bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability indicating method for famotidine in pharmaceuticals using porous graphitic carbon column
Authors: Helali Nawel , Monser Lotfi 
Published: January 2008

AbstractA simple, sensitive and rapid HPLC method was developed and validated for the simultaneous determination of famotidine (FMT) and related impurities in pharmaceuticals. Chromatographic separation was accomplished within 10 min on a porous graphitic carbon (PGC) column using 50:50 v/v ACN–water containing 0.5% pentane sulphonic acid (PSA) as the mobile phase. Separation was achieved with a flow rate of 1 mL/min and a detection wavelength of 265 nm. The calibration curves were linear over a concentration range of 1.5–100 μg/mL. The intra‐ and interday RSDs (n = 5) for the retention times and peak area were all less than 2%. The method was sensitive with an LOD (S/N = 3) of 0.1 μg/mL for FMT, imp. C and 0.05 μg/mL for imp. 2, A and D. All recoveries were greater than 98%. The method was demonstrated to be precise, accurate and specific with no interference from the tablet ingredients and separation of the drug peak from the peaks of the degradation products (oxidative degradation and acid and base degradation). The results indicated that the proposed method could be used for the determination of FMT in commercial dosage forms and as a stability‐indicating assay.
A dual spectrophotometric/contactless conductivity detector for CE determination of incompletely separated amino acids
Authors: Zikmundová Jana , Tuma Petr , Opekar František 
Published: January 2008

AbstractA new application is described of a dual photometric/contactless conductivity detector to CE determination of incompletely separated compounds. These compounds are differentiated when one of them provides signals in both the cells of the detector, whereas the other yields a signal in only one cell. The technique has been applied to determination of proline and tyrosine in a dietary supplement.
Intraspecific patterns of ectoparasite abundances on Paraguayan bats: effects of host sex and body size
Authors: Presley Steven J. , Willig Michael R. 
Published: January 2008

Abstract:Although levels of parasitism can vary greatly among individual bats of the same species, little is known about the characteristics of hosts that affect such variation. Bats were captured via mist nets from June 1995 to July 1997 from 28 localities throughout Paraguay. Over 17 500 ectoparasites were collected from 2909 bats; however, analyses of ectoparasite abundance were restricted to more abundant taxa of host and ectoparasite. We quantified the abundances of 29 taxa of ectoparasite on 19 species of bat host, as well as total abundance of ectoparasites regardless of taxonomic affiliation for 22 species of bat from Paraguay. The effects of host sex and host body size on these estimates of ectoparasite abundance were evaluated separately for each species of host. Ectoparasites did not respond consistently to host body size: ectoparasite abundance increased with host body size in 12 instances and decreased with host body size in 11 instances. Regardless of the existence or direction of effects of host body size on ectoparasite abundance, female hosts generally harboured more ectoparasites than did male hosts. Differences in host quality associated with the sex of bats, especially those related to behaviour, may be a more important determinant of ectoparasite abundance than are differences in size. Opportunities for host transfer are critical for species persistence of ectoparasites; consequently, ectoparasite populations on host individuals that form social groups or colonies should be larger, less prone to stochastic extinction, and have greater opportunity for speciation.
THE PHOTO‐REACTIVITY OF AROMATIC SUBSTANCES WITH OXYGEN*
Authors: Rosenberg J. L. , Humphries Frederick S. 
Published: January 2008

Summary The quenching reaction of oxygen with photo‐excited aromatics, although almost diffusion‐controlled in many cases, has some specific requirements with respect to the electronic details of the excited state. This is shown in the difference between the quenching constants for monomer and dimer of the same dye, where the dimer is recognized principally by excitation delocalization.Evidence is reviewed for the view that oxygen becomes vibrationally excited as a result of the quenching reaction, and that this hot oxygen is an essential intermediate in photo‐oxidations. A new result is the stimulation of O2 quenching by CO2, a known catalyst for vibrational relaxation in O2.
A STUDY OF THE EFFECT OF MOLECULAR OXYGEN ON ATOMIC OXYGEN‐HYDROCARBON REACTIONS*
Authors: Allen Eric R. , Cadle Richard D. 
Published: January 2008

Abstract— Investigations of the systems O—CH4 and, O—n‐C4H10 have been made, using techniques for producing atomic oxygen in the presence and absence of ground state molecular oxygen. The results indicated that the initial rate of removal of atomic oxygen from both systems was accelerated by the presence of molecular oxygen, whereas the initial rate of removal of hydrocarbon, for n‐butane, was affected little if at all.The relative concentrations of atomic oxygen, hydrocarbon and molecular oxygen appeared to govern the overall stoichiometry. It is concluded that rate constants observed in the absence of O2 and when [RH] ≥ [O], are probably a more reliable measure of the primary step:O + RH→Products.
CHEMILUMINESCENT REACTIONS OF SO
Authors: Halstead C. J. , Thrush B. A. 
Published: January 2008

Abstract— The rapid bimolecular reaction SO + O3= SO2+O2+ 106 kcal/moleyields electronically excited SO2 in the 3B1 and 1B2 states with some vibrational excitation, as well as SO2 in its electronic ground state. It is shown that k1= 1.5 x 1012 exp (‐2100/RT) cm2 mole‐1 s‐1 and that the formation of electronically excited SO2 involves higher activation energies.
EXCITED STATE INTERACCIÓNS IN MACROMOLECULES*
Authors: LONGWORTH J. W. 
Published: January 2008

Abstract— (1) The single tryptophanyl residue of ribonuclease T1 is shown to be in an environment that has no neighboring polar groups. (2) Exciplex formation involving the tryptophanyl residues of urea‐denatured ribonuclease T1 and Staphylococcus nuclease occurs at 298°K, but formation of the complex is suppressed at 77°K. (3) There is no tyrosyl fluorescence or phosphorescence in the luminescence of tryptophanyltyrosine or ribonuclease T1. The only species that emits is the tryptophanyl residue. (4) The transfer of electronic energy absorbed by tyrosyl residues to form a tryptophanyl excited singlet state has been demonstrated, by an analysis of the excitation spectra, for both L‐tryptophanyl‐L‐tyrosine and ribonuclease T1. (5) An interaction between the excited states of tyrosyl residues and vicinal disulfide linkage has been observed with oxytocin and ribonuclease A.RESUMENEl estado excitado es químicamente diferente del correspondiente estado fundamental, una de las diferencias reside en la distinta interacción con grupos vecinos. Las siguientes reacciones del estado excitado son de particular interés; (a) formación de un complejo con un estado fundamental aromático, “excimer”; (b) formación de un complejo donor‐aceptor con otro compuesto “exciplex”; (c) transferencia de energía electrónica de un compuesto a otro, transferencia de energía; (d) ionización; (f) formación de radicales iibres. Se discutirán ejempios de estas reacciones que involucran el estado excitado singulete de residuos aromáticos en polipéptidos y proteinas, ambos a 298 y 77°K, además del rol que esas interacciones tienen en el comportamiento fluorescente de proteinas, poniendo especial énfasis en dos proteinas, Ribonucleasa T1, y Stuphilococus nuclease. Los estados triplete de residuos de aminoácidos aromáticos en proteinas y polipéptidos no interaccionan fuertemente con grupos vecinos; sin embargo el estado triplete de la tirosina interacciona con una unión de disulfuro adyacente en un oligopéptide y en Ribonucleasa A, y este fenómeno parece estar relacionado con la fotólisis de uniones de sulfuro en proteinas.
PHOTOCHEMICAL CYCLOADDITIONS OF ORGANIC COMPOUNDS
Authors: RIVAS CARLOS , PAYO ELISEO , MANTECÓN JOAQUÍN , CORTÉS LUIS 
Published: January 2008

Abstract— Oxetanes were synthesized by 1,2‐photoaddition of benzophenone to several methyl‐substituted furans. The photochemical conversion of oxobicyclic analogues of norbornadiene to the corresponding oxoquadricyclenes was studied, and finally the sensitized 1,2‐photoaddition of citraconic anhydride to furan was accomplished.RESUMENSe han sintetizado oxetanos por fotoadición 1,2 de benzofenona a distintos metil furanos. Se ha estudiado la conversión fotoquímica de análogos oxobicíclicos del norbonadieno, y finalmente se ha logrado la fotoadición 1,2 sensitivizada de anhidrido citracónico a furano.
Aminoglycosides Affect IntracellularSalmonella entericaSerovars Typhimurium and Virchow
Authors: Menashe Ofir , Kaganskaya Elena , Baasov Timor , Yaron Sima 
Published: January 2008

ABSTRACTThe high antibacterial activity and selectivity of aminoglycosides and their low activity against intracellular bacteria associated with eukaryotic cells make them the antibiotics of choice for the elimination of extracellular bacteria during intracellular studies. Given the evidence that aminoglycosides can penetrate the eukaryotic cell membrane, the goal of this study was to examine the influence of aminoglycosides on macrophage-associatedSalmonella. Herein, we show that gentamicin, kanamycin, and tobramycin at concentrations between 15 to 150 μg ml−1do not kill intracellularSalmonellabut have other effects on the bacterial physiology. By usingSalmonella entericaserovars Typhimurium and Virchow harboring luciferase reporter plasmid, we observed that the light produced by intracellularSalmonelladeclined immediately upon exposure to aminoglycosides, indicating that the bacteria were under stress. The extent of this effect was dependent on the macrophage host, on the identity of the aminoglycoside and its concentration, on the exposure time, and on theSalmonellaserovar.Salmonellaassociated with Nramp1-negative macrophages, in which the phagosomal pH is higher, were more susceptible to aminoglycosides thanSalmonellaassociated with Nramp1-expressing macrophages. These results verify that aminoglycosides affect intracellular bacteria and that the extent of this effect is dependent on the acidity level within the phagosome, suggesting that for the study of intracellular bacteria, the aminoglycoside concentration should be limited to two to five times the MIC for the bacterial strain studied. This precaution should guarantee the complete execution of extracellular bacteria with minimal effects on the intracellular bacteria and the host cells.
A Climatology of Cold-Season Nonconvective Wind Events in the Great Lakes Region
Authors: Lacke Matthew C. , Knox John A. , Frye John D. , Stewart Alan E. , Durkee Joshua D. , Fuhrmann Christopher M. , Dillingham Sarah M. 
Published: January 2008

Abstract
A 44-yr climatology of nonconvective wind events (NCWEs) for the Great Lakes region has been created using hourly wind data for 38 first-order weather stations during the months of November through April. The data were analyzed in terms of the two National Weather Service (NWS) criteria for a high-wind watch or warning: sustained winds of at least 18 m s−1 for at least 1 h or a wind gust of at least 26 m s−1 for any duration. The results indicate a pronounced southwest quadrant directional preference for nonconvective high winds in this region. Between 70% and 76% of all occurrences that satisfied the NWS criteria for NCWEs were associated with wind directions from 180° through 270°. Within the southwest quadrant, the west-southwest direction is preferred, with 14%–35% of all NCWEs coming from this particular compass heading. This directional preference is borne out in five out of six stations with high occurrences of cold-season NCWEs (Buffalo, New York; Dayton, Ohio; Lansing, Michigan; Moline, Illinois; Springfield, Illinois). Given the geographic spread of these stations, a nontopographic cause for the directional preference of cold-season NCWEs is indicated. The connection between NCWEs and low pressure systems found in this climatology and in case studies suggests that midlatitude cyclone dynamics may be a possible cause of the directional preference.
Bias-Corrected Short-Range Ensemble Forecasts of Near-Surface Variables during the 2005/06 Cool Season
Authors: Yussouf Nusrat , Stensrud David J. 
Published: January 2008

Abstract
A postprocessing method initially developed to improve near-surface forecasts from a summertime multimodel short-range ensemble forecasting system is evaluated during the cool season of 2005/06. The method, known as the bias-corrected ensemble (BCE) approach, uses the past complete 12 days of model forecasts and surface observations to remove the mean bias of near-surface variables from each ensemble member for each station location and forecast time. In addition, two other performance-based weighted-average BCE schemes, the exponential smoothing method BCE and the minimum variance estimate BCE, are implemented and evaluated. Values of root-mean-squared error from the 2-m temperature and dewpoint temperature forecasts indicate that the BCE approach outperforms the routinely available Global Forecast System (GFS) model output statistics (MOS) forecasts during the cool season by 9% and 8%, respectively. In contrast, the GFS MOS provides more accurate forecasts of 10-m wind speed than any of the BCE methods. The performance-weighted BCE schemes yield no significant improvement in forecast accuracy for 2-m temperature and 2-m dewpoint temperature when compared with the original BCE, although the weighted BCE schemes are found to improve the forecast accuracy of the 10-m wind speed. The probabilistic forecast guidance provided by the BCE system is found to be more reliable than the raw ensemble forecasts. These results parallel those obtained during the summers of 2002–04 and indicate that the BCE method is a promising and inexpensive statistical postprocessing scheme that could be used in all seasons.
IRON-DEFICIENCY ANEMIA IS ASSOCIATED WITH CEREBRAL SINOVENOUS THROMBOSIS: A CASE SERIES
Authors: Kavadas Fotini D. , Moharir Mahendranath D. , Brandao Leonardo R. , de Veber Gabrielle 
Published: January 2008

INTRODUCTION: Iron-deficiency anemia is a relatively common but preventable condition in children that may have significant adverse implications on children's growth and development. Iron-deficiency anemia has also been sporadically reported in association with cerebral sinovenous thrombosis (CSVT).
OBJECTIVE: The objective of this study was to describe the largest case series to date of iron-deficiency anemia in association with CSVT as an advocacy measure for its prevention in children.
METHODS: Patients were identified through the Canadian Pediatric Ischemic Stroke Registry database (Toronto site). Included were patients who were older than 1 month to 18 years, met criteria for iron-deficiency anemia, and had radiographically confirmed CSVT.
RESULTS: Thirty-six patients who had CSVT and were older than 1 month to 18 years presented to the Hospital for Sick Children, Toronto, from January 2004 to December 2005. Six (17%) of these patients had iron-deficiency anemia; 2 were female adolescents, and 4 were male toddlers. All patients had historical and laboratory evidence of iron-deficiency anemia. Other risk factors, such as dehydration or inflammatory disorders, were present in all patients, but we did not detect significant inherited hypercoagulable disorders or acquired thrombophilia in any of them.
CONCLUSIONS: This report strengthens the evidence of an association between iron-deficiency anemia and CSVT. We suggest that children who have CSVT should be screened for iron deficiency. Advocacy to prevent iron deficiency is important, because this condition may have serious long-term and irreversible developmental consequences.
DIAGNOSIS OF AIRWAY MALACIA VIA VIRTUAL BRONCHOSCOPY
Authors: Bilan Nemat , Miabi Zinat , Saiiah Melli 
Published: January 2008

INTRODUCTION: The term “malacia” refers to softness; in medical terminology, it refers to weakness of bone or cartilage. Laryngomalacia is the most common congenital abnormality of the larynx, and the patient may experience recurrent aspiration. Tracheomalacia refers to tracheal weakness and usually causes airway collapse as a result of cartilage defect. Bronchomalacia describes the weakness and collapsibility of 1 or both main bronchi. All of these diseases can be diagnosed by bronchoscopy, but this method is invasive and may interfere with the diagnosis. Furthermore, it is intolerable in young individuals who are severely ill and in patients with coagulopathy.
OBJECTIVE: This study was conducted to examine the role of virtual bronchoscopy in the diagnosis of laryngotracheobronchomalacia.
METHODS: In a periexperimental study during 3 years (November 2003 through October 2006), 35 patients who had clinical signs and symptoms of airway malacia were surveyed via virtual bronchoscopy.
RESULTS: The percentage of boys and girls was 65.7% and 34.3%, respectively, and the mean age was 3.7 ± 1.6 months. The result of virtual bronchoscopy for laryngomalacia, bronchomalacia, tracheomalacia, laryngotracheomalacia and laryngobronchomalacia was 42.8%, 25.7%, 20%, 8.5%, and 2.9%, respectively.
CONCLUSIONS: Virtual bronchoscopy, because of its noninvasive character, its speed imaging, and its excellent ability of assessment of airway stenosis can be considered as a substitution for bronchoscopy.
MANNOSE-BINDING LECTIN (MBL) GENE POLYMORPHISMS AND SERUM MBL LEVELS IN CHILDREN WITH RECURRENT RESPIRATORY TRACT INFECTION
Authors: Li Qiu , Chen Mis Jia , Ou Xi , Wang Mo , Yang Xiqiang , Zhang Wei , She Pingli 
Published: January 2008

INTRODUCTION: Mannose-binding lectin (MBL) is a plasma collectin and is considered an important component of innate immunity. Its plasma concentration is, for the most, part genetically determined by a series of single nucleotide polymorphisms located both in the structural gene and in the promoter region. MBL deficiency may be associated with increased susceptibility to infectious disease and autoimmune disorders.
OBJECTIVE: Our goal was to establish the reference serum level of MBL in children, investigate the correlation between MBL gene polymorphisms and its serum level in Chinese Han nationality, and MBL gene polymorphisms and serum level in children with recurrent respiratory tract infections.
METHODS: The concentrations of oligomerized MBL in plasma were measured by enzyme-linked immunosorbent assay, and MBL gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction with sequence-specific primers.
RESULTS: The median MBL level in 470 normal children was 2536 ng/mL (range: 0–7860 ng/mL), and P2.5 to P97.5 was 161 to 5070 ng/mL. Two promoter polymorphisms, -550 and -221, and coding variants at codon 54 of the MBL gene affected the protein level significantly, and the most frequent genotype in Hans was HYPA/HYPA. Serum MBL levels were significantly lower in patients with recurrent respiratory tract infections (RRTIs) compared with healthy controls (H = 6.661; P &lt; .05), and the frequency of the promoter LXP haplotype was significantly higher in patients with RRTIs than in controls (χ2 = 4.71; P = .03). The prevalence of the B allele in patients with RRTIs was higher than that in controls, but the difference did not reach significance (χ2 = 0.18; P &gt; .05).
CONCLUSIONS: The MBL reference value in China is 161 ng/mL. Children with MBL concentrations of &lt;161 ng/mL, therefore, were deemed to be MBL deficient, and LXP is a risk factor for recurrent respiratory tract infections in this population.
IDENTIFICATION OF THE OBESE CHILD: ADEQUACY OF BODY MASS INDEX AND FAT MASS INDEX FOR CLINICAL PRACTICE AND EPIDEMIOLOGY
Authors: Hassan Nayera , El-Masry Sahar 
Published: January 2008

INTRODUCTION: There is no agreement among researchers on adiposity indexes and on the best cutoff to define obesity.
OBJECTIVE: The objective of this study was to evaluate the validity of BMI and fat mass index (FMI) as indicators of obesity in 272 boys and 242 girls who were aged 3 to 5 years.
METHODS: Bioelectrical impedance analysis was used to calculate percentage fat mass (%FM) and FMI (fat mass/stature2). Boys and girls were considered obese when %FM was ≥ 25 and ≥ 30, respectively. Cutoffs of BMI (weight/stature2) and FMI were tested at 90th, 95th, and 97th percentiles.
RESULTS: There were strong, significant correlations between BMI or FMI and %FM, but there was no significant correlation between BMI or FMI and stature; therefore, both BMI and FMI are useful indexes to assess fatness and obesity. With the use of %FM as the criterion for obesity, however, the highest prevalence of obesity was found at the 90th percentile for both genders. BMI and FMI had high specificities and lower but variable sensitivities. FMI is associated with a level of sensitivity that is somewhat higher than that of BMI. Almost all children who were not obese were classified correctly, whereas many obese children were not correctly identified.
CONCLUSIONS: FMI is a specific indicator of childhood obesity, and at 90th percentile, it has moderately high sensitivity. BMI should be used with caution as an indicator of childhood obesity.
DIAGNOSTIC VALUE OF IN SITU POLYMERASE CHAIN REACTION IN CHILDHOOD LEPROSY
Authors: Dayal Rajeshwar , Singh S. P. , Mathur P. P. , Katoch V. M. , Katoch K. , Natrajan M. 
Published: January 2008

OBJECTIVE: Our aim was to assess the diagnostic value of in situ polymerase chain reaction (PCR) in leprosy, particularly for enhancing histopathological diagnosis.
METHODS: We prospectively studied 20 children (aged &lt;16 years) with leprosy. Clinical examination of each case was performed, and skin smear for acid-fast bacillus was prepared. A biopsy of the lesion site was performed for histopathological examination and in situ PCR testing.
RESULTS: Histopathological examination confirmed the clinical diagnosis in only 45% of the cases; nonspecific histopathology was reported for the remaining 55% of the cases. In situ PCR showed a positivity of 57.1% in the early/localized form of leprosy (indeterminate/borderline tuberculoid) and 61.5% in the borderline borderline/borderline lepromatous group. When compared with the histopathological examination, a significant enhancement of 15% in diagnosis was seen. With in situ PCR, the diagnosis could be confirmed in 4 (36.3%) of 11 cases with nonspecific histopathological features (which is common in early disease) in addition to confirmation of 8 (88.8%) of 9 histopathologically confirmed tissue sections. Histopathology and in situ PCR combined together confirmed the diagnosis in 13 (65%) of the 20 cases.
CONCLUSIONS: In situ PCR is an important diagnostic tool, especially in early and doubtful cases of leprosy.