bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conference proceedings as a source of scientific information: A bibliometric analysis
Authors: Lisée Cynthia , Larivière Vincent , Archambault Éric 
Published: June 2008

AbstractWhile several authors have argued that conference proceedings are an important source of scientific knowledge, the extent of their importance has not been measured in a systematic manner. This article examines the scientific impact and aging of conference proceedings compared to those of scientific literature in general. It shows that the relative importance of proceedings is diminishing over time and currently represents only 1.7% of references made in the natural sciences and engineering, and 2.5% in the social sciences and humanities. Although the scientific impact of proceedings is losing ground to other types of scientific literature in nearly all fields, it has grown from 8% of the references in engineering papers in the early 1980s to its current 10%. Proceedings play a particularly important role in computer sciences, where they account for close to 20% of the references. This article also shows that not unexpectedly, proceedings age faster than cited scientific literature in general. The evidence thus shows that proceedings have a relatively limited scientific impact, on average representing only about 2% of total citations, that their relative importance is shrinking, and that they become obsolete faster than the scientific literature in general.
Synthesis of 5‐Substituted 1H‐Tetrazoles by the Copper‐Catalyzed [3+2] Cycloaddition of Nitriles and Trimethylsilyl Azide
Authors: Jin Tienan , Kitahara Fukuzou , Kamijo Shin , Yamamoto Yoshinori 
Published: June 2008

AbstractThe copper‐catalyzed [3+2] cycloaddition between various nitriles and trimethylsilyl azide in DMF/MeOH produced the corresponding 5‐substituted 1H‐tetrazoles in good to high yields. It was proposed that the reaction proceeds through the formation in situ of a copper azide species and subsequent [3+2] cycloaddition with the nitriles. Furthermore, we found that a copper and triethylamine combined catalyst also promoted the cycloaddition of nitriles and trimethylsilyl azide to afford the 5‐substituted 1H‐tetrazoles at relatively low reaction temperatures. The copper azide species would be formed by reaction of the copper catalyst with Et3N⋅HN3 generated in situ.
Eastern Antarctic Peninsula precipitation delivery mechanisms: process studies and back trajectory evaluation
Authors: Russell Andrew , McGregor Glenn R. , Marshall Gareth J. 
Published: June 2008

AbstractThe atmospheric circulation patterns that result in precipitation events at a site on the eastern Antarctic Peninsula (AP) are investigated using back trajectories (BTs) driven by ERA‐40 data. Moisture delivery occurs from the east and west depending on the location of blocking events in the South Atlantic and Pacific Oceans. Observations are sparse in this region, so our process studies compare the trajectories (and the ERA‐40 fields from which they were derived) with advanced very high resolution radiometer (AVHRR) satellite images. It is found that the trajectories represent these transport mechanisms very well and that they are relatively insensitive to the initial trajectory elevation. Copyright © 2008 Royal Meteorological Society
Ruin theory for classical risk process that is perturbed by diffusion with risky investments
Authors: Lin Xiang 
Published: June 2008

AbstractIn this paper, we study the ruin theory for classical risk process that is perturbed by diffusion with risky investments. We obtain the upper bound for the minimal ruin probability. We also investigate the relationships between the adjustment coefficient and the diffusion volatility parameter, the risk‐free rate and the correlation coefficient by numerical calculation. We give the relationships between ruin and investment. Copyright © 2008 John Wiley & Sons, Ltd.
Prolonged weakening of the geomagnetic field (GMF) affects the immune system of rats
Authors: Roman Adam , Tombarkiewicz Barbara 
Published: June 2008

AbstractThe aim of this study was to find out how a long‐term shielding of the geomagnetic field (GMF) affected the immune system of rats. Male and female Wistar rats were kept up to an age of 2 months in a natural GMF (about 37 µT). Afterwards, the rats were divided into four groups (males and females separately): control rats were maintained in ambient GMF, while experimental animals were housed under conditions of a weakened GMF (below 12 µT) achieved with steel cages. After 6 months, the rats were sacrificed by decapitation. Spleens and thymuses were isolated and weighed. Peritoneal cells were eluted and cultured in vitro to study their ability to produce nitric oxide (NO) and to synthesize superoxide anion (O−2), important microbicidal molecules of macrophages. The number of macrophages was estimated by a crystal violet staining method. We found that the long‐term shielding of the GMF could influence the functioning of the immune system in a sex‐dependent manner. The deprivation of the GMF delayed physiological thymus involution, that effect being more strongly expressed in females. The weakening of the GMF resulted in an increased number of peritoneal macrophages, especially in males. The shielding of the GMF diminished the ability of macrophages to release NO and to synthesize O−2, those effects being more powerfully expressed in males and females, respectively. It is proposed that the observed changes in the immune system occur as a consequence of the protective effect of GMF shielding on the circadian rhythm‐dependent level of melatonin. Bioelectromagnetics 30:21–28, 2009. © 2008 Wiley‐Liss, Inc.
Rational improvement of simvastatin synthase solubility in Escherichia coli leads to higher whole‐cell biocatalytic activity
Authors: Xie Xinkai , Pashkov Inna , Gao Xue , Guerrero Jennifer L. , Yeates Todd O. , Tang Yi 
Published: June 2008

AbstractSimvastatin is the active pharmaceutical ingredient of the blockbuster cholesterol lowering drug Zocor. We have previously developed an Escherichia coli based whole‐cell biocatalytic platform towards the synthesis of simvastatin sodium salt (SS) starting from the precursor monacolin J sodium salt (MJSS). The centerpiece of the biocatalytic approach is the simvastatin synthase LovD, which is highly prone to misfolding and aggregation when overexpressed from E. coli. Increasing the solubility of LovD without decreasing its catalytic activity can therefore elevate the performance of the whole‐cell biocatalyst. Using a combination of homology structural prediction and site‐directed mutagenesis, we identified two cysteine residues in LovD that are responsible for nonspecific intermolecular crosslinking, which leads to oligomer formation and protein aggregation. Replacement of Cys40 and Cys60 with alanine residues resulted in marked gain in both protein solubility and whole‐cell biocatalytic activities. Further mutagenesis experiments converting these two residues to small or polar natural amino acids showed that C40A and C60N are the most beneficial, affording 27% and 26% increase in whole cell activities, respectively. The double mutant C40A/C60N combines the individual improvements and displayed ∼50% increase in protein solubility and whole‐cell activity. Optimized fed‐batch high‐cell‐density fermentation of the double mutant in an E. coli strain engineered for simvastatin production quantitatively (>99%) converted 45 mM MJSS to SS within 18 h, which represents a significant improvement over the performance of wild‐type LovD under identical conditions. The high efficiency of the improved whole‐cell platform renders the biocatalytic synthesis of SS an attractive substitute over the existing semisynthetic routes. Biotechnol. Bioeng. 2009;102: 20–28. © 2008 Wiley Periodicals, Inc.
Evaluation of a critical process parameter: Oxygen limitation during cultivation has a fully reversible effect on gene expression of Bordetella pertussis
Authors: Streefland Mathieu , van de Waterbeemd Bas , Kint Joeri , van der Pol Leo A. , Beuvery E. Coen , Tramper Johannes , Martens Dirk E. 
Published: June 2008

AbstractModern (bio)pharmaceutical process development requires thorough investigation of all process parameters that are critical to product quality. The impact of a disturbance of such a parameter during processing needs to be known so that a rational decision can be made about the release of the product. In cultivation processes the dissolved oxygen (DO) concentration is generally accepted as being a critical parameter. In this article the impact of a 90 min period of oxygen limitation during the cultivation of the strictly aerobic Bordetella pertussis bacterium is investigated. The cultivation is the most important process step for the manufacturing of a vaccine against whooping cough disease. Samples were taken immediately before and after oxygen limitation and at the end of cultivation of four oxygen limited and three control cultivations. DNA microarray analysis of the full transcriptome of the B. pertussis bacterium revealed that a 90 min period of oxygen limitation has a substantial effect on overall gene expression patterns. In total 104 genes were identified as a significant hit at any of the sample points, of which 58 were directly related to oxygen limitation. The other genes were mainly affected towards the end of cultivation. Of all genes involved in oxygen limitation none were identified to show a significant difference between the oxygen limited and control cultivations at the end of the batch. This indicates a fully reversible effect of oxygen limitation on gene expression. This finding has implications for the risk assessment of dissolved oxygen concentration as a critical process parameter. Biotechnol. Bioeng. 2009;102: 161–167. © 2008 Wiley Periodicals, Inc.
Twenty‐four well plate miniature bioreactor system as a scale‐down model for cell culture process development
Authors: Chen Aaron , Chitta Rajesh , Chang David , Amanullah Ashraf 
Published: June 2008

AbstractIncreasing the throughput and efficiency of cell culture process development has become increasingly important to rapidly screen and optimize cell culture media and process parameters. This study describes the application of a miniaturized bioreactor system as a scaled‐down model for cell culture process development using a CHO cell line expressing a recombinant protein. The microbioreactor system (M24) provides non‐invasive online monitoring and control capability for process parameters such as pH, dissolved oxygen (DO), and temperature at the individual well level. A systematic evaluation of the M24 for cell culture process applications was successfully completed. Several challenges were initially identified. These included uneven gas distribution in the wells due to system design and lot to lot variability, foaming issues caused by sparging required for active DO control, and pH control limitation under conditions of minimal dissolved CO2. A high degree of variability was found which was addressed by changes in the system design. The foaming issue was resolved by addition of anti‐foam, reduction of sparge rate, and elimination of DO control. The pH control limitation was overcome by a single manual liquid base addition. Intra‐well reproducibility, as indicated by measurements of process parameters, cell growth, metabolite profiles, protein titer, protein quality, and scale‐equivalency between the M24 and 2 L bioreactor cultures were very good. This evaluation has shown feasibility of utilizing the M24 as a scale‐down tool for cell culture application development under industrially relevant process conditions. Biotechnol. Bioeng. 2009;102: 148–160. © 2008 Wiley Periodicals, Inc.
Anaerobic mineralization of pentachlorophenol (PCP) by combining PCP‐dechlorinating and phenol‐degrading cultures
Authors: Yang Suyin , Shibata Atsushi , Yoshida Naoko , Katayama Arata 
Published: June 2008

AbstractThe dechlorination and mineralization of pentachlorophenol (PCP) was investigated by simultaneously or sequentially combining two different anaerobic microbial populations, a PCP‐dechlorinating culture capable of the reductive dechlorination of PCP to phenol and phenol‐ degrading cultures able to mineralize phenol under sulfate‐ or iron‐reducing conditions. In the simultaneously combined mixture, PCP (about 35 µM) was mostly dechlorinated to phenol after incubation for 17 days under sulfate‐reducing conditions or for 22 days under iron‐reducing conditions. Thereafter, the complete removal of phenol occurred within 40 days under both conditions. In the sequentially combined mixture, most of the phenol, the end product of PCP dechlorination, was degraded within 12 days of inoculation with the phenol degrader, without a lag phase, under both sulfate‐ and iron‐reducing conditions. In a radioactivity experiment, [14C–U]–PCP was mineralized to 14CO2 and 14CH4 by the combined anaerobic microbial activities. Analysis of electron donor and acceptor utilization and of the production and consumption of H2, CO2, and CH4 suggested that the dechlorinating and degrading microorganisms compete with other microorganisms to perform PCP dechlorination and part of the phenol degradation in complex anoxic environments in the presence of electron donors and acceptors. The presence of a small amount of autoclaved soil slurry in the medium was possibly another advantageous factor in the successful dechlorination and mineralization of PCP by the combined mixtures. This anaerobic–anaerobic combination technology holds great promise as a cost‐effective strategy for complete PCP bioremediation in situ. Biotechnol. Bioeng. 2009;102: 81–90. © 2008 Wiley Periodicals, Inc.
Microalgae for oil: Strain selection, induction of lipid synthesis and outdoor mass cultivation in a low‐cost photobioreactor
Authors: Rodolfi Liliana , Chini Zittelli Graziella , Bassi Niccolò , Padovani Giulia , Biondi Natascia , Bonini Gimena , Tredici Mario R. 
Published: June 2008

AbstractThirty microalgal strains were screened in the laboratory for their biomass productivity and lipid content. Four strains (two marine and two freshwater), selected because robust, highly productive and with a relatively high lipid content, were cultivated under nitrogen deprivation in 0.6‐L bubbled tubes. Only the two marine microalgae accumulated lipid under such conditions. One of them, the eustigmatophyte Nannochloropsis sp. F&M‐M24, which attained 60% lipid content after nitrogen starvation, was grown in a 20‐L Flat Alveolar Panel photobioreactor to study the influence of irradiance and nutrient (nitrogen or phosphorus) deprivation on fatty acid accumulation. Fatty acid content increased with high irradiances (up to 32.5% of dry biomass) and following both nitrogen and phosphorus deprivation (up to about 50%). To evaluate its lipid production potential under natural sunlight, the strain was grown outdoors in 110‐L Green Wall Panel photobioreactors under nutrient sufficient and deficient conditions. Lipid productivity increased from 117 mg/L/day in nutrient sufficient media (with an average biomass productivity of 0.36 g/L/day and 32% lipid content) to 204 mg/L/day (with an average biomass productivity of 0.30 g/L/day and more than 60% final lipid content) in nitrogen deprived media. In a two‐phase cultivation process (a nutrient sufficient phase to produce the inoculum followed by a nitrogen deprived phase to boost lipid synthesis) the oil production potential could be projected to be more than 90 kg per hectare per day. This is the first report of an increase of both lipid content and areal lipid productivity attained through nutrient deprivation in an outdoor algal culture. The experiments showed that this marine eustigmatophyte has the potential for an annual production of 20 tons of lipid per hectare in the Mediterranean climate and of more than 30 tons of lipid per hectare in sunny tropical areas. Biotechnol. Bioeng. 2009;102: 100–112. © 2008 Wiley Periodicals, Inc.
Characterization of materials eliciting foreign body reaction in stapled human gastrointestinal anastomoses
Authors: Lim C B B , Goldin R D , Darzi A , Hanna G B 
Published: June 2008

Abstract

Background
Staples are made of titanium, which elicits minimal tissue reaction. The authors have encountered foreign body reaction associated with stapled human gastrointestinal anastomoses, although the literature has no reports of this. The aim of this study was to identify the refractile foreign materials causing this reaction.

Methods
Histological sections were taken from 14 gastrointestinal specimens from patients with a history of a stapled anastomosis within the specimen excised. These were reviewed by light and polarization microscopy. Scanning electron microscopy and energy dispersive X-ray analysis were carried out on these sections, staples and stapler cartridges used for gastrointestinal surgery.

Results
Foreign bodies rich in fluorine were found in three patients, and those rich in carbon in 12. Other elements identified included oxygen, calcium, sodium, potassium, magnesium, aluminium and silicon. One specimen was found to contain titanium with no surrounding foreign body reaction. Stapler cartridges contained carbon, oxygen, fluorine, calcium, sodium, potassium, magnesium, aluminium, silicon and traces of titanium. Staples were composed of pure titanium with some fibrous material on the surface containing elements found in stapler cartridges.

Conclusion
The presence of foreign body reaction was confirmed in stapled human gastrointestinal anastomoses. The source of refractile materials eliciting this reaction was the stapler cartridges.
Rho-kinase signalling mediates endotoxin hypersensitivity after partial hepatectomy
Authors: Slotta J E , Laschke M W , Menger M D , Thorlacius H 
Published: June 2008

AbstractBackgroundExcessive loss of functional liver mass results in hepatic dysfunction and is associated with an increased sensitivity to infection. This experimental study investigated the role of Rho-kinase in hepatectomy-induced sensitization to endotoxin.MethodsMale C57BL/6J mice underwent 68 per cent hepatectomy and were injected 24 h later with 100 µg Escherichia coli lipopolysaccharide (LPS). Simultaneously, animals received either fasudil or Y-27632 for Rho-kinase inhibition, or phosphate-buffered saline. Untreated hepatectomized animals served as positive controls and sham-operated animals as negative controls. Liver injury and inflammatory parameters were assessed 6 h after LPS challenge by serum alanine aminotransferase (ALT) levels, histomorphology and enzyme-linked immunosorbent assay.ResultsHepatectomy resulted in a significant susceptibility to LPS, as indicated by inflammatory leucocyte recruitment (mean(s.e.m.) 10(1) leucocytes per high-power field), hepatocellular disintegration (ALT 22·4(3·1) µkat/l) and apoptotic cell death (3·8(0·2) per cent). Rho-kinase inhibition reduced leucocytic infiltration by more than 33 per cent, abolished hepatocellular apoptosis entirely, and reduced tumour necrosis factor α expression by more than 48 per cent and CXC chemokine expression by more than 36 per cent.ConclusionHepatectomy increased susceptibility to LPS by Rho-kinase-dependent mechanisms. Blocking Rho-kinase signalling decreased LPS-induced liver injury in hepatectomized mice.
Urinary dysfunction after rectal cancer treatment is mainly caused by surgery
Authors: Lange M M , Maas C P , Marijnen C A M , Wiggers T , Rutten H J , Kranenbarg E Klein , van de Velde C J H 
Published: June 2008

Abstract

Background
Urinary dysfunction (UD) is common after rectal cancer treatment, but the contribution of each treatment component (surgery and radiotherapy) to its development remains unclear. This study aimed to evaluate UD during 5 years after total mesorectal excision (TME) and to investigate the influence of preoperative radiotherapy (PRT) and surgical factors.

Methods
Patients with operable rectal cancer were randomized to TME with or without PRT. Questionnaires concerning UD were completed by 785 patients before and at several time points after surgery. Possible risk factors, including PRT, demographics, tumour location, and type and extent of resection, were investigated by multivariable regression analysis.

Results
Long-term incontinence was reported by 38·1 per cent of patients, of whom 72·0 per cent had normal preoperative function. Preoperative incontinence (relative risk (RR) 2·75, P = 0·001) and female sex (RR 2·77, P &lt; 0·001) were independent risk factors. Long-term difficulty in bladder emptying was reported by 30·6 per cent of patients, of whom 65·0 per cent had normal preoperative function. Preoperative difficulty in bladder emptying (RR 2·94, P &lt; 0·001), peroperative blood loss (RR 1·73, P = 0·028) and autonomic nerve damage (RR 2·82, P = 0·024) were independent risk factors. PRT was not associated with UD.

Conclusion
UD is a significant clinical problem after rectal cancer treatment and is not related to PRT, but rather to surgical nerve damage.
Intermittent Pringle manoeuvre is not associated with adverse long-term prognosis after resection for colorectal liver metastases
Authors: Wong K H V , Hamady Z Z R , Malik H Z , Prasad R , Lodge J P A , Toogood G J 
Published: June 2008

Abstract

Background
Intermittent clamping of the porta hepatis, or the intermittent Pringle manoeuvre (IPM), is often used to control inflow during parenchymal liver transection. The aim of this study was to determine whether IPM is associated with an adverse long-term outcome after liver resection for colorectal liver metastasis (CRLM).

Methods
All patients undergoing resection for CRLM in 1993–2006, for whom data on IPM were recorded, were included in the study. A total of 563 patients was available for analysis.

Results
IPM was performed in 289 (51·3 per cent) of the patients. The duration of IPM ranged from 2 to 104 (median 22) min. There were no differences in clinicopathological features or postoperative morbidity between patients who had an IPM and those who did not. The median survival of patients undergoing IPM was 55·7 months compared with 48·9 months in those not having an IPM (P = 0·406). There was no difference in median disease-free survival between the two groups (22·1 versus 19·9 months respectively; P = 0·199).

Conclusion
IPM is not associated with an adverse long-term prognosis in patients undergoing liver resection for CRLM.
Survival benefit in a randomized clinical trial of faecal occult blood screening for colorectal cancer
Authors: Lindholm E , Brevinge H , Haglind E 
Published: June 2008

Abstract

Background
Early detection of colorectal cancer could reduce cancer-specific mortality. The aim of this trial was to evaluate the effect of faecal occult blood test (FOBT) screening on colorectal cancer mortality in a Swedish population.

Methods
All 68 308 citizens in Göteborg born between 1918 and 1931 were randomized to a screening or a control group at the age of 60–64 years. All were screened two to three times with rehydrated Hemoccult-II®. Compliance was 70·0 per cent (23 916 individuals). Those with a positive test result were offered sigmoidoscopy and a double-contrast enema. The primary endpoint was death from colorectal cancer.

Results
After a mean of 9 years from the last screening, there was a significant reduction in colorectal cancer mortality in the screening group compared with the control group. The overall risk ratio of death from colorectal cancer was 0·84 (95 per cent confidence interval 0·71 to 0·99). The groups did not differ in incidence of colorectal cancer or in overall mortality.

Conclusion
FOBT screening significantly reduces colorectal cancer mortality.