bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular-scale investigation of C60/p-sexiphenyl organic heterojunction interface
Authors: Zhong Jian Qiang , Huang Han , Mao Hong Ying , Wang Rui , Zhong Shu , Chen Wei
Published: April 2011

In situ low-temperature scanning tunneling microscopy (LT-STM) and ultraviolet photoelectron spectroscopy (UPS) experiments have been carried out to investigate the interface properties at the C60/p-sexiphenyl (6P) organic–organic heterojunction interface, including the interfacial energy level alignment and the supramolecular packing structures. As revealed by UPS measurements, the vacuum level is almost aligned at the C60/6P interface, suggesting that the interface is dominated by weak intermolecular interactions, such as van der Waals and π–π interactions. In situ LT-STM experiments also indicate the formation of a molecularly sharp C60/6P interface with hexagonally-close-packed C60 layers nucleated atop 6P layer on graphite.
High-performance gate-all-around polycrystalline silicon nanowire with silicon nanocrystals nonvolatile memory
Authors: Hung Min-Feng , Wu Yung-Chun , Tang Zih-Yun
Published: April 2011

Nonvolatile memory (NVM) that is based on gate-all-around (GAA) and polycrystalline silicon (poly-Si) nanowires structure with silicon nanocrystals (NCs) as the storage nodes is demonstrated. The GAA poly-Si–SiO2–Si3N4–SiO2–poly-Si (SONOS) NVMs are also fabricated and compared. The GAA NCs NVMs have a 4.2 V of threshold voltage shift at 18 V for 1 ms, and are faster than the GAA SONOS NVMs do. In reliability studies, this NVM shows superior endurance after 104 program/erase (P/E) cycles, and loses only 14% of its charges lose after ten years at 85 °C.
Heat transfer and friction factor inside elliptic tubes fitted with helical screw-tape inserts
Authors: Moawed M.
Published: April 2011

Experimental investigation of heat transfer and friction factor characteristics of elliptic tubes with different twist ratios (Y) and pitch ratios (S) has been conducted under laminar flow condition. All data are obtained using cold water flowing in the tube side and hot water flowing in the annuli side of the heat exchanger. The experiments covered a range of Reynolds numbers, 5.7×102≤Re≤1.31×103. Heat transfer and friction factor analyses are presented for different conditions of Re, S, and Y. The results indicate that the helical screw element of different Y and S has an effect on the results of heat transfer coefficient and friction factor. The averaged Nusslet number (Nu) increases with an increase in Re and it decreases with an increase in Y and S. For a fixed Reynolds number, the friction factor (f) increases with a decrease in Y and S for the elliptic tubes. The thermal performance factor (η) is introduced to indicate the percentage increase in Nu over the percentage increase in f. The maximum percentage increase in Nu over the percentage increase in f (maximum increase in η) is 19.7% and 42.3% at the values of S and Y equal to 1 and 0.22, respectively. Correlations of the average Nusselt number and friction factor with Re, S, and Y are presented.
Nanostructured three-dimensional thin film silicon solar cells with very high efficiency potential
Authors: Vanecek Milan , Babchenko Oleg , Purkrt Adam , Holovsky Jakub , Neykova Neda , Poruba Ales , Remes Zdenek , Meier Johannes , Kroll Ulrich
Published: April 2011

We report on the experimental realization of amorphous/microcrystalline silicon tandem solar cells (Micromorph) based on our three-dimensional design. An enhancement is reached in the short-circuit current by 40%, with an excellent open-circuit voltage of 1.41V and a fill factor of 72%. We have used nanoholes or microholes dry etched into the ZnO front contact layer. Monte Carlo optical modeling shows that stable efficiency of amorphous silicon p-i-n solar cells in over 12% range is possible. For the Micromorph cells, efficiency over 15% with the thickness of amorphous Si below 200 nm and of microcrystalline Si around 500 nm is possible.
Depletion of the In2O3(001) and (111) surface electron accumulation by an oxygen plasma surface treatment
Authors: Bierwagen Oliver , Speck James S. , Nagata Takahiro , Chikyow Toyohiro , Yamashita Yoshiyuki , Yoshikawa Hideki , Kobayashi Keisuke
Published: April 2011

Using x-ray photoemission spectroscopy (XPS) and current-voltage (I-V) measurements of Hg contacts we show that the surface electron accumulation layer of In2O3 can be removed by an oxygen plasma treatment. For the untreated sample, XPS measured a downward band bending toward the surface and a conduction band peak, and the I-V curve was linear which indicated the presence of a surface accumulation layer. After the treatment an upward bending, the absence of the conduction band peak, and a nonlinear I-V curve indicated the absence of the surface accumulation layer. The sheet resistance of the surface accumulation layer of >45 kΩ was deduced from the increase of the total sheet resistance upon the treatment. The removal of the surface electron accumulation layer opens up the possibility to use Schottky contacts for electrical characterization and device applications of semiconducting In2O3.
Optical anisotropy and photoluminescence polarization in single InAlAs quantum dots
Authors: Ohno S. , Adachi S. , Kaji R. , Muto S. , Sasakura H.
Published: April 2011

We have investigated the optical anisotropy in individual self-assembled quantum dots. The linear polarization analysis of the positive trion photoluminescence reveals the effect of the strain-induced valence band mixing since the positive trion has the spin-paired holes and therefore exchange interaction has no influence. Meanwhile, the neutral exciton indicates the complex polarization states due to both the in-plain asymmetries of the dot shape and the strain distributions. The experimental and theoretical polarization analysis has been performed for tens of InAlAs quantum dots and the correlation between the important parameters was investigated.
Direct determination of flat-band voltage for metal/high κ oxide/semiconductor heterointerfaces by electric-field-induced second-harmonic generation
Authors: Chang C.-L. , Lee W. C. , Chu L. K. , Hong M. , Kwo J. , Chang Y.-M.
Published: April 2011

We have employed electric-field-induced second-harmonic (EFISH) generation to determine the flat-band voltage (VFB) of Cr/ALD-Al2O3/MBE-HfO2/n-Si (001) MOS structure. Due to the phase sensitivity of EFISH signal to the electric field in the space charge region, the VFB of −1.20±0.07 V was determined by analyzing the relative phase change in the EFISH signal as a function of the applied gate voltage. The obtained value is in good agreement with that estimated by the capacitance-voltage measurement. This study demonstrated an all-optical technique to directly determine the flat-band voltage for the high κ oxide/Si heterointerfaces.
Li-doped B2C graphene as potential hydrogen storage medium
Authors: An Hui , Liu Chun-sheng , Zeng Zhi , Fan Chao , Ju Xin
Published: April 2011

Based on first-principles density functional theory, we show that Li-doped B2C graphene can serve as a high-capacity hydrogen storage medium with the gravimetric density of 7.54 wt %. The present results indicate that the strong binding of Li onto the substrate comes from the hybridizations of B 2p and C 2p orbitals with the partial occupancy of Li 2p orbitals. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of H2 molecules and the resulting adsorption energy is in the range of 0.12–0.22 eV/H2. The system reported here is favorable for the reversible hydrogen adsorption/desorption at the room temperature.
Room-temperature spin-dependent tunneling through molecules
Authors: Wang S. , Yue F. J. , Shi J. , Shi Y. J. , Hu A. , Du Y. W. , Wu D.
Published: April 2011

We have fabricated assemblies of molecular junctions comprised of superparamagnetic Fe3O4 nanoparticles self-assembled with alkane molecules of different lengths as the spacer. The electrical resistance increases exponentially over nearly two decades as the molecular length varies from 0.7 to 2.5 nm, indicating that electrons tunnel through the molecules that are chemically bonded with Fe3O4 nanoparticles. Up to ∼21% room-temperature magnetoresistance is observed. Remarkably, the tunneling magnetoresistance ratio stays nearly independent of molecular length, which entails room-temperature spin-conserving transport in organic molecules.
Effect of surface passivation on dopant distribution in Si quantum dots: The case of B and P doping
Authors: Ma Jie , Wei Su-Huai , Neale Nathan R. , Nozik Arthur J.
Published: April 2011

Despite many efforts, the doping behavior in Si quantum dots (QDs) is still not well understood. Theoretical work shows that boron as an acceptor prefers to stay near the surface and phosphorous as a donor may stay close to the center in a perfectly hydrogen passivated QD. However, experiment studies seem suggesting an opposite trend. Using first-principle methods, we show that the discrepancy could be explained by the imperfectness of surface passivation of the QD. We find that, in QDs with hydrogen deficient or oxygen rich surfaces, phosphorous prefers the surface sites and boron may stay inside, consistent with experiment observations.
Phox homology band 4.1/ezrin/radixin/moesin-like proteins function as molecular scaffolds that interact with cargo receptors and Ras GTPases
Authors: Ghai Rajesh , Mobli Mehdi , Norwood Suzanne J. , Bugarcic Andrea , Teasdale Rohan D. , King Glenn F. , Collins Brett M.
Published: April 2011

Following endocytosis, the fates of receptors, channels, and other transmembrane proteins are decided via specific endosomal sorting pathways, including recycling to the cell surface for continued activity. Two distinct phox-homology (PX)-domain-containing proteins, sorting nexin (SNX) 17 and SNX27, are critical regulators of recycling from endosomes to the cell surface. In this study we demonstrate that SNX17, SNX27, and SNX31 all possess a novel 4.1/ezrin/radixin/moesin (FERM)-like domain. SNX17 has been shown to bind to Asn-Pro-Xaa-Tyr (NPxY) sequences in the cytoplasmic tails of cargo such as LDL receptors and the amyloid precursor protein, and we find that both SNX17 and SNX27 display similar affinities for NPxY sorting motifs, suggesting conserved functions in endosomal recycling. Furthermore, we show for the first time that all three proteins are able to bind the Ras GTPase through their FERM-like domains. These interactions place the PX-FERM-like proteins at a hub of endosomal sorting and signaling processes. Studies of the SNX17 PX domain coupled with cellular localization experiments reveal the mechanistic basis for endosomal localization of the PX-FERM-like proteins, and structures of SNX17 and SNX27 determined by small angle X-ray scattering show that they adopt non-self-assembling, modular structures in solution. In summary, this work defines a novel family of proteins that participate in a network of interactions that will impact on both endosomal protein trafficking and compartment specific Ras signaling cascades.
Conserved
Arabidopsis
ECHIDNA protein mediates
trans
–Golgi-network trafficking and cell elongation
Authors: Gendre Delphine , Oh Jaesung , Boutté Yohann , Best Jacob G. , Samuels Lacey , Nilsson Robert , Uemura Tomohiro , Marchant Alan , Bennett Malcolm J. , Grebe Markus , Bhalerao Rishikesh P.
Published: April 2011

Multiple steps of plant growth and development rely on rapid cell elongation during which secretory and endocytic trafficking via the
trans
-Golgi network (TGN) plays a central role. Here, we identify the ECHIDNA (ECH) protein from
Arabidopsis thaliana
as a TGN-localized component crucial for TGN function.
ECH
partially complements loss of budding yeast
TVP23
function and a
Populus ECH
complements the
Arabidopsis ech
mutant, suggesting functional conservation of the genes. Compared with wild-type, the
Arabidopsis ech
mutant exhibits severely perturbed cell elongation as well as defects in TGN structure and function, manifested by the reduced association between Golgi bodies and TGN as well as mislocalization of several TGN-localized proteins including vacuolar H
+
-ATPase subunit a1 (VHA-a1). Strikingly,
ech
is defective in secretory trafficking, whereas endocytosis appears unaffected in the mutant. Some aspects of the
ech
mutant phenotype can be phenocopied by treatment with a specific inhibitor of vacuolar H
+
-ATPases, concanamycin A, indicating that mislocalization of VHA-a1 may account for part of the defects in
ech
. Hence, ECH is an evolutionarily conserved component of the TGN with a central role in TGN structure and function.
Collapse kinetics and chevron plots from simulations of denaturant-dependent folding of globular proteins
Authors: Liu Zhenxing , Reddy Govardhan , O’Brien Edward P. , Thirumalai D.
Published: April 2011

Quantitative description of how proteins fold under experimental conditions remains a challenging problem. Experiments often use urea and guanidinium chloride to study folding whereas the natural variable in simulations is temperature. To bridge the gap, we use the molecular transfer model that combines measured denaturant-dependent transfer free energies for the peptide group and amino acid residues, and a coarse-grained
C

α

-side chain model for polypeptide chains to simulate the folding of src SH
3
domain. Stability of the native state decreases linearly as [
C
] (the concentration of guanidinium chloride) increases with the slope,
m
, that is in excellent agreement with experiments. Remarkably, the calculated folding rate at [
C
] = 0 is only 16-fold larger than the measured value. Most importantly ln 
k
obs
(
k
obs
is the sum of folding and unfolding rates) as a function of [
C
] has the characteristic
V
(chevron) shape. In every folding trajectory, the times for reaching the native state, interactions stabilizing all the substructures, and global collapse coincide. The value of

(
m

f

is the slope of the folding arm of the chevron plot) is identical to the fraction of buried solvent accessible surface area in the structures of the transition state ensemble. In the dominant transition state, which does not vary significantly at low [
C
], the core of the protein and certain loops are structured. Besides solving the long-standing problem of computing the chevron plot, our work lays the foundation for incorporating denaturant effects in a physically transparent manner either in all-atom or coarse-grained simulations.
Sheikhs on barrels: what Saudi Arabians think about energy security
Authors: Bambawale Malavika Jain , Sovacool Benjamin K.
Published: April 2011

The concept of energy security as understood by a sample of Saudi Arabian residents representing different demographic and occupational characteristics is explored. Based on a review of the academic literature concerning energy security for Saudi Arabia, a working set of eight testable hypotheses, related to (1) energy trade, (2) centralization and participation in energy decisions, (3) pricing of energy products, (4) research and development in new energy technologies, (5) security of supply and domestic resource depletion, (6) affordability of energy, (7) energy efficiency, and (8) water availability, is created. These hypotheses are then compared with the results of a survey instrument completed by 298 Saudi respondents, before the article concludes with implications for policy-makers and energy analysts.
SUMO modification of cell surface Kv2.1 potassium channels regulates the activity of rat hippocampal neurons
Authors: Plant Leigh D. , Dowdell Evan J. , Dementieva Irina S. , Marks Jeremy D. , Goldstein Steve A.N.
Published: April 2011

Voltage-gated Kv2.1 potassium channels are important in the brain for determining activity-dependent excitability. Small ubiquitin-like modifier proteins (SUMOs) regulate function through reversible, enzyme-mediated conjugation to target lysine(s). Here, sumoylation of Kv2.1 in hippocampal neurons is shown to regulate firing by shifting the half-maximal activation voltage (V1/2) of channels up to 35 mV. Native SUMO and Kv2.1 are shown to interact within and outside channel clusters at the neuronal surface. Studies of single, heterologously expressed Kv2.1 channels show that only K470 is sumoylated. The channels have four subunits, but no more than two non-adjacent subunits carry SUMO concurrently. SUMO on one site shifts V1/2 by 15 mV, whereas sumoylation of two sites produces a full response. Thus, the SUMO pathway regulates neuronal excitability via Kv2.1 in a direct and graded manner.
Dynamic Epidemic Model for Influenza with Clinical Complications
Authors: Wang Sen-Te , Chen Li-Sheng , Lee Long-Teng , Chen Hsiu-Hsi
Published: April 2011

Objective.

To incorporate clinical complications in the susceptible-infectious-recovered model to estimate parameters needed in dynamic changes of infectious diseases and to further evaluate the impact of disease-controlling methods.

Methods.

We developed a new extended epidemic model that incorporates of disease-related complications. This model was applied to empirical data on influenza during the epidemic season of 2001–2002 in Taipei County, Taiwan, to estimate the transmission parameters that were converted to the basic reproductive rate (R0). The proposed model, in conjunction with estimated parameters, was applied in quantifying the efficacy of different preventive strategies.

Results.

During the study period there were 5 outbreaks of influenza. The estimated transmission probability for outbreak 1 was 0.135, with corresponding estimate of R0, 2.7; for outbreak 2, 0.165, with estimated R0, 3.3; for outbreak 3, 0.15, with R0, 4.5; for outbreak 4, 0.165, with R0, 5; and for outbreak 5, 0.165, with R0 5. The efficacy of antiviral prophylaxis to reduce the total episodes was 18% (95% CI, 15%–21%) under the coverage rate of 30%, 31% (95% CI, 26%–36%) under the coverage rate of 50%, and 73% (95% CI, 59%–90%) under the coverage rate of 80%. The corresponding figures for the efficacy of vaccination were 17% (95% CI, 15%–20%), 41% (95% CI, 35%–48%), and 76% (95% CI, 61%–95%). Combination of both methods would yield efficacy of 32% (95% CI, 28%–38%), 59% (95% CI, 49%–71%), and 88% (95% CI, 66%–118%), respectively.

Conclusions.

We demonstrate how to apply a novel extended model to empirical surveillance data of an influenza study for estimating parameters pertaining to dynamic changes in the infection process. These parameters were further used to evaluate the impact of antiviral prophylaxis alone, vaccination alone, or the use of both methods.
Patient-Care Practices Associated with an Increased Prevalence of Hepatitis C Virus Infection among Chronic Hemodialysis Patients
Authors: Shimokura Gayle , Chai Feng , Weber David J. , Samsa Gregory P. , Xia Guo-liang , Nainan Omana V. , Tobler Leslie H. , Busch Michael P. , Alter Miriam J.
Published: April 2011

Objective.

To identify patient-care practices related to an increased prevalence of hepatitis C virus (HCV) infection among chronic hemodialysis patients.

Design.

Survey.

Setting.

Chronic hemodialysis facilities in the United States.

Participants.

Equal-probability 2-stage cluster sampling was used to select 87 facilities from all Medicare-approved providers treating 30–150 patients; 53 facilities and 2,933 of 3,680 eligible patients agreed to participate.

Methods.

Patients were tested for HCV antibody and HCV RNA. Data on patient-care practices were collected using direct observation.

Results.

The overall prevalence of HCV infection was 9.9% (95% confidence interval [CI], 8.2%–11.6%); only 2 of 294 HCV-positive patients were detected solely by HCV RNA testing. After adjusting for non-dialysis-related HCV risk factors, patient-care practices independently associated with a higher prevalence of HCV infection included reusing priming receptacles without disinfection (odds ratio [OR], 2.3 [95% CI, 1.4–3.9]), handling blood specimens adjacent to medications and clean supplies (OR, 2.2 [95% CI, 1.3–3.6]), and using mobile carts to deliver injectable medications (OR, 1.7 [95% CI, 1.0–2.8]). Independently related facility covariates were at least 10% patient HCV infection prevalence (OR, 3.0 [95% CI, 1.8–5.2]), patient-to-staff ratio of at least 7: 1 (OR, 2.4 [95% CI, 1.4–4.1]), and treatment duration of at least 2 years (OR, 2.4 [95% CI, 1.3–4.4]).

Conclusions.

This study provides the first epidemiologic evidence of associations between specific patient-care practices and higher HCV infection prevalence among hemodialysis patients. Staff should review practices to ensure that hemodialysis-specific infection control practices are being implemented, especially handling clean and contaminated items in separate areas, reusing items only if disinfected, and prohibiting mobile medication and clean supply carts within treatment areas.
Deriving Measures of Intensive Care Unit Antimicrobial Use from Computerized Pharmacy Data: Methods, Validation, and Overcoming Barriers
Authors: Schwartz David N. , Evans R. Scott , Camins Bernard C. , Khan Yosef M. , Lloyd James F. , Shehab Nadine , Stevenson Kurt ,   Centers for Disease Control and Prevention Epicenter Program
Published: April 2011

Objective.

To outline methods for deriving and validating intensive care unit (ICU) antimicrobial utilization (AU) measures from computerized data and to describe programming problems that emerged.

Design.

Retrospective evaluation of computerized pharmacy and administrative data.

Setting.

ICUs from 4 academic medical centers over 36 months.

Interventions.

Investigators separately developed and validated programming code to report AU measures in selected ICUs. Use of antibacterial and antifungal drugs for systemic administration was categorized and expressed as antimicrobial-days (each day that each antimicrobial drug was given to each patient) and patient-days receiving antimicrobials (each day that any antimicrobial drug was given to each patient). Monthly rates were compiled and analyzed centrally, with ICU patient-days as the denominator. Results were validated against data collected from manual review of medical records. Frequent discussion among investigators aided identification and correction of programming problems.

Results.

AU data were successfully programmed though a reiterative process of computer code revision. After identifying and resolving major programming errors, comparison of computerized patient-level data with data collected by manual review of medical records revealed discrepancies in antimicrobial-days and patient-days receiving antimicrobials that ranged from less than 1% to 17.7%. The hospital from which numerator data were derived from electronic records of medication administration had the least discrepant results.

Conclusions.

Computerized AU measures can be derived feasibly, but threats to validity must be sought out and corrected. The magnitude of discrepancies between computerized AU data and a gold standard based on manual review of medical records varies, with electronic records of medication administration providing maximal accuracy.
Predictors of Rectal Carriage of Carbapenem-Resistant Enterobacteriaceae (CRE) among Patients with Known CRE Carriage at Their Next Hospital Encounter
Authors: Schechner Vered , Kotlovsky Tali , Tarabeia Jalal , Kazma Meital , Schwartz David , Navon-Venezia Shiri , Carmeli Yehuda
Published: April 2011

Background.

Carbapenem-resistant Enterobacteriaceae (CRE) are important extremely drug-resistant pathogens that have emerged during the past decade. Early identification and isolation of carriers are key components of an effective infection control strategy in healthcare facilities. Very little is known about the natural history of CRE carriage. We aimed to determine the predictors of a positive CRE rectal screen test among patients with known CRE carriage screened at their next hospital encounter.

Methods.

A case-control study was conducted. Sixty-six patients who tested positive for CRE carriage were surveyed for CRE rectal carriage at the next hospital encounter; screen-positive patients were compared with screen-negative control patients. Data were extracted from the patients' medical records and from the hospital computerized database.

Results.

Twenty-three case patients and 43 control patients were identified. Predictors for a positive CRE rectal carriage test were (1) prior fluoroquinolone use (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.10–16.6), (2) admission from an institution or another hospital (OR, 4.04; 95% CI, 1.33–12.37), and (3) time interval less than or equal to 3 months since the first positive CRE test (OR, 3.59; 95% CI, 1.24–10.37). Among patients with no predictor variables, the likelihood of having a positive screen test at the next hospital encounter was 1/7. If they had at least 1 predictor, the likelihood increased to 1/2.

Conclusions.

Prior fluoroquinolone use, transfer from another healthcare facility, and admission less than or equal to 3 months since the first CRE isolation are predictors of persistent CRE rectal carriage. These predictors can be used in designing CRE prevention strategies.
PONDEROSA, an automated 3D-NOESY peak picking program, enables automated protein structure determination
Authors: Lee Woonghee , Kim Jin Hae , Westler William M. , Markley John L.
Published: April 2011

Summary: PONDEROSA (Peak-picking Of Noe Data Enabled by Restriction of Shift Assignments) accepts input information consisting of a protein sequence, backbone and sidechain NMR resonance assignments, and 3D-NOESY (13C-edited and/or 15N-edited) spectra, and returns assignments of NOESY crosspeaks, distance and angle constraints, and a reliable NMR structure represented by a family of conformers. PONDEROSA incorporates and integrates external software packages (TALOS+, STRIDE and CYANA) to carry out different steps in the structure determination. PONDEROSA implements internal functions that identify and validate NOESY peak assignments and assess the quality of the calculated three-dimensional structure of the protein. The robustness of the analysis results from PONDEROSA's hierarchical processing steps that involve iterative interaction among the internal and external modules. PONDEROSA supports a variety of input formats: SPARKY assignment table (.shifts) and spectrum file formats (.ucsf), XEASY proton file format (.prot), and NMR-STAR format (.star). To demonstrate the utility of PONDEROSA, we used the package to determine 3D structures of two proteins: human ubiquitin and Escherichia coli iron-sulfur scaffold protein variant IscU(D39A). The automatically generated structural constraints and ensembles of conformers were as good as or better than those determined previously by much less automated means.

Availability: The program, in the form of binary code along with tutorials and reference manuals, is available at http://ponderosa.nmrfam.wisc.edu/.

Contact:  whlee@nmrfam.wisc.edu; markley@nmrfam.wisc.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Characterization of DRA0282 from Deinococcus radiodurans for its role in bacterial resistance to DNA damage
Authors: Das Anubrata D. , Misra Hari S.
Published: April 2011

DRA0282, a hypothetical protein, was found in a pool of nucleotide-binding proteins inDeinococcus radioduranscells recovering from gamma radiation stress. This pool exhibited an unusual inhibition of nuclease activity by ATP. The N terminus of DRA0282 showed similarity to human Ku80 homologues, while the C terminus showed no similarities to known proteins. The recombinant protein required Mn2+for its interaction with DNA and protected dsDNA from exonuclease III degradation. The binding of the protein to supercoiled DNA with aKdof ~2.93 nM was nearly 20-fold stronger than its binding to ssDNA and nearly 67-fold stronger than its binding to linear dsDNA.Escherichia colicells expressing DRA0282 showed a RecA-dependent enhancement of UV and gamma radiation tolerance. The ΔdrA0282mutant ofD. radioduransshowed a dose-dependent response to gamma radiation. At 14 kGy, the ΔdrA0282mutant showed nearly 10-fold less survival, while at this dose bothpprA : : catΔdrA0282andpprA : : catmutants were nearly 100-fold more sensitive than the wild-type. These results suggested that DRA0282 is a DNA-binding protein with a preference for superhelical DNA, and that it plays a role in bacterial resistance to DNA damage through a pathway in which PprA perhaps plays a dominant role inD. radiodurans.
Different compartments of apical CA1 dendrites have different plasticity thresholds for expressing synaptic tagging and capture
Authors: Sajikumar Sreedharan , Korte Martin
Published: April 2011

The consolidation process from short- to long-term memory depends on the type of stimulation received from a specific neuronal network and on the cooperativity and associativity between different synaptic inputs converging onto a specific neuron. We show here that the plasticity thresholds for inducing LTP are different in proximal and distal compartments of apical dendrites. In addition, we show interactions between the proximal and distal compartments of the apical dendrites by providing evidence that even a subthreshold stimulus can activate plasticity-related proteins, such as PKMζ, enabling associativity between two distinct dendritic compartments in apical dendrites to occur.
A genetic variation in APE1 is associated with gastric cancer survival in a Chinese population
Authors: Zhao Qinghong , Wang Wei , Zhang Zhengdong , Wang Shizhi , Wang Meilin , Zhou Jianwei , Gong Weida , Tan Yongfei , Wang Baolin , Chen Guoyu
Published: April 2011

Altered DNA repair can be associated with aggressive tumor biology and impact on survival of cancer patients. We investigated whether genetic variation of human apurinic/apyrimidinic (AP) endonuclease, a key multifunctional gene involved in the base excision repair pathway, would play a role in gastric cancer survival outcomes. We genotyped APE1 rs1760944 by the TaqMan method in 925 gastric cancer patients. Analyses of association between the polymorphism and survival outcomes were carried out using the Kaplan–Meier method, Cox proportional hazards models, and the log–rank test. Survival analyses for all patients showed that the differences in median survival time between gastric cancer carriers with APE1 rs1760944 TT (55 months) and those with GT/GG (78 months), were statistically significant (P = 0.025, log–rank test). Kaplan–Meier survival estimates revealed that gastric cancer patients carrying the GT/GG genotypes had a higher survival than TT, and this protective effect was also more pronounced among subgroups with tumor size >5 cm (hazard ratio = 0.66, 95% confidence interval = 0.49–0.88), diffuse‐type gastric cancer (0.76, 0.60–0.97), T3 depth of invasion (0.73, 0.57–0.93), lymph node metastasis (0.73, 0.58–0.92), no distant metastasis (0.81, 0.66–0.99), and TNM stage III and IV (0.75, 0.58–0.99 for stage III; 0.50, 0.29–0.88 for stage IV). Our results showed that the genetic variant rs1760944 in APE1 was associated with gastric cancer survival in a Chinese population. Larger studies are needed to verify our findings in different populations. (Cancer Sci 2011; 102: 1293–1297)
Intensive expression of UNC‐51‐like kinase 1 is a novel biomarker of poor prognosis in patients with esophageal squamous cell carcinoma
Authors: Jiang Shan , Li Yong , Zhu Ying‐Hui , Wu Xiao‐Qi , Tang Jun , Li Zheng , Feng Gong‐Kan , Deng Rong , Li Dan‐Dan , Luo Rong‐Zhen , Zhang Mei‐Fang , Qin Wei , Wang Xin , Jia Wei‐Hua , Zhu Xiao‐Feng
Published: April 2011

The serine/threonine kinase UNC‐51‐like kinase 1 (ULK1) plays an essential role in autophagosome formation, although the exact molecular mechanism is unknown. The present study was first to investigate the clinical and prognostic significance of ULK1 in esophageal squamous cell carcinoma (ESCC). Protein and mRNA levels of ULK1 in normal esophageal epithelial cells, ESCC cell lines, paired ESCC lesions and the adjacent noncancerous tissues were examined using western blot and real‐time RT‐PCR. The results showed that only the ULK1 protein level was upregulated in ESCC samples compared with normal esophageal cells and tissues. Also, we found that protein stabilization of ULK1 was higher in ESCC cell lines. Furthermore, immunohistochemical staining of ULK1 was performed on the tissue microarray containing 248 ESCC and 51 normal esophageal tissues. A total of 70.2% ESCC specimens showed intensive expression of ULK1 in contrast to the undetectable expression of ULK1 in normal esophageal tissues. Statistical analysis revealed that ULK1 expression was significantly correlated with T status (P = 0.048). Moreover, patients with higher ULK1 expression were associated with shorter overall survival time. Multivariate analysis suggested that ULK1 expression and N status (P < 0.001) were independent prognostic indicators for the survival of patients. Functional studies showed that suppression of ULK1 expression in ESCC cell lines by specific small interfering RNA resulted in inhibition of cell proliferation and induction of apoptosis under starvation conditions. These findings provide evidence that ULK1 represents a novel and clinically useful biomarker for ESCC patients and plays an important role during the progression of ESCC. (Cancer Sci 2011; 102: 1568–1575)
Reaching out towards cannabis: approach‐bias in heavy cannabis users predicts changes in cannabis use
Authors: Cousijn Janna , Goudriaan Anna E. , Wiers Reinout W.
Published: April 2011

Aims  Repeated drug exposure can lead to an approach‐bias, i.e. the relatively automatically triggered tendencies to approach rather that avoid drug‐related stimuli. Our main aim was to study this approach‐bias in heavy cannabis users with the newly developed cannabis Approach Avoidance Task (cannabis‐AAT) and to investigate the predictive relationship between an approach‐bias for cannabis‐related materials and levels of cannabis use, craving, and the course of cannabis use.

Design, settings and participants  Cross‐sectional assessment and six‐month follow‐up in 32 heavy cannabis users and 39 non‐using controls.

Measurements  Approach and avoidance action‐tendencies towards cannabis and neutral images were assessed with the cannabis AAT. During the AAT, participants pulled or pushed a joystick in response to image orientation. To generate additional sense of approach or avoidance, pulling the joystick increased picture size while pushing decreased it. Craving was measured pre‐ and post‐test with the multi‐factorial Marijuana Craving Questionnaire (MCQ). Cannabis use frequencies and levels of dependence were measured at baseline and after a six‐month follow‐up.

Findings  Heavy cannabis users demonstrated an approach‐bias for cannabis images, as compared to controls. The approach‐bias predicted changes in cannabis use at six‐month follow‐up. The pre‐test MCQ emotionality and expectancy factor were associated negatively with the approach‐bias. No effects were found on levels of cannabis dependence.

Conclusions  Heavy cannabis users with a strong approach‐bias for cannabis are more likely to increase their cannabis use. This approach‐bias could be used as a predictor of the course of cannabis use to identify individuals at risk from increasing cannabis use.
Low-dose 5-fluorouracil in combination with salicylic acid as a new lesion-directed option to treat topically actinic keratoses: histological and clinical study results
Authors: Stockfleth E. , Kerl H. , Zwingers T. , Willers C.
Published: April 2011

Background Actinic keratoses (AKs) arise after chronic sun exposure. Because long-term ultraviolet (UV) damage may induce proliferation of atypical keratinocytes, treatment of AKs is recommended.

Objectives To compare 5-fluorouracil 0·5%/salicylic acid 10·0% [low-dose 5-FU/SA (Actikerall®)] with diclofenac 3% in hyaluronic acid (diclofenac HA) and vehicle for the treatment of AKs.

Methods This was a randomized, placebo-controlled, double-blind, parallel-group, multicentre trial. Patients received topical low-dose 5-FU/SA once daily, its vehicle or diclofenac HA twice daily for a maximum of 12 weeks. The final evaluation was at week 20. The primary objectives were to demonstrate the histological clearance rate of one predefined lesion. The secondary objectives were the improvement of treated lesions, tolerability and safety.

Results There were 470 patients with 4–10 AK lesions each (grade I or II) on the face/forehead or bald scalp included in the study. Low-dose 5-FU/SA was superior to diclofenac HA (P <0·01) and vehicle (P <0·0001) for histological clearance of one representative lesion 8 weeks post-treatment. In 72·0%, 59·1% and 44·8% of patients in the low-dose 5-FU/SA, diclofenac HA and vehicle groups, respectively, the week-20 biopsy revealed no AKs. Significantly more lesions were cleared with low-dose 5-FU/SA (74·5%) compared with diclofenac HA (54·6%; P <0·001) or vehicle (35·5%; P <0·001). Low-dose 5-FU/SA was superior in terms of complete clinical clearance: 55·4%, vs. diclofenac HA (32·0%, P <0·001) and vehicle (15·1%P <0·001). Application-site disorders (mainly burning and inflammation) were more frequent with low-dose 5-FU/SA but mainly of mild to moderate intensity.

Conclusions Topical low-dose 5-FU/SA demonstrated higher histological and clinical clearance rates vs. diclofenac HA or vehicle. Low-dose 5-FU/SA is an effective lesion-directed treatment for AKs.
Inducing apoptosis in chemotherapy‐resistant B‐lineage acute lymphoblastic leukaemia cells by targeting HSPA5, a master regulator of the anti‐apoptotic unfolded protein response signalling network
Authors: Uckun Fatih M. , Qazi Sanjive , Ozer Zahide , Garner Amanda L. , Pitt Jason , Ma Hong , Janda Kim D.
Published: April 2011

We present previously unknown evidence that the immunoglobulin heavy chain binding protein BIP/HSPA5, also known as glucose regulated protein (GRP)78, serving as a pivotal component of the pro‐survival axis of the unfolded protein response (UPR) signalling network, is abundantly expressed in relapsed B‐lineage acute lymphoblastic leukaemia (ALL) and contributes to chemotherapy resistance of leukaemic B‐cell precursors. The resistance of B‐lineage ALL cells to the standard anti‐leukaemic drug vincristine was overcome by the HSPA5 inhibitor epigallocatechin gallate, which inhibits the anti‐apoptotic function of HSPA5 by targeting its ATP‐binding domain. Notably, chemotherapy‐resistant B‐lineage ALL cells underwent apoptosis within 48 h of exposure to a doxorubicin‐conjugated cell‐penetrating cyclic anti‐HSPA5 peptide targeting surface‐expressed HSPA5 molecules on leukaemia cells. The identification of the HSPA5 as a chemoresistance biomarker and molecular target for B‐lineage ALL may lead to new anti‐leukaemic treatment strategies that are much needed.
Evaluation of two new recombinant guinea‐pig lipocalins, Cav p 2 and Cav p 3, in the diagnosis of guinea‐pig allergy
Authors: Hilger C. , Swiontek K. , Kler S. , Diederich C. , Lehners C. , Vogel L. , Vieths S. , Hentges F.
Published: April 2011

Cite this as: C. Hilger, K. Swiontek, S. Kler, C. Diederich, C. Lehners, L. Vogel, S. Vieths and F. Hentges, Clinical & Experimental Allergy, 2011 (41) 899–908.

Background
Guinea‐pigs, classical laboratory animals now often kept as pets, regularly elicit important allergic reactions. Two guinea‐pig allergens have been described previously to some extent; however, biomolecular and immunological data are lacking.

Objective
To identify major guinea‐pig allergens, produce them as recombinant proteins and define their allergenic potential and clinical importance in allergic patients.

Methods
Protein extracts were prepared from various guinea‐pig tissues and allergens were purified by ion exchange chromatography. The N‐termini of two immunoglobulin E (IgE)‐reactive proteins were determined and degenerate primers were designed for cDNA amplification by RT‐PCR. Allergenic properties of recombinant proteins were assayed by immunoblotting, ELISA and mediator release assays. Specific IgE were quantified in the sera of 26 guinea‐pig‐allergic patients.

Results
Major IgE‐reactive proteins were detected in submaxillary and harderian gland extracts. Two proteins were identified and the cDNAs were cloned. The 17 kDa protein expressed in the harderian gland corresponds to the previously described Cav p 2. The 19 kDa protein, Cav p 3, is a new allergen expressed in the submaxillary gland. Recombinant Cav p 2 and Cav p 3 were recognized by IgE antibodies from 65% and 54% of guinea‐pig‐allergic patients, respectively. Both proteins demonstrated equivalent allergenic activity in the mediator release assays.

Conclusion and Clinical Relevance
Two major guinea‐pig allergens, Cav p 2 and Cav p 3, have been characterized and produced as recombinant proteins. Combined to guinea‐pig serum albumin, the new allergens proved to be valuable in the component‐resolved diagnosis of guinea‐pig allergy.
Specific immunotherapy in children
Authors: Bufe A. , Roberts G.
Published: April 2011

Subcutaneous immunotherapy (SCIT) with allergen extracts in children with allergic rhinitis, with or without co‐seasonal asthma, has developed into a routine treatment although the scientific evidence for its efficacy is not as strong as for adults. In the hands of experienced allergists, this treatment has been proven to be safe. The development of allergen tablets for sublingual immunotherapy (SLIT) may open a new age of more convenient, safer SIT. In children, in particular, the evidence for the long‐term efficacy of SLIT, its ability to prevent the development of asthma and polysensitization and its comparability to SCIT will be required before it will replace the traditional subcutaneous route. Issues of compliance represent an important drawback of SLIT. We need ways of improving this. Treatment of asthma by immunotherapy is still restricted to clearly defined patients with mild to moderate asthma with symptoms that are related to the specific allergen sensitization. In these patients, symptoms and use of anti‐inflammatory therapy can be reduced by SIT.

Cite this as: A. Bufe and G. Roberts, Clinical & Experimental Allergy, 2011 (41) 1256–1262.
The utilization of knowledge of and interest in research and development among primary care staff by means of strategic communication – a staff cohort study
Authors: Morténius Helena , Marklund Bertil , Palm Lars , Fridlund Bengt , Baigi Amir
Published: April 2011

Objective  The obvious gap between evidence and practice in health care is unfavourable for patient care and requires the promotion of a scientific attitude among health care professionals. The aim of the present study was to determine the utilization of knowledge of and interest in research and development among primary care staff by means of a strategic communication process.

Method  A cohort consisting of primary care staff (n = 1276) was designed and strategic communication was utilized as a platform over a 7‐year period. Quantitative and qualitative methods were taken in account.

Results  We found that 97% of the staff had gained knowledge of research and development, 60% of whom remained interested in the subject. The oral communication channel was the most powerful for creating research interest. Organizational culture was a barrier to interest in science.

Conclusion  The study demonstrates a significant increase in knowledge and interest among primary care staff as a result of a strategic communication process.

Practice implications  Strategic communication should lead to a more evenly distributed research commitment among all health care professionals, thus facilitating communication between them and patients in order to clarify, for example, the causes of disease.
Leptin is not the Critical Signal for Kisspeptin or Luteinising Hormone Restoration During Exit from Negative Energy Balance
Authors: True C. , Kirigiti M. A. , Kievit P. , Grove K. L. , Smith M. S.
Published: April 2011

Low levels of the adipocyte hormone leptin are considered to be the key signal contributing to inhibited gonadotrophin‐releasing hormone (GnRH) release and reproductive acyclicity during negative energy balance. Hypoleptinaemia‐induced inhibition of GnRH may be initiated with upstream inhibition of the secretagogue kisspeptin (Kiss1) because GnRH neurones do not express leptin receptors. The present study aimed to determine whether eliminating the hypoleptinaemia associated with caloric restriction (CR), by restoring leptin to normal basal levels, could reverse the suppression of the reproductive neuroendocrine axis. Fifty percent CR resulted in significant suppression of anteroventral periventricular Kiss1 mRNA, arcuate nucleus (ARH) Kiss1 and neurokinin B (NKB) mRNA levels and serum luteinising hormone (LH). Restoring leptin to normal basal levels did not restore Kiss1 or NKB mRNA or LH levels. Surprisingly, leptin did not activate expression of phosphorylated signal‐transducer and activator of transcription‐3 in ARC Kiss1 neurones, indicating that these neurones may not relay leptin signalling to GnRH neurones. Previous work in fasting models showing restoration of LH used a pharmacological dose of leptin. Therefore, in a 48‐h fast study, replacement of leptin to pharmacological levels was compared with replacement of leptin to normal basal levels. Maintaining leptin at normal basal levels during the fast did not prevent inhibition of LH. By contrast, pharmacological levels of leptin did maintain LH at control values. These results suggest that, although leptin may be a permissive signal for reproductive function, hypoleptinaemia is unlikely to be the critical signal responsible for ARC Kiss1 and LH inhibition during negative energy balance.
Psychometric properties of the Turkish version of the Perception of Aggression Scale
Authors: BILGIN H. , TULEK Z. , OZCAN N.
Published: April 2011

Accessible summary

There is a distinct lack of studies that explore the perceptions of aggressive behaviour in health care at the national and international levels.

There is also a lack of tools to evaluate the perceptions of aggression in the Turkish language.

This study examines psychometric validation of the Perception of Aggression Scale to gain an insight into aggression in different cultures.

The aim of this study was to investigate the psychometric properties of the Turkish version of the Perception of Aggression Scale. Cross‐sectional data were collected by the completion of questionnaires by 350 nursing students from two nursing schools in Istanbul, Turkey. The psychometric properties of the Turkish version of the scale were analysed by using factor analysis (principal component analysis), assessment of internal consistency and reliability, and Spearman's rank correlation coefficients. The two‐factor structure was confirmed by principal component analysis: the first factor treated aggression as functional and the second as dysfunctional. The correlation between the means of the items and dimensions was moderate (r for factor 1: 0.47–0.73; r for factor 2: 0.29–0.70). The coefficient of internal consistency of the scale was 0.85 for factor 1 and 0.81 for factor 2. Thus, Turkish version of Perception of Aggression Scale is a valid and reliable tool. It is essential to understand perceptions of aggressive behaviour in order to establish effective management strategies to tackle untoward events in clinical settings.