Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.612
Filter
1.
Front Public Health ; 12: 1441465, 2024.
Article in English | MEDLINE | ID: mdl-39114523

ABSTRACT

Introduction: Increased uncertainty is a major feature of the current society that poses significant challenges to university students' mental health and academics. However, current research has not paid sufficient attention to this issue, and no study has explored the underlying mechanisms between intolerance of uncertainty and academic burnout among university students. Methods: This study examined the association between uncertainty intolerance and academic burnout among university students and the role of self-regulatory fatigue and self-compassion in light of the theory of limited resources. Convenience sampling was used to survey 1,022 Chinese university students. Results: The findings demonstrated that intolerance of uncertainty significantly influenced university students' academic burnout with self-regulatory fatigue serving as a key mediator. Additionally, self-compassion can effectively moderate the effects of intolerance of uncertainty on self-regulatory fatigue and academic burnout. Discussion: These results indicated that the depletion of cognitive resources brought about by uncertainty in the current highly uncertain social environment may be one of the key pathways to academic burnout among university students. Furthermore, current research provides insights into how to mitigate the negative effects of uncertainty on university students.


Subject(s)
Students , Humans , Universities , Female , Students/psychology , Male , Uncertainty , Young Adult , Surveys and Questionnaires , China/epidemiology , Empathy , Adult , Fatigue/psychology , Burnout, Professional/psychology , Burnout, Psychological/psychology
2.
Acta Diabetol ; 2024 Aug 03.
Article in English | MEDLINE | ID: mdl-39096329

ABSTRACT

AIMS: The impact of macrovascular and microvascular complications, the common vascular complications of type 2 diabetes, on long-term mortality has been well evaluated, but the impact of different complications of newly diagnosed type 2 diabetes (diagnosed within the past 2 years) on long-term mortality has not been reported. We aimed to investigate the relationship between all-cause mortality and vascular complications in U.S. adults (aged ≥ 20 years) with newly diagnosed type 2 diabetes. METHODS: We used data from the 1999-2018 National Health and Nutritional Examination Surveys (NHANES). Cox proportional hazard models was used to assess hazard ratios (HR) and 95% confidence intervals for all-cause mortality. RESULTS: A total of 928 participants were enrolled in this study. At a mean follow-up of 10.8 years, 181 individuals died. In the fully adjusted model, the hazard ratio (HR) (95% confidence interval [CI]) of all-cause mortality for individuals with any single complication compared with those with newly diagnosed type 2 diabetes without complications was 2.24 (1.37, 3.69), and for individuals with two or more complications was 5.34 (3.01, 9.46).Co-existing Chronic kidney disease (CKD) and diabetic retinopathy (DR) at baseline were associated with the highest risk of death (HR 6.07[2.92-12.62]), followed by CKD and cardiovascular disease (CVD) (HR 4.98[2.79-8.89]) and CVD and DR (HR 4.58 [1.98-10.57]). CONCLUSION: The presence of single and combined diabetes complications exerts a long-term synergistic adverse impact on overall mortality in newly diagnosed U.S. adults with type 2 diabetes, underscoring the importance of comprehensive complication screening to enhance risk stratification and treatment.

3.
Res Sq ; 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39108482

ABSTRACT

Background: Urate concentration and the physiological regulation of urate homeostasis exhibit clear sex differences. DNA methylation has been shown to explain a substantial proportion of serum urate variance, mediate the genetic effect on urate concentration, and co-regulate with cardiometabolic traits. However, whether urate concentration is associated with DNA methylation in a sex-dependent manner is unknown. Additionally, it is worth investigating if urate changes after perturbations, such as vaccination, are associated with DNA methylation in a sex-specific manner. Methods: We investigated the association between DNA methylation and serum urate concentrations in a Dutch cohort of 325 healthy individuals. Urate concentration and DNA methylation were measured before and after Bacillus Calmette-Guérin (BCG) vaccination, used as a perturbation associated with increased gout flares. The association analysis included united, interaction, and sex-stratified analysis. Validation of the identified CpG sites was conducted using three independent cohorts. Results: 215 CpG sites were associated with serum urate in males, while 5 CpG sites were associated with serum urate in females, indicating sex-specific associations. Circulating urate concentrations significantly increased after BCG vaccination, and baseline DNA methylation was associated with differences in urate concentration before and after vaccination in a sex-specific manner. The CpG sites associated with urate concentration in males were enriched in neuro-protection pathways, whereas in females, the urate change-associated CpG sites were related to lipid and glucose metabolism. Conclusion: Our study enhances the understanding of how epigenetic factors contribute to regulating serum urate levels in a sex-specific manner. These insights have significant implications for the diagnosis, prevention, and treatment of various urate-related diseases and highlight the importance of personalized and sex-specific approaches in medicine.

4.
Transl Oncol ; 48: 102077, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39106550

ABSTRACT

Cytochrome P450 F3 (CYP4F3) is recognized as a disease-associated immune response initiator that is involved in the synthesis of cholesterol, steroids, and lipids. This study identified the upregulation of CYP4F3 expression in colorectal cancer (CRC) and its association with poor patient prognosis through a comparative analysis between CRC tumor tissues with normal tissues from public databases. The overexpression of CYP4F3 in CT26.wt and SW620, promoted cell proliferation and migration, a reduction of cellular oxidative stress, an up-regulation of the oxidative stress-related pathway NRF2, and an inhibition of cellular ferroptosis. Additionally, inhibition of NRF2 activity stimulated cellular ferroptosis when CYP4F3 was overexpressed. Ferroptosis, characterized by iron-dependent lipid peroxidation, is a non-apoptotic way of cell death with a critical role in cancer development. When given a ferroptosis agonist to CYP4F3-overexpression CRC cells, NRF2 was activated, and cell proliferation and migration were reduced. Furthermore, the mice subcutaneously injected with CYP4F3-overexpression CT26.wt cells formed significantly larger tumors compared to the CYP4F3-vector CT26.wt cell group. This study systematically identified an important role of CYP4F3 in CRC development as a regulator of CRC cells to escape ferroptosis via NRF2, highlighting the significance of CYP4F3 as a potential therapeutic target for CRC.

5.
Pain Physician ; 27(5): E579-E587, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39087967

ABSTRACT

BACKGROUND: Hip fracture surgeries in elderly patients often require spinal or general anesthesia, posing risks of severe hypotension and inadequate pain management. The optimal anesthesia type for minimizing these risks remains undetermined. Preliminary studies suggest that a combination of fascia iliaca block (FIB) and low-dose low-specific-gravity spinal anesthesia (LLSA) might offer a solution, but comprehensive evidence is lacking. OBJECTIVES: This study aimed to assess the efficacy of combining FIB with LLSA for reducing severe hypotension and enhancing analgesia during hip fracture surgery in elderly patients. STUDY DESIGN: A prospective, randomized controlled trial was conducted. SETTING: An operating theatre of a tertiary hospital. METHODS: The study comprised 68 patients. They were separated into 2 equal parallel groups 34 patients each: the FIB+LLSA group and the general anesthesia (GA) group. Patients aged 75-96 undergoing primary hip arthroplasty for hip fracture were randomized to receive either FIB+LLSA or GA. The primary outcome was the incidence of severe hypotension; secondary outcomes included postoperative pain, use of rescue analgesia, vasopressor dosage, and complications. RESULTS: We found a significantly lower incidence of severe hypotension in the FIB+LLSA group compared to the GA group (32.4% vs 67.6%). Additionally, postoperative pain scores were significantly lower, and the need for rescue analgesia was reduced in the FIB+LLSA group. Vasopressor use during surgery was also significantly lower in the FIB+LLSA group. The hospital stay was shorter in the FIB+LLSA group, with an average of 5.9 days compared to 6.7 days in the GA group. LIMITATIONS: The study's limitations include its single-center nature, which may limit the generalizability of the findings. Additionally, the inability to conduct a double-blind study could introduce biases, though measures were taken to minimize this. The sample size might not be sufficient to determine the broader implications of LLSA. CONCLUSIONS: Combining FIB with LLSA for elderly patients undergoing hip fracture surgery significantly reduces the incidence of severe intraoperative hypotension and postoperative pain. It also decreases the need for rescue analgesia and shortens hospital stays, suggesting that FIB+LLSA could be a beneficial regional anesthesia technique for elderly hip fracture surgery patients, aligning with enhanced recovery protocols.


Subject(s)
Anesthesia, Spinal , Hip Fractures , Hypotension , Nerve Block , Humans , Hip Fractures/surgery , Aged , Anesthesia, Spinal/methods , Anesthesia, Spinal/adverse effects , Aged, 80 and over , Female , Male , Nerve Block/methods , Prospective Studies , Pain, Postoperative/prevention & control , Pain, Postoperative/drug therapy , Analgesia/methods , Fascia
6.
World J Radiol ; 16(6): 203-210, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38983838

ABSTRACT

BACKGROUND: Development of distant metastasis (DM) is a major concern during treatment of nasopharyngeal carcinoma (NPC). However, studies have demonstrated improved distant control and survival in patients with advanced NPC with the addition of chemotherapy to concomitant chemoradiotherapy. Therefore, precise prediction of metastasis in patients with NPC is crucial. AIM: To develop a predictive model for metastasis in NPC using detailed magnetic resonance imaging (MRI) reports. METHODS: This retrospective study included 792 patients with non-distant metastatic NPC. A total of 469 imaging variables were obtained from detailed MRI reports. Data were stratified and randomly split into training (50%) and testing sets. Gradient boosting tree (GBT) models were built and used to select variables for predicting DM. A full model comprising all variables and a reduced model with the top-five variables were built. Model performance was assessed by area under the curve (AUC). RESULTS: Among the 792 patients, 94 developed DM during follow-up. The number of metastatic cervical nodes (30.9%), tumor invasion in the posterior half of the nasal cavity (9.7%), two sides of the pharyngeal recess (6.2%), tubal torus (3.3%), and single side of the parapharyngeal space (2.7%) were the top-five contributors for predicting DM, based on their relative importance in GBT models. The testing AUC of the full model was 0.75 (95% confidence interval [CI]: 0.69-0.82). The testing AUC of the reduced model was 0.75 (95%CI: 0.68-0.82). For the whole dataset, the full (AUC = 0.76, 95%CI: 0.72-0.82) and reduced models (AUC = 0.76, 95%CI: 0.71-0.81) outperformed the tumor node-staging system (AUC = 0.67, 95%CI: 0.61-0.73). CONCLUSION: The GBT model outperformed the tumor node-staging system in predicting metastasis in NPC. The number of metastatic cervical nodes was identified as the principal contributing variable.

7.
Vaccine ; 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38981740

ABSTRACT

The Bacille Calmette-Guerin (BCG) vaccine is a well-established inducer of innate immune memory (also termed trained immunity), causing increased cytokine production upon heterologous secondary stimulation. Innate immune responses are known to be influenced by season, but whether seasons impact induction of trained immunity is not known. To explore the influence of season on innate immune memory induced by the BCG vaccine, we vaccinated healthy volunteers with BCG either during winter or spring. Three months later, we measured the ex vivo cytokine responses against heterologous stimuli, analyzed gene expressions and epigenetic signatures of the immune cells, and compared these with the baseline before vaccination. BCG vaccination during winter induced a stronger increase in the production of pro-inflammatory cytokines by peripheral blood mononuclear cells (PBMCs) upon stimulation with different bacterial and fungal stimuli, compared to BCG vaccination in spring. In contrast, winter BCG vaccination resulted in lower IFNγ release in PBMCs compared to spring BCG vaccination. Furthermore, NK cells of the winter-vaccinated people had a greater pro-inflammatory cytokine and IFNγ production capacity upon heterologous stimulation. BCG had only minor effects on the transcriptome of monocytes 3 months later. In contrast, we identified season-dependent epigenetic changes in monocytes and NK cells induced by vaccination, partly explaining the higher immune cell reactivity in the winter BCG vaccination group. These results suggest that BCG vaccination during winter is more prone to induce a robust trained immunity response by activating and reprogramming the immune cells, especially NK cells. (Dutch clinical trial registry no. NL58219.091.16).

8.
Cell ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38971151

ABSTRACT

Homologous recombination deficiency (HRD) is prevalent in cancer, sensitizing tumor cells to poly (ADP-ribose) polymerase (PARP) inhibition. However, the impact of HRD and related therapies on the tumor microenvironment (TME) remains elusive. Our study generates single-cell gene expression and T cell receptor profiles, along with validatory multimodal datasets from >100 high-grade serous ovarian cancer (HGSOC) samples, primarily from a phase II clinical trial (NCT04507841). Neoadjuvant monotherapy with the PARP inhibitor (PARPi) niraparib achieves impressive 62.5% and 73.6% response rates per RECIST v.1.1 and GCIG CA125, respectively. We identify effector regulatory T cells (eTregs) as key responders to HRD and neoadjuvant therapies, co-occurring with other tumor-reactive T cells, particularly terminally exhausted CD8+ T cells (Tex). TME-wide interferon signaling correlates with cancer cells upregulating MHC class II and co-inhibitory ligands, potentially driving Treg and Tex fates. Depleting eTregs in HRD mouse models, with or without PARP inhibition, significantly suppresses tumor growth without observable toxicities, underscoring the potential of eTreg-focused therapeutics for HGSOC and other HRD-related tumors.

9.
Heliyon ; 10(12): e33090, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38988582

ABSTRACT

Purpose: Plenty of studies have explored the diagnosis and prognosis of IgA nephropathy (IgAN) based on machine learning (ML), but the accuracy lacks the support of evidence-based medical evidence. We aim at this problem to guide the precision treatment of IgAN. Methods: Embase, Pubmed, Cochrane Library, and Web of Science were searched systematically until February 24th, 2024, for publications on ML-based diagnosis and prognosis of IgAN. Subgroup analysis or meta-regression was conducted according to modeling method, follow-up time, endpoint definition, and variable type. Further, the rank sum test was applied to compare the discrimination ability of prognosis. Results: A total of 47 studies involving 51,935 patients were eligible. Among the 38 diagnostic models, the pooled C-index was 0.902 (95 % CI: 0.878-0.926) in 27 diagnostic models. Of the 162 prognostic models, the C-index for model discrimination of 144 prognostic models was 0.838 (95 % CI: 0.827-0.850) in training. The overall discrimination ability of prognosis was as follows: COX regression > new ML models (e.g. ANN, DT, RF, SVM, XGBoost) > traditional ML models (logistic regression) > Naïve Bayesian network (P < 0.05). External validation of IIgAN-RPT in 19 models showed a pooled C-index of 0.801 (95 % CI: 0.784-0.817). Conclusions: New ML models have shown application values that are as good as traditional ML models, both in diagnosis and prognosis. In addition, future models are desired to use a more sensitive prognostic endpoint (albuminuria), improve predictive ability in moderate progression risk, and ultimately translate into clinically applicable intelligent tools.

11.
Langmuir ; 40(29): 15140-15149, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-38978384

ABSTRACT

The metal-support interaction is crucial for the performance of Cu-based catalysts. However, the distinctive properties of the support metal element itself are often overlooked in catalyst design. In this paper, a sheet Cu-Zn-Ce with [Ce3+-OV-Ce4+] located on the surface was designed by the sol-gel method. Through EPR and X-ray photoelectron spectroscopy (XPS), the relationship between the content of oxygen vacancies and Ce was revealed. Ce itself induces the generation of [Ce3+-OV-Ce4+]. Through ICP-MS, XPS, and SEM-mapping, the Ce-induced formation of [Ce3+-OV-Ce4+] located on the catalyst surface was demonstrated. CO2-TPD and DFT calculations further revealed that [Ce3+-OV-Ce4+] enhanced CO2 adsorption, leading to a 10% increase in methanol selectivity compared to Cu-Zn-Ce synthesized via the coprecipitation method.

12.
Nat Aging ; 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38987646

ABSTRACT

Emerging evidence suggests that neurological and other post-acute sequelae of COVID-19 can persist beyond or develop following SARS-CoV-2 infection. However, the long-term trajectories of cognitive change after a COVID-19 infection remain unclear. Here we investigated cognitive changes over a period of 2.5 years among 1,245 individuals aged 60 years or older who survived infection with the original SARS-CoV-2 strain in Wuhan, China, and 358 uninfected spouses. We show that the overall incidence of cognitive impairment among older COVID-19 survivors was 19.1% at 2.5 years after infection and hospitalization, evaluated using the Telephone Interview for Cognitive Status-40. Cognitive decline primarily manifested in individuals with severe COVID-19 during the initial year of infection, after which the rate of decline decelerated. Severe COVID-19, cognitive impairment at 6 months and hypertension were associated with long-term cognitive decline. These findings reveal the long-term cognitive trajectory of the disease and underscore the importance of post-infection cognitive care for COVID-19 survivors.

13.
Biochem Biophys Res Commun ; 727: 150317, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38959733

ABSTRACT

Abnormalities in osteoclastic generation or activity disrupt bone homeostasis and are highly involved in many pathologic bone-related diseases, including rheumatoid arthritis, osteopetrosis, and osteoporosis. Control of osteoclast-mediated bone resorption is crucial for treating these bone diseases. However, the mechanisms of control of osteoclastogenesis are incompletely understood. In this study, we identified that inosine 5'-monophosphate dehydrogenase type II (Impdh2) positively regulates bone resorption. By histomorphometric analysis, Impdh2 deletion in mouse myeloid lineage cells (Impdh2LysM-/- mice) showed a high bone mass due to the reduced osteoclast number. qPCR and western blotting results demonstrated that the expression of osteoclast marker genes, including Nfatc1, Ctsk, Calcr, Acp5, Dcstamp, and Atp6v0d2, was significantly decreased in the Impdh2LysM-/- mice. Furthermore, the Impdh inhibitor MPA treatment inhibited osteoclast differentiation and induced Impdh2-cytoophidia formation. The ability of osteoclast differentiation was recovered after MPA deprivation. Interestingly, genome-wide analysis revealed that the osteoclastic mitochondrial biogenesis and functions, such as oxidative phosphorylation, were impaired in the Impdh2LysM-/- mice. Moreover, the deletion of Impdh2 alleviated ovariectomy-induced bone loss. In conclusion, our findings revealed a previously unrecognized function of Impdh2, suggesting that Impdh2-mediated mechanisms represent therapeutic targets for osteolytic diseases.


Subject(s)
IMP Dehydrogenase , Mitochondria , Osteoclasts , Osteogenesis , Osteoporosis , Ovariectomy , Oxidative Phosphorylation , Animals , Osteoporosis/metabolism , Osteoporosis/etiology , Osteoporosis/genetics , Osteoporosis/pathology , Mice , Female , Osteoclasts/metabolism , Osteoclasts/pathology , Mitochondria/metabolism , Mitochondria/pathology , IMP Dehydrogenase/metabolism , IMP Dehydrogenase/genetics , IMP Dehydrogenase/deficiency , Mice, Knockout , Mice, Inbred C57BL , Cell Differentiation , Bone Resorption/metabolism , Bone Resorption/genetics , Bone Resorption/pathology , Bone Resorption/etiology
14.
Int Immunopharmacol ; 139: 112707, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39032472

ABSTRACT

Telmisartan, an angiotensin II type 1 receptor (AT1R) blocker, exhibits broad anti-tumor activity. However, in vitro, anti-proliferative effects are shown at doses far beyond the therapeutic plasma concentration. Considering the role of tumor microenvironment in glioma progression, glioma-astrocyte co-cultures were employed to test the anti-tumor potential of low-dose telmisartan. When a high dose was required for a direct anti-proliferative effect on glioma cell lines, a low dose significantly inhibited glioma cell proliferation and migration in the co-culture system. Under co-culture conditions, upregulated IL-6 expression in astrocytes played a critical role in glioma progression. Silencing IL-6 in astrocytes or IL-6R in glioma cells reduced proliferation and migration. Telmisartan (5 µM) inhibited astrocytic IL-6 expression, and its anti-tumor effects were reversed by silencing IL-6 or IL-6R and inhibiting signal transducer and activator of transcription 3 (STAT3) activity in glioma cells. Moreover, the telmisartan-driven IL-6 downregulation was not imitated by losartan, an AT1R blocker with little capacity of peroxisome proliferator-activated receptor-gamma (PPARγ) activation, but was eliminated by a PPARγ antagonist, indicating that the anti-glioma effects of telmisartan rely on its PPARγ agonistic activity rather than AT1R blockade. This study highlights the importance of astrocytic IL-6-mediated paracrine signaling in glioma growth and the potential of telmisartan as an adjuvant therapy for patients with glioma, especially those with hypertension.

15.
ACS Nano ; 18(28): 18650-18662, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38959157

ABSTRACT

Peptide design and drug development offer a promising solution for combating serious diseases or infections. In this study, using an AI-human negotiation approach, we have designed a class of minimal model peptides against tuberculosis (TB), among which K7W6 exhibits potent efficacy attributed to its assembly-induced function. Comprising lysine and tryptophan with an amphiphilic α-helical structure, the K7W6 sequence exhibits robust activity against various infectious bacteria causing TB (including clinically isolated and drug-resistant strains) both in vitro and in vivo. Moreover, it synergistically enhances the effectiveness of the first-line antibiotic rifampicin while displaying low potential for inducing drug resistance and minimal toxicity toward mammalian cells. Biophysical experiments and simulations elucidate that K7W6's exceptional performance can be ascribed to its highly selective and efficient membrane permeabilization activity induced by its distinctive self-assembly behavior. Additionally, these assemblies regulate the interplay between enthalpy and entropy during K7W6-membrane interaction, leading to the peptide's two-step mechanism of membrane interaction. These findings provide valuable insights into rational design principles for developing advanced peptide-based drugs while uncovering the functional role played by assembly.


Subject(s)
Entropy , Humans , Peptides/chemistry , Peptides/pharmacology , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Antitubercular Agents/pharmacology , Antitubercular Agents/chemistry , Rifampin/chemistry , Rifampin/pharmacology , Animals
16.
Front Med (Lausanne) ; 11: 1374177, 2024.
Article in English | MEDLINE | ID: mdl-38952862

ABSTRACT

Background: The role of macrophages in the symptomatic and structural progression of pulmonary fibrosis (PF) has garnered significant scholarly attention in recent years. This study employs a bibliometric approach to examine the present research status and areas of focus regarding the correlation between macrophages and PF, aiming to provide a comprehensive understanding of their relationship. Methodology: The present study employed VOSviewer, CiteSpace, and Microsoft Excel software to visualize and analyze various aspects such as countries, institutions, authors, journals, co-cited literature, keywords, related genes, and diseases. These analyses were conducted using the Web of Science core collection database. Results: A comprehensive collection of 3,479 records pertaining to macrophages and PF from the period of 1990 to 2023 was obtained. Over the years, there has been a consistent increase in research literature on this topic. Notably, the United States and China exhibited the highest level of collaboration in this field. Through careful analysis, the institutions, authors, and prominent journals that hold significant influence within this particular field have been identified as having the highest publication output. The pertinent research primarily concentrates on the domains of Biology and Medicine. The prevailing keywords encompass pulmonary fibrosis, acute lung injury, idiopathic pulmonary fibrosis, and others. Notably, TGFß1, TNF, and CXCL8 emerge as the most frequently studied targets, primarily associated with signaling pathways such as cytokine-cytokine receptor interaction. Additionally, cluster analysis of related diseases reveals their interconnectedness with ailments such as cancer. Conclusion: The present study employed bibliometric methods to investigate the knowledge structure and developmental trends in the realm of macrophage and PF research. The findings shed light on the introduction and research hotspots that facilitate a more comprehensive understanding of macrophages and PF.

17.
Front Chem ; 12: 1427451, 2024.
Article in English | MEDLINE | ID: mdl-38952891

ABSTRACT

In solid propellants, combustion catalysts play a crucial role. Here, we introduce a convenient method for the self-assembly of UIO-66 (Mn) in the presence of water, leading to the preparation of Mn/C aerogels. The aerogels were successfully utilized in the thermocatalytic decomposition of ammonium perchlorate (AP). The results indicate that the incorporation of 2% mass fraction of Mn/C aerogels enhances the peak temperature of AP decomposition by approximately 87.5°C. Mn/C aerogels demonstrate excellent catalytic performance. In combination with kinetics, we propose a thermal catalytic mechanism.

18.
BMC Cancer ; 24(1): 805, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38969990

ABSTRACT

BACKGROUND: Differentiation of glioma and solitary brain metastasis (SBM), which requires biopsy or multi-disciplinary diagnosis, remains sophisticated clinically. Histogram analysis of MR diffusion or molecular imaging hasn't been fully investigated for the differentiation and may have the potential to improve it. METHODS: A total of 65 patients with newly diagnosed glioma or metastases were enrolled. All patients underwent DWI, IVIM, and APTW, as well as the T1W, T2W, T2FLAIR, and contrast-enhanced T1W imaging. The histogram features of apparent diffusion coefficient (ADC) from DWI, slow diffusion coefficient (Dslow), perfusion fraction (frac), fast diffusion coefficient (Dfast) from IVIM, and MTRasym@3.5ppm from APTWI were extracted from the tumor parenchyma and compared between glioma and SBM. Parameters with significant differences were analyzed with the logistics regression and receiver operator curves to explore the optimal model and compare the differentiation performance. RESULTS: Higher ADCkurtosis (P = 0.022), frackurtosis (P<0.001),and fracskewness (P<0.001) were found for glioma, while higher (MTRasym@3.5ppm)10 (P = 0.045), frac10 (P<0.001),frac90 (P = 0.001), fracmean (P<0.001), and fracentropy (P<0.001) were observed for SBM. frackurtosis (OR = 0.431, 95%CI 0.256-0.723, P = 0.002) was independent factor for SBM differentiation. The model combining (MTRasym@3.5ppm)10, frac10, and frackurtosis showed an AUC of 0.857 (sensitivity: 0.857, specificity: 0.750), while the model combined with frac10 and frackurtosis had an AUC of 0.824 (sensitivity: 0.952, specificity: 0.591). There was no statistically significant difference between AUCs from the two models. (Z = -1.14, P = 0.25). CONCLUSIONS: The frac10 and frackurtosis in enhanced tumor region could be used to differentiate glioma and SBM and (MTRasym@3.5ppm)10 helps improving the differentiation specificity.


Subject(s)
Brain Neoplasms , Glioma , Humans , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/secondary , Brain Neoplasms/pathology , Glioma/diagnostic imaging , Glioma/pathology , Female , Male , Middle Aged , Adult , Diagnosis, Differential , Aged , Diffusion Magnetic Resonance Imaging/methods , ROC Curve , Magnetic Resonance Imaging/methods
19.
Chem Commun (Camb) ; 60(64): 8411-8414, 2024 Aug 06.
Article in English | MEDLINE | ID: mdl-39028271

ABSTRACT

The first examples of RE/Si FLPs (RE: rare-earth metal, FLPs: frustrated Lewis pairs), namely Yb/Si FLPs were synthesized, where Yb⋯Si distances are in the range of 3.55 to 3.72 Å. These FLPs react with triphenylphosphine sulfide and aryl isocyanide to produce novel silylyne group transfer products through dissociation of naphthalene.

20.
Environ Sci Atmos ; 4(7): 740-753, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-39006766

ABSTRACT

Isoprene affects new particle formation rates in environments and experiments also containing monoterpenes. For the most part, isoprene reduces particle formation rates, but the reason is debated. It is proposed that due to its fast reaction with OH, isoprene may compete with larger monoterpenes for oxidants. However, by forming a large amount of peroxy-radicals (RO2), isoprene may also interfere with the formation of the nucleating species compared to a purely monoterpene system. We explore the RO2 cross reactions between monoterpene and isoprene oxidation products using the radical Volatility Basis Set (radical-VBS), a simplified reaction mechanism, comparing with observations from the CLOUD experiment at CERN. We find that isoprene interferes with covalently bound C20 dimers formed in the pure monoterpene system and consequently reduces the yields of the lowest volatility (Ultra Low Volatility Organic Carbon, ULVOC) VBS products. This in turn reduces nucleation rates, while having less of an effect on subsequent growth rates.

SELECTION OF CITATIONS
SEARCH DETAIL