Changes In Area Research Articles

Factors associated with waitlist clinical deterioration among United States lung transplant recipients under the continuous distribution system

BackgroundLung continuous distribution (CD), implemented on March 9, 2023, changed the calculation and relative importance of medical urgency and posttransplant survival in prioritizing candidates for transplant. We aimed to identify factors associated with waitlist clinical deterioration and change in expected posttransplant survival from listing to transplant in the current system. MethodsWe used Organ Procurement and Transplantation Network (OPTN) data to conduct a retrospective study of 2,395 adult, lung-only transplant recipients added to the waiting list and transplanted between March 09, 2023, and March 08, 2024. We used multivariable linear regression to identify factors associated with change in waitlist area under the curve (WLAUC) and posttransplant area under the curve (PTAUC), representing expected survival (in days) without and with transplant, respectively. ResultsIn multivariable analysis, longer waiting time (β=-1.3 per 7 days; p<0.001), male birth sex (β=-11; p=0.006), diagnosis group D (β=-27; p<0.001), and blood type O (β=-13; p<0.001) were associated with greater clinical deterioration from listing to transplant. Older (β=3.2 per 10-year increase in age; p=0.023) and taller (β=3.0 per 5 cm increase in height; p=0.003) recipients were less likely to clinically deteriorate from listing to transplant. Diagnosis group D (β=-4.7, p=0.032) and blood type O (β=-4.2, p=0.025) recipients had lower expected posttransplant survival at transplant compared to listing. ConclusionOur findings suggest the need to further investigate and address factors associated with waitlist clinical deterioration under CD. Future analysis of the effect of waitlist clinical deterioration on posttransplant outcomes under CD is needed.

Metatarsal sliding osteotomy is effective without altering plantar pressure in Morton's neuroma: Retrospective case series.

Various operative methods for the treatment of Morton's neuroma have been discussed, and osteotomy of the metatarsal bone has been reported recently. However, there has been no report of pedobarographic changes after metatarsal osteotomy. Pedobarographic changes of other metatarsal area after the surgery may cause transfer metatarsalgia, and thorough analysis of the pedobarographic data should be performed peri-operatively. The purpose of this study is to investigate the post-operative pedobarographic changes of sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma. Forty patients (45 feet) who underwent metatarsal sliding osteotomy of the 3rd metatarsal bone for treating Morton's neuroma from November 2013 to December 2021 were retrospectively reviewed. Proximal sliding osteotomy was performed at the proximal 3rd metatarsal bone through dorsal approach. Clinical outcomes were evaluated with American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal Interphalangeal Scale (AOFAS LMIS), Foot Function Index (FFI), and Visual Analogue Scale (VAS). Plain radiograph and pedobarogram were performed to evaluate the radiologic and pedobarographic outcomes. AOFAS score was improved from 52.8±9.0 (18-62) to 88.8±9.8 (78-100) and FFI was improved from 61.8±4.9 (50-70) to 32.2±5.1 (23-42) on average. The 3rd metatarsal bone was shortened by 3.1±0.8mm and dorsally shifted by 1.5±0.4mm after the surgery. Plantar intermetatarsal distances between 2nd and 3rd and 3rd and 4th metatarsal heads were significantly increased post-operatively. Average forefoot pressure and maximum pressure of the 2nd to 4th metatarsal head were not significantly changed between pre-operatively and post-operatively. Proximal metatarsal sliding osteotomy of the 3rd metatarsal bone shows a satisfactory result in both clinical and pedobarographical evaluations. It could be an effective treatment of permanent indirect decompression of Morton's neuroma with avoiding recurred neuroma, adhesion of tissue, paresthesia, and transfer metatarsalgia.

Bouncing dynamics of a droplet impacting onto a superhydrophobic surface with pillar arrays

A superhydrophobic surface (SHS) patterned with pillar arrays has been demonstrated to achieve excellent water repellency and is highly effective for self-cleaning, anti-icing/frosting, etc. However, the droplet impact dynamics and the related mechanism for contact time (tc*) reduction remain elusive, especially when different arrangements of pillar arrays are considered. This study aims to bridge this gap by exploring a droplet impinging on an SHS with square pillar arrays in a cuboid domain. This fluid dynamics problem is numerically simulated by applying the lattice Boltzmann method. The influences of the droplet diameter (D*), the Weber number (Wew), and the pillar spacing and height (s* and h*) on the droplet dynamics and tc* are investigated. The numerical results show that the droplet can exhibit different bouncing patterns, normal or pancake bouncing, depending on Wew, s*, and h*. Pancake bouncing usually occurs when Wew ≥1.28, h*≥1, and s* ≈ 1, yielding a small tc*. Among all cases, a small tc* can be attained when the conversion rate of kinetic energy to surface energy (ΔĖsur*) right after the impacting exceeds a critical value around 0.038. This relation broadens that given in A. M. Moqaddam et al. [J. Fluid Mech. 824, 866–885 (2017)], which reported that the large total change of surface area renders small tc*. Furthermore, the maximum impacting force remains nearly the same in all cases, regardless of the bouncing patterns.

Ginsenoside Rg1 Regulates the Activation of Astrocytes Through lncRNA-Malat1/miR-124-3p/Lamc1 Axis Driving PI3K/AKT Signaling Pathway, Promoting the Repair of Spinal Cord Injury.

To investigate the regulation of ginsenoside Rg1 on the PI3K/AKT pathway through the lncRNA-Malat1/miR-124-3p/ Laminin gamma1 (Lamc1) axis, activating astrocytes (As) to promote the repair of spinal cord injury (SCI). Bioinformatics analysis was used to predict miRNA targeting Lamc1 and lncRNA targeting miR-124-3p, which were then validated through a dual-luciferase assay. Following transfection, the relationships between Malat1, miR-124-3p, and Lamc1 expression levels were assessed by qRT-PCR and Western blot (WB). Immunofluorescence staining and immunohistochemistry were utilized to measure Lamc1 expression, while changes in cavity area were observed through hematoxylin-eosin (HE) staining. Basso-Beattie-Bresnahan (BBB) scale and footprint analysis were used to evaluate functional recovery. WB was performed to assess the expression of PI3K/AKT pathway-related protein. Rg1 was found to upregulate Malat1 expression, which in turn modulated the Malat1/miR-124-3p/Lamc1 axis. Furthermore, Rg1 activated the PI3K/Akt signaling pathway, significantly reducing the SCI cavity area and improving hind limb motor function. However, knockout of Malat1 hindered these effects, and inhibition of miR-124-3p reversed the silencing effects of Malat1. Rg1 can induce Malat1 expression to activate the Lamc1/PI3K/AKT signaling pathway by sponging with miR-124-3p, thereby regulating As activity to repair SCI.

Simultaneous determination of ethylene oxide, 2-chloroethanol and ethylene glycol residues in medical device products by gas chromatography

A gas chromatography-based method was developed for the simultaneous and rapid determination of ethylene oxide (EO), 2-chloroethanol (ECH), and ethylene glycol (EG) residues in medical devices after EO sterilization. A sample weighing 2.5 g was added with 5 mL of ethanol as the extraction medium, and the residual substances in the sample were extracted at 40 ℃ for 4 h. The samples were separated on a DB-WAX capillary column (30 m×0.53 mm×1.0 μm) and determined using a hydrogen flame ionization detector. The temperature was maintained at 40 ℃ for 5 min, increased to 120 ℃ at a rate of 40 ℃/min, held for 5 min, and then increased to 200 ℃ at a rate of 6 ℃/min, held for 2 min. The flow rate of the nitrogen gas was 3 mL/min. The split ratio was 5∶1. The inlet and detector temperatures were 200 and 300 ℃, respectively. The changes in the chromatographic peak areas over time (0.5-10 h) under different temperatures (20, 30, 40, and 50 ℃) were investigated, and the optimal extraction condition was determined to be 40 ℃ for 4 h. In the experiments, quantification was performed using an external standard method. EO, ECH, and EG exhibited good peak shapes and separation effects as well as good linearity within their respective ranges. The linear correlation coefficients for EO, ECH, and EG were greater than 0.99. The limits of detection (LODs) for EO, ECH, and EG were in the range of 0.10-0.40 μg/g, and the limits of quantification (LOQs) were in the range of 0.30-1.20 μg/g. The average recoveries under different spiked levels were in the range of 91.08%-116.08%, and the relative standard deviations (n=6) were in the range of 0.56%-8.45%. EO, ECH, and EG residues were found to exist at different levels in the medical devices tested. In particular, disposable infusion sets must be paid careful attention. ECH and EG were not detected in disposable sterile medical devices made of non-polyvinyl chloride materials, which may be due to the fact that the products themselves did not contain chloride ions, they were not exposed to chlorine-containing substances during their production, sterilization, storage, transportation, use, etc. This study established a method to detect EO residues in disposable medical devices, and has the advantages of simple operation, excellent specificity, accurate quantification, and good reproducibility. It can simultaneously detect three residual substances in medical devices while meeting the actual detection requirements for EO, ECH, and EG residues. The method can be used to scientifically and effectively evaluate the risk of EO residues in single-use medical devices sterilized with EO, and will be helpful for improving the quality of medical devices, ensuring the safety of device use, and providing a reference for regulatory supervision and testing.

Three-Dimensional Speckle Tracking Echocardiography Assessment of Right Ventricular Function in Chronic Coronary Syndrome Patients After Percutaneous Coronary Intervention.

This study aimed to assess alterations in right ventricular (RV) function following percutaneous coronary intervention (PCI) in patients with chronic coronary syndromes utilizing three-dimensional speckle tracking echocardiography (3D-STE). A prospective study was conducted involving 136 patients diagnosed with chronic coronary syndromes undergoing PCI, constituting the study group, alongside 110 age- and gender-matched healthy volunteers serving as the control group. Echocardiographic evaluations, including both conventional and three-dimensional assessments, were performed on all study participants at 1-week, 6, and 12 months post-PCI. Parameters such as tricuspid annular plane systolic excursion (TAPSE) were derived from conventional echocardiography, while tricuspid lateral annular systolic velocity (S') was measured via tissue Doppler imaging. 3D-STE was utilized to quantify metrics including right ventricular fractional area change (RVFAC), right ventricular free wall longitudinal strain (RVFWLS), right ventricular global longitudinal strain (RVGLS), right ventricular stroke volume (RVSV), and right ventricular ejection fraction (RVEF). TAPSE, S', RVFAC, RVFWLS, RVGLS, RVSV, and RVEF exhibited significant increases from 1-week to 6 months post-PCI (p < 0.05). However, from 6 to 12 months post-PCI, RVFAC, RVGLS, RVSV, and RVEF demonstrated no notable changes (p > 0.05). Meanwhile, TAPSE, S', and RVFWLS sustained significant elevations: TAPSE (19.63±3.253% to 22.603±2.885%, p < 0.001); S' (10.57±2.643 to 12.61±2.189cm/s, p < 0.001); RVFWLS (18.64±2.745% to 19.926±3.291%, p = 0.002). At 12 months post-PCI, S', RVFAC, RVGLS, RVSV, and RVEF remained lower than those of the healthy control group, but the differences were not statistically significant (p > 0.05). However, RVFWLS was significantly lower compared to the healthy control group (19.926 ± 3.291%vs. 22.10 ± 1.994%, p < 0.001). Following PCI, right ventricular systolic function in patients with chronic coronary syndromes improves significantly over time. However, even at the 12-month post-PCI mark, RVFWLS remains lower than that of the control group. Notably, 3D-STE emerges as a noninvasive method for quantifying right ventricular systolic function post-PCI in chronic coronary syndrome patients.

ARRHYTHMOGENIC ATRIAL REMODELING DURING PREGNANCY IN MICE

Pregnancy is associated with greater vulnerability to supraventricular tachyarrhythmias (SVT). As the underlying mechanisms remain to be elucidated, we investigated whether pregnancy induces atrial remodeling that might contribute to this. Atrial electrophysiological and contractile properties were examined in non-pregnant (NP) and pregnant (P) mice. Cell shortening and Ca2+ imaging were measured on atrial myocytes. Atrial action potential and ionic currents were recorded using patch-clamp technique. Atrial mRNA and protein expression were analyzed using qPCR and Western blot. The P-wave area on the ECG increased by 50% during pregnancy, suggesting atrial enlargement, confirmed by echocardiography. The atrial myocytes were longer in P mice, adding further evidence to the physiological hypertrophy associated with pregnancy. Echocardiography showed a 50% increase in atrial fractional area change during pregnancy, indicating much stronger contraction. A similar increase in cell shortening was observed in P mice and was associated with a decrease in sarcomere length and changes in myofilament protein phosphorylation. However, pregnancy did not affect L-type Ca2+ current, Ca2+ transients, and SR Ca2+ load. Myocytes from P mice showed twice as many spontaneous contractions and spontaneous diastolic Ca2+ releases. Moreover, pregnancy was associated with a 50% increase in action potential duration, linked to a reduction in the density of the transient outward K+ current Ito and the underlying KV4.3 channel. During pregnancy, atrial tissues undergo substantial remodeling, potentially contributing to the development of SVT.

Surgical results of tetralogy of Fallot repair with pulmonary valve preservation techniques

The long-term complications arising from chronic pulmonary insufficiency after surgical correction of tetralogy of Fallot (TOF) are well documented. In our center, innovative techniques for pulmonary valve (PV) preservation have been adopted and developed for over 10 years. All patients with TOF and PV stenosis who underwent surgery at our center between January 2008 and December 2022 were included in this study. Patients were evaluated using echocardiography during follow-up, comparing those who underwent classic surgery with transannular patch (TAP) placement and those who underwent PV preservation techniques. Of the 134 patients, 99 (73.9%) were successfully treated using PV preservation techniques. At the time of surgery, the median age was 4.3 months (interquartile range [IQR] 3.4-5.9 months). The median preoperative PV z-score was -2.87 (IQR -3.61;-2.48). The median follow-up time from surgery was 6.6 years (IQR 3.5-8.4 years). During the median follow-up, the right ventricular area change fraction was 47% (IQR 43-50%) in patients treated with PV preservation and 43% (IQR 41-47%) in the TAP group (p=0.005). These data were associated with better PV function in patients treated with preservation. Specifically, insufficiency was mild in 12%, moderate in 35%, and severe in 53% of patients in the TAP group. Conversely, insufficiency was mild in 53%, moderate in 35%, and severe in 11% of patients treated with preservation (p<0.001). Annular integrity and PV function can be preserved during early TOF correction. PV preservation can prevent the long-term development of pulmonary insufficiency and right ventricular dysfunction.

Beach Area Changes and Resilience of the Eastern Coasts Before and After Typhoon Goni

&lt;i&gt;Due to climate change, waves have become increasingly stronger, making the analysis of beach changes before and after typhoons crucial for addressing beach erosion. This study utilized low-cost, high-efficiency video monitoring to analyze beach changes at 14 locations along Korea's east coast before and after typhoon impacts. Shorelines were extracted from 180 s average orthoimages using the Pixel Intensity Moving Average Extraction technique, and beach areas were calculated. The study focused on the recovery period following typhoon-induced erosion. During Typhoon Goni (2015), erosion reached up to 38% at Bongpo Beach, with a maximum affected area of 7,741 m&lt;sup&gt;2&lt;/sup&gt; at Goraebul Beach. Post-typhoon recovery exceeded 89%, with most beaches returning to pre-typhoon conditions. The erosion period averaged 7 d, while recovery took approximately 27 d. Erosion was significantly influenced by natural forces such as waves, tides, and wind. The erosion period showed minimal correlation with wave energy, whereas the recovery period exhibited some correlation. Further long-term analysis, incorporating additional wave data and typhoon impact periods, is needed. Future research will aim to collect extensive typhoon data to systematically analyze erosion and recovery cycles in relation to external forces.&lt;/i&gt;

Predicting Changes in Potential Habitats of an Endemic Plant Species under SSP Scenarios: A Case Study of &amp;lt;italic&amp;gt;Eranthis byunsanensis&amp;lt;/italic&amp;gt;

Background and objective: Climate change significantly impacts the growth environments of organisms that have adapted to natural environments. Endemic plants, which are native to specific regions, are particularly vulnerable to these changes. The conservation of these plants is a crucial national task. Currently, there is a lack of research on the habitat characteristics and conservation measures of specific species in Korea. This indicates a need for systematic research on field surveys of habitats for valuable species, the establishment of environmental variables, and long-term changes in suitable habitat areas. Therefore, this study aimed to identify the geographical distribution characteristics and select the optimal environmental variables for Eranthis byunsanensis, an endemic plant in the Korean Peninsula.Methods: To achieve this, we utilized an ensemble model in the R package biomod2 to analyze the current potential habitat and understand its distribution characteristics. We then predicted the changes in potential habitats for the mid-future (2041-2070) and the long-term future (2071-2100) based on climate change scenarios (SSP 1-2.6 and SSP 5-8.5). Finally, we conducted a comparative analysis of the differences between the scenarios.Results: Long-term projections indicate that potential habitat area is larger under SSP1-2.6, a scenario with active climate change mitigation policies, than under SSP5-8.5. Under SSP1-2.6, habitat remained relatively stable with expansion observed in coastal Gangwon-do. In contrast, SSP5-8.5, characterized by extreme climate change, led to significant habitat decline in Jeollabuk-do. Inland Jeollabuk-do experienced rapid habitat loss with a northeastward shift, while habitat along the East Sea coast of Gangwon-do expanded.Conclusion: This study's analysis of habitat change can serve as a crucial foundation for the conservation and management of endemic plants. Furthermore, it is expected to contribute to the development of response strategies to climate change and the identification of alternative habitats for endemic plants.

Influence of annealing temperature on Fe₂O₃ nanoparticles: Synthesis optimization and structural, optical, morphological, and magnetic properties characterization for advanced technological applications

In this study, Iron oxide nanoparticles (Fe₂O₃ NPs) were synthesized using iron chloride hexahydrate (FeCl3·6H2O) and ammonia solution through a straightforward co-precipitation method. The nanoparticles were annealed at temperatures of 100 °C, 300 °C, 500 °C, 700 °C, and 900 °C, with one sample left unannealed. Comprehensive analyses were performed using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Zeta potential, Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and UV–Vis Spectrophotometry. The XRD patterns confirmed the presence of both Maghemite (γ-Fe2O3) and Hematite (α-Fe2O3) phases, with a phase transition observed between 100 °C and 300 °C, and the most pronounced transition occurring at 500 °C. At this optimal temperature, the crystallite size was 19.14 nm, the average particle size was 37.36 nm, and the band gap energy was measured at 1.76 eV. SEM images revealed that nanoparticles formed clusters as the annealing temperature increased. The zeta potential measurements showed a range from 6.12 mV at 100 °C to −1.9 mV at 900 °C, indicating changes in particle stability. DLS analysis indicated a size increase from 86.81 nm at 300 °C to 1577 nm at 900 °C, reflecting aggregation trends. The reduction in band gap energy with higher temperatures is attributed to enhanced crystallinity and increased particle size. The magnetic properties of Fe₂O₃ NPs were evaluated using a Physical Property Measurement System (PPMS), revealing an increase in magnetic response with rising annealing temperatures. The transition from superparamagnetic γ-Fe₂O₃ to weakly ferromagnetic α-Fe₂O₃ was confirmed through changes in the hysteresis loop area and shape. These findings suggest that 500 °C is the optimal annealing temperature for producing Fe₂O₃ NPs with desirable properties for applications in targeted drug delivery, MRI contrast enhancement, and environmental remediation. This research advances the engineering of Fe₂O₃ NPs, paving the way for their use in various technological applications.

Geomorphological Changes of the Terrestrial Features of the Euphrates River between the Cities of Al-Kifl and Al-Mishkhab Using Geographic Information Systems (GIS)

The study area occupies part of the southwestern part of the sedimentary plain from the city of Al-Kifl and Najaf to the city of Al-Mashkhab, which is predominantly characterized by extraversion, which made the study area a low topographical variation. However, this variation contributed significantly to determining the geomorphological forms of the Euphrates River course as well as the direction of the course, which was consistent with the direction of the surface slope from the northwest towards the southeast. Thus, the natural characteristics of the study area vary from geological structure, surface, climate, soil and natural vegetation. When taking into account the true longitudinal extension of the Euphrates River course of (59) km, we find that these characteristics have a prominent impact in causing geomorphological changes in the study area.

Assessment of the Risk of Crack Formation at a Hybrid Bonding Interface Using Numerical Analysis

Hybrid bonding technology has recently emerged as a promising solution for advanced semiconductor packaging technologies. However, several reliability issues still pose challenges for commercialization. In this study, we investigated the possibility of crack formation caused by chemical mechanical polishing (CMP) defects and the misalignment of the hybrid bonding structure. Crack formation and thermomechanical stress were analyzed for two common hybrid bonding structures with misalignment using a numerical simulation. The effects of annealing temperature and dishing value on changes in the non-bonding area and peeling stress were systematically analyzed. The calculated peeling stresses were compared to the bonding strength of each bonding interface to find vulnerable regions prone to cracking. The non-bonding area in the bonding structure increased with a decreasing annealing temperature and an increasing dishing value. To achieve a sufficient bonding area of more than 90%, the annealing temperature should be greater than 200 °C. During the heating period of the annealing process, the SiCN-to-SiCN bonding interface was the most vulnerable cracking site with the highest peeling stress. An annealing temperature of 350 °C carries a significant risk of cracking. On the other hand, an annealing temperature lower than 250 °C will minimize the chance of cracking. The SiCN-to-SiO2 bonding interface, which has the lowest adhesion energy and a large coefficient of thermal expansion (CTE) mismatch, was expected to be another possible cracking site. During cooling, the SiCN-to-Cu bonding interface was the most vulnerable site with the highest stress. However, the simulated peeling stresses were lower than the adhesion strength of the bonded interface, indicating that the chance of cracking during the cooling process was very low. This study provides insights into minimizing the non-bonding area and preventing crack formation, thereby enhancing the reliability of hybrid bonding structures.

Exploring Potential Adaptation Strategies for Smallholder Farmers to Climate Change: A Case Study at Abala Abaya, Wolaita Zone, South Ethiopia

Background: The frequency and intensity of extreme weather events are expected to increase as a result of climate change, which will contribute to changes in precipitation and temperature, and therefore will affect food security. Research issues related to increasing the sustainability of the agricultural sector, eliminating climate risks in agriculture are coming to the fore. This is especially relevant in arid regions. Objectives: This study aimed to assess the adaptation strategies of smallholder farmers to climate change in Abela Abaya, Wolaita Zone, Southern Ethiopia. Finding optimal practices adapted to random extreme events is fundamental for sustainable food production. In particular, the study attempted to understand the preferences of smallholder farmers in adaptation strategies to climate change in the study area; the main influencing factors determining the choice of adaptation strategies to climate change by smallholder farmers in the study area. Methods: To investigate this issue, qualitative and quantitative data were used within a descriptive research approach to assess potential adaptation strategies of smallholder farmers to climate change. Data on demographic, socio-economic, institutional, physical and psychological factors for adaptation strategies of smallholder farmers were collected through specially designed and pre-tested questionnaires, interviews and focus group discussions (FGDs). Rural counties for the study were selected using simple random sampling due to the same agroecology. The multivariate probit (MVP) model was used as it is a type of correlated binary response regression model that allows for the simultaneous identification and assessment of the impact of a set of independent factors on each of the possible approaches. Five adaptation methods are identified as dependent variables for the Multi-Variate Probit. These include Soil and Water Conservation (SWC) practices, use of drought-tolerant varieties, adjustment of planting dates, use of agroforestry, and implementation of water harvesting. The following were selected as independent variables for the current study. Results: Most farmers (96.7%) acknowledge the ongoing climate change and are concerned that their agriculture will not suffer under the new conditions. This is justified by the fact that farmers confirm their observations regarding the increase in air temperature, the increase in the frequency of plant diseases and the decrease in precipitation. At the same time, only 36.2% of the surveyed farmers reported that society is aware of the possible risks associated with global warming and is trying to adapt agricultural activities to new climatic conditions. In particular, the current study revealed for the first time that smallholder farmers in Abela Abaya primarily prefer approaches such as soil and water conservation (71.6%), adjustment of planting dates (59.4%), and agroforestry (44.5%). Conclusion: The study identified the most influential factors on the adoption of adapted agricultural practices in a specific region of Abala Abaya (Wolaita Zone, Southern Ethiopia), namely, household heads’ access to education, frequency of extension visits, access to climate information and land slope. Thus, decision makers can design and adopt appropriate programs based on the current results to preserve smallholder farming and maintain food security at the national level.

Hydrogel composition and mechanical stiffness of 3D bioprinted cell-loaded scaffolds promote cartilage regeneration

ObjectiveTo investigate the impact of different component ratios and mechanical stiffness of the gelatin-sodium alginate composite hydrogel scaffold, fabricated through 3D bioprinting, on the viability and functionality of chondrocytes.MethodsThree different concentrations of hydrogel, designated as low, medium, and high, were prepared. The rheological properties of the hydrogel were characterized to optimize printing parameters. Subsequently, the printability and shape fidelity of the cell-loaded hydrogel scaffolds were statistically evaluated, and the chondrocyte viability was observed. Dynamic mechanical analysis was conducted to measure the modulus, thereby assessing the scaffold’s stiffness. Following a 21-day culture period, RT-PCR, histological staining, and immunostaining were employed to assess chondrocyte activity, chondrosphere aggregates formation, and cartilage matrix production.ResultsBased on rheological analysis, optimal printing temperatures for each group were determined as 27.8°C, 28.5°C, and 30°C. The optimized printing parameters could ensure the molding effect of the scaffolds on the day of printing, with the actual grid area of the scaffolds was close to the theoretical grid area. And the scaffolds exhibited good cell viability (93.24% ± 0.99%, 92.04% ± 1.49%, and 88.46% ± 1.53%). After 7 days of culture, the medium and high concentration groups showed no significant change in grid area compared to the day of printing (p &amp;gt; 0.05), indicating good morphological fidelity. As the hydrogel’s bicomponent ratio increased, both the storage modulus and loss modulus increased, while the loss factor remained relatively constant. The highest number of chondrocytes-formed chondrosphere aggregates in the medium concentration group was observed by light microscopy. RT-PCR results indicated significantly higher expression levels of chondrogenic genes SOX9, Agg, and Col-II in the low and medium concentration groups compared to the high concentration group (p &amp;lt; 0.05). Histological staining results showed that the middle concentration group formed the highest number of typical cartilage lacunae.ConclusionThe aforementioned results indicate that in 3D bioprinted cell-loaded GA-SA composite hydrogel scaffolds, the scaffolds with the composition ratio (10:3) and mechanical stiffness (∼155 kPa) exhibit sustained morphological fidelity, effectively preserve the hyaline phenotype of chondrocytes, and are more conducive to cartilage regeneration.

Parametrical synthesis of various radio devices with the set quantity of identical cascades of type «the nonlinear part – the mixed two-port network»

Background. Presence of possibility of analytical definition of a part of parametres of various radio devices, optimum by criterion of maintenance of preset values of modules and phases of transfer functions on necessary quantity of frequencies, considerably reduces time of numerical optimisation of other part of parametres by criterion of formation demanded frequency response and phase response in a strip of frequencies. Till now such problems dared concerning radio devices only with one cascade of type «a nonlinear part - the coordination the device» or «the coordination the device – a nonlinear part». In quality «the coordination devices were used the jet, resistive, complex or mixed two-port networks. The problem of multicascade radio devices with jet two-port networks is solved also. Change of basis for the coordination two-port networks and a place of inclusion of a nonlinear part leads to change of area of a physical realizability. Aim. Working out of algorithms of parametrical synthesis of radio devices with any quantity of identical and unequal cascades of type «a nonlinear part ‑the coordination the mixed two-port network» by criterion of maintenance of the set frequency characteristics. Nonlinear parts are presented in the form of a nonlinear element and parallel either consecutive on a current or pressure of a feedback. Methods. The theory of two-port networks, matrix algebra, a decomposition method, a method of synthesis of actuation microwave devices, numerical methods of optimisation. Results. In interests of achievement of the specified purpose systems of the algebraic equations are generated and solved. Models of optimum two-port networks in the form of mathematical expressions for definition of interrelations between elements of their classical matrix of transfer and for search of dependences of mixed of two-poles from frequency are received. It is shown, that at certain parities between quantity of cascades and values of resistance of a source of a signal and loading of the one-cascade radio device frequency characteristics of one-cascade and multicascade radio devices appear identical or similar. Such schemes are named by equivalent. Conclusion. The comparative analysis of theoretical results (frequency response and phase response radio devices, value of parametres), received by mathematical modelling in system MathCad, and the experimental results received by схемотехнического of modelling in systems OrCad and MicroCap, shows their satisfactory coincidence.

Predicting the habitat suitability and species richness of plants of Great Himalayan National Park under different climate change scenarios.

This study elucidates the distribution of plants in Great Himalayan National Park (GHNP), India, in current and different future climate change scenarios. The distribution of plants and habitat suitability in GHNP due to climate change was analyzed by MaxEnt, species distribution model (SDM) algorithm. In this study, species presence records were retrieved through field survey and published literature. We have projected the distribution of 44 plant species using MaxEnt and tested whether GHNP is performing well in conserving the plant species. Initially, we have constructed a model for each species and created the habitat suitability map from average of ascii files and later we added the maps of all species in order to make binary map to show the species richness in the selected climate scenarios. The model was created using the HADGEM-2 global circulation model in 2050 and 2070years by using climate change situations of RCP 2.6 and RCP 8.5. The area under curve (AUC) values in the final models of 44 plant species were in the range 0.70-0.97 that indicates statistically significant results. The model identified precipitation of driest month followed by altitude and annual mean temperature as most determining variables in the distribution of plants of GHNP in selected climate scenarios. In the present study, we found that overall suitable habitat increased for nine species, decreased for thirty-four, and unchanged for one plant species in terms of percent area change from current to future scenarios. So these nine species were found to be more adaptable towards changing climate than the other plant species in this study. The species richness was high in western and southwestern parts of GHNP in the current scenario, however under future climatic scenarios, species richness shows a decreasing trend. Based on our findings, it can be concluded that GHNP should be prioritized for conserving the plant species.

Evaluating Impact of Surgical Myocardial Revascularization on Global Left Ventricular Systolic Function and Immediate Postoperative Outcome using Transesophageal Echocardiography

Abstract Background and Aims: Surgical myocardial revascularization is supposed to improve the global left ventricular (LV) function by improving the blood supply in significantly occluded coronary arteries. Transesophageal echocardiography (TEE) provides an excellent opportunity to evaluate cardiac function in operating room. Present study was aimed at evaluating impact of surgical myocardial revascularization on global LV systolic function. Comparison of LV fractional shortening (LV-FS), fractional area change (LV-FAC), ejection fraction (LV-EF), indexed LV volumes (indexed LV volumes at end diastole, LV volumes at end systole) and “Tei” (Myocardial performance) index obtained prior and after surgical myocardial revascularization was done for quantitative analysis. Also, the determinants of immediate postoperative outcome were evaluated based on need of pharmacological and/or mechanical cardiovascular support, mechanical ventilation, intensive care unit (ICU) stay, morbidity and mortality in immediate postoperative period. These outcome measures were correlated with baseline values of TEE derived echo indices. Methods: One hundred and ten subjects with significant coronary artery disease scheduled for elective myocardial revascularization surgery. Fourteen subjects were excluded due to presence of either hemodynamic instability requiring either pharmacological or mechanical cardiovascular support, before coronary revascularization (n = 6), presence of Grade III mitral regurgitation (MR) in baseline TEE (n = 2) and arrythmias (n = 6). Ninety six subjects were evaluated for global LV systolic function using TEE before and after surgical revascularization. Subjects were followed in ICU for the outcome. Immediate postoperative outcome was measured as “good” or “poor” based on vasoactive inotropic score, requirement of Intra-aortic balloon counter pulsation (IABP) and mechanical cardiovascular support (VA-ECMO) to maintain cardiac output, duration of mechanical ventilation, postoperative ICU stay, morbidity and mortality. Results: In 96 subjects analyzed, there was a significant improvement in TEE derived LV-FS (38.60 ± 16.38 vs. 31.31 ± 13.14) (P = 0.002), FAC (51.94 ± 16.06 vs. 43.99 ± 16.02) (P ≤ 0.001), EF (53.08 ± 9.97 vs. 46.71 ± 7.53) (P &lt; 0.00001), LV end diastolic volume index (34.84 ± 13.43 vs. 40.08 ± 17.22) (P = 0.0188) and “Tei” index (0.47 ± 0.13 vs. 0.53 ± 0.13) (P = 0.0007). Thirty three subjects required either prolonged stay in ICU (&gt;7 days), (n = 20) and/or mechanical ventilatory support (&gt;24 h), (n = 10) and/or mechanical cardiovascular support (IABP/VA ECMO placement), (n = 7) and/or suffered mortality (n = 2) in postoperative period were categorized as “poor” outcome. Presence of type II diabetes mellitus, Chronic obstructive pulmonary disease (COPD), higher grade of ischemic MR, larger LV end diastolic volume, use of cardiopulmonary bypass and allogenic blood transfusion during surgery were the determinants of “poor” outcome. Conclusion: Surgical myocardial revascularization improved global LV systolic function irrespective of baseline LV EF. Immediate postoperative outcome was strongly determined by presence of diabetes, COPD, higher grade of ischemic MR and larger LV end diastolic volumes. Preoperative (Baseline) LV EF and myocardial performance index did not determine “poor” postoperative outcome following surgical myocardial revascularization in subjects with LVEF &gt;35%.

Research trends of collaborative governance in climate change: a bibliometric analysis

Purpose Climate change, a complex global issue, has prompted a wide range of actors – from nations to tiny communities – to seek solutions to mitigate its consequences. The growing emphasis on collaborative governance has resulted in substantial research on the topic. This paper aims to address the existing research void by using a bibliometric approach to investigate the evolution of studies on collaborative governance in the context of climate change. Design/methodology/approach This study conducted a bibliometric mapping of research on collaborative governance on climate change issues from the first study presented in 2007 to the research conducted in 2023, using 222 articles derived from the Scopus database and Web of Science. Steps for comprehensive bibliometric literature mapping via the VOSviewer software. Findings The study includes a complete overview of significant themes, including the most cited research, contributions from authors, countries, and institutions, as well as network analysis including co-citation, bibliographic coupling, and co-occurrence. Notably, the study looks at which countries have made the most substantial contributions, with the United States dominating with 40 studies over the last decade. The analysis reveals that collaborative governance in climate change, emphasizing its importance as a tool for governments and communities to mitigate climate risks. This is consistent with research emphasizing the need for coordination across multiple players to accomplish effective climate adaptation. The paper focuses on nine diverse research clusters, including community engagement, urban governance, disaster response and economic implications. Research limitations/implications This study is restricted to bibliometric analysis, which is conducted using sources from the Scopus and Web of Science databases. Future research is required to investigate the use of additional databases that offer a wider range of sources. In the interim, this investigation provides an overview of the concept of Collaborative Governance, which has the potential to serve as a strategy for the adaptation and resilience to climate change in global regions, cities and urban areas. Originality/value This study conducts a rigorous bibliometric review that improves our theoretical knowledge and practical use of collaborative governance in addressing climate change. It reveals innovative trends, research gaps and important recommendations for future studies, strengthening the strategic approach to collaborative climate action.

Enhancing Climate Resiliency Through Improving Ecosystem Services in Shoreline Municipalities – Lessons from Canada

The accelerated impacts of climate change in waterfront areas and the proven inefficacy of the aging hardened shoreline infrastructure have driven shoreline management practices to evolve toward the enhancement of ecosystem services at the land-water interface. Gaining momentum as an adaptive approach in regenerative projects, living shorelines are comprised of natural ecosystem components used in combination or in place of traditional hard engineering methods to provide coastal protective services and erosion mitigation. The success of living shorelines in protecting shoreline property and ecosystem integrity varies based on the biogeomorphology and hydrology of the region and is also heavily reliant on social acceptance of the chosen approach and best practice for implementation. The relatively lower lifecycle cost and associated co-benefits of living shorelines have well positioned them as a promising alternative approach in theory. There are, however, gaps in regional long-term datasets and evidence-based guidelines. This research provides an overview of the underlying geopolitical readiness for integrating nature-based solutions in climate adaptation strategies within shoreline municipalities based on a comprehensive literature review complimented by expert interviews. The synthesized data can inform decisions for minimizing the destructive effects of traditional shoreline erosion prevention approaches and encourage successful implementation of solutions that offer ecological, health, social, and economic benefits.