bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term survival after esophagectomy for early esophageal squamous cell carcinoma in Linxian, China
Authors: Song Philip I. , Liang Hao , Fan Jin‐Hu , Wei Wen‐Qiang , Wang Guo‐Qing , Qiao You‐Lin
Published: April 2011

Background and Objectives

Linxian in Henan Province, China, has among the highest rates of esophageal cancer worldwide. Little is known about long‐term survival after esophagectomy for early neoplastic lesions found during early detection screening. A long‐term survival analysis was performed for 315 patients from Linxian who received esophagectomy for early esophageal squamous cell carcinoma (ESCC).

Methods

Cases that received esophagectomy for early ESCC were age‐ and gender‐matched with two healthy controls, and Kaplan–Meier survival analyses were performed for both groups.

Results

Ten‐year survival was 77% for cases and 64% for controls, and this difference was not statistically significant (P = 0.33). There were no significant differences in survival based on age or gender (P > 0.05). Cases with ESCC in situ had significantly better survival than cases with invasive ESCC (P = 0.035).

Conclusions

Survival of cases who received esophagectomy for early ESCC was not significantly different from survival of age‐ and gender‐matched controls. Early intervention probably improved survival rates for these patients who otherwise would most likely have developed advanced esophageal carcinoma. Early screening and intervention are highly relevant in areas with a high risk of esophageal cancer such as Linxian, China. J. Surg. Oncol. 2011;104:176–180. © 2011 Wiley‐Liss, Inc.
Experimental design applied to the analysis of volatile compounds in apple juice by headspace solid‐phase microextraction
Authors: Llorente Daniel Díaz , Abrodo Pilar Arias , de la Fuente Enrique Dapena , Álvarez Jaime González , Álvarez Maria Dolores Gutiérrez , Gomis Domingo Blanco
Published: April 2011

A simple and fast method based on solid‐phase microextraction (SPME) followed by fast gas chromatography (Fast GC) has been developed for the analysis of volatile compounds in Asturian apple juices employed in the cider production. Three different fiber coatings have been checked (PDMS, PDMS‐DVB and CAR‐PDMS) and PDMS‐DVB has been presented to be the most suitable one. Experimental design has been employed in the optimization of extraction factors and robustness assessment. The use of Fast GC allowed the separation of 14 compounds (esters, aldehydes and alcohols) in approximately 4 min, clearly reducing the analysis time when compared to conventional GC. Good linearity, recoveries and repeatability of the solid‐phase microextraction were obtained with r2 values, recoveries and relative standard deviations ranging from 0.9822 to 0.9998, 83.2 to 109.8% and 0.5 to 11.7%, respectively, using standard solution.
Mixed aqueous solutions as dilution media in the determination of residual solvents by static headspace gas chromatography
Authors: D'Autry Ward , Zheng Chao , Wolfs Kris , Yarramraju Sitaramaraju , Hoogmartens Jos , Van Schepdael Ann , Adams Erwin
Published: April 2011

Static headspace (HS) sampling has been commonly used to test for volatile organic chemicals, usually referred to as residual solvents (RS) in pharmaceuticals. If the sample is not soluble in water, organic solvents are used. However, these seriously reduce the sensitivity in the determination of some RS. Here, mixed aqueous dilution media (a mixture of water and an organic solvent like dimethyl formamide, dimethyl sulfoxide or dimethyl acetamide) were studied as alternative media for static HS‐gas chromatographic analysis. Although it has been known that mixed aqueous dilution media can often improve sensitivity for many RS, this study used a systematic approach to investigate phase volumes and the organic content in the HS sampling media. Reference solutions using 18 different class 1, 2 and 3 RS were evaluated. The effect of salt addition was also studied in this work. A significant increase in the peak area was observed for all RS using mixed aqueous dilution media, when compared with organic solvents alone. Matrix effects related to the mixed aqueous dilution media were also investigated and reported. Repeatability and linearity obtained with mixed aqueous dilution media were found to be similar to those observed with pure organic solvents.
Validated dispersive liquid–liquid microextraction for analysis of organophosphorous pesticides in water
Authors: Alves Andreia Cristina Henriques , Gonçalves Maria Margarida Pontes Boavida , Bernardo Maria Manuel Serrano , Mendes Benilde Simões
Published: April 2011

Dispersive liquid–liquid microextraction (DLLME) combined with gas chromatography and mass spectrometry (GC‐MS) was applied to the determination of six organophosphorous pesticides (OPPs) in water samples. The analytes included in this study were prophos, diazinon, chlorpyrifos methyl, methyl parathion, fenchlorphos and chlorpyrifos. Several extraction and dispersion solvents were tested for dispersive liquid–liquid microextraction of these analytes and the best results were obtained using chloroform as extraction solvent and 2‐propanol as dispersion solvent. Calibration curves of the analytes in water samples were constructed in the concentration range from 100 to 1100 ng/L for prophos, diazinon and methyl parathion and in the range from 100 to 1000 ng/L for chlorpyrifos methyl, fenchlorphos and chlorpyrifos. Limits of detection (LODs) were in the range of 1.5–9.1 ng/L and limits of quantification (LOQs) were in the range of 5.1–30.3 ng/L, below the maximum admissible level for drinking water. Relative standard deviations (RSDs) were between 6.5 and 10.1% in the concentration range of 100–1000 ng/L. The relative recoveries (%RRs) of tap, well and irrigation water samples fortified at 800 ng/L were in the range of 46.1–129.4%, with a larger matrix effect being detected in tap water.
Antibiotic prophylaxis in uncontaminated neck dissection
Authors: Man Li‐Xing , Beswick Daniel M. , Johnson Jonas T.
Published: April 2011

Objectives/Hypothesis:

To describe our institution's experience with antibiotic prophylaxis in uncontaminated neck dissection and to identify risk factors associated with postoperative wound infection.

Study Design:

Retrospective chart review.

Methods:

Between April 2006 and June 2010, 244 patients underwent 273 uncontaminated neck dissections at a single tertiary care center. Patient factors, operative details, and postoperative complications were recorded. Patients were separated into three groups: no prophylactic antibiotics, intraoperative antibiotics only, and intra‐ and postoperative antibiotics.

Results:

Wound infections occurred after nine of the 273 procedures (3.3%). All of the wound infections occurred in patients receiving intraoperative antibiotics only (4 of 157) or intra‐ and postoperative antibiotics (5 of 75) (P = .11). The development of a wound infection was not associated with age, sex, history of tobacco and alcohol use, history of head and neck surgery, or history of radiation or chemotherapy. Wound infection was independently associated with operative time (adjusted odds ratio, 1.35; 95% confidence interval, 1.07–1.71; P = .011, for each additional hour of surgery) and with radical or extended neck dissection (adjusted odds ratio, 14.61; 95% confidence interval, 2.37–90.01, P = .004).

Conclusions:

Our data did not support the use of antibiotic prophylaxis in routine uncontaminated neck dissection. Prophylactic antibiotics, however, may be indicated for more extensive lymphadenectomy procedures.
Temporal bone histopathology in neurofibromatosis type 2
Authors: Nam Sung‐Il , Linthicum Fred H. , Merchant Saumil N.
Published: April 2011

Objectives/Hypothesis:

To describe the histopathologic findings in the temporal bone in patients with neurofibromatosis type 2 (NF2). The literature contains limited data on otopathology of NF2.

Study Design:

Basic science study.

Methods:

Twenty‐six temporal bones from 16 patients with NF2 were examined by light microscopy. The diagnosis of NF2 was made on the basis of bilateral cochleovestibular schwannomas. Clinical information was obtained from review of the medical records.

Results:

The tumors were multicentric in origin in 19 of 26 (73%) ears. Typically, tumors were seen arising within the internal auditory canal and from various locations within the labyrinth. The majority of schwannomas showed high cellularity with involvement of the labyrinth. Most cases showed significant degrees of degeneration of sensory and neural elements within the cochlea. Fusion tumors were sometimes seen as a result of a schwannoma merging with an adjacent meningioma. Fifteen of 26 (58%) ears showed facial nerve involvement by schwannoma.

Conclusions:

Cochleovestibular schwannomas in NF2 are aggressive neoplasms; they are often multicentric and demonstrate a propensity to involve the labyrinth. There is often associated secondary degeneration within the cochlea. These features make total removal of these tumors and their removal with preservation of hearing more difficult than with sporadic unilateral cochleovestibular schwannoma.
Management of complex tympanojugular paragangliomas including endovascular intervention
Authors: Sanna Mario , Shin Seung‐Ho , De Donato Giuseppe , Sivalingam Shailendra , Lauda Lorenzo , Vitullo Francesca , Piazza Paolo
Published: April 2011

Objectives/Hypothesis:

To identify complex cases of tympanojugular paraganglioma (TJP) and to analyze their management and surgical outcome. To present strategy and guidelines on how to deal with the perioperative complicating factors.

Study Design:

Retrospective analysis.

Methods:

We retrospectively studied 212 TJP patients to identify the complex cases and analyzed their management and surgical outcome. The criteria for complex TJP are: 1) very large size; 2) large intradural extension (IDE); 3) extension to the cavernous sinus, foramen magnum, and clivus; 4) significant involvement of the internal carotid artery (ICA); 5) a solitary ICA on the lesion side; 6) involvement of the vertebral artery; 7) dominant or unilateral sigmoid sinus on the lesion side; 8) bilateral or multiple paragangliomas; and 9) recurrence.

Results:

Sixty patients were classified as complex. Forty‐five patients had tumors with IDE. Twenty patients with tumor involving ICA underwent preoperative endovascular intervention. Two patients had a solitary ICA and two others unilateral sigmoid sinus on the lesion side. Thirteen patients had multicentric tumors, and three patients had bilateral ones. The main procedure was the infratemporal fossa approach type A. Total removal was achieved in 46 patients, and five of them experienced recurrence.

Conclusions:

It is essential to carefully investigate the hemodynamics of the brain in planning surgery. A proper preoperative endovascular intervention facilitates gross total tumor removal. In bilateral paragangliomas, lower cranial nerves' function should be preserved at least unilaterally. Staged removal is recommended for a tumor with a large intradural component.
Robotic facelift thyroidectomy: II. Clinical feasibility and safety
Authors: Terris David J. , Singer Michael C. , Seybt Melanie W.
Published: April 2011

Objectives:

A number of remote access thyroidectomy techniques have been described in the last several years. These approaches are technically challenging, can be performed on only a limited patient population, and have been associated with significant complications. We describe a novel robotic facelift approach for thyroidectomy and report our initial clinical experience.

Design:

Planned analysis of a prospectively maintained database with institutional review board approval.

Methods:

Robotic facelift thyroidectomy (RFT) was performed on all patients. Demographic and surgical data were obtained and analyzed. Data collected included patient age, gender, body mass index (BMI), pathology, complications, and duration of surgery.

Results:

A total of 18 RFT procedures were undertaken in 14 patients. There were 13 females and 1 male, with a mean age of 33.7 ± 18.1 years (range: 12–70). The mean BMI was 26.9 ± 4.5. The procedures included 13 lobectomies, one bilateral thyroidectomy, and 3 completion thyroidectomies. All but the first procedure was performed on an outpatient basis without use of a drain. There were no conversions to open surgery, no permanent nerve injuries, and no cases of hypoparathyroidism. Operative times ranged from 97 to 193 minutes.

Conclusions:

RFT is a feasible remote access thyroidectomy approach. It appears from our initial experience that it may be performed in a safe and reproducible manner without a drain and on an outpatient basis. Additional clinical experience is warranted to further validate this technique.
Evaluation of the hybrid‐L24® electrode using microcomputed tomography
Authors: Driscoll Colin L.W. , Carlson Matthew L. , Fama Anthony F. , Lane John I.
Published: April 2011

Objectives/Hypothesis:

To compare electrode array position, and depth of insertion of the Cochlear Hybrid‐L24® electrode array following traditional cochleostomy and round window (RW) insertion.

Study Design:

Prospective cadaveric temporal bone study.

Methods:

Ten cadaveric temporal bones were implanted with the Hybrid‐L24® electrode array; half were introduced through a RW approach, whereas the other half were inserted through a traditional scala tympani cochleostomy. A micro‐CT scanner was then used to evaluate electrode position, intracochlear trauma, and depth of insertion.

Results:

All electrodes were inserted into the scala tympani without significant resistance. No electrodes demonstrated tip fold‐over or through‐fracturing of the osseous spiral lamina, basilar membrane, or spiral ligament. The average angular depth of insertion for all 10 electrodes was 252.4°. Compared to cochleostomy insertions, electrodes inserted through the RW more commonly acquired a proximal perimodiolar orientation, followed a more predictable course, and less commonly contacted critical soft tissue structures.

Conclusions:

The results of this study demonstrate that the Hybrid‐L24® electrode can be successfully inserted using a RW or traditional cochleostomy technique with minimal intracochlear trauma. Our data also suggests that with this model, RW insertions may provide particular advantages with respect to hearing preservation over the traditional cochleostomy approach. Laryngoscope, 2011
An imprecise goal programming approach for modeling design team's preferences in quality function deployment planning process
Authors: Cherif Mohamed Sadok , Aouni Belaïd , Chabchoub Habib
Published: April 2011

The Quality Function Deployment (QFD) is an approach that facilitates designing product by analyzing and projecting the Customer's Needs (CNs) in the Engineering Characteristics (ECs) of a product. The aim of QFD planning process is to determine the target levels for ECs of a product that achieve high level of overall customers' satisfaction. However, integrating design team's preferences in this preliminary stage of product design could make the design more realistic and could also avoid unfeasibility in posterior phases of the product development processes. Moreover, this process is performed within an imprecise environment, and more than one factor must be taken into account in determining targets levels of ECs; especially, the limited resources and increased market competition. This paper presents an imprecise goal programming approach to determine the best aspiration levels of ECs in QFD planning process. Based on benchmarking data of ECs, the concept of satisfaction functions will be utilized to integrate explicitly the design team's preferences and incorporate the competitive analysis of target market into the modelling and solution processes. In addition, the relationships linking CNs and ECs and the ECs to each other are integrated by functional relationships. The proposed approach will be illustrated through an example of product development of an emulsification dynamite packing machine. Copyright © 2011 John Wiley & Sons, Ltd.
Assessing the effectiveness of ethics legislation in influencing parliamentary attitudes toward corruption: a cross national comparison between the UK and Ireland
Authors: Smith Gillian
Published: April 2011

The 1990s saw political corruption emerge as a priority for political parties in Ireland. The scandals that emerged from a succession of tribunals created the impetus for change. New legislation was introduced by the Rainbow Coalition (1994–1997) in an effort to prevent corruption, creating clearly defined rules concerning funding of politicians and political expenditure during elections. The legislation also facilitated increased transparency surrounding political and bureaucratic decision making, which limits the scope for corrupt activity. There is currently a call from several political parties, from the Public Relations Institute of Ireland, and from others, to introduce legislation concerning the position of lobbyists in the Irish policy‐making process. Some see a register of lobbyists as a means to increase transparency and improve the public perception of lobbyists. To assess whether legislation can have an effect on the interplay of politicians and lobbyists, it is helpful to examine whether the ethics legislation that was introduced in the 1990s has had any effect on legislative attitudes to corruption. This effect of the ethics legislation was assessed by surveying legislators' attitudes to corrupt scenarios and comparing them to UK legislators' attitudes. This was carried out by creating a typology of Oireachtas Members similar to previous UK studies. A cross national comparison of legislative attitudes suggests that Irish legislators' attitudes are shaped by their constituency role. This has a stronger influence on them than the ethics legislation. The ethics legislation has not been very effective and it has not created a political culture that is intolerant of corruption. Similarly it may take more than legislation to alter the perceptions of lobbyists. Copyright © 2011 John Wiley & Sons, Ltd.
Lobbying regulation in Ireland: some thoughts from the international evidence
Authors: Murphy Gary , Hogan John , Chari Raj
Published: April 2011

Throughout the liberal democratic world, the practice of lobbying governments and policy makers is considered integral to the process of policy formulation. Lobbying in Ireland has come to the fore of public policy debates given the catastrophic collapse of the Irish economy since late 2008 and the role played by lobbyists in contemporary Irish politics. This article offers the results of one of the first significant questionnaires on lobbying regulation given to politicians, lobbyists and administrators in the Republic of Ireland. The aim of this article is to present Irish policy makers with a range of options to consider in relation to devising a system of lobbying regulation to promote transparency. We present insights into international best practice in terms of lobbying regulations so that Irish policy makers can reach informed decisions when considering this matter. Copyright © 2011 John Wiley & Sons, Ltd.
Tobacco smuggling: case study of a pro‐health lobbying initiative
Authors: Jennings Lorna
Published: April 2011

The Irish Cancer Society (ICS) is an organization with significant credibility in the health arena. As the national cancer charity, the Society since its foundation in 1963 has played a key role in the development of cancer policy in Ireland. With regard to areas outside the remit of health however, it became very clear during the December 2008 Pre‐Budget lobby that further progress on the issue of tax on tobacco would not be made and proposals not taken seriously, if the Society remained exclusively in the health arena. It was clear that the ICS needed to move into the fiscal space and engage on an economic level to gain traction with political audiences. To achieve this engagement, the Society needed to expand its knowledge and capacity around the issue. The process of economic engagement started with the April 2009 Pre‐Budget submission by economist Jim Power. Immediately, there was an indication that the process of engaging had begun when the Government responded with the argument about smuggling being responsible for high prices. This was a greater level of debate on the price issue than had been previously achieved and began a process with the government and the political audience that was far more in‐depth than the Society had ever taken part in. The lobbying campaign conducted by the Society brought the argument to the political audience and educated key stakeholders in addition to countering opposition arguments. In terms of the public affairs agenda of the ICS' successfully moving into the economic space, being taken seriously in that space, was and is a hugely significant achievement for a health charity. Copyright © 2011 John Wiley & Sons, Ltd.
Making a difference? The effects of Teach For America in high school
Authors: Xu Zeyu , Hannaway Jane , Taylor Colin
Published: April 2011

Teach For America (TFA) selects and places graduates from the most competitive colleges as teachers in the lowest‐performing schools in the country. This paper is the first study that examines TFA effects in high school. We use rich longitudinal data from North Carolina and estimate TFA effects through cross‐subject student and school fixed effects models. We find that TFA teachers tend to have a positive effect on high school student test scores relative to non‐TFA teachers, including those who are certified in field. Such effects offset or exceed the impact of additional years of experience and are particularly strong in science. © 2011 by the Association for Public Policy Analysis and Management.
Klinische Anwendung der Gentherapie. Bisherige Erfahrungen und Zukunft
Authors: Langer Barbara , Cichutek Klaus
Published: April 2011

Gentherapie = Therapie mit Genen: Wie kann das denn funktionieren? Gene sind ja in jeder unserer Körperzellen und im Erbgut der Keimzellen befinden sich die Gene, die wir vererben. Sind diese betroffen? So oder ähnlich dürften nicht nur die Laien, sondern auch die Forscher reagiert haben, als sie Ende der 1980er Jahre in den USA und Anfang der 1990er Jahre in Deutschland von den ersten klinischen Gentherapievorhaben hörten.
Gentherapie der septischen Granulomatose: Chancen und Risiken. Der Weg zur erfolgreichen Therapie einer angeborenen Immundefizienz
Authors: Schwäble Joachim , Schultze‐Strasser Stephan , Stein Stefan , Grez Manuel
Published: April 2011

Im Jahre 2004 sind am Universitätsklinikum Frankfurt zwei Patienten mit X‐CGD gentherapeutisch behandelt worden. Nach einer initialen Phase mit Nachweis ausreichender Mengen Oxidase‐positiver Zellen im Blut der Patienten und einer deutlichen klinischen Besserung vorbestehender Infektionsherde kam es zu einem Verlust der Transgenexpression durch epigenetische Veränderungen des viralen Promotors. Ferner entwickelte sich durch Insertionsmutagenese eine klonale Expansion in der Hämatopoese und schließlich ein myelodysplastisches Syndrom mit Monosomie 7 bei beiden Patienten. In der Zusammenschau mit anderen Gentherapiestudien zur X‐CGD zeigt sich, dass bislang ein langanhaltendes Engraftment funktionierender genkorrigierter Zellen nur im Zusammenhang mit einer Insertionsmutagenese beobachtet wurde. Zukünftige gentherapeutische Strategien zur Behandlung der X‐CGD müssen das Risiko einer Insertionsmutagenese minimieren und gleichzeitig die Effektivität des Engraftments genkorrigierter Zellen steigern. Dies soll durch den Einsatz von SIN‐Vektoren sowie einer Intensivierung der Konditionierung der Patienten erreicht werden.
Personalisierte Therapie der HIV‐Infektion
Authors: Winckler Thomas
Published: April 2011

Für die Suche nach Impfstoffen oder neuen Therapien gegen die HIV‐Infektion ist der rasche Wandel des Virus die größte Herausforderung. Eine neue Strategie könnte die Therapie mit körpereigenen Immunzellen sein, die ex vivo gegen das “persönliche” Virus scharf gemacht werden.
Neue Malariawirkstoffe: Screening gegen den kompletten Parasiten oder Target‐basiert – welcher Weg ist der richtige?
Authors: Schlitzer Martin
Published: April 2011

Malaria ist immer noch eine der bedeutendsten Infektionskrankheiten der Welt. Der Wert der momentan zur Verfügung stehenden Malariatherapeutika wird durch zwei Faktoren begrenzt: Resistenz und Toxizität.
Longitudinal monitoring of the safety of drugs by using a web‐based system: the case of pregabalin
Authors: Härmark Linda , van Puijenbroek Eugene , van Grootheest Kees
Published: April 2011

Purpose

Information about the time course of adverse drug reactions (ADRs) is often lacking. If this information would be available, it could help increase patient's adherence to drugs when experiencing an ADR. The aim of this study was to demonstrate how a web‐based intensive monitoring system using the patient as a source of information can be used to gather longitudinal safety data of a drug. In this study, pregabalin was used as an example.

Methods

First‐time users of pregabalin were approached in Dutch pharmacies between 1 August 2006 and 31 January 2008. After online registration, patients received questionnaires by email 2 weeks, 6 weeks, 3 months and 6 months after the start of the drug use. Data on patient characteristics, drug use and ADRs were collected and analysed.

Results

A total of 1373 patients registered for the pregabalin study. Of these patients, 1051 (76.5%) filled in at least one questionnaire. On an aggregated level, the ADR profile remained relatively stable over time. Incidence densities showed that the five most frequently reported reactions occurred early in the treatment. Initially, the majority of the patients did not undertake any action when experiencing an ADR. Recovery did not seem to be completely dependent of drug cessation.

Conclusions

With web‐based intensive monitoring, it is possible to study the time course of ADRs. This method can be a valuable addition to pharmacovigilance because it can generate other types of information as compared with spontaneous reporting and other intensive monitoring methodologies. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of aromatic oxazolyl‐ and carboxyl‐functionalized polymers: Atom transfer radical polymerization of styrene initiated by 2‐[(4‐bromomethyl)phenyl]‐4,5‐dihydro‐4,4‐dimethyloxazole
Authors: Summers Gabriel J. , Maseko Rejoice B. , Beebeejaun B. M. Parveen , Summers Carol A.
Published: April 2011

The synthesis of a new compound, 2‐[(4‐bromomethyl)phenyl]‐4,5‐dihydro‐4,4‐dimethyloxazole (1), and its utility in the synthesis of oxazoline‐functionalized polystyrene by atom transfer radical polymerization (ATRP) methods are described. Aromatic oxazolyl‐functionalized polymers were prepared by the ATRP of styrene, initiated by (1) in the presence of copper(I) bromide/2,2′‐bipyridyl catalyst system, to afford the corresponding α‐oxazolyl‐functionalized polystyrene (2). The polymerization proceeded via a controlled free radical polymerization process to produce the corresponding α‐oxazolyl‐functionalized polymers with predictable number‐average molecular weights, narrow molecular weight distributions in high‐initiator efficiency reactions. Post‐ATRP chain end modification of α‐oxazolyl‐functionalized polystyrene (2) to form the corresponding α‐carboxyl‐functionalized polystyrene (3) was achieved by successive acid‐catalyzed hydrolysis and saponification reactions. The polymerization processes were monitored by gas chromatography analyses. The unimolecular‐functionalized initiator and functionalized polymers were characterized by thin layer chromatography, spectroscopy, size exclusion chromatography, and nonaqueous titration analysis. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
Synthesis and optical and transport properties of a phenyl‐substituted polythiophene
Authors: Debebe Siraye E. , Gedefaw Desta A. , Mammo Wendimagegn , Yohannes Teketel , Tinti Francesca , Zanelli Alberto , Fattori Valeria , Camaioni Nadia
Published: April 2011

The synthesis and characterization of a novel polythiophene substituted with a 2′‐pentyloxy‐5′‐(1″′‐oxooctyl) phenyl group (PPOPT) is reported. The bulk transport properties of thin films of PPOPT are investigated by admittance spectroscopy. The dramatic effect of the phenyl side chain on the mobility of positive carriers in films of PPOPT is described. The photophysics of PPOPT in both solution and thin film is also investigated and correlated to substituent‐driven intrachain and interchain arrangements. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Ethylene homopolymerizaton and copolymerizaton by vanadium(III) complexes containing tridentate or tetradentate iminopyrrolyl ligands
Authors: Mu Jing‐Shan , Shi Xin‐Cui , Li Yue‐Sheng
Published: April 2011

Iminopyrrolyl vanadium(III) complexes 2a–b bearing tridentate ligands [C4H3NCHNC6H4L]VCl2(THF) [L = 2‐P(C6H5)2 (2a), 2‐SMe (2b)] and complexes 2c–d with tetradentate ligands [(C4H3NCHN)2R]VCl(THF) [R = 1,2‐C6H4 (2c), 1,2‐C2H4 (2d)] have been synthesized in high yields. With diethylaluminium chloride as a cocatalyst, complexes 2a–d were investigated as efficient catalysts for ethylene polymerization under various reaction conditions, and exhibited high catalytic activity and remarkable thermal stability. With these complexes, high molecular weight polymers with unimodal molecular weight distributions were obtained, indicating that the polymerization reaction took place in a single‐site nature. Ethylene/1‐hexene copolymerizations were also investigated in the presence of Et2AlCl. Both increasing ligand denticity and introducing softer atom into the sidearm of the ligands significantly influenced catalytic activity, comonomer incorporation, and the molecular weights of the resultant polymers, suggesting that both the steric and the electronic effects of the ligands played an important role in adjusting chain propagation and transfer rate. The chain transfer mechanisms involved in the copolymerization process were investigated by carefully analyzing the microstructure of the copolymers. The signals of vinyl, disubstituted and tri‐substituted vinylene double bond end groups were detected in the copolymer obtained by 2a/Et2AlCl system but not in those by 2b–c/Et2AlCl systems, indicating that bulky electron‐donating group, P(C6H5)2, may lead to those unusual transfer reactions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and photovoltaic properties of low‐bandgap 4,7‐dithien‐2‐yl‐2,1,3‐benzothiadiazole‐based poly(heteroarylenevinylene)s
Authors: Wen Shanpeng , Pei Jianing , Li Pengfei , Zhou Yinhua , Cheng Weidong , Dong Qingfeng , Li Zaifang , Tian Wenjing
Published: April 2011

Three novel low‐bandgap copolymers containing alkylated 4,7‐dithien‐2‐yl‐2,1,3‐benzothiadiazole (HBT) and different electron‐rich functional groups (dialkylfluorene (PFV‐HBT), dialkyloxyphenylene (PPV‐HBT) and dialkylthiophene (PTV‐HBT)) were prepared by Horner polycondensation reactions and characterized by 1H NMR, gel permeation chromatography, and elemental analysis. The alkyl side chain brings these polymeric materials good solubility in common organic solvents, which is critical for the manufacture of solar cells in a cost‐effective manner. The copolymers exhibit low optical bandgap from 1.48 to 1.83 eV. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the copolymers were measured by cyclic voltammetry. Theoretical calculations revealed that the variation laws of HOMO and the LUMO energy levels are well consistent with cyclic voltammetry measurement. The bulk heterojunction photovoltaic devices with the structure of ITO/PEDOT‐PSS/polymer:PCBM/LiF/Al were fabricated by using the three copolymers as the donor and (6,6)‐phenyl‐C61‐butyric acid methyl ester (PCBM) as the acceptor in the active layer. The device based on PTV‐HBT:PCBM (1:4 w/w) achieved a power conversion efficiency of 1.05% under the illumination of AM 1.5, 100 mW/cm2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
Hydrophilic dual‐responsive magnetite/PMAA core/shell microspheres with high magnetic susceptibility and ph sensitivity via distillation‐precipitation polymerization
Authors: Ma Wanfu , Xu Shuai , Li Jumei , Guo Jia , Lin Yao , Wang Changchun
Published: April 2011

A facile and effective approach to preparation of dual‐responsive magnetic core/shell composite microspheres is reported. The magnetite(Fe3O4)/poly(methacrylic acid) (PMAA) composite microspheres were synthesized through encapsulating γ‐methacryloxypropyltrimethoxysilane (MPS)‐modified magnetite colloid nanocrystal clusters (MCNCs) with crosslinked PMAA shell. First, the 200‐nm‐sized MCNCs were fabricated through solvothermal reaction, and then the MCNCs were modified with MPS to form active vinyl groups on the surface of MCNCs, and finally, a pH‐responsive shell of PMAA was coated onto the surface of MCNCs by distillation‐precipitation polymerization. The transmission electron microscopy (TEM) and vibrating sample magnetometer characterization showed that the obtained composite microspheres had well‐defined core/shell structure and high saturation magnetization value (35 emu/g). The experimental results indicated that the thickness and degree of crosslinking of PMAA shell could be well‐controlled. The pH‐induced change in size exhibited by the core/shell microspheres reflected the PMAA shell contained large amount of carboxyl groups. The carboxyl groups and high saturation magnetization make these microspheres have a great potential in biomolecule separation and drug carriers. Moreover, we also demonstrated that other magnetic polymeric microspheres, such as Fe3O4/PAA, Fe3O4/PAM, and Fe3O4/PNIPAM, could be synthesized by this approach. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
A new mechanism for ocean–atmosphere coupling in midlatitudes
Authors: Czaja A. , Blunt N.
Published: April 2011

The role of moist convection in ‘transferring’ upward surface ocean conditions throughout the troposphere is studied using reanalysis data for the extratropical Northern and Southern Hemispheres in winter. It is found that conditions for the development of a convective air column from the sea surface to the tropopause are met frequently over all major western boundary currents and their extension in the oceanic interior (sometimes for as much as 50% of the time). These frequent occurrences are shown to be jointly controlled by oceanic advection of warm waters and, on the atmospheric side, the downward displacement of the tropopause associated with synoptic weather systems.

Based on these results, it is proposed that the oceans can influence the atmosphere directly through convection in midlatitudes, as is commonly thought to occur in the Tropics. Analysis of the Richardson numberRifound at low levels suggests that moist symmetric instability (0< Ri≤ 1) is a key process involved in linking surface ocean temperatures to atmospheric lapse rates, in addition to standard upright convection. These lowRiprocesses are not currently parametrized in climate models, which raises the possibility that the extratropical oceanic influence on climate might be underestimated in the current generation of models. Copyright © 2011 Royal Meteorological Society
Methods and evaluations for surveillance in industry, business, finance, and public health
Authors: Frisén Marianne
Published: April 2011

An overview on surveillance in different areas is given. Even though methods have been developed under different scientific cultures, the statistical concepts can be the same. When the statistical problems are the same, progress in one area can be used also in other areas. The aim of surveillance is to detect an important change in an underlying process as soon as possible after the change has occurred. In practice, we have complexities such as gradual changes and multivariate settings. Approaches to handling some of these complexities are discussed. The correspondence between the measures for evaluation and the aims of the application is important. Thus, the choice of evaluation measure deserves attention. The commonly used ARL criterion should be used with care. Copyright © 2011 John Wiley & Sons, Ltd.
What Happened to the ‘Development’ in Sustainable Development? Business Guidelines Two Decades After Brundtland
Authors: Barkemeyer Ralf , Holt Diane , Preuss Lutz , Tsang Stephen
Published: April 2011

Over 20 years ago Our Common Future presented a conceptualization and explanation of the concept of sustainable development. Since then, numerous alternative definitions of the concept have been offered, of which at least some are exclusive to each other. At the same time, the role of business in the transition to sustainable development has increasingly received attention. Bringing these two trends in sustainable development together, this paper returns to the Brundtland version of the concept to examine to what extent the original principles of sustainable development are still embedded within key business guidelines, namely the UN Global Compact, the OECD Guidelines for Multinational Enterprises, the ICC Business Charter for Sustainable Development, the CAUX Principles, the Global Sullivan Principles and the CERES Principles. The findings suggest that these business guidelines tend to emphasize environmental rather than social aspects of sustainable development, in particular to the detriment of the original Brundtland prioritization of the needs of the poorest. Furthermore, the attention to environmental aspects stresses win–win situations and has a clear managerialist focus; whereas more conceptual environmental issues concerning systems interdependencies, critical thresholds or systemic limits to growth find little attention. The normative codes and principles targeted at the private sector therefore not only add another voice to the multiple discourses on sustainable development but also contribute to a reinterpretation of the original agenda set by Brundtland towards conceptualizations of sustainable development around the needs of industrialized rather than developing countries. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
COIM: An object‐process based method for analyzing architectures of complex, interconnected, large‐scale socio‐technical systems
Authors: Osorio Carlos A. , Dori Dov , Sussman Joseph
Published: April 2011

There is growing evidence for the relevance of human behavioral factors in successful development of new products, processes, and services. The evidence is even clearer when the forces affecting the development and evolution of long‐lived, large, and open complex socio‐technical systems are examined. Methods that study the architecture of these systems can help scholars and practitioners to better understand, manage, and develop socio‐technical systems. We propose an approach and a method to address these needs that is grounded in the theory of systems architecture and builds on the strengths of Object Process Methodology (OPM) and the process for representing Complex Large‐scale Interconnected Open Socio‐technical (CLIOS) systems. We do so by integrating these methods into the CLIOS‐OPM Integrated Method (COIM). COIM is conducive to studying a system's architecture and its evolution, as it is enhanced by a set of qualitative methods for answering questions about the reasons (why) and process (how) of change in human‐made systems over time. © 2011 Wiley Periodicals, Inc.
Project management vs. systems engineering management: A practitioners' view on integrating the project and product domains
Authors: Sharon Amira , de Weck Olivier L. , Dori Dov
Published: April 2011

While most Systems Engineering Management (SEM) applications use some subset of traditional Project Management (PM) methods and tools, the actual practice of systems engineering management involves continuous cognitive zigzagging between systems engineering—the product domain—and project management—the project domain. Focusing on seven PM methods, we examine two research questions regarding systems engineering practitioners: (1) While conducting SEM, do they perceive a notion of a project domain, a product domain, and a combined project‐product domain? (2) What is the extent to which, and ways by which, systems engineering practitioners deem PM methods as effective for supporting SEM? Using analysis of structured questionnaires among 24 participants, we verified that project and product are indeed viewed as two complementary facets of SEM, and that certain PM methods address both domains better than others with respect to particular examined factors. © 2011 Wiley international, Inc.
Overcoming in vivo barriers to targeted nanodelivery
Authors: Chrastina Adrian , Massey Kerri A. , Schnitzer Jan E.
Published: April 2011

Nanoparticles have been investigated as promising nanocarriers for delivery of imaging and therapeutic agents for several decades, but have met with limited success. Although enormous progress in the fields of nanotechnology and nanoscience has been achieved, basic discoveries have not yet translated into effective targeted therapies. Nanoparticles can potentially improve the pharmacokinetics and pharmacodynamics of drugs; however, the complexity of in vivo systems imposes multiple barriers that severely inhibit efficiency and have to be overcome to fully exploit the theoretical potential of nanoparticles. Here, we address two major challenges to effective systemic nanodelivery. Both limited penetration across the vascular endothelium and uptake by the reticuloendothelial system (RES) substantially impede effectiveness of nanoparticle delivery into tissues. Although the design of nanoparticles with extended circulation half‐life is essential, it is not sufficient for effective penetration of nanoparticles across the formidable barrier formed by the vascular endothelium. Current nanodelivery systems rely on passive transvascular exchange and tissue accumulation. They require high dosages to create large concentration gradients that drive nanoparticles passively across the blood–tissue interface. However, passive accumulation has resulted in only a fractional dosage of nanoparticles penetrating into target tissue. This inevitably diminishes therapeutic efficacy and aggravates potential side effects. Although there are multiple ways to augment passive delivery, active delivery of targeted nanoparticles across the vascular endothelium could significantly increase the therapeutic index and decrease side effects of nanoparticle‐based drug delivery systems. Use of active transendothelial transport pathways, such as caveolae, may provide an effective solution to both target and deliver nanoparticles. WIREs Nanomed Nanobiotechnol 2011 3 421–437 DOI: 10.1002/wnan.143

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Mononuclear Complexes of Iron(II) Based on Symmetrical Tripodand Ligands: Novel Parent Systems for the Development of New Spin Crossover Metallomesogens
Authors: Seredyuk Maksym , Gaspar Ana B. , Kusz Joachim , Gütlich Philipp
Published: April 2011

The synthesis and characterization of a series of mononuclear tripodand‐based FeII complexes by means of Mössbauer andUV/Vis spectroscopic as well as magnetic methods is reported. The complexes were obtained from the reactions of FeII salt with heterocyclic aldehydes (imd = imidazole‐4(5)‐carboxaldehyde, py = picolinaldehyde, or 6‐Mepy = 6‐methylpicolinaldehyde) and a symmetric triamine [tren = tris(2‐aminoethyl)amine, tame = 2,2,2‐tris(aminomethyl)ethane, or tach = 1,3,5‐cis,cis‐cyclohexanetriamin]. Because of extreme rigidity of the capping triamine tach, the molecular structure of {Fe[tach(imd)3](BF4)2} (1) features an unprecedented tapered trigonal prismatic FeN6 polyhedron. The molecular structures of the complexes {Fe[tach(py)3](ClO4)2} (2), {Fe[tame(imd)3](ClO4)2} (3), {Fe[tame(py)3](ClO4)2} (4) and {Fe[tame(6‐Mepy)3](ClO4)2} (5) are quite similar and exhibit pseudo‐octahedral arrangements of the coordination polyhedron. Compound 1 is in the high spin state, whereas compounds 2–5 are in the low spin state at all investigated temperatures (10–400 K). Chemical modification of the ligands in 2–5 to introduce liquid crystalline properties is expected to decrease the ligand field strength sufficiently to transform the electronic LS ground state to spin crossover behavior in the room temperature region.
N2 Activation in NiI–NN–NiI Units: The Influence of Alkali Metal Cations and CO Reactivity
Authors: Horn Bettina , Pfirrmann Stefan , Limberg Christian , Herwig Christian , Braun Beatrice , Mebs Stefan , Metzinger Ramona
Published: April 2011

After single electron reduction of the dinitrogen complex [LtBuNi(μ‐η1:η1‐N2)NiLtBu] (I) with KC8, reaction of the resulting compound K[LtBuNi(μ‐η1:η1‐N2)NiLtBu] (II) with sodium sand yields KNa[LtBuNi(μ‐η1:η1‐N2)NiLtBu] (1), which contains two different alkali metal ions. Treatment of I with two equivalents of sodium sand leads to the symmetric complex Na2[LtBuNi(μ‐η1:η1‐N2)NiLtBu] (2). Complexes 1 and 2 were investigated by single crystal X‐ray diffraction analysis as well as by Raman spectroscopy, and the results were compared with the data of K2[LtBuNi(μ‐η1:η1‐N2)NiLtBu] (III), which contains two K+ ions. Thus, it became obvious that the nature of the alkali metal ion M in compounds M2[LtBuNi(μ‐η1:η1‐N2)NiLtBu] has hardly any influence on the degree of NN bond activation. Furthermore, it was shown that treatment of the dinickel(I) complex III with CO leads to the dinickel(0) compound K2[LtBuNi(CO)]2 (4) and N2. Reaction of the unreduced dinickel(I) complex I with CO leads to a more simple replacement of the N2 ligand and formation of [LtBuNi(CO)] (3).
Cytoprotective properties of rifampicin are related to the regulation of detoxification system and bile acid transporter expression during hepatocellular injury induced by hydrophobic bile acids
Authors: González Raúl , Cruz Adolfo , Ferrín Gustavo , López‐Cillero Pedro , Briceño Javier , Gómez Miguel A. , Rufián Sebastián , Padillo Javier , De la Mata Manuel , Marin Jose J. G. , Muntané Jordi
Published: April 2011

Background/Purpose

Rifampicin has been used for the treatment of patients with jaundice and pruritus. This study evaluated the effect of rifampicin on the expression of different detoxification systems and bile acid transporters during in‐vivo and in‐vitro experimental models of cholestasis.

Methods

Rifampicin was administered to glycochenodeoxycholic acid (GCDCA)‐treated human hepatocytes and bile duct‐obstructed rats. Different parameters related to cell death, and the expression of phase I and II drug metabolizing enzymes (DME) and bile acid transporters were determined.

Results

The induction of hepatocellular injury induced by cholestasis was associated with a reduction in cytochrome P4503A4 (CYP3A4), CYP7A1, and UDP‐glucuronosyltransferase 2B4 (UGT2B4) expression, as well as an increase in import (Na+‐taurocholate co‐transporting polypeptide, NTCP) system expression. The beneficial properties of rifampicin were associated with an increase in DME and export bile acid systems (multidrug resistance‐associated protein 4, MRP4, and bile acid export pump to bile duct, BSEP) expression, as well as a reduction in NTCP expression.

Conclusions

The beneficial effect of rifampicin in cholestasis is associated with an increase in DME expression involved in toxic, bile acid and cholesterol metabolism, as well as a reduction in the bile acid importing system in hepatocytes.