An Intrinsic Stable Layered Oxide Cathode for Practical Sodium-Ion Battery: Solid Solution Reaction, Near-Zero-Strain and Marvelous Water Stability.

Non-aqueous solvents, in particular N,N-dimethylaniline (NMP), are widely applied for electrode fabrication since most sodium layered oxide cathode materials are readily damaged by water molecules. However, the expensive price and poisonousness of NMP unquestionably increase the cost of preparation and post-processing. Therefore, developing an intrinsically stable cathode material that can implement the water-soluble binder to fabricate an electrode is urgent. Herein, a stable nanosheet-like Mn-based cathode material is synthesized as a prototype to verify its practical applicability in sodium-ion batteries (SIBs). The as-prepared material displays excellent electrochemical performance and remarkable water stability, and it still maintains a satisfactory performance of 79.6% capacity retention after 500 cycles even after water treatment. The in situ X-ray diffraction (XRD) demonstrates that the synthesized material shows an absolute solid-solution reaction mechanism and near-zero-strain. Moreover, the electrochemical performance of the electrode fabricated with a water-soluble binder shows excellent long-cycling stability (67.9% capacity retention after 500 cycles). This work may offer new insights into the rational design of marvelous water stability cathode materials for practical SIBs.

Social anxiety modulating early processing for social threat words: an ERP study.

Even though some recent research revealed individuals with HSA typically display enhanced processing in the early stages of emotional information processing due to hypervigilance and vulnerability to negative stimuli, it is still unclear whether social anxiety affects the time course underlying processing bias for emotional stimuli. Therefore, the present study aimed to explore the early stage of processing social threat stimuli in high social anxiety (HSA) individuals by recording RTs and EEG data in the emotional Stroop task. Behavioral data showed that the HSA group responded to the threat words faster than neutral words (i.e. negative bias), but no emotional effects in the low social anxiety (LSA) group. Although the P1 component did not show any early effects, ERP data exhibited an enhanced N170 for HSA than for LSA groups. Threat words elicited larger N170 than neutral words in the LSA group only; this emotion effect was not evident in the HSA group. These findings indicated that social anxiety modulates early processing for social threat words. This study revealed the neural mechanisms underlying early emotional processing in individuals with social anxiety, providing insights for the evaluation and intervention of social anxiety.

Relationship between medication burden and medication experience in stable patients with schizophrenia: the mediating effect of medication belief.

BACKGROUND: Individuals with schizophrenia require prolonged antipsychotic medication treatment. But more than 50% of individuals with schizophrenia experience adverse medication experiences during their antipsychotic treatments. Such individuals often adjust or discontinue medication, leading to disease relapse and impaired social functioning. Psychiatric nurses should pay close attention to the medication experiences of individuals with schizophrenia. This research explore the relationship between medication burden and medication experience, as well as the mediating effect of medication belief in stable patients with schizophrenia. METHODS: A convenience sample of hospitalized stable patients with schizophrenia were selected from Daqing Third Hospital and Baiyupao Hospital from September 2023 to December 2023. A survey was conducted with them using a questionnaire consisting of general information questionnaire, The Subjective Well-being Under Neuroleptic Treatment Scale(SWN), The Living with Medicines Questionnaire(LMQ), Beliefs about Medicines Questionnaire-Specific (BMQ-Specific). Pearson correlation analysis was used to explore the correlation between LMQ, BMQ-Specific and SWN scores, and multiple linear regression analysis was used to explore the influencing factors of medication experience in patients with schizophrenia. AMOS 24.0 was used to construct the structural equation modeling(SEM), and the mediation effect of the SEM was tested using Bootstrap method. RESULTS: According to the sample size calculation requirements of structural equation model, a total of 300 samples were required in this study, and 400 effective questionnaires were actually collected in this study, which met the sample size requirements for constructing structural equation models. Bootstrap test showed that the mediation effect was significant. The total effect of medication burden on medication experience was significant (Z=-12.146, 95%CI (-0.577, -0.417), P < 0.001). The indirect effect of medication burden on medication experience, that is, the mediating effect of medication belief was significant (Z=-4.839, 95%CI (-0.217, -0.096), P < 0.001). The direct effect of medication burden on medication experience was significant (Z=-7.565, 95%CI (-0.437, -0.257), P < 0.001). This model belongs to partial mediation model. CONCLUSIONS: Psychiatric nurses can enhance the patients' medication experience by reducing medication burden and strengthening medication beliefs. Therefore, the results also provide theoretical references and decision-making foundations for psychiatric nursing professionals to develop appropriate management strategies for individuals with schizophrenia.

Two-dimensional Cu Plates with Steady Fluid Fields for High-rate Nitrate Electroreduction to Ammonia and Efficient Zn-Nitrate Batteries.

Nitrate electroreduction reaction (eNO3 -RR) to ammonia (NH3) provides a promising strategy for nitrogen utilization, while achieving high selectivity and durability at an industrial scale has remained challenging. Herein, we demonstrated that the performance of eNO3 -RR could be significantly boosted by introducing two-dimensional Cu plates as electrocatalysts and eliminating the general carrier gas to construct a steady fluid field. The developed eNO3 -RR setup provided superior NH3 Faradaic efficiency (FE) of 99 %, exceptional long-term electrolysis for 120 h at 200 mA cm-2, and a record-high yield rate of 3.14 mmol cm-2 h-1. Furthermore, the proposed strategy was successfully extended to the Zn-nitrate battery system, providing a power density of 12.09 mW cm-2 and NH3 FE of 85.4 %, outperforming the state-of-the-art eNO3 -RR catalysts. Coupled with the COMSOL multiphysics simulations and in situ infrared spectroscopy, the main contributor for the high-efficiency NH3 production could be the steady fluid field to timely rejuvenate the electrocatalyst surface during the electrocatalysis.

White matter damage as a consequence of vascular dysfunction in a spontaneous mouse model of chronic mild chronic hypoperfusion with eNOS deficiency.

Vascular cognitive impairment and dementia (VCID) is the second most common form of dementia after Alzheimer's disease (AD). Currently, the mechanistic insights into the evolution and progression of VCID remain elusive. White matter change represents an invariant feature. Compelling clinical neuroimaging and pathological evidence suggest a link between white matter changes and neurodegeneration. Our prior study detected hypoperfused lesions in mice with partial deficiency of endothelial nitric oxide (eNOS) at very young age, precisely matching to those hypoperfused areas identified in preclinical AD patients. White matter tracts are particularly susceptible to the vascular damage induced by chronic hypoperfusion. Using immunohistochemistry, we detected severe demyelination in the middle-aged eNOS-deficient mice. The demyelinated areas were confined to cortical and subcortical areas including the corpus callosum and hippocampus. The intensity of demyelination correlated with behavioral deficits of gait and associative recognition memory performances. By Evans blue angiography, we detected blood-brain barrier (BBB) leakage as another early pathological change affecting frontal and parietal cortex in eNOS-deficient mice. Sodium nitrate fortified drinking water provided to young and middle-aged eNOS-deficient mice completely prevented non-perfusion, BBB leakage, and white matter pathology, indicating that impaired endothelium-derived NO signaling may have caused these pathological events. Furthermore, genome-wide transcriptomic analysis revealed altered gene clusters most related to mitochondrial respiratory pathways selectively in the white matter of young eNOS-deficient mice. Using eNOS-deficient mice, we identified BBB breakdown and hypoperfusion as the two earliest pathological events, resulting from insufficient vascular NO signaling. We speculate that the compromised BBB and mild chronic hypoperfusion trigger vascular damage, along with oxidative stress and astrogliosis, accounting for the white matter pathological changes in the eNOS-deficient mouse model. We conclude that eNOS-deficient mice represent an ideal spontaneous evolving model for studying the earliest events leading to white matter changes, which will be instrumental to future therapeutic testing of drug candidates and for targeting novel/specific vascular mechanisms contributing to VCID and AD.

Cumulative genetic score of KIAA0319 affects reading ability in Chinese children: moderation by parental education and mediation by rapid automatized naming.

KIAA0319, a well-studied candidate gene, has been shown to be associated with reading ability and developmental dyslexia. In the present study, we investigated whether KIAA0319 affects reading ability by interacting with the parental education level and whether rapid automatized naming (RAN), phonological awareness and morphological awareness mediate the relationship between KIAA0319 and reading ability. A total of 2284 Chinese children from primary school grades 3 and 6 participated in this study. Chinese character reading accuracy and word reading fluency were used as measures of reading abilities. The cumulative genetic risk score (CGS) of 13 SNPs in KIAA0319 was calculated. Results revealed interaction effect between CGS of KIAA0319 and parental education level on reading fluency. The interaction effect suggested that individuals with a low CGS of KIAA0319 were better at reading fluency in a positive environment (higher parental educational level) than individuals with a high CGS. Moreover, the interaction effect coincided with the differential susceptibility model. The results of the multiple mediator model revealed that RAN mediates the impact of the genetic cumulative effect of KIAA0319 on reading abilities. These findings provide evidence that KIAA0319 is a risk vulnerability gene that interacts with environmental factor to impact reading abilities and demonstrate the reliability of RAN as an endophenotype between genes and reading associations.

Metal-Free Stereoconvergent C-H Borylation of Enamides.

Enamides, functional derivatives of enamines, play a significant role as synthetic targets. However, the stereoselective synthesis of these molecules has posed a longstanding challenge in organic chemistry, particularly for acyclic enamides that are less thermodynamically stable. In this study, we present a general strategy for constructing ß-borylenamides by C-H borylation, which provides a versatile platform for generating the stereodefined enamides. Our approach involves the utilization of metalloid borenium cation, generated through the reaction of BBr3 and enamides in the presence of two different additives, avoiding any exogenous catalyst. Importantly, the stereoconvergent nature of this methodology allows for the use of starting materials with mixed E/Z configurations, thus highlighting the unique advantage of this chemistry. Mechanistic investigations have shed light on the pivotal roles played by the two additives, the reactive boron species, and the phenomenon of stereoconvergence.

Lymphocyte-to-monocyte ratio associated with severe post-stenotic aortic dilation in a case-control study.

BACKGROUND: Calcific aortic valve stenosis (CAVS) represents a serious health threat to elderly patients. Post-stenotic aortic dilation, a common feature in CAVS patients, might progress into aneurysm and even dissection, potential consequences of CAVS, and predicts a poor prognosis. This study sought to investigate the association of lymphocyte-to-monocyte ratio (LMR), an inflammatory biomarker, with severe post-stenotic aortic dilation in a case-control study in Chinese population. MATERIALS AND METHODS: 208 consecutive patients with CAVS were recruited retrospectively in a case-control study in Chinese population, from July 1, 2015 to June 31, 2018. LMR was statistically analyzed using the ROC curve and binary logistic regression analyses for its prognostic value in severe post-stenotic aortic dilation. RESULTS: LMR was significantly reduced in patients with severe post-stenotic aortic dilation (2.72 vs. 3.53, p = 0.002 < 0.05) compared to patients without severe post-stenotic aortic dilation. There was an inverse correlation observed between the maximal diameter of ascending aorta and LMR in the overall patients (r = - 0.217, p = 0.002 < 0.05). For post-stenotic aortic dilation, the prevalence of high-LMR group was statistically lower than that of low-LMR group (19.7% vs. 43.9%, p < 0.001). The maximal diameter of ascending aorta was significantly reduced in the high-LMR group (4.35 vs. 4.76, p = 0.003 < 0.05) compared to low-LMR group. Additionally, LMR was identified in the multivariate analysis independently associated with severe post-stenotic aortic dilation (AUC 0.743, 95% CI: [0.573-0.964], p = 0.025). CONCLUSIONS: This study provided the evidence of an inverse correlation between severe post-stenotic aortic dilation and LMR. LMR is potentially independently associated with severe post-stenotic aortic dilation.

Beating signals in CdSe quantum dots measured by low-temperature 2D spectroscopy.

Advances in ultrafast spectroscopy can provide access to dynamics involving nontrivial quantum correlations and their evolutions. In coherent 2D spectroscopy, the oscillatory time dependence of a signal is a signature of such quantum dynamics. Here, we study such beating signals in electronic coherent 2D spectroscopy of CdSe quantum dots (CdSe QDs) at 77 K. The beating signals are analyzed in terms of their positive and negative Fourier components. We conclude that the beatings originate from coherent LO-phonons of CdSe QDs. No evidence for the QD size dependence of the LO-phonon frequency was identified.

Microenvironment Engineering for the Electrocatalytic CO2 Reduction Reaction.

Rather than just focusing on the catalyst itself in the electrocatalytic CO2 reduction reaction (eCO2 RR), as previously reviewed elsewhere, we herein extend the discussion to the special topic of the microenvironment around the electrocatalytic center and present a comprehensive overview of recent research progress. We categorize the microenvironment based on the components relevant to electrocatalytic active sites, i.e., the catalyst surface, substrate, co-reactants, electrolyte, membrane, and reactor. Supported by most of the reported articles, the relevant factors affecting the catalytic performance of eCO2 RR are then discussed in detail, and existing challenges and potential solutions are mentioned. Perspectives for the future research on eCO2 RR, including the integration of different microenvironment factors, the extension to industrial application by coupling with carbon capture and conversion, and separation of products, are also discussed.

Birefringent Silk Fibroin Hydrogel Constructed via Binary Solvent-Exchange-Induced Self-Assembly.

Birefringent hydrogels have a strong potential for applications in biomedicine and optics as they can modulate the optical and mechanical anisotropy in confined two-dimensional geometries. However, production of birefringent hydrogels with hierarchical structures, mechanical properties, and biorelated behavior that are analogous to biological tissues is still challenging. Starting from the silk fibroin (SF)-ionic liquid solution system, this study aimed to rationally design a "binary solvent-exchange-induced self-assembly (BSEISA)" strategy to produce birefringent SF hydrogels (SFHs). In this method, the conformational transition rate of SF can be effectively controlled by the exchange rate of the binary solvents. Therefore, this method provides the possibility of controlling the conformation and orientation of SF. Molecular simulations confirmed that methanol is more effective in driving ß-sheet formation than other often used solvents, such as formic acid and water. The formed ß-sheets act as the physical cross-links that connect disparate protein chains, thereby forming continuous and stable three-dimensional (3D) hydrogel networks. The resultant BSEISA-SFHs are transparent and birefringent with mechanical characteristics similar to those of soft biological tissues, such as lens and cartilage. Interestingly, our results revealed that the evolution of experimental birefringent fringes perfectly matched the changes in stress distribution predicted using finite element analysis. Owing to the unique birefringence of BSEISA-SFHs, together with the advantages in mechanical performance, these hydrogels are anticipated to act as good tissue surrogates for understanding the mechanical response of biological tissues.

Metal-Free Directed C-H Borylation of Pyrroles.

Robust strategies to enable the rapid construction of complex organoboronates in selective, practical, low-cost, and environmentally friendly modes remain conspicuously underdeveloped. Here, we develop a general strategy for the site-selective C-H borylation of pyrroles by using only BBr3 directed by pivaloyl groups, avoiding the use of any metal. The site-selectivity is generally dominated by chelation and electronic effects, thus forming diverse C2-borylated pyrroles against the steric effect. The formed products can readily engage in downstream transformations, enabling a step-economic process to access drugs such as Lipitor. DFT calculations (wB97X-D) demonstrate the preferred positional selectivity of this reaction.

Expression of pulmonary arterial elastin in rats with hypoxic pulmonary hypertension using H2S.

Object: This study analyses the changes of pulmonary arterial elastin expression inhibited by hydrogen sulfide (H2S) in rats with hypoxic pulmonary hypertension.Method: The research used 30 healthy rats and randomly divided them into control group, hypoxia group, and hypoxia + sodium hydrosulfide group. Each group contains 10 samples. The right catheterization was selected to measure the mean pulmonary artery pressure (mPAP). The RV/LV + S ratio was calculated through separating the right ventricle and the left ventricle plus the interventricular septum. Optical microscopy was used to observe the changes of pulmonary vascular structure. The research used immunohistochemistry to express the levels of elastin and transforming growth factor beta (TGF-ß).Results: The ratios of Mpap and RV/LV + S in the hypoxic group exceed the control group. The hypoxia + sodium hydrosulfide group (hypoxia + NaHS) is lower than the hypoxic group. In the hypoxic group, the elastic expressions of medium and small pulmonary artery smooth muscle cells exceed the control group. The expression of elastin in hypoxic + NaHS medium and small pulmonary artery smooth muscle cells is lower than that of the control group.The protein expression levels of α-SM-actin in muscle arterial smooth muscle of pulmonary arterioles in hypoxic group, control group and hypoxic + NaHS group were 49.84% + 6.27%, 56.84% + 6.38%, 23.82% + 3.84%, 27.51% + 3.24%, 29.00% + 4.05%, 34.72% + 3.38%.Conclusion: Hydrogen sulfide in rats with hypoxic pulmonary hypertension can inhibit the expression of elastin in its extracellular matrix, which also has remarkable regulation function in forming HPH and remodeling hypoxic pulmonary vascular structure.

Radical-Polar Crossover Annulation: A Platform for Accessing Polycyclic Cyclopropanes.

Photoredox-mediated radical/polar crossover (RPC) processes provide unique solutions to challenging annulations. Herein, we describe an approach to the cyclopropanation of olefins that are embedded within bicyclic scaffolds. Whereas these systems are notoriously recalcitrant toward classical cyclopropanation approaches, RPC cyclopropanation can be executed with ease, leading to polycarbocyclic and polyheterocyclic cyclopropanes. The cyclopropanation proceeds through a photoredox-enabled Giese-type radical addition followed by an intramolecular anionic substitution reaction on a neopentyl leaving group.

Compressed Sensing for Reconstructing Coherent Multidimensional Spectra.

We apply two sparse reconstruction techniques, the least absolute shrinkage and selection operator (LASSO) and the sparse exponential mode analysis (SEMA), to two-dimensional (2D) spectroscopy. The algorithms are first tested on model data, showing that both are able to reconstruct the spectra using only a fraction of the data required by the traditional Fourier-based estimator. Through the analysis of the sparsely sampled experimental fluorescence-detected 2D spectra of LH2 complexes, we conclude that both SEMA and LASSO can be used to significantly reduce the required data, still allowing one to reconstruct the multidimensional spectra. Of the two techniques, it is shown that SEMA offers preferable performance, providing more accurate estimation of the spectral line widths and their positions. Furthermore, SEMA allows for off-grid components, enabling the use of a much smaller dictionary than that of the LASSO, thereby improving both the performance and the lowering of the computational complexity for reconstructing coherent multidimensional spectra.

Endothelial-to-Mesenchymal Transition in Calcific Aortic Valve Disease.

Calcific aortic valve disease (CAVD) represents a significant threat to cardiovascular health worldwide, and the incidence of this sclerocalcific valve disease has rapidly increased along with a rise in life expectancy. Compelling evidence has suggested that CAVD is an actively and finely regulated pathophysiological process even though it has been referred to as "degenerative" for decades. A striking similarity has been noted in the etiopathogenesis between CAVD and atherosclerosis, a classical proliferative sclerotic vascular disease.1 Nevertheless, pharmaceutical trials that attempted to target inflammation and dyslipidemia have produced disappointing results in CAVD. While senescence is a well-documented risk factor, the sophisticated regulatory networks have not been adequately explored underlying the aberrant calcification and osteogenesis in CAVD. Valvular endothelial cells (VECs), a type of resident effector cells in aortic leaflets, are crucial in maintaining valvular integrity and homeostasis, and dysfunctional VECs are a major contributor to disease initiation and progression. Accumulating evidence suggests that VECs undergo a phenotypic and functional transition to mesenchymal or fibroblast-like cells in CAVD, a process known as the endothelial-to-mesenchymal transition (EndMT) process. The relevance of this transition in CAVD has recently drawn great interest due to its importance in both valve genesis at an embryonic stage and CAVD development at an adult stage. Hence EndMT might be a valuable diagnostic and therapeutic target for disease prevention and treatment. This mini-review summarized the relevant literature that delineates the EndMT process and the underlying regulatory networks involved in CAVD.

Stored red blood cells enhance in vivo migration of dendritic cells by promoting reactive oxygen species-induced cytoskeletal rearrangement.

BACKGROUND: A complex array of physicochemical changes occurs in red blood cells (RBCs) during storage, leading to enhanced posttransfusion clearance. Dendritic cells (DCs) play crucial roles in the engulfment of aged RBCs; however, it is unclear how stored RBCs (sRBCs) modulate their responses to inflammatory stimuli and DC migration ability. STUDY DESIGN AND METHODS: In this study, we examined whether sRBCs affect the migration ability of DCs and elucidated the detailed mechanisms mediating this process. Murine RBCs were incubated with marrow DCs after removing the storage supernatant. The effects of sRBCs on cytokine secretion from DCs, surface marker expression, and homing ability were examined. RESULTS: More sRBCs were internalized by DCs than fresh RBCs (fRBCs), and RBC accumulation significantly promoted the expression of allostimulatory molecules and the secretion of Th1-type cytokines in the presence of lipopolysaccharide (LPS). In particular, the lymphoid-tissue homing ability of transfused DCs treated with sRBCs (sRBC-DCs) was also significantly greater than that of fRBCs. Up regulation of CCR7 and improved organization of the cytoskeleton were observed in sRBC-DCs, and blocking Rho/Rho-associated protein kinase (ROCK), PI3K/Akt, and NF-κB pathways greatly hindered cytoskeletal rearrangement. Moreover, high levels of reactive oxygen species (ROS) were detected in sRBC-DCs, and treatment with N-acetylcysteine simultaneously decreased the lymph node-homing ability of DCs and phosphorylation of RhoA, ROCK1, and cortactin. CONCLUSIONS: sRBCs initiated differential immune responses compared to fRBCs, and the presence of LPS augmented this phenomenon. Up regulation of CCR7 and ROS production promotes cytoskeletal reorganization and contributes to the increased homing of sRBCs-DCs.

Noninvasive imaging of hepatocyte IL-6/STAT3 signaling pathway for evaluating inflammation responses induced by end-stage stored whole blood transfusion.

OBJECTIVE: To monitor the inflammatory storage lesions of end-stage stored whole blood (SWB) using a noninvasive STAT3 signal pathway mouse model. RESULTS: In this study, we present a hydrodynamic transfection-based STAT3-Luc mouse model in which hepatocyte STAT3 signal pathway activation can be monitored by measuring luciferase activity using a noninvasive imaging system. Such a mouse model may reflect systemic IL-6 and inflammation levels by monitoring the activation of STAT3. During end-stage SWB transfusion, in vivo imaging of STAT3-Luc mice showed obvious luciferase activity in the hepatic region, which was consistent with an increase in IL-6 levels in the liver homogenate and circulation. We also confirmed that the mononuclear phagocytic system contributed to the elevation of serum and liver IL-6 after end-stage SWB transfusion. CONCLUSION: The hepatocyte STAT3 signaling pathway, which is activated by end-stage SWB transfusion, is associated with the elevation of systemic IL-6 secreted by macrophages. The STAT3-Luc mouse may serve as a mouse model for monitoring inflammation responses after end-stage SWB transfusion.

Predictive Roles of Neutrophil-to-Lymphocyte Ratio and C-Reactive Protein in Patients with Calcific Aortic Valve Disease.

The neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) are emerging indirect blood markers to roughly reflect the inflammation level in our body while some pathological changes occurring in aortic valve tissue. Few recent studies demonstrated that NLR is related to calcific aortic valve disease (CAVD). However, the extent of the relationship between them and the impact of CRP on CAVD are not clear. This study aimed to investigate the diagnostic influence and surgical predictive effect of NLR and CRP on CAVD.A total of 278 consecutive patients with CAVD (123 patients with bicuspid aortic valve and others with tricuspid aortic valve) and 108 healthy individuals who were included in the control group were enrolled in the study. The NLR was calculated from the complete blood count, and the CRP was measured from peripheral blood samples. Echocardiography was used to evaluate the severity of aortic stenosis. Intraoperation/postoperation indicators were collected in 166 patients from the total consecutive patients who underwent aortic valve replacement (AVR) alone.Significantly higher NLR was measured in both the BAV group (1.96 ± 0.78 versus 0.97 ± 0.15, P < 0.001) and the TAV group (2.51 ± 2.03 versus 0.97 ± 0.15, P < 0.001) compared with the control group. Moreover, the NLR level was significantly higher (P < 0.001) and the CRP level was significantly lower (P = 0.007) of the TAV group than that of the BAV group; a significant positive correlation between the NLR and the maximum gradient of aortic valve was detected. Furthermore, there was a moderate correlation between the NLR and the postoperative mechanical ventilation time.Our results indicated that the NLR and CRP were novel and useful predictive factors in patients with CAVD, and these two potential factors have guiding significance for the prediction of different pathological typing (BAV or TAV). Higher NLR level will not extend the cardiopulmonary bypass time (CPB); however, it will prolong the operation time and the postoperative mechanical ventilation time.