bluuebunny/crossref_metadata_2025 huggingface dataset:
Assembly of 4‐Substituted 3‐Nitro‐1,2,3,4‐tetrahydropyridines via Organocatalytic Michael Addition
Authors: Huo Lele , Ma Anqi , Zhang Yihua , Ma Dawei
Published: March 2012

An organocatalytic Michael addition of protected 2‐amino‐1‐nitroethanes to α,β‐unsaturated aldehydes followed by treatment with TFA afforded 4‐substituted 3‐nitro‐1,2,3,4‐tetrahydropyridines with good diastereoselectivity and excellent enantioselectivity. Good yields were observed in the case of β‐aryl‐substituted α,β‐unsaturated aldehydes as the substrates, while moderate yields were obtained when β‐alkyl‐substituted α,β‐unsaturated aldehydes were used.
Crystallization kinetics of PE‐b‐isotacticPMMA diblock copolymer synthesized using SiMe2(Ind)2ZrMe2 and MAO cocatalyst
Authors: Atiqullah Muhammad , Hossain Mohammad M. , Kamal Muhammad S. , Al‐Harthi Mamdouh A. , Khan Masiullah J. , Hossaen Anwar , Hussain Ikram
Published: March 2012

Polyethylene‐b‐poly(methyl methacrylate) (PE‐b‐PMMA) diblock copolymer has important interfacial applications. Hence, a PE‐b‐isotactic PMMA diblock copolymer was synthesized using SiMe2(Ind)2ZrMe2 and MAO cocatalyst. The polymerization mechanism and the origin of PMMA isotacticity were duly explained. An appropriate nonisothermal Avrami‐Erofeev crystallization model was developed to compare the crystallization kinetics of the above copolymer with that of a PE homopolymer. For both polymers, the model well matched the entire differential scanning calorimeter crystallinity profile, notably for a single Avrami‐Erofeev index, and predicted cylindrical crystal growth. This model particularly overcomes the limitations of the published nonisothermal crystallization models, and provides interesting insight into PE crystallization. The PMMA block significantly decreased the heats of crystallization and fusion, % crystallinity, and the relative crystallization function; increased the nonisothermal crystallization rate constant; and introduced minimal dilution effect whereas the PE block formed a continuous or percolated phase. This study correlates catalyst structure, copolymer block tacticity, and PE nonisothermal crystallization and melting behavior. © 2012 American Institute of Chemical Engineers AIChE J, 59: 200–214, 2013
Fortschritte in der Fingerabdruckanalyse
Authors: Hazarika Pompi , Russell David A.
Published: March 2012

Fingerabdrücke werden seit dem späten 19. Jahrhundert in forensischen Untersuchungen zur Identifizierung von Personen genutzt. Darüber hinaus hat sich inzwischen aber gezeigt, dass Fingerabdrücke noch viel mehr Informationen über ein Individuum liefern können. Wir stellen hier bemerkenswerte Fortschritte bei Fingerabdrucktechnologien vor, mit denen sich, simultan zur Identitätsklärung, chemisch nachweisen lässt, ob eine Person Rauschgifte eingenommen oder mit Sprengstoffen oder Rauschgiften hantiert hat.
Using polymeric materials to control stem cell behavior for tissue regeneration
Authors: Zhang Nianli , Kohn David H.
Published: March 2012

Patients with organ failure often suffer from increased morbidity and decreased quality of life. Current strategies of treating organ failure have limitations, including shortage of donor organs, low efficiency of grafts, and immunological problems. Tissue engineering emerged about two decades ago as a strategy to restore organ function with a living, functional engineered substitute. However, the ability to engineer a functional organ is limited by a limited understanding of the interactions between materials and cells that are required to yield functional tissue equivalents. Polymeric materials are one of the most promising classes of materials for use in tissue engineering, due to their biodegradability, flexibility in processing and property design, and the potential to use polymer properties to control cell function. Stem cells offer potential in tissue engineering because of their unique capacity to self‐renew and differentiate into neurogenic, osteogenic, chondrogenic, and myogenic lineages under appropriate stimuli from extracellular components. This review examines recent advances in stem cell–polymer interactions for tissue regeneration, specifically highlighting control of polymer properties to direct adhesion, proliferation, and differentiation of stem cells, and how biomaterials can be designed to provide some of the stimuli to cells that the natural extracellular matrix does. (Part C) 96:63–81, 2012. © 2012 Wiley Periodicals, Inc.
Organ repair and regeneration: An overview
Authors: Baddour Joëlle A. , Sousounis Konstantinos , Tsonis Panagiotis A.
Published: March 2012

A number of organs have the intrinsic ability to regenerate, a distinctive feature that varies among organisms. Organ regeneration is a process not fully yet understood. However, when its underlying mechanisms are unraveled, it holds tremendous therapeutic potential for humans. In this review, we chose to summarize the repair and regenerative potential of the following organs and organ systems: thymus, adrenal gland, thyroid gland, intestine, lungs, heart, liver, blood vessels, germ cells, nervous system, eye tissues, hair cells, kidney and bladder, skin, hair follicles, pancreas, bone, and cartilage. For each organ, a review of the following is presented: (a) factors, pathways, and cells that are involved in the organ's intrinsic regenerative ability, (b) contribution of exogenous cells – such as progenitor cells, embryonic stem cells, induced pluripotent stem cells, and bone marrow‐, adipose‐ and umbilical cord blood‐derived stem cells – in repairing and regenerating organs in the absence of an innate intrinsic regenerative capability, (c) and the progress made in engineering bio‐artificial scaffolds, tissues, and organs. Organ regeneration is a promising therapy that can alleviate humans from diseases that have not been yet cured. It is also superior to already existing treatments that utilize exogenous sources to substitute for the organ's lost structure and/or function(s). (Part C) 96:1–29, 2012. © 2012 Wiley Periodicals, Inc.
Development of a fast LC‐MS/MS assay for the determination of deferiprone in human plasma and application to pharmacokinetics
Authors: Song Ta‐Shu , Hsieh Yow‐Wen , Peng Ching‐Tien , Liu Cheng‐Hsiung , Chen Tai‐Lin , Hour Mann‐Jen
Published: March 2012

A fast and accurate liquid chromatography/tandem mass spectrometric (LC‐MS/MS) assay was first developed and validated for the determination of deferiprone in human plasma. The analytes were extracted with acetonitrile from only 50 μL aliquots of human plasma to achieve the protein precipitation. After extraction, chromatographic separation of analytes in human plasma was performed using a Synergi Fusion‐RP 80A column at 30 °C. The mobile phase consisted of methanol and 0.2% formic acid containing 0.2 mM EDTA (60:40, v/v). The flow rate of the mobile phase was 0.8 mL/min. The total run time for each sample analysis was 4 min. Detection was performed using electrospray ionization in positive ion multiple reaction monitoring mode by monitoring the precursor‐to‐parent ion transitions m/z 140.1 → 53.1 for deferiprone and m/z 143.1 → 98.1 for internal standard. A linear range was established from 0.1 to 20 µg/mL. The limit of detection was determined as 0.05 µg/mL. The validated method was estimated for linearity, recovery, stability, precision and accuracy. Intraday and interday precisions were 4.3–5.5 and 4.6–7.3%, respectively. The recovery of deferiprone was in the range of 80.1–86.8%. The method was successfully applied to a pharmacokinetic study of deferiprone in six thalassemia patients. Copyright © 2012 John Wiley & Sons, Ltd.
Anatomical examination of the great inguinal blood vessels in preterm and term neonates
Authors: Eifinger Frank , Lazaridis Elpida Chochliourou , Roth Bernhard , Koebke Jürgen
Published: March 2012

It is generally accepted that vessel cannulation is technically more difficult and results in more complications in neonates. A sound anatomical knowledge of the inguinal area is therefore important in the selection of appropriately sized central line catheters as well as the approach to central vessel access. Eleven stillborns were investigated. Birth weight (mean: 2,414 g, 900–4,100 g) and gestational age (mean 34 1/7 weeks', 27 6/7–42 1/7) varied within normal range. The outer diameters of the femoral artery (FA), femoral vein (FV), and great saphenous vein (GSV) were determined. The distance between the anterior superior iliac spine and the pubic tubercle was set as 100% and the vessel intersection points were calculated as percentage values of the inguinal ligament length, starting at the iliac spine. The FA has a diameter of 1.9 ± 0.5 mm without correlation to gestational age. The FA crosses the inguinal ligament centrally. The FV has a diameter of 3.1 ± 1.0 mm and does have correlation to gestational age. The FV crosses the inguinal ligament at 63–64%. The GSV has a diameter of 1.4 ± 0.7 mm. Its point of intersection at the level of the inguinal ligament is 68–70%. We conclude that cannulation of the femoral artery or vein should not be performed too far (<1 cm) from the inguinal ligament. The course of the GSV is not suitable for catheter insertion. Clin. Anat. 27:376–382, 2014. © 2012 Wiley Periodicals, Inc.
Silica Based Cocatalysts for Heterogeneous Olefin Dimerization and Ethene Polymerization Reactions with Nickel Complexes
Authors: Dötterl Matthias , Alt Helmut G.
Published: March 2012

We have developed a new buffered silica‐based Lewis acid cocatalyst for olefin dimerization and polymerization reactions with nickel complexes. The Lewis acidities of EtAlCl2 and Et2AlCl‐modified silicas were adjusted by the addition of BiPh3 or N‐methylpyrrole buffers. The buffered heterogeneous cocatalysts were employed to activate nickel complexes for selective propene dimerization reactions to give dimers in 91 % yield. Buffer addition also reduced the rate of ligand abstraction from the catalytically active nickel center. In combination with a nickel diimine complex, ethene was polymerized to give 69 wt % polyethylene and 31 wt % oligomers. The polyethylene displayed a molecular mass of 154 kg mol−1 and a polydispersity index (PDI) of 3.26. The oligomers consisted of 93 % butenes, 46 % thereof being 1‐butene. Furthermore, triphenylbismuth‐buffered Lewis acidic chloroaluminate ionic liquids were coated on surface‐modified silica to yield a supported ionic liquid phase (SILP) system. Dimer selectivities of up to 94 % were obtained with the SILP system in nickel‐catalyzed propene dimerization reactions. The newly developed silica‐based cocatalysts provide promising new olefin dimerization systems suitable for fixed bed applications.
Homo‐ and Heteronuclear meso,meso‐(E)‐Ethene‐1,2‐diyl‐Linked Diporphyrins: Preparation, X‐ray Crystal Structure, Electronic Absorption and Emission Spectra and Density Functional Theory Calculations
Authors: Locos Oliver , Bašić Bruno , McMurtrie John C. , Jensen Paul , Arnold Dennis P.
Published: March 2012

Homo‐ and heteronuclear meso,meso‐(E)‐ethene‐1,2‐diyl‐linked diporphyrins have been prepared by the Suzuki coupling of porphyrinylboronates and iodovinylporphyrins. Combinations comprising 5,10,15‐triphenylporphyrin (TriPP) on both ends of the ethene‐1,2‐diyl bridge M210 (M2=H2/Ni, Ni2, Ni/Zn, H4, H2Zn, Zn2) and 5,15‐bis(3,5‐di‐tert‐butylphenyl)porphyrinato‐nickel(II) on one end and H2, Ni, and ZnTriPP on the other (M211), enable the first studies of this class of compounds possessing intrinsic polarity. The compounds were characterized by electronic absorption and steady state emission spectra, 1H NMR spectra, and for the Ni2 bis(TriPP) complex Ni210, single crystal X‐ray structure determination. The crystal structure shows ruffled distortions of the porphyrin rings, typical of NiII porphyrins, and the (E)‐C2H2 bridge makes a dihedral angle of 50° with the mean planes of the macrocycles. The result is a stepped parallel arrangement of the porphyrin rings. The dihedral angles in the solid state reflect the interplay of steric and electronic effects of the bridge on interporphyrin communication. The emission spectra in particular, suggest energy transfer across the bridge is fast in conformations in which the bridge is nearly coplanar with the rings. Comparisons of the fluorescence behaviour of H410 and H2Ni10 show strong quenching of the free base fluorescence when the complex is excited at the lower energy component of the Soret band, a feature associated in the literature with more planar conformations. TDDFT calculations on the gas‐phase optimized geometry of Ni210 reproduce the features of the experimental electronic absorption spectrum within 0.1 eV.
Gallium Hydride Complexes Stabilised by Multidentate Alkoxide Ligands: Precursors to Thin Films of Ga2O3 at Low Temperatures
Authors: Pugh David , Bloor Leanne G. , Parkin Ivan P. , Carmalt Claire J.
Published: March 2012

The donor‐functionalised alkoxides {Me3−xN(CH2CH2O)x} (Lx; x=1, 2) have been used to form gallium hydride complexes [{GaH2(L1)}2] and [{GaH(L2)}2] that are stable and isolable at room temperature. Along with a heteroleptic gallium tris(alkoxide) complex [Ga(L1)3] and the dimeric complex [{GaMe(L2)}2], these compounds have been used as single‐source precursors for the deposition of Ga2O3 by aerosol‐assisted chemical vapour deposition (AACVD) with toluene as solvent. The resulting films were mostly transparent, indicating low levels of carbon contamination, and they were also mainly amorphous. However, [Ga(L1)3] did contain visibly crystalline material deposited at a substrate temperature of 450 °C, by far the lowest ever observed for the CVD of gallium oxide.
Elucidation of Mycobacterium tuberculosis Type II Dehydroquinase Inhibitors using a Fragment Elaboration Strategy
Authors: Tran Anh Thu , West Nicholas P. , Britton Warwick J. , Payne Richard J.
Published: March 2012

A library of novel Mycobacterium tuberculosis type II dehydroquinase (DHQase) inhibitors were discovered through the use of a fragment elaboration approach. Putative active site binding fragments were initially assessed in silico which led to the selection of two small aromatic fragments for further investigation. Synthetic elaboration of the fragments provided a library of 34 inhibitors that exhibited low‐micromolar inhibition of type II DHQase. A number of these inhibitors also showed antibacterial activity in the low‐micromolar range in screens against M. tuberculosis in vitro; these now serve as lead compounds for further development of therapeutics for the treatment of tuberculosis.
Diosgenin promotes oligodendrocyte progenitor cell differentiation through estrogen receptor‐mediated ERK1/2 activation to accelerate remyelination
Authors: Xiao Lin , Guo Dazhi , Hu Chun , Shen Weiran , Shan Lei , Li Cui , Liu Xiuyun , Yang Wenjing , Zhang Weidong , He Cheng
Published: March 2012

Differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes is a prerequisite for remyelination after demyelination, and impairment of this process is suggested to be a major reason for remyelination failure. Diosgenin, a plant‐derived steroid, has been implicated for therapeutic use in many diseases, but little is known about its effect on the central nervous system. In this study, using a purified rat OPC culture model, we show that diosgenin significantly and specifically promotes OPC differentiation without affecting the viability, proliferation, or migration of OPC. Interestingly, the effect of diosgenin can be blocked by estrogen receptor (ER) antagonist ICI 182780 but not by glucocorticoid and progesterone receptor antagonist RU38486, nor by mineralocorticoid receptor antagonist spirolactone. Moreover, it is revealed that both ER‐alpha and ER‐beta are expressed in OPC, and diosgenin can activate the extracellular signal‐regulated kinase 1/2 (ERK1/2) in OPC via ER. The pro‐differentiation effect of diosgenin can also be obstructed by the ERK inhibitor PD98059. Furthermore, in the cuprizone‐induced demyelination model, it is demonstrated that diosgenin administration significantly accelerates/enhances remyelination as detected by Luxol fast blue stain, MBP immunohistochemistry and real time RT‐PCR. Diosgenin also increases the number of mature oligodendrocytes in the corpus callosum while it does not affect the number of OPCs. Taking together, our results suggest that diosgenin promotes the differentiation of OPC into mature oligodendrocyte through an ER‐mediated ERK1/2 activation pathway to accelerate remyelination, which implicates a novel therapeutic usage of this steroidal natural product in demyelinating diseases such as multiple sclerosis (MS). © 2012 Wiley Periodicals, Inc.
Assessment of ecologically relevant hydrological variables influencing a cold‐region river and its delta: the Athabasca River and the Peace–Athabasca Delta, northwestern Canada
Authors: Monk Wendy A. , Peters Daniel L. , Baird Donald J.
Published: March 2012

Natural and anthropogenically driven changes in upstream watershed conditions strongly influence the hydrological, geomorphological and ecological processes within downstream riverine and deltaic ecosystems. The goal of our study was to examine temporal trends and spatial patterns in ecologically relevant hydrological variables within the Athabasca River watershed and the downstream Peace–Athabasca Delta (PAD), located in northwestern Canada. Temporal trends for a suite of indicators of hydrologic alteration, appropriate for cold regions environments, were explored using non‐parametric Mann–Kendall trend analysis. Results in the Lower Athabasca River (LAR) watershed were placed in a watershed‐scale context. Across the two study periods (A – 1958–2009 and B – 1974–2009), results indicated decreasing trends in several key drivers of deltaic system hydrology, including short‐term and long‐term maximum and minimum runoff. In addition, an increasing trend in hydrograph variability was observed within the watershed. A spatially discrete pattern was apparent from the data, with a greater number of significant trends noted within the headwater region as compared with other areas of the watershed. Although earlier dates of annual freeze‐up were observed across the watershed, there were few observable patterns in ice‐on/ice‐off conditions on the river. If these historical trends in freeze‐up continue on the LAR, water levels in the PAD channels and inland wetlands could be affected, leading to reduced habitat diversity and altered ecosystem productivity. The study illustrates significant natural variability in the hydrological regime within the LAR that should be considered in future water management frameworks to ensure the preservation and maintenance of this Ramsar wetland site, particularly in the context of projected climate change and the increased water demands arising from upstream development associated with the Alberta Oil Sands. Copyright © 2012 John Wiley & Sons, Ltd.
Benchmarking the thermodynamic analysis of water molecules around a model beta sheet
Authors: Huggins David J.
Published: March 2012

Water molecules play a vital role in biological and engineered systems by controlling intermolecular interactions in the aqueous phase. Inhomogeneous fluid solvation theory provides a method to quantify solvent thermodynamics from molecular dynamics or Monte Carlo simulations and provides an insight into intermolecular interactions. In this study, simulations of TIP4P‐2005 and TIP5P‐Ewald water molecules around a model beta sheet are used to investigate the orientational correlations and predicted thermodynamic properties of water molecules at a protein surface. This allows the method to be benchmarked and provides information about the effect of a protein on the thermodynamics of nearby water molecules. The results show that the enthalpy converges with relatively little sampling, but the entropy and thus the free energy require considerably more sampling to converge. The two water models yield a very similar pattern of hydration sites, and these hydration sites have very similar thermodynamic properties, despite notable differences in their orientational preferences. The results also predict that a protein surface affects the free energy of water molecules to a distance of approximately 4.0 Å, which is in line with previous work. In addition, all hydration sites have a favorable free energy with respect to bulk water, but only when the water–water entropy term is included. A new technique for calculating this term is presented and its use is expected to be very important in accurately calculating solvent thermodynamics for quantitative application. © 2012 Wiley Periodicals, Inc.
Plasmon‐enhanced Raman scattering of coaxial hybrid nanowires made with light‐emitting polymer and gold
Authors: Park Se Hee , Park Dong Hyuk , Hong Young Ki , Lee Seok Ho , Kim Dae‐Chul , Dhakal Krishna Prasad , Joo Jinsoo , Kim Jeongyong
Published: March 2012

We report on the plasmon‐enhanced Raman scattering of coaxial hybrid nanowires (NWs) made with light emitting poly(3‐methylthiophene) (P3MT) and gold (Au) core or coating. Absorption spectra of coaxial hybrid NWs showed the absorption peaks because of localized surface plasmon (SP) excitation at ~ 567 and ~ 610 nm, in addition to the π–π* transition peaks of P3MT. Raman spectra of a single strand of coaxial hybrid NW and plain P3MT NW was obtained by using three different wavelengths of laser excitation of 514, 633, and 785 nm. We found that Raman intensities of hybrid coaxial NWs were enhanced by 4 to 15 times over those of plain P3MT NWs with the Raman excitation wavelengths close to the observed SP energies of coaxial NWs. We attributed the observed enhancement of the Raman signal to the resonance of the incident laser with the matching SP energies, rather than the possible doping level change, in hybrid coaxial NWs. Copyright © 2012 John Wiley & Sons, Ltd.
Patterns of lymph node metastasis and their influence on outcomes in patients with submandibular gland carcinoma
Authors: Han Myung Woul , Cho Kyung‐Ja , Roh Jong‐Lyel , Choi Seung‐Ho , Nam Soon Yuhl , Kim Sang Yoon
Published: March 2012

Background and Objectives

Little is known about lymph node metastasis and the extent of neck dissection (ND) in patients with submandibular gland (SMG) carcinoma. We therefore evaluated the metastatic topography of neck lymph nodes in patients with SMG carcinoma and the influence of metastases on tumor recurrence and patient survival.

Methods

The pattern of lymph node spread was analyzed in 64 patients with SMG carcinoma treated from January 1994 to January 2009. Disease‐free survival (DFS), overall survival (OS), and distant metastasis‐free survival (DMFS) were calculated, and the clinicopathological factors associated with each were analyzed.

Results

Positive pathological lymph nodes were detected in 31 (48.4%) patients and was found to correlate significantly with histologic grade (P < 0.001) on univariate analysis. Eight patients (19.5%) had occult cervical metastases. The 5‐year DFS, OS, and DMFS rates were 46.8, 56.2, and 58.5%, respectively, and 23 patients (35.9%) experienced systemic failure. Multivariate analyses revealed that T‐classification (P = 0.043) and N‐classification (P = 0.006) were significantly independent predictors of DFS, whereas only N‐classification (P = 0.049) was significantly associated with DMFS.

Conclusions

Elective ND should be recommended for preoperatively suspected high‐grade malignancy in SMG carcinoma. Patients with nodal metastasis should receive more effective therapy to hinder recurrence and distant metastasis. J. Surg. Oncol. 2012; 106:475–480. © 2012 Wiley Periodicals, Inc.
Assessment of prognostic factors after primary tumor resection in metastatic colon cancer patients: A Veteran's Affairs Central Cancer Registry (VACCR) analysis, 1995–2008
Authors: Gonsalves Wilson I. , Wolpert Joseph , Tashi Tsewang , Ganti Apar K , Subbiah Shanmuga , Ternent Charles , Silberstein Peter T.
Published: March 2012

Background

Resection of the primary tumor in metastatic colon cancer may occur for palliation of bleeding or obstruction despite distant metastases. This study evaluates clinicopathologic features that serve as prognostic markers in those patients with stage IV colon cancer who undergo resection of their primary tumor.

Methods

Retrospective analysis of stage IV colon cancer patients who underwent surgical resection of the primary tumor from 1995 to 2008 was done via the Veteran's Affairs Central Cancer Registry. Age, Charlson co‐morbidity index score, extent of metastases, sex, number of lymph nodes examined, lymph node ratio (LNR), type of surgery, use of adjuvant chemotherapy, primary tumor site, and grade were studied with respect to overall survival by using log‐rank and Kaplan–Meier analysis.

Results

There were 2,625 patients with stage IV colon cancer who had primary tumor resection. Age at diagnosis, Charlson co‐morbidity index score, lymph node ratio, and use of chemotherapy were found to be independent predictors of survival by multivariate analysis.

Conclusion

Clinicopathologic factors such as LNR, use of chemotherapy, age, co‐morbidities, site of primary colon tumor, and number of sites of metastasis are all independent predictors of overall survival in patients who undergo primary colon tumor resection in the metastatic setting. J. Surg. Oncol. 2012; 106:486–490. © 2012 Wiley Periodicals, Inc.
Results of surgical resection in pelvic Ewing's sarcoma
Authors: Puri Ajay , Gulia Ashish , Jambhekar N.A. , Laskar S.
Published: March 2012

Objective

To evaluate the results of patients with non‐metastatic Ewing's sarcoma of the pelvis treated with surgical resection as part of their multimodality treatment

Methods

Twenty‐six patients treated between September 2000 and September 2009 were evaluated. Thirteen resections included the acetabulum and 13 did not. Thirteen resections excluding the acetabulum had no reconstruction. Arthrodesis was done in two, extracorporeal radiation and reimplantation in two, and pseudarthrosis in nine patients.

Results

Three patients had involved margins. Seventeen patients had good response to chemotherapy and nine were poor responders. Twenty‐one patients were available for follow‐up. The follow‐up ranged from 4 to 129 months (mean 36 months). Thirteen patients are currently alive. There was one local recurrence. On Kaplan–Meier analysis the overall survival was 72% at 5 years. The 3‐year survival in good responders to chemotherapy was 94% compared to 30% in poor responders. The Musculoskeletal Tumor Society Score ranged from 23 to 29, with patients in whom the acetabulum was retained having better function compared to patients in whom acetabulum was resected.

Conclusion

Surgery provides good local control and oncologic outcomes with acceptable function in these patients. J. Surg. Oncol. 2012; 106:417–422. © 2012 Wiley Periodicals, Inc.
Observations of bromine explosions in smog chamber experiments above a model salt pan
Authors: Buxmann Joelle , Balzer Natalja , Bleicher Sergej , Platt Ulrich , Zetzsch Cornelius
Published: March 2012

Reactive halogen species (RHS), such as Cl, Br, or BrO, can have significant influence on chemical processes in the troposphere, including the destruction of ozone, change in the chemical balance of OH and HO2, and increased deposition of toxic compounds (like mercury), with potential consequences for the global climate. Previous studies have shown that salt lakes can provide a significant source for gaseous RHS. Environmental conditions, such as salt composition, relative humidity (RH), pH, and temperature (T), might have a strong influence on reactive bromine levels. In our laboratory experiments, NaCl salt containing 0.33% NaBr by weight was exposed to simulated sunlight in a Teflon smog chamber under various conditions of RH and ozone concentrations. BrO levels were observed by a differential optical absorption spectrometer in combination with a multireflection cell (White cell). The concentrations of OH and Cl radicals were quantified by the radical clock method. We present the first direct observation of BrO from the “bromine explosion” (autocatalytic release of reactive bromine from salt surfaces—key to ozone destruction) in the laboratory above a simulated salt pan. The maximum BrO mixing ratio of 6419 ± 71 ppt at 60% RH was observed to be one order of magnitude higher than at 37% RH and 2% RH. The release of RHS from the salt pan is possibly controlled by the thickness of the quasi‐liquid layer, covering the reactive surface of the halide crystals, as the layer thickness strongly depends on RH. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 312–326, 2012
Diagnostic modalities for distant metastasis in head and neck squamous cell carcinoma: Are we changing life expectancy?
Authors: Spector Matthew E. , Chinn Steven B. , Rosko Andrew J. , Worden Francis P. , Ward P. Daniel , Divi Vasu , McLean Scott A. , Moyer Jeffrey S. , Prince Mark E. P. , Wolf Gregory T. , Chepeha Douglas B. , Bradford Carol R.
Published: March 2012

Objectives/Hypothesis:

To determine if the various imaging modalities for distant metastasis (DM) diagnosis alters life expectancy in head and neck squamous cell carcinoma (HNSCC).

Study Design:

Retrospective.

Methods:

One hundred seventy patients (mean age, 59.1 years; male:female, 135:35) with HNSCC who developed DM were reviewed. The main outcome measures were the method of DM diagnosis and time from DM diagnosis to death while controlling for clinical parameters (age, gender, tobacco status, primary tumor site, initial TNM classification, number and site of DM, administration of palliative chemotherapy).

Results:

Tumor subsites were: 40 oral cavity, 75 oropharynx, 36 larynx, 10 hypopharynx, one nasopharynx, and eight unknown primary. Of the patients, 16.5% (28/170) had distant metastasis at presentation; the remaining 142 patients were diagnosed with DM at a median of 324 days from diagnosis. Although patients diagnosed with DM by positron‐emission tomography (PET) scan were more likely to have multiple DM sites (P = .0001), there were no differences in life expectancy in patients who were diagnosed with or without PET scan (median, 185 vs. 165 days, P = .833). There were no differences in life expectancy based on age, gender, site of primary tumor, or number/site of DM. The use of palliative chemotherapy resulted in a significantly longer life expectancy (median, 285 vs. 70 days; P = .001).

Conclusions:

Although a PET scan is more likely to diagnose multiple DM sites, there was no difference in life expectancy based on imaging modality. Patients who are symptomatic from their distant metastasis have a worse life expectancy, and palliative chemotherapy was able to increase life expectancy, even in patients who were symptomatic from the distant metastasis.
Minimally invasive options for salivary calculi
Authors: Witt Robert L. , Iro Heinrich , Koch Michael , McGurk Mark , Nahlieli Oded , Zenk Johannes
Published: March 2012

The aim of this study was to review the advantages, limitations, and international interdisciplinary expert perspectives and contrasts of salivary gland endoscopy and transoral techniques in the diagnosis and management of salivary gland calculi and their adaptation in North America. The transition from transcervical approaches to strictly sialendoscopic approaches is a broad chasm and often not feasible. Sialendoscopy, sialendoscopy‐assisted, intraoral, and transcervical approaches all have surgical value. Diagnostic sialendoscopy, interventional sialendoscopy, sialendoscopy‐assisted, and transoral techniques have been a major step forward, not only in providing an accurate means of diagnosing and locating intraductal obstructions, but also in permitting minimally invasive surgical treatment that can successfully manage blockages precluding sialoadenectomy in most cases. A flexible methodology is required. Multiple or combined measured may prove effective.
Involvement of physician extenders in ambulatory otolaryngology practice
Authors: Bhattacharyya Neil
Published: March 2012

Objectives/Hypothesis:

Determine the penetration and point‐of‐care patterns for physician extenders in ambulatory otolaryngology practice.

Study Design:

Cross‐sectional analysis of national database.

Methods:

The National Ambulatory Medical Care Survey was examined for 2008 and 2009, extracting all cases of ambulatory visits to an otolaryngology outpatient setting. Visit types were then segregated according to providers seen including physician, advanced practice clinicians (APCs) (nurse practitioner and/or physician assistant) and nurses. Visit types were determined (physician alone, physician with APC, or APC alone) as well as type of patient seen (new vs. established patient). The top 10 diagnoses were compiled according to provider visit type.

Results:

An estimated 38.6 ± 3.7 million outpatient office otolaryngology visits were studied. An APC was seen in 6.3 ± 2.0% of visits (physician assistant, 4.6 ± 1.9% visits; nurse practitioner, 1.7 ± 0.9% of visits), and a nurse was involved in 25.1 ± 7.6% of visits. Nurse practitioners were more likely see patients independently (47.7%) than were physician assistants (23.3%). APCs were more likely to be involved with established patient visits (7.2 ± 2.3%) rather than new patient visits (4.3 ± 1.8%, P = .08). Disorders of the external and middle ears were the most common diagnoses seen by APCs.

Conclusions:

Although APCs are expected to expand numbers in otolaryngology, contemporary data indicate that current penetration of APCs into ambulatory otolaryngology care remains relatively limited. These data provide an initial assessment for future modeling of APCs and otolaryngologic care.
Chondroitin Sulfate and Epidermal Growth Factor Immobilization after Plasma Polymerization: A Versatile Anti‐Apoptotic Coating to Promote Healing Around Stent Grafts
Authors: Charbonneau Cindy , Ruiz Juan‐Carlos , Lequoy Pauline , Hébert Marie‐Josée , De Crescenzo Gregory , Wertheimer Michael R. , Lerouge Sophie
Published: March 2012

Bioactive coatings constitute an interesting approach to enhance healing around implants, such as stent‐grafts used in endovascular aneurysm repair. Three different plasma techniques, namely NH3 plasma functionalization and atmospheric‐ or low‐pressure plasma polymerization, are compared to create amino groups and covalently bind CS and EGF bioactive molecules on PET. The latter presents the greatest potential. CS + EGF coating is shown to strongly decrease cell apoptosis and cell depletion in serum‐free medium, while increasing cell growth compared to unmodified PET. This versatile biomimetic coating holds promise in promoting vascular repair around stent‐grafts, where resistance to apoptosis is a key issue.

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LKB1 mutations and their correlation with LKB1 and Rheb expression in bladder cancer
Authors: Tigli Hatice , Seven Didem , Tunc Murat , Sanli Oner , Basaran Serife , Ulutin Turgut , Buyru Nur
Published: March 2012

Although there are extensive studies on the genetics of bladder cancer, several questions remain unanswered. One of the pathways which are altered in bladder cancer is the mTOR signaling pathway. In the present study, we analyzed the expression of Rheb gene and genetic alterations in the LKB1 gene which are the key components of mTOR pathway. Nine exons of the LKB1 gene were analyzed by direct sequencing in 51 bladder cancer patients. To investigate the expression of Rheb and LKB1, real‐time quantitative RT‐PCR was performed in bladder tumor and normal bladder tissue samples. We did not observed a statistically significant difference in Rheb or LKB1 expression between the tumor and normal tissue samples. We detected a novel missense mutation creating stop codon in a high percent of the tumor samples. Five different single nucleotide substitutions were also observed in the introns. Our results indicate that LKB1 gene may play a role in the progression of bladder cancer. © 2012 Wiley Periodicals, Inc.
Automatic off‐resonance correction in spiral imaging with piecewise linear autofocus
Authors: Smith Travis B. , Nayak Krishna S.
Published: March 2012

Off‐resonance generates blurring artifacts in spiral images. Applications that often utilize spiral trajectories, such as fine‐resolution imaging and rapid scanning, typically preclude the measurement of accurate field maps needed for effective off‐resonance correction. Automatic deblurring, or autofocus, algorithms have been developed to estimate the field map directly from the corrupted data prior to off‐resonance correction, eliminating the need for field map measurements. These algorithms rely in whole or in part on optimizing an objective function, and suffer from problems related to the accurate minimization and utility of the function. Here, a new method is presented to correct off‐resonance blurring automatically without an objective function using a piecewise linear framework. Local linear field maps are estimated with a combination of k‐space spectral analysis and mapdrift, an image feature‐based correlation technique, for subsequent piecewise linear deblurring. This approach enables field map estimation without optimization, provides accurate off‐resonance correction, is suitable for low signal‐to‐noise ratio and fine‐resolution applications, and does not require access to the raw data. Deblurred images from fine‐resolution spiral scans of a phantom and healthy volunteers at 3T show that the proposed method can be superior to conventional autofocus and comparable to field map‐based correction. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Endothelin ETB Receptors Are Involved in the Relaxation to the Pig Urinary Bladder neck
Authors: Arteaga José Luis , Orensanz Luis M. , Martínez María Pilar , Barahona María Victoria , Martínez‐Sáenz Ana , Fernandes Vítor S. , Bustamante Salvador , Carballido Joaquín , Benedito Sara , García‐Sacristán Albino , Prieto Dolores , Hernández Medardo
Published: March 2012

Aims

The involvement of endothelin receptors in the contraction of the lower urinary tract smooth muscle is well established. There is scarce information, however, about endothelin receptors mediating relaxation of the bladder outlet region. The current study investigates the possible existence of endothelin ETB receptors involved in the relaxation of pig bladder neck.

Methods

ETB receptor expression was determined by immunohistochemistry and urothelium‐denuded bladder neck strips were mounted in organ baths for isometric force recording.

Results

ETB‐immunoreactivity (ETB‐IR) was observed within nerve fibers among smooth muscle bundles and urothelium. BQ3020 (0.01–300 nM), an ETB receptor agonist, produced concentration‐dependent relaxations which were reduced by BQ788, an ETB receptor antagonist, and by inhibitors of protein kinase A (PKA) and large (BKCa)‐ or small (SKCa)‐conductance Ca2+‐activated K+ channels. Pretreatment with BKCa or SKCa channel inhibitors plus PKA blocking did not cause further inhibition compared with that exerted by inhibiting BKCa or SKCa channels only. BQ3020‐induced relaxation was not modified by blockade of either nitric oxide (NO) synthase, guanylyl cyclase, cyclooxygenase (COX) or of intermediate‐conductance Ca2+‐activated‐(IKCa), ATP‐dependent‐(KATP), or voltage‐gated‐(Kv) K+ channels. Under non‐adrenergic non‐cholinergic (NANC) conditions, electrical field stimulation (0.5–16 Hz) evoked frequency‐dependent relaxations, which were reduced by BQ788 and potentiated by threshold concentrations of BQ3020.

Conclusions

These results suggest that BQ3020 produces relaxation of the pig bladder neck via activation of muscle endothelin ETB receptors, NO/cGMP‐ and COX‐independent‐, cAMP–PKA pathway‐dependent‐mechanisms, and involving BKCa and SKCa channel activation. ETB receptors are also involved in the NANC inhibitory neurotransmission. Neurourol. Urodynam. 31:688–694, 2012. © 2012 Wiley Periodicals, Inc.
Household income and spiritual well‐being but not body mass index as determinants of poor self‐rated health among African American adolescents
Authors: Powell‐Young Yolanda M.
Published: March 2012

Very little is known about predictors of subjective health status among African American adolescents. This study was designed to determine whether selected anthropometric, psychological, lifestyle behavioral, and structural variables predicted poor self‐rated general health in a cross‐sectional nonclinical sample of 310 female African American adolescents, 14–18 years old. The odds of reporting poor self‐rated health were 2–3 times greater for African American teens from lower socioeconomic households when compared to teens residing in higher socioeconomic households and for those reporting infrequent participation in activities that promote spiritual well‐being compared to those who participate more frequently in activities that enhance spiritual health. Findings indicate that socioeconomic level and engagement in behaviors that enhance healthy spirituality appear to be the most salient predictors of self‐rated health. In addition to biodiversity considerations that influence perceptions of health status, culturally focused interventions should integrate variables shown to influence self‐rated health among African American teens. These inclusions may inform a more integrated understanding of health, health outcomes, and health disparities in this vulnerable population. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:219–230, 2012
Patient turnover and the relationship between nurse staffing and patient outcomes
Authors: Park Shin Hye , Blegen Mary A. , Spetz Joanne , Chapman Susan A. , De Groot Holly
Published: March 2012

High patient turnover (patient throughput generated by admissions, discharges, and transfers) contributes to increased demands and resources for care. We examined how the relationship between registered nurse (RN) staffing and failure‐to‐rescue (FTR) varied with patient turnover levels by analyzing quarterly data from the University HealthSystem Consortium. The data included 42 hospitals, representing 759 nursing units and about 1 million inpatients. Higher RN staffing was associated with lower FTR. When patient turnover increased from 48.6% to 60.7% on nonintensive units (non‐ICUs), the beneficial effect of non‐ICU RN staffing on FTR was reduced by 11.5%. RN staffing should be adjusted according to patient turnover because turnover increases patient care demand beyond that presented by patient count, and outcomes may be adversely affected. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:277–288, 2012
Methylation of the RASSF1A promoter is predictive of poor outcome among patients with Wilms tumor
Authors: Ohshima Junjiro , Haruta Masayuki , Fujiwara Yuiko , Watanabe Naoki , Arai Yasuhito , Ariga Tadashi , Okita Hajime , Koshinaga Tsugumichi , Oue Takaharu , Hinotsu Shiro , Nakadate Hisaya , Horie Hiroshi , Fukuzawa Masahiro , Kaneko Yasuhiko
Published: March 2012

Background

Wilms tumor (WT) has a survival rate of 90% following multimodality therapy. Nevertheless, there are some groups of patients with event‐free survival rates less than 75%. In addition to clinical prognostic factors, loss of heterozygosity at 1p and/or 16q has been used to determine treatment intensity. However, the incidence of this abnormality is low, and new biomarkers are still needed.

Procedure

We analyzed methylation status of three tumor suppressor genes; Ras‐association domain family 1 protein, isoform A (RASSF1A), DCR2, and CASP8, in 84 WTs using conventional methylation‐specific PCR (cMSP), and the results were correlated with outcome. Furthermore, we analyzed the methylation status of RASSF1A by quantitative MSP (qMSP) in 171 WTs, and evaluated clinical and genetic differences between the methylated and unmethylated tumors.

Results

RASSF1A was the most frequently methylated gene identified by cMSP, and associated with a poor outcome. Patients with a RASSF1A‐methylated tumor had shorter overall and event‐free survival periods (P = 0.043 and 0.018, respectively), when a cut‐off value of 7% by qMSP was used. The methylation was more frequent in tumors of older children than younger children (P < 0.001), and in advanced‐stage tumors than early stage tumors (P = 0.001). However, multivariate analysis could not confirm the prognostic significance of RASSF1A methylation, possibly because of a small number of advanced stage tumors examined. RASSF1A methylation was correlated with LOH at 1p and/or 16q (P = 0.017), but not with WT1 abnormality, suggesting the methylation and LOH to involve the same tumorigenic pathway.

Conclusions

The methylation status of RASSF1A might be a novel biomarker to predict outcome of WT patients. Pediatr Blood Cancer 2012;59:499–505. © 2012 Wiley Periodicals, Inc.
Physical aging and thermal aging resistance of polycarbonate/poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) blends
Authors: Suzuki Shuta , Nishitsuji Shotaro , Inoue Takashi
Published: March 2012

The effect of thermal annealing on the mechanical properties of polycarbonate (PC) was investigated by tensile testing, Izod impact testing, and differential scanning calorimetry (DSC). An endothermic peak appeared in the DSC curve by annealing at various temperatures below Tg. The peak area, as a measure of the degree of physical aging, increased with annealing time. The Izod impact strength decreased suddenly just before an endothermic peak became detectable. The results imply that at the very early stage of physical aging, a trigger for the ductile‐to‐brittle transition may be initiated. By blending hydrogenated styrene‐butadiene‐styrene block copolymer (SEBS), the embrittlement by annealing was prevented. That is, in the PC/SEBS blends, the physical aging of PC matrix proceeded in the same way as in neat PC; however, the Izod impact strength did not decrease. This thermal aging resistance seems to originate from the negative pressure effect of SEBS particles that provides dilational stress fields for PC matrix to enhance the local segment motions. POLYM. ENG. SCI., 52:1958–1963, 2012. © 2012 Society of Plastics Engineers
Preparation and experimental parameters analysis of laser melt electrospun poly(L‐lactide) fibers via orthogonal design
Authors: Li Xiuyan , Liu Huichao , Liu Jianli , Wang Jiaona , Li Congju
Published: March 2012

Laser melt electrospinning is a novel technology to produce micro/nanofibers. This solvent‐free process is more suitable for biomedical applications. In this work, the electrospun poly(L‐lactide) (PLLA) fibers with diameters ranging from 2 to 7 μm were prepared by this method, and four influencing factors of melt flow rate (MFR), laser current, collector distance, and applied voltage were investigated on the PLLA fiber diameters and its standard deviation (SD) with an orthogonal design method. The results of range analysis showed the order of significance levels as follows: applied voltage, laser current, collector distance, and MFR for fiber diameter. The SD of fiber diameter can be listed in the following order: applied voltage, MFR, laser current, and collector distance. POLYM. ENG. SCI., 52:1964–1967, 2012. © 2012 Society of Plastics Engineers