bluuebunny/crossref_metadata_2025 huggingface dataset:
Disease‐Specific Differentiation Between Drugs and Non‐Drugs Using Principal Component Analysis of Their Molecular Descriptor Space
Authors: García‐Sosa Alfonso T. , Oja Mare , Hetényi Csaba , Maran Uko
Published: May 2012

The physicochemical descriptor space has been extensively mapped and described in the literature for orally administered drugs and lead compounds. However, consideration of negative examples (non‐drugs) or disease pathophysiology is not common in many studies. In the present work, a principal component analysis was carried out using drugs and non‐drugs taking into account disease‐ and organ‐specific categories, as well as different administration routes in addition to oral. The study involves 1386 relevant small‐molecules including natural and synthetic products. Drug‐specific as well as disease‐category‐specific or organ‐specific regions and their respective threshold sets (ranges of descriptors) relative to non‐drugs were elucidated on the scores plot and validated with external, independent sets of drugs and non‐drugs. The respective loadings plot of molecular descriptors was rationalized in terms of physicochemically relevant groups related to the components of solvation free energy. The results of this analysis can contribute to the improved profiling of drug candidates and libraries making use of disease‐ and organ‐specificity coded by physicochemical descriptors and ligand binding efficiency.
An optimized velocity selective arterial spin labeling module with reduced eddy current sensitivity for improved perfusion quantification
Authors: Meakin James A. , Jezzard Peter
Published: May 2012

Velocity‐selective (VS) arterial spin labeling is a promising method for measuring perfusion in areas of slow or collateral flow by eliminating the bolus arrival delay associated with other spin labeling techniques. However, B0 and B1 inhomogeneities and eddy currents during the VS preparation hinder accurate quantification of perfusion with VS arterial spin labeling. In this study, it is demonstrated through simulations and experiments in healthy volunteers that eddy currents cause erroneous tagging of static tissue. Consequently, mean gray matter perfusion is overestimated by up to a factor of 2, depending on the VS preparation used. A novel eight‐segment B1 insensitive rotation VS preparation is proposed to reduce eddy current effects while maintaining the B0 and B1 insensitivity of previous preparations. Compared to two previous VS preparations, the eight‐segment B1 insensitive rotation is the most robust to eddy currents and should improve the quality and reliability of VS arterial spin labeling measurements in future studies. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Natalist Policies in the United States
Authors: Lopoo Leonard M. , Raissian Kerri M.
Published: May 2012

This retrospective reviews the policies that affect the fertility of American women, both policies designed to alter fertility intentionally as well as those that change childbearing unintentionally. Becker's seminal work on the economics of fertility serves as the theoretical foundation for this literature. After describing Becker's economic model, we review the empirical literature on fertility responses to social welfare policies, tax policies, the mandated health care coverage of infertility treatments, abortion policies, and government‐sponsored family planning services. We also address several Supreme Court cases that have played an important role in the interpretation of these policies. Where relevant, this retrospective describes the distributional effects of these natalist policies. We also discuss the limitations of this literature and identify important gaps. Unlike most developed countries that have created strategies to increase fertility to support their ageing population, the United States spends considerably less time and thought on this issue. Our reading of the literature suggests that we have many public policies that have affected and continue to influence the fertility choices made by families in the United States and that this is a topical area that deserves more attention in policy debates.
Advanced glycation end product Nε‐carboxymethyllysine induces endothelial cell injury: the involvement of SHP‐1‐regulated VEGFR‐2 dephosphorylation
Authors: Liu Shing Hwa , Sheu Wayne Huey Herng , Lee Maw Rong , Lee Wen Jane , Yi Yu Chiao , Yang Tzung Jie , Jen Jen Fon , Pan Hung Chuan , Shen Chin Chang , Chen Wen Bao , Tien Hsing Ru , Sheu Meei Ling
Published: May 2012

Nε‐carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes‐induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML‐related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)‐mediated SH2 domain‐containing tyrosine phosphatase‐1 (SHP‐1) activation by CML inhibits the VEGF receptor‐2 (VEGFR‐2, KDR/Flk‐1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR‐2 activation in parallel with the increased SHP‐1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP‐1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP‐1 with VEGFR‐2. Consistently, SHP‐1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [3H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML‐increased SHP‐1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP‐1 and CML was increased, but phospho‐VEGFR‐2 staining was decreased in the aortic endothelium of streptozotocin‐induced and high‐fat diet‐induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP‐1‐regulated VEGFR‐2 dephosphorylation through NADPH oxidase‐derived ROS is involved in the CML‐triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Improvement of interfacial interaction, dispersion, and properties of chlorosulfonated polyethylene/sio2 nanocomposites using CSPE‐g‐Sio2 nanoparticles synthesized under ultrasonics
Authors: Bai Xuefeng , He Xuelian , Zhang Jun , Zhu Xiao , Zhang Haiyang , Cheng Ruihua , Liu Boping
Published: May 2012

Chlorosulfonated polyethylene (CSPE) is a widely used elastomer because of the resistance to gases and aggressive chemicals, fire‐retarding, and electric insulating properties. Silica nanoparticles were usually introduced into the elastomer to improve its critical properties. However, there were some problems of strong aggregation and poor dispersion of nanoparticles in the nanocomposites. In this work, an efficient approach of grafting matrix CSPE onto silica surface was proposed to solve the problems. CPSE‐g‐SiO2 nanoparticles were prepared via an in situ radical reaction between Cl in CSPE and SiOH on silica surface under ultrasonics. The successful chemical graft reaction was confirmed using Fourier transform infrared, ultraviolet–visible spectroscopy, 1H‐NMR, and X‐ray photoelectron spectroscopy. Thermogravimetric analysis indicated that the grafting amount of CSPE was 4.68 wt%. Grafting CSPE onto silica surface significantly improved the dispersion of CSPE‐g‐SiO2 nanoparticles in CSPE matrix and the interfacial interaction. Therefore, the mechanical, thermal stability, damping capacity, and rheology properties of CSPE/CSPE‐g‐SiO2 nanocomposites were improved. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Carbon nanotubes grafting PBO fiber: A study on the interfacial properties of epoxy composites
Authors: Zhang Chunhua , Xu Huifang , Jiang Zaixing , Zhu Fenglei , Huang Yudong
Published: May 2012

To improve the interfacial performance of poly[p‐phenylene benzobisoxazole] (PBO) fiber and epoxy resin, a modified multiwalled carbon nanotubes (MWCNTs‐Ecp) were used to achieve this purpose through grafting onto PBO fiber surface using a gamma ray radiation method. Experimental results indicated that the equilibrium wetting rate and equilibrium adsorption amount of the modified PBO fiber for epoxy resin and acetone were all higher than that of as received PBO fiber. The interfacial shear strength (IFSS) of single fiber composite increased from 31.4 to 77.5 MPa after modification. The fracture models of composites are changed from pure interfacial failure to combination failure of interface and resin interlayer. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Synthesize of polymer–silicate nanocomposites by in situ metal‐catalyzed living radical polymerization
Authors: Abbasian Mojtaba , Mahi Robab
Published: May 2012

Polymer–silicate nanocomposites were synthesized with atom transfer radical polymerization (ATRP). An ATRP initiator, consisting of a quaternary ammonium salt moiety and an α‐phenyl chloroacetyl chloride moiety, were intercalated into the interlayer spacings of the layered silicate. Subsequent ATRP of styrene with CuCl/2,2′‐bipyridine (bipy) as the catalyst with the initiator‐modified silicate afforded homopolymers with predictable molecular weights and low polydispersities, both characteristics of living radical polymerization. The polystyrene nanocomposites contained both intercalated and exfoliated silicate structures. The prepared materials were characterized by XRD, SEM, TEM, FTIR, and 1H NMR techniques. Effect of silicate on thermal properties and glass transition temperature of polystyrene was investigated using thermogravimetric analysis and differential scanning calorimetric techniques. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Polyamide 6‐wheat straw composites: Degradation kinetics
Authors: Amintowlieh Yasaman , Sardashti Amirpouyan , Simon Leonardo C.
Published: May 2012

Degradation kinetics of ground wheat straw (WS), polyamide 6, and a WS‐polyamide 6 composites obtained from extrusion were investigated. 15 wt% of ground WS was melt blended with other additives naming; lithium chloride salt (LiCl) and N‐butylbenzenesulfonamide plasticizer (N‐BBSA) as matrix treatments. The additives were added to reduce the melting point of polyamide 6 and ease of composite processing (reduction in processing temperature and time). Two commonly used non‐isothermal kinetic models were used to investigate the degradation kinetics of WS and the composite. Thermal gravimetric analysis was utilized to measure the thermal stability and degradation kinetics of different composite formulation. The activation energy of WS was identified by iso‐conversional Friedman kinetic method. Through this method, WS activation energy was found to be around 141.4 kJ/mol. Composite kinetic studies were based on the Coats and Redfern procedure. It was concluded that the composite activation energy was correlated to the residual weight percentage of the composite at the maximum thermal degradation temperature. The onset of degradation of WS was dictated by the thermal stability of its lignin content and was found to be around 188°C. WS, however, did not go through a major degradation up to 245°C at which drastic decomposition starts. This temperature range overlaps with processing temperature of Polyamide 6 and required matrix/WS treatments. Addition of salt and plasticizer individually or with each other at any level decreased the onset of degradation temperature. Addition of plasticizer at 4 wt% level, however, shifted the degradation peak to higher temperature representing a more thermally stable composite. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Prior event rate ratio adjustment: numerical studies of a statistical method to address unrecognized confounding in observational studies
Authors: Yu Menggang , Xie Dawei , Wang Xingmei , Weiner Mark G. , Tannen Richard L.
Published: May 2012

Purpose

The purpose of this study was to evaluate a statistical method, prior event rate ratio (PERR) adjustment, and an alternative, PERR‐ALT, both of which have the potential to overcome “unmeasured confounding,” both analytically and via simulation.

Methods

Formulae were derived for the target estimates of both PERR methods, which were compared with results from simulations to ensure their validity. In addition to the theoretical insights gained, relative biases of both PERR methods for estimating exposure effects were also investigated via simulation studies and compared empirically with electronic medical record database study results.

Results

Theoretical derivations closely matched simulated results. In simulation studies, both PERR methods significantly reduce bias from unmeasured confounding compared with the standard Cox model. When there is no interaction between unmeasured confounders and time intervals, the estimate from PERR‐ALT is unbiased, whereas the estimate from PERR has well‐controlled relative bias. When interactions exist, relative biases tend to increase but not greatly, especially when the exposure effect is relatively large in comparison with the interaction effects. When the event rate is low and the sample size is limited, PERR is more computationally stable than PERR‐ALT. In empiric study comparisons with randomized controlled trials, both PERR methods show potential to reduce bias from the standard Cox model similarly when unmeasured confounding is present.

Conclusions

Extensive simulation studies and theoretical derivation show that PERR‐based methods may reduce bias from unmeasured confounders when the exposure effect is relatively large in comparison with confounder–exposure interaction. The rare study event situation warrants further investigation. Copyright © 2012 John Wiley & Sons, Ltd.
Merging of the National Cancer Institute–funded cooperative oncology group data with an administrative data source to develop a more effective platform for clinical trial analysis and comparative effectiveness research: a report from the Children's Oncology Group
Authors: Aplenc R. , Fisher B. T. , Huang Y. S. , Li Y. , Alonzo T. A. , Gerbing R. B. , Hall M. , Bertoch D. , Keren R. , Seif A. E. , Sung L. , Adamson P. C. , Gamis A.
Published: May 2012

Purpose

The National Cancer Institute–funded cooperative oncology group trials have improved overall survival for children with cancer from 10% to 85% and have set standards of care for adults with malignancies. Despite these successes, cooperative oncology groups currently face substantial challenges. We are working to develop methods to improve the efficiency and effectiveness of these trials. Specifically, we merged data from the Children's Oncology Group (COG) and the Pediatric Health Information Systems (PHIS) to improve toxicity monitoring, to estimate treatment‐associated resource utilization and costs, and to address important clinical epidemiology questions.

Methods

COG and PHIS data on patients enrolled on a phase III COG trial for de novo acute myeloid leukemia at 43 PHIS hospitals were merged using a probabilistic algorithm. Resource utilization summary statistics were then tabulated for the first chemotherapy course based on PHIS data.

Results

Of 416 patients enrolled on the phase III COG trial at PHIS centers, 392 (94%) were successfully matched. Of these, 378 (96%) had inpatient PHIS data available beginning at the date of study enrollment. For these, daily blood product usage and anti‐infective exposures were tabulated and standardized costs were described.

Conclusions

These data demonstrate that patients enrolled in a cooperative group oncology trial can be successfully identified in an administrative data set and that supportive care resource utilization can be described. Further work is required to optimize the merging algorithm, map resource utilization metrics to the National Cancer Institute Common Toxicity Criteria for monitoring toxicity, to perform comparative effectiveness studies, and to estimate the costs associated with protocol therapy. Copyright © 2012 John Wiley & Sons, Ltd.
Comparative effectiveness research using matching‐adjusted indirect comparison: an application to treatment with guanfacine extended release or atomoxetine in children with attention‐deficit/hyperactivity disorder and comorbid oppositional defiant disorder
Authors: Signorovitch James , Erder M. Haim , Xie Jipan , Sikirica Vanja , Lu Mei , Hodgkins Paul S. , Wu Eric Q.
Published: May 2012

Objectives

To illustrate a matching‐adjusted indirect comparison by comparing the efficacy of guanfacine extended release (GXR) and atomoxetine (ATX) in reducing oppositional symptoms in children with attention‐deficit/hyperactivity disorder and comorbid oppositional defiant disorder.

Methods

Individual patient data were used from a GXR trial; only published summary data were used from ATX trials. In a matching‐adjusted indirect comparison, individual patients from the GXR trial were weighted such that their mean baseline characteristics matched those published for ATX trials. Placebo‐arm outcomes were then compared to further assess balance between the matched populations. Changes in the Conners' Parent Rating Scale‐Revised Short Form Oppositional Subscale from baseline to endpoint among GXR‐treated and ATX‐treated patients were then compared.

Results

Before matching, the GXR (n = 143) and ATX (n = 98) trial populations had significant differences in baseline characteristics and placebo‐arm outcomes. After matching, baseline characteristics were well balanced across trials, and placebo‐arm outcomes became nearly identical. Comparing active treatment arms across the matched populations, GXR was associated with a significantly greater reduction in mean Conners' Parent Rating Scale‐Revised Short form oppositional subscale compared with ATX {−5.0 [95% confidence interval (CI): −6.6 to −3.4] vs. −2.4 [CI: −3.7 to −1.1], p = 0.01, effect size = 0.58}.

Conclusions

In the absence of head‐to‐head randomized trials, matching‐adjusted indirect comparisons can provide timely and reliable comparative evidence for decision makers and can be applied even when very few trials are available for the treatments of interest. Copyright © 2012 John Wiley & Sons, Ltd.
Confronting “confounding by health system use” in Medicare Part D: comparative effectiveness of propensity score approaches to confounding adjustment
Authors: Polinski Jennifer M. , Schneeweiss Sebastian , Glynn Robert J. , Lii Joyce , Rassen Jeremy A.
Published: May 2012

Purpose

Under Medicare Part D, patient characteristics influence plan choice, which in turn influences Part D coverage gap entry. We compared predefined propensity score (PS) and high‐dimensional propensity score (hdPS) approaches to address such “confounding by health system use” in assessing whether coverage gap entry is associated with cardiovascular events or death.

Methods

We followed 243,079 Medicare patients aged 65+ years with linked prescription, medical, and plan‐specific data in 2005–2007. Patients reached the coverage gap and were followed until an event or year's end. Exposed patients were responsible for drug costs in the gap; unexposed patients (patients with non‐Part D drug insurance and Part D patients receiving a low‐income subsidy) received financial assistance. Exposed patients were 1:1 PS‐matched or hdPS‐matched to unexposed patients. The PS model included 52 predefined covariates; the hdPS model added 400 empirically identified covariates. Hazard ratios for death and any of five cardiovascular outcomes were compared. In sensitivity analyses, we explored residual confounding using only low‐income subsidy patients in the unexposed group.

Results

In unadjusted analyses, exposed patients had no greater hazard of death (HR = 1.00; 95%CI, 0.84–1.20) or other outcomes. PS‐matched (HR = 1.29; 0.99–1.66) and hdPS‐matched (HR = 1.11; 0.86–1.42) analyses showed elevated but non‐significant hazards of death. In sensitivity analyses, the PS analysis showed a protective effect (HR = 0.78; 0.61–0.98), whereas the hdPS analysis (HR = 1.06; 0.82–1.37) confirmed the main hdPS findings.

Conclusion

Although the PS‐matched analysis suggested elevated but non‐significant hazards of death among patients with no financial assistance during the gap, the hdPS analysis produced lower estimates that were stable across sensitivity analyses. Copyright © 2012 John Wiley & Sons, Ltd.
Changes in antipsychotic use among patients with severe mental illness after a Food and Drug Administration advisory
Authors: Dusetzina Stacie B. , Busch Alisa B. , Conti Rena M. , Donohue Julie M. , Caleb Alexander G. , Huskamp Haiden A.
Published: May 2012

Purpose

A 2003 Food and Drug Administration advisory warned of increased hyperlipidemia and diabetes risk for patients taking second‐generation antipsychotics (SGAs). After the advisory, a professional society consensus statement provided treatment recommendations and stratified SGAs into high, intermediate, and low metabolic risk. We examine subsequent changes in incident and prevalent SGA use among individuals with severe mental illness.

Methods

We created a retrospective cohort using Florida Medicaid's claims from 2001 to 2006. We included non‐Medicare eligible adults with bipolar disorder or schizophrenia who filled an SGA prescription. We assessed changes in overall and agent‐specific use, discontinuations, interruptions, and therapeutic alternative use among prevalent users and agent‐specific use among incident users. Pre‐advisory utilization was compared with utilization initially after the advisory and two subsequent periods.

Results

Among prevalent users, overall SGA use decreased slightly, and no increases in treatment interruptions or discontinuations were observed after the advisory and consensus statement publication. Compared with the pre‐advisory period, in the months immediately after the advisory, the use of the highest metabolic‐risk agent, olanzapine, decreased by 34% among prevalent users with bipolar disorder (adjusted risk ratio [aRR] = 0.66, 95%CI = 0.59–0.74) and 26% among prevalent users with schizophrenia (aRR = 0.74, 95%CI = 0.72–0.76). A greater decrease was estimated among incident users with bipolar disorder (aRR = 0.37, 95%CI = 0.29–0.47) and schizophrenia (aRR = 0.42, 95%CI = 0.35–0.51) during this period. During each subsequent post‐advisory period, olanzapine use continued to decrease whereas quetiapine, ziprasidone, and aripiprazole use increased.

Conclusions

The metabolic risk advisory and the published consensus statement were associated with a selective reduction in olanzapine use without evidence of treatment disruptions among this population. Copyright © 2012 John Wiley & Sons, Ltd.
Impact of phosphorus gettering parameters and initial iron level on silicon solar cell properties
Authors: Vähänissi Ville , Haarahiltunen Antti , Talvitie Heli , Yli‐Koski Marko , Savin Hele
Published: May 2012

We have studied experimentally the effect of different initial iron contamination levels on the electrical device properties of p‐type Czochralski‐silicon solar cells. By systematically varying phosphorus diffusion gettering (PDG) parameters, we demonstrate a strong correlation between the open‐circuit voltage (Voc) and the gettering efficiency. Similar correlation is also obtained for the short‐circuit current (Jsc), but phosphorus dependency somewhat complicates the interpretation: the higher the phosphorus content not only the better the gettering efficiency but also the stronger the emitter recombination. With initial bulk iron concentration as high as 2 × 1014 cm−3, conversion efficiencies comparable with non‐contaminated cells were obtained, which demonstrates the enormous potential of PDG. The results also clearly reveal the importance of well‐designed PDG: to achieve best results, the gettering parameters used for high purity silicon should be chosen differently as compared with for a material with high impurity content. Finally we discuss the possibility of achieving efficient gettering without deteriorating the emitter performance by combining a selective emitter with a PDG treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Sexual problems, communication patterns, and depressive symptoms in couples coping with metastatic breast cancer
Authors: Milbury Kathrin , Badr Hoda
Published: May 2012

Background

The treatment of breast cancer tends to result in physical side effects (e.g., vaginal dryness, stomatitis, and atrophy) that can cause sexual problems. Although studies of early‐stage breast cancer have demonstrated that sexual problems are associated with increased depressive symptoms for both patients and their partners, comparatively little is known about these associations in metastatic breast cancer (MBC) and how patients and partners cope together with sexual problems. We examined the links between sexual problems, depressive symptoms, and two types of spousal communication patterns (mutual constructive and demand–withdraw) in 191 couples in which the patient was initiating treatment for MBC.

Methods

Patients and partners separately completed paper‐and‐pencil surveys.

Results

Multilevel models indicated that high levels of sexual problems were significantly associated with more depressive symptoms only for patients who reported low levels of mutual constructive communication (p < 0.01) and high levels of demand–withdraw communication (p < 0.0001). In contrast, for partners, greater sexual problems were associated with more depressive symptoms regardless of the communication pattern reported. These associations remained significant when we controlled for patients' reports of average pain and functional and physical well‐being and couples' dyadic adjustment.

Conclusions

Sexual problems were associated with depressive symptoms for both MBC patients and their partners. The way in which patients and partners talk with one another about cancer‐related problems seems to influence this association for patients. MBC patients may benefit from programs that teach couples how to minimize demand–withdraw communication and instead openly and constructively discuss sexual issues and concerns. Copyright © 2012 John Wiley & Sons, Ltd.
Thermal Decomposition and Ignition of PBXN‐110 Plastic‐Bonded Explosive
Authors: Aydemir Erdogan , Ulas Abdullah , Serin Nadir
Published: May 2012

Due to safety requirements, insensitive behavior in slow or fast thermal heating (cook‐off) conditions is a desired behavior for today’s munitions. The ignition time of munitions under slow or fast cook‐off conditions is an important parameter in the design of insensitive munitions. The critical temperature, which mainly depends on the chemical, physical, and the geometrical properties of the energetic material, is the determining factor whether the material will end up with thermal initiation or not, when it is exposed to an external heat source. In this study a slow cook‐off test setup is designed and developed and the tests for a generic munition containing PBXN‐110 plastic‐bonded explosive are performed in order to obtain temperature distribution in the test item, ignition time, ignition temperature, and ignition location. In this paper the development procedure and the experimental results of the slow cook‐off tests are explained. Moreover, the kinetic parameters such as activation energy and pre‐exponential factor for the plastic‐bonded explosive obtained from the TGA tests are presented.
Preface: Phys. Status Solidi C 5/2012
Authors: Hoffmann Axel , Christen Jürgen
Published: May 2012

The 11th International Conference on Physics of Light–Matter Coupling in Nanostructures 2011 (PLMCN 11) was held in Berlin, 4–8 April 2011.

The idea of the PLMCN conference series is to bring together scientists active in the fields of semiconductor optics and material science dealing with modern technologies of wide‐band‐gap semiconductors and organic materials, both in academia and industry. This conference traditionally combines new generations of opto‐electronic devices like nanolasers, polariton lasers, single photon emitters and basic physical principles like spin dynamics in quantum dots and microcavities. Furthermore, progress in epitaxial growth of Bragg mirrors and quantum structures in arsenides, nitrides and oxides is in the focus of interest.

With the 2011 PLMCN conference in Berlin the scientific lifework of Dieter Bimberg was honored who has accomplished tremendous pioneering work in the field of optoelectronic devices like quantum dots and nanolasers, PCB (printed circuit board) lasers, and electrically driven single‐photon emitters.

The organizers thank the participants of PLMCN 2011 for continuing the spirit of now 11 annual conferences – Saint Nectaire, France (2000); Rome, Italy (2001); Rithymnon, Greece (2002); Acireale, Italy (2003); Saint‐Petersburg, Russia (2004); Glasgow, Scotland (2005); Magdeburg, Germany (2006); Havana, Cuba (2007); Tokyo, Japan (2008); Lecce, Italy (2009), and Cuernavaca, Mexico (2010) (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Framework for Sustainable Food Packaging Design
Authors: Grönman Kaisa , Soukka Risto , Järvi‐Kääriäinen Terhen , Katajajuuri Juha‐Matti , Kuisma Mika , Koivupuro Heta‐Kaisa , Ollila Margareetta , Pitkänen Marja , Miettinen Olli , Silvenius Frans , Thun Rabbe , Wessman Helena , Linnanen Lassi
Published: May 2012

The environmental impacts of packages have been found to be relatively small compared with the food items they contain. Furthermore, from the environmental and operational point of view, the most significant task of the package is to protect the product, which is important to acknowledge in the packaging design process. This study introduces a guiding framework for designing sustainable food packaging. In this approach, the entire life cycle of the product–package combination is taken into consideration. The emphasis is on the prevention of food losses in packaging design as a major environmental criterion. Consideration of the properties of both the package and the product itself when designing the final package will lead to a better end result with smaller product losses and environmental impacts. By using different assessment methods in the different stages of the packaging design, the sustainability of the package can be enhanced. The decision making of the packaging designer is facilitated with methods that are introduced step by step and in a certain order that will also allow for corrective measures through back‐loops in the design process. The purpose is to integrate sustainability aspects at all stages firmly into the design process. Copyright © 2012 John Wiley & Sons, Ltd.
From molecules to mastication: the development and evolution of teeth
Authors: Jheon Andrew H. , Seidel Kerstin , Biehs Brian , Klein Ophir D.
Published: May 2012

Teeth are unique to vertebrates and have played a central role in their evolution. The molecular pathways and morphogenetic processes involved in tooth development have been the focus of intense investigation over the past few decades, and the tooth is an important model system for many areas of research. Developmental biologists have exploited the clear distinction between the epithelium and the underlying mesenchyme during tooth development to elucidate reciprocal epithelial/mesenchymal interactions during organogenesis. The preservation of teeth in the fossil record makes these organs invaluable for the work of paleontologists, anthropologists, and evolutionary biologists. In addition, with the recent identification and characterization of dental stem cells, teeth have become of interest to the field of regenerative medicine. Here, we review the major research areas and studies in the development and evolution of teeth, including morphogenesis, genetics and signaling, evolution of tooth development, and dental stem cells. WIREs Dev Biol 2013, 2:165–182. doi: 10.1002/wdev.63

This article is categorized under:

Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms

Vertebrate Organogenesis > From an Epithelial Primordium (Non-Tubular)

Birth Defects > Craniofacial and Nervous System Anomalies
The Implications of Positive Peritoneal Lavage Cytology in Potentially Resectable Pancreatic Cancer
Authors: Yoshioka Ryuji , Saiura Akio , Koga Rintaro , Arita Junichi , Takemura Nobuyuki , Ono Yoshihiro , Yamamoto Junji , Yamaguchi Toshiharu
Published: May 2012

Background

The clinical implications of peritoneal lavage cytology (CY) status in patients with potentially resectable pancreatic cancer have not been established.

Method

We retrospectively reviewed clinical data from 254 consecutive patients who underwent macroscopically curative resection for pancreatic cancer from February 2003 to December 2010 in our institution. Correlations between CY status and survival and clinicopathological findings were investigated.

Results

Of the 254 patients, 20 were CY+ (7.9 %). There were no significant differences between CY+ and CY− patients in background data (age, sex, the level of preoperative tumor marker, and adjuvant chemotherapy). Patients with positive serosal invasion were more likely to be CY+ than those with negative serosal invasion (P < 0.001) by univariate analysis. The median overall survival of CY+ patients and CY− patients was 23.8 months (95 % CI = 17.6–29.8) and 26.5 months (95 % CI = 20.7–32.3), respectively (P = 0.302). The median recurrence‐free survival of CY+ and CY− patients was 8.1 months (95 % CI = 0.0–17.9) and 13.5 months (95 % CI = 11.5–15.5), respectively (P = 0.089).

Conclusion

CY+ status without other distant metastasis does not necessarily preclude resection in patients with pancreatic cancer.
Synthesis and Characterization of Polyols Derived from Corn Oil by Epoxidation and Ozonolysis
Authors: de Souza Victor Hugo Rodrigues , Silva Simone Adriane , Ramos Luiz Pereira , Zawadzki Sônia Faria
Published: May 2012

In the present study, epoxidation and ozonolysis led to a decrease of 40.8 and 51.9 % in the degree of unsaturation of corn oil, respectively. Both products were initially characterized by Fourier transform infrared spectroscopy and 1H‐ and 13C‐nuclear magnetic resonance spectroscopies. The heteronuclear single‐quantum correlation spectroscopy (HSQC) analysis of the polyol obtained by epoxidation showed that carbinol hydrogen signals, located between 3.65 and 3.47 ppm, were correlated to carbon signals between 74.4 and 71.7 ppm. HSQC analysis of the polyol obtained by ozonolysis revealed these same chemical shifts at 3.64 and 62.9 ppm, respectively. Compared to pure corn oil, the differential scanning calorimetry of both corn oil‐based polyols displayed the absence of any detectable melting peaks. However, the epoxidized derivative had a higher thermal stability than the ozonated sample, as shown by thermogravimetric analysis.
Identification of the Unsaturated Heptadecyl Fatty Acids in the Seed Oils of Thespesia populnea and Gossypium hirsutum
Authors: Dowd Michael K.
Published: May 2012

The fatty acid composition of the seed oils of Thespesia populnea and cotton variety SG‐747 (Gossypium hirsutum) were studied to identity their 17‐carbon fatty acids. With a combination of chemical derivatization, gas chromatography, and mass spectrometry, 8‐heptadecenoic acid, 9‐heptadecenoic acid, and 8,11‐heptadecadienoic acids were identified in both oils. Additionally, traces of 10‐heptadecenoic acid were identified in the T. populnea oil. Although these odd‐carbon number fatty acids are present in only minor amounts in cottonseed oil, they make up about ~2 % of the fatty acids in T. populnea seed oil. The identification of these acids indicates that fatty acid α‐oxidation is not restricted to cyclopropene fatty acids in these plants, but also occurs with unsaturated fatty acids. Combined with malvalic acid (generally accepted as being formed by α‐oxidation of sterculic acid), ~7 % of the fatty acids in T. populnea seed have under gone α‐oxidization. The results should help clarify the composition of T. populnea seed oil, which has been reported inconsistently in the literature.
Systems and synthetic biology of the vessel wall
Authors: Frueh Jennifer , Maimari Nataly , Lui Ying , Kis Zoltan , Mehta Vikram , Pormehr Negin , Grant Calum , Chalkias Emmanuel , Falck-Hansen Mika , Bovens Sandra , Pedrigi Ryan , Homma Taka , Coppola Gianfillippo , Krams Rob
Published: May 2012

Atherosclerosis is intimately coupled to blood flow by the presence of predilection sites. The coupling is through mechanotransduction of endothelial cells and approximately 2000 gene are associated with this process. This paper describes a new platform to study and identify new signalling pathways in endothelial cells covering an atherosclerotic plaque. The identified networks are synthesized in primary cells to study their reaction to flow. This synthetic approach might lead to new insights and drug targets.
Inducing phase‐locking and chaos in cellular oscillators by modulating the driving stimuli
Authors: Jensen Mogens H. , Krishna Sandeep
Published: May 2012

Inflammatory responses in eucaryotic cells are often associated with oscillations in the nuclear‐cytoplasmic translocation of the transcription factor NF‐kB. In most laboratory realizations, the oscillations are triggered by a cytokine stimulus. We use a mathematical model to show that an oscillatory external stimulus can synchronize the NF‐kB oscillations into states where the ratios of the internal to external frequency are close to rational numbers. We predict a response diagram of the TNF‐driven NF‐kB system which exhibits bands of synchronization known as “Arnold tongues”. We suggest that when the amplitude of the external stimulus exceeds a certain threshold, chaotic dynamics of the nuclear NF‐kB concentration may occur. This behavior seems independent of the shape of the external oscillation and the non‐linearities transducing this signal.
Beyond Ricardo: The Link between Intra-Industry Trade and Peace
Authors: Peterson Timothy M. , Thies Cameron G.
Published: May 2012

In this article, it is argued that horizontal intra-industry trade is associated with reduced conflict propensity within dyads. Horizontal intra-industry trade is characterized by participation in international markets for similar – in many cases, branded – commodities, resulting from economies of scale and consumer tastes for variety. Conversely, inter-industry trade in accordance with the Ricardian and Heckscher–Ohlin models, while providing valuable trade gains, in some instances provokes vulnerability to trade partners, such that its overall impact on dyadic conflict is ambiguous. Support for this expectation is found in empirical tests spanning from 1963 to 2001. Additionally, there is evidence that development is insufficient to preclude conflict when jointly developed dyads engage in no intra-industry trade.
Statistics of joint spacing in rock layers
Authors: RABINOVITCH AVINOAM , BAHAT DOV , GREENBERG REVITAL
Published: May 2012

We show that spacing statistics can be obtained for all fracture densities by the same equation. Using the simple ‘shear lag’ theory, it is demonstrated that the results adequately fit experimental measurements. Theoretically, it is shown that two parameters are sufficient to characterize all spacing distributions. It is found that no real spacing saturation exists. Rather, a very low increase in joint densities occurs for a very high incremental stress increase. Moreover the transition to this kind of saturation is gradual and not abrupt. In this way the high density distributions with very small inter-joint distances, which pose a problem for saturation models, are directly explained. Correlation with creep experiments is also established. Comparison of our method with Weibull statistics is performed.
Visions of Atomic-Scale Tomography
Authors: Kelly Thomas F. , Miller Michael K. , Rajan Krishna , Ringer Simon P.
Published: May 2012

A microscope, by definition, provides structural and analytical information about objects that are too small to see with the unaided eye. From the very first microscope, efforts to improve its capabilities and push them to ever-finer length scales have been pursued. In this context, it would seem that the concept of an ultimate microscope would have received much attention by now; but has it really ever been defined? Human knowledge extends to structures on a scale much finer than atoms, so it might seem that a proton-scale microscope or a quark-scale microscope would be the ultimate. However, we argue that an atomic-scale microscope is the ultimate for the following reason: the smallest building block for either synthetic structures or natural structures is the atom. Indeed, humans and nature both engineer structures with atoms, not quarks. So far as we know, all building blocks (atoms) of a given type are identical; it is the assembly of the building blocks that makes a useful structure (see Figure 1). Thus, would a microscope that determines the position and identity of every atom in a structure with high precision and for large volumes be the ultimate microscope? We argue, yes. In this article, we consider how it could be built, and we ponder the answer to the equally important follow-on questions: who would care if it is built, and what could be achieved with it?
Pioneers in Optics: Marie Alfred Cornu and John Frederick William Herschel
Authors: Davidson Michael W.
Published: May 2012

Marie Alfred Cornu was born in Orleans, France, on March 6, 1841, and was educated at the École Polytechnique and the École des Mines. He became employed as a physics professor at the École Polytechnique in 1867, a position he maintained for the rest of his life. Cornu made a wide variety of contributions to the fields of optics and spectroscopy but is most noted for significantly increasing the accuracy of contemporary calculations of the speed of light.
Atom Probe Tomography of Compound Semiconductors for Photovoltaic and Light-Emitting Device Applications
Authors: Choi Pyuck-Pa , Cojocaru-Mirédin Oana , Abou-Ras Daniel , Caballero Raquel , Raabe Dierk , Smentkowski Vincent S. , Park Chan Gyung , Gu Gil Ho , Mazumder Baishakhi , Wong Man Hoi , Hu Yan-Ling , Melo Thiago P. , Speck James S.
Published: May 2012

Compound semiconductors belong to the most important materials for optoelectronic applications. Many of them exhibit favorable optical properties, such as a direct energy band gap (in contrast to silicon) and high-absorption coefficients over a wide spectral range. Moreover, varying the composition of the compound or substituting some of its elements often allows for controlled band gap engineering and optimization for specific applications. Because many compound semiconductors enable efficient conversion of light into electricity and vice versa, they are commonly used materials for optoelectronic devices.
Imaging the Cell's Third Dimension
Authors: Model Michael A.
Published: May 2012

Shape and size are among the most basic and obvious characteristics of a cell (or of any physical object, for that matter). When a cell is observed through a microscope, one only sees its projection onto the image plane. Rather paradoxically, there are no easy techniques to visualize and measure cell's third dimension—thickness. For example, confocal microscopy requires fluorescent labeling, multiple scanning with a high-power objective, possibly correction for the refractive index mismatch, and even then, generation of a complete three-dimensional profile is not very straightforward or precise. Other techniques for imaging the cell vertical profile, such as ion conductance, digital holographic, or atomic force microscopy, are rather complex and not available to most users.
Project MICRO: Science Excitement in Middle Schools
Authors: Schooley Caroline
Published: May 2012

MICRO, an acronym for Microscopy In Curriculum—Research Outreach, is the outreach program for middle schools sponsored by the Microscopy Society of America (MSA). Middle schools are the battleground for minds of young people because this is an important time for students to make decisions about whether to take science classes in high school. Unfortunately, the majority of middle school teachers are not adequately prepared to teach science; therefore, additional exposure to science may encourage students' interest.
NetNotes
Authors: Phillips Thomas E.
Published: May 2012

Selected postings to the Microscopy Listserver from January 1, 2012 to February 29, 2012. Complete listings and subscription information can be obtained at http://www.microscopy.com. Postings may have been edited to conserve space or for clarity.
High-Resolution Metrology in the TEM
Authors: Schamp C. T.
Published: May 2012

The transmission electron microscope (TEM) is well known as the technique of choice for visualization and measurement of features at near-atomic length scales, particularly for semiconductor devices. For example, a critical measurement of interest may be the thickness of the gate oxide in a transistor. The accuracy of these measurements is based on calibrated distances at each magnification. The term accuracy conveys the extent to which the measurement minimizes the difference between the measured value and the true value. The associated term precision is the closeness of agreement in a series of measurements locating the end-points of a measurement line. This article describes a method that increases the accuracy of metrology measurements applied to a high-resolution TEM image.
Observed seasonal variations in exospheric effective temperatures
Authors: Mierkiewicz E. J. , Roesler F. L. , Nossal S. M.
Published: May 2012

High spectral resolution line profile observations indicate a reproducible semi‐annual variation in the geocoronal hydrogen Balmer α effective temperature. These observations were made between 08 January 2000 and 21 November 2001 from Pine Bluff Observatory (WI) with a second generation double etalon Fabry‐Perot annular summing spectrometer operating at a resolving power of 80,000. This data set spans sixty‐four nights of observations (1404 spectra in total) over 20 dark‐moon periods. A two cluster Gaussian model fitting procedure is used to determine Doppler line widths, accounting for fine structure contributions to the line, including those due to cascade; cascade contributions at Balmer α are found to be 5 ± 3%. An observed decrease in effective temperature with increasing shadow altitude is found to be a persistent feature for every night in which a wide range of shadow altitudes were sampled. A semiannual variation is observed in the column exospheric effective temperature with maxima near day numbers 100 and 300 and minima near day numbers 1 and 200. Temperatures ranged from ∼710 to 975 K. Average MSIS model exobase temperatures for similar conditions are approximately 1.5× higher than those derived from the Balmer α observations, a difference likely due to contributions to the observed Balmer α column emission from higher, cooler regions of the exosphere.