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1.
Biochem Pharmacol ; 226: 116338, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38848780

RESUMO

ITFG2, as an immune-modulatory intracellular protein that modulate the fate of B cells and negatively regulates mTORC1 signaling. ITFG2 is highly expressed in the heart, but its pathophysiological function in heart disease is unclear. In this study, we found that in MI mice, overexpression of ITFG2 via an AAV9 vector significantly reduced the infarct size and ameliorated cardiac function. Knockdown of endogenous ITFG2 by shRNA partially aggravated ischemia-induced cardiac dysfunction. In cardiac-specific ITFG2 transgenic (TG) mice, myocardial infarction size was smaller, eject fraction (EF) and fractional shortening (FS) was higher compared to those in wild-type (WT) mice, suggesting ITFG2 reversed cardiac dysfunction induced by MI. In hypoxic neonatal cardiomyocytes (NMCMs), overexpression of ITFG2 maintained mitochondrial function by increasing intracellular ATP production, reducing ROS levels, and preserving the mitochondrial membrane potential (MMP). Overexpression of ITFG2 reversed the mitochondrial respiratory dysfunction in NMCMs induced by hypoxia. Knockdown of endogenous ITFG2 by siRNA did the opposite. Mechanism, ITFG2 formed a complex with NEDD4-2 and ATP 5b and inhibited the binding of NEDD4-2 with ATP 5b leading to the reduction ubiquitination of ATP 5b. Our findings reveal a previously unknown ability of ITFG2 to protect the heart against ischemic injury by interacting with ATP 5b and thereby regulating mitochondrial function. ITFG2 has promise as a novel strategy for the clinical management of MI.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38848169

RESUMO

This study aims to elucidate the effect of alprostadil (ALP) plus cilostazol (CIL) on the treatment outcomes and inflammatory factors in patients with lower extremity arteriosclerosis obliterans (LEASO) receiving evidence-based care. Firstly, 130 patients with LEASO were selected from February 2020 to February 2023 and then randomly divided into two groups with 65 patients each. Excluding the dropouts, 59 patients in the control group (6 cases of dropout) received ALP and 62 patients in the research group (3 cases of dropout) received ALP plus CIL. Both groups were cared for in accordance with the evidence-based care model. Treatment outcomes, arteriosclerosis indexes (blood flow of dorsalis pedis artery [DPA], ankle-brachial index [ABI] and toe-brachial index [TBI]), hemorheological parameters (erythrocyte aggregation index [EAI], erythrocyte deformation index [EDI], high blood viscosity [HBV] and haematocrit [HCT]), inflammatory factors (interleukin [IL]-6, IL-8 and tumour necrosis factor [TNF]-α) and complications (nausea, diarrhoea, headache and transaminase elevation) were compared between the control and research groups. Results show that the overall response rate was markedly higher in the research group (90.32%) than in the control group (74.58%). Additionally, the blood flow of DPA, ABI and TBI in the research group significantly increased after the treatment and were higher than those in the control group. Meanwhile, the EAI, EDI, HBV, HCT, IL-6, IL-8 and TNF-α were significantly lower. The two groups did not differ markedly in the complication rate. The above findings suggest that ALP plus CIL is effective for patients with LEASO receiving evidence-based care. It can significantly improve arteriosclerosis indexes and hemorheological parameters while inhibiting serum inflammatory responses, with some certain safety.

3.
World J Clin Cases ; 12(16): 2894-2903, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38899300

RESUMO

BACKGROUND: For patients with acute paraplegia caused by spinal giant cell tumor (GCT) who require emergency decompressive surgery, there is still a lack of relevant reports on surgical options. This study is the first to present the case of an acute paraplegic patient with a thoracic spinal GCT who underwent an emergency total en bloc spondylectomy (TES). Despite tumor recurrence, three-level TES was repeated after denosumab therapy. CASE SUMMARY: A 27-year-old female patient who underwent single-level TES in an emergency presented with sudden severe back pain and acute paraplegia due to a thoracic spinal tumor. After emergency TES, the patient's spinal cord function recovered, and permanent paralysis was avoided. The postoperative histopathological examination revealed that the excised neoplasm was a rare GCT. Unfortunately, the tumor recurred 9 months after the first surgery. After 12 months of denosumab therapy, the tumor size was reduced, and tumor calcification. To prevent recurrent tumor progression and provide a possible cure, a three-level TES was performed again. The patient returned to an active lifestyle 1 month after the second surgery, and no recurrence of GCT was found at the last follow-up. CONCLUSION: This patient with acute paraplegia underwent TES twice, including once in an emergency, and achieved good therapeutic results. TES in emergency surgery is feasible and safe when conditions permit; however, it may increase the risk of tumor recurrence.

4.
Acta Pharmacol Sin ; 45(7): 1425-1437, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38839936

RESUMO

Cardiac fibrosis is a pathological scarring process that impairs cardiac function. N-acetyltransferase 10 (Nat10) is recently identified as the key enzyme for the N4-acetylcytidine (ac4C) modification of mRNAs. In this study, we investigated the role of Nat10 in cardiac fibrosis following myocardial infarction (MI) and the related mechanisms. MI was induced in mice by ligation of the left anterior descending coronary artery; cardiac function was assessed with echocardiography. We showed that both the mRNA and protein expression levels of Nat10 were significantly increased in the infarct zone and border zone 4 weeks post-MI, and the expression of Nat10 in cardiac fibroblasts was significantly higher compared with that in cardiomyocytes after MI. Fibroblast-specific overexpression of Nat10 promoted collagen deposition and induced cardiac systolic dysfunction post-MI in mice. Conversely, fibroblast-specific knockout of Nat10 markedly relieved cardiac function impairment and extracellular matrix remodeling following MI. We then conducted ac4C-RNA binding protein immunoprecipitation-sequencing (RIP-seq) in cardiac fibroblasts transfected with Nat10 siRNA, and revealed that angiomotin-like 1 (Amotl1), an upstream regulator of the Hippo signaling pathway, was the target gene of Nat10. We demonstrated that Nat10-mediated ac4C modification of Amotl1 increased its mRNA stability and translation in neonatal cardiac fibroblasts, thereby increasing the interaction of Amotl1 with yes-associated protein 1 (Yap) and facilitating Yap translocation into the nucleus. Intriguingly, silencing of Amotl1 or Yap, as well as treatment with verteporfin, a selective and potent Yap inhibitor, attenuated the Nat10 overexpression-induced proliferation of cardiac fibroblasts and prevented their differentiation into myofibroblasts in vitro. In conclusion, this study highlights Nat10 as a crucial regulator of myocardial fibrosis following MI injury through ac4C modification of upstream activators within the Hippo/Yap signaling pathway.


Assuntos
Fibrose , Camundongos Endogâmicos C57BL , Infarto do Miocárdio , Animais , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Camundongos , Masculino , Proteínas de Sinalização YAP/metabolismo , Fibroblastos/metabolismo , Citidina/análogos & derivados , Citidina/farmacologia , Camundongos Knockout , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Acetiltransferase N-Terminal E/metabolismo , Via de Sinalização Hippo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Células Cultivadas , Transdução de Sinais , Acetiltransferases N-Terminal/metabolismo , Miocárdio/patologia , Miocárdio/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
5.
Se Pu ; 42(6): 564-571, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-38845517

RESUMO

Protein phosphorylation plays an important role in cellular signaling and disease development. Advances in mass spectrometry-based proteomics have enabled qualitative and quantitative phosphorylation studies as well as in-depth biological explorations for biomarker discovery and signaling pathway analysis. However, the dynamic changes that occur during phosphorylation and the low abundance of target analytes render direct analysis difficult because mass spectral detection offers no selectivity, unlike immunoassays such as Western blot and enzyme-linked immunosorbent assay (ELISA). The present study aimed to solve one of the key problems in the specific and efficient isolation of phosphorylated peptides. A method based on a magnetic carbon nitride composite coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the enrichment and analysis of phosphopeptides with low abundance in complex samples. Magnetic carbon nitride composite was synthesized and characterized by electron microscopy, infrared spectroscopy, and X-ray diffractometry. The composite showed a well-distributed two-dimensional layered structure and functional groups with excellent paramagnetic performance. Two classical phosphoproteins, namely, α- and ß-caseins, were selected as model phosphorylated samples to assess the performance of the proposed enrichment technique. The magnetic carbon nitride composite exhibited high selectivity and sensitivity for phosphopeptide enrichment. The limit of detection was determined by MALDI-TOF-MS analysis to be 0.1 fmol. The selectivity of the method was investigated using the digest mixtures of α-casein, ß-casein, and bovine serum albumin (BSA) with different mass ratios (1∶1∶1000, 1∶1∶2000, and 1∶1∶5000). Direct analysis of the samples revealed the dominance of spectral signals from the abundant peptides in BSA. After enrichment with the magnetic carbon nitride composite, the high concentration of background proteins was washed away and only the signals of the phosphopeptides were captured. The signals from the casein proteins were clearly observed with little background noise, indicating the high selectivity of the composite material. The robustness of the method was tested by assessing the reusability of the same batch of magnetic carbon nitride materials over 20 cycles of enrichment. The composite showed nearly the same enrichment ability even after several cycles of reuse, demonstrating its potential applicability for a large number of clinical samples. Finally, the method was applied to the analysis of phosphopeptides from several commonly used phosphoprotein-containing samples, including skimmed milk digest, human serum, and human saliva; these samples are significant in the analysis of food quality, disease biomarkers, and liquid biopsies for cancer. Without enrichment, no phosphopeptide was detected because of the high abundance of nonphosphopeptide materials dominating the spectral signals obtained. After pretreatment with the developed magnetic carbon nitride composite, most of the phosphosites were identified with high selectivity and sensitivity via MALDI-TOF-MS. These results revealed the practicality of the developed approach for clinical applications. In addition, our method may potentially be employed for phosphoproteomics with real complex biological samples.


Assuntos
Nitrilas , Fosfopeptídeos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fosfopeptídeos/análise , Fosfopeptídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Nitrilas/química , Caseínas/química , Caseínas/análise , Fosforilação , Proteômica/métodos , Magnetismo
6.
Cell Mol Neurobiol ; 44(1): 50, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856921

RESUMO

In recent years, spatial transcriptomics (ST) research has become a popular field of study and has shown great potential in medicine. However, there are few bibliometric analyses in this field. Thus, in this study, we aimed to find and analyze the frontiers and trends of this medical research field based on the available literature. A computerized search was applied to the WoSCC (Web of Science Core Collection) Database for literature published from 2006 to 2023. Complete records of all literature and cited references were extracted and screened. The bibliometric analysis and visualization were performed using CiteSpace, VOSviewer, Bibliometrix R Package software, and Scimago Graphica. A total of 1467 papers and reviews were included. The analysis revealed that the ST publication and citation results have shown a rapid upward trend over the last 3 years. Nature Communications and Nature were the most productive and most co-cited journals, respectively. In the comprehensive global collaborative network, the United States is the country with the most organizations and publications, followed closely by China and the United Kingdom. The author Joakim Lundeberg published the most cited paper, while Patrik L. Ståhl ranked first among co-cited authors. The hot topics in ST are tissue recognition, cancer, heterogeneity, immunotherapy, differentiation, and models. ST technologies have greatly contributed to in-depth research in medical fields such as oncology and neuroscience, opening up new possibilities for the diagnosis and treatment of diseases. Moreover, artificial intelligence and big data drive additional development in ST fields.


Assuntos
Bibliometria , Transcriptoma , Humanos , Transcriptoma/genética , Publicações , Animais
7.
BMC Surg ; 24(1): 157, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755649

RESUMO

BACKGROUND: Fractures involving the posterior acetabulum with its rich vascular and neural supply present challenges in trauma orthopedics. This study evaluates the effectiveness of 3D printing technology with the use of custom-made metal plates in the treatment of posterior wall and column acetabular fractures. METHODS: A retrospective analysis included 31 patients undergoing surgical fixation for posterior wall and column fractures of the acetabulum (16 in the 3D printing group, utilizing 3D printing for a 1:1 pelvic model and custom-made plates based on preoperative simulation; 15 in the traditional group, using conventional methods). Surgical and instrument operation times, intraoperative fluoroscopy frequency, intraoperative blood loss, fracture reduction quality, fracture healing time, preoperative and 12-month postoperative pain scores (Numeric Rating Scale, NRS), hip joint function at 6 and 12 months (Harris scores), and complications were compared. RESULTS: The surgical and instrument operation times were significantly shorter in the 3D printing group (p < 0.001). The 3D printing group exhibited significantly lower intraoperative fluoroscopy frequency and blood loss (p = 0.001 and p < 0.001, respectively). No significant differences were observed between the two groups in terms of fracture reduction quality, fracture healing time, preoperative pain scores (NRS scores), and 6-month hip joint function (Harris scores) (p > 0.05). However, at 12 months, hip joint function and pain scores were significantly better in the 3D printing group (p < 0.05). Although the incidence of complications was lower in the 3D printing group (18.8% vs. 33.3%), the difference did not reach statistical significance (p = 0.433). CONCLUSION: Combining 3D printing with individualized custom-made metal plates for acetabular posterior wall and column fractures reduces surgery and instrument time, minimizes intraoperative procedures and blood loss, enhancing long-term hip joint function recovery. CLINICAL TRIAL REGISTRATION: 12/04/2023;Trial Registration No. ChiCTR2300070438; http://www.chictr.org.cn .


Assuntos
Acetábulo , Placas Ósseas , Fixação Interna de Fraturas , Fraturas Ósseas , Impressão Tridimensional , Humanos , Estudos Retrospectivos , Acetábulo/cirurgia , Acetábulo/lesões , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Resultado do Tratamento , Fraturas Ósseas/cirurgia , Duração da Cirurgia , Adulto Jovem , Desenho de Prótese , Idoso
8.
Small ; : e2401134, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816761

RESUMO

Strain engineering has been widely used to optimize platinum-based oxygen reduction reaction (ORR) catalysts for proton exchange membrane fuel cells (PEMFCs). PtM3 (M is base metals), a well-known high-compressive-strain intermetallic alloy, shows promise as a low platinum ORR catalyst due to high intrinsic activity. However, during the alloying of Pt with a threefold amount of M, a notable phase separation between Pt and M may occur, with M particles rapidly sintering while Pt particles grow slowly, posing a challenge in achieving a well-defined PtM3 intermetallic alloy. Here, an entropy-driven Ostwald ripening reversal phenomenon is discovered that enables the synthesis of small-sized Pt(FeCoNiCu)3 intermetallic ORR catalysts. High entropy promotes the thermodynamic driving force for the alloying Pt with M, which triggers the Ostwald ripening reversal of sintered FeCoNiCu particles and facilitates the formation of uniform Pt(FeCoNiCu)3 intermetallic catalysts. The prepared Pt(FeCoNiCu)3 catalysts exhibit a high specific activity of 3.82 mA cm-2, along with a power density of ≈1.3 W cm-2 at 0.67 V and 94 °C with a cathode Pt loading of 0.1 mg cm-2 in H2-air fuel cell.

9.
J Hepatol ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38670321

RESUMO

BACKGROUND & AIMS: The precise pathomechanisms underlying the development of non-alcoholic steatohepatitis (NASH, also known as metabolic dysfunction-associated steatohepatitis [MASH]) remain incompletely understood. In this study, we investigated the potential role of EF-hand domain family member D2 (EFHD2), a novel molecule specific to immune cells, in the pathogenesis of NASH. METHODS: Hepatic EFHD2 expression was characterized in patients with NASH and two diet-induced NASH mouse models. Single-cell RNA sequencing (scRNA-seq) and double-immunohistochemistry were employed to explore EFHD2 expression patterns in NASH livers. The effects of global and myeloid-specific EFHD2 deletion on NASH and NASH-related hepatocellular carcinoma were assessed. Molecular mechanisms underlying EFHD2 function were investigated, while chemical and genetic investigations were performed to assess its potential as a therapeutic target. RESULTS: EFHD2 expression was significantly elevated in hepatic macrophages/monocytes in both patients with NASH and mice. Deletion of EFHD2, either globally or specifically in myeloid cells, improved hepatic steatosis, reduced immune cell infiltration, inhibited lipid peroxidation-induced ferroptosis, and attenuated fibrosis in NASH. Additionally, it hindered the development of NASH-related hepatocellular carcinoma. Specifically, deletion of myeloid EFHD2 prevented the replacement of TIM4+ resident Kupffer cells by infiltrated monocytes and reversed the decreases in patrolling monocytes and CD4+/CD8+ T cell ratio in NASH. Mechanistically, our investigation revealed that EFHD2 in myeloid cells interacts with cytosolic YWHAZ (14-3-3ζ), facilitating the translocation of IFNγR2 (interferon-γ receptor-2) onto the plasma membrane. This interaction mediates interferon-γ signaling, which triggers immune and inflammatory responses in macrophages during NASH. Finally, a novel stapled α-helical peptide targeting EFHD2 was shown to be effective in protecting against NASH pathology in mice. CONCLUSION: Our study reveals a pivotal immunomodulatory and inflammatory role of EFHD2 in NASH, underscoring EFHD2 as a promising druggable target for NASH treatment. IMPACT AND IMPLICATIONS: Non-alcoholic steatohepatitis (NASH) represents an advanced stage of non-alcoholic fatty liver disease (NAFLD); however, not all patients with NAFLD progress to NASH. A key challenge is identifying the factors that trigger inflammation, which propels the transition from simple fatty liver to NASH. Our research pinpointed EFHD2 as a pivotal driver of NASH, orchestrating the over-activation of interferon-γ signaling within the liver during NASH progression. A stapled peptide designed to target EFHD2 exhibited therapeutic promise in NASH mice. These findings support the potential of EFHD2 as a therapeutic target in NASH.

10.
J Phys Chem Lett ; 15(16): 4501-4507, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38634716

RESUMO

The fine-tuning of the geometric and electronic structures of active sites plays a crucial role in catalysis. However, the intricate entanglement between the two aspects results in a lack of interpretable design for active sites, posing a challenge in developing high-performance catalysts. Here, we find that surface reconstruction induced by phase transition in intermetallic alloys enables synergistic geometric and electronic structure modulation, creating a desired active site microenvironment for propane dehydrogenation. The resulting electron-rich four-coordinate Rh1 site in the RhGe0.5Ga0.5 intermetallic alloy can accelerate the desorption of propylene and suppress the side reaction and thus exhibits a propylene selectivity of ∼98% with a low deactivation constant of 0.002 h-1 under propane dehydrogenation at 550 °C. Furthermore, we design a computational workflow to validate the rationality of the microenvironment modulation induced by the phase transition in an intermetallic alloy.

11.
Environ Health Perspect ; 132(4): 47008, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38625811

RESUMO

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are widely detected in pregnant women and associated with adverse outcomes related to impaired placental function. Human chorionic gonadotropin (hCG) is a dimeric glycoprotein hormone that can indicate placental toxicity. OBJECTIVES: Our aim was to quantify the association of serum PFAS with placental hCG, measured as an intact molecule (hCG), as free alpha-(hCGα) and beta-subunits (hCGß), and as a hyperglycosylated form (h-hCG), and evaluate effect measure modification by social determinants and by fetal sex. METHODS: Data were collected from 326 pregnant women enrolled from 2015 to 2019 in the UPSIDE study in Rochester, New York. hCG forms were normalized for gestational age at the time of blood draw in the first trimester [multiple of the median (MoM)]. Seven PFAS were measured in second-trimester maternal serum. Multivariate imputation by chained equations and inverse probability weighting were used to evaluate robustness of linear associations. PFAS mixture effects were estimated by Bayesian kernel machine regression. RESULTS: Perfluorohexane sulfonic acid (PFHxS) [hCGß: 0.29 log MoM units per log PFHxS; 95% confidence interval (CI): 0.08, 0.51] and perfluorodecanoic acid (PFDA) (hCG: -0.09; 95% CI: -0.16, -0.02) were associated with hCG in the single chemical and mixture analyses. The PFAS mixture was negatively associated with hCGα and positively with hCGß. Subgroup analyses revealed that PFAS associations with hCG differed by maternal race/ethnicity and education. Perfluoropentanoic acid (PFPeA) was associated with hCGß only in Black participants (-0.23; 95% CI: -0.37, -0.09) and in participants with high school education or less (-0.14; 95% CI: -0.26, -0.02); conversely, perfluorononanoic acid (PFNA) was negatively associated with hCGα only in White participants (-0.15; 95% CI: -0.27, -0.03) and with hCGß only in participants with a college education or greater (-0.19; 95% CI: -0.36, -0.01). These findings were robust to testing for selection bias, confounding bias, and left truncation bias where PFAS detection frequency was <100%. Two associations were negative in male (and null in female) pregnancies: Perfluoroundecanoic acid (PFUnDA) with hCGα, and PFNA with h-hCG. CONCLUSIONS: Evidence was strongest for the association between PFHxS and PFDA with hCG in all participants and for PFPeA and PFNA within subgroups defined by social determinants and fetal sex. PFAS mixture associations with hCGα and hCGß differed, suggesting subunit-specific types of toxicity and/or regulation. Future studies will evaluate the biological, clinical and public health significance of these findings. https://doi.org/10.1289/EHP12950.


Assuntos
Ácidos Alcanossulfônicos , Ácidos Decanoicos , Poluentes Ambientais , Ácidos Graxos , Fluorocarbonos , Ácidos Pentanoicos , Humanos , Feminino , Masculino , Gravidez , Placenta , New York/epidemiologia , Teorema de Bayes , Gonadotropina Coriônica
12.
Front Biosci (Landmark Ed) ; 29(4): 166, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38682188

RESUMO

OBJECTIVE: The aims of this study were to evaluate the correlation between chemokine (C-X-C) ligand 7 (CXCL7) expression and glycolysis and to explore the prognostic significance of CXCL7 in colorectal cancer (CRC). METHODS: The expression of CXCL7 and lactate dehydrogenase A (LDH-A) was measured by immunohistochemistry in tissue from 158 CRC patients. Patients were divided into high expression and low expression groups based on receiver operating characteristic curves and a cut-off value. The correlation between CXCL7 and LDH-A expression was evaluated. The overall survival (OS) times of CRC patients were explored. The risk factors related to prognosis were assessed. RESULTS: Significantly higher expression of CXCL7 and LDH-A was detected in CRC tissue than in non-CRC tissue, and was associated with N stage and tumor-node-metastasis (TNM) stage. CXCL7 expression was strongly correlated with LDH-A expression in CRC tissue. High expression of CXCL7 was validated as an independent risk factor for OS. CONCLUSION: Increased expression of CXCL7 was positively correlated with LDH-A expression and was an independent risk factor for CRC prognosis.


Assuntos
Biomarcadores Tumorais , Neoplasias Colorretais , L-Lactato Desidrogenase , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/genética , Imuno-Histoquímica , L-Lactato Desidrogenase/metabolismo , Prognóstico , Fatores de Risco
13.
Nano Lett ; 24(18): 5578-5584, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38682925

RESUMO

The lattice parameter of platinum-based intermetallic compounds (IMCs), which correlates with the intrinsic activity of the oxygen reduction reaction (ORR), can be modulated by crystal phase engineering. However, the controlled preparation of IMCs with unconventional crystal structures remains highly challenging. Here, we demonstrate the synthesis of carbon-supported PtCu-based IMC catalysts with an unconventional L10 structure by a composition-regulated strategy. Experiment and machine learning reveal that the thermodynamically favorable structure changes from L11 to L10 when slight Cu atoms are substituted with Co. Benefiting from crystal-phase-induced strain enhancement, the prepared L10-type PtCu0.8Co0.2 catalyst exhibits much-enhanced mass and specific activities of 1.82 A mgPt-1 and 3.27 mA cmPt-2, which are 1.91 and 1.73 times higher than those of the L11-type PtCu catalyst, respectively. Our work highlights the important role of crystal phase in determining the surface strain of IMCs, and opens a promising avenue for the rational preparation of IMCs with different crystal phases by doping.

14.
J Am Chem Soc ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592685

RESUMO

The determination of catalytically active sites is crucial for understanding the catalytic mechanism and providing guidelines for the design of more efficient catalysts. However, the complex structure of supported metal nanocatalysts (e.g., support, metal surface, and metal-support interface) still presents a big challenge. In particular, many studies have demonstrated that metal-support interfaces could also act as the primary active sites in catalytic reactions, which is well elucidated in oxide-supported metal nanocatalysts but is rarely reported in carbon-supported metal nanocatalysts. Here, we fill the above gap and demonstrate that metal-sulfur interfaces in sulfur-doped carbon-supported metal nanocatalysts are the primary active sites for several catalytic hydrogenation reactions. A series of metal nanocatalysts with similar sizes but different amounts of metal-sulfur interfaces were first constructed and characterized. Taking Ir for quinoline hydrogenation as an example, it was found that their catalytic activities were proportional to the amount of the Ir-S interface. Further experiments and density functional theory (DFT) calculations suggested that the adsorption and activation of quinoline occurred on the Ir atoms at the Ir-S interface. Similar phenomena were found in p-chloronitrobenzene hydrogenation over the Pt-S interface and benzoic acid hydrogenation over the Ru-S interface. All of these findings verify the predominant activity of metal-sulfur interfaces for catalytic hydrogenation reactions and contribute to the comprehensive understanding of metal-support interfaces in supported nanocatalysts.

15.
Environ Res ; 251(Pt 2): 118719, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38490622

RESUMO

In southern China, winter green manure is widely used in rice cropping systems for improving grain yields and soil fertility. Cd pollution has recently been reported in some of these paddy fields. Research on the in-depth understanding of how green manuring affects Cd absorption in rice is limited. This study aimed to investigate the impacts of different green manures, including single plantation and mixed plantation on the absorption of Cd by rice and explore the underlying mechanisms. Pot experiments demonstrated that compared with winter fallow-rice, green manuring treatments considerably decreased rice Cd content, promoted the conversion of bioavailable Cd fraction into a more stable form, induced the formation of iron plaque, and increased the content of humic-like fraction (HF) in soil dissolved organic matter (DOM). Treatment with mixed plantation resulted in a greater decrease in rice Cd content and an increase in HF and iron plaque contents than single plantation. Hydroponic experiments confirmed that both iron plaque and green manure-derived DOM significantly reduced the Cd content in rice seedlings. In conclusion, green manure incorporation is an efficient measure for the safe utilization of Cd-contaminated soil, and mixed plantation of different green manures exerts stronger effects.


Assuntos
Cádmio , Ferro , Esterco , Oryza , Poluentes do Solo , Oryza/metabolismo , Oryza/crescimento & desenvolvimento , Cádmio/análise , Cádmio/metabolismo , Ferro/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Esterco/análise , China , Agricultura/métodos , Substâncias Húmicas/análise , Solo/química
16.
IEEE Trans Vis Comput Graph ; 30(5): 2580-2590, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38437094

RESUMO

VR exergames offer an engaging solution to combat sedentary behavior and promote physical activity. However, challenges emerge when playing these games in shared spaces, particularly due to the presence of bystanders. VR's passthrough functionality enables players to maintain awareness of their surrounding environment while immersed in VR gaming, rendering it a promising solution to improve users' awareness of the environment. This study investigates the passthrough's impact on player performance and experiences in shared spaces, involving an experiment with 24 participants that examines Space (Office vs. Corridor) and Passthrough Function (With vs. Without). Results reveal that Passthrough enhances game performance and environmental awareness while reducing immersion. Players prefer an open area to an enclosed room, whether with or without Passthrough, finding it more socially acceptable. Additionally, Passthrough appears to encourage participation among players with higher self-consciousness, potentially alleviating their concerns about being observed by bystanders. Our findings provide valuable insights for designing VR experiences in shared spaces, underscoring the potential of VR's passthrough to enhance user experiences and promote VR adoption in these environments.


Assuntos
Jogos Eletrônicos de Movimento , Realidade Virtual , Humanos , Interface Usuário-Computador , Gráficos por Computador , Exercício Físico
17.
IEEE Trans Vis Comput Graph ; 30(5): 2033-2043, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38437113

RESUMO

Users' perceived image quality of virtual reality head-mounted displays (VR HMDs) is determined by multiple factors, including the HMD's structure, optical system, display and render resolution, and users' visual acuity (VA). Existing metrics such as pixels per degree (PPD) have limitations that prevent accurate comparison of different VR HMDs. One of the main limitations is that not all VR HMD manufacturers released the official PPD or details of their HMDs' optical systems. Without these details, developers and users cannot know the precise PPD or calculate it for a given HMD. The other issue is that the visual clarity varies with the VR environment. Our work has identified a gap in having a feasible metric that can measure the visual clarity of VR HMDs. To address this gap, we present an end-to-end and user-centric visual clarity metric, omnidirectional virtual visual acuity (OVVA), for VR HMDs. OVVA extends the physical visual acuity chart into a virtual format to measure the virtual visual acuity of an HMD's central focal area and its degradation in its noncentral area. OVVA provides a new perspective to measure visual clarity and can serve as an intuitive and accurate reference for VR applications sensitive to visual accuracy. Our results show that OVVA is a simple yet effective metric for comparing VR HMDs and environments.


Assuntos
Óculos Inteligentes , Realidade Virtual , Gráficos por Computador , Acuidade Visual
18.
Se Pu ; 42(3): 234-244, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38503700

RESUMO

Ziziphi Spinosae Semen refers to the dried seed of Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou. The seed is composed of a reddish brown coat and a yellow kernel. A comparative study was conducted to investigate differences in the chemical composition and their relative contents between the seed coat and kernel of Ziziphi Spinosae Semen. First, the chemical compounds found in the seed coat and kernel were characterized and identified using ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The analytical results tentatively identified 57 chemical compounds based on reference-compound comparison, literature retrieval, and chemical-database (e. g., MassBank) searches; these compounds included 14 triterpenes, 23 flavonoids, 7 alkaloids, 6 carboxylic acids, and 7 other types of compounds. The mass error of the identified compounds was within the mass deviation range of 5×10-6 (5 ppm). Next, two methods of multivariate statistical analysis, namely, principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), were used to compare the differential compounds between the two seed parts. A total of 17 differential compounds were screened out via OPLS-DA based on a variable importance in projection (VIP) value of >5. The results revealed that betulinic acid, betulonic acid, alphitolic acid, and jujuboside Ⅰ mainly existed in the seed coat whereas the 13 other compounds, such as spinosin, jujuboside A, and 6‴-feruloylspinosin, mainly existed in the seed kernel. Therefore, these 17 differential compounds can be used to distinguish between the two seed parts. Finally, a semiquantitative method was established using UPLC and a charged aerosol detector (CAD) with inverse gradient compensation in the mobile phase. Six representative compounds with different types were selected to examine the CAD response consistency: magnoflorine (alkaloid), spinosin (flavone), 6‴-feruloylspinosin (flavone), jujuboside A (triterpenoid saponin), jujuboside B (triterpenoid saponin), and betulinic acid (triterpenoid acid). The results showed that the relative standard deviation (RSD) of the average response factors at different levels of these six compounds was 7.04% and that their response intensities were similar. Moreover, each compound in the fingerprint demonstrated good response consistency, and the peak areas obtained directly reflected the contents of each compound. Based on the semiquantitative fingerprints obtained, betulinic acid and oleic acid were considered the main components of the seed coat. The betulinic acid content in the seed coat was approximately 7 times higher than that in the seed kernel. Spinosin, jujuboside A, linoleic acid, betulinic acid, and oleic acid were the main components of the seed kernel. The spinosin content in the seed kernel was 18 times higher than that in the seed coat. In addition, the jujuboside A content in the seed kernel was 24 times higher than that in the seed coat. The proposed method can accurately determine the main components and compare the relative contents of these components in different seed parts. In summary, this study identified the differences in chemical components between the seed coat and kernel of Ziziphi Spinosae Semen and clarified the main components and their relative contents in these parts. The findings can not only provide a basis for the identification of chemical compounds and quality research on different parts of Ziziphi Spinosae Semen but also promote the development and utilization of this traditional Chinese medicine.


Assuntos
Alcaloides , Medicamentos de Ervas Chinesas , Flavonas , Saponinas , Triterpenos , Ziziphus , Medicamentos de Ervas Chinesas/química , Ácido Betulínico , Saponinas/química , Ácidos Oleicos , Cromatografia Líquida de Alta Pressão , Ziziphus/química , Sementes
19.
Chem Commun (Camb) ; 60(31): 4226-4229, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38526318

RESUMO

We introduce a straightforward, yet effective strategy to combat the performance decline of proton-exchange membrane fuel cells in low-humidity environments. Our method centers on air-oxidizing carbon supports, significantly improving proton and oxygen transport within the cathode catalyst layer.

20.
J Orthop Surg Res ; 19(1): 111, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38308324

RESUMO

The 5'-HOXD genes are important for chondrogenesis in vertebrates, but their roles in osteoarthritis (OA) are still ambiguous. In our study, 5'-HOXD genes involvement contributing to cartilage degradation and OA was investigated. In bioinformatics analysis of 5'-HOXD genes, we obtained the GSE169077 data set related to OA in the GEO and analyzed DEGs using the GEO2R tool attached to the GEO. Then, we screened the mRNA levels of 5'-HOXD genes by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). We discovered that OA chondrocyte proliferation was inhibited, and apoptosis was increased. Moreover, it was discovered that SOX9 and COL2A1 were downregulated at mRNA and protein levels, while matrix metalloproteinases (MMPs) and a disintegrin-like and metalloproteinase with thrombospondin motifs (ADAMTSs) were upregulated. According to the results of differentially expressed genes (DEGs) and qRT-PCR, we evaluated the protein level of HOXD11 and found that the expression of HOXD11 was downregulated, reversed to MMPs and ADAMTSs but consistent with the cartilage-specific factors, SOX9 and COL2A1. In the lentivirus transfection experiments, HOXD11 overexpression reversed the effects in OA chondrocytes. In human OA articular cartilage, aberrant subchondral bone was formed in hematoxylin-eosin (H&E) and Safranin O and fast green (SOFG) staining results. Furthermore, according to immunohistochemistry findings, SOX9 and HOXD11 expression was inhibited. The results of this study established that HOXD11 was downregulated in OA cartilage and that overexpression of HOXD11 could prevent cartilage degradation in OA.


Assuntos
Cartilagem Articular , Osteoartrite , Animais , Humanos , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Metaloproteinases da Matriz/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
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