bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Polymorphic Forms of Rifaximin
Authors: Kogawa Ana Carolina , Antonio Selma Gutierrez , Salgado Hérida Regina Nunes 
Published: June 2016

Abstract
Rifaximin is a gut-selective oral antimicrobial that has no systemic adverse effects compared with placebo. It is used for the treatment of hepatic encephalopathy, traveler's diarrhea, irritable bowel syndrome, Clostridium difficile infection, ulcerative colitis, and acute diarrhea. The crystalline form present in rifaximin, α, has minimal systemic absorption compared to the amorphous form. The objective of this study was to obtain polymorphic forms of rifaximin using recrystallization processes. The forms were characterized and studied by thermal analysis, X-ray powder diffraction, scanning electron microscopy, and solubility testing. Six polymorphic forms of rifaximin, designated I–VI, were obtained by the crystallization process by evaporation of the solvent. Some polymorphic forms obtained in this work may not have the same excellent tolerability as the reference medicine; therefore, studies such as these are extremely important and point to the need for greater requirements by the regulatory agencies overseeing polymorph analysis of the raw materials used in the manufacture of medicines marketed globally. These analyses are not required in the majority of official compendia. Partnerships among industries, research centers, and universities would be a viable way to consolidate research in this area and contribute to improving the quality of solid drugs.
A New Chelating Reagent: Its Synthesis/Characterization and Application for the Determination of Cd(II) and Ni(II) in Various Food and Make-Up Product Samples by FAAS Using Simultaneous Microextraction Sampling
Authors: Saçmacı Şerife , Saçmacı Mustafa 
Published: June 2016

Abstract
A new and simple dispersive liquid–liquid simultaneous microextraction procedure was developed for the rapid separation and simultaneous extraction/preconcentration of Cd(II) and Ni(II) at ultratrace amounts. Microextraction of the analytes was carried out in the presence of 2-methyl-5-[(Z)-pyridin-4-yldiazenyl]quinolin-8-ol as the chelating reagent. Chloroform and ethanol were used as the extraction and dispersive solvents. Various parameters that influence the microextraction procedure's efficiency—such as pH, centrifugation rate and time, reagent concentration, and sampling volume on the recovery of analytes—were examined. The calibration curves were linear in the range of 0.01–1.25 and 0.075–5 mg/L with LODs of 0.25 and 0.84 μg/L, and with a preconcentration factor of 94, for Cd(II) and Ni(II), respectively. Precision was &gt;1.0%. The accuracy of the method was confirmed by analyzing the Certified Standard Reference Material (CWW-TMD: Certified wastewater-Trace metals, wastewater). The results show that the dispersive liquid–liquid simultaneous microextraction pretreatment is a sensitive, rapid, simple, green, and safe method for the separation/preconcentration of cadmium and nickel.
Chemometrics Tools in Detection and Quantitation of the Main Impurities Present in Aspirin/Dipyridamole Extended-Release Capsules
Authors: El-Ragehy Nariman A , Yehia Ali M , Hassan Nagiba Y , Tantawy Mahmoud A , Abdelkawy Mohamed 
Published: June 2016

Abstract
Aspirin (ASP) and dipyridamole (DIP) in combination is widely used in the prevention of secondary events after stroke and transient ischemic attack. Salicylic acid is a well-known impurity of ASP, and the DIP extended-release formulation may contain ester impurities originating from the reaction with tartaric acid. UV spectral data analysis of the active ingredients in the presence of their main impurities is presented using multivariate approaches. Four chemometric-assisted spectrophotometric methods, namely, partial least-squares, concentration residuals augmented classical least-squares (CRACLS), multivariate curve resolution (MCR) alternating least-squares (ALS), and artificial neural networks, were developed and validated. The quantitative analyses of all the proposed calibrations were compared by percentage recoveries, root mean square error of prediction, and standard error of prediction. In addition, r2 values between the pure and estimated spectral profiles were used to evaluate the qualitative analysis of CRACLS and MCR-ALS. The lowest error was obtained by the CRACLS model, whereas the best correlation was achieved using MCR-ALS. The four multivariate calibration methods could successfully be applied for the extended-release formulation analysis. The application results were also validated by analysis of the stored dosage-form solution, which showed a susceptibility of DIP esterification in the extended-release formulation. Statistical comparison between the proposed and official methods showed no significant difference.
Sensitive Determination of Uranium in Natural Waters Using UV-Vis Spectrometry After Preconcentration by Ion-Imprinted Polymer-Ternary Complexes
Authors: Bicim Tulin , Yaman Mehmet 
Published: June 2016

Abstract
The main purpose of this study was to achieve a substantial increase in the sensitivity of the uranium determination using UV-Vis spectrometry. To achieve this goal, ion-imprinted polymers were prepared for the uranyl (imprint) ion by the formation of a ternary (salicylaldoxime and 4-vinylpyridine) complex in 2-methoxy ethanol (porogen) following copolymerization with methacrylic acid. The synthesized polymers were characterized by FTIR analysis and thermogravimetric analysis. In the preconcentration step, the optimal pH was determined to be between values of 3.5 and 6.5. The adsorbed UO22+ was completely eluted by 10 mL of 3.0 mol L−1 HClO4. The developed method was applied to uranium (VI) determination in natural water samples. By using the initial volume of 500 mL and final volume of 5 mL, a concentration of 1 μg L−1 can be determined by applying the developed method in this study.
Changing Patterns of Fungal Toxins in Crops: Challenges for Analysts
Authors: Miller J David 
Published: June 2016

Abstract
This short review discusses the need to manage climate-driven expansion of old toxins in new geographic areas (e.g., aflatoxin or fumonisin in corn in historically cooler areas, and ergot where rainfall and cropping patterns have changed). In addition, a renewed consideration of the toxins that can occur in feed sources used in cool-season dairy areas is needed (e.g., silage and distillers dry grains with solubles). A separate issue concerns genetic changes that are occurring in the species that cause Fusarium head blight/Gibberella ear rot. Small differences in climate appear to determine the distribution of the two dominant populations (native to the new world and from Asia). The chemotype that produces deoxynivalenol via the monoacetate at the 3 position results in the accumulation of somewhat more deoxynivalenol than the native population, which involves the monoacetate at the 15 position. There are also genetic changes occurring that have resulted in populations that produce different metabolites. Similarly, an increase in the area where Aspergillus flavus can thrive and the discovery of the sexual stage of this fungus have raised the potential of genetic change accelerated by climate. To address all these issues, new methods and increased availability of reference standards, as well as training and awareness, will be required.
HIV‐positive pregnant and postpartum women's perspectives about Option B+ in Malawi: a qualitative study
Authors: Katirayi Leila , Namadingo Hazel , Phiri Mafayo , Bobrow Emily A , Ahimbisibwe Allan , Berhan Aida Yemane , Buono Nicole , Moland Karen Marie , Tylleskär Thorkild 
Published: June 2016

IntroductionThe implementation of lifelong antiretroviral treatment (ART) for all pregnant women (Option B+) in Malawi has resulted in a significant increase in the number of HIV‐positive pregnant women initiating treatment. However, research has highlighted the challenge of retaining newly initiated women in care. This study explores barriers and facilitators that affect a woman's decision to initiate and to adhere to Option B+.MethodsA total of 39 in‐depth interviews and 16 focus group discussions were conducted. Eligible women were ≥18 years old, living with HIV and either pregnant and receiving antenatal care from a study site or had delivered a child within the last 18 months, breastfed their child and received services at one of the study sites. Eligible women were identified by healthcare workers (HCWs) in the antenatal clinic and ART unit. Focus groups were also conducted with HCWs employed in these departments. Qualitative data were analyzed using Maxqda version 10 (VERBI Software, Berlin, Germany).ResultsThe general perception towards the drug regimen used in Option B+ was positive; women reported fewer side effects and acknowledged the positive benefits of ART. Women felt hopeful about prolonging their life and having an HIV‐uninfected baby, yet grappled with the fact that ART is a lifelong commitment. Women and HCWs discussed challenges with the counselling services for prevention of mother‐to‐child HIV transmission under the new Option B+ guidelines, and many women struggled with initiating ART on the same day as learning their HIV status. Women wanted to discuss their circumstances with their husbands first, receive a CD4 count and obtain an HIV test at another facility to confirm their HIV status. HCWs expressed concern that women might just agree to take the drugs to please them. HCWs also discussed concerns around loss to follow‐up and drug resistance.ConclusionsAlthough Option B+ has significantly increased the number of women initiating ART, there are still challenges that need to be addressed to strengthen initiation, adherence and retention in care. Strategies to strengthen the counselling services upon diagnosis need to be developed to improve same‐day initiation of ART and long‐term adherence.
Supercontinuum generation using a selectively water-filled photonic crystal fiber for enhancement in the visible spectral region
Authors: Yoshida Eiichi , Wada Akira , Karasawa Naoki 
Published: June 2016

Abstract
We generated a supercontinuum from a selectively water-filled photonic crystal fiber (PCF) for enhancement in the visible spectral region using an optical pulse from a Ti:sapphire oscillator at 804 nm. We prepared a 7-cm-long fused silica PCF, where the holes adjacent to the central core were filled with water, using a UV-curable adhesive to close holes selectively before filling holes with water by capillary force. Compared with that of the PCF without water, the group velocity dispersion curve of the selectively water-filled PCF became flatter near 800 nm and the intensity in the visible spectral region of the supercontinuum became higher and more uniform. The spectra simulated using the calculated dispersion properties of the selectively water-filled PCF showed good agreement with the experimental spectra.
Stability evaluation of parameter estimation of multi-Rayleigh model for ultrasound B-mode image of liver fibrosis
Authors: Mori Shohei , Ohashi Minori , Hirata Shinnosuke , Hachiya Hiroyuki 
Published: June 2016

Abstract
A diagnosis of liver fibrosis using an ultrasound B-mode image has the advantages of real-time observation and noninvasive properties. In our previous study, a multi-Rayleigh model was proposed to express a probability density function (PDF) of echo amplitudes from a fibrotic liver. From the multi-Rayleigh model, fibrosis parameters, such as the amount of fibrotic tissue and its progressive ratio, can be extracted. To quantitatively evaluate liver fibrosis using the multi-Rayleigh model, it is important to evaluate the stability of the estimation method of multi-Rayleigh model parameters. In this study, a numerical simulation using random variables following the multi-Rayleigh model was performed and the estimation stability of the parameters of the multi-Rayleigh model with two components was examined. From the simulation results, it was found that estimation becomes unstable under a certain condition owing to statistical variations of moments, which are inputs in the estimation algorithm. The instability of estimated parameters could be evaluated by focusing on changes in moments upon changes in multi-Rayleigh model parameters. It was indicated that we can evaluate the reliability of the estimated parameters of the multi-Rayleigh model only from the estimated values.
Shear wavelength estimation based on inverse filtering and multiple-point shear wave generation
Authors: Kitazaki Tomoaki , Kondo Kengo , Yamakawa Makoto , Shiina Tsuyoshi 
Published: June 2016

Abstract
Elastography provides important diagnostic information because tissue elasticity is related to pathological conditions. For example, in a mammary gland, higher grade malignancies yield harder tumors. Estimating shear wave speed enables the quantification of tissue elasticity imaging using time-of-flight. However, time-of-flight measurement is based on an assumption about the propagation direction of a shear wave which is highly affected by reflection and refraction, and thus might cause an artifact. An alternative elasticity estimation approach based on shear wavelength was proposed and applied to passive configurations. To determine the elasticity of tissue more quickly and more accurately, we proposed a new method for shear wave elasticity imaging that combines the shear wavelength approach and inverse filtering with multiple shear wave sources induced by acoustic radiation force (ARF). The feasibility of the proposed method was verified using an elasticity phantom with a hard inclusion.
Integrated microRNA, gene expression and transcription factors signature in papillary thyroid cancer with lymph node metastasis
Authors: Ab Mutalib Nurul-Syakima , Othman Sri Noraima , Mohamad Yusof Azliana , Abdullah Suhaimi Shahrun Niza , Muhammad Rohaizak , Jamal Rahman 
Published: June 2016

Background. Papillary thyroid carcinoma (PTC) is the commonest thyroid malignancy originating from the follicle cells in the thyroid. Despite a good overall prognosis, certain high-risk cases as in those with lymph node metastasis (LNM) have progressive disease and poorer prognosis. MicroRNAs are a class of non-protein-coding, 19-24 nucleotides single-stranded RNAs which regulate gene expression and these molecules have been shown to play a role in LNM. The integrated analysis of miRNAs and gene expression profiles together with transcription factors (TFs) has been shown to improve the identification of functional miRNA-target gene-TF relationships, providing a more complete view of molecular events underlying metastasis process.Objectives. We reanalyzed The Cancer Genome Atlas (TCGA) datasets on PTC to identify differentially expressed miRNAs/genes in PTC patients with LNM-positive (LNM-P) versus lymph node negative (LNN) PTC patients and to investigate the miRNA-gene-TF regulatory circuit that regulate LNM in PTC.Results. PTC patients with LNM (PTC LNM-P) have a significantly shorter disease-free survival rate compared to PTC patients without LNM (PTC LNN) (Log-rank Mantel Cox test,p= 0.0049). We identified 181 significantly differentially expressed miRNAs in PTC LNM-P versus PTC LNN; 110 were upregulated and 71 were downregulated. The five topmost deregulated miRNAs were hsa-miR-146b, hsa-miR-375, hsa-miR-31, hsa-miR-7-2 and hsa-miR-204. In addition, 395 miRNAs were differentially expressed between PTC LNM-P and normal thyroid while 400 miRNAs were differentially expressed between PTC LNN and normal thyroid. We found four significant enrichment pathways potentially involved in metastasis to the lymph nodes, namely oxidative phosphorylation (OxPhos), cell adhesion molecules (CAMs), leukocyte transendothelial migration and cytokine--cytokine receptor interaction. OxPhos was the most significantly perturbed pathway (p= 4.70E−06) involving downregulation of 90 OxPhos-related genes. Significant interaction of hsa-miR-301b with HLF, HIF and REL/NFkB transcription factors were identified exclusively in PTC LNM-P versus PTC LNN.Conclusion. We found evidence of five miRNAs differentially expressed in PTC LNM-P. Alteration in OxPhos pathway could be the central event in metastasis to the lymph node in PTC. We postulate that hsa-miR-301b might be involved in regulating LNM in PTC via interactions with HLF, HIF and REL/NFkB. To the best of our knowledge, the roles of these TFs have been studied in PTC but the precise role of this miRNA with these TFs in LNM in PTC has not been investigated.
Freshwater gastropods diversity hotspots: three new species from the Uruguay River (South America)
Authors: Gutiérrez Gregoric Diego E. , de Lucía Micaela 
Published: June 2016

Background:The Atlantic Forest is globally one of the priority ecoregions for biodiversity conservation. In Argentina, it is represented by the Paranense Forest, which covers a vast area of Misiones Province between the Paraná and Uruguay rivers. The Uruguay River is a global hotspot of freshwater gastropod diversity, here mainly represented by Tateidae (genusPotamolithus) and to a lesser extent Chilinidae. The family Chilinidae (Gastropoda, Hygrophila) includes 21 species currently recorded in Argentina, and three species in the Uruguay River. The species of Chilinidae occur in quite different types of habitats, but generally in clean oxygenated water recording variable temperature ranges. Highly oxygenated freshwater environments (waterfalls and rapids) are the most vulnerable continental environments. We provide here novel information on three new species of Chilinidae from environments containing waterfalls and rapids in the Uruguay River malacological province of Argentina.Materials and Methods:The specimens were collected in 2010. We analyzed shell, radula, and nervous and reproductive systems, and determined the molecular genetics. The genetic distance was calculated for two mitochondrial markers (cytochromecoxidase subunit I–COI- and cytochrome b -Cyt b-) for these three new species and the species recorded from the Misionerean, Uruguay River and Lower Paraná-Río de la Plata malacological provinces. In addition, the COI data were analyzed phylogenetically by the neighbor-joining and Bayesian inference techniques.Results:The species described here are different in terms of shell, radula and nervous and reproductive systems, mostly based on the sculpture of the penis sheath. Phylogenetic analyses grouped the three new species with those present in the Lower Paraná-Río de la Plata and Uruguay River malacological provinces.Discussion:Phylogenetic analyses confirm the separation between the Uruguay River and the Misionerean malacological provinces in northeast Argentina. These new endemic species from the Uruguay River add further support to the suggestion that this river is a diversity hotspot of freshwater gastropods (with 54 species present in this basin, 15 of them endemic). These endemic species from environments with rapids and waterfalls should be taken into account by government agencies before the construction of dams that modify those ecologic niches in the Uruguay River.
Sonographic Prediction of Pediatric Renal Scarring With Full Parameter Normalization
Authors: Stember Joseph N. , Lynch Dustin , Behr Gerald , Alam Shumyle 
Published: June 2016

ObjectivesTo predict the chronic kidney disease (CKD) state for pediatric patients based on scaled renal cortical echogenicity.MethodsSonograms from a cohort of 26 patients, half of whom had stage 4 or 5 CKD, whereas the other half had normal renal function, were analyzed. For each patient image, a region of interest (ROI) was drawn around the renal cortex for comparison with an ROI drawn around the hepatic parenchyma. The latter ROI was shifted spatially to normalize the signal attenuations and time‐gain compensations of the two organs’ ROIs. Then the average pixel intensity of the renal ROI was divided by the corresponding hepatic value, resulting in scaled renal cortical echogenicity.ResultsThe average scaled renal cortical echogenicity was higher for diseased than healthy kidneys by roughly a factor of 2 (2.01 [95% confidence interval, 1.62–2.40] versus 1.05 [95% confidence interval, 0.88–1.23] for normal kidneys). This difference was statistically significant (P < .001).ConclusionsOur results show that the pediatric CKD state correlates with rigorously calculated scaled renal cortical echogenicity.
Artificial periodic irregularities in the high‐latitude ionosphere excited by the HAARP facility
Authors: Bakhmetieva N. V. , Grach S. M. , Sergeev E. N. , Shindin A. V. , Milikh G. M. , Siefring C. L. , Bernhardt P. A. , McCarrick M. 
Published: June 2016

AbstractWe present results of the new observations of artificial periodic irregularities (APIs) in the ionosphere using the High Frequency Active Auroral Research Program (HAARP) heating facility carried out in late May and early June 2014.The objective of this work is to detect API using high‐latitude facility and analyze possible differences of the temporal and spatial variations of the API echoes in the high (HAARP) and middle (Sura) latitudes. Irregularities were created by the powerful wave of X mode and were sounded using the short probing pulses signals of X mode. API echoes were observed in the D, E, and F regions of the ionosphere. Amplitudes and characteristic times of the API echoes were measured. The API growth and decay times at HAARP (high latitudes) observed were similar to those at the Sura heating facility (midlatitudes).
Dual assimilation of satellite soil moisture to improve streamflow prediction in data‐scarce catchments
Authors: Alvarez‐Garreton Camila , Ryu Dongryeol , Western Andrew W. , Crow Wade T. , Su Chun‐Hsu , Robertson David R. 
Published: June 2016

AbstractThis paper explores the use of active and passive microwave satellite soil moisture products for improving streamflow prediction within four large (>5000km2) semiarid catchments in Australia. We use the probability distributed model (PDM) under a data‐scarce scenario and aim at correcting two key controlling factors in the streamflow generation: the rainfall forcing data and the catchment wetness condition. The soil moisture analysis rainfall tool (SMART) is used to correct a near real‐time satellite rainfall product (forcing correction scheme) and an ensemble Kalman filter is used to correct the PDM soil moisture state (state correction scheme). These two schemes are combined in a dual correction scheme and we assess the relative improvements of each. Our results demonstrate that the quality of the satellite rainfall product is improved by SMART during moderate‐to‐high daily rainfall events, which in turn leads to improved streamflow prediction during high flows. When employed individually, the soil moisture state correction scheme generally outperforms the rainfall correction scheme, especially for low flows. Overall, the combined dual correction scheme further improves the streamflow predictions (reduction in root mean square error and false alarm ratio, and increase in correlation coefficient and Nash‐Sutcliffe efficiency). Our results provide new evidence of the value of satellite soil moisture observations within data‐scarce regions. We also identify a number of challenges and limitations within the schemes.