bluuebunny/crossref_metadata_2025_split huggingface dataset:
The complicated influence of branching on crystallization behavior of poly(ethylene terephthalate)
Authors: Li Guang , Yang Shenglin , Jiang Jianming , Jin Junhong , Wu Chengxun 
Published: July 2008

AbstractThe randomly branched poly(ethylene terephthalate) (BPET) was prepared by bulk polycondensation from dimethyl terephthalate (DMT) and ethylene glycol (EG), with 0.4–5.0 mol % (with respect to DMT) of glycerol (GL) as a branching agent. The glass transition and crystallization behavior was studied by differential scanning calorimetry (DSC). It was found that the glass transition temperature of BPET reduced with the increasing content of GL until 1.2 mol %, and then increases a little at high degrees of branching. When compared with a linear PET, the crystallization temperature of BPET from the melt shifted to higher temperature as GL content was smaller than 1.2 mol %, and then became lower while GL load was added. Nonisothermal crystallization kinetics was studied through the modified Avrami analysis. It was revealed that the overall crystallization rate parameter of BPET became larger when the GL content was less than 1.2 mol %, then turned to lower at higher branching degree. This indicated that low degree of branching could enhance the overall crystallization of poly(ethylene terephthalate) (PET), whereas high degree of branching in the range of 3.5–5.0 mol % would block the development of crystallization. On the basis of Hoffman's secondary crystallization theory, the product σσe of the free energy of formation per unit area of the lateral and folding surface was calculated. According to the change of the product σσe with the degree of branching, a possible explanation was presented to illuminate this diverse effect of different degrees of branching on crystallization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The shift towards multi‐disciplinarity in information science
Authors: Chua Alton Y.K. , Yang Christopher C. 
Published: July 2008

AbstractThis article analyzes the collaboration trends, authorship and keywords of all research articles published in the Journal of American Society for Information Science and Technology (JASIST). Comparing the articles between two 10‐year periods, namely, 1988–1997 and 1998–2007, the three‐fold objectives are to analyze the shifts in (a) authors' collaboration trends (b) top authors, their affiliations as well as the pattern of coauthorship among them, and (c) top keywords and the subdisciplines from which they emerge. The findings reveal a distinct tendency towards collaboration among authors, with external collaborations becoming more prevalent. Top authors have grown in diversity from those being affiliated predominantly with library/information‐related departments to include those from information systems management, information technology, businesss, and the humanities. Amid heterogeneous clusters of collaboration among top authors, strongly connected cross‐disciplinary coauthor pairs have become more prevalent. Correspondingly, the distribution of top keywords' occurrences that leans heavily on core information science has shifted towards other subdisciplines such as information technology and sociobehavioral science.
Folate‐related gene polymorphisms as risk factors for cleft lip and cleft palate
Authors: Mills James L. , Molloy Anne M. , Parle‐McDermott Anne , Troendle James F. , Brody Lawrence C. , Conley Mary R. , Cox Christopher , Pangilinan Faith , Orr David J. A. , Earley Michael , McKiernan Eamon , Lynn Ena C. , Doyle Anne , Scott John M. , Kirke Peadar N. 
Published: July 2008

AbstractBACKGROUND:Cleft lip with or without cleft palate (CLP) and cleft palate only (CPO) have an inherited component and, many studies suggest, a relationship with folate. Attempts to find folate‐related genes associated with clefts have, however, often been inconclusive. This study examined four SNPs related to folate metabolism (MTHFR 677 C→T, MTHFR 1298 A→C, MTHFD1 1958 G→A, and TC II 776 C→G) in a large Irish population to clarify their relationship with clefts.METHODS:Cases and their parents were recruited from major surgical centers performing cleft repairs in Ireland and a support organization. Data on risk factors, medical history, and DNA were collected. Controls were pregnant women from the greater Dublin area (n = 1,599).RESULTS:CLP cases numbered 536 and CPO cases 426 after exclusions. CPO mothers were significantly more likely than controls to be MTHFR 677 TT, OR 1.50 (95% CI: 1.05–2.16; p = .03). Log‐linear analysis showed a borderline association (p = .07). Isolated CPO case mothers were significantly more likely than controls to be homozygous for the MTHFD1 1958 G→A variant, OR 1.50 (95%CI: 1.08–2.09; p = .02). When multiple cases were added, both CPO cases and case mothers were significantly more likely to be AA (p = .02 and p = .007, respectively). The CLP case‐control and mother‐control analyses also showed significant effects, ORs 1.38 (95% CI: 1.05–1.82; p = .03) and 1.39 (95% CI: 1.04–1.85; p = .03), respectively.CONCLUSIONS:Associations were found for both CPO and CLP and MTHFD1 1958 G→A in cases and case mothers. MTHFR 677 C→T could be a maternal risk factor for clefts but the association was not strong. Because multiple comparisons were made, these findings require additional investigation. Given the known association between MTHFD1 1958 G→A and NTDs, these findings should be explored in more detail. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.
Optimized evolution in the cytostat: A Monte Carlo simulation
Authors: Gilbert Alan , Srienc Friedrich 
Published: July 2008

AbstractRational genetic alterations of a microorganism for a specific purpose are not possible in many situations where our knowledge of the relationship between phenotype and genotype is limited. In such cases evolutionary techniques must be applied. Evolutionary methods are usually time consuming; therefore, more efficient techniques are highly desirable. In this work we present the optimization of strain development in a cytostat. The time required for mutant strain isolation is dependent on the total cells present, the wild‐type specific growth rate, the beneficial mutation probability, the mutant specific growth rate, and several bioreactor operating conditions. These parameters are highly related, and a theoretical model, as developed here, is needed to define the conditions that optimize the isolation. The model is based on a discrete, stochastic description of mutant formation and selection in the background of abundant wild‐type cells. Using the model, we determined the optimal cytostat operating strategy for mutant isolation that varies according to the probability of beneficial mutations. It is also shown that mutants with as little as a 5% growth advantage can be isolated in less than 15 days which is significantly faster than in a chemostat. The described optimal mutant isolation procedure is expected to be particularly useful for the generation of industrial strains that are robust in challenging growth conditions. Biotechnol. Bioeng. 2009;102: 221–231. © 2008 Wiley Periodicals, Inc.
Precipitation and recovery of metal sulfides from metal containing acidic wastewater in a sulfidogenic down‐flow fluidized bed reactor
Authors: Gallegos‐Garcia Marisol , Celis Lourdes B. , Rangel‐Méndez René , Razo‐Flores Elías 
Published: July 2008

AbstractThis study reports the feasibility of recovering metal precipitates from a synthetic acidic wastewater containing ethanol, Fe, Zn, and Cd at an organic loading rate of 2.5 g COD/L‐day and a COD to sulfate ratio of 0.8 in a sulfate reducing down‐flow fluidized bed reactor. The metals were added at increasing loading rates: Fe from 104 to 320 mg/L‐day, Zn from 20 to 220 mg/L‐day, and Cd from 5 to 20 mg/L‐day. The maximum COD and sulfate removals attained were 54% and 41%, respectively. The biofilm reactor was operated at pH as low as 5.0 with stable performance, and no adverse effect over COD consumption or sulfide production was observed. The metals precipitation efficiencies obtained for Fe, Zn, and Cd exceeded 99.7%, 99.3%, and 99.4%, respectively. The total recovered precipitate was estimated to be 90% of the theoretical mass expected as metal sulfides. The precipitate was mainly recovered from the bottom of the reactor and the equalizer. The analysis of the precipitates showed the presence of pyrite (FeS2), sphalerite (ZnS) and greenockite (CdS); no metal hydroxides or carbonates in crystalline phases were identified. This study is the first in reporting the feasibility to recover metal sulfides separated from the biomass in a sulfate reducing process in one stage. Biotechnol. Bioeng. 2009;102: 91–99. © 2008 Wiley Periodicals, Inc.
Sterilization of ginseng using a high pressure CO2 at moderate temperatures
Authors: Dehghani Fariba , Annabi Nasim , Titus Mamata , Valtchev Peter , Tumilar Aldric 
Published: July 2008

AbstractThe aim of this study was to determine the feasibility of using high pressure CO2 for sterilization of Ginseng powder, as an alternative method to conventional techniques such as γ‐irradiation and ethylene oxide. The Ginseng sample used in this study was originally contaminated with fungi and 5 × 107 bacteria/g that was not suitable for oral use. This is the first time that high pressure CO2 has been used for the sterilization of herbal medicine to decrease the total aerobic microbial count (TAMC) and fungi. The effect of the process duration, operating pressure, temperature, and amount of additives on the sterilization efficiency of high pressure CO2 were investigated. The process duration was varied over 15 h; the pressure between 100 and 200 bar and the temperature between 25 and 75°C. A 2.67‐log reduction of bacteria in the Ginseng sample was achieved after long treatment time of 15 h at 60°C and 100 bar, when using neat carbon dioxide. However, the addition of a small quantity of water/ethanol/H2O2 mixture, as low as 0.02 mL of each additive/g Ginseng powder, was sufficient for complete inactivation of fungi within 6 h at 60°C and 100 bar. At these conditions the bacterial count was decreased from 5 × 107 to 2.0 × 103 TAMC/g complying with the TGA standard for orally ingested products. A 4.3 log reduction in bacteria was achieved at 150 bar and 30°C, decreasing the TAMC in Ginseng sample to 2,000, below the allowable limit. However, fungi still remained in the sample. The complete inactivation of both bacteria and fungi was achieved within 2 h at 30°C and 170 bar using 0.1 mL of each additive/g Ginseng. Microbial inactivation at this low temperature opens an avenue for the sterilization of many thermally labile pharmaceutical and food products that may involve sensitive compounds to γ‐radiation and chemically reactive antiseptic agents. Biotechnol. Bioeng. 2009;102: 569–576. © 2008 Wiley Periodicals, Inc.
In situ magnetic separation for extracellular protein production
Authors: Käppler Tobias , Cerff Martin , Ottow Kim , Hobley Timothy , Posten Clemens 
Published: July 2008

AbstractA new approach for in situ product removal from bioreactors is presented in which high‐gradient magnetic separation is used. This separation process was used for the adsorptive removal of proteases secreted by Bacillus licheniformis. Small, non‐porous bacitracin linked magnetic adsorbents were employed directly in the broth during the fermentation, followed by in situ magnetic separation. Proof of the concept was first demonstrated in shake flask culture, then scaled up and applied during a fed batch cultivation in a 3.7 L bioreactor. It could be demonstrated that growth of B. licheniformis was not influenced by the in situ product removal step. Protease production also remained the same after the separation step. Furthermore, degradation of the protease, which followed first order kinetics, was reduced by using the method. Using a theoretical modeling approach, we could show that protease yield in total was enhanced by using in situ magnetic separation. The process described here is a promising technique to improve overall yield in bio production processes which are often limited due to weak downstream operations. Potential limitations encountered during a bioprocess can be overcome such as product inhibition or degradation. We also discuss the key points where research is needed to implement in situ magnetic separation in industrial production. Biotechnol. Bioeng. 2009;102: 535–545. © 2008 Wiley Periodicals, Inc.
Generation of human embryonic stem cell‐derived mesoderm and cardiac cells using size‐specified aggregates in an oxygen‐controlled bioreactor
Authors: Niebruegge Sylvia , Bauwens Céline L. , Peerani Raheem , Thavandiran Nimalan , Masse Stephane , Sevaptisidis Elias , Nanthakumar Kumar , Woodhouse Kim , Husain Mansoor , Kumacheva Eugenia , Zandstra Peter W. 
Published: July 2008

AbstractThe ability to generate human pluripotent stem cell‐derived cell types at sufficiently high numbers and in a reproducible manner is fundamental for clinical and biopharmaceutical applications. Current experimental methods for the differentiation of pluripotent cells such as human embryonic stem cells (hESC) rely on the generation of heterogeneous aggregates of cells, also called “embryoid bodies” (EBs), in small scale static culture. These protocols are typically (1) not scalable, (2) result in a wide range of EB sizes and (3) expose cells to fluctuations in physicochemical parameters. With the goal of establishing a robust bioprocess we first screened different scalable suspension systems for their ability to support the growth and differentiation of hESCs. Next homogeneity of initial cell aggregates was improved by employing a micro‐printing strategy to generate large numbers of size‐specified hESC aggregates. Finally, these technologies were integrated into a fully controlled bioreactor system and the impact of oxygen concentration was investigated. Our results demonstrate the beneficial effects of stirred bioreactor culture, aggregate size‐control and hypoxia (4% oxygen tension) on both cell growth and cell differentiation towards cardiomyocytes. QRT‐PCR data for markers such as Brachyury, LIM domain homeobox gene Isl‐1, Troponin T and Myosin Light Chain 2v, as well as immunohistochemistry and functional analysis by response to chronotropic agents, documented the impact of these parameters on cardiac differentiation. This study provides an important foundation towards the robust generation of clinically relevant numbers of hESC derived cells. Biotechnol. Bioeng. 2009;102: 493–507. © 2008 Wiley Periodicals, Inc.
Effect of enzyme supplementation at moderate cellulase loadings on initial glucose and xylose release from corn stover solids pretreated by leading technologies
Authors: Kumar Rajeev , Wyman C.E. 
Published: July 2008

AbstractModerate loadings of cellulase enzyme supplemented with β‐glucosidase were applied to solids produced by ammonia fiber expansion (AFEX), ammonia recycle (ARP), controlled pH, dilute sulfuric acid, lime, and sulfur dioxide pretreatments to better understand factors that control glucose and xylose release following 24, 48, and 72 h of hydrolysis and define promising routes to reducing enzyme demands. Glucose removal was higher from all pretreatments than from Avicel cellulose at lower enzyme loadings, but sugar release was a bit lower for solids prepared by dilute sulfuric acid in the Sunds system and by controlled pH pretreatment than from Avicel at higher protein loadings. Inhibition by cellobiose was observed to depend on the type of substrate and pretreatment and hydrolysis times, with a corresponding impact of β‐glucosidase supplementation. Furthermore, for the first time, xylobiose and higher xylooligomers were shown to inhibit enzymatic hydrolysis of pure glucan, pure xylan, and pretreated corn stover, and xylose, xylobiose, and xylotriose were shown to have progressively greater effects on hydrolysis rates. Consistent with this, addition of xylanase and β‐xylosidase improved performance significantly. For a combined mass loading of cellulase and β‐glucosidase of 16.1 mg/g original glucan (about 7.5 FPU/g), glucose release from pretreated solids ranged from 50% to75% of the theoretical maximum and was greater for all pretreatments at all protein loadings compared to pure Avicel cellulose except for solids from controlled pH pretreatment and from dilute acid pretreatment by the Sunds pilot unit. The fraction of xylose released from pretreated solids was always less than for glucose, with the upper limit being about 60% of the maximum for ARP and the Sunds dilute acid pretreatments at a very high protein mass loading of 116 mg/g glucan (about 60 FPU). Biotechnol. Bioeng. 2009;102: 457–467. © 2008 Wiley Periodicals, Inc.
Expression of merA, amoA and hao in continuously cultured Nitrosomonas europaea cells exposed to zinc chloride additions
Authors: Radniecki Tyler S. , Semprini Lewis , Dolan Mark E. 
Published: July 2008

AbstractThe effects of ZnCl2 additions on a mercuric reductase, merA, ammonia monooxygenase, amoA, and hydroxylamine (NH2OH) oxidoreductase, hao, gene expression were examined in continuously cultured Nitrosomonas europaea cells. The reactor was operated for 85 days with a 6.9 d hydraulic retention time and with four successive additions of ZnCl2 achieving maximum concentrations from 3 to 90 µM Zn2+. Continuously cultured N. europaea cells were more resistant to Zn2+ inhibition than previously examined batch cultured cells due to the presence of Mg2+ in the growth media, suggesting that Zn2+ enters the cell through Mg2+ import channels. The maximum merA up‐regulation was 45‐fold and expression increased with increases in Zn2+ concentration and decreased as Zn2+ concentrations decreased. Although Zn2+ irreversibly inactivated ammonia oxidation in N. europaea, the addition of either 600 µM CuSO4 or 2250 µM MgSO4 protected N. europaea from ZnCl2 inhibition, indicating a competition between Zn2+ and Cu2+/Mg2+ for uptake and/or AMO active sites. Since ZnCl2 inhibition is irreversible and amoA was up‐regulated at 30 and 90 µM additions, it is hypothesized that de novo synthesis of the AMO enzyme is needed to overcome inhibition. The up‐regulation of merA during exposure to non‐inhibitory Zn2+ levels indicates that merA is an excellent early warning signal for Zn2+ inhibition. Biotechnol. Bioeng. 2009;102: 546–553. © 2008 Wiley Periodicals, Inc.
High‐level cell‐free synthesis yields of proteins containing site‐specific non‐natural amino acids
Authors: Goerke Aaron R. , Swartz James R. 
Published: July 2008

AbstractWe describe an E. coli‐based cell‐free system for the production of proteins with a non‐natural amino acid (nnAA) incorporated site‐specifically (modified protein). The mutant Methanococcus jannaschii tyrosyl‐tRNA synthetase (mTyrRS) and tRNATyr pair were used as orthogonal elements. The mTyrRS experienced proteolysis and modified protein yields improved with higher synthetase addition (200–300 µg/mL). Product yields were also improved by increasing levels of total protein to 20 mg protein/mL and available vesicle surface area to 0.5 m2/mL. This new E. coli‐based cell‐free procedure produced up to 400 µg/mL of eCAT109pAz, 660 µg/mL of eDHFR10pAz, and 210 µg/mL of mDHFR31pAz with p‐azido‐L‐phenylalanine (pAz) incorporated site‐specifically at the amber nonsense codon. O‐methyl‐L‐tyrosine and p‐acetyl‐L‐phenylalanine were incorporated by similar protocols. The desired specificity for incorporation of the nnAA by the cell‐free system was confirmed. Additionally, the modified proteins were enzymatically active and reactive for copper(I)‐catalyzed (3 + 2) cycloadditions (click chemistry). Biotechnol. Bioeng. 2009;102: 400–416. © 2008 Wiley Periodicals, Inc.
Endoscopic ultrasonography-detected low-volume ascites as a predictor of inoperability for oesophagogastric cancer
Authors: Sultan J , Robinson S , Hayes N , Griffin S M , Richardson D L , Preston S R 
Published: July 2008

Abstract

Background
Endoscopic ultrasonography (EUS) can detect low-volume ascites (LVA) not apparent on computed tomography. The aim of this study was to assess the importance of LVA for management of patients with oesophagogastric (OG) cancer.

Methods
Patients with LVA were identified from a prospective OG cancer unit database between January 2002 and January 2006.

Results
Of 1118 patients staged with OG cancer, 802 had EUS. The incidence of LVA was 8·4 per cent overall but fell to 6·5 per cent when those with metastases on computed tomography were excluded. Only patients with gastric and OG junction carcinoma had LVA. Staging laparoscopy in the 21 patients with LVA revealed that 11 (52 per cent) were inoperable. The remainder had laparotomy and complete (R0) resection was possible in only five (50 per cent). In 106 patients who had staging laparoscopy after EUS without LVA, 37 (34·9 per cent) were inoperable and 56 of the remaining 69 (81 per cent) had R0 resection.

Conclusion
The presence of LVA on EUS is uncommon in patients with OG cancer but very important, being indicative of incurable disease in 76 per cent. This information will be helpful in counselling patients regarding management options and the low likelihood of potentially curative treatment.
Systematic review of randomized controlled trials of the effectiveness of biofeedback for pelvic floor dysfunction
Authors: Koh C E , Young C J , Young J M , Solomon M J 
Published: July 2008

Abstract

Background
Pelvic floor dysfunction (PFD) is a type of functional constipation. The effectiveness of biofeedback as a treatment remains unclear.

Methods
A systematic review of all randomized controlled trials evaluating the effectiveness of biofeedback in adults with PFD was carried out. All online databases from 1950 to 2007 were searched. This was supplemented by hand searching references of retrieved articles.

Results
Seven trials fulfilled the inclusion criteria. Three compared biofeedback with non-biofeedback treatments and four compared different biofeedback modalities. Electromyography feedback was most widely utilized. The trials were heterogeneous with varied inclusion criteria, treatment protocols and definitions of success. Most had methodological limitations. Quality of life and psychological morbidity were assessed rarely. Meta-analysis of the studies involving any form of biofeedback compared with any other treatment suggested that biofeedback conferred a sixfold increase in the odds of treatment success (odds ratio 5·861 (95 per cent confidence interval 2·175 to 15·794); random-effects model).

Conclusion
Although biofeedback is the recommended treatment for PFD, high-quality evidence of effectiveness is lacking. Meta-analysis of the available evidence suggests that biofeedback is the best option, but well designed trials that take into account quality of life and psychological morbidity are needed.
A laboratory demonstration illustrating bioseparations using colorful proteins
Authors: Cohen Theodore M. , Rohs Amanda E. , Lefebvre Brian G. 
Published: July 2008

AbstractA simple in class laboratory illustrating the principles of ion exchange chromatography as a bioseparation technique is described. A protein's isoelectric point as a driving force for ion exchange chromatography is easily demonstrated by using combinations of proteins with natural color or fluorescence, such as DsRed2, enhanced green fluorescent protein (EGFP), and flavodoxin. Simple equipment is required for this separation which can be performed on a desk top. The experiment can stimulate a range of discussion about process parameters that would create a more efficient separation of the proteins, other types of chromatography, and bioseparations in general.
Primordial soup, fool's gold, and spontaneous generation
Authors: McNichol Jesse 
Published: July 2008

AbstractThis study provides a concise background to the biochemical search for the origin of life, as grounded in the field of prebiotic chemistry. It is intended to provide a good summary of competing theories and place them in a broader context, raising questions about weaknesses in any particular theory. This material is relevant for science educators at all levels, and will stimulate interest in a wide variety of students.