bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescence Intensity Modulation in Photochromic Conjugated Polymer Systems
Authors: Harbron Elizabeth J. 
Published: May 2013

AbstractThe ability to modulate fluorescence intensity with a light signal enables a variety of applications based on fluorescence imaging. One approach to fluorescence photomodulation involves using a photochromic moiety that responds to a light signal in conjunction with a nearby fluorophore. We employ conjugated polymers based on poly(p‐phenylene vinylene) (PPV) as the fluorophore in photochrome‐fluorophore systems for fluorescence modulation. Advantages of using conjugated polymers for this purpose include their intrinsic energy migration processes that enable amplified fluorescence quenching as well as their processability. Here we present examples of PPV‐based photomodulation systems that employ photochromic dyes from three common photochromic families: azobenzenes, spironaphthoxazines, and diarylethenes. In all cases we observe reversible fluorescence quenching due to fluorescence resonance energy transfer to the photogenerated form of the photochrome. Examples of the photomodulation of photochromic PPV systems in organic solution, polymer films, and conjugated polymer nanoparticles are presented.
Rapid and label‐free identification of normal spermatozoa based on image analysis and micro‐Raman spectroscopy
Authors: Huang Zufang , Chen Guannan , Chen Xiwen , Wang Jing , Chen Jinhua , Lu Peng , Chen Rong 
Published: May 2013

AbstractSemen analysis is performed for evaluation of fertility disorders, however it is susceptible to subjectivity of investigators, and lacking of objective criterion for sperm cell quality remains a problem. There is an ongoing debate on which criteria should be employed to define normal spermatozoa. Here, the aim of our study is to evaluate the possibility of label‐free and rapid identification of normal sperm cell through the use of image analysis combined with micro‐Raman spectroscopy. By using a smooth‐surfaced and hydrophobic substrate, spermatozoa smear was rapidly prepared for microscopic imaging and acrosome area can be clearly visualized without any extra stains; then a self‐written image analysis program was utilized to segment sperm head and acrosome area and automatically calculates morphological indices. Most important, intensity ratio of 1055 cm–1 to 1095 cm–1 from the obtained Raman spectra is found to indicate a potential biomarker for assessing the sperm DNA integrity. Our preliminary study demonstrates that micro‐Raman spectroscopy combined with image analysis can be a potentially useful tool for rapid and label‐free identification of normal sperm cell by providing both morphological and biochemical information. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kombucha‐synthesized bacterial cellulose: Preparation, characterization, and biocompatibility evaluation
Authors: Zhu Changlai , Li Feng , Zhou Xinyang , Lin Lin , Zhang Tianyi 
Published: May 2013

AbstractBacterial cellulose (BC) is a natural biomaterial with unique properties suitable for tissue engineering applications, but it has not yet been used for preparing nerve conduits to repair peripheral nerve injuries. The objectives of this study were to prepare and characterize the Kampuchea‐synthesized bacterial cellulose (KBC) and further evaluate the biocompatibility of KBC with peripheral nerve cells and tissues in vitro and in vivo. KBC membranes were composed of interwoven ribbons of about 20–100 nm in width, and had a high purity and the same crystallinity as that of cellulose Iα. The results from light and scanning electron microscopy, MTT assay, flow cytometry, and RT‐PCR indicated that no significant differences in the morphology and cell function were observed between Schwann cells (SCs) cultured on KBC membranes and glass slips. We also fabricated a nerve conduit using KBC, which was implanted into the spatium intermusculare of rats. At 1, 3, and 6 weeks post‐implantation, clinical chemistry and histochemistry showed that there were no significant differences in blood counts, serum biochemical parameters, and tissue reactions between implanted rats and sham‐operated rats. Collectively, our data indicated that KBC possessed good biocompatibility with primary cultured SCs and KBC did not exert hematological and histological toxic effects on nerve tissues in vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1548–1557, 2014.
Passive films on metallic biomaterials under simulated physiological conditions
Authors: Pound B. G. 
Published: May 2013

AbstractThe metallic materials used for implantable medical devices are predominantly stainless steels, Ti and its alloys, and Co‐Cr alloys. The corrosion resistance of each of these materials is associated with a passive oxide film on its surface. Since corrosion resistance is crucial to implant performance, considerable effort has been focused on understanding the nature of the passive film present under physiological conditions. Surface analytical techniques and electrochemical impedance spectroscopy have been used in a number of studies to investigate the passive film formed on metallic biomaterials in simulated physiological solutions. This review focuses on the surface characteristics of these materials with regard to composition, thickness, and impedance of the passive films. Of particular interest are changes in the films with surface treatment and the nature of the films developed over time in the simulated solutions. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1595–1604, 2014.
Host response to microgel coatings on neural electrodes implanted in the brain
Authors: Gutowski Stacie M. , Templeman Kellie L. , South Antoinette B. , Gaulding Jeffrey C. , Shoemaker James T. , LaPlaca Michelle C. , Bellamkonda Ravi V. , Lyon L. Andrew , García Andrés J. 
Published: May 2013

AbstractThe performance of neural electrodes implanted in the brain is often limited by host response in the surrounding brain tissue, including astrocytic scar formation, neuronal cell death, and inflammation around the implant. We applied conformal microgel coatings to silicon neural electrodes and examined host responses to microgel‐coated and uncoated electrodes following implantation in the rat brain. In vitro analyses demonstrated significantly reduced astrocyte and microglia adhesion to microgel‐coated electrodes compared to uncoated controls. Microgel‐coated and uncoated electrodes were implanted in the rat brain cortex and the extent of activated microglia and astrocytes as well as neuron density around the implant were evaluated at 1, 4, and 24 weeks postimplantation. Microgel coatings reduced astrocytic recruitment around the implant at later time points. However, microglial response indicated persistence of inflammation in the area around the electrode. Neuronal density around the implanted electrodes was also lower for both implant groups compared to the uninjured control. These results demonstrate that microgel coatings do not significantly improve host responses to implanted neural electrodes and underscore the need for further improvements in implantable materials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1486–1499, 2014.
Thiol‐ene/acrylate substrates for softening intracortical electrodes
Authors: Ware Taylor , Simon Dustin , Liu Clive , Musa Tabassum , Vasudevan Srikanth , Sloan Andrew , Keefer Edward W. , Rennaker Robert L. , Voit Walter 
Published: May 2013

AbstractNeural interfaces have traditionally been fabricated on rigid and planar substrates, including silicon and engineering thermoplastics. However, the neural tissue with which these devices interact is both 3D and highly compliant. The mechanical mismatch at the biotic–abiotic interface is expected to contribute to the tissue response that limits chronic signal recording and stimulation. In this work, novel ternary thiol‐ene/acrylate polymer networks are used to create softening substrates for neural recording electrodes. Thermomechanical properties of the substrates are studied through differential scanning calorimetry and dynamic mechanical analysis both before and after exposure physiological conditions. This substrate system softens from more than 1 GPa to 18 MPa on exposure to physiological conditions: reaching body temperature and taking up less than 3% fluid. The impedance of 177 µm2 gold electrodes electroplated with platinum black fabricated on these substrates is measured to be 206 kΩ at 1 kHz. Specifically, intracortical electrodes are fabricated, implanted, and used to record driven neural activity. This work describes the first substrate system that can use the full capabilities of photolithography, respond to physiological conditions by softening markedly after insertion, and record driven neural activity for 4 weeks. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1–11, 2014.
Hamiltonian Cycle Systems Which Are Both Cyclic and Symmetric
Authors: Buratti Marco , Merola Francesca 
Published: May 2013

AbstractThe notion of a symmetric Hamiltonian cycle system (HCS) of a graph Γ has been introduced and studied by J. Akiyama, M. Kobayashi, and G. Nakamura [J Combin Des 12 (2004), 39–45] for , by R. A. Brualdi and M. W. Schroeder [J Combin Des 19 (2011), 1–15] for , and then naturally extended by V. Chitra and A. Muthusamy [Discussiones Mathematicae Graph Theory, to appear] to the multigraphs and . In each case, there must be an involutory permutation ψ of the vertices fixing all the cycles of the HCS and at most one vertex. Furthermore, for , this ψ should be precisely the permutation switching all pairs of endpoints of the edges of I.An HCS is cyclic if it is invariant under some cyclic permutation of all the vertices. The existence question for a cyclic HCS of has been completely solved by Jordon and Morris [Discrete Math (2008), 2440–2449]—and we note that their cyclic construction is also symmetric for (mod 8). It is then natural to study the existence problem of an HCS of a graph or multigraph Γ as above which is both cyclic and symmetric. In this paper, we completely solve this problem: in the case of even order, the final answer is that cyclicity and symmetry can always cohabit when a cyclic solution exists. On the other hand, imposing that a cyclic HCS of odd order is also symmetric is very restrictive; we prove in fact that an HCS of with both properties exists if and only if is a prime.
Population‐based analysis of prognostic indicators in sebaceous carcinoma of the head and neck
Authors: Thomas W. Walsh , Fritsch Valerie A. , Lentsch Eric J. 
Published: May 2013

Objectives/HypothesisDue to the rarity of sebaceous carcinoma of the head and neck, few large series have been reported and prognostic factors remain largely undetermined. This study presents prognostic factors in survival in sebaceous carcinoma of the head and neck.Study DesignRetrospective analysis was performed using the Surveillance Epidemiology and End Results (SEER) database for patients diagnosed with sebaceous carcinoma of the head and neck (SCHN).MethodsClinicopathologic, treatment data, and 5‐year disease specific survival were analyzed using univariable and multivariable regression analysis and Kaplan‐Meier methodology.ResultsOf the 1,433 patients identified to have SCHN, 16 were node‐positive (1.14%). On multivariable analysis, independent prognostic indicators were: age at diagnosis (HR = 1.03, P = .021), tumor grade (HR = 4.97, P = .038), and distant metastasis (HR = 7.52, P = .006). Nodal metastasis occurred exclusively with poorly or undifferentiated tumors and was not a significant prognostic factor on multivariable analysis.ConclusionElderly patients and patients with poorly differentiated tumors and/or distant disease at presentation have the highest risk of disease‐specific mortality. Lymph node metastasis does not appear to be an independent prognostic factor in sebaceous cell carcinoma.Level of Evidence2b. Laryngoscope, 123:2165–2169, 2013
The effect of anterior palatine blocks on bleeding in hereditary hemorrhagic telangiectasia nasal surgery
Authors: Guthrie Carly C. , Karnezis Tom T. , Orosco Ryan K. , Bishop Michael L. , Davidson Terence M. 
Published: May 2013

Objectives/HypothesisWhen combined with local sphenopalatine (SP) injection and moderate hypotension, transoral or transcutaneous local injection of the anterior palatine (AP) vessels reduces intraoperative bleeding in hereditary hemorrhagic telangiectasia (HHT) patients undergoing nasal surgery.Study DesignRetrospective chart review of 55 consecutive HHT patients undergoing a bevacizumab injection for recalcitrant epistaxis. Nineteen patients received local injections to only the SP vasculature, and 36 patients received AP and SP injections.MethodsMain outcome variable was estimated blood loss during nasal surgery. Independent variables included sex, age, epistaxis severity score, surgical techniques (including laser), and blood pressure parameters (baseline, preinduction, and postintubation).ResultsThe mean blood loss in HHT patients receiving SP injections alone was 111 mL, whereas it was 22 mL for those receiving both AP + SP injections. This difference between groups approached statistical significance (P = .075). Blood pressure parameters were similar in both groups with no appreciable difference between intraoperative systolic and mean arterial blood pressure.ConclusionsThe addition of either sublabial or transcutaneous AP injection to the standard SP block markedly reduces blood loss in HHT epistaxis nasal surgery.Level of Evidence4. Laryngoscope, 123:2598–2600, 2013
Wrong site surgery in otolaryngology–head and neck surgery
Authors: Liou Tzyy‐Nong , Nussenbaum Brian 
Published: May 2013

Objectives/HypothesisWrong site surgery has received high public awareness this past decade, yet discussion specific to otolaryngology is limited.Study DesignLiterature review.MethodsWe searched the MEDLINE database on PubMed from 1980 to 2013 and pursued the citations of key references further. We conducted a review of the literature and public patient safety reports on the scope, root causes, and prevention of wrong site surgery with emphasis on otolaryngology.ResultsA review of the literature reveals that otolaryngology procedures constitute 0.3% to 4.5% of all wrong site surgery events, and wrong site surgery accounts for 4% to 6% of all medical errors in otolaryngology. A significant proportion (9% to 21%) of otolaryngologists reported experiences with wrong site surgery over their career, and the events most frequently resulted in temporary injuries to the patient with few cases of permanent disability or death. Although otolaryngology procedures have similar root causes for wrong site events as other specialties, inverted imaging and ambiguity in site marking are particular challenges. Site‐marking practices are variable among otolaryngologists, as it is not applicable to many otolaryngology procedures, yet these are common procedures that also constitute the majority of wrong site cases reported in otolaryngology.ConclusionsFuture interventions to address these challenges related to otolaryngology–head and neck surgery might involve a standardized protocol to confirm imaging accuracy, a specialty‐ or procedure‐specific checklist, a standardized alternative to site marking when marking is impractical, and other innovations. Evaluation of these interventions is becoming easier given the increasing mandatory reporting of these events that provides more reliable incidence data. Laryngoscope, 124:104–109, 2014
A randomized study of suprastomal stents in laryngotracheoplasty surgery for grade III subglottic stenosis in children
Authors: Preciado Diego 
Published: May 2013

Objectives/HypothesisStudies comparing the relative effectiveness of suprastomal stents in laryngotracheoplasty surgery are lacking in the literature. The goal of this study was to compare the performance of two widely used short‐term suprastomal stents in open airway surgery.Study DesignProspective, randomized study of a single surgeon's outcomes for grade III subglottic stenosis (SGS) in children.MethodsThe open Aboulker Teflon stent versus the cut, closed, soft Silastic Montgomery T‐tube stent for short‐term stenting in double‐stage laryngotracheoplasty (dsLTP) were compared.ResultsTwenty‐four patients were recruited into the study; 12 received an Aboulker (A) stent and 12 a cut, soft, Silastic (S) stent. There was no statistically significant difference in the operation specific decannulation rate between the two stent groups. Patients who received S stents were found to tolerate postoperative feeding better than those with A stents. The median time to decannulate, however, was longer for those receiving S stents (5.5 vs. 3.5 months, P = .02). Furthermore, those receiving S stents had increased need for airway dilation after stent removal (1.75 vs. 0.17 dilations per patient, P = .02) and increased presence of granulation tissue in the airway at the time of stent removal. Multivariate analysis showed the type of stent used independently correlated to time to decannulate (P = .022).ConclusionsCompared to the Teflon Aboulker stents, closed, soft, Silastic stents are associated with improved feeding in the postoperative period. Their use, however, also correlates with worsened granulation tissue formation and longer time to decannulation in patients undergoing dsLTP for grade III SGS.Level of Evidence1b. Laryngoscope, 124:207–213, 2014
Impact of synechiae after endoscopic sinus surgery on long‐term outcomes in chronic rhinosinusitis
Authors: Henriquez Oswaldo A. , Schlosser Rodney J. , Mace Jess C. , Smith Timothy L. , Soler Zachary M. 
Published: May 2013

Objectives/HypothesisSynechiae are one of the most common unwanted outcomes after endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS). However, there has been scant investigation into the true significance of synechiae formation after ESS. The aim of this study was to evaluate the impact of synechiae formation on health‐related quality of life (HRQoL) outcomes after ESS in patients with CRS.Study DesignProspective, multi‐institutional cohort.MethodsRhinosinusitis Disability Index (RSDI) and Chronic Sinusitis Survey (CSS) scores were measured in adult patients before and after undergoing ESS for CRS. Differences in HRQoL were evaluated between those who developed sinonasal synechiae and those who did not, controlling for demographic factors, medical comorbidities, and measures of disease severity at baseline.ResultsA total of 286 patients underwent ESS, with 55 (19.2%) developing synechiae in the follow‐up period. Patients developing synechiae reported significantly less improvement on the RSDI total scores (13.5 vs. 21.4, P = 0.008), RSDI physical subscores (5.3 vs. 8.3, P = 0.007), RSDI emotional subscores (2.9 vs. 5.8, P = 0.008), CSS total scores (14.5 vs. 21.2, P = 0.093), and CSS symptom subscores (19.9 vs 30.3, P = 0.069) compared to those who did not develop synechiae postoperatively. These differences persisted even after controlling for baseline differences in disease severity.ConclusionsSynechiae of the sinonasal cavity commonly occurs following ESS, particularly in those undergoing revision surgeries. Although both groups improve, the degree of HRQoL improvement appears to be less in those who form postoperative synechiae after surgery compared to those who do not.Level of Evidence2c. Laryngoscope, 123:2615–2619, 2013
Development of a porous poly(DL‐lactic acid‐co‐glycolic acid)‐based scaffold for mastoid air‐cell regeneration
Authors: Gould Toby W. A. , Birchall John P. , Mallick Ali S. , Alliston Tamara , Lustig Lawrence R. , Shakesheff Kevin M. , Rahman Cheryl V. 
Published: May 2013

Objectives/HypothesisTo develop a porous, biodegradable scaffold for mastoid air‐cell regeneration.Study DesignIn vitro development of a temperature‐sensitive poly(DL‐lactic acid‐co‐glycolic acid)/poly(ethylene glycol) (PLGA/PEG) scaffold tailored for this application.MethodsHuman mastoid bone microstructure and porosity were investigated using micro‐computed tomography. PLGA/PEG‐alginate scaffolds were developed, and scaffold porosity was assessed. Human bone marrow mesenchymal stem cells (hBM‐MSCs) were cultured on the scaffolds in vitro. Scaffolds were loaded with ciprofloxacin, and release of ciprofloxacin over time in vitro was assessed.ResultsPorosity of human mastoid bone was measured at 83% with an average pore size of 1.3 mm. PLGA/PEG‐alginate scaffold porosity ranged from 43% to 78% depending on the alginate bead content. The hBM‐MSCs proliferate on the scaffolds in vitro, and release of ciprofloxacin from the scaffolds was demonstrated over 7 to 10 weeks.ConclusionsThe PLGA/PEG‐alginate scaffolds developed in this study demonstrate similar structural features to human mastoid bone, support cell growth, and display sustained antibiotic release. These scaffolds may be of potential clinical use in mastoid air‐cell regeneration. Further in vivo studies to assess the suitability of PLGA/PEG‐alginate scaffolds for this application are requiredLevel of EvidenceN/A. Laryngoscope, 123:3156–3161, 2013
Efficient concomitant and remanence field artifact reduction in ultra‐low‐field MRI using a frequency‐space formulation
Authors: Hsu Yi‐Cheng , Vesanen Panu T. , Nieminen Jaakko O. , Zevenhoven Koos C.J. , Dabek Juhani , Parkkonen Lauri , Chern I‐Liang , Ilmoniemi Risto J. , Lin Fa‐Hsuan 
Published: May 2013

PurposeFor ultra‐low‐field MRI, the spatial‐encoding magnetic fields generated by gradient coils can have strong concomitant fields leading to prominent image distortion. Additionally, using superconducting magnet to pre‐polarize magnetization can improve the signal‐to‐noise ratio of ultra‐low‐field MRI. Yet the spatially inhomogeneous remanence field due to the permanently trapped flux inside a superconducting pre‐polarizing coil modulates magnetization and causes further image distortion.MethodWe propose a two‐stage frequency–space (f–x) formulation to accurately describe the dynamics of spatially‐encoded magnetization under the influence of concomitant and remanence fields, which allows for correcting image distortion due to concomitant and remanence fields.ResultsOur method is computationally efficient as it uses a combination of the fast Fourier transform algorithm and a linear equation solver. With sufficiently dense discretization in solving the linear equation, the performance of this f–x method was found to be stable among different choices of the regularization parameter and the regularization matrix.ConclusionWe present this method together with numerical simulations and experimental data to demonstrate how concomitant and remanence field artifacts in ultra‐low‐field MRI can be corrected efficiently. Magn Reson Med 71:955–965, 2014. © 2013 Wiley Periodicals, Inc.