bluuebunny/crossref_metadata_2025_split huggingface dataset:
Responses of soil respiration to elevated CO2, air warming, and changing soil water availability in a model old‐field grassland
Authors: WAN SHIQIANG , NORBY RICHARD J. , LEDFORD JOANNE , WELTZIN JAKE F. 
Published: September 2007

AbstractResponses of soil respiration to atmospheric and climatic change will have profound impacts on ecosystem and global carbon (C) cycling in the future. This study was conducted to examine effects on soil respiration of the concurrent driving factors of elevated atmospheric CO2 concentration, air warming, and changing precipitation in a constructed old‐field grassland in eastern Tennessee, USA. Model ecosystems of seven old‐field species were established in open‐top chambers and treated with factorial combinations of ambient or elevated (+300 ppm) CO2 concentration, ambient or elevated (+3 °C) air temperature, and high or low soil moisture content. During the 19‐month experimental period from June 2003 to December 2004, higher CO2 concentration and soil water availability significantly increased mean soil respiration by 35.8% and 15.7%, respectively. The effects of air warming on soil respiration varied seasonally from small reductions to significant increases to no response, and there was no significant main effect. In the wet side of elevated CO2 chambers, air warming consistently caused increases in soil respiration, whereas in the other three combinations of CO2 and water treatments, warming tended to decrease soil respiration over the growing season but increase it over the winter. There were no interactive effects on soil respiration among any two or three treatment factors irrespective of time period. Treatment‐induced changes in soil temperature and moisture together explained 49%, 44%, and 56% of the seasonal variations of soil respiration responses to elevated CO2, air warming, and changing precipitation, respectively. Additional indirect effects of seasonal dynamics and responses of plant growth on C substrate supply were indicated. Given the importance of indirect effects of the forcing factors and plant community dynamics on soil temperature, moisture, and C substrate, soil respiration response to climatic warming should not be represented in models as a simple temperature response function, and a more mechanistic representation including vegetation dynamics and substrate supply is needed.
Elevated atmospheric CO2: a nurse plant substitute for oak seedlings establishing in old fields
Authors: DAVIS MARK A. , REICH PETER B. , KNOLL MARY J. B. , DOOLEY LEE , HUNDTOFT MARJORIE , ATTLESON INGRID 
Published: September 2007

AbstractIt has been hypothesized that elevated levels of atmospheric CO2 (eCO2) may facilitate the encroachment of woody plants into grasslands by reducing water stress. In east‐central Minnesota, sandy soils frequently create drought conditions for plants, and water limitation inhibits the establishment of oaks into old fields situated on these soils. Some have argued that eCO2 should slow secondary succession by favoring fast‐growing early successional species. However, if oak encroachment into old fields is being inhibited by water stress, then eCO2 could accelerate old‐field succession in this region. The purpose of this study was to test the hypothesis that eCO2 will increase the establishment success of oak seedlings in an old field environment. The study was conducted with CO2 levels controlled by free air CO2 enrichment (FACE). In May 1999, four oak (Quercus ellipsoidalis) acorns were planted in each of 24 plots in each of six experimental FACE rings (n= 576), three of which received elevated levels (550 ppm) of CO2. Half the plots in each ring were weeded during the first three summers of the experiment. In summer 2000, water input was manipulated during a 3.5‐week period, during which half the plots received regular watering while the other half received no water. Summer 2001 was dry, receiving 35% less rainfall than the mean level. Under hot and dry conditions, eCO2 increased soil water levels in unweeded plots and enhanced oak establishment (survival and growth) in weeded plots. In 2006, after the eighth growing season following planting, survival was five times greater under elevated than ambient CO2. The results showed that under hot and dry conditions, eCO2 can act like a nurse plant for tree seedlings growing in bare and unshaded areas, increasing seedling survival and growth, and thereby expanding the establishment window for trees encroaching into a grassland environment.
Ecosystem responses to water and nitrogen amendment in a California grassland
Authors: HARPOLE W. STANLEY , POTTS DANIEL L. , SUDING KATHARINE N. 
Published: September 2007

AbstractThe world's ecosystems are experiencing simultaneous changes in the supply of multiple limiting resources. Two of these, water and nitrogen (N) can strongly limit grassland production and can affect community composition and biogeochemical cycles in different ways. Grassland ecosystems in California may be particularly vulnerable to current and predicted changes in precipitation and N deposition, and ecosystem responses to potential interactive effects of water and N are not well understood. Here, we show strong colimitation of plant production resulting from factorial addition of water and N. In addition, water and N addition in combination led to increased dominance of the two most abundant grass species, while N addition regardless of water availability led to decreased species diversity. Late season carbon (C) flux response to water addition depended on N. Only plots that received additional water, but not N, still showed net ecosystem C uptake at the end of the experiment. Our results suggest that grassland ecosystem response to N deposition will be strongly dependent on future precipitation patterns.
p63 expression in ovarian tumours: a marker for Brenner tumours but not transitional cell carcinomas
Authors: Liao X Y , Xue W C , Shen D H , Ngan H Y S , Siu M K , Cheung A N 
Published: September 2007

Aims:  To investigate p63 expression in ovarian neoplasms.Methods and results:  Immunohistochemistry using an antibody that detects all p63 isoforms was performed on 103 primary ovarian neoplasms of different histological types. Diffuse nuclear immunoreactivity of p63 was demonstrated in the 17 benign and five borderline Brenner tumours. Only one of the six malignant Brenner tumours displayed p63 expression. p63 immunoreactivity was absent in all the ovarian transitional cell carcinomas (TCC), but was demonstrated extensively in TCCs of the urinary bladder. Besides focal p63 expression in epidermal basal cells of immature and mature teratomas, all other ovarian lesions were devoid of p63 expression. p63 expression was also demonstrated in cervical transitional cell metaplasia and Walthard cell nests of fallopian tubes.Conclusions:  Expression of p63 protein is apparently cell lineage specific and in ovarian neoplasms is confined to benign and borderline Brenner tumours. The loss of expression in malignant Benner tumours suggests a role for p63 in Brenner carcinogenesis. The distinct patterns of p63 expression in TCCs in the ovary and urinary bladder may help in their differential diagnosis.
Immunohistochemical detection of galectin‐1 in renal biopsy specimens of children and its possible role in proteinuric glomerulopathies
Authors: Ostalska‐Nowicka D , Zachwieja J , Nowicki M , Kaczmarek E , Siwińska A , Witt M 
Published: September 2007

Aims:  Galectin‐1 is an endogenous lectin that specifically binds to β‐galactoside structures. It has been associated with developmental mechanisms ranging from differentiation to apoptosis and exerts immunoregulatory functions in autoimmune diseases. The aim was to determine the immunohistochemical expression of galectin‐1 in renal biopsy specimens of children with primary idiopathic proteinuric glomerulopathies.Methods and results:  We examined 18 children with minimal change disease (MCD), 30 with diffuse mesangial proliferation (DMP) and 11 with focal segmental glomerulosclerosis (FSGS). An indirect immunohistochemical protocol using a polyclonal antibody directed against galectin‐1 was applied. Galectin‐1 was detected in renal podocytes in DMP and FSGS cases, while control glomeruli and MCD were negative. Galectin‐1 immunoreactivity was found within parietal epithelial cells in patients with FSGS.Conclusions:  These results suggest a possible role for galectin‐1 in the pathogenesis of primary glomerulopathies in children as a kind of podocyte‐related self‐protective activity and probably involvement of epithelial cells of Bowman’s capsule in inflammatory processes. Immunohistochemistry using galectin‐1 antibodies may further be helpful in histological distinction between MCD and DMP.
Pitfalls in the diagnosis of prostatic cancer: retrospective review of 1791 cases with clinical outcome
Authors: Berney D M , Fisher G , Kattan M W , Oliver R T D , Møller H , Fearn P , Eastham J , Scardino P , Cuzick J , Reuter V E , Foster C S 
Published: September 2007

Aims:  To assess the possible reasons for error in the diagnosis of prostatic cancer with available follow‐up data.Method and results:  A cohort of 1791 cases of prostatic cancer diagnosed in the UK between 1990 and 1996 was examined. All cases were clinically localized at presentation, treated by non‐curative methods and detailed follow‐up was available. A panel of genitourinary pathologists reviewed the pathology of all cases. One hundred and thirty‐three (7.5%) of cases were reassigned to a non‐malignant diagnosis. Where possible, reasons for the initial diagnosis were given. These included severe atrophy, inflammatory induced atypia, sclerosing adenosis, atypical adenomatous hyperplasia and basal cell hyperplasia. Follow‐up of these patients showed an extremely low death rate from prostatic cancer: lower than that for the Gleason combined score of five or less tumours diagnosed in this series.Conclusions:  Many morphological entities potentially mimic prostatic cancer and may be responsible for misdiagnosis in routine specimens. Continuing education in prostatic morphology and immunohistochemistry may have helped reduce this error rate.
Alteration of adhesion molecule expression and cellular polarity in hepatocellular carcinoma
Authors: Cao Y , Chang H , Li L , Cheng R‐C , Fan X‐N 
Published: September 2007

Aims:  To study the expression of adhesion molecules in human liver and their possible roles during hepatocarcinogenesis.Methods and results:  The expression of adhesion molecules in normal liver tissues, benign including probable premalignant lesions and malignant lesions was systematically investigated by immunohistochemistry and Western blotting. In normal liver, both hepatocytes and bile duct cells expressed symplekin, desmoglein 1/2, desmocollin 2, desmoplakin and plakophilin 2, but did not express desmocollin 1/3 or plakophilin 1. In benign hepatocyte lesions, expression of the adherens junctions and desmosomes was uniform and slightly increased, but symplekin appeared to show reduced expression in dysplastic lesions. In hepatocellular carcinoma (HCC), the expression of adhesion molecules was often heterogeneous and of abnormal location. Tumour cells with an abnormal distribution or loss of adhesion molecules showed an apolar arrangement of tissue architecture. The expression levels of the adhesion molecules correlated with the differentiation grades of HCC cells.Conclusions:  The decreased expression of symplekin may be an early step in the transformation of hepatocytes, whereas alteration of the expression of adherens junctions and desmosomes may indicate more serious changes.
Antioxidant and pro‐oxidant properties of chlorhexidine and its interaction with calcium hydroxide solutions
Authors: Yeung S. Y. , Huang C. S. , Chan C. P. , Lin C. P. , Lin H. N. , Lee P. H. , Jia H. W. , Huang S. K. , Jeng J. H. , Chang M. C. 
Published: September 2007

AbstractAim  To evaluate the antioxidant and pro‐oxidant properties of chlorhexidine (CHX).Methodology  The scavenging and generation of reactive oxygen species (ROS) by CHX in the presence or absence of saturated Ca(OH)2 solutions was evaluated. The reaction emitted chemiluminescence in the presence of lucigenin thus was determined by a luminometer to evaluate the levels of ROS production. Changes in DNA conformation were analysed by agarose gel electrophoresis. Paired Student's t‐test was used to compare the difference between groups.Results  Chlorhexidine (0.00002–0.02%) effectively scavenged 56–88% of the superoxide radicals generated by the xanthine/xanthine oxidase reaction. Through analysis of PUC18 DNA conformation changes, CHX was shown to be a mild scavenger of hydroxyl radicals generated by H2O2 plus FeCl2. However, CHX (>0.083%) decreased the mobility of PUC18 plasmid DNA with potential production of DNA–DNA cross‐link and severe DNA breaks (presence of DNA smear) at further higher concentrations. Furthermore, CHX induced ROS production including H2O2 and superoxide radicals in 0.1N NaOH (pH = 12.76) or Ca(OH)2 (pH = 12.5) solutions.Conclusion  Chlorhexidine exhibited both antioxidant and pro‐oxidant properties under different conditions. These events are possibly involved in the killing of root canal and periodontal microorganisms when CHX and Ca(OH)2 were used in combination or separately. Potential genotoxicity and tissue damage when extruded into the periradicular tissue and at higher concentrations should be considered during periodontal and endodontic practice.
A 20‐year follow‐up study of endodontic variables and apical status in a Swedish population
Authors: Eckerbom M. , Flygare L. , Magnusson T. 
Published: September 2007

AbstractAim  To re‐examine a population after 20 years and evaluate changes in prevalence of endodontic treatment and apical periodontitis, as well as the technical quality of root fillings.Methodology  One hundred and fifteen out of an original 200 patients living in the northern part of Sweden were re‐examined with a full mouth radiographic survey after 20 years. Frequencies of root canal treated teeth, apical periodontitis and quality parameters of root fillings were registered.Results  The frequency of root canal treated teeth increased significantly (P < 0.05) from 13.9% at the first investigation to 17.7% after 20 years. There was also a statistically significant increase (P < 0.05) in teeth with apical periodontitis from 3.3% to 6.8%. Apical periodontitis both in connection with root canal treated teeth and teeth without endodontic treatment, had increased during the follow‐up period. Even though the quality of the root fillings had improved, there was no corresponding improvement of the apical status in teeth with root fillings.Conclusions  There is still a great need for endodontic treatment in the Swedish population, and no improvement in apical health was found during this 20‐year follow up.
Glucose penetration and fluid transport through coronal root structure and filled root canals
Authors: Shemesh H. , Van Den Bos M. , Wu M.‐K. , Wesselink P. R. 
Published: September 2007

AbstractAim  To measure glucose penetration and fluid transport through coronal root structure and compare it with leakage along the coronal region of root fillings.Methodology  A total of 50 single‐rooted teeth were selected and divided into three groups. Ten roots were sectioned longitudinally and the apical portion was removed leaving a total length of 9 mm. These 20 half‐roots served as group 1: root structure (n = 20). The canals of the remaining 40 roots were prepared to size 50 and filled with vertically compacted injectable filling material and sealer. Group 2: Resilon + Epiphany (n = 20) and group 3: gutta‐percha + AH26 (n = 20). The apical portion of the root was removed. Glucose penetration through the coronal root structure and coronal root fillings was checked over a period of 4 weeks and fluid transport was measured after completion of the glucose penetration test. Differences between the groups were statistically analysed with the Kruskal–Wallis test and the Mann–Whitney test.Results  The three groups presented significantly different glucose penetration (P < 0.05). The two groups of filled canals showed significant glucose leakage whilst the root structure group did not show any leakage. In the fluid transport model, the root structure group also did not show any leakage. No significant difference in leakage existed between the two vertically compacted filling materials, Resilon with Epiphany sealer and gutta‐percha with AH26 in both models (P > 0.05).Conclusion  Under the conditions of this study, in both models used, no leakage was observed through root structure. Filled canals were associated with penetration of glucose regardless of the material used.
Push‐out bond strengths of the dentine–sealer interface with and without a main cone
Authors: Jainaen A. , Palamara J. E. A. , Messer H. H. 
Published: September 2007

AbstractAim  To evaluate the push‐out bond strength of the dentine–sealer interface with and without main cone for three resin sealers.Methodology  Thirty extracted maxillary premolar teeth with two separate canals were prepared using 0.04 taper Profile instruments to size 35–45. Teeth were divided into three groups for filling using AH Plus™, EndoREZ® or Resilon® sealers. In each tooth, one canal was filled with a matching single‐cone technique, and other was filled with sealer alone. A 1 mm slice of mid‐root dentine was prepared for the push‐out test. Failure modes after push‐out were examined under microscopy and field emission‐scanning electron microscopy. Data were analysed using two‐way anova and paired t‐tests, with significance set at P < 0.05.Results  Overall, the epoxy resin‐based sealer provided the highest push‐out bond strengths. Push‐out bond strengths were significantly higher (P < 0.001) when canals were filled with sealer alone than those filled with main cone and sealer (AH Plus™ 6.6 and 2.0 MPa, respectively; Resilon® 3.4 and 0.4 MPa; EndoREZ® 0.9 and 0.4 MPa). Sealers appeared to behave differently as thin films in association with a main cone, compared with bulk material. They failed in cohesive mode within the thin film, leaving a layer of sealer on the canal surface. Bulk sealer showed predominantly adhesive failure at the dentine–sealer interface, with a clean dentine wall and with resin tags either partially pulled out or sheared off at the interface.Conclusion  Push‐out bond strengths of resin sealers were much lower when the sealer was present as a thin layer.
Maternal smoking in pregnancy and reproductive hormones in adult sons
Authors: Ramlau‐Hansen C. H. , Thulstrup A. M. , Olsen J. , Ernst E. , Andersen C. Y. , Bonde J. P. 
Published: September 2007

SummarySmoking during pregnancy has been reported to alter levels of reproductive hormones in adult sons. From a Danish pregnancy cohort established in 1984–1987, 347 out of 5109 sons were selected according to their exposure to tobacco smoke in foetal life. From February 2005 to January 2006, a blood sample from each young man (18–21 years) was collected and analysed for reproductive hormones. There were no apparent trends of increasing or decreasing hormonal levels with increased exposure to maternal tobacco smoking during pregnancy. Only the free testosterone/free estradiol ratios increased with increased maternal smoking during pregnancy (p for trend = 0.05). No trends for increasing odds ratios for high follicle‐stimulating hormone (≥25 percentile) or low inhibin B (≤25 percentile) in relation to maternal smoking were observed. We found no major indication of long‐term effects of pre‐natal exposure to tobacco smoke on the levels of reproductive hormones later in life, but the data may suggest a shift in the hypothalamo‐pituitary‐gonadal axis towards higher androgenicity. This result was, however, of only borderline significance and could be because of chance.
Massive deletion in AZFb/b+c and azoospermia with Sertoli cell only and/or maturation arrest
Authors: Yang Y. , Ma M. Y. , Xiao C. Y. , Li L. , Li S. W. , Zhang S. Z. 
Published: September 2007

SummaryRecent studies have revealed that AZF deletion in Y chromosome is the most common known molecular genetic cause of spermatogenetic failure leading to male infertility. Characteristics of AZFa, AZFb and AZFc deletions and their association with spermatogenic impairment have been reported in a large number of populations. However, the distributions of those larger deletions resulted from P5/proximal‐P1, P5/distal‐P1 and P4/distal‐P1 recombinations are still unclear as the literature on their frequencies is limited, and the contribution of these deletions to spermatogenetic failure remain to be confirmed by population studies. In this study, we investigated such massive deletions in 387 idiopathic azoospermic, 269 oligozoospermic patients and 315 men with normal spermatogenesis using 21 AZFb/c specific sequence‐tagged sites. As a result, nine uninterrupted massive deletions were observed exclusively in men with azoospermia caused by either Sertoli cell only (SCO) or maturation arrest (MA). Prevalence of the deletion was 2.33%, in which five deletions arose from non‐allelic homologous recombination between the palindromes P5 and P1 and two between P4 and P1. In other two deletions, novel proximal breakpoints in the interval region between P4 and P3 were observed. Our findings strongly support that the massive deletions in the AZFb or AZFb+c regions are important genetic causes of SCO and/or MA resulting in azoospermia and, besides the P5/proximal‐P1, P5/distal‐P1 and P4/distal‐P1 deletions there may be other massive deletions in these regions resulting in severe spermatogenic impairment.
Promoting evidence‐based childhood fever management through a peer education programme based on the theory of planned behaviour
Authors: Edwards Helen , Walsh Anne , Courtney Mary , Monaghan Sarah , Wilson Jenny , Young Jeanine 
Published: September 2007

Aims and objectives.  This study examined effectiveness of a theoretically based education programme in reducing inappropriate antipyretic use in fever management.Background.  Paediatric nurses’ inconsistent, ritualistic antipyretic use in fever management is influenced by many factors including inconsistent beliefs and parental requests. Determinants of antipyretic administration, identified by the theory of planned behaviour, were belief‐based attitudes and subjective norms.Design.  A quasi‐experiment explored group effects of a peer education programme, based on the theory of planned behaviour, on factors influencing paediatric nurses’ antipyretic administration. Surveys and chart audits collected data from medical wards at experimental and control hospitals one month pre and one and four months postpeer education programme.Methods.  All nurses employed in targeted wards were eligible to participate in surveys and all eligible charts were audited. The peer education programme consisted of four one‐hour sessions targeting evidence‐based knowledge, myths and misconceptions, normative, attitudinal and control influences over and rehearsal of evidence‐based fever management. All nurses in experimental hospital targeted wards were eligible to attend. Peer education and support facilitated session information reaching those unable to attend sessions.Results.  Two‐way univariate anovas explored between subject, experimental and control group and within subject factors, pre, post and latency data. Significant interactions in normative influence (p = 0·01) and intentions (p = 0·01), a significant main group effect in control influence (p = 0·01) and a significant main effect between audit data across time points (p = 0·03) highlight peer education programme effectiveness in behaviour change. Normative, control and intention changes postpeer education programme were maintained in latency data; mean temperature was not.Conclusion.  The peer education programme, based on a behaviour change theory, initiated and maintained evidence‐based intentions for antipyretics use in fever management.Relevance to clinical practice.  The promotion of evidence‐based change in organizational unit intentions and behaviour highlights the crucial role peer support and education can play in continuing educational programmes.