bluuebunny/crossref_metadata_2025 huggingface dataset:
Copolymerizations of tetrafluoroethylene and perfluoropropylvinyl ether in supercritical carbon dioxide: Polymer synthesis, characterization, and thermal properties
Authors: Xu Anhou , Yuan Wang Zhang , Zhao Junhong , Li Hong , Zhang Heng , Zhang Yongming
Published: October 2011

Tetrafluoroethylene (TFE) and perfluoropropylvinyl ether (PPVE) were copolymerized in supercritical carbon dioxide (sc‐CO2) with a perfluorodiacyl initiator bis(perfluoro‐2‐n‐propoxypropionyl) peroxide (BPPP). The resultant copolymers with stable perfluoroalkyl end groups were obtained, avoiding the decomposition during processing and applications. Reactivity ratios of TFE and PPVE were first reported. The rTFE and rPPVE values are about 8 and 0.08, respectively. Such parameters are significant for the modification of PTFE through copolymerization of TFE and PPVE. It is found that through increasing the reaction pressure from 8.5 to 25 MPa, while rTFE increases by 12.0%, rPPVE decreases by 9.0%, which should be ascribed to the enhancement of the polarity of CO2 under high pressures. Because the reactivity of TFE is by two orders of magnitude higher than that of PPVE; on one hand, the copolymerization rate falls rapidly with the decrease of TFE feed ratio; on the other hand, TFE content in the copolymer decreases with the reaction time. All copolymers containing different fractions of PPVE enjoy outstanding thermal stability. The DSC result indicates that there exist two forms of crystals with highly regular molecular arrangement or less ordered chain packing which is disturbed by perfluoropropyl pendants. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Atom transfer radical polymerization of methylmethacrylate and styrene initiated by 3,5‐bis(perfluorobenzyloxy)benzyl 2‐bromopropanoate
Authors: Çanak Tuba Çakır , Selçukoğlu Mukaddes , Hamuryudan Esin , Serhatlı İ. Ersin
Published: October 2011

The synthesis of polymethylmethacrylate (pMMA) and polystyrene (pSt) were realized with newly synthesized initiator, 3,5‐bis(perfluorobenzyloxy)benzyl 2‐bromopropanoate (FBr) in the presence of copper bromide (CuBr) and N,N,N′,N″,N″‐pentamethyl‐diethylenetriamine (PMDETA) by using atom transfer radical polymerization (ATRP). The perfluorinated aromatic group containing initiator was prepared by esterification of the (3,5‐bis[(perfluorobenzyl)oxy]‐phenyl alcohol. Both initiator and polymers were characterized by 1H‐NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. The ATRP was supported by an increase in the molecular weight of the forming polymers and also by their monomodal molecular weight distribution. Contact angle measurements of water and ethylene glycol on films of synthesized polymers indicated higher degree of hydrophobicity than that of pure pMMA and pure pSt. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Quantitative analysis of interfacial tension effect on the impact strength of organic flame retardants and acrylonitrile‐butadiene‐styrene blends
Authors: Jia Lina , Li Bin , Shi Baoli , Zhang Hongjie , Lan Yongqiang , Zhang Xin , Wang Yue , Wang Lili
Published: October 2011

For a polymeric blend containing powder additive, quantitative analysis of its mechanical performances with interfacial tension methodology is generally a difficult work because it needs at least two groups of consistent and comparable surface tension data, either for the polymer matrix or for the powder additive, to calculate their interfacial tension. In this article, to quantitatively analyze the effect of interfacial tension on the impact strength of acrylonitrile‐butadiene‐styrene/flame retardants (ABS/FR) blends, the surface tension components (STC) of three organic flame retardant powders, FR‐245 (2,4,6‐tris(2,4,6‐tribromophenoxy)‐1,3,5 triazine), decabromodiphenyl oxide, and charringefoaming agent were measured through the combination of contact angle (CA) and inverse gas chromatography technique. The relationship of the STC measured from CA between ABS resin and its homopolymer components (polyacrylonitrile, polybutadiene, and polystyrene) was also researched. Then, the interfacial tension between the three FR and ABS was calculated. It was found that the impact strength of the ABS/FR blends decreased almost linearly with the increase of the interfacial tension, and the linear correlation degree reached a very high value, 0.9969. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of LDHs/PMMA nanocomposites: Effect of two different intercalated anions on the mechanical and thermal properties
Authors: Nogueira Telma , Botan Rodrigo , Wypych Fernando , Lona Liliane
Published: October 2011

Poly(methyl methacrylate) (PMMA)/layered double hydroxides (LDH) nanocomposites were synthesized by in situ bulk polymerization. The LDHs were synthesized by coprecipitation method. Eight LDHs having different compositions were produced, varying the divalent/trivalent cations (Zn/Al, Mg/Fe), the ratio between these cations (2: 1 and 4: 1) and the LDH intercalated anions (dodecyl sulfate and laurate). The LDH percentage (wt %) in the PMMA was fixed at 1%. The thermal properties of the nanocomposites were evaluated by thermal analysis (thermogravimetric—TGA and differential scanning calorimetry—DSC). Most of the nanocomposites presented higher thermal resistance than PMMA and the best results were presented by the following nanocomposites: PMMA/(Zn/Al 2: 1 laurate) and PMMA/(Zn/Al 4: 1 laurate). The dynamic mechanical properties of the nanocomposites were investigated and compared to those obtained for PMMA. It was noticed that PMMA/(Mg/Fe 4: 1 laurate) nanocomposite presented an elastic modulus 2.2 times higher than PMMA at 40°C. This investigation demonstrated that the addition of low concentrations of selected LDHs can enhance some desired properties of PMMA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The significance of shore height in intertidal macrobenthic seagrass ecology and conservation
Authors: Barnes R. S. K. , Ellwood M. D. F.
Published: October 2011

Benthic faunal assemblages of an intertidal seagrass bed were sampled at three shore heights (LWN, MLW, LWS) at the mouth, mid‐point and head of the Steenbok Channel in South Africa's premier seagrass site, the warm‐temperate Knysna estuarine bay, Garden Route National Park.

Faunal abundance, species richness, species diversity, and proportion of rare species were relatively uniform along the Channel, as were faunal abundance, species diversity and proportion of rare species down the shore. Overall species richness per station, however, was significantly lower at LWN than at either MLW or LWS, although the distribution of species richness over the shore did not depart from random at one of the three sites. Overall faunal abundance and those of individual component species were dispersed patchily through the bed.

The nature of the faunal assemblages present, however, varied significantly throughout the bed, both along the Channel at each shore‐height horizon, and down the shore at each site. LWN assemblages formed a unit distinct from those at MLW and LWS. Overall, the shore‐height axis accounted for 47% and the along‐shore axis 28% of total assemblage variation.

Faunal assemblages were randomly structured at each nodal intersection point of the down‐shore and along‐shore axes, but were significantly non‐randomly assembled down the shore at each site and along the Channel at each shore‐height horizon except at the LWN level.

Components of total assemblage variance were largest at the smallest scale investigated (1 m).

Higher seagrass horizons are not just progressively more impoverished versions of lower ones and although macrofaunal assemblage composition is heavily influenced by shore height much of the ecological structure of faunal assemblages seems little affected by tidal horizon. These findings are discussed in relation to conservation of the vulnerable seagrass Nanozostera capensis at Knysna, a system affected by subsistence exploitation of its intertidal benthic invertebrates.

Copyright © 2011 John Wiley & Sons, Ltd.
Historical Tracks and Trail Resources as Delineated by Near‐field Ground‐penetrating Radar: Two Case Studies
Authors: Weissling Blake P.
Published: October 2011

The information content of the near‐field coupling‐wave zone of ground‐penetrating radar is explored in the context of cultural resource investigations at two archaeological sites in Washington State and New Mexico. While the coupling‐wave zone is frequently assumed to be information‐poor in the context of very shallow resources, and routinely filtered out for the benefit of accentuating deeper resources, this study advocates careful inspection of this data zone. In both case studies, cultural resources most likely related to animal/human/vehicular trails or trackways were detected in unprocessed (raw) horizontal amplitude slices. The ability of radar to ‘see’ these resources is conjectured to be related to soil or sediment compaction. Copyright © 2011 John Wiley & Sons, Ltd.
Marginal structural models for estimating principal stratum direct effects under the monotonicity assumption
Authors: Chiba Yasutaka
Published: October 2011

In epidemiological and clinical research, investigators are frequently interested in estimating the direct effect of a treatment on an outcome that is not relayed by intermediate variables. In 2009, VanderWeele presented marginal structural models (MSMs) for estimating direct effects based on interventions on the mediator. This paper focuses on direct effects based on principal stratification, i.e. principal stratum direct effects (PSDEs), which are causal effects within latent subgroups of subjects where the mediator is constant, regardless of the exposure status. We propose MSMs for estimating PSDEs. We demonstrate that the PSDE can be estimated readily using MSMs under the monotonicity assumption.
Metabolic ensemble modeling for strain engineers
Authors: Tan Yikun , Liao James C.
Published: October 2011

Previous mathematical modeling efforts have made significant contributions to the development of systems biology for predicting biological behavior quantitatively. However, dynamic metabolic model construction remains challenging due to uncertainties in mechanistic structures and parameters. In addition, parameter estimation and model validation often require designated experiments conducted only for purpose of modeling. Such difficulties have hampered the progress of modeling in biology and biotechnology. To circumvent these problems, ensemble approaches have been used to account for uncertainties in model structure and parameters. Specifically, this review focuses on approaches that utilize readily available fermentation data for parameter screening and model validation. Time course data for metabolite measurements, if available, can further calibrate the model. The basis for this approach is explained in non‐mathematical terms accessible to experimentalists. Information gained from such an approach has been shown to be useful in designing Escherichia coli strains for metabolic engineering and synthetic biology.
Three‐reaction model for the anaerobic digestion of microalgae
Authors: Mairet Francis , Bernard Olivier , Cameron Elliot , Ras Monique , Lardon Laurent , Steyer Jean‐Philippe , Chachuat Benoît
Published: October 2011

Coupling an anaerobic digester to a microalgal culture has received increasing attention as an alternative process for combined bioenergy production and depollution. In this article, a dynamic model for anaerobic digestion of microalgae is developed with the aim of improving the management of such a coupled system. This model describes the dynamics of inorganic nitrogen and volatile fatty acids since both can lead to inhibition and therefore process instability. Three reactions are considered: Two hydrolysis–acidogenesis steps in parallel for sugars/lipids and for proteins, followed by a methanogenesis step. The proposed model accurately reproduces experimental data for anaerobic digestion of the freshwater microalgae Chlorella vulgaris with an organic loading rate of 1 gCOD L−1 d−1. In particular, the three‐reaction pathway allows to adequately represent the observed decoupling between biogas production and nitrogen release. The reduced complexity of this model makes it suitable for developing advanced, model‐based control and monitoring strategies. Biotechnol. Bioeng. 2012; 109:415–425. © 2011 Wiley Periodicals, Inc.
Clinical significance of liver ischaemia after pancreatic resection
Authors: Hackert T , Stampfl U , Schulz H , Strobel O , Büchler M W , Werner J
Published: October 2011

Background

Liver ischaemia after pancreatic resection is a rare but potentially serious complication. The aim of this study was to determine the impact of postoperative liver ischaemia after pancreatic resection.

Methods

All consecutive patients undergoing pancreatic resection between January 2007 and August 2008 in the Department of Surgery in Heidelberg were identified retrospectively from a prospectively collected database and analysed with a focus on postoperative hepatic perfusion failure. Laboratory data, computed tomography (CT) findings, symptoms, therapy and outcome were recorded.

Results

A total of 762 patients underwent pancreatic resection in the study period. Seventeen patients (2·2 per cent) with a postoperative increase in liver enzymes underwent contrast-enhanced CT for suspected liver perfusion failure. The types of perfusion failure were hypoperfusion without occlusion of major hepatic vessels (6 patients) and ischaemia with arterial (5) and/or portal vein (6) involvement. The overall mortality rate was 29 per cent (5 of 17 patients). Therapy included conservative treatment (7), radiological or surgical revascularization and necrosectomy or resection of necrotic liver tissue (10). Outcome varied from full recovery (4 patients) to moderate systemic complications (6) and severe complications (7) including death. Simultaneous involvement of the portal vein and hepatic artery was always fatal.

Conclusion

Postoperative liver perfusion failure is a rare but potentially severe complication following pancreatic surgery requiring immediate recognition and, if necessary, radiological or surgical intervention.
Assessment of haemorrhoidal artery network using colour duplex imaging and clinical implications
Authors: Ratto C , Parello A , Donisi L , Litta F , Zaccone G , Doglietto G B
Published: October 2011

Background

Dearterialization should reduce arterial overflow to haemorrhoids. The purpose of this study was to assess the topography of haemorrhoidal arteries.

Methods

Fifty patients with haemorrhoidal disease were studied. Using endorectal ultrasonography, six sectors were identified within the lower rectal circumference. Starting from the highest level (6 cm above the anorectal junction), the same procedure was repeated every 1 cm until the lowest level was reached (1 cm above the anorectal junction). Colour duplex imaging examinations identified haemorrhoidal arteries related to the rectal wall layers, and the arterial depth was calculated.

Results

Haemorrhoidal arteries were detected in 64·3, 66·0, 66·0, 98·3, 99·3 and 99·7 per cent of the sectors 6, 5, 4, 3, 2 and 1 cm above the anorectal junction respectively (P < 0·001). Most of the haemorrhoidal arteries were external to the rectal wall at 6 and 5 cm (97·9 and 90·9 per cent), intramuscular at 4 cm (55·0 per cent), and within the submucosa at 3, 2 and 1 cm above the anorectal junction (67·1, 96·6 and 100 per cent) (P < 0·001). The mean arterial depth decreased significantly from 8·3 mm at 6 cm to 1·9 mm at 1 cm above the anorectal junction (P < 0·001).

Conclusion

This study demonstrated that the vast majority of haemorrhoidal arteries lie within the rectal submucosa at the lowest 2 cm above the anorectal junction. This should therefore be the best site for performing haemorrhoidal dearterialization. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
Aptamers can Discriminate Alkaline Proteins with High Specificity
Authors: Yu Hanyang , Jiang Bing , Chaput John C.
Published: October 2011

Aptamers are single‐stranded nucleic acids that fold into stable three‐dimensional structures with ligand binding sites that are complementary in shape and charge to a desired target. Aptamers are generated by an iterative process known as in vitro selection, which permits their isolation from pools of random sequences. While aptamers have been selected to bind a wide range of targets, it is generally thought that these molecules are incapable of discriminating strongly alkaline proteins due to the attractive forces that govern oppositely charged polymers (e.g., polyelectrolyte effect). Histones, eukaryotic proteins that make up the core structure of nucleosomes are attractive targets for exploring the binding properties of aptamers because these proteins have positively charged surfaces that bind DNA through noncovalent sequence‐independent interactions. Previous selections by our lab and others have yielded DNA aptamers with high affinity but low specificity to individual histone proteins. Whether this is a general limitation of aptamers is an interesting question with important practical implications in the future development of protein affinity reagents. Here we report the in vitro selection of a DNA aptamer that binds to histone H4 with a Kd of 13 nM and distinguishes other core histone proteins with 100 to 480‐fold selectivity, which corresponds to a ΔΔG of up to 3.4 kcal mol−1. This result extends our fundamental understanding of aptamers and their ability to fold into shapes that selectively bind alkaline proteins.
A Novel Synthesis of Bioactive Catechols by Layer‐by‐Layer Immobilized Tyrosinase in an Organic Solvent Medium
Authors: Guazzaroni Melissa , Pasqualini Marina , Botta Giorgia , Saladino Raffaele
Published: October 2011

Commercial and extracted mushroom tyrosinases were supported on Eupergit C 250 L and protected by a coating of oppositely charged polyelectrolytes by means of the layer‐by‐layer technique. The kinetic parameters (Km, Vmax, and Vmax/Km) of these novel biocatalysts in both organic and aqueous media were evaluated, showing tyrosinase to be more reactive in organic solvent than in buffer solution. Heterogeneous tyrosinase systems were used for the oxidation of a large group of phenol derivatives to the corresponding catechols. Different enzyme reactivities were found depending on the substrate structure. The catalyst activity was retained for successive runs. Catechols are difficult to synthesize through traditional chemical methods under environmentally friendly conditions; the use of immobilized tyrosinase opens a novel synthetic alternative to this interesting biologically active family of substances.
Electrokinetic Restoration of Sulfate‐Accumulated Saline Greenhouse Soil
Authors: Cho Jung‐Min , Kim Do‐Hyung , Yang Jung‐Seok , Baek Kitae
Published: October 2011

Electrokinetic (EK) process was performed to restore sulfate‐originated saline soil and to evaluate the effect of treatment duration. Sulfate and potassium were the major ionic salts in the saline soil used in this study. A constant voltage gradient of 1 V/cm was applied for 8, 12, and 16 days. After EK treatment, anions and cations were transported toward anode and cathode, respectively, by electromigration. Chloride was completely removed, and 85.6% of nitrate was removed after 8 days of treatment. The increase of treatment period from 8 to 12 days had a negligible effect on the enhancement in the rate of sulfate removal; however, over 70% was removed after16 days. At the end of experiment, the electrical conductivity (EC) of the soil, an indicator of soil salinity, decreased to 1.93 dS/m from an initial value of 5.3 dS/m, and the distribution of sulfate was similar to that of EC. The operation time of 16 days was sufficient to restore the sulfate‐originated saline soil using the EK process.
The position and size of individual focal adhesions are determined by intracellular stress‐dependent positive regulation
Authors: Deguchi Shinji , Matsui Tsubasa S. , Iio Kazushi
Published: October 2011

It remains unclear how the subcellular positions and sizes of individual focal adhesions (FAs) are determined in stationary cells. The elucidation of spatial regulation mechanisms is important for accurate understanding of the cellular response to mechanical stress. Through a theoretical analysis on previously reported cell behavior, the present study demonstrates a close correlation between the appearances of mechanosensitive elements and intracellular stress reflecting traction stress that the cell exerts on the substrate. The magnitude and distribution of stress were predicted in this analysis by mimicking intrinsic actomyosin contraction independent of extracellular stimuli. Positions of FAs and actin stress fibers corresponded to the local maximum and minimum stress points, respectively, and thus were determined by the global configuration of cell adhesions. Furthermore, their subcellular sizes were in agreement with the predicted stress magnitudes that were dependent on the local mechanical environment. These results suggest that a positive regulation (i.e., force and cell adhesion enhance each other) functions in the organization of individual FAs in nonmigrating cells. © 2011 Wiley Periodicals, Inc.
The podosome marker protein Tks5 regulates macrophage invasive behavior
Authors: Burger Karen L. , Davis Amanda L. , Isom Scott , Mishra Nilamadhab , Seals Darren F.
Published: October 2011

Tks5 is a Src substrate and adaptor protein previously recognized for its regulation of cancer cell invasion through modulation of specialized adhesion structures called podosomes/invadopodia. Here we show for the first time that Tks5 localizes to the podosomes of primary macrophages, and that Tks5 protein levels increase concurrently with podosome deposition during the differentiation of monocytes into macrophages. Similar results are reported for model THP‐1 cells, which differentiate into macrophages and form proteolytically active podosomes in response to a PKC signaling agonist (PMA) and with sensitivity to a PKC inhibitor (bisindolylmaleimide). Genetic manipulation of Tks5 expression (silencing and overexpression) in stable THP‐1 cell lines does not independently alter this macrophage differentiation process. Nor do these cells lose the ability to focalize F‐actin and its accessory proteins into podosome‐like structures following PMA treatment. However, Tks5 directly controls podosome‐associated gelatin degradation and invasion through collective changes in adhesion, chemotaxis, and the expression/proteolytic activity of MMP9. The Src family kinase‐dependent phosphorylation of Tks5 is also implicated in the regulation of THP‐1 macrophage invasive behavior. These results therefore define a previously unappreciated function of Tks5 signaling specific to the functional attributes of the macrophage podosome in adhesion, motility, and extracellular matrix‐remodeling. © 2011 Wiley Periodicals, Inc.
The significance of a marginal excision after preoperative radiation therapy for soft tissue sarcoma of the extremity
Authors: Dagan Roi , Indelicato Daniel J. , McGee Lisa , Morris Christopher G. , Kirwan Jessica M. , Knapik Jacquelyn , Reith John , Scarborough Mark T. , Gibbs C. Parker , Marcus Robert B. , Zlotecki Robert A.
Published: October 2011

BACKGROUND:

Marginal excision of soft tissue sarcoma (STS), defined as resection through the tumor pseudocapsule or surrounding reactive tissue, increases the likelihood of local recurrence and necessitates re‐excision or postoperative radiation. However, its impact after preoperative radiation therapy (RT) remains unclear. This study therefore investigated the significance of marginal margins in patients treated with preoperative RT for extremity STS, reporting long‐term local control and limb preservation endpoints.

METHODS:

The records of 317 adults at the University of Florida with nonmetastatic extremity STS treated from 1980 to 2008 with preoperative RT as part of a limb conservation strategy were reviewed. The median follow‐up was 4.7 years (8.3 years for living patients). The median tumor size was 10 cm (range, 2‐36 cm), and 86% were high grade. The median RT dose was 50.4 Gy (range, 12.5‐57.6 Gy). Margins were classified as wide/radical (n = 105), marginal (n = 179), contaminated (n = 15), positive (n = 17), or unknown (n = 1). Endpoints were local control (LC), amputation‐free survival (AFS), cause‐specific survival (CSS), and overall survival (OS).

RESULTS:

Five‐year CSS and OS rates were 62% and 59%, respectively. Five‐year LC and AFS was 93% and 89%, respectively. AFS by margin status was 64%, 83%, 97%, and 92% for positive, contaminated, marginal, and wide/radical margins, respectively (P<.005). Marginal excision following preoperative RT resulted in equivalent LC and AFS compared with wide/radical margins.

CONCLUSIONS:

Marginal resection after preoperative RT does not compromise LC or AFS in extremity STS. This finding may be related to radiosterilization of tumor cells within the reactive zone following preoperative RT. Cancer 2012;118: 3199–207. © 2011 American Cancer Society.
Aquaporin 1 is an independent prognostic factor in pleural malignant mesothelioma
Authors: Kao Steven Chuan‐Hao , Armstrong Nicola , Condon Bridget , Griggs Kim , McCaughan Brian , Maltby Sarah , Wilson Alan , Henderson Douglas W. , Klebe Sonja
Published: October 2011

BACKGROUND:

Malignant mesothelioma (MM) is an aggressive cancer of serosal membranes, mostly pleura. It is related to asbestos exposure and its incidence in most industrialized countries is projected to remain stable or to increase until 2020. Prognosis remains poor. Clinical prognostic scoring systems lack precision. No prognostic tissue markers are available. Aquaporin 1 (AQP1) is a cell membrane channel involved in water transport, cell motility, and proliferation. A blocker and an agonist are available.

METHODS:

Two independent cohorts of MM were studied. Cohort 1 consisted of 80 consecutive patients who underwent radical surgery (extrapleural pneumonectomy [EPP]). Cohort 2 included 56 conservatively managed patients from another institution. Clinical information was obtained from files. Diagnoses were histologically verified. Immunohistochemical labeling for AQP1 was performed on tumor tissue and the percentage of positive cells was scored.

RESULTS:

We demonstrated expression of AQP1 in normal and neoplastic mesothelium at the apical aspect of the cell, in keeping with a role in water transport. For both cohorts, expression of AQP1 by ≥50% of tumor cells was associated with significantly enhanced survival (9.4 months vs 30.4 months in EPP patients and 5 months vs 15 months in conservatively treated patients). This was independent of established prognostic factors, including histologic subtype, pathologic stage, sex, and age at time of diagnosis.

CONCLUSION:

Expression of AQP1 correlated significantly with prognosis in MM, irrespective of treatment or established prognostic factors. Immunohistochemical labeling for AQP1 should be included in the routine histopathologic workup. An agonist or blocker may become useful for treatment. Cancer 2011;. © 2011 American Cancer Society.
Prognosis and risk factors for early‐stage adenoid cystic carcinoma of the major salivary glands
Authors: Bhayani Mihir K. , Yener Murat , El‐Naggar Adel , Garden Adam , Hanna Ehab Y. , Weber Randal S. , Kupferman Michael E.
Published: October 2011

BACKGROUND:

Adenoid cystic carcinoma (ACC) is characterized by slow growth, frequent local recurrences, and distant metastasis (DM). However, these findings frequently are reported in patients with advanced‐stage tumors, but the outcomes of early‐stage tumors are poorly defined. We sought to evaluate the risk factors for the development of DM in early‐stage ACC.

METHODS:

We retrospectively reviewed the charts of 60 patients who were diagnosed with clinical early‐stage (T1‐2/N0) ACC to determine the risk factors for development of DM and survival of these patients.

RESULTS:

DM was detected in 12 (20%) of the patients, with a median latency of 31.5 months after diagnosis. Univariate analysis revealed that DM was associated with age ≥45 years, pathologically positive lymph nodes, extracapsular spread (ECS) from lymph nodes, high‐grade histology, and solid tumor subtype. Multivariate analysis revealed solid tumor subtype and ECS to be significantly associated with DM. Disease‐specific survival rates at 5 and 10 years for patients with DM were 80% and 40%, respectively, and were both 100% for patients without DM.

CONCLUSION:

Although the majority of patients with clinical early‐stage ACC of the major salivary glands have favorable prognosis, a significant percentage of patients will develop DM. Solid tumor subtype and nodal ECS were independent predictors of DM in early‐stage ACC of major salivary glands. Other clinical and pathological variables may also contribute. These subgroups had poor overall and disease‐specific survival. Such patients should be observed closely for the development of DM. Systemic therapy should be considered at the time of diagnosis. Cancer 2011. © 2011 American Cancer Society.
Pretherapeutic uracil and dihydrouracil levels of colorectal cancer patients are associated with sex and toxic side effects during adjuvant 5‐fluorouracil–based chemotherapy
Authors: Wettergren Yvonne , Carlsson Göran , Odin Elisabeth , Gustavsson Bengt
Published: October 2011

BACKGROUND:

In Nordic countries, the standard treatment of colorectal cancer (CRC) in the adjuvant setting is bolus 5‐fluorouracil (5‐FU) plus leucovorin alone or in combination with oxaliplatin. 5‐FU competes with the natural occurring pyrimidine uracil (Ura) as a substrate for dihydropyrimidine dehydrogenase (DPD; enzyme commission number 1.3.1.2). Low DPD activity is associated with toxicity during treatment. Pretherapeutic detection of DPD deficiency could prevent severe toxicity otherwise limiting drug administration. Assays showing that DPD deficiency impairs breakdown of Ura to dihydrouracil (UH2) seem promising for clinical use.

METHODS:

Urine was collected from 56 untreated volunteers and 143 patients with CRC before adjuvant treatment. Ura and UH2 were analyzed using a column‐switching high‐performance liquid chromatography method that incorporates reversed‐phase and cation‐exchange columns. Ura, UH2, and UH2/Ura levels were related to toxicity.

RESULTS:

Ura and UH2 in patients were not different from controls. UH2 was significantly higher in women compared with men. The UH2/Ura ratio, however, did not differ according to sex. Low UH2 and UH2/Ura levels were associated with diarrhea in men. Women experiencing thrombocytopenia had significantly higher Ura compared with women with no thrombocytopenia. The UH2/Ura ratio correlated negatively with total toxicity score in men (r = −0.39, P = .020).

CONCLUSION:

Pretherapeutic Ura and UH2 levels per se may be related to risk of side effects during adjuvant 5‐FU–based treatment, whereas the UH2/Ura ratio may not always reveal such a risk. Sex is a strong risk factor for toxicity, showing the importance of evaluating male and female patients separately. Cancer 2011;. © 2011 American Cancer Society.
Polymorphic markers associated with severe oxaliplatin‐induced, chronic peripheral neuropathy in colon cancer patients
Authors: Won Hong‐Hee , Lee Jeeyun , Park Joon Oh , Park Young Suk , Lim Ho Yeong , Kang Won Ki , Kim Jong‐Won , Lee Soo‐Youn , Park Se Hoon
Published: October 2011

BACKGROUND:

To identify potential genetic markers for severe oxaliplatin‐induced chronic peripheral neuropathy (OXCPN), the authors performed a genome‐wide association analysis of patients with colon cancer who received oxaliplatin‐based chemotherapy.

METHODS:

This was a prospective study in which DNA was purified in peripheral blood from patients with colon cancer who received oxaliplatin. The primary endpoint was the development of severe (grade 2 lasting for >7 days or grade 3) OXCPN. For the discovery set, genotyping was done for 96 patients who received adjuvant fluorouracil and oxaliplatin using the a genome‐wide human single‐nucleotide polymorphism (SNP) array. An association between polymorphisms and severe OXCPN was investigated. At the same time, 247 patients who received oxaliplatin‐based, first‐line chemotherapy for advanced disease were enrolled as a validation set.

RESULTS:

Among the 32 genotyped candidate SNPs selected from the discovery set, 9 SNPs in 8 genes (tachykinin, precursor 1[TAC1]; forkhead box C1 [FOXC1]; integrin, alpha 1 [ITGA1]; acylphosphatase 2, muscle type [ACYP2]; deleted in lymphocytic leukemia, 7 [DLEU7]; B‐cell translocation gene 4 [BTG4]; calcium/calmodulin‐dependent protein kinase II inhibitor 1 [CAMK2N1]; and phenylalanyl‐tRNA synthase 2 [FARS2]) had nominal replication (P < .05). The most significant association was observed at reference SNP number (rs)10486003 in TAC1 (P = 4.84 × 10−7) in combined data from 2 sets. Five SNPs (rs10486003, rs2338, rs830884, rs843748, and rs797519) were significant in a multiple regression analysis (P < .05). Overall prediction accuracy calculated by the regression model was 72.8% (95% confidence interval, 65.8%‐79.9%) in the model development and 75.9% (95% confidence interval, 66.9%‐84.9%) in the model evaluation.

CONCLUSIONS:

The current results indicated that a genome‐wide pharmacogenomic approach is useful for identifying novel polymorphism predictors of severe OXCPN that may be used in personalized chemotherapy. Cancer 2011;. © 2011 American Cancer Society.
Final results of a phase 2A study for the treatment of metastatic neuroendocrine tumors with a fixed activity of 90Y‐DOTA‐D‐Phe1‐Tyr3 octreotide
Authors: Savelli Giordano , Bertagna Francesco , Franco Fabio , Dognini Ludovica , Bosio Giovanni , Migliorati Elena , Rodella Carlo , Biasiotto Giorgio , Bettinsoli Giovanni , Minari Chiara , Zaniboni Alberto , Ferrari Chiara , Tomassetti Paola , Ferrari Vittorio , Giubbini Raffaele
Published: October 2011

BACKGROUND:

The objective of this study was to assess the efficacy of 90Y‐DOTA‐D‐Phe1‐Tyr3 octreotide (90Y‐DOTATOC) therapy with a fixed activity of 2.56 GigaBequerels bimonthly in patients with advanced stage, well differentiated neuroendocrine carcinomas.

METHODS:

In total, 38 patients were enrolled in this phase 2A protocol. All patients had gastroenteropancreatic neuroendocrine tumors in sharp clinical and radiologic progression despite previous surgery, chemotherapy, and biotherapy. Their survival rate after therapy with 90Y‐DOTATOC was compared with a chronologic control group of patients who had received biotherapy and chemotherapy and with results from a previous similar study. The progression‐free survival rate after peptide receptor radionuclide therapy with 90Y‐DOTATOC was determined for all patients until they had documented disease progression according to Response Criteria in Solid Tumors, tumor‐related death, or censoring.

RESULTS:

Seventeen patients (43.6%) had a partial response, 10 patients (25.6%) had stable disease, and 11 patients (28.2%) had progressive disease. A statistically significant difference was observed (P < .001) between the response to 90Y‐DOTATOC treatment and the response to biotherapy with somatostatin analogs and chemotherapy and also between the current results and the results from a previous similar study (P < .05). At the time of the current evaluation with ongoing follow‐up for 30 patients, the median progression‐free survival was 22.3 months.

CONCLUSIONS:

The results from this phase 2 study indicated that the treatment of metastatic neuroendocrine tumors with fixed 90Y‐DOTATOC activity is useful and safe. Cancer 2011;. © 2011 American Cancer Society.
Impact of race on survival in patients with clinically nonmetastatic prostate cancer who deferred primary treatment
Authors: Koscuiszka Michael , Hatcher David , Christos Paul J. , Rose Amy E. , Greenwald Holly S. , Chiu Ya‐lin , Taneja Samir S. , Mazumdar Madhu , Lee Peng , Osman Iman
Published: October 2011

BACKGROUND:

Prostate cancer (PCa) racial disparity studies typically focus on survival differences after curative treatment. The authors of this report hypothesized that comparing mortality rates between African American (AA) and Caucasian American (CA) patients who deferred primary treatment for clinically nonmetastatic PCa may provide a better assessment of the impact of race on the natural course of PCa.

METHODS:

The pathology database of the New York Veterans Administration Medical Center (VAMC), an equal access‐of‐care facility, was searched for patients with biopsy‐proven PCa. Inclusion criteria included 1) no evidence of metastatic disease or death within 3 years after diagnosis, 2) no primary treatment, and 3) a minimum of 5 years of follow‐up for survivors.

RESULTS:

In total, 518 patients met inclusion criteria between 1990 and 2005. AA patients were younger (P = .02) and had higher median prostate‐specific antigen (PSA) levels (P = .001) at the time of diagnosis compared with CA patients. In a multivariate model, higher Gleason score and PSA level were associated with increased mortality (P = .001 and P = .03, respectively), but race was not a predictor of death from PCa.

CONCLUSIONS:

The current data suggested that race did not have a major impact on survival in patients with PCa who deferred primary treatment for clinically nonmetastatic disease. Cancer 2012;118: 3145–52. © 2011 American Cancer Society.
3′‐deoxy‐3′‐[18F]fluorothymidine positron emission tomography for response assessment in soft tissue sarcoma
Authors: Benz Matthias R. , Czernin Johannes , Allen‐Auerbach Martin S. , Dry Sarah M. , Sutthiruangwong Piriya , Spick Claudio , Radu Caius , Weber Wolfgang A. , Tap William D. , Eilber Fritz C.
Published: October 2011

BACKGROUND:

This study sought to determine whether [18F]fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) imaging allows assessment of tumor viability and proliferation in patients with soft tissue sarcomas who are treated with neoadjuvant therapy.

METHODS:

Twenty patients with biopsy‐proven, resectable, high‐grade soft tissue sarcoma underwent [18F]FLT PET/CT imaging before and after neoadjuvant therapy. Histologic subtypes included sarcomas not otherwise specified (n = 5), malignant peripheral nerve sheath tumors (n = 3), gastrointestinal stromal tumors (n = 3), leiomyosarcomas (n = 3), angiosarcomas (n = 2), and others (n = 4). Changes in [18F]FLT peak standardized uptake value (SUVpeak) were correlated with percent necrosis in excised tissue, whereas posttreatment [18F]FLT tumor uptake was correlated with thymidine kinase 1 (TK1) expression and Ki‐67 staining indices in excised tumor tissue.

RESULTS:

Tumor FLT SUVpeak averaged 7.1 ± 3.7 g/mL (range, 1.9‐16.1 g/mL) at baseline and decreased significantly to 2.7 ± 1.6 g/mL (range, 0.8‐6.0 g/mL) at follow‐up (P < .001); however, marked reductions in SUV were not specific for histopathological response. The posttreatment SUVpeak did not correlate with TK1 (P = .27) or Ki‐67 expression (P = .21).

CONCLUSIONS:

Marked reductions in [18F]FLT tumor uptake in response to neoadjuvant treatment were observed in most patients with sarcoma. However, these reductions were not specific for histopathologic response to neoadjuvant therapy. Furthermore, posttreatment [18F]FLT tumor uptake was unrelated to tumor proliferation by Ki‐67 and TK1 staining. These results question the value of [18F]FLT PET imaging for treatment response assessments in patients with soft tissue sarcoma. Cancer 2012;118: 3135–44. © 2011 American Cancer Society.
Differential projections from the lateral habenula to the rostromedial tegmental nucleus and ventral tegmental area in the rat
Authors: Gonçalves Luciano , Sego Chemutai , Metzger Martin
Published: October 2011

The mesopontine rostromedial tegmental nucleus (RMTg) is a mostly γ‐aminobutyric acid (GABA)ergic structure believed to be a node for signaling aversive events to dopamine (DA) neurons in the ventral tegmental area (VTA). The RMTg receives glutamatergic inputs from the lateral habenula (LHb) and sends substantial GABAergic projections to the VTA, which also receives direct projections from the LHb. To further specify the topography of LHb projections to the RMTg and VTA, small focal injections of the anterograde tracerPhaseolus vulgarisleucoagglutinin were aimed at different subdivisions of the LHb. The subnuclear origin of LHb inputs to the VTA and RMTg was then confirmed by injections of the retrograde tracer cholera toxin subunit b into the VTA or RMTg. Furthermore, we compared the topographic position of retrogradely labeled neurons in the RMTg resulting from VTA injections with that of anterogradely labeled axons emerging from the LHb. As revealed by anterograde and retrograde tracing, LHb projections were organized in a strikingly topographic manner, with inputs to the RMTg mostly arising from the lateral division of the LHb (LHbL), whereas inputs to the VTA mainly emerged from the medial division of the LHb (LHbM). In the RMTg, profusely branched LHb axons were found in close register with VTA projecting neurons and were frequently apposed to the latter. Overall, our findings demonstrate that LHb inputs to the RMTg and VTA arise from different divisions of the LHb and provide direct evidence for a disynaptic pathway that links the LHbL to the VTA via the RMTg. J. Comp. Neurol. 520:1278–1300, 2012. © 2011 Wiley Periodicals, Inc.
The astrocytic lineage marker calmodulin‐regulated spectrin‐associated protein 1 (Camsap1): Phenotypic heterogeneity of newly born Camsap1‐expressing cells in injured mouse brain
Authors: Yoshioka Nozomu , Asou Hiroaki , Hisanaga Shin‐Ichi , Kawano Hitoshi
Published: October 2011

Calmodulin‐regulated spectrin‐associated protein 1 (Camsap1) has been recognized as a new marker for astrocytic lineage cells and is expressed on mature astrocytes in the adult brain (Yamamoto et al. [2009] J. Neurosci. Res. 87:503–513). In the present study, we found that newly born Camsap1‐expressing cells exhibited regional heterogeneity in an early phase after stab injury of the mouse brain. In the surrounding area of the lesion site, Camsap1 was expressed on quiescent astrocytes. At 3 days after injury, Camsap1 immunoreactivity was upregulated on glial fibrillary acidic protein‐immunoreactive (GFAP‐ir) astrocytes. Some of these astrocytes incorporated bromodeoxyuridine (BrdU) together with re‐expression of the embryonic cytoskeleton protein nestin. In the neighboring region of the lesion cavity, Camsap1 was expressed on GFAP‐negative cells. At 3 days after injury, GFAP‐ir astrocytes were absent around the lesion cavity. At this stage, NG2‐ir cells immunopositive for Camsap1 and immunonegative for GFAP were distributed in border of the lesion cavity. By 10 days, Camsap1 immunoreactivity was exclusively detected on GFAP‐ir reactive astrocytes devoid of NG2 immunoreactivity. BrdU pulse‐chase labeling assay suggested the differentiation of Camsap1+/NG2+ cells into Camsap1+/GFAP+ astrocytes. In the subependymal zone of the lateral ventricle, Camsap1‐ir cells increased after injury. Camsap1 immunoreactivity was distributed on ependymal and subependymal cells bearing various astrocyte markers, and BrdU incorporation was enhanced on such Camsap1‐ir cells after injury. These results suggest that newly born reactive astrocytes are derived from heterogeneous Camsap1‐expressing cells in the injured brain. J. Comp. Neurol. 520:1301–1317, 2012. © 2011 Wiley Periodicals, Inc.
Coordinate development of skin cells and cutaneous sensory axons in zebrafish
Authors: O'Brien Georgeann S. , Rieger Sandra , Wang Fang , Smolen Gromoslaw A. , Gonzalez Robert E. , Buchanan JoAnn , Sagasti Alvaro
Published: October 2011

Peripheral sensory axons innervate the epidermis early in embryogenesis to detect touch stimuli. To characterize the time course of cutaneous innervation and the nature of interactions between sensory axons and skin cells at early developmental stages, we conducted a detailed analysis of cutaneous innervation in the head, trunk, and tail of zebrafish embryos and larvae from 18 to 78 hours postfertilization. This analysis combined live imaging of fish expressing transgenes that highlight sensory neurons and skin cells, transmission electron microscopy (TEM), and serial scanning electron microscopy (sSEM). In zebrafish, the skin initially consists of two epithelial layers, and all of the axons in the first wave of innervation are free endings. Maturation of the epithelium coincides with, but does not depend on, its innervation by peripheral sensory axons. We found that peripheral axons initially arborize between the two epithelial skin layers, but not within the basal lamina, as occurs in other organisms. Strikingly, as development proceeds, axons become tightly enveloped within basal keratinocytes, an arrangement suggesting that keratinocytes may serve structural or functional roles, akin to Schwann cells, in somatosensation mediated by these sensory neurons. J. Comp. Neurol., 2012. © 2011 Wiley Periodicals, Inc.
Basic Principles for Rational Design of High‐Performance Nanostructured Silicon‐Based Thermoelectric Materials
Authors: Yang Chun Cheng , Li Sean
Published: October 2011

Recently, nanostructured silicon‐based thermoelectric materials have drawn great attention owing to their excellent thermoelectric performance in the temperature range around 450 °C, which is eminently applicable for concentrated solar thermal technology. In this work, a unified nanothermodynamic model is developed to investigate the predominant factors that determine the lattice thermal conductivity of nanocrystalline, nanoporous, and nanostructured bulk Si. A systematic study shows that the thermoelectric performance of these materials can be substantially enhanced by the following three basic principles: 1) artificial manipulation and optimization of roughness with surface/interface patterning/engineering; 2) grain‐size reduction with innovative fabrication techniques in a controllable fashion; and 3) optimization of material parameters, such as bulk solid–vapor transition entropy, bulk vibrational entropy, dimensionality, and porosity, to decrease the lattice thermal conductivity. These principles may be used to rationally design novel nanostructured Si‐based thermoelectric materials for renewable energy applications.
Estimation of rotor position in a three‐phase SRM at standstill and low speeds
Authors: Komatsuzaki Akitomo , Bamba Tatsunori , Miki Ichiro
Published: October 2011

Switched reluctance motors (SRMs) are widely employed as industrial drives because they are inexpensive, simple, and sturdy, and further, they deliver a robust and reliable performance. SRMs are controlled with a rotor position sensor attached to the motor shaft. Normally, encoders, resolvers, or Hall sensors are used as position sensors. The use of these sensors, however, increases the size and cost of the machine and degrades its performance. Therefore, to overcome these difficulties, several sensorless drive techniques have been reported. This paper presents a method for estimating the position of a rotor in an SRM, based on calculation of the space vector of the phase inductance at standstill and low speeds. The position at standstill is obtained simply without making use of the magnetic characteristics of the motor or any additional hardware. Assuming the inductance waveform to be a sine wave, the position of the rotor at standstill is obtained from the phase inductance vectors of all phases. At low speeds, position estimation is carried out by applying a DC link voltage to the unenergized phases. The validity of the proposed method is experimentally verified. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(2): 55–63, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21205