bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variable carbon recovery of Walkley‐Black analysis and implications for national soil organic carbon accounting
Authors: Lettens S. , De Vos B. , Quataert P. , Van Wesemael B. , Muys B. , Van Orshoven J. 
Published: May 2007

SummaryThere is considerable interest in the computation of national and regional soil carbon stocks, largely as the result of the provisions of the Kyoto Protocol. Such stocks are often calculated and compared without proper reference to the uncertainties induced by different analytical methodologies. We illustrate the nature and magnitude of these uncertainties with the present soil organic carbon (SOC) study in Belgium. TheSOCrecovery of the Walkley‐Black method was investigated based on a database of 475 samples of silt loam and sandy soils, which cover different soil depths and vegetation types in northern Belgium. The organic carbon content of the soil samples was measured by the original Walkley‐Black method and by a total organic carbon analyser. The recovery was computed as the ratio of these two results per soil sample. Land use, texture and soil sampling depth had a significant influence on the recovery as well as their three‐way interaction term (land use × texture × sampling depth). The impact of a land use, texture and sampling depth dependent Walkley‐Black correction on the year 2000SOCinventory of Belgium was determined by regression analysis. Based on new correction factors, the nationalSOCstocks increased by 22% for the whole country, ranging from 18% for cropland to 31% for mixed forest relative to the standard correctedSOCinventory. The new recovery values influenced therefore not only C stocks in the year 2000, but also the expectedSOCchange following land use change. Adequate correction of Walkley‐Black measurements is therefore crucial for the absolute and comparativeSOCassessments that are required for Kyoto reporting and must be computed to take into account the regional status of soil and land use. ‘Universal’ corrections are probably an unrealistic expectation.
Factors controlling the water repellency induced by fire in calcareous Mediterranean forest soils
Authors: Arcenegui V. , Mataix‐Solera J. , Guerrero C. , Zornoza R. , Mayoral A. M. , Morales J. 
Published: May 2007

SummaryWater repellency (WR) is a property affected by fire and of crucial importance in the hydrological behaviour of soils after burning. In dry Mediterranean areas knowledge of the factors that control the development of water repellency by fire is of particular interest. We examined such factors in two calcareous soils, a Regosol and a Luvisol, representative of forest areas of southeast Spain. Heating temperature (200–500°C), vegetation type (Rosmarinus officinalis, Pinus halepensis and Brachypodium retusum), quantity of vegetation litter (control, low and high) and type of soil were selected as factors for assessing the WR induced by fire. The two soils exhibited markedly different WR responses after heating, the Regosol being much more susceptible than the Luvisol. Characteristics such as organic matter and clay content seem to determine the different WR responses to heating. We found that the type and quantity of vegetation litter also control the persistence of induced WR. In general, the order of increasing WR was Brachypodium < Pinus < Rosmarinus, and larger amounts of litter induced more WR. Maximum values of WR, most of them classified as severe (901−3600 s), were found in the range of 300−350°C, whereas beyond this temperature WR was destroyed. These results show that water repellency induced by combustion could be limited by environmental factors such as vegetation type and availability of litter, and that soil type and its characteristics also play a decisive role.
Variation of chemical properties as affected by soil erosion on hillslopes and terraces
Authors: Ni S. J. , Zhang J. H. 
Published: May 2007

SummaryThe variation in soil nutrients is crucial to the understanding of productivity of soil undergoing erosion overall, as the latter can result in a decline in soil quality and crop production in the whole landscape. Two toposequences (a long slope and terraced field series) were selected from hilly areas of the Sichuan Basin, China, to determine the effects of soil redistribution rates and topographic changes on P, K and CaCO3 contents, and examine the contribution of water and tillage erosion to the variation and distribution pattern in these chemical properties within different landscapes. For the long slope, soil loss occurred at upper slope positions and soil accumulation was present at lower slope positions. However, terrace banks create a line of zero downslope transport of soil, and lead to abrupt changes in 137Cs inventories over very short distances between the upper (or lower) part of the terrace and the lower (or upper) part of the neighbouring terrace. Extractable K concentrations are significantly related to 137Cs inventories on both the long slope and terraced fields, which suggests that the distribution of extractable K is closely linked to soil redistribution. However, it is noticeable that no close relationship between extractable P concentrations and 137Cs inventories was found on the terraced fields, while there was a highly significant correlation between the two variables on the long slope. The variation in extractable P by soil redistribution was enhanced on the long slope, but was concealed on the terraced fields due to the presence of CaCO3. It is suggested that the variation in extractable P not only depends on soil redistribution in relation to fine soil particles, but is also influenced by other factors such as P‐fixation onto CaCO3, the concentration of which itself is linked to soil erosion and redistribution. Therefore, extractable P dynamics with reference to soil erosion are relatively complex on carbonate‐rich soil and parent materials in areas such as those represented by the Sichuan Basin. Tillage erosion, the dominant soil redistribution process on terraced fields, was found to be a major contributor to the variation in soil chemical properties in the terraced field landscape, while water erosion plays an important role in the variation in soil chemical properties in the long slope landscape. In the case of carbonate‐rich soils or parent materials, however, tillage erosion did not create accumulations of extractable P in depressions, whereas water erosion results in extractable P losses at upper slope positions and accumulation at lower slope positions.
Safety and efficacy of a sucrose‐formulated recombinant factor VIII product for the treatment of previously treated patients with haemophilia A in China
Authors: SHI J. , ZHAO Y. , WU J. , SUN J. , WANG L. , YANG R. 
Published: May 2007

Summary.  The use of plasma‐derived products has contributed to a high rate of blood‐borne infections among haemophilia patients in China. Recombinant factor VIII (rFVIII) products that are manufactured without human or bovine albumin and include dedicated viral inactivation steps, hold a significant safety advantage over plasma products. However, there is little information published on the use of rFVIII products in non‐caucasian populations. This is the first reported evaluation of the efficacy and safety of a rFVIII product in Chinese haemophiliacs.An open‐label, non‐randomized, prospective, multicentre trial enroled previously treated Chinese patients with haemophilia A. All treatments were administered using a sucrose‐formulated rFVIII‐FS (Kogenate®).Forty‐nine patients received totals of 291 infusions (mean, 5.94/patient) and 742 140 IU rFVIII‐FS (mean, 2550.3 IU/infusion). Of the 60 acute bleeding episodes that were treated, 90% were successfully managed with only one (81.7%) infusion or two (8.3%) infusions. Physicians reported haemostasis control for acute bleeds to be ‘Excellent’ or ‘Improved’ with rFVIII‐FS therapy. No FVIII inhibitors were detected in any patient. Only one treatment‐related adverse event was reported, which was mild dizziness that resolved spontaneously. rFVIII‐FS was efficacious, safe and well tolerated in the treatment of previously treated patients with haemophilia A in China.
Expression of granzyme A in human polymorphonuclear neutrophils
Authors: Hochegger Kathrin , Eller Philipp , Huber Julia M. , Bernhard David , Mayer Gert , Zlabinger Gerhard J. , Rosenkranz Alexander R. 
Published: May 2007

SummaryPolymorphonuclear neutrophils (PMNs) are the first line of defence against invading pathogens. They contain a multitude of antimicrobial and potentially cytotoxic substances packed in granules and secretory vesicles. Here, we show that granzyme A (GzmA) is constitutively expressed in human PMNs, but not in the promyelocytic cell line HL‐60, by performing flow cytometry, western blot, enzyme‐linked immunosorbent assay and quantitative polymerase chain reaction. To further track the intracellular localization of GzmA, we performed subcellular fractionation and found GzmA to be present in peroxidase‐negative granules. Finally, stimulation with opsonized Escherichia coli or the bioincompatible haemodialysis membrane cuprophane led to up‐regulation of GzmA expression at the transcriptional level as well as at the translational level. In conclusion, we provide clear evidence that GzmA is constitutively expressed in human PMNs and can be up‐regulated upon stimulation. These findings may also indicate a role for GzmA in PMNs in defence against invading pathogens.
Reduced CCR4, interleukin‐13 and GATA‐3 up‐regulation in response to type 2 cytokines of cord blood T lymphocytes in infants at genetic risk of type 1 diabetes
Authors: Luopajärvi Kristiina , Skarsvik Susanne , Ilonen Jorma , Åkerblom Hans K. , Vaarala Outi 
Published: May 2007

SummaryAberrancies in T‐cell polarization including expression of chemokine receptors have been reported in human leucocyte antigen (HLA) class II associated autoimmune diseases, such as type 1 diabetes (T1D) and rheumatoid arthritis. We asked whether these aberrancies are present at birth in newborn infants carrying the HLA risk haplotypes for T1D. Sixty‐seven cord blood (CB) samples from infants were screened for T1D‐associated HLA risk genotypes (HLA‐DR4‐DQ8 and/or DR3‐DQ2 without protective alleles). CB lymphocytes were stimulated with phytohaemagglutinin in type 1 (interleukin (IL)‐12, anti‐IL4) or type 2 (IL‐4, anti‐IL12) cytokine environment for 6 days. The expression of chemokine and cytokine receptors on T cells was determined by flow cytometry, secretion of cytokines was analysed with enzyme‐linked immunosorbent assay, and transcription factors were analysed using real‐time reverse transcriptase–polymerase chain reaction. After culture of CB lymphocytes in type 2 cytokine environment newborn infants carrying DR4‐DQ8 haplotype (n = 18) showed reduced percentage of CD4 T cells expressing CCR4 (P = 0·009) and the level of CCR4 mRNA was decreased (P = 0·008). In addition, lower secretion of IL‐13 and expression of GATA‐3 in CB lymphocytes cultured in type 2 cytokine environment were found in the infants with DR4‐DQ8 haplotype (P = 0·020 and P = 0·004, respectively) in comparison to newborn infants without DR4‐DQ8 and DR3‐DQ2 haplotypes (n = 37). Poor in vitro induction of type 2 immune responses in newborn infants with DR4‐DQ8 haplotype suggests that the HLA genotype associated with risk of autoimmunity may affect the T cell polarization already at birth, which in turn may contribute to the risk for autoimmunity later in life.
The effect of condensation pressure on selected physical properties of mineral trioxide aggregate
Authors: Nekoofar M. H. , Adusei G. , Sheykhrezae M. S. , Hayes S. J. , Bryant S. T. , Dummer P. M. H. 
Published: May 2007

AbstractAim  To examine the effect of condensation pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA).Methodology  White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one‐way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel.Result  A trend was observed for higher condensation pressures to produce lower surface hardness values. A condensation pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P < 0.001). A condensation pressure of 1.68 MPa conferred the maximum compressive strength; however, it was not statistically different. Higher condensation pressures resulted in fewer voids and microchannels when analysed with SEM. In specimens prepared with lower condensation pressures distinctive crystalline structures were observed. They tended to appear around microchannels.Conclusion  Condensation pressure may affect the strength and hardness of MTA. Use of controlled condensation pressure in sample preparation for future studies is suggested.
Hydration mechanisms of mineral trioxide aggregate
Authors: Camilleri J. 
Published: May 2007

AbstractAim  To report the hydration mechanism of white mineral trioxide aggregate (White MTA, Dentsply, Tulsa Dental Products, Tulsa, OK, USA).Methodology  The chemical constitution of white MTA was studied by viewing the powder in polished sections under the scanning electron microscope (SEM). The hydration of both white MTA and white Portland cement (PC) was studied by characterizing cement hydrates viewed under the SEM, plotting atomic ratios, performing quantitative energy dispersive analyses with X‐ray (EDAX) and by calculation of the amount of anhydrous clinker minerals using the Bogue calculation.Results  Un‐hydrated MTA was composed of impure tri‐calcium and di‐calcium silicate and bismuth oxide. The aluminate phase was scarce. On hydration the white PC produced a dense structure made up of calcium silicate hydrate, calcium hydroxide, monosulphate and ettringite as the main hydration products. The un‐reacted cement grain was coated with a layer of hydrated cement. In contrast MTA produced a porous structure on hydration. Levels of ettringite and monosulphate were low. Bismuth oxide was present as un‐reacted powder but also incorporated with the calcium silicate hydrate.Conclusions  White MTA was deficient in alumina suggesting that the material was not prepared in a rotary kiln. On hydration this affected the production of ettringite and monosulphate usually formed on hydration of PC. The bismuth affected the hydration mechanism of MTA; it formed part of the structure of C‐S‐H and also affected the precipitation of calcium hydroxide in the hydrated paste. The microstructure of hydrated MTA would likely be weaker when compared with that of PC.
A comparative study of three periapical radiographic techniques for endodontic working length estimation
Authors: Kazzi D. , Horner K. , Qualtrough A. C. , Martinez‐Beneyto Y. , Rushton V. E. 
Published: May 2007

AbstractAim  To compare the diagnostic quality of endodontic working length estimation films produced using film holders with those taken using the bisecting angle technique and to assess the level of acceptance of film holders by operator and patient.Methodology  Five post‐graduate and 20 final year undergraduate students attending a UK Dental School produced working length radiographs using either the paralleling or the bisecting angle technique. The paralleling group used one of two film holders, the Endoray II or the XCP Endodontic Instrument, on alternate patients. An assessment of the ease of use of the device and the patients’ views on the comfort of the examination were recorded. Each radiograph was examined simultaneously by two assessors, scored for film faults and diagnostic acceptability. Statistical data was derived using the Mann–Whitney U test and Cohen's kappa.Results  The rates of unacceptable radiographs for the XCP Endodontic Instrument, Endoray II and the bisecting angle techniques were 12.2%, 21.4% and 48.6%, respectively. The combined percentage of unacceptable paralleling technique films (16.7%) was highly significantly different (P < 0.001) when compared with the bisecting angle technique (48.6%). The paralleling technique produced a significant reduction in incorrect vertical angulation (P < 0.001), cone cutting (P < 0.001) and incorrect film placement (P < 0.001). Film holders were rated either excellent or good in 90% of examinations by operators and 47.5% of patients reported no discomfort.Conclusions  These results support the use of the film holders for endodontic working length estimation.
Leakage of food‐borne Enterococcus faecalis through temporary fillings in a simulated oral environment
Authors: Kampfer J. , Göhring T. N. , Attin T. , Zehnder M. 
Published: May 2007

AbstractAim  To evaluate the hypothesis that food‐borne viable Enterococcus faecalis cells could enter the root canal space via coronal leakage.Methodology  In a simulated oral environment under mastication the capacity of a calcium sulphate‐based temporary filling material (Cavit W) to prevent leakage of E. faecalis from a cheese through the endodontic access cavity into the pulp chamber was assessed. Standardized class I access cavities were prepared in human maxillary molars. These were filled with Cavit of either 2 or 4 mm thickness (n = 16, each). Empty access cavities served as positive, teeth filled with a light‐curing composite material acted as negative controls (n = 8, each). A cheese containing viable E. faecalis cells was placed on the occlusal aspects of test and control teeth, which were subsequently subjected to 680 mastication loads per day for 1 week in a masticator device perfused with artificial saliva at 37 °C. Leakage of E. faecalis from the cheese into the pulp chamber was assessed by culture on a kanamycin aesculin azide agar and compared between groups using Fisher's exact test.Results  All of the positive controls showed pure growth of E. faecalis. In addition, one of the negative control teeth leaked. The 4 mm application of Cavit prevented leakage of E. faecalis significantly better than the corresponding 2 mm application: 1 of 16 specimens compared with 6 of 16 specimens had leakage, respectively (P < 0.05).Conclusions  The current results substantiate the suspicion that food‐derived microbiota could enter the necrotic root canal system via microleakage.
The influence of sodium hypochlorite and EDTA on the chemical composition of dentine
Authors: Ramirez‐Bommer C. , Gulabivala K. , Figueiredo J. A. P. , Young A. 
Published: May 2007

Aim  To characterise changes in the chemical composition of dentine after exposure to sodium hypochlorite and ethylenediaminetetracetic acid (EDTA) using ATR‐FTIR and Raman spectroscopy.Methodology  Crown dentine was acquired from recently extracted molars stored in formal‐saline (group A) or saline and frozen at −2oC (group B); it was then ground and sieved into a range of particle sizes. Samples from both groups (n = 5 each) were analysed with FTIR to investigate the influence of storage medium and to assign FTIR spectral peaks for collagen, carbonate, phosphate. As no differences were found, the samples were pooled for subsequent experiments. Ten samples of particle size range 38–75 μm were used to study the effect of mass ratio of NaOCl (2.5%): dentine over 5–10 min. Thirty samples of all sizes were reacted with 2.5% sodium hypochlorite at 1:0.5 (dentine:NaOCl) mass ratio for 2–10 min; EDTA (n = 90) for 5–1440 min; NaOCl for 10 min followed by EDTA for 10 mins (n = 30); the latter samples were further exposed to NaOCl for 10 min after obtaining FTIR spectra.Results  FTIR spectra from the surface of the particles (~1.5 μm depth) were obtained for all the samples and Raman spectra (40 μm depth) were obtained for one sample each reacted either with NaOCl or EDTA. Spectral peak assignment was confirmed by previous data. Storage media had no effect on outcome measures used. The dentine:NaOCl ratio influenced collagen depletion. NaOCl affected the collagen FTIR peaks, mostly in the first 2–4 min, but only influenced the phosphate and carbonate peaks slightly. EDTA affected the phosphate:collagen peaks, which reduced over time, whilst the collagen peak values showed an increase. The two solutions (NaOCl and EDTA) used alternately, respectively increased collagen or phosphate peaks depending on the final solution used.Conclusions  These series of investigations confirmed that sodium hypochlorite depletes the organic content of dentine and EDTA depletes the inorganic content. Used alternately, they have the ability to progressively degrade dentine structure.
Outcome of secondary root canal treatment – Systematic review of the literature
Authors: Ng Y.‐L. , Mann V. , Gulabivala K. 
Published: May 2007

Aims  To assess the success rates of secondary root canal treatment (2oRCT) and identify factors influencing outcome.Methodology  Longitudinal clinical studies investigating outcome of 2oRCT were identified by electronic (medline) and hand searches. Inclusion criteria were data on: number of samples, those successful and definition of success. Two reviewers independently assessed the studies and extracted the data onto a proforma. The pooled weighted success rates by each potential prognostic factor were estimated using the binomial random effect model (MLwiN version 2.02) whilst their pooled effects (expressed as odds ratio) on success rates were estimated using fixed and random effects meta‐analysis with DerSimonean and Laird's methods (Stata version 9.2). Meta‐regression models were used to explore potential sources of statistical heterogeneity. Study characteristics considered in the meta‐regression analyses were: decade of publication, study‐specific criteria for success (radiographic, combined radiographic & clinical), unit of outcome measure (tooth and root), duration after treatment when assessing success (at least 4 years or shorter), geographic location of the study (North American, Scandinavian and other countries), and qualification of the operator (undergraduate students, postgraduate students, general dental practitioners, specialist or mixed group).Results  Of the 41 studies identified, 18 studies published between 1921 and 2005 were included. The majority of studies were retrospective (n = 13) and only five prospective. The pooled weighted success rate of 2oRCT judged by complete healing was 77.6% (95% CI 73.2%, 81.4%) and by incomplete healing, 77.4% (95% CI 64.1%, 86.7%). The success rates were similar by ‘year of publication’ and ‘country of study’. Eighteen clinical factors were investigated in various combinations in previous studies. The most frequently investigated were ‘periapical status’ (n = 13), ‘size of lesion’ (n = 7), ‘culture results prior to RF’ (n = 5), and ‘apical extent of root filling (RF)’ (n = 4). The effect of different aspects of previous treatment and re‐treatment technique has been poorly tested.Conclusions  The pooled weighted estimated success rate of 2oRCT was 77%, which was significantly (P ≤ 0.001) influenced by the presence and size of pre‐operative periapical lesion. The effects of existing canal content, procedural error and re‐treatment technique were poorly investigated.