Volume Changes Research Articles

Blood volume reduction due to rapid plasma loss after birth in preterm piglets

Abstract Background Understanding changes in blood volume after preterm birth is critical to preventing cardiovascular deterioration in preterm infants. The aims were to determine if blood volume is higher in preterm than term piglets and if blood volume changes in the hours after birth. Methods Paired blood volume measurements were conducted in preterm piglets (98/115d gestation, ~28wk gestation infant) at 0.5–5 h (n = 12), 0.5-9 h (n = 44) and 5–11 h (n = 7) after birth, and in a term cohort at 0.5–9 h (n = 40) while under intensive care. Results At 30 min after birth, blood volume was significantly lower in preterm piglets compared to term piglets. By 9 h after birth, blood volume had reduced by 18% in preterm piglets and 13% in term piglets. By 5–9 h after birth, preterm piglets had significantly lower blood volumes than at term (61 ± 10 vs. 76 ± 11 mL/kg). Conclusions In contrast to clinical resources, preterm piglets have a lower blood volume than at term. Substantial reductions in blood volume after birth leave some preterm piglets hypovolemic. If this also occurs in preterm infants, this may have important clinical consequences. Modern studies of blood volume changes after birth are essential for improving preterm outcomes. Impact Preterm piglets do not have a higher blood volume than their term counterparts, in contrast to current clinical estimates. Rapid reduction in blood volume after birth leads to hypovolemia in some preterm piglets. There is a critical need to understand blood volume changes after birth in preterm infants in order to improve clinical management of blood volume.

Effects of rapid maxillary expansion on upper airway parameters in OSA children with maxillary restriction: A CBCT study.

Rapid maxillary expansion (RME) has been proposed as an effective treatment for pediatric obstructive sleep apnea (OSA) and maxillary restriction in children. This study aimed to evaluate the effect of RME appliances on the nasomaxillary complex dimensions in children with OSA and maxillary constriction. This prospective longitudinal study included 34 children aged 8-12 years with maxillary restriction and OSA confirmed by polysomnography who had completed RME therapy. The nasomaxillary complex is segmented into the nasal cavity, maxillary sinuses, and nasopharynx. The effect of RME on nasomaxillary complex dimensions was assessed pre and posttreatment using cone-beam computed tomography, analysis, while a second standard overnight polysomnography (PSG) was performed to assess changes in respiratory parameters. Significant improvements were observed, including inferior maxillary dislocation (S-S1 distance and N-ANS), increased anterior and posterior facial height, and a 5.43 events/h reduction in Apnea-Hypopnea Index (p < .001). The nasal cavity volume increased by 2439 (±584) mm3 (p < .001), nasopharynx size increased by 883 (±479) mm3 (p = .008), mid cross-sectional area increased by 31.74 (±14.50) mm2 (p < .001), and the distance between the right and left maxillary sinuses increased by 8.37 (±3.67) mm (p < .001) all exhibited positive changes, with some insignificant variations in volume change (p = .254). RME treatment was found to be effective in improving nasal cavity and nasopharyngeal dimensions, leading to improved respiratory parameters in children with OSA and maxillary constriction. While these results are promising, considerations about the potential long-term benefits of RME on future growth are important. The study provides valuable insights into the efficacy of RME as a treatment option for this pediatric population.

Evaluation of acute thrombus regression effect of edoxaban for deep vein thrombosis in patients with cancer: a single-center prospective observational study.

Although there are reports on the recurrence prevention in the chronic phase using direct oral anticoagulants (DOACs) for deep vein thrombosis (DVT) in patients with cancer, acute thrombus regression effect using DOACs has not been assessed. This study aimed to assess the thrombus regression effect of initial treatment using edoxaban for acute lower-extremity DVT in patients with active cancer. In this observational study, among the inpatients with cancer and lower-extremity DVT who underwent initial treatment with edoxaban at our hospital from November 2019 to December 2021, 34 consenting patients were recruited in this study. The quantitative ultrasound thrombus (QUT) score of thrombus volume was calculated at baseline (before administration) and 7-14 days after the start of edoxaban administration, using lower-extremity venous ultrasound to evaluate changes in thrombus volume. The primary and secondary endpoints were the acute thrombus regression effect of edoxaban and the impact of patients' clinical frailty on the thrombus regression effect, respectively. Anticoagulant therapy with edoxaban significantly reduced QUT score (p < 0.001). In addition, regardless of the Clinical Frailty Scale scores, QUT score decreased significantly. Initial treatment with edoxaban was effective for lower-extremity DVT in patients with cancer. In addition, the effect was the same independent of the degree of frailty.

Enhancing Lithium-Ion Diffusion Kinetics in a 3D Lithium Metal Host through Surface Modification with Hierarchical Multimetal Oxides.

Lithium metal is a promising anode candidate to achieve high-energy-density lithium metal batteries (LMBs) due to its ultrahigh theoretical capacity (3860 mA h g-1) and low electrochemical potential (-3.04 V vs S.H.E). Unfortunately, the commercialization of lithium metal anodes is hindered by the growth of Li dendrites and the infinite Li volume changes during the cycling process. Herein, we introduce a 3D hierarchical multimetal oxide nanowire framework as a current collector for Li metal anodes. The hierarchical metal oxide layers of CoO and CuxO provide abundant Li nucleation sites and thus offer uniform Li plating and regulate Li nucleation during the charge/discharge process. As a result, half cells present a prolonging Coulombic efficiency of 97% at 1 mA cm-2 with a capacity of 1 mA h cm-2 for over 300 cycles. A stable cyclability of symmetric cells is demonstrated under 1 mA cm-2 with a capacity of 1 mA h cm-2 for 1500 h. Full cells paired with an LFP cathode show a stable capacity of 131.5 mA h g-1 with a capacity retention of 92% for 200 cycles. These results will shed insights into the design of 3D Cu current collectors for high-performance composite Li metal anodes.

Effect of alloying elements on zinc-induced liquid metal embrittlement in steels: A first-principles study

Liquid metal embrittlement (LME) induced by Zn melt in galvanized steels during spot-welding poses a significant challenge to the advancement of the automotive industry. A critical strategy to address this challenge is identifying promising alloying elements capable of mitigating LME. High-throughput first-principles calculations were employed to investigate the segregation behavior of 22 common alloying elements at the Σ5(310) grain boundary of iron and their impact on the grain boundary energy. The results indicate that volume distortion upon doping of the alloying elements predominantly influences their segregation behavior, while the weak bonding between Zn and Fe is responsible for the grain boundary embrittlement. Exploration of solute interaction between Zn and the other alloying element in the Fe grain boundary model reveals that the attraction between metallic doping elements and Zn correlates with both the elastic effects and the magnetic properties of the dopant, while the repulsion between non-metallic elements and Zn is primarily governed by the elastic effects. Separating the grain boundary strengthening energy into mechanical and chemical contributions shows that they correlate linearly with variations in volume of the doping site and changes in bond energy for bonds associated with the doping site at the grain boundary, respectively. Accordingly, the strengthening effect of the doping elements can be estimated by evaluating the induced changes in local volume and bond energies on grain boundaries. Furthermore, potential alloying elements to mitigate the Zn-induced LME are screened and discussed, with B and Mo being the most promising candidates.

Damage-Tolerant and Self-Repairing Web-Like Borate Type Binder Enable Stable Operation of Efficient Si-Based Anodes.

Novel binder designs are shown to be fruitful in improving the electrochemical performance of silicon (Si)-based anodes. However, issues with mechanical damage from dramatic volume change and poor lithium-ion (Li+) diffusion kinetics in Si-based materials still need to be addressed. Herein, an aqueous self-repairing borate-type binder (SBG) with a web-like architecture and high ionic conductivity is designed for Si and SiO electrodes. The 3D web-like architecture of the SBG binder enables uniform stress distribution, while its self-repairing ability promotes effective stress dissipation and mechanical damage repair, thereby enhancing the damage tolerance of the electrode. The tetracoordinate boron ions ( ) in the SBG binder boosts the Li transportation kinetics of Si-based electrodes. Based on dynamic covalent and ionic conductive boronic ester bonds, the diverse requirements of the binder, including uniform stress distribution, self-repairing ability, and high ionic conductivity, can be met by simple components. Consequently, the proposed straightforward multifunction design strategy for binders based on dynamic boron chemistry provides valuable insights into fabricating high-performance Si-based anodes.

Heterostructure Engineering Enables MoSe2 with Superior Alkali-Ion Storage

Molybdenum diselenide (MoSe2) is a promising anode for alkali-ion storage due to its intrinsic advantages. However, MoSe2 still encounters the issues of structural instability and poor rate performance caused by drastic volume change and sluggish reaction kinetics. Reasonable design of electrode structure is crucial for achieving superior electrochemical performance. Herein, a novel hierarchical structure coupled with 1D/1D subunits is elaborately designed and constructed, in which the MoSe2/CoSe2 heterostructure is the “trunk” and the N-doped carbon nanotubes are the “branches” (MoSe2/CoSe2/NCNTs). Benefiting from the properties endowed by unique configurations, MoSe2/CoSe2/NCNTs electrodes manifest faster reaction kinetics and better structure durability. Evaluated as an anode for LIBs and SIBs, MoSe2/CoSe2/NCNTs deliver high reversible capacity, superior rate capability (452 at 10 A g−1 in LIBs and 296 at 10 A g−1 in SIBs), and prominent cycle life (553 after 2000 cycles at 5 A g−1 in LIBs and 310 after 2000 cycles at 5 A g−1 in SIBs). Such design conception can also provide guidance for the development of other high-performance electrodes.

The Value of Aortic Volume and Intraluminal Thrombus Quantification for Predicting Aortic Events after Endovascular Thoracic Aneurysm Repair

Objectives: To assess the ability of the aortic aneurysm volume (AAV), aneurysmal lumen volume (ALV), and aneurysmal thrombus volume (ATV) to predict the need for aortic reintervention when using the maximal aortic diameter as a reference. Methods: This monocentric retrospective study included 31 consecutive patients who underwent successful thoracic endovascular aortic repair (TEVAR) to treat an atheromatous thoracic aortic aneurysm. All patients underwent clinical and computed tomography angiography (CTA) for 3 years after TEVAR. The patients were categorized into group 0 if no aortic reintervention was required during the follow-up period and categorized into group 1 if they experienced a type I or III endoleak or aneurysm diameter increase requiring intervention. The maximum aneurysm sac diameter and the AAV, ALV, and ATV were calculated using CTA images obtained preoperatively (T0) and at 6–12 months (T1), 24 months (T2), and 36 months (T3) postoperatively, and their changes over time were analyzed. Correlations between diameter and changes in AAV, ALV, and ATV were assessed, and the association between diameter and volume changes and reintervetion was examined. The cutoff values for predicting the need for reintervention was determined using a receiver operating characteristic (ROC) curve. The accuracy of volume change versus diameter change for predicting the need for reintervention was analyzed. Results: There were no significant differences in terms of the mean aneurysm diameter or AAV, ALV or ATV between the groups at preoperative CTA or after one year of follow-up imaging. The mean ATV was higher in group 1 than in group 0 at 2 years (187.6 ± 86.3 mL vs. 114.7 ± 64.7 mL; p = 0.057) and after 3 years (195.0 ± 86.7 mL vs. 82.1 ± 39.9 mL; p = 0.013). The maximal diameter was greater in group 1 than in group 0 at 3 years (67.3 ± 9.5 mm vs. 55.3 ± 12.6 mm; p = 0.044). The rate of AAV change between T0 and T1 was significantly higher in group 1 (7 ± 4.5%) than in group 0 (−6 ± 6.8%; p &lt; 0.001). The rate of ATV change between T1-T3 was significantly higher in group 1 than in group 0 (34 ± 40.9% vs. −13 ± 14.4% (p = 0.041)); similar results were observed for the rate of ATV change between T2 and T3 (27 ± 50.1% for group 1 vs. −8 ± 49.5% in group 0 (p &lt; 0.001)). According to our multivariate analysis, the annual growth rate for AAV between T0 and T1 was the only independent factor that was significantly associated with aortic reintervention (area under the curve (AUC) = 0.84, OR = 1.57, p = 0.025; optimal cutoff +0.4%). An increase in the annual growth rate of the ATV between T0 and T3 was independently associated with the need for aortic reintervention (area under the curve (AUC) = 0.90, OR = 1.11, p = 0.0347; optimal cutoff +10.1%). Conclusions: Aortic volume analysis can predict the need for aortic reintervention more accurately and earlier than maximal aortic diameter.

Differences in circulating blood volume changes during emergence from general anesthesia in transcatheter aortic valve implantation and MitraClip implantation.

We aimed to compare changes in the circulating blood volume (CBV) during emergence from general anesthesia in patients undergoing transcatheter aortic valve implantation (TAVI) and MitraClip implantation. We included 97 patients who underwent TAVI or MitraClip implantation. The primary outcome was the rate of change in the estimated CBV associated with emergence from general anesthesia. The secondary outcomes were hemoglobin and hematocrit values before and after emergence from anesthesia for each procedure. Additionally, the independent factors associated with changes in the estimated CBV were assessed using multiple regression analysis. In the TAVI group, the hemoglobin concentration increased from 9.6g/dL before emergence from anesthesia to 10.8g/dL after emergence (P < 0.001; mean difference, 1.2g/dL, 95% confidence interval [CI] 1.1-1.3g/dL). Conversely, no statistically significant change was observed in the hemoglobin concentration before and after emergence from anesthesia in the MitraClip group. The mean rate of change in the estimated CBV was - 15.4% (standard deviation [SD] 6.4%) in the TAVI group and - 2.4% (SD, 4.7%) in the MitraClip group, indicating a significant decrease in the estimated CBV in the former than in the latter (P < 0.001; mean difference, 13.0%; 95% CI 9.9-16.1%). Emergence from general anesthesia increased the hemoglobin concentration and decreased the estimated CBV in patients undergoing TAVI but did not elicit significant changes in patients undergoing MitraClip implantation. These results may provide a rationale for minimizing blood transfusions during general anesthesia in patients undergoing these procedures.

Dynamic Mechanism of Cerebral Venous Disruption: Longitudinal Evidence From a Community-Based Cohort.

This study aims to investigate the temporal and spatial patterns of structural brain injury related to deep medullary veins (DMVs) damage. This is a longitudinal analysis of the population-based Shunyi cohort study. Baseline DMVs numbers were identified on susceptibility-weighted imaging. We assessed vertex-wise cortex maps and diffusion maps at both baseline and follow-up using FSL software and the longitudinal FreeSurfer analysis suite. We performed statistical analysis of global measurements and voxel/vertex-wise analysis to explore the relationship between DMVs number and brain structural measurements. A total of 977 participants were included in the baseline, of whom 544 completed the follow-up magnetic resonance imaging (age 54.97±7.83 years, 32% men, mean interval 5.56±0.47 years). A lower number of DMVs was associated with a faster disruption of white matter microstructural integrity, presented by increased mean diffusivity and radial diffusion (β=0.0001 and SE=0.0001 for both, P=0.04 and 0.03, respectively), in extensive deep white matter (threshold-free cluster enhancement P<0.05, adjusted for age and sex). Of particular interest, we found a bidirectional trend association between DMVs number and change in brain volumes. Specifically, participants with mild DMVs disruption showed greater cortical enlargement, whereas those with severe disruption exhibited more significant brain atrophy, primarily involving clusters in the frontal and parietal lobes (multiple comparison corrected P<0.05, adjusted for age, sex, and total intracranial volume). Our findings posed the dynamic pattern of brain parenchymal lesions related to DMVs injury, shedding light on the interactions and chronological roles of various pathological mechanisms.

ZOom Delivered Intervention Against Cognitive decline (ZODIAC) COVID-19 pandemic adaptations to the Post-Ischaemic Stroke Cardiovascular Exercise Study (PISCES): protocol for a randomised controlled trial of remotely delivered fitness training for brain health

BackgroundStroke increases subsequent dementia risk yet there are no specific post-stroke therapies to protect cognition. Cardiorespiratory exercise is recommended for secondary prevention of stroke and may be neuroprotective. The Post Ischaemic Stroke Cardiovascular Exercise Study (PISCES) aims to reduce post-stroke secondary neurodegeneration and cognitive decline. During the pandemic, we pivoted to a ZOom Delivered Intervention Against Cognitive decline (ZODIAC) protocol, reducing pandemic-amplified barriers to exercise.MethodsWe present pandemic adaptions for a multicentre phase IIb assessor-blinded randomised controlled trial of ischaemic stroke survivors testing the efficacy and feasibility of an 8-week home-based exercise intervention delivered at 2 months post-stroke. We compare cardiorespiratory exercise (intervention arm) versus balance and stretching (active control arm). Participants are assessed with magnetic resonance imaging (MRI), fitness, blood, microbiome, and neuropsychological tests at three study visits: before and after the exercise intervention and at 12 months. Modifications to the original protocol include pre-exercise safety home visits, commercial delivery of exercise equipment to facilitate assessor blinding, and reconsideration of statistical plan to allow pooling of the studies. We have reduced in-person study visits from 27 to 3. Primary outcome remains between-group (intervention versus control) difference in brain volume change; secondary outcome is between-group difference in global cognitive ability to allow remote administration of a validated cognitive scale.DiscussionRemotely delivered exercise interventions reduce participant burden and may reduce barriers to recruitment. A decrease in the number of in-person study visits can be supported by greater information capture via self-reported questionnaires and phone surveys.Trial registrationProspectively ACTRN12616000942459. Registered on July 2016.

Dynamic Covalent BondsRegulate Zinc Plating/Stripping Behaviors for High-Performance Zinc Ion Batteries.

Artificial interfaces provide a comprehensive approach to controlling zinc dendrite and surface corrosion in zinc-based aqueous batteries (ZABs). However, due to consistent volume changes during zinc plating/stripping, traditional interfacial layers cannot consistently adapt to the dendrite surface, resulting in uncontrolled dendrite growth and hydrogen evolution. Herein, dynamic covalent bonds exhibit the Janus effect towards zinc deposition at different current densities, presenting a holistic strategy for stabilizing zinc anode. The PBSC intelligent artificial interface consisting of dynamic B-O covalent bonds is developed on zinc anode to mitigate hydrogen evolution and restrict dendrite expansion. Owing to the reversible dynamic bonds, PBSC exhibits shape self-adaptive characteristics at low current rates, which rearranges the network to accommodate volume changes during zinc plating/stripping, resisting hydrogen evolution. Moreover, the rapid association of B-O dynamic bonds enhances mechanical strength at dendrite tips, presenting a shear-thickening effect and suppressing further dendrite growth at high current rates. Therefore, the assembled symmetrical battery with PBSC maintains a stable cycle of 4500 hours without significant performance degradation and the PBSC@Zn||V2O5 pouch cell demonstrates a specific capacity exceeding 170 mAh g-1. Overall, the intelligent interface with dynamic covalent bonds provides innovative approaches for zinc anode interfacial engineering and enhances cycling performance.

Dynamic Covalent Bonds Regulate Zinc Plating/Stripping Behaviors for High‐Performance Zinc Ion Batteries

Artificial interfaces provide a comprehensive approach to controlling zinc dendrite and surface corrosion in zinc‐based aqueous batteries (ZABs). However, due to consistent volume changes during zinc plating/stripping, traditional interfacial layers cannot consistently adapt to the dendrite surface, resulting in uncontrolled dendrite growth and hydrogen evolution. Herein, dynamic covalent bonds exhibit the Janus effect towards zinc deposition at different current densities, presenting a holistic strategy for stabilizing zinc anode. The PBSC intelligent artificial interface consisting of dynamic B‐O covalent bonds is developed on zinc anode to mitigate hydrogen evolution and restrict dendrite expansion. Owing to the reversible dynamic bonds, PBSC exhibits shape self‐adaptive characteristics at low current rates, which rearranges the network to accommodate volume changes during zinc plating/stripping, resisting hydrogen evolution. Moreover, the rapid association of B‐O dynamic bonds enhances mechanical strength at dendrite tips, presenting a shear‐thickening effect and suppressing further dendrite growth at high current rates. Therefore, the assembled symmetrical battery with PBSC maintains a stable cycle of 4500 hours without significant performance degradation and the PBSC@Zn||V2O5 pouch cell demonstrates a specific capacity exceeding 170 mAh g‐1. Overall, the intelligent interface with dynamic covalent bonds provides innovative approaches for zinc anode interfacial engineering and enhances cycling performance.

The Effect of Computerized Cognitive Training, with and without Exercise, on Cortical Volume and Thickness and Its Association with Gait Speed in Older Adults: A Secondary Analysis of a Randomized Controlled Trial

Background: Slower walking is associated with changes in cortical volume and thickness. Computerized cognitive training (CCT) and exercise improve cortical volume and thickness and thus, may promote gait speed. Slowing of gait is predictive of Alzheimer’s disease. Objective: To examine: 1) the effect of CCT, with or without physical exercise, on cortical volume and thickness and; 2) the association of changes in cortical volume and thickness with changes in gait speed. Methods: A subset of 124 adults (n = 53), aged 65–85 years, enrolled in an 8-week randomized controlled trial and completed T1-weighted MRI and 4-meter walk at baseline and 8 weeks. Participants were randomized to: 1) active control (BAT; n = 19); 2) CCT (n = 17); or 3) CCT preceded by exercise (Ex-CCT; n = 17). Change in cortical volume and thickness were assessed and compared across all groups using Freesurfer. RESULTS: BAT versus CCT increased left rostral middle frontal gyrus volume (p = 0.027) and superior temporal gyrus thickness (p = 0.039). Ex-CCT versus CCT increased left cuneus thickness (p &lt; 0.001) and right post central gyrus thickness (p = 0.005), and volume (p &lt; 0.001). Ex-CCT versus BAT increased left (p = 0.001) and right (p = 0.020) superior parietal gyri thickness. There were no significant between-group differences in gait speed (p &gt; 0.175). Increased left superior parietal volume (p = 0.036, r = 0.340) and thickness (p = 0.002, r = 0.348), right post central volume (p = .017, r = 0.341) and thickness (p = 0.001, r = 0.348), left banks of superior temporal sulcus thickness (p = 0.002, r = 0.356), and left precuneus thickness (p &lt; 0.001, r = 0.346) were associated with increased gait speed. CONCLUSIONS: CCT with physical exercise, but not CCT alone, improves cortical volume and thickness in older adults. These changes may contribute to the maintenance of gait speed in aging.

Impurities in 4H silicon carbide: Site preference, lattice distortion, solubility, and charge transition levels

4H Silicon carbide (SiC) is widely recognized as one of the most advanced wide bandgap semiconductors used in the production of high-efficiency power electronic devices. Impurities play a crucial role in achieving the desired electrical properties in 4H-SiC, yet the understanding of impurities in this material remains limited. In this study, first-principles formation-energy calculations were employed to establish a comprehensive database of formation-energy diagrams for impurities in 4H-SiC. This database includes valuable information on site preference, lattice distortion, solubility, and charge transition levels (CTLs) of the impurities. The site preference for each impurity is closely related to factors such as the Fermi energy, chemical potential, and the impurity species itself. To assess the lattice distortion caused by each impurity, a comparison was made between the volume changes before and after doping. Moreover, the solubility of each impurity was determined using the detailed balance theory, thereby enabling a direct measure of the maximum impurity concentration achievable in the material. Based on the CTLs, the impurities in 4H-SiC were classified into four categories: n-type impurities, p-type impurities, amphoteric impurities, and non-electroactive impurities. This comprehensive property database for impurities in 4H-SiC provides valuable insights for tailoring the material properties through controlled doping, thereby ultimately leading to enhanced performance of power electronic devices.

Regional Pulmonary Ventilation Assessment Method and System Based on Impedance Sensing Information from the Pentapulmonary Lobes

Regional lung ventilation assessment is a critical tool for the early detection of lung diseases and postoperative evaluation. Biosensor-based impedance measurements, known for their non-invasive nature, among other benefits, have garnered significant attention compared to traditional detection methods that utilize pressure sensors. However, solely utilizing overall thoracic impedance fails to accurately capture changes in regional lung air volume. This study introduces an assessment method for lung ventilation that utilizes impedance data from the five lobes, develops a nonlinear model correlating regional impedance with lung air volume, and formulates an approach to identify regional ventilation obstructions based on impedance variations in affected areas. The electrode configuration for the five lung lobes was established through numerical simulations, revealing a power–function nonlinear relationship between regional impedance and air volume changes. An analysis of 389 pulmonary function tests refined the equations for calculating pulmonary function parameters, taking into account individual differences. Validation tests on 30 cases indicated maximum relative errors of 0.82% for FVC and 0.98% for FEV1, all within the 95% confidence intervals. The index for assessing regional ventilation impairment was corroborated by CT scans in 50 critical care cases, with 10 validation trials showing agreement with CT lesion localization results.

Changes in monsoon precipitation in East Asia under a 2°C interglacial warming.

Past intervals of warming provide the unique opportunity to observe how the East Asia monsoon precipitation response happened in a warming world. However, the available evaluations are primarily limited to the last glacial-to-interglacial warming, which has fundamental differences from the current interglacial warming, particularly in changes in ice volume. Comparative paleoclimate studies of earlier warm interglacial periods can provide more realistic analogs. Here, we present high-resolution quantitative reconstructions of temperature and precipitation from north-central China over the past 800 thousand years. We found that the average precipitation increase, estimated by the interglacial data, was only around one-half of that estimated for the glacial-to-interglacial data, which is attributed to the amplification of climate change by ice volume variations. Analysis of the interglacial data suggests an increase in monsoon precipitation of ~100 mm for a warming level of 2°C on the Chinese Loess Plateau.

Structural Changes in the Dynamics of China’s Exports and Imports

The economic policy pursued has turned China into a major trading power. In terms of GDP, the Chinese economy has been the first economy in the world for a number of recent years; China’s rapidly growing trade flows have made it the largest trading partner for many countries. Over the past twenty years there has been rapid growth in exports and imports. The article puts forward a hypothesis about the presence of structural instability in the dynamics of Chinese exports for the period from 2000 to 2020. The hypothesis was confirmed and two periods were identified in the dynamics of exports and imports with different natures of the main development trend: from 2000 to 2008 and from 2009 to 2020. For each stage, trend equations were selected that describe the dynamics of exports and imports and an interval forecast of indexes for 2021 was made. Materials and methods. During the work, dynamic, structural analysis of analytical and statistical information was used; methods of analytical, logical, systemic, correlation and regression analysis were used, as well as analysis of structural changes. The analysis was carried out using the Statistica 10.0 program.Results. A change in the value of the import coverage ratio by exports was revealed before and after structural changes in the dynamics of the main foreign economic indexes and an assessment of their statistical significance was given. An analysis of the influence of export dynamics on GDP dynamics was carried out and it was found that before structural changes, the influence of export dynamics on GDP dynamics was statistically insignificant, and after a structural change, export dynamics began to have a direct impact on changes in China’s GDP. Conclusion. Analysis of official statistical data on the main indexes of China’s foreign economic activity for the period from 2000 to 2020 allowed us to note that the volume of Chinese exports increased over the period 2010-2019 from $1.58 trillion in 2010 (10.34% of global exports), to $2.50 trillion in 2019 (12.81% of global exports). In 2019, China continued to rank first in terms of export value among all countries in the world. Despite the challenging year of 2020, China’s exports reached almost 2.6 trillion US dollars and increased by 4% compared to 2019.China also occupies a leading position in the export of high-tech goods - their volume is 731.9 billion US dollars, the share of exports in the global volume is 25%. At the same time, the dynamics of Chinese exports for the period from 2000 to 2020 was heterogeneous and characterized by structural instability. Two stages can be distinguished with different characteristics of the main development trend: from 2000 to 2008 and from 2009 to 2020. Based on this, the authors came to the conclusion that to describe the main trend in the development of export and import dynamics for the period from 2000 to 2008, the exponential model is best suited. To describe the main trend in the development of export and import dynamics in the period from 2009 to 2020 - logarithmic model. A study of the consistency of changes in export and import volumes showed that in the period from 2009 to 2020 was characterized by greater consistency in China’s main foreign trade flows than the period from 2000 to 2008. In the period before the structural change in the dynamics of exports and imports, the coverage ratio varied from 105.7% to 127.6%; in the period after the structural change, the coverage ratio changed from 108.9% to 135.4%.Checking the statistical significance of the differences in the coefficient of coverage of imports by exports before and after the structural change showed that the differences are not statistically significant. In the period from 2000 to 2008 the dynamics of China’s exports did not have a statistically significant impact on the dynamics of the country’s GDP. From 2009 to 2020 after structural changes in the nature of the dynamics of the main indexes of China’s foreign trade, changes in exports began to have a statistically significant impact on the dynamics of GDP. A 1% increase in China’s exports now results in a 0.25% increase in GDP.The practical significance of the paper is determined by the developed methodology for analyzing structural changes in the dynamics of exports and imports, examined using the example of China.

Impact of Transjugular Intrahepatic Portosystemic Shunt on Hepatocellular Carcinoma: Prospective Cohort of Liver Transplant Candidates’ Analysis

Abstract Background Transjugular intrahepatic portosystemic shunt (TIPS) is used to mitigate the side effects of portal hypertension. However, its impact on hepatocellular carcinoma (HCC) remains unclear. Aims We aimed to evaluate its effect on HCC dynamics and patients’ survival. Methods We analysed 43’734 liver transplant candidates diagnosed with HCC from the prospective Scientific Registry of Transplant Recipients database (1985-2022). A total 7’404 patients with and without TIPS were propensity score matched 1:3. We assessed wait-list changes in total tumor volume, HCC count, and alpha-fetoprotein levels. We examined survival rates from time of listing and post-transplantation, as well as the incidence of HCC recurrence post-transplantation. Results Pre-matching, TIPS patients exhibited poorer liver function and less advanced HCCs. Post-matching, TIPS correlated with a decrease in HCC nodules count (-0.24 vs 0.11, p = 0.008) over a median waiting period of 225 days (IQR 94; 441) and better overall survival rate from listing (93.0% vs 89.1% at one year, p = 0.0003). TIPS was not associated with altered changes in waitlist tumor volume (0.26 vs -0.07 cm3/month, p = 0.26) and AFP (14.62 vs 12.67 ng/mL, p = 0.79) compared to the non-TIPS group. Post-transplant survival rates (91.8% vs 91.7% at one year, p = 0.25) and HCC recurrence (5.2% vs 5.4% at 5 years, p = 0.73) were similar, with a median follow-up of 5.6 years (IQR 2.7; 9.6) Conclusion TIPS improved waitlist survival and is associated with decreased HCC nodule count, potentially due to a better efficacy in HCC treatment. However, TIPS did not have a measurable impact on HCC growth or aggressiveness.

Predominant P3-Type Solid-Solution Phase Transition Enables High-Stability O3-Type Na-Ion Cathodes.

Layered O3-type oxides are one of the most promising cathode materials for Na-ion batteries owing to their high capacity and straightforward synthesis. However, these materials often experience irreversible structure transitions at elevated cutoff voltages, resulting in compromised cycling stability and rate performance. To address such issues, understanding the interplay of the composition, structure, and properties is crucial. Here, we successfully introduced a P-type characteristic into the O3-type layered structure, achieving a P3-dominated solid-solution phase transition upon cycling. This modification facilitated a reversible transformation of the O3-P3-P3' structure with minimal and gradual volume changes. Consequently, the Na0.75Ni0.25Cu0.10Fe0.05Mn0.15Ti0.45O2 cathode exhibited a specific capacity of approximately 113 mAh/g, coupled with exceptional cycling performance (maintaining over 70% capacity retention after 900 cycles). These findings shed light on the composition-structure-property relationships of Na-ion layered oxides, offering valuable insights for the advancement of Na-ion batteries.