Search

Vertebral osteomyelitis (VO) is a rare, slowly progressing disease that often causes neuromuscular complications. Epidural block is a non-surgical treatment used in patients with radicular pain to deliver drugs to the epidural space; it is generally known to be a safe method, but it can occasionally cause infection. Herein, we present a rare case of VO with severe neuromuscular complications that developed in a patient who underwent lumbar transforaminal epidural block for back pain. Imaging studies showed VO, multiple pyogenic abscesses, and compressive cervical myelopathy. Electrodiagnostic studies showed clear evidence of cervical myelopathy and polyradiculopathy. With early treatment using a multidisciplinary approach, including medical treatment, surgery, and comprehensive rehabilitation, recovery of motor weakness and functional improvement were achieved after 2 months of treatment. Electrodiagnostic studies are advantageous for localizing and determining the degree of neuromuscular damage following VO. A multidisciplinary approach to the diagnosis and treatment of VO could improve patients’ prognosis, functional ability, and quality of life.

Objective To investigate the relationship between maximal tongue protrusion length (MTPL) and dysphagia in post-stroke patients.Methods Free tongue length (FTL) was measured using the quick tongue-tie assessment tool and MTPL was measured using a transparent plastic ruler in 47 post-stroke patients. The MTPL-to-FTL (RMF) ratio was calculated. Swallowing function in all patients was evaluated via videofluoroscopic swallowing study (VFSS), PenetrationAspiration Scale (PAS), Functional Oral Intake Scale (FOIS), and Videofluoroscopic Dysphagia Scale (VDS).Results The MTPL and RMF values were significantly higher in the non-aspirator group than in the aspirator group (MTPL, p=0.0049; RMF, p

Large-eddy simulation with the thickened flame model (LES/TFM) is conducted to simulate a three-dimensional dual swirl partially premixed methane/air gas turbine model combustor. Finite-rate chemis...

Gasoline compression ignition (GCI) is an internal combustion engine technology that can improve the soot-NOx tradeoff and CO2 emissions of conventional diesel powertrains. GCI also offers a pathway to alleviate the operational and durability demands being placed on current lean aftertreatment systems for meeting upcoming criteria pollutant regulations. High-pressure fuel injection equipment is a key enabling subsystem for GCI and optimization along with the combustion, air and aftertreatment systems requires the use of simulation-based design tools like 1D hydraulic models or 3D-CFD. However, these tools require fuel property specifications to accurately capture the flow, spray, and combustion processes at conditions relevant to GCI. This work presents a surrogate formulation methodology that matches the entire measured chemical species listing of any gasoline as closely as possible and generates the required fuel properties over a specified range. It can be used when direct determination is not feasible or when properties are unknown at every condition of interest. Measurements of liquid density, viscosity, heat capacity and thermal conductivity were conducted on E10 certification gasoline from −20 to 150°C and 0–2500 bar (g) to validate the calculation methodology. Density did not exceed 1.6% difference with measured data, while heat capacity remained within 27%. Viscosity and thermal conductivity had maximum errors of 173% and 46%, respectively. This was due to the lack of appropriate pressure dependencies for these properties in the calculation methodology. The maximum error in modeled viscosity was reduced to 53% after employing a simple viscosity-pressure correlation for generic hydrocarbons.

The safe operation of aeronautical engines requires an understanding of flame ignition, propagation and extinction. In this study, direct numerical simulations are performed using a 29 species reduced chemical mechanism for jet fuel surrogate Jet A to understand the flame quenching process. Initially laminar spherical flames of varying sizes and equivalence ratios are subject to an identical periodic domain of decaying and isotropic high intensity turbulence with a turbulent Reynolds number of 2400. All cases become quenched, except for the larger kernel with lower Karlovitz number. An analysis of the flame structure shows broadened preheat zone, flame shortening on the product side, differential species diffusion and partial fuel pyrolysis in the fresh mixture. Two extinction mechanisms are identified arising from flame shortening and high flame stretch. Flame shortening occurs due to turbulence-chemistry interactions that resemble the flame–flame interaction in a laminar counterflow reactant-to-reactant configuration, which contorts and breaks up the ignition kernel. Flame stretch is a local effect that attenuates the heat release rate and causes the flame to retreat towards the product mixtures, similar to what has been observed for reactant-to-product laminar counterflow flames. Chemical explosive mode analysis was also performed to quantify the flame structure and local combustion mode. The diffusion–reaction balance in pinched-off flame islands favors extinction of these smaller structures, while auto-ignition modes are observed within the flame kernel after fresh mixture is engulfed and preheated in the product kernel. Statistics of the density-weighted displacement speed conditional on local combustion mode indicates strong correlation between the local extinction mode and negative displacement speed. The local balance between diffusion and reaction ultimately determines the propensity for local extinction in both laminar and turbulent flames, the extent of which has an impact on global flame propagation.

The solution processability of a gelating polyurea network has enabled its blending with polymers, allowing facile preparation of bicontinuous nanoporous materials. To exploit the method for synthesizing various functional porous structures, a deeper understanding of the structure-forming mechanism and the relationship between the experimental parameters and the morphology is crucial. Herein, we experimentally show that the thermodynamic parameters of the mixture of the covalent network and polymer govern the formation of initial blend morphology, and control over the covalent network’s gelation kinetics under solvent evaporation is critical to obtain the nanoscale structures otherwise difficult to achieve. We first investigated the phase behaviors of various covalent network/polymer mixtures in solutions and the morphologies of their resultant blends and porous structures. The different morphologies were mapped in a single diagram based on the polymer composition and the empirical descriptor devised to include the components’ mutual interactions and relative sizes. To capture the phase-separated structures at the nanoscale, we found that the two coexisting phenomena should be controlled: the gelation via interconnection of the covalent network nanogel particles and the growth of phase-separated domains with solvent evaporation. We proposed a general mechanism involving the interplay of gelation and phase separation with an evaporative cue using a ternary phase diagram of the polymer/covalent network/solvent. This work lays the groundwork for designing and optimizing functional porous materials derived from gelating covalent network/polymer mixtures, in addition to establishing an empirical approach in a reactive colloidal polymer/polymer mixture system.

This study was aimed at evaluating the orbital decompressive effect of endoscopic transorbital approach (TOA) in the management of sphenoorbital meningioma involving the orbit. Patients treated with TOA for this tumor from December 2016 to December 2019 were included, and the data were reviewed. Pre- and postoperative clinical and imaging findings were compared with a volumetric study. Eighteen patients (two men and 16 women) were included. Lateral wall hyperostosis (13 patients), extraconal tumor infiltration (18 patients), intraconal tumor infiltration (seven patients), and superior and lateral rectus encasement (nine patients) were found. Intraconal tumor infiltration in the posterior orbit affected compressive optic neuropathy (CON) more often than other tumor manifestations. The orbital soft tissue volume decreased to 91.18% ± 8.19% compared to that in the contralateral side preoperatively. The postoperative volume increased to 113.73% ± 12.92% compared to the preoperative volume. The average values of LogMAR visual acuity and visual field index score of ten patients with CON improved from 0.80 to 0.42 and 48.9 to 65.9%, respectively. All 17 patients with proptosis showed improvement after surgery. There were no significant complications associated with the surgery. Additional treatment, including gamma knife surgery, was applied to 12 cases for the remaining tumor. This minimally invasive surgical debulking procedure was successful in treating sphenoorbital meningioma without significant adverse events. Lateral orbital wall decompression and limited intraorbital tumor resection were effective for compressive orbitopathy from the tumor.

The HyChem ( hy brid chem istry) approach is utilized for modeling the combustion behaviors of gasoline fuels. The approach combines an experimentally constrained, lumped-step model for fuel pyrolysis under the high-temperature combustion condition and a detailed foundation fuel chemistry model to describe the subsequent oxidation of the pyrolysis products. We present results obtained for two Shell gasoline fuels as examples. The results show that with the parameters in the lumped reactions determined by matching the experiment time history data of key products of gasoline pyrolysis, the HyChem reaction models capture the ignition delay times and laminar flame speeds over a wide range of thermodynamic conditions. The HyChem approach is also extended to model the negative-temperature coefficient (NTC) behaviors for the gasoline fuels. The results show that the NTC-enabled models are capable of capturing the ignition delays under both high-temperature conditions and the conditions under which the NTC behaviors are important. The relationship between fuel composition and combustion properties is analyzed. Finally, the HyChem models are reduced to about 40 species to enable turbulent combustion modeling of gasoline fuels in practical engine simulations.

Background/objectives To compare postoperative lagophthalmos after maximal levator resection (MLR) and frontalis suspension (FS) in congenital ptosis patients with poor levator function (LF). Methods A cross-sectional study was performed to compare postoperative outcomes in patients with preoperative LF ≤ 4 mm who had undergone MLR or FS at a single tertiary institution, and who had visited the outpatient clinic between February 2017 and August 2018. Main outcome measures were as follows: (1) Preoperative LF and margin reflex distance 1 (MRD1), (2) Postoperative MRD1, lagophthalmos and grade of superficial punctate keratopathy (SPK). Results Our study comprised 152 eyelids of 122 patients. There were 71 eyelids in the MLR group and 81 eyelids in the FS group. The MLR group had comparable mean postoperative MRD1 (2.8 ± 0.8 mm) to the FS with autogenous fascia lata (AFL) group (3.0 ± 0.7 mm), while the FS with preserved fascia lata (PFL) group had the lowest mean postoperative MRD1 (2.2 ± 1.0 mm). The PFL group had significantly less lagophthalmos (0.6 ± 1.0 mm) than the AFL (1.9 ± 1.4 mm) and maximal levator resection (1.9 ± 1.7 mm) groups. In the MLR group, there was no significant difference in postoperative surgical measurements between the LF 0-2 mm group and LF 2.5-4 mm group in terms of exposure keratopathy, degree of lagophthalmos and MRD1. Conclusion MLR is an effective alternative to FS in congenital ptosis patients with poor levator function, with the risk of postoperative lagophthalmos related to postoperative MRD1 rather than preoperative LF.

Several compression-ignition and low-temperature combustion strategies require a fuel where the ignition-delay-time (IDT) is highly sensitive to the fuel-to-air equivalence ratio (ϕ). Quantitative prediction of ϕ-sensitivity (i.e., the change in IDT with respect to ϕ) would enable rapid screening of the numerous possible (bio)fuel candidates for this desired high ϕ-sensitivity characteristic. We propose a new ϕ-sensitivity metric (η), which is primarily a function of only temperature (T) and pressure (P). We assess the reliability of 0-D (perfectly homogeneous) simulation and state-of-the-art reaction mechanisms for two well-studied fuels, namely, iso-octane and a primary reference fuel (PRF80). 0-D simulation results are in good agreement with experimental constant volume IDT data at low- and intermediate-temperatures, while systematic deviations are observed at higher temperatures (where full 3-D computational fluid dynamics simulations are required for accurate prediction). We also perform a traditional single-parameter sensitivity analysis to determine the key reactions that affect ϕ-sensitivity. This is followed by a more rigorous Bayesian uncertainty quantification (UQ) analysis to elucidate the possible sources for the discrepancies at high T. Due to the computational cost of UQ, we train artificial neural networks to rapidly predict η for randomly perturbed sets of low- and intermediate-temperature reaction rate parameters. The primary implications of this study are that experimental ϕ-sensitivity data can be used to refine and validate proposed reaction mechanisms, while machine learning and uncertainty quantification of 0-D simulations are essential for quantitative prediction of ϕ-sensitivity in order to rapidly screen fuel candidates.

Real transportation fuels are complex mixtures of a variety of hydrocarbon components. Predicting NOx formation in practical combustors burning real fuels is usually made with the assumption that the NOx submodels developed and tested for small hydrocarbon combustion are applicable to mixtures of large hydrocarbons as found in real fuels. Additionally, NOx data are scarce for flames of real fuels. The aims of the current study are (i) to provide reliable NOx data in flames of a typical jet fuel, and (ii) to test our capability to predict these data by combining a recently proposed HyChem reaction model of jet A combustion (Xu et al., 2018) with the NOx submodel of Glarborg (2018). Specifically, NOx concentrations were measured in stretch-stabilized premixed flames of methane and Jet A (POSF10325) from fuel lean to rich conditions and of ethylene at a fuel-rich equivalence ratio. This range of stoichiometries allows both thermal NO and prompt NO pathways to be tested. The results show reasonably good agreement between the experimental data and model predictions for all flames tested, although the model appears to underpredict NOx concentrations in the Jet A flames under fuel rich conditions. Sensitivity analyses were conducted to illustrate the influence of the reaction pathways and flame boundary conditions on NOx predictions. The analyses also suggest that additional prompt NO reaction pathways may play a role in flames of large hydrocarbons.

To achieve carbon neutral ambition, hydrogen (H2) has recently received significant attention as a zerocarbon fuel for internal combustion engines (ICEs) across transportation sectors. As a critical element in the analysis-led design process, a hydrogen kinetic mechanism needs to be thoroughly evaluated to support the development of high-efficiency H2-ICE combustion system concepts. In this study, recently published H2 kinetic mechanisms were reviewed and down-selected for evaluations against available laboratory data in ignition delay time (IDT) and laminar flame speed (LFS) measurements. The examination was subsequently extended to high-fidelity three-dimensional (3-D) computational fluid dynamics (CFD), spark-ignited, H2 engine simulations. Discrepancies identified at engine-relevant conditions led to a kinetics tailoring campaign based on the H2 mechanism developed by Burke et al. (2012). Selected reactions identified via global sensitivity analysis were optimized under the engine-relevant pressure-temperature conditions. The reaction rate coefficients were adjusted within the experimental and theoretical uncertainty limits by adopting a Monte-Carlo sampling approach as a searching algorithm to generate candidate mechanisms. Finally, the optimized mechanism was validated sequentially from low-dimensional (0-D and 1-D) to high-fidelity 3D CFD engine simulations. Overall, the optimized H2 kinetic model led to significantly improved predictions on capturing engine in-cylinder pressure trace and heat release rate.

Copolyurea networks (co-UNs) were synthesized via crosslinking polymerization of a mixture of tetrakis(4-aminophenyl)methane (TAPM) and melamine with hexamethylene diisocyanate (HDI) using the organic sol-gel polymerization method. The subsequent thermal treatment of between 200 and 400 °C induced the sintering of the powdery polyurea networks to form porous frameworks via urea bond rearrangement and the removal of volatile hexamethylene moieties. Incorporating melamine into the networks resulted in a higher nitrogen content and micropore ratio, whereas the overall porosity decreased with the melamine composition. The rearranged network composed of the tetraamine/melamine units in an 80:20 ratio showed the highest carbon dioxide adsorption quantity at room temperature. The results show that optimizing the chemical structure and porosity of polyurea-based networks can lead to carbon dioxide adsorbents working at elevated temperatures.

The minimization of auto-ignition risk is critical to the design of premixers of high power aeroderivative gas turbines as an increased use of highly reactive future fuels (for example, hydrogen or higher hydrocarbons) is anticipated. Safety factors based on ignition delays of homogeneous mixtures are generally used to guide the choice of a residence time for a given premixer. However, auto-ignition chemistry under aeroderivative conditions is fast (0.5–2 ms) and can be initiated within typical premixer residence times. The analysis of what takes place in this short period necessarily involves the study of low-temperature auto-ignition precursor chemistry, but precursors can change with fuel and local reactivity. Chemical explosive modes (CEMs) are a natural alternative to study this as they can provide a measure for auto-ignition risk by considering the whole thermochemical state in the framework of an eigenvalue problem. When transport effects are included by coupling the evolution of the chemical explosive modes to turbulence, it is possible to obtain a measure of spatial auto-ignition risk where both chemical (e.g., ignition delay) and aerodynamic (e.g., local residence time) influences are unified. In this article, we describe a method that couples large eddy simulation (LES) to newly developed, reduced auto-ignition chemical kinetics to study auto-ignition precursors in an example premixer representative of real life geometric complexity. A blend of pure methane and di-methyl ether (DME), a common fuel used for experimental auto-ignition studies, was transported using the reduced mechanism (38 species/238 reactions) under engine conditions at increasing levels of DME concentrations until exothermic auto-ignition kernels were formed. The resolution of species profiles was ensured by using a thickened flame model where dynamic thickening was carried out with a flame sensor modified to work with multistage heat release. This paper is outlined as follows: First, a reduced mechanism is constructed and validated for modeling methane as well as DME auto-ignition. Second, sensitivity analysis is used to show the need for chemical explosive modes. Third, the thickened flame model modifications are described and then applied to an example premixer at 25 bar/890 K preheat. The chemical explosive mode analysis closely follows the large thermochemical changes in the premixer as a function of DME concentrations and identifies where the premixer is sensitive and flame anchoring is likely to occur.

The HyChem (Hybrid Chemistry) approach has recently been proposed for modeling high-temperature combustion of real, multi-component fuels. The approach combines lumped reaction steps for fuel thermal and oxidative pyrolysis with detailed chemistry for the oxidation of the resulting pyrolysis products. Determining the pyrolysis submodel requires extensive experimentation on speciation measurements. Recent work has been directed to learn HyChem from an existing HyChem model for a similar fuel, which requires less data. However, the approach usually shows substantial discrepancies with experimental data within the Negative Temperature Coefficient (NTC) regime, as the low-temperature chemistry is more fuel-specific than high-temperature chemistry. This paper proposes a machine learning approach to learn the HyChem models that can cover both high-temperature and low-temperature regimes. Specifically, we develop a HyChem model using the experimental datasets of ignition delay times covering a wide range of temperatures and equivalence ratios. The chemical kinetic model is treated as a neural network model, and we then employ stochastic gradient descent (SGD), a technique that was developed for deep learning, for the training. We demonstrate the approach in learning the HyChem model for F-24, which is a Jet-A derived fuel, and compare the results with previous work employing genetic algorithms. The results show that the SGD approach can achieve comparable model performance with genetic algorithms but the computational cost is reduced by 1000 times. In addition, with regularization in SGD, the SGD approach changes the kinetic parameters from their original values much less than genetic algorithm and is thus more likely to retrain mechanistic meanings. Finally, our approach is built upon open-source packages and can be applied to the development and optimization of chemical kinetic models for internal combustion engine simulations.

The minimization of autoignition risk is critical to the design of premixers of high power aeroderivative gas turbines as an increased use of highly reactive future fuels (for example, hydrogen or higher hydrocarbons) is anticipated. Safety factors based on ignition delays of homogeneous mixtures, are generally used to guide the choice of a residence time for a given premixer. However, autoignition chemistry at aeroderivative conditions is fast (0.5–2 milliseconds) and can be initiated within typical premixer residence times. The analysis of what takes place in this short period necessarily involves the study of low-temperature autoignition precursor chemistry, but precursors can change with fuel and local reactivity. Chemical Explosive Modes are a natural alternative to study this as they can provide a measure of autoignition risk by considering the whole thermochemical state in the framework of an eigenvalue problem. When transport effects are included by coupling the evolution of the Chemical Explosive Modes to turbulence, it is possible to obtain a measure of spatial autoignition risk where both chemical (e.g. ignition delay) and aerodynamic (e.g. local residence time) influences are unified. In this article, we describe a method that couples Large Eddy Simulation to newly developed, reduced autoignition chemical kinetics to study autoignition precursors in an example pre-mixer representative of real life geometric complexity. A blend of pure methane and dimethyl ether (DME), a common fuel used for experimental autoignition studies, was transported using the reduced mechanism (38 species / 238 reactions) at engine conditions at increasing levels of DME concentration until exothermic autoignition kernels were formed. The resolution of species profiles was ensured by using a thickened flame model where dynamic thickening was carried out with a flame sensor modified to work with multi-stage heat release. The paper is outlined as follows: First, a reduced mechanism is constructed and validated for modeling methane as well as di-methyl ether (DME) autoignition. Second, sensitivity analysis is used to show the need for Chemical Explosive Modes. Third, the thickened flame model modifications are described and then applied to an example premixer at 25 bar / 890K preheat. The Chemical Explosive Mode analysis closely follows the large thermochemical changes in the premixer as a function of DME concentration and identifies where the premixer is sensitive and flame anchoring is likely to occur.

Purpose To evaluate the surgical outcome and safety of acellular human dermal allograft as a new lining material to the exposed orbit after exenteration. Methods Retrospective case series of patients who underwent orbital exenteration followed by reconstruction with meshed-type acellular dermal allograft from 2009 to 2018 in a single tertiary institution. Results There were 14 eyes (2 right, 12 left) of 14 patients (6 men, 8 women). Mean age at operation was 69.1 ± 16.5 years. Indication for surgery was malignancy in all patients. One patient underwent subtotal exenteration, while the rest underwent total exenteration. SureDerm Meshed was used in 12 patients, AlloDerm Meshed in 1, and CGDerm Meshed in 1. Mean follow-up period was 12.1 months. Full or nearly full epithelialization occurred in 10 of 14 patients (71.4%) at 1 month and 9 of 12 patients (75.0%) at 3 months. There was delayed epithelialization in 3 patients due to poor wound care (n = 1), adjuvant radiotherapy (n = 1), and adjuvant radiotherapy followed by cerebrospinal fluid leak (n = 1). Conclusions Meshed acellular human dermal allograft showed good success in reconstruction after orbital exenteration and may be considered as an alternative lining material to split-thickness skin graft after orbital exenteration.

A criterion based on chemical explosive mode analysis (CEMA) is proposed to identify different local combustion modes, such as auto-ignition, diffusion-assisted ignition, and local extinction in laminar and turbulent premixed flames. The criterion is employed to distinguish between two different propagation modes of one-dimensional (1-D) freely propagating premixed flames, that is the canonical deflagration wave controlled by heat and species back-diffusion, which features a unique flame speed, and the auto-ignition controlled reaction front propagation, which may feature an arbitrary propagation speed. In the CEMA based diagnostic, the local chemistry and diffusion source terms are projected to the chemical explosive mode (CEM), such that the roles of diffusion and chemistry in the CEM can be quantified and compared for identification of the flame propagation mode. The new criterion is further applied to analyze two-dimensional (2-D) DNS datasets of homogeneous charge compression ignition (HCCI) combustion of n-heptane/air with different levels of thermal stratification. Both flame propagation modes are observed and contribute significantly to the overall flame burning in the case with a high level of thermal stratification, while the flame propagation is found dominated by the auto-ignition mode in the case with a low level of thermal stratification, which agrees with the finding in previous studies.

Purpose : To investigate a disposal method of disposing contact lenses and the recognition of environmental pollution by micro plastics which may be caused by the wrong disposal method of domestic contact lens wearers.Methods : Two hundred sixty one adults(124 males, 137 females, mean age 21.48±3.14 years) were participated in this study. They were given the questionnaire survey on contact lenses purchasing place, type of contact lenses, duration of wearing contact lenses, the disposal method of disposing contact lenses and the recognition of the occurrence of environmental pollution.Results : It appeared that eyeglass shop(50.0%) and contact lens shop(48.3%) were the main purchasing places, and the most common type of contact lenses were disposable lenses(38.5%) and daily wearing lenses(52.5%). On the duration of wearing contact lenses they answered more than 5 years(29.3%), less than 1 year (26.0%), less than 1 year to less than 3 years (26.0%), and on wearing a contact lens during a week they did 1-2 days (32.0%), 1 week (28.0%), 5-6 days (22.4%) and 3-4 days (17.6%). It was shown “no(78.3%)” and “yes(21.7%)” to the questionnaire of whether they received information or education about a disposal method at the place where the contact lens was purchased, and “no(87.5%)” and “yes(12.5%)” to the questionnaire of whether they received information or education from schools, public institutions or public media such as the internet. As for the disposal methods, landfill waste(45.6%), recycled garbage(29.6%), and drainage(16.8%) from the sink or toilet responded in order. Although men were more educated and informed about disposal than women (t=3.63189, p

The Hybrid Chemistry (HyChem) approach has been proposed previously for combustion chemistry modeling of real, liquid fuels of a distillate origin. In this work, the applicability of the HyChem approach is tested for single-component fuels using JP10 as the model fuel. The method remains the same: an experimentally constrained, lumped single-fuel model describing the kinetics of fuel pyrolysis is combined with a detailed foundational fuel chemistry model. Due to the multi-ring molecular structure of JP10, the pyrolysis products were found to be somewhat different from those of conventional jet fuels. The lumped reactions were therefore modified to accommodate the fuel-specific pyrolysis products. The resulting model shows generally good agreement with experimental data, which suggests that the HyChem approach is also applicable for developing combustion reaction kinetic models for single-component fuels.

A Hybrid Chemistry (HyChem) approach has been recently developed for the modeling of real fuels; it incorporates a basic understanding about the combustion chemistry of multicomponent liquid fuels that overcomes some of the limitations of the conventional surrogate fuel approach. The present work extends this approach to modeling the combustion behaviors of a two-component bio-derived jet fuel (Gevo, designated as C1) and its blending with a conventional, petroleum-derived jet fuel (Jet A, designated as A2). The stringent tests and agreement between the HyChem models and experimental measurements for the combustion chemistry, including ignition delay and laminar flame speed, of C1 highlight the validity as well as potential wider applications of the HyChem concept in studying combustion chemistry of complex liquid hydrocarbon fuels. Another aspect of the present study aims at answering a central question of whether the HyChem models for neat fuels can be simply combined to model the combustion behaviors of fuel blends. The pyrolysis and oxidation of several blends of A2 and C1 were investigated. Flow reactor experiments were carried out at pressure of 1 atm, temperature of 1030 K, with equivalence ratios of 1.0 and 2.0. Shock tube measurements were performed for the blended fuel pyrolysis at 1 atm from 1025 to 1325 K. Ignition delay times were also measured using a shock-tube. Good agreement between measurements and model predictions was found showing that formation of the products as well as combustion properties of the blended fuels were predicted by a simple combination of the HyChem models for the two individual fuels, thus demonstrating that the HyChem models for two jet fuels of very different compositions are “additive.”

PURPOSE To investigate the clinical features and outcomes of diffuse large B-cell lymphoma (DLBCL) involving the eye and ocular adnexa in an East Asian population and emphasize the importance of prompt biopsy and treatment in unusually progressive ocular adnexal DLBCL for better visual outcomes. METHODS Retrospective case series of 38 patients diagnosed with DLBCL involving the eye and ocular adnexa between 1995 and 2018 at a single tertiary institution. RESULTS There were 38 patients (22 men, 16 women), 22 (57.9%) of which had ocular adnexal lymphoma (OAL) and 16 (42.1%), vitreoretinal lymphoma (VRL). The OAL group showed higher rates of unilateral involvement (p = 0.01) and localized disease presentation (p = 0.01). Thirteen (59.1%) of 22 OAL patients were primary diseases and 9 (40.9%) were secondary. Between primary and secondary OAL groups, there was no statistical difference in clinical characteristics such as age, gender and laterality (p = 0.47, p = 0.19 and p = 0.66, respectively). All secondary OAL cases were either disseminated or relapsed by definition and only two cases (15%) of primary OAL showed disseminated presentation (p

The formation of soot precursors during combustion of three positional isomers of methylcyclohexene was investigated in flow reactor experiments and through density functional theory simulations. As evidenced by a recently published structure-property model, the sooting tendencies of these compounds differ from those of structurally similar molecules – suggesting new or unusual reaction chemistry. It was demonstrated that 1-methyl-1-cyclohexene and 4-methyl-1-cyclohexene preferentially react via a retro-Diels–Alder pathway leading to ring opening and molecular weight reduction. 3-methyl-1-cyclohexene, which exhibits much higher yield sooting index, preferentially reacts via dehydrogenation to cyclohexadienes and toluene – consistent with higher soot formation. It was demonstrated that the relative stability of the first radical intermediate plays a considerable role in determining the branching ratio between formation of soot precursors and ring opened retro-Diels–Alder reaction products. This study underscores the importance that small structural features can have in determining the ultimate fate of carbon during combustion processes.

Dermoid cysts may occur in the orbit, most commonly in the superolateral area. Malignant transformation of such lesions has been previously reported; however, most turn out to be squamous cell carcinoma. The authors' patient initially presented with mild proptosis and limitation in extraocular movements. Preliminary biopsy showed whitish amorphous material and abundant hairs filling the thin-walled cyst, consistent with dermoid cyst. The patient underwent tumor resection via lateral orbitotomy with bone window and transorbital endoscopic approach for the dural involvement. Final biopsy showed dermoid cyst with pilosebaceous malignant transformation showing p53 expression and 30% of Ki-67 index. Adjuvant radiotherapy was performed. To the best of the authors' knowledge, this is the first reported case of this type. Despite its rarity, there should always be a high index of suspicion and complete work-up for an accurate diagnosis.