bluuebunny/crossref_metadata_2025 huggingface dataset:
EGFR gene copy number as a predictive biomarker for the treatment of metastatic colorectal cancer with anti-EGFR monoclonal antibodies: a meta-analysis
Authors: Yang Zu-Yao , Shen Wei-Xi , Hu Xue-Feng , Zheng Da-Yong , Wu Xin-Yin , Huang Ya-Fang , Chen Jin-Zhang , Mao Chen , Tang Jin-Ling
Published: August 2012

Background

Epidermal growth factor receptor gene copy number (EGFR GCN) has been heavily investigated as a potential predictive biomarker for the treatment of metastatic colorectal cancer (mCRC) with anti-EGFR monoclonal antibodies (MAbs). The objective of this study was to systematically review current evidences on this issue.

Methods

PubMed, EMBASE, The Cochrane Library, Chinese Biomedical Literature Database, Wanfang Data, and the conference abstracts of American Society of Clinical Oncology and European Society of Medical Oncology were comprehensively searched. Studies that reported the objective response rate (ORR), progression-free survival, and/or overall survival of mCRC patients treated with anti-EGFR MAbs, stratified by EGFR GCN status, were included. The effect measures for binary outcome (response) and time-to-event outcomes (progression-free survival and overall survival) were risk difference and hazard ratio, respectively. Statistical heterogeneity among the studies was assessed by the Cochran’s Q-test and the I
2 statistic. If appropriate, a quantitative synthesis of data from different studies would be conducted with a random-effects model.

Results

Nineteen eligible studies were identified. The criteria for increased EGFR GCN (GCN+) were highly inconsistent across different studies. The prevalence of GCN + ranged from 6.9% to 88.9%, and the difference in ORR between patients with GCN + and those with non-increased EGFR GCN (GCN-) varied from −28% to 84%. Because of the significant heterogeneity, no quantitative synthesis of data was performed. There was a general trend towards higher ORR in patients with GCN+. The difference in ORRs between patients with GCN + and those with GCN- was even greater in KRAS wild-type patients, while in KRAS mutated patients the difference often did not exist. Almost all patients with EGFR amplification responded to the treatment. However, the prevalence of EGFR amplification was generally low. Incomplete data on progression-free survival and overall survival seemingly supported the findings on ORR.

Conclusions

Although increased EGFR GCN is generally associated with a better outcome of anti-EGFR MAbs treatment, especially among patients with wild-type KRAS, the clinical utility of this biomarker for selecting recipients of anti-EGFR MAbs would be severely limited by the heterogeneous scoring system and the poor reproducibility of EGFR GCN enumeration due to technical reasons.
Continuous beta-lactam infusion in critically ill patients: the clinical evidence
Authors: Abdul-Aziz Mohd H , Dulhunty Joel M , Bellomo Rinaldo , Lipman Jeffrey , Roberts Jason A
Published: August 2012

There is controversy over whether traditional intermittent bolus dosing or continuous infusion of beta-lactam antibiotics is preferable in critically ill patients. No significant difference between these two dosing strategies in terms of patient outcomes has been shown yet. This is despite compelling in vitro and in vivo pharmacokinetic/pharmacodynamic (PK/PD) data. A lack of significance in clinical outcome studies may be due to several methodological flaws potentially masking the benefits of continuous infusion observed in preclinical studies. In this review, we explore the methodological shortcomings of the published clinical studies and describe the criteria that should be considered for performing a definitive clinical trial. We found that most trials utilized inconsistent antibiotic doses and recruited only small numbers of heterogeneous patient groups. The results of these trials suggest that continuous infusion of beta-lactam antibiotics may have variable efficacy in different patient groups. Patients who may benefit from continuous infusion are critically ill patients with a high level of illness severity. Thus, future trials should test the potential clinical advantages of continuous infusion in this patient population. To further ascertain whether benefits of continuous infusion in critically ill patients do exist, a large-scale, prospective, multinational trial with a robust design is required.
Purification and characterization of a novel plant lectin from Pinellia ternata with antineoplastic activity
Authors: Zuo Zhenyu , Fan Handong , Wang Xue , Zhou Wei , Li Lingling
Published: August 2012

A novel Pinellia ternata lectin was purified from the bulbs of a Chinese herb Pinellia ternata using a combination of hydrophobic chromatography and DEAE-ion exchange chromatography. The lectin was found to be a homodimer of 12093.3 Da subunits as determined by gel filtration and MS. Biochemical characterization of the lectin revealed the existence of a glycoprotein, which contains 3.22% neutral sugars. The N-terminal 10-amino acid sequence of the lectin, QGVNISGQVK, has not been reported for other lectins. The lectin had a special agglutinating activity with mouse erythrocytes at a minimum concentration of 8.0 ug/ml. The lectin was stable in the pH range of pH 5–12 and temperatures up to 80°C for 30 min. The results of MTT experiment showed that the lectin had significant effect towards tumor cells, the maximum inhibition of cell proliferation with Sarcoma 180, HeLa and K562 cell line were 85.2%, 74.6% and 59.4% respectively. Experimental therapy in vivo also showed that PTL apparently inhibited transplanted tumor in mice. Flow cytometric analysis demonstrated that PTL inhibited the proliferation of Sarcoma 180 in a time- and dose-dependent manner through inhibiting the transition of G1/S and subsequently inducing G0/G1 cell cycle arrest. Thus, Pinellia ternata lectin displays a high potential for antitumor activity.
The association of carotid intima media thickness with retinol binding protein-4 and total and high molecular weight adiponectin in type 2 diabetic patients
Authors: Mansouri Masoumeh , Heshmat Ramin , Tabatabaei-Malazy Ozra , Sharifi Farshad , Badamchizadeh Zohreh , Alatab Sudabeh , Omidfar Kobra , Fakhrzadeh Hossein , Larijani Bagher
Published: August 2012

Background

The aim of this study was to investigate whether carotid intima media thickness (CIMT) is associated with serum level of retinol- binding protein-4 (RBP4) and total and high molecular weight (HMW) adiponectin in type 2 diabetes (T2DM) without clinical symptom of atherosclerotic disease.

Method

101 type 2 diabetic patients (mean age, 53.63 ± 8.42 years) and 42 body mass index (BMI) matched control (mean age 50.1 ± 8.4) were recruited. The CIMT was assessed by using B-mode ultrasonography, while serum levels of RBP4 and total and HMW adiponectin were measured by using enzyme linked immunosorbant assay (ELISA). Linear regression analysis was performed with CIMT as dependent variable and adipokines and cardio metabolic risk factors as independent variables.

Result

The CIMT was higher in diabetic group compared to control group (p <0.05). The mean concentration of RBP4 and total and HMW adiponectin did not differ between two groups.

Age (B = 0.44 P <0.05), blood pressure (B = 0.37 P = <0.05), waist circumference (B = −0.21 P <0.05) and TG (B = 0.1 P <0.05) were identified as independent predictors for CIMT in diabetic group, while RBP4 and adiponectin were not associated with CIMT neither in diabetic group nor in control group.

Conclusion

In conclusion, the present study showed that serum levels of RBP4 or total and HMW adiponectin were not potential predictors of CIMT in type 2 diabetic patients who exposed to this risk factor at least for nine years.
Existence of solution for impulsive hybrid differential equation
Authors: Adams Brandi M , Davis Naleceia , Epps Paige , Miller Frederick , Mullen DeAndrai , Vatsala Aghalaya S
Published: August 2012

Purpose

Many problems in science and engineering can be modeled by nonlinear differential equations with initial conditions. The logistic equation is used widely in the study of population growth and decay. The logistic equation also has applications in ecology, statistics, medicine, chemistry, and physics, to name a few. Over time, the population growth or decay tends toward the stable equilibrium. However, in reality, some populations approach extinction or grow away from the equilibrium, and a new equilibrium will be formed. In addition, due to natural causes or unpredictable circumstances like explosions in an oil rig, hurricanes, or flooding at some time, t, the population will jump down or up in a small interval of time. These combined situations can be modeled as impulsive hybrid differential equations. In general, solutions to the nonlinear differential equations cannot be computed analytically.

Methods

It is known that a fruitful method,which is both theoretical and computational, is the generalized monotone method with coupled lower and upper solutions. Furthermore, under uniqueness assumption, we proved the existence of a unique solution.

Results

In this work, we extend the generalized monotone method with coupled upper and lower solutions to impulsive hybrid nonlinear differential equation.

Conclusions

Finally, we provide some numerical examples.
Dystrophic neurites express C9orf72 in Alzheimer's disease brains
Authors: Satoh Jun-ichi , Tabunoki Hiroko , Ishida Tsuyoshi , Saito Yuko , Arima Kunimasa
Published: August 2012

Introduction

Chromosome 9 open reading frame 72 (C9orf72) is an evolutionarily conserved protein with unknown function, expressed at high levels in the brain. An expanded hexanucleotide GGGGCC repeat located in the first intron of the C9orf72 gene represents the most common genetic cause of familial frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Previous studies by immunohistochemistry with two different anti-C9orf72 antibodies named sc-138763 and HPA023873 showed that C9orf72 is expressed chiefly in the cytoplasm of neurons, and is concentrated in the synaptic terminals in the brains of FTD/ALS with or without C9orf72 repeat expansion as well as those of controls. At present, a pathological role of C9orf72 in the process of neurodegeneration remains unknown.

Methods

Using immunohistochemistry we studied C9orf72 expression in the frontal cortex and the hippocampus of six Alzheimer's disease (AD) and 13 control cases, including ALS, Parkinson's disease, multiple system atrophy, and non-neurological cases.

Results

The HPA023873 antibody showed a cross-reactivity to glial fibrillary acidic protein, and therefore stained intensely reactive astrocytes in AD and non-AD brains. Both sc-138763 and HPA023873 antibodies labeled the neuronal cytoplasm and the neuropil with variable intensities, and intensely stained a cluster of p62-negative, UBQLN1-positive swollen neurites, which were distributed in the CA1 region and the molecular layer in the hippocampus of both AD and non-AD brains. Most notably, both of these antibodies reacted strongly with dystrophic neurites accumulated on senile plaques in AD brains.

Conclusion

These results suggest a general role of C9orf72 in the process of neurodegeneration in a range of human neurodegenerative diseases.
A perioperative infusion of sodium bicarbonate does not improve renal function in cardiac surgery patients: a prospective observational cohort study
Authors: Heringlake Matthias , Heinze Hermann , Schubert Maria , Nowak Yvonne , Guder Janina , Kleinebrahm Maria , Paarmann Hauke , Hanke Thorsten , Schön Julika
Published: August 2012

Introduction

Cardiac-surgery-associated-acute-kidney-injury (CSA-AKI) is associated with increased morbidity and mortality. Recent data from patients undergoing on-pump coronary artery bypass grafting suggest that a perioperative infusion of sodium-bicarbonate may decrease the incidence of CSA-AKI. The present study aims to analyze the renoprotective effects of a 24h infusion of sodium-bicarbonate in a large, heterogeneous group of cardiac surgical patients

Methods

Starting in 4/2009, all patients undergoing cardiac surgery at our institution were enrolled in a prospective trial analyzing the relationship between preoperative cerebral oxygen saturation and postoperative organ dysfunction. We used this prospectively sampled data set to perform a cohort analysis of the renoprotective efficiency of a 24h continuous perioperative infusion of sodium-bicarbonate on the incidence of CSA-AKI that was routinely introduced in 7/2009. After exclusion of patients with endstage chronic kidney disease, off-pump procedures, and emergency cases, perioperative changes in renal function were assessed in 280 patients treated with a perioperative infusion of 4 mmol sodium-bicarbonate / kg body weight in comparison with a control cohort of 304 patients enrolled from April to June in this prospective cohort study.

Postoperative changes in urine flow, plasma creatinine, estimated creatinine clearance, and the need for renal replacement therapy were determined according to AKI injury network criteria. Concomitantly, hemodynamics, treatments, complications, and clinical outcomes were recorded. Univariate statistical analyses were performed para- and nonparametrically, as appropriate.

Results

With the exception of a lower prevalence of a history of myocardial infarction and a lower preoperative use of intravenous heparin in the bicarbonate-group, no significant between group differences in patient demographics, surgical risk, type, and duration of surgery were observed. Patients in the bicarbonate group had a lower mean arterial blood pressure after induction of anesthesia, needed more fluids, more vasopressors, and a longer treatment time in the high dependency unit. Despite a higher postoperative diuresis, no differences in the incidence of AKI grade 1 to 3 and the need for renal replacement were observed.

Conclusions

Routine perioperative administration of sodium bicarbonate failed to improve postoperative renal function in a large population of cardiac surgical patients.
Proteogenomic characterization and mapping of nucleosomes decoded by Brd and HP1 proteins
Authors: LeRoy Gary , Chepelev Iouri , DiMaggio Peter A , Blanco Mario A , Zee Barry M , Zhao Keji , Garcia Benjamin A
Published: August 2012

Background

Histone post-translational modifications (PTMs) constitute a branch of epigenetic mechanisms that can control the expression of eukaryotic genes in a heritable manner. Recent studies have identified several PTM-binding proteins containing diverse specialized domains whose recognition of specific PTM sites leads to gene activation or repression. Here, we present a high-throughput proteogenomic platform designed to characterize the nucleosomal make-up of chromatin enriched with a set of histone PTM binding proteins known as histone PTM readers. We support our findings with gene expression data correlating to PTM distribution.

Results

We isolated human mononucleosomes bound by the bromodomain-containing proteins Brd2, Brd3 and Brd4, and by the chromodomain-containing heterochromatin proteins HP1β and HP1α. Histone PTMs were quantified by mass spectrometry (ChIP-qMS), and their associated DNAs were mapped using deep sequencing. Our results reveal that Brd- and HP1-bound nucleosomes are enriched in histone PTMs consistent with actively transcribed euchromatin and silent heterochromatin, respectively. Data collected using RNA-Seq show that Brd-bound sites correlate with highly expressed genes. In particular, Brd3 and Brd4 are most enriched on nucleosomes located within HOX gene clusters, whose expression is reduced upon Brd4 depletion by short hairpin RNA.

Conclusions

Proteogenomic mapping of histone PTM readers, alongside the characterization of their local chromatin environments and transcriptional information, should prove useful for determining how histone PTMs are bound by these readers and how they contribute to distinct transcriptional states.
Estimating Shrinkage, Microfibril Angle and Density of Eucalyptus Wood Using near Infrared Spectroscopy
Authors: Hein Paulo Ricardo Gherardi
Published: August 2012

Developing calibration models from near infrared (NIR) spectra for quickly and reasonably estimating key wood traits has become a prime step in tree breeding programmes. While the optimal procedures for the calibration of NIR-based models for chemical-related wood traits, stiffness and wood density of wood are relatively well established, relatively few studies have dealt with NIR calibrations for wood shrinkage and cellulose microfibril angle (MFA) of cell walls. MFA has major effects on wood stiffness and shrinkage; however, this ultra-structural cell wall feature has been under-utilised by breeding programmes due to the difficulty in measuring it. The aim of this study was to develop NIR models for estimating radial and tangential shrinkage and MFA in Eucalyptus wood. The calibration for MFA provided NIR predicted values suitable for making a selection of the most favourable trees for a given end-use in breeding programmes. The correlation ( r2p) between NIR predicted and X-ray diffraction derived values of MFA was 0.75 and the root mean standard error of the predictions was 1.3 degrees. These estimates appear to be adequate for selecting potential trees in genetic investigations. Calibrations were also established for predicting the dimensional stability of the wood. However, the statistics for shrinkage indicated that the models were not satisfactory as they provided NIR estimated values of limited applicability. Further studies would be useful for establishing adequate protocols for NIR calibrations of these important (but complicated to measure) wood characteristics.
The Potential Use of near Infrared Spectroscopy to Discriminate between Different Pine Species and Their Hybrids
Authors: Espinoza Jesús A. , Hodge Gary R. , Dvorak William S.
Published: August 2012

There is growing interest in the use of pine hybrids in commercial forestry plantations in the tropics and sub-tropics. However, the production of pine hybrid seeds can be difficult and is dependent on the presence of an adequate number of male and female strobili, timely application of the pollination bag, good pollination techniques and reasonable weather conditions. After pollination, a wait of two or more years is required for cones to mature and for seeds to be collected. The seeds collected from artificial hybrid crosses in an orchard are assumed to be true hybrids, but might also be the (female) pure species if pollen contamination has occurred prior to or during bagging of the male strobili. Confirming hybridity in pines is often very difficult in the seedling stage when only needle morphological characteristics are used. In this study, we examined ground oven-dried needle samples of 16 pine species from different geographic regions using near infrared (NIR) spectroscopy to determine if this method is effective in distinguishing between pine species. We also created three “simulated hybrids” by manually mixing needles from three sets of parental pure species. The raw near infrared reflectance spectroscopy data were transformed using standard normal variate and de-trending techniques and a model was developed to distinguish between pure pine species and their “hybrids” using discriminant analysis. A total of 120 paired-species models were developed (one for each potential hybrid of the 16 species). For each of the 120 paired-species models, there were 20 independent observations in a validation data set and the 2400 observations were classified with 94% accuracy. Models were also developed for each of six species-simulated hybrid data sets. A total of 120 independent validation observations were classified as either parental species or simulated hybrid with 90% accuracy. The results indicate that NIR spectroscopy can be used as an effective tool to distinguish between pure pine species and suggest that it will also distinguish hybrids from their parents. Using NIR spectroscopy to verify hybridity in pines might be quicker and less expensive and, in some cases, as accurate as using molecular techniques.
Assessment of Titratable Acidity in Fruit Using Short Wave near Infrared Spectroscopy. Part B: Intact Fruit Studies
Authors: Subedi Phul P. , Walsh Kerry B. , Hopkins David. W.
Published: August 2012

Interactance spectra (700–1100 nm) of intact fruit possess features interpreted as being due to the dilution and perturbation of water OH stretching and combination bands (with the second and third overtones of OH stretching at 960 nm and 740 nm, respectively), while the contribution from citric acid CH2 and OH stretching and combination bands are not obvious. A model developed using interactance spectra collected from the cut surfaces of lime fruit (mean ± SD of 7.3 ± 0.51 g citric acid equivalents 100 mL−1, units subsequently presented as% w/v) achieved prediction results of RMSEP=0.16%, rp2 = 0.79, bias = −0.03%. However, for intact lime fruit, model calibration results ( RMSECV=0.16, rcv2 = 0.85) were markedly better than prediction results ( RMSEP=0.30, rp2 = 0.49). For a low total titratable acidity (TTA) product, peach (with spectra collected across fruit maturity stages; mean ± SD of 0.88 ± 0.17%), calibration results were relatively poor ( RMSECV=0.09%, rcv2 = 0.79) and the model failed in prediction ( RMSEP=0.10%, rp2 = 0.00, bias = 0.02%). It is concluded that interactance geometry shortwave (700–1100 nm) near infrared spectroscopy using diode array instrumentation and an interactance optical geometry suited to on-line or field-portable instrumentation used for Brix and DM assessment is not appropriate for assessment of the acidity of intact low TTA fruit and has limited use for high TTA fruit.
Diesel Oil Quality Parameter Determinations Using Support Vector Regression and near Infrared Spectroscopy for Hydrotreating Feedstock Monitoring
Authors: Alves Julio Cesar L. , Poppi Ronei J.
Published: August 2012

Production monitoring and final quality control of diesel can be performed in refineries using near infrared (NIR) spectroscopy combined with regression algorithms. Partial least squares (PLS) is the multivariate regression approach commonly used for such purposes, but it is deficient for modelling complex data sets, such as found in diesel production at refineries. On the other hand, support vector regression (SVR) has demonstrated greater efficiency with high generalisation performance. The aim of this work was to develop regression models using SVR to improve the effectiveness of determining feedstock quality parameters monitored for hydrotreating process control refinery diesel production. SVR and PLS models were developed for the parameters aniline point, cetane index, density and temperature of distillation (initial boiling point and 50%, 85% and 90% recovered). The results indicate the superior modelling capability of SVR. SVR models predicted test set samples with root mean squares errors which were 21% to 54% lower than those predicted using PLS. The NIR determinations presented root mean square error lower than the reproducibility values specified by the established reference methods.
Evaluation of Agricultural Feedstock-Robust near Infrared Calibrations for the Estimation of Process Parameters in Anaerobic Digestion
Authors: Krapf Lutz Christian , Gronauer Andreas , Schmidhalter Urs , Heuwinkel Hauke
Published: August 2012

An external validation of near infrared (NIR) calibrations for the estimation of process parameters of anaerobic digestion (AD) is reported. Our results, which were obtained using slurry from 26 agricultural biogas plants that were fed with various types of energy crops and livestock residues, support the use of NIR spectroscopy for the screening of AD process parameters, even under challenging conditions. With a root mean square error of prediction ( RMSEP) of 5 g kg−1 fresh matter (FM) for the volatile solids and of 0.2 g kg−1 FM for ammonium (NH4-N), both parameters were soundly estimated. Total volatile fatty acids (VFA), with a RMSEP of 0.9 g kg−1 FM, confirmed the use of NIR analysis for the rapid detection of the accumulation of the total acidity in the slurry. For the tested samples, the alkalinity was found to be a function of the concentrations of NH4-N and total VFA and, hence, can be as well estimated with NIR spectroscopy with a precision of 1 g kg−1 FM. By applying the models to a series of samples that were spiked with propionic acid, the specific estimation of this single acid was demonstrated.
Detection of creatine kinase macroenzymes
Authors: Davidson D Fraser , Scott Julie G
Published: August 2012

Background

It is vital to detect macroenzymes in patients’ plasma or serum since their presence may lead to spurious elevation of enzyme activity, thereby causing diagnostic confusion. Our service for macroenzyme detection has been made available to laboratories throughout the UK. This report describes our laboratory's experience with macro-creatine kinase (CK) detection over a 10-year period.

Methods

In each sample received, the presence of macro-CK was looked for by both polyethylene glycol percent precipitable activity (%PPA) and isoenzyme electrophoresis (IsoEP). The accumulated findings over 10 years were reviewed.

Results

Out of a total number of 255 requests received from throughout the UK, 30 patients (11.8%) were found to be positive for macro-CK (28 type 1 and 2 type 2). Among those found to be positive, the total CK elevation was relatively modest and the %PPA positively correlated with macro-CK by IsoEP and densitometry (Spearman rs = 0.631). The upper reference limit for %PPA of CK could be increased from 37% to 45% after assessment by both an International Federation of Clinical Chemistry-approved calculation and by receiver operating characteristic curve analysis.

Conclusions

Adoption of this change would allow for a more cost-effective investigation protocol. More than 80% of those positive for macro-CK type 1 (immunoglobulin bound) were female, which conforms to findings in many autoimmune processes.
The yeast rapid tRNA decay pathway competes with elongation factor 1A for substrate tRNAs and acts on tRNAs lacking one or more of several modifications
Authors: Dewe Joshua M. , Whipple Joseph M. , Chernyakov Irina , Jaramillo Laura N. , Phizicky Eric M.
Published: August 2012

The structural and functional integrity of tRNA is crucial for translation. In the yeast Saccharomyces cerevisiae, certain aberrant pre-tRNA species are subject to nuclear surveillance, leading to 3′ exonucleolytic degradation, and certain mature tRNA species are subject to rapid tRNA decay (RTD) if they are appropriately hypomodified or bear specific destabilizing mutations, leading to 5′-3′ exonucleolytic degradation by Rat1 and Xrn1. Thus, trm8-Δ trm4-Δ strains are temperature sensitive due to lack of m7G46 and m5C and the consequent RTD of tRNAVal(AAC), and tan1-Δ trm44-Δ strains are temperature sensitive due to lack of ac4C12 and Um44 and the consequent RTD of tRNASer(CGA) and tRNASer(UGA). It is unknown how the RTD pathway interacts with translation and other cellular processes, and how generally this pathway acts on hypomodified tRNAs. We provide evidence here that elongation factor 1A (EF-1A) competes with the RTD pathway for substrate tRNAs, since its overexpression suppresses the tRNA degradation and the growth defect of strains subject to RTD, whereas reduced levels of EF-1A have the opposite effect. We also provide evidence that RTD acts on a variety of tRNAs lacking one or more different modifications, since trm1-Δ trm4-Δ mutants are subject to RTD of tRNASer(CGA) and tRNASer(UGA) due to lack of m2,2G26 and m5C, and since trm8-Δ, tan1-Δ, and trm1-Δ single mutants are each subject to RTD. These results demonstrate that RTD interacts with the translation machinery and acts widely on hypomodified tRNAs.
Characterization of a Natural Dye by Spectroscopic and Chromatographic Techniques
Authors: Espinosa-Morales Y. , Reyes J. , Hermosín B. , Azamar-Barrios J. A.
Published: August 2012

Natural dyes have been extracted from both plants and animal to give color to textiles and handicrafts. This is the case of purple dye extracted fromJusticia spicigera Schldt, an acanthaceae used as a color source since pre-Hispanic period in the Mayan area of Mexico and Central America. Spectroscopic (UV-Vis and FT-IR) and chromatographic (PY-GC/MS) techniques were employed in order to characterize some of their chemical properties. UV-VIS absorption spectra indicates a λmaxpeak at 581 nm, value associated to anthocyanins group under bathochromic effect. On the other hand, a structural characterization realized by FT-IR and Py-GC/MS indicated the presence of polar hydroxibenzoic acids and phenolic compounds which are characteristics of the molecular structure of anthocyanins.
Foreing Produced Shell Objects in the Templo Mayor of Tenochtitlan
Authors: Castro Adrián Velázquez , Arellano Belem Zúñiga , García Guerrero José María
Published: August 2012

The analyses of work traces in the shell objects found in the offerings of the Great Temple of Tenochtitlan, by scanning electron microscopy (SEM), has allowed to find an important group of objects made locally in Tenochtitlan. These shell pieces have been found in the constructive stages IVb to VII (1469-1520). Recently, another groups of objects have been found that present different work traces and that seems to be foreign productions. In this paper this new data will be presented and it will be discuss the possible origin of the objects.
Comparative Study of Two Blue Pigments from the Maya Region of Yucatan
Authors: Fernández-Sabido Silvia , Palomo-Carrillo Yoly , Burgos-Villanueva Rafael , de Coss Romeo
Published: August 2012

A comparative study of two blue pigment found in separate megalithic structures in Yucatán México is presented. The first sample (M1) is a piece of turquoise stucco discovered at the top of a building known as Structure-2 in the town of Dzilam González. The second sample (M2) is a residual blue powder that was contained in a Oxcum Café type ceramic vessel recovered in the rubble of the Kabul building in Izamal city. The interest in characterizing these samples increases with the possibility of finding in them evidence of Maya Blue, a dye created in the eighth century by the Maya people, whose extraordinary physical and chemical properties have been studied in laboratories around the world. Maya Blue was a tailored technology used for several centuries, even during the Spanish occupation, throughout Mesoamerica. Despite 80 years of study, the mysteries of its composition, traditional preparation and obsolescence have not yet been fully resolved. Using different spectroscopic techniques (SEM, EDX, XRD, FTIR, UV-Vis DR) we have studied and compared the blue colorants in M1 and M2. Results indicate that M1 is Maya Blue. Despite some similarities in the infrarred vibrational spectra of the two samples, we have determinated that M2 is not Maya Blue but a non-Mesoamerican mineral pigment known as Ultramarine which was probably introduced to America by Europeans.
Technical Study of a set of Metallic Artifacts from the Maya Site of Lagartero, Chiapas, Mexico
Authors: Guerrero Gabriela Peñuelas , Cosme Ingrid Jiménez , López Pilar Tapia , Ruvalcaba Sil José Luis , Arenas Jesús , Lemoine Aurore , Vargas Jannen Contreras , Portilla Patricia Ruiz , Torres Sonia Rivero
Published: August 2012

During the excavations made at a burial of the post-Classic Mayan period (1220-1521 A.D.) in the pyramid number 2 of the pre-Hispanic site of Lagartero, Chiapas, Mexico, a set of four small metallic artifacts depicting reptile’s heads, were recovered. The objects were in poor conservation conditions and were taken to the Metal Conservation Laboratory of the National School of Conservation (ENCRyM- INAH) for suitable cleaning and conservation treatments.

Analyses allowed identifying important technological features such as gilding remains. The analytical techniques included optical microscopy followed by X-Ray Fluorescence Spectroscopy (XRF), and Scanning Electron Microscope-coupled with Energy Dispersive Spectrometer (MEB-EDS). For the elemental depth profile a combined Particle X-Ray Emission Spectroscopy and Rutherford Backscattering Spectrometry (PIXE–RBS) analysis was carried out.

The results indicate that the objects are made of a copper alloy, and then gilded probably using electrochemical replacement gilding (thickness has less than 1 μm). This technology has been observed in other metallic objects recovered from the Chichen-Itza Cenote in Yucatan, but it was not available in Mesoamerican areas so far. So, it could imply that these artifacts might have been imported from South American areas.
Identifying the Criteria for Determining Status Burials by Results of Integrated Analysis
Authors: Saprykina Irina A. , Zelentsova Olga V.
Published: August 2012

Chemical-technology investigation was carried out for 95 belt sets from the burials of 8th−11thcenturies. In its course three groups of burials were separated on the basis of archaeology-statistical features; the Group 3 was identified as status one. All the groups contain belt sets made from the cooper-based alloys which include silver (6.98−92.87%) and amalgam. The major scheme of the belt sets (Groups 1, 2, 3) production is casting in moulds with print of used plaques; there are belt sets in Groups 1 and 2 which were made in different way (lost wax casting, casting in moulds with print of special matrix, forging). Chemical and technology parameters of the belt sets from the elite burials of the Group 3 are similar to the parameters of the belt sets discovered in the common burials of the Groups 1 and 2. There are a number of burials in the Group 1 the belt sets of which according to their chemical-technology characteristics could be attributing to the “award”.
New Insights into Ancient Maya Building Materials: Characterization of Mortar, Plaster, and Coquina Flagstones from Toniná
Authors: Riquelme Francisco , Cuevas-García Martha , Alvarado-Ortega Jesús , Taylor Shannon , Ruvalcaba-Sil José Luis , Linares-López Carlos , Aguilar-Franco Manuel , Yadeun-Angulo Juan
Published: August 2012

This work shows current research on lithic raw material used by the ancient Maya of Toniná. The core of the city of Toniná lies on a steep-sided hill of calcareous sandstones from the shallow marine deposits dated as Oligocene, in the Chiapas Highlands of Southern Mexico. Results of paleontological fieldwork in Toniná show several biostrome sediments mound-like with tabular bafflestones and large coquina flagstones, which are sheet-like rocks enriched with fossil mollusk shells, corals, encrusted organisms, and calcareous debris. The people of Toniná intentionally selected and carved these rocks for use as building blocks and bricks on floors, walls, and stairways. At least two coquina flagstones measuring about 1.90 m long were identified in an archeological context most likely associated with carved stelae. Also non-marine carbonate rocks such as a crudely banded travertine and spongy calcareous tufa from recent sediments of freshwater environments surrounding Toniná were used by the Maya as a raw material on walls, columns, reliefs and murals base.

Results of the chemical, mineralogical and micromorphological analysis on plaster and bedding mortars from the walls of Toniná display a slightly interbedded lime of sparry calcite cemented in a highly porous groundmass with silt-to pebble-size of calcareous and siliciclastic rock-crushed aggregates, sand, and soil remains. Lime fabric reveals enclosing quartz grains, granular calcite crystals, and carbonaceous inclusions which may suggest that the lime has been made from a burnt grain-rich limestone with fibrous cement and porous microfabric. WDX analysis in lime lumps of plaster reveal an average amount of 1.37 wt% MgO associated with a limestone source ranging from regular to a magnesium-enriched limestone (1 to 2 wt %). XRF detect a strontium-rich level in the calcite matrix of plaster which is as high as that of fossil shells, tufa, and coquina. Finally, XRD shows that the mean amount of calcite in plaster is 95 wt% and lower amount (2-2.5w%) of siliciclastic minerals: quartz and albite. In contrast, calcite in mortar ranges less than 90.1 wt%. The concentrations of non-carbonate minerals, such as quartz and albite, are higher than those in plaster because mortar incorporates more siliciclastic rock remains, sand and clay.
Additions of Minerals in Clays of Morelia Region, Mexico: Effects on Volumetric Stabilization and Color
Authors: Molina W. Martínez , Sil J. L. Ruvalcaba , Guzmán E. M. Alonso , Rentería A. Flores , Ortega M. Manrique , Acosta A. A. Torres
Published: August 2012

Clays were used intensively in cultural heritage’s monuments and objects. Conservation procedures can be performed specifically for earthen materials using stabilized clays, considering that the aesthetic features must be preserved in order to avoid drastic differences and the lost of their patrimonial value.

This work presents the study of the mechanical behavior of clay stabilized with different materials following the norm ASTM D 6276 – 99a, for lime stabilization. The effects of other stabilizers on the clay were studied as well. For these purposes, lime, gypsum, Portland cement (type II), sodium hydroxide, and dehydrated cactus fibers of white cactus opuntia in concentrations of 2, 4, 6, 8 and 10 wt% were added to a clay from Morelia region.

Atterberg limits were determined to calculate the linear and volumetric stabilization. The best volumetric stabilization values were chosen to prepare samples to measure the mechanical behavior under compression, tension and flexion strengths. Colorimetric measurements were also performed on the stabilized clays to determine the best preparation with the most suitable aesthetic qualities to perform conservation treatments on monuments and cultural heritage constructions made with earthen materials.

The highest values for compression were observed for gypsum and mucilage additions while the highest tension was obtained for mucilage ones. Gypsum addition had the bigger rupture module under flexion. On the other hand, the color of the stabilized clay is closer to the original clay color for cement, lime and mucilage preparations.
Self Sacrifice Awls in Cantona, Puebla, Mexico
Authors: Maldonado N. Valentín , Roldán G. Pérez
Published: August 2012

In the ancient city of Cantona (600 B.C a 1050 A.D.) in the region of Puebla, Mexico, a great number of awls made of animal bones were found inside several offerings and burials. The present paper presents the identification of species used to elaborate these awls, along with the formal characteristics of the objects and their manufacturing techniques. The last was studied through experimental archaeology and the analysis of modified traces by Scanning Electron Microscopy (SEM).
Silver Nanoparticles for SERS Identification of Dyes
Authors: Casanova-González Edgar , García-Bucio Angélica , Ruvalcaba-Sil José Luis , Santos-Vasquez Víctor , Esquivel Baldomero , Roldán María Lorena , Domingo Concepción
Published: August 2012

Coinage metals nanoparticles have been widely used in last decade for enhancing the Raman signal of a variety of compounds. Several preparation methods have been proposed, including chemical reduction of gold or silver salts with sodium citrate, hydroxylamine or sodium borohydride, microwave-assisted reduction with glucose, Tollens mirror, electrodeposition, vacuum evaporation and pulsed-laser deposition.

In this work, gold and silver nanoparticles were prepared by chemical reduction with sodium citrate and hydroxilmanine, characterized by UV-Vis spectroscopy and High Resolution Transmission Electronic Microscopy and tested as SERS substrate. Carminic acid, cochineal, axiote, muitle and zacatlaxcalli SERS spectra were recorded at different pH. Natural dyes samples were prepared by extraction from its natural sources, following traditional recipes. Although differs for each dye, best results were achieved by performing SERS experiments at pH neutral to basic.
Ascenso y hegemonía: pensando a las potencias emergentes desde América del Sur
Authors: Schenoni Luis L.
Published: August 2012

El presente trabajo se enmarca en el actual debate sobre potencias emergentes intentando un aporte desde una perspectiva latinoamericana. Para ello trabajará algunas disyuntivas teóricas que se han tornado difíciles de resolver para el mainstream racionalista de la disciplina, desarrollando un modelo de cambio complementario del programa realista actual. Argumentaremos que este marco presenta algunas ventajas para el estudio de diversas cuestiones relativas a las relaciones de poder en América del Sur, destacando en particular dos preguntas: ¿qué características de la política exterior del Brasil han logrado constituirlo en una potencia emergente? ¿Y por qué los países de la región no han desarrollado una política exterior acorde al desafío que significa el ascenso de su principal contraparte regional?
A União Europeia entre o alargamento e a vizinhança: os casos dos Balcãs ocidentais e do Cáucaso do sul
Authors: Simão Licínia , Rodrigues Sónia
Published: August 2012

O artigo trata as políticas da UE para a sua periferia a leste, com enfoque nos Balcãs ocidentais e no Cáucaso do sul. Partindo de uma abordagem comparativa, o artigo argumenta que a construção de uma ordem regional normativa, com objetivos claros de estabilização por meio da integração de geometria variável, tem encontrado limites. O artigo identifica essas dinâmicas e procura retirar lições da abordagem europeia aos Balcãs e ao Cáucaso.
A paradiplomacia financeira no Brasil da República Velha, 1890-1930
Authors: Maia José Nelson Bessa , Saraiva José Flávio Sombra
Published: August 2012

Neste artigo, visa-se a analisar um caso de extroversão de governos estaduais no campo do financiamento externo no período da chamada República Velha (1890-1930) no Brasil. Com base na definição de "paradiplomacia financeira", argumenta que a experiência histórica brasileira nesse aspecto teria sido um caso típico de ação paradiplomática. Amplo levantamento estatístico dos empréstimos externos por estados, o resgate das fontes documentais primárias sobre o assunto e a contextualização histórica pertinente dão sustentação à caracterização do período como uma fase de paradiplomacia financeira precoce.
A Rodada Doha, as mudanças no regime do comércio internacional e a política comercial brasileira
Authors: Cesar Susan Elizabeth Martins , Sato Eiiti
Published: August 2012

Este trabalho tem como objetivo discutir os atuais desafios do multilateralismo tradicional no comércio, visíveis nos impasses da Rodada Doha, diante das novas realidades do comércio internacional globalizado, caracterizado pela dispersão e fragmentação da produção sob a lógica das cadeias de valor globais (CVG). O artigo discute a forma em que essas transformações estão desafiando pressupostos tradicionais do sistema multilateral de comércio e as negociações da Rodada Doha. Tomando o caso do Brasil como exemplo, o artigo argumenta que o descompasso entre a agenda negociadora e as novas realidades do comércio internacional reside nos próprios países-membros da OMC que, em sua maioria, ainda não pautam suas políticas comerciais e suas estratégias de inserção internacional por essas novas dinâmicas do comércio internacional. Por fim, o trabalho mostra que a política comercial brasileira durante a última década esteve desalinhada com essa nova realidade ao dar demasiada ênfase às formas tradicionais de negociação comercial, deixando de considerar as modificações essenciais ocorridas nos padrões de comércio na esteira do processo de globalização.
Construcción participativa del regionalismo estratégico: ¿hacia una agenda medioambiental externa del Mercosur?
Authors: Stuhldreher Amalia
Published: August 2012

El artículo analiza la búsqueda de posiciones comunes del Mercosur Ambiental, teniendo en cuenta la evolución del proceso regional. Desde el constructivismo social se pretende identificar las contribuciones de las comunidades epistémicas y de la sociedad civil para definir una agenda ambiental para Brasil y Argentina, y se describen algunas perspectivas.
Sustained vowels and continuous speech in the auditory-perceptual evaluation of dysphonia severity
Authors: Maryn Youri , Roy Nelson
Published: August 2012

PURPOSE: Auditory-perceptual evaluation of dysphonia may be influenced by the type of speech/voice task used to render judgements during the clinical evaluation, i.e., sustained vowels versus continuous speech. This study explored (a) differences in listener dysphonia severity ratings on the basis of speech/voice tasks, (b) the influence of speech/voice task on dysphonia severity ratings of stimuli that combined sustained vowels and continuous speech, and (c) the differences in inter-rater reliability of dysphonia severity ratings between both speech tasks. METHODS: Five experienced listeners rated overall dysphonia severity in sustained vowels, continuous speech and concatenated speech samples elicited by 39 subjects with various voice disorders and degrees of hoarseness. RESULTS: Data confirmed that sustained vowels are rated significantly more dysphonic than continuous speech. Furthermore, dysphonia severity in concatenated speech samples is least determined by the sustained vowel. Finally, no significant difference was found in inter-rater reliability between dysphonia severity ratings of sustained vowels versus continuous speech. CONCLUSION: Based upon the results, both types of speech/voice tasks (i.e., sustained vowel and continuous speech) should be elicited and judged by clinicians in the auditory-perceptual rating of dysphonia severity.
Evaluation of oral functions of the stomatognathic system according to the levels of asthma severity
Authors: Castro Mariana San Jorge de , Toro Adyléia Aparecida Dalbo Contrera , Sakano Eulália , Ribeiro José Dirceu
Published: August 2012

PURPOSE: To compare the orofacial functions (chewing, swallowing and speech) in children with asthma and healthy children. METHODS: A cross sectional study including 54 children of both genders with ages between 7 and 10 years was conducted. Twenty-seven of these subjects composed the experimental group, and were subdivided into two severity levels of asthma: Group I - mild intermittent and persistent asthma; Group II - persistent moderate to severe asthma. Twenty-seven healthy children were included in the control group (Group III). Speech-language pathology evaluation used the adapted Orofacial Myofunctional Assessment Protocol. Adaptation consisted in the exclusion of the structural part of the test, since this was not the aim of the study. The structural part was excluded because it was not the aim of this study. RESULTS: It was found alterations in oral functions, with significant differences between the three groups. These alterations showed no correlation with asthma severity, since the highest rate of alterations was found in Group I (mild asthma). CONCLUSION: Regardless of the severity level, children with asthma have altered patterns of chewing, swallowing and speech.