Polyimide (PI) aerogels have attracted great attention owing to their low density and excellent thermal stability. However, hydrophobic surface modification is required for PI aerogels to improve ...their ability in oil/water separation due to their amphiphilic characteristic. Two-dimensional MXenes (transition metal carbides/nitrides) can be utilized as nanofillers to enhance the properties of polymers because of their unique layered structure and versatile interface chemistry. Herein, the robust, lightweight, and hydrophobic PI/MXene three-dimensional architectures were fabricated via freeze-drying of polyamide acid/MXene suspensions and thermal imidization. Polyamide acid was synthesized using N-N-dimethylacetamide and 4,4′-oxydianiline. MXene (Ti3C2T x ) dispersion was obtained via the etching of Ti3AlC2 and ultrasonic exfoliation. Taking advantage of the strong interaction between PI chains and MXene nanosheets, the interconnected, highly porous, and hydrophobic PI/MXene aerogels with low density were fabricated, resulting in the improved compressive performance, remarkable oil absorption capacity, and efficient separation of oil and water. For the PI/MXene-3 aerogel (weight ratio, 5.2:1) without any surface modification, the water contact angle was 119° with a density of 23 mg/cm3. This aerogel can completely recover to its original height after 50 compression–release cycles, exhibiting superelasticity and exceptional fatigue-resistant ability. It also showed high absorption capacities to various organic liquids ranging from approximately 18 to 58 times of their own weight. This hybrid aerogel can rapidly separate the chloroform, soybean oil, and liquid paraffin from the water–oil system. The thermally stable hybrid aerogel also exhibited excellent fire safety properties and outstanding reusability under an extreme environment.
Fabricating high-performance MXene-based polymer nanocomposites is a huge challenge because of the poor dispersion and interfacial interaction of MXene nanosheets in the polymer matrix. To address ...the issue, MXene nanosheets were successfully exfoliated and subsequently modified by long-chain cationic agents with different chain lengths, i.e., decyltrimethylammonium bromide (DTAB), octadecyltrimethylammonium bromide (OTAB), and dihexadecyldimethylammonium bromide (DDAB). With the long-chain groups on their surface, modified Ti
C
(MXene) nanosheets were well dispersed in
,
-dimethylformamide (DMF), resulting in the formation of uniform dispersion and strong interfacial adhesion within a polystyrene (PS) matrix. The thermal stability properties of cationic modified Ti
C
/PS nanocomposites were improved considerably with the temperatures at 5% weight loss increasing by 20 °C for DTAB-Ti
C
/PS, 25 °C for OTAB-Ti
C
/PS and 23 °C for DDAB-Ti
C
/PS, respectively. The modified MXene nanosheets also enhanced the flame-retardant properties of PS. Compared to neat PS, the peak heat release rate (PHRR) was reduced by approximately 26.4%, 21.5% and 20.8% for PS/OTAB-Ti
C
, PS/DDAB-Ti
C
and PS/DTAB-Ti
C
, respectively. Significant reductions in CO and CO
productions were also obtained in the cone calorimeter test and generally lower pyrolysis volatile products were recorded by PS/OTAB-Ti
C
compared to pristine PS. These property enhancements of PS nanocomposites are attributed to the superior dispersion, catalytic and barrier effects of Ti
C
nanosheets.
High‐efficiency algorithms are proposed for numerically integrating elasto‐plastic rate equations for the purpose of simulating metal failure effects under repeated loading conditions. Results are ...obtained with a newly established elasto‐plasticity model which can automatically simulate both low and high cycle fatigue failure effects, with reference to neither damage‐like variables nor ad hoc failure criteria. Novelties are incorporated in a few respects. First, multiaxial loading processes with arbitrarily changing principal stresses and axes can be treated in a broad sense beyond usually treated proportional loading cases. Second, by means of the commonly used J2‐invariant of the deviatoric stress, multiaxial loading cases can be directly treated just as in the uniaxial loading case. Third, high cost in time consumption can be considerably reduced in evaluating both low and high cycle failure effects. Numerical examples are presented for simulating uniaxial and multiaxial fatigue failure effects and simulation results are in good agreement with experimental data. Results show that the computation speed with the new algorithms exceeds 600 times faster than usual integration algorithms.
New Oe Stars in LAMOST DR5 Li, Guang-Wei; Shi, Jian-Rong; Yanny, Brian ...
Astrophysical journal/The Astrophysical journal,
08/2018, Volume:
863, Issue:
1
Journal Article
Peer reviewed
Open access
Stars of spectral type Oe are very rare. To date, only 13 Oe stars have been identified within our Galaxy. In this paper, we present six new Oe stars and four new B0e stars found in LAMOST DR5. ...Repeated spectral observations of the same Oe stars show some emission-line variability. The Hβ emission of TYC 4801-17-1 shows rapid V/R variation. Phase lags in the V/R ratio of TYC 4801-17-1 spectra are also seen. We found that the unusual O4.5 star RL 128 is an Oe star with variable H intensity and its Ca ii triplet emission appears when H emission reaches maximum intensity. These newly identified early-type Oe and B0e stars significantly increase the known sample.
To assess the impact of preoperative infection with the contemporary strain of severe acute respiratory coronavirus 2 (SARS-CoV-2) on postoperative mortality, respiratory morbidity and extrapulmonary ...complications after elective, noncardiac surgery.
An ambidirectional observational cohort study.
A tertiary and teaching hospital in Shanghai, China.
All adult patients (≥ 18 years of age) who underwent elective, noncardiac surgery under general anesthesia at Huashan Hospital of Fudan University from January until March 2023 were screened for eligibility. A total of 2907 patients were included.
Preoperative coronavirus disease 2019 (COVID-19) positivity.
The primary outcome was 30-day postoperative mortality. The secondary outcomes included postoperative pulmonary complications (PPCs), myocardial injury after noncardiac surgery (MINS), acute kidney injury (AKI), postoperative delirium (POD) and postoperative sleep quality. Multivariable logistic regression was used to assess the risk of postoperative mortality and morbidity imposed by preoperative COVID-19.
The risk of 30-day postoperative mortality was not associated with preoperative COVID-19 adjusted odds ratio (aOR), 95% confidence interval (CI): 0.40, 0.13–1.28, P = 0.123 or operation timing relative to diagnosis. Preoperative COVID-19 did not increase the risk of PPCs (aOR, 95% CI: 0.99, 0.71–1.38, P = 0.944), MINS (aOR, 95% CI: 0.54, 0.22–1.30; P = 0.168), or AKI (aOR, 95% CI: 0.34, 0.10–1.09; P = 0.070) or affect postoperative sleep quality. Patients who underwent surgery within 7 weeks after COVID-19 had increased odds of developing delirium (aOR, 95% CI: 2.26, 1.05–4.86, P = 0.036).
Preoperative COVID-19 or timing of surgery relative to diagnosis did not confer any added risk of 30-day postoperative mortality, PPCs, MINS or AKI. However, recent COVID-19 increased the risk of POD. Perioperative brain health should be considered during preoperative risk assessment for COVID-19 survivors.
•Preoperative COVID-19 did not confer added risk of 30-day postoperative mortality.•Preoperative COVID-19 was not associated with increased risk of PPCs, MINS or AKI.•Recent COVID-19 (within 7 weeks prior to surgery) increased the risk of POD.•Postoperative sleep was not affected by preoperative COVID-19.
Mitochondrial disorders preferentially affect tissues with high energy requirements, such as the retina and corneal endothelium, in human eyes. Mesenchymal stem cell (MSC)-based treatment has been ...demonstrated to be beneficial for ocular degeneration. However, aside from neuroprotective paracrine actions, the mechanisms underlying the beneficial effect of MSCs on retinal and corneal tissues are largely unknown. In this study, we investigated the fate and associated characteristics of mitochondria subjected to intercellular transfer from MSCs to ocular cells.
MSCs were cocultured with corneal endothelial cells (CECs), 661W cells (a photoreceptor cell line) and ARPE-19 cells (a retinal pigment epithelium cell line). Immunofluorescence, fluorescence activated cell sorting and confocal microscopy imaging were employed to investigate the traits of intercellular mitochondrial transfer and the fate of transferred mitochondria. The oxygen consumption rate of recipient cells was measured to investigate the effect of intercellular mitochondrial transfer. Transcriptome analysis was performed to investigate the expression of metabolic genes in recipient cells with donated mitochondria.
Mitochondrial transport is a ubiquitous intercellular mechanism between MSCs and various ocular cells, including the corneal endothelium, retinal pigmented epithelium, and photoreceptors. Additionally, our results indicate that the donation process depends on F-actin-based tunneling nanotubes. Rotenone-pretreated cells that received mitochondria from MSCs displayed increased aerobic capacity and upregulation of mitochondrial genes. Furthermore, living imaging determined the ultimate fate of transferred mitochondria through either degradation by lysosomes or exocytosis as extracellular vesicles.
For the first time, we determined the characteristics and fate of mitochondria undergoing intercellular transfer from MSCs to various ocular cells through F-actin-based tunneling nanotubes, helping to characterize MSC-based treatment for ocular tissue regeneration.
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The regenerative capacity of the central nervous system is very limited and few effective treatments are currently available for spinal cord injury. It is therefore a priority to develop new ...drugs that can promote structural and functional recovery after spinal cord injury. Previous studies have shown that peptides can promote substantial repair and regeneration of injured tissue. While amphibians have a pronounced ability to regenerate the spinal cord, few studies have investigated the effect of amphibian spinal cord-derived peptides on spinal cord injury. Here we report for the first time the successful identification and isolation of a new polypeptide, VD11 (amino acid sequence: VDELWPPWLPC), from the spinal cord of an endemic Chinese amphibian (Odorrana schmackeri). In vitro experiments showed that VD11 promoted the secretion of nerve growth factor and brain-derived neurotrophic factor in BV2 cells stimulated with lipopolysaccharide, as well as the proliferation and synaptic elongation of PC12 cells subjected to hypoxia. In vivo experiments showed that intravertebral injection of VD11 markedly promoted recovery of motor function in rats with spinal cord injury, alleviated pathological damage, and promoted axonal regeneration. Furthermore, RNA sequencing and western blotting showed that VD11 may affect spinal cord injury through activation of the AMPK and AKT signaling pathways. In summary, we discovered a novel amphibian-derived peptide that promotes structural and functional recovery after spinal cord injury.
Breast cancer is the most prevalent cancer among women globally, and surgical procedures continue to be the primary treatment. However, over 50% of patients experience preoperative anxiety due to the ...unknown and fear associated with surgery. Although drug therapy is commonly used to address this anxiety, its side effects have led to a heated debate regarding its effectiveness. Consequently, non-pharmacological therapies, such as preoperative education, have emerged as an alternative approach to alleviate anxiety. WeChat, a widely popular social media platform, offers a public platform that can potentially be utilized for effective preoperative education. This study aims to evaluate the use of WeChat public platform as a tool for preoperative education in patients undergoing breast surgery.
This is a prospective, randomized, and controlled trial will involve 392 adult women scheduled for breast cancer resection. Participants will be randomly assigned to either the WeChat education group or the regular group. In addition to regular preoperative visits, the WeChat education group will also watch science videos through the WeChat public platform. The regular group will only receive education from ward nurses during preoperative visits. The primary outcome measure will be the incidence of preoperative anxiety, defined by scores of the State Anxiety Inventory (SAI) exceeding 40 points. Secondary outcome measures include the incidence of severe anxiety (SAI > 44) on the day before surgery, incidence of anxiety 72 h after surgery, incidence of severe anxiety 72 h after surgery, NRS scores for pain at rest and during activity 24, 48, and 72 h after surgery, incidence of nausea and vomiting within 24 h after surgery, subjective sleep score at 1 week postoperatively, quality of life QoR-15 scores at 1 and 3 months postoperatively, incidence of chronic pain at 3 months postoperatively, bowel function recovery, length of hospital stay, and hospitalization expenses.
This is the first clinical trial to investigate the use of WeChat public platform for delivering preoperative education on perioperative anxiety in breast cancer patients. By utilizing the renowned WeChat public platform, our study aims to improve patient outcomes by providing video education that explains the disease, surgery, and anesthesia in a more accessible manner, thereby reducing the incidence of perioperative anxiety. If our hypothesis is confirmed, this non-pharmacological approach can be universally acknowledged as a cost-effective and practical method in clinical care. Its application can also be extended to other medical fields beyond breast cancer.
ClinicalTrials.gov, NCT05291494. Registered on 29 December 2021.
With the development of industry and agriculture, the increasingly serious problems of environmental pollution and water quality deterioration that affect human health need to be solved. Materials ...containing both Fe and Mn, the two most abundant metal elements, have been widely used for wastewater decontamination since they are nontoxic, low-cost, easy to prepare, and highly efficient. This review systematically summarizes the synthesis methods of Fe–Mn-based unloaded materials (such as spinel-type, perovskite-type, layered double hydroxides, metal–organic framework, and its derivatives) and loaded materials (carbon materials, oxides, and other loaded materials). Furthermore, the progress and problems of the application of Fe–Mn-based materials in the fields of Fenton, photo-Fenton, electro-Fenton, persulfate, and sulfite catalysis processes are analyzed. Different activation mechanisms of Fe–Mn-based materials, such as radical pathways and nonradical pathways (like direct electron transfer pathways, singlet oxygen, and high valence metals, etc.) are described. Finally, the application potential of Fe–Mn-based materials in environmental remediation is clarified and the future research directions are pointed out. It is expected that this review can provide new inspiration for subsequent research on the application of Fe–Mn based materials for wastewater treatment.
The increasing antibiotic resistance driven by Pseudomonas aeruginosa typically leads to uncontrolled and persistent inflammatory damage, which is primarily attributed to the virulence and biofilms ...produced by the bacteria. Herein, we present a novel anti-infective drug strategy designed to inhibit the bacterial quorum sensing system, thereby attenuating P. aeruginosa virulence, and modulating inflammation from drug-resistant bacterial infections. We discovered new quorum sensing LasR/LasB inhibitors derived from the structural modification of a ligustilide derivative library. Of these compounds, 5f demonstrated significant inhibitory activity against LasB (LasB-gfp, IC50 = 8.7 μM) and a moderate inhibitory effect on P. aeruginosa biofilms (IC50 = 7.4 μM). Through live image analysis in a fluorescent protein-labeled zebrafish larva model, we observed that compound 5f significantly inhibited the migration of macrophages. Moreover, compound 5f effectively attenuated quorum sensing-mediated virulence factors and biofilm formation by P. aeruginosa. It also alleviated the inflammatory response by P. aeruginosa-infected macrophages through the downregulation of mitogen-activated protein kinase and NF-κB signal-transduction pathways. Notably, in vivo experiments, this compound demonstrated marked therapeutic effects in acute lung injury models induced by lipopolysaccharides from P. aeruginosa. These results indicate that compound 5f has the potential to be a novel anti-infective candidate against drug-resistant infections caused by P. aeruginosa.
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