bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Some Density Functional Theory Methods and Force Field Models in Describing Various Interaction Modes of Benzene Dimer
Authors: Zhou Yu-wei , Zhang Igor Ying , Wu Jian-ming , Wu An-an , Xu Xin
Published: January 2012

Benzene dimer (bz2) is the simplest prototype of the π-π interactions. Such interactions are ubiquitous in diverse areas of science and molecular engineering. In the present work, we have made assessment on some modern density functional methods including B97-D, BLYP-D3, M06–2X, XYG3, and force field models including CHARMM, AMBER, MM3, AMOEBA on six important interaction modes of bz2. Our results not only highlight the usefulness of these cost-effective methods, which can be used as economic substitutes of the expensive CCSD(T) for complex real-world systems, but also indicate their weakness in the description of the π-π interactions, which points to the future direction for further improvements.
Photodissociation of 2-Bromobutane by Ion-velocity Map Imaging Technique
Authors: Zhou Dan-na , Mao Rui , Zhang Li-min , Zhang Qun , Chen Yang
Published: January 2012

The photodissociation dynamics of 2-bromobutane has been investigated at 233.62 and 233.95 nm by ion-velocity map imaging technique coupled with resonance-enhanced multiphoton ionization. The speed and angular distribution of Br and Br* fragments were determined from the map images. The two Gaussian components, shown in the speed distributions of Br and Br* atoms, are suggested to attribute to the two independent reaction paths of photodissociation for 2-bromobutane at 233.62 and 233.95 nm. The high-energy component is related to the prompt dissociation along the C-Br stretching mode, and the low-energy component to the dissociation from the repulsive mode with bending and C-Br stretching combination. The contributions of the excited 3Q0, 3Q1, and 1Q1 states to the products (Br and Br*) were discussed. Relative quantum yield of 0.924 for Br(2P3/2) at about 234 nm in the photodissociation of 2-bromobutane is derived.
Mass Spectrometry Study of OH-initiated Photooxidation of Toluene
Authors: Huang Ming-qiang , Zhang Wei-jun , Wang Zhen-ya , Fang Li , Kong Rui-hong , Shan Xiao-bin , Liu Fu-yi , Sheng Liu-si
Published: January 2012

The composition of products formed from photooxidation of the aromatic hydrocarbon toluene was investigated. The OH-initiated photooxidation experiments were conducted by irradiating toluene/CH3ONO/NO/air mixtures in a smog chamber, the gaseous products were detected under the supersonic beam conditions by utilizing vacuum ultraviolet photoionization mass spectrometer using synchrotron radiation in real-time. And an aerosol time-of-flight mass spectrometer was used to provide on-line measurements of the individual secondary organic aerosol particle resulting from irradiating toluene. The experimental results demonstrated that there were some differences between the gaseous products and that of particle-phase, the products of glyoxal, 2-hydroxyl-3-oxo-butanal, nitrotoluene, and methyl-nitrophenol only existed in the particle-phase. However, furane, methylglyoxal, 2-methylfurane, benzaldehyde, cresol, and benzoic acid were the predominant photooxidation products in both the gas phase and particle phase.
Preparation of Aryldiazonium Salt Monolayers on Si(100) Surface by Chemomechanical Method
Authors: Shi Li-qiu , Zhang Lin , Yu Feng , Yan Yong-da , Sun Tao , Dong Shen
Published: January 2012

Functionalizing and patterning of the silicon surface can be realized simultaneously by the chemomechanical method. The oxide-coated crystalline silicon (100) surface is scratched with a diamond tool in the presence of aryldiazonium salt (C6H5N2BF4). Scratching activates the silicon surface by removing the passivation oxide layer to expose fresh Si atoms. The surface morphologies before and after chemomechanical reaction are characterized with atomic force microscopy. Time-of-flight secondary ion mass spectroscopy confirms the presence of C6H5 and provides evidence for the formation of self-assembled monolayer (SAM) on silicon surface via Si—C covalent bonds by scratching the silicon in the presence of C6H5N2BF4.C6H5 groups further bond with surface Si atoms via Si—C covalent bonds as confirmed from infrared spectroscopy results. We propose that chemomechanical reaction, which occurred during scratching the silicon surface, produce C6H5 groups from aryldiazonium salt. The relevant adhesion of SAM is measured. It is found that SAM can reduce the adhesion of silicon. The monolayer can be used as anti-adhesion monolayer for micro/nanoelectromechanical systems components under different environments and operating conditions.
Smyd2 controls cytoplasmic lysine methylation of Hsp90 and myofilament organization
Authors: Donlin Laura T. , Andresen Christian , Just Steffen , Rudensky Eugene , Pappas Christopher T. , Kruger Martina , Jacobs Erica Y. , Unger Andreas , Zieseniss Anke , Dobenecker Marc-Werner , Voelkel Tobias , Chait Brian T. , Gregorio Carol C. , Rottbauer Wolfgang , Tarakhovsky Alexander , Linke Wolfgang A.
Published: January 2012

Protein lysine methylation is one of the most widespread post-translational modifications in the nuclei of eukaryotic cells. Methylated lysines on histones and nonhistone proteins promote the formation of protein complexes that control gene expression and DNA replication and repair. In the cytoplasm, however, the role of lysine methylation in protein complex formation is not well established. Here we report that the cytoplasmic protein chaperone Hsp90 is methylated by the lysine methyltransferase Smyd2 in various cell types. In muscle, Hsp90 methylation contributes to the formation of a protein complex containing Smyd2, Hsp90, and the sarcomeric protein titin. Deficiency in Smyd2 results in the loss of Hsp90 methylation, impaired titin stability, and altered muscle function. Collectively, our data reveal a cytoplasmic protein network that employs lysine methylation for the maintenance and function of skeletal muscle.
What a nostril knows: Olfactory nerve-evoked AMPA responses increase while NMDA responses decrease at 24-h post-training for lateralized odor preference memory in neonate rat
Authors: Yuan Qi , Harley Carolyn W.
Published: January 2012

Increased AMPA signaling is proposed to mediate long-term memory. Rat neonates acquire odor preferences in a single olfactory bulb if one nostril is occluded at training. Memory testing here confirmed that only trained bulbs support increased odor preference at 24 h. Olfactory nerve field potentials were tested at 24 h in slices from trained and untrained bulbs. A larger AMPA component and a smaller NMDA component characterized responses in the bulb receiving odor preference training. Field potential changes were not seen in a bulbar region separate from the lateral odor-encoding area. These results support models in which memory is mediated by increased olfactory nerve-mitral cell AMPA signaling, and memory stability is promoted by decreased NMDA-mediated signaling.
CYP701A8: A Rice ent-Kaurene Oxidase Paralog Diverted to More Specialized Diterpenoid Metabolism
Authors: Wang Qiang , Hillwig Matthew L. , Wu Yisheng , Peters Reuben J.
Published: January 2012

All higher plants contain an ent-kaurene oxidase (KO), as such a cytochrome P450 (CYP) 701 family member is required for gibberellin (GA) phytohormone biosynthesis. While gene expansion and functional diversification of GA-biosynthesis-derived diterpene synthases into more specialized metabolism has been demonstrated, no functionally divergent KO/CYP701 homologs have been previously identified. Rice (Oryza sativa) contains five CYP701A subfamily members in its genome, despite the fact that only one (OsKO2/CYP701A6) is required for GA biosynthesis. Here we demonstrate that one of the other rice CYP701A subfamily members, OsKOL4/CYP701A8, does not catalyze the prototypical conversion of the ent-kaurene C4α-methyl to a carboxylic acid, but instead carries out hydroxylation at the nearby C3α position in a number of related diterpenes. In particular, under conditions where OsKO2 catalyzes the expected conversion of ent-kaurene to ent-kaurenoic acid required for GA biosynthesis, OsKOL4 instead efficiently reacts with ent-sandaracopimaradiene and ent-cassadiene to produce the corresponding C3α-hydroxylated diterpenoids. These compounds are expected intermediates in biosynthesis of the oryzalexin and phytocassane families of rice antifungal phytoalexins, respectively, and can be detected in rice plants under the appropriate conditions. Thus, it appears that OsKOL4 plays a role in the more specialized diterpenoid metabolism of rice, and our results provide evidence for divergence of a KO/CYP701 family member from GA biosynthesis. This further expands the range of enzymes recruited from the ancestral GA primary pathway to the more complex and specialized labdane-related diterpenoid metabolic network found in rice.
Application of the ellipsoid modeling of the average shape of nanosized crystallites in powder diffraction
Authors: Katerinopoulou Anna , Balic-Zunic Tonci , Lundegaard Lars F.
Published: January 2012

Anisotropic broadening correction in X-ray powder diffraction by an ellipsoidal formula is applied on samples with nanosized crystals. Two cases of minerals with largely anisotropic crystallite shapes are presented. The properly applied formalism not only improves the fitting of the theoretical and observed diffraction diagrams but also gives direct information about realistic crystallite shapes and sizes. The approach is demonstrated using the Rietveld refinement programTOPASand it is easily adaptable to other similar software.
The effect of gravity on the Debye–Scherrer ring in small-angle neutron scattering
Authors: Mildner D. F. R. , Cubitt R.
Published: January 2012

Gravity distorts the circular contours found for small-angle neutron scattering data from azimuthally symmetric scattering systems when taken at long wavelength and with large wavelength spreads. The resolution is calculated for a Debye–Scherrer ring and compared with results from measurements taken on a sample of opal.
A new polymorph of 1-ferrocenyl-3-(3-nitroanilino)propan-1-one
Authors: Stevanović Dragana , Pejović Anka , Novaković Sladjana B. , Bogdanović Goran A. , Divjaković Vladimir , Vukićević Rastko D.
Published: January 2012

Recrystallization of the title compound, [Fe(C5H5)(C14H13N2O3)], from a mixture ofn-hexane and dichloromethane gave the new polymorph, denoted (I), which crystallizes in the same space group (P\overline{1}) as the previously reported structure, denoted (II). The Fe—C distances in (I) range from 2.015 (3) to 2.048 (2) Å and the average value of the C—C bond lengths in the two cyclopentadienyl (Cp) rings is 1.403 (13) Å. As indicated by the smallest C—Cg1—Cg2—C torsion angle of 1.4° (Cg1 andCg2 are the centroids of the two Cp rings), the orientation of the Cp rings in (I) is more eclipsed than in the case of (II), for which the value was 15.3°. Despite the pronounced conformational similarity between (I) and (II), the formation of self-complementary N—H...O hydrogen-bonded dimers represents the only structural motif common to the two polymorphs. In the extended structure, molecules of (I) utilize C—H...O hydrogen bonds and, unlike (II), an extensive set of intermolecular C—H...π interactions. Fingerprint plots based on Hirshfeld surfaces are used to compare the packing of the two polymorphs.
Symptoms of Mental Health Problems: Children’s and Adolescents’ Understandings and Implications for Gender Differences in Help Seeking
Authors: MacLean Alice , Hunt Kate , Sweeting Helen
Published: January 2012

Amidst concerns that young people’s mental health is deteriorating, it is important to explore their understandings of symptoms of mental health problems and beliefs around help seeking. Drawing on focus group data from Scottish school pupils, we demonstrate how they understood symptoms of mental health problems and how their characterisations of these symptoms as ‘rare’ and ‘weird’ informed participants’ perceptions that peers, teachers and parents would respond to disclosure in stigmatising ways. Consequently, participants suggested that they would delay or avoid disclosing symptoms of mental health problems. We highlight subtle gender and age differences and outline implications for policy and practice.
Meta‐analysis: coeliac disease and the risk of all‐cause mortality, any malignancy and lymphoid malignancy
Authors: Tio M. , Cox M. R. , Eslick G. D.
Published: January 2012

Background

Coeliac disease has been associated with an increased risk of mortality and malignancy. However, the strength of this association is conflicting among different studies.

Aim

To perform a systematic review and quantitative meta‐analysis to determine the risk of all‐cause mortality, any malignancy and lymphoid malignancy in coeliac disease patients.

Methods

Four electronic databases (Medline, PubMed, Embase and Current Contents Connect) were searched to 4 January 2012, with no language restrictions. From 8698 citations identified, a total of 17 studies met our inclusion criteria.

Results

The all‐cause mortality meta‐analysis showed an increased risk for all‐cause mortality in coeliac patients [odds ratio (OR) 1.24; 95% confidence interval (CI) 1.19–1.30]. A subgroup analysis showed that patients identified by positive serology alone were also at an increased risk of all‐cause mortality (OR 1.16; 95% CI 1.02–1.31). The non‐Hodgkin lymphoma (NHL) meta‐analysis showed an increased risk for NHL in coeliac patients (OR 2.61; 95% CI 2.04–3.33). A subgroup analysis showed that patients identified by positive serology alone were also at an increased risk of NHL (OR 2.55; 95% CI 1.02–6.36). The T‐cell non‐Hodgkin lymphoma (TNHL) meta‐analysis showed an increased risk of TNHL (OR 15.84; 95% CI 7.85–31.94). The any malignancy meta‐analysis showed no increased risk (OR 1.07; 95% CI 0.89–1.29).

Conclusions

Patients with coeliac disease are at an increased risk of mortality and non‐Hodgkin lymphoma, particularly T‐cell non‐Hodgkin lymphoma; they do not have an increased risk of any malignancy overall. Serologically defined patients with coeliac disease have an elevated risk of mortality and non‐Hodgkin lymphoma.
Meta‐analysis: diagnostic medical radiation exposure in inflammatory bowel disease
Authors: Chatu S. , Subramanian V. , Pollok R. C. G.
Published: January 2012

Background

Diagnostic imaging plays a pivotal role in the diagnosis and management of inflammatory bowel disease (IBD); however, increasing use has led to concerns about the malignant potential of ionising radiation. Several studies have demonstrated that diagnostic imaging can result in exposure to potentially harmful levels of ionising radiation in IBD patients.

Aim

To determine the pooled prevalence of increased exposure and pooled odds ratio of risk factors associated with exposure to potentially harmful levels of diagnostic medical radiation.

Methods

We searched Medline, EMBASE, CINHAL and reference lists of identified articles, without language restrictions in October 2011.

Results

Six studies with 1704 participants provided data on the proportion of patients receiving potentially harmful levels of radiation defined as ≥50 milli‐sieverts (mSv)‐equivalent to 5 CT abdomen scans. The pooled prevalence was 8.8% (95% CI 4.4–16.8) for IBD patients and 11.1% (95% CI 5.7–20.5%) and 2% (95% CI 0.8–4.9%) for Crohn's disease and ulcerative colitis patients respectively. Five studies involving 2627 participants provided data for risk factors. IBD‐related surgery and corticosteroid use were significant with pooled adjusted odds ratio of 5.4 (95% CI 2.6–11.2) and 2.4 (95% CI 1.7–3.4) respectively.

Conclusions

About 1 in 10 patients may be exposed to potentially harmful levels of diagnostic medical radiation. Corticosteroid use and IBD related surgery increased this risk. Strategies to reduce radiation exposure while assessing disease activity need to be considered.
Systematic review: the treatment of noncardiac chest pain with antidepressants
Authors: Nguyen T. M. T. , Eslick G. D.
Published: January 2012

Background

Noncardiac chest pain (NCCP) is a common condition, affecting approximately 25% of the general population. The cause of NCCP can be classified as gastro‐oesophageal reflux disease (GERD)‐related NCCP, where antireflux therapy is the main treatment modality or alternatively as non‐GERD‐related NCCP, where pain modulators, including antidepressants, are utilised.

Aim

To provide a systematic review evaluating the evidence for the use of antidepressants in the treatment of non‐GERD‐related NCCP.

Methods

A computerised literature and manual search was conducted to identify relevant randomised, placebo‐controlled studies, published in any language for the evaluation of the effectiveness of antidepressant as a therapeutic intervention for NCCP.

Results

Six randomised placebo‐controlled trials of antidepressant treatment for NCCP were identified. The medications included were selective serotonin reuptake inhibitors [paroxetine (n = 2), sertraline (n = 1)], tricyclic antidepressant [impramine (n = 1)], serotonin–norepinephrine reuptake inhibitor [venlafaxine (n = 1)] and a triazolopyridine [trazodone (n = 1)]. The percentage reduction in chest pain was statistically significant with venlafaxine (50% vs. 10%; P < 0.001), sertraline (63% vs. 15%; P = 0.02) and imipramine (52% vs. 1%; P = 0.03). The improvement in chest pain symptoms was independent of improvement in depression scores. Clinical global improvement also significantly improved in patients on venlafaxine, sertraline, paroxetine and trazodone. The percentage of patients in treatment groups reporting adverse effects were relatively high compared with those in placebo groups, although majority were statistically insignificant or significance was not reported. Nonetheless, adverse events were the reported reason for discontinuation of trials in 53% of patients from the antidepressant groups compared with 29% from the placebo group.

Conclusions

There is modest evidence for the benefit of antidepressants in reducing NCCP and improving patients’ general health. However, there is significant heterogeneity amongst the studies with several study limitations to warrant more rigorous trials and to assess the usefulness of low‐dose antidepressants in non‐GERD NCCP.
Pharmacokinetic predictions for patients with renal impairment: focus on peptides and protein drugs
Authors: Czock David , Keller Frieder , Seidling Hanna M.
Published: January 2012

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Renal impairment may affect the pharmacokinetics of peptide and protein drugs.

• Molecular size is a predictor. Small molecules are eliminated by the kidneys, whereas large molecules (>67 kDa) are not.

• Urinary recovery of peptide and protein drugs in healthy volunteers is not predictive for pharmacokinetic changes in patients with renal impairment.

WHAT THIS STUDY ADDS

• An apparently continuous non‐linear relationship between molecular weight and pharmacokinetic alterations as observed in patients with severe renal impairment or end‐stage renal disease is described.

• Potentially relevant pharmacokinetic changes were found for drugs with a molecular weight below 50 kDa.

• Analysis of observed pharmacokinetics in patients with severe renal impairment may be a useful approach, especially when urinary recovery in healthy volunteers is not predictive.

AIM Drug dosage adjustments in renal impairment are usually based on estimated individual pharmacokinetics. The extent of pharmacokinetic changes in patients with renal impairment must be known for this estimation. If measured data are not available, an estimate based on drug elimination in urine of healthy subjects or patients with normal renal function is commonly made. This is not reliable, however, if renal drug metabolism is involved, as is presumably the case for many peptide and protein drugs. In the present study a new method to predict pharmacokinetic changes for such drugs based on molecular weight was derived.

METHODS Articles reporting measured pharmacokinetics of peptide and protein drugs in patients with severe renal impairment or end‐stage renal disease were identified from the scientific literature, the pharmacokinetic parameter values were extracted and a statistical data synthesis was performed. A sigmoid Emax model was applied and fitted to the data and the prediction error was analyzed.

RESULTS Overall, 98 peptide and protein drugs were identified. Relevant pharmacokinetic data in patients with renal impairment were found for 21 of these drugs. The average drug clearance was 30% and the average prolongation in half‐life was 3.1‐fold for low molecular weight peptides or proteins. The median root squared percentage of the prediction error was 18% (drug clearance) and 12% (half‐life).

CONCLUSION An apparently continuous non‐linear relationship between molecular weight and pharmacokinetic alterations in patients with severe renal impairment was found. The derived equations could be used as a rough guide for decisions on drug dosage adjustments in such patients.
The use of tumour volumetrics to assess response to therapy in anticancer clinical trials
Authors: Goldmacher Gregory V. , Conklin James
Published: January 2012

Serial evaluations of tumour burden using imaging, mainly computed tomography and magnetic resonance imaging, form the basis for assessing treatment response in many clinical trials of anticancer therapeutics. Traditionally, these evaluations have been based on linear measurements of tumour size. Such measurements have limitations related to variability in technical factors, tumour morphology and reader decisions. Measurements of entire tumour volumes may overcome some of the limitations of linear tumour measurements, improving our ability to detect small changes reliably and increasing statistical power per subject in a trial. Certain technical factors are known to affect the accuracy and precision of volume measurements, and work is in progress to define these factors more thoroughly and to qualify tumour volume as a biomarker for the purposes of drug development.
The effects of febuxostat on the pharmacokinetic parameters of rosiglitazone, a CYP2C8 substrate
Authors: Naik Himanshu , Wu Jing‐tao , Palmer Robert , McLean Lachy
Published: January 2012

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Febuxostat is a xanthine oxidase inhibitor approved for lowering serum urate levels in hyperuricaemic gout patients. It is extensively metabolized both by conjugation via uridine diphosphate glucuronosyltransferase enzymes and by oxidation via cytochrome P450 enzymes.

WHAT THIS STUDY ADDS

• Using rosiglitazone as a CYP2C8 substrate, we have demonstrated that febuxostat does not impede CYP2C8 metabolic activity, because febuxostat had no impact on rosiglitazone pharmacokinetic parameters. We therefore suggest that febuxostat can be safely co‐administered with CYP2C8‐metabolized drugs.

AIMS To determine the effect of febuxostat on cytochrome P450 2C8 (CYP2C8) activity using rosiglitazone as a CYP2C8 substrate.

METHODS Healthy subjects received febuxostat 120 mg daily (regimen A) or matching placebo (regimen B) for 9 days along with a single oral dose of rosiglitazone 4 mg on day 5 in a double‐blind, randomized, cross‐over fashion (≥7 day washout between periods). Plasma samples for analysis of the impact of febuxostat on the pharmacokinetics (PK) of rosiglitazone and its metabolite, N‐desmethylrosiglitazone, were collected for 120 h after co‐administration.

RESULTS Of the 39 subjects enrolled, 36 completed the study and were included in the PK analyses. Rosiglitazone PK parameters were comparable between regimens A and B. Median time to maximal plasma concentration, mean maximal plasma concentration (Cmax), area under the concentration‐time curve (AUC) from time zero to the last quantifiable concentration (AUC0–tlqc), AUC from time zero to infinity (AUC0–∞), and terminal elimination half‐life for regimen A were 0.50 h, 308.6 ng ml−1, 1594.9 ng h ml−1, 1616.0 ng h ml−1 and 4.1 h, respectively, and for regimen B they were 0.50 h, 327.6 ng ml−1, 1564.5 ng h ml−1, 1584.2 ng h ml−1 and 4.0 h, respectively. Point estimates for the ratio of regimen A to regimen B (90% confidence intervals) for rosiglitazone Cmax, AUC0–tlqc and AUC0–∞ central values were 0.94 (0.89–1.00), 1.02 (1.00–1.04) and 1.02 (1.00–1.04), respectively.

CONCLUSIONS Co‐administration of febuxostat had no effect on rosiglitazone or N‐desmethylrosiglitazone PK parameters, suggesting that febuxostat can be given safely with drugs metabolized through CYP2C8.
Construct validation of the Nurse Cultural Competence Scale: a hierarchy of abilities
Authors: Perng Shoa‐Jen , Watson Roger
Published: January 2012

Aim.  The aim of this study was to describe the development of a Nurse Cultural Competence Scale using Mokken scaling.

Background.  The psychometrics of the present cultural competence assessment tools has been questioned. The levels of competence measured by existing tools are not capable of indicating individual differences.

Design.  This study employed a cross‐sectional design. A convenience sample of 172 on‐the‐job nursing students in a college of technology in Taiwan was recruited.

Methods.  Based on previous literature, the Nurse Cultural Competence Scale comprising 41 items was developed to measure the concept of cultural awareness, cultural knowledge, cultural sensitivity and cultural skill. Mokken scaling analysis was conducted to investigate the unidimensionality and hierarchical nature of the scale.

Results.  From the 41 items entered into the Mokken scaling procedure, 20 form a strong Mokken scale. The 20 items form a reliable and statistically significant scale which is negatively skewed. The ordering of the items from lowest to highest difficulty shows a hierarchy.

Relevance to clinical practice.  Nursing managers and educators may use this scale to assess the levels of cultural competence of their members or students and then provide the education according to individual needs.
IL28B rs12979860 polymorphism does not influence outcomes of hepatitis B virus infection
Authors: Peng L. J. , Guo J. S. , Zhang Z. , Shi H. , Wang J. , Wang J. Y.
Published: January 2012

rs12979860 in interleukin 28B (IL28B) gene is associated with response to interferon‐α therapy and natural viral clearance in hepatitis C. The role of this polymorphism is less known in hepatitis B virus (HBV) infection. We evaluated whether rs12979860 was associated with outcomes of HBV infection. There were 651 individuals with persistent infection (387 with liver cirrhosis, 264 without cirrhosis) and 226 healthy individuals who recovered from HBV infection. The genotypic distributions were compared between different phenotypes pertaining to disease progression and HBV markers. The polymorphism had no association with clearance of hepatitis B surface antigen and hepatitis B e antigen, HBV‐DNA level, apparent hepatitis onset and liver cirrhosis (P > 0.05). These results suggest that rs12979860 does not have such a strong effect in hepatitis B compared to hepatitis C.
Origin and population history of a recent colonizer, the yellow warbler in Galápagos and Cocos Islands
Authors: CHAVES J. A. , PARKER P. G. , SMITH T. B.
Published: January 2012

Abstract The faunas associated with oceanic islands provide exceptional examples with which to examine the dispersal abilities of different taxa and test the relative contribution of selective and neutral processes in evolution. We examine the patterns of recent differentiation and the relative roles of gene flow and selection in genetic and morphological variation in the yellow warbler (Dendroica petechia aureola) from the Galápagos and Cocos Islands. Our analyses suggest aureola diverged from Central American lineages colonizing the Galápagos and Cocos Islands recently, likely less than 300 000 years ago. Within the Galápagos, patterns of genetic variation in microsatellite and mitochondrial markers suggest early stages of diversification. No intra‐island patterns of morphological variation were found, even across steep ecological gradients, suggesting that either (i) high levels of gene flow may be homogenizing the effects of selection, (ii) populations may not have had enough time to accumulate the differences in morphological traits, or (iii) yellow warblers show lower levels of ‘evolvability’ than some other Galápagos species. By examining genetic data and morphological variation, our results provide new insight into the microevolutionary processes driving the patterns of variation.
Role of p53‐dependent placental apoptosis in the reproductive and developmental toxicities of caffeine in rodents
Authors: Huang Jing , Zhou Shu , Ping Jie , Pan Xiaoliang , Liang Gai , Xu Dan , Kou Hao , Bao Chong , Wang Hui
Published: January 2012

The aim of the present study was to evaluate the role of placental apoptosis in mediating the reproductive and developmental toxicity of caffeine in rodents.

Female Kunming mice were treated with caffeine (60, 120 and 240 mg/kg per day) before and during pregnancy. The conception rate, maternal bodyweight gain, placental weight and indices of fetal developmental, including the rate of intrauterine growth retardation (IUGR; i.e. the actual number of fetuses exhibiting IUGR as a percentage of the total number of fetuses), were determined on gestational day (GD) 18.

Female Wistar rats were treated with caffeine (20, 60 and 180 mg/kg per day) from GD11 to GD20. The IUGR rate, maternal plasma angiotensin (Ang) II and prolactin concentrations, placental pathology, expression of angiotensin AT1 and AT2 receptors and apoptosis‐related proteins were measured on GD20.

In mice, caffeine treatment dose‐dependently reduced the total conception rate, delayed conception and decreased maternal bodyweight gain, placental weight, fetal bodyweight and fetal body and tail lengths, whereas the IUGR rate was increased.

In rats, caffeine treatment dose‐dependently decreased placental weight and fetal bodyweight and increased the IUGR rate. Abnormal placental structures and decreased maternal plasma prolactin concentrations were observed following 180 mg/kg per day caffeine treatment, which resulted in increases in renin–angiotensin system (RAS) activity, including maternal plasma AngII concentrations and placental AT1B and AT2 receptor expression, and Bax and p53 expression, but decreases in placental Bcl‐2 expression.

On the basis of the results of the present study, it appears that caffeine ingestion has detrimental effects on the reproductive system and fetal development in rodents that are associated with chronic activation of the maternal and placental RAS, and induction of p53‐dependent placental apoptosis.
Fatal subarachnoid hemorrhage caused by Aspergillus arteritis without angiographic abnormalities
Authors: Miki Yasuo , Tomiyama Masahiko , Haga Rie , Nishijima Haruo , Suzuki Chieko , Nishijima Michiharu , Midorikawa Hiroshi , Sannohe Seiya , Kurotaki Hidekachi , Wakabayashi Koichi , Baba Masayuki
Published: January 2012

No source of bleeding is detected by angiogram in 15–20% of patients with nonaneurysmal subarachnoid hemorrhage (SAH). This negative angiographic finding might suggest a benign prognosis. We describe a case of fatal SAH caused by Aspergillus arteritis without formation of fusiform dilatation or aneurysms. A 76‐year‐old man with a 2‐month history of progressive visual loss due to pachymeningitis around the optic nerves suffered from SAH in the bilateral sylvian fissures. Repetitive serum galactomannan assay and angiography showed no abnormality. Post mortem examination revealed marked proliferation of Aspergillus in the granulomas of the frontal base dura mater. In addition, major trunks and several branches of the bilateral middle cerebral arteries were invaded by Aspergillus hyphae, which destroyed the walls in the absence of dilatation and aneurysms. Invasive aspergillosis of the CNS often forms a mycotic aneurysm. However, four autopsy cases of nonaneurysmal SAH due to invasive aspergillosis have been reported. The present case is the second autopsy case of Aspergillus arteritis without angiographic abnormality, resulting in fatal SAH. Aggressive and continuous antifungal therapy is absolutely necessary in suspected cases of invasive aspergillosis of the CNS, even if angiography is negative and therapeutic markers of aspergillosis are normal.
Pericytes as a new target for pathological processes in CADASIL
Authors: Dziewulska Dorota , Lewandowska Eliza
Published: January 2012

CADASIL is a generalized angiopathy caused by mutations in NOTCH 3 gene leading to degeneration and loss of vascular smooth muscle cells (VSMC) in small arteries and arterioles. Since the receptor protein encoded by NOTCH 3 gene is expressed not only on VSMC but also on pericytes, pericytes and capillary vessels can be damaged by CADASIL. To check this hypothesis we examined microvessels in autopsy brains and skin‐muscle biopsies of CADASIL patients. We found degeneration and loss of pericytes in capillary vessels. Pericytes were shrunken and their cytoplasm contained numerous vacuoles, big vesicular structures and complexes of enlarged pathological mitochondria. Degenerative changes were also observed within endothelial‐pericytic connections, especially within peg‐and‐socket junctions. Nearby pericyte cell membranes or inside infoldings, deposits of granular osmiophilic material (GOM) were usually seen. In the affected capillaries endothelial cells revealed features of degeneration, selective death or swelling, leading to narrowing or occlusion of the capillary lumen. Our findings indicate that in CADASIL not only VSMC but also pericytes are severely damaged. Pericyte involvement in CADASIL can result in increased permeability of capillary vessels and disturbances in cerebral microcirculation, leading to white matter injury. Since in capillaries pericytes regulate vessel contractility, their degeneration can also cause defective vasomotor reactivity, the phenomenon observed very early in CADASIL, before development of histopathological changes in vessel walls.
Transplanted bone marrow stromal cells protect neurovascular units and ameliorate brain damage in stroke‐prone spontaneously hypertensive rats
Authors: Ito Masaki , Kuroda Satoshi , Sugiyama Taku , Maruichi Katsuhiko , Kawabori Masahito , Nakayama Naoki , Houkin Kiyohiro , Iwasaki Yoshinobu
Published: January 2012

This study was aimed to assess whether bone marrow stromal cells (BMSC) could ameliorate brain damage when transplanted into the brain of stroke‐prone spontaneously hypertensive rats (SHR‐SP). The BMSC or vehicle was stereotactically engrafted into the striatum of male SHR‐SP at 8 weeks of age. Daily loading with 0.5% NaCl‐containing water was started from 9 weeks. MRIs and histological analysis were performed at 11 and 12 weeks, respectively. Wistar‐Kyoto rats were employed as the control. As a result, T2‐weighted images demonstrated neither cerebral infarct nor intracerebral hemorrhage, but identified abnormal dilatation of the lateral ventricles in SHR‐SP. HE staining demonstrated selective neuronal injury in their neocortices. Double fluorescence immunohistochemistry revealed that they had a decreased density of the collagen IV‐positive microvessels and a decreased number of the microvessels with normal integrity between basement membrane and astrocyte end‐feet. BMSC transplantation significantly ameliorated the ventricular dilatation and the breakdown of neurovascular integrity. These findings strongly suggest that long‐lasting hypertension may primarily damage neurovascular integrity and neurons, leading to tissue atrophy and ventricular dilatation prior to the occurrence of cerebral stroke. The BMSC may ameliorate these damaging processes when directly transplanted into the brain, opening the possibility of prophylactic medicine to prevent microvascular and parenchymal‐damaging processes in hypertensive patients at higher risk for cerebral stroke.
Characterization of chromosomal aberrations in thymic MALT lymphoma
Authors: Kominato Satoru , Nakayama Takahisa , Sato Fumihiko , Yamada Seiji , Xia Hongjing , Fujiyoshi Yukio , Hattori Hideo , Inagaki Hiroshi
Published: January 2012

Mucosa‐associated lymphoid tissue (MALT) lymphoma arising in the thymus is a rare disorder that shows a strong association with autoimmune disease. Several MALT‐lymphoma‐specific and ‐associated chromosomal abnormalities, including t(11;18), t(14;18), t(1;14), trisomy 3 and trisomy 18, are known to occur. The former translocation results in apoptosis inhibitor 2 gene (API2)–MALT lymphoma‐associated translocation 1 (MALT1) fusion. In this study, we examined 14 cases of thymic MALT lymphomas for API2–MALT1 fusion using multiplex reverse transcription polymerase chain reaction and looked for trisomy 3, trisomy 18 and abnormalities of MALT1 and IGH genes using fluorescence in situ hybridization. Thymic MALT lymphoma cases had a high frequency of trisomy 3 (7/14 cases), a very low incidence of trisomy 18 (1/14) and no detectable MALT1‐associated (0/13) or IGH‐associated (0/13) gene abnormalities including t(11;18). A review of the literature showed that the pattern of chromosomal aberrations in thymic MALT lymphoma was similar to those of thyroid and salivary gland MALT lymphomas. Although frequently detected, trisomy 3 was not associated with any of the clinicopathological factors analyzed, suggesting that trisomy 3 may play a role in lymphoma development. In conclusion, the present study showed that thymic MALT lymphoma has a characteristic pattern of chromosomal aberrations that may be similar to those of other autoimmune‐associated MALT lymphomas.
Unilateral glomerulocystic kidney disease associated with tuberous sclerosis complex in a neonate
Authors: Murakami Ayumi , Gomi Kiyoshi , Tanaka Mio , Ohyama Makiko , Itani Yasufumi , Ishikawa Hiroshi , Aida Noriko , Furuya Mitsuko , Tanaka Yukichi
Published: January 2012

We report a case of glomerular cystic kidney disease (GCKD) associated with tuberous sclerosis complex (TSC) in a neonate. The patient displayed progressive abdominal enlargement attributed to GCKD associated with TSC. After birth, the right kidney was resected because it compressed his liver and right lung, and possible malignancy could not be excluded. Macroscopically, the resected kidney was markedly enlarged, and histologically the kidney had numerous glomerular cysts accompanied by papillary epithelial growth. Notably, a small area of normal parenchyma was observed at the lower pole. The epithelial cells of the cysts displaying a papillary growth pattern were positive for mTOR, phosphorylated mTOR, and phosphorylated S6 ribosomal protein (p‐S6). The morphologically noncystic, normal‐looking tubular epithelium was also positive for p‐S6. These results imply that one more molecular event might be necessary for cyst formation in GCKD associated with TSC, in addition to the activation of mTOR signaling.
Ecological implications of behavioural syndromes
Authors: Sih Andrew , Cote Julien , Evans Mara , Fogarty Sean , Pruitt Jonathan
Published: January 2012

Ecology Letters (2012)

Interspecific trait variation has long served as a conceptual foundation for our understanding of ecological patterns and dynamics. In particular, ecologists recognise the important role that animal behaviour plays in shaping ecological processes. An emerging area of interest in animal behaviour, the study of behavioural syndromes (animal personalities) considers how limited behavioural plasticity, as well as behavioural correlations affects an individual’s fitness in diverse ecological contexts. In this article we explore how insights from the concept and study of behavioural syndromes provide fresh understanding of major issues in population ecology. We identify several general mechanisms for how population ecology phenomena can be influenced by a species or population’s average behavioural type, by within‐species variation in behavioural type, or by behavioural correlations across time or across ecological contexts. We note, in particular, the importance of behavioural type‐dependent dispersal in spatial ecology. We then review recent literature and provide new syntheses for how these general mechanisms produce novel insights on five major issues in population ecology: (1) limits to species’ distribution and abundance; (2) species interactions; (3) population dynamics; (4) relative responses to human‐induced rapid environmental change; and (5) ecological invasions.
Central obesity as measured by waist circumference is predictive of severity of lower urinary tract symptoms
Authors: Lee Richard K. , Chung Doreen , Chughtai Bilal , Te Alexis E. , Kaplan Steven A.
Published: January 2012

Study Type – Prognosis (cohort)

Level of Evidence 2a

What's known on the subject? and What does the study add?

The metabolic syndrome, or Syndrome X, has traditionally been associated with an increased risk of cardiovascular disease and sexual dysfunction. Emerging data however now suggest that the metabolic syndrome may also have a heretofore unrecognized negative effect on voiding function as well. Weight loss through either behavioural modification or bariatric surgery has been shown to lead to improvement in stress and urge incontinence as well as LUTS. A potential relationship may be drawn between obesity and BPH.

This study adds the knowledge that WC can represent a simple metric not only for elements of the metabolic syndrome but also for worsened voiding. These obese men may be at high risk of male pelvic dysfunction.

OBJECTIVES

To determine if central obesity as measured by waist circumference (WC) is a risk factor in metabolic dysfunction, which includes hypertension, dyslipidaemia and type 2 diabetes (DM2).

To test the hypothesis that central obesity and WC are associated with and predictive of the severity of voiding dysfunction.

METHODS

Men aged ≥40 years with moderate or severe lower urinary tract symptoms (LUTS, International Prostate Symptom Score ≥ 8) with no previous treatment were included for study.

Subjects were divided into three groups according to WC (<90, 90–99 and ≥100 cm).

Baseline parameters including International Prostate Symptom Score, prostate volume, serum prostate‐specific antigen, presence of erectile dysfunction and ejaculatory dysfunction, and the prevalence of hypertension, coronary artery disease and DM2 were compared among the three WC categories.

The association between WC and all parameters assessed was tested using multivariate logistic regression analysis.

RESULTS

In the 409 consecutive men analysed, WC was significantly and positively associated with prostate volume, serum prostate‐specific antigen and International Prostate Symptom Score.

Higher WCs were also significantly associated with a greater prevalence of hypertension, coronary artery disease, DM2 and obesity as well as the presence of erectile dysfunction and ejaculatory dysfunction.

CONCLUSIONS

Increased WC is associated with worsened voiding.

There was a significantly increased prevalence of components of the metabolic syndrome in patients with higher WC.

Obese men, in particular those with other features of the metabolic syndrome, are at increased risk of male pelvic dysfunction and can be easily recognized by measurement of WC.
A taxonomy of virtual worlds usage in education
Authors: Duncan Ishbel , Miller Alan , Jiang Shangyi
Published: January 2012

Virtual worlds are an important tool in modern education practices as well as providing socialisation, entertainment and a laboratory for collaborative work. This paper focuses on the uses of virtual worlds for education and synthesises over 100 published academic papers, reports and educational websites from around the world. A taxonomy is then derived from these papers, delineating current theoretical and practical work on virtual world usage, specifically in the field of education. The taxonomy identifies rich veins of current research and practice in associated educational theory and in simulated worlds or environments, yet it also demonstrates the paucity of work in important areas such as evaluation, grading and accessibility.

Practitioner notes

What is already known about this topic

The use of virtual worlds for supporting education is widespread and increasing.

There are numerous studies on virtual worlds usage in education.

Virtual worlds are mainly used for collaborative‐ or simulation‐based education.

What this paper adds

An analysis and synthesis of over 100 academic papers and virtual worlds, multi‐user virtual environments and virtual learning environments.

A taxonomic differentiation based upon population, educational activity and learning theory.

A balance sheet of the disadvantages and advantages of using virtual worlds in education.

Identification of under developed areas of research into virtual worlds in education.

Implications for practice and/or policy

Motivates the use of virtual worlds to support experiential learning, where real world experiential learning is difficult to achieve due to barriers of time, cost and place.

Identification of difficulties and challenges in the educational use of virtual worlds. These may be overcome through future work or help identify where the use of virtual worlds is not appropriate.

Identification of where the current development or research focus is: pedagogy, collaboration, enquiry‐based learning and identity, etc.
Assessing the effectiveness of a 3‐D instructional game on improving mathematics achievement and motivation of middle school students
Authors: Bai Haiyan , Pan Wei , Hirumi Astusi , Kebritchi Mansureh
Published: January 2012

This research study assessed the effectiveness of a three‐dimensional mathematics game, DimensionM, through a pretest–posttest control group quasi‐experimental design. Participants consisted of 437 eighth graders. The classrooms were randomly assigned either to the treatment group that utilized DimensionM as a supplement to regular classroom instructions or to the control group that received regular class instructions without any computer activities. The results of the analysis on the pretest–posttest data revealed that the DimensionM game increased mathematical knowledge acquisition in algebra and maintained student motivation to learn. The findings suggest that the implementation of DimensionM in mathematics education can greatly benefit middle school students learning algebra.

Practitioner Notes

What is already known about this topic

Evaluations on the effectiveness of instructional games are known in the community of both practitioners and experienced researchers in educational research.

What this paper adds

This paper specifically added to the literature by evaluating the effectiveness of the novel instructional game, the DimensionM game, on increasing middle school student mathematical knowledge acquisition in algebra and maintaining student motivation to learn.

Implications for practice and/or policy

The study results suggested that the implementation of DimensionM in mathematics education can benefit middle school students' learning of algebra and can be helpful to maintain their motivation in learning.