Saturation Parameters Research Articles

Identification Analysis of Fluid Type in the Low Resistivity Zone of Well Z-2 Field "Z", South Sumatera

Hydrocarbon reserves are one of the main points that are very important in the sustainability of the productivity of an oil and gas field. This important point is greatly influenced by several parameters that can be obtained by various measurements and analysis. One of the most influential parameters in the analyses of the amount of hydrocarbon reserves in a reservoir is the water saturation value. The water saturation parameter will also be greatly influenced by the electrical parameters of the fluid-containing rock in the reservoir. Sometimes the electrical parameters of this rock, in this case resistivity becomes one of the benchmark parameters, whether the zone or reservoir has potential or is interesting to be developed or produced. However, there are several reservoirs or zones that experience low resistivity effects which will give an initial indication that the zones or reservoirs are not attractive or have no effect on development. In this Z field, there is a zone that experiences low resistivity effects, making this zone unattractive for production. So to be able to make these zones attractive for production, an identification analysis was carried out on Zones A and B in this Z field to determine the type or type of fluid from the two zones. The initial analysis was carried out petrographically from rock sample incisions at certain depths in Zones A and B so that it is known that the cause of the low resistivity effect in the two zones is the presence of pyrite minerals and illite clay which are the main causes of the low resistivity effect. Furthermore, an analysis of the identification of fluid types was carried out using the double apparent resistivity method with the results obtained that in Zones A and B there are 2 types of fluids, namely hydrocarbons and water with a depth limit of 3650 ft in Zone A and 4558 ft in Zone B. By knowing the type of fluid, the hydrocarbons contained in these two zones should be able to increase interest in the production of these zones as a potential zone for production, but it is necessary to perforate at a depth range indicated by the hydrocarbon fluid and carry out initial production tests to prove the results of the analysis in this study.

Tube-first Technique as a Conduit for Easy and Fast Nasal Fiberoptic Intubation

Background: Classical nasal fiberoptic bronchoscope intubation may be a challenging and lengthy procedure with a 1-10% failure rate. Objectives: This study aimed to compare among patients with difficult airway intubation undergoing general anesthesia, the safety, and efficacy of Tube-First (TF) nasal fiberoptic bronchoscope intubation against the Classic (CL) procedure. Methods: This single-blinded, parallel-group, randomized trial enrolled 40 adult patients with known difficult airways and scheduled for surgery under general anesthesia. The patients were randomly allocated into two (n=20 each) patient groups. In the CL group, the endotracheal tube and fiberoptic bronchoscope were inserted together through the nostril; in the TF group, the endotracheal tube insertion preceded the fiberoptic bronchoscope. In both groups, the bronchoscope was used to visualize the vocal cords and removed after ensuring the endotracheal tube position. The primary (efficacy) outcomes were the time elapsing from the bronchoscope insertion and visualizing the vocal cords (T1) and the time elapsing from the bronchoscope advancing initiation to its removal (T2). The secondary (safety) outcomes included oxygen saturation and hemodynamic parameters during the procedure. Results: The TF group showed a significant T1 and T2 mean reduction compared to those of the CL group (37.15 ± 3.87 and 64.25 ± 8.28 vs. 55.05±4.52 and 88.25±5.49 seconds, respectively; p < 0.0001). The oxygen saturation was comparable in both groups with no desaturation (SpO2 < 90%) cases. The heart rate and mean arterial blood pressure changes were significantly lower in the TF group compared to the CL group. Conclusion: Among patients with difficult airway intubation undergoing general anesthesia, we found the Tube-First intubation approach was quicker and safer compared to the classical intubation technique.

Safety of Lumason® (SonoVue®) in special populations and critically ill patients.

Evidence for the safe use of Lumason® (SonoVue®), an ultrasound enhancing agent (UEA), in special patient populations is critical to enable healthcare professionals to make informed decisions concerning its use in such patients. Herein, we provide insight on the safety and tolerability of Lumason® in special patient populations. Findings are presented from clinical pharmacology studies conducted in patients with compromised cardiopulmonary conditions, from a retrospective study performed in critically ill patients, and from post-marketing surveillance data from over 20 years of market use of Lumason® (SonoVue®). No detrimental effects of Lumason® on cardiac electrophysiology were observed in patients with coronary artery disease (CAD), and no significant effects on pulmonary hemodynamics were noted in patients with pulmonary hypertension or congestive heart failure. Similarly, no effects on several assessments of pulmonary function (e.g., FVC) were observed in patients with chronic obstructive pulmonary disease (COPD), and no clinically meaningful changes in O2 saturation or other safety parameters were observed after administration of Lumason® to patients with diffuse interstitial pulmonary fibrosis (DIPF). The retrospective study of critically ill patients revealed no significant difference for in-hospital mortality between patients administered Lumason® for echocardiography versus those who had undergone echocardiography without contrast agent. Post-marketing surveillance revealed very low reporting rates (RR) for non-serious and serious adverse events and that serious hypersensitivity reactions were rare. These findings confirm that Lumason® is a safe and well tolerated UEA for use in special populations and critically ill patients.

Influence of saturable absorber parameters on the hybrid mode-locking performance of fiber lasers

In this paper, we numerically study the influence of saturable absorber parameters, namely, modulation depth, recovery time, and saturation energy, on the performance of an ultrafast fiber laser that is mode-locked by a hybrid scheme of a saturation absorber (SA) and a nonlinear polarization rotation (NPR). Maps of mode-locked states related to intracavity wave-plates are created to evaluate the operation of hybrid mode-locking under different modulation depths of the SA. Along with the improvement of modulation depth of the SA, the mode-locked pulse results from a combination effect of the SA and NPR. The numerical analysis reveals that the SA parameters can significantly impact the pulse profile, peak power, and operation state. Moreover, they can also impact the selection of NPR mode-locked points, resulting in variation in stable single pulse output. A higher modulation depth can suppress the unstable multiple pulses’ operation and convert them into harmonic mode-locked pulses. The obtained results indicate that the selection of appropriate SA parameters can effectively improve the output characteristics of hybrid mode-locked fiber lasers.

Sliding-Mode Control Under Denial-of-Service Attacks: An Event-Triggered Quantized State Feedback Approach

This brief is concerned with the robust stabilization issue of cyber-physical systems (CPSs) under periodic Denial-of-Service (DoS) attacks with quantized feedback sliding-mode control (SMC) based on event-triggered mechanism(ETM). The ETM is introduced for reducing the load of network communication, and states generated by the ETM are quantized to construct the available information of the design of sliding-mode controller. Sufficient conditions for robust stabilization of the system under periodic DoS attacks are proposed to ensure the reachability of sliding manifold. In addition, a lower bound of the quantized measurement saturation parameter is derived to guarantee the quantizer capture system states in only one step under periodic DoS attacks. After that, this brief proves that the execution time interval of the ETM has a positive lower bound and thus no Zeno behaviors occur. The effectiveness of this proposed method is finally verified by an example of a satellite control system.

Neutron star mass–radius constraints using the high-frequency quasi-periodic oscillations of GRB 200415A

Context. Quasi-periodic oscillations (QPOs) observed in a giant flare of a strongly magnetized neutron star (magnetar) carry crucial information for extracting the properties od neutron stars. Aims. The aim of this study is to constrain the mass and radius of the neutron star model for GRB 200415A by identifying the observed QPOs with crustal torsional oscillations and comparing these with experimental constraints on the nuclear matter properties. The frequencies of the crustal torsional oscillations are determined by solving the eigenvalue problem with the Cowling approximation, assuming a magnetic field of about 1015 G. Methods. We find that the observed QPOs can be identified with several overtones of crustal oscillations for carefully selected combinations of the nuclear saturation parameters. Thus, we can inversely constrain the neutron star mass and radius for GRB 200415A by comparing them to the values of nuclear saturation parameters obtained from terrestrial experiments. Results. We impose further constraints on the neutron star mass and radius while the candidate neutron star models examined here are consistent with the constraints obtained from other available astronomical and experimental observations.

In vivo monitoring of hemoglobin derivatives in a rat thermal injury model using spectral diffuse reflectance imaging

IntroductionTo demonstrate the feasibility of our previously proposed Diffuse reflectance spectral imaging (DRSI) method for in vivo monitoring of oxygenated hemoglobin, deoxygenated hemoglobin, methemoglobin, tissue oxygen saturation, and methemoglobin saturation in a rat scald burn wound model and assess whether the method could be used for differentiating the burn depth groups in rats based on the hemoglobin parameters. MethodologySuperficial dermal burns (SDBs), deep dermal burns (DDBs), and deep burns (DBs) were induced in rat dorsal skin using a Walker–Mason method. An approach based on multiple regression analysis for spectral diffuse reflectance images aided by Monte Carlo simulations for light transport was used to quantify the hemoglobin parameters. Canonical discriminant analysis (CDA) was performed to discriminate SDB, DDB, and DB. ResultsCDA using the total hemoglobin concentration, tissue oxygen saturation, and methemoglobin saturation as the independent variables showed good performance for discriminating the SDB, DDB, and DB groups immediately after burn injury and the SDB group from the DDB and DB groups 24–72 h after burn injury. ConclusionsThe DRSI method with multiple regression analysis for quantification of oxygenated hemoglobin, deoxygenated hemoglobin, and methemoglobin proved to be reliable for monitoring these hemoglobin derivatives in the rat experimental burn injury model. The parameters of tissue oxygen saturation, methemoglobin saturation, and total hemoglobin concentration are promising for the differentiating the degree of burn injury using CDA.

Comparative Analysis of Oxygen Saturation by Pulse Oximetry and Arterial Blood Gas in Hypoxemic Patients in a Tertiary Care Hospital.

Oxygen saturation is essential for medical care and is closely regulated within the body. Arterial blood gas (ABG) analysis is used to evaluate critically ill individuals' ventilation, oxygenation, acid-base status, and metabolic condition. Pulse oximetry is an easy and non-invasive way to measure the status of oxygen saturation non-invasively in clinical settings and provides a quick and precise assessment of oxygenation and reduces medical errors. SpO2 may not always be a reliable predictor of arterial oxygen saturation (SaO2), and hypoxemic, hemodynamically compromised, and critically ill patients may have lower SpO2 accuracy. A study is needed to assess and compare various oxygen saturation methods. The study aimed to compare the oxygen saturation levels measured by pulse oximetry and ABG analysis in hypoxemic patients. The objectives were tocompare the values between SaO2, PaO2, and SpO2 values obtained from the patients, and correlate the study parameters among both techniques. The study was conducted from February 2021 to June 2022 among the 102 hypoxemic patients who were admitted to the emergency and surgical intensive care unit (ICU) of Sree Balaji Medical College and Hospital in Chennai. Primary data on ABGanalysis and pulse oximetry readings were collected from the study subjects. The patient and their past medical records, physical exam, chest x-ray findings, pulse oximetry, and ABG results were all reviewed. Each patient had their ABG, and pulse oximetry measured simultaneously. A comparison was made between SpO2 and partial pressure of oxygen (PaO2) and arterial oxygen saturation (SaO2) parameters using a paired t-test. The correlation was done against the SpO2 and ABG parameters and assessed for association using the correlation coefficient value; gender was also considered while correlating. An observational study was done among 102 study samples to comparatively analyze the oxygen saturation by two methods, namely pulse oximetry and ABG, in hypoxemic patients. While comparing the mean values of SaO2 and SpO2, they were 84.41 ± 4.24 and 80.58 ± 5.77, respectively, and this difference was statistically very significant (p< 0.001). While comparing the mean values of PaO2 and SaO2, they were 61.02 ± 5.01 and 84.41 ± 4.24, respectively, and this difference was statistically significant (p = 0.043). While comparing the mean values of PaO2 and SpO2, they were 61.02 ± 5.01 and 80.58 ± 5.77, respectively, and this difference was statistically significant (p = 0.054). Among the study population, with regard to the correlation factor, there is notably a very high and strong positive correlation between SaO2 and SpO2 and between SpO2 and PaO2. There was a negative correlation between SpO2 and finger abnormalities and between SpO2 and blood pressure. The ABGmethod is considered the gold standard. When SpO2 levels fall below 90%, pulse oximetry may not be accurate enough to reliably assess oxygenation. In such cases, where alveolar hypoventilation is suspected, it is recommended to complement pulse oximetry with ABG studies. This is because ABG analysis provides a more comprehensive assessment of oxygenation and acid-base status, which can aid in the diagnosis and management of respiratory conditions.

Study on the Applicability of Saturated Hydrocarbon Parameters in the Evaluation of Lacustrine Source Rocks and Oils Based on Thermal Simulation Experiments

Saturated hydrocarbons are widely used in the valuation of source rocks and oils, but the applicability of related parameters has received less attention. Based on the thermal simulation experiments on Mesozoic source rocks in the Yingen-Ejinaqi Basin, and the GC-MS analysis of the saturated hydrocarbon fractions of the expelled oils and extracts from solid residues, the applicability of the parameters related to lacustrine source rocks and oil were discussed. The results indicated that: Controlled by thermal degradation, both the relative abundance of the tricyclic terpenoids in terpenoids and the pregnane (including L pregnane) in steroids increased with the increase in maturity. Maturity had little effect on some environmental parameters of lacustrine source rocks and oils, such as Pr/Ph and gammacerane index, they were still effective even at the high-over maturity stage. But maturity had a significant influence on the method of using saturated hydrocarbons to identify the source of organic matter, because only at the thermal stage of Ro &lt; 1.45%, might it effectively identify the source of organic matter by using the dominant peak of n-alkanes method and the relative abundance of C27–C29 steranes method. Most saturated hydrocarbon maturity parameters had their valid scope of application, such as C29 20S/(20S + 20R) steranes, C29αββ/(ααα + αββ) steranes and C31αβ22S/(22S + 22R) homohopanes were only effective when the Ro value was below 2.06%, for the parameter’s value would be “inverted” in the stage of over-maturity (Ro &gt; 2.06%). However, the parameter Ts/(Ts + Tm) was effective in the whole thermal evolution process, reflecting good applicability. This study clarifies the validity of the application of commonly used saturated hydrocarbon parameters, and it can provide some reference for relevant studies.

Hybrid Mode-Locked Fiber Ring Laser Using Graphene Saturable Absorbers to Generate 20 and 50-GHz Pulse Trains

Optical pulses at high repetition rates are generated using rational harmonic mode locking and saturable absorber made of graphene nanoparticles in a fiber laser. The pulse generation from the fiber laser is modeled by solving the Generalized Nonlinear Schrodinger Equation. The computation involved varying the various saturable absorption parameters, such as linear and nonlinear absorption coefficients. Experimentally stable pulse trains at 20 GHz and 50 GHz are generated with a pulse width of ∼ 2.7 ps. This result agrees with the simulation.

Sleep Architecture and Daytime Sleepiness in Patients with Erectile Dysfunction.

Obstructive sleep apnea is considered a risk factor for erectile dysfunction. The aim of this study was to determine sleep architecture and assess daytime sleepiness in patients with erectile dysfunction. The study group included 280 patients. The 107 enrolled patients had reported erectile dysfunction. The control group consisted of 173 patients who had no history of erectile dysfunction. The Epworth sleepiness scale (ESS) was used to measure the subjects' level of daytime sleepiness. All patients underwent a standardized overnight, single-night polysomnography in sleep laboratory. In the erectile dysfunction group, we observed increased ESS total score and N1 sleep phase duration. Mean and minimal oxygen saturation and mean oxygen desaturation were decreased in comparison to the control group. In summary, subjects with erectile dysfunction have altered sleep architecture, oxygen saturation parameters and increased daytime sleepiness.

Novel fluid typing method of NMR dual-TW logging in mixed-wet reservoirs

In mixed wetting reservoirs, the fluids typing is difficult by using nuclear magnetic resonance (NMR) logging. The data processing and interpretation method of NMR dual-waiting time (TW) activation faces serious challenges and the previous NMR time-domain analysis (TDA) of NMR dual-TW logging for water-wet condition is not applicable. The petrophysical characteristics under mixed-wet conditions was studied and the oil-wet factor was defined, and new NMR logging response equations was investigated and the echo train difference between long and short wait times were derived. The relaxation parameters of fluids and water saturation was finally calculated by the genetic algorithm. Therefore, a new improved TDA method was proposed for mixed-wet reservoirs. To verify the method, a petrophysical model was set and some simulations proved it accurate. A case study from Chang 8, Ordos Basin, China, was studied, and the oil saturation and volume in the flushed zone were calculated. From the oil-testing results, two cross-plots for fluid typing were constructed based on the calculated oil saturation in flushed zone, T2 geomean difference of dual-TW NMR logging. The practical application shows that the novel TDA method of NMR dual-TW logging for mixed-wet reservoirs is efficient for the fluid identification.

Improving Clinical Decision-Making: A Focus on Early Warning Systems and Scoring Methods

Dear Editor, Examinations, laboratory tests, radiology, and clinical experience are required to make the most appropriate clinical decisions. There is no single universal clinical decision-making method advocated in routine medical literature. Often, this process is driven by experience, exploration, and clinical gestalt. Clinician management serves as a subjective decision tool in disease management. It has been extensively studied in the literature, particularly in entities such as pulmonary embolism, difficult airway prediction, and severe COVID-19 (1). By combining parameters such as laboratory-vital parameters and combined hematological parameters, clinical decision-making tools have been developed (2-3). Early warning systems (EWS) help predict which patients will require critical care by evaluating physiological parameters in busy and crowded workspaces. These scores, which can be measured through vital parameters and a simple physical examination, ensure the effective use of resources (4). In intensive care units (ICUs), complex systems are used to predict mortality. APACHE II is the most well-known score used in intensive care, consisting of many parameters that are computationally difficult. Vital parameters, biochemical tests, and blood gas analysis results are used when calculating APACHE II (5). On the other hand, important features of scores used in the emergency department are their quick and easy calculation, requiring no professional knowledge. The VitalPAC Early Warning Score (ViEWS), developed by Prytherch et al. in 2010, is an EWS that includes six physiological parameters. This score records the pulse rate, systolic blood pressure, respiratory minute rate, body temperature, level of consciousness (assessed by AVPU), and peripheral oxygen saturation (SpO2) parameters. ViEWS is created based on the degree of deviation of these six parameters from their normal ranges. Additional points are given if the patient receives oxygen support. The total ViEWS value, calculated by considering each parameter, provides information about the patient's prognosis (6). By adding the rapid lactate level to ViEWS (ViEWS-L), a score that better predicts outcomes in the geriatric population was developed (7). The Modified Early Warning Score (MEWS) is one of the triage scoring methods used to identify patients in need of intensive and critical care, and to expedite their transfer to the intensive care unit. It evaluates systolic blood pressure, heart rate, respiratory rate, body temperature, and neurological status. MEWS is included in routine nursing care procedures in some countries and is routinely assessed by nurses. ICU admission rates and mortality rates increase for those who score 5 or more on this scale, although this threshold may vary in different populations or clinical situations. In a Korean study analyzing sepsis patients, combining lactate with the MEWS score improved the prediction of the need for intensive care (8). The National Early Warning Score (NEWS) is another scoring system used to determine clinical deterioration and follow-up level for all hospitalized patients, as well as to predict clinically high-risk patients. It is calculated by evaluating respiratory rate, oxygen saturation, oxygen support status, blood pressure, body temperature, and neurological status. The NEWS-L score, obtained by combining NEWS with lactate, has been reported to be superior to NEWS alone in geriatric critically ill patients (9). However, contrary to the geriatric patient study, Özkan's study reported that NEWS-L was not superior to NEWS and that they exhibited similar predictive abilities (10). As a result, researchers are actively working on new parameters and scoring systems to optimize resource utilization and predict critical illness. Researchers should be encouraged to investigate studies on EWS lactate combinations or other combinations.

Optimization of acquisition parameters for cortical inhomogeneous magnetization transfer (ihMT) imaging using a rapid gradient echo readout.

Imaging biomarkers with increased myelin specificity are needed to better understand the complex progression of neurological disorders. Inhomogeneous magnetization transfer (ihMT) imaging is an emergent technique that has a high degree of specificity for myelin content but suffers from low signal to-noise ratio (SNR). This study used simulations to determine optimal sequence parameters for ihMT imaging for use in high-resolution cortical mapping. MT-weighted cortical image intensity and ihMT SNR were simulated using modified Bloch equations for a range of sequence parameters. The acquisition time was limited to 4.5 min/volume. A custom MT-weighted RAGE sequence with center-out k-space encoding was used to enhance SNR at 3 T. Pulsed MT imaging was studied over a range of saturation parameters, and the impact of the turbo factor on the effective ihMT resolution was investigated. 1 mm isotropic ihMTsat maps were generated in 25 healthy adults. Greater SNR was observed for larger number of bursts consisting of 6-8 saturation pulses each, combined with a high readout turbo factor. However, that protocol suffered from a point spread function that was more than twice the nominal resolution. For high-resolution cortical imaging, we selected a protocol with a higher effective resolution at the cost of a lower SNR. We present the first group-average ihMTsat whole-brain map at 1 mm isotropic resolution. This study presents the impact of saturation and excitation parameters on ihMTsat SNR and resolution. We demonstrate the feasibility of high-resolution cortical myelin imaging using ihMTsat in less than 20 min.

Thermal maturity of crude oils in the Baiyun sag, Pearl River Mouth basin, South China Sea: Insights from biomarkers，aromatic hydrocarbon and adamantane compounds

The Baiyun Sag in the Pearl River Mouth Basin is a hydrocarbon-rich depression in which oil and natural gas fields coexist. The complex characteristics of oil and condensate in the sag have been long-term issues, and one of the questions is the formation stage of black oil, volatile oil and gas condensate in the sag. In this study, to accurately estimate the thermal maturity of oil in the Baiyun Sag, maturity parameters derived from normal alkanes, terpanes, steranes and aromatic hydrocarbons were systematically investigated. In addition, adamantane parameters were used to verify both the oil and condensate maturity. The results show that the saturated hydrocarbon biomarker parameters are not suitable for providing a complete understanding of the oil maturity in the Baiyun Sag. A qualitative evaluation method for various maturity stages of oil was proposed based on the methylphenanthrene distribution fractions, phenyldibenzothiophene maturity parameters, and diamantane concentration. Subsequently, the maturity was quantitatively evaluated using empirical equations based on methyl diamantine. The equations were selected by comparing the calculated equivalent reflectance (Rc) with the qualitatively determined maturity stage of the crude oil. Finally, the calculated vitrinite reflectance values indicated an overestimation of the maturity of light oils and condensate oils, which were thought to be produced in the late oil window (Ro: 1.0%∼1.3%) to wet gas stage (Ro: >1.3%). The new results indicate that the black oils with Rc values ranging between 0.72% and 1.05% was generated during the peak oil window. The Rc values of gas condensates in the eastern and northeastern structural belts range from 1.20% to 1.24%, suggesting that they are products of the late oil window. The maturity levels of gas condensates in the Panyu Low Uplift are the highest (Rc: 1.14%–1.46%) in the sag. They were produced in the late oil to wet gas stages. The oil maturity characteristics confirm the oil exploration potentials of the eastern and northeastern structural belts of the Baiyun Sag.

Nuclear masses and the equation of state of nuclear matter

Abstract The incompressible liquid-drop (ILD) model reproduces masses of stable nuclei rather well. Here we show how the ILD volume, surface, symmetry, and Coulomb energies are related to the equation of state of nuclear matter using the Oyamatsu–Iida (OI) macroscopic nuclear model, which has reasonable many-body energy and isoscalar inhomogeneity gradient energy. We use 304 update interactions, covering wide ranges of the incompressibility K0 of symmetric matter and the density slope of symmetry energy L, which fit almost equally empirical mass and radius data of stable nuclei. Thus, the K0 and L dependences are nearly frozen in stable nuclei as in the ILD model, leading to clear correlations among interaction and saturation parameters. Furthermore, we assume that the surface energy of the OI model is twice as large as the gradient energy using the size equilibrium conditions of the ILD and OI models. Then, the four energies of the ILD and OI models agree well for stable nuclei with A ≳ 40. Meanwhile, the OI model with L ≲ 100 MeV predicts the latest mass data better than those of stable nuclei, and we suggest 20 ≲ L ≲ 90 MeV, although the lower boundary is not constrained well.

A Comparative Study of Antiretroviral (Lopinavir/Ritonavir) and Remdesivir Used in the Pandemic in Iraq on the Clinical Outcome in Patients with SARS-CoV-2.

The SARS-CoV-2 virus, which emerged in December 2019, has infected millions worldwide and caused many deaths. Due to its high mortality rate, several studies assessed the effectiveness of different drugs against COVID-19, mainly in reducing the hospitalization rate among the elderly and compromised patients. Lopinavir-ritonavir combination and remdesivir were among the medications used to treat COVID-19. Due to considerable differences in the effectiveness and clinical outcomes of the two treatments, this study aimed to compare the clinical outcomes between COVID-19 patients treated with antiretrovirals (lopinavir-ritonavir) and remdesivir. A total of 33 patients on lopinavir-ritonavir and 35 on remdesivir were selected for this study. A retrospective comparative analysis was conducted based on demographic characteristics, hospital stay, laboratory parameters of C-reactive protein (CRP) and plasma blood oxygen saturation (SPO2), clinical treatment, and a clinical outcome assessment extracted from hospital archive data. Both treatments improved patient outcomes, yet there was a significant difference between lopinavir-ritonavir and remdesivir groups in platelet count, CRP, SPO2, and monocyte results, with remdesivir showing better clinical outcomes. No significant difference was reported in white blood cells, lymphopenia, and lactate dehydrogenase between the two treatments. It is still necessary to conduct further research to determine how effective the two treatments are in treating severe COVID-19 cases due to the limited number of available studies and the inconsistency in research methods and measurements.

Digital art in designing an artistic image

The research aim lies in describing new approaches in art. The use of digital art allows displaying an artistic image that perceives new ideals. The development of digital art in the era of global digitization implies introducing several modern tools for designing an artistic image. The paper raises the issue of the media of digital works, including photographic paper and canvas. The technological and automated side of some or all digital works is also described. The question of their uniqueness or singularity is raised. The paper reveals the aesthetic aspect of a computer-designed work, which depends primarily on the parameters of brightness, contrast, and saturation of the creative software used, as well as the parameters chosen for printing. Since this aspect is the same as for a traditional work reproduced in printed form, from a purely artistic point of view, a digital work can resemble a traditional work in every way if it borrows elements from it, such as hand-painted or digitally drawn textures. Moreover, when traditional techniques are combined with digital techniques, creative ways are likely to multiply because of the variety of techniques. Consideration is given to the use of correction tools to facilitate modification of the composition.

Adaptive output feedback control of uncertain nonlinear systems with input saturation

AbstractThis article concerns with the tracking control problem for a class of control‐affine nonlinear systems subject to input saturation, parametric uncertainties and unmodeled uncertainties. The proposed scheme consists of a nested‐saturation‐function‐based controller integrated with feedforward model compensation. A saturated linear extended state observer (SLESO) and parameter adaptation law are constructed to compensate for the unmodeled uncertainties and parametric uncertainties, respectively. By using these mechanisms, the steady‐state tracking performance can be guaranteed through uncertainty compensation. Additionally, the issue of conservativeness in the input saturation problem is effectively addressed through online‐updating the available unsaturated region, which improves transient performance. The proposed scheme results in asymptotic stability when unmodeled uncertainties are constants and ultimate boundedness when unmodeled uncertainties are time‐varying. Finally, simulation studies are presented to demonstrate the effectiveness of the proposed approach.

Preoperative visualization of midline-crossing subcutaneous arteries in transverse abdominal flaps using photoacoustic tomography

Photoacoustic tomography is a noninvasive vascular imaging modality that uses near-infrared pulsed laser light and ultrasound to visualize vessels. We previously demonstrated the utility of photoacoustic tomography for anterolateral thigh flap surgery involving body-attachable vascular mapping sheets. However, it was not possible to obtain clear separate images of arteries and veins. In this study, we tried to visualize subcutaneous arteries that cross the midline of the abdomen, since these arteries are known to be important for obtaining large perfusion areas in transverse abdominal flaps. Four patients scheduled to undergo breast reconstruction with abdominal flaps were examined. Photoacoustic tomography was performed preoperatively. The tentative arteries and veins were traced according to the S-factor, an approximate hemoglobin oxygen saturation parameter calculated using 2 laser excitation wavelengths (756 and 797nm). Intraoperatively, arterial-phase indocyanine green (ICG) angiography was performed after abdominal flap elevation. Images of vessels speculated to be arteries by preoperative photoacoustic tomography were merged with those of intraoperative ICG angiography and analyzed in an 8×4-cm2 area below the umbilical region. The S-factor was used to visualize the midline-crossing subcutaneous arteries in all 4 patients. A matching analysis compared preoperative tentative arteries according to photoacoustic tomography with ICG angiography results in the 8×4-cm2 area below the umbilical region and indicated a 71.3-82.1% match (average: 76.9% match). This study demonstrates that the S-factor, a noninvasive, label-free imaging modality, can be used to successfully visualize subcutaneous arteries. This information can aid in selecting perforators for abdominal flap surgery.