bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Basis for the Inhibition of the Chromatin Repressor BAHD1 by the Bacterial Nucleomodulin LntA
Authors: Lebreton Alice , Job Viviana , Ragon Marie , Le Monnier Alban , Dessen Andréa , Cossart Pascale , Bierne Hélène
Published: January 2014

The nucleus has emerged as a key target for nucleomodulins, a family of effectors produced by bacterial pathogens to control host transcription or other nuclear processes. The virulence factor LntA from
Listeria monocytogenes
stimulates interferon responses during infection by inhibiting BAHD1, a nuclear protein involved in gene silencing by promoting heterochromatin formation. So far, whether the interaction between LntA and BAHD1 is direct and sufficient for inhibiting BAHD1 activity is unknown. Here, we functionally characterized the molecular interface between the two proteins
in vitro
and in transfected or infected human cells. Based on the known tridimensional structure of LntA, we identified a dilysine motif (K180/K181) in the elbow region of LntA and a central proline-rich region in BAHD1 as crucial for the direct LntA-BAHD1 interaction. To better understand the role played by the dilysine motif in the functionality of LntA, we solved the crystal structure of a K180D/K181D mutant to a 2.2-Å resolution. This mutant highlights a drastic redistribution of surface charges in the vicinity of a groove, which likely plays a role in nucleomodulin target recognition. Mutation of the strategic dilysine motif also abolished the recruitment of LntA to BAHD1-associated nuclear foci and impaired the LntA-mediated stimulation of interferon responses upon infection. Last, the strict conservation of residues K180 and K181 in LntA sequences from 188
L. monocytogenes
strains of different serotypes and origins further supports their functional importance. Together, these results provide structural and functional details about the mechanism of inhibition of an epigenetic factor by a bacterial nucleomodulin.

IMPORTANCE
Pathogens have evolved various strategies to deregulate the expression of host defense genes during infection, such as targeting nuclear proteins. LntA, a secreted virulence factor from the bacterium
Listeria monocytogenes
, stimulates innate immune responses by inhibiting a chromatin-associated repressor, BAHD1. This study reveals the structural features of LntA required for BAHD1 inhibition. LntA interacts directly with a central domain of BAHD1 via a surface patch of conserved positive charges, located nearby a groove on the elbow region of LntA. By demonstrating that this patch is required for LntA function, we provide a better understanding of the molecular mechanism allowing a bacterial pathogen to control host chromatin compaction and gene expression.
Systemic Spread and Propagation of a Plant-Pathogenic Virus in European Honeybees, Apis mellifera
Authors: Li Ji Lian , Cornman R. Scott , Evans Jay D. , Pettis Jeffery S. , Zhao Yan , Murphy Charles , Peng Wen Jun , Wu Jie , Hamilton Michele , Boncristiani Humberto F. , Zhou Liang , Hammond John , Chen Yan Ping
Published: January 2014

Emerging and reemerging diseases that result from pathogen host shifts are a threat to the health of humans and their domesticates. RNA viruses have extremely high mutation rates and thus represent a significant source of these infectious diseases. In the present study, we showed that a plant-pathogenic RNA virus, tobacco ringspot virus (TRSV), could replicate and produce virions in honeybees,Apis mellifera, resulting in infections that were found throughout the entire body. Additionally, we showed that TRSV-infected individuals were continually present in some monitored colonies. While intracellular life cycle, species-level genetic variation, and pathogenesis of the virus in honeybee hosts remain to be determined, the increasing prevalence of TRSV in conjunction with other bee viruses from spring toward winter in infected colonies was associated with gradual decline of host populations and winter colony collapse, suggesting the negative impact of the virus on colony survival. Furthermore, we showed that TRSV was also found in ectoparasiticVarroamites that feed on bee hemolymph, but in those instances the virus was restricted to the gastric cecum ofVarroamites, suggesting thatVarroamites may facilitate the spread of TRSV in bees but do not experience systemic invasion. Finally, our phylogenetic analysis revealed that TRSV isolates from bees, bee pollen, andVarroamites clustered together, forming a monophyletic clade. The tree topology indicated that the TRSVs from arthropod hosts shared a common ancestor with those from plant hosts and subsequently evolved as a distinct lineage after transkingdom host alteration. This study represents a unique example of viruses with host ranges spanning both the plant and animal kingdoms.

IMPORTANCEPathogen host shifts represent a major source of new infectious diseases. Here we provide evidence that a pollen-borne plant virus, tobacco ringspot virus (TRSV), also replicates in honeybees and that the virus systemically invades and replicates in different body parts. In addition, the virus was detected inside the body of parasiticVarroamites, which consume bee hemolymph, suggesting thatVarroamites may play a role in facilitating the spread of the virus in bee colonies. This study represents the first evidence that honeybees exposed to virus-contaminated pollen could also be infected and raises awareness of potential risks of new viral disease emergence due to host shift events. About 5% of known plant viruses are pollen transmitted, and these are potential sources of future host-jumping viruses. The findings from this study showcase the need for increased surveillance for potential host-jumping events as an integrated part of insect pollinator management programs.
New Insights into Dissemination and Variation of the Health Care-Associated Pathogen Acinetobacter baumannii from Genomic Analysis
Authors: Wright Meredith S. , Haft Daniel H. , Harkins Derek M. , Perez Federico , Hujer Kristine M. , Bajaksouzian Saralee , Benard Michael F. , Jacobs Michael R. , Bonomo Robert A. , Adams Mark D.
Published: January 2014

Acinetobacter baumannii
is a globally important nosocomial pathogen characterized by an increasing incidence of multidrug resistance. Routes of dissemination and gene flow among health care facilities are poorly resolved and are important for understanding the epidemiology of
A. baumannii
, minimizing disease transmission, and improving patient outcomes. We used whole-genome sequencing to assess diversity and genome dynamics in 49 isolates from one United States hospital system during one year from 2007 to 2008. Core single-nucleotide-variant-based phylogenetic analysis revealed multiple founder strains and multiple independent strains recovered from the same patient yet was insufficient to fully resolve strain relationships, where gene content and insertion sequence patterns added additional discriminatory power. Gene content comparisons illustrated extensive and redundant antibiotic resistance gene carriage and direct evidence of gene transfer, recombination, gene loss, and mutation. Evidence of barriers to gene flow among hospital components was not found, suggesting complex mixing of strains and a large reservoir of
A. baumannii
strains capable of colonizing patients
.

IMPORTANCE
Genome sequencing was used to characterize multidrug-resistant
Acinetobacter baumannii
strains from one United States hospital system during a 1-year period to better understand how
A. baumannii
strains that cause infection are related to one another. Extensive variation in gene content was found, even among strains that were very closely related phylogenetically and epidemiologically. Several mechanisms contributed to this diversity, including transfer of mobile genetic elements, mobilization of insertion sequences, insertion sequence-mediated deletions, and genome-wide homologous recombination. Variation in gene content, however, lacked clear spatial or temporal patterns, suggesting a diverse pool of circulating strains with considerable interaction between strains and hospital locations. Widespread genetic variation among strains from the same hospital and even the same patient, particularly involving antibiotic resistance genes, reinforces the need for molecular diagnostic testing and genomic analysis to determine resistance profiles, rather than a reliance primarily on strain typing and antimicrobial resistance phenotypes for epidemiological studies.
Twin-Arginine Translocation System in Helicobacter pylori: TatC, but Not TatB, Is Essential for Viability
Authors: Benoit Stéphane L. , Maier Robert J.
Published: January 2014

The twin-arginine translocation (Tat) system, needed to transport folded proteins across biological membranes, has not been characterized in the gastric pathogen
Helicobacter pylori
. Analysis of all
H. pylori
genome sequences available thus far reveals the presence of single copies of
tatA
,
tatB
, and
tatC
needed for the synthesis of a fully functional Tat system. Based on the presence of the twin-arginine hallmark in their signal sequence, only four
H. pylori
proteins appear to be Tat dependent: hydrogenase (HydA), catalase-associated protein (KapA), biotin sulfoxide reductase (BisC), and the ubiquinol cytochrome oxidoreductase Rieske protein (FbcF). In the present study, targeted mutations were aimed at
tatA
,
tatB
,
tatC
, or
queA
(downstream gene control). While double homologous recombination mutations in
tatB
and
queA
were easily obtained, attempts at disrupting
tatA
proved unsuccessful, while deletion of
tatC
led to partial mutants following single homologous recombination, with cells retaining a chromosomal copy of
tatC
. Double homologous recombination
tatC
mutants were obtained only when a plasmid-borne, isopropyl-β-
d
-thiogalactopyranoside (IPTG)-inducible copy of
tatC
was introduced prior to transformation. These conditional
tatC
mutants could grow only in the presence of IPTG, suggesting that
tatC
is essential in
H. pylori
.
tatB
and
tatC
mutants had lower hydrogenase and catalase activities than the wild-type strain did, and the ability of
tatC
mutants to colonize mouse stomachs was severely affected compared to the wild type. Chromosomal complementation of
tatC
mutants restored hydrogenase and catalase activities to wild-type levels, and additional expression of
tatC
in wild-type cells resulted in elevated Tat-dependent enzyme activities. Unexpectedly, the
tat
strains had cell envelope defects.

IMPORTANCE
This work reports the first characterization of the twin-arginine translocation (Tat) system in the gastric pathogen
Helicobacter pylori
. While
tatB
mutants were easily obtained, only single-crossover partial
tatC
mutants or conditional
tatC
mutants could be generated, indicating that
tatC
is essential in
H. pylori
, a surprising finding given the fact that only four proteins are predicted to be translocated by the Tat system in this bacterium. The levels of activity of hydrogenase and catalase, two of the predicted Tat-dependent enzymes, were affected in these mutants. In addition, all
tat
mutants displayed cell envelope defects, and
tatC
mutants were deficient in mouse colonization.
Bowel dysfunction after rectal cancer treatment: a study comparing the specialist's versus patient's perspective
Authors: Chen Tina Yen-Ting , Emmertsen Katrine Jøssing , Laurberg Søren
Published: January 2014

Objectives

To investigate how bowel dysfunction after sphincter-preserving rectal cancer treatment, known as low anterior resection syndrome (LARS), is perceived by rectal cancer specialists, in relation to the patient's experience.

Design

Questionnaire study.

Setting

International.

Participants

58 rectal cancer specialists (45 colorectal surgeons and 13 radiation oncologists).

Research procedure

The Low Anterior Resection Syndrome Score (LARS score) is a five-item instrument for evaluation of LARS, which was developed from and validated on 961 patients. The 58 specialists individually completed two LARS score-based exercises. In Exercise 1, they were asked to select, from a list of bowel dysfunction issues, five items that they considered to disturb patients the most. In Exercise 2, they were given a list of scores to assign to the LARS score items, according to the impact on quality of life (QOL).

Outcome measures

In Exercise 1, the frequency of selection of each issue, particularly the five items included in the LARS score, was compared with the frequency of being selected at random. In Exercise 2, the answers were compared with the original patient-derived scores.

Results

Four of the five LARS score issues had the highest frequencies of selection (urgency, clustering, incontinence for liquid stool and frequency of bowel movements), which were also higher than random. However, the remaining LARS score issue (incontinence for flatus) showed a lower frequency than random. Scores assigned by the specialists were significantly different from the patient-derived scores (p<0.01). The specialists grossly overestimated the impact of incontinence for liquid stool and frequent bowel movements on QOL, while they markedly underestimated the impact of clustering and urgency. The results did not differ between surgeons and oncologists.

Conclusions

Rectal cancer specialists do not have a thorough understanding of which bowel dysfunction symptoms truly matter to the patient, nor how these symptoms affect QOL.
SBAR improves communication and safety climate and decreases incident reports due to communication errors in an anaesthetic clinic: a prospective intervention study
Authors: Randmaa Maria , Mårtensson Gunilla , Leo Swenne Christine , Engström Maria
Published: January 2014

Objectives

We aimed to examine staff members’ perceptions of communication within and between different professions, safety attitudes and psychological empowerment, prior to and after implementation of the communication tool Situation-Background-Assessment-Recommendation (SBAR) at an anaesthetic clinic. The aim was also to study whether there was any change in the proportion of incident reports caused by communication errors.

Design

A prospective intervention study with comparison group using preassessments and postassessments. Questionnaire data were collected from staff in an intervention (n=100) and a comparison group (n=69) at the anaesthetic clinic in two hospitals prior to (2011) and after (2012) implementation of SBAR. The proportion of incident reports due to communication errors was calculated during a 1-year period prior to and after implementation.

Setting

Anaesthetic clinics at two hospitals in Sweden.

Participants

All licensed practical nurses, registered nurses and physicians working in the operating theatres, intensive care units and postanaesthesia care units at anaesthetic clinics in two hospitals were invited to participate.

Intervention

Implementation of SBAR in an anaesthetic clinic.

Primary and secondary outcomes

The primary outcomes were staff members’ perception of communication within and between different professions, as well as their perceptions of safety attitudes. Secondary outcomes were psychological empowerment and incident reports due to error of communication.

Results

In the intervention group, there were statistically significant improvements in the factors ‘Between-group communication accuracy’ (p=0.039) and ‘Safety climate’ (p=0.011). The proportion of incident reports due to communication errors decreased significantly (p<0.0001) in the intervention group, from 31% to 11%.

Conclusions

Implementing the communication tool SBAR in anaesthetic clinics was associated with improvement in staff members’ perception of communication between professionals and their perception of the safety climate as well as with a decreased proportion of incident reports related to communication errors.

Trial registration

ISRCTN37251313.
Effects of a school-based prevention programme on smoking in early adolescence: a 6-month follow-up of the ‘Eigenständig werden’ cluster randomised trial
Authors: Isensee Barbara , Hansen Julia , Maruska Karin , Hanewinkel Reiner
Published: January 2014

Objectives

To test the effects of a school-based prevention programme on students’ smoking-related behaviour, attitudes and knowledge 6 months after implementation over 2 school-years has ended.

Design

Two-arm prospective cluster randomised controlled trial with a follow-up survey 6 months after end of programme implementation, that is, 26 months after baseline.

Setting

45 public secondary schools from four federal states in Germany (Bremen, Hesse, North Rhine-Westphalia, Schleswig-Holstein).

Participants

A total of 3444 students from 172 classes with a mean age of 10.37 years (SD=0.59) and 47.9% girls at baseline. Analysis sample with follow-up up data merged to baseline data comprises 2513 datasets (73%).

Intervention

‘Eigenständig werden 5+6’, a school-based prevention programme for grades 5 and 6 to enhance substance-specific and general life skills, consisting of 14 units (à 90 min) and two workshops (4–6 h) being taught over a time period of 2 school-years by trained teachers.

Outcome measures

Lifetime and current smoking, incidence of smoking in baseline never smokers, smoking-related knowledge, attitudes, perceived norms of smoking and self-efficacy to refuse cigarette offers were assessed in students.

Results

6 months after the end of programme implementation, students of intervention classes showed significantly lower rates for lifetime smoking (adjusted OR=0.63; 95% CI 0.41 to 0.96; p=0.026) and incidence of smoking (adjusted OR=0.66; 95% CI 0.43 to 1.00; p=0.047), a higher increase of smoking-related knowledge (adjusted β=9.38; 95% CI 6.73 to 12.04; p<0.001) and a greater change in attitudes towards a more critical perception of risks and disadvantages of smoking (adjusted β=0.10; 95% CI 0.03 to 0.16; p=0.002). No group differences were found for current smoking, perceived norms of smoking and self-efficacy to refuse cigarette offers.

Conclusions

Participation in the school-based prevention programme ‘Eigenständig werden 5+6’ may have small effects on smoking behaviour and attitudes and a moderate effect on smoking-related knowledge.

Trial registration

Current Controlled Trials ISRCTN99442407
Identity cards help patients identify their doctors
Authors: Zucco Liana , Desmond Gabrielle , Carpenter Bernadette
Published: January 2014

Patients admitted to hospital are immediately overloaded with information from staff in A&E, to subsequent acute medical and inpatient wards. Essential details are conveyed to patients at each step, including diagnosis, management and identification of various team members involved in their care. An initial audit within our South London hospital revealed only one third of patients admitted onto a single medical ward could recall the name of a single member of their treating team, and less than 10% retained that information over 5 days. Identification (ID) cards were devised to facilitate clear transfer of information detailing the patient’s treating team. These ID cards were piloted through a series of PDSA cycles on one inpatient medical ward following a consultant led ward round. Post intervention, 67% managed to recall a single member of the treating team, with 67% retaining this information 5 days later, a dramatic improvement. ID cards were then trialed on one surgical ward, demonstrating equally impressive results with over 87% of patients recalling their named consultant following ID card implementation, up from 54% initially. Similar trends were demonstrated for recalling other treating team members. This simple measure improved patients ability to recall and retain names of a least a single member of their treating team, encouraged communication between patients and medical team and ultimately improved patient satisfaction and quality of care. ID cards were quick and easy to implement and have been approved by the hospital patient safety committee to implement throughout the Trust.
Prevalence of functional gastrointestinal disorders among consecutive new patient referrals to a gastroenterology clinic
Authors: Shivaji Uday N , Ford Alexander C
Published: January 2014

Objective

Functional gastrointestinal disorders (FGIDs) are common in the community. Many patients will consult a physician in primary care, but the burden that these diseases represent to secondary care has not been studied for many years. We therefore examined this subject.

Design

Unselected consecutive new adult patient referrals were recruited during a 3-year period from January 2010 until December 2012. Medical records were reviewed retrospectively and the following data were recorded: age and sex of the patient, symptoms reported or signs noted at the first consultation, all investigations requested and ultimate diagnosis after investigation to the level deemed appropriate by the consulting physician.

Setting

A luminal gastroenterology clinic at a teaching hospital.

Results

There were a total of 613 new patient referrals (mean age 54.2 years, 357 (58.2%) female). In total, 214 (34.9%) patients were diagnosed as having an FGID. Among the 214 patients diagnosed with an FGID, 65.9% were female, compared with 54.1% without an FGID (p=0.005). Mean age of those with an FGID was 47.9 years, compared with 57.5 years among those without (p<0.001). The total number of symptoms reported was significantly higher among patients with an FGID, but the total number of investigations did not differ.

Conclusions

More than one-third of new patient referrals to a luminal gastroenterology clinic were diagnosed with an FGID. These conditions form a large part of the workload in secondary care gastroenterology, and primary care commissioning needs to reflect this.
Characteristics of low-speed vehicle run-over events in children: an 11-year review
Authors: Griffin Bronwyn R , Watt Kerrianne , Shields Linda E , Kimble Roy M
Published: January 2014

Objectives

The purpose of this study was to investigate the characteristics associated with fatal and non-fatal low-speed vehicle run-over (LSVRO) events in relation to person, incident and injury characteristics, in order to identify appropriate points for intervention and injury prevention.

Methods

Data on all known LSVRO events in Queensland, Australia, over 11 calendar years (1999–2009) were extracted from five different databases representing the continuum of care (prehospital to fatality) and manually linked. Descriptive and multivariate analyses were used to analyse the sample characteristics in relation to demographics, health service usage, outcomes, incident characteristics, and injury characteristics.

Results

Of the 1641 LSVRO incidents, 98.4% (n=1615) were non-fatal, and 1.6% were fatal (n=26). Over half the children required admission to hospital (56%, n=921); mean length of stay was 3.4 days. Younger children aged 0–4 years were more frequently injured, and experienced more serious injuries with worse outcomes. Patterns of injury (injury type and severity), injury characteristics (eg, time of injury, vehicle type, driver of vehicle, incident location), and demographic characteristics (such as socioeconomic status, indigenous status, remoteness), varied according to age group. Almost half (45.6%; n=737) the events occurred outside major cities, and approximately 10% of events involved indigenous children. Parents were most commonly the vehicle drivers in fatal incidents. While larger vehicles such as four-wheel drives (4WD) were most frequently involved in LSVRO events resulting in fatalities, cars were most frequently involved in non-fatal events.

Conclusions

This is the first study, to the authors’ knowledge, to analyse the characteristics of fatal and non-fatal LSVRO events in children aged 0–15 years on a state-wide basis. Characteristics of LSVRO events varied with age, thus age-specific interventions are required. Children living outside major cities, and indigenous children, were over-represented in these data. Further research is required to identify the burden of injury in these groups.
Endovascular treatment with flow diverters of recanalized and multitreated aneurysms initially treated by endovascular approach
Authors: Benaissa Azzedine , Januel Anne-Christine , Herbreteau Denis , Berge Jérôme , Aggour Mohamed , Kadziolka Krzysztof , Cognard Christophe , Pierot Laurent
Published: January 2014

Purpose

To evaluate the feasibility, safety and efficacy of endovascular treatment with flow diverters in patients with recanalized and multitreated aneurysms in a retrospective, multicenter, single-arm study.

Methods

The study included 29 patients with 29 recanalized aneurysms who were treated by flow diverters (Silk or Pipeline devices). Pre- and post-procedural complications and morbidity and mortality rates were evaluated and functional outcomes (modified Rankin Score (mRS)) at 1 month (short-term) and 3–4 months (mid-term) were compared with preoperative mRS (before the procedure). Mid-term angiographic follow-up was performed assessing aneurysmal occlusion by the Montreal scale (complete occlusion, neck remnant, aneurysm remnant).

Results

Placement of the flow diverters was achieved in all patients. Two misdeployments of the flow diverters necessitated balloon dilation in two patients, which was associated with stent delivery in one patient. Permanent morbidity related to treatment was 6.9% (2/29), transient morbidity was 10.3% (3/29) and there were no deaths resulting from the treatment. One patient died from a myocardial infarct 4 weeks after the procedure. 25/29 patients (86.2%) had a good final functional outcome, 26/29 (89.7%) had an unchanged functional outcome and 2/29 patients (6.9%) had clinical worsening. Angiographic follow-up showed complete occlusion in 17/28 patients (60.7%), neck remnants in 6/28 patients (21.4%) and residual aneurysms in 5/28 (17.9%).

Conclusions

Flow diverter placement is feasible and safe in patients with recanalized and multitreated aneurysms. The procedure is associated with a high percentage of good functional outcomes as well as good mid-term anatomical results (82.1%).
DYNAMICS OF NONAUTONOMOUS MATTER BREATHER WAVE IN A TIME-DEPENDENT HARMONIC TRAP WITH NONLINEAR INTERACTION MANAGEMENT
Authors: LIU ZHI-GANG , MA XIAO-XIAO
Published: January 2014

In this paper, we study on breathers of Bose–Einstein condensate analytically in a time-dependent parabolic trap with a complex potential. It is found that the breather can be reflected by the parabolic potential or split into many humps and valleys with the time evolution. The nonlinear tunneling behavior of breather colliding on the parabolic potential is observed. The results provide many possibilities to manipulate breather experimentally in the condensate system.
Separation of static and dynamic thermodynamic parameters for the interaction between pyropheophorbide methyl ester and copper
Authors: Al-Omari Saleh
Published: January 2014

The interaction between pyropheophorbide methyl ester (PPME) and the ionic metal of copper ( Cu 2+) was investigated using fluorescence and UV-vis techniques. By analysis of the fluorescence spectra, it was observed that Cu 2+ has a strong ability to quench the intrinsic fluorescence of PPME through dynamic and static quenching process. The binding constants of Cu 2+ with PPME were determined at different temperatures depending on the results of fluorescence quenching. Based on the modified form of the Stern–Volmer equation, static binding constant (kS) and the dynamic binding constant (kD) of Cu 2+-PPME association were obtained at different temperatures. The static thermodynamic function of the enthalpy change (ΔHS), the dynamic thermodynamic function of the enthalpy change (ΔHD), the static thermodynamic function of the entropy change (ΔSS), and the dynamic thermodynamic function of the entropy change (ΔSD) for the binding interaction were determined according to the van't Hoff equation. The values of static Gibbs free energy change (ΔGS) and dynamic Gibbs free energy change (ΔGD) were determined to be negative indicating that the interaction process was a spontaneous. ΔHD and ΔSD values were positive indicating that the dynamic quenching process of Cu 2+-PPME interaction was driven mainly by hydrophobic forces. For the static binding quenching, ΔHS and ΔSS values were negative which indicated that hydrogen bond, electrostatic interaction, and van der Waals interaction were important driving forces for PPME- Cu 2+ association. Both static and dynamic fluorescence quenching were related to the distance between PPME and Cu 2+ indicating that the electron transfer process occurred.
INTRODUCTION
Authors: FLOMENBOM OPHIR , VELONIA KELLY , COTLET MIRCEA
Published: January 2014

In this document, we present the articles of the Special Issue on measuring & solving single molecules. These include reviews and articles about the state-of-the-art experimental and mathematical methods and applications in life sciences, biophysics and materials science. Ways of solving pitfalls in this field are presented in various articles. This Special Issue can intrigue, inspire and help scientifically both young and established scientists working in this field.
INSIGHTS IN ENZYME FUNCTIONAL DYNAMICS AND ACTIVITY REGULATION BY SINGLE MOLECULE STUDIES
Authors: JØRGENSEN SUNE K. , HATZAKIS NIKOS S.
Published: January 2014

The advent of advanced single molecule measurements heralded the arrival of a wealth of dynamic information revolutionizing our understanding of protein dynamics and behavior in ways not deducible by conventional bulk assays. They offered the direct observation and quantification of the abundance and life time of multiple states and transient intermediates in the energy landscape that are typically averaged out in non-synchronized ensemble measurements, thus providing unprecedented insights into complex biological processes. Here we survey the current state of the art in single-molecule fluorescence microscopy methodology for studying the mechanism of enzymatic activity and the insights on protein functional dynamics. We will initially discuss the strategies employed to date, their limitations and possible ways to overcome them, and finally how single enzyme kinetics can advance our understanding on mechanisms underlying function and regulation of proteins.

[Formula: see text]Special Issue Comment: This review focuses on functional dynamics of individual enzymes and is related to the review on ion channels by Lu,44 the reviews on mathematical treatment of Flomenbom45 and Sach et al.,46 and review on FRET by Ruedas-Rama et al.41
Carbyne Polysulfide as a Novel Cathode Material for Rechargeable Magnesium Batteries
Authors: NuLi Yanna , Chen Qiang , Wang Weikun , Wang Ying , Yang Jun , Wang Jiulin
Published: January 2014

We report the formation of carbyne polysulfide by coheating carbon containing carbyne moieties and elemental sulfur. The product is proved to have a sp2hybrid carbon skeleton with polysulfide attached on it. The electrochemical performance of carbyne polysulfide as a novel cathode material for rechargeable magnesium batteries is firstly investigated. The material exhibits a high discharge capacity of 327.7 mAh g−1at 3.9 mA g−1. These studies show that carbyne polysulfide is a promising candidate as cathode material for rechargeable Mg batteries if the capacity retention can be significantly improved.
The Global Burden of Road Injury: Its Relevance to the Emergency Physician
Authors: Chekijian Sharon , Paul Melinda , Kohl Vanessa P. , Walker David M. , Tomassoni Anthony J. , Cone David C. , Vaca Federico E.
Published: January 2014

Background. Road traffic crash fatalities in the United States are at the lowest level since 1950. The reduction in crash injury burden is attributed to several factors: public education and prevention programs, traffic safety policies and enforcement, improvements in vehicle design, and prehospital services coupled with emergency and acute trauma care. Globally, the disease burden of road traffic injuries is rising. In 1990, road traffic injuries ranked ninth in the ten leading causes of the global burden of disease. By 2030, estimates show that road traffic injuries will be the fifth leading causes of death in the world. Historically, emergency medicine has played a pivotal role in contributing to the success of the local, regional, and national traffic safety activities focused on crash and injury prevention.Objective. We report on the projected trend of the global burden of road traffic injuries and fatalities and describe ongoing global initiatives to reduce road traffic morbidity and mortality.Discussion. We present key domains where emergency medicine can contribute through international collaboration to address global road traffic-related morbidity and mortality.Conclusion. International collaborative programs and research offer important opportunities for emergency medicine physicians to make a meaningful impact on the global burden of disease.
On Two-Dimensional Quaternion Wigner-Ville Distribution
Authors: Bahri Mawardi
Published: January 2014

We present the two-dimensional quaternion Wigner-Ville distribution (QWVD). The transform is constructed by substituting the Fourier transform kernel with the quaternion Fourier transform (QFT) kernel in the classical Wigner-Ville distribution definition. Based on the properties of quaternions and the QFT kernel we obtain three types of the QWVD. We discuss some useful properties of various definitions for the QWVD, which are extensions of the classical Wigner-Ville distribution properties.
Pre-Conditioning with CDP-Choline Attenuates Oxidative Stress-Induced Cardiac Myocyte Death in a Hypoxia/Reperfusion Model
Authors: González-Pacheco Héctor , Méndez-Domínguez Aurelio , Hernández Salomón , López-Marure Rebeca , Vazquez-Mellado Maria J. , Aguilar Cecilia , Rocha-Zavaleta Leticia
Published: January 2014

Background. CDP-choline is a key intermediate in the biosynthesis of phosphatidylcholine, which is an essential component of cellular membranes, and a cell signalling mediator. CDP-choline has been used for the treatment of cerebral ischaemia, showing beneficial effects. However, its potential benefit for the treatment of myocardial ischaemia has not been explored yet.Aim. In the present work, we aimed to evaluate the potential use of CDP-choline as a cardioprotector in anin vitromodel of ischaemia/reperfusion injury.Methods. Neonatal rat cardiac myocytes were isolated and subjected to hypoxia/reperfusion using the coverslip hypoxia model. To evaluate the effect of CDP-choline on oxidative stress-induced reperfusion injury, the cells were incubated with H2O2during reperfusion. The effect of CDP-choline pre- and postconditioning was evaluated using the cell viability MTT assay, and the proportion of apoptotic and necrotic cells was analyzed using the Annexin V determination by flow cytometry.Results. Pre- and postconditioning with 50 mg/mL of CDP-choline induced a significant reduction of cells undergoing apoptosis after hypoxia/reperfusion. Preconditioning with CDP-choline attenuated postreperfusion cell death induced by oxidative stress.Conclusion. CDP-choline administration reduces cell apoptosis induced by oxidative stress after hypoxia/reperfusion of cardiac myocytes. Thus, it has a potential as cardioprotector in ischaemia/reperfusion-injured cardiomyocytes.
On the Agaciro Equation via the Scope of Green Function
Authors: Atangana Abdon , Rusagara Innocent
Published: January 2014

We have undertaken an investigation of a kind of third‐order equation called Agaciro equation within the folder of both integer and fractional order derivative. In the way of deriving the general exact solution of this equation, we employed the philosophy of the Green function together with some integral transform operators and special functions including but not limited to the Laplace, Fourier, and Mellin transform. We presented some examples of exact solution of this class of third‐order equations for integer and fractional order derivative. It is important to point out that the value of Agaciro equation can be extended to describe assorted phenomenon in sciences.
Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles
Authors: Piao Changhao , Jiang Chao , Qiao Hongtao , Cho Chongdu , Lu Sheng
Published: January 2014

The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs) dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM) controller and double-integral sliding mode (DISM) controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag) is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.
Development of a Controlled Release of Salicylic Acid Loaded Stearic Acid-Oleic Acid Nanoparticles in Cream for Topical Delivery
Authors: Woo J. O. , Misran M. , Lee P. F. , Tan L. P.
Published: January 2014

Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs) with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and itsin vitrorelease study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging thein vitrorelease.
Long-Term Use of ProbioticsLactobacillusandBifidobacteriumHas a Prophylactic Effect on the Occurrence and Severity of Pouchitis: A Randomized Prospective Study
Authors: Tomasz Banasiewicz , Zoran Stojcev , Jarosław Walkowiak , Ryszard Marciniak , Marcin Grochowalski , Robert Burdyński , Piotr Krokowicz , Lukasz Krokowicz , Jacek Paszkowski , Piotr Gronek , Przemysław Pyda , Michał Drews
Published: January 2014

Aim. The aim of the study was to assess the impact of the long-term use of the composite probiotics in patients after restorative proctocolectomy.Method. Forty-three patients (20 females and 23 males, aged 21 to 68 years) after restorative proctocolectomy were included in the study. After randomization patients were divided into placebo group and treatment group with oral intake of probiotic containingLactobacillus acidophilus,Lactobacillus delbrueckii subsp. bulgaricus, andBifidobacterium bifidus. Patients were investigated during initial visit and during final visit after 9 months. All patients were subjected to standard clinical and endoscopic examination with microscopic study of the specimens. Concentrations of calprotectin and pyruvate kinase isoenzyme M2-PK were determined in all cases.Results. The average severity of pouchitis and the number of patients with pouchitis significantly decrease after 9 months of the probiotic taking. The concentrations of calprotectin and pyruvate kinase isoenzyme M2-PK significantly decreased after the therapy.Conclusions. Nine months of the probiotic treatment (Lactobacillus acidophilus,Lactobacillus delbrueckii subsp. bulgaricus, andBifidobacterium bifidus) reduced the number of patients with pouchitis, decreased the PDAI score, and also decreased the fecal pyruvate kinase and calprotectin. The long-term probiotics use is safe and well accepted and can be an effective method of the pouchitis prevention.
Chronic Kidney Disease—Effect of Oxidative Stress
Authors: Meenakshi Sundaram Subha Palaneeswari , Nagarajan Sivakumar , Manjula Devi Arcot Jagdeeshwaran
Published: January 2014

Chronic kidney disease (CKD) is a growing health problem with increasing incidence. The annual mortality of end-stage renal disease patients is about 9%, which is 10–20 fold higher than the general population, approximately 50% of these deaths are due to cardiovascular (CV) disease. CV risk factors, such as diabetes, hypertension, and hyperlipidemia, are strongly associated with poor outcome. Many other nontraditional risk factors such as inflammation, infection, oxidative stress, anemia, and malnutrition are also present. In this review we will focus on the role of oxidative stress in chronic kidney disease.
Dielectric Behaviour of Some Woven Fabrics on the Basis of Natural Cellulosic Fibers
Authors: Mustata Florin St. C. , Mustata Adriana
Published: January 2014

The electrical permittivity of the weaves obtained from natural cellulosic yarns or mixed with synthetic fibers was established with capacitor method. The highest value of relative electrical permittivity in case of the woven fabric from natural cellulosic fibers has been observed at the weave made of pure hemp (13.55) and the lowest at the weave obtained from the pure jute—weave packing (1.87). Electrical permittivity value of the pure jute weave packing is comparable to that of the permittivity for the glass thread, when the work conditions are as follows: temperature 25°C and air humidity 35%. The relative electrical permittivity of the weave is depending on the degree of crimping yarns especially in the weft direction, technological density in direction of the warp and weft, and surface mass of the weave.
Effect of Intermittent Positive Pressure Ventilation on Depth of Anaesthesia during and after Isoflurane Anaesthesia in Sulphur-Crested Cockatoos (Cacatua galerita galerita)
Authors: Chemonges Saul
Published: January 2014

This study aimed to determine the effect of intermittent positive pressure ventilation (IPPV) on the depth of inhalation anaesthesia in parrots. Anaesthesia was induced with 3.0% isoflurane in six Sulphur-crested Cockatoos (Cacatua galerita galerita) and maintained using either 1.5% or 3.0% during spontaneous ventilation (SV) or IPPV at 6 (IPPV-6) or 12 (IPPV-12) breaths per minute. The time taken for the appearance of somatic reflexes and the return of SV after IPPV was recorded. During recovery, the body jerk, beak, eye, and shivering reflexes appeared after 126 ± 27 s, 133 ± 26 s, 165 ± 34 s, and 165 ± 44 s, respectively. All cockatoos developed apnoea after IPPV-12 and only some did after IPPV-6. Return of SV after IPPV-12 was delayed compared to IPPV-6. Recovery times after the SV runs were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Similarly, after IPPV, the recovery times were significantly different between 1.5% and 3.0% isoflurane anaesthesia. Recovery times after 3.0% inhaled isoflurane were longer than those of 1.5% inhaled isoflurane. In conclusion, cockatoos recovering from isoflurane anaesthesia are likely to exhibit body jerk, beak, eye, and shivering reflexes in that order. IPPV increases the depth of anaesthesia in a rate and dose-related manner and prolongs recovery.
A Cross-Layer Approach to Minimize the Energy Consumption in Wireless Sensor Networks
Authors: Catarinucci Luca , Colella Riccardo , Del Fiore Giuseppe , Mainetti Luca , Mighali Vincenzo , Patrono Luigi , Stefanizzi Maria Laura
Published: January 2014

Energy efficiency represents one of the primary challenges in the development of wireless sensor networks (WSNs). Since communication is the most power consuming operation for a node, many current energy-efficient protocols are based on duty cycling mechanisms. However, most of these solutions are expensive from both the computational and the memory resources point of view and; therefore, they result in being hardly implementable on resources constrained devices, such as sensor nodes. This suggests to combine new communication protocols with hardware solutions able to further reduce the nodes' power consumption. In this work, a cross-layer solution, based on the combined use of a duty-cycling protocol and a new kind of active wake-up circuit, is presented and validated by using a test bed approach. The resulting solution significantly reduces idle listening periods by awakening the node only when a communication is detected. Specifically, an MAC scheduler manages the awakenings of a commercial power detector connected to the sensor node, and, if an actual communication is detected, it enables the radio transceiver. The effectiveness of the proposed cross-layer protocol has been thoroughly evaluated by means of tests carried out in an outdoor environment.
Incidence and Time to Return to Training for Stress Fractures during Military Basic Training
Authors: Wood Alexander M. , Hales Richard , Keenan Andre , Moss Alexandra , Chapman Michael , Davey Trish , Nelstrop Andrew
Published: January 2014

Currently, little is known about the length of time required to rehabilitate patients from stress fractures and their return to preinjury level of physical activity. Previous studies have looked at the return to sport in athletes, in a general population, where rehabilitation is not as controlled as within a captive military population. In this study, a longitudinal prospective epidemiological database was assessed to determine the incidence of stress fractures and the time taken to rehabilitate recruits to preinjury stage of training. Findings demonstrated a background prevalence of 5% stress fractures in Royal Marine training; femoral and tibial stress fractures take 21.1 weeks to return to training with metatarsal stress fractures being the most common injury taking 12.2 weeks. Rehabilitation from stress fractures accounts for 814 weeks of recruit rehabilitation time per annum. Stress fracture incidence is still common in military training; despite this stress fracture recovery times remain constant and represent a significant interruption in training. It takes on average 5 weeks after exercise specific training has restarted to reenter training at a preinjury level, regardless of which bone has a stress fracture. Further research into their prevention, treatment, and rehabilitation is required to help reduce these burdens.
Microwave Synthesis, Characterization, and Photoluminescence Properties of Nanocrystalline Zirconia
Authors: Singh A. K. , Nakate Umesh T.
Published: January 2014

We report synthesis of ZrO2nanoparticles (NPs) using microwave assisted chemical method at 80°C temperature. Synthesized ZrO2NPs were calcinated at 400°C under air atmosphere and characterized using FTIR, XRD, SEM, TEM, BET, and EDS for their formation, structure, morphology, size, and elemental composition. XRD results revealed the formation of mixed phase monoclinic and tetragonal ZrO2phases having crystallite size of the order 8.8 nm from most intense XRD peak as obtained using Scherrer formula. Electron microscope analysis shows that the NPs were less than 10 nm and highly uniform in size having spherical morphology. BET surface area of ZrO2NPs was found to be 65.85 m2/g with corresponding particle size of 16 nm. The band gap of synthesized NPs was found to be 2.49 eV and PL spectra of ZrO2synthesized NPs showed strong peak at 414 nm, which corresponds to near band edge emission (UV emission) and a relatively weak peak at 475 and 562 nm.