bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of rapid thermally annealed GaP(001) surfaces in vacuum
Authors: Rokugawa Hiroshi , Adachi Sadao 
Published: January 2010

AbstractMorphology of rapid thermally annealed GaP(001) surfaces has been investigated using spectroscopic ellipsometry (SE), optical microscopy, ex situ atomic force microscopy, electron probe microanalysis (EPMA) and X‐ray photoelectron spectroscopy (XPS). The samples were annealed in vacuum for t = 2 s at temperatures T = 20–900 °C. The SE, optical microscopy and XPS spectra suggest that thermal annealing causes little influence on the GaP surface at T ≤ 600 °C; however, micro‐ and macroscopic roughening occur at T > 600 °C and T ≥ 750 °C, respectively, with a generation of Ga droplets at T ≥ 750 °C. The presence of the Ga droplets is confirmed by the EPMA measurements. The droplet density can be expressed as NGa ∝ exp (Ea/kBT) with an activation energy of Ea ∼ 2.3 eV. The XPS data indicate the change in the surface oxide composition from the native oxide to the Ga oxide (Ga2O3 and Ga2O) after annealing at T ≥ 750 °C. Possible annealing‐induced degradation steps are proposed to provide as complete a picture as possible. Copyright © 2010 John Wiley & Sons, Ltd.
Interface analysis of pure Sn, pure Ag and SnAg binary alloys in H2SO4
Authors: Ameer M. A. , Ghoneim A. A. , Heakal F. , Fekry A. M. 
Published: January 2010

AbstractThe electrochemical and passivation properties of three selected binary xSnAg (x = 26, 50 and 70 wt%) alloys were studied by means of open‐circuit potential variation, potentiodynamic curves and a.c. impedance spectroscopy techniques.The specimens were polarized between −1.0 and 0.5 V versus saturated calomel electrode (SCE) in naturally oxygenated sulfuric acidsolutions of different concentrations The experimental results indicate that icorr increases with increasing either the acid concentration or the Sn content in the solid phase. Electrochemical impedance spectroscopyresults measured at the free corrosion potential confirm that alloy I (26SnAg) characterizes by thicker passive film with higher protective ability compared to the other two samples richer in tin component. The exponential variation of the relative thickness of the surface film on any of the tested samples assumes an almost constant thickness for a thin barrier layer and a much larger outer porous layer that dominates the total film thickness on the alloy. Copyright © 2010 John Wiley & Sons, Ltd.
How firms respond to being rated
Authors: Chatterji Aaron K. , Toffel Michael W. 
Published: January 2010

AbstractWhile many rating systems seek to help buyers overcome information asymmetries when making purchasing decisions, we investigate how these ratings also influence the companies being rated. We hypothesize that ratings are particularly likely to spur responses from firms that receive poor ratings, and especially those that face lower‐cost opportunities to improve or that anticipate greater benefits from doing do. We test our hypotheses in the context of corporate environmental ratings that guide investors to select ‘socially responsible,’ and avoid ‘socially irresponsible,’ companies. We examine how several hundred firms responded to corporate environmental ratings issued by a prominent independent social rating agency, and take advantage of an exogenous shock that occurred when the agency expanded the scope of its ratings. Our study is among the first to theorize about the impact of ratings on subsequent performance, and we introduce important contingencies that influence firm response. These theoretical advances inform stakeholder theory, institutional theory, and economic theory. Copyright © 2010 John Wiley & Sons, Ltd.
Foxa2 and Nurr1 Synergistically Yield A9 Nigral Dopamine Neurons Exhibiting Improved Differentiation, Function, and Cell Survival
Authors: Lee Hyun-Seob , Bae Eun-Ji , Yi Sang-Hoon , Shim Jae-Won , Jo A-Young , Kang Jin-Sun , Yoon Eun-Hye , Rhee Yong-Hee , Park Chang-Hwan , Koh Hyun-Chul , Kim Hyun-Jung , Choi Hueng-Sik , Han Jeung-Whan , Lee Yong-Sung , Kim Jaesang , Li Jia-Yi , Brundin Patrik , Lee Sang-Hun 
Published: January 2010

Abstract
Effective dopamine (DA) neuron differentiation from neural precursor cells (NPCs) is prerequisite for precursor/stem cell-based therapy of Parkinson's disease (PD). Nurr1, an orphan nuclear receptor, has been reported as a transcription factor that can drive DA neuron differentiation from non-dopaminergic NPCs in vitro. However, Nurr1 alone neither induces full neuronal maturation nor expression of proteins found specifically in midbrain DA neurons. In addition, Nurr1 expression is inefficient in inducing DA phenotype expression in NPCs derived from certain species such as mouse and human. We show here that Foxa2, a forkhead transcription factor whose role in midbrain DA neuron development was recently revealed, synergistically cooperates with Nurr1 to induce DA phenotype acquisition, midbrain-specific gene expression, and neuronal maturation. Thus, the combinatorial expression of Nurr1 and Foxa2 in NPCs efficiently yielded fully differentiated nigral (A9)-type midbrain neurons with clearly detectable DA neuronal activities. The effects of Foxa2 in DA neuron generation were observed regardless of the brain regions or species from which NPCs were derived. Furthermore, DA neurons generated by ectopic Foxa2 expression were more resistant to toxins. Importantly, Foxa2 expression resulted in a rapid cell cycle exit and reduced cell proliferation. Consistently, transplantation of NPCs transduced with Nurr1 and Foxa2 generated grafts enriched with midbrain-type DA neurons but reduced number of proliferating cells, and significantly reversed motor deficits in a rat PD model. Our findings can be applied to ongoing attempts to develop an efficient and safe precursor/stem cell-based therapy for PD.
Hypoxia Promotes Efficient Differentiation of Human Embryonic Stem Cells to Functional Endothelium
Authors: Prado-Lopez Sonia , Conesa Ana , Armiñán Ana , Martínez-Losa Magdalena , Escobedo-Lucea Carmen , Gandia Carolina , Tarazona Sonia , Melguizo Dario , Blesa David , Montaner David , Sanz-González Silvia , Sepúlveda Pilar , Götz Stefan , O'Connor José Enrique , Moreno Rubén , Dopazo Joaquín , Burks Deborah J. , Stojkovic Miodrag 
Published: January 2010

Abstract
Early development of mammalian embryos occurs in an environment of relative hypoxia. Nevertheless, human embryonic stem cells (hESC), which are derived from the inner cell mass of blastocyst, are routinely cultured under the same atmospheric conditions (21% O2) as somatic cells. We hypothesized that O2 levels modulate gene expression and differentiation potential of hESC, and thus, we performed gene profiling of hESC maintained under normoxic or hypoxic (1% or 5% O2) conditions. Our analysis revealed that hypoxia downregulates expression of pluripotency markers in hESC but increases significantly the expression of genes associated with angio- and vasculogenesis including vascular endothelial growth factor and angiopoitein-like proteins. Consequently, we were able to efficiently differentiate hESC to functional endothelial cells (EC) by varying O2 levels; after 24 hours at 5% O2, more than 50% of cells were CD34+. Transplantation of resulting endothelial-like cells improved both systolic function and fractional shortening in a rodent model of myocardial infarction. Moreover, analysis of the infarcted zone revealed that transplanted EC reduced the area of fibrous scar tissue by 50%. Thus, use of hypoxic conditions to specify the endothelial lineage suggests a novel strategy for cellular therapies aimed at repair of damaged vasculature in pathologies such as cerebral ischemia and myocardial infarction.
Neurons Generated from APP/APLP1/APLP2 Triple Knockout Embryonic Stem Cells Behave Normally in Vitro and in Vivo: Lack of Evidence for a Cell Autonomous Role of the Amyloid Precursor Protein in Neuronal Differentiation
Authors: Bergmans Bruno A. , Shariati S. Ali M. , Habets Ron L.P. , Verstreken Patrik , Schoonjans Luc , Müller Ulrike , Dotti Carlos G. , De Strooper Bart 
Published: January 2010

Abstract
Alzheimer's disease amyloid precursor protein (APP) has been implicated in many neurobiologic processes, but supporting evidence remains indirect. Studies are confounded by the existence of two partially redundant APP homologues, APLP1 and APLP2. APP/APLP1/APLP2 triple knockout (APP tKO) mice display cobblestone lissencephaly and are perinatally lethal. To circumvent this problem, we generated APP triple knockout embryonic stem (ES) cells and differentiated these to APP triple knockout neurons in vitro and in vivo. In comparison with wild-type (WT) ES cell-derived neurons, APP tKO neurons formed equally pure neuronal cultures, had unaltered in vitro migratory capacities, had a similar acquisition of polarity, and were capable of extending long neurites and forming active excitatory synapses. These data were confirmed in vivo in chimeric mice with APP tKO neurons expressing the enhanced green fluorescent protein (eGFP) present in a WT background brain. The results suggest that the loss of the APP family of proteins has no major effect on these critical neuronal processes and that the apparent multitude of functions in which APP has been implicated might be characterized by molecular redundancy. Our stem cell culture provides an excellent tool to circumvent the problem of lack of viability of APP/APLP triple knockout mice and will help to explore the function of this intriguing protein further in vitro and in vivo.
Ultrasonographic prediction of homozygous α0‐thalassemia using placental thickness, fetal cardiothoracic ratio and middle cerebral artery Doppler: alone or in combination?
Authors: Leung K. Y. , Cheong K. B. , Lee C. P. , Chan V. , Lam Y. H. , Tang M. 
Published: January 2010

AbstractObjectiveTo compare the predictive values of three ultrasonographic parameters: placental thickness (PT), fetal cardiothoracic ratio (CTR) and middle cerebral artery peak systolic velocity (MCA‐PSV), alone or in combination, in pregnancies affected by homozygous α0‐thalassemia at 12–20 weeks' gestation.MethodsPregnant women at risk of carrying a fetus affected by homozygous α0‐thalassemia were studied from 1995 to 2006 using serial ultrasonography at 12–15 weeks, 16–20 weeks and 30 weeks' gestation. We measured CTR and PT from 1995, and MCA‐PSV as well from 1997. An invasive prenatal test was offered if cardiomegaly with or without placentomegaly was detected but the MCA‐PSV results were used only retrospectively for analysis.ResultsOf a total of 777 at‐risk fetuses studied, 138 (17.8%) were affected by homozygous α0‐thalassemia. At 12–15 weeks' gestation, 598 ultrasound examinations were performed. CTR was better than both PT and MCA‐PSV in the prediction of affected pregnancies. The highest sensitivity (98.3%) was achieved by the combination of CTR and/or MCA‐PSV at a false‐positive rate of 15.8%. At 16–20 weeks' gestation, 410 ultrasound examinations were performed, 121 of which were at the patient's first visit and 289 of which were at a follow‐up visit. Both CTR and MCA‐PSV predicted the affected pregnancies equally well. The sensitivity of CTR was 100.0%, but the false‐positive rate was 5.2%. In contrast, the false‐positive rate of MCA‐PSV alone was 1.4% and that of the combination of CTR and MCA‐PSV was 0%, although their sensitivities were less than 65%.ConclusionsThe data suggest that adding MCA‐PSV to CTR in the prediction of homozygous α0‐thalassemia can increase the sensitivity at 12–15 weeks and decrease the false‐positive rate at 16–20 weeks' gestation. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Role of Collaborative Academic Partnerships in Surgical Training, Education, and Provision
Authors: Riviello Robert , Ozgediz Doruk , Hsia Renee Y. , Azzie Georges , Newton Mark , Tarpley John 
Published: January 2010

AbstractThe global disparities in both surgical disease burden and access to delivery of surgical care are gaining prominence in the medical literature and media. Concurrently, there is an unprecedented groundswell in idealism and interest in global health among North American medical students and trainees in anesthesia and surgical disciplines. Many academic medical centers (AMCs) are seeking to respond by creating partnerships with teaching hospitals overseas. In this article we describe six such partnerships, as follows: (1) University of California San Francisco (UCSF) with the Bellagio Essential Surgery Group; (2) USCF with Makerere University, Uganda; (3) Vanderbilt with Baptist Medical Center, Ogbomoso, Nigeria; (4) Vanderbilt with Kijabe Hospital, Kenya; (5) University of Toronto, Hospital for Sick Children with the Ministry of Health in Botswana; and (6) Harvard (Brigham and Women’s Hospital and Children’s Hospital Boston) with Partners in Health in Haiti and Rwanda. Reflection on these experiences offers valuable lessons, and we make recommendations of critical components leading to success. These include the importance of relationships, emphasis on mutual learning, the need for “champions,” affirming that local training needs to supersede expatriate training needs, the value of collaboration in research, adapting the mission to locally expressed needs, the need for a multidisciplinary approach, and the need to measure outcomes. We conclude that this is an era of cautious optimism and that AMCs have a critical opportunity to both shape future leaders in global surgery and address the current global disparities.
C‐Reactive Protein Is an Early Predictor of Septic Complications After Elective Colorectal Surgery
Authors: Ortega‐Deballon Pablo , Radais François , Facy Olivier , d’Athis Philippe , Masson David , Charles Pierre E. , Cheynel Nicolas , Favre Jean‐Pierre , Rat Patrick 
Published: January 2010

AbstractBackgroundNowadays, most patients who undergo colorectal surgery are discharged early. An early predictor of septic complications could avoid readmissions and decrease morbidity. CRP could be a good predictor allowing a safe discharge.MethodsA prospective, observational study was conducted from November 2007 to October 2008. All patients who underwent elective colorectal surgery were included. Clinical (temperature, pulse, abdominal tenderness, bowel movements) and laboratory data (C‐reactive protein, leukocyte count) were recorded and evaluated as early predictors of septic complications (namely, anastomotic leaks). All detected leaks were considered fistulas, independently of their clinical significance. Clinical and inflammatory parameters were analyzed with univariate and multivariate techniques; logistic regression was performed and areas under the receiver operating characteristic curve were compared.ResultsA total of 133 patients were included. The overall incidence of anastomotic leaks was 15.5% and mortality was 4.5%. C‐reactive protein at postoperative days 2 and 4 was a good predictor of anastomotic leak (areas under the curve were 0.715 and 0.845, respectively) and other postoperative septic complications (areas under the curve were 0.804 and 0.787), showing the highest accuracy among clinical and laboratory data. A cutoff of 125 mg/l in the level of C‐reactive protein at postoperative day 4 yielded a sensitivity of 81.8% and a negative predictive value of 95.8% for the detection of anastomotic leakage.ConclusionsC‐reactive protein is a simple way to ensure a safe discharge from hospital after elective colorectal surgery. Patients with CRP values >125 mg/l on the fourth postoperative day should not be discharged.
Peritoneal Infusion with Cold Saline Decreased Postoperative Intra‐Abdominal Adhesion Formation
Authors: Fang Cheng‐Chung , Chou Tzung‐Hsin , Lin Geng‐Shiau , Yen Zui‐Shen , Lee Chien‐Chang , Chen Shyr‐Chyr 
Published: January 2010

AbstractBackgroundPostoperative intra‐abdominal adhesion is a common morbidity after laparotomy. We try to determine whether peritoneal infusion with cold saline may decrease postoperative intra‐abdominal adhesion formation.MethodsNinety‐six male BALB/c mice weighing 25‐30 g were randomized into four groups: (I) adhesion model with infusion of 4°C cold saline, (II) adhesion model with infusion of room temperature saline, (III) adhesion model without infusion of saline, and (IV) sham operation without infusion of saline. Adhesion scores, incidence of adhesion, and serum cytokines were measured at postoperative days 1, 3, 7, and 14.ResultsGroup I had lower adhesion scores than groups II and III (P < 0.0001). IL‐6, IL‐10, and TNF‐α were significantly increased in the groups I, II, and III compared to group IV (P < 0.0001). IL‐6 in group I was significantly decreased compared to that in group III (P < 0.0004). IL‐10 in group I was significantly increased compared to that in groups II (P < 0.0001) and III (P < 0.05). TNF‐α in group I was significantly decreased compared to that in groups II (P < 0.0004), and III (P < 0.05).ConclusionPeritoneal infusion with cold saline may decrease the degree of postoperative intra‐abdominal adhesion formation.
Peritoneal Damage: The Inflammatory Response and Clinical Implications of the Neuro‐Immuno‐Humoral Axis
Authors: Sammour Tarik , Kahokehr Arman , Soop Mattias , Hill Andrew G. 
Published: January 2010

AbstractBackgroundThe peritoneum is a bilayer serous membrane that lines the abdominal cavity. We present a review of peritoneal structure and physiology, with a focus on the peritoneal inflammatory response to surgical injury and its clinical implications.MethodsWe conducted a nonsystematic clinical review. A search of the Ovid MEDLINE database from 1950 through January 2009 was performed using the following search terms: peritoneum, adhesions, cytokine, inflammation, and surgery.ResultsThe peritoneum is a metabolically active organ, responding to insult through a complex array of immunologic and inflammatory cascades. This response increases with the duration and extent of injury and is central to the concept of surgical stress, manifesting via a combination of systemic effects, and local neural pathways via the neuro‐immuno‐humoral axis. There may be a decreased systemic inflammatory response after minimally invasive surgery; however, it is unclear whether this is due to a reduced local peritoneal reaction.ConclusionsInterventions that dampen the peritoneal response and/or block the neuro‐immuno‐humoral pathway should be further investigated as possible avenues of enhancing recovery after surgery, and reducing postoperative complications.
Pediatric Gaucher disease type I and mild growth hormone deficiency: a new feature?
Authors: Biasucci Giacomo , Manfredi Piera 
Published: January 2010

AbstractA 5‐year‐old girl was referred to the Department of Pediatrics and Neonatology, Guglielmo da Saliceto Hospital, Italy, because of growth retardation. Clinical and laboratory investigations showed pallor, hepatosplenomegaly, anemia and low/normal platelet count. Further investigations led to the diagnosis of Gaucher disease (GD). We believe this is the first report of growth hormone deficiency in a growth‐retarded child with GD. After 1 year of imiglucerase replacement enzyme therapy, her bone age had normalized, linear growth rate had accelerated, and insulin growth factor‐1 (IGF‐1) and, perhaps more interestingly, growth hormone deficiency, had normalized. While the pathophysiological mechanisms underlying compromised growth in GD are poorly understood, the response to imiglucerase reported in this patient suggests that growth hormone deficiency is related to the underlying metabolic disorder in GD, rather than a primary endocrine pathology. Growth hormone deficiency adds to an already extensive list of possible clinical manifestations of this heterogeneous and complex disorder.
Plant fecundity and pre‐dispersal reproductive losses in a common and a rareEuphorbiaspecies (Euphorbiaceae)
Authors: Boieiro Mário , Serrano Artur R. M. , Rego Carla , Espadaler Xavier 
Published: January 2010

AbstractComparative studies on the reproductive biology of closely related plant species have provided valuable information to understand the causes and consequences of common‐rare differences with possible applications for the management of threatened populations. The magnitude and spatiotemporal variability of seed production and pre‐dispersal reproductive losses were studied for 3 years in the rare endemicEuphorbia welwitschiiand in its widespread congenerE. characias. The factors responsible for a decrease in potential seed production in these species were the lack of a functional ovary in the cyathium, ovary and fruit abortion, seed predation by insects and seed abortion. InE. characias, the mothAcroclita subsequanawas also responsible for minor reproductive losses. The proportion of male cyathia varied significantly between seasons, populations and species, being consistently higher inE. characiasthan inE. welwitschii. Reproductive losses that resulted in ovary, fruit and seed abortion affected mostly the endemic species and were heavier in the populations located near the sea due to local adverse climatic conditions. Seed predators inflicted higher reproductive losses to the endemic species than to its widespread congener and their impact was particularly heavy at Risco. The twoEuphorbiaspecies differed markedly in cyathia production, withE. welwitschiiproducing systematically a lower number of cyathia than its widespread congener and this, together with higher levels of ovary, fruit and seed abortion, seemed to be the main reasons for the low reproductive output of this rare species.
A demographic analysis of population responses to the manipulation of adult males in Calomys venustus (Rodentia, Sigmodontinae)
Authors: Priotto José , Gómez Daniela , Polop Jaime 
Published: January 2010

AbstractIn many species of mammals, adults play an important role in influencing the survival and/or reproduction of juveniles. Adult males could have a negative effect on population density when their absence becomes a limiting factor in female fertilization. We tested the hypotheses that the absence of overwintering males (adult males) reduces the population growth rate through a delay in the onset of reproductive activity of Cohort 1 females in Calomys venustus populations. The study was carried out in two control and two experimental enclosures (0.25 ha). Adult males were removed after their offspring were born. Weekly trapping sessions were carried out from spring to autumn. To estimate population growth rates (λ), apparent survival (ϕ) and seniority probability (γ) were estimated using capture–mark‐recapture models. Models were constructed with these two parameters and recapture probability (p) constrained to vary as a function of time, enclosure and/or treatment. We derived estimates of population growth rates through the estimates of ϕ and γ. The best models for ϕ and γ did not show a treatment effect. Variability between the four enclosures was greater than between control and experimental enclosures. Enclosures had different growth rates at the beginning of the study but were equaled at the end. Temporal variation in population growth rates was a result of temporal variation of γ. The two controls showed the highest growth rates earlier in time. The results did not support the hypothesis tested in this study. It seems that the number of overwintering males do not affect the population growth rate.