bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retinoic acid modulates chondrogenesis in the developing mouse cranial base
Authors: Kwon Hyuk‐Jae , Shin Jeong‐Oh , Lee Jong‐Min , Cho Kyoung‐Won , Lee Min‐Jung , Cho Sung‐Won , Jung Han‐Sung 
Published: August 2011

AbstractThe retinoic acid (RA) signaling pathway is known to play important roles during craniofacial development and skeletogenesis. However, the specific mechanism involving RA in cranial base development has not yet been clearly described. This study investigated how RA modulates endochondral bone development of the cranial base by monitoring the RA receptor RARγ, BMP4, and markers of proliferation, programmed cell death, chondrogenesis, and osteogenesis. We first examined the dynamic morphological and molecular changes in the sphenooccipital synchondrosis‐forming region in the mouse embryo cranial bases at E12–E16. In vitro organ cultures employing beads soaked in RA and retinoid‐signaling inhibitor citral were compared. In the RA study, the sphenooccipital synchondrosis showed reduced cartilage matrix and lower BMP4 expression while hypertrophic chondrocytes were replaced with proliferating chondrocytes. Retardation of chondrocyte hypertrophy was exhibited in citral‐treated specimens, while BMP4 expression was slightly increased and programmed cell death was induced within the sphenooccipital synchondrosis. Our results demonstrate that RA modulates chondrocytes to proliferate, differentiate, or undergo programmed cell death during endochondral bone formation in the developing cranial base. J. Exp. Zool. (Mol. Dev. Evol.) 316:574–583, 2011. © 2011 Wiley Periodicals, Inc.
Neuroprotection by rosiglitazone in transient focal cerebral ischemia might not be mediated by glutamate transporter‐1#
Authors: Verma Rajkumar , Mishra Vikas , Gupta Konica , Sasmal Dinakar , Raghubir Ram 
Published: August 2011

AbstractGlutamate transport represents a key mechanism for maintaining low level of glutamate in the extracellular milieu to restrict the excitotoxic action of glutamate released during ischemia/reperfusion (I/R) injury. Recently, it has been reported that glutamate transporter‐1 (GLT‐1) is a novel target for peroxisome proliferator‐activated receptor‐γ (PPARγ) agonist, which shows neuroprotection following oxygen glucose deprivation (OGD) in neuronal–astrocytic cocultures. Hence, the present study was undertaken to investigate the role of rosiglitazone in neuroprotection mediated by GLT‐1 following focal cerebral I/R injury in rat. We found that rosiglitazone (2 mg/kg i.p) administered pre‐ or post‐I/R injury significantly improved behavioral outcome and decreased cerebral infarct volume. However, no significant changes were observed in GLT‐1 mRNA and protein expression in rosiglitazone‐treated rats following 1 hr of ischemia/24 hr of reperfusion (1/24 hr I/R) injury. Interestingly, bioinformatics analysis also does not reveal any PPAR response element on the GLT‐1/EAAT2 promoter region. Further rosiglitazone neither increased [3H]glutamate uptake in glia‐enriched preparations nor caused any change in glutamine synthetase activity. On the other hand, there was a significant (P < 0.05) downregulation in tumor necrosis factor‐α and interleukin‐1β gene expression, which were more pronounced in the posttreatment group. The posttreatment with rosiglitazone also significantly reduced the increase in prostaglandin E2 level in the ischemic brain. Therefore, the present findings suggest that the neuroprotective effect of rosiglitazone does not seem to be mediated by modulation of GLT‐1 protein expression/activity in a focal cerebral ischemia model. However, the results do provide increasing evidence that the neuroprotective effect may be mediated by its antiinflammatory action. © 2011 Wiley‐Liss, Inc.
Sirt1 overexpression in neurons promotes neurite outgrowth and cell survival through inhibition of the mTOR signaling
Authors: Guo Wenjing , Qian Lei , Zhang Jing , Zhang Wei , Morrison Alastair , Hayes Philip , Wilson Steve , Chen Tongsheng , Zhao Jie 
Published: August 2011

AbstractThe mammalian nicotinamide‐adenine dinucleotide (NAD)‐dependent deacetylase Sirt1 impacts different processes involved in the maintenance of brain integrity and in the pathogenic pathways associated with several neurodegenerative disorders, including Alzheimer's disease. Here we used human Sirt1 transgenic mice to demonstrate that neuron‐specific Sirt1 overexpression promoted neurite outgrowth and improved cell viability under normal and nutrient‐limiting conditions in primary culture systems and that Sirt1‐overexpressing neurons exhibited higher tolerance to cell death or degeneration induced by amyloid‐β1–42 oligomers. Coincidentally, we found that enhanced Sirt1 expression in neurons downregulated the mammalian target of rapamycin (mTOR) protein levels and its phosphorylation without changes in its mRNA levels, which was accompanied by concomitant inhibition of the mTOR downstream signaling activity as revealed by decreased p70S6 kinase (p70S6K) phosphorylation at Thr389. Consistently with this, using a Sirt1 siRNA transfection approach, we observed that reduction of endogenous mouse Sirt1 led to increased levels of mTOR and phosphorylation of itself and p70S6K as well as impaired cell survival and neurite outgrowth in wild‐type mouse primary neurons, corroborating a suppressing effect of mTOR by Sirt1. Correspondingly, the mTOR inhibitor rapamycin markedly improved neuronal cell survival in response to nutrient deprivation and significantly enhanced neurite outgrowth in wild‐type mouse neurons. The protective effect of rapamycin was extended to neurons even with Sirt1 siRNA knockdown that displayed developmental abnormalities compared with siRNA control‐treated cells. Collectively, our findings suggest that Sirt1 may act to promote growth and survival of neurons in the central nervous system via its negative modulation of mTOR signaling. © 2011 Wiley‐Liss, Inc. © 2011 Wiley‐Liss, Inc.
In situ cosmogenic exposure ages from the Isle of Skye, northwest Scotland: implications for the timing of deglaciation and readvance from 15 to 11 ka
Authors: Small David , Rinterknecht Vincent , Austin William , Fabel Derek , Miguens‐Rodriguez Maria , xu Sheng 
Published: August 2011

AbstractWe present 10 in situ cosmogenic exposure ages from two moraines on the Isle of Skye. The Strollamus medial moraine was deposited during deglaciation of the Devensian ice sheet and yields a mean exposure age from five samples of 14.3 ± 0.9 ka. The moraine age indicates that a significant ice mass existed on Skye at the time of a regional readvance recorded in Wester Ross, northwest Scotland. Taken at face value the ages suggest that deglaciation did not occur until well into Greenland Interstade 1. The Slapin moraine represents the local limit of the Loch Lomond Readvance (LLR) and yields a mean exposure age from five samples of 11.5 ± 0.7 ka, which is consistent with deposition relating to the LLR. These ages suggest that the maximum extent may have been reached late in the stadial and that some glaciers may have remained active until after the climatic amelioration that marks its end. This scenario is considered unlikely given the nature of the climate during this period, which leads us to call for a locally calibrated production rate. Copyright © 2011 John Wiley & Sons, Ltd.
Holocene migration of oceanic front systems over the Conrad Rise in the Indian Sector of the Southern Ocean
Authors: Katsuki Kota , Ikehara Minoru , Yokoyama Yusuke , Yamane Masako , Khim Boo‐Keun 
Published: August 2011

AbstractThere has been limited previous research about Holocene climate variability in the Indian Sector of the Southern Ocean. Here we examine centennial‐scale changes in diatom assemblages and stable isotopic ratios since 10 000 cal a BP in a high‐accumulation‐rate sediment core from the Conrad Rise. Although abundances of dominant diatom taxa (Fragilariopsis kerguelensis and Thalassiothrix antarctica) are comparatively constant, relative abundances of secondary taxa fluctuate. Before c. 9900 cal a BP, winter sea‐ice and cold water covered the Conrad Rise. Following deglaciation the sea‐ice retreated from the Conrad Rise, lagging that of the Atlantic and eastern Indian Sectors by about 1500 a. The Polar Front moved southward during the early Holocene optimum and north Antarctic Zone waters covered the Conrad Rise for about 650 a. After 9300 cal a BP, solar insolation strongly influenced sea surface temperature and primary productivity in the Southern Ocean. In the high‐latitude Indian Sector, productivity increased 1500 a after the onset of late Holocene neoglaciation. Periodic δ18O and cold‐water diatom taxa spikes (at intervals of 200 and 300–500 a, respectively) occurred after 9300 cal a BP, probably associated with solar activity. Fluctuations in short‐term sea surface temperature and cold‐water taxa are synchronous with changes in δD observed in an east Antarctic ice core. Copyright © 2011 John Wiley & Sons, Ltd.
Allelic loss of susceptibility loci and the occurrence of BRAF and RAS mutations in patients with familial non‐medullary thyroid cancer
Authors: Na Kuk Young , Kim Ra Mi , Song Eun‐Mi , Lee Ji Hyun , Lee Jandee , Soh Euy‐Young 
Published: August 2011

AbstractObjectivesApproximately 5% of non‐medullary thyroid cancer (NMTC) diagnoses are made against a background of familial predisposition and, in such instances, the disease is termed familial non‐medullary thyroid cancer (FNMTC). To date, neither genetic alterations causing FNMTC nor genes predisposing to the condition have been described. The objective of the present study was to evaluate loss of heterozygosity (LOH) at the four known susceptibility loci (fPTC/PRN, NMTC1, MNG1, and TCO1) and to compare the mutation rates of RAS/RAF genes in patients with FNMTC and sporadic NMTC.MethodsFourteen FNMTCs in patients from seven families were analyzed in terms of involvement of the four susceptibility loci, and 63 thyroid cancer tumors [FNMTC (29) and NMTC (34)] were evaluated for the occurrence of mutations in BRAF, and H‐, N‐, and K‐RAS, using polymerase chain reaction, single‐strand conformation polymorphism (PCR‐SSCP) analysis, and direct sequencing.ResultsOnly five (35.7%) tumors showed loss of LOH at the three susceptibility loci (NMTC1, MNG1, or TCO1). These allelic losses did not show a specific pattern. Four (13.8%) FNMTCs and one (2.9%) NMTC had H‐RAS (codon 12) mutations. Further, mutation of BRAF V600E was observed in 12 (41.4%) FNMTCs and 29 (85.3%) NMTCs.ConclusionFour known susceptibility loci are infrequently involved in FNMTC. Although further studies are needed, the present findings additionally suggest that somatic activation of oncogenes via BRAF and RAS mutation plays a role in FNMTC tumorigenesis. J. Surg. Oncol. 2012; 105:10–14. © 2011 Wiley Periodicals, Inc.
Multidisciplinary head and neck cancer clinic and adherence with speech pathology
Authors: Starmer Heather , Sanguineti Giuseppe , Marur Shanthi , Gourin Christine G. 
Published: August 2011

AbstractObjectives:To determine the effect of referral patterns on compliance with speech–language pathology (SLP) treatment of voice and swallowing difficulties in patients with head and neck cancer (HNCA).Study Design:Retrospective cohort study.Methods:Patients with newly diagnosed oropharyngeal HNCA referred for pretreatment SLP evaluation comprised the study population. Compliance was measured by participation in SLP therapy during and after head and neck treatment, as well as by the number of missed and completed visits. Outcomes were compared between patients who were initially evaluated through the multidisciplinary clinic and those evaluated outside of the multidisciplinary clinic format.Results:The final study sample included 118 individuals with oropharyngeal tumors. All patients were treated with primary radiotherapy with or without chemotherapy. Patients evaluated initially through the multidisciplinary clinic had more SLP visits than those who did not participate in the multidisciplinary clinic (mean = 1.8 vs. 0.2, P <.0001). Participation in SLP treatment was significantly greater for patients ≥60 years of age (odds ratio [OR] = 2.4, P =.032) and for patients who participated in the multidisciplinary clinic (OR = 19.3, P <.0001). Tumor stage, sex, race, marital status, and insurance status were not associated with patient compliance. Multivariate analysis revealed that participation in a multidisciplinary clinic was the only significant variable associated with SLP treatment compliance (OR = 12.9, P <.0001), after controlling for all other variables.Conclusions:Patients evaluated in a multidisciplinary clinic are more likely to comply with SLP treatment recommendations.
Congenital choristomas of the oral cavity in children
Authors: Chai Raymond L. , Ozolek John A. , Branstetter Barton F. , Mehta Deepak K. , Simons Jeffrey P. 
Published: August 2011

AbstractObjectives/Hypothesis:To review our institutional experience with oral cavity choristomas in children.Study Design:Retrospective case series and medical record review.Methods:Medical records including clinic notes, operative reports, radiologic studies, and pathology specimens were reviewed. All imaging studies and pathology material were reviewed by a head and neck radiologist and pediatric pathologist, respectively.Results:Sixteen patients (10 males and 6 females) with congenital oral cavity choristomas were identified. Mean age at diagnosis was 1.8 months. Location of the lesions included tongue (n = 9) and floor of mouth (n = 7). Preoperative imaging included magnetic resonance imaging (n = 6), computed tomography (n = 5), plain radiography (n = 1), and no imaging (n = 4). Radiographically, the lesions were consistently lobular with well‐defined margins, but other imaging features often mimicked other masses that can arise in the tongue and floor of mouth. Symptoms were present in five of 16 patients and included difficulty feeding, swelling with upper respiratory infection, and partial airway obstruction. Complete surgical excision was performed in 15 of 16 patients; mean age at the time of surgery was 12.7 months. One patient underwent marsupialization. No complications were noted perioperatively. No recurrences of choristoma were seen. On histologic examination, the predominant component was cystic with cyst linings of respiratory epithelium (n = 5), gastric (foveolar) epithelium (n = 1), or both (n = 10).Conclusions:This study supports surgical excision as an effective intervention for children with oral cavity choristomas. Because the etiology of these cysts is unknown and diagnostic terminology is widely variable, we propose a more descriptive diagnosis based on the histology (i.e., lingual choristoma [or lingual developmental cyst] with respiratory epithelium or lingual choristoma [or lingual developmental cyst] with gastric epithelium).
The effect of heat treatment on superconductivity of Zn‐doped YBa2Cu3‐xZnxO7‐y
Authors: Xue Z. , Fu H. , Dong A. , Che G. , Wang Y. 
Published: August 2011

AbstractYBa2Cu3‐xZnxO7‐y compounds with x = 0, 0.05, 0.15, and 0.30 have been synthesized by standard solid state reaction method. The crystal structure, lattice parameters, and oxygen content are not changed by the substitution of Zn for Cu since both valence state and ionic radius are almost identical for Zn and Cu elements in YBa2Cu3‐xZnxO7‐y. However, the superconducting transition temperature Tc decreases with the increase of Zn content, reflecting the Tc‐suppression effect of Zn substitution. Heat treatment experiments indicate that the heat treatment at low temperature is beneficial to improve the superconductivity of the sample. But Tc decreases with the increase of annealing temperature when the treatment temperature is above 300°C, and finally the superconductivity disappears at approximately 920°C, 700°C and 550°C for the samples with x = 0.0, 0.05 and 0.15, respectively. Our experiments indicate that the superconductivity of the sample with higher Zn content is more sensitive to the oxygen content, and a small decrease in the oxygen content can lead to a considerable decrease of Tc.
Erosion mechanisms of aluminium nitride ceramics at different impact angles
Authors: Grilec K. , Ćurković L. , Kumić I. , Baršić G. 
Published: August 2011

AbstractIn this paper, erosion wear behaviour of aluminium nitride (AlN) ceramics is studied. The influence of particle hardness and shape on erosion of the AlN surface is examined. The effect of varying the impingement angle on the weight loss and the roughness parameters of AlN ceramics testing sample is also determined. Therefore, erosive wear behaviour of AlN ceramics was investigated using SiC and SiO2 particles as erodents, at following impact angles: 30°, 45°, 60°, 75° and 90°. Scanning electron microscopy (SEM) was used to analyze the eroded surfaces in order to determine erosion mechanisms. The roughness parameters (Ra, Rz and Rmax), before and after erosion with SiO2 and SiC particles at 30° and 90° angles of impingement, respectively, were determined using a profilometer. It was found that the impact angle is influencing the erosion wear of the AlN ceramics and maximum erosion takes place at impact angle of 90°. The results indicate that hard, angular SiC particles cause more damage than softer, more rounded SiO2 particles.
Effects of type of shielding gas upon local mechanical properties of laser welded joint in heat‐treatable steel
Authors: Bauer B. , Kralj S. , Kožuh Z. , Dorn L. 
Published: August 2011

AbstractSmall additions of oxygen or carbon dioxide to argon shielding at laser beam welding can increase welding speed and productivity and decrease the mechanical properties of welded joints. The effect of the type of active shielding gas mixtures based on argon with additions of oxygen and/or carbon dioxide upon the local mechanical properties of laser welded joints of heat‐treatable steel 25 CrMo 4 was studied. Microshear test method has been used to investigate the local mechanical properties of welded joints, including microshear strength, microshear plasticity and microshear thoughness. The obtained data were statistically processed, and a mathematical modeling of mechanical properties applying the method of response surfaces was carried out. The analysis revealed that the impact of the used shielding gas mixtures upon the local mechanical properties of the joint is not very significant. The results indicate that the microshear test can be used successfully for estimation of the local mechanical properties distribution of laser welded joints.
Assessment of sharply notched specimens under high mean stress by means of the local‐strain‐approach
Authors: Schneider R. , Wuttke U. , Berger C. 
Published: August 2011

AbstractIm vorliegenden Beitrag wird aufbauend auf dem Örtlichen Konzept ein Bewertungsverfahren erläutert, mit dem sich die Schwingfestigkeit scharf gekerbter Bauteile unter hoher Mittelspannung rechnerisch abschätzen lässt. Die Erweiterung des Konzeptes besteht im Wesentlichen in der Berücksichtigung der zyklischen Spannungsrelaxation im Kerbgrund. Die Beschreibung des Konzeptes erfolgt anhand einer klassischen Schraube‐Mutterverbindung, die ein sehr gutes Beispiel für zyklisch beanspruchte Bauteile bei hohen Mittellasten ist. Eine Überleitung der Örtlichen Bewertung auf das im Allgemeinen bei Schrauben angewendete Nennspannungskonzept erfolgt am Beispiel der kombinierten Biege‐ und Axialbeanspruchung.
Effect of the geometry on the description of the water absorption by composite materials using diffusion models
Authors: da Silva W. P. , e Silva C. M. D. P. S. , Farias V. S. O. , Lima A. G. B. 
Published: August 2011

AbstractIn this paper, the influence of the geometric representation of samples of a composite material on the description of its water absorption is studied. It is supposed that diffusion models with boundary condition of the first kind satisfactorily describe the absorption, and that the volume and effective mass diffusivity are constant during the process. The geometries used to represent the samples are: infinite slab, rectangular plate and parallelepiped. The effective mass diffusivity is determined by coupling of the analytical solution corresponding to the model to an optimizer based on the inverse method. For the dimensions of the samples, based on statistical indicators obtained in the simulation of each model, it can be concluded that the best geometric representation is the parallelepiped. However, if there is no interest about the moisture distribution within the sample and the only objective of the research is to describe the water absorption kinetics, the infinite slab can also be used.
Melting and glass transition as mixing processes
Authors: Hoffmann H.‐J. 
Published: August 2011

AbstractMelting of chemically bonded solids has been explained recently by transitions of electrons in higher electron states. Such transitions are shown to cause decomposition of the crystals into many units or sub‐systems build‐up of one or few atoms that mix in the melt. Most chemical elements possess molar melting entropies, ΔSm, in the order of the universal molar gas constant, R, or less, which is expected for mixing of a small number of differing groups of particles totalling one mole. Only in the case of crystals with bonding via sp3‐ and similar hybrids the molar melting entropy is much larger. This observation can be interpreted by a massive change of the phonon spectra of the melting solids in addition to the decomposition into mixing units. Upon cooling the melt below the glass transition temperature, Tg, the mixed decomposition products of the melt are frozen in. This frozen‐in mixing entropy cannot be removed from the undercooled melt and – finally – the glass by thermal conduction and remains stored in the glass until the absolute zero of the temperature. Removal of the mixing entropy is possible only by reordering of the constituents or crystallisation. Since the entropy is frozen‐in near and above Tg not only entropy but also enthalpy is frozen‐in, which is often neglected in the literature. The specific amounts of the entropy and enthalpy frozen‐in are not unique for a given glass but depend on the status of relaxation.
Respiratory diseases in Greater Buenos Aires and meteorological variables
Authors: Alessandro Adelia P. 
Published: August 2011

AbstractThis paper provides a preliminary assessment of the relationship between atmospheric conditions and respiratory diseases based on the analysis of disease occurrence in patients during the period August 2004 to September 2007. To this effect, medical records from a medical services firm were examined, as well as temperature data (daily, maximum, minimum, dew point), pressure and relative humidity, measured at the meteorological station of Ezeiza (34.49°S, 58.32°W). The analysis revealed a strong seasonal relationship, with a peak in winter (low temperatures) and a minimum in summer. The annual cycle explains 76.24% of the total of the variance of the series. Most patients were below 10 years of age and older than 71. The best correlations were observed between daily values of the number of patients presenting with disease symptoms (N) and temperature, and between monthly values of N and maximum temperature (coefficients of − 0.73 and − 0.91, respectively). Multiple correlation between all meteorological variables obtained with the Stepwise method, made it possible to estimate the expected number of patients on daily and monthly scales. Mean geopotential height fields at 1000 hPa corresponding to days with the lowest number of patients have opposite synoptic characteristics to those of days with the largest number of patients. The same occurs with the fields corresponding to consecutive days with less than 40 patients per day and consecutive days with more than 300 patients per day. The fields corresponding to extremely high values show a positive pressure anomaly and consequent cold air advection over Buenos Aires and surrounding areas. Copyright © 2011 Royal Meteorological Society