characterized by less precipitation before 1886 (about 421.9 mm) and more precipitation thereafter (about 550.7 mm). As a consequence, the JJA precipitation of 1860‐1897 showed an evident positive trend with a rate of about 57.9 mm per decade. These precipitation variations were confirmed by other datasets. However, it is worth noting that our reconstruction underestimates the historical precipitation values (by about 22.5%) because of rainfall/snowfall events missed in Weng's diary and the poor ability of the regression models to capture extreme years. In the future, new methods of reconstructing precipitation with the consideration of missed rainfall/snowfall events are needed. Copyright © 2012 Royal Meteorological Society
Trouble in Paradise: the 2007–2009 Global Economic Recession and Hawai'i's Visitor Industry
Authors: Spencer Daniel M.
Published: February 2012

This is a case study of the impact of the global economic recession of 2007–2009 on Hawai'i's visitor industry. The industry responded to the downturn largely with advertising blitzes to its primary market on the US mainland. Notwithstanding these efforts, diminished lift capacity and visitor arrivals, combined with widespread discounting, resulted in a 26% decrease in real visitor spending in 2009 versus that in 2006. The industry recovered during 2010 and 2011, but major hotel foreclosures, State bond downgrades and lost accommodations jobs are enduring scars. The experience demonstrated anew Hawai'i's need to strengthen its visitor industry and diversify its economy. Copyright © 2012 John Wiley & Sons, Ltd.
Laryngotracheal reconstruction with resorbable microplate buttressing
Authors: Javia Luv R. , Zur Karen B.
Published: February 2012

Objectives/Hypothesis:

In patients undergoing laryngotracheal reconstruction (LTR), malacic segments of trachea can pose challenges to successful reconstruction. Malacic segments may inadequately support cartilage grafts used in augmentation surgery, sometimes requiring cricotracheal or tracheal resections. We describe a novel technique of LTR with resorbable microplate buttressing of malacic lateral tracheal segments.

Study Design:

Retrospective case series.

Methods:

Review of technique, treatment outcomes, and complications of seven children with subglottic stenosis and tracheomalacia requiring a microplate‐augmented LTR technique.

Results:

Seven infants ranging from 26 months to 9 years of age successfully underwent LTR for subglottic stenosis. Six children had a grade III subglottic stenosis. The seventh child had grade II subglottic stenosis, bilateral vocal fold paralysis, an elliptical cricoid, and an obstructing giant suprastomal fibroma. Five children underwent a double‐stage LTR with resorbable microplates sutured bilaterally to support severely malacic lateral tracheal segments. A cricotracheal resection would not have been feasible in one child due to the resection length and inadequate tracheal mobilization. Two children underwent a single‐stage LTR with unilateral application of a microplate. Six children were decannulated within 3 months and continue without airway symptoms or complications. One child, who is just over 2 months from reconstructive surgery, is being setup for decannulation. No complications were encountered.

Conclusions:

LTR with resorbable microplate buttressing of malacic lateral tracheal segments is technically feasible, safe, and can avoid more extensive surgery requiring tracheal resection. Further experience may support the use of this technique in challenging airway reconstructions. Laryngoscope, 2012
Dominance Measuring Method Performance under Incomplete Information about Weights
Authors: Mateos Alfonso , Jiménez Antonio , Blanco José F.
Published: February 2012

In multi‐attribute utility theory, it is often not easy to elicit precise values for the scaling weights representing the relative importance of criteria. A very widespread approach is to gather incomplete information. A recent approach for dealing with such situations is to use information about each alternative's intensity of dominance, known as dominance measuring methods. Different dominance measuring methods have been proposed, and simulation studies have been carried out to compare these methods with each other and with other approaches but only when ordinal information about weights is available. In this paper, we use Monte Carlo simulation techniques to analyse the performance of and adapt such methods to deal with weight intervals, weights fitting independent normal probability distributions or weights represented by fuzzy numbers. Moreover, dominance measuring method performance is also compared with a widely used methodology dealing with incomplete information on weights, the stochastic multicriteria acceptability analysis (SMAA). SMAA is based on exploring the weight space to describe the evaluations that would make each alternative the preferred one. Copyright © 2012 John Wiley & Sons, Ltd.
Supraorbitary to infraorbitary nerve transfer for restoration of midface sensation in face transplantation: Cadaver feasibility study
Authors: Rodriguez‐Lorenzo Andres , Audolfsson Thorir , Rozen Shai , Kildal Morten , Nowinski Daniel
Published: February 2012

Background:

The collected experience from facial allotransplantations has shown that the recovery of sensory function of the face graft is unpredictable. Unavailability of healthy donor nerves, especially in central face defects may contribute to this fact. Herein, the technical feasibility of transferring the supraorbitary nerve (SO) to the infraorbitary nerve (IO) in a model of central facial transplantation was investigated.

Methods:

Five heads from fresh cadavers were dissected with the aid of 3× loupe magnification. Measurements of the maximum length of dissection of the SO nerve through a supraciliary incision and the IO nerve from the skin of the facial flap to the infraorbital foramen were performed. The distance between supraorbital and infraorbital foramens and the calibers of both nerves were also measured. In all dissections, we simulated a central allotransplantation procedure and assessed the feasibility of directly transferring the SO to the IO nerve.

Results:

The average maximum length of dissection for the IO and SO nerve was 1.4 ± 0.3 cm and 4.5 ± 1.0 cm, respectively. The average distance between the infraorbital and supraorbital foramina was 4.6 ± 0.3 cm. The average calibers of the nerves were of 1.1 ± 0.2 mm for the SO nerve and 2.9 ± 0.4 mm for the IO nerve. We were able to perform tension‐free SO to IO nerve coaptations in all specimens.

Conclusion:

SO to IO nerve transfer is an anatomically feasible procedure in central facial allotransplantation. This technique could be used to improve the restoration of midfacial sensation by the use of a healthy recipient nerve in case of the recipient IO nerves are not available secondary to high‐energy trauma. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
1H and 13C{1H} NMR spectral parameters of sulfur mustards, nitrogen mustards, and lewisites: Computing and Predicting of Reference Spectra for Chemical Identification
Authors: Haapaniemi Esa , Mesilaakso Markku
Published: February 2012

The 1H and 13C{1H} chemical shifts and 1H spin–spin couplings of sulfur mustards, nitrogen mustards, and lewisites scheduled in the Chemical Weapons Convention, and those of bis(2‐chloromethyl)disulfide, were determined in CDCl3, CD2Cl2, and (CD3)2CO. Accurate parameters of this kind of series can be used for evaluating the current molecular modeling programs and the chemical shift and coupling constant prediction possibilities of the programs. Several prediction tests were made with commercial programs, and the results are reported here. Copyright © 2012 John Wiley & Sons, Ltd.
A coupling method for soil structure interaction problems
Authors: Souli M. , Shahrour I.
Published: February 2012

This paper describes a soil‐structure coupling method to simulate blast loading in soil and structure response. For the last decade, simulation of soil behavior under blast loading and its interaction with semi buried structure in soil becomes the focus of computational engineering in civil and mechanical engineering communities. In current design practice, soil‐structure interaction analysis often assumes linear elastic properties of the soil and uses small displacement theory. However, there are numerous problems, which require a more advanced approach that account for soil‐structure interaction and appropriate constitutive models for soil. In simplified approaches, the effect of soil on structure is considered using spring‐dashpot‐mass system, and the blast loading is modeled using linearly decaying pressure–time history based on equivalent trinitrotoluene and standoff distance, using ConWep, a computer program based on semi‐empirical equations. This strategy is very efficient from a CPU time computing point of view but may not provide accurate results for the dynamic response of the structure, because of its significant limitations, mainly when soil behavior is strongly nonlinear and when the buried charge is close to the structure. In this paper, both soil and explosive are modeled using solid elements with a constitutive material law for soil, and a Jones–Wilkins–Lee equation of state for explosive. One of the problems we have encountered when solving fluid structure interaction problems is the high mesh distortion at the contact interface because of high fluid nodal displacements and velocities. Similar problems have been encountered in soil structure interaction problems. To prevent high mesh distortion for soil, a new coupling algorithm is performed at the soil structure interface for structure loading. The coupling method is commonly used for fluid structure interaction problems in automotive and aerospace industry for fuel sloshing tank, and bird impact problems, but rarely used for soil structure interaction problems, where Lagrangian contact type algorithms are still dominant. Copyright © 2012 John Wiley & Sons, Ltd.
A comparison of the effect of age on levator ani and obturator internus muscle cross‐sectional areas and volumes in nulliparous women
Authors: Morris Vikky C. , Murray Meghan P. , DeLancey John O.L. , Ashton‐Miller James A.
Published: February 2012

Aims

Functional tests have demonstrated minimal loss of vaginal closure force with age. So we tested the null hypotheses that age neither affects the maximum cross‐sectional area (CSA) nor the volume of the levator muscle. Corresponding hypotheses were also tested in the adjacent obturator internus muscle, which served as a control for the effect of age on appendicular muscle in these women.

Methods

Magnetic resonance images of 15 healthy younger (aged 21–25 years) and 12 healthy older nulliparous women (aged >63 years) were selected to avoid the confounding effect of childbirth. Models were created from tracing outlines of the levator ani muscle in the coronal plane, and obturator internus in the axial plane using 3D Slicer v. 3.4. Muscle volumes were calculated using Slicer, while CSA was measured using Imageware™ at nine locations. The hypotheses were tested using repeated measures analysis of variance with P < 0.05 being considered significant.

Results

The effect of age did not reach statistical significance for the decrease in levator ani muscle maximum CSA or the decrease in volume (4.3%, P = 0.62 and 10.9%, 0.12, respectively). However, age did significantly adversely decrease obturator internus muscle maximum CSA and volume (24.5% and 28.2%, P < 0.001, respectively). Significant local age‐related changes were observed dorsally in both muscles.

Conclusions

Unlike the adjacent appendicular muscle, obturator internus, the levator ani muscle in healthy nullipara does not show evidence of significant age‐related atrophy. Neurourol. Urodynam. 31:481–486, 2012. © 2012 Wiley Periodicals, Inc.
Is laparoscopic surgery an option to support prophylactic colectomy in adolescent patients with Familial Adenomatous Polyposis (FAP)?
Authors: Vitellaro Marco , Ferrari Andrea , Trencheva Koiana , Sala Paola , Massimino Maura , Piva Luigi , Bertario Lucio
Published: February 2012

Background

Prophylactic surgery is still considered the standard treatment for patients with Familial Adenomatous Polyposis (FAP). Laparoscopic (Lap) surgery has been introduced as an alternative approach. The aim was to evaluate the feasibility and short‐ to long‐term outcomes after prophylactic FAP surgery in adolescent.

Procedures

A retrospective review of a database of adolescent patients with FAP identified through the Hereditary Colorectal Tumor Registry in a single Institution between 2005 and 2011. Patients underwent Lap total colectomy (TC) with ileo‐rectal anastomosis (IRA) or proctocolectomy (PC) with ileal‐pouch anal anastomosis (IPAA). The main outcomes were: Hospital stay, postoperative complications, desmoid tumor rates, tumor recurrence, long‐term complications.

Results

Sixteen consecutive patients with median age 16 (range 13–19) and median BMI 22 (17–29) underwent surgery. [correction made here after initial online publication]. Of them 14 patients had LAP TC with IRA and 2 had PC with IPAA. Operative time (median, range) was TC/IRA 270 (210–330) minutes; PC/IPAA 370 (360–380) minutes. Length of extraction site was cm (median, range) 6(5–8). Lymph Node harvest (median, range) 81 (32–139). Postoperative stay days (median, range) were 6 (4–24). Five patients (31.2%) showed dysplasia on the pathological report and 3 of them showed severe dysplasia. Median follow‐up time (FU) was 39 months, range (10–82). The anastomotic leak rate for 30 days was 2 (12.5%). Pouch failure was 0. Post‐surgical desmoid tumors rate was 1 (6.2%) and there was no tumor recurrence. Anastomotic stricture, SBO and mortality were zero.

Conclusions

Lap approach is feasible and shows acceptable postoperative outcomes. Lap surgery can be an appealing alternative for prophylactic surgery in adolescent FAP patients. Pediatr Blood Cancer 2012; 59: 1223–1228. © 2012 Wiley Periodicals, Inc.
New aspects of neuroblastoma treatment: ASPHO 2011 symposium review
Authors: Zage Peter E. , Louis Chrystal U. , Cohn Susan L.
Published: February 2012

Neuroblastoma is the most common extracranial solid tumor of childhood, and the outcomes for children with high‐risk and relapsed disease remain poor. However, new international strategies for risk stratification and for treatment based on novel tumor targets and including immunotherapy are being employed in attempts to improve the outcomes of children with neuroblastoma. A new international neuroblastoma risk classification system has been developed which is being incorporated into cooperative group clinical trials in North America, Japan, and Europe, resulting in standardized approaches for the initial evaluation and treatment stratification of neuroblastoma patients. Furthermore, novel treatment regimens are being developed based on improved understanding of neuroblastoma biology and on the recruitment of the immune system to specifically target neuroblastoma tumors. These approaches will lead to new therapeutic strategies that likely will improve the outcomes for children with neuroblastoma worldwide. Pediatr Blood Cancer 2012; 58: 1099–1105. © 2012 Wiley Periodicals, Inc.
Rhabdomyosarcoma: Review of the Children's Oncology Group (COG) soft‐tissue Sarcoma committee experience and rationale for current COG studies
Authors: Malempati Suman , Hawkins Douglas S.
Published: February 2012

The prognosis for children and adolescents with rhabdomyosarcoma (RMS) has improved with refinements in multi‐modal therapy. Since 1972, the Intergroup Rhabdomyosarcoma Study Group (now the Children's Oncology Group Soft‐Tissue Sarcoma Committee) has conducted serial studies for RMS. This review describes the IRSG and COG experience with RMS, presents the current risk stratification definitions, and provides rationale for the current generation of COG RMS studies. Pediatr Blood Cancer 2012; 59: 5–10. © 2012 Wiley Periodicals, Inc.
FLT3 mutation status is a predictor of early death in pediatric acute promyelocytic leukemia: A report from the Children's Oncology Group
Authors: Kutny Matthew A. , Moser Barry K. , Laumann Kristina , Feusner James H. , Gamis Alan , Gregory John , Larson Richard A. , Powell Bayard L. , Stock Wendy , Willman Cheryl L. , Woods William G. , Meshinchi Soheil
Published: February 2012

Background

FLT3 mutations (FLT3/Mut) are prevalent in de novo AML and are associated with early relapse. The prevalence and prognostic significance of FLT3/Mut have not been well defined in childhood acute promyelocytic leukemia (APL).

Procedure

Diagnostic specimens from 104 pediatric APL patients were screened for FLT3/Mut (FLT3/ITD or FLT3/ALM). FLT3/Mut status was correlated with disease characteristics and clinical outcome for patients treated on CALGB C9710 (n = 50).

Results

Forty‐two of the 104 patients (40%) had either FLT3/ITD (n = 28, 27%) or FLT3/ALM (n = 15, 14%). Median diagnostic WBC count was 23,400 cells/µl vs. 3,600 cells/µl for those with and without FLT3/Mut (P < 0.001), and similar results for the cohort of 50 patients treated on C9710 (P < 0.001). In patients treated on C9710, presence of a FLT3 mutation was highly correlated with diagnostic WBC count >10,000 (P = 0.004), microgranular variant histology (P = 0.035), and a lower remission rate (P = 0.009). In patients who received ATRA (C9710 or CCG‐2911, n = 58), those with FLT3/Mut had an induction death rate of 30% (7/23) compared to 3% (1/35) in FLT3/WT patients (P = 0.005). In patients with high WBC counts (>10,000), those with FLT3/Mut had a significantly higher risk of induction death versus FLT3/WT patients (47% vs. 0%, P = 0.05). FLT3/Mut was not associated with adverse outcome in those who survived induction therapy.

Conclusions

FLT3/Mut are prevalent in pediatric APL and are associated with high WBC count and increased induction death. This study provides further evidence for testing APL patients for FLT3/Mut and the potential role for FLT3 inhibitors in this disease. Pediatr Blood Cancer 2012;59:662–667. © 2012 Wiley Periodicals, Inc.
Value of routine bone marrow examination in pediatric acute myeloid leukemia (AML): A study of the Dutch Childhood Oncology Group (DCOG)
Authors: Hageman Ilse M.G. , Peek Annemarie M.L. , de Haas Valérie , Damen‐Korbijn Carin M. , Kaspers Gertjan J.L.
Published: February 2012

Background

The outcome of the treatment of pediatric acute myeloid leukemia (AML) is still disappointing, due to relatively high treatment‐related mortality and relapse rates (30–40%). Past treatment protocols have called for routine screening via bone marrow aspiration (BMA) after achievement of first complete remission (CR1) to detect relapse at an early stage. However, supporting evidence for this policy is lacking for non‐FAB type‐M3 patients.

Procedure

We therefore retrospectively studied the clinical relevance of routine BMA in an unselected cohort of all pediatric AML patients in the Netherlands.

Results

Of 440 patients, data for 349 patients, of whom 148 suffered bone marrow relapse (BM‐relapse), could be analyzed. A total of 1,790 BMAs had been performed, 1,648 (92%) routinely, and 142 (8%) on indication when a relapse was suspected. Forty routine BMAs showed BM‐relapse (2% of all routine BMAs), while as many as 108 (76%) hematological relapses were confirmed by BMA on indication (P < 0.001). Therefore, 1 in 41 routine BMAs, as opposed to 1 in 1.3 BMAs performed on indication, detected a BM‐relapse.

Conclusions

Routine BMA after CR1 did not significantly contribute to early detection of relapsed AML. These results suggest that BMA after achievement of CR1 should only be performed on indication or within a clinical research setting. Pediatr Blood Cancer 2012; 59: 1239–1244. © 2012 Wiley Periodicals, Inc.
Construction of phthalocyanine‐terminated polystyrene nanoarchitectures
Authors: de Loos Femke , de la Torre Gema , Torres Tomás , Cornelissen Jeroen J. L. M. , Rowan Alan E. , Nolte Roeland J. M.
Published: February 2012

Nanostructuring of phthalocyanine‐based materials is a powerful tool towards the preparation of new materials with outstanding properties. It has been previously shown that porphyrin‐functionalized and phthalocyanine‐functionalized polymers give rise to nanosized aggregates. With the goal in mind of searching new phthalocyanine‐containing polymeric materials that are able to self‐organize into stable supramolecular nanostructures, we have prepared unsymmetrically functionalized Zn(II) phthalocyanines that are able to behave as initiators in the atom transfer radical polymerization of styrene. Hybrid phthalocyanine–polystyrene materials of different tail lengths have been prepared, and their self‐organization behavior was studied by means of UV–Vis spectroscopy and transmission electron microscopy. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of 9,9‐bis(4‐aminophenyl)fluorene‐based benzoxazine and properties of its high‐performance thermoset
Authors: Chang Hou Chien , Lin Ching Hsuan , Tian Yu Wei , Feng Yu Ren , Chan Li Hsin
Published: February 2012

A benzoxazine (P‐bapf) based on 9,9‐bis(4‐aminophenyl)fluorene (BAPF), phenol, and formaldehyde was successfully prepared using two‐pot and one‐pot procedures. In the two‐pot approach, BAPF initially reacted with 2‐hydroxybenzaldehyde, leading to 9,9‐bis(4‐(2‐hydroxybenzylideneimino)phenyl)fluorene. The imine linkages of 9,9‐bis(4‐(2‐hydroxybenzylideneimino)phenyl)fluorene were then reduced by sodium borohydride, forming 9,9‐bis(4‐(2‐hydroxybenzylamino)phenyl)fluorene. Finally, paraformaldehyde was added to induce ring closure condensation, forming benzoxazine (P‐bapf). In the one‐pot approach, P‐bapf was obtained directly by reacting BAPF, phenol, and paraformaldehyde in various solvents. Among the solvents, we found that using toluene/ethanol (2/1, v/v) as a solvent leads to the best purity and yield. No gelation was observed in the preparation. The structure of the resulting benzoxazine was confirmed by 1H, 13C, 1H1H and 1H13C NMR spectra. P‐bapf exhibits a photoluminescent emission at 395 nm under an excitation of 275 nm. After curing, the resulting P‐bapf thermoset exhibits Tg as high as 236 °C, and the Tg can be further increased to 260 °C by copolymerization with an equal equivalent of cresol novolac epoxy. The 5% degradation temperature of the P‐bapf thermoset reaches as high as 413 °C (N2) and 431 °C (air). The refractive index at 589 nm is as high as 1.70, demonstrating a high refractive index characteristic of fluorene linkage. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Controlled random and alternating copolymerization of (meth)acrylates, acrylonitrile, and (meth)acrylamides with vinyl ethers by organotellurium‐, organostibine‐, and organobismuthine‐mediated living radical polymerization reactions
Authors: Mishima Eri , Yamago Shigeru
Published: February 2012

Random and alternating copolymerizations of acrylates, methacrylates, acrylonitorile, and acrylamides with vinyl ethers under organotellurium‐, organostibine‐, and organobismuthine‐mediated living radical polymerization (TERP, SBRP, and BIRP, respectively) have been studied. Structurally well‐controlled random and alternating copolymers with controlled molecular weights and polydispersities were synthesized. The highly alternating copolymerization occurred in a combination of acrylates and vinyl ethers and acrylonitorile and vinyl ethers by using excess amount of vinyl ethers over acrylates and acrylonitorile. On the contrary, alternating copolymerization did not occur in a combination of acrylamides and vinyl ethers even excess amount of vinyl ethers were used. The reactivity of polymer‐end radicals to a vinyl ether was estimated by the theoretical calculations, and it was suggested that the energy level of singly occupied molecular orbital (SOMO) of polymer‐end radical species determined the reactivity. By combining living random and alternating copolymerization with living radical or living cationic polymerization, new block copolymers, such as (PBA‐alt‐PIBVE)‐block‐(PtBA‐co‐PIBVE), PBA‐block‐(PBA‐alt‐PIBVE), and (PTFEA‐alt‐PIBVE)‐block‐PIBVE, with controlled macromolecular structures were successfully synthesized. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Mechanical properties of glass continuous poly(cyclohexylethylene) block copolymers
Authors: Mansour Ameara S. , Lodge Timothy P. , Bates Frank S.
Published: February 2012

The bulk mechanical properties of linear triblock and pentablock copolymers that self‐assemble into hexagonally packed cylinders with glassy, unentangled matrices of poly(cyclohexylethylene) (PCHE for a homopolymer, C for a block copolymer) with rubbery poly(ethylene‐alt‐propylene) (P) and semicrystalline polyethylene (E) minority components are examined. The tensile properties of high C content CEC triblock copolymer could not be quantified; however, CPC can plastically deform under uniaxial strain, unlike brittle PCHE. Both CECEC and CPCPC pentablock copolymers exhibited ductile tensile behavior, but the tensile properties of blends of these two pentablock copolymers show that the addition of crystallinity in the minority phase prevents strain softening after yielding and necking, which indicates that these samples deform only via crazing. On the other hand, the white gage region of CPCPC and the ability of CPCPC to neck indicate that high C content materials deform via shear yielding and crazing when the minority component is a rubbery material. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Wrapping corrections beyond the 𝔰𝔩(2) sector in 𝒩 = 4 SYM
Authors: Beccaria M. , Macorini G. , Ratti C.
Published: February 2012

The 𝔰𝔩(2) sector of 𝒩 = 4 SYM theory has been much studied and the anomalous dimensions of those operators are well known. Nevertheless, many interesting operators are not included in this sector. We consider a class of twist operators beyond the 𝔰𝔩(2) subsector introduced by Freyhult, Rej and Zieme. They are spin n, length‐3 operators. At one‐loop they can be identified with three gluon operators. At strong coupling, they are associated with spinning strings with two spins in AdS space and charge in S5. We exploit the Y‐system to compute the leading weak‐coupling four loop wrapping correction to their anomalous dimension. The result is written in closed form as a function of the spin n. We combine the wrapping correction with the known four loop asymptotic Bethe Ansatz contribution and analyze special limits in the spin n. In particular, at large n, we prove that a generalized Gribov‐Lipatov reciprocity holds. At negative unphysical spin, we present a simple BFKL‐like equation predicting the rightmost leading poles.
Transport and response coefficients in the blackfold approach
Authors: Camps J.
Published: February 2012

The blackfold approach is an effective theory for higher dimensional black holes. In this approach, black holes are described as materials: they are characterised by speeds of sound, viscosities and elastic moduli. These can be computed from first principles in general relativity by generalising techniques developed in AdS/CFT contexts. Apart from its intrinsic interest, this approach is a dramatic simplification of the Einstein equations that can be used to tackle important open problems of higher dimensional gravity.
Quadratic deformation of Minkowski space
Authors: Cervantes D. , Cervantes R. , Lledó M.A. , Nadal F.A.
Published: February 2012

We present a deformation of the Minkowski space as embedded into the conformal space (in the formalism of twistors) based in the quantum versions of the corresponding kinematic groups. We compute explicitly the star product, whose Poisson bracket is quadratic. We show that the star product although defined on the polynomials can be extended differentiably. Finally we compute the Eucliden and Minkowskian real forms of the deformation.
A brief review on the problem of divergence in Krein space quantization
Authors: Payandeh F. , Moghaddam Z.Gh. , Fathi M.
Published: February 2012

In this paper we have a brief review on the problem of divergence in quantum field theory and its elimination using the method of Krein space quantization. In this method, the auxiliary negative frequency states have been utilized, the modes of which do not interact with the physical states and are not affected by the physical boundary conditions. It is remarkable that Krein space quantization is similar to Pauli‐Villars regularization, so we can call it the “Krein regularization”. Considering the QED in Krein space quantization, it could be shown that the theory is automatically regularized. Calculation of the three primitive divergent integrals, the vacuum polarization, electron self energy and vertex function using Krein space method leads to finite values, since the infrared and ultraviolet divergencies do not appear. For another example, the Casimir stress on a spherical shell in de Sitter spacetime for a massless scalar field could be calculated using Krein space quantization.
Quantum backreaction in string theory
Authors: Evnin O.
Published: February 2012

There are situations in string theory when a finite number of string quanta induce a significant backreaction upon the background and render the perturbation theory infrared‐divergent. The simplest example is D0‐brane recoil under an impact by closed strings. A more physically interesting case is backreaction on the evolution of a totally compact universe due to closed string gas. Such situations necessitate qualitative amendments to the traditional formulation of string theory in a fixed classical background. In this contribution to the proceedings of the XVII European Workshop on String Theory in Padua, I review solved problems and current investigations in relation to this kind of quantum backreaction effects.
From supersymmetric to non‐supersymmetric black holes
Authors: Galli P. , Ortín T. , Perz J. , Shahbazi C.S.
Published: February 2012

Methods similar to those used for obtaining supersymmetric black hole solutions can be employed to find also non‐supersymmetric solutions. We briefly review some of them, with the emphasis on the non‐extremal deformation ansatz of [1].
Ohmic and rectifying contacts on bulk AlN for radiation detector applications
Authors: Erlbacher Tobias , Bickermann Matthias , Kallinger Birgit , Meissner Elke , Bauer Anton J. , Frey Lothar
Published: February 2012

In this paper we report on ohmic and rectifying contacts fabricated on undoped bulk AlN substrates for radiation detector applications. The ohmic Ni contacts exhibit negligible contact resistances. Current conduction is dominated by field enhanced thermal emission from traps 0.4 to 0.6 eV below the conduction band. The Pt Schottky contacts show excellent rectifying behaviour. In forward conduction, device current is again limited by the Poole‐Frenkel effect. The Schottky barrier features very low reverse leakage currents, and voltages of up to ‐200 V can be applied. The capability of bulk AlN for radiation detectors at room temperature is demonstrated. Suitability is deduced from both X‐ray absorption experiments and low reverse leakage currents of the fabricated Schottky diodes. Additionally, the AlN substrate is almost blind to sun light due to its wide band gap. Still, reduction of recombination sites in AlN is required to achieve maximum detector performance. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristics of AlN crystal growth depending on m‐ and a‐axis oriented off‐angle of c‐sapphire substrate
Authors: Maeda Noritoshi , Hirayama Hideki , Fugikawa Sachie
Published: February 2012

For the achievement of high‐efficiency AlGaN‐based deep‐ultraviolet (DUV) light‐emitting diodes (LEDs), we investigated the characteristics of AlN crystal growth depending on m‐ and a‐axis oriented off‐angle of c‐sapphire substrate. In order to reduce threading dislocation density (TDD) in AlN crystal growth, we used ammonia (NH3) pulse‐flow multilayer (ML) growth technique in the metal‐organic chemical vapor phase deposition (MOCVD). We found that a macrostep geometry (large step‐bunching) is generated on the surface of AlN template grown on m‐axis oriented (0001) sapphire substrate. On the other hand, macrostep‐free surface can be obtained for AlN grown on a‐axis oriented sapphire. We also found that cracks are easier generated in AlN grown on a‐axis oriented sapphire. It is considered that step‐flow growth is easily obtained for the growth of a‐axis oriented case due to that the atom site of the step edge in the growth is more stable. On the other hand, for m‐axis oriented case, step‐bunching is considered to occur because atoms are easily drifted during the growth due to that the atom site of the edge steps are more unstable. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Current transport through an n‐doped, nearly lattice matched GaN/AlInN/GaN heterostructure
Authors: Corbett B. , Charash R. , Damilano B. , Kim‐Chauveau H. , Cordero N. , Shams H. , Lamy J.‐M. , Akhter M. , Maaskant P. P. , Frayssinet E. , Mierry P. de , Duboz J.‐Y.
Published: February 2012

The low refractive index of AlInN makes it a strong candidate as a waveguide cladding layer for lasers emitting from the blue to the green. A sequence of AlInN layers interfaced periodically with GaN is needed to provide a smooth surface for growth of quantum wells. The current transport across a highly doped single 54 nm thick layer of AlInN clad by GaN is analysed and is shown to be dominated by the heterointerfaces. Greater than 1 V is required to obtain current densities required in lasers of several kA/cm2. Frequency dependent electrical reflection measurements show that a 20 nm wide depletion zone is present at the interfaces even under bias and despite the high doping levels. A thermally activated resistive shunting of the interface is relevant at low voltages while the current is dominated by tunnelling at laser current densities. A low defect density AlInN/GaN multilayer structure requires > 10 V in order to drive current at levels needed in a laser diode. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ge(100) surfaces prepared in vapor phase epitaxy process ambient
Authors: Brückner Sebastian , Barrigón Enrique , Supplie Oliver , Kleinschmidt Peter , Dobrich Anja , Löbbel Claas , Rey‐Stolle Ignacio , Döscher Henning , Hannappel Thomas
Published: February 2012

Ge(100) substrates essential for subsequent III–V integration were studied in the hydrogen ambient of a metalorganic vapor phase epitaxy reactor. We confirmed thermal oxide and carbon removal by X‐ray photoelectron spectroscopy, characterized the (2 × 1)/(1 × 2) surface reconstruction by low energy electron diffraction, and employed reflection anisotropy spectroscopy for optical in situ analysis. Our Ge(100) spectra de‐ viate from reference data of clean surfaces prepared in ultra‐high vacuum, most probably due to the presence of hydrogen bonds. The observation was correlated with Fourier‐transform infrared spectroscopy showing coupled H–Ge–Ge–H stretch modes associated with a monohydride termination of the Ge(100) surface. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)