Pediatric orbital cellulitis: Case report of an unusual etiology and pathogen

Orbital cellulitis is an uncommon condition with risks to sight and life. As a complication of maxillofacial injuries, the literature suggests this is only possible with fractures or direct inoculation, and there are no reports to the contrary. Here, we make the first report of a possible etiology by which orbital cellulitis developed in a 14-year-old boy even without skin breach or bony fractures; as well as a rare causative pathogen. He presented with facial abscess and progressive orbital cellulitis after blunt facial trauma, requiring functional endoscopic sinus surgery with needle aspiration of facial abscess externally. Cultures showed growth of Streptococcus constellatus/Parvimonas micra, and he received further antibiotics with full recovery. The pathophysiology of orbital cellulitis in this patient is attributed to vascular congestion and local pressure from maxillofacial contusion and maxillary hemoantrum, with impaired paranasal sinus ventilation encouraging anaerobic bacterial growth. Further progression led to facial abscess formation and intraorbital spread with orbital cellulitis. The pediatric demographic is injury-prone, and self-reporting of symptoms can be delayed. Hence, increased suspicion of complicated injuries and orbital cellulitis may be required when managing maxillofacial contusions so that prompt treatment can be given.

Accurate Storm Surge Prediction with a Parametric Cyclone and Neural Network Hybrid Model

Storm surges are one of the most devastating coastal disasters. Numerous efforts have continuously been made to achieve better prediction of storm surge variation. In this paper, we propose a parametric cyclone and neural network hybrid model for accurate, long lead-time storm surge prediction. The model was applied to the northeastern coastal region of Taiwan, i.e., Longdong station. A total of 14 historical typhoon events were used for model training and validation, and the results and questions associated with this hybrid approach carefully discussed. Overall, the proposed method reduced the complexity of network structure while retaining the important typhoon indicators. In particular, local pressure and winds estimated from the storm parameters through physically-based parametric cyclone models allow for inferring the possible future influence of a typhoon, unlike the simple collection and direct usage of observation data from local stations in earlier works. Meanwhile, the error-tolerance capability of the neural network alleviated some discrepancy in the model inputs and enabled good surge prediction. Further, the proposed method showed better and faster convergence thanks to the retention of storm information and the reduced dimensions of the search space. The hybrid model presented excellent performance or maintained reasonable capability for short lead-time and long lead-time storm surge prediction. Compared with the pure neural network model under the same network dimensions, the present model demonstrated great improvement in accuracy as the prediction lead time increased to 8 h, e.g., 33–40% (13–21%) and 32–37% (18–29%) RMSE and CE, respectively, in the training/validation phase.

Dust Settling and Clumping in MRI-turbulent Outer Protoplanetary Disks

Planetesimal formation is a crucial yet poorly understood process in planet formation. It is widely believed that planetesimal formation is the outcome of dust clumping by the streaming instability (SI). However, recent analytical and numerical studies have shown that the SI can be damped or suppressed by external turbulence, and at least the outer regions of protoplanetary disks are likely weakly turbulent due to magneto-rotational instability (MRI). We conduct high-resolution local shearing-box simulations of hybrid particle-gas magnetohydrodynamics (MHD), incorporating ambipolar diffusion as the dominant nonideal MHD effect, applicable to outer disk regions. We first show that dust backreaction enhances dust settling toward the midplane by reducing turbulence correlation time. Under modest level of MRI turbulence, we find that dust clumping is in fact easier than the conventional SI case, in the sense that the threshold of solid abundance for clumping is lower. The key to dust clumping includes dust backreaction and the presence of local pressure maxima, which in our work is formed by the MRI zonal flows overcoming background pressure gradient. Overall, our results support planetesimal formation in the MRI-turbulent outer protoplanetary disks, especially in ring-like substructures.

Effect of the cure time on the Mechanical Properties of Silicone Rubber used as Socket Liners

This work is focused on the upper part of the prosthesis which is called a socket, it is in contact connect with the amputated part. The shear force between skin and socket, local pressure, sweating, and bacteria generation, all lead to skin inflammation and a bad smell. Consequently, the prosthesis became uncomfortable for a patient. To address this issue silicone rubber liners is proposed to use because it can absorb moisture, stress distribution, and anti-bacterial. The curing time and temperature are important factors for determining crosslink density, from the results obtained, can be noticed that, the cross-link density can greatly affect the silicone rubber properties, it can have a direct effect on the tensile strength, modulus of elasticity, percentage of elongation as well as the water absorption, and the cure time (15 min.) shoes the best resalt. As a result, using it making the prosthesis more comfortable and acceptable to the patient. In this paper, the effect of cure time on physical properties was studied.

Bottom-Pressure Development Due to an Abrupt Slope Reduction at Stepped Spillways

Fluctuating bottom-pressures on stepped chutes are relevant for the spillway design. An abrupt slope reduction causes a local alteration of the bottom-pressure development. Little information is available regarding the air–water flow properties near an abrupt slope reduction on stepped chutes, particularly on the local pressure evolution. Nevertheless, the option of providing a chute slope reduction may be of interest in spillway layout. The experiments presented herein include pressure distributions on both vertical and horizontal step faces, subsequent to an abrupt slope reduction on stepped chutes. A relatively large-scale physical model including abrupt slope reductions from 50° to 18.6° and from 50° to 30° was used, operated with skimming flow. The data indicate a substantial influence of the tested slope reductions on the bottom-pressure development. In the vicinity of the slope reduction, the mean pressure head near the edge of the horizontal step face reached 0.4 to 0.6 times the velocity head upstream of the slope reduction, for critical flow depths normalized by the step height ranging between 2.6 and 4.6.

Clinically-translatable High-fidelity Photoacoustic Tomography Enhanced by Virtual Point Sources

Photoacoustic tomography (PAT), a hybrid imaging modality that acoustically detects the optical absorption contrast, is a promising technology for imaging hemodynamic functions in deep tissues. Particularly, PAT is capable of measuring the blood oxygenation level using hemoglobin as the endogenous contrast. However, the most clinically compatible PAT configuration usually employs a linear ultrasound transducer array and often suffers from the poor image fidelity, mostly due to the limited detection view of the transducer array. PAT can be improved by employing highly-absorbing contrast agents such as droplets and nanoparticles, which, however, have low clinical translation potential due to safety concerns and regulatory hurdles. Moreover, unlike hemoglobin, these exogenous contrast agents cannot report the functional hemodynamic information. In this work, we have developed a new methodology that can improve PAT’s image fidelity without hampering its functional capability or clinical translation potential. By using clinically-approved microbubbles as virtual point sources that strongly scatter the local pressure waves generated by surrounding hemoglobin, we can overcome the limited-detection-view problem and achieve high-fidelity functional PAT in deep tissues, a technology referred to as virtual-point-source PAT (VPS-PAT). We have thoroughly investigated the working principle of VPS-PAT by numerical simulations and phantom validations, showing the acoustic origin of signal enhancement and the superiority over traditional PAT. We have also demonstrated proof-of-concept applications of functional VPT-PAT for in vivo small-animal studies with physiological challenges. We expect that VPS-PAT can find broad applications in biomedical research and accelerated translation to clinical impact.

Anatomical Assessment vs. Pullback REsting full-cycle rAtio (RFR) Measurement for Evaluation of Focal and Diffuse CoronarY Disease: Rationale and Design of the “READY Register”

Background: The morphology and functional severity of coronary stenosis show poor correlation. However, in clinical practice, the visual assessment of the invasive coronary angiography is still the most common means for evaluating coronary disease. The fractional flow reserve (FFR), the coronary flow reserve (CFR), and the resting full-cycle ratio (RFR) are established indices to determine the hemodynamic significance of a coronary stenosis.Design/Methods: The READY register (NCT04857762) is a prospective, multicentre register of patients who underwent invasive intracoronary FFR and RFR measurement. The main aim of the registry is to compare the visual estimate of coronary lesions and the functional severity of the stenosis assessed by FFR, as well as the RFR pullback. Characterizations of the coronary vessel for predominantly focal, diffuse, or mixed type disease according to visual vs. RFR pullback determination will be compared. The secondary endpoint of the study is a composite of major adverse cardiac events, including death, myocardial infarction, and repeat coronary revascularization at 1 year. These endpoints will be compared in patients with non-ischemic FFR in the subgroup of cases where the local pressure drop indicates a focal lesion according to the definition of ΔRFR > 0.05 (for <25 mm segment length) and in the subgroup without significant ΔRFR. In case of an FFR value above 0.80, an extended physiological analysis is planned to diagnose or exclude microvascular disease using the CFR/FFR index. This includes novel flow dynamic modeling for CFR calculation (CFRp−3D).Conclusion: The READY register will define the effect of RFR measurement on visual estimation-based clinical decision-making. It can identify a prognostic value of ΔRFR during RFR pullback, and it would also explore the frequency of microvascular disease in the patient population with FFR > 0.80.Clinical Trial Registration:ClinicalTrials.gov (NCT04857762).

Environmental and anthropogenic gravity contributions at the Þeistareykir geothermal field, North Iceland

Continuous high-resolution gravimetry is increasingly used to monitor mass distribution changes in volcanic, hydrothermal or other complex geosystems. To quantify the often small target signals, gravity contributions from, e.g. atmospheric mass changes, global and local hydrology should be accounted for. We set up three iGrav superconducting gravity meters for continuous monitoring of the Þeistareykir geothermal field in North Island. Additionally, we installed a set of hydrometeorological sensors at each station for continuous observation of local pressure changes, soil moisture, snow and vertical surface displacement. We show that the contribution of these environmental parameters to the gravity signal does not exceed 10 µGal (1 µGal = 10–8 m s−2), mainly resulting from vertical displacement and snow accumulation. The seasonal gravity contributions (global atmosphere, local and global hydrology) are in the order of ± 2 µGal at each station. Using the environmental observations together with standard gravity corrections for instrumental drift and tidal effects, we comprehensively reduced the iGrav time-series. The gravity residuals were compared to groundwater level changes and geothermal mass flow rates (extraction and injection) of the Þeistareykir power plant. The direct response of the groundwater levels and a time-delayed response of the gravity signal to changes in extraction and injection suggest that the geothermal system is subject to a partially confined aquifer. Our observations indicate that a sustainable “equilibrium” state of the reservoir is reached at extraction flow rates below 240 kg s−1 and injection flow rates below 160 kg s−1. For a first-order approximation of the gravity contributions from extracted and injected masses, we applied a simplified forward gravity model. Comparison to the observed gravity signals suggest that most of the reinjected fluid is drained off through the nearby fracture system.

Improvement of dynamic venous function after thermal ablation with steam vein occlusion – 6-weeks and 1-year follow-up after 167 treatments

BACKGROUND: In this paper, the method of steam vein occlusion for the treatment of the great/small saphenous vein (GSV/SSV) was analyzed in terms of a therapeutic influence on the dynamic parameters of global vein function, its effects on subjective symptoms based on chronic venous insufficiency (CVI) and the side effects of the steam vein sclerosis (SVS). It has been questioned whether the effects of this method lead to a recommendation for routine clinical practice. METHODS: The venous drainage and the venous refilling time (T0) of the leg treated were determined by photoplethysmography (Elcat, Wolfratshausen, Germany) before, six weeks and one year after the intervention to examine the effects on global venous function. Further changes of clinical symptoms and findings were assessed by the Venous Clinical Severity Score (VCSS), preoperatively and after one year, and the complication rate at 6-week follow-up was monitored. RESULTS: The SVS was performed on 167 veins (GSV: 124; SSV: 43) in a total of 156 patients. Eight patients (5.1%) did not attend the 6-week follow-up, while 29 patients (18.6%) were lost in the 1-year follow-up. Patients were suffering from symptoms such as leg pain and leg edema, which resulted in a VCSS of 9.4 (cumulated mean score of all patients) preoperatively. The T0 was reduced to mean values of 20.6 s (GSV cohort) and 21 s (SSV cohort). The VCSS improved to 6.0 after one year. This correlated with the hemodynamic parameters. The T0 increased in the GSV cohort after six weeks to 31.8 s, p < 0.001, and showed a nonsignificant improvement to 32.2 s, p = 0.509, in the 1-year check. The T0 also increased in the SSV cohort significantly after 6 weeks to 30.1 s, p < 0.001, and showed a nonsignificant reduction after one year, p = 0.289. A total of 71%of the GSV and 69.8%of the SSV of the patients involved no complications following the treatment. Light complications (grade 1) occurred (reddening, hematoma, hyperpigmentation) in the majority: 24.2%of the GSV and 18.6%of the SSV. We noticed one grade 3 complication with thrombosis in the SSV cohort, which led to a pulmonary embolism. Forty-seven complete questionnaires were analyzed (responder rate: 28.1%); 40.4%of the patients had light complaints after the treatment, such as pain, warmth or local pressure sensations (Fig. 7); 63%of those patients noticed only slight pain at a maximum of 3 out of 10. The majority (91%) would recommend this procedure. CONCLUSION: The SVS revealed endoluminal catheter-based intervention to abolish venous reflux of the G/SSV as safe. As one therapeutic target is to eliminate venous reflux, effectiveness of a method cannot be based on sonographic data alone; one must further assess patients’ symptoms and dynamic venous function. This data shows an improvement of patients’ symptoms which correlated well with the improvement of the venous function in digital photoplethysmography. The SVS can be recommended as a catheter-based treatment in the future.