bluuebunny/crossref_metadata_2025 huggingface dataset:
Telescopic Videorhinoscopy: A Useful Addition to the Clinical Practice of Rhinology
Authors: Yanagisawa Eiji , Walker Rondi K. , Alberti Paul W.
Published: February 2017

Telescopic videorhinoscopy using a rigid telescope and a color video camera is an effective method of demonstrating and documenting the anatomy and pathology of the nose. Its chief value is in making an accurate diagnosis. It is also an excellent method of teaching endoscopic surgery of the nose and sinuses. The authors present a useful method of telescopic videography of intranasal structures using Hopkins rigid telescopes and a reasonably priced video home system color camera. Telescopic videorhinoscopy is a useful addition to the daily practice and teaching of rhinology.
Breathing During Sleep Immediately after Uvulopalatopharyngoplasty
Authors: Johnson Jonas T. , Sanders Mark H.
Published: February 2017

Uvulopalatopharyngoplasty (UPPP) has been acclaimed in the treatment of obstructive sleep apnea (OSA). Evaluation of the effect of UPPP has usually been done 6 to 8 weeks postoperatively. Recently, a patient died suddenly at home of unknown causes 48 hours following UPPP. Autopsy evaluation demonstrated no evidence of hemorrhage, aspiration, or airway edema; however, it caused us to reassess our postoperative program. Three obese patients (192%, 162%, and 157% of ideal body weight) with OSA underwent polysomnography on the second postoperative night.

The mean duration of the postoperative apneas was not significantly different; however, the nadir SaO2 during apnea in one patient was significantly lower postoperatively. Those individuals with awake hypercapnia and hypoxemia who had significant sleep associated hemoglobin unsaturation preoperatively may be at greatest risk. These observations indicate that careful postoperative monitoring is warranted in this group of patients.
Post‐Tonsillectomy Hemorrhage: Incidence, Prevention and Management
Authors: Handler Steven D. , Miller Linda , Richmond Kenneth H. , Baranak Christine Corso
Published: February 2017

Tonsillectomy (with or without adenoidectomy) continues to be a commonly performed operation in the United States. Over the years, the incidence of post‐tonsillectomy hemorrhage (reported between 0% and 20%) has decreased, but continues to pose serious problems. We reviewed 1,445 tonsillectomies performed over a 2‐year period to study the incidence of post‐tonsillectomy hemorrhage. Thirty‐eight of 1,445 children (2.62%) had postoperative bleeding. The incidence of primary hemorrhage (within 24 hours) was 0.14%. Delayed hemorrhage requiring operative intervention or observation in the hospital was 1.03% and 0.76%, respectively. Ten patients (0.69%) had delayed hemorrhage of a minor nature that had stopped by the time they reached the hospital; these children were treated with observation alone and did not require hospitalization or operative intervention. The proposed reasons for this low rate of post‐tonsillectomy hemorrhage include complete preoperative coagulation screening, meticulous attention to surgical technique, use of suction‐cautery to obtain hemostasis and, possibly, use of postoperative antibiotics. Management of hemorrhage is discussed with respect to observation, surgical intervention, and blood transfusion.
Is No Treatment Good Treatment in the Management of Acoustic Neuromas in the Elderly?
Authors: Nedzelski J. M. , Canter R. J. , Kassel E. E. , Rowed D. W. , Tator C. H.
Published: February 2017

Two hundred twenty‐eight patients with acoustic neuromas were seen between 1974 and 1985. Twenty‐eight received no surgical treatment. Five patients who had undergone previous partial excision were excluded. The mean age was 71 years. The mean expected survival was 14.3 years. The mean follow‐up interval was 51 months (range 12 to 120 months). All patients underwent at least two CAT scans (mean =4). Tumor size ranged from 4 mm to 30 mm.

Three patients underwent insertion of ventricular‐peritoneal shunt for hydrocephalus (mean 16 months after presentation) and two patients partial tumor removal (mean 30 months after presentation). Tumor growth was measured in each patient using CAT scanning.

Monitoring by clinical examination and regular CAT scanning is possible, but in this study 20% of patients required surgical treatment within one third of their expected survival time. This suggests that an expectant attitude for this group of patients may be a debatable form of management.
Achieving Symmetry in Browplasty
Authors: Jarchow Robert C.
Published: February 2017

As is well known by facial plastic surgeons, the browplasty serves to augment the favorable aesthetic effect of blepharoplasty as well as delay or reduce the effect on the forehead that the ptotic brow creates in compensatory elevation. A method of achieving postoperative symmetry in performing direct browplasty is described utilizing: 1. direct measurement of the amount of preoperative ptosis; and 2. known anatomic reference points in which to correlate these measurements on the face. The surgical technique involving a layered plastic closure is also described in order to further obtain the most desirable postoperative result.
Long‐Term Results with Nasofrontal Duct Reconstruction
Authors: Porto Dennis P. , Duvall Arndt J.
Published: February 2017

The findings and results of 50 consecutive nasofrontal duct reconstructions are analyzed and presented. Postoperative recurrence of frontal sinus disease occurred in 14% of the cases and there were no significant postoperative or intraoperative complications. There was no instance of failure in patients with a history of trauma to the nasofrontal duct and only two recurrences in patients with mucocele or pyocele. Nasofrontal duct reconstruction offers more direct access to the ethmoid cell system than osteoplastic flap obliteration. In addition, it is a lesser procedure with fewer complications. The physiologic function of the sinus is restored without the risk of burying disease. Nasofrontal duct reconstruction is an effective option for the treatment of chronic frontal sinus disease if the sinus mucosa is not irreversibly damaged.
Head and Neck War Injuries: 10‐Year Experience at the American University of Beirut Medical Center
Authors: Zaytoun George M. , Shikhani Allan H. , Salman Salah D.
Published: February 2017

Lebanon has witnessed over the past 10 years fierce outbreaks of violence resulting in heavy casualties. Head and neck injuries secondary to bullets, shrapnel, and/or glass were quite frequent: 1,357 injuries in 1,021 patients were taken care of by members of the Department of Otolaryngology between 1975 and 1984. They were distributed as follows:

Head

Neck

Maxilla
24%
Musculoskeletal and soft tissues
24.0%

Mandible
18%
Laryngotracheal
4.0%

Nasal complex
10%
Vascular
2.5%

Oral cavity
8%
Pharyngeal
3.5%

Orbit
6%

Fractures of the mandible were treated by closed reduction in 54% of cases and by open reduction in 46%; 74% healed well and 26% required secondary surgery. Primary repair of oral cavity injuries resulted in healing in 68% of cases; 32% had dehiscences or fistulae.

In around one‐third of the orbital injuries, the orbital contents herniated into the maxillary sinus, so orbital floor repairs had to be done with good results in 82% of cases.

The nasal fractures were treated by closed reduction in 75% of cases and open reduction when the wound was open in the rest.

The overall infection rate was 12%. The most common offending organisms were, in order of frequency, S. aureus, P. aeruginosa, and E. coli.
Variable Histotoxicity of Histoacryl When Used in a Subcutaneous Site: An Experimental Study
Authors: Toriumi Dean M. , Raslan Wasim F. , Friedman Michael , Tardy M. Eugene
Published: February 2017

Histoacryl (butyl‐2‐cyanoacrylate) is one of the least histotoxic cyanoacrylate derivatives and is used as a tissue adhesive. Clinical applications primarily include skin closure (blepharoplasty incisions, etc.). In a recent study, we demonstrated that Histoacryl elicits minimal histotoxicity when used to glue bone grafts to rabbit‐ear cartilage. Acute inflammation was limited to areas where Histoacryl escaped from between the bone graft and ear cartilage to contact well‐vascularized soft tissue. In this study, Histoacryl was applied between bone graft and cartilage in one rabbit ear and adjacent to well‐vascularized soft tissue with no graft in the opposite ear. Histologic analysis revealed minimal if any inflammation when small amounts of glue was used in the nonvascular region between bone graft and cartilage. However, subcutaneous implantation contacting well‐vascularized soft tissue resulted in increased acute inflammation and prolonged foreign‐body giant‐cell response. Further studies are required to rule out any long‐term problems associated with subcutaneous implantation of Histoacryl.
Autologous Fat Injection for Vocal Cord Medialization in the Canine Larynx
Authors: Hill David P. , Meyers Arlen D. , Harris James
Published: February 2017

This study examined the use of autologous fat as an alternative to Teflon® and collagen as the implantable material in vocal cord medialization. Five animals underwent left recurrent laryngeal nerve sections with subsequent fat harvest and implantation into the left true vocal cords. Three animals were killed after 48 hours and 2 after 3 weeks; their larynges were examined with light microscopy.

The results of the 48‐hour samples show moderate acute inflammation and few areas of focal necrosis. The 3‐week samples show no necrotic foci, minimal foreign‐body reaction, and maintenance of structure and volume of the injected fat.

Autologous fat may prove to be a valuable alternative to nonautologous injectable material in vocal cord augmentation.
Update: Ansa Cervicalis to Recurrent Laryngeal Nerve Anastomosis for Unilateral Laryngeal Paralysis
Authors: Crumley Roger L.
Published: February 2017

Twenty cases of unilateral laryngeal paralysis are reported. Satisfactory follow‐up intervals and data (videostroboscopy and glottographic analysis) were available on 12 patients.

The excellent to normal phonatory quality achieved in many of these patients indicates that the ansa cervicalis to recurrent laryngeal nerve anastomosis is the procedure of choice in selected patients with unilateral vocal cord paralysis. Excellent medialization of the paralyzed cord, as well as correction of arytenoid malposition and thyroarytenoid muscle atrophy appear to explain the technique's success, since the reinnervated cord neither abducts nor adducts.

We feel that this technique is the procedure of choice in younger patients, or those who use their voices professionally, since the phonatory quality achieved is superior to Teflon® injection or Isshiki thyroplasty, and the technique is reversible.
Iodine‐125 Seed Implantation as an Adjunct to Surgery in Advanced Recurrent Squamous Cell Cancer of the Head and Neck
Authors: Park Robert I. , Liberman Fishel Z. , Lee Ding-Jen , Goldsmith Manning M. , Price John C.
Published: February 2017

Survival for extensive recurrent squamous cell carcinomas of the head and neck remains poor, with the major cause of death being local recurrence. Surgical implantation of iodine‐125 interstitial seeds allows tumoricidal doses of radiation to be delivered to residual tumor while minimizing radiation doses to the surrounding tissues. From 1978 to 1988, 39 implantations were performed on 35 patients for extensive recurrent squamous cell carcinoma of the head and neck. The decision for implantation was based on positive margins or close to resection margins from frozen sections after salvage resection. The determinate 5‐year disease‐free survival was 41%, with both the overall and no evidence of disease 5‐year survivals being 29%. Significant complications occurred in 36% of all cases. This figure increased to 56% when flap reconstruction was required. Possible reasons for this seemingly high complication rate are discussed. Considering the advanced nature of these recurrent carcinomas, surgical resection with iodine‐125 seed implantation appears to be an effective method of managing disease that might otherwise be judged unresectable and treated for palliation only.
Neurotologic Findings in Basilar Migraine
Authors: Olsson James E.
Published: February 2017

Treatment of a patient with otologic symptoms and associated migraine‐like headache presents the otolaryngologist with formidable problems. Although clinical practice and scientific publications recognize their frequent association, relationships have yet to be well defined. This study seeks to add order to disarray by delineating symptoms and signs of a clearly identified group of migraine patients. Fifty patients with well‐defined basilar migraine underwent a thorough neurotologic examination, as well as comprehensive auditory and vestibular testing. Patients were selected from 5880 patients seen over a 2‐year period and were prospectively entered into the study after detailed questionnaires and testing were completed for each patient. The most common symptoms found were dysequilibrium, phonophobia, and head pressure. The most common signs were positional nystagmus, low‐frequency hearing loss, abnormal loudness discomfort level, and an abnormality on caloric examination. Advanced vestibular testing showed abnormal amplitude scaling, abnormal toes‐down pertubation, and an abnormal sway (condition 6) on dynamic posturography. There was frequently an asymmetry on computerized rotation. The author concludes that the majority of patients have subtle findings on testing, but a few have severe peripheral injury due to the basilar migraine. Findings are consistent with the theory that basilar migraine is a central nervous system maladaptation syndrome which creates otoneurologic symptoms and, in a small percentage of cases, may injure the peripheral end‐organ.
Future Directions of Laser Phototherapy for Diagnosis and Treatment of Malignancies: Fantasy, Fallacy, or Reality?
Authors: Castro Dan J. , Saxton Romaine E. , Lufkin Robert B. , Haugland Richard P. , Zwarun Andrew A. , Fetterman Harold R. , Soudant Jacques , Castro Donna J. , Ward Paul H. , Kangarloo Hooshang
Published: February 2017

A new and highly promising adjunctive modality for the diagnosis and therapy of malignancies is under development using lasers and tumor targeting dyes. To reach the eventual goal of clinical treatment, several current “fantasies and fallacies” regarding laser applications in medicine must be identified and their problems clearly outlined. A multidisciplinary scientific approach is also required to enable the clinical practicality of this laser targeting approach. Many new dyes and laser wavelengths are being tested to improve specific tumor uptake and/or retention, lower systemic toxicity, increase tissue penetration, and identify fluorochromes with synergistic properties to further enhance laser tumoricidal effects. Rapid technological advancements in magnetic resonance imaging may now provide an extremely sensitive way to detect and monitor laser‐tissue effects, and allow efficient interstitial laser phototherapy of deep and sometimes inaccessible tumors. The current and future prospectives of the emerging field of laser phototherapy are described.
The Problem of Pediatric Laryngotracheal Stenosis: A Clinical and Experimental Study on the Efficacy of Autogenous Cartilaginous Grafts Placed Between the Vertically Divided Halves of the Posterior Lamina of the Cricoid Cartilage
Authors: Cotton Robin T.
Published: February 2017

Acquired laryngotracheal stenosis is a well‐documented complication of endotracheal intubation. Severe acquired laryngotracheal stenosis in children responds to surgical reconstruction, including the use of grafts and stents. The most commonly described graft material is autogenous cartilage, placed in the anterior laryngotracheal complex. The role of autogenous cartilaginous grafts sewn between the divided lamina of the posterior cricoid cartilage is less well established. Several authors report good clinical results using autogenous cartilaginous grafts to the posterior larynx; the single reported animal study of grafts to the posterior larynx failed to show significant benefit. This study was undertaken to examine the hypothesis that there is no difference in survival of anteriorly placed or posteriorly placed cartilaginous grafts in the larynx of growing rabbits, and to report on 61 pediatric patients with laryngotracheal stenosis treated with autogenous cartilaginous grafts placed between the vertically divided posterior lamina of the cricoid cartilage. The animal study showed that posteriorly placed grafts survived with viability equal to or better than that of anteriorly placed grafts. The clinical study showed that 59 of the 61 patients were decannulated with satisfactory vocal quality, good exercise tolerance and sleep patterns, and with no mortality.
Developing Soil Conservation Strategies with Technical and Community Knowledge in a Degrading Sub‐Humid Mountainous Landscape
Authors: Guzman Christian D. , Tilahun Seifu A. , Dagnew Desslegn C. , Zegeye Assefa D. , Yitaferu Birru , Kay Robert W. , Steenhuis Tammo S.
Published: February 2017

Worldwide, soil erosion has greatly decreased agricultural productivity and continues unabatedly despite decades of developing sustainability and soil conservation strategies. Current strategies need integrated interdisciplinary perspectives to develop more effective measures, especially in degrading mountainous landscapes where rising sediment concentrations persist. By comparing spatio‐temporal field observations and community perceptions with the Geographic Information System (GIS)‐based universal soil loss equation (USLE), this study critically examined theorized erosion patterns (by USLE) in a degraded landscape (Shanko Bahir, Ethiopia) to improve soil conservation strategy development. Daily hydro‐sedimentological data (showing 792 mm of rainfall leading to 3·2 Mg ha−1 y−1 of sediment yield) revealed mild but variable erosion patterns in 2012. Overlooking hydrology hindered the USLE's suitability for conservation planning. For instance, the median infiltration rate (33 mm h−1) was rarely exceeded (3·5% of events), meaning runoff‐induced erosion risk were not well predicted spatio‐temporally by the USLE R‐factor. Conversely, heterogeneous local perspectives explicitly considered accumulated runoff, saturation (“the water at the top level rests on the bottom”), fertility, and gullies as drivers of erosion (“black soil breaks and forms gorges”). Additionally, they designated steeper mono‐cropped lands as at risk (incidentally also highlighted by USLE). Observational evidence showed steeper midslope areas decreasing in topsoil depth by 14 mm, flatter downslope areas by 0·8 mm, and the mild upslope areas increasing 2 mm. Operationalizing effective soil conservation strategies will require expanding beyond (USLE‐based) technical knowledge to incorporate local stakeholders and consider the main hydrological processes causing erosion in sub‐humid mountainous landscapes: saturated pathways, downslope saturation, subsurface flow, and gully formation. Copyright © 2017 John Wiley & Sons, Ltd.
Technical Note: Insertion of digital lesions in the projection domain for dual‐source, dual‐energy CT
Authors: Ferrero Andrea , Chen Baiyu , Li Zhoubo , Yu Lifeng , McCollough Cynthia
Published: February 2017

Purpose

To compare algorithms performing material decomposition and classification in dual‐energy CT, it is desirable to know the ground truth of the lesion to be analyzed in real patient data. In this work, we developed and validated a framework to insert digital lesions of arbitrary chemical composition into patient projection data acquired on a dual‐source, dual‐energy CT system.

Methods

A model that takes into account beam‐hardening effects was developed to predict the CT number of objects with known chemical composition. The model utilizes information about the x‐ray energy spectra, the patient/phantom attenuation, and the x‐ray detector energy response. The beam‐hardening model was validated on samples of iodine (I) and calcium (Ca) for a second‐generation dual‐source, dual‐energy CT scanner for all tube potentials available and a wide range of patient sizes. The seven most prevalent mineral components of renal stones were modeled and digital stones were created with CT numbers computed for each patient/phantom size and x‐ray energy spectra using the developed beam‐hardening model. Each digital stone was inserted in the dual‐energy projection data of a water phantom scanned on a dual‐source scanner and reconstructed with the routine algorithms in use in our practice. The geometry of the forward projection for dual‐energy data was validated by comparing CT number accuracy and high‐contrast resolution of simulated dual‐energy CT data of the ACR phantom with experimentally acquired data.

Results

The beam‐hardening model and forward projection method accurately predicted the CT number of I and Ca over a wide range of tube potentials and phantom sizes. The images reconstructed after the insertion of digital kidney stones were consistent with the images reconstructed from the scanner, and the CT number ratios for different kidney stone types were consistent with data in the literature. A sample application of the proposed tool was also demonstrated.

Conclusion

A framework was developed and validated for the creation of digital objects of known mineral composition, and for inserting the digital objects into projection data from a commercial dual‐source, dual‐energy CT scanner. Among other applications, it will allow a systematic investigation of the impact of scan and reconstruction parameters on kidney stone dual‐energy properties under rigorously controlled conditions.
Adaptive modelling of delamination initiation and propagation using an equivalent single‐layer shell approach
Authors: Främby Johannes , Fagerström Martin , Brouzoulis Jim
Published: February 2017

A major challenge for crash failure analysis of laminated composites is to find a modelling approach, which is both sufficiently accurate, for example, able to capture delaminations, and computationally efficient to allow full‐scale vehicle crash simulations. Addressing this challenge, we propose a methodology based on an equivalent single‐layer shell formulation which is adaptively through‐the‐thickness refined to capture initiating and propagating delaminations. To be specific, single shell elements through the laminate thickness are locally and adaptively enriched using the extended finite element method such that delaminations can be explicitly modelled without having to be represented by separate elements. Furthermore, the shell formulation is combined with a stress recovery technique which increases the accuracy of predicting delamination initiations. The paper focuses on the parameters associated with identifying, introducing and extending the enrichment areas; especially on the impact of these parameters on the resulting structural deformation behaviour. We conclude that the delamination enrichment must be large enough to allow the fracture process to be accurately resolved, and we propose a suitable approach to achieve this. The proposed methodology for adaptive delamination modelling shows potential for being computationally efficient, and thereby, it has the potential to enable efficient and accurate full vehicle crash simulations of laminated composites. Copyright © 2017 John Wiley & Sons, Ltd.
Experimental Study on Impact‐induced Initiation Thresholds of Polytetrafluoroethylene/Aluminum Composite
Authors: Ge Chao , Dong Yongxiang , Maimaitituersun Wubuliaisan , Ren Yuming , Feng Shunshan
Published: February 2017

Impact experiments were conducted with a gas gun to investigate the impact‐induced initiation thresholds of a polytetrafluoroethylene/aluminum (73.5 wt % and 26.5 wt %) composite. Targets of steel, aluminum, and low‐density polyethylene materials and sample rods of four different lengths were used to decouple the effects of impact pressure and loading strain rate. By subjecting the samples to different loading conditions, it was shown that the impact‐induced initiation of polytetrafluoroethylene/aluminum is decided by the impact pressure and the loading strain rate simultaneously. The impact pressure and strain‐rate thresholds for initiation were arrested by the experiments. A 30° inclined steel target was used to produce a compression‐shear configuration as a comparison with the normal impact experiments. The initiation was more likely to happen; it demonstrated a shear‐induced initiation mechanism, and a lower initiation strain‐rate threshold was observed under oblique impact. Based on the experimental results, two theoretical curves were proposed to predict the impact‐induced initiation of polytetrafluoroethylene/aluminum under normal and 30° oblique impact.
IAP Antagonists Enhance Apoptotic Response to Enzalutamide in Castration‐Resistant Prostate Cancer Cells via Autocrine TNF‐α Signaling
Authors: Pilling Amanda B. , Hwang Ok , Boudreault Alain , Laurent Alain , Hwang Clara
Published: February 2017

BACKGROUND

Castration‐resistant prostate cancer (CRPC) remains incurable and identifying effective treatments continues to present a clinical challenge. Although treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, prolongs survival in prostate cancer patients, responses can be limited by intrinsic resistance or acquired resistance. A potential mechanism of resistance to androgen axis inhibition is evasion of apoptosis. Inhibitor of apoptosis proteins (IAPs) are found to be overexpressed in prostate cancer and function to block apoptosis and promote survival signaling. Novel, small‐molecule IAP antagonists, such as AEG40995, are emerging as a strategy to induce apoptosis and increase therapeutic response in cancer.

METHODS

Human prostate cancer cell lines LNCaP and C4‐2 were treated with enzalutamide with or without addition of IAP antagonist AEG40995 and proliferation and survival were determined by MTS and clonogenic assay. Western blot was used to evaluate IAP protein expression changes and PARP‐1 cleavage was assessed as indication of apoptosis. Flow cytometry was performed to analyze apoptosis in treated cells. Caspase activity was determined by luminescence assay. Quantitative real‐time PCR and immunometric ELISA was used to assess TNF‐α (transcript and protein levels, respectively) in response to treatment.

RESULTS

In this study, we demonstrate that IAP antagonist AEG40995 exhibits minimal effects on prostate cancer cell proliferation or survival, but rapidly degrades cIAP1 protein. Combination treatment with enzalutamide demonstrates that AEG40995 increases apoptosis and reduces proliferation and clonogenic survival in cell line models of prostate cancer. Mechanistically, we demonstrate that apoptosis in response to enzalutamide and IAP antagonist requires activation of caspase‐8, suggesting extrinsic/death receptor apoptosis signaling. Assessment of TNF‐α in response to combination treatment with enzalutamide and AEG40995 reveals increased mRNA expression and autocrine protein secretion. Blocking TNF‐α signaling abrogates the apoptotic response demonstrating that TNF‐α plays a critical role in executing cell death in response to this drug combination.

CONCLUSIONS

These findings suggest that IAP antagonists can increase sensitivity and amplify the caspase‐mediated apoptotic response to enzalutamide through TNF‐α signaling mechanisms. Combination with an IAP antagonist increases enzalutamide sensitivity, lowers the apoptotic threshold and may combat drug resistance in patients with prostate cancer. Prostate 77:866–877, 2017. © 2017 Wiley Periodicals, Inc.
Structural properties of amyloid β(1‐40) dimer explored by replica exchange molecular dynamics simulations
Authors: Watts Charles R. , Gregory Andrew J. , Frisbie Cole P. , Lovas Sándor
Published: February 2017

Replica exchange molecular dynamics simulations (300 ns) were used to study the dimerization of amyloid β(1‐40) (Aβ(1‐40)) polypeptide. Configurational entropy calculations revealed that at physiological temperature (310 K, 37°C) dynamic dimers are formed by randomly docked monomers. Free energy of binding of the two chains to each other was −93.56 ± 6.341 kJ mol−1. Prevalence of random coil conformations was found for both chains with the exceptions of increased β‐sheet content from residues 16‐21 and 29‐32 of chain A and residues 15‐21 and 30‐33 of chain B with β‐turn/β‐bend conformations in both chains from residues 1‐16, 21‐29 of chain A, 1‐16, and 21‐29 of chain B. There is a mixed β‐turn/β‐sheet region from residues 33‐38 of both chains. Analysis of intra‐ and interchain residue distances shows that, although the individual chains are highly flexible, the dimer system stays in a loosely packed antiparallel β‐sheet configuration with contacts between residues 17‐21 of chain A with residues 17‐21 and 31‐36 of chain B as well as residues 31‐36 of chain A with residues 17‐21 and 31‐36 of chain B. Based on dihedral principal component analysis, the antiparallel β‐sheet‐loop‐β‐sheet conformational motif is favored for many low energy sampled conformations. Our results show that Aβ(1‐40) can form dynamic dimers in aqueous solution that have significant conformational flexibility and are stabilized by collapse of the central and C‐terminal hydrophobic cores with the expected β‐sheet‐loop‐β‐sheet conformational motif. Proteins 2017; 85:1024–1045. © 2017 Wiley Periodicals, Inc.
Radial junction solar cells prepared on single crystalline silicon wafers by metal‐assisted etching
Authors: Baytemir Gulsen , Es Firat , Alagoz Arif Sinan , Turan Rasit
Published: February 2017

Radial junction solar cells have been proposed as an alternative device geometry to conventional planar solar cells with its remarkable electrical and optical performance. In this geometry, densely packed nano/micropillars allow minority carrier collection in the radial direction and shorten carrier diffusion length to p–n junction. Besides, reduced reflection from surface and increased light trapping in nano/micropillars enhance solar cell efficiency. In this study, photolithography and metal‐assisted etching (MAE) techniques are used to form well‐ordered silicon micropillar arrays; standard doping, passivation, and metallization steps are followed to form radial junction solar cells. The effect of micropillar length on optical and electrical performance of the solar cells have been investigated. We observed that optical reflection from solar cells surface decreased with increasing micropillar length, hence solar cell short circuit current (Jsc) and efficiency (ɳ) increased. Our best solar cell efficiency is 15.6% and this is one of the highest reported values obtained from the radial junction solar cells prepared by MAE technique.
A novel source of atomic hydrogen for passivation of defects in silicon
Authors: Hamer Phillip , Bourret‐Sicotte Gabrielle , Martins George , Wenham Alison , Bonilla Ruy S. , Wilshaw Peter
Published: February 2017

Palladium membranes have been used for decades for the separation of hydrogen from other gasses. In this letter the use of thin palladium leaves to act as sources of atomic hydrogen for silicon samples is explored. It has been assumed in the past that although hydrogen diffuses through palladium in atomic form, the atoms recombine to form molecular hydrogen at the surface. In this letter it is shown that hydrogen supplied to one surface of a palladium leaf can result in atomic hydrogen being released from the opposite surface at low pressure. This is demonstrated through the use of a palladium leaf in a direct plasma system which allows for atomic hydrogen to be supplied to a sample while avoiding exposure to UV radiation from the plasma and high energy charged particles. This method is shown to provide significant atomic hydrogen to silicon samples and improve passivation of silicon surfaces.

Method of Shielded Hydrogen Passivation: Schematic of direct plasma chamber with a shield inserted between the plasma and the silicon sample.
Development of spin‐dependent relativistic open‐shell Hartree–Fock theory with time‐reversal symmetry (II): The restricted open‐shell approach
Authors: Nakano Masahiko , Nakamura Ryota , Seino Junji , Nakai Hiromi
Published: February 2017

An open‐shell Hartree–Fock (HF) theory for spin‐dependent two‐component relativistic calculations, termed the Kramers‐restricted open‐shell HF (KROHF) method, is developed. The present KROHF method is defined as a relativistic analogue of ROHF using time‐reversal symmetry and quaternion algebra, based on the Kramers‐unrestricted HF (KUHF) theory reported in our previous study (Int. J. Quantum Chem., doi:10.1002/qua.25356). As seen in the nonrelativistic ROHF theory, the ambiguity of the KROHF Fock operator gives physically meaningless spinor energies. To avoid this problem, the canonical parametrization of KROHF to satisfy Koopmans' theorem is also discussed based on the procedure proposed by Plakhutin et al. (J. Chem. Phys. 2006, 125, 204110). Numerical assessments confirmed that KROHF using Plakhutin's canonicalization procedure correctly gives physical spinor energies within the frozen‐orbital approximation under spin–orbit interactions.
Chylothorax and central vein thrombosis, an under‐recognized association: a case series
Authors: Kho Sze Shyang , Tie Siew Teck , Chan Swee Kim , Yong Mei Ching , Chai Sing Ling , Voon Pei Jye
Published: February 2017

Chylothorax is defined as the presence of chyle in the pleural cavity. Central vein thrombosis is an under‐recognized cause of chylothorax in the adult population and is commonly related to central venous catheterization. Case 1 illustrates a patient with AIDS and disseminated tuberculosis with left chylothorax and central vein thrombosis after a month of antituberculosis therapy. Case 2 was a patient with advanced seminoma who presented with left chylothorax and central vein thrombosis while on chemotherapy. Chylothorax resolved with anticoagulation for both cases. Case 3 was a lymphoma patient with central vein thrombosis who developed chylothorax during chemotherapy. Chylothorax resolved with the continuation of anticoagulation and did not recur despite his progressive underlying lymphoma. There was no central venous catheterization in any of these three cases. These cases illustrate the unique association of central vein thrombosis and chylothorax and the importance of anticoagulation in its management.
Clustering complex time‐series databases by using periodic components
Authors: Giordano Francesco , Rocca Michele La , Parrella Maria Lucia
Published: February 2017

Clustering methods for time series have been widely studied and applied within a range of different fields. They are generally based on the choice of a relevant metric. The aim of this paper is to propose and discuss a clustering technique in the frequency domain for stationary time series. The idea of the new procedure consists in analyzing the discrete component of the spectrum, avoiding the introduction of any metric for the classification of the time series. The novel technique is suitable for time series that show strong periodic components and is based on an efficient algorithm requiring less computational and memory resources, making it appropriate for large and complex temporal databases. The problem of the selection of the optimal partition is also addressed along with a proposal that takes into account the stability of the clusters and the efficiency of the procedure in classifying the time series among the different groups. The results of a simulation study show the relative merits of the proposed procedure compared to other spectral‐based approaches. An application to a large time‐series database provided by a big electric company is also discussed. The application showed the good performance of the proposed technique, which was able to classify the time series in a few groups of customers with homogeneous electricity demand patterns.
Stable Semiconducting Ink Based on a Polypyrrole/Carbon‐Quantum‐Dot Aqueous Colloidal Suspension: A Potential Sensor for Volatile Organics Present in Food
Authors: Bhattacharjee Lopamudra , Mohanta Kallol , Ravichandran Joghee , Bhattacharjee Rama R.
Published: February 2017

Water dispersible conducting carbon quantum dots (CQDs) have been modified with PPy through a unique surface confined auto‐catalytic process. Viscoelastic and electronic characteristics of the concentrated CQD‐PPy aqueous suspension confirmed semiconducting ink‐like behavior. The ink forms stable impression on paper, glass and fabric. CQD‐PPy ink coated substrates respond selectively towards different flavors (VOCs) originating in packaged food items.
Fast and Eco–friendly Microwave‐Assisted Synthesis of Silver Nanoparticles using Rosemary Essential Oil as Renewable Reducing Agent.
Authors: González‐Rivera José , Duce Celia , Ierardi Vincenzo , Longo Iginio , Spepi Alessio , Tiné Maria Rosaria , Ferrari Carlo
Published: February 2017

A green and fast methodology was developed to synthesize silver nanoparticles using rosemary essential oil (EO) as a renewable reducing agent. The synthesis process was microwave (MW) assisted, using a coaxial dipole antenna immersed into the reaction medium. This configuration was used to promote both: i) rosemary EO extraction by hydrodistillation, and ii) silver nanoparticle synthesis in an aqueous solution at atmospheric pressure. The effect of two different silver salt substrates and the time reaction on the morphology of the silver nanoparticles was explored. The coaxial microwave‐assisted hydrodistillation of rosemary yields 0.4 % (w/w) in 30 min and contains ethers (17 %), ketones (50 %) and alcohols (15 %). Silver nanoparticles with a tuneable particle size (from 7 to 18 nm) and morphology (from spherical to round‐like shapes) were obtained in reaction times ranging from 2 to 30 min. The nanoparticle formation was followed by UV‐vis spectroscopy and SEM imaging.
Mechanical Stirring Induces Heteroaggregate Formation and Self‐assembly of Pseudoenantiomeric Oxymethylene Helicene Oligomers in Solution
Authors: Sawato Tsukasa , Saito Nozomi , Shigeno Masanori , Yamaguchi Masahiko
Published: February 2017

A mixture of pseudoenantiomeric oxymethylene helicene (P)‐pentamers and (M)‐hexamers formed heteroaggregates and self‐assembled as a result of mechanical stirring in solution at 25 °C. No aggregation occurred without stirring, and heteroaggregation was accelerated at high stirring rates. Repeatedly alternating between mechanical stirring and stopping respectively induced and then ceased the heteroaggregation. Sonication also promoted the heteroaggregation, which did not occur at high pressures or during centrifugation. Mechanisms based on friction due to mechanical stirring, which generated local and temporal high‐temperature domains, are considered. It is shown that different methods of mechanical stimulation, namely, stirring and surface contact, induce enantiomeric heteroaggregate formation.
Investigating the role of a district science coordinator
Authors: Whitworth Brooke A. , Maeng Jennifer L. , Wheeler Lindsay B. , Chiu Jennifer L.
Published: February 2017

This study explored the professional responsibilities of district science coordinators, their professional development (PD) experiences, the relationship between their role, responsibilities, district context, and background, and barriers encountered in their work. A national sample (n = 122) of self‐identified science coordinators completed a Science Coordinator Role Survey. Participants’ responses were analyzed using descriptive and correlational statistics. Following analysis of survey data, 16 participants (13.1%) were purposefully selected for semi‐structured follow‐up interviews. Results indicated the majority of respondents identified themselves as Caucasian, female, and had served in their position for less than 10 years. The typical science coordinator held a degree in a science content area and was a former science teacher. Respondents without science degrees tended to hold positions at small, remote, or rural school districts with responsibilities in multiple content areas. Participants also reported barriers of not having enough PD opportunities, lack of time, lack of emphasis on science instruction, and a lack of power to enforce policies within a district. Results characterize the professional responsibilities of coordinators, provide insight into the role of a science coordinator, and into how to create targeted PD for coordinators. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 54: 914–936, 2017
Non‐visualization of choroid plexus of fourth ventricle as first‐trimester predictor of posterior fossa anomalies and chromosomal defects
Authors: Martinez‐Ten P. , Illescas T. , Adiego B. , Estevez M. , Bermejo C. , Wong A. E. , Sepulveda W.
Published: February 2017

Objective

To assess non‐visualization of the choroid plexus of the fourth ventricle (CP‐4V) as a simple, qualitative and reproducible first‐trimester ultrasound feature of the posterior fossa for the prediction of central nervous system (CNS) anomalies and chromosomal defects.

Methods

First‐trimester three‐dimensional ultrasound datasets of the fetal brain were obtained prospectively from 65 consecutive normal singletons and retrospectively from 27 fetuses identified as having an abnormal posterior fossa on first‐trimester ultrasound examination, and randomly combined to form the final study group. The stored ultrasound volumes were analyzed offline by two accredited sonologists, who were not aware of the final diagnoses. The CP‐4V was assessed by multiplanar navigation and classified as visible or non‐visible in its normal position depending on whether or not the echogenic structure that separates the fourth ventricle from the cisterna magna was identified in both midsagittal and axial planes. Correlation with subsequent second‐trimester ultrasound, fetal magnetic resonance imaging, or postmortem or postnatal findings was performed to determine the predictive value of the first‐trimester findings.

Results

Among the 92 ultrasound datasets analyzed, 73 (79%) were acquired transabdominally and 19 (21%) transvaginally. The CP‐4V was classified as visible in 64 cases and non‐visible in 28 cases, with agreement between the two observers in both sagittal and axial planes in all but one case. Twelve of the 28 (43%) fetuses with non‐visible CP‐4V were subsequently diagnosed as having a CNS malformation (open spina bifida (n = 6), Dandy–Walker malformation (n = 2), Blake's pouch cyst (n = 2), cephalocele (n = 1) and megacisterna magna (n = 1)). In addition, 20 of these 28 (71%) fetuses had aneuploidy (trisomy 18 (n = 10), triploidy (n = 5), trisomy 13 (n = 3), Turner syndrome (n = 1) or trisomy 21 (n = 1)). There was only one false‐positive case, in which the CP‐4V was classified as absent in a normal fetus.

Conclusions

Non‐visualization of the CP‐4V in the first trimester appears to be a strong marker of posterior fossa anomalies and chromosomal defects. Qualitative evaluation of this anatomic structure is simple, feasible and reproducible, and its routine assessment during the first‐trimester scan may facilitate the early detection of CNS anomalies and associated fetal aneuploidy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
Maternal hemodynamics early in labor: a possible link with obstetric risk?
Authors: Valensise H. , Tiralongo G. M. , Pisani I. , Farsetti D. , Lo Presti D. , Gagliardi G. , Basile M. R. , Novelli G. P. , Vasapollo B.
Published: February 2017

Objective

To determine if hemodynamic assessment in ‘low‐risk’ pregnant women at term with an appropriate‐for‐gestational age (AGA) fetus can improve the identification of patients who will suffer maternal or fetal/neonatal complications during labor.

Methods

This was a prospective observational study of 77 women with low‐risk term pregnancy and AGA fetus, in the early stages of labor. Hemodynamic indices were obtained using the UltraSonic Cardiac Output Monitor (USCOM®) system. Patients were followed until the end of labor to identify fetal/neonatal and maternal outcomes, and those which developed complications of labor were compared with those delivering without complications.

Results

Eleven (14.3%) patients had a complication during labor: in seven there was fetal distress and in four there were maternal complications (postpartum hemorrhage and/or uterine atony). Patients who developed complications during labor had lower cardiac output (5.6 ± 1.0 vs 6.7 ± 1.3 L/min, P = 0.01) and cardiac index (3.1 ± 0.6 vs 3.5 ± 0.7 L/min/m2, P = 0.04), and higher total vascular resistance (1195.3 ± 205.3 vs 1017.8 ± 225.6 dynes × s/cm5, P = 0.017) early in labor, compared with those who did not develop complications. Receiver–operating characteristics curve analysis to determine cut‐offs showed cardiac output ≤ 5.8 L/min (sensitivity, 81.8%; specificity, 69.7%), cardiac index ≤ 2.9 L/min/m2 (sensitivity, 63.6%; specificity, 76.9%) and total vascular resistance > 1069 dynes × s/cm5 (sensitivity, 81.8%; specificity, 63.6%) to best predict maternal or fetal/neonatal complications.

Conclusions

The study of maternal cardiovascular adaptation at the end of pregnancy could help to identify low‐risk patients who may develop complications during labor. In particular, low cardiac output and high total vascular resistance are apparently associated with higher risk of fetal distress or maternal complications. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.
Junior faculty core curriculum to enhance faculty development
Authors: Guillet Ronnie , Holloway Robert G. , Gross Robert A. , Libby Katie , Shapiro Janine R.
Published: February 2017

Introduction

Senior Instructors and Assistant Professors in their first academic appointment may not have all the tools for an efficient start to their careers. Although many institutions provide access to mentoring programs and seminars on faculty development, the timing and format of the offerings often conflict with ongoing responsibilities of the faculty, particularly clinical faculty.

Methods

We established a collaboration between the Clinical and Translational Science Institute (CTSI) and the University of Rochester Medical Center Office for Faculty Development with the goal of developing a week-long Junior Faculty Core Curriculum that would better suit faculty schedules. We convened focus groups and with their help, identified themes for inclusion in the course. Speakers were identified from among local senior faculty. University leadership was enlisted in promoting the course. Individual speakers and course content were evaluated daily, at the end of the week-long course, and 6 months later. Planning for subsequent years incorporated the feedback. Yearly evaluations and subsequent course modification continued.

Results

Junior faculty from nearly every department in the Medical Center were represented. There was high learner satisfaction and participation however several limitations were identified and addressed in subsequent years. The focus on principles and available resources, not specific skills or content was appropriate. Daily interactions among participants from a wide variety of departments fostered networking among faculty who may not otherwise have met and discussed common interests

Conclusions

The ultimate value of such an early, intensive faculty development program will depend on whether it equips junior faculty to organize, develop, and achieve their academic goals better than alternative formats. This will require further study.