bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐term survival of intensive care and hospital patient cohorts compared with the general Australian population: a relative survival approach
Authors: Ghelani Dhaval , Moran John L. , Sloggett Andy , Leeson Richard J. , Peake Sandra L.
Published: April 2009

Rationale  Long‐term post‐hospital survival of intensive care cohorts has been poorly characterized. The relative survival of septic and non‐septic intensive care and general hospital patient cohorts, compared with the Australian population, was determined

Methods  A retrospective cohort study in a tertiary‐level adult intensive care. Index intensive care admissions, July 1993 to June 1999, with sepsis and surviving hospital, constituted the intensive care sepsis cohort; residual patients, the intensive care non‐sepsis cohort. Hospital cohorts, infected and non‐infected, and Charlson Comorbidity Score (CCS) were obtained electronically, from ICD‐9 codes. Follow‐up was until death, or for a minimum of 4.2 years, to a maximum of 9.6 years. Time‐to‐death was sourced from the State registry. Relative survival was determined using the Esteve method and excess hazard modelled by covariate adjusted generalized linear models.

Results  The ICU sepsis (n = 224) and non‐sepsis (n = 1798) cohorts were of mean (standard deviation, SD) age of 63.2 (15.6) and 59.8 (18.9) years; with co‐morbidity score 1.2 (1.3) and 0.5 (0.9) respectively. Hospitalized infected (n = 8455) and non‐infected (n = 51 152) cohorts were of age 56.5 (22.2) and 52.2 (20.9) years; co‐morbidity score 0.4 (0.9) and 0.3 (0.9) respectively. Relative survival of all cohorts was less than the Australian population; for the two intensive care cohorts, progressive relative survival decline suggested a perpetuating excess mortality. Both age and CCS increments were associated with progressive increases in excess hazard. There was a reduced hazard for intensive care sepsis versus non‐sepsis cohorts; 0.42 [95% confidence interval (CI): 0.25–0.71, P = 0.001] and surgical versus medical patients, 0.64 (95% CI: 0.50–0.84, P = 0.001); and an excess hazard for men, 1.38 (95% CI: 1.08–1.74, P = 0.009).

Conclusions  Adverse long‐term survival of intensive care and hospital patients was demonstrated. For hospital patients there was additional infection‐related mortality risk, not evident for ICU patients after case mix control.
Beech carbon productivity as driver of ectomycorrhizal abundance and diversity
Authors: DRUEBERT CHRISTINE , LANG CHRISTA , VALTANEN KERTTU , POLLE ANDREA
Published: April 2009

We tested the hypothesis that carbon productivity of beech (Fagus sylvatica) controls ectomycorrhizal colonization, diversity and community structures. Carbon productivity was limited by long‐term shading or by girdling. The trees were grown in compost soil to avoid nutrient deficiencies. Despite severe limitation in photosynthesis and biomass production by shading, the concentrations of carbohydrates in roots were unaffected by the light level. Shade‐acclimated plants were only 10% and sun‐acclimated plants were 74% colonized by ectomycorrhiza. EM diversity was higher on roots with high than at roots with low mycorrhizal colonization. Evenness was unaffected by any treatment. Low mycorrhizal colonization had no negative effects on plant mineral nutrition. In girdled plants mycorrhizal colonization and diversity were retained although 14C‐leaf feeding showed almost complete disruption of carbon transport from leaves to roots. Carbohydrate storage pools in roots decreased upon girdling. Our results show that plant carbon productivity was the reason for and not the result of high ectomycorrhizal diversity. We suggest that ectomycorrhiza can be supplied by two carbon routes: recent photosynthate and stored carbohydrates. Storage pools may be important for ectomycorrhizal survival when photoassimilates were unavailable, probably feeding preferentially less carbon demanding EM species as shifts in community composition were found.
A vacuolar iron transporter in tulip, TgVit1, is responsible for blue coloration in petal cells through iron accumulation
Authors: Momonoi Kazumi , Yoshida Kumi , Mano Shoji , Takahashi Hideyuki , Nakamori Chihiro , Shoji Kazuaki , Nitta Akira , Nishimura Mikio
Published: April 2009

Blue color in flowers is due mainly to anthocyanins, and a considerable part of blue coloration can be attributed to metal‐complexed anthocyanins. However, the mechanism of metal ion transport into vacuoles and subsequent flower color development has yet to be fully explored. Previously, we studied the mechanism of blue color development specifically at the bottom of the inner perianth in purple tulip petals of Tulipa gesneriana cv. Murasakizuisho. We found that differences in iron content were associated with the development of blue‐ and purple‐colored cells. Here, we identify a vacuolar iron transporter in T. gesneriana (TgVit1), and characterize the localization and function of this transporter protein in tulip petals. The amino acid sequence of TgVit1 is 85% similar that of the Arabidopsis thaliana vacuolar iron transporter AtVIT1, and also showed similarity to the AtVIT1 homolog in yeast, Ca2+‐sensitive cross‐complementer 1 (CCC1). The gene TgVit1 was expressed exclusively in blue‐colored epidermal cells, and protein levels increased with increasing mRNA expression and blue coloration. Transient expression experiments revealed that TgVit1 localizes to the vacuolar membrane, and is responsible for the development of the blue color in purple cells. Expression of TgVit1 in yeast rescued the growth defect of ccc1 mutant cells in the presence of high concentrations of FeSO4. Our results indicate that TgVit1 plays an essential role in blue coloration as a vacuolar iron transporter in tulip petals. These results suggest a new role for involvement of a vacuolar iron transporter in blue flower color development.
Assessment of liver graft function and regeneration by galactosyl‐human serum albumin (99mTc‐GSA) liver scintigraphy in adult living‐donor liver transplantation
Authors: Iida Taku , Isaji Shuji , Yagi Shintaro , Hori Tomohide , Taniguchi Kentaro , Ohsawa Ichiro , Mizuno Shugo , Usui Masanobu , Sakurai Hiroyuki , Yamagiwa Kentaro , Yamakado Kouichiro , Uemoto Shinji
Published: April 2009

Abstract:  Background:  In adult living‐donor liver transplantation (LDLT), the assessment of the graft functional reserve is very important. We evaluated the graft functional reserve by technetium‐99m‐diethylenetriaminepenta‐acetic acid‐galactosyl‐human serum albumin (99mTc‐GSA) liver scintigraphy.

Patients and method:  From May 2003 to September 2006, 99mTc‐GSA studies were performed in 27 adult recipients on two, four wk after LDLT, the receptor index [ratio of liver to heart‐plus‐liver radioactivity at 15 minutes (LHL15)] (LHL15) was calculated. Recipients were divided into two groups according to LHL15 on two wk after LDLT (group H; >0.935, group L; <0.935). Liver functional tests and recipients’ background parameters were evaluated between the two groups.

Result:  Group L accompanied higher preoperative model for end‐stage liver disease (MELD) score (p = 0.038), lower graft‐recipient weight ratio (GRWR) (p = 0.032) and older donor age (p = 0.003) compared with group H. There was no significant difference in the graft regeneration rate between two groups. The three‐yr cumulative survival rate was 76.1% in group L and 88.9% in group H.

Conclusion:  In LDLT, LHL15 has the potential to assess the graft function and predict the recipients’ outcome. Graft function after LDLT may be related closely to the pretransplant MELD score, GRWR, and donor age.
Environment and host‐plant genotype effects on the seasonal dynamics of a predatory mite on cassava in sub‐humid tropical Africa
Authors: Zundel Christine , Nagel Peter , Hanna Rachid , Korner Fränzi , Scheidegger Urs
Published: April 2009

1 In tropical dry seasons, survival of small arthropods such as predatory mites is often negatively affected by low relative humidity (RH). For species that do not diapause or migrate to refuges, the ability of the habitat to mitigate climatic conditions becomes crucial.

2 The relative effect of macro‐habitat (dry grassland hill, humid multiple cropping area, humid riparian forest) and microhabitat (host‐plant genotypes with hairy, semi‐hairy and glabrous apices) on the seasonal dynamics of the phytoseiid mite Typhlodromalus aripo, a predator of Mononychellus tanajoa on cassava, was examined in a field experiment during a dry season. The effect of RH and plant genotype on T. aripo egg survival was determined in an environment control chamber.

3 Predator abundance was higher in humid multiple cropping areas and on hairy cassava compared with the other habitat types and cassava genotypes.

4 Discriminant and regression analyses showed that the predator’s dry season persistence was related to high RH, high plant vigour and hairy apices, but not to prey abundance.

5 In the controlled climate experiment, the effect of host‐plant morphology was evident only at the intermediate RH level of 55%. An effect of apex hairiness was not found.

6 It is concluded that the effect of genotype on T. aripo persistence diminishes under low RH conditions, and that supportive effects of apex hairs become effective only in the field, probably through protection from wind and/or intraguild predation. Humid multiple cropping areas planted with hairy and vigorous cassava genotypes are suitable dry season reservoirs for T. aripo.
Adaptation of protein expression by Escherichia coli in the gastrointestinal tract of gnotobiotic mice
Authors: Alpert Carl , Scheel Jacqueline , Engst Wolfram , Loh Gunnar , Blaut Michael
Published: April 2009

The gastrointestinal tract of mammals is inhabited by several hundred bacterial species. While the effects of the gut microbiota upon the host have been widely studied, the microbial response to host factors has only recently attracted attention. In order to investigate the influence of the host on the physiology of gastrointestinal bacteria, a simplified model of host–bacteria interaction was created by associating germfree mice with commensal Escherichia coli. Here we demonstrate the feasibility of analysing the bacterial response to the conditions in the digestive system by a proteomics‐based approach. Two‐dimensional gel electrophoresis (2D‐GE) followed by electrospray ionization‐tandem mass spectrometry (ESI‐MS/MS) was used to identify bacterial proteins from caecal and faecal samples. In a set of 60 arbitrarily chosen spots of stably and differentially expressed proteins, 50 different bacterial proteins were identified. Their ascribed functions suggest that the host‐associated bacteria adapt their metabolism to the conditions in the intestine by utilizing arginine, asparagine and aspartate as well as glucose/galactose, ribose, maltose, glucuronate, galacturonate and gluconate as substrates. Thirteen proteins not previously detected on 2D‐gels and 10 proteins with unknown or poorly characterized physiological function were identified, while the existence of three proteins had so far only been inferred from predictions or by homology.
The European Democratic Challenge: The Forging of a Supranational Volonté Générale
Authors: José Menéndez Agustin
Published: April 2009

This article explores in a systematic manner the different components of the democratic legitimacy of the Union from the standpoint of deliberative democratic theory. Contrary to standard accounts, it is claimed that the democratic deficit must be disaggregated, given that the Union has not only several shortcomings, but also some democratic surpluses. On the one hand, the Union was created to tackle the democratic deficit of nation states, and has been partially successful in mending the mismatch between the scope of application of their legal systems and the geographical reach of the consequences of legal decisions. Moreover, the European legal order is based on a synthetic constitutional law, which reflects the common constitutional traditions of the Member States, which lend democratic legitimacy to the whole European legal order. On the other hand, the lack of a democratically written and ratified constitution is a central part of the democratic challenge of the Union. But equally important is the structural bias in favour of certain material legal results, which stems from the interplay of the division of competences and the plurality of law‐making procedures.
In ataxia‐teleangiectasia betamethasone response is inversely correlated to cerebellar atrophy and directly to antioxidative capacity
Authors: Russo I. , Cosentino C. , Del Giudice E. , Broccoletti T. , Amorosi S. , Cirillo E. , Aloj G. , Fusco A. , Costanzo V. , Pignata C.
Published: April 2009

Background and purpose:  Ataxia‐telangiectasia (A‐T) is a rare autosomal recessive disorder caused by alterations of the A‐T mutated (ATM) gene. Although A‐T is a noncurable disease, we, previously, documented a clear improvement of cerebellar functions during a short‐term betamethasone trial. The aim of this study was to define the underlying biochemical mechanism.

Methods:  In six A‐T patients receiving a short‐term steroid therapy, intracellular glutathione (GSH) levels were evaluated with a colorimetric assay. The lipid peroxidation level and reactive oxygen species (ROS) production were evaluated using commercial assays. All the parameters were compared with the improvement of cerebellar functions expressed as delta (Δ) of the Scale for the Assessment and Rating of Ataxia (SARA).

Results:  We observed an inverse correlation between Δ SARA and the severity of cerebellar atrophy and between the latter and basal GSH values. Four of the five patients with the highest Δ SARA also had the highest GSH values. Moreover, even though basal ROS values were comparable in patients and controls, in the only patient studied at different time‐points of therapy, a remarkable reduction in ROS levels was documented.

Conclusion:  We suggest that antioxidative mechanisms play a role in favouring the improvement of cerebellar functions observed in A‐T patients receiving a short‐term betamethasone trial.
Prevalence of Constipation Symptoms in Fecally Incontinent Nursing Home Residents
Authors: Schnelle John F. , Simmons Sandra F. , Beuscher Linda , Peterson Emily N. , Habermann Ralf , Leung Felix
Published: April 2009

OBJECTIVES: To determine the prevalence of constipation symptoms and the effects of a brief toileting assistance trial on constipation in a sample of fecally incontinent nursing home (NH) residents.

DESIGN: Observational study.

SETTING: Five NHs.

PARTICIPANTS: One hundred eleven fecally incontinent NH residents.

MEASURES: Research staff measured bowel movement frequency every 2 hours for 10 days. The following week, residents were offered toileting assistance every 2 hours for 2 days to determine resident straining, time required for a bowel movement, and resident perceptions of feeling empty after a bowel movement. Constipation data were abstracted from the medical record.

RESULTS: The frequency of bowel movements during usual NH care was low (mean=0.32 per person per day), and most episodes were incontinent. The frequency of bowel movements increased significantly, to 0.82 per person per day, and most episodes were continent during the 2 days that research staff provided toileting assistance. Eleven percent of residents showed evidence of straining, and 21% of the time after a continent bowel movement, residents reported not feeling empty. Five percent of participants had medical record or Minimum Data Set documentation indicative of constipation symptoms.

CONCLUSION: Low rates of bowel movements during the day that are potentially indicative of constipation were immediately improved during a 2‐day trial of toileting assistance in approximately 68% of the residents, although other symptoms of constipation remained in a subset of residents who increased toileting frequency.
Novel Side Branch Ostial Stent
Authors: CHEN SHAO‐LIANG , LV SHU‐ZHENG , KWAN TAK W.
Published: April 2009

Bifurcation lesions are technically challenging and plagued by a high incidence of restenosis, especially at the side branch orifice, which results in a more frequent need for revascularization during the follow‐up period. This report discusses two clinical experiences with a novel side branch ostial stent, the BIGUARD™ stent, designed for the treatment of bifurcation lesions; procedural success with no in‐hospital complications was observed in types IVb and Ia lesions.
Pattern and Trend of Deliberate Self‐Harm in Western Nepal
Authors: Subba Sonu H. , Binu Valsalakumari S. , Menezes Ritesh G. , Kanchan Tanuj , Arun Mohanram , Patil Rajkumar , Pant Sadip , Saha Archana , De Asis , Rana Manu S.
Published: April 2009

Abstract:  Acts of deliberate self‐harm (DSH) not only affect the people directly involved, but also have grave psychological and social impact on the family and community. In the present study, a cohort of 173 cases of DSH reported from April 2002 to March 2005 was retrospectively analyzed, by perusing the medicolegal register maintained by the Emergency Department at the Western Regional Hospital, Pokhara in the Western Development Region of Nepal. The data were entered and analyzed using SPSS Version 10.1. More than two‐thirds of total cases were females. About 60% of cases were observed in the age group of 15–24 years. Poisoning (89.6%) was the most preferred method of deliberate self‐harm. Organophosphate pesticides were consumed in nearly two‐thirds of the poisoning cases. The majority of cases were reported during the months of May to July and had occurred during the last quarter of the day. More than a twofold increase was observed in the frequency of cases during the 3‐year study period. The said observations were compared and contrasted with the available literature across the globe. The presentation is concluded by highlighting the limitations encountered in Nepal and the scope to overcome the same.
A Preliminary Assessment of the Identification of Saw Marks on Burned Bone*
Authors: Marciniak Stephanie‐Marie
Published: April 2009

Abstract:  This study assesses the degree of modification to the saw mark characteristics of dismembered skeletal remains when exposed to a controlled outdoor fire of limited duration. The sample consists of 36 adult pig hind limbs which were dismembered fleshed. Six handsaws and six power saws were used, with three limbs dismembered and burned for each of the saw types. Results indicate that fire exposure affects the visibility and identifiability of saw mark striae. With the handsaws, the bow saw, hacksaw, and keyhole saw were consistently recognizable. In the power saw group, the saw marks of the jigsaw, reciprocating saw, and chainsaw remained identifiable. Although the bone ends exhibited thermal alterations, the false starts were well preserved with minimal damage. Given the parameters of this study, it is possible to identify the class of saw based on the diagnostic characteristics present on the cremated bones.
Receptivity of African American Adolescents to an HIV‐Prevention Curriculum Enhanced by Text Messaging
Authors: Cornelius Judith B. , St. Lawrence Janet S.
Published: April 2009

PURPOSE.  This study assessed African American adolescents’ receptivity to an HIV‐prevention curriculum enhanced by text messaging.

DESIGN AND METHODS.  Two focus groups were conducted with 14 African American adolescents regarding how an HIV‐prevention curriculum could be enhanced for text messaging delivery.

RESULTS.  The adolescents were receptive to the idea of text messaging HIV‐prevention information but wanted to receive a maximum of three messages per day during the hours of 4:00–6:00 p.m.

PRACTICE IMPLICATIONS.  By taking the findings of this study, nurses, other healthcare providers, and community‐based organizations can adapt evidence‐based interventions for text messaging delivery to individuals at high risk for HIV infection.
Three Intervention Models for Exploring Oral Health in Pregnant Minority Adolescents
Authors: Murphey Christina , Rew Lynn
Published: April 2009

PURPOSE.  Maintaining oral health is important for pregnant minority adolescents and their offspring's present and future well‐being. The purpose of this article is to identify the scope of oral health problems and describe three models to guide pediatric nursing research and interventions related to oral health in pregnant minority adolescents.

CONCLUSIONS.  Identifying and understanding the risks of poor oral health in pregnant minority adolescents will assist those who plan and provide care for this vulnerable population.

PRACTICE IMPLICATIONS.  Utilizing more than one model or a combination of models may be necessary for improving oral health outcomes in this population.
THE EFFECT OF IRRIGATION WITH TREATED WASTEWATER ON “CHEMLALI” OLIVE OIL QUALITY
Authors: BEDBABIS SAIDA , PALESE ASSUNTA MARIA , ROUINA BÉCHIR BEN , RHOUMA ALI , GARGOURI KAMEL , BOUKHRIS MAKKI
Published: April 2009

The aim of this work was to study the effect of the irrigation with treated wastewater (TWW) on the quality parameters of “Chemlali” olive oil through two crop seasons (2004/2005 and 2006/2007). The results showed that irrigation with TWW did not affect the examined oil quality indices (free acidity, specific ultraviolet absorbance K232 and K270). During the two crop seasons, the mean values of these parameters are lower than the upper limits established for the best commercial olive oil quality designated as “Extra Virgin.” However, a significant increase of palmitic, palmitoleic, linoleic, linolenic and stearic acid contents was found in the 2006/2007 crop season in the plot irrigated with TWW as compared to the one treated with well water. In addition, a decrease of oleic acid and polyphenol content was observed at the end of experimental period.

PRACTICAL APPLICATIONS

The availability of fresh water is very scarce in the Middle East and North Africa. Yet consequently, good quality water is used to irrigate crops more sensitive to water shortage than olive trees. Brackish water or recycled wastewater can be used for irrigation, minimizing the exploitation of natural water resources. In Tunisia, treated wastewater (TWW) is commonly used to irrigate olive trees. The aim of the present study was to assess changes in quality characteristics (free acidity, specific ultraviolet absorbance K232 and K270, fatty acid composition and total phenolic compounds) of “Chemlali” olive oil obtained from trees irrigated with TWW.
FRACTURE BEHAVIOR AND MECHANISM OF PUFFED CEREAL DURING COMPRESSION
Authors: ROOPA B.S. , MAZUMDER PRITAM , BHATTACHARYA SUVENDU
Published: April 2009

Texture of puffed cereals was determined to develop an instrumental method and to provide a mechanism of compaction under compressive stress. A model solidlike puffed rice at different moisture contents (2.0–8.5%) was subjected to compression testing to determine the fracture/failure characteristics. The force–deformation curves showed three zones and two firmnesses during compression. The different textural parameters were sensitive to moisture content above 6%. The microstructure of puffed rice consisted of many closed air cells having thin cell walls (10–15 µm) while a compressed sample showed breaking of cell walls with simultaneous development of fracture lines. A mechanism of compaction or failure at macromolecular level for puffed rice has been proposed based on texture data and microstructure.

PRACTICAL APPLICATION

The acceptance of a snack food largely depends on the texture which in turn is related to fracture characteristics. The present paper offers a general method for determining the texture of snacks and similar brittle food products. The developed indices can describe the texture of a snack food. The mechanism of failure, developed in the present work, can also be applied for low‐density foods and for prediction of their behavior during compression.
Direct-to-indirect transition observed in quantum dot photoluminescence with nanoprobe indentation
Authors: Ozasa Kazunari , Maeda Mizuo , Hara Masahiko , Kakoi Hiroki , Xu Lixia , Liang Yuan-Hua , Arai Yoshio
Published: April 2009

Photoluminescence (PL) of InGaAs∕GaAs quantum dots (QDs) is found to be enhanced and then quenched by localized-strain effects induced by the indentation of a nanoprobe. By using a nanoprobe with a flat cylindrical apex of 600nm in radius, the quench of individual fine PL peaks originating from single QDs was analyzed to obtain the relation between the QD location relative to the nanoprobe and the indentation force required to quench the PL. By analyzing direct-to-indirect transition in the band lineup of the QDs and surrounding GaAs matrix through numerical simulation, the authors concluded that the PL quench should be attributed to the crossover of the Γ band of InGaAs and the X band of InGaAs. The bowing parameter of the InGaAs X band of 1050±50meV was deduced by fitting the simulation result to the experimental data.
Nanoscale current transport through Schottky contacts on wide bandgap semiconductors
Authors: Giannazzo F. , Roccaforte F. , Iucolano F. , Raineri V. , Ruffino F. , Grimaldi M. G.
Published: April 2009

The current transport through Schottky contacts on wide band gap semiconductors (GaN and SiC) was studied on nanoscale by conductive atomic force microscopy. Two very different metal-semiconductor systems were investigated: (i) a uniform (∼5 nm thick) Pt contact on GaN, and (ii) a discontinuous contact formed by self-assembled Au nanoclusters on SiC. The local current-voltage (I-V) measurements allowed to demonstrate the “laterally inhomogeneous” electrical behavior of the Pt/GaN contact, which was formed by a distribution of nanoscale patches with different barrier heights. This behavior was explained in terms of the inhomogeneities of the Pt/GaN interface and/or of the electrically active defects present in the GaN epilayer. The standard deviation of the local barrier height histogram (σΦ) was correlated with the dependence of the ideality factor (n) on temperature, deduced from conventional I-V measurements at variable temperatures on macroscopic Pt/GaN diodes. The local Schottky barrier height at the interface between the single metal nanoparticle and the semiconductor was determined in the system of self-assembled Au nanoclusters on SiC. The histogram of the Schottky barrier heights was measured on samples with different cluster size distributions and the dependence of the barrier height on the cluster size was demonstrated.
X-ray investigation of buried SiGe islands for devices with strain-enhanced mobility
Authors: Hrauda N. , Zhang J. J. , Stangl J. , Rehman-Khan A. , Bauer G. , Stoffel M. , Schmidt O. G. , Jovanovich V. , Nanver L. K.
Published: April 2009

In this work self-organized SiGe islands are used as stressors for Si capping layers, which later act as carrier channels in field effect transistors. To be able to address individual islands and to obtain a sufficiently narrow distribution of their properties, the SiGe islands are grown by molecular beam epitaxy on prepatterned Si substrates, with a regular two-dimensional array of pits. This combination of lithographic patterning and self-assembled island growth combines the advantages of both approaches and leads to very homogeneous island shape, size, and chemical composition. For processing, 4in. wafers are used, and fields with pit periods between 600 and 1000nm are defined by optical lithography. After growth of a Si buffer layer several monolayers of Ge are deposited, leading to island formation (dome or barn shaped) in the pits. Subsequent Si capping is performed at a low substrate temperature of 300°C to avoid intermixing and shape changes of the buried islands. The Ge distribution in the buried islands and the strain distribution in the islands and the surrounding Si matrix are assessed by x-ray diffraction experiments, combined with three-dimensional model simulations using finite elements. Tensile strain values in the Si cap up to 8×10−3 can be achieved using this approach, which is difficult to achieve using other methods without introduction of dislocations.
Field enhanced surface treatment of needle-shaped TiO2 cathode for improvement in field emission
Authors: Fukuyama C. , Murakami K. , Abo S. , Wakaya F. , Takai M. , Takimoto T. , Kumashiro Y. , Takaoka Y.
Published: April 2009

Electron emission characteristics of needle-shaped titanium dioxide (TiO2) cathodes fabricated by a printing method and the change in current densities before and after ultraviolet (UV) light irradiation were investigated. A field enhanced surface treatment by applying a high electric field to the printed TiO2 cathodes was found to be effective for improvement in field emission, resulting in protrusion of TiO2 nanorods from the cathode surface and field emission at and above 2.5V∕μm with a current density of about 1mA∕cm2 at 8V∕μm. The emission current density of TiO2 cathodes can be increased by UV light irradiation with gradual increase and decrease from and to the initial level with and without UV light.
Field emission microscopy study of zinc oxide nanowires on tungsten tip
Authors: Zhang Xianxiang , Zhang Gengmin , Bai Xin , Zhao Xingyu , Xiao Jing , Wu Yue , Lu Fengyuan , Guo Dengzhu
Published: April 2009

This article focuses on the field emission from a small number of zinc oxide (ZnO) nanowires. ZnO nanowires were grown directly on W tips and their field emission was studied in a traditional field emission microscope (FEM). The FEM pattern of a single ZnO nanowire was ring shaped, indicating that most of the emission from the (0001) facets of the ZnO nanowires came from their circumferences. Scanning electron microscopy observation, measurement of dependence of the emission current on the applied cathode voltage (I-V behavior), and acquirement of FEM patterns were performed before and after heat treatment of the samples, respectively. The heat treatment was found to play either a favorable or an unfavorable role. It could lead to a stable emission or damage of the emitters, depending on the heating conditions.
Quantum electron transport through carbon nanotubes with electron-phonon coupling
Authors: Ishii Hiroyuki , Kobayashi Nobuhiko , Hirose Kenji
Published: April 2009

The channel-length dependence of the resistance of the carbon nanotubes on micron-order length is studied at finite temperature using the time-dependent wave-packet approach based on the Kubo formula within a tight-binding approximation. The authors clarify how the transport properties of the carbon nanotubes are changed from the ballistic to the diffusive regime due to electron-phonon scattering. They also obtain the reasonable mean free path, relaxation time, and temperature dependence of resistivity.
Priming in Systemic Plant Immunity
Authors: Jung Ho Won , Tschaplinski Timothy J. , Wang Lin , Glazebrook Jane , Greenberg Jean T.
Published: April 2009

Plants possess inducible systemic defense responses when locally infected by pathogens. Bacterial infection results in the increased accumulation of the mobile metabolite azelaic acid, a nine-carbon dicarboxylic acid, in the vascular sap of
Arabidopsis
that confers local and systemic resistance against the pathogen
Pseudomonas syringae
. Azelaic acid primes plants to accumulate salicylic acid (SA), a known defense signal, upon infection. Mutation of the
AZELAIC ACID INDUCED 1 (AZI1)
gene, which is induced by azelaic acid, results in the specific loss of systemic immunity triggered by pathogen or azelaic acid and of the priming of SA induction in plants. Furthermore, the predicted secreted protein AZI1 is also important for generating vascular sap that confers disease resistance. Thus, azelaic acid and AZI1 are components of plant systemic immunity involved in priming defenses.
A Bipedal DNA Brownian Motor with Coordinated Legs
Authors: Omabegho Tosan , Sha Ruojie , Seeman Nadrian C.
Published: April 2009

A substantial challenge in engineering molecular motors is designing mechanisms to coordinate the motion between multiple domains of the motor so as to bias random thermal motion. For bipedal motors, this challenge takes the form of coordinating the movement of the biped's legs so that they can move in a synchronized fashion. To address this problem, we have constructed an autonomous DNA bipedal walker that coordinates the action of its two legs by cyclically catalyzing the hybridization of metastable DNA fuel strands. This process leads to a chemically ratcheted walk along a directionally polar DNA track. By covalently cross-linking aliquots of the walker to its track in successive walking states, we demonstrate that this Brownian motor can complete a full walking cycle on a track whose length could be extended for longer walks. We believe that this study helps to uncover principles behind the design of unidirectional devices that can function without intervention. This device should be able to fulfill roles that entail the performance of useful mechanical work on the nanometer scale.
New Molecular Detection Tools Adapted to Emerging Rhinoviruses and Enteroviruses
Authors: Tapparel Caroline , Cordey Samuel , Van Belle Sandra , Turin Lara , Lee Wai-Ming , Regamey Nicolas , Meylan Pascal , Mühlemann Kathrin , Gobbini Francesca , Kaiser Laurent
Published: April 2009

Human rhinoviruses (HRV), and to a lesser extent human enteroviruses (HEV), are important respiratory pathogens. Like other RNA viruses, these picornaviruses have an intrinsic propensity to variability. This results in a large number of different serotypes as well as the incessant discovery of new genotypes. This large and growing diversity not only complicates the design of real-time PCR assays but also renders immunofluorescence unfeasible for broad HRV and HEV detection or quantification in cells. In this study, we used the 5′ untranslated region, the most conserved part of the genome, as a target for the development of both a real-time PCR assay (Panenterhino/Ge/08) and a peptide nucleic acid-based hybridization oligoprobe (Panenterhino/Ge/08 PNA probe) designed to detect all HRV and HEV species members according to publicly available sequences. The reverse transcription-PCR assay has been validated, using not only plasmid and viral stocks but also quantified RNA transcripts and around 1,000 clinical specimens. These new generic detection PCR assays overcame the variability of circulating strains and lowered the risk of missing emerging and divergent HRV and HEV. An additional real-time PCR assay (Entero/Ge/08) was also designed specifically to provide sensitive and targeted detection of HEV in cerebrospinal fluid. In addition to the generic probe, we developed specific probes for the detection of HRV-A and HRV-B in cells. This investigation provides a comprehensive toolbox for accurate molecular identification of the different HEV and HRV circulating in humans.
Human-Specific Modulation of Transcriptional Activity Provided by Endogenous Retroviral Insertions
Authors: Gogvadze Elena , Stukacheva Elena , Buzdin Anton , Sverdlov Eugene
Published: April 2009

Many phenotypic differences exist between
Homo sapiens
and its closest relatives, chimpanzees, and these differences can arise as a result of variations in the regulation of certain genes common to these closely related species. Human-specific endogenous retroviruses (HERVs) and their solitary long terminal repeats (LTRs) are probable candidates for such a role due to the presence of regulatory elements, such as enhancers, promoters, splice sites, and polyadenylation signals. In this study we show for the first time that HERVs can participate in the specific antisense regulation of human gene expression owing to their LTR promoter activity. We found that two HERV LTRs situated in the introns of genes
SLC4A8
(for sodium bicarbonate cotransporter) and
IFT172
(for intraflagellar transport protein 172) in the antisense orientation serve in vivo as promoters for generating RNAs complementary to the exons of enclosing genes. The antisense transcripts formed from LTR promoter were shown to decrease the mRNA level of the corresponding genes. The human-specific regulation of these genes suggests their involvement in the evolutionary process.
JNK and p38 Mitogen-Activated Protein Kinase Pathways Contribute to Porcine Circovirus Type 2 Infection
Authors: Wei Li , Zhu Zhongwu , Wang Jing , Liu Jue
Published: April 2009

Infection with a wide variety of viruses often perturbs host cell signaling pathways including the Jun NH2-terminal kinase/stress-activated kinase (JNK/SAPK) and the p38 mitogen-activated protein kinase (p38/MAPK), which are important components of cellular signal transduction pathways. The present study demonstrated for the first time that porcine circovirus type 2 (PCV2), which is the primary causative agent of an emerging swine disease, postweaning multisystemic wasting syndrome, can activate JNK1/2 and p38 MAPK pathways in PCV2-infected PK15 cells. However, PCV2 at an early stage of infection, as well as UV-irradiated PCV2, failed to activate these two MAPK families, which demonstrated that PCV2 replication was necessary for their activation. We further found that PCV2 activated the phosphorylation of JNK1/2 and p38 MAPK downstream targets c-Jun and ATF-2 with virus replication in the cultured cells. The roles of these kinases in PCV2 infection were further evaluated using specific inhibitors: the JNK inhibitor 1 for JNK1/2 and SB202190 for p38. Inhibition of JNK1/2 and p38 kinases by these specific inhibitors did result in significant reduction of PCV2 viral mRNA transcription and protein synthesis, viral progeny release, and blockage of PCV2-induced apoptotic caspase-3 activation in the infected cells. Taken together, these data suggest that JNK/SAPK and p38 MAPK pathways play important roles in the PCV2 replication and contribute to virus-mediated changes in host cells.
Monotypic Human Immunodeficiency Virus Type 1 Genotypes across the Uterine Cervix and in Blood Suggest Proliferation of Cells with Provirus
Authors: Bull Marta E. , Learn Gerald H. , McElhone Scott , Hitti Jane , Lockhart David , Holte Sarah , Dragavon Joan , Coombs Robert W. , Mullins James I. , Frenkel Lisa M.
Published: April 2009

Understanding the dynamics and spread of human immunodeficiency virus type 1 (HIV-1) within the body, including within the female genital tract with its central role in heterosexual and peripartum transmission, has important implications for treatment and vaccine development. To study HIV-1 populations within tissues, we compared viruses from across the cervix to those in peripheral blood mononuclear cells (PBMC) during effective and failing antiretroviral therapy (ART) and in patients not receiving ART. Single-genome sequences of the C2-V5 region of HIV-1
env
were derived from PBMC and three cervical biopsies per subject. Maximum-likelihood phylogenies were evaluated for differences in genetic diversity and compartmentalization within and between cervical biopsies and PBMC. All subjects had one or more clades with genetically identical HIV-1
env
sequences derived from single-genome sequencing. These sequences were from noncontiguous cervical biopsies or from the cervix and circulating PBMC in seven of eight subjects. Compartmentalization of virus between genital tract and blood was observed by statistical methods and tree topologies in six of eight subjects, and potential genital lineages were observed in two of eight subjects. The detection of monotypic sequences across the cervix and blood, especially during effective ART, suggests that cells with provirus undergo clonal expansion. Compartmentalization of viruses within the cervix appears in part due to viruses homing to and/or expanding within the cervix and is rarely due to unique viruses evolving within the genital tract. Further studies are warranted to investigate mechanisms producing monotypic viruses across tissues and, importantly, to determine whether the proliferation of cells with provirus sustain HIV-1 persistence in spite of effective ART.
Recurrent spontaneous abortion and polycystic ovarian disease: comparison of two regimens to induce ovulation.
Authors: Johnson P , Pearce J M
Published: April 2009

OBJECTIVE--To determine whether pituitary suppression before induction of ovulation reduces the rate of spontaneous abortion in women with polycystic ovarian disease and primary recurrent spontaneous abortions. DESIGN--Closed, randomised, sequential trial. Pairs of women were allocated to each treatment by the toss of a coin. SETTING--Supraregional clinic for women who had had recurrent spontaneous abortions. SUBJECTS--Forty two women with polycystic ovarian disease and primary recurrent spontaneous abortions. INTERVENTIONS--Ovulation was induced by clomiphene or pituitary suppression with buserelin followed by pure follicle stimulating hormone. MAIN OUTCOME MEASURES--Preference for a particular treatment was noted. A preference occurred when one woman in a pair had a successful pregnancy (defined as one of over 12 weeks' gestation) and one had a spontaneous abortion; the preference was for the treatment resulting in the successful pregnancy. RESULTS--Spontaneous abortions occurred in 11 of 20 women given clomiphene compared with two of 20 who had pituitary suppression. Eleven preferences were found for buserelin and two for clomiphene. In seven pairs both women had successful pregnancies. One pair was discarded because one of the women did not become pregnant. The ratio of luteinising hormone concentration to follicular diameter was found to be a possible diagnostic indicator of spontaneous abortion. CONCLUSION--Pituitary suppression before induction of ovulation significantly reduces the risk of spontaneous abortion in women with polycystic ovarian disease and primary recurrent spontaneous abortions.
MicroRNA: a new frontier in kidney and blood pressure research
Authors: Liang Mingyu , Liu Yong , Mladinov Domagoj , Cowley Allen W. , Trivedi Hariprasad , Fang Yi , Xu Xialian , Ding Xiaoqiang , Tian Zhongmin
Published: April 2009

MicroRNA (miRNA) has emerged rapidly as a major new direction in many fields of research including kidney and blood pressure research. A mammalian genome encodes several hundred miRNAs. These miRNAs potentially regulate the expression of thousands of proteins. miRNA expression profiles differ substantially between the kidney and other organs as well as between kidney regions. miRNAs may be functionally important in models of diabetic nephropathy, podocyte development, and polycystic disease. miRNAs may be involved in the regulation of arterial blood pressure, including possible involvement in genetic elements of hypertension. Studies of miRNAs could generate diagnostic biomarkers for kidney disease and new mechanistic insights into the complex regulatory networks underlying kidney disease and hypertension. Further progress in the understanding of miRNA biogenesis and action and technical improvements for target identification and miRNA manipulation will be important for studying miRNAs in renal function and blood pressure regulation.
Aldosterone-induced mesangial cell proliferation is mediated by EGF receptor transactivation
Authors: Huang Songming , Zhang Aihua , Ding Guixia , Chen Ronghua
Published: April 2009

Aldosterone (Aldo) stimulates glomerular mesangial cell (MC) proliferation, in part, through an ERK1/2-dependent pathway. In this study, we examined whether Aldo activation of ERK1/2 in MC is mediated through redox-dependent EGF receptor (EGFR) transactivation, as well as the involvement of other signaling mechanisms in Aldo-induced MC proliferation. Aldo increased human MC proliferation, as determined by [3H]thymidine incorporation and cell counts. This increase in proliferation was blocked by inhibition of the mineralocorticoid receptor (MR). Continuing our observations downstream in the signaling pathway, we examined the ability of Aldo to activate both the Ras/MAPK and the PI3K signaling pathways. Aldo increased Ki-RasA and Ki-RasA:GTP levels, and sequentially phosphorylated c-Raf, MAPK kinase (MEK1/2), and ERK1/2. Ki-RasA small interfering RNA (siRNA), the c-Raf inhibitor GW5074, and the MEK1/2 inhibitor PD98059 reduced Aldo-induced cell proliferation by ∼65%. Aldo also increased phosphorylation of PI3K, Akt, the mammalian target of rapamycin (mTOR), and the 70-kDa ribosomal S6 kinase (p70S6K1). Inhibition of the PI3K pathways by the selective PI3K inhibitor LY 294002, an Akt inhibitor, or the mTOR inhibitor rapamycin reduced cell proliferation by 51%. Combining LY 294002 and PD98059 completely blocked Aldo-induced MC proliferation. Next, we confirmed that Aldo exerts its effect on MAPK and PI3K activation, as well as on cell proliferation, by activating the EGFR. Pretreatment with the EGFR antagonist AG1478 inhibited MC proliferation, as well as the activation of Ras/MAPK and PI3K/Akt, suggesting that Ras/MAPK and PI3K/Akt activation occur downstream of EGFR activation. Finally, we examined the role of reactive oxygen species (ROS) in Aldo-induced transactivation of the EGFR. Aldo-induced ROS were predominantly generated by mitochondria. Pretreatment with the antioxidant N-acetyl-l-cysteine, catalase, SOD, mitochondrial respiratory chain complex I inhibitor rotenone (Rot), NADPH oxidase inhibitor apocynin, and DPI significantly inhibited Aldo-stimulated MC proliferation as well as EGFR transactivation. However, Rot reduced MC proliferation more potently than apocynin and DPI. In conclusion, Aldo stimulated cell proliferation through MR-mediated, redox-sensitive EGFR transactivation, which was dependent on the Ki-RasA/c-Raf/MEK/ERK and PI3K/Akt/mTOR/p70S6K1 signaling pathways in human MCs.
Calculation of the equilibrium pH in a multiple-buffered aqueous solution based on partitioning of proton buffering: a new predictive formula
Authors: Nguyen Minhtri K. , Kao Liyo , Kurtz Ira
Published: April 2009

Upon the addition of protons to an aqueous solution containing multiple buffers, the final H+concentration ([H+]) at equilibrium is determined by the partitioning of added H+among the various buffer components. In the analysis of acid-base chemistry, the Henderson-Hasselbalch equation and the Stewart strong ion formulation can only describe (rather than predict) the equilibrium pH following a proton load since these formulas calculate the equilibrium pH only when the reactant concentrations at equilibrium11 The term “equilibrium” refers to the steady state proton and reactant concentrations when the buffering of excess protons by the various buffers is complete. are already known. In this regard, it is simpler to directly measure the equilibrium pH rather than measure the equilibrium reactant concentrations to calculate the equilibrium pH. As these formulas cannot predict the final equilibrium [H+] following a proton load to a multiple-buffered aqueous solution, we developed a new quantitative approach for predicting the equilibrium [H+] that is based on the preequilibrium22 The term “preequilibrium” refers to the initial proton and reactant concentrations immediately upon addition of protons and before the buffering of excess protons by the various buffers. concentrations of all buffers in an aqueous solution. The mathematical model used to derive our equation is based on proton transfer buffer equilibria without requiring the incorporation of electroneutrality considerations. The model consists of a quartic polynomial equation that is derived based solely on the partitioning of H+among the various buffer components. We tested the accuracy of the model using aqueous solutions with various buffers and measured the equilibrium pH values following the addition of HCl. Our results confirmed the accuracy of our new equation ( r2= 1; measured pH vs. predicted pH), indicating that it quantitatively accounts for the underlying acid-base phenomenology.