Chronological-Programmed Black Phosphorus Hydrogel for Responsive Modulation of the Pathological Microenvironment in Myocardial Infarction.

Electroactive hydrogels have garnered extensive interest as a promising approach to myocardial tissue engineering. However, the challenges of spatiotemporal-specific modulation of individual pathological processes and achieving nontoxic bioresorption still remain. Herein, inspired by the entire postinfarct pathological processes, an injectable conductive bioresorbable black phosphorus nanosheets (BPNSs)-loaded hydrogel (BHGD) was developed via reactive oxide species (ROS)-sensitive disulfide-bridge and photomediated cross-linking reaction. Significantly, the chronologically programmed BHGD hydrogel can achieve graded modulation during the inflammatory, proliferative, and maturation phases of myocardial infarction (MI). More details, during early infarction, the BHGD hydrogel can effectively reduce ROS levels in the MI area, inhibit cellular oxidative stress damage, and promote macrophage M2 polarization, creating a favorable environment for damaged myocardium repair. Meanwhile, the ROS-responsive structure can protect BPNSs from degradation and maintain good conductivity under MI microenvironments. Therefore, the BHGD hydrogel possesses tissue-matched modulus and conductivity in the MI area, facilitating cardiomyocyte maturation and electrical signal exchange, compensating for impaired electrical signaling, and promoting vascularization in infarcted areas in the maturation phase. More importantly, all components of the hydrogel degrade into nontoxic substances without adverse effects on vital organs. Overall, the presented BPNS-loaded hydrogel offers an expandable and safe option for clinical treatment of MI.

Ceramides and pro-inflammatory cytokines for the prediction of acute coronary syndrome: a multi-marker approach.

BACKGROUND: There is a growing body of evidence supporting the significant involvement of both ceramides and pro-inflammatory cytokines in the occurrence and progression of acute coronary syndrome (ACS). METHODS: This study encompassed 216 participants whose laboratory variables were analysed using standardised procedures. Parameters included baseline serum lipid markers, comprising total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglycerides (TGs), lipoprotein(a) (LPa), fasting blood glucose, B-natriuretic peptide and hypersensitive C-reactive protein. Liquid chromatography-tandem mass spectrometry measured the concentrations of plasma ceramides. Enzyme-linked immunosorbent assay quantified tumour necrosis factor-α (TNF-α), interleukin 6 (IL6) and IL8. The correlation between ceramides and inflammatory factors was determined through Pearson's correlation coefficient. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression evaluated the diagnostic potential of models incorporating traditional risk factors, ceramides and pro-inflammatory cytokines in ACS detection. RESULTS: Among the 216 participants, 138 (63.89%) were diagnosed with ACS. Univariate logistic regression analysis identified significant independent predictors of ACS, including age, gender, history of diabetes, smoking history, TGs, TNF-α, IL-6, ceramide (d18:1/16:0), ceramide (d18:1/18:0), ceramide (d18:1/24:0), ceramide (d18:1/20:0) and ceramide (d18:1/22:0). Multivariate logistic regression analysis revealed significant associations between gender, diabetes mellitus history, smoking history, LPa, IL-6, ceramide (d18:1/16:0) and ACS. Receiver operating characteristic analysis indicated that model 4, which integrated traditional risk factors, IL-6 and ceramide (d18:1/16:0), achieved the highest area under the curve (AUC) of 0.827 (95% CI 0.770-0.884), compared with model 3 (traditional risk factors and ceramide [d18:1/16:0]) with an AUC of 0.782 (95% CI 0.720-0.845) and model 2 (traditional risk factors and IL-6), with an AUC of 0.785 (95% CI 0.723-0.846) in ACS detection. CONCLUSIONS: In summary, incorporating the simultaneous measurement of traditional risk factors, pro-inflammatory cytokine IL-6 and ceramide (d18:1/16:0) can improve the diagnostic accuracy of ACS.

Novel Evodiamine-Based Sulfonamide Derivatives as Potent Insecticide Candidates Targeting Insect Ryanodine Receptors.

Pests represent an important impediment to efficient agricultural production and pose a threat to global food security. On the basis of our prior research focused on identifying insecticidal leads targeting insect ryanodine receptors (RyRs), we aimed to identify evodiamine scaffold-based novel insecticides. Thus, a variety of evodiamine-based derivatives were designed, synthesized, and assessed for their insecticidal activity against the larvae of Mythimna separata (M. separata) and Plutella xylostella (P. xylostella). The preliminary bioassay results revealed that more than half of the target compounds exhibited superior activity compared to evodiamine, matrine, and rotenone against M. separata. Among these, compound 21m displayed the most potent larvicidal efficiency, with a remarkable mortality rate of 93.3% at 2.5 mg/L, a substantial improvement over evodiamine (10.0% at 10 mg/L), matrine (10.0% at 200 mg/L), and rotenone (30.0% at 200 mg/L). In the case of P. xylostella, compounds 21m and 21o displayed heightened larvicidal activity, boasting LC50 values of 9.37 × 10-2 and 0.13 mg/L, respectively, surpassing that of evodiamine (13.41 mg/L), matrine (291.78 mg/L), and rotenone (18.39 mg/L). A structure-activity relationship analysis unveiled that evodiamine-based derivatives featuring a cyclopropyl sulfonyl group at the nitrogen atom of the B ring and a fluorine atom in the E ring exhibited more potent larvicidal effects. This finding was substantiated by calcium imaging experiments and molecular docking, which suggested that 21m could target insect RyRs, including resistant mutant RyRs of P. xylostella (G4946E and I4790M), with higher affinity than chlorantraniliprole (CHL). Additionally, cytotoxicity assays highlighted that the potent compounds 21i, 21m, and 21o displayed favorable selectivity and low toxicity toward nontarget organisms. Consequently, compound 21m emerges as a promising candidate for further development as an insecticide targeting insect RyRs.

Injectable Asymmetric Adhesive-Antifouling Bifunctional Hydrogel for Peritoneal Adhesion Prevention.

Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro-wound healing properties of existing anti-adhesion barriers, this work reports an injectable adhesive-antifouling bifunctional hydrogel (AAB-hydrogel). This AAB-hydrogel can be constructed by "two-step" injection. The tissue adhesive hydrogel based on gallic acid-modified chitosan and aldehyde-modified dextran is prepared as the bottom hydrogel (B-hydrogel) by Schiff base reaction. The aldehyde-modified zwitterionic dextran/carboxymethyl chitosan-based hydrogel is formed on the B-hydrogel surface as the antifouling top hydrogel (T-hydrogel). The AAB-hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti-adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion-cecum defect model. Results suggest that the AAB-hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB-hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB-hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.

Association of age-adjusted Charlson comorbidity index with adverse outcomes in patients undergoing transcatheter aortic valve replacement: A retrospective cohort study.

Patients undergoing transcatheter aortic valve replacement (TAVR) have a high comorbid burden. Our objective was to assess the association between the age-adjusted Charlson comorbidity index (Age-CCI) and mortality and readmission rates within 1-year post-TAVR. Data were extracted from the Medical Information Mart for Intensive Care IV database (MIMIC-IV version 2.0). The primary endpoint was a composite outcome of all-cause mortality or readmission within 1-year after TAVR. To examine the associations of Age-CCI with outcomes, we used multivariable Cox proportional hazards regression, restricted cubic spline (RCS), and Kaplan-Meier curves. A total of 785 patients (52.9% male) with a median age of 84.0 years were assessed. More than half of our patients had an Age-CCI ≥ 7. After adjustment for potential confounders, we found that a 1 unit increase in Age-CCI was associated with a 10% increase in mortality and readmission rates after TAVR (HR = 1.10, 95% CI: 1.04-1.17, P < .001). High Age-CCI (Age-CCI ≥ 7) compared with the low Age-CCI (Age-CCI < 7) showed a 36% increase of mortality and readmission rates (HR = 1.36, 95% CI: 1.07-1.73, P = .013). The RCS curve analysis showed a continuous linear relationship between Age-CCI and the composite outcome risk (P for non-linearity = .671). The Kaplan-Meier survival analysis showed that patients with Age-CCI ≥ 7 had a poorer prognosis than those with Age-CCI < 7 (log-rank P < .001). Subgroup analyses showed the results remained stable. Age-CCI is independently associated with all-cause mortality and readmission in patients treated with TAVR, which may help clinicians risk-stratify patients and offer an opportunity to improve patient outcomes.

Injectable spontaneously formed asymmetric adhesive hydrogel with controllable removal for wound healing.

Healing large-scale wounds has been a long-standing challenge in the field of biomedicine. Herein, we propose an injectable oxidated sodium alginate/gelatin/3,3'-dithiobis(propionic hydrazide)-aurum (Alg-CHO/gelatin/DTPH-Au) hydrogel filler with asymmetric adhesion ability and removability, which is formed by the Schiff-base reaction between aldehyde-based sodium alginate and multi-amino crosslinkers (gelatin and DTPH), combined with the coordination interaction between Au nanoparticles and disulfide bond of DTPH. Consequently, the prepared Alg-CHO/gelatin/DTPH-Au hydrogel exhibits high mechanical properties and injectable behaviors owing to its multiple-crosslinked interactions. Moreover, because various types of interaction bonding form on the contact side with the tissue, denser crosslinking of the upper layer relative to the lower layer occurs. Combined with the temperature difference between the upper and lower surfaces, this results in asymmetric adhesive properties. Owing to the photothermal effect, the reversible coordination interaction between Au nanoparticles and DTPH and the change in the triple helix structure of gelatin to a coil structure impart the filler-phased removability and antibacterial ability. The choice of all natural polymers also allows for favorable degradability of the wound filler and outstanding biocompatibility. Based on these features, this versatile wound filler can achieve a wide range of applications in the field of all-skin wound repair.

Non-linear association between aspartate aminotransferase to alanine aminotransferase ratio and mortality in critically ill older patients: A retrospective cohort study.

BACKGROUND: The aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio has been shown to be associated with poor clinical outcomes across various patient groups. However, little is unclear about the association between the two in critically ill older patients. Therefore, we aim to investigate the association of the AST/ALT ratio with hospital mortality in this special population. METHODS: In this retrospective cohort study, we extracted elderly patients (age ≥ 65 years) from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary outcome was in-hospital mortality. The association between the AST/ALT ratio and hospital mortality was studied using univariable and multivariable Cox regression analysis, as well as restricted cubic splines (RCS). Survival analysis was performed using the Kaplan-Meier (KM) method according to the AST/ALT ratio. RESULTS: Among the 13,358 eligible patients, the mean age was 77.6 years, 7,077 patients (52.9%) were male, and 2,511 patients (18.8%) died in hospital. The AST/ALT ratio was found to be independently associated with in-hospital mortality (HR = 1.05, 95% CI: 1.01-1.09, P = 0.022) after adjusting for potential confounders. Furthermore, a non-linear relationship and saturation effect were observed between them, with the inflection point being 1.80. When the AST/ALT ratio was less than 1.80, we found that every 1 unit increase in the AST/ALT ratio resulted in a 39% increased risk of in-hospital mortality (HR = 1.39, 95% CI: 1.18-1.64, P < 0.001). However, when the AST/ALT ratio was greater than 1.80, the association became saturated (HR = 1.01, 95% CI: 0.96-1.07, P = 0.609). Sensitivity and subgroup analyses showed the results were robust. CONCLUSION: In critically ill older patients, the association between the AST/ALT ratio and in-hospital mortality was non-linear and showed a saturation effect. An elevated AST/ALT ratio was significantly associated with increased in-hospital mortality when the AST/ALT ratio was less than 1.80.

A Zwitterionic Hydrogel with Anti-Oxidative and Anti-Inflammatory Properties for the Prevention of Peritoneal Adhesion by Inhibiting Mesothelial-Mesenchymal Transition.

Postoperative peritoneal adhesion is a serious clinical complication. Various hydrogel barriers have been developed to prevent peritoneal adhesion. However, it remains a challenge to design a hydrogel with desirable physicochemical properties and bioactivities. In this study, a zwitterionic polysaccharide-based multifunctional hydrogel is developed using epigallocatechin-3-gallate (EGCG) to prevent postoperative abdominal adhesion. This hydrogel is simple to use and has desirable properties, such as excellent injectability, self-healing, and non-swelling properties. The hydrogel also has ultralow fouling capabilities, such as superior bactericidal performance, cell and protein adhesion, and low immunogenicity resistance. Moreover, the hydrogel exhibits good antioxidant activity, which is attributed to the integration of EGCG. Furthermore, the detailed mechanism from in vivo and in vitro experimental studies illustrates that hydrogel compositions can synergistically prevent adhesion formation through multiple pathways, including anti-inflammatory and antioxidant capabilities and inhibition effects on the mesothelial-mesenchymal transition (MMT) process induced by transforming growth factor (TGF-ß). In summary, this zwitterionic multifunctional hydrogel has great potential to prevent postoperative adhesion formation in the clinical setting.

Differentiating the DF effect in episodic memory: evaluating the contribution of the procedures of collaborative memory.

Existing research has demonstrated a significant directed forgetting (DF) effect in memory. However, it remains unclear whether this phenomenon would occur in the context of interpersonal collaboration. Additionally, the contribution of emotional valence to the DF effect in item memory and source memory (which are subtypes of episodic memory) also needs to be explored. To address these issues, we conducted two experiments that combined the collaborative memory paradigm with the item-method procedure of DF. In both experiments, positive, neutral, or negative words were presented as stimuli, each followed by an R/F cue during encoding. We conducted two recalls, labeled Recall 1 and Recall 2, which consisted of both memory tasks. Recall 1 was performed either individually or collaboratively, whereas Recall 2 was done individually. Experiment 1 and Experiment 2 adopted the free-flowing procedure and the turn-taking procedure of collaborative memory, respectively. We obtained three implications from our current findings. (a) The occurrence of the DF effect in item memory was found regardless of the procedure of collaborative memory, and it was insensitive to the emotional valence of words or to whether participants had collaborated or not. These patterns demonstrate that both the mechanisms of elaborative rehearsal and active suppression/encoding blocking were engaged across words of different emotional valences and in nominal and collaborative circumstances. (b) In source memory, the DF effect showed different patterns in ongoing and post-collaborative memory, which underpins the dual-process models. (c) The amplitude of the DF effect was sensitive to the interaction of emotional valence by the status of collaboration, and the impact of collaboration differed between the two experiments, offering telling evidence of different aspects of the retrieval strategy disruption hypothesis (RSDH). Directions for identifying more influential factors are put forward.

Myeloid-specific knockout of SHP2 regulates PI3K/PLCγ signaling pathway to protect against early myocardial infarction injury.

OBJECTIVES: To study the effects of myeloid-specific knockout of SHP2 on early myocardial infarction and explore its molecular mechanism. METHODS: The model of myocardial infarction was established by using SHP2 in myeloid-specific knockout mice, and the effect of SHP2MAC-KO on myocardial function was detected by echocardiography. The effects of SHP2 on myocardial infarct size in myeloid-specific knockout mice was examined by TTC assay and Masson staining. Then, the detection of apoptosis was performed using TUNEL staining and inflammatory cell infiltration was observed using immunohistochemical staining. Moreover, macrophages in mouse hearts were selected by Flow Cytometry and treated with PI3K inhibitors respectively. Western blotting was then used to detect protein expression of p-SHP2 and PI3K/PLCγ signaling pathway. The phagocytic ability of cells was detected by endocytosis test, and the expression of inflammatory cytokines was detected by ELISA. RESULTS: Specific knockout of SHP2 in mice with myocardial infarction can improve the cardiac function, decrease infarct size, and reduce apoptosis as well as inflammatory cell infiltration. It also can mediate the PI3K/PLCγ signaling pathway in macrophages, which in turn enhances the endocytosis of macrophages and reduces the expression of inflammatory cytokines in macrophages. CONCLUSIONS: Myeloid-specific knockout of SHP2 regulates PI3K/PLCγ signaling pathway to protect against early myocardial infarction injury.

Chronic intermittent hypobaric hypoxia improves iron metabolism disorders via the IL-6/JAK2/STAT3 and Epo/STAT5/ERFE signaling pathways in metabolic syndrome rats.

AIM: Our previous study demonstrated that chronic intermittent hypobaric hypoxia (CIHH) improved iron metabolism disorder in obese rats through the downregulation of hepcidin. This study aimed to observe the molecular mechanism of CIHH in improving iron metabolism disorders, especially by Janus kinase/signal transducer and activation of the transcription (JAK/STAT) signaling pathway in metabolic syndrome (MS) rats. METHODS: Six-week-old male Sprague-Dawley rats were randomly divided into four groups: CON, CIHH (subjected to hypobaric hypoxia simulating 5000-m altitude for 28 days, 6 h daily), MS (induced by high fat diet and fructose water), and MS+CIHH. The serum levels of glucose, lipid metabolism, iron metabolism, interleukin-6 (IL-6), erythropoietin (Epo) and hepcidin were measured. The protein expressions of JAK2, STAT3, STAT5, bone morphogenetic protein 6 (BMP6), small mothers against decapentaplegic 1 (SMAD1) and hepcidin were examined. The mRNA expressions of erythroferrone (ERFE) and hepcidin were analyzed. RESULTS: The MS rats displayed obesity, hyperglycemia, hyperlipidemia, iron metabolism disorder, increased IL-6 and hepcidin serum levels, upregulation of JAK2/STAT3 signaling pathway, decreased Epo serum levels, downregulation of STAT5/ERFE signaling pathway in spleen, upregulation of BMP/SMAD signaling pathway in liver, and increased hepcidin mRNA and protein expression compared to CON rats. All the aforementioned abnormalities in MS rats were ameliorated in MS + CIHH rats. CONCLUSIONS: CIHH improved iron metabolism disorders, possibly by inhibiting IL-6/JAK2/STAT3 and activating Epo/STAT5/ERFE signaling pathway, thus downregulating hepcidin in MS rats.

The Plasma Concentration of Ticagrelor and Aspirin as a Predictor of Bleeding Complications in Chinese Acute Coronary Syndrome Patients With Dual Antiplatelet Therapy: A Prospective Observational Study.

PURPOSE: This study evaluated the association among the plasma concentration of ticagrelor, ARC124910XX, aspirin, and salicylic acid with the risk of recent bleeding in patients with the acute coronary syndrome. To this end, we developed an accurate model to predict bleeding. METHODS: A total of 84 patients included in this study cohort between May 2021 and November 2021. The risk factors were identified by univariate and multivariate analyses, and statistically significant risk factors identified in the multivariate analysis were included in the nomogram. We used the calibration curve and the receiver operating characteristic curve to verify the accuracy of the prediction model. RESULTS: Multivariable logistic analysis showed that ticagrelor concentration (odds ratio [OR]: 2.47, 95% confidence interval [CI], 1.51-4.75, P = 0.002), ST-segment elevation acute myocardial infarction (OR: 32.2, 95% CI, 2.37-780, P = 0.016), and lipid-lowering drugs (OR: 11.52, 95% CI, 1.91-110, P = 0.015) were positively correlated with bleeding. However, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker (OR: 0.04, 95% CI, 0.004-0.213, P < 0.001) was negatively correlated with bleeding. The receiver operating characteristic curve analysis showed that ticagrelor concentration and these factors together predict the occurrence of bleeding (area under receiver operating characteristic curve = 0.945, 95% CI, 0.896-0.994) and that ticagrelor concentration >694.90 ng/mL is the threshold of bleeding concentration (area under receiver operating characteristic curve = 0.696, 95% CI, 0.558-0.834). CONCLUSION: In patients with acute coronary syndrome treated with dual antiplatelet therapy, ticagrelor concentration >694.90 ng/mL was an independent risk factor for bleeding (OR: 2.47, 95% CI, 1.51-4.75, P = 0.002), but ARC124910XX and salicylic acid concentration did not affect bleeding risk ( P > 0.05).

Strongly adhesive zwitterionic composite hydrogel paints for surgical sutures and blood-contacting devices.

Hydrogels show eminent advantages in biomedical and pharmaceutical fields. However, their application as coating materials for biomedical devices is limited by several key challenges, such as lack of universality, weak mechanical strength, and low adhesion to the substrate. Here we report versatile and tough adhesion composite hydrogel paints (CHPs), which consist of zwitterionic copolymers and microgels, both with reactive groups. The CHPs exhibit tunable rheology and thickness, hydrophilicity, biofouling resistance, durability, and convenient fabrication on metal, polymer, and inorganic surfaces with arbitrary shapes. As a proof-of-concept, the CHP-surgical sutures demonstrate exceptional lubrication, drug delivery, anti-infection, and anti-fibrous capsule properties. Moreover, the CHP-PVC tubing effectively prevents thrombus formation in vitro and ex vivo rabbit blood circulation without anticoagulants. This work provides valuable insights for enhancing and developing integrated hydrogel technologies for biomedical devices. STATEMENT OF SIGNIFICANCE: The combination of hydrogel and biomedical devices can enable numerous existing applications in medicine. In this study, inspired by the principle of microgel reinforcement in industrial paints, we propose a simple and versatile zwitterionic composite hydrogel paints (CHPs) strategy, which can be easily applied to diverse substrates with arbitrary shapes by covalent grafting between complementary groups by brush, dip, or spray. The CHPs integrated universality, tough adhesion, mechanical durability, and anti-biofouling properties because of their unique chemical composition and coating structure design. This strategy provides a simple and versatile route for surface modification of biomedical devices.

Speckle-tracking echocardiography provides sensitive measurements of subtle early alterations associated with cardiac dysfunction in T2DM rats.

BACKGROUND: Diabetic cardiomyopathy results in cardiac structural and functional abnormalities. Previous studies have demonstrated that inhibiting the RhoA/ROCK signalling pathway increases the injury resistance of cardiomyocytes. The early detection of cardiac structural and functional alterations may facilitate an improved understanding of the pathophysiologic progress and guide therapy. This study aimed to identify the optimal diagnostic measures for the subtle early alterations of cardiac dysfunction in type 2 diabetes mellitus (T2DM) rats. METHODS: Twenty-four rat models were divided into four groups and received treatments for 4 weeks: the CON group (control rats), the DM group (T2DM rats), the DMF group (T2DM rats receiving fasudil) and the CONF group (control rats receiving fasudil) group. Left ventricular (LV) structure was quantified by histological staining and transmission electron microscopy. LV function and myocardial deformation were assessed by high-frequency echocardiography. RESULTS: Treatment with fasudil, a ROCK inhibitor, significantly protected against diabetes-induced myocardial hypertrophy, fibrosis and mitochondrial dysfunction. Impaired LV performance was found in T2DM rats, as evidenced by significant reductions in the ejection fraction (EF), fractional shortening (FS) and the mitral valve (MV) E/A ratio (which decreased 26%, 34% and 20%, respectively). Fasudil failed to improve the conventional ultrasonic parameters in T2DM rats, but the myocardial deformation measured by speckle-tracking echocardiography (STE) were significantly improved (global circumferential strain, GCS: P = 0.003; GCS rate, GCSR: P = 0.021). When receiver operating characteristic (ROC) curves were used in combination with linear regression analysis, STE parameters were found to be characterized by both optimal prediction of cardiac damage [AUC (95% CI): fractional area change, FAC: 0.927 (0.744, 0.993); GCS: 0.819 (0.610, 0.945); GCSR: 0.899 (0.707, 0.984)] and stronger correlations with cardiac fibrosis (FAC: r = -0.825; GCS: r = 0.772; GCSR: r = 0.829) than conventional parameters. CONCLUSION: The results suggest that STE parameters are more sensitive and specific than conventional parameters in predicting the subtle cardiac functional changes that occur in the early stage, providing new insight into the management of diabetic cardiomyopathy.

Benefits and Detriments of Social Collaborative Memory in Turn-Taking and Directed Forgetting.

Collaborative recall by groups of people can evoke both memory detriments (e.g., collaborative inhibition) and benefits (e.g., error pruning and post-collaborative memory benefit). Yet, it remains indeterminate whether these effects are due to the emotional valence of stimuli and/or the specific subtypes of episodic memory tested (i.e., item memory and source memory), and whether they are related to the research procedure of directed forgetting (DF). We introduced item-method DF into collaborative memory research using a turn-taking procedure. The to-be-recalled words were studied in different emotional valences and were followed by either an R or F cue, which, respectively, instructed participants to remember or forget the words presented. We conducted two recall sessions (Recall 1 and Recall 2) that included the two subtypes of episodic memory. Recall 1 was performed either individually or collaboratively, while Recall 2 was always performed individually. We observed three major findings: (a) a collaborative memory decrement - collaborative inhibition - was minimally affected in both item memory and source memory tasks by either the emotional valence of the stimuli or the DF cue; (b) a collaborative memory benefit - error pruning of item memory - persisted within both ongoing and post-collaboration, while error pruning of source memory only presented in ongoing collaboration, thus demonstrating the relevance of dual-process models that differentiate automatic familiarity and effortful recollection processes; and (c) there was no post-collaborative memory benefit, indicating the importance of the type of collaborative procedure. We discuss these results in terms of various theories, including the retrieval strategy disruption hypothesis (RSDH) which asserts that memory strategies tend to be disrupted in collaboration but are facilitated within post-collaboration. Also, we describe the implications of these results and directions for exploring other influential factors in future research.

CircHSPG2 knockdown attenuates hypoxia-induced apoptosis, inflammation, and oxidative stress in human AC16 cardiomyocytes by regulating the miR-1184/MAP3K2 axis.

Circular RNAs (circRNAs) have been identified as vital regulators in cardiovascular diseases, including acute myocardial infarction (AMI). In this study, the function and mechanism of circRNA heparan sulfate proteoglycan 2 (circHSPG2) in hypoxia-induced injury in AC16 cardiomyocytes were investigated. AC16 cells were stimulated with hypoxia to establish an AMI cell model in vitro. Real-time quantitative PCR and western blot assays were performed to quantify the expression levels of circHSPG2, microRNA-1184 (miR-1184), and mitogen-activated protein kinase kinase kinase 2 (MAP3K2). Counting Kit-8 (CCK-8) assay was used to measure cell viability. Flow cytometry was performed to detect cell cycle and apoptosis. Enzyme-linked immunosorbent assay (ELISA) was used to determine the expression of inflammatory factors. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were used to analyze the relationship between miR-1184 and circHSPG2 or MAP3K2. In AMI serum, circHSPG2 and MAP3K2 mRNA were highly expressed and miR-1184 was down-regulated. Hypoxia treatment elevated HIF1α expression and repressed cell growth and glycolysis. Moreover, hypoxia promoted cell apoptosis, inflammation, and oxidative stress in AC16 cells. Hypoxia-induced circHSPG2 expression in AC16 cells. CircHSPG2 knockdown alleviated hypoxia-induced AC16 cell injury. CircHSPG2 directly targeted miR-1184, and miR-1184 targeted and suppressed MAP3K2. Inhibition of miR-1184 or overexpression of MAP3K2 abolished the alleviated effect of circHSPG2 knockdown on hypoxia-induced AC16 cell injury. Overexpression of miR-1184 relieved hypoxia-induced impairment in AC16 cells by MAP3K2. CircHSPG2 could regulate MAP3K2 expression through miR-1184. CircHSPG2 knockdown protected AC16 cells from hypoxia-induced injury by regulating the miR-1184/MAP3K2 cascade.

A biocompatible cell cryoprotectant based on sulfoxide-containing amino acids: mechanism and application.

The preservation of cells at cryogenic temperatures requires the presence of cryoprotectants (CPAs). Dimethyl sulfoxide (DMSO), as a state-of-the-art CPA, is widely used for the storage of many types of cells. However, its intrinsic toxicity is still an obstacle for its applications in clinical practice. Herein, we report a DMSO analogue, L-methionine sulfoxide (Met(O)-OH), as a CPA for cell cryopreservation. The molecular-level cryopreservation roles of Met(O)-OH were investigated by experiments and molecular dynamics simulations. The results also found that Met(O)-OH showed high ice recrystallization inhibition (IRI) activity and the ice crystals in Met(O)-OH solution tend to be relatively round and smooth; moreover, the ice size was significantly reduced to 30.26 µm compared with pure water (135.87 µm) or DMSO solution (45.08 µm). At the molecular level, Met(O)-OH could stably bind the surface of the ice crystals and form more stable hydrogen bonds with ice compared with L-methionine. Moreover, Met(O)-OH could significantly reduce the damage to cells caused by osmotic shock and did not change the cell viability even at high concentration (4%). Based on these results, nucleated L929 cells and anuclear sheep red blood cells (SRBCs) were used as cell models to investigate the cryopreservation activity of Met(O)-OH. The results suggested that, under the optimum protocol, Met(O)-OH showed an effective post-thaw survival efficiency with ultrarapid freezing, and the post-thaw survival efficiency of L929 cells reached 84.0%. This work opens up the possibility for an alternative to traditional toxic CPA DMSO, and provides insights for the development of DMSO analogues with non-toxic/low toxicity for cell cryoprotection applications.

A self-gelling powder based on polyacrylic acid/polyacrylamide/quaternate chitosan for rapid hemostasis.

In order to improve the hemostatic effect of the hemostatic dressing for non-compressible wounds, unknown bleeding points and irregularly shaped wounds, a self-gelling hemostasis powder based on polyacrylic acid/polyacrylamide/quaternate chitosan (PAA/PAM/QCS) is prepared in this study. When in contact with water, the PAA/PAM/QCS can fuse and rapidly form a stable hydrogel in a short time (< 0.25 min). The PAA/PAM ratio is the main parameter that modulates the formation of the self-gel. The PAA/PAM self-gel can be formed only when the PAA/PAM ratio is 5:5, and the introduction of QCS does not influence the self-gelling behaviors and hydrogel stability. Moreover, the PAA/PAM/QCS self-gel shows good adhesive properties on wet tissue surfaces. In addition, the introduction of QCS improves the antibacterial activity of the self-gelling hemostasis powder. Furthermore, the prepared PAA/PAM/QCS powder can rapidly adsorb lots of blood, aggregate blood cells and platelets. The hemostatic results in vivo show that PAA/PAM/QCS powder is superior to the control group and commercial product groups (chitosan powder) with performance similar to hemostatic zeolite in terms of the amount of bleeding and hemostatic time. Therefore, the PAA/PAM/QCS self-gelling powder shows great application prospects for rapid hemostasis.

Short-term effects of levosimendan use for venoarterial extracorporeal membrane oxygenation: A systematic review and meta-analysis.

OBJECTIVE: Levosimendan has been demonstrated to reduce the incidence of cardiogenic shock and facilitate weaning from cardiopulmonary bypass. However, the beneficial effects of levosimendan treatment on hospital outcomes in patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) are uncertain. We performed a systematic review and meta-analysis to evaluate the short-term effects of levosimendan use for patients undergoing VA-ECMO. METHODS: We searched PubMed, Embase, and the Cochrane Library for English articles published from inception to July 15, 2021. Observational studies comparing levosimendan versus non- levosimendan for VA-ECMO were considered eligible for the current study. RESULTS: Nine observational studies with 1058 patients were included. In-hospital mortality was 46.3% in the levosimendan group as compared with 50.7% in the control group. Levosimendan significantly reduced in-hospital mortality in patients undergoing VA-ECMO compared with the control group (RR, 0.80; 95% CI, 0.67-0.95; p = 0.013). The incidence of weaning from VA-ECMO was 79.3% in the levosimendan group as compared with 63.4% in the control group. Levosimendan significantly increase the incidence of weaning from VA-ECMO in patients as compared with the control group (RR, 1.20; 95% CI, 1.07-1.34; p = 0.002). In the one-way sensitivity analysis for estimating the effect of each study on mortality or weaning from VA-ECMO, omission of each study did not make a significant difference. CONCLUSIONS: Our study indicates that levosimendan use significantly reduced in-hospital mortality and increase the incidence of weaning in patients undergoing VA-ECMO.