bluuebunny/crossref_metadata_2025 huggingface dataset:
Bi-Criteria System Optimum Traffic Assignment in Networks With Continuous Value of Time
Authors: Wang Xin , Huang Hai-Jun
Published: April 2013

For an elastic demand transportation network with continuously distributed value of time, the system disutility can be measured either in time units or in cost units. The user equilibrium model and the system optimization model are each formulated in two different criteria. The conditions required for making the system optimum link flow pattern equivalent to the user equilibrium link flow pattern are derived. Furthermore, a bi-objective model has been developed which minimizes simultaneously the system travel time and the system travel cost. The existence of a pricing scheme with anonymous link tolls which can decentralize a Pareto system optimum into the user equilibrium has been investigated.
Deadhead Trip Minimization in City Bus Transportation: A Real Life Application
Authors: Nasibov Efendi , Eliiyi Uğur , Ertaç Mefharet Özkilçik , Kuvvetli Ümit
Published: April 2013

The quality of public transportation services is one of the most important performance indicators of modern urban policies for both planning and implementation aspects. Therefore, along with the size of the city, the significance of appropriate cost evaluation and optimization of all related transportation activities increases as well. One of the most important cost factors for the public transport agencies is naturally the fuel consumption of the vehicles. In this study, the attention is focused on the metropolitan bus transport service. The specific aim is to minimize a significant portion of total fuel utilization that occurs due to the so called deadhead trip or dead mileage, which is defined as the idle distance covered by the vehicle between the garage and the route terminal stops without carrying any passengers. In this study, the results of four mathematical models for minimizing the total deadhead trip distance covered in city bus services of Izmir are presented. The models vary due to the inclusion of garage capacity restrictions or operator distinction for supporting both operational and strategical decisions. All models are applied to the recent bus schedule data, which consist of 293 routes, 1,424 buses and 10 garages, for obtaining the optimal route bus-garage allocations and garage capacities. The results of the Decentralized-Capacitated model, which is appropriate for quick implementation, promise a 7.8% reduction in total dead mileage. While on the other hand, if all garage capacities can be expanded and the bus service is maintained only by one operator as modelled in the Centralized-Uncapacitated case, even a 31.4% improvement is possible in the long term. The environmental gains as well as the financial benefits to be achieved when the solutions are actually implemented, justify the practical contribution of the study.
Identifying structural barriers to an effective HIV response: using the National Composite Policy Index data to evaluate the human rights, legal and policy environment
Authors: Gruskin Sofia , Ferguson Laura , Alfven Tobias , Rugg Deborah , Peersman Greet
Published: April 2013

Introduction

Attention to the negative effects of structural barriers on HIV efforts is increasing. Reviewing national legal and policy environments with attention to the international human rights commitments of states is a means of assessing and providing focus for addressing these barriers to effective HIV responses.

Methods

Law and policy data from the 171 countries reporting under the Declaration of Commitment from the 2001 United Nations General Assembly Special Session on HIV/AIDS were analyzed to assess attention to human rights in national legal and policy environments as relevant to the health and rights of key populations such as people who inject drugs, men who have sex with men and sex workers.

Results

Seventy‐eight governments and civil society in 106 countries report the existence of laws and policies which present obstacles to accessing HIV services for key populations. Laws and policies which positively affect access to HIV‐related services, in and of themselves constituting structural interventions, were also reported. The dissonance between laws and how this impacts the availability and use of HIV‐related services deserve greater attention.

Conclusions

Recognition of the harms inherent in laws that constitute structural barriers to effective HIV responses and the potential positive role that a supportive legal environment can play suggests the need for legal reform to ensure an enabling regulatory framework within which HIV services can be effectively delivered and used by the populations who need them. Moving beyond laws and policies, further efforts are required to determine how to capture information on the range of structural barriers. Teasing apart the impact of different barriers, as well as the structural interventions put in place to address them, remains complicated. Capturing the impact of policy and legal interventions can ultimately support governments and civil society to ensure the human rights of key populations are protected in national HIV responses.
Highly Elastic Micropatterned Hydrogel for Engineering Functional Cardiac Tissue
Authors: Annabi Nasim , Tsang Kelly , Mithieux Suzanne M. , Nikkhah Mehdi , Ameri Afshin , Khademhosseini Ali , Weiss Anthony S.
Published: April 2013

Heart failure is a major international health issue. Myocardial mass loss and lack of contractility are precursors to heart failure. Surgical demand for effective myocardial repair is tempered by a paucity of appropriate biological materials. These materials should conveniently replicate natural human tissue components, convey persistent elasticity, promote cell attachment, growth and conformability to direct cell orientation and functional performance. Here, microfabrication techniques are applied to recombinant human tropoelastin, the resilience‐imparting protein found in all elastic human tissues, to generate photocrosslinked biological materials containing well‐defined micropatterns. These highly elastic substrates are then used to engineer biomimetic cardiac tissue constructs. The micropatterned hydrogels, produced through photocrosslinking of methacrylated tropoelastin (MeTro), promote the attachment, spreading, alignment, function, and intercellular communication of cardiomyocytes by providing an elastic mechanical support that mimics their dynamic mechanical properties in vivo. The fabricated MeTro hydrogels also support the synchronous beating of cardiomyocytes in response to electrical field stimulation. These novel engineered micropatterned elastic gels are designed to be amenable to 3D modular assembly and establish a versatile, adaptable foundation for the modeling and regeneration of functional cardiac tissue with potential for application to other elastic tissues.
Exciton Dynamics in Semiconductor Nanocrystals
Authors: Wheeler Damon A. , Zhang Jin Z.
Published: April 2013

This review article provides an overview of recent advances in the study and understanding of dynamics of excitons in semiconductor nanocrystals (NCs) or quantum dots (QDs). Emphasis is placed on the relationship between exciton dynamics and optical properties, both linear and nonlinear. We also focus on the unique aspects of exciton dynamics in semiconductor NCs as compared to those in bulk crystals. Various experimental techniques for probing exciton dynamics, particularly time‐resolved laser methods, are reviewed. Relevant models and computational studies are also briefly presented. By comparing different materials systems, a unifying picture is proposed to account for the major dynamic features of excitons in semiconductor QDs. While the specific dynamic processes involved are material‐dependent, key processes can be identified for all the materials that include electronic dephasing, intraband relaxation, trapping, and interband recombination of free and trapped charge carriers (electron and hole). Exciton dynamics play a critical role in the fundamental properties and functionalities of nanomaterials of interest for a variety of applications including optical detectors, solar energy conversion, lasers, and sensors. A better understanding of exciton dynamics in nanomaterials is thus important both fundamentally and technologically.
5‐Azacytidine treatment for relapsed or refractory acute myeloid leukemia after intensive chemotherapy
Authors: Ivanoff Sarah , Gruson Berengere , Chantepie Sylvain P. , Lemasle Emilie , Merlusca Lavinia , Harrivel Veronique , Charbonnier Amandine , Votte Patrick , Royer Bruno , Marolleau Jean‐Pierre
Published: April 2013

Despite progress in the understanding of leukemia pathophysiology, the treatment of acute myeloid leukemia (AML) remains challenging. In patients with refractory or relapsed (R/R) AML, the prognosis is still poor and this group is targeted for new drug development. We reviewed the outcome of 47 patients, with R/R AML after at least one course of intensive chemotherapy, treated with 5‐azacytidine in three different French institutions. The overall response rate was 38% including complete remission in 21%, partial remission in 11%, and hematological improvement in 6% of cases. Median time to relapse was 6 (range, 1–39) months. Median overall survival was 9 months (not reached by responders vs. 4.5 months for nonresponders patients, P = 0.0001). Univariate analysis identified the absence of peripheral blood blasts and <20% bone marrow blasts as prognostic factors for both overall response and survival, but not age, ECOG/PS, type of AML, cytogenetic, status of the disease, number of previous lines of therapy, previous hematological stem cell transplantation, or white blood cells count. Bone marrow blasts percentage <20% was the only independent prognostic factor identified by multivariate analysis for overall response (P = 0.0013) and survival (P = 0.0324). Six patients in remission could proceed to an allogenic hematological stem cell transplantation. The drug‐related grade 3/4 adverse events were hematopoietic toxicities (38%) and infection (32%). In conclusion, this study suggests that a salvage therapy with 5‐azacytidine is an interesting option for patients with R/R AML after intensive chemotherapy. Prospective randomized studies are needed to demonstrate a superiority of this approach over others strategies. Am. J. Hematol. 88:601–605, 2013. © 2013 Wiley Periodicals, Inc.
Comparable long‐term outcomes after reduced‐intensity conditioning versus myeloablative conditioning allogeneic stem cell transplantation for adult high‐risk acute lymphoblastic leukemia in complete remission
Authors: Eom Ki‐Seong , Shin Seung‐Hwan , Yoon Jae‐Ho , Yahng Seung‐Ah , Lee Sung‐Eun , Cho Byung‐Sik , Kim Yoo‐Jin , Kim Hee‐Je , Min Chang‐Ki , Kim Dong‐Wook , Lee Jong‐Wook , Min Woo‐Sung , Park Chong‐Won , Lee Seok
Published: April 2013

The role of reduced‐intensity conditioning (RIC) in adult acute lymphoblastic leukemia (ALL) remains unclear because of the small sample size, short follow‐up duration, various regimens for conditioning and graft‐versus‐host disease (GVHD) prophylaxis, and the heterogeneity of selection criteria for transplantation. We compared long‐term outcomes of 60 consecutive RIC transplants (fludarabine plus melphalan) with 120 myeloablative conditioning (MAC) transplants (total body irradiation plus cyclophosphamide) for adult high‐risk ALL in first or second complete remission. All transplants received a uniform strategy of pretransplant chemotherapy and GVHD prophylaxis. Compared to MAC transplants, RIC transplants had older age (46 years vs. 33 years, P < 0.001) and higher proportions of transplantation using peripheral blood (93.3% vs. 13.3%; P < 0.001) but otherwise showed similar characteristics. After a median follow‐up of 67 months, RIC transplants showed comparable nonrelapse mortality (21.2% vs. 24.3%) and disease‐free survival (50.8% vs. 54.9%) to MAC transplants, although relapse risk was higher (34.2% vs. 26.4%; HR, 2.07; P = 0.019) in multivariate analysis. Other independent factors associated with better outcomes were the presence of chronic GVHD and transplantation in first complete remission. Interestingly, the negative impact of RIC on relapse risk was seen only for Philadelphia‐positive ALL transplants (32.7% vs. 19.6%; HR, 3.46; P = 0.020), while no difference was found between RIC and MAC for Philadelphia‐negative ALL transplants (35.0% vs. 32.1%; HR, 1.39; P = 0.429). RIC can be considered as a reasonable choice for providing a sufficient long‐term graft‐versus‐leukemia effect for adult high‐risk ALL patients ineligible for MAC. Am. J. Hematol. 88:634–641, 2013. © 2013 Wiley Periodicals, Inc.
Clinical and genetic study of a family with a paternally inherited 15q11–q13 duplication
Authors: Marini Carla , Cecconi Antonella , Contini Elisa , Pantaleo Marilena , Metitieri Tiziana , Guarducci Silvia , Giglio Sabrina , Guerrini Renzo , Genuardi Maurizio
Published: April 2013

Interstitial chromosome 15q11–q13 duplications are associated with developmental delay, behavioral problems and additional manifestations, including epilepsy. In most affected individuals the duplicated chromosome is maternally derived, whereas paternal inheritance is more often associated with a normal phenotype. Seizures have not been described in patients with paternal dup 15q11–q13. We describe a family with five individuals in three generations with a paternally‐inherited 15q11–q13 duplication, four of whom exhibited abnormal phenotypic characteristics, including seizures. The 18‐year‐old female proband presented with moderate intellectual disability, obesity, and epilepsy. Her brother manifested learning disability and behavioral problems. They both inherited the 15q11–q13 dup from their father who had a normal phenotype. Their paternal uncle and grandfather also had the duplication and were reported to have had seizures. Array‐CGH and MLPA analyses showed that the duplication included the TUBGCP5, CYFIP1, MKRN3, MAGEL2, NDN, SNRPN, UBE3A, ATP10A, GABRB3, GABRA5, GABRG3, and OCA2 genes. This report provides evidence for intrafamilial phenotypic variability of paternal dup 15q11–q13, ranging from normal to intellectual disability and seizures, and potentially expanding the phenotype of paternal 15q11–q13 interstitial duplications. © 2013 Wiley Periodicals, Inc.
Electrochemical grafting of 4‐phenoxybenzoic acid units onto oxidized carbon fibers as a first step for high temperature composites
Authors: Soulis Spyridon , Triantou Despina , Simitzis Johannis
Published: April 2013

The electropolymerization of 4‐phenoxybenzoic acid (4‐PBA) onto carbon fibers (CFs) was studied as a way to synthesize coated CFs with grafted poly(para‐phenyl ether ketone) (p‐PEK) and enhance their wettability by matrices such as PEK or PEEK. Since the pristine CFs were not electrochemically active enough, a proper electrochemical oxidation treatment using sulfuric acid was applied, capable of creating oxygen‐containing groups onto their surface. The groups formed in the oxidized CFs were electron acceptors and their amount was quasi‐quantitatively evaluated based on their ability to absorb dye from aqueous solutions. The graft electropolymerization of 4‐PBA onto the CFs electrode was achieved at anodic potentials using cyclic voltammetry (CV). The grafted coating had a thickness of up to 0.35 μm. The materials were characterized using FTIR, NMR, SEM, and TGA. A possible reaction mechanism is proposed, for the grafting of 4‐PBA units onto the carboxyl groups of the treated CFs. The coated CFs were more thermally stable compared to the treated CFs without grafting. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1466–1478, 2013
Preparation, characterization, and release properties of hydrogels based on hyaluronan for pharmaceutical and biomedical use
Authors: Roig‐Roig Ferran , Solans Conxita , Esquena Jordi , García‐Celma María José
Published: April 2013

Hyaluronic acid (HA) is a natural polysaccharide that is widely distributed in the human body. Its physicochemical properties and high biocompatibility make it a good candidate for biomedical and pharmaceutical uses. In the present work, we report HA‐based hydrogels that could be applied as drug delivery systems or as implants for the treatment of joint diseases. We use butanediol diglycidyl ether as a chemical crosslinker to obtain HA hydrogels. Using a new dissolution tester and ketoprofen (KP) as a model drug, we study the release properties of the hydrogels. We obtain homogeneous and transparent hydrogels with high strength and elasticity. The swelling ratio (SR) depends on the crosslinker concentration and pH of the medium. We also reveal differences between the release profile of KP from swollen and unswollen hydrogels. The characteristics and differences in KP release profiles depending on the SR suggest the possibility of obtaining controlled release from HA‐based hydrogels. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1377‐1382, 2013
Preparation and characterization of high‐performance poly(ether ether ketone) fibers with improved spinnability based on thermotropic liquid crystalline poly(aryl ether ketone) copolymer
Authors: Luan Jiashuang , Zhang Shuling , Zhang Mei , Geng Zhi , Wang Yang , Wang Guibin
Published: April 2013

High‐performance poly(ether ether ketone) (PEEK) fibers were prepared by melt‐spinning in the presence of thermotropic liquid crystalline poly(aryl ether ketone) copolymer (FPAEKLCP). The rheological and mechanical properties, birefringence, orientation, and crystallization of the resulting PEEK/FPAEKLCP fibers were characterized by using a melt flow indexer, capillary rheometer, single fiber electronic tensile strength tester, polarized light microscopy (PLM), and wide‐angle X‐ray diffraction (WAXD), respectively. The results indicate that the melt viscosity of PEEK significantly reduced by introducing FPAEKLCP, followed by the improvements in the spinnability and the quality of as‐spun fibers. The tensile properties of PEEK/FPAEKLCP fibers mainly depend on the content of FPAEKLCP, drawing temperature, drawing ratio, and annealing processes. Moreover, the tensile strength and modulus of PEEK/FPAEKLCP fibers are obviously higher than those of neat PEEK fibers under the same processing conditions. This should be attributed to an enhancement in the orientation and crystallization of PEEK compounded with FPAEKLCP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1406‐1414, 2013
A multifunctional luminescent europium photostabilizer based on a novel hindered amine ligand and phenanthroline
Authors: Wu Jiajie , Feng Jiachun
Published: April 2013

A novel hindered amine ligand, mono‐2,2,6,6‐tetramethyl‐4‐piperidyl‐succinate (MTPS), has been designed to chelate europium(III) ion with 1,10‐phenanthroline (Phen) as a coligand to prepare polymer photostabilizer. The luminescent property of the stabilizer and its efficiency of protecting polymer matrix from photodegradation have also been investigated. Under UV excitation, the stabilizer has red light emission in both ethanol solution and polypropylene (PP) matrix. The PP sheets containing the stabilizer display significantly improved photostability, which may be attributed to MTPS which scavenges radical, as well as Phen which makes the complex dissipate the absorbed ultraviolet light in a harmless manner. These preliminary results demonstrate that the introduction of the stabilizer can endow polymer matrices not only excellent photoluminescent properties but also improved photostability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1399‐1405, 2013
The biotransformation of oleuropein in rats
Authors: Lin Peiyan , Qian Weidong , Wang Xiaoying , Cao Li , Li Shaofen , Qian Tianxiu
Published: April 2013

A highly sensitive and specific LC‐MS/MS method was developed to investigate thein vivobio‐transformation of oleuropein in rat. Rat feces and urine samples collected after oral administration were determined by liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative‐ion mode. The assay procedure involves a simple liquid–liquid extraction of parent oleuropein and the metabolite from rat feces and urine with ethyl acetate. Chromatographic separation was operated with 0.1% formic acid aqueous and methanol in gradient program at a flow rate of 0.50 mL/min on an RP‐C18column with a total run time of 31 min. This method was successfully applied to simultaneous determination of oleuropein and its metabolites in rat feces and urine. De‐glucosylation, hydrolysis, oxygenation and methylation were found to comprise the major metabolic pathway of oleuropein in rat gastrointestinal tract and three metabolites were absorbed into the blood circulatory system within 24 h after oral administration. Copyright © 2013 John Wiley & Sons, Ltd.
5′‐Trityl‐Substituted Thymidine Derivatives as a Novel Class of Antileishmanial Agents: Leishmania infantum EndoG as a Potential Target
Authors: Casanova Elena , Moreno David , Gigante Alba , Rico Eva , Genes Carlos Mario , Oliva Cristina , Camarasa María‐José , Gago Federico , Jiménez‐Ruiz Antonio , Pérez‐Pérez María‐Jesús
Published: April 2013

Two series of 5′‐triphenylmethyl (trityl)‐substituted thymidine derivatives were synthesized and tested against Leishmania infantum axenic promastigotes and amastigotes. Several of these compounds show significant antileishmanial activity, with IC50 values in the low micromolar range. Among these, 3′‐O‐(isoleucylisoleucyl)‐5′‐O‐(3,3,3‐triphenylpropanoyl)thymidine displays particularly good activity against intracellular amastigotes. Assays performed to characterize the nature of parasite cell death in the presence of the tritylthymidines indicated significant alterations in mitochondrial transmembrane potential, an increase in superoxide concentrations, and also significant decreases in DNA degradation during the cell death process. Results point to the mitochondrial nuclease LiEndoG as a target for the action of this family of compounds.
The influence of adjuvant radiotherapy dose on overall survival in patients with resected pancreatic adenocarcinoma
Authors: Hall William A. , Colbert Lauren E. , Liu Yuan , Gillespie Theresa , Lipscomb Joseph , Hardy Claire , Kooby David A. , Prabhu Roshan S. , Kauh John , Landry Jerome C.
Published: April 2013

BACKGROUND

Adjuvant radiotherapy (A‐RT) for patients with resected pancreatic adenocarcinoma (PAC) is controversial. In the current study, the authors aim to determine whether there is an association between overall survival (OS) and A‐RT dose.

METHODS

National Cancer Data Base (NCDB) data were obtained for all patients who received A‐RT for resected PAC from 1998 through 2002. Univariate and multivariate survival analyses were performed along with Kaplan‐Meier estimates for A‐RT levels < 40 grays (Gy), 40 Gy to < 50 Gy, 50 Gy to < 55 Gy, and ≥ 55 Gy.

RESULTS

A total of 1385 patients met the inclusion criteria. The median age of the patients was 64 years (range, 29 years‐87 years). All patients underwent surgical resection and A‐RT with or without chemotherapy. A total of 231 patients were diagnosed with stage I disease, 273 were diagnosed with stage II disease, 734 were diagnosed with stage III disease, and 126 were diagnosed with stage IVA disease (according to the fifth edition of the American Joint Committee on Cancer); 21 were found to have an unknown stage of disease. The median A‐RT dose was 45 Gy (range, 1.63 Gy‐69 Gy). The median OS was 21 months (95% confidence interval [95% CI], 19 months‐23 months). On multivariate analysis, an A‐RT dose < 40 Gy (hazards ratio [HR], 1.30 [95% CI, 1.03‐1.66]; P = .031), an A‐RT dose of 40 Gy to < 50 Gy (HR, 1.17 [95% CI, 1.00‐1.37]; P = .05), and an A‐RT dose ≥ 55 Gy (HR, 1.44 [95% CI, 1.08‐1.93]; P = .013) predicted worse OS compared with the reference category of 50 Gy to < 55 Gy.

CONCLUSIONS

A‐RT doses of < 40 Gy, 40 Gy to < 50 Gy, and ≥ 55 Gy were found to be associated with an inferior OS. The dose of A‐RT delivered appears to influence OS and a prospective study evaluating the addition of optimally delivered A‐RT for patients with resected PAC is needed. Cancer 2013;119:2350–2357. © 2013 American Cancer Society.
Providing QoS strategies and cloud‐integration to web servers by means of aspects
Authors: Giunta Rosario , Messina Fabrizio , Pappalardo Giuseppe , Tramontana Emiliano
Published: April 2013

The main responsibilities of a web server are to listen from the communication channel and to prepare replies to requests. Additional responsibilities include adapting processing activities, for example, through scheduling or request filtering, so as to satisfy Quality of Service (QoS) requirements. Typical QoS‐related concerns address behavioural constraints (e.g. response time bounds, satisfiable by scheduling the most urgent requests first) and resource monitoring, for optimal use. Although such concerns are spread across several web server components, they should be handled separately from communication‐related ones, for the sake of modularity.

For this purpose, we advocate recourse to aspect‐oriented programming and illustrate it by showing how a QoS‐related layer can be smoothly superimposed on top of a well‐known, unmodified, web server Jigsaw. As part of the provided support, requests are assessed and partitioned into those that can be appropriately handled by using local resources and those needing further resources. For the latter requests, cloud‐based resources are gathered. Aspect‐orientation enables new QoS‐related code to be separated from web server modules so as to keep existing code unaltered, while runtime behaviour is modified with the measures needed to handle QoS concerns. Copyright © 2013 John Wiley & Sons, Ltd.
ERK differentially regulates Th17‐ and Treg‐cell development and contributes to the pathogenesis of colitis
Authors: Liu Houpu , Yao Suxia , Dann Sara M. , Qin Hongwei , Elson Charles O. , Cong Yingzi
Published: April 2013

Although the development of T‐cell subsets is mainly regulated by a master transcriptional regulator and phosphorylation of the STAT protein in response to distinct cytokine stimulation, accumulating data indicate that other signaling pathways are also involved in regulating or fine‐tuning T‐cell lineage commitment. In this report, we investigated the role of ERK, mitogen‐activated protein kinase (MAPK), in Th17 and Treg cell development. We demonstrate that blockade of ERK activation inhibited Th17‐cell development while upregulating Treg cells under Th17 polarization conditions. Inhibition of ERK decreased IL‐6 induction of RAR‐related orphan receptor γt but enhanced TGF‐β induction of Foxp3, and ERK inhibitor‐treated T cells under Th17 conditions possessed suppressive function in vitro because they produced more IL‐10 and TGF‐β and inhibited naïve T‐cell proliferation and IFN‐γ production at levels comparable with that of Treg cells. Furthermore, ERK inhibitor‐treated T cells under Th17 polarization conditions had a decreased potency to induce colitis in vivo. Collectively, our data demonstrated that the ERK pathway differentially regulates Th17‐ and Treg‐cell differentiation, and thus interfering with the ERK pathway could represent a therapeutic treatment for inflammatory bowel diseases and other Th17‐related autoimmune diseases.
Synthesis of Chiral Spirocyclopentenyl‐β‐lactams through Phosphane‐Catalyzed [3+2] Annulation of Allenoates with 6‐Alkylidenepenicillanates
Authors: Santos Bruna S. , Pinho e Melo Teresa M. V. D.
Published: April 2013

The first examples of phosphane‐catalyzed [3+2] annulation of allenoates to 6‐alkylidenepenicillanates leading to chiral spirocyclopentenyl‐β‐lactams are reported. The synthesis of this new type of β‐lactams involved the generation of either two or three consecutive stereogenic centers, including a quaternary chiral center. Although the reported methodology is highly diastereoselective, the regioselectivity is dependent on the nature of the methylenepenicillanate derivative and on the nature of the allenoate γ‐substituent.
A Genetically Encodable Ligand for Transfer Hydrogenation
Authors: Mayer Clemens , Hilvert Donald
Published: April 2013

Simple tripeptides are shown here to be versatile ligands for iridium‐catalyzed transfer hydrogenations affording large acceleration effects. A water‐soluble iridium complex with Gly‐Gly‐Phe, for example, catalyzes the reduction of diverse ketones, aldehydes, and imines by formate with turnover frequencies rivaling or outperforming those of established ligand systems. Regioselective reduction of coenzyme NAD+ to NADH illustrates the potential utility of this system for biotechnological applications. Because peptides are genetically encodable, they represent an attractive class of foldamer ligands for creating artificial metalloenzymes.
Toxic, cytotoxic, and genotoxic effects of a glyphosate formulation (Roundup®SL–Cosmoflux®411F) in the direct‐developing frogEleutherodactylus johnstonei
Authors: Meza‐Joya Fabio Leonardo , Ramírez‐Pinilla Martha Patricia , Fuentes-Lorenzo Jorge Luis
Published: April 2013

The aerial spraying of glyphosate formulations in Colombia to eradicate illegal crops has generated great concern about its possible impact on nontarget organisms, particularly amphibians. This study evaluated the toxic, cytotoxic, and genotoxic effects of a glyphosate formulation (Roundup®SL–Cosmoflux®411F) in the direct‐developing frogEleutherodactylus johnstoneiby estimating the median lethal application rate (LC50), median hemolytic application rate (HD50), and extent of DNA damage using the in vitro and in vivo Comet assays. Toxicity results indicated that the application rate [37.4 µg acid equivalent (a.e.)/cm2] equivalent to that used in aerial spraying (3.74 kg a.e./ha) is not lethal in male and female adult frogs, whereas neonates are highly sensitive. Glyphosate formulation at application rates above 5.4 µg a.e./cm2(in vivo) and concentrations above 95 µg a.e./mL (in vitro) showed clear evidence of cytotoxicity. In vivo and in vitro exposure ofE. johnstoneierythrocytes to the glyphosate formulation induced DNA breaks in a dose‐dependent manner with statistically significant values (P < 0.05) at all doses tested. DNA damage initially increased with the duration of exposure and then decreased, suggesting that DNA repair events were occurring during in vivo and in vitro exposures. These results are discussed from the perspective of possible ecotoxicological risks to anuran species from exposure to glyphosate formulation. Environ. Mol. Mutagen. 54:362–373, 2013. © 2013 Wiley Periodicals, Inc.
Ultrahigh Durable PtPd/C Nanowire Networks Catalyst Synthesized by Modified Phase Transfer Method for Methanol Oxidation
Authors: Chu Y.‐Y. , Wang Z.‐B. , Cao J. , Gu D.‐M. , Yin G.‐P.
Published: April 2013

A novel PtPd/C nanowire catalyst with interconnected network and fewer great grain boundaries has been successfully prepared by templateless and modified phase‐transfer method using cetyltrimethylammonium bromide as a capping in ethylene glycol solution by microwave‐assisted process. Its structure, composition, and morphology are characterized by X‐ray diffraction, energy dispersive analysis of X‐ray, and transmission electron microscopy, respectively. The electrochemical measurements demonstrate that the highly dispersed and uniform PtPd/C nanowire networks catalyst has a significantly higher electrocatalytic activity and durability for the methanol oxidation as compared to solid solution PtPd/C. The greatly improved durability of PtPd/C nanowire networks catalyst is mainly a consequence of the unique interconnected network structure with fewer grain boundaries, which provide more facile pathway for the electron transfer, and inhibit the particle growth and agglomeration, as well as prevent the particles embedded in the microporous of carbon support to enhance the Pt utilization.
Chromothripsis in Hodgkin lymphoma
Authors: Nagel Stefan , Meyer Corinna , Quentmeier Hilmar , Kaufmann Maren , Drexler Hans G. , MacLeod Roderick A. F.
Published: April 2013

Chromosomal rearrangements are common features of most cancers, where they contribute to deregulated gene expression. Chromothripsis is a recently described oncogenic mechanism whereby small genomic pieces originating from one chromosomal region undergo massive rearrangements in a single step. Here, we document chromothripsis in Hodgkin lymphoma (HL) cell lines by genomic profiling, showing alternating amplicons of defined chromosomal regions. In L‐1236 cells, fluorescent in situ hybridization analyses identified aberrations affecting amplified chromosomal segments that derived from the long arm regions of chromosomes 3 and 9 and that colocalized to a derivative chromosome 6, indicating the cataclysmic origin of this mutation. The ABL1 gene at 9q34 was targeted by these rearrangements leading to its overexpression in L‐1236 cells, correlating with pharmacological resistance to treatment with the kinase inhibitor dasatinib. Collectively, we identified and characterized chromothriptic rearrangements in HL cell lines to serve as models for analyzing this novel oncogenomic mechanism. © 2013 Wiley Periodicals, Inc.
The semidiurnal tide in the middle atmosphere of Mars
Authors: Kleinböhl Armin , John Wilson R. , Kass David , Schofield John T. , McCleese Daniel J.
Published: April 2013

Atmospheric thermal tides are global oscillations in atmospheric fields that are subharmonics of a solar day. While atmospheric tides on Earth are mainly relevant in the upper atmosphere, on Mars, they dominate temperature variations and winds throughout the atmosphere. Observations and model simulations to date have suggested that the migrating diurnal tide is the predominant mode in the Martian atmosphere, and that the semidiurnal tide is only relevant in the tropical middle atmosphere during conditions of high dust loading. New comprehensive observations by the Mars Climate Sounder in a geometry that allows coverage of multiple local times show that the semidiurnal tide is a dominant response of the Martian atmosphere throughout the Martian year. The maximum semidiurnal amplitude of ~ 16 K is found at southern winter high latitudes, which makes it the largest tidal amplitude observed in the Martian middle atmosphere outside of dust storm conditions. The semidiurnal tide can be successfully modeled due to recent advances of Mars General Circulation Models (MGCMs) that include the radiatively active treatment of water ice clouds. Tidal forcing occurs through absorption of radiation by aerosols and points to the vertical structure of dust and clouds and their radiative effects as being essential for our understanding of the thermal structure and the general circulation of the Martian atmosphere. As with terrestrial GCMs trying to quantify mechanisms affecting climate, future Mars modeling efforts will require microphysical schemes to control aerosol distributions, and vertically and temporally resolved measurements of temperature and aerosols will be essential for their validation.
Sensitivity of the oceanic carbon reservoir to tropical surface wind stress variations
Authors: Ridder N. N. , Meissner K. J. , England M. H.
Published: April 2013

The impact of variations of the Walker cell on the ocean carbon cycle is assessed using a coupled climate model. Idealized wind perturbations are investigated, with the trade winds increased/decreased by 10%, 20%, and 30%. A global‐mean reduction in oceanic carbon storage is found for increased equatorial easterlies, while moderately decreased trade winds give increased uptake. There is a nonlinear response to weakened tropical winds due to Pacific Ocean biological pump changes; with reduced nutrient upwelling resulting in decreased biological activity and remineralization in the deep ocean. This partially offsets the increased carbon uptake due to weaker trade winds. The overall change in net carbon storage reaches −26.2 PgC (12 ppm) in the 30% increase case and 4.2 PgC (−2 ppm) in the 20% decrease cases. Regional dissolved inorganic carbon (DIC) changes reach −3.3 mmol m−3 (2.1 mmol m−3) in the 10% decrease (increase) case. Gradually increasing wind perturbations give a similar pattern of DIC response to the full equilibrated solution.
USING IN‐LINE RESERVOIR OPERATIONAL STRATEGY TO IMPROVE DEZ MAIN IRRIGATION CANAL PERFORMANCE
Authors: Hashemy S. M. , Monem M. J. , Isapoor S. , van Overloop P. J.
Published: April 2013

In this study an in‐line storage strategy is applied to improve the existing operational performance of an upstream‐controlled 13‐pool irrigation canal. Three pools in the upstream, middle and downstream sections of the main canal are considered as in‐line reservoirs. Decentralized proportional‐integral (PI) controllers are designed to regulate their upstream water levels based on a mixed control method. Each regulator is coupled to its upstream in‐line reservoir. The objectives of the controlled system are keeping the upstream water level of each regulator at the target levels; reducing delay times of flow travelling in the canal and compensating for mismatches between upstream supply and downstream demands. Existing and proposed operational methods are compared, using the hydrodynamic modelling package Sobek, considering a severe and sudden increasing– decreasing flow condition. In this case study, the water level profiles and controller performance indicators imply that in‐line storage in the main canal decreases water level deviations in most of the pools in the range of 24–57 % in comparison with the current operation. Moreover, using in‐line reservoirs decreases the delay times especially in the downstream part of the canal. Copyright © 2013 John Wiley & Sons, Ltd.
Hepatoprotective effects of syringin on fulminant hepatic failure induced by D‐galactosamine and lipopolysaccharide in mice
Authors: Gong Xia , Zhang Li , Jiang Rong , Wang Chang‐Dong , Yin Xin‐Ru , Wan Jing‐Yuan
Published: April 2013

The prognosis for fulminant hepatic failure (FHF) still remains extremely poor with a high mortality and, therefore, better treatments are urgently needed. Syringin, a main active substance isolated from Eleutherococcus senticosus, has been reported to exhibit immunomodulatory and anti‐inflammatory properties. In this study, we investigated the effects and underlying mechanisms of syringin on lipopolysaccharide (LPS) and D‐galactosamine (D‐GalN)‐induced FHF in mice. Mice were administered syringin (10, 30 and 100 mg kg–1, respectively) intraperitoneally (i.p) 30 min before LPS/D‐GalN then mortality and liver injury were evaluated subsequently. We found that syringin dose‐dependently attenuated LPS/D‐GalN‐induced FHF, as indicated by reduced mortality, inhibited aminotransferase and malondialdehyde (MDA) content, an increased glutathione (GSH) concentration and alleviated pathological liver injury. In addition, syringin inhibited LPS/D‐GalN‐induced hepatic caspase‐3 activation and hepatocellular apoptosis, myeloperoxidase (MPO) activity and intercellular adhesion molecule‐1 (ICAM‐1) expression, as well as hepatic tissues tumor necrosis factor‐alpha (TNF‐α) production and NF‐κB activation in a dose‐dependent manner. These experimental data indicate that syringin might alleviate the FHF induced by LPS/D‐GalN through inhibiting NF‐κB activation to reduce TNF‐α production. Copyright © 2013 John Wiley & Sons, Ltd.
Synergistic effect between bioactive glass foam and a perfusion bioreactor on osteogenic differentiation of human adipose stem cells
Authors: Silva A. R. P. , Paula A. C. C. , Martins T. M. M. , Goes A. M. , Pereria M. M.
Published: April 2013

Tissue engineering is a multidisciplinary science that combines a structural scaffold and cells to form a construct able to promote regeneration of injured tissue. Bioactive glass foam produced by sol–gel is an osteoinductive material with a network of interconnected macropores necessary for cell colonization. The use of human adipose‐derived stem cell (hASC) presents advantages as the potential for a large number of cells, rapid expansion in vitro and the capability of differentiating into osteoblasts. The use of a bioreactor in three‐dimensional cell culture enables greater efficiency for cell nutrition and application of mechanical forces, important modulators of bone physiology. The hASC seeded in a bioactive glass scaffold and cultured in osteogenic Leibovitz L‐15 medium in a bioreactor with a flow rate of 0.1 mL min−1 demonstrated a significant increase in cell proliferation and viability and alkaline phosphatase (ALP) activity peak after 14 days. The immunofluorescence assay revealed an expression of osteopontin, osteocalcin and type I collagen from 7 to 21 days after culture. The cells changed from a spindle shape to a cuboidal morphology characteristic of osteoblasts. The polymerase chain reaction assay confirmed that osteopontin, osteocalcin, and ALP genes were expressed. These results indicate that hASCs differentiated into an osteogenic phenotype when cultured in bioactive glass scaffold, osteogenic Leibovitz L‐15 medium and a perfusion bioreactor. Therefore, these results highlight the synergism between a bioactive glass scaffold and the effect of perfusion on cells and indicate the differentiation into an osteogenic phenotype. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 818–827, 2014.
Biodegradable weft‐knitted intestinal stents: Fabrication and physical changes investigation in vitro degradation
Authors: Li Gang , Li Yi , Lan Ping , Li Jiashen , Zhao Zheng , He Xiaowen , Zhang Jing , Hu Hong
Published: April 2013

Biodegradable stents can alleviate intestinal obstruction and stenosis in patients. The objective of this study was to develop a biodegradable polydioxanone (PDO) stent using weft‐knitting technology and then investigate its biodegradation behaviors in vitro. PDO monofilament with linear density of 100 ± 10 tex was knitted into a tubular stent using a tubular weft‐knitting machine. The physical and mechanical properties were evaluated according to the British standard BS EN 13895:2003 and ISO 7198:1998. The biodegradation behaviors of PDO weft‐knitted stent in a phosphate buffer solution (pH = 6.8 ± 0.2, 37 ± 0.5°C) were then investigated. The results showed that the stent maintained more than 60% of its original radial force above 12 weeks. During the 16 weeks of degradation, weight, crystallization, and pH change indicated the degradation medium was diffused into the chain segments of low molecular weight due to the rupture of ester bonds in the monofilament. Fourier transform infrared spectroscopy results demonstrated that the chemical structure of PDO polymer is stable during the in vitro degradation. In conclusion, this biodegradable stent can find valuable applications in treatment of intestinal obstruction and stenosis clinically. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 982–990, 2014.
Retrieving cirrus microphysical properties from stellar aureoles
Authors: DeVore J. G. , Kristl J. A. , Rappaport S. A.
Published: April 2013

The aureoles around stars caused by thin cirrus limit nighttime measurement opportunities for ground‐based astronomy, but can provide information on high‐altitude ice crystals for climate research. In this paper we attempt to demonstrate quantitatively how this works. Aureole profiles can be followed out to ~0.2° from stars and ~0.5° from Jupiter. Interpretation of diffracted starlight is similar to that for sunlight, but emphasizes larger particles. Stellar diffraction profiles are very distinctive, typically being approximately flat out to a critical angle followed by gradually steepening power‐law falloff with slope less steep than −3. Using the relationship between the phase function for diffraction and the average Fourier transform of the projected area of complex ice crystals, we show that defining particle size in terms of average projected area normal to the propagation direction of the starlight leads to a simple, analytic approximation representing large‐particle diffraction that is nearly independent of crystal habit. A similar analytic approximation for the diffraction aureole allows it to be separated from the point spread function and the sky background. Multiple scattering is deconvolved using the Hankel transform leading to the diffraction phase function. Application of constrained numerical inversion to the phase function then yields a solution for the particle size distribution in the range between ~50 μm and ~400 μm. Stellar aureole measurements can provide one of the very few, as well as least expensive, methods for retrieving cirrus microphysical properties from ground‐based observations.
Determination of the piston velocity for water‐air interfaces using flux chambers, acoustic Doppler velocimetry, and IR imaging of the water surface
Authors: Gålfalk Magnus , Bastviken David , Fredriksson Sam , Arneborg Lars
Published: April 2013

The transport of gasses dissolved in surface waters across the water‐atmosphere interface is controlled by the piston velocity (k). This coefficient has large implications for, e.g., greenhouse gas fluxes but is challenging to quantify in situ. At present, empirical k‐wind speed relationships from a small number of studies and systems are often extrapolated without knowledge of model performance. This study compares empirical k estimates from flux chamber and surface water gas concentration measurements (chamber method), eddy cell modeling and dissipation rates of turbulent kinetic energy (dissipation method), and a surface divergence method based on IR imaging, at a fetch limited coastal observation station. We highlight strengths and weaknesses of the methods, and relate measured k values to parameters such as wave height, and surface skin velocities. The chamber and dissipation methods yielded k values in the same order of magnitude over a 24 h period with varying wind conditions (up to 10 m s−1, closest weather station) and wave heights (0.01–0.30 m). The surface divergence method most likely did not resolve the small turbulent eddies that cause the main divergence. Flux chamber estimates showed the largest temporal variability, with lower k values than the dissipation method during calm conditions, where the dissipation method failed as waves and instrument noise dominated over the turbulence signal. There was a strong correspondence between k from chambers, the RMS of surface velocities from IR imaging, and wave height. We propose a method to estimate area integrated values of k from wave measurements.
The benefits of photodynamic therapy on vertebral bone are maintained and enhanced by combination treatment with bisphosphonates and radiation therapy
Authors: Lo Victor C. K. , Akens Margarete K. , Wise‐Milestone Lisa , Yee Albert J. M. , Wilson Brian C. , Whyne Cari M.
Published: April 2013

Photodynamic therapy (PDT) has been shown to ablate tumors within vertebral bone and yield short‐term improvements in vertebral architecture and biomechanical strength, in particular when combined with bisphosphonate (BP) treatment. Longer‐term outcomes of PDT combined with current treatments for skeletal metastases are essential to understand its therapeutic potential. The objective of this study is to evaluate the response of vertebrae to PDT after a longer (6‐week) time period, alone and combined with previous BP or radiation treatment (RT). Sixty‐three female rnu/rnu rats were randomized to six treatment groups: untreated control, BP‐only, RT‐only, PDT‐only, combined BP + PDT and combined RT + PDT. L2 vertebrae were structurally analyzed through µCT‐based analysis, axial compressive load‐to‐failure testing and histological analysis of morphology, osteoid formation and osteoclast activity. Combined BP + PDT treatment yielded the largest improvements in bone architecture with combined RT + PDT treatment yielding similar findings, but of a lesser magnitude. Mechanically, ultimate force and stress were correlated to stereological parameters that demonstrated a positive structural effect from combinatory treatment. Increased osteoid formation was observed in both combination therapies without any significant differences in osteoclast activity. Overall, multimodality treatment demonstrated a sustained positive effect on vertebral structural integrity, motivating PDT as a minimally‐invasive adjuvant treatment for spinal metastases. © 2012 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1398–1405, 2013