bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel compression rat model for developmental spinal stenosis
Authors: Cheung Prudence W. H. , Hu Yong , Cheung Jason P. Y. 
Published: January 2019

ABSTRACTDevelopmental spinal stenosis (DSS) is characterized by pre‐existing circumferential narrowing of the bony spinal canal which predisposes neural tissue to compression. This study aims to create a reproducible animal model mimicking DSS for investigation of its pathoanatomy. Developmental spinal canal constriction was simulated using circumferential compression. Eighteen female Sprague–Dawley rats (13.0–14.5 weeks‐old) underwent circumferential compression at L4‐L5 using silicone sheets; or dorsal compression using overlapping silicone sheets; or as controls. A series of outcome scores were used for locomotor function assessment, together with electrophysiological and histological assessment. Assessment time‐points were at preoperative, postoperative 1‐week, 2‐weeks, 3‐weeks, 1‐month, and pre‐sacrifice. Statistical analyses were performed. At all postoperative time‐points, circumferential group had the worst mean Basso, Beattie and Bresnahan locomotor scores with significant difference from the control group (p < 0.05), as well as the lowest mean Louisville Swim Scale scores, as compared to the dorsal (p < 0.05) and to the control (p < 0.01) groups. Circumferential group had worse mean foot fault score for both hindlimbs (p < 0.01 to p < 0.05) and highest error rate in foot placement accuracy, especially higher than dorsal (p < 0.05) and control (p < 0.05) groups at pre‐sacrifice. Electrophysiological assessment revealed postoperative increase in P1 latency was higher in circumferential than dorsal compression. Highest postoperative mean P1 latency was observed for both paws at all postoperative time‐points for circumferential group (except at postoperative 1‐week). Circumferential group had lower myelin‐to‐axonal area ratio and higher g‐ratio than both the dorsal and control groups (p < 0.001). For each study group, hindlimb P1 latency and P1‐N1 amplitude were each correlated with g‐ratio (p < 0.05); and mean myelin‐to‐axonal area ratio correlated with P1 latency of both hindlimbs (p < 0.05). Based on these more severe axonal demyelination and neurological deficits, a valid DSS rat model is created with somatosensory evoked potential neuro‐monitoring technique. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Retrospective cohort study of 4,591 dental implants: Analysis of risk indicators for bone loss and prevalence of peri‐implant mucositis and peri‐implantitis
Authors: French David , Grandin H. Michelle , Ofec Ronen 
Published: January 2019

AbstractBackgroundDue to the risk of peri‐implantitis, following dental implant placement, this study aimed to evaluate risk indicators associated with marginal bone loss from a retrospective open cohort study of 4,591 dental implants, placed in private practice, with 5‐ to 10‐year follow‐up. Furthermore, the prevalence of mucositis and peri‐implantitis among the study cohort was evaluated, comparing strict versus relaxed criteria for bleeding on probing.MethodsPeriapical radiographs were used to evaluate changes in crestal bone level. Peri‐implant soft tissue was evaluated using an ordinal mucosal index in comparison with the conventional binary threshold for bleeding (i.e., present or not). Periodontal probing depth was not evaluated. Linear mixed models were used to evaluate bone level over time, and other risk indicators, at the patient and implant level.ResultsRisk indicators found to have a significant impact on bone level included: autoimmune disease, heavy smoking, bisphosphonate therapy, implant location, diameter and design, and the presence of a bone defect at site of implantation. The prevalence of mucositis at the implant level was 38.6% versus 14.2% at 6 to 7 years, when using strict versus relaxed criteria, respectively. The prevalence of peri‐implantitis after 6 to 7 years was 4.7% and 3.6% when using strict versus relaxed criteria, respectively.ConclusionsThe results of this study identify several risk factors associated with bone loss. Furthermore, the prevalence of mucositis and peri‐implantitis was shown to be lower at both the implant and the patient when using strict versus relaxed criteria based on the assessment of oral health surrounding dental implants.
Reconstructive limb‐salvage surgery after lower extremity soft tissue sarcoma resection: A 20‐year experience
Authors: Bridgham Kelly M. , El Abiad Jad M. , Lu Zhen A. , Bhat Deepa , Darrach Halley , Morris Carol D. , Levin Adam S. , Sacks Justin M. 
Published: January 2019

BackgroundReconstructive surgery is often required following lower extremity soft tissue sarcoma resection. The relationship between the method of plastic surgery reconstruction and postoperative wound healing or functional oncologic outcomes in this patient population is poorly understood.MethodsWe performed a retrospective review on all adult patients that underwent soft tissue reconstruction following resection of lower extremity soft tissue sarcomas between 1996 and 2016 at our institution.ResultsOne hundred and thirty‐six patients were identified. Wound complications occurred within 6‐months postoperatively in 72 patients (52.9%). Average time to heal was 13.0 weeks. Limb survival was 94.9%. 16.9% and 36.8% of patients had evidence of local recurrence or metastatic disease, respectively. There was no significant difference in the incidence of overall wound complications, time to heal, limb survival, local recurrence, or metastatic disease between the different reconstructive methods.ConclusionsIn our cohort, the utilization of different reconstructive techniques did not correlate with a difference in postoperative wound complications or oncologic outcomes. Local flaps can effectively reconstruct the majority of lower extremity sarcoma defects that cannot be closed primarily. However, alternative reconstructive techniques may be utilized when indicated without a significant increase in postoperative morbidity in this patient population.
Determination of multi‐class antibiotic residues in compost by microwave‐enhanced accelerated solvent extraction and ultra performance convergence chromatography with tandem mass spectrometry
Authors: Lu Xue‐feng , Zhou Yang , Zhang Jian , Ren Yu‐peng 
Published: January 2019

AbstractThis work reports the development and application of a multi‐class compound analysis method for the determination of 20 antibiotic residues in compost. Samples were processed by microwave‐enhanced accelerated solvent extraction at 120°C for 7.5 min. Salting‐out homogeneous liquid‐liquid extraction was used to remove water and water‐soluble impurities from the extract before ultra performance convergence chromatography with tandem mass spectrometry analysis. By using the supercritical fluid (carbon dioxide) and organic solvent (methanol) as the mobile phase, the 20 antibiotics and the internal standard were well separated in 8.2 min without obvious matrix effect. Method validation was performed and good trueness (relative error in the range of ±5.0%) and precision (inter‐ and intraday relative standard deviations < 10.8%) were obtained. Method detection and quantitation limits were 0.8–1.9 and 2.7–7.1 ng/g, respectively. Recoveries were assessed at three concentration levels (10, 60, and 400 ng/g) and acceptable mean values (70.4–111.9%) were found. This method has also been used to analyze real samples, and the average concentrations of antibiotics (excepting the concentrations < method quantitation limits) were determined up to 123.6 ng/g. The results showed the method could be helpful for the analysis of multi‐class antibiotics in environmental samples.
Revisiting age‐related admission following tonsillectomy in the pediatric population
Authors: Evans Sean S. , Cho Do Yeon , Richman Joshua , Kulbersh Brian 
Published: January 2019

Objectives/HypothesisThe objectives of this study were to examine patient outcomes using a 36‐month age cutoff as a strict admission criterion following tonsillectomy, and review the safety and determine the plausibility of same‐day discharge of children under 3 years old following tonsillectomy.Study DesignRetrospective chart review.MethodsA chart review of patients aged 24 to 42 months undergoing tonsillectomy over a 3‐year period was conducted. Patients were stratified into <36 months and ≥ 36 months cohorts. Data collected included demographics, medical/sleep history, inpatient records, 30‐day emergency department visits, and readmission data. Bivariate comparisons were made using χ2 and Wilcoxon tests for categorical and continuous variables.ResultsBetween July 2014 and July 2017, 427 patients aged 24 to 42 months underwent tonsillectomy at our institution. Thirty‐day emergency department visit, readmission, and greater‐than‐expected length of stay rates were 3.0% versus 3.7% (P = .75), 1.0 versus 1.8% (P = .61), and 4.7% versus 4.5% (P = 1.00) between the younger and older cohorts, respectively, with no difference in complication rates identified based on age.ConclusionsNo significant difference in adverse outcomes was appreciated based on a cutoff of 36 months of age at a tertiary center over 3 years. There should continue to be ongoing studies addressing strict age‐related admission criteria.Level of Evidence4 Laryngoscope, 129:E389–E394, 2019
Tracking Lagrangian transport in Lake Geneva: A 3D numerical modeling investigation
Authors: Cimatoribus A. A. , Lemmin U. , Barry D. A. 
Published: January 2019

AbstractLake Geneva, the largest freshwater lake in Western Europe, is subject to important environmental pressures from its densely populated shores and watershed. To maintain and improve water quality in this lake, as well as in other enclosed or semi‐enclosed basins, it is essential to understand and be able to predict how nutrients and pollutants are transported within it. A 3D numerical modeling study of Lagrangian transport in Lake Geneva is presented, showing the dispersion of water (based on tracking inert water particles) inflowing from the lake's main tributary, the Rhône River. The relation between dominant winds, circulation patterns, and transport was analyzed. The results demonstrated that transport within the lake is highly inhomogeneous in space and intermittent in time, because water mass movements are controlled by the wind‐induced formation of large‐scale gyres and their subsequent breakdown into smaller ones. Particle spreading was shown to be sensitive to the depth of the initial particle release, and to the mean depth of the particles’ trajectory. However, several preferential pathways could be identified. Some water particles rapidly (days) traveled across the entire lake, through the near‐shore region in the upper layer, while others remained trapped for months, particularly in the central region of the lake at depth. Deeper particles tended to remain longer in the lake, due to the insulating effect of stratification, bathymetry obstacles, and slower currents at greater depth.
Zwitterionic Functionalizable Scaffolds with Gyroid Pore Architecture for Tissue Engineering
Authors: Kostina Nina Yu. , Blanquer Sebastien , Pop‐Georgievski Ognen , Rahimi Khosrow , Dittrich Barbara , Höcherl Anita , Michálek Jiří , Grijpma Dirk W. , Rodriguez‐Emmenegger Cesar 
Published: January 2019

AbstractStereolithography‐assisted fabrication of hydrogels of carboxybetaine methacrylamide (CBMAA) and a α,ω‐methacrylate poly(d,l‐lactide‐block‐ethylene glycol‐block‐
d,l‐lactide) (MA‐PDLLA‐PEG‐PDLLA‐MA) telechelic triblock macromer is presented. This technique allows printing complex structures with gyroid interconnected porosity possessing extremely high specific area.Hydrogels are characterized by infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and laser scanning confocal microscopy (LSCM). The copolymerization with zwitterionic comonomer leads hydrogels with high equilibrium water content (EWC), up to 700% while maintaining mechanical robustness. The introduction of carboxybetaine yields excellent resistance to nonspecific protein adsorption while providing a facile way for specific biofunctionalization with a model protein, fluorescein isothiocyanate labeled bovine serum albumin (BSA). The homogeneous protein immobilization across the hydrogel pores prove the accessibility to the innermost pore volumes.The remarkably low protein adsorption combined with the interconnected nature of the porosity allowing fast diffusion of nutrient and waste product and the mimicry of bone trabecular, makes the hydrogels presented here highly attractive for tissue engineering.
NIR‐Induced Disintegration of CuS‐Loaded Nanogels for Improved Tumor Penetration and Enhanced Anticancer Therapy
Authors: Zhang Zihao , Zhang Xucheng , Ding Yuxue , Long Peihua , Guo Jia , Wang Changchun 
Published: January 2019

AbstractNanocarrier‐based cancer therapy suffers from poor tumor penetration and unsatisfied therapeutical efficacy, as its vascular extravasation efficiency is often compromised by the intrinsic physiological heterogeneity in tumor tissues. In this work, novel near infrared (NIR)‐responsive CuS‐loaded nanogels are prepared to deliver anticarcinogen into the tumor. These hybrid polymeric nanogels possess high photothermal conversion efficiency, and are able to load a large amount of antitumor drug (e.g., doxorubicin [DOX]). More importantly, the thermal heat could induce self‐destruction of the big‐size framework of hybrid nanogels into small nanoparticles, which greatly facilitates tumor penetration to release DOX deep inside the tumor, as validated by photoacoustic (PA) imaging which exhibits 26.3 times enhancement at the interior region compared to signals of groups without laser irradiation. Such structural alteration, combined with strong photothermal and chemotherapy effects, leads to remarkable inhibition of tumor growth in mice. As a result, this NIR‐induced disintegration of CuS‐loaded nanogels provides a novel drug delivery strategy and might open a new window for clinical cancer treatment.
Promoted Proliferation of Hematopoietic Stem Cells Enabled by a Hyaluronic Acid/Carbon Nanotubes Antioxidant Hydrogel
Authors: Zhang Yuanhao , Tong Yudong , Pan Xiuwei , Cai Haibo , Gao Yun , Zhang Weian 
Published: January 2019

AbstractReactive oxygen species (ROS) level is closely associated with the physiological function of hematopoietic stem cells (HSCs) in ex vivo culture systems. Previously developed hydrogels in use of HSCs culture have generally failed in considering their antioxidant property. In the present work, antioxidant hydrogels are constructed to evaluate the biological effect of ROS on HSCs proliferation by suppressing oxidative stress damage. Functionalized carbon nanotubes (CNTs), which act as potential antioxidants, are physically encapsulated in biocompatible hyaluronic acid (HA) hydrogels to achieve long‐term antioxidant activity. Consequently, these hybrid hydrogels exhibit enhanced physical properties and superior scavenging capability on oxides and peroxides compared to the pure HA hydrogel. The results indicate that ROS significantly inhibit the biological characteristics of HSCs. Nevertheless, the proliferation ability and pluripotency are dramatically improved when the culture system is supplied with the antioxidant hydrogel, revealing that the CNT‐incorporated hydrogel can effectively relieve oxidative stress response in HSCs and reduce apoptosis from ROS. Therefore, the HA/CNT hydrogel can provide a novel strategy to establish an artificial microenvironment with a low ROS level for HSCs proliferation.
Resonance Effects in High‐Frequency Heating of Isolated Protonated Poly(ethylene oxide) Chains in a Vacuum
Authors: Dubrovskii Sergey A. , Balabaev Nikolay K. 
Published: January 2019

AbstractHeating of isolated protonated poly(ethylene oxide) (PEO) chains in an intense high‐frequency electric field in a vacuum is studied using molecular dynamics (MD) simulations. The chain heats up, absorbing the energy of the field due to internal friction. The absorption coefficient depends on the frequency of the field, and also on the length and temperature of the chain. At high temperatures, the absorption spectrum has two distinct peaks in the frequency range from 1 to 100 GHz. Near these peaks and at higher frequencies, the chain rotates as a single whole and takes stretched conformations. The frequency of rotation is determined by the length and degree of stretching of the chain. This frequency and the frequencies of the absorption peaks are inversely proportional to the chain length. The observed behavior is explained by considering the chain as a damped spatial oscillator in which both the linear (conventional) and nonlinear resonances arise.
Mechanical and tribological performance of polyamide 12 reinforced with graphene nanoplatelets and paraffin oil nanocomposites
Authors: Hassan A. E. M. , EiD A. I. , El‐Sheikh M. , Ali W.Y. 
Published: January 2019

AbstractWith polymeric nanocomposites many problems due to their extensive applications such as aerospace, automobiles, coatings, and packaging materials were solved. In this study, polyamide 12/graphene nanoplatelets impregnated by paraffin oil were fabricated by a hot compression technique. Elastic modulus has been determined by compression tests using a universal testing machine. Microhardness of unfilled polyamide 12 and its nanocomposites has been measured by Vickers microhardness testing machine. Tribological properties of the unfilled polyamide 12 and its nanocomposites have been investigated by pin‐on‐disc tester under applied normal loads of 10 N, 20 N and 30 N, 1.2 m/s sliding speed, and 212 m sliding distance. The results showed that the elastic modulus and microhardness of polyamide 12/graphene nanoplatelets (PA12/GNPs) nanocomposites are higher than that of the unfilled polyamide 12, and then gradually increased by adding paraffin oil contents. Tribological properties showed that polyamide 12/graphene nanoplatelets nanocomposites have lower coefficient of friction and wear rates in comparison with polyamide 12. By adding paraffin oil contents to the unfilled polyamide 12 and its nanocomposites, coefficient of friction and wear rates gradually decreased. Worn surfaces were imaged using scanning electron microscope.
Comparative analysis of wear behavior of garnet and fly ash reinforced Al7075 hybrid composite
Authors: Mishra S. , Patnaik A. , Kumar S.R. 
Published: January 2019

AbstractAl7075 hybrid composites reinforced with varying weight percentage (0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%) of each of garnet and fly ash were fabricated and characterized for their comparative wear assessment. The sliding wear test was conducted on a reciprocating tribometer in dry medium under the working conditions of applied normal load (2 N, 4 N, 6 N, 8 N), sliding velocities (0.04 m/s, 0.08 m/s, 0.12 m/s, 0.16 m/s), sliding distance (20 m, 40 m, 60 m, 80 m) and working temperature (25 °C, 50 °C, 75 °C, 100 °C). The experiments were performed as per steady‐state condition and Taguchi (L25) orthogonal array design to evaluate specific wear rate of the Al7075 hybrid composites. The finding of results indicated that the wear rate was decreased with the increase in the filler content in both the case of garnet and fly ash reinforced Al7075 hybrid composites. The results from Taguchi experiments suggested that the filler content and load were the most significant factors affecting wear behavior of composites while temperature and sliding distance are the least significant factors. Also, the garnet reinforced Al7075 hybrid composite indicated less specific wear rate as compared to that of fly ash reinforced Al7075 hybrid composite.
Development of XIAP Antagonists Based On De Novo 8,5‐Fused Bicyclic Lactams
Authors: Sheng Zhaojun J. , Shi Yiming M. , Xu Ximing , Bellynck Sébastien , Zhang Kun , Du Zhiyun Y. , Xu Xuetao , Maurel François , Dong Chang‐Zhi 
Published: January 2019

AbstractIn order to develop original water soluble antagonists of X‐linked inhibitor of apoptosis protein (XIAP), a novel bicyclic scaffold was designed based on 8,5‐fused bicyclic lactam. During its preparation, a spontaneous rearrangement from 8,5‐ to 7,5‐fused bicyclic lactam was observed and confirmed by MS and NMR analyses, in particular the HMBC spectra. DFT calculations were performed to understand the corresponding mechanism. It was finally prevented through changing the reaction order in the synthesis route and a Smac mimetic with this core structure, ZJ‐1 was successfully obtained. The structure of this new bicyclic scaffold was well confirmed by HRMS and NMR (1H, 13C, NOESY) analyses. ZJ‐1 presented in addition a binding affinity to XIAP‐BIR3, nearly 6 times better than that of AVPI, similar to the reported SM‐128 in an in vitro fluorescence polarization (FP) assay. This preliminary result suggests that this new bicyclic scaffold could be very attractive in the development of novel anticancer agents targeting XIAP.
Effect of vasopressin on a porcine model of persistent pulmonary hypertension of the newborn
Authors: Amer Reem , Elsayed Yasser N. , Graham Marjory Ruth , Sikarwar Anurag S. , Hinton Martha , Dakshinamurti Shyamala 
Published: January 2019

AbstractBackgroundPersistent pulmonary hypertension of the newborn (PPHN) is due to a failure of pulmonary vascular relaxation. Vasopressin, a systemic vasoconstrictor acting on smooth muscle AVPR1a receptors, is used in treatment of PPHN. We sought to determine acute effects of vasopressin infusion on pulmonary hemodynamics in a large animal model of hypoxic PPHN.MethodsPPHN was induced in 6 newborn piglets by 72 h normobaric hypoxia (FiO2 = 0.10); controls were 7 age‐matched 3‐day‐old piglets. Animals were anesthetized and ventilated with central venous and arterial lines, and after stabilization, randomized using a crossover design to normoxic or hypoxic ventilation, then 30 min infusion of 0.0012 U/kg/min vasopressin, followed by 45 min vasopressin washout period. Echocardiographic parameters and oxygen consumption were measured before and after vasopressin. Relaxation to vasopressin was tested in isolated PPHN and control pulmonary arteries by isometric myography. Expression of AVPR1a receptor mRNA was quantified in arterial and myocardial tissues.ResultsVasopressin did not alleviate hypoxia‐responsiveness of PPHN pulmonary circuit. There were no significant differences in pulmonary hypertension, cardiac function indices, or oxygenation indices after vasopressin infusion. Vasopressin did not dilate control or PPHN pulmonary arteries, and AVPR1 was minimally expressed.ConclusionsVasopressin does not have a direct pulmonary vasodilator effect in PPHN, within the timeframe studied.