bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and Characterization of the Acetone Carboxylase of Cupriavidus metallidurans Strain CH34
Authors: Rosier Caroline , Leys Natalie , Henoumont Céline , Mergeay Max , Wattiez Ruddy
Published: April 2012

Acetone carboxylase (Acx) is a key enzyme involved in the biodegradation of acetone by bacteria. Except for the
Helicobacteraceae
family, genome analyses revealed that bacteria that possess an Acx, such as
Cupriavidus metallidurans
strain CH34, are associated with soil. The Acx of CH34 forms the heterohexameric complex α
2
β
2
γ
2
and can carboxylate only acetone and 2-butanone in an ATP-dependent reaction to acetoacetate and 3-keto-2-methylbutyrate, respectively.
Biogenesis of Outer Membrane Vesicles in Serratia marcescens Is Thermoregulated and Can Be Induced by Activation of the Rcs Phosphorelay System
Authors: McMahon Kenneth J. , Castelli Maria E. , Vescovi Eleonora García , Feldman Mario F.
Published: April 2012

Outer membrane vesicles (OMVs) have been identified in a wide range of bacteria, yet little is known of their biogenesis. It has been proposed that OMVs can act as long-range toxin delivery vectors and as a novel stress response. We have found that the formation of OMVs in the Gram-negative opportunistic pathogen
Serratia marcescens
is thermoregulated, with a significant amount of OMVs produced at 22 or 30°C and negligible quantities formed at 37°C under laboratory conditions. Inactivation of the synthesis of the enterobacterial common antigen (ECA) resulted in a hypervesiculation phenotype, supporting the hypothesis that OMVs are produced in response to stress. We demonstrate that the phenotype can be reversed to wild-type (WT) levels upon the loss of the Rcs phosphorelay response regulator RcsB, but not RcsA, suggesting a role for the Rcs phosphorelay in the production of OMVs. MS fingerprinting of the OMVs provided evidence of cargo selection within wild-type cells, suggesting a possible role for
Serratia
OMVs in toxin delivery. In addition, OMV-associated cargo proved toxic upon injection into the haemocoel of
Galleria mellonella
larvae. These experiments demonstrate that OMVs are the result of a regulated process in
Serratia
and suggest that OMVs could play a role in virulence.
Germination Protein Levels and Rates of Germination of Spores of Bacillus subtilis with Overexpressed or Deleted Genes Encoding Germination Proteins
Authors: Stewart Kerry-Ann V. , Yi Xuan , Ghosh Sonali , Setlow Peter
Published: April 2012

Deletion of
Bacillus subtilis
spores' GerA germinant receptor (GR) had no effect on spore germination via the GerB plus GerK GRs, and loss of GerB plus GerK did not affect germination via GerA. Loss of one or two GRs also did not affect levels of GRs that were not deleted. Overexpression of GRs 5- to 18-fold increased rates of germination via the overexpressed GR and slowed germination by other GRs up to 15-fold. However, overexpression of one or two GRs had no effect on levels of GRs that were not overexpressed. These results suggest that either interaction between different GRs reduces the activity of GRs in triggering spore germination or all GRs compete for interaction with a limiting amount of a downstream signaling molecule in the germination pathway. Overexpression or deletion of GRs also had no effect on spores' levels of the GerD protein needed for normal GR-dependent germination or of the SpoVAD protein likely involved in dipicolinic acid release early in germination. Loss of GerD also had no effect on levels of GRs or SpoVAD. Spores of a strain lacking the only
B. subtilis
prelipoprotein diacylglycerol transferase, GerF, also had no detectable GerD or the GerA's C subunit, both of which are most likely lipoproteins; GerA's A subunit was also absent. However, levels of GerB's C subunit, also almost certainly a lipoprotein, and GerK's A subunit were normal in
gerF
spores. These results with g
erF
spores were consistent with effects of loss of GerF on spore germination by different GRs.
The Phosphodiesterase DipA (PA5017) Is Essential for Pseudomonas aeruginosa Biofilm Dispersion
Authors: Roy Ankita Basu , Petrova Olga E. , Sauer Karin
Published: April 2012

Although little is known regarding the mechanism of biofilm dispersion, it is becoming clear that this process coincides with alteration of cyclic di-GMP (c-di-GMP) levels. Here, we demonstrate that dispersion byPseudomonas aeruginosain response to sudden changes in nutrient concentrations resulted in increased phosphodiesterase activity and reduction of c-di-GMP levels compared to biofilm and planktonic cells. By screening mutants inactivated in genes encoding EAL domains for nutrient-induced dispersion, we identified in addition to the previously reported ΔrbdAmutant a second mutant, the ΔdipAstrain (PA5017 [dispersion-inducedphosphodiesterase A]), to be dispersion deficient in response to glutamate, nitric oxide, ammonium chloride, and mercury chloride. Using biochemical andin vivostudies, we show that DipA associates with the membrane and exhibits phosphodiesterase activity but no detectable diguanylate cyclase activity. Consistent with these data, a ΔdipAmutant exhibited reduced swarming motility, increased initial attachment, and polysaccharide production but only somewhat increased biofilm formation and c-di-GMP levels. DipA harbors an N-terminal GAF (cGMP-specific phosphodiesterases,adenylyl cyclases, andFhlA) domain and two EAL motifs within or near the C-terminal EAL domain. Mutational analyses of the two EAL motifs of DipA suggest that both are important for the observed phosphodiesterase activity and dispersion, while the GAF domain modulated DipA function bothin vivoandin vitrowithout being required for phosphodiesterase activity. Dispersion was found to require protein synthesis and resulted in increaseddipAexpression and reduction of c-di-GMP levels. We propose a role of DipA in enabling dispersion inP. aeruginosabiofilms.
Myxococcus xanthus Developmental Cell Fate Production: Heterogeneous Accumulation of Developmental Regulatory Proteins and Reexamination of the Role of MazF in Developmental Lysis
Authors: Lee Bongsoo , Holkenbrink Carina , Treuner-Lange Anke , Higgs Penelope I.
Published: April 2012

Myxococcus xanthus
undergoes a starvation-induced multicellular developmental program during which cells partition into three known fates: (i) aggregation into fruiting bodies followed by differentiation into spores, (ii) lysis, or (iii) differentiation into nonaggregating persister-like cells, termed peripheral rods. As a first step to characterize cell fate segregation, we enumerated total, aggregating, and nonaggregating cells throughout the developmental program. We demonstrate that both cell lysis and cell aggregation begin with similar timing at approximately 24 h after induction of development. Examination of several known regulatory proteins in the separated aggregated and nonaggregated cell fractions revealed previously unknown heterogeneity in the accumulation patterns of proteins involved in type IV pilus (T4P)-mediated motility (PilC and PilA) and regulation of development (MrpC, FruA, and C-signal). As part of our characterization of the cell lysis fate, we set out to investigate the unorthodox MazF-MrpC toxin-antitoxin system which was previously proposed to induce programmed cell death (PCD). We demonstrate that deletion of
mazF
in two different wild-type
M. xanthus
laboratory strains does not significantly reduce developmental cell lysis, suggesting that MazF's role in promoting PCD is an adaption to the mutant background strain used previously.
The association between lung function and fatal stroke in a community followed for 4 decades
Authors: Gulsvik Anne Kristine , Gulsvik Amund , Skovlund Eva , Thelle Dag Steinar , Mowé Morten , Humerfelt Sjur , Wyller Torgeir Bruun
Published: April 2012

Background

Previous studies, all of <20 years of follow-up, have suggested an association between lung function and the risk of fatal stroke. This study investigates the stability of this association in a cohort followed for 4 decades.

Methods

The Bergen Clinical Blood Pressure Survey was conducted in Norway in 1964–1971. The risk of fatal stroke associated with forced expiratory volume after one second (FEV1) was estimated with Cox proportional hazards regression, making progressive adjustment for potential confounders.

Results

Of 5617 (84%) participants with recorded baseline FEV1, 462 died from stroke over 152 786 subsequent person-years of follow-up according to mortality statistics of 2005; mean (SD) follow-up was 27 (12) years. An association between baseline FEV1(L) and fatal stroke was observed; HR=1.38 (95% CI 1.11 to 1.71) and HR=1.62 (95% CI 1.22 to 2.15) for men and women, respectively (adjusted for age and height). The findings were not explained by smoking, hypertension, diabetes, atherosclerosis, socioeconomic status, obstructive lung disease, physical inactivity, cholesterol or body mass index and persisted in subgroups of never-smokers, subgroups without respiratory symptoms and survivors of the first 20 years of follow-up. For male survivors with a valid FEV1at follow-up (1988–1990) (n=953), baseline FEV1(L) indicated a possible strong and independent association to the risk of fatal stroke after adjustments for individual changes in FEV1(ml/year) (HR 1.95 (95% CI 0.98 to 3.86)).

Conclusion

There is a consistent, independent and long-lasting association between lung function and fatal stroke, probably irrespective of changes during adult life.
Levels and predictors of exercise referral scheme uptake and adherence: a systematic review
Authors: Pavey Toby , Taylor Adrian , Hillsdon Melvyn , Fox Kenneth , Campbell John , Foster Charlie , Moxham Tiffany , Mutrie Nanette , Searle John , Taylor Rod
Published: April 2012

Background

The effectiveness of exercise referral schemes (ERS) is influenced by uptake and adherence to the scheme. The identification of factors influencing low uptake and adherence could lead to the refinement of schemes to optimise investment.

Objectives

To quantify the levels of ERS uptake and adherence and to identify factors predictive of uptake and adherence.

Methods

A systematic review and meta-analysis was undertaken. MEDLINE, EMBASE, PsycINFO, Cochrane Library, ISI WOS, SPORTDiscus and ongoing trial registries were searched (to October 2009) and included study references were checked. Included studies were required to report at least one of the following: (1) a numerical measure of ERS uptake or adherence and (2) an estimate of the statistical association between participant demographic or psychosocial factors (eg, level of motivation, self-efficacy) or programme factors and uptake or adherence to ERS.

Results

Twenty studies met the inclusion criteria, six randomised controlled trials (RCTs) and 14 observational studies. The pooled level of uptake in ERS was 66% (95% CI 57% to 75%) across the observational studies and 81% (95% CI 68% to 94%) across the RCTs. The pooled level of ERS adherence was 49% (95% CI 40% to 59%) across the observational studies and 43% (95% CI 32% to 54%) across the RCTs. Few studies considered anything other than gender and age. Women were more likely to begin an ERS but were less likely to adhere to it than men. Older people were more likely to begin and adhere to an ERS.

Limitations

Substantial heterogeneity was evident across the ERS studies. Without standardised definitions, the heterogeneity may have been reflective of differences in methods of defining uptake and adherence across studies.

Conclusions

To enhance our understanding of the variation in uptake and adherence across ERS and how these variations might affect physical activity outcomes, future trials need to use quantitative and qualitative methods.
SMALL RATIONAL CURVES ON THE MODULI SPACE OF STABLE BUNDLES
Authors: LIU MIN
Published: April 2012

For a smooth projective curve C with genus g ≥ 2 and a degree 1 line bundle [Formula: see text] on C, let [Formula: see text] be the moduli space of stable vector bundles of rank r over C with the fixed determinant [Formula: see text]. In this paper, we study the small rational curves on M and estimate the codimension of the locus of the small rational curves. In particular, we determine all small rational curves when r = 3.
UNICITY OF MEROMORPHIC FUNCTIONS SHARING SOME SMALL FUNCTIONS REGARDLESS OF MULTIPLICITIES
Authors: QUANG SI DUC
Published: April 2012

The purpose of this article is twofold. The first is to prove a unicity theorem for meromorphic functions sharing five small functions regardless of multiplicities. This is an improvement of the results of Yahua–Jianyong, Yao and Yi, Thai and Tan. The second is to prove a finiteness theorem for meromorphic functions that share three small functions ignoring multiplicity and another small function with multiplicities truncated by 2.
MODELING THE DIFFERENCES IN THE DEVELOPMENT OF A NEW ANTIBIOTIC CLASS VERSUS THE DEVELOPMENT OF A NEXT GENERATION ANTIBIOTIC ON THE TOTAL RESISTANCE IN A HOSPITAL SETTING
Authors: JOYNER MICHELE L.
Published: April 2012

The increase in antibiotic resistance continues to pose a major public health risk leading to a more intense focus on ways to limit and even reduce this threat. One such effort is the push for twenty new classes of antibiotics by the year 2020. Most of the current antibiotics used today are derivations of antibiotics first introduced forty to fifty years ago. In this paper, we develop mathematical models to simulate the difference between implementing a next generation antibiotic versus a new class antibiotic within a hospital setting. Using these models, we simulate the short term and long term effects of using the new antibiotic to combat existing levels of antimicrobial resistance. In addition to analyzing the difference in antibiotic classes, we also analyze the effects of the method of administration of the new antibiotic. Simulations suggest a need in the long term for the development of new classes of antibiotics administered in a very structured, targeted manner.
Impaired cerebrovascular autoregulation and reduced CO2 reactivity after long duration spaceflight
Authors: Zuj K. A. , Arbeille Ph. , Shoemaker J. K. , Blaber A. P. , Greaves D. K. , Xu D. , Hughson R. L.
Published: April 2012

Long duration habitation on the International Space Station (ISS) is associated with chronic elevations in arterial blood pressure in the brain compared with normal upright posture on Earth and elevated inspired CO2. Although results from short-duration spaceflights suggested possibly improved cerebrovascular autoregulation, animal models provided evidence of structural and functional changes in cerebral vessels that might negatively impact autoregulation with longer periods in microgravity. Seven astronauts (1 woman) spent 147 ± 49 days on ISS. Preflight testing (30–60 days before launch) was compared with postflight testing on landing day ( n = 4) or the morning 1 ( n = 2) or 2 days ( n = 1) after return to Earth. Arterial blood pressure at the level of the middle cerebral artery (BPMCA) and expired CO2 were monitored along with transcranial Doppler ultrasound assessment of middle cerebral artery (MCA) blood flow velocity (CBFV). Cerebrovascular resistance index was calculated as (CVRi = BPMCA/CBFV). Cerebrovascular autoregulation and CO2 reactivity were assessed in a supine position from an autoregressive moving average (ARMA) model of data obtained during a test where two breaths of 10% CO2 were given four times during a 5-min period. CBFV and Doppler pulsatility index were reduced during −20 mmHg lower body negative pressure, with no differences pre- to postflight. The postflight indicator of dynamic autoregulation from the ARMA model revealed reduced gain for the CVRi response to BPMCA ( P = 0.017). The postflight responses to CO2 were reduced for CBFV ( P = 0.056) and CVRi ( P = 0.047). These results indicate that long duration missions on the ISS impaired dynamic cerebrovascular autoregulation and reduced cerebrovascular CO2 reactivity.
Dietary obesity increases NO and inhibits BKCa-mediated, endothelium-dependent dilation in rat cremaster muscle artery: association with caveolins and caveolae
Authors: Howitt Lauren , Grayson T. Hilton , Morris Margaret J. , Sandow Shaun L. , Murphy Timothy V.
Published: April 2012

Obesity is a risk factor for hypertension and other vascular disease. The aim of this study was to examine the effect of diet-induced obesity on endothelium-dependent dilation of rat cremaster muscle arterioles. Male Sprague-Dawley rats (213 ± 1 g) were fed a cafeteria-style high-fat or control diet for 16–20 wk. Control rats weighed 558 ± 7 g compared with obese rats 762 ± 12 g ( n = 52–56; P < 0.05). Diet-induced obesity had no effect on acetylcholine (ACh)-induced dilation of isolated, pressurized (70 mmHg) arterioles, but sodium nitroprusside (SNP)-induced vasodilation was enhanced. ACh-induced dilation of arterioles from control rats was abolished by a combination of the KCa blockers apamin, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34), and iberiotoxin (IBTX; all 0.1 μmol/l), with no apparent role for nitric oxide (NO). In arterioles from obese rats, however, IBTX had no effect on responses to ACh while the NO synthase (NOS)/guanylate cyclase inhibitors Nω-nitro-l-arginine methyl ester (l-NAME; 100 μmol/l)/1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 μmol/l) partially inhibited ACh-induced dilation. Furthermore, NOS activity (but not endothelial NOS expression) was increased in arteries from obese rats. l-NAME/ODQ alone or removal of the endothelium constricted arterioles from obese but not control rats. Expression of caveolin-1 and -2 oligomers (but not monomers or caveolin-3) was increased in arterioles from obese rats. The number of caveolae was reduced in the endothelium of arteries, and caveolae density was increased at the ends of smooth muscle cells from obese rats. Diet-induced obesity abolished the contribution of large-conductance Ca2+-activated K+ channel to ACh-mediated endothelium-dependent dilation of rat cremaster muscle arterioles, while increasing NOS activity and inducing an NO-dependent component.
The CFTR and ENaC debate: how important is ENaC in CF lung disease?
Authors: Collawn James F. , Lazrak Ahmed , Bebok Zsuzsa , Matalon Sadis
Published: April 2012

Cystic fibrosis (CF) is caused by the loss of the cystic fibrosis transmembrane conductance regulator (CFTR) function and results in a respiratory phenotype that is characterized by dehydrated mucus and bacterial infections that affect CF patients throughout their lives. Much of the morbidity and mortality in CF results from a failure to clear bacteria from the lungs. What causes the defect in the bacterial clearance in the CF lung has been the subject of an ongoing debate. Here we discuss the arguments for and against the role of the epithelial sodium channel, ENaC, in the development of CF lung disease.
Tramadol Pretreatment Enhances Ketamine-Induced Antidepressant Effects and Increases Mammalian Target of Rapamycin in Rat Hippocampus and Prefrontal Cortex
Authors: Yang Chun , Li Wen-Yuan , Yu Hai-Yin , Gao Zhi-Qin , Liu Xiang-Liu , Zhou Zhi-Qiang , Yang Jian-Jun
Published: April 2012

Several lines of evidence have demonstrated that acute administration of ketamine elicits fast-acting antidepressant effects. Moreover, tramadol also has potential antidepressant effects. The aim of this study was to investigate the effects of pretreatment with tramadol on ketamine-induced antidepressant activity and was to determine the expression of mammalian target of rapamycin (mTOR) in rat hippocampus and prefrontal cortex. Rats were intraperitoneally administrated with ketamine at the dose of 10 mg/kg or saline 1 h before the second episode of the forced swimming test (FST). Tramadol or saline was intraperitoneally pretreated 30 min before the former administration of ketamine or saline. The locomotor activity and the immobility time of FST were both measured. After that, rats were sacrificed to determine the expression of mTOR in hippocampus and prefrontal cortex. Tramadol at the dose of 5 mg/kg administrated alone did not elicit the antidepressant effects. More importantly, pretreatment with tramadol enhanced the ketamine-induced antidepressant effects and upregulated the expression of mTOR in rat hippocampus and prefrontal cortex. Pretreatment with tramadol enhances the ketamine-induced antidepressant effects, which is associated with the increased expression of mTOR in rat hippocampus and prefrontal cortex.
Optimal Inequalities for Power Means
Authors: Li Yong-Min , Long Bo-Yong , Chu Yu-Ming , Gong Wei-Ming
Published: April 2012

We present the best possible power mean bounds for the product for any p > 0, α ∈ (0,1), and all a, b > 0 with a ≠ b. Here, Mp(a, b) is the pth power mean of two positive numbers a and b.
Fundamental Problems of the Electrodynamics of Heterogeneous Media
Authors: Grinchik N. N. , Grinchik Yu. N.
Published: April 2012

The consistent physic-mathematical model of propagation of an electromagnetic wave in a heterogeneous medium is constructed using the generalized wave equation and the Dirichlet theorem. Twelve conditions at the interfaces of adjacent media are obtained and justified without using a surface charge and surface current in explicit form. The conditions are fulfilled automatically in each section of counting schemes for calculations. A consistent physicomathematical model of interaction of nonstationaly electric and thermal fields in a layered medium with allowance or mass transfer is constructed. The model is based on the methods of thermodynamics and on the equations of an electromagnetic field and is formulated without explicit separation of the charge carriers and the charge of an electric double layer.
Stress Corrosion Cracking of Steel and Aluminum in Sodium Hydroxide: Field Failure and Laboratory Test
Authors: Prawoto Y. , Sumeru K. , Wan Nik W. B.
Published: April 2012

Through an investigation of the field failure analysis and laboratory experiment, a study on (stress corrosion cracking) SCC behavior of steel and aluminum was performed. All samples were extracted from known operating conditions from the field failures. Similar but accelerated laboratory test was subsequently conducted in such a way as to mimic the field failures. The crack depth and behavior of the SCC were then analyzed after the laboratory test and the mechanism of stress corrosion cracking was studied. The results show that for the same given stress relative to ultimate tensile strength, the susceptibility to SCC is greatly influenced by heat treatment. Furthermore, it was also concluded that when expressed relative to the (ultimate tensile strength) UTS, aluminum has similar level of SCC susceptibility to that of steel, although with respect to the same absolute value of applied stress, aluminum is more susceptible to SCC in sodium hydroxide environment than steel.
Making Things Right: Nurses' Experiences with Workplace Bullying—A Grounded Theory
Authors: Gaffney Donna A. , DeMarco Rosanna F. , Hofmeyer Anne , Vessey Judith A. , Budin Wendy C.
Published: April 2012

While bullying in the healthcare workplace has been recognized internationally, there is still a culture of silence in many institutions in the United States, perpetuating underreporting and insufficient and unproven interventions. The deliberate, repetitive, and aggressive behaviors of bullying can cause psychological and/or physical harm among professionals, disrupt nursing care, and threaten patient safety and quality outcomes. Much of the literature focuses on categories of bullying behaviors and nurse responses. This qualitative study reports on the experiences of nurses confronting workplace bullying. We collected data from the narratives of 99 nurses who completed an open-ended question embedded in an online survey in 2007. A constructivist grounded theory approach was used to analyze the data and shape a theory of how nursesmake things rightwhen confronted with bullying. In a four-step process, nurses place bullying in context, assess the situation, take action, and judge the outcomes of their actions. While many nurses do engage in a number of effective yet untested strategies, two additional concerns remain: inadequate support among nursing colleagues and silence and inaction by nurse administrators. Qualitative inquiry has the potential to guide researchers to a greater understanding of the complexities of bullying in the workplace.
The Clinical Role of CT-Based Morphologic Description in Severely Calcified Coronary Arteries Ectasia Encountering Acute Coronary Syndrome
Authors: Liu Yen-Yu , Tsai Jui-Peng , Hung Chung-Lieh , Li Jiun-Yi , Kuo Jen-Yuan
Published: April 2012

Diffuse coronary arteries ectasia combined with calcification is seldom reported. Acute coronary syndrome, a potentially life-threatening disease, accompanied with coronary ectasia and diffuse calcification, made percutaneous coronary intervention difficult and risky owing to increasing complications rate. Dual-source computed tomography and three-dimensional volume rendering images help cardiovascular surgeon easier to localize the ideal site and facilitate the procedure.
Broadband/Wideband Magnetoelectric Response
Authors: Park Chee-Sung , Priya Shashank
Published: April 2012

A broadband/wideband magnetoelectric (ME) composite offers new opportunities for sensing wide ranges of both DC and AC magnetic fields. The broadband/wideband behavior is characterized by flat ME response over a given AC frequency range and DC magnetic bias. The structure proposed in this study operates in the longitudinal-transversal (L-T) mode. In this paper, we provide information on (i) how to design broadband/wideband ME sensors and (ii) how to control the magnitude of ME response over a desired frequency and DC bias regime. A systematic study was conducted to identify the factors affecting the broadband/wideband behavior by developing experimental models and validating them against the predictions made through finite element modeling. A working prototype of the sensor with flat bands for both DC and AC magnetic field conditions was successfully obtained. These results are quite promising for practical applications such as current probe, low-frequency magnetic field sensing, and ME energy harvester.
Alveolar Soft Part Sarcomas: Molecular Pathogenesis and Implications for Novel Targeted Therapies
Authors: Mitton Bryan , Federman Noah
Published: April 2012

Alveolar soft part sarcoma (ASPS) is a very rare soft tissue sarcoma which arises primarily in children and young adults. Despite its unique histology and well-characterized genetic translocation, many questions remain regarding the pathogenesis and treatment of this tumor type. Though collective clinical experience with this tumor type spans more than 60 years, there has been little progress made in treating this uncommon but frequently fatal disease. This paper focuses on the available data regarding its molecular pathogenesis and insights into targeted therapeutics as well as the results of clinical trials performed to date to hopefully improve the outcome of patients with this rare malignancy.
Synthesis of PEG‐Iodine‐Capped Gold Nanoparticles and Their Contrast Enhancement in In Vitro and In Vivo for X‐Ray/CT
Authors: Kim Sun-Hee , Kim Eun-Mi , Lee Chang-Moon , Kim Dong Wook , Lim Seok Tae , Sohn Myung-Hee , Jeong Hwan-Jeong
Published: April 2012

We designed gold nanoparticles (AuNPs) capped with iodine and polyethylene glycol (PEG) to provide effective enhancement for X‐ray CT imaging. The methoxy PEG‐iodine‐capped AuNPs were prepared through the chemisorption of iodine and substitution of methoxy PEG‐SH onto the surface of gold nanoparticles, and severe aggregation in TEM was not observed. The binding energies of Au 4f7/2 and I 3d5/2 of the methoxy PEG‐iodine‐capped AuNPs were obtained as 84.1 eV and 619.3 eV, respectively. The binding energy shift of methoxy PEG‐iodine‐capped AuNPs would be resulted from the chemisorption between gold nanoparticles and iodine atoms. The methoxy PEG‐iodine‐capped AuNPs have higher enhancement compared to PEG‐capped gold nanoparicles in the same amount of gold in vitro. After postinjection of methoxy PEG‐iodine‐capped AuNPs into the mice, dramatic contrast enhancement at the heart, aorta, liver, and kidney was observed, this was maintained up to 5 days, and there was no evidence of apparent toxicity. In conclusion, methoxy PEG‐iodine‐capped AuNPs might be a good candidate as a CT contrast agent for blood pool imaging, and this will also contribute to the prolongation of a blood circulation time for X‐ray CT imaging.
An Oseen Two‐Level Stabilized Mixed Finite‐Element Method for the 2D/3D Stationary Navier‐Stokes Equations
Authors: Wang Aiwen , Zhao Xin , Qin Peihua , Xie Dongxiu
Published: April 2012

We investigate an Oseen two‐level stabilized finite‐element method based on the local pressure projection for the 2D/3D steady Navier‐Stokes equations by the lowest order conforming finite‐element pairs (i.e., Q1 − P0 and P1 − P0). Firstly, in contrast to other stabilized methods, they are parameter free, no calculation of higher‐order derivatives and edge‐based data structures, implemented at the element level with minimal cost. In addition, the Oseen two‐level stabilized method involves solving one small nonlinear Navier‐Stokes problem on the coarse mesh with mesh size H, a large general Stokes equation on the fine mesh with mesh size h = O(H)2. The Oseen two‐level stabilized finite‐element method provides an approximate solution (uh, ph) with the convergence rate of the same order as the usual stabilized finite‐element solutions, which involves solving a large Navier‐Stokes problem on a fine mesh with mesh size h. Therefore, the method presented in this paper can save a large amount of computational time. Finally, numerical tests confirm the theoretical results. Conclusion can be drawn that the Oseen two‐level stabilized finite‐element method is simple and efficient for solving the 2D/3D steady Navier‐Stokes equations.
A Necessary Characteristic Equation of Diffusion Processes Having Gaussian Marginals
Authors: Mudakkar Syeda Rabab
Published: April 2012

The aim of this work is to characterize one‐dimensional homogeneous diffusion process, under the assumption that marginal density of the process
is Gaussian. The method considers the forward Kolmogorov equation and
Fourier transform operator approach. The result establishes the necessary
characteristic equation between drift and diffusion coefficients for homogeneous and nonhomogeneous diffusion processes. The equation for homogeneous
diffusion process leads to characterize the possible diffusion processes that
can exist. Two well‐known examples using the necessary characteristic equation are also given.
Exploring Registered Psychiatric Nurses' Responses towards Service Users with a Diagnosis of Borderline Personality Disorder
Authors: McGrath Bridget , Dowling Maura
Published: April 2012

This study explored registered psychiatric nurses' (RPNs') interactions and level of empathy towards service users with a diagnosis of borderline personality disorder (BPD). A qualitative approach was used, and 17 RPNs were interviewed using a semistructured interview schedule incorporating the “staff-patient interaction response scale” (SPIRS). Four themes emerged following data analysis: “challenging and difficult,” “manipulative, destructive and threatening behaviour,” “preying on the vulnerable resulting in splitting staff and other service users,” and “boundaries and structure.” Additionally, low levels of empathy were evident in the majority of participants' responses to the SPIRS. The findings provide further insight on nurses' empathy responses and views on caring for service users with BPD and further evidence for the need for training and education for nurses in the care of service users diagnosed with BPD.
Vest-over-Pant Method for Closure of Residual Cavity of Liver Hydatid Cyst
Authors: Behdad Saba , Behdad Akbar , Behdad Samin , Hosseinpour Mehrdad
Published: April 2012

Objective. Although several therapeutic strategies have proven to be effective for hydatid cyst of liver, but surgery is still the most common therapy despite its morbidity and mortality. Furthermore, a variety of technique has been recommended for managing the residual cavity after cystectomy. We report here a new technical method for the reconstruction of hydatid cyst residual cavity with using overlapping flaps of liver edges (Vest over Pant). Methods. In this technique after removing the cyst, the edges of one side of cyst cavity were sutured to the base of the cavity using three to four mattress sutures), and edges of other side of liver was overlapped on the dorsal part of previous layer using four to five mattress sutures. Therefore residual cavity dead space was obliterated with two surfaces of cavity. Results. Fifty males were treated by our method. The average cyst volume was  mL. There was no intraabdominal sepsis, bile leakage, or hepatic necrosis. In follow-up ultrasound study, residual cavities were disappeared one month after operation. Conclusion. Overlapping flaps of liver edges (Vest over Pant) provides easy, safe closure of cyst with preservation of the liver anatomy.
Alternative Blood Products and Clinical Needs in Transfusion Medicine
Authors: Whitsett Carolyn , Vaglio Stefania , Grazzini Giuliano
Published: April 2012

The primary focus of national blood programs is the provision of a safe and adequate blood supply. This goal is dependent on regular voluntary donations and a regulatory infrastructure that establishes and enforces standards for blood safety. Progress in ex vivo expansion of blood cells from cell sources including peripheral blood, cord blood, induced pluripotent stem cells, and human embryonic stem cell lines will likely make alternative transfusion products available for clinical use in the near future. Initially, alloimmunized patients and individuals with rare blood types are most likely to benefit from alternative products. However, in developed nations voluntary blood donations are projected to be inadequate in the future as blood usage by individuals 60 years and older increases. In developing nations economic and political challenges may impede progress in attaining self-sufficiency. Under these circumstances, ex vivo generated red cells may be needed to supplement the general blood supply.
Probe-Based Confocal Laser Endomicroscopy Evaluation of Colon Preneoplastic Lesions, with Particular Attention to the Aberrant Crypt Foci, and Comparative Assessment with Histological Features Obtained by Conventional Endoscopy
Authors: Mascolo Massimo , Staibano Stefania , Ilardi Gennaro , Siano Maria , Vecchione Maria Luisa , Esposito Dario , De Rosa Gaetano , De Palma Giovanni Domenico
Published: April 2012

The colorectal carcinoma represents one of the most common and aggressive malignancies, still characterized by an unacceptable mortality rate, mainly due to the high metastatic potential and to a late diagnosis. In the last years, the research community focused on the chance of improving the endoscopic screening to detect neoplastic lesions in a very early stage. Several studies proposed aberrant colonic crypt foci as the earliest recognizable step of transformation in colonic multiphase carcinogenesis. We previously demonstrated the clinical applicability and predictive power of probe-based confocal laser endoscopy (pCLE) in superficial colorectal neoplastic lesions and also characterizedin vivoa case of dysplasia-associated lesional mass (DALM) in ulcerative colitis. Now, we aim to evaluate the accuracy of pCLE in the detection of ACF comparing in double-blind manner the microendoscopic and histopathological features resulting from colonic biopsy. By pCLE, we identified specific crypt architecture modifications associated with changes in cellular infiltration and vessels architecture, highlighting a good correspondence between pCLE features and histology.
Solitary Fibrous Tumors and So-Called Hemangiopericytoma
Authors: Penel Nicolas , Amela Eric Yaovi , Decanter Gauthier , Robin Yves-Marie , Marec-Berard Perrine
Published: April 2012

We have reviewed the literature data regarding the spectrum of tumors including solitary fibrous tumor and hemangiopericytoma with special focus on definition of the disease, discussion of the criteria for malignancy, and the key elements of standard treatment of localized disease. We have discussed the emerging concepts on the tumor biology and the different systemic treatments (chemotherapy and molecular-targeted therapies).
Salivaricin G32, a Homolog of the PrototypeStreptococcus pyogenesNisin-Like Lantibiotic SA-FF22, Produced by the Commensal SpeciesStreptococcus salivarius
Authors: Wescombe Philip A. , Dyet Kristin H. , Dierksen Karen P. , Power Daniel A. , Jack Ralph W. , Burton Jeremy P. , Inglis Megan A. , Wescombe Anna L. , Tagg John R.
Published: April 2012

Salivaricin G32, a 2667 Da novel member of the SA-FF22 cluster of lantibiotics, has been purified and characterized fromStreptococcus salivariusstrain G32. The inhibitory peptide differs from theStreptococcus pyogenes—produced SA-FF22 in the absence of lysine in position 2. The salivaricin G32 locus was widely distributed in BLIS-producingS. salivarius, with 6 (23%) of 26 strains PCR-positive for the structural gene,slnA. As for most other lantibiotics produced byS. salivarius, the salivaricin G32 locus can be megaplasmid encoded. Another member of the SA-FF22 family was detected in twoStreptococcus dysgalactiaeof bovine origin, an observation supportive of widespread distribution of this lantibiotic within the genusStreptococcus. Since the inhibitory spectrum of salivaricin G32 includesStreptococcus pyogenes, its production byS. salivarius, either as a member of the normal oral microflora or as a commercial probiotic, could serve to enhance protection of the human host againstS. pyogenesinfection.
Sensing Properties of a Fabry-Perot Dielectric Structure and Dimer Nanoparticles
Authors: Polemi A. , Shuford K. L.
Published: April 2012

We investigate the use of a Fabry-Perot dielectric structure combined with differently shaped nanoparticles for Surface Enhanced Raman Scattering. In particular, we show how an ideal two-layer Fabry-Perot configuration enhances the local surface field of silver nanoparticles positioned on the surface of the structure. We develop the concept using disc dimers and then extend the discussion to bowtie nanoparticles. The structure is excited by a single emitter, which couples to the nanoparticles through the dielectric layers, producing a wide aperture field that can be used to excite multiple dimers. We show how an array of nanoparticles can be properly arranged in order to increase the total scattering signal generated from the structure. The layered geometry produces robust field properties in between nanoparticles, making the overall sensing characteristics less sensitive to the interparticle seperation distance and incident polarization.
BothCD4+andCD8+Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin fromBordetella pertussisin Infants, Children, and Adults
Authors: Dirix Violette , Verscheure Virginie , Vermeulen Françoise , De Schutter Iris , Goetghebuer Tessa , Locht Camille , Mascart Françoise
Published: April 2012

Infant CD4+T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8+T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8+T-cell responses uponBordetella pertussisinfection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γsecretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4+and CD8+T lymphocytes are involved in IFN-γproduction. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4+lymphocytes were the major source of this cytokine. IFN-γsynthesis by CD8+cells was CD4+T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γsynthesis by CD4+cells was sometimes inhibited by CD8+lymphocytes, suggesting the presence of CD8+regulatory T cells. The role of this dual IFN-γsecretion by CD4+and CD8+T lymphocytes in pertussis remains to be investigated.
Suboptimal Immune Reconstitution in Vertically HIV Infected Children: A View on How HIV Replication and Timing of HAART Initiation Can Impact on T and B-cell Compartment
Authors: Cotugno Nicola , Douagi Iyadh , Rossi Paolo , Palma Paolo
Published: April 2012

Today, HIV-infected children who have access to treatment face a chronic rather than a progressive and fatal disease. As a result, new challenges are emerging in the field. Recent lines of evidence outline several factors that can differently affect the ability of the immune system to fully reconstitute and to mount specific immune responses in children receiving HAART. In this paper, we review the underlying mechanisms of immune reconstitution after HAART initiation among vertically HIV-infected children analyzing the possible causes of suboptimal responses.
Oxidative Carbonylation of 2-Propyn-1-ol and 2-Methyl-3-butyn-2-ol in an Oscillatory Mode
Authors: Gorodsky Sergey Nikolaevich
Published: April 2012

The oscillatory modes of oxidative carbonylation reaction of two new substrates—2-methyl-3-butyn-2-ol and 2-propyn-1-ol in homogeneous system PdI2-KI-CO-O2-CH3OH are found. Borders of oscillatory areas are drawn, the basic products of reaction are identified, and probable processes routes are offered.
Glyoxal Formation and Its Role in Endogenous Oxalate Synthesis
Authors: Lange Jessica N. , Wood Kyle D. , Knight John , Assimos Dean G. , Holmes Ross P.
Published: April 2012

Calcium oxalate kidney stones are a common condition affecting many people in the United States. The concentration of oxalate in urine is a major risk factor for stone formation. There is evidence that glyoxal metabolism may be an important contributor to urinary oxalate excretion. Endogenous sources of glyoxal include the catabolism of carbohydrates, proteins, and fats. Here, we review all the known sources of glyoxal as well as its relationship to oxalate synthesis and crystal formation.
Effects of Abiotic Factors on the Geographic Distribution of Body Size Variation and Chromosomal Polymorphisms in Two Neotropical Grasshopper Species (Dichroplus: Melanoplinae: Acrididae)
Authors: Bidau Claudio J. , Miño Carolina I. , Castillo Elio R. , Martí Dardo A.
Published: April 2012

We review the effects of abiotic factors on body size in two grasshopper species with large geographical distributions:Dichroplus pratensisandD. vittatus, inhabiting Argentina in diverse natural habitats. Geographical spans for both species provide an opportunity to study the effects of changes in abiotic factors on body size. The analyses of body size distribution in both species revealed a converse Bergmannian pattern: body size is positively correlated with latitude, altitude, and seasonality that influences time available for development and growth. Allen’s rule is also inverted. Morphological variability increases towards the ends of the Bergmannian clines and, inD. pratensis, is related with a central-marginal distribution of chromosomal variants that influence recombination. The converse Bergmannian patterns influence sexual size dimorphism in both species but in different fashions. Body size variation at a microspatial scale inD. pratensisis extremely sensitive to microclimatic clines. We finally compare our results with those for other Orthopteran species.
Robust Adaptive Control via Neural Linearization and Compensation
Authors: Rodríguez Roberto Carmona , Yu Wen
Published: April 2012

We propose a new type of neural adaptive control via dynamic neural networks. For a class of unknown nonlinear systems, a neural identifier-based feedback linearization controller is first used. Dead-zone and projection techniques are applied to assure the stability of neural identification. Then four types of compensator are addressed. The stability of closed-loop system is also proven.
Newborn Screening Services in Bahrain between 1985 and 2010
Authors: Al Arrayed Shaikha , Al Hajeri Amani
Published: April 2012

Introduction. The incidence of genetic blood disease in Bahrain has declined gradually since 1984 when the Ministry of Health (MOH) instituted a prevention campaign. The national NBS program for hemoglobinopathies was started in May 2007, financed by the national budget.Setting. Genetics department, Salmaniya Medical Complex, MOH, Bahrain.Methodology. The genetics, nursing, pathology, and pediatric departments were involved in the study. This service was offered to all infants. Cord blood samples were collected at birth and were then sent to the laboratory.Results. During 3.5 years after the program was implemented, we screened 38,940 newborns (NBs), of which 17,375 were screened in 2008, 10,248 in 2009, and 11,317 in 2010. The number of affected NBs was 128 in both 2007 and 2008, 58 in 2009, and 47 in 2010, as the average number of affected NBs in 2010 was 4 per month. The incidence of affected NBs was found to be 0.7% in 2008, 0.6% in 2009, and 0.4% in 2010.Conclusion. NBS is an essential step for the early diagnosis and treatment of affected NBs, future recurrence of the disease in the same family. In Bahrain, the number of affected NBs has declined by 75% during the last 20.
Nanocytology of Rectal Colonocytes to Assess Risk of Colon Cancer Based on Field Cancerization
Authors: Damania Dhwanil , Roy Hemant K. , Subramanian Hariharan , Weinberg David S. , Rex Douglas K. , Goldberg Michael J. , Muldoon Joseph , Cherkezyan Lusik , Zhu Yuanjia , Bianchi Laura K. , Shah Dhiren , Pradhan Prabhakar , Borkar Monica , Lynch Henry , Backman Vadim
Published: April 2012

Developing a minimally invasive and cost-effective prescreening strategy for colon cancer is critical because of the impossibility of conducting colonoscopy on the entire at-risk population. The concept of field carcinogenesis, in which normal-appearing tissue away from a tumor has molecular and, consequently, nano-architectural abnormalities, offers one attractive approach to identify high-risk patients. In this study, we investigated whether the novel imaging technique partial wave spectroscopic (PWS) microscopy could risk-stratify patients harboring precancerous lesions of the colon, using an optically measured biomarker (Ld) obtained from microscopically normal but nanoscopically altered cells. Rectal epithelial cells were examined from 146 patients, including 72 control patients, 14 patients with diminutive adenomas, 20 patients with nondiminutive/nonadvanced adenomas, 15 patients with advanced adenomas/high-grade dysplasia, 12 patients with genetic mutation leading to Lynch syndrome, and 13 patients with cancer. We found that the Ld obtained from rectal colonocytes was well correlated with colon tumorigenicity in our patient cohort and in an independent validation set of 39 additional patients. Therefore, our findings suggest that PWS-measured Ld is an accurate marker of field carcinogenesis. This approach provides a potential prescreening strategy for risk stratification before colonoscopy. Cancer Res; 72(11); 2720–7. ©2012 AACR.