bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solution Combustion Synthesis and Characterization of Magnetite, Fe3O4, Nanopowders
Authors: Ianoş Robert , Tăculescu Alina , Păcurariu Cornelia , Lazău Ioan 
Published: March 2012

Combustion synthesis of Fe3O4 and properties of the resulted powders have been discussed in relation to reaction atmosphere (in air/in the absence of air) and used fuel (sucrose, citric acid and glucose). Conducting the combustion reactions in air caused the rapid oxidation of Fe2+ to Fe3+ under the influence of the atmospheric oxygen; therefore the final reaction product was a mixture of α‐Fe2O3 and γ‐Fe2O3. In order to avoid the oxidation of Fe2+ to Fe3+ a simple but efficient solution has been suggested: combustion reactions were carried out in a round bottom flask and the evolving gases were bubbled in a beaker filled with water. This solution allowed the preparation of Fe3O4 nanopowders, with crystallite size varying from 10 nm (glucose) to 18 nm (citric acid). Depending on the used fuel, the specific surface area of the magnetite powders varied between 56 m2/g (citric acid) and 106 m2/g (glucose). The saturation magnetization of Fe3O4 powders prepared in the absence of air ranged between 55.3 emu/g (glucose) and 59.4 emu/g (sucrose).
Effects of TiO2 Starting Materials on the Solid‐State Formation of Li4Ti5O12
Authors: Shin Jin‐Wook , Hong Chang‐Hoon , Yoon Dang‐Hyok 
Published: March 2012

This study examined the formation mechanism of Li4Ti5O12 by a solid‐state reaction between Li2CO3 and TiO2 for applications in lithium ion batteries. To explain the intermittent existence of rutile TiO2 in the final Li4Ti5O12, five types of TiO2 which had different anatase/rutile ratios were used as starting materials. Anatase to rutile‐phase transformation occurred from 600°C, which is significantly lower than the typical TiO2 transition temperature, when a pure anatase TiO2 and Li2CO3 mixture were heat‐treated. Moreover, this rutile TiO2 transformed from pure anatase TiO2 was found to be more rigid in the solid‐state reaction than an intact rutile or anatase‐rutile mixture, existing in the final Li4Ti5O12, even after heat treatment at 900°C for 15 h. This difference is explained by the anatase/rutile‐phase boundaries where an amorphous Li‐precursor was located, enhancing the solid‐state reaction due to the decreased diffusion path. Based on the observations, different formation mechanisms of Li4Ti5O12 depending on the types of TiO2 starting materials were proposed.
Implementation of TMA and digitalization in routine diagnostics of breast pathology
Authors: Rossing Henrik Holm , Talman Maj‐Lis Møller , Lænkholm Anne‐Vibeke , Wielenga Vera Timmermans 
Published: March 2012

To ensure optimal treatment of breast cancer patients, breast tumours are classified based on clinico‐pathological features. As part of this process, routine diagnostics of breast tumours includes histological typing and grading, as well as profiling by use of an immunohistochemistry panel of antibodies, probes and in situ hybridization. This will, as a minimum, include assessment of oestrogen receptor (OR) and HER2. The individual preparation and staining of many breast tumours in a large laboratory with this standard panel is thus time consuming and costly. Herein, we show that in breast cancer routine diagnostics the use of the tissue microarray technique in combination with digitalization of the stained multi‐slides is not only economical, with a considerable cost reduction, but it also enhances standardization of tumour profiling. We demonstrate that 2 mm breast tumour cores correlate with the corresponding tumour on whole mount slides, regarding staining/hybridizing results with the biomarkers in our panel consisting of human epidermal growth factor receptor 2, OR and Topiomerase IIa. Furthermore, we show that simultaneous staining/hybridizing of multiple breast tumour specimens reduces variation of staining/hybridizing quality, hereby increasing reliability of interpretation. By scanning and digitalization of the stained and hybridized multi‐slides, we could optimize documentation and filing of the results. Our work is an example of translational research by implementing a tool in daily diagnostics originally developed for high throughput analyses in the search for prognostic and predictive markers in targeted medicine.
Comparing the efficacy of team based learning strategies in a problem based learning curriculum
Authors: Anwar Khurshid , Shaikh Abdul Ahad , Dash Nihar Ranjan , Khurshid Saqib 
Published: March 2012

We introduced two variants of team based learning (TBL) strategies in pathology course to seek their efficacy in a problem based learning (PBL) curriculum. The TBL strategy was adopted in two different sessions. One during regular resource session (RS‐TBL) and other during a weekly review session (RVS‐TBL) of the PBL curriculum. The study involved 104 second year students during their 8 weeks of cardiovascular‐respiratory units and 3 weeks of hematology units. RS‐TBL was adopted for cardiovascular‐respiratory unit and RVS‐TBL for hematology unit. The first 8 weeks of the course were implemented as RS‐TBL and the last 3 weeks as RVS‐TBL. The results showed that the group performance was markedly improved than individual performance in both RS‐TBL and RVS‐TBL (p < 0.001). Comparison between the RS‐TBL and RVS‐TBL revealed that individual student and group performance was better in the RVS‐BL (p < 0.001). The result of the student attitudinal survey indicated an 88% agreement that TBL enhanced their understanding of pathology concepts and critical analysis. Most of the participants (85%) found RVS‐TBL to be more useful. Post‐TBL, end of semester examination results proved beneficial for the students in risk. The study demonstrated that RVS‐TBL may be preferably adopted to enhance the philosophy of TBL in a PBL curriculum.
A single‐centre randomized controlled clinical trial on the adjunct treatment of intra‐bony defects with autogenous bone or a xenograft: results after 12 months
Authors: Aghazadeh Ahmad , Rutger Persson G. , Renvert Stefan 
Published: March 2012

AbstractBackgroundLimited evidence exists on the efficacy of regenerative treatment of peri‐implantitis.Material and MethodsSubjects receiving antibiotics and surgical debridement were randomly assigned to placement of autogenous bone (AB) or bovine‐derived xenograft (BDX) and with placement of a collagen membrane. The primary outcome was evidence of radiographic bone fill and the secondary outcomes included reductions of probing depth (PD) bleeding on probing (BOP) and suppuration.ResultsTwenty‐two subjects were included in the AB and 23 subjects in the BDX group. Statistical analysis failed to demonstrate differences for 38/39 variables assessed at baseline. At 12 months, significant better results were obtained in the BDX group for bone levels (p < 0.001), BOP (p = 0.004), PI (p = 0.003) and suppuration (p < 0.01). When adjusting for number of implants treated per subject, a successful treatment outcome PD ≤ 5.0 mm, no pus, no bone loss and BOP at 1/4 or less sites the likelihood of defect fill was higher in the BDX group (LR: 3.2, 95% CI: 1.0–10.6, p < 0.05).ConclusionsBovine xenograft provided more radiographic bone fill than AB. The success for both surgical regenerative procedures was limited. Decreases in PD, BOP, and suppuration were observed.
Boundary work of dentists in everyday work
Authors: Franzén Cecilia 
Published: March 2012

AbstractObjectiveThe Swedish policy objectives in dental care provision – to meet public demands for dental care and to increase the cost‐effectiveness of the service – require dentists to work in teams with dental hygienists and dental nurses. This study focused on the role of dentists in the distribution of work tasks within teams in one Swedish Public Dental Service organisation. Dental clinics were viewed as micro‐political arenas in which dentists attempt to demarcate professional boundaries in response to teamwork.MethodsSemi‐structured interviews, observations and documents were used. The interviewed individuals were seven dentists employed at two clinics, the managers of each clinic and the general manager. The dentists were interviewed to investigate how they defend or blur professional boundaries. They were also observed at work. The clinic managers and the general manager were interviewed to identify their expectations of dentists concerning work division. The documents comprised organisational plans and annual reports.ResultsDentists demarcated professional boundaries by utilising various power resources: treatment responsibility, specialist knowledge, discretion, and avoidance of work considered to be low status work. The dentists also contributed to blurred boundaries between themselves and the other dental professionals by discussing patient treatment, giving and receiving advice, and assisting the others in skill development.ConclusionAlthough dentists' boundary work could obstruct implementation of policy objectives, dentists' behaviour contributed to effective collaboration within the teams.
Estimation of herbaceous biomass from species composition and cover
Authors: Axmanová Irena , Tichý Lubomír , Fajmonová Zuzana , Hájková Petra , Hettenbergerová Eva , Li Ching‐Feng , Merunková Kristina , Nejezchlebová Martina , Otýpková Zdenka , Vymazalová Marie , Zelený David 
Published: March 2012

AbstractQuestionsBiomass is an important ecological property, but its measurement is destructive and time‐consuming and therefore generally missing for historical vegetation plots. Here we propose and test indirect estimation of herbaceous biomass using models based on easily obtainable variables, namely plant height and cover. We compare these models with Ellenberg indicator values for nutrients (EIVs Nutrients), which are sometimes used as an alternative measure of productivity.LocationCzech Republic, western Slovakia.MethodsAbove‐ground biomass (dry weight; g·m−2) was regressed against the following explanatory variables: (1) Cover E1, total percentage cover of the herb layer visually estimated in the field; (2) Biomass estimate‐raw, ‐adjusted and ‐median, calculated from plant covers and heights (according to a local flora); and (3) mean EIVs Nutrients calculated per plot. For the analyses, we used four data sets containing a total of 469 plots from different vegetation types: ‘Wet meadows’, ‘Dry grasslands’, ‘Fen–dry grassland transects’ and ‘Forest herb layer’. To test the applicability of different biomass estimates we chose an example of a species richness–productivity relationship in the ‘Wet meadows’ data set and describe differences in resulting patterns.ResultsBoth cover of herb layer and calculated ‘biomass volumes’ were more accurate in predicting biomass dry weight than EIVs Nutrients. The best results were obtained from the Biomass estimate‐median model that combines median stand height and total cover of the herb layer. Cover E1 showed relatively tight correlations with biomass, particularly in sparse vegetation, but was a rather poor predictor when cover values were high. This was especially noticeable in application of the Cover E1 model in analysis of the species richness–productivity relationship.ConclusionsIn contrast to biomass, cover of the herb layer has a fixed upper limit (100%), which may lead to misinterpretations in dense, structurally diverse vegetation. Most promising is the Biomass estimate‐median method, which can be applied both to already sampled plots by calculating median height from average species heights according to local floras and to newly sampled plots using the median of plant heights measured in the field. Therefore, we propose it as a rapid, non‐destructive alternative to biomass harvest.
Substrate variations that affect the nucleic acid clamp activity of reverse transcriptases
Authors: Oz‐Gleenberg Iris , Herzig Eytan , Voronin Nickolay , Hizi Amnon 
Published: March 2012

We have recently shown that reverse transcriptases (RTs) perform template switches when there is a very short (two‐nucleotide) complementarity between the 3′ ends of the primer (donor) strand and the DNA or RNA template acceptor strands [Oz‐Gleenberg et al. (2011) Nucleic Acids Res39, 1042–1053]. These dinucleotide pairs are stabilized by RTs that are capable of ‘clamping’ together the otherwise unstable duplexes. This RT‐driven stabilization of the micro‐homology sequence promotes efficient DNA synthesis. In the present study, we have examined several factors associated with the sequence and structure of the DNA substrate that are critical for the clamp activity of RTs from human immunodeficiency virus type 1 (HIV‐1), murine leukemia virus (MLV), bovine immunodeficiency virus (BIV) and the long terminal repeat retrotransposon Tf1. The parameters studied were the minimal complementarity length between the primer and functional template termini that sustains stable clamps, the effects of gaps between the two template strands on the clamp activity of the tested RTs, the effects of template end phosphorylations on the RT‐associated clamp activities, and clamp activity with a long ‘hairpin’ double‐stranded primer comprising both the primer and the complementary non‐functional template strands. The results show that the substrate conditions for clamp activity of HIV‐1 and MLV RTs are more stringent, while Tf1 and BIV RTs show clamp activity under less rigorous substrate conditions. These differences shed light on the dissimilarities in catalytic activities of RTs, and suggest that clamp activity may be a potential new target for anti‐retroviral drugs.
Perioperative Outcomes of Laparoscopic Radical Nephrectomy for Renal Cell Carcinoma in Patients With Dialysis‐Dependent End‐Stage Renal Disease
Authors: Yamashita Kaori , Ito Fumio , Nakazawa Hayakazu 
Published: March 2012

AbstractThe aims of this study were: (i) to analyze the perioperative outcomes of laparoscopic radical nephrectomy for renal cell carcinoma in patients with dialysis‐dependent end‐stage renal disease and (ii) to reveal perioperative management problems that are unique to these patients. Between June 2004 and June 2011, laparoscopic radical nephrectomy was performed in 39 patients who had renal cell carcinoma and dialysis‐dependent end‐stage renal disease. The operative outcomes of these patients were compared with the operative outcomes of 104 non‐end‐stage renal disease patients with sporadic renal cell carcinoma who underwent laparoscopic radical nephrectomy during the same period. Laparoscopic surgery was completed in thirty‐eight end‐stage renal disease patients. One patient was converted to open surgery because of an intraoperative injury to the inferior vena cava. This patient was excluded from the analysis. The mean operative time was 240 min; blood loss, 157 mL; and postoperative hospital stay, 9.6 days. Postoperative complications were observed in six patients, as follows: retroperitoneal hematoma and abscess in one patient, thrombosis of the arteriovenous fistula in three patients, pneumonia in one patient, and gastrointestinal bleeding in one patient. Eleven patients required blood transfusions. There was no significant difference between the end‐stage renal disease patients and the non‐end‐stage renal disease patients in the mean operative time or the amount of blood loss. In conclusion, laparoscopic radical nephrectomy is feasible for dialysis‐dependent end‐stage renal disease patients, as well as for non‐end‐stage renal disease patients; however, end‐stage renal disease patients may have a higher probability of experiencing non‐life‐threatening complications.
GEOCHEMISTRY OF CRUDE OILS, SEEPAGE OILS AND SOURCE ROCKS FROM BELIZE AND GUATEMALA: INDICATIONS OF CARBONATE‐SOURCED PETROLEUM SYSTEMS
Authors: Petersen H.I. , Holland B. , Nytoft H.P. , Cho A. , Piasecki S. , de la Cruz J. , Cornec J.H. 
Published: March 2012

This study reviews the stratigraphy and the poorly documented petroleum geology of the Belize‐Guatemala area in northern Central America. Guatemala is divided by the east‐west trending La Libertad arch into the North and South Petén Basins. The arch is the westward continuation of the Maya Mountains fault block in central Belize which separates the Corozal Basin in northern Belize from the Belize Basin to the south. Numerous petroleum seeps have been reported in both of these basins. Small‐scale oil production takes place in the Corozal Basin and the North and South Petén Basins. For this study, samples of crude oil, seepage oil and potential source rocks were collected from both countries and were investigated by organic geochemical analyses and microscopy. The oil samples consisted of non‐biodegraded crude oils and slightly to severely biodegraded seepage oils, both of which were generated from source rocks with similar thermal maturities. The crude oils were generated from marine carbonate source rocks and could be divided into three groups:Group 1 oils come from the North Petén Basin (Guatemala) and the western part of the Corozal Basin (Belize), and have a typical carbonate‐sourced geochemical composition. The oils correlate with extracts of organic‐rich limestones assigned to the Upper Cretaceous “Xan horizon” in the Xan oilfield in the North Petén Basin. The oils were generated from a single source facies in the North Petén Basin, but were charged from two different sub‐basins.Group 2 oils comprise crudes from the South Petén Basin. They have characteristics typical of carbonate‐sourced oils, but these characteristics are less pronounced than those of Group 1 oils. A mixed marine/lacustrine source facies deposited under strongly reducing conditions in a local kitchen area is inferred.Group 3 oils come from the Corozal Basin, Belize. A carbonate but also a more “shaly” source rock composition for these oils is inferred. A severely biodegraded seepage oil from Belmopan, the capital of Belize, resembles a nearby crude oil. The eastern sub‐basin in the North Petén Basin may potentially be the kitchen area for these oils, and for the seepage oils found in the western part of the Corozal Basin.The seepage oils from the Corozal and Belize Basins are moderately to severely biodegraded and were generated from carbonate source rocks. Some of the seepage oils have identical C27–29 sterane distributions to the Group 2 oils, but “biodegradation insensitive” biomarker ratios show that the seepage oils can be divided into separate sub‐groups. Severely and slightly biodegraded seepage oils in the Belize Basin were probably almost identical prior to biodegradation.Lower Cretaceous limestones from the Belize Basin have petroleum generation potential, but the samples are immature. The kitchen for the seepage oils in the Belize Basin remains unknown.
POTENTIAL PETROLEUM SOURCE ROCKS IN THE TERMIT BASIN, NIGER
Authors: Harouna M. , Philp R.P. 
Published: March 2012

Potential source rocks from wells in the Termit Basin, eastern Republic of Niger, have been analysed using standard organic geochemical techniques. Samples included organic‐rich shales of Oligocene, Eocene, Paleocene, Maastrichtian, Campanian and Santonian ages. TOC contents of up to 20.26%, Rock Eval S2 values of up to 55.35 mg HC/g rock and HI values of up to 562 mg HC/g TOC suggest that most of the samples analysed have significant oil‐generating potential. Kerogen is predominantly Types II, III and II–III.Biomarker distributions were determined for selected samples. Gas chromatograms are characterized by a predominance of C17– C21 and C27– C29 n‐alkanes. Hopane distributions are characterized by 22S/(22S+22R) ratios for C32 homohopanes ranging from 0.31 to 0.59. Gammacerane was present in Maastrichtian‐Campanian and Santonian samples. Sterane distributions are dominated by C29 steranes which are higher than C27 and C28 homologues.Biomarker characteristics were combined with other geochemical parameters to interpret the oil‐generating potential of the samples, their probable depositional environments and their thermal maturity. Results indicate that the samples were in general deposited in marine to lacustrine environments and contain varying amounts of higher plant or bacterial organic matter. Thermal maturity varies from immature to the main oil generation phase. The results of this study will contribute to an improved understanding of the origin of the hydrocarbons which have been discovered in Niger, Chad and other rift basins in the Central African Rift System.
Phosphorylation of epidermal growth factor receptor and chromosome 7 polysomy in gastric adenocarcinoma
Authors: ZHANG Fan , TANG Jian Min , WANG Li , SHEN Jing Ying , ZHENG Lin , WU Ping Ping , ZHANG Mei , YAN Zhao Wen 
Published: March 2012

OBJECTIVE:  To investigate the phosphorylation of epidermal growth factor receptor (EGFR) and its potentially associated chromosomal aberrations in gastric adenocarcinoma.METHODS:  Phosphorylated EGFR (pEGFR) was detected by immunohistochemistry on 145 specimens including 60 tumoral, 60 non‐tumoral, 12 tumor‐adjacent intramucosal dysplasia from patients with gastric adenocarcinoma and 13 mucosae from cancer‐free patients. EGFR gene amplification and chromosome 7 (Chr‐7) polysomy were detected by fluorescence in situ hybridization.RESULTS:  Positivity of pEGFR was found in 50 tumoral (83.3%) and 42 non‐tumoral specimens (70.0%). There was an association between tumoral and non‐tumoral zones on immunostains of pEGFR (r = 0.353, P = 0.006). Nuclear pEGFR usually presented in mucosae with Helicobacter pylori infection, stromal reaction or vascular invasion. Cytoplasmic pEGFR was correlated with local cancer extension (r = 0.337, P = 0.014) and inversely related with gastrokine 2, which had been previously detected in the same specimens. Eleven intramucosal dysplastic specimens were also positive for pEGFR while 13 mucosae from cancer‐free patients were all negative. No EGFR gene amplification was observed. However, seven tumor specimens showed Chr‐7 polysomy (11.7%) in which 5 were strongly positive for pEGFR.CONCLUSIONS:  EGFR phosphorylation may be one of the mechanisms that promote tumor initiation and expansion in gastric adenocarcinoma. Detection of pEGFR with analysis of its nuclear or cytoplasmic patterns could be clinicopathologically valuable. Chr‐7 polysomy may partially contribute to EGFR activation in gastric adenocarcinoma, although its role does not predominate.