bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical Characterization of Released Thin Films by Contact Loading
Authors: Zhang Rongjing , Shilo Doron , Ravichandran Guruswami , Bhattacharya Kaushik 
Published: August 2006

AbstractThe design of reliable micro electro-mechanical systems (MEMS) requires understanding of material properties of devices, especially for free-standing thin structures such as membranes, bridges, and cantilevers. The desired characterization system for obtaining mechanical properties of active materials often requires load control. However, there is no such device among the currently available tools for mechanical characterization of thin films. In this paper, a new technique, which is load-controlled and especially suitable for testing highly fragile free-standing structures, is presented. The instrument developed for this purpose has the capability of measuring both the static and dynamic mechanical response and can be used for electro∕magneto∕thermo mechanical characterization of actuators or active materials. The capabilities of the technique are demonstrated by studying the behavior of 75nm thick amorphous silicon nitride (Si3N4) membranes. Loading up to very large deflections shows excellent repeatability and complete elastic behavior without significant cracking or mechanical damage. These results indicate the stability of the developed instrument and its ability to avoid local or temporal stress concentration during the entire experimental process. Finite element simulations are used to extract the material properties such as Young’s modulus and residual stress of the membranes. These values for Si3N4 are in close agreement with values obtained using a different technique, as well as those found in the literature. Potential applications of this technique in studying functional thin film materials, such as shape memory alloys, are also discussed.
Solar Production of Hydrogen Using “Self-Assembled” Polyoxometalate Photocatalysts
Authors: Muradov N. , T-Raissi A. 
Published: August 2006

Abstract
The near-term and cost-effective production of solar hydrogen from inexpensive and readily available hydrogen containing compounds (HCCs) can boost the prospects of future hydrogen economy. In this paper, we assess the prospects of the solar-assisted conversion of HCCs into hydrogen using polyoxometalate (POM) based photocatalysts, such as isopolytungstates (IPT) and silicotungstic acid (STA). Upon exposure to solar photons, IPT aqueous solutions containing various HCCs (e.g., alcohols, alkanes, organic acids, sugars, etc.) produce hydrogen gas and corresponding oxygenated compounds. The presence of small amounts of colloidal platinum increases the rate of hydrogen evolution by one order of magnitude. A solar photocatalytic flat-bed reactor, approximately 1.2m×1.2m in size, was fabricated and tested for the production of hydrogen from water-alcohol solutions containing IPT and STA and small amounts of colloidal Pt. The solar photoreactor tests demonstrated steady-state production of hydrogen gas for several days. IPT immobilized on granules of anion exchange resins with quaternary ammonium active groups show good photocatalytic activity for hydrogen production from water-alcohol solutions exposed to near-UV or solar radiation.
Comparative Analysis of Prevalence, Risk Factors, and Molecular Epidemiology of Antibiotic-Associated Diarrhea Due to
Clostridium difficile
,
Clostridium perfringens
, and
Staphylococcus aureus
Authors: Asha N. J. , Tompkins D. , Wilcox M. H. 
Published: August 2006

ABSTRACT

We prospectively studied the comparative epidemiology and risk factors for
Clostridium difficile
,
Clostridium perfringens
, and
Staphylococcus aureus
antibiotic-associated diarrhea (AAD). Four thousand six hundred fifty-nine inpatient fecal specimens (11 months) were tested for
C. difficile
cytotoxin,
C. perfringens
enterotoxin, and
S. aureus
by Vero cell assay, enzyme-linked immunosorbent assay, and growth on fresh blood agar, respectively. Two distinct age-, sex-, and location-matched control patient groups were used for multivariate logistic regression risk factor analyses: symptomatic patients who were AAD pathogen negative and asymptomatic patients with histories of recent antimicrobial therapy. All AAD pathogen isolates were DNA fingerprinted. In AAD cases, the prevalences of
C. difficile
cytotoxin,
C. perfringens
enterotoxin, and
S. aureus
were 12.7%, 3.3%, and 0.2%, respectively (15.8% overall). Age of >70 years was a common risk factor. Other risk factors for infective AAD and
C. difficile
AAD included length of hospital stay and use of feeding tubes (length of stay odds ratios [OR], 1.017 and 1.012; feeding tube OR, 1.864 and 2.808). Female gender and use of antacids were significantly associated with increased risk of
C. perfringens
AAD (OR, 2.08 and 2.789, respectively), but unlike what was found for
C. difficile
AAD, specific antibiotic classes were not associated with increased risk. A limited number of genotypes caused the majority of
C. difficile
and
C. perfringens
AAD cases. Similar to what was found for
C. difficile
AAD, there was epidemiological evidence of
C. perfringens
AAD case clustering and reinfection due to different strains.
C. difficile
AAD was approximately 4 and 60 times more common than
C. perfringens
AAD and
S. aureus
AAD, respectively. Risk factors for these AAD pathogens differed, highlighting the need to define specific control measures. There is evidence of nosocomial transmission in cases of
C. perfringens
AAD.
Characterization of a Large Outbreak by CTX-M-1-Producing
Klebsiella pneumoniae
and Mechanisms Leading to In Vivo Carbapenem Resistance Development
Authors: Mena Ana , Plasencia Virginia , García Laura , Hidalgo Olga , Ayestarán José Ignacio , Alberti Sebastián , Borrell Nuria , Pérez José L. , Oliver Antonio 
Published: August 2006

ABSTRACT

All extended-spectrum β-lactamase (ESBL)-producing
Enterobacteriaceae
isolates from patients admitted to and adult intensive care unit were prospectively documented from 2002 to 2005, when a large outbreak (51 patients affected) of multiresistant ESBL-producing
Klebsiella pneumoniae
infection was detected. The involvement of a single
K. pneumoniae
clone was demonstrated by pulsed-field gel electrophoresis. In addition to the ESBL-mediated resistance, the epidemic strain uniformly showed cross-resistance to ciprofloxacin, gentamicin, tobramycin, trimethoprim-sulfamethoxazole, and tetracycline, whereas resistance to the β-lactam-β-lactamase inhibitor combinations was variable. The ESBL involved was CTX-M-1, as demonstrated by isoelectric focusing, PCR amplification, and sequencing. CTX-M-1 as well as the aminoglycoside resistance determinants were encoded in a 50-kb plasmid that could be transferred to
Escherichia coli
only by transformation. In two of the infected patients, carbapenem resistance development (MICs of 8 to 12, 16, and >32 μg/ml for imipenem, meropenem, and ertapenem, respectively) was documented, both in clinical samples and in intestinal colonization studies. The analysis of the outer membrane proteins of the carbapenem-susceptible and -resistant isolates revealed that the former expressed only one of the two major porins, OmpK36, whereas the latter did not express either of them. In one of the cases, the lack of expression of OmpK36 was demonstrated to be mediated by the interruption of the coding sequence by the insertion sequence IS
26
. This is the first report of a large outbreak of CTX-M-1-producing
Enterobacteriaceae
and, curiously, the first documented description in the literature of CTX-M-1 in
K. pneumoniae
, despite the fact that this enzyme has been found in multiple species. Furthermore, we document and characterize for the first time carbapenem resistance development in CTX-M-1-producing
Enterobacteriaceae
.
Sensitive, Seminested PCR Amplification of VP1 Sequences for Direct Identification of All Enterovirus Serotypes from Original Clinical Specimens
Authors: Nix W. Allan , Oberste M. Steven , Pallansch Mark A. 
Published: August 2006

ABSTRACT
A reverse transcription-seminested PCR (RT-snPCR) assay was developed for the detection and identification of enterovirus (EV) RNA in clinical specimens. Three conserved protein motifs were identified by aligning the VP3 and VP1 sequences of prototype EV strains. Consensus degenerate primers were designed from a conserved VP3 motif and a distal VP1 motif for the first PCR. Consensus-degenerate hybrid oligonucleotide primers were designed from an internal VP1 motif and used with the same distal VP1 motif for the second, seminested PCR step. The primers were designed for broad target specificity and amplified all recognized and proposed EV serotypes and other antigenic variant strains tested. The VP1 RT-snPCR assay was slightly more sensitive than our in-house EV 5′ nontranslated region RT-snPCR assay, detecting as few as 10 RNA copies per reaction. As an example application, the VP1 RT-snPCR assay was used to identify EVs in clinical specimens. A product of the expected size was successfully amplified and sequenced from cerebrospinal fluid; serum; stool suspensions; and nasopharyngeal, eye, and rectal swab specimens, allowing unambiguous identification of the infecting virus in all cases. The VP1 sequences derived from the RT-snPCR products allow rapid phylogenetic and molecular epidemiologic analysis of strains circulating during the EV season and comparison with EV sequences from past seasons or from different locations around the world.
Bacteremia Caused by
Solobacterium moorei
in a Patient with Acute Proctitis and Carcinoma of the Cervix
Authors: Lau Susanna K. P. , Teng Jade L. L. , Leung Kit-Wah , Li Norris K. H. , Ng Kenneth H. L. , Chau Kam-Yu , Que Tak-Lun , Woo Patrick C. Y. , Yuen Kwok-Yung 
Published: August 2006

ABSTRACT

We describe a case of
Solobacterium moorei
bacteremia in a 43-year-old woman presenting with acute proctitis complicating radiotherapy for cervical carcinoma. Phenotypic tests failed to identify the bacterium, which was subsequently identified by 16S rRNA gene sequencing. 16S rRNA gene sequencing could help better define the pathogenicity of
S. moorei
.
Community-Acquired Meningitis and Sepsis Caused by
Chryseobacterium meningosepticum
in a Patient Diagnosed with Thalassemia Major
Authors: Ozkalay Nisel , Anil Murat , Agus Neval , Helvaci Mehmet , Sirti Seral 
Published: August 2006

ABSTRACT

Chryseobacterium meningosepticum
is a rare pathogen in cases of bacterial meningitis in adults and adolescents. We report on the case history of a 17-year-old boy with thalassemia major and meningitis and sepsis caused by
C. meningosepticum
in splenectomized. The patient received vancomycin therapy for 21 days and was discharged in a state of complete recovery.
Identification of
Histoplasma capsulatum
,
Blastomyces dermatitidis
, and
Coccidioides
Species by Repetitive-Sequence-Based PCR
Authors: Pounder June I. , Hansen Dewey , Woods Gail L. 
Published: August 2006

ABSTRACT

The performance of repetitive-sequence-based PCR (rep-PCR) using the DiversiLab system for identification of
Coccidioides
species,
Blastomyces dermatitidis
, and
Histoplasma capsulatum
was assessed by comparing data obtained to colony morphology and microscopic characteristics and to nucleic acid probe results. DNA from cultures of 23
Coccidioides
, 24
B. dermatitidis
, 24
H. capsulatum
, 3
Arthrographis
, and 2
Malbranchea
isolates was extracted using a microbial DNA isolation kit as recommended by Bacterial Barcodes, Inc. Rep-PCR and probe results agreed for 97.2% of the dimorphic fungi when ≥85% similarity was used as the criterion for identification. Two
H. capsulatum
isolates were not identified, but no isolates were misidentified. From 43 of those cultures (15
Coccidioides
, 14
B. dermatitidis
, 14
H. capsulatum
, 3
Arthrographis
, and 2
Malbranchea
), DNA also was extracted using an IDI lysis kit, a simpler method. Rep-PCR and probe results agreed for 97.7% of the dimorphic fungi when a criterion of ≥90% similarity was used for identification. One
H. capsulatum
isolate could not be identified; no isolates were misidentified. Using ≥85% similarity for identification resulted in one misidentification. These data suggest that the DiversiLab system can be used to identify
Coccidioides
and
B. dermatitidis
and, possibly,
H. capsulatum
isolates.
Genetic Diversity of Competence Gene Loci in Clinical Genotypes of
Streptococcus mutans
Authors: Klein Marlise I. , Bang Sungyon , Flório Flávia M. , Höfling José Francisco , Gonçalves Reginaldo B. , Smith Daniel J. , Mattos-Graner Renata O. 
Published: August 2006

ABSTRACT

The frequencies of 21 competence genes were analyzed in 94 genotypes of
Streptococcus mutans
. These include those of a main regulatory system (
comCDE
), structural, and other regulatory orthologues identified in the genome of strain UA159. PCR and Southern blot analysis revealed that all genes are widespread within the species.
Multicenter Comparison of Nucleic Acid Extraction Methods for Detection of Severe Acute Respiratory Syndrome Coronavirus RNA in Stool Specimens
Authors: Petrich A. , Mahony J. , Chong S. , Broukhanski G. , Gharabaghi F. , Johnson G. , Louie L. , Luinstra K. , Willey B. , Akhaven P. , Chui L. , Jamieson F. , Louie M. , Mazzulli T. , Tellier R. , Smieja M. , Cai W. , Chernesky M. , Richardson S. E. 
Published: August 2006

ABSTRACT
The emergence of a novel coronavirus (CoV) as the cause of severe acute respiratory syndrome (SARS) catalyzed the development of rapid diagnostic tests. Stool samples have been shown to be appropriate for diagnostic testing for SARS CoV, although it has been recognized to be a heterogeneous and difficult sample that contains amplification inhibitors. Limited information on the efficiency of extraction methods for the purification and concentration of SARS CoV RNA from stool samples is available. Our study objectives were to determine the optimal extraction method for SARS CoV RNA detection and to examine the effect of increased specimen volume for the detection of SARS CoV RNA in stool specimens. We conducted a multicenter evaluation of four automated and four manual extraction methods using dilutions of viral lysate in replicate mock stool samples, followed by quantitation of SARS CoV RNA using real-time reverse transcriptase PCR. The sensitivities of the manual methods ranged from 50% to 100%, with the Cortex Biochem Magazorb method, a magnetic bead isolation method, allowing detection of all 12 positive samples. The sensitivities of the automated methods ranged from 75% to 100%. The bioMérieux NucliSens automated extractor and miniMag extraction methods each had a sensitivity of 100%. Examination of the copy numbers detected and the generation of 10-fold dilutions of the extracted material indicated that a number of extraction methods retained inhibitory substances that prevented optimal amplification. Increasing the volume of sample input did improve detection. This information could be useful for the extraction of other RNA viruses from stool samples and demonstrates the need to evaluate extraction methods for different specimen types.
Use of Seroconversion Panels To Estimate Delay in Detection of Anti-Human Immunodeficiency Virus Antibodies by Enzyme-Linked Immunosorbent Assay of Pooled Compared to Singleton Serum Samples
Authors: Novack Lena , Galai Noya , Yaari Arieh , Orgel Mordechai , Shinar Eilat , Sarov Batia 
Published: August 2006

ABSTRACT
The transfusion of unsafe blood worldwide accounts for 5 to 15% of new human immunodeficiency virus (HIV) infections, most of which occur in sub-Saharan Africa. While developed countries now apply PCR testing of pooled samples, some developing countries still do not have universal screening policies. More efficient low-cost procedures for the screening of pooled samples have the potential to encourage mass screening efforts in resource-poor settings. The aim of this study was to estimate the delay in the detection of HIV antibodies in pooled serum samples compared to that in singleton serum samples by enzyme-linked immunosorbent assay (ELISA) and to evaluate the risk of transfusion-transmitted HIV infection during the window period. Serial blood samples obtained from five HIV seroconversion panels were mixed with HIV-seronegative blood samples to create pools of 6, 12, 16, 24, 32, and 48 samples. The delay in detection of the first anti-HIV antibody-positive sample in tests with pooled samples was calculated for each pool size and compared to that obtained by testing of singleton samples and statistically evaluated by a robust log-linear regression analysis. The risk of a false-negative (FN) result caused by dilution was estimated by use of the incidence risk/window period model. The additional risk of transmission related to ELISA screening of pooled samples for HIV did not exceed 9% of the current risk of an FN result (estimated to be 1/1,067,000). The countries with virus prevalence rates in donors of less than 15% are expected to save up to 30% in the number of tests. ELISA screening of pooled samples could be considered in settings where the testing of blood supplies for HIV is not routinely done.
Pyrosequencing as a Rapid Tool for Identification of GES-Type Extended-Spectrum β-Lactamases
Authors: Poirel Laurent , Naas Thierry , Nordmann Patrice 
Published: August 2006

ABSTRACT
A pyrosequencing technique was used for identification of extended-spectrum β-lactamases (ESBLs) of GES type. These β-lactamases are isolated increasingly emerging in gram-negative bacteria worldwide. This rapid and reliable identification method is interesting, since GES variants, including not only expanded-spectrum cephalosporins but also carbapenems, cephamycins, and monobactams, are the only ESBLs that possess different hydrolysis profiles.
Increasing Appearance of Reassortant Influenza B Virus in Taiwan from 2002 to 2005
Authors: Tsai Huey-Pin , Wang Hsuan-Chen , Kiang David , Huang Sheng-Wen , Kuo Pin-Hwa , Liu Ching-Chuan , Su Ih-Jen , Wang Jen-Ren 
Published: August 2006

ABSTRACT
Genetic and antigenic analyses of influenza B virus field strains isolated in Taiwan from 1998 to 2005 were performed. To investigate the molecular evolution of influenza B viruses, sequence analysis of the hemagglutinin (HA1 subunit) and neuraminidase genes was performed. All influenza B viruses isolated between 1998 and 2000 belonged to the B/Yamagata/16/88 lineage. The B/Victoria/2/87 lineage, which was cocirculating with the Yamagata lineage, was identified in Taiwan in March 2001. Concurrently, there was an increasing prevalence of this lineage in many parts of the world, including North America and Europe, during the 2001-2002 season. Since 2002, genetic reassortants of influenza B virus with the Victoria lineage of hemagglutinin and the Yamagata lineage of neuraminidase have been found at a rate of 46%. Therefore, in 2002, at least three sublineages of influenza B virus strains, the B/Shanghai/361/2002-like strain (Yamagata lineage), the B/Hong Kong/330/01-like strain (Victoria lineage), and the B/Hong Kong/1351/02-like strain (B reassortant lineage), were identified in Taiwan. The results showed that genetically distinct lineages can cocirculate in the population and that the reassortment among these strains plays a role in generating the genetic diversity of influenza B viruses. Interestingly, from January to April 2005, B reassortant viruses became dominant (73%) in Taiwan, which indicated that a mismatch had occurred between the influenza B vaccine strain recommended for the 2004-2005 season in the Northern hemisphere by the World Health Organization and the epidemic strain.
Chronic vulvovaginal pruritus treated successfully with GnRH analogue
Authors: Banerjee A K , de Chazal R 
Published: August 2006

Abstract
A Medline search shows that this is the first reported case where vulvovaginal pruritus was treated successfully with a GnRH analogue. The report describes a patient with chronic premenstrual vulvovaginal pruritus thought to be attributable to autoimmune progesterone dermatitis.
A new dieback disease of Acacia cyclops in South Africa caused by Pseudolagarobasidium acaciicola sp.nov.
Authors: Wood Alan R. , Ginns J. 
Published: August 2006

Acacia cyclops A. Cunn. ex G. Don (Fabaceae, Mimosoideae), originating from Western Australia, is a serious environmental weed in South Africa. A dieback disease of A. cyclops occurring in South Africa is described, and a fungus herein named Psuedolagarobasidium acaciicola Ginns sp.nov. (Basidiomycetes, Polyporales, Hyphodermataceae) was consistently isolated from diseased roots of A. cyclops trees showing early dieback symptoms. Isolates of P. acaciicola caused 100% mortality in pathogenicity screening tests using seedlings of A. cyclops. Saplings of A. cyclops were inoculated with one isolate of P. acaciicola, and all plants were killed within 2–3 months. No control plants died. Psuedolagarobasidium acaciicola was reisolated from all inoculated plants that died. Trees growing in the field were inoculated at two sites on two occasions. Most inoculated trees died within 2 years, whereas no control plants died. Eventually P. acaciicola fruited in vitro and in vivo allowing the basidiomes and cultures to be described. This fungus has potential to be developed as a bioherbicide to aid in the control of this serious environmental weed.
Characterization of programmed cell death in the endosperm cells of tomato seed: two distinct death programs
Authors: DeBono Allan G. , Greenwood John S. 
Published: August 2006

Programmed cell death (PCD) is a requisite, genetically controlled process in plants resulting in the death of particular cells and tissues and the recycling of the cellular constituents back to the organism. PCD in the lateral and micropylar endosperm cells during and following germination of tomato ( Solanum lycopersicum L.) seeds was characterized by transmission electron microscopy, by terminal d-UTP nick-end labelling of nuclei, and agarose gel electrophoretic analysis of genomic DNA. Postgerminative cells of lateral and micropylar endosperm displayed morphologies and terminal d-UTP nick-end labelling positive nuclei consistent with PCD. PCD was not detected in the lateral endosperm in the absence of the embryo. The embryo’s effect on promoting lateral endosperm PCD could be substituted with gibberellic acid at 50 μmol/L. Micropylar endosperm cells undergo PCD irrespective of incubation with or without the embryo; gibberellic acid only hastens the onset of PCD morphology. Precursor protease vesicles, novel endoplasmic reticulum derived organelles considered markers of PCD, were observed in postgerminative lateral and micropylar endosperm cells. Internucleosomal laddering was not detected in endospermic DNA. These results suggest that a late postimbibition gibberellic acid linked mechanism promotes PCD in the lateral endosperm, whereas the promotion of PCD in the micropylar endosperm occurs early in, or prior to, imbibition.