bluuebunny/crossref_metadata_2025_split huggingface dataset:
CONTROL OF AIRBORNE NANOPARTICLES RELEASE DURING COMPOUNDING OF POLYMER NANOCOMPOSITES
Authors: TSAI SU-JUNG CANDACE , ASHTER ALI , ADA EARL , MEAD JOEY L. , BARRY CAROL F. , ELLENBECKER MICHAEL J. 
Published: February 2009

Polymer nanocomposites, which contain nanoparticles dispersed in a polymer matrix, provide improved properties at low filler loadings. These materials are already produced commercially, with twin-screw extrusion being the preferred process for compounding the nanoparticles and polymer melts. Several recent studies have demonstrated that nanoparticles can enter the body through inhalation, but the risk assessments for nanoparticle exposures are incomplete. Recently, concerns had been expressed that airborne nanoparticles released during compounding might present significant exposure to extruder operators. To assess the impact of the nanoparticles during twin-screw compounding of nanocomposites, researchers with experience in occupational and environmental health and polymer manufacturing monitored the compounding process for a model nanoalumina-containing nanocomposite using a TSI Fast Mobility Particle Spectrometer (FMPS). FMPS measurements were taken at background locations, source locations, and operators' breathing zones. In parallel to the FMPS real time measurement, airborne nanoparticles were collected using polycarbonate filters fitted with filmed grids driven by a personal air sampling pump. Filter samples were analyzed for particle morphology and elemental composition, and the results were found to be in good agreement with particle measurements by FMPS. Engineering controls and administrative controls were applied to reduce particle release from the compounding process and other operations in the laboratory. The administrative controls dramatically eliminated nanoparticles in the laboratory air, reducing total concentration by as much as 53 000 particles/cm3. Engineering controls were investigated and significant reductions of particle release were attained. The primary solution to reduce exposure level of nanoalumina is to isolate the releasing source. Overall, the engineering controls and administrative controls were effective in reducing airborne nanoparticle release during compounding.
A Standard and Software for Numerical Metadata
Authors: Eijkhout Victor , Fuentes Erika 
Published: February 2009

We propose a standard for generating, manipulating, and storing metadata describing numerical problems, in particular properties of matrices and linear systems. The standard comprises:
–an API for metadata generating and querying software, and
–an XML format for permanent storage of metadata.
The API is open-ended, allowing for other parties to define additional metadata categories to be generated and stored within this framework. Furthermore, we present two software libraries, NMD and AnaMod, that implement this standard, and that contain a number of computational modules for numerical metadata. The libraries, more than simply illustrating the use of the standard, provide considerable utility to numerical researchers.
Multivariate partial fraction expansion
Authors: Stoutemyer David R. 
Published: February 2009

The Derive computer-algebra program has Expand as one of the menu choices: The user is prompted for successively less main expansion variables, which can be all of the variables or any proper subset. It is clear how to proceed when the expression is a polynomial: Fully distribute with respect to all expansion variables, but collect as coefficient polynomials all terms that share the same exponents for the expansion variables. Derive uses a partially factored form, so the collected coefficient polynomials can be fortuitously partially factored.
For rational expressions the expand function does partial fraction expansion because it is the most useful kind of rational expansion. However, most other computer algebra systems and examples in the literature focus on partial fraction expansion with respect to only one variable, where any other variables are considered mere parameters. For consistency with multivariate polynomial expansion, we wanted a useful and well-defined meaning for multivariate partial fraction expansion. This paper provides such a definition and a corresponding algorithm.
Computing a rational in between
Authors: Emiris Ioannis , Mourrain Bernard , Tsigaridas Elias 
Published: February 2009

We are interested in the following problem: Given two (distinct) real algebraic numbers in isolating interval representation, that is an isolating interval with rational endpoints and a square free polynomial with integer coefficients, can we compute a number between them as a rational function of the coefficients of the polynomials that define these two numbers?
Assume that the order of the two numbers is known (we will remove this assumption in the sequel). If we are given intervals that contain the real algebraic numbers and a procedure to refine them, we can solve our problem as follows: We refine the intervals until they become disjoint, this will happen eventually since we assume that the algebraic numbers are not equal, and then we compute a rational between the intervals, which separates the algebraic numbers. However, this iterative approach depends on separation bounds, e.g. [7]. We present a direct method, which is applicable when we allow in addition to compute the floor of a polynomial expression that involves real algebraic numbers.

The problem arises when we wish to compute rational numbers that isolate the roots of an integer polynomial of small degree, say ≤ 5 [2]. Also in geometry, in order to analyse the intersection of two quadrics
P
and
Q
[6], one needs to determine the real roots of the polynomial det(
P
+
xQ
) = 0, their multiplicities and a value in between each of these roots. Another motivation comes from the arrangement of quadrics [4] In this case a rational is needed separating two real roots of two polynomials with real algebraic numbers as coefficients. The real roots of such polynomials can be expressed as real algerbaic numbers and so we face the problem of computing a rational separating two real algebraic numbers.
Transmembrane voltage regulates binding of annexin V and lactadherin to cells with exposed phosphatidylserine
Authors: Smith Christina , Gibson Donald F , Tait Jonathan F 
Published: February 2009

AbstractBackgroundCells expose phosphatidylserine during apoptosis. The voltage across the plasma membrane also decreases or disappears during apoptosis, but the physiological significance of this is unknown.ResultsHere we show that transmembrane potential regulates membrane binding of two unrelated proteins that recognize exposed phosphatidylserine on apoptotic cells. In Jurkat T leukemia cells and K562 promyelocytic leukemia cells undergoing apoptosis, extracellular binding of annexin V was increased by decreasing membrane potential in a dose-dependent manner. Studies with phospholipid vesicles showed that the effect was mediated via an increase in binding affinity. The effect was independent of the apoptotic stimulus. The same phenomenon occurred with lactadherin, a structurally unrelated protein that also binds to apoptotic cells via phosphatidylserine and is essential for in vivo clearance of dying cells.ConclusionAlterations in membrane potential regulate the binding of annexin V and lactadherin to cell membranes, and may also influence the membrane binding of other classes of phosphatidylserine-binding proteins.
ER stress affects processing of MHC class I-associated peptides
Authors: Granados Diana P , Tanguay Pierre-Luc , Hardy Marie-Pierre , Caron Étienne , de Verteuil Danielle , Meloche Sylvain , Perreault Claude 
Published: February 2009

AbstractBackgroundViral infection and neoplastic transformation trigger endoplasmic reticulum (ER) stress. Thus, a large proportion of the cells that must be recognized by the immune system are stressed cells. Cells respond to ER stress by launching the unfolded protein response (UPR). The UPR regulates the two key processes that control major histocompatibility complex class I (MHC I)-peptide presentation: protein synthesis and degradation. We therefore asked whether and how the UPR impinges on MHC I-peptide presentation.ResultsWe evaluated the impact of the UPR on global MHC I expression and on presentation of the H2Kb-associated SIINFEKL peptide. EL4 cells stably transfected with vectors coding hen egg lysozyme (HEL)-SIINFEKL protein variants were stressed with palmitate or exposed to glucose deprivation. UPR decreased surface expression of MHC I but did not affect MHC I mRNA level nor the total amount of intracellular MHC I proteins. Impaired MHC I-peptide presentation was due mainly to reduced supply of peptides owing to an inhibition of overall protein synthesis. Consequently, generation of H2Kb-SIINFEKL complexes was curtailed during ER stress, illustrating how generation of MHC I peptide ligands is tightly coupled to ongoing protein synthesis. Notably, the UPR-induced decline of MHC I-peptide presentation was more severe when the protein source of peptides was localized in the cytosol than in the ER. This difference was not due to changes in the translation rates of the precursor proteins but to increased stability of the cytosolic protein during ER stress.ConclusionOur results demonstrate that ER stress impairs MHC I-peptide presentation, and that it differentially regulates expression of ER- vs. cytosol-derived peptides. Furthermore, this work illustrates how ER stress, a typical feature of infected and malignant cells, can impinge on cues for adaptive immune recognition.
Short hairpin RNA-mediated knockdown of protein expression in Entamoeba histolytica
Authors: Linford Alicia S , Moreno Heriberto , Good Katelyn R , Zhang Hanbang , Singh Upinder , Petri William A 
Published: February 2009

Abstract

Background

Entamoeba histolytica is an intestinal protozoan parasite of humans. The genome has been sequenced, but the study of individual gene products has been hampered by the lack of the ability to generate gene knockouts. We chose to test the use of RNA interference to knock down gene expression in Entamoeba histolytica.

Results
An episomal vector-based system, using the E. histolytica U6 promoter to drive expression of 29-basepair short hairpin RNAs, was developed to target protein-encoding genes in E. histolytica. The short hairpin RNAs successfully knocked down protein levels of all three unrelated genes tested with this system: Igl, the intermediate subunit of the galactose- and N-acetyl-D-galactosamine-inhibitable lectin; the transcription factor URE3-BP; and the membrane binding protein EhC2A. Igl levels were reduced by 72%, URE3-BP by 89%, and EhC2A by 97%.

Conclusion
Use of the U6 promoter to drive expression of 29-basepair short hairpin RNAs is effective at knocking down protein expression for unrelated genes in Entamoeba histolytica, providing a useful tool for the study of this parasite.
Role of oxidative stress and intracellular glutathione in the sensitivity to apoptosis induced by proteasome inhibitor in thyroid cancer cells
Authors: Du Zhen-Xian , Zhang Hai-Yan , Meng Xin , Guan Yifu , Wang Hua-Qin 
Published: February 2009

Abstract

Background
The proteasome inhibitor bortezomib has shown impressive clinical activity alone and in combination with conventional and other novel agents for the treatment of multiple myeloma (MM) and some solid cancers. Although bortezomib is known to be a selective proteasome inhibitor, the downstream mechanisms of cytotoxicity and drug resistance are poorly understood.

Methods
Proteasome activity, intracellular glutathione (GSH) and ROS levels, as well as activities of GSH synthesis enzymes were measured using spectrophotometric methods. Cell death was analyzed using flow cytometry and caspase activity assay. The expression level of GSH synthesis enzymes were measured using real-time RT-PCR.

Results
At concentrations that effectively inhibited proteasome activity, bortezomib induced apoptosis in FRO cells, but not in ARO cells. Bortezomib elevated the amount of glutathione (GSH) and the treatment with bortezomib increased the level of mRNA for GCL, a rate-limiting enzyme in glutathione synthesis. Furthermore, depletion of GSH increases apoptosis induced by bortezomib, in contrast, repletion of GSH decreases bortezomib-mediated cell death.

Conclusion
GSH protects cells from proteasome inhibition-induced oxidative stress and glutathione-dependent redox system might play an important role in the sensitivity to proteasome inhibition-induced apoptosis.
Development of the forward parachute reaction and the age of walking in near term infants: a longitudinal observational study
Authors: Romeo Domenico MM , Cioni Matteo , Scoto Mariacristina , Palermo Filippo , Pizzardi Alessandra , Sorge Anna , Romeo Mario G 
Published: February 2009

Abstract

Background
Near term infants are a main part of preterms. They are at higher risk for mortality and morbidity than term infants and could show a quite different development of tone and reflexes from them. The aim of the present study was to describe longitudinally, in a large sample of healthy near term infants, the development of the forward parachute reaction (FPR) and its correlation with the age of acquisition of independent walking.

Methods
The assessment of FPR (as absent, incomplete or complete) was performed at 3, 6, 9, 12 months of corrected age in 484 infants, with a gestational age between 35.0 and 36.9 weeks. The age of acquisition of independent walking was monitored until its appearance. A correlation analysis was done between the age of walking and the acquisition of a complete or incomplete FPR, using the Spearman Rank correlation. The Mann-Withney U test was used to identify significant gestational age differences for the age of FPR appearance.

Results
Most of infants had a two-step development pattern. In fact, they showed at first an incomplete and then a complete FPR, which was observed more frequently at 9 months. An incomplete FPR only, without a successive maturation to a complete FPR, was present in the 21% of the whole sample. Infants with a complete FPR walked at a median age of 13 months, whereas those with an incomplete FPR only walked at a median age of 14 months.

Conclusion
We identified two groups within our sample of near term infants. The first group showed a progressive maturation of FPR, whereas the second one was characterised by the inability to get a complete pattern, within the one year observation's period. Furthermore, we observed a trend toward a delayed acquisition of independent walking in the latter group of infants.
Differential susceptibility to obesity between male, female and ovariectomized female mice
Authors: Hong Jina , Stubbins Renee E , Smith Rebekah R , Harvey Alison E , Núñez Nomelí P 
Published: February 2009

Abstract

Background
The prevalence of obesity has increased dramatically. A direct comparison in the predisposition to obesity between males, premenopausal females, and postmenopausal females with various caloric intakes has not been made. To determine the effects of sex and ovarian hormones on the susceptibility to obesity, we conducted laboratory studies with mice. To eliminate confounders that can alter body weight gain, such as age and food consumption; we used mice with the same age and controlled the amount of calories they consumed.

Methods
We determined sex-specific susceptibility to obesity between male, non-ovariectomized female, and ovariectomized female mice. To compare susceptibility to gaining body weight between males and females, animals from each sex were exposed to either a 30% calorie-restricted, low-fat (5% fat), or high-fat (35% fat) diet regimen. To establish the role of ovarian hormones in weight gain, the ovaries were surgically removed from additional female mice, and then were exposed to the diets described above. Percent body fat and percent lean mass in the mice were determined by dual energy x-ray absorptiometry (DEXA).

Results
In all three diet categories, male mice had a greater propensity of gaining body weight than female mice. However, ovariectomy eliminated the protection of female mice to gaining weight; in fact, ovariectomized female mice mimicked male mice in their susceptibility to weight gain. In summary, results show that male mice are more likely to become obese than female mice and that the protection against obesity in female mice is eliminated by ovariectomy.

Conclusion
Understanding metabolic differences between males and females may allow the discovery of better preventive and treatment strategies for diseases associated with body weight such as cancer and cardiovascular disease.
ErratumTo: Genotypic detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis strains by DNA sequencing: a randomized trial
Authors: Abdelaal Amina , El-Ghaffar Hassan Abd , Zaghloul Mohammad Hosam Eldeen , El mashad Noha , Badran Ehab , Fathy Amal 
Published: February 2009

Abstract
Correction to Genotypic detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis strains by DNA sequencing: a randomized trial Amina Abdelaal, Hassan Abd El-Ghaffar, Mohammad Hosam Eldeen Zaghloul, Noha El mashad, Ehab Badran, Amal Fathy Annals of Clinical Microbiology and Antimicrobials 2009, 8:4 (30 January 2009)
Novel point mutations attenuate autotaxin activity
Authors: Koh Eunjin , Bandle Russell W , Roberts David D , Stracke Mary L , Clair Timothy 
Published: February 2009

Abstract

Background
The secreted enzyme autotaxin (ATX) stimulates tumor cell migration, tumorigenesis, angiogenesis, and metastasis. ATX hydrolyzes nucleotides, but its hydrolysis of lysophospholipids to produce lysophosphatidic acid (LPA) accounts for its biological activities. ATX has been identified only as a constitutively active enzyme, and regulation of its activity is largely unexplored. In spite of its presence in plasma along with abundant putative substrate LPC, the product LPA is found in plasma at unexpectedly low concentrations. It is plausible that the LPA-producing activity of ATX is regulated by its expression and by access to substrate(s). For this reason studying the interaction of enzyme with substrate is paramount to understanding the regulation of LPA production.

Results
In this study we determine ATX hydrolytic activities toward several artificial and natural substrates. Two novel point mutations near the enzyme active site (H226Q and H434Q) confer attenuated activity toward all substrates tested. The Vmax for LPC compounds depends upon chain length and saturation; but this order does not differ among wild type and mutants. However the mutant forms show disproportionately low activity toward two artificial substrates, pNpTMP and FS-3. The mutant forms did not significantly stimulate migration responses at concentrations that produced a maximum response for WT-ATX, but this defect could be rescued by inclusion of exogenous LPC.

Conclusion
H226Q-ATX and H434Q-ATX are the first point mutations of ATX/NPP2 demonstrated to differentially impair substrate hydrolysis, with hydrolysis of artificial substrates being disproportionately lower than that of LPC. This implies that H226 and H434 are important for substrate interaction. Assays that rely on hydrolyses of artificial substrates (FS-3 and pNpTMP), or that rely on hydrolysis of cell-derived substrate, might fail to detect certain mutated forms of ATX that are nonetheless capable of producing LPA in the presence of sufficient exogenous substrate. H420Q-ATX could not be differentiated from WT-ATX, indicating that histidine at position 420 is not required for any of the activities of ATX tested in this study.
Serous adenocarcinoma of the fallopian tube, associated with verrocous carcinoma of the uterine cervix: a case report of synchronic rare gynecological tumors
Authors: Cantu de Leon David , Perez Montiel Delia , Tabarez Adan , Martinez Rocio Mendez , Cetina Lucely 
Published: February 2009

Abstract

Background
Synchronous gynecological tumors are rare; it is even rarer to find the rarest of gynecological tumors that of the fallopian tube, together with a histological sub-type as rare as verrucous cervix.

Case presentation
We report a synchronic fallopian tube adenocarcinoma and a verrucous cervical cancer. A 85-year-old woman with postmenopausal genital hemorrhage, endometrial biopsy was reported as squamous metaplasia, an exploratory laparotomy was performed finding a tubal tumor diagnosed as adenocarcinoma, a staging procedure was performed. Final staging revealed IB1 cervical carcinoma and IA G3 fallopian tube carcinoma. Adjuvant treatment with chemotherapy was not accepted by the patient. The patient has remained in follow-up, and at 9 months, there has been no documented evidence of recurrent disease.

Conclusion
Reasons for our presentation of this work are: first, due to the rarity of these, and second, because of the usefulness of possessing a case report for establishing a norm for later behavior with respect to treatment of these patients.
HIV-1 TAR miRNA protects against apoptosis by altering cellular gene expression
Authors: Klase Zachary , Winograd Rafael , Davis Jeremiah , Carpio Lawrence , Hildreth Richard , Heydarian Mohammad , Fu Sidney , McCaffrey Timothy , Meiri Eti , Ayash-Rashkovsky Mila , Gilad Shlomit , Bentwich Zwi , Kashanchi Fatah 
Published: February 2009

Abstract

Background
RNA interference is a gene regulatory mechanism that employs small RNA molecules such as microRNA. Previous work has shown that HIV-1 produces TAR viral microRNA. Here we describe the effects of the HIV-1 TAR derived microRNA on cellular gene expression.

Results
Using a variation of standard techniques we have cloned and sequenced both the 5' and 3' arms of the TAR miRNA. We show that expression of the TAR microRNA protects infected cells from apoptosis and acts by down-regulating cellular genes involved in apoptosis. Specifically, the microRNA down-regulates ERCC1 and IER3, protecting the cell from apoptosis. Comparison to our cloned sequence reveals possible target sites for the TAR miRNA as well.

Conclusion
The TAR microRNA is expressed in all stages of the viral life cycle, can be detected in latently infected cells, and represents a mechanism wherein the virus extends the life of the infected cell for the purpose of increasing viral replication.