bluuebunny/crossref_metadata_2025_split huggingface dataset:
The identification and evaluation of natural and synthetic esters in mineral oils
Authors: Bondioli Paolo , Piero Sabarino G. 
Published: July 2006

AbstractThe use of mineral‐based lubricating oils blended with vegetable oils or their derivatives has raised the question of the detection, identification, and quantitative evaluation of these substances in formulated products. This paper addresses the problem in a systematic way, and suggests some possible solutions by means of analytical pathways using column chromatography, GLC, and HPLC techniques. The methods suggested allow the identification and evaluation of fatty acid esters with mono‐ and polyalcohols.
The impact of detergent chemistry on TBN retention
Authors: van Dam W. , Broderick D. H. , Freerks R. L. , Small V. R. , Willis W. W. 
Published: July 2006

AbstractHistorically, the characterisation of fresh and used diesel engine lubricants has been based on a limited number of analytical techniques. One of the most important methods of analysis has been total base number (TBN) measurement. Although TBN measurements are informative, easy, and quick, it can be misleading to base the judgement of an oil's performance solely on one criterion.This paper offers some observations from a field test, showing that some detergent types gave unacceptable performance even though the TBNs were at an acceptable level. It is hypothesised that some detergents do not effectively neutralise all acidic species present in the lubricant, thereby reserving their own base, while in fact the oil may no longer provide sufficient protection against bearing corrosion. This hypothesis is supported by bench and engine test data. It is recommended that, at a minimum, total acid number (TAN) measurements be included in any analysis, and where time and cost permit, wear metals content, oxidation, soot content, and viscosity should also be evaluated.
Tribology of SiC/SiC Ceramic Matrix Composites in Liquid Oxygen in Relation to the Design of Hydrostatic Bearings
Authors: Bozet J. L. , Nélis M. , Leuchs M. , Bickel M. 
Published: July 2006

AbstractThis paper reports on the characterisation of ceramic matrix composites (CMCs) for bearing applications in liquid oxygen (LOX). Compatibility tests were performed to determine the safety and feasibility of subsequent research operations. Tribological tests were then made on a pin‐on‐disc apparatus using LOX as the working environment. The measurement of friction and wear allowed a comparison between different kinds of CMCs and 440C steel materials. As a logical progression a real geometry test rig is now being built. The design of a hybrid journal bearing has been finished and the manufacturing of the rig components started.
Evaluation Tests of Industrial Vacuum Bearings for Space Use
Authors: Obara S. , Sasaki A. , Haraguchi M. , Imagawa K. , Kawashima N. , Nishimura M. 
Published: July 2006

AbstractThe tribological performance of industrial vacuum bearings for space use was experimentally evaluated. The bearings selected for investigation were an 8 mm bore deep‐groove ball bearing lubricated with a sputtered MoS2 film and one lubricated with an ion‐plated Ag film, commercially available from three Japanese bearing manufacturers. Based on survey results of tribological requirements for existing satellite mechanisms, four types of bearing tests were defined and conducted: a vacuum test at room temperature, an atmosphere resistance test, a thermal vacuum test, and a vibration test. In addition to these tests, the variation in the tribological performance of the industrial bearings was also investigated. The results of more than 80 tests demonstrated that the industrial vacuum bearings had sufficient lubrication lives with low frictional torque and the data were reasonably repeatable, indicating a potential for space use.
Modelling Combustion Engine Degradation Processes
Authors: Stodola Jiří 
Published: July 2006

AbstractThis paper looks at combustion engine wear processes, including the categorisation of wear products (adhesive, abrasive, spherical, laminar, fatigue, corrosive, non‐ferrous, and other particles), and the evaluation of the trends in wear processes resulting from deterministic balance equations dealing with the processes of production and removal of wear products in combustion engine lubrication systems. The practical application of this approach to engine‐lubricant system wear has been quantified for a statistically significant set of data for engines with potential for friction coefficient reduction, with selective verification. The actual technical condition of the combustion engine has been evaluated by a multidimensional statistical evaluation. The model allows the qualitative description by means of a number of quantifiable variables (tribological, ecological, or economical parameters of the engine‐lubricant system).
Peripherally Inserted Central Venous Catheters Are Not Superior to Central Venous Catheters in the Acute Care of Surgical Patients on the Ward
Authors: Turcotte Simon , Dubé Serge , Beauchamp Gilles 
Published: July 2006

AbstractBackgroundPeripherally inserted central venous catheters (PICC) have supplanted central venous catheters (CVC) for the administration of intravenous antibiotics and total parenteral nutrition to patients in our hospital. From the literature, it appears that this change has occurred in a number of other surgical units. Accounting for the change are the expected advantages of low complication rates at insertion, prolonged use without complications and interruption, and cost‐ and time‐savings.MethodsWe have proceeded with a review of the literature to understand and justify this change in practice. Our hypothesis was that the routine adoption of PICC instead of CVC for the acute care of surgical patients has occurred in the absence of strong scientific evidence. Our aim was to compare the associated infectious, thrombotic, phlebitic, and other common complications, as well as PICC and CVC durability. Articles concerning various aspects of PICC‐ and CVC‐related complications in the acute care of adult patients were selected from the literature. Studies were excluded when they primarily addressed the use of long‐term catheters, outpatient care, and pediatric patients. Data were extracted from 48 papers published between 1979 and 2004.ResultsOur results show that infectious complications do not significantly differ between PICC and CVC. Thrombotic complications appear to be more significant with PICC and to occur early after catheterization. Phlebitic complications accounted for premature catheter removal in approximately 6% of PICC. Finally, prospective data suggest that approximately 40% of PICC will have to be removed before completion of therapy, possibly more often and earlier than CVC.ConclusionsWe believe that there is no clear evidence that PICC is superior to CVC in acute care settings. Each approach offers its own advantages and a different profile of complications. Therefore, the choice of central venous access should be individualized for surgical patients on the ward. More comparative prospective studies are needed to document the advantages of PICC over CVC.
Biliary Cystadenoma and Other Complicated Cystic Lesions of The Liver: Diagnostic and Therapeutic Challenges
Authors: Teoh Anthony Y.B. , Ng Simon S.M. , Lee K.F. , Lai Paul B.S. 
Published: July 2006

AbstractIntroductionBiliary cystadenomas are complicated cystic lesions of the liver. They are rare and pose considerable diagnostic and therapeutic challenges.MethodsWe present our experience managing these lesions by performing a retrospective review of all patients with a preoperative diagnosis of or histologically proven biliary cystadenoma who underwent surgery between January 1995 and January 2005 at our institution. Altogether, 20 patients (16 women, 4 men) with a mean age of 58 years underwent a total of 22 operations. The diagnosis of biliary cystadenoma was based on exclusion of other pathologic entities and the presence of radiologic characteristics of biliary cystadenoma. Abdominal ultrasonography (US), computed tomography, or both were performed in all patients. US‐guided fine‐needle aspiration cytology was performed in seven patients and all of them were negative for malignancy. A preoperative diagnosis of biliary cystadenoma was made in 16 patients based on clinical and radiologic features and was correct in 6 of them. Diagnosis of biliary cystadenoma was not suspected in four patients.ResultsThe overall diagnostic accuracy was 30%. Enucleation was the most common surgical procedure and was performed in 10 patients. The mean follow‐up period was 5.5 ± 2.8 years. No recurrence was detected in patients with confirmed biliary cystadenoma after adequate excision.ConclusionsThe findings of this study highlight the difficulty with preoperative diagnosis of biliary cystadenoma, which has seldom been discussed in the literature. Preoperative differentiation by means of radiologic imaging is inaccurate (30%). Any therapy short of complete excision leads to local recurrence and risk of malignant transformation. Complete excision of any suspicious lesion remains the best method of diagnosis and treatment.
Identification of Risk Factors for Perioperative Mortality in Acute Mesenteric Ischemia
Authors: Acosta‐Merida Maria Asuncion , Marchena‐Gomez Joaquin , Hemmersbach‐Miller Marion , Roque‐Castellano Cristina , Hernandez‐Romero Juan Maria 
Published: July 2006

AbstractIntroductionAcute intestinal ischemia is in most cases a lethal condition with a low survival rate. Risk factors of perioperative mortality are poorly defined. The aim of this study was to define risk factors that predict an adverse outcome of acute mesenteric ischemia (AMI).MethodsA total of 132 consecutive patients (73 men, 59 women), mean ± SD age 71.96 ± 13.64 years, who underwent surgery because of AMI in a university tertiary care center were evaluated over a period of 10 years. Clinical features, laboratory findings, etiologic factors, and surgical procedures were recorded and assessed as possible risk factors for perioperative mortality.ResultsOf 132 patients, 86 (65.2%) died during the perioperative period as a direct result of AMI. Significant univariate predictors of perioperative mortality were age (P = 0.01), cardiopathy (P = 0.002), digoxin intake (P = 0.015), shock (P = 0.01), urea plasma level (P < 0.001), creatinine (P < 0.001), potassium (P = 0.042), low pH (P = 0.015) and bicarbonate (P = 0.035); hemoglobin ≥ 2.48 mmol/L (P = 0.035); time delay to surgery (P = 0.023); colonic involvement (P < 0.001); small and large bowel involvement (P < 0.001); arterial versus venous ischemia (P = 0.007); and intestinal resection (P < 0.001). In the multivariate analysis, the variables previous cardiac illness (P = 0.045), urea plasma levels (P < 0.001), and small and large bowel involvement were identified as independent risk factors of perioperative mortality. Intestinal resection (P < 0.001) was a favorable predictor.ConclusionsAge, time delay to surgery, shock, and acidosis significantly increase the risk of mortality due to AMI, whereas intestinal resection has a protective effect. However, only previous cardiac illness, acute renal failure, and large bowel ischemia have a negative effect as independent risk factors of mortality of AMI.
A late Quaternary chironomid-inferred temperature record from the Sierra Nevada, California, with connections to northeast Pacific sea surface temperatures
Authors: Potito Aaron P. , Porinchu David F. , MacDonald Glen M. , Moser Katrina A. 
Published: July 2006

AbstractChironomid remains from a mid-elevation lake in the Sierra Nevada, California, were used to estimate quantitative summer surface water temperatures during the past ∼15,000 yr. Reconstructed temperatures increased by ∼3°C between lake initiation and the onset of the Holocene at ∼10,600 cal yr BP (calibrated years before present). Temperatures peaked at 6500 cal yr BP, displayed high variability from 6500 to 3500 cal yr BP, and stabilized after 3500 cal yr BP. This record generally tracks reconstructed Santa Barbara Basin sea surface temperatures (SSTs) through much of the Holocene, highlighting the correspondence between SST variability and California land temperatures during this interval.
Characterization of a Novel Plant Promoter Specifically Induced by Heavy Metal and Identification of the Promoter Regions Conferring Heavy Metal Responsiveness
Authors: Qi Xiaoting , Zhang Yuxiu , Chai Tuanyao 
Published: July 2006

Abstract
The bean (Phaseolus vulgaris) stress-related gene number 2 (PvSR2) gene responds to heavy metals but not to other forms of environmental stresses. To elucidate its heavy metal-regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region (−1623/+48) of PvSR2. Deletions from the 5′ end revealed that a sequence between −222 and −147 relative to the transcriptional start site was sufficient for heavy metal-specific induction of the promoter region of PvSR2. Detailed analysis of this 76-bp fragment indicated that heavy metal-responsive elements were localized in two regions (−222/−188 and −187/−147), each of which could separately confer heavy metal-responsive expression on the β-glucuronidase gene in the context of a minimal cauliflower mosaic virus 35S promoter. Region I (−222/−188) contains a motif (metal-regulatory element-like sequence) similar to the consensus metal-regulatory element of the animal metallothionein gene, and mutation of this motif eliminated the heavy metal-inducible function of region I. Region II (−187/−147) had no similarity to previously identified cis-acting elements involved in heavy metal induction, suggesting the presence of a novel heavy metal-responsive element. Transformed tobacco (Nicotiana tabacum) seedlings expressing β-glucuronidase under control of the PvSR2 promoter region (−687/+48) showed heavy metal-specific responsive activity that depended on the type and concentration of the heavy metal and the type of organ. These findings further our understanding of the regulation of PvSR2 expression and provide a new heavy-metal-inducible promoter system in transgenic plants.
Programmed Cell Death-Involved Aluminum Toxicity in Yeast Alleviated by Antiapoptotic Members with Decreased Calcium Signals
Authors: Zheng Ke , Pan Jian-Wei , Ye Lan , Fu Yu , Peng Hua-Zheng , Wan Bai-Yu , Gu Qing , Bian Hong-Wu , Han Ning , Wang Jun-Hui , Kang Bo , Pan Jun-Hang , Shao Hong-Hong , Wang Wen-Zhe , Zhu Mu-Yuan 
Published: July 2006

Abstract
The molecular mechanisms of aluminum (Al) toxicity and tolerance in plants have been the focus of ongoing research in the area of stress phytophysiology. Recent studies have described Al-induced apoptosis-like cell death in plant and animal cells. In this study, we show that yeast (Saccharomyces cerevisiae) exposed to low effective concentrations of Al for short times undergoes enhanced cell division in a manner that is dose and cell density dependent. At higher concentrations of Al or longer exposure times, Al induces cell death and growth inhibition. Several apoptotic features appear during Al treatment, including cell shrinkage, vacuolation, chromatin marginalization, nuclear fragmentation, DNA degradation, and DNA strand breaks, as well as concomitant cell aggregation. Yeast strains expressing Ced-9, Bcl-2, and PpBI-1 (a plant Bax inhibitor-1 isolated from Phyllostachys praecox), respectively, display more resistance to Al toxicity compared with control cells. Data from flow cytometric studies show these three antiapoptotic members do not affect reactive oxygen species levels, but decrease calcium ion (Ca2+) signals in response to Al stress, although both intracellular reactive oxygen species and Ca2+ levels were increased. The data presented suggest that manipulation of the negative regulation process of programmed cell death may provide a novel mechanism for conferring Al tolerance.
RNA Interference-Based Gene Silencing as an Efficient Tool for Functional Genomics in Hexaploid Bread Wheat
Authors: Travella Silvia , Klimm Theres E. , Keller Beat 
Published: July 2006

Abstract
Insertional mutagenesis and gene silencing are efficient tools for the determination of gene function. In contrast to gain- or loss-of-function approaches, RNA interference (RNAi)-induced gene silencing can possibly silence multigene families and homoeologous genes in polyploids. This is of great importance for functional studies in hexaploid wheat (Triticum aestivum), where most of the genes are present in at least three homoeologous copies and conventional insertional mutagenesis is not effective. We have introduced into bread wheat double-stranded RNA-expressing constructs containing fragments of genes encoding Phytoene Desaturase (PDS) or the signal transducer of ethylene, Ethylene Insensitive 2 (EIN2). Transformed plants showed phenotypic changes that were stably inherited over at least two generations. These changes were very similar to mutant phenotypes of the two genes in diploid model plants. Quantitative real-time polymerase chain reaction revealed a good correlation between decreasing mRNA levels and increasingly severe phenotypes. RNAi silencing had the same quantitative effect on all three homoeologous genes. The most severe phenotypes were observed in homozygous plants that showed the strongest mRNA reduction and, interestingly, produced around 2-fold the amount of small RNAs compared to heterozygous plants. This suggests that the effect of RNAi in hexaploid wheat is gene-dosage dependent. Wheat seedlings with low mRNA levels for EIN2 were ethylene insensitive. Thus, EIN2 is a positive regulator of the ethylene-signaling pathway in wheat, very similar to its homologs in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa). Our data show that RNAi results in stably inherited phenotypes and therefore represents an efficient tool for functional genomic studies in polyploid wheat.
Ectopic Expression of KNOTTED1-Like Homeobox Protein Induces Expression of Cytokinin Biosynthesis Genes in Rice
Authors: Sakamoto Tomoaki , Sakakibara Hitoshi , Kojima Mikiko , Yamamoto Yuko , Nagasaki Hiroshi , Inukai Yoshiaki , Sato Yutaka , Matsuoka Makoto 
Published: July 2006

Abstract
Some phytohormones such as gibberellins (GAs) and cytokinins (CKs) are potential targets of the KNOTTED1-like homeobox (KNOX) protein. To enhance our understanding of KNOX protein function in plant development, we identified rice (Oryza sativa) genes for adenosine phosphate isopentenyltransferase (IPT), which catalyzes the rate-limiting step of CK biosynthesis. Molecular and biochemical studies revealed that there are eight IPT genes, OsIPT1 to OsIPT8, in the rice genome, including a pseudogene, OsIPT6. Overexpression of OsIPTs in transgenic rice inhibited root development and promoted axillary bud growth, indicating that OsIPTs are functional in vivo. Phenotypes of OsIPT overexpressers resembled those of KNOX-overproducing transgenic rice, although OsIPT overexpressers did not form roots or ectopic meristems, both of which are observed in KNOX overproducers. Expression of two OsIPT genes, OsIPT2 and OsIPT3, was up-regulated in response to the induction of KNOX protein function with similar kinetics to those of down-regulation of GA 20-oxidase genes, target genes of KNOX proteins in dicots. However, expression of these two OsIPT genes was not regulated in a feedback manner. These results suggest that OsIPT2 and OsIPT3 have unique roles in the developmental process, which is controlled by KNOX proteins, rather than in the maintenance of bioactive CK levels in rice. On the basis of these findings, we concluded that KNOX protein simultaneously decreases GA biosynthesis and increases de novo CK biosynthesis through the induction of OsIPT2 and OsIPT3 expression, and the resulting high-CK and low-GA condition is required for formation and maintenance of the meristem.
Globally dispersed Y chromosomal haplotypes in wild and domestic sheep
Authors: Meadows J. R. S. , Hanotte O. , Drögemüller C. , Calvo J. , Godfrey R. , Coltman D. , Maddox J. F. , Marzanov N. , Kantanen J. , Kijas J. W. 
Published: July 2006

SummaryTo date, investigations of genetic diversity and the origins of domestication in sheep have utilised autosomal microsatellites and variation in the mitochondrial genome. We present the first analysis of both domestic and wild sheep using genetic markers residing on the ovine Y chromosome. Analysis of a single nucleotide polymorphism (oY1) in theSRYpromoter region revealed that alleleA‐oY1was present in all wild bighorn sheep (Ovis canadensis), two subspecies of thinhorn sheep (Ovis dalli), European Mouflon (Ovis musimon) and the Barbary (Ammontragis lervia).A‐oY1also had the highest frequency (71.4%) within 458 domestic sheep drawn from 65 breeds sampled from Africa, Asia, Australia, the Caribbean, Europe, the Middle East and Central Asia. Sequence analysis of a second locus, microsatelliteSRYM18, revealed a compound repeat array displaying fixed differences, which identified bighorn and thinhorn sheep as distinct from the European Mouflon and domestic animals. Combined genotypic data identified 11 male‐specific haplotypes that represented at least two separate lineages. Investigation of the geographical distribution of each haplotype revealed that one (H6) was both very common and widespread in the global sample of domestic breeds. The remaining haplotypes each displayed more restricted and informative distributions. For example, H5 was likely founded following the domestication of European breeds and was used to trace the recent transportation of animals to both the Caribbean and Australia. A high rate of Y chromosomal dispersal appears to have taken place during the development of domestic sheep as only 12.9% of the total observed variation was partitioned between major geographical regions.
Health‐related quality of life among 3–4‐year‐old children born with very low birthweight
Authors: Chien Li‐Yin , Chou Yi‐Hung , Ko Yi‐Li , Lee Ching‐Fang 
Published: July 2006

Aim.  This paper reports a study comparing health‐related quality of life at 3–4 years of age among children born with very low birthweight (≤1500 g) to a group of non‐very low birthweight controls, and to examine biological, environmental, demographic and health factors associated with quality of life of children born with very low birthweight.Background.  Advances in modern medicine have increased the survival of infants with very low birthweight, but its impact on quality of life of children during preschool years has been less studied.Methods.  The study sample included 118 children born with very low birthweight and 170 non‐very low birthweight controls in Taiwan. Primary caregivers of the study children completed structured questionnaires during the period November 2002 to April 2003. Health‐related quality of life was measured using the Mandarin version of the TZO‐AZL Preschool Children Quality of Life instrument. This tool has four dimensions: physical, emotional, cognitive and social functions. Higher scores indicate better quality of life.Findings.  Children born with very low birthweight had statistically significantly lower mean quality of life scores in all the four dimensions compared with controls. Among the former, those who had current physical health problems scored lower in all dimensions of quality of life. Primary caregivers with higher educational levels and increased ages of the children were associated with improved scores in the emotional and social functions. Birth gestational age was negatively associated with cognitive function. Length of stay in the neonatal intensive care unit was negatively associated with scores for the social function aspect of quality of life.Conclusion.  Regular monitoring of the quality of life among very low birthweight children is needed. Nurses need to assess the child's current health state, birth gestational age, and the primary caregiver's educational level in order to identify those who are at risk for low quality of life and intervene early.