bluuebunny/crossref_metadata_2025 huggingface dataset:
A single-sided representation for the homogeneous Green's function of a unified scalar wave equation
Authors: Wapenaar Kees
Published: June 2017

A unified scalar wave equation is formulated, which covers three-dimensional (3D) acoustic waves, 2D horizontally-polarised shear waves, 2D transverse-electric EM waves, 2D transverse-magnetic EM waves, 3D quantum-mechanical waves and 2D flexural waves. The homogeneous Green's function of this wave equation is a combination of the causal Green's function and its time-reversal, such that their singularities at the source position cancel each other. A classical representation expresses this homogeneous Green's function as a closed boundary integral. This representation finds applications in holographic imaging, time-reversed wave propagation and Green's function retrieval by cross correlation. The main drawback of the classical representation in those applications is that it requires access to a closed boundary around the medium of interest, whereas in many practical situations the medium can be accessed from one side only. Therefore, a single-sided representation is derived for the homogeneous Green's function of the unified scalar wave equation. Like the classical representation, this single-sided representation fully accounts for multiple scattering. The single-sided representation has the same applications as the classical representation, but unlike the classical representation it is applicable in situations where the medium of interest is accessible from one side only.
In-situ shear-banding quantification of surfactant solutions in straight microfluidic channels
Authors: Lutz-Bueno Viviane , Pasquino Rossana , Haward Simon J. , Shen Amy Q. , Fischer Peter
Published: June 2017

Surfactant molecules aggregate into various micellar morphologies, depending on temperature, concentration, formulation, and flow. Micellar solutions are known to undergo shear-banding when subjected to strong shear rates, as the fluid spontaneously divides itself into bands of high and low-shear rate, both under the same applied shear stress. This phenomenon occurs because of the complex structure of micellar solutions, which undergo phase transitions upon applied flow, changing the viscosity accordingly. Here, we study shear-banding of micellar solutions in one of the simplest microfluidic geometries, a straight planar channel with rectangular cross section. Four solutions with similar zero-shear viscosity and nonlinear rheological response, but different structures are compared to investigate the flow-structure relation and its impact on shear-banding. Micellar solutions are prepared by adding different amounts of the same organic salt, sodium salicylate, to surfactant molecules with different headgroups, i.e., cetyltrimethylammonium bromide and cetylpyridinium chloride. From spatially resolved microparticle image velocimetry and flow-induced birefringence measurements, the shear rate and shear stress profiles developed on the xy-plane of a planar microchannel are obtained from a series of volumetric flow rates. Based on these profiles, in-situ rheological parameters, such as the local viscosity, are calculated by applying the stress-optical rule. The local response in a microfluidic channel is compared to the bulk rheological response in a rotational rheometer and clear correlations are found especially for the stress plateau region, the fingerprint of shear-banding. Based on the local rheological characterization of these micellar solutions, the development and growth of shear-bands is observed and quantified. The role of salt concentration and surfactant headgroup on the resulting micellar morphology is discussed, as well as its impact on the development of shear-banding.
Emergency Department Urinary Antibiograms Differ by Specific Patient Group
Authors: Jorgensen S. , Zurayk M. , Yeung S. , Terry J. , Dunn M. , Nieberg P. , Wong-Beringer A.
Published: June 2017

Patients presenting to the emergency department (ED) represent a heterogeneous population comprised of all ages, various backgrounds, such as from the community and skilled-nursing facilities (SNFs), and at various risks for resistant pathogens. The aim of this study was to compare patient group-specific urinary antibiograms in the ED. Adults presented to the ED with an ICD 9/10 code urinary tract infection (UTI) diagnosis during July 2015 to June 2016 were randomly selected (
n
= 500) to extract relevant demographic, laboratory, and clinical data from the medical record. Urinary
Escherichia coli
antibiograms were compared between institutional versus ED and among ED patients (male versus female; age of 18 to 64 years versus ≥65 years; female aged 18 to 50 years versus >50 years; home versus SNF; and admitted versus discharged).
E. coli
grew from 56% (145/259) of the positive urine cultures. Overall ciprofloxacin (CIP), trimethoprim-sulfamethoxazole (SXT), and cefazolin (CFZ) susceptibilities were <71%. Differences in antibiograms were the following: lower CFZ and SXT susceptibilities in ED versus institutional (CFZ, 67% versus 86% [
P
= 0.001]; SXT, 66% versus 74% [
P
= 0.02]), lower ampicillin and gentamicin susceptibilities in females aged 18 to 50 years versus >50 years (32% versus 52% [
P
= 0.04]; 78% versus 93% [
P
= 0.02]), lower CIP susceptibilities in the elderly (64% versus 81%;
P
= 0.03), SNF versus home (35% versus 77%;
P
< 0.001), admitted versus discharged (63% versus 78%;
P
= 0.04), and lower SXT susceptibilities in patients aged <65 years versus the elderly (58% versus 71%;
P
= 0.01). Nitrofurantoin showed >80% susceptibility in all groups. Patient group-specific urinary antibiograms revealed distinct differences in
E. coli
susceptibility and should be developed to better inform empirical UTI therapy selection in the ED.
Is This the Carbapenemase Test We've Been Waiting for? A Multicenter Evaluation of the Modified Carbapenem Inactivation Method
Authors: Butler-Wu Susan M. , Abbott April N.
Published: June 2017

A plethora of phenotypic methods exist for the detection of carbapenemases; however, clinical laboratories have struggled for years with accurate, objective phenotypic detection of carbapenemase activity in
Enterobacteriaceae
. In this issue of the
Journal of Clinical Microbiology
, V. M. Pierce et al. (J Clin Microbiol 55:2321–2333, 2017,
https://doi.org/10.1128/JCM.00193-17
) report on a multicenter evaluation of the modified carbapenem inactivation method (mCIM). The high sensitivity, specificity, reproducibility, and ease of interpretation associated with the mCIM for
Enterobacteriaceae
will likely lead to its adoption by clinical laboratories.
Clostridium difficile PCR Cycle Threshold Predicts Free Toxin
Authors: Senchyna Fiona , Gaur Rajiv L. , Gombar Saurabh , Truong Cynthia Y. , Schroeder Lee F. , Banaei Niaz
Published: June 2017

There is no stand-alone
Clostridium difficile
diagnostic that can sensitively and rapidly detect fecal free toxins. We investigated the performance of the
C. difficile
PCR cycle threshold (

C
T

) for predicting free toxin status. Consecutive stool samples (
n
= 312) positive for toxigenic
C. difficile
by the GeneXpert
C. difficile
/Epi
tcdB
PCR assay were tested with the rapid membrane C. Diff Quik Chek Complete immunoassay (RMEIA). RMEIA toxin-negative samples were tested with the cell cytotoxicity neutralization assay (CCNA) and tgcBIOMICS enzyme-linked immunosorbent assay (ELISA). Using RMEIA alone or in combination with CCNA and/or ELISA as the reference method, the accuracy of

C
T

was measured at different

C
T

cutoffs. Using RMEIA as the reference method, a

C
T

cutoff of 26.35 detected toxin-positive samples with a sensitivity, specificity, positive predictive value, and negative predictive value of 96.0% (95% confidence interval [CI], 90.2% to 98.9%), 65.9% (95% CI, 59.0% to 72.2%), 57.4% (95% CI, 52.7% to 62%), and 97.1% (95% CI, 92.8% to 98.9), respectively. Inclusion of CCNA in the reference method improved

C
T

specificity to 78.0% (95% CI, 70.7% to 84.2%). Intercartridge lot

C
T

variability measured as the average coefficient of variation was 2.8% (95% CI, 1.2% to 3.2%). Standardizing the input stool volume did not improve

C
T

toxin specificity. The median

C
T

values were not significantly different between stool samples with Bristol scores of 5, 6, and 7, between pediatric and adult samples, or between presumptive 027 and non-027 strains. In addition to sensitively detecting toxigenic
C. difficile
in stool, on-demand PCR may also be used to accurately predict toxin-negative stool samples, thus providing additional results in PCR-positive stool samples to guide therapy.
Impaired Downregulation of NKG2D Ligands by Nef Proteins from Elite Controllers Sensitizes HIV-1-Infected Cells to Antibody-Dependent Cellular Cytotoxicity
Authors: Alsahafi Nirmin , Richard Jonathan , Prévost Jérémie , Coutu Mathieu , Brassard Nathalie , Parsons Matthew S. , Kaufmann Daniel E. , Brockman Mark , Finzi Andrés
Published: June 2017

HIV-1 Nef clones isolated from a rare subset of HIV-1-infected elite controllers (EC), with the ability to suppress viral load to undetectable levels in the absence of antiretroviral therapy, are unable to fully downregulate CD4 from the plasma membrane of CD4
+
T cells. Residual CD4 left at the plasma membrane allows Env-CD4 interaction, which leads to increased exposure of Env CD4-induced epitopes and increases susceptibility of infected cells to antibody-dependent cellular cytotoxicity (ADCC). ADCC is mediated largely by natural killer (NK) cells, which control their activation status through the cumulative signals received through activating and inhibitory receptors. Recently, the activating NKG2D receptor was demonstrated to positively influence ADCC responses. Since HIV-1 Nef has been reported to reduce the expression of NKG2D ligands, we evaluated the relative abilities of Nef from EC and progressors to downmodulate NKG2D ligands. Furthermore, we assessed the impact of EC and progressor Nef on the ADCC susceptibility of HIV-1-infected cells. We observed a significantly increased expression of NKG2D ligands on cells infected with viruses coding for Nef from EC. Importantly, NKG2D ligand expression levels correlated with enhanced susceptibility of HIV-1-infected cells to ADCC. The biological significance of this correlation was corroborated by the demonstration that antibody-mediated blockade of NKG2D significantly reduced ADCC of cells infected with viruses carrying Nef from EC. These results suggest the involvement of NKG2D-NKG2D ligand interactions in the enhanced susceptibility of EC HIV-1-infected cells to ADCC responses.

IMPORTANCE
Attenuated Nef functions have been reported in HIV-1 isolated from EC. The inability of elite controller Nef to fully remove CD4 from the surface of infected cells enhanced their susceptibility to elimination by ADCC. We now show that downregulation of NKG2D ligands by HIV-1 Nef from EC is inefficient and leaves infected cells susceptible to ADCC. These data suggest a critical role for NKG2D ligands in anti-HIV-1 ADCC responses.
Polymorphic Nature of Human T-Cell Leukemia Virus Type 1 Particle Cores as Revealed through Characterization of a Chronically Infected Cell Line
Authors: Meissner Morgan E. , Mendonça Luiza M. , Zhang Wei , Mansky Louis M.
Published: June 2017

Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 cell-to-cell transmission is dependent on the release of infectious virus particles into the virological synapse. The HTLV-1 particle structure is still poorly understood, and previous studies analyzed viruses produced by transformed lymphocytic cell lines chronically infected with HTLV-1, particularly the MT-2 cell line, which harbors truncated proviruses and expresses aberrant forms of the Gag protein. In this study, we demonstrate that the chronically infected SP cell line harbors a relatively low number of proviruses, making it a more promising experimental system for the study of the HTLV-1 particle structure. We first identified the genomic sites of integration and characterized the genetic structure of the
gag
region in each provirus. We also determined that despite encoding a truncated Gag protein, only the full-length Gag protein was incorporated into virus particles. Cryo-transmission electron microscopy analyses of the purified virus particles revealed three classes of particles based upon capsid core morphology: complete cores, incomplete cores, and particles without distinct electron densities that would correlate with the capsid region of a core structure. Observed cores were generally polygonal, and virus particles were on average 115 nm in diameter. These data corroborate particle morphologies previously observed for MT-2 cells and provide evidence that the known poor infectivity of HTLV-1 particles may correlate with HTLV-1 particle populations containing few virus particles possessing a complete capsid core structure.

IMPORTANCE
Studies of retroviral particle core morphology have demonstrated a correlation between capsid core stability and the relative infectivity of the virus. In this study, we used cryo-transmission electron microscopy to demonstrate that HTLV-1 particles produced from a distinct chronically infected cell line are polymorphic in nature, with many particles lacking organized electron densities that would correlate with a complete core structure. These findings have important implications for infectious HTLV-1 spread, particularly in the context of cell-to-cell transmission, a critical step in HTLV-1 transmission and pathogenesis.
In VitroReplication of Chelonid Herpesvirus 5 in Organotypic Skin Cultures from Hawaiian Green Turtles (Chelonia mydas)
Authors: Work Thierry M. , Dagenais Julie , Weatherby Tina M. , Balazs George H. , Ackermann Mathias
Published: June 2017

Fibropapillomatosis (FP) is a tumor disease of marine turtles associated with chelonid herpesvirus 5 (ChHV5), which has historically been refractory to growth in tissue culture. Here we show, for the first time,de novoformation of ChHV5-positive intranuclear inclusions in cultured green turtle cells, which is indicative of active lytic replication of the virus. The minimal requirements to achieve lytic replication in cultured cells included (i) eitherin vitrocultures of ChHV5-positive tumor biopsy specimens (plugs) or organotypic cultures (rafts) consisting of ChHV5-positive turtle fibroblasts in collagen rafts seeded with turtle keratinocytes and (ii) keratinocyte maturation induced by raising raft or biopsy cultures to the air-liquid interface. Virus growth was confirmed by detailed electron microscopic studies that revealed intranuclear sun-shaped capsid factories, tubules, various stages of capsid formation, nuclear export by budding into the perinuclear space, tegument formation, and envelopment to completede novovirus production. Membrane synthesis was also observed as a sign of active viral replication. Interestingly, cytoplasmic particles became associated with keratin filaments, a feature not seen in conventional monolayer cell cultures, in which most studies of herpesvirus replication have been performed. Our findings draw a rich and realistic picture of ChHV5 replication in cells derived from its natural host and may be crucial not only to better understand ChHV5 circulation but also to eventually complete Koch's postulates for FP. Moreover, the principles described here may serve as a model for culture of other viruses that are resistant to replication in conventional cell culture.

IMPORTANCEA major challenge in virology is the study of viruses that cannot be grown in the laboratory. One example is chelonid herpesvirus 5 (ChHV5), which is associated with fibropapillomatosis, a globally distributed, debilitating, and fatal tumor disease of endangered marine turtles. Pathological examination shows that ChHV5 is shed in skin. Here we show that ChHV5 will growin vitroif we replicate the complex three-dimensional structure of turtle skin. Moreover, lytic virus growth requires a close interplay between fibroblasts and keratinocytes. Finally, the morphogenesis of herpesviral growth in three-dimensional cultures reveals a far richer, and likely more realistic, array of capsid morphologies than that encountered in traditional monolayer cell cultures. Our findings have applications to other viruses, including those of humans.
Follicular Regulatory T Cells Are Highly Permissive to R5-Tropic HIV-1
Authors: Miller Shannon M. , Miles Brodie , Guo Kejun , Folkvord Joy , Meditz Amie L. , McCarter Martin D. , Levy David N. , MaWhinney Samantha , Santiago Mario L. , Connick Elizabeth
Published: June 2017

Follicular regulatory T (TFR) cells are a subset of CD4+T cells in secondary lymphoid follicles. TFR cells were previously included in the follicular helper T (TFH) cell subset, which consists of cells that are highly permissive to HIV-1. The permissivity of TFR cells to HIV-1 is unknown. We find that TFR cells are more permissive than TFH cells to R5-tropic HIV-1ex vivo. TFR cells expressed more CCR5 and CD4 and supported higher frequencies of viral fusion. Differences in Ki67 expression correlated with HIV-1 replication. Inhibiting cellular proliferation reduced Ki67 expression and HIV-1 replication. Lymph node cells from untreated HIV-infected individuals revealed that TFR cells harbored the highest concentrations of HIV-1 RNA and highest levels of Ki67 expression. These data demonstrate that TFR cells are highly permissive to R5-tropic HIV-1 bothex vivoandin vivo. This is likely related to elevated CCR5 levels combined with a heightened proliferative state and suggests that TFR cells contribute to persistent R5-tropic HIV-1 replicationin vivo.

IMPORTANCEIn chronic, untreated HIV-1 infection, viral replication is concentrated in secondary lymphoid follicles. Within secondary lymphoid follicles, follicular helper T (TFH) cells have previously been shown to be highly permissive to HIV-1. Recently, another subset of T cells in secondary lymphoid follicles was described, follicular regulatory T (TFR) cells. These cells share some phenotypic characteristics with TFH cells, and studies that showed that TFH cells are highly permissive to HIV-1 included TFR cells in their definition of TFH cells. The permissivity of TFR cells to HIV-1 has not previously been described. Here, we show that TFR cells are highly permissive to HIV-1 bothex vivoandin vivo. The expression of Ki67, a marker of proliferative capacity, is predictive of expression of viral proteins, and downregulating Ki67 leads to concurrent decreases in expression of viral proteins. Our study provides new insight into HIV-1 replication and a potential new cell type to target for future treatment.
Conserved Vδ1 Binding Geometry in a Setting of Locus-Disparate pHLA Recognition by δ/αβ T Cell Receptors (TCRs): Insight into Recognition of HIV Peptides by TCRs
Authors: Shi Yi , Kawana-Tachikawa Ai , Gao Feng , Qi Jianxun , Liu Chuansheng , Gao Jia , Cheng Hao , Ueno Takamasa , Iwamoto Aikichi , Gao George F.
Published: June 2017

Given the limited set of T cell receptor (TCR) V genes that are used to create TCRs that are reactive to different ligands, such as major histocompatibility complex (MHC) class I, MHC class II, and MHC-like proteins (for example, MIC molecules and CD1 molecules), the Vδ1 segment can be rearranged with Dδ-Jδ-Cδ or Jα-Cα segments to form classical γδTCRs or uncommon αβTCRs using a Vδ1 segment (δ/αβTCR). Here we have determined two complex structures of the δ/αβTCRs (S19-2 and TU55) bound to different locus-disparate MHC class I molecules with HIV peptides (HLA-A*2402-Nef138-10 and HLA-B*3501-Pol448-9). The overall binding modes resemble those of classical αβTCRs but display a strong tilt binding geometry of the Vδ1 domain toward the HLA α1 helix, due to a conserved extensive interaction between the CDR1δ loop and the N-terminal region of the α1 helix (mainly in position 62). The aromatic amino acids of the CDR1δ loop exploit different conformations (“aromatic ladder” or “aromatic hairpin”) to accommodate distinct MHC helical scaffolds. This tolerance helps to explain how a particular TCR V region can similarly dock onto multiple MHC molecules and thus may potentially explain the nature of TCR cross-reactivity. In addition, the length of the CDR3δ loop could affect the extent of tilt binding of the Vδ1 domain, and adaptively, the pairing Vβ domains adjust their mass centers to generate differential MHC contacts, hence probably ensuring TCR specificity for a certain peptide-MHC class I (pMHC-I). Our data have provided further structural insights into the TCR recognition of classical pMHC-I molecules, unifying cross-reactivity and specificity.

IMPORTANCEThe specificity of αβ T cell recognition is determined by the CDR loops of the αβTCR, and the general mode of binding of αβTCRs to pMHC has been established over the last decade. Due to the intrinsic genomic structure of the TCR α/δ chain locus, some Vδ segments can rearrange with the Cα segment, forming a hybrid VδCαVβCβ TCR, the δ/αβTCR. However, the basis for the molecular recognition of such TCRs of their ligands is elusive. Here an αβTCR using the Vδ1 segment, S19-2, was isolated from an HIV-infected patient in an HLA-A*24:02-restricted manner. We then solved the crystal structures of the S19-2 TCR and another δ/αβTCR, TU55, bound to their respective ligands, revealing a conserved Vδ1 binding feature. Further binding kinetics analysis revealed that the S19-2 and TU55 TCRs bind pHLA very tightly and in a long-lasting manner. Our results illustrate the mode of binding of a TCR using the Vδ1 segment to its ligand, virus-derived pHLA.
Allosteric HIV-1 Integrase Inhibitors Lead to Premature Degradation of the Viral RNA Genome and Integrase in Target Cells
Authors: Madison Michaela K. , Lawson Dana Q. , Elliott Jennifer , Ozantürk Ayşe Naz , Koneru Pratibha C. , Townsend Dana , Errando Manel , Kvaratskhelia Mamuka , Kutluay Sebla B.
Published: June 2017

Recent evidence indicates that inhibition of HIV-1 integrase (IN) binding to the viral RNA genome by allosteric integrase inhibitors (ALLINIs) or through mutations within IN yields aberrant particles in which the viral ribonucleoprotein complexes (vRNPs) are eccentrically localized outside the capsid lattice. These particles are noninfectious and are blocked at an early reverse transcription stage in target cells. However, the basis of this reverse transcription defect is unknown. Here, we show that the viral RNA genome and IN from ALLINI-treated virions are prematurely degraded in target cells, whereas reverse transcriptase remains active and stably associated with the capsid lattice. The aberrantly shaped cores in ALLINI-treated particles can efficiently saturate and be degraded by a restricting TRIM5 protein, indicating that they are still composed of capsid proteins arranged in a hexagonal lattice. Notably, the fates of viral core components follow a similar pattern in cells infected with eccentric particles generated by mutations within IN that inhibit its binding to the viral RNA genome. We propose that IN-RNA interactions allow packaging of both the viral RNA genome and IN within the protective capsid lattice to ensure subsequent reverse transcription and productive infection in target cells. Conversely, disruption of these interactions by ALLINIs or mutations in IN leads to premature degradation of both the viral RNA genome and IN, as well as the spatial separation of reverse transcriptase from the viral genome during early steps of infection.

IMPORTANCE
Recent evidence indicates that HIV-1 integrase (IN) plays a key role during particle maturation by binding to the viral RNA genome. Inhibition of IN-RNA interactions yields aberrant particles with the viral ribonucleoprotein complexes (vRNPs) eccentrically localized outside the conical capsid lattice. Although these particles contain all of the components necessary for reverse transcription, they are blocked at an early reverse transcription stage in target cells. To explain the basis of this defect, we tracked the fates of multiple viral components in infected cells. Here, we show that the viral RNA genome and IN in eccentric particles are prematurely degraded, whereas reverse transcriptase remains active and stably associated within the capsid lattice. We propose that IN-RNA interactions ensure the packaging of both vRNPs and IN within the protective capsid cores to facilitate subsequent reverse transcription and productive infection in target cells.
Prenatal markers and longitudinal follow-up in simple and complex gastroschisis
Authors: Hijkoop Annelieke , IJsselstijn Hanneke , Wijnen René M H , Tibboel Dick , Rosmalen Joost van , Cohen-Overbeek Titia E
Published: June 2017

Objective

We aimed to identify gestational-age corrected prenatal ultrasound markers of complex gastroschisis, and to compare physical growth and neurodevelopment between children with simple and complex gastroschisis.

Design

We included prenatally diagnosed gastroschisis patients from 2000 to 2012 who joined our longitudinal follow-up programme. Associations between complex gastroschisis and prenatal ultrasound markers collected at 30 weeks’ gestation and prior to delivery were tested using logistic regression. Physical growth (SD scores (SDS)), mental and psychomotor developmental index (MDI, PDI; Bayley Scales of Infant Development) were recorded at 12 and 24 months. Data were analysed using general linear models and compared with population norms.

Results

Data of 61 children were analysed (82% of eligible cases). Extra-abdominal bowel dilatation at 30 weeks’ gestation was significantly associated with complex gastroschisis (OR (95% CI): 5.00 (1.09 to 22.98)), with a high negative (88%) but low positive (40%) predictive value. The mean (95% CI) height SDS at 12 months (−0.46 (–0.82 to –0.11)), and weight SDS at 12 and 24 months (−0.45 (–0.85 to –0.05), and −0.44 (−0.87 to –0.01), respectively) fell significantly below 0 SDS. MDI and PDI were significantly below 100 at 24 months; 93 (88 to 99) and 83 (78 to 87), respectively). Children with complex gastroschisis had a significantly lower PDI (76 (68 to 84)) than those with simple gastroschisis (94 (90 to 97), p<0.001).

Conclusions

Prenatal ultrasound markers could not reliably distinguish between simple and complex gastroschisis. Children with complex gastroschisis may be at increased risk for delayed psychomotor development; they should be monitored more closely, and offered timely intervention.
Ibuprofen exposure in early neonatal life does not affect renal function in young adolescence
Authors: Raaijmakers Anke , Zhang Zhen-Yu , Levtchenko Elena , Simons Sinno HP , Cauwenberghs Nicholas , Heuvel Lambertus P van den , Jacobs Lotte , Staessen Jan A , Allegaert Karel
Published: June 2017

Introduction

Ibuprofen exposure results in acute transient renal dysfunction in preterm neonates, but we are unaware of data on long-term renal safety.

Methods

In a previously studied cohort of extreme low birth weight (ELBW, <1000 g) cases, the PREMATurity as predictor of children’s Cardiovascular-renal Health study generated data on renal function (renal length, estimated glomerular filtration rate based on cystatin C (eGFRcysC) at the age of 11 years. This data set in 93 ELBW cases may also generate data on long-term drug safety on ibuprofen. In this post hoc analysis, we linked markers of renal function in young adolescence in ELBW cases with their perinatal (prenatal maternal, setting at birth, treatment modalities including drug prescription during neonatal stay, neonatal creatinine values, postdischarge growth) characteristics, including but not limited to ibuprofen exposure during neonatal stay.

Results

Ibuprofen exposure was not associated with significant differences in renal length or eGFRcysC. Moreover, we were unable to identify any other risk factor (perinatal characteristics, postnatal creatinine trends, postdischarge growth) on renal outcome in this cohort.

Conclusions

Neonatal exposure to ibuprofen did not affect renal function. Larger studies are needed to explore the confounders of variability in renal function in former ELBW cases. This matters since ELBW relates to risk for hypertension, cardiovascular events and renal disease in later life and identification of risk factors holds the promise of secondary prevention.

Trial registration number

NCT02147457.
Tension enterothorax and hepatothorax due to a diaphragmatic hernia: successful emergency repair of a life-threatening condition
Authors: Martinou Eirini , Gatenby Piers
Published: June 2017

A 70-year-old female patient presented with acute severe respiratory distress at a district general hospital. Medical history included type 2 diabetes, recurrent pulmonary embolisms and pre-existing diaphragmatic hernia containing part of the liver. Despite initial treatment with steroid inhalers, her clinical picture rapidly deteriorated requiring emergency intubation and positive pressure ventilation. Imaging investigations revealed tension enterothorax and hepatothorax with tracheal deviation. The patient was transferred and underwent an emergency laparotomy at the Regional Oesophagogastric Unit. A large diaphragmatic hernia (central tendon defect) which contained the duodenum, porta hepatis, right lobe of liver, gallbladder and right colon was reduced and successfully repaired. Her postoperative course was uneventful with no signs of recurrence at 2 months follow-up.

This case describes an extremely rare and life-threatening condition of tension enterothorax and hepatothorax, which should be considered in the differential diagnosis of acute respiratory distress with tracheal deviation.
Large bladder calculus masking a stone in single-system ureterocele
Authors: Bhaskar Ved , Sinha Rahul Janak , Purkait Bimalesh , Singh Vishwajeet
Published: June 2017

Ureterocele in an elderly is a rare entity. The presence of stone within ureterocele along with a large bladder calculus is an even rarer presentation. This phenomenon has not been reported so far to the best of our knowledge. We present an unusual case of a large bladder calculus with a concomitant stone in the associated ureterocele. The diagnosis was missed in the first instance due to the masking effect by the larger bladder calculus. Herein, we discuss this case and its management.
Postgastric bypass hypoglycaemia in a patient with end-stage renal disease: a diagnostic and management pitfall
Authors: Khalid Sameen , Bilal Anika , Asad-ur-Rahman F N U , Pratley Richard
Published: June 2017

Roux-en-Y gastric bypass (RYGB) surgery is currently one of the most popular procedures to aid weight loss. Hypoglycaemia associated with gastric bypass surgery is an underdiagnosed but life-threatening potential consequence of the surgical procedure. We present a case of a 44-year-old woman with end-stage renal disease presenting with refractory hypoglycaemia after 10 years of RYGB. Extensive history and work-up excluded medications, renal disease, insulinoma and dumping syndrome as the cause of hypoglycaemia. Dietary modifications or pharmacological trial of drugs did not ameliorate her symptoms with progressive worsening of hypoglycaemia leading to continuous dextrose infusion. Distal pancreatectomy was performed with subsequent resolution of hypoglycaemia. Surgical pathology results showed diffuse hyperplastic islet cells, confirming the diagnosis of postgastric bypass hypoglycaemia.
Does leisure time physical activity protect against low back pain? Systematic review and meta-analysis of 36 prospective cohort studies
Authors: Shiri Rahman , Falah-Hassani Kobra
Published: June 2017

Background

There are plausible mechanisms whereby leisure time physical activity may protect against low back pain (LBP) but there have been no quality systematic reviews and meta-analyses of the subject.

Objective

This review aims to assess the effect of leisure time physical activity on non-specific LBP.

Methods

Literature searches were conducted in PubMed, Embase, Web of Science, Scopus and Google Scholar databases from their inception through July 2016. Methodological quality of included studies was evaluated. A random-effects meta-analysis was performed, and heterogeneity and publication bias were assessed.

Results

Thirty-six prospective cohort studies (n=158 475 participants) qualified for meta-analyses. Participation in sport or other leisure physical activity reduced the risk of frequent or chronic LBP, but not LBP for>1 day in the past month or past 6–12 months. Risk of frequent/chronic LBP was 11% lower (adjusted risk ratio (RR)=0.89, CI 0.82 to 0.97, I2=31%, n=48 520) in moderately/highly active individuals, 14% lower (RR=0.86, CI 0.79 to 0.94, I2=0%, n=33 032) in moderately active individuals and 16% lower (RR=0.84, CI 0.75 to 0.93, I2=0%, n=33 032) in highly active individuals in comparison with individuals without regular physical activity. For LBP in the past 1–12 months, adjusted RR was 0.98 (CI 0.93 to 1.03, I2=50%, n=32 654) for moderate/high level of activity, 0.94 (CI 0.84 to 1.05, I2=3%, n=8549) for moderate level of activity and 1.06 (CI 0.89 to 1.25, I2=53%, n=8554) for high level of activity.

Conclusions

Leisure time physical activity may reduce the risk of chronic LBP by 11%–16%. The finding, however, should be interpreted cautiously due to limitations of the original studies. If this effect size is proven in future research, the public health implications would be substantial.
Acute kidney injury associated with endurance events—is it a cause for concern? A systematic review
Authors: Hodgson LE , Walter E , Venn RM , Galloway R , Pitsiladis Y , Sardat F , Forni LG
Published: June 2017

Introduction

A growing body of evidence suggests even small rises in serum creatinine (SCr) are of considerable clinical relevance. Given that participants in endurance events are exposed to potential (repeated) renal insults, a systematic review was undertaken to collate current evidence for acute kidney injury (AKI), complicating such events.

Methods

A systematic review of studies and case reports meeting inclusion criteria on Medline and EMBASE (inception to October 2015). Included: studies with markers of renal function before and after endurance or ultraendurance events; case reports of severe AKI. Two reviewers assessed risk of bias using the Newcastle-Ottawa scale.

Results

Eleven case report publications (n=27 individuals) of severe AKI, were retrieved, with risk factors including systemic illness or nephrotoxic medications usually identified. From 30 studies of endurance and ultraendurance events, mean rise in SCr was 29 (±12.3) µmol/L after marathon or ultramarathon (17 studies, n=568 participants) events. Where follow-up tests were conducted, SCr returned to baseline within 48 hours. Rises in biomarkers suggest potential parenchymal insult, rather than simply muscle breakdown. However, evidence of long-term deleterious effects is lacking.

Conclusions

Raised levels of SCr are reported immediately after endurance events. It is not clear whether this is either clinically significant, or if repeated participation predisposes to long-term sequelae. The aetiology of severe exercise-associated AKI is usually multifactorial, with risk factors generally identified in the rare cases reported. On-site biochemistry, urine analysis and biomarkers of AKI may help identify collapsed runners who are at significant short-term risk and allow suitable follow-up.
Video analysis of high-magnitude head impacts in men’s collegiate lacrosse
Authors: Kindschi Kari , Higgins Michael , Hillman Andrea , Penczek Gregory , Lincoln Andrew
Published: June 2017

Background/aim

Lacrosse is one of the fastest growing sports in the USA. Efforts to minimise head injuries focus on promoting safe play through player and coach education, rules enforcement and use of effective protective equipment. The study aims to determine event characteristics of high-magnitude head impacts in men’s collegiate lacrosse competitions through video analysis.

Methods

Seventeen Division I men’s collegiate lacrosse players wore instrumented helmets that collected biomechanical measures of head impacts. During 15 competitions, the magnitude of linear acceleration, rotational velocity and helmet impact location were recorded. Impacts with linear accelerations above a 70gthreshold were correlated with video to confirm impact location and to determine event characteristics—source of impact and player activity at the time of impact.

Results

A total of 122 high-magnitude impacts were reviewed on video. Player-to-player contact (n=94, 77.0%) was the most common impact mechanism, followed by stick-to-player contact (n=11, 9.0%). Impacts occurred most often when the athlete was delivering a body check (n=39, 32.0%), fighting for loose ball possession (n=35, 28.7%) or attacking the goal (n=35, 28.7%). The most frequent impact locations were the front of the helmet (n=46, 37.8%) and the left side of the helmet (n=26, 21.3%).

Conclusions

In men’s collegiate lacrosse games, the majority of high-magnitude head impacts resulted from player-to-player contact when the sensored athlete did not have possession of the ball. Video analysis provides the game context for head impact mechanisms, which is critical to developing sport-specific injury prevention strategies.
Antiglycating potential of acesulfame potassium: an artificial sweetener
Authors: Ali Ahmad , More Tejashree Anil , Hoonjan Amaritpal Kaur , Sivakami Subramanian
Published: June 2017

Sweeteners have replaced the natural sugars in the food and beverage industry because of many reasons, such as hyperglycemia and cost. Saccharin, sucralose, aspartame and acesulfame-K are the most commonly used sweeteners. In the present study, the abovementioned artificial sweeteners were used to assess their glycating properties by established methods such as browning, fructosamine assay, determination of carbonyl content, protein aggregation, and measurement of fluorescence. Amadori and advanced glycation end products (AGEs) are formed as a result of the interaction between carbonyl groups of reducing sugars and amino groups of proteins and other macromolecules during glycation. The objective of this study was to investigate the influence of artificial sweeteners on the formation of AGEs and protein oxidation in an in vitro model of glucose-mediated protein glycation. The results indicated that the abovementioned artificial sweeteners do not enhance the process of glycation. On the other hand, acesulfame-K was found to have antiglycating potential as it caused decreased formation of Amadori products and AGEs. Further studies are essential in the characterization of Amadori products and AGEs produced as a result of interaction between sweeteners and proteins, which are interfered with by sweeteners. This study is significant in understanding the probable role of artificial sweeteners in the process of glycation and the subsequent effect on macromolecular alteration.
Can a bottom-moored echo sounder array provide a survey-comparable index of abundance?
Authors: De Robertis Alex , Levine Robert , Wilson Christopher D.
Published: June 2017

A small number of stationary echo sounders have the potential to produce abundance indices where fish repeatedly occupy localized areas (e.g., spawning grounds). To investigate this possibility, we deployed three trawl-resistant moorings with a newly designed autonomous echo sounder for ∼85 days during the walleye pollock (Gadus chalcogrammus) spawning season in Shelikof Strait, Alaska. Backscatter observed from the moorings was highly correlated with ship-based acoustic surveys, suggesting that the mooring observations reflect abundance over much larger areas than the observation volume of the acoustic beam. A retrospective analysis of a 19-year time series of prespawning walleye pollock surveys was used to select mooring locations and determine that three to five moorings can produce an index of walleye pollock backscatter comparable to that produced by a ship-based survey covering ∼18 000 km2 (mean prediction error of <11% for five moorings). The three moorings deployed in Shelikof Strait yielded a backscatter estimate that was within ∼15%–20% of that observed during the survey. Thus, it appears feasible to design a relatively sparse mooring array to provide abundance information and other aspects of fish behavior in this environment.
Trajectory of light ray slightly above the equatorial plane in Kerr geometry and its deflection
Authors: Chakraborty Sarani , Sen A.K.
Published: June 2017

Deflection angle for a light ray travelling in the equatorial plane of a rotating Kerr mass has been calculated in the past by various investigators. Considering the light ray to be travelling only slightly above the equatorial plane, calculations have been made in the present paper for such a ray’s deflection angle. We calculate deflection angles for the light ray at various heights above the equatorial plane, which are small compared to the impact parameter and derive corresponding analytical expressions for deflection angle.
Polysymplectic formulation for topologically massive Yang–Mills field theory
Authors: Berra-Montiel Jasel , del Río Eslava , Molgado Alberto
Published: June 2017

We analyze the De Donder–Weyl covariant field equations for the topologically massive Yang–Mills theory. These equations are obtained through the Poisson–Gerstenhaber bracket described within the polysymplectic framework. Even though the Lagrangian defining the system of our interest is singular, we show that by appropriately choosing the polymomenta one may obtain an equivalent regular Lagrangian, thus avoiding the standard analysis of constraints. Further, our simple treatment allows us to only consider the privileged [Formula: see text]-forms in order to obtain the correct field equations, in opposition to certain examples found in the literature.
Heterogeneous Differential Evolution with Memory Enhanced Brownian and Quantum Individuals for Dynamic Optimization Problems
Authors: Wu Weizu , Xie Dongqing , Liu Liqun
Published: June 2017

In order to solve the dynamic optimization problem (DOP), this paper proposes to use a heterogeneous differential evolution (HDE) algorithm framework with memory enhanced Brownian and quantum (MEBQ) individual scheme. The proposed HDE/MEBQ algorithm has the following two advantages when solving DOP. First and foremost, the HDE optimization framework can satisfy the problem requirement of different characteristics. DOP is actually a continuous process to solve different kinds of optimization problems to meet new requirements when the search environmental change occurs. Therefore, HDE/MEBQ is able to fastly respond to the environmental changes of DOP as the HDE framework uses multiple populations with heterogeneous parameters and operators to meet different search requirements in various search environments. Secondly, according to the phenomenon that most of the environmental changes may not be too drastic in real-world applications, historical information in the past may be useful for finding the optimum solution in the new environment. Thus, the MEBQ scheme used in HDE/MEBQ provides helpful historical evolutionary information from the elite ancestors for guiding individuals to evolve in a new environment strongly and to obtain faster convergence and a more precise solution. We evaluated HDE/MEBQ on several DOPs from CEC 2009 and compared with several state-of-the-art dynamic evolutionary algorithms. The results show that HDE/MEBQ performs superior in statistics and gets very competitive results in most of the test conditions, especially in complex DOPs.
Quasirecognition of E6(q) by the orders of maximal abelian subgroups
Authors: Momen Zahra , Khosravi Behrooz
Published: June 2017

In [Li and Chen, A new characterization of the simple group [Formula: see text], Sib. Math. J. 53(2) (2012) 213–247.], it is proved that the simple group [Formula: see text] is uniquely determined by the set of orders of its maximal abelian subgroups. Also in [Momen and Khosravi, Groups with the same orders of maximal abelian subgroups as [Formula: see text], Monatsh. Math. 174 (2013) 285–303], the authors proved that if [Formula: see text], where [Formula: see text] is not a Mersenne prime, then every finite group with the same orders of maximal abelian subgroups as [Formula: see text], is isomorphic to [Formula: see text] or an extension of [Formula: see text] by a subgroup of the outer automorphism group of [Formula: see text]. In this paper, we prove that if [Formula: see text] is a finite group with the same orders of maximal abelian subgroups as [Formula: see text], then [Formula: see text] has a unique nonabelian composition factor which is isomorphic to [Formula: see text].
Cayley sum graph of ideals of commutative rings
Authors: Chelvam T. Tamizh , Selvakumar K. , Ramanathan V.
Published: June 2017

Let [Formula: see text] be a commutative ring, [Formula: see text] the set of all ideals of [Formula: see text] and [Formula: see text], a subset of [Formula: see text]. The Cayley sum graph of ideals of [Formula: see text], denoted by Cay[Formula: see text], is a simple undirected graph with vertex set is the set [Formula: see text] and, for any two distinct vertices [Formula: see text] and [Formula: see text] are adjacent if and only if [Formula: see text] or [Formula: see text], for some [Formula: see text] in [Formula: see text]. In this paper, we study connectedness, Eulerian and Hamiltonian properties of Cay[Formula: see text]. Moreover, we characterize all commutative Artinian rings [Formula: see text] whose Cay[Formula: see text] is toroidal.
Generating Current Constraints to Guarantee RLC Power Grid Safety
Authors: Moudallal Zahi , Najm Farid N.
Published: June 2017

A critical task during early chip design is the efficient verification of the chip power distribution network. Vectorless verification, developed since the mid-2000s as an alternative to traditional simulation-based methods, requires the user to specify current constraints (budgets) for the underlying circuitry and checks if the corresponding voltage variations on all grid nodes are within a user-specified margin. This framework is extremely powerful, as it allows for efficient and early verification, but specifying/obtaining current constraints remains a burdensome task for users and a hurdle to adoption of this framework by the industry. Recently, the
inverse
problem has been introduced: Generate circuit current constraints that, if satisfied by the underlying logic circuitry, would guarantee grid safety from excessive voltage variations. This approach has many potential applications, including various grid quality metrics, as well as voltage drop-aware placement and floorplanning. So far, this framework has been developed assuming only resistive and capacitive (RC) elements in the power grid model. Inductive effects are becoming a significant component of the power supply noise and can no longer be ignored. In this article, we extend the constraints generation approach to allow for inductance. We give a rigorous problem definition and develop some key theoretical results related to maximality of the current space defined by the constraints. Based on this, we then develop three constraints generation algorithms that target the peak total chip power that is allowed by the grid, the uniformity of current distribution across the die area, and a combination of both metrics.