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Search Results (554)

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Keywords = pulse-to-pulse intervals

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13 pages, 1651 KiB  
Article
Evaluation of Non-Invasive Hemoglobin Monitoring in Perioperative Patients: A Retrospective Study of the Rad-67TM (Masimo)
by Philipp Helmer, Andreas Steinisch, Sebastian Hottenrott, Tobias Schlesinger, Michael Sammeth, Patrick Meybohm and Peter Kranke
Diagnostics 2025, 15(2), 128; https://doi.org/10.3390/diagnostics15020128 - 8 Jan 2025
Viewed by 283
Abstract
Background: Hemoglobin (Hb) is a crucial parameter in perioperative care due to its essential role for oxygen transport and tissue oxygenation. Accurate Hb monitoring allows for timely interventions to address perioperative anemia and, thus, prevent morbidity and mortality. Traditional Hb measurements rely [...] Read more.
Background: Hemoglobin (Hb) is a crucial parameter in perioperative care due to its essential role for oxygen transport and tissue oxygenation. Accurate Hb monitoring allows for timely interventions to address perioperative anemia and, thus, prevent morbidity and mortality. Traditional Hb measurements rely on invasive blood sampling, which significantly contributes to iatrogenic anemia and poses discomfort and increased infection risks. The advent of non-invasive devices like Masimo’s Rad-67™, which measures Hb using pulse CO-oximetry (SpHb), offers a promising alternative. This study evaluates the accuracy of SpHb compared to clinical standard blood gas analysis (BGA) in perioperative patients. Methods: This retrospective study analyzed 335 paired Hb measurements with an interval <15 min between SpHb and BGA in the operating theater and post-anesthesia care unit of a university hospital. Patients experiencing hemodynamic instability, acute bleeding, or critical care were excluded. Statistical analysis included Bland–Altman plots and Pearson correlation coefficients (PCCs) to assess the agreement between SpHb and BGA. Potential confounders, e.g., patient age, skin temperature, sex, perfusion index (PI), and atrial fibrillation, were also analyzed. Results: The bias of the SpHb compared to BGA according to Bland–Altman was 0.00 g/dL, with limits of agreement ranging from −2.70 to 2.45 g/dL. A strong correlation was observed (r = 0.79). Overall, 57.6% of the paired measurements showed a deviation between the two methods of ≤±1 g/dL; however, this applied to only 33.3% of the anemic patients. Modified Clark’s Error Grid analysis showed 85.4% of values fell within clinically acceptable limits. Sex was found to have a statistically significant, but not clinically relevant, effect on accuracy (p = 0.02). Conclusions: The Rad-67TM demonstrates reasonable accuracy for non-invasive SpHb, but exhibits significant discrepancies in anemic patients with overestimating low values. While it offers potential for reducing iatrogenic blood loss, SpHb so far should not replace BGA in critical clinical decision-making. Full article
(This article belongs to the Special Issue Wearable Sensors for Health Monitoring and Diagnostics)
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14 pages, 869 KiB  
Article
Tidal Volume Challenge to Assess Volume Responsiveness with Dynamic Preload Indices During Non-Cardiac Surgery: A Prospective Study
by Panagiota Griva, Emmanouil I. Kapetanakis, Orestis Milionis, Konstantina Panagouli, Maria Fountoulaki and Tatiana Sidiropoulou
J. Clin. Med. 2025, 14(1), 101; https://doi.org/10.3390/jcm14010101 - 27 Dec 2024
Viewed by 420
Abstract
Background/Objectives: The aim of this study is to assess whether changes in Pulse Pressure Variation (PPV) and Stroke Volume Variation (SVV) following a VtC can predict the response to fluid administration in patients undergoing surgery under general anesthesia with protective mechanical ventilation. [...] Read more.
Background/Objectives: The aim of this study is to assess whether changes in Pulse Pressure Variation (PPV) and Stroke Volume Variation (SVV) following a VtC can predict the response to fluid administration in patients undergoing surgery under general anesthesia with protective mechanical ventilation. Methods: A total of 40 patients undergoing general surgery or vascular surgery without clamping the aorta were enrolled. Protective mechanical ventilation was applied, and the radial artery was catheterized in all patients. The protocol began one hour after the induction of general anesthesia and the stabilization of hemodynamic parameters. The parameters PPV6 and SVV6 were recorded during ventilation with a Vt of 6 mL/kg Ideal Body Weight (IBW) (T1). Then, the Vt was increased to 8 mL/kg IBW for 3 min without changing other respiratory parameters. After the VtC, the parameters PPV8 and SVV8 (T2) were recorded. After the stabilization of hemodynamic parameters, volume expansion (VE) was administered with colloid fluid of 6 mL/kg IBW. Parameters before (T3) and 5 min after fluid challenge (T4) were recorded. The change in the Stroke Volume Index (SVI) before and after VE was used to indicate fluid responsiveness. Patients were classified as fluid responders (SVI ≥ 10%) or non-responders (SVI < 10%). Results: The parameter ΔPPV(6–8) demonstrated good predictive ability to predict fluid responsiveness, evidenced by an Area Under the Curve (AUC) of 0.86 [95% Confidence Interval (CI) 0.74 to 0.95, p < 0.0001]. The threshold of ΔPPV(6–8) exceeding 2% identified responders with a sensitivity of 83% (95% CI 0.45 to 1.0, p < 0.0001) and a specificity of 73% (95% CI 0.48 to 1.0, p < 0.0001). The parameter ΔSVV(6–8) also revealed good predictive ability, reflected by an AUC of 0.82 (95% CI 0.67 to 0.94, p < 0.0001). The criterion ΔSVV(6–8) greater than 2% pinpointed responders with a sensitivity of 83% (95% CI 0.71 to 1.0, p < 0.001) and a specificity of 77% (95% CI 0.44 to 1.0, p < 0.001). Conclusions: This study demonstrates that VtC possesses good predictive ability for fluid responsiveness in patients undergoing general surgery. Full article
(This article belongs to the Section General Surgery)
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11 pages, 8503 KiB  
Article
Dye Laser Applications in Cosmetic Dermatology: Efficacy and Safety in Treating Vascular Lesions and Scars
by Alessandro Clementi, Giovanni Cannarozzo, Simone Amato, Elena Zappia, Luigi Bennardo, Simone Michelini, Cristiano Morini, Mario Sannino, Caterina Longo and Steven Paul Nistico
Cosmetics 2024, 11(6), 227; https://doi.org/10.3390/cosmetics11060227 - 23 Dec 2024
Viewed by 607
Abstract
Cosmetic dermatology increasingly utilizes laser technologies to address various aesthetic concerns. This study evaluates the efficacy of the flash-lamp pulsed-dye laser (FPDL) in treating vascular and scar-related conditions. A cohort of 71 patients with diverse vascular lesions, including facial telangiectasia, port-wine stains (PWSs), [...] Read more.
Cosmetic dermatology increasingly utilizes laser technologies to address various aesthetic concerns. This study evaluates the efficacy of the flash-lamp pulsed-dye laser (FPDL) in treating vascular and scar-related conditions. A cohort of 71 patients with diverse vascular lesions, including facial telangiectasia, port-wine stains (PWSs), striae rubrae, erythematous acne scars, facial traumatic scars, and keloids, was treated using the FPDL (Synchro Vas-Q, Deka MELA). Treatment protocols varied based on lesion type, with sessions ranging from one to eight at intervals of four to eight weeks. Clinical outcomes were assessed using a four-point grading scale and patient satisfaction surveys. Results indicated that 70.4% of patients achieved excellent clearance of lesions, while 16.9% and 9.9% showed moderate-good and slight clearance, respectively. Minimal or no improvement was observed in 2.8% of cases. High patient satisfaction was reported, correlating with effective lesion reduction and manageable side effects, primarily post-operative purpura. The study underscores FPDL’s selective efficacy for hemoglobin-rich lesions and its safety profile, advocating for its continued use in cosmetic dermatological practices. These findings contribute to the growing evidence supporting laser therapy as a pivotal tool in aesthetic medicine, emphasizing the importance of tailored treatment protocols and patient education for optimal outcomes. Full article
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17 pages, 818 KiB  
Article
Synergistic Effects of a Rotating Magnetic Field and Pulsed Light on Key Quality Characteristics of Refrigerated Pork: A Novel Approach to Shaping Food Quality
by Paulina Duma-Kocan, Mariusz Rudy, Marian Gil, Renata Stanisławczyk, Anna Krajewska, Dariusz Dziki and Bogdan Saletnik
Appl. Sci. 2024, 14(24), 12013; https://doi.org/10.3390/app142412013 - 22 Dec 2024
Viewed by 588
Abstract
The combined effects of pulsed light and a rotating magnetic field on the quality of raw pork loin stored under refrigerated conditions were studied. Muscles from the same carcass were divided into six distinct portions. Three portions were designated as untreated control samples, [...] Read more.
The combined effects of pulsed light and a rotating magnetic field on the quality of raw pork loin stored under refrigerated conditions were studied. Muscles from the same carcass were divided into six distinct portions. Three portions were designated as untreated control samples, while the other three underwent experimental procedures involving exposure to pulsed light and a rotating magnetic field. Comprehensive laboratory analyses were conducted at specific intervals during the storage period to evaluate changes and assess the impact of storage duration on the samples. The results demonstrated that the combined use of a magnetic field and pulsed light significantly extended the shelf life of raw pork. A significant (p < 0.05) reduction in total microbial count was observed in treated samples compared to the control group throughout all storage periods. The treatment also improved all sensory attributes and reduced purge loss during refrigerated storage. Additionally, the applied treatment significantly (p < 0.05) lowered the hardness and rigidity on day 10, as well as the chewiness of the pork loin on days 1 and 10 of storage. The novelty and innovation of this study lie in the application of a rotating magnetic field combined with a pulsed light beam to enhance the properties of raw pork. This approach resulted in a synergistic effect, notably decelerating the deterioration of meat quality, extending its shelf life, and reducing energy consumption during processing. These outcomes hold significant potential for environmental, economic, and social benefits. Full article
(This article belongs to the Section Food Science and Technology)
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22 pages, 952 KiB  
Article
Machine Learning Model Discriminate Ischemic Heart Disease Using Breathome Analysis
by Basheer Abdullah Marzoog, Peter Chomakhidze, Daria Gognieva, Nina Vladimirovna Gagarina, Artemiy Silantyev, Alexander Suvorov, Ekaterina Fominykha, Malika Mustafina, Ershova Natalya, Aida Gadzhiakhmedova and Philipp Kopylov
Biomedicines 2024, 12(12), 2814; https://doi.org/10.3390/biomedicines12122814 - 11 Dec 2024
Viewed by 705
Abstract
Background: Ischemic heart disease (IHD) impacts the quality of life and is the most frequently reported cause of morbidity and mortality globally. Aims: To assess the changes in the exhaled volatile organic compounds (VOCs) in patients with vs. without ischemic heart disease (IHD) [...] Read more.
Background: Ischemic heart disease (IHD) impacts the quality of life and is the most frequently reported cause of morbidity and mortality globally. Aims: To assess the changes in the exhaled volatile organic compounds (VOCs) in patients with vs. without ischemic heart disease (IHD) confirmed by stress computed tomography myocardial perfusion (CTP) imaging. Objectives: IHD early diagnosis and management remain underestimated due to the poor diagnostic and therapeutic strategies including the primary prevention methods. Materials and Methods: A single center observational study included 80 participants. The participants were aged ≥ 40 years and given an informed written consent to participate in the study and publish any associated figures. Both groups, G1 (n = 31) with and G2 (n = 49) without post stress-induced myocardial perfusion defect, passed cardiologist consultation, anthropometric measurements, blood pressure and pulse rate measurements, echocardiography, real time breathing at rest into PTR-TOF-MS-1000, cardio-ankle vascular index, bicycle ergometry, and immediately after performing bicycle ergometry repeating the breathing analysis into the PTR-TOF-MS-1000, and after three minutes from the end of the second breath, repeat the breath into the PTR-TOF-MS-1000, then performing CTP. LASSO regression with nested cross-validation was used to find the association between the exhaled VOCs and existence of myocardial perfusion defect. Statistical processing performed with R programming language v4.2 and Python v.3.10 [^R], STATISTICA program v.12, and IBM SPSS v.28. Results: The VOCs specificity 77.6% [95% confidence interval (CI); 0.666; 0.889], sensitivity 83.9% [95% CI; 0.692; 0.964], and diagnostic accuracy; area under the curve (AUC) 83.8% [95% CI; 0.73655857; 0.91493173]. Whereas the AUC of the bicycle ergometry 50.7% [95% CI; 0.388; 0.625], specificity 53.1% [95% CI; 0.392; 0.673], and sensitivity 48.4% [95% CI; 0.306; 0.657]. Conclusions: The VOCs analysis appear to discriminate individuals with vs. without IHD using machine learning models. Other: The exhaled breath analysis reflects the myocardiocytes metabolomic signature and related intercellular homeostasis changes and regulation perturbances. Exhaled breath analysis poses a promise result to improve the diagnostic accuracy of the physical stress tests using machine learning models. Full article
(This article belongs to the Section Molecular and Translational Medicine)
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15 pages, 6575 KiB  
Article
Tunable Characteristics of Optical Frequency Combs from InGaAs/GaAs Two-Section Mode-Locked Lasers
by Dengqun Weng, Yanbo Liang, Zhongliang Qiao, Xiang Li, Jia Xu Brian Sia, Zaijin Li, Lin Li, Hao Chen, Zhibin Zhao, Yi Qu, Guojun Liu, Chongyang Liu and Hong Wang
Sensors 2024, 24(24), 7905; https://doi.org/10.3390/s24247905 - 11 Dec 2024
Viewed by 514
Abstract
We observed tunable characteristics of optical frequency combs (OFCs) generated from InGaAs/GaAs double quantum wells (DQWs) asymmetric waveguide two-section mode-locked lasers (TS-MLLs). This involves an asymmetric waveguide mode-locked semiconductor laser (AWML-SL) operating at a center wavelength of net modal gain of approximately 1.06 [...] Read more.
We observed tunable characteristics of optical frequency combs (OFCs) generated from InGaAs/GaAs double quantum wells (DQWs) asymmetric waveguide two-section mode-locked lasers (TS-MLLs). This involves an asymmetric waveguide mode-locked semiconductor laser (AWML-SL) operating at a center wavelength of net modal gain of approximately 1.06 µm, which indicates a stable pulse shape, with the power-current(P-I) characteristic curve revealing a small difference between forward and reverse drive currents in the gain region. Under different operating conditions, the laser exhibits the characteristics of OFCs. And the pulse interval in the timing and the peak interval in the frequency domain show a periodic alternating change trend with the increase in the gain current. This tunable characteristic is reported for the first time. The study demonstrates the feasibility of generating tunable optical combs using a monolithic integrated two-section mode-locked semiconductor laser (MI-TS-MLL). This has important reference value for the application of OFCs generated from MI-TS-MLLs or integrated optical chips. Full article
(This article belongs to the Section Optical Sensors)
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10 pages, 733 KiB  
Article
Validity of Pleth Variability Index to Predict Fluid Responsiveness in Patients Undergoing Cervical Spine Surgery in the Modified Prone Position
by Won Uk Koh, Dong-Ho Lee, Young-Jin Ro and Hee-Sun Park
Medicina 2024, 60(12), 2018; https://doi.org/10.3390/medicina60122018 - 7 Dec 2024
Viewed by 620
Abstract
Background and Objective: The modified prone position, which is an alteration of the standard prone position, reduces cardiac preload. Dynamic variables including stroke volume variation (SVV), pulse pressure variation (PPV), and pleth variability index (PVI) are reliable predictors for fluid responsiveness during [...] Read more.
Background and Objective: The modified prone position, which is an alteration of the standard prone position, reduces cardiac preload. Dynamic variables including stroke volume variation (SVV), pulse pressure variation (PPV), and pleth variability index (PVI) are reliable predictors for fluid responsiveness during surgery. To the best of our knowledge, no studies assessing dynamic variables for fluid responsiveness have been conducted in the modified prone position. This study aimed to evaluate the ability of PVI to predict fluid responsiveness in the modified prone position during cervical spine surgery. Materials and Methods: PVI, SVV, and PPV were recorded at the following times: before and after a 4 mL/kg crystalloid load in the supine position (T1, T2); after placement in the modified prone position (T3); and before and after a 4 mL/kg crystalloid administration in the modified prone position (T4, T5). Fluid responsiveness was defined as stroke volume (SV) ≥ 15%, assessed by the FloTrac/Vigileo™ (Edwards Lifesciences Corp, Irvine, CA, USA). Receiver operating characteristic (ROC) curves were analyzed to identify changes in each dynamic variable that could predict fluid responsiveness in the modified prone position. Results: Data from a total of 43 subjects were analyzed. In the supine position, 21 subjects were responders. After subjects were placed in the modified prone position, SV significantly decreased, while PVI, SVV, and PPV significantly increased (p < 0.001 for all). In the modified prone position, 13 subjects were responders, and the areas under the ROC curves for ΔPVI, ΔSVV, and ΔPPV after fluid loading were 0.524 (95% confidence interval [CI] 0.329–0.730, p = 0.476), 0.749 (95% CI 0.566–0.931, p = 0.004), and 0.790 (95% CI 0.641–0.938, p < 0.001), respectively. Conclusions: Crystalloid pre-loading could not mitigate the decrease in SV caused by the modified prone position. Changes in PVI were less reliable in predicting fluid responsiveness in the modified prone position. Full article
(This article belongs to the Section Intensive Care/ Anesthesiology)
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10 pages, 1187 KiB  
Article
L-Arginine Supplementation Did Not Impact the Rapid Recovery of Cardiovascular and Autonomic Function Following Exercise in Physically Active Healthy Males: A Triple-Blind Randomised Placebo-Controlled Crossover Trial
by Andrey Alves Porto, Luana Almeida Gonzaga, Felipe Ribeiro, Camila Marcondes de Oliveira, Luiz Carlos Marques Vanderlei and Vitor Engrácia Valenti
Nutrients 2024, 16(23), 4067; https://doi.org/10.3390/nu16234067 - 27 Nov 2024
Viewed by 781
Abstract
Background and Aims: Post-exercise recovery strategies include massage, low-intensity active exercise, thermal contrast, hydration, and nutritional and herbal approaches. These strategies aim to accelerate recovery, enhance performance, and optimise the physical training process. L-arginine (L-ARG) is the physiological precursor of nitric oxide (NO), [...] Read more.
Background and Aims: Post-exercise recovery strategies include massage, low-intensity active exercise, thermal contrast, hydration, and nutritional and herbal approaches. These strategies aim to accelerate recovery, enhance performance, and optimise the physical training process. L-arginine (L-ARG) is the physiological precursor of nitric oxide (NO), a crucial mediator of vasodilation and the inhibition of platelet aggregation. A previous study reported that L-ARG supplementation could significantly reduce the systolic blood pressure (SBP) and diastolic blood pressure (DBP). This study aimed to investigate the effects of L-ARG on autonomic and cardiovascular recovery immediately following submaximal exercise. Methods and Results: Thirty-two healthy individuals were subjected to two experimental protocols. The first protocol included 60 min of rest, a treadmill warm-up, and load increments until reaching 80% of their maximum HR. Before this protocol, the subjects consumed 3 g of starch (placebo protocol). The second protocol was identical, but the subjects consumed 3 g of L-ARG. Heart rate recovery (HRR), heart rate variability (HRV), and blood pressure (BP) responses were assessed. No significant differences in HRR were found (p = 0.944) regarding the root mean square of successive differences in the RR interval (RMSSD30) of HRV (p = 0.562) or in the BP responses (mean arterial pressure (MAP), p = 0.687; pulse pressure (PP), p = 0.929) between the protocols. Conclusions: L-ARG supplementation did not significantly alter immediate post-exercise autonomic recovery in healthy males. Full article
(This article belongs to the Section Nutrition and Public Health)
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18 pages, 6503 KiB  
Article
High-Performance Memristive Synapse Based on Space-Charge-Limited Conduction in LiNbO3
by Youngmin Lee and Sejoon Lee
Nanomaterials 2024, 14(23), 1884; https://doi.org/10.3390/nano14231884 - 23 Nov 2024
Viewed by 751
Abstract
Advancing neuromorphic computing technology requires the development of versatile synaptic devices. In this study, we fabricated a high-performance Al/LiNbO3/Pt memristive synapse and emulated various synaptic functions using its primary key operating mechanism, known as oxygen vacancy-mediated valence charge migration (VO [...] Read more.
Advancing neuromorphic computing technology requires the development of versatile synaptic devices. In this study, we fabricated a high-performance Al/LiNbO3/Pt memristive synapse and emulated various synaptic functions using its primary key operating mechanism, known as oxygen vacancy-mediated valence charge migration (VO-VCM). The voltage-controlled VO-VCM induced space-charge-limited conduction and self-rectifying asymmetric hysteresis behaviors. Moreover, the device exhibited voltage pulse-tunable multi-state memory characteristics because the degree of VO-VCM was dependent on the applied pulse parameters (e.g., polarity, amplitude, width, and interval). As a result, synaptic functions such as short-term memory, dynamic range-tunable long-term memory, and spike time-dependent synaptic plasticity were successfully demonstrated by modulating those pulse parameters. Additionally, simulation studies on hand-written image pattern recognition confirmed that the present device performed with high accuracy, reaching up to 95.2%. The findings suggest that the VO-VCM-based Al/LiNbO3/Pt memristive synapse holds significant promise as a brain-inspired neuromorphic device. Full article
(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)
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12 pages, 4725 KiB  
Article
LOTUS Software to Process Wearable EmbracePlus Data
by Jack S. Fogarty
Sensors 2024, 24(23), 7462; https://doi.org/10.3390/s24237462 - 22 Nov 2024
Viewed by 609
Abstract
The Empatica EmbracePlus is a recent innovation in medical-grade wristband wearable sensors that enable unobtrusive continuous measurement of pulse rate, electrodermal activity, skin temperature, and various accelerometry-based actigraphy measures using a minimalistic smartwatch design. The advantage of this lightweight wearable is the potential [...] Read more.
The Empatica EmbracePlus is a recent innovation in medical-grade wristband wearable sensors that enable unobtrusive continuous measurement of pulse rate, electrodermal activity, skin temperature, and various accelerometry-based actigraphy measures using a minimalistic smartwatch design. The advantage of this lightweight wearable is the potential for holistic longitudinal recording and monitoring of physiological processes that index a suite of autonomic functions, as well as to provide ecologically valid insights into human behaviour, health, physical activity, and psychophysiological processes. Given the longitudinal nature of wearable recordings, EmbracePlus data collection is managed by storing raw timeseries in short ‘chunks’ in avro file format organised by universal standard time. This is memory-efficient but requires programming expertise to compile the raw data into continuous file formats that can be processed using standard techniques. Currently, there are no accessible tools available to compile and analyse raw EmbracePlus data over user-defined time periods. To address that, we introduce the LOTUS toolkit, an open-source graphical user interface that allows users to reconstitute and process EmbracePlus datasets over select time intervals. LOTUS is available on GitHub, and currently allows users to compile raw EmbracePlus data into unified timeseries stored in more familiar Excel or Matlab file formats to facilitate signal processing and analysis. Future work will expand the toolkit to process Empatica E4 and other wearable signal data, while also integrating more sophisticated functions for feature extraction and analysis. Full article
(This article belongs to the Special Issue Wearable Sensors for Behavioral and Physiological Monitoring)
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21 pages, 14998 KiB  
Article
Anti-Maneuvering Repeater Jamming Using Up- and Down-Chirp Modulation in Spaceborne Synthetic Aperture Radar
by Yu Sha, Xiaoxiao Feng, Tingcun Wei, Jiang Du and Weidong Yu
Remote Sens. 2024, 16(22), 4260; https://doi.org/10.3390/rs16224260 - 15 Nov 2024
Viewed by 723
Abstract
With the continuous development of synthetic aperture radar (SAR) jamming technology, low-power maneuvering repeater jammers are now flexible and can be located on multiple unmanned aerial vehicles (UAVs) and unmanned vehicles (UVs) at the same time, which greatly increases the difficulty of the [...] Read more.
With the continuous development of synthetic aperture radar (SAR) jamming technology, low-power maneuvering repeater jammers are now flexible and can be located on multiple unmanned aerial vehicles (UAVs) and unmanned vehicles (UVs) at the same time, which greatly increases the difficulty of the anti-maneuvering repeater jamming method for spaceborne SAR. Due to the low-power transmission, the locations of the low-power repeater jammers and the protected areas in the imaged swath are relatively close in distance, while the transmission delay of the jamming is approximately equal to the pulse repetition interval (PRI). According to this phenomenon, an anti-maneuvering repeater jamming method using up- and down-chirp modulation is proposed in this paper. After alternately transmitting up- and down-chirp modulation signals, echoes of the jamming and the protected area are recorded in the same location within the echo-receiving window and are related to different chirp modulations. To remove the jamming echoes, de-chirping and frequency filtering are adopted after echo data segmentation. With jamming interference removal using frequency notch filtering, parts of the spectra corresponding to the desired echoes of the imaged swath are simultaneously removed. To recover the unwanted removed range spectra, linear prediction is introduced to improve the focusing quality. Finally, simulation results on both point and distributed targets validate the proposed anti-maneuvering repeater jamming method by using up- and down-chirp modulation. Full article
(This article belongs to the Section Satellite Missions for Earth and Planetary Exploration)
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14 pages, 3429 KiB  
Article
Heat Capacities of α-, β-, and γ- Polymorphs of Glycine
by Václav Pokorný, Vojtěch Štejfa, Jakub Havlín, Michal Fulem and Květoslav Růžička
Molecules 2024, 29(22), 5366; https://doi.org/10.3390/molecules29225366 - 14 Nov 2024
Viewed by 565
Abstract
As a part of our effort to establish reliable thermodynamic data for amino acids, the heat capacity and phase behavior are reported for two stable polymorphs (α and γ) of glycine (aminoacetic acid, CAS RN: 56-40-6). Prior to heat capacity measurement, thermogravimetric analysis [...] Read more.
As a part of our effort to establish reliable thermodynamic data for amino acids, the heat capacity and phase behavior are reported for two stable polymorphs (α and γ) of glycine (aminoacetic acid, CAS RN: 56-40-6). Prior to heat capacity measurement, thermogravimetric analysis and X-ray powder diffraction were performed to determine decomposition temperatures and initial crystal structures, respectively. The literature heat capacities obtained by adiabatic calorimetry are available in the temperature interval (7–304). The literature data were used for validating performance of our relaxation (heat-pulse) calorimeter, which was used for measurement of the heat capacity of α-glycine in the temperature interval (2–267) K. The crystal heat capacities of the α- and γ-glycine were extended towards higher temperatures using Tian–Calvet calorimetry in the temperature interval (262–358) and power compensation DSC in the temperature interval (310–449) K. As a result, reference heat capacities and thermodynamic functions for the crystalline phase from 0 K up to 450/435 K for α/γ-glycine were developed. The literature heat capacities for β-glycine over the range 0 K to 295 K were treated in the same manner in order to provide thermodynamic data for all three polymorphs existing at the atmospheric pressure. Full article
(This article belongs to the Special Issue Exclusive Feature Papers in Physical Chemistry, 2nd Edition)
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11 pages, 876 KiB  
Article
Retinal Microvascular Changes in Association with Endothelial Glycocalyx Damage and Arterial Stiffness in Patients with Retinal Vein Occlusion: A Cross-Sectional Study
by Konstantinos Pappelis, Alexia Risi-Koziona, Chrysa Agapitou, Emmanouil Korakas, John Thymis, George Pavlidis, Stamatios Lampsas, Aikaterini Kountouri, Loukia Pliouta, Ilias Georgalas, Panagiotis Theodossiadis, Vaia Lambadiari, Ignatios Ikonomidis and Irini Chatziralli
Biomedicines 2024, 12(11), 2564; https://doi.org/10.3390/biomedicines12112564 - 9 Nov 2024
Viewed by 663
Abstract
Background/Objectives: To investigate the potential association between the endothelial dysfunction and arterial stiffness with retinal changes observed through optical coherence tomography (OCT) and OCT-angiography (OCT-A) in patients with retinal vein occlusion (RVO). Methods: Participants in this cross-sectional study were 28 patients with RVO. [...] Read more.
Background/Objectives: To investigate the potential association between the endothelial dysfunction and arterial stiffness with retinal changes observed through optical coherence tomography (OCT) and OCT-angiography (OCT-A) in patients with retinal vein occlusion (RVO). Methods: Participants in this cross-sectional study were 28 patients with RVO. The demographic and clinical characteristics of all participants were recorded. Comprehensive ophthalmologic examinations were performed, including fundus photography, OCT and OCT-A. Endothelial dysfunction was assessed by measuring the endothelial glycocalyx thickness via the perfused boundary region (PBR5-25). Arterial stiffness was evaluated by measuring the carotid-femoral pulse wave velocity (PWV), the central systolic and diastolic blood pressures (cSBP and cDBP) and the augmentation index (Aix). For each ophthalmological outcome, we generated a saturated linear regression model with demographic and systemic vascular parameters serving as independent variables. Regression coefficients with the corresponding 95% confidence intervals (CIs) were reported. A p value < 0.05 was considered as statistically significant. Results: A 1 m/s increase in PWV was associated with a 0.6% reduction in inferior macular vessel density (VD) (p = 0.050). A 10 mmHg increase in cSBP was associated with a 0.03 mm2 increase in foveal avascular zone (FAZ) area (p = 0.033). A 1% increase in Aix was associated with a 0.005 mm2 increase in FAZ area (p = 0.008). A 1 μm increase in PBR5-25 was associated, on average, with a 4.4% decrease in superior peripapillary VD (p = 0.027). Conclusions: In patients with RVO, structural and microvascular retinal parameters were significantly associated with markers of endothelial dysfunction and arterial stiffness. Full article
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21 pages, 1515 KiB  
Review
Effects of Extracted Pulse Proteins on Lipid Targets for Cardiovascular Risk Reduction: Systematic Review and Meta-Analysis of Randomized Controlled Trials
by Shuting Yang, Songhee Back, Shannan M. Grant, Sabrina Ayoub-Charette, Victoria Chen, Erika J. Lin, Lukas Haintz, Yue-Tong Chen, Elmirah Ahmad, Jacqueline Gahagan, Christopher P. F. Marinangeli, Vanessa Ha, Tauseef Ahmad Khan, Sonia Blanco Mejia, Andreea Zurbau, Russell J. de Souza, Joseph Beyene, Marcia M. English, Vladimir Vuksan, Robert G. Josse, Lawrence A. Leiter, Cyril W. C. Kendall, David J. A. Jenkins, John L. Sievenpiper and Laura Chiavaroliadd Show full author list remove Hide full author list
Nutrients 2024, 16(21), 3765; https://doi.org/10.3390/nu16213765 - 1 Nov 2024
Viewed by 2006
Abstract
Background: Many clinical practice guidelines recommend dietary pulses for the prevention and management of cardiovascular disease and diabetes. The impact of extracted pulse proteins remains unclear. We therefore conducted a systematic review and meta-analysis of randomized controlled trials of the effect of extracted [...] Read more.
Background: Many clinical practice guidelines recommend dietary pulses for the prevention and management of cardiovascular disease and diabetes. The impact of extracted pulse proteins remains unclear. We therefore conducted a systematic review and meta-analysis of randomized controlled trials of the effect of extracted pulse proteins on therapeutic lipid targets. Methods and Findings: MEDLINE, Embase, and the Cochrane Library were searched through April 2024 for trials of ≥3-weeks. The primary outcome was low-density lipoprotein-cholesterol (LDL-C). The secondary outcomes were other lipid targets. Independent reviewers extracted data and assessed the risk of bias. Subgroup analyses included by pulse type and the certainty of evidence was assessed using GRADE. Results: Seven included trials (14 trial comparisons, n = 453) with a median of 4-weeks duration and dose of 35 g/day showed that extracted pulse proteins decreased LDL-C by −0.23 mmol/L (95% confidence interval: −0.36 to −0.10 mmol/L, p < 0.001). Similar effects were observed for non-high-density lipoprotein-cholesterol and apolipoprotein B. No interactions were found by pulse type. Subgroup analyses revealed effect modification by sex, with greater proportions of females seeing greater reductions. GRADE was generally moderate. Conclusions: Extracted pulse proteins likely result in moderate reductions in LDL-C and other lipid targets. Future studies on various types of extracted pulse proteins including assessments by sex are warranted. Full article
(This article belongs to the Special Issue Consumption of Bean and Human Health)
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Article
Influence of Opening Time Interval of Gate Signals on Suppression of Horizontally Polarized Signal of Infrared Pulsed Laser
by Xinyang Wu, Dongdong Wang, Di Song, Jiaqi Wang, Jiawei Guo, Peng Ren, He Cai, Yaqing Jin, Yonghong Yu, You Wang and Jing Liu
Materials 2024, 17(21), 5276; https://doi.org/10.3390/ma17215276 - 30 Oct 2024
Viewed by 471
Abstract
Since the beginning of the 21st century, infrared Nd:YVO4 pulsed lasers have been widely applied, especially in some actual industrial processes. In the working process of a laser-aided etching device, the “match-head” effect must be effectively controlled by suppressing the first giant [...] Read more.
Since the beginning of the 21st century, infrared Nd:YVO4 pulsed lasers have been widely applied, especially in some actual industrial processes. In the working process of a laser-aided etching device, the “match-head” effect must be effectively controlled by suppressing the first giant pulse for a solid-state Q-switched laser. In the process of optimizing the infrared Nd:YVO4 pulsed laser by adjusting the slope parameters of the radio frequency (RF) modulation to suppress the first giant pulse, it has been found that an abnormal horizontally polarized emission with a very short time appears before the formal vertically polarized emission when the gate signal is artificially started. Actually, abnormal horizontally polarized emissions will bring some unexpected machining traces during the production process and even greater dangers. The experimental results show that with the increase in the slope duration of an RF signal, the existence time of abnormal output horizontally polarized light will be shortened, and the horizontal giant pulse and vertical giant pulse are well suppressed. When the slope duration is greater than 0.18 ms, both horizontal and vertical giant pulses will disappear. The horizontally polarized light can be thoroughly suppressed when the slope duration is greater than 13.7 ms. Compared with the method of adding a polarizer to eliminate abnormal output horizontally polarized light, this method does not add elements in the laser, ensuring that the laser volume is relatively small, and does not affect the quality of the normal output laser. The research conclusion is thought to be of great practical significance, especially for processing transparent materials. Full article
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