Small Volume Research Articles

Multi-objective optimization research of open and closed air brayton cycle

Air Brayton cycle obtains the significant advantages of high efficiency, compact structure, easy medium requirement and so on, which is one of the most suitable choices for the mobile nuclear power conversion system. In this paper, system-component combined design method is used to establish the open and closed air Brayton cycle of diverse configurations. Based on performance and compactness targets, the multi-objective optimization is carried out to find the optimal design by nondominated sorting genetic algorithm II and entropy weight method. According to the analysis, the closed intercooling reheating recuperating cycle is the configuration with the best comprehensive performance, with cycle efficiency of 33.58 %, power density of 175.39 kW m−3 and power mass ratio of 68.60 kW t−1. The open simple recuperating cycle is the configuration with the smallest volume and mass, with cycle efficiency of 20.01 %, system volume of 6.56 m3 and system mass of 19.98 t. The closed intercooling recuperating cycle is the most balanced configuration, with cycle efficiency of 31.33 %, volume of 9.06 m3 and system mass of 24.97 t. Based on the optimal results, off-design performance analysis of different environmental conditions is also carried out for the configurations above.

Socioemotional Dysfunction From Temporal Lobe Involvement in Frontotemporal Dementia: A Preliminary Report.

Socioemotional changes, rather than cognitive impairments, are the feature that defines behavioral variant frontotemporal dementia (bvFTD). Investigators have attributed the socioemotional changes in bvFTD and other dementias to frontal lobe dysfunction; however, recent work implies a further contribution from right anterior temporal disease. The authors evaluated relationships between regional brain atrophy and socioemotional changes in both bvFTD and early-onset Alzheimer's disease (EOAD). This study explored the neuroanatomical correlations of performance on the Socioemotional Dysfunction Scale (SDS), an instrument previously shown to document socioemotional changes in bvFTD, among 13 patients with bvFTD not preselected for anterior temporal involvement and 16 age-matched patients with early-onset Alzheimer's disease (EOAD). SDS scores were correlated with volumes of regions of interest assessed with tensor-based morphometric analysis of MRI images. As expected, the bvFTD group had significantly higher SDS scores overall and smaller frontal regions compared with the EOAD group, which in turn had smaller volumes in temporoparietal regions. SDS scores significantly correlated with lateral anterior temporal lobe (ATL) atrophy, and a regression analysis that controlled for diagnosis indicated that SDS scores predicted lateral ATL volume. Within the bvFTD group, higher SDS scores were associated with smaller lateral and right ATL regions, as well as a smaller orbitofrontal cortex. Within the EOAD group, higher SDS scores were associated with a smaller right parietal cortex. This study confirms that, in addition to orbitofrontal disease, there is a prominent right and lateral ATL origin of socioemotional changes in bvFTD and further suggests that right parietal involvement contributes to socioemotional changes in EOAD.

Amygdala Volume and Depression Symptoms in Young Adolescents Who Use Cannabis

IntroductionBoth cannabis use and depressive symptomology increase in prevalence throughout adolescence. Concurrently, the brain is undergoing neurodevelopment in important limbic regions, such as the amygdala. Prior research indicates the amygdala may also be related to cannabis use and depressive symptoms. We aimed to investigate the effects of adolescent cannabis use on amygdala volumes as well as the interaction of cannabis use and amygdala morphometry on depressive symptoms in youth. MethodTwo-hundred-twenty-four participants (ages 12-15), balanced by sex assigned at birth, were selected from a sub-sample of the Adolescent Brain Cognitive Development (ABCD) Study based on hair toxicology and self-report measures of cannabis use. Participants positive for cannabinoids in hair and/or self-reported cannabis use were demographically matched to youth with no self-reported or confirmed cannabis use. The guardians of these youth reported depression symptoms on the Child Behavioral Checklist. Linear mixed effect models were run investigating cannabis use group on amygdala volumes bilaterally, controlling for whole brain volume and random effects of scanner type. Additional analyses examined cannabis group status and bilateral amygdala volume on depression symptoms. ResultsCannabis use was not significantly associated with amygdala volume but was associated with increased depressive symptoms (p<0.01). Cannabis group interacted with amygdala volume, such that individuals with smaller volumes had increased depressive symptoms within the cannabis group (p’s<0.01-0.02). ConclusionAberrations in amygdala volume based on cannabis use were not found in early adolescence; however, more depressive symptoms were related to cannabis group. Youth who use cannabis and have smaller amygdala volumes were at increased risk for depressive symptomology, suggesting potential neurovulnerabilities to cannabis use.

Сравнительная оценка качества жизни детей с бронхиальной астмой в разных возрастных группах.

The purpose of the study: assessment of quality of life indicators and their impact on life parameters in children aged 6–17 years with bronchial asthma. Materials and methods. The study was performed using the Russian version of the SF‑36 questionnaire, which was filled out by children with bronchial asthma of younger age (6–14 years old) with their parents, older age (15–17 years old), independently. The survey was conducted among 408 children (6–17 years old) on the basis of the pulmonology department of the Republican Children’s Clinical Hospital and children’s polyclinics of the Republic of North Ossetia-Alania. The average age in the sample is 13.0 years, of which 76.2% are boys, 23.8% are girls. A comparative analysis of quality of life indicators was carried out in four age groups: 6–8 years (12.3%), 9–11 years (16.7%), 12–14 years (28.2%), 15–17 years (42.8%). The average values and the standard deviation (M±SD) were determined. The processing of the obtained data was carried out using the SPSS application software package (vers. 21). Results. According to the design of the study, the assessment of the health status of children was carried out in different age groups from 6 to 17 years old. The most unsatisfactory assessments of their health were revealed in three older age groups, especially pronounced at the age of 12–14 years. At the same time, half of the surveyed children (50.2%) did not improve their health during the year and more than 8% of them began to feel worse. It was revealed that bronchial asthma affects the parameters of quality of life: the physical and psychological condition of children suffers, their social adaptation is disrupted. With equal indicators of these components in girls, boys have a slightly higher physical component than the mental one. When comparing the age groups, a more significant violation of the mental component of the quality of life with the age of children was revealed. The largest number of children with bronchial asthma (31.1%) experience significant limitations during heavy physical exertion. A direct correlation has been revealed between the increase in difficulty with physical exertion and their performance in a smaller volume with age. According to the evaluation scales, the total indicators of the quality of life of children with bronchial asthma are interpreted unambiguously, low, and amount to slightly more than 47 points. Older children who have pronounced negative symptoms and need correction of therapeutic and preventive measures require special attention. At the same time, the existing complex problems in the organization of effective dispensary monitoring of children with bronchial asthma are being updated. Conclusion. The obtained quantitative measures of the health of children suffering from bronchial asthma indicate a low level of quality of life for patients in all age groups. For the identified risk groups, a full-fledged individual monitoring of the condition of patients should be organized in the polyclinic link of children’s healthcare in the region with the development of targeted rehabilitation programs to improve and preserve the health of children with bronchial asthma. This approach will provide additional information about the child’s condition and will help improve treatment outcomes. Taking into account the results obtained, it is necessary to continue further studies of the quality of life in children suffering from bronchial asthma.

Wafer-Scale Fabrication of Single-Crystalline Calcium Fluoride Thin-Film on Insulator by Ion-Cutting

Developing bulk materials into thin-films not only enables multiple physical fields to interact strongly within a smaller volume but also enhances the stability, scalability, and integrability of the system. This transformation has been witnessed to lead to significant improvements in the performance of devices utilizing diverse materials across various fields. Calcium Fluoride (CaF2), with remarkable optical properties such as ultralow optical loss and strong nonlinear features, is a preferable material for building ultra-high-Q resonators and stimulating light-matter interaction with low threshold. However, the integration of CaF2 material has remained elusive due to its low hardness and high thermal expansion, which plagues the large-scale fabrication of CaF2 thin film. Here, an optimized ion-cutting technique is proposed for engineering CaF2 thin films theoretically and experimentally. Taking the thermal expansion into consideration, we employ the Lithium niobate (LN) as substrate, and utilize accessible ion implantation, wafer bonding and precisely designed annealing process to attain the CaF2-LN and the CaF2-on-insulator (CaFOI) with high film thickness uniformity and maintained crystalline quality. The perspectives of our work are also illustrated by numerical simulation for further verifying the potential of integrated photonic applications, which could be extended to monolithic optical network by means of large-scale manufacturing method.

Towards Efficient Neural Decoder for Dexterous Finger Force Predictions.

Dexterous control of robot hands requires a robust neural-machine interface capable of accurately decoding multiple finger movements. Existing studies primarily focus on single-finger movement or rely heavily on multi-finger data for decoder training, which requires large datasets and high computation demand. In this study, we investigated the feasibility of using limited single-finger surface electromyogram (sEMG) data to train a neural decoder capable of predicting the forces of unseen multi-finger combinations. We developed a deep forest-based neural decoder to concurrently predict the extension and flexion forces of three fingers (index, middle, and ring-pinky). We trained the model using varying amounts of high-density EMG data in a limited condition (i.e., single-finger data). We showed that the deep forest decoder could achieve consistently commendable performance with 7.0% of force prediction errors and R2 value of 0.874, significantly surpassing the conventional EMG amplitude method and convolutional neural network approach. However, the deep forest decoder accuracy degraded when a smaller amount of data was used for training and when the testing data became noisy. The deep forest decoder shows accurate performance in multi-finger force prediction tasks. The efficiency aspect of the deep forest lies in the short training time and small volume of training data, which are two critical factors in current neural decoding applications. This study offers insights into efficient and accurate neural decoder training for advanced robotic hand control, which has the potential for real-life applications during human-machine interactions.

A Single-Clamp Inchworm Actuator with Two Piezoelectric Stacks.

Inchworm piezoelectric actuators have attracted much attention in the field of precision positioning due to the advantages of a large stroke, high output force, and high resolution. However, traditional inchworm piezoelectric actuators use two sets of clamps and a set of drive structures to achieve stepping motion, which generally requires at least three piezoelectric stacks, resulting in a complex structure and the control system. Several methodologies have been advanced to minimize the utilization of piezoelectric stacks. However, there still exists the issue of excessive volume. Therefore, an inchworm piezoelectric actuator with a single-clamp and single drive structure is proposed in the study, which provides a compact size and smaller volume. The clamping mechanism comprises two sets of clamping feet with opposite displacement, which alternate contact with the guide frame and adjustable plate to ensure that the clamping mechanism always has frictional force and accomplishes the stepping motion. The testing of the actuator's step distance, output force, and other parameters was conducted utilizing a displacement sensor. Experimental results indicate that the actuator achieved a maximum speed of 174.3 μm/s and an output force of 8.6 N when the frequency and voltage were 19 Hz and 150 V.

Larger putamen in individuals at risk and with manifest bipolar disorder.

Individuals at risk for bipolar disorder (BD) have a wide range of genetic and non-genetic risk factors, like a positive family history of BD or (sub)threshold affective symptoms. Yet, it is unclear whether these individuals at risk and those diagnosed with BD share similar gray matter brain alterations. In 410 male and female participants aged 17-35 years, we compared gray matter volume (3T MRI) between individuals at risk for BD (as assessed using the EPIbipolar scale; n = 208), patients with a DSM-IV-TR diagnosis of BD (n = 87), and healthy controls (n = 115) using voxel-based morphometry in SPM12/CAT12. We applied conjunction analyses to identify similarities in gray matter volume alterations in individuals at risk and BD patients, relative to healthy controls. We also performed exploratory whole-brain analyses to identify differences in gray matter volume among groups. ComBat was used to harmonize imaging data from seven sites. Both individuals at risk and BD patients showed larger volumes in the right putamen than healthy controls. Furthermore, individuals at risk had smaller volumes in the right inferior occipital gyrus, and BD patients had larger volumes in the left precuneus, compared to healthy controls. These findings were independent of course of illness (number of lifetime manic and depressive episodes, number of hospitalizations), comorbid diagnoses (major depressive disorder, attention-deficit hyperactivity disorder, anxiety disorder, eating disorder), familial risk, current disease severity (global functioning, remission status), and current medication intake. Our findings indicate that alterations in the right putamen might constitute a vulnerability marker for BD.

Smaller subcortical volume relates to greater weight gain in girls with initially healthy weight.

Among 3614 youth who were 9 to 12 years old and initially did not have overweight or obesity (12% [n = 385] developed overweight or obesity), we examined the natural progression of weight gain and brain structure development during a 2-year period with a high risk for obesity (e.g., pre- and early adolescence) to determine the following: 1) whether variation in maturational trajectories of the brain regions contributes to weight gain; and/or 2) whether weight gain contributes to altered brain development. Data were gathered from the Adolescent Brain Cognitive Development (ABCD) Study. Linear mixed-effects regression models controlled for puberty, caregiver education, handedness, and intracranial volume (random effects: magnetic resonance scanner [MRI] scanner and participant). Because pubertal development occurs earlier in girls, analyses were stratified by sex. For girls, but not boys, independent of puberty, greater increases in BMI were driven by smaller volumes over time in the bilateral accumbens, amygdala, hippocampus, and thalamus, right caudate and ventral diencephalon, and left pallidum (all p < 0.05). The results suggest a potential phenotype for identifying obesity risk because underlying differences among regions involved in food intake were related to greater weight gain in girls, but not in boys. Importantly, 2 years of weight gain may not be sufficient to alter brain development, highlighting early puberty as a critical time to prevent negative neurological outcomes.

Characterizing the voxel-based approaches in radioembolization dosimetry with reDoseMC.

Yttrium-90 ( ) represents the primary radioisotope used in radioembolization procedures, while holmium-166 ( ) is hypothesized to serve as a viable substitute for due to its comparable therapeutic potential and improved quantitative imaging. Voxel-based dosimetry for these radioisotopes relies on activity images obtained through PET or SPECT and dosimetry methods, including the voxel S-value (VSV) and the local deposition method (LDM). However, the evaluation of the accuracy of absorbed dose calculations has been limited by the use of non-ideal reference standards and investigations restricted to the liver. The objective of this study was to expand upon these dosimetry characterizations by investigating the impact of image resolutions, voxel sizes, target volumes, and tissue materials on the accuracy of and dosimetry techniques. A specialized radiopharmaceutical dosimetry software called reDoseMC was developed using the Geant4 Monte Carlo toolkit and validated by benchmarking the generated kernels with published data. The decay spectra of both and were also compared. Multiple VSV kernels were generated for the liver, lungs, soft tissue, and bone for isotropic voxel sizes of 1 mm, 2 mm, and 4 mm. Three theoretical phantom setups were created with 20 or 40mm activity and mass density inserts for the same three voxel sizes. To replicate the limited spatial resolutions present in PET and SPECT images, image resolutions were modeled using a 3D Gaussian kernel with a Full Width at Half Maximum (FWHM) ranging from 0 to 16mm and with no added noise. The VSV and LDM dosimetry methods were evaluated by characterizing their respective kernels and analyzing their absorbed dose estimates calculated on theoretical phantoms. The ground truth for these estimations was calculated usingreDoseMC. The decay spectra obtained through reDoseMC showed less than a 1% difference when compared to previously published experimental data for energies below 1.9MeV in the case of and less than 1% for energies below 1.5MeV for . Additionally, the validation kernels for VSV exhibited results similar to those found in published Monte Carlo codes, with source dose depositions having less than a 3% error margin. Resolution thresholds ( ), defined as resolutions that resulted in similar dose estimates between the LDM and VSV methods, were observed for . They were 1.5mm for bone, 2.5 mm for soft tissue and liver, and 8.5 mm for lungs. For , the accuracy of absorbed dose deposition was found to be dependent on the contributions of absorbed dose from photons. Volume errors due to variations in voxel size impacted the final dose estimates. Larger target volumes yielded more accurate mean doses than smaller volumes. For both radioisotopes, the radial dose profiles for the VSV and LDM approximated but never matched the referencestandard. reDoseMC was developed and validated for radiopharmaceutical dosimetry. The accuracy of voxel-based dosimetry was found to vary widely with changes in image resolutions, voxel sizes, chosen target volumes, and tissue material; hence, the standardization of dosimetry protocols was found to be of great importance for comparable dosimetryanalysis.

Prospective comparison of two methods for correct ureteral stent placement in pediatric laparoscopic pyeloplasty

Ureteral stent placement during laparoscopic pyeloplasty is a common procedure in pediatric patients. Although an apparently safe maneuver, ascending placement of the stent can lead to complex removal or repositioning reinterventions. In this study we compare two methods for intraoperative verification of correct positioning. Prospective observational study collecting data on laparoscopic pyeloplasties in pediatric patients in our center over three years. We carried out descriptive and univariate comparative analyses. Data were compared between ultrasound and reflux visualized by the catheter after intraoperative salineinjection into the bladder through the urethral catheter. We recorded time to catheter visualization in both ultrasonography and in reflux from the start of bladder instillation, as well as bladder volume at the time of placement verification with each method. Data were collected from 20 patients (15 male and 5 female) with a median age of 48 months. Pyeloplasty was successful in 100% of the sample (as observed by ultrasound and MAG-3), while one patient had postoperative leak requiring nephrostomy placement. Correct distal positioning of the ureteral stent could be verified by intraoperative ultrasound and reflux in all cases. Using reflux, the bladder volume needed to verify correct positioning exceeded the age-related maximum in half the cohort, while on ultrasound, the stent was visualized in the bladder without reaching the maximum bladder capacity for age in any case (p=0.02 comparing percentages). Likewise, mean time to verification was lower with ultrasound than with reflux (61.8s versus 115s), but without these differences reaching statistical significance (p=0.14). The present study is the first to compare two methods to verify the correct positioning of the ureteral stent in laparoscopic pyeloplasties in pediatric patients. Our results show that both intraoperative ultrasound and visualization of reflux are useful methods, although ultrasound requires a lower volume of saline instilled through the bladder catheter for verification. This work can be very useful for the daily clinical practice of urologists and pediatric surgeons. Both intraoperative ultrasound and visualization of reflux are useful methods to verify the correct positioning of the ureteral stent in laparoscopic pyeloplasty of pediatric patients. With ultrasound, a smaller volume is required to check for reflux. Although ultrasound is faster for verification, there are no differences in procedural times.

Sex-dependent polymorphism in urinary output is reversed upon deletion of exchange protein directly activated by cAMP (Epac)

It is well-described that there are notable sex-dependent differences in urinary production with females having a smaller volume and greater urinary concentrating ability. Apart from contribution of the androgenic inputs, the underlying signaling intermediates remain largely unexplored. We previously showed that exchange protein directly activated by cAMP (Epac) is a critical regulator of water-solute transport in the proximal tubule and collecting duct. Deletion of either Epac1 or Epac2 isoforms increases urinary output and Na+ excretion. Here, we used metabolic cage balance studies to test whether Epac signaling mediates sex-dependent differences in urinary production. We found that concomitant deletion of Epac1&amp;2 moderately increases 24h urinary volume by 38% (from 1.82+/-0.13 to 2.52+/-0.21 ml) in males, but drastically augment urinary production in females by 320% (from 1.39+/-0.10 to 4.45+/-0.37 ml). This was associated with only a mild though significant reduction in urinary osmolarity in males by 35%, whereas urine osmolarity was markedly decreased from 2511+/-5 to 977+/-60 mOsm in females. Consistently, plasma osmolarity was not different in EpacWT versus Epac1&amp;2−/− males, but became significantly more hypertonic in Epac1&amp;2−/− females. We further determine the functional consequences of impaired Epac cascade on fluid reabsorption in the proximal tubule and collecting duct in males and females. Deletion of Epac1 and Epac2 decreases NHE-3 expression in the proximal tubule in an additive manner. In addition, Na+/H+-dependent recovery after acidification was drastically reduced in freshly isolated split-opened proximal tubules from Epac1&amp;2−/− mice when compared to EpacWT. Interestingly, the reduction of NHE-3 expression was more pronounced in Epac1&amp;2−/− females (by 89%) than in males (by 59%). Immunofluorescence confocal images revealed much more diffuse intracellular distribution of AQP2 water channel in Epac1&amp;2−/− females when compared to males. Furthermore, osmotically-driven water influx was reduced in principal cells within split-opened collecting ducts of Epac1&amp;2−/− females but not males, when compared to respective EpacWT. In summary, our results reveal a substantially greater role of Epac signaling in renal water handling in females than in males. Interestingly, Epac1&amp;2 deletion leads to a reversed pattern of sexual dimorphism in urinary production with females excreting larger volumes of hypotonic urine than males. This research was supported by NIH-NIDDK DK117865, DK119170, AHA EIA35260097 (to O. Pochynyuk). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Therapeutic interventions using the peritoneal and coelomic cavity in dogs, cats, and exotic pets.

To provide a video tutorial describing intraperitoneal (IP) and intracoelomic (IC) therapeutics (IP/IC fluid therapy, euthanasia, direct peritoneal resuscitation). Dogs, cats, and exotic pets. Peritoneal and coelomic centesis allows for delivery of fluids or to perform euthanasia. The peritoneal and coelomic membranes contain a vast network of capillaries and lymphatics that allow absorption of fluids and blood products. Needles are inserted aseptically IP or IC at species-specific locations to avoid iatrogenic damage. In mammals, the needle is inserted in a periumbilical location at a 1- to 2-cm radius from the umbilicus, while the needle is inserted into the ventral inguinal fossa in chelonians and lateroventrally in lizards and snakes. Direct peritoneal resuscitation is a human technique in which a dextrose/electrolyte solution infused IP reduces ischemia-reperfusion injury, edema, and tissue necrosis to improve mortality in patients with diseases like shock and sepsis or who require acute abdominal surgery. Isotonic crystalloids are given IP/IC at 10- to 20-mL/kg doses (smaller volumes in reptiles) and blood products at standard calculated doses. Sodium pentobarbital without phenytoin (3 mL/4.5 kg) is used for IP/IC euthanasia. Being aware of multiple routes for fluid and blood product administration allows treatment in animals for which intravenous or intraosseous catheterization is undesirable or impossible. While intravenous or intraosseous routes are always preferred, especially for resuscitation, familiarity with locations for IP/IC fluid and euthanasia is useful. Techniques like direct peritoneal resuscitation are not currently used in animals but might be translated to veterinary cases in the future.

A study of polarity effect for various ionization chambers in kilovoltage x-ray beams.

Ionization chambers play an essential role in dosimetry measurements for kilovoltage (kV) x-ray beams. Despite their widespread use, there is limited data on the absolute values for the polarity correction factors across a range of commonly employed ionization chambers. This study aimed to investigate the polarity effects for five different ionization chambers in kV x-ray beams. Two plane-parallel chambers being the Advanced Markus and Roos and three cylindrical chambers; 3D PinPoint, Semiflex and Farmer chamber (PTW, Freiburg, Germany), were employed to measure the polarity correction factors. The kV x-ray beams were produced from an Xstrahl 300 unit (Xstrahl Ltd., UK). All measurements were acquired at 2cm depth in a PTW-MP1 water tank for beams between 60 kVp (HVL 1.29mm Al) and 300 kVp (HVL 3.08mm Cu), and field sizes of 2-10cm diameter for 30cm focus-source distance (FSD) and 4 × 4 cm2 - 20 × 20 cm2 for 50cm FSD. The ionization chambers were connected to a PTW-UNIDOS electrometer, and the polarity effect was determined using the AAPM TG-61 code of practice methodology. The study revealed significant polarity effects in ionization chambers, especially in those with smaller volumes. For the plane-parallel chambers, the Advanced Markus chamber exhibited a maximum polarity effect of 2.5%, whereas the Roos chamber showed 0.3% at 150 KVp with the 10cm circular diameter open-ended applicator. Among the cylindrical chambers at the same beam energy and applicator, the Pinpoint chamber exhibited a 3% polarity effect, followed by Semiflex with 1.7%, and Farmer with 0.4%. However, as the beam energy increased to 300 kVp, the polarity effect significantly increased reaching 8.5% for the Advanced Markus chamber and 13.5% for the PinPoint chamber at a 20 × 20 cm2 field size. Notably, the magnitude of the polarity effect increased with both the field size and beam energy, and was significantly influenced by the size of the chamber's sensitive volume. The findings demonstrate that ionization chambers can exhibit substantial polarity effects in kV x-ray beams, particularly for those chambers with smaller volumes. Therefore, it is important to account for polarity corrections when conducting relative dose measurements in kV x-ray beams to enhance the dosimetry accuracy and improve patient dose calculations.

ПОРІВНЯЛЬНИЙ АНАЛІЗ МЕТОДІВ МОДЕЛЮВАННЯ МЕТАЛУРГІЙНИХ ПРОЦЕСІВ

In modern conditions, modeling of technological processes is one of the most promising methods of conducting research on industrial facilities, which is characterized by a low cost compared to conducting research on real metallurgical units. Modeling, as a research method, is based on the reproduction of a real technological process in a smaller volume, in comparison with a real technological process while observing the scale of similarity. In the global practice of researching metallurgical processes, the following methods of modeling technological processes are used: mathematical modeling; low-temperature physical modeling; high-temperature physical modeling. When studying the metallurgical processes of the steelmaking direction, the most complete data is provided by high-temperature physical modeling. At the same time, it allows to study both permanent technological processes and innovative ones. As for the methods of low-temperature physical modeling, they are somewhat limited in the context of informativeness, but they differ in their low cost. Mathematical modeling is promising for modeling established technological processes and needs some clarification with practical data. An urgent task for modern metallurgical science is the development of methods for increasing the accuracy of the results of low-temperature modeling and bringing them closer to high-temperature modeling while maintaining an acceptable cost of modeling.

TCE degradation of modified graphite felt cathode in a flow-through electro-Fenton system and its H2O2 production ability in a real contaminated field

A modified graphite felt (MGF) was prepared with carbon black (CB) and polytetrafluoron (PTFE) for cathodic electrochemical H2O2 production, which was used in a flow-through cathodic electro-Fenton reactor to degrade chlorinated hydrocarbons. Cathode electrode was floating on aqueous surface and 369.1 mg/L H2O2 could be produced after 1 h 150 mA power applied without O2 aeration. The main O2 source for H2O2 production was confirmed from air with this floating position. In a 2.0 L flow-through cathodic electro-Fenton system, 95.97 % degradation efficiency for 5.0 mg/L trichloroethylene (TCE) was achieved in 90 min with 13.4 mL/min influent rate. Reducing the reactor volume to 0.14 L, 5.0 mg/L TCE could be degraded completely in 10 min with continuous 4 L influent. The mixed chlorinated hydrocarbons (TCE, cis-1,1-dichloroethylene, 1,2-dichloroethane, and dichloromethane) were also rapidly degraded in 20 min. The flow-through cathodic electro-Fenton reactor presented excellent degradation ability for chlorinated hydrocarbons with a smaller volume. In the simulated sand tank system, after continuously operated 27 days, H2O2 concentration in electrode well was still remained at 80 mg/L. In the contaminated field in Tianjin, China, H2O2 yield of MGF in groundwater could keep at about 60 mg/L after 220 min operating.

Cryogenic and ultrasonic-assisted micro-drilling of printed circuit boards using high-frequency-amplitude spindle

Printed circuit boards (PCBs) are key components in computers, 5G, 6G, and other wireless communication devices. On the other hand, the manufacture of micro-holes in PCBs faces severe challenges. Conventional micro-drilling methods often encounter challenges such as poor surface quality and limited tool life. To overcome these issues, a novel micro-drilling method called cryogenic and ultrasonic-assisted micro-drilling (CUAMD) has been developed. This study compared four drilling methods to investigate the benefits of cryogenic and ultrasonic-assisted drilling in hybrid machining processes: conventional micro-drilling (CMD), cryogenic-assisted micro-drilling (CAMD), ultrasonic-assisted micro-drilling (UAMD), and cryogenic and ultrasonic-assisted micro-drilling (CUAMD). The experimental results unequivocally indicate that the utilization of cryogenic-assisted drilling leads to a significant reduction in cutting heat during the machining process. This not only contributes to an improvement in machining accuracy but also exerts a positive influence on tool life and surface morphology. Ultrasonic-assisted drilling separates chips into smaller volumes through high-frequency-vibration, effectively reducing the cutting forces. The high frequency of 38.25 kHz and high amplitude vibration of 5.16 μm of the ultrasonic spindle induced vibrations on the drill bit. Liquid nitrogen with a pressure and temperature of 28 kPa and − 196 °C, respectively, was used in the cryogenic-assisted method. The superior machining performance of the CUAMD approach was evaluated by comparing it to various methods, including cutting forces, tool flank wear, entrance/exit hole morphology, and chip formation. The CUAMD method avoids chip entanglement, suppresses burrs, and reduces the maximum cutting force, maximum torque, and exit hole damage factor Fd by 47.7 %, 56.1 %, and 42.5 %, respectively, compared with CMD.

Improved design and performance of the global rectenna system for wireless power transmission applications around 2.45 GHz

This work proposes a new conception of the global microstrip rectenna system operating around 2.45 GHz. This improved rectenna system associates a receiving antenna with a rectifier circuit. This rectenna is printed on an FR4 substrate. The proposed antenna is a 1×4 microstrip antenna patch array with pentagonal patches using the defective ground structure method and operates with circular polarization. To show the effectiveness of this array, the results obtained by the computer simulation technology microwave studio (CST MWS) software prove that this array is good in terms of high gain, high directivity, high efficiency, wideband, small volume, and well-adaptation, and all these results are confirmed by another solver high-frequency structure simulator (HFSS). The improved rectifier is a microstrip rectifier that uses an HSMS2852 Schottky diode by using a series topology. The effectiveness of this rectifier is proved by the simulation results using advanced design system (ADS) software in terms of well-matching input impedance, high efficiency, and important output direct current (DC) voltage value. The proposed rectenna system is more efficient compared with the existing works and is very appropriate for several applications of wireless power transmission to power supply electronic instruments in various fields cleanly on our planet.

An update on the study of synovial fluid in the geriatric patient.

The characteristics of synovial fluid (SF) in geriatric patients differ from those in younger patients. In Mexico, epidemiologic data on the incidence of different rheumatic diseases in geriatric patients are scarce. To describe the physical characteristics of geriatric SF and the prevalence of crystals in knee and other joint aspirates from patients with previously diagnosed joint disease. A retrospective study was performed with a baseline of 517 SF samples between 2011 and 2023. White blood cell count was performed by Neubauer chamber and crystals were identified by polarized light microscopy. Descriptive statistical analysis was performed and prevalence was reported as a percentage. The mean age of the adults was 73.5±5.0 years, 54.4% were women and 45.6% were men. The mean SF volume was 6.3±9.5mL in older adults and 15.3±24.9mL in those younger than 65 years. The mean viscosity in older adults was 9.5±4.5mm and the mean leukocyte count was 7352±16,402leukocytes/mm3. Seventy percent of the older adults' SFs were referred to the laboratory for osteoarthritis (OA), with lower proportions for rheumatoid arthritis (RA) (14.6%) and gout (5.1%). Of the crystals observed in the geriatric population, 14.6% corresponded to monosodium urate crystals (CUM) and 18.9% to calcium pyrophosphate crystals (CPP). The characteristics of LS in older adults were smaller volume, increased viscosity, and non-inflammatory. The main diagnoses were OA, RA, and gout. The crystal content of the SF of the geriatric population corresponded mainly to CPP.

Nurses’ preferences regarding MenACWY conjugate vaccines attributes: a discrete choice experiment in Spain

ObjectivesImmunisation against preventable diseases as meningitis is crucial from a public health perspective to face challenges posed by these infections. Nurses hold a great responsibility for these programs, which highlights the importance of understanding their preferences and needs to improve the success of campaigns. This study aimed to investigate nurses' preferences regarding Meningococcus A, C, W, and Y (MenACWY) conjugate vaccines commercialised in Spain. Study designA national-level discrete choice experiment (DCE) was conducted. MethodsA literature review and a focus group informed the DCE design. Six attributes were included: pharmaceutical form, coadministration evidence, shelf-life, package contents, single-doses per package, and package volume. Conditional logit models quantified preferences and relative importance (RI). ResultsThirty experienced primary care nurses participated in this study. Evidence of coadministration with other vaccines was the most important attribute (RI = 43.78%), followed by package size (RI = 22.17%), pharmaceutical form (RI = 19.07%), and package content (RI = 11.80%). There was a preference for evidence of coadministration with routine vaccines (odds ratio [OR] = 2.579, 95% confidence interval [95%CI] = 2.210–3.002), smaller volumes (OR = 1.494, 95%CI = 1.264–1.767), liquid formulations (OR = 1.283, 95%CI = 1.108–1.486) and package contents including only vial/s (OR = 1.283, 95%CI = 1.108–1.486). No statistical evidence was found for the remaining attributes. ConclusionsEvidence of coadministration with routine vaccines, easy-to-store packages, and fully liquid formulations were drivers of nurses’ preferences regarding MenACWY conjugate vaccines. These findings provide valuable insights for decision-makers to optimize current campaigns.