bluuebunny/crossref_metadata_2025 huggingface dataset:
Phonon thermal conductivity of monolayer MoS2
Authors: Wang Xiaonan , Tabarraei Alireza
Published: May 2016

We use nonequilibrium molecular dynamics modeling using Stillinger–Weber interatomic potential to investigate the thermal properties of monolayer molybdenum disulfide (MoS2) nanoribbons. We study the impact of factors such as length, edge chirality, monovacancies, and uniaxial stretching on the thermal conductivity of MoS2 nanoribbons. Our results show that longer ribbons have a higher thermal conductivity, and the thermal conductivity of infinitely long zigzag and armchair MoS2 nanoribbons is, respectively, 54 W/mK and 33 W/mK. This is significantly lower than the thermal conductivity of some other graphene-like two-dimensional materials such as graphene and boron nitride. While the presence of molybdenum or sulfur vacancies reduces the thermal conductivity of ribbons, molybdenum vacancies have a more deteriorating effect on thermal conductivities. We also have studied the impact of uniaxial stretching on the thermal conductivity of MoS2 nanoribbons. The results show that in contrast to three dimensional materials, thermal conductivity of MoS2 is fairly insensitive to stretching. We have used the phonon dispersion curves and group velocities to investigate the mechanism of this unexpected behavior. Our results show that tensile strain does not alter the phonon dispersion curves and hence the thermal conductivity does not change.
Field electron emission from pencil-drawn cold cathodes
Authors: Chen Jiangtao , Yang Bingjun , Liu Xiahui , Yang Juan , Yan Xingbin
Published: May 2016

Field electron emitters with flat, curved, and linear profiles are fabricated on flexible copy papers by direct pencil-drawing method. This one-step method is free of many restricted conditions such as high-temperature, high vacuum, organic solvents, and multistep. The cold cathodes display good field emission performance and achieve high emission current density of 78 mA/cm2 at an electric field of 3.73 V/μm. The approach proposed here would bring a rapid, low-cost, and eco-friendly route to fabricate but not limited to flexible field emitter devices.
Acoustoelectric transport at gigahertz frequencies in coated epitaxial graphene
Authors: Hernández-Mínguez A. , Tahraoui A. , Lopes J. M. J. , Santos P. V.
Published: May 2016

Epitaxial graphene (EG) produced from SiC surfaces by silicon sublimation is emerging as a material for electronic applications due to its good electronic properties and availability over large areas on a semiconducting substrate. In this contribution, we report on the transport of charge carriers in EG on SiC using high-frequency (>1 GHz) surface acoustic waves (SAWs). In our devices, the EG is coated with hydrogen-silsesquioxane, SiO2, and a ZnO layer. This allows the efficient generation of SAWs and is compatible with the deposition of a metal top gate. Measurements of frequency- and time-resolved power scattering parameters confirm the generation and propagation of SAWs with frequencies of up to more than 7 GHz. Furthermore, the ZnO coating enhances the acoustoelectric currents by two orders of magnitude as compared to our previous uncoated samples. These results are an important step towards the dynamic acoustic control of charge carriers in graphene at gigahertz frequencies.
Spatially correlated structural and optical characterization of a single InGaAs quantum well fin selectively grown on Si by microscopy and cathodoluminescence techniques
Authors: David S. , Roque J. , Rochat N. , Bernier N. , Piot L. , Alcotte R. , Cerba T. , Martin M. , Moeyaert J. , Bogumilowizc Y. , Arnaud S. , Bertin F. , Bassani F. , Baron T.
Published: May 2016

Structural and optical properties of InGaAs quantum well fins (QWFs) selectively grown on Si using the aspect ratio trapping (ART) method in 200 nm deep SiO2 trenches are studied. A new method combining cathodoluminescence, transmission electron microscopy, and precession electron diffraction techniques is developed to spatially correlate the presence of defects and/or strain with the light emission properties of a single InGaAs QWF. Luminescence losses and energy shifts observed at the nanoscale along InGaAs QWF are correlated with structural defects. We show that strain distortions measured around threading dislocations delimit both high and low luminescent areas. We also show that trapped dislocations on SiO2 sidewalls can also result in additional distortions. Both behaviors affect optical properties of QWF at the nanoscale. Our study highlights the need to improve the ART growth method to allow integration of new efficient III-V optoelectronic components on Si.
Magnetoconductance of a hybrid quantum ring: Effects of antidot potentials
Authors: Kim Nammee , Park Dae-Han , Kim Heesang
Published: May 2016

The electronic structures and two-terminal magnetoconductance of a hybrid quantum ring are studied. The backscattering due to energy-resonance is considered in the conductance calculation. The hybrid magnetic-electric quantum ring is fabricated by applying an antidot electrostatic potential in the middle of a magnetic quantum dot. Electrons are both magnetically and electrically confined in the plane. The antidot potential repelling electrons from the center of the dot plays a critical role in the energy spectra and magnetoconductance. The angular momentum transition in the energy dispersion and the magnetoconductance behavior are investigated in consideration of the antidot potential variation. Results are shown using a comparison of the results of the conventional magnetic quantum dot.
Magnetic flux distortion in two-phase liquid metal flow: Model experiment
Authors: Kumar M. , Bergez W. , Tordjeman Ph. , Arinero R. , Paumel K.
Published: May 2016

In this paper, we present the model experiments in order to study the magnetic flux distortion of a two-phase liquid metal flow excited by an AC magnetic field in a range of pulsation where Faraday induction and Lorentz force effects are significant. These experiments realized with solid aluminum rods allow to characterize the effects of flow velocity (0 ≲ U≤1 ms−1), void fraction (0≤α≤6.9 %), pulsation of the AC magnetic field (1.5×103≤ω≤12.5×103 rad s−1), and of two different void geometries. The results are analyzed on the basis of a first order expansion of magnetic flux in U and α. Despite the strong coupling between Faraday induction and Lorentz force effects, the results show that the contributions of U and α on a magnetic flux distortion can be well separated at both low magnetic Reynolds number and α values. These results are independent of void geometry.
Increased resistance to a generalist herbivore in a salinity-stressed
non-halophytic plant
Authors: Renault Sylvie , Wolfe Scott , Markham John , Avila-Sakar Germán
Published: May 2016

Plants often grow under the combined stress of several factors. Salinity and herbivory, separately, can severely hinder plant growth and reproduction, but the combined effects of both factors are still not clearly understood. Salinity is known to reduce plant tissue nitrogen content and growth rates. Since herbivores prefer tissues with high N content, and biochemical pathways leading to resistance are commonly elicited by salt-stress, we hypothesized that plants growing in saline conditions would have enhanced resistance against herbivores. The non-halophyte, Brassica juncea , and the generalist herbivore Trichoplusia ni were used to test the prediction that plants subjected to salinity stress would be both more resistant and more tolerant to herbivory than those growing without salt stress. Plants were grown under different NaCl levels, and either exposed to herbivores and followed by removal of half of their leaves, or left intact. Plants were left to grow and reproduce until senescence. Tissue quality was assessed, seeds were counted and biomass of different organs measured. Plants exposed to salinity grew less, had reduced tissue nitrogen, protein and chlorophyll content, although proline levels increased. Specific leaf area, leaf water content, transpiration and root:shoot ratio remained unaffected. Plants growing under saline condition had greater constitutive resistance than unstressed plants. However, induced resistance and tolerance were not affected by salinity. These results support the hypothesis that plants growing under salt-stress are better defended against herbivores, although in B. juncea this may be mostly through resistance, and less through tolerance.
Fatal Spontaneous Clostridium bifermentans Necrotizing Endometritis: A Case Report and Literature Review of the Pathogen
Authors: Hale Andrew , Kirby James E. , Albrecht Mary
Published: May 2016

Clostridium bifermentans is a rare pathogen in humans. A fatal case of fulminant endometritis with toxic shock and capillary leak secondary to C bifermentans infection in a young woman is described, and this is compared to all 13 previously described cases of C bifermentans infection.
Distinguishing disruptive mood dysregulation disorder from pediatric bipolar disorder
Authors: Noller Diana T.
Published: May 2016

This article outlines diagnostic criteria and features of the newly established diagnosis disruptive mood dysregulation disorder (DMDD), and discusses how this disorder differs from bipolar disorder in childhood. The chronic, severe, nonepisodic irritability seen in patients with DMDD contrasts with the characteristic episodic mood swing symptoms of bipolar disorder. Differentiating between the two diagnoses is important in regard to prognostic and treatment considerations, as children with DMDD are more likely to develop a mood disorder later in life rather than to develop classic bipolar disorder. Research is needed to establish clear treatment guidelines for DMDD.
Metallosis Presenting as a Progressive Neurologic Deficit Four Years After a Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis
Authors: Richman Seth H. , Razzano Andrew J. , Morscher Melanie A. , Riley Patrick M.
Published: May 2016

Study Design.

A case report.

Objective.

The aim of this study was to report a case of progressive pain and paraparesis secondary to metallosis four years after a pediatric posterior spinal fusion (PSF).

Summary of Background Data.

Metallosis as a late complication of pediatric spinal surgery is rarely reported. Myelographic computed tomography (CT) can be helpful in establishing the diagnosis. The use of serum chromium levels as a means of definitive diagnosis has been suggested, but has only been reported retrospectively.

Methods.

A 19-year-old male presented four years after PSF for adolescent idiopathic scoliosis with sudden onset of pain and neurologic deficits. Radiographs and CT scan suggested infection. Intraoperatively, no purulent material was noted, but black and yellowish corrosive debris was found around the right L1 pedicle screw, so it was removed and the cavity packed with tobramycin impregnated calcium sulfate beads. After surgery, neurologic deficits worsened. CT myelogram showed irregular opacification of the thecal sac at the level of the conus. A posterior laminectomy and decompression was performed with removal of all debris and spinal instrumentation. Metallosis within the spinal canal was noted and serum chromium levels were obtained.

Results.

The patient was discharged one week after admission with improvement of pain and gradual improvement in neurologic examination. Three years postdischarge, the patient is asymptomatic and examination shows bilateral clonus. Serum chromium levels declined from a high of 4.5 μg/L operatively to 0.8 at final follow-up (normal: 0.2–0.6 μg/L).

Conclusion.

Although uncommon, metallosis should be considered in the differential diagnosis of any late presenting case of pain, infection-like symptoms, or neurologic deficits after pediatric PSF. CT myelography and serum chromium levels may help guide diagnosis; however, surgical exploration is needed for definitive diagnosis and treatment.

Level of Evidence: 4
Prosthetic Replacement of the Ocular Surface Ecosystem Scleral Lens Therapy for Exposure Keratopathy
Authors: Chahal Jasdeep S. , Heur Martin , Chiu Gloria B.
Published: May 2016

Objectives:

To investigate the utility of Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) scleral lenses in patients with exposure keratopathy, with outcomes based on changes in visual acuity, visual function, and corneal staining.

Methods:

A retrospective interventional case series of patients evaluated and treated from September 2009 through June 2014 at a single multi-specialty institutional practice. Eighteen of 29 patients with exposure keratoconjunctivitis, lagophthalmos, ectropion, or lid retraction, referred to USC Eye Institute after failing conventional therapies completed PROSE scleral lens fitting and were included in the study. Visual function was assessed before and after PROSE fitting with the Ocular Surface Disease Index (OSDI) survey. Visual acuity (VA) and corneal staining changes were also evaluated before and after treatment.

Results:

Visual acuity improved from 0.60±0.68 logMAR pre-PROSE to 0.25±0.34 logMAR (Z=−3.81, P=0.00014) post-PROSE, which corresponds to an improvement of about 20/80 to 20/35 on Snellen VA. Ocular Surface Disease Index scores improved from 56.54±29.75 pre-PROSE to 24.98±21.23 post-PROSE (Z=−2.98, P=0.0029), and corneal staining values decreased from 2.17±0.84 pre-PROSE to 0.64±0.70 post-PROSE (Z=−3.27, P=0.011).

Conclusions:

The results suggest that PROSE scleral lens therapy is effective in patients with exposure keratopathy who had failed conventional therapies and can serve as an alternative to lid surgery.
Eyelid Mass in Boston Keratoprosthesis Type 2
Authors: Choi Catherine J. , Stagner Anna M. , Jakobiec Frederick A. , Chodosh James , Yoon Michael K.
Published: May 2016

Boston keratoprosthesis type 2 is used to treat severe corneal blindness secondary to cicatricial or autoimmune ocular surface disease. This case report describes an atypical eyelid mass in a 41-year-old woman with Stevens–Johnson syndrome who underwent placement of Boston keratoprosthesis type 2 in the left eye. The postoperative course was complicated by methicillin-sensitive Staphylococcus aureus keratitis and endophthalmitis requiring replacement of the keratoprosthesis. Three months thereafter, the patient presented with a progressively enlarging upper eyelid mass adjacent to the keratoprosthesis optic causing distortion of the eyelid. Excisional biopsy revealed an elongated cystic mass abutting the superior aspect of the optic. Pathologic examination was consistent with a conjunctival cyst with lipogranulomatous reaction. Removal of eyelid margins and conjunctiva, and placement of a full-thickness blepharotomy are standard steps in placement of Boston keratoprosthesis type 2, which can lead to conjunctival cysts and lipogranulomas that present as eyelid masses.
Clostridium difficile Infection in Inflammatory Bowel Disease: A Nursing-Based Quality Improvement Strategy
Authors: Axelrad Jordan E. , Shah Brijen J.
Published: May 2016

Objectives:

Patients with inflammatory bowel disease (IBD) have a higher prevalence of Clostridium difficile infection (CDI) and worse outcomes. Research has highlighted the inconsistent care that is provided to patients with IBD, and at our institution, the CDI testing rate was 41%. The present quality improvement intervention sought to increase CDI testing for inpatients with IBD with a flare.

Methods:

Eighty-nine patients admitted to our gastrointestinal unit over a 9-month period with IBD flare were eligible for the study. If a patient did not have a test for CDI ordered, the floor nurse collected stool and alerted the provider to order the test. The primary outcome was percent of eligible patients receiving a test. Secondary outcomes included rate of CDI, length of hospital stay, and readmission rate within 6 months.

Results:

There was a significant increase in testing for CDI to 75% (p = .0151). Patients who received a test were more likely to have CDI (p = .0316), shorter hospital stays (p = .0095), and fewer readmissions (p = .0366).

Conclusion:

This study used the nursing admission workflow to increase the rate of CDI testing. Future studies should further characterize inconsistencies in IBD care and implement quality improvements.
An Electronic Alert System Is Associated With a Significant Increase in Pharmacologic Venous Thromboembolism Prophylaxis Rates Among Hospitalized Inflammatory Bowel Disease Patients
Authors: Mathers Bradley , Williams Emmanuelle , Bedi Gurneet , Messaris Evangelos , Tinsley Andrew
Published: May 2016

Background:

Utilization of pharmacologic venous thromboembolism (VTE) prophylaxis in inflammatory bowel disease (IBD) patients seems to be suboptimal with reported rates as low as 50% in some studies. Implementation of an electronic alert system seems to be an effective tool for increasing VTE prophylaxis rates in medical inpatients. To date, no studies have assessed whether this approach is associated with improved rates of pharmacologic VTE prophylaxis specifically in IBD patients.

Aims:

To determine the efficacy of an electronic alert in improving VTE prophylaxis rates in hospitalized IBD patients.

Methods:

We conducted a retrospective cohort study of 576 hospitalized IBD patients. The medical record of each patient was then examined to determine whether pharmacologic VTE prophylaxis was both ordered and administered, the timing of pharmacologic VTE prophylaxis, and reasons for any missed doses.

Results:

The VTE pharmacologic prophylaxis rate was improved from 60% to 81.2% following the implementation of the electronic alert system (p < .001). An increase in prophylaxis rates was seen in both medical (26.3% vs. 62.8%, p < .001) and surgical services (83.7% vs. 95.5%, p < .001). In patients who received pharmacologic VTE prophylaxis, 16% of all ordered doses were not administered and 57.3% of missed doses were the result of patient refusal. Hospitalization after implementation of the electronic alert system (odds ratio [OR] 4.71, 95% confidence interval [CI] 2.94–7.57) and admission to a surgical service (OR 14.3, 95% CI 8.62–24.39) were predictive of VTE pharmacologic prophylaxis orders.

Conclusions:

The introduction of an electronic alert system was associated with a significant increase in rates of pharmacologic VTE prophylaxis. However, orders were often delayed and doses not always administered. The most common reason that ordered doses were not given was patient refusal.
Increasing Follow-up Outcomes of At-Risk Alcohol Patients Using Motivational Interviewing
Authors: Wagner Andrew J. , Garbers Rachael , Lang Ann , Borgert Andrew J. , Fisher Mason
Published: May 2016

Our trauma division implemented a screening, brief intervention, and referral to treatment (SBIRT) program in 2009 and has maintained more than 92% screening rate for all inpatient admissions since inception. Brief interventions are proven to be more likely to effect and reinforce change if a follow-up contact is made with patients. This led to discussion regarding whether identified patients were more likely to follow up with our SBIRT wellness specialist using motivational interviewing or with our partners, exercise physiology, who use traditional interviewing techniques. We retrospectively reviewed more than 3,000 inpatient admissions in which screening for at-risk alcohol use were positive. Fifty-one percent of identified patients were referred for wellness specialist consultation with a follow-up rate of 52% compared with a follow-up rate of only 21% in the exercise physiology group. Motivational interviewing is more effective in encouraging at-risk alcohol users to participate in follow-up care.
Bicyclist Safety Behaviors in an Urban Northeastern, United States City: An Observational Study
Authors: Wolfe Elizabeth Suzanne , Arabian Sandra Strack , Salzler Matthew J. , Bugaev Nikolay , Rabinovici Reuven
Published: May 2016

Bicycling is gaining popularity in the United States, and laws and safety recommendations are being established to keep bicyclists safer. To improve road safety for bicyclists, there is a need to characterize their compliance with road laws and safety behaviors. Adult bicyclists were observed at three high-traffic intersections in Boston, MA, with state recommendations of wearing a helmet and riding in a bike lane. State law compliance for displaying reflectors during the day and of a front light and a rear light/reflector at night, obeying traffic signals, and giving pedestrians the right of way was also observed. Variables were compared between personal and shared/rented bicyclists and analyzed by time of day. A total of 1,685 bicyclists were observed. Because of the speed of the bicyclists and obstructed views, only a sampling of 802 bicyclists was observed for reflectors/front light. Overall, 74% wore a helmet, 49% had reflectors/front lights, 95% rode in bike lanes, 87% obeyed traffic signals, and 99% gave the right of way to pedestrians. Compared with shared bicyclists (n = 122), personal bicyclists (n = 1563) had a higher helmet-wearing behaviors (77% vs. 39%, p = .0001). Shared bicyclists had a higher (p = .0001) compliance with reflectors/lights (100%) than personal bicyclists (39%, n = 265). Boston bicyclists ride in bike lanes, obey traffic signals, give pedestrians the right of way, and wear helmets while having suboptimal compliance with light/reflector use. Educational programs and stricter law enforcement aimed at these safety behaviors should be part of the effort to improve safety for all road users.
Delayed Sternal Closure After Continuous Flow Left Ventricle Assist Device Implantation: Analysis of Risk Factors and Impact on Outcomes and Costs
Authors: Quader Mohammed , LaPar Damien J. , Wolfe Luke , Ailawadi Gorav , Rich Jeffrey , Speir Alan , Fonner Clifford , Kasirajan Vigneshwar
Published: May 2016

Patient and institutional factors predictive of delayed sternal closure (DSC) practice and its impact on clinical and cost outcomes when compared with primary sternal closure (PSC) following continuous-flow left ventricular assist device (CF-LVAD) implantation were examined. Statewide Society of Thoracic Surgeons and hospital cost data on CF-LVADs implanted were analyzed. Between January 2007 and December 2013, 558 CF-LVADs were implanted (PSC = 464, 83.2%; DSC = 94, 16.8%). Among the six institutions implanting CF-LVADs, DSC practice ranged from 3.1% to 37.8%. Compared with PSC, the DSC group had higher body mass index (BMI), renal failure, anemia, IIb/IIIa inhibitor use, emergency surgery, and extracorporeal membrane oxygenation (ECMO) support. Delayed sternal closure patients had significantly longer bypass time (139 ± 63 min vs. 107.6 ± 42 min) and higher use of intraoperative blood products (82% vs. 69%) and right ventricular assist device (RVAD) support (4.3% vs. 0.2%). Postoperative morbidities and mortality (23.4% vs. 6.5%; p ≤ 0.0001) were higher in the DSC group compared with PSC. Mean hospital costs for DSC were higher than PSC ($249,144 ± 123,273 vs. $155,915 ± 95,032; p ≤ 0.0001). Multivariate predictors of DSC include institution with higher DSC practice, preoperative ECMO support, use of IIb/IIIa inhibitors, tricuspid valve surgery, and intraoperative red blood cell transfusion. Delayed sternal closure was an independent risk factor for postoperative mortality, odds ratio 3.0 (1.2–7.2).
Short article: Fatigue in the long term after HCV treatment in HIV–HCV-coinfected patients: functional limitations persist despite viral clearance in patients exposed to peg-interferon/ribavirin-containing regimens (ANRS CO13-HEPAVIH cohort)
Authors: Marcellin Fabienne , Protopopescu Camelia , Poizot-Martin Isabelle , Miailhes Patrick , Esterle Laure , Wittkop Linda , Spire Bruno , Bocquier Aurélie , Salmon-Ceron Dominique , Dabis François , Carrieri Maria Patrizia
Published: May 2016

Objectives

To analyze the impact of fatigue on individuals’ global, cognitive, physical, and psychosocial functioning in the long term after hepatitis C virus (HCV) treatment and its relationship with HCV clearance among patients coinfected with HIV and HCV exposed to peg-interferon/ribavirin-containing regimens.

Patients and methods

The study sample included 107 coinfected patients treated for HCV during follow-up in the French ANRS CO13-HEPAVIH cohort. Analyses used scores from the Fatigue Impact Scale (FIS), assessed before treatment initiation and at last available measure after the end of treatment (2 years in median). Patient proportions with a clinically significant improvement in fatigue impact, defined as a decrease higher than 10 points in the 160-point global FIS score, were compared between HCV clearers and chronic HCV patients (Fisher’s exact test). Relationships between HCV clearance and FIS scores were analyzed in linear regression models adjusted for sex, time since end of HCV treatment, and pretreatment scores.

Results

Twenty-nine percent of patients showed a clinically significant improvement in fatigue (15/57 in HCV clearers vs. 16/50 in chronic HCV patients, P=0.52). HCV clearance was not significantly associated with FIS scores in multivariate models.

Conclusion

The role of HCV clearance in coinfected patients’ functional recovery in the long term after peg-interferon/ribavirin treatment may be lesser than expected. Additional studies are needed in patients treated with direct-acting antiviral agents. In the meantime, the effectiveness of palliative care and targeted psychological treatments such as cognitive-behavioral therapy in reducing fatigue impact needs to be assessed in the many HCV-cured patients with HIV exposed to suboptimal interferon-based first-generation therapies.
Current updates in nasal bone reshaping
Authors: Ozucer Berke , Özturan Orhan
Published: May 2016

Purpose of review

To review recent studies on nasal osseocartilaginous anatomy, osteotomy techniques and contemporary methods of nasal bone reshaping carried out under direct vision.

Recent findings

Current cadaver studies on osseocartilaginous vault anatomy, osteotomy techniques provide valuable information that can reduce outcome variability and increase reliability of osteotomies. Nevertheless, osteotomes have limitations and contemporary approaches – namely, piezoelectric instrumentations, osteoectomy, and osteotomy carried out under direct vision–can provide valuable solutions to certain shortcomings. Contrary to widespread understanding, extended wide periosteal dissection is the common thread in newly introduced methods which claim enhanced control, reduced soft tissue trauma, and reproducible results. Comparative and cadaver studies show promising results regarding protection of underlying mucosa, reduced comminuted fractures, reduced postoperative ecchymosis, and edema.

Improvements in nasal bone reshaping are promising for better esthetic and functional outcomes. Nevertheless, these approaches need to be validated by randomized controlled trials and test of time before being incorporated in routine surgical practice.
Adolescent gun violence prevention: what we know, and what we can do to keep young people safe
Authors: Dodson Nancy A.
Published: May 2016

Purpose of review

This review will focus on recent research, initiatives, and legislation regarding the issue of gun violence as it pertains to adolescents.

Recent findings

Homicide and suicide continue to be major killers of adolescents in the United States. Gun homicide kills teens in the most urban areas of the United States at the same rate as suicide kills teens in the most rural areas of the United States. Research on assault-injured youth sheds light on risk factors for teen gun homicide, and has found high rates of illegal gun carrying and retaliatory attitudes among at-risk teens. Suicide research continues to show a strong correlation between gun ownership and accessibility, and risk of completed suicide. Stand Your Ground laws and campus carry laws present unique threats to different populations of American teens.

Given the enormous toll that gun violence takes on adolescent lives, pediatricians should ask about guns in the home and become involved in efforts to strengthen laws that would decrease gun violence.
Clinical Use of Infliximab Trough Levels and Antibodies to Infliximab in Pediatric Patients With Inflammatory Bowel Disease
Authors: Merras‐Salmio Laura , Kolho Kaija‐Leena
Published: May 2016

Objectives:

Optimizing infliximab (IFX) treatment in pediatric patients with inflammatory bowel disease (IBD) by using serum infliximab (S‐IFX) trough levels and antibodies to IFX is recommended. There is need for studies assessing this strategy in clinical practice.

Methods:

We retrospectively identified all pediatric patients with IBD (n = 146, median age 14.8 years) treated with IFX at our tertiary referral center from 2003 to 2014. All were analyzed for IFX trough levels (S‐IFX, n = 475), and IFX antibody (IFX‐Ab, n = 219) titers were included. Both were analyzed using enzyme‐linked immunosorbent assay. We correlated these parameters with concurrently analyzed fecal calprotectin levels and the treatment outcome.

Results:

If IFX had no efficacy, or a loss of response occurred, 40 of 64 (63%) had trough levels <2.0 mg/L, with negative IFX‐Ab in 37 of 59 (63%). If the S‐IFX was very low (<0.2 mg/L), 4 of 36 still had negative IFX‐Ab. Concurrent azathioprine therapy did not relate to IFX‐Ab. Fecal calprotectin was significantly lower in patients with clinical remission or ongoing therapy compared with those with subsequent loss of efficacy: medians 95 μg/g (33–308) and 670 μg/g (264–1473), P < 0.0001. The S‐IFX median was substantially higher in patients with either remission or ongoing therapy, compared with those with no or loss of efficacy: 3.7 mg/L (1.8–5.4) and 1.2 mg/L (0.03–4.4, P = 0.01), respectively.

Conclusions:

Measuring IFX trough levels and fecal calprotectin has a potential impact on the treatment strategies and should be included in clinical routine. Low IFX trough levels associate with increased antibodies to IFX in most, but not in all cases.
Middle Cerebral Artery Stroke in a Neonate With a Congenital Hypercoagulable Condition Following Repair of an H-type Tracheoesophageal Fistula
Authors: Garcia Megan L. , Caldwell Katharine , Kellund Anna , Reyes Cynthia
Published: May 2016

We report a case of middle cerebral artery stroke with heterozygosity for 2 separate hypercoagulable conditions following repair of an H-type tracheoesophageal fistula (TEF) in an infant. Neonatal stroke is rare, occurring in 1 in 4000 births annually in the United States. Stroke after pediatric surgery occurs in approximately 0.05% of patients. Etiologies of stroke in neonates include cardiac, hematologic, vascular, traumatic, metabolic, pharmacologic, infectious, and hypoxemic insults. Thrombophilia has been described in 42% to 78% of neonates with neonatal stroke. Stroke after repair of an H-type TEF has not been reported as a postoperative complication. Manipulation of the carotid artery during this operation is presumed to have contributed to a thromboembolic event in this infant with a hypercoagulable state. Whereas preoperative workup may not be indicated due to the low prevalence of neonatal stroke, workup for a congenital hypercoaguable condition may be considered in infants with stroke as a postoperative complication. This report provides a concise review of the etiology and treatment of stroke and hypercoagulable states in neonates as well as presents the case of a previously undescribed complication of repair of an H-type TEF.
Invasive Duct Carcinoma of the Breast With Dominant Signet-Ring Cell Differentiation: A Microsatellite Stable Tumor With Aggressive Behavior
Authors: Chatterjee Debajyoti , Bal Amanjit , Das Ashim , Kohli Pavneet S. , Singh Gurpreet , Mittal Bhagwant Rai
Published: May 2016

Aims:

Invasive duct carcinoma, no special type (IDC, NST), of the breast with signet-ring cell differentiation is uncommon. This study was undertaken to describe the clinicopathologic characteristics of IDC, NST, with dominant signet-ring cell differentiation, and look for microsatellite instability in these tumors.

Methods:

Cases of IDC, NST, with dominant signet-ring cell differentiation, diagnosed over the past 2 years, were retrieved. Detailed clinical and pathologic analyses were performed. Immunohistochemistry was performed for estrogen receptor, progesterone receptors, Her-2 neu, Ki-67, E-cadherin, CK7, and CK20. Microsatellite instability was examined using immunohistochemistry for the 4 mismatch repair proteins: MLH1, MSH2, MSH6, and PMS2.

Results:

Of the total 1646 cases of IDC, NST, only 5 cases showed dominant signet-ring cells (ranging from 70% to 100%) and strong E-cadherin positivity and were diagnosed as IDC, NST, with dominant signet-ring cell differentiation. The age ranged from 32 to 65 years. Two cases were of histologic grade 3 and the remaining cases were grade 2 tumors. Four patients had T2 tumor and 1 had T3 tumor. All cases had axillary lymph node metastasis and distant metastasis was present in 1 case. All cases were microsatellite stable.

Conclusions:

Signet-ring cell differentiation in IDC, NST, is rare and associated with a high histologic grade. Lymph node metastasis and distant metastasis are common, indicating an aggressive clinical behavior. Thus, they should be recognized separately as they may warrant aggressive management. However, these are microsatellite-stable tumors in contrast to signet-ring cell tumors of other organs.
Usage of DNA Fingerprinting Technology for Quality Control in Molecular Lab Bench Work
Authors: McIntosh Linda Y. , Lal Janella E. , Qin Dahui
Published: May 2016

One of the major quality assurance (QA) goals in many molecular laboratories is to avoid sample pipetting errors on the lab bench; especially when pipetting into multiwell plates. A pipetting error can cause a switch in patient samples, which can lead to recording the wrong results for the patient samples involved. Such pipetting errors are difficult to identify when it happens in lab bench work. DNA fingerprinting is a powerful tool in determining sample identities. Our laboratory has explored the usage of this technology in our QA process and successfully established that DNA fingerprinting can be used to monitor possible sample switch in gene rearrangement lab bench work. We use florescent light to quench the florescence in the gene rearrangement polymerase chain reaction products. After that, DNA fingerprinting technology is used to identify the sample DNA in the gene rearrangement polymerase chain reaction plate. The result is compared with the corresponding patient’s blood sample DNA to determine whether there is a sample switch during the lab bench work.
Pelvic Floor Health Education: Can a Workshop Enhance Patient Counseling During Pregnancy?
Authors: Hyakutake Momoe T. , Han Vanessa , Cundiff Geoffrey W. , Baerg Lauren , Koenig Nicole A. , Lee Terry , Geoffrion Roxana
Published: May 2016

Objectives

Pelvic floor disorders commonly affect women's quality of life. Their etiology is multifactorial, yet pregnancy and vaginal delivery (VD) are major inciting risk factors. Our objectives were to assess pelvic floor health information given by maternity providers to their pregnant patients, to create a pelvic floor health information workshop, and to determine its impact on women's preferences for mode of delivery.

Methods

This descriptive study recruited primiparous women with a singleton gestation at St Paul's Hospital in Vancouver, Canada. Participants received a 2-hour workshop describing pelvic floor disorders and pregnancy, modes of delivery, as well as strategies for maintaining pelvic floor health and preventing disease. Women completed questionnaires assessing baseline knowledge and level of comfort with different modes of delivery before and after the workshop.

Results

Forty participants completed the workshop. Seventy percent had an obstetrician, 20% had a midwife, and 10% had a family physician. Five percent of the participants reported receiving information regarding pelvic organ prolapse as well as urinary and fecal incontinence. The workshop did not influence women's preferred mode of delivery, including VD (P = 1.00), forceps-assisted VD (P = 0.48), vacuum-assisted VD (P = 0.68), postlabor cesarean delivery (P = 0.32), and elective cesarean delivery (P = 0.86).

Conclusions

Current antenatal care is lacking in the area of pelvic floor health education. Patient counseling can be enhanced via a standard workshop. Concerns about negatively influencing women's preferences for mode of delivery are unwarranted, as the pelvic floor health workshop, given during pregnancy, did not significantly change participants' preferences.
Colovaginal Fistulas: Presentation, Evaluation, and Management
Authors: Berger Mitchell B. , Khandwala Nikhila , Fenner Dee E. , Burney Richard E.
Published: May 2016

Objective

The objective of this study was to review a single institution's experience with colovaginal fistulas to provide guidance toward identification and management of this problem.

Methods

Patients with colovaginal fistulas treated by 2 senior surgeons between January 1, 1990, and June 31, 2011, were identified. A retrospective chart review was then performed to determine presenting characteristics and history, evaluation for the fistulas, and treatment outcomes.

Results

Nineteen patients were identified. The mean age was 63.5 years and median parity of 2. 37% complained of flatus per vagina, 89% reported stool per vagina, and 68% noted vaginal discharge. Ninety-five percent had previously undergone hysterectomy. The fistulas were identified at the left vaginal apex in 90% of the subjects. Self-reported history and/or operative findings suggested diverticulitis as the most common etiology (79% of the subjects). All subjects underwent sigmoid resection with primary anastomosis, with complete symptom resolution in 84%.

Conclusions

Patients with colovaginal fistulas commonly present for primary evaluation by gynecologists. A triad of symptoms and history should trigger a high index of suspicion for colovaginal fistulas: (1) complaints of stool or flatus per vagina or foul-smelling vaginitis resistant to treatment, (2) previous hysterectomy, and (3) history of diverticulitis. The fistulas can often be visualized on speculum examination at the left vaginal apex. Rolling the patient from left to right lateral decubitus positions during a contrast enema study can improve its sensitivity. Repair of colovaginal fistulas via rectosigmoid resection and primary reanastomosis is safe and effective. We recommend multidisciplinary management involving colorectal surgery and gynecology.
Kidney Transplant Outcomes After Primary, Repeat and Kidney After Nonrenal Solid Organ Transplantation
Authors: Sood Puneet , Gao Xiaotian , Mehta Rajil , Landsittel Douglas , Wu Christine , Nusrat Rabeeya , Puttarajappa Chethan , Tevar Amit D. , Hariharan Sundaram
Published: May 2016

Background

Improvements in renal allograft outcomes have permitted kidney transplantation after prior kidney allograft failure as well as after nonrenal solid organ transplantation. This study compares renal allograft outcomes in the 3 groups, that is, primary, repeat, and kidney after nonrenal solid organ transplantation, where transplant group was coded as a time-dependent variable.

Methods

We retrospectively reviewed registry data for kidney transplant recipients at University of Pittsburgh Medical Center from January 2000 to December 2011. We compared overall graft survival between the 3 groups using Cox regression modeling. We calculated 1-, 3-, and 5-year graft survival and half-lives for each group where feasible.

Results

The study cohort (N = 2014) consisted of group A (primary kidney transplant, n = 1578, with 7923.2 years of follow-up time), group B (repeat kidney transplant, n = 314, with 1566.7 years of follow-up time) and group C (kidney post-nonrenal solid organ transplant, n = 176, with 844.8 years of follow-up time). Of the 1578 patients in the primary kidney transplant group, 74 later received a repeat transplant and thus also have follow-up counted in the repeat kidney transplant group. The median follow-up was 56, 53, and 55 months, respectively. The 5-year actuarial and death-censored graft survival was 68.69%, 68.79%, and 66.48% and 65.53%, 67.68%, and 62.92%, respectively (P = 0.70). There was no difference in overall graft survival in the Cox-adjusted analysis (group B: odds ratio, 1.02; 95% confidence interval, 0.84-1.26; P = 0.79; group C: odds ratio, 0.96; 95% confidence interval, 0.75-1.23; P = 0.76).

Conclusions

The adjusted kidney graft survivals in the 3 groups were similar.
Phages rarely encode antibiotic resistance genes: a cautionary tale for virome analyses
Authors: Enault François , Briet Arnaud , Bouteille Léa , Roux Simon , Sullivan Matthew B. , Petit Marie-Agnès
Published: May 2016

Antibiotic resistance genes (ARG) are pervasive in gut microbiota, but it remains unclear how often ARG are transferred, particularly to pathogens. Traditionally, ARG spread is attributed to horizontal transfer mediated either by DNA transformation, bacterial conjugation or generalized transduction. However, recent viral metagenome (virome) analyses suggest that ARG are frequently carried by phages, which is inconsistent with the traditional view that phage genomes rarely encode ARG. Here we used exploratory and conservative bioinformatic strategies found in the literature to detect ARG in phage genomes, and experimentally assessed a subset of ARG predicted using exploratory thresholds. ARG abundances in 1,181 phage genomes were vastly over-estimated using exploratory thresholds (421 predicted vs 2 known), due to low similarities and matches to protein unrelated to antibiotic resistance. Consistent with this, 4 ARG predicted using exploratory thresholds were experimentally evaluated and failed to confer antibiotic resistance inEscherichia coli. Re-analysis of available human-or mouse-associated viromes for ARG and their genomic context suggested thatbona fideARG attributed to phages in viromes were previously over-estimated. These findings provide guidance for documentation of ARG in viromes, and re-assert that ARG are rarely encoded in phages.
Resource limitation reveals a twofold benefit of eusociality
Authors: Fronhofer Emanuel A. , Liebig Jürgen , Mitesser Oliver , Poethke Hans Joachim
Published: May 2016

Explaining the evolution and maintenance of cooperative breeding or eusociality remains a challenge. Surprisingly, fundamental ecological factors, specifically competition for limited resources and resource variance, are frequently ignored in models of animal sociality. We here develop a mathematical model that includes density-dependent population growth and quantify the influence of cooperative foraging on resource use efficiency. We derive optimal resource sharing strategies, ranging from egalitarian to cooperatively breeding and eusocial groups. We find that, while egalitarian resource sharing is a risk-reducing foraging strategy, eusociality yields additional benefits: like egalitarian strategies, eusocial groups can reduce their members’ starvation risk by reducing resource variance. Additionally, eusocial groups increase their reproductive output by increasing intra-group variance in resources allocated to reproduction. This allows reproduction even when resources are so scarce that solitary animals would not be able to reproduce. In a majority of environmental situations and life-histories, this twofold benefit of eusociality increased resource use efficiency and led to supersaturation, that is, to a strong increase in carrying capacity. Supersaturation provides indirect benefits to group members even for low intra-group relatedness and represents one potential explanation for the evolution and maintenance of eusociality and cooperative breeding.
Seed size and its rate of evolution correlate with species diversification across angiosperms
Authors: Igea J. , Miller E. F. , Papadopulos A. S. T. , Tanentzap A. J.
Published: May 2016

Species diversity varies greatly across the different taxonomic groups that comprise the Tree of Life (ToL). This imbalance is particularly conspicuous within angiosperms, but is largely unexplained. Seed mass is one trait that may help clarify why some lineages diversify more than others because it confers adaptation to different environments, which can subsequently influence speciation and extinction. The rate at which seed mass changes across the angiosperm phylogeny may also be linked to diversification by increasing reproductive isolation and allowing access to novel ecological niches. However, the magnitude and direction of the association between seed mass and diversification has not been assessed across the angiosperm phylogeny. Here, we show that absolute seed size and the rate of change in seed size are both associated with variation in diversification rates. Based on the largest available angiosperm phylogenetic tree, we found that smaller-seeded plants had higher rates of diversification, possibly due to improved colonisation potential. The rate of phenotypic change in seed size was also strongly positively correlated with speciation rates, providing rare, large-scale evidence that rapid morphological change is associated with species divergence. Our study now reveals that variation in morphological traits and, importantly, the rate at which they evolve can contribute to explaining the extremely uneven distribution of diversity across the ToL.
4-Benzyl-2-(4-chlorobenzylidene)-3,4-dihydro-2H-1,4-benzothiazin-3(4H)-one
Authors: Ellouz Mohamed , Sebbar Nada Kheira , Essassi El Mokhtar , Ouzidan Younes , Mague Joel T. , Zouihri Hafid
Published: May 2016

The title compound, C22H16ClNOS, has three aromatic systems,viz. (i) a phenyl ring, (ii) a chlorobenzene ring and (iii) a 1,4-benzothiazine fused-ring system (r.m.s. deviation of the ten fitted atoms = 0.023 Å). The dihedral angle between planes (ii) and (iii) is 1.68 (8)°, indicating a coplanar arrangement, and between plane (i) and each of (ii) and (iii) is 85.61 (8) and 86.74 (8)°, respectively, indicating the phenyl ring is approximately perpendicular to the remaining residue. In the crystal, pairwise methylene-C—H...O(carbonyl) hydrogen bonds form dimers which stack along theb-axis direction.
Inclusive education in New Zealand: rhetoric and reality
Authors: Selvaraj Judith Anne
Published: May 2016

Purpose

– New Zealand continues to struggle with interpreting and implementing its current policy of inclusion, especially as it relates to children traditionally known as having “special educational needs”. The purpose of this paper is to trace the discursive development of institutionalised Special Education in New Zealand and examines how the funding and policy mechanisms of neoliberalism within which rights-based inclusion was introduced have complicated the planning and delivery of services in schools.

Design/methodology/approach

– The paper draws on Gillian Fulcher’s (1989) discourses of disability as they are expressed through policy documents and educational reports to examine the language and values that have underpinned the development of Special Education policy and provision in New Zealand.

Findings

– The paper has identified and attempted to explain the extent to which traditional forms of exclusion have continued to structure current policy and practice despite a paradigm shift to inclusion. It argues that this has militated against clear understanding, acceptance and success of this major paradigm shift.

Research limitations/implications

– In examining the social nature of disability, and its implications in the structures of education today, it is possible to consider opportunities for acting to address these.

Originality/value

– The value of this work is in taking an historical approach to help understand why there continues be a distance between policy rhetoric and the reality of its implementation in practice.