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1.
J Colloid Interface Sci ; 678(Pt C): 191-199, 2025 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-39293363

RESUMO

Deuterium labeling is a highly valuable yet challenging subject of research in various scientific fields. Conventional deuteration methods often involve harsh reaction conditions and suffer from limited reactivity and selectivity. Herein, we report a visible light-driven C-X (X = halogen) to C-D (D = deuterium) exchange strategy over copper-doped cadmium sulfide quantum dots (Cu-CdS QDs) under mild conditions, eliminating the need for noble metal catalysts and expensive deuterium sources. The conversion of aryl halides into deuterated products using Cu-CdS QDs reaches up to 99%, which is four times higher than that achieved using pristine CdS QDs. The substantial enhancement in the photocatalytic activity of the QDs can be primarily attributed to the generation of long-lived charge carriers (approximately 6 µs) induced by Cu doping. Mechanistic studies reveal that the Cu dopants considerably retard the recombination of photoinduced carriers by creating intermediate energy levels that serve as hole trapping centers in CdS QDs, thereby improving the electron utilization efficiency in energetically demanding photoreduction reactions. Additionally, the introduction of Cu increases the energy offset between the conduction band of CdS QDs and molecular acceptors, facilitating the electron transfer process. Upon visible light irradiation, a series of aryl halides can be efficiently converted into the desired deuterated compounds using D2O as the deuterium source. This work demonstrates that regulating charge carrier dynamics in ultrasmall QD-based photocatalysts is a promising strategy for promoting organic transformations.

2.
Nano Lett ; 24(37): 11648-11653, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39225486

RESUMO

Energetic carriers generated by localized surface plasmon resonance (LSPR) provide an efficient way to drive chemical reactions. However, their dynamics and impact on surface reactions remain unknown due to the challenge in observing hot holes. This makes it difficult to correlate the reduction and oxidation half-reactions involving hot electrons and holes, respectively. Here we detect hot holes in their chemical form, Ag(I), on a Ag surface using surface-enhanced Raman scattering (SERS) of SO32- as a hole-specific label. It allows us to determine the dynamic correlations of hot electrons and holes. We find that the equilibrium of holes is the key factor of the surface chemistry, and the wavelength-dependent plasmonic chemical anode refilling (PCAR) effect plays an important role, in addition to the LSPR, in promoting the electron transfer. This method paves the way for visualizing hot holes with nanoscale spatial resolution toward the rational design of a plasmonic catalytic platform.

3.
Angew Chem Int Ed Engl ; 63(35): e202409656, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-38837290

RESUMO

Perovskite quantum dots (QDs) have shown attractive prospects in the field of visible photocatalysis, especially in the synthesis of high value-added chemicals. However, under aerobic conditions, the stable operation of QD catalysts has been limited by the reactive oxygen species (ROS) generated by photoexcitation, especially superoxide species O2⋅-. Here, we propose a strategy of Ce3+ doping in perovskite QDs to guide superoxide species for photocatalytic oxidation reactions. In C(sp3)-H bond oxidation of hydrocarbons, superoxide species were rapidly generated and efficiently utilized on the surface of perovskite QDs, which achieves the stable operation of the catalytic system and obtains a high product conversion rate (15.3 mmol/g/h for benzaldehydes). The mechanism studies show that the strong Ce-oxygen affinity accelerates the relaxation process of photoinduced exciton transfer to superoxide species and inhibits the radiative recombination pathway. This work provides a new idea of utilizing oxygen species on perovskite surface and broadens the design strategy of high-performance QD photocatalysts.

4.
Aging (Albany NY) ; 16(8): 7217-7248, 2024 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-38656880

RESUMO

AIM: In 2019, to examine the functions of METTL3 in liver and underlying mechanisms, we generated mice with hepatocyte-specific METTL3 homozygous knockout (METTL3Δhep) by simultaneously crossing METTL3fl/fl mice with Alb-iCre mice (GPT) or Alb-Cre mice (JAX), respectively. In this study, we explored the potential reasons why hepatocyte-specific METTL3 homozygous disruption by Alb-iCre mice (GPT), but not by Alb-Cre mice (JAX), resulted in acute liver failure (ALF) and then postnatal lethality. MAIN METHODS: Mice with hepatocyte-specific METTL3 knockout were generated by simultaneously crossing METTL3fl/fl mice with Alb-iCre mice (GPT; Strain No. T003814) purchased from the GemPharmatech Co., Ltd., (Nanjing, China) or with Alb-Cre mice (JAX; Strain No. 003574) obtained from The Jackson Laboratory, followed by combined-phenotype analysis. The publicly available RNA-sequencing data deposited in the NCBI Gene Expression Omnibus (GEO) database under the accession No.: GSE198512 (postnatal lethality), GSE197800 (postnatal survival) and GSE176113 (postnatal survival) were mined to explore the potential reasons why hepatocyte-specific METTL3 homozygous deletion by Alb-iCre mice (GPT), but not by Alb-Cre mice (JAX), leads to ALF and then postnatal lethality. KEY FINDINGS: Firstly, we observed that hepatocyte-specific METTL3 homozygous deficiency by Alb-iCre mice (GPT) or by Alb-Cre mice (JAX) caused liver injury, abnormal lipid accumulation and apoptosis. Secondly, we are surprised to find that hepatocyte-specific METTL3 homozygous deletion by Alb-iCre mice (GPT), but not by Alb-Cre mice (JAX), led to ALF and then postnatal lethality. Our findings clearly demonstrated that METTL3Δhep mice (GPT), which are about to die, exhibited the severe destruction of liver histological structure, suggesting that METTL3Δhep mice (GPT) nearly lose normal liver function, which subsequently contributes to ALF, followed by postnatal lethality. Finally, we unexpectedly found that as the compensatory growth responses of hepatocytes to liver injury induced by METTL3Δhep (GPT), the proliferation of METTL3Δhep hepatocytes (GPT), unlike METTL3Δhep hepatocytes (JAX), was not evidenced by the significant increase of Ki67-positive hepatocytes, not accompanied by upregulation of cell-cycle-related genes. Moreover, GO analysis revealed that upregulated genes in METTL3Δhep livers (GPT), unlike METTL3Δhep livers (JAX), are not functionally enriched in terms associated with cell cycle, cell division, mitosis, microtubule cytoskeleton organization, spindle organization, chromatin segregation and organization, and nuclear division, consistent with the loss of compensatory proliferation of METTL3Δhep hepatocytes (GPT) observed in vivo. Thus, obviously, the loss of the compensatory growth capacity of METTL3Δhep hepatocytes (GPT) in response to liver injury might contribute to, at least partially, ALF and subsequently postnatal lethality of METTL3Δhep mice (GPT). SIGNIFICANCE: These findings from this study and other labs provide strong evidence that these phenotypes (i.e., ALF and postnatal lethality) of METTL3Δhep mice (GPT) might be not the real functions of METTL3, and closely related with Alb-iCre mice (GPT), suggesting that we should remind researchers to use Alb-iCre mice (GPT) with caution to knockout gene in hepatocytes in vivo.


Assuntos
Hepatócitos , Falência Hepática Aguda , Metiltransferases , Animais , Camundongos , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/patologia , Fígado/metabolismo , Falência Hepática Aguda/genética , Falência Hepática Aguda/patologia , Falência Hepática Aguda/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , Camundongos Knockout
5.
J Exp Clin Cancer Res ; 43(1): 62, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38419081

RESUMO

BACKGROUND: In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold­inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC). METHODS: CCK-8 assay, colony formation assay, tumor sphere formation assay, qRT-PCR, Western blot were employed to examine the effects of hyperthermia (HT), HT + oridonin(Ori) or HT + radiotherapy (RT) on the proliferation and stemness of NPC cells. RNA sequencing was applied to gain differentially expressed genes upon hyperthermia. Gain-of-function and loss-of-function experiments were used to evaluate the effects of RNAi-mediated Cirbp silencing or Cirbp overexpression on the sensitivity or resistance of NPC cells and cancer stem-like cells to hyperthermia by CCK-8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay, and in subcutaneous xenograft animal model. miRNA transient transfection and luciferase reporter assay were used to demonstrate that Cirbp is a direct target of miR-377-3p. The phosphorylation levels of key members in ATM-Chk2 and ATR-Chk1 pathways were detected by Western blot. RESULTS: Our results firstly revealed that hyperthermia significantly attenuated the stemness of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)­like population. Moreover, hyperthermia substantially improved the sensitivity of radiation­resistant NPC cells and CSC­like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti­tumor­killing activity of hyperthermia against NPC cells and CSC­like cells, whereas ectopic expression of Cirbp compromised tumor­killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377-3p improved the sensitivity of NPC cells and CSC­like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp almost completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance. CONCLUSION: Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377-3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.


Assuntos
Diterpenos do Tipo Caurano , Hipertermia Induzida , MicroRNAs , Neoplasias Nasofaríngeas , Animais , Humanos , Neoplasias Nasofaríngeas/patologia , Sincalida/metabolismo , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/terapia , Carcinoma Nasofaríngeo/patologia , MicroRNAs/genética , Células-Tronco Neoplásicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica
6.
Angew Chem Int Ed Engl ; 63(10): e202318817, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38224169

RESUMO

Plasmonic catalysis has emerged as a promising approach to solar-chemical energy conversion. Notably, hot carriers play a decisive role in plasmonic catalysis since only when their energy matches with the LUMO or HOMO energy of the reactant molecule, can the reaction be activated. However, the hot carrier energy depends on the intrinsic physicochemical properties of the plasmonic metal substrate and the interaction with incident light. Tuning the hot carrier energy is of great significance for plasmonic catalysis but remains challenging. Here, we demonstrate that the energy of hot electrons can be significantly elevated to an unprecedented level through the coordination of amines on Ag surface. The bonding of amines and Ag reduces the work function of nanoparticles, leading to the increase of hot electron energy by 0.4 eV. This enhancement of energy promotes the cleavage of C-X (X=Cl, F) bonds upon excitation by visible light. This study provides new insights for promoting plasmonic charge transfer and enhancing the photocatalytic performance of plasmon-mediated systems.

7.
J Chromatogr Sci ; 62(2): 127-131, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36988013

RESUMO

The reliable and accurate determination of corrosive anions at sub- to low-µg/L levels is a challenging analytical problem. In this manuscript, a simultaneous determination method of cations and anions in power plant water samples was established by large volume injection ion chromatography. The analytical parameters including separation column, the suppressor current and the elute concentration were optimized. Results showed good separation under the optimum conditions, and the calibration curves of all analytes were linear with good coefficient of determination (r2) >0.997, and the mean recoveries for all analytes ranged from 75.62 to 118.58% with RSD of 0.07-4.83%. The established method was successfully applied to determine the cations and anions in realwaste water samples from coal-fired power, and was verified by inductively coupled plasma optical emission spectrometry and electrometric titration. The relative deviation between methods was all below 6.72%, which indicated good accuracy of the established ion chromatography method. The results could also provide reference for the precise and rapid detection of cations and anions in environmental water samples.

8.
PhytoKeys ; 236: 17-27, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38050631

RESUMO

Gelidocalamusalbozonatus W. G. Zhang, S. R. Yi & Y. L. Li, a new species of Gelidocalamus, collected from Pengshui County of Chongqing City in China, was described and illustrated herein. In this study, key morphological characters were compared between the new species and other eight "gelido-" members of Gelidocalamus. By using scanning electron microscopy (SEM), its leaf epidermal characters were observed in comparison with those of another three Gelidocalamus representatives. Our results show that the new taxon has the typical characteristics of the genus Gelidocalamus, both macromorphologically and micromorphologically. Moreover, it was most similar to G.tessellatus, but differed by a ring of white tomenta below per node, culm sheath base with densely purple verrucous setae and foliage leaf blades mesophyll.

9.
Front Bioeng Biotechnol ; 11: 1297507, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38116197

RESUMO

Introduction: Currently, cannulated screws (CSs) and dynamic hip screws (DHSs) are widely used for the treatment of femoral neck fractures, but the postoperative complications associated with these internal fixations remain high. In response to this challenge, our team proposes a new approach involving triangular-supported fixation and the development of the proximal femoral bionic nail (PFBN). The primary objective of this study is to investigate the biomechanical differences among CSs, DHSs, and the PFBN in their capacity to stabilize femoral neck fractures. Methods: A normal proximal femur model was constructed according to the CT data of a normal healthy adult. A femoral neck fracture model was constructed and fixed with CSs, DHSs, and the PFBN to simulate the fracture fixation model. Abaqus 6.14 software was used to compare the biomechanical characters of the three fracture fixation models. Results: The maximum stresses and displacements of the normal proximal femur were 45.35 MPa and 2.83 mm, respectively. Under axial loading, the PFBN was more effective than DHSs and CSs in improving the stress concentration of the internal fixation and reducing the peak values of von Mises stress, maximum principal stress, and minimum principal stress. The PFBN fixation model exhibits superior overall and fracture section stability in comparison to both the DHS fixation model and the CS fixation model under axial loading. Notably, the maximum stress and peak displacement of the PFBN and bone were lower than those of the DHS and CS fixation models under bending and torsional loading. Conclusion: The PFBN shows considerable improvement in reducing stress concentration, propagating stress, and enhancing the overall stability in the femoral neck fracture fixation model compared to DHSs and CSs. These enhancements more closely correspond to the tissue structure and biomechanical characteristics of the proximal femur, demonstrating that the PFBN has great potential for therapeutic purposes in treating femoral neck fractures.

10.
Plants (Basel) ; 12(22)2023 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-38005730

RESUMO

Cadmium (Cd) is a severe heavy metal pollutant globally. Zoysia japonica is an important perennial warm-season turf grass that potentially plays a role in phytoremediation in Cd-polluted soil areas; however, the molecular mechanisms underlying its Cd stress response are unknown. To further investigate the early gene response pattern in Z. japonica under Cd stress, plant leaves were harvested 0, 6, 12, and 24 h after Cd stress (400 µM CdCl2) treatment and used for a time-course RNA-sequencing analysis. Twelve cDNA libraries were constructed and sequenced, and high-quality data were obtained, whose mapped rates were all higher than 94%, and more than 601 million bp of sequence were generated. A total of 5321, 6526, and 4016 differentially expressed genes were identified 6, 12, and 24 h after Cd stress treatment, respectively. A total of 1660 genes were differentially expressed at the three time points, and their gene expression profiles over time were elucidated. Based on the analysis of these genes, the important mechanisms for the Cd stress response in Z. japonica were identified. Specific genes participating in glutathione metabolism, plant hormone signal and transduction, members of protein processing in the endoplasmic reticulum, transporter proteins, transcription factors, and carbohydrate metabolism pathways were further analyzed in detail. These genes may contribute to the improvement of Cd tolerance in Z. japonica. In addition, some candidate genes were highlighted for future studies on Cd stress resistance in Z. japonica and other plants. Our results illustrate the early gene expression response of Z. japonica leaves to Cd and provide some new understanding of the molecular mechanisms of Cd stress in Zosia and Gramineae species.

11.
Front Plant Sci ; 14: 1269286, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37719216

RESUMO

Introduction: Choline participates in plant stress tolerance through glycine betaine (GB) and phospholipid metabolism. As a salt-sensitive turfgrass species, Kentucky bluegrass (Poa pratensis) is the main turfgrass species in cool-season areas. Methods: To improve salinity tolerance and investigate the effects of choline on the physiological and lipidomic responses of turfgrass plants under salinity stress conditions, exogenous choline chloride was applied to Kentucky bluegrass exposed to salt stress. Results: From physiological indicators, exogenous choline chloride could alleviate salt stress injury in Kentucky bluegrass. Lipid analysis showed that exogenous choline chloride under salt-stress conditions remodeled the content of phospholipids, glycolipids, and lysophospholipids. Monogalactosyl diacylglycerol, digalactosyl diacylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and lysophosphatidylcholine content were increased and phosphatidic acid content were decreased in plants after exogenous choline chloride under salt treatment. Plant leaf choline content increased, but GB was not detected in exogenous choline chloride treatment plants under nonstress or salt-stress conditions. Discussion: GB synthesis pathway related genes showed no clear change to choline chloride treatment, whereas cytidyldiphosphate-choline (CDP-choline) pathway genes were upregulated by choline chloride treatment. These results reveal that lipid remodeling through choline metabolism plays an important role in the salt tolerance mechanism of Kentucky bluegrass. Furthermore, the lipids selected in this study could serve as biomarkers for further improvement of salt-sensitive grass species.

12.
Nat Commun ; 14(1): 4673, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37537156

RESUMO

Dihalogenation of alkenes to the high-added value vicinal dihalides is a prominent process in modern synthetic chemistry. However, their effective conversion still requires the use of expensive and hazardous agents, sacrificial half-reaction coupling or primary energy input. Here, we show a photocatalytically assisted shuttle (p-shuttle) strategy for redox-neutral and reversible vicinal dihalogenation using low-cost and stable 1,2-dihaloethane under visible light illumination. Energetic hot electrons from metal-halide perovskite QDs enable the challenging photocatalytic reactions. Ultrafast laser transient absorption spectroscopy have unveiled the energy matching of the hot electrons with the high reduction potential of 1,2-dihaloethane, via two consecutive photoexcitation process. Powered by the sustainable energy as the only energy input, our new catalytic system using metal-halide perovskite QDs for dibromination, dichlorination and even unexplored hetero-dihalogenation, shows good tolerance with a wide range of alkenes at room temperature. In contrast to homogeneous photocatalysts, chalcogenide QDs and other semiconductor catalysts, perovskite QDs deliver previously unattainable performance in photoredox shuttle vicinal dihalogenation with the turnover number over 120,000. This work provides new opportunities in visible-light-driven heterogeneous catalysis for unlocking novel chemical transformations.

13.
Aging (Albany NY) ; 15(12): 5550-5568, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37335109

RESUMO

AIMS: N6-methyladenosine (m6A), the most abundant and conserved epigenetic modification of mRNA, participates in various physiological and pathological processes. However, the roles of m6A modification in liver lipid metabolism have yet to be understood entirely. We aimed to investigate the roles of the m6A "writer" protein methyltransferase-like 3 (Mettl3) in liver lipid metabolism and the underlying mechanisms. MAIN METHODS: We assessed the expression of Mettl3 in liver tissues of diabetes (db/db) mice, obese (ob/ob) mice, high saturated fat-, cholesterol-, and fructose-induced non-alcoholic fatty liver disease (NAFLD) mice, and alcohol abuse and alcoholism (NIAAA) mice by quantitative reverse-transcriptase PCR (qRT-PCR). Hepatocyte-specific Mettl3 knockout mice were used to evaluate the effects of Mettl3 deficiency in mouse liver. The molecular mechanisms underlying the roles of Mettl3 deletion in liver lipid metabolism were explored by multi-omics joint analysis of public data from the Gene Expression Omnibus database and further validated by qRT-PCR and Western blot. KEY FINDINGS: Significantly decreased Mettl3 expression was associated with NAFLD progression. Hepatocyte-specific knockout of Mettl3 resulted in significant lipid accumulation in the liver, increased serum total cholesterol levels, and progressive liver damage in mice. Mechanistically, loss of Mettl3 significantly downregulated the expression levels of multiple m6A-modified mRNAs related to lipid metabolism, including Adh7, Cpt1a, and Cyp7a1, further promoting lipid metabolism disorders and liver injury in mice. SIGNIFICANCE: In summary, our findings demonstrate that the expression alteration of genes related to lipid metabolism by Mettl3-mediated m6A modification contributes to the development of NAFLD.


Assuntos
Transtornos do Metabolismo dos Lipídeos , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Metiltransferases/genética , Metiltransferases/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Metabolismo dos Lipídeos/genética , Expressão Gênica
14.
Chem Commun (Camb) ; 59(19): 2799-2802, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36789697

RESUMO

Light, as a powerful energy source, has motivated the many endeavors of chemists in photochemical transformations. We were delighted to find that light has an inhibition effect on hydrogenation reactions. Exploring this previously unperceived effect will bring renewed understanding of interactions of light and matter. This work provides a breakthrough in ways to remotely control chemical reactions by light.

15.
Comb Chem High Throughput Screen ; 26(1): 241-245, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35579163

RESUMO

BACKGROUND: Glanders is a rare zoonotic disease caused by Burkholderia mallei. Humans can be infected by B. mallei, which causes cutaneous lymphadenitis and pneumonia, leading to sepsis and death in severe cases. CASE PRESENTATION: We report a case of a 60-year-old male who was diagnosed with glanders. The patient who had a history of diabetes presented with cough, expectoration, and fever. Computed tomography (CT) imaging showed B. mallei infection in the right upper lobe of the lung with mediastinal lymph node involvement and the lingual segment of the left lung. Moreover, the posterior basal segment of the lower lobe of both lungs had inflammation. Subsequently, B. mallei infection was confirmed by lymph node biopsy and bronchoalveolar lavage multiplex PCR-based targeted gene sequencing. After meropenem treatment, the patient was discharged, and CT imaging showed reduced absorption of pulmonary inflammatory lesions. CONCLUSIONS: Glanders is a rare disease that can cause skin infection, lymphadenitis, and pneumonia, and in severe cases, it can be life-threatening. The diagnosis of this disease mainly relies on microbiological culture and pathological biopsy. Diagnosis is also facilitated by multiplex PCRbased targeted gene sequencing. Glanders is treated with cephalosporins, carbapenems, and other sensitive antibiotics.


Assuntos
Burkholderia mallei , Mormo , Linfadenite , Pneumonia , Cavalos , Animais , Masculino , Humanos , Pessoa de Meia-Idade , Burkholderia mallei/genética , Mormo/diagnóstico , Mormo/tratamento farmacológico , Mormo/microbiologia , Pulmão/microbiologia , Pulmão/patologia , Linfadenite/patologia
16.
Front Chem ; 10: 1085035, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36451928

RESUMO

[This corrects the article DOI: 10.3389/fchem.2022.978698.].

17.
Micromachines (Basel) ; 13(12)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36557478

RESUMO

With the development of microelectronic technology, the integration of electronic systems is increasing continuously. Electronic systems are becoming more and more sensitive to external electromagnetic environments. Therefore, to improve the robustness of radio frequency (RF) microwave circuits, it is crucial to study the reliability of semiconductor devices. In this paper, the temporary failure mechanism of a gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) in a navigation low-noise amplifier (LNA) under the jamming of ultra-wideband (UWB) electromagnetic pulses (EMP) is investigated. The failure process and failure mechanism of pHEMT under UWB EMP are elaborated by analyzing the internal electric field, current density, and temperature distribution. In detail, as the amplitude of UWB EMP increases, the output current, carrier mobility, and transconductance of pHEMT decrease, eventually resulting in gain compression. The injection experiment on LNA, which effectively verified the failure mechanism, indicates that the gain of pHEMT is suppressed instantaneously under the jamming of UWB EMP and the navigation signal cannot be effectively amplified. When UWB EMP amplitude increases to nearly 10 V, the BeiDou Navigation Satellite System (BDS) carrier signal is suppressed by nearly 600 ns. Experimental results accord well with the simulation of our model. UWB EMP jamming is a new and efficient type of electromagnetic attack system based on the device saturation effect. The performance degradation and failure mechanism analysis contribute to RF reinforcement design.

18.
J Orthop Surg Res ; 17(1): 512, 2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36434736

RESUMO

OBJECTIVE: Lymphocyte-to-C-reactive protein (CRP) ratio (LCR) is a novel biomarker for predicting poor prognosis in many diseases. This study aims to analyze the association between preoperative LCR and 1-year mortality in elderly patients with displaced FNF undergoing hemiarthroplasty. METHODS: Between May 2017 and May 2019, a retrospective study including 364 elderly patients undergoing hemiarthroplasty for displaced FNF was performed. LCR was defined as the ratio of preoperative lymphocyte count to CRP level. The optimal cutoff value of LCR was determined by receiver operating characteristic curve, and all patients were categorized into low-LCR group and high-LCR group accordingly. The relationship between LCR and 1-year mortality was evaluated by using univariate and multivariate Cox regression analysis. Furthermore, the complications within 30 days after surgery, length of hospital stay, and perioperative red blood cell transfusion were also analyzed stratified by LCR. RESULTS: A total of 47 patients (12.9%) died within 1-year follow-up after surgery. The optimal cutoff value for LCR was 30,560 (specificity 76.6% and sensitivity 63.4%). Low-LCR (≤ 30,560) group had a higher mortality rate than high-LCR group (23.53% vs. 5.21%, P < 0.001). In multivariate analysis, low LCR, hypoalbuminemia, and Age-Adjusted Charlson Comorbidity Index ≥ 6 were identified as independent predictors for 1-year mortality. Moreover, low level of LCR was associated with high rate of total complications (19.6% vs. 11.4%, P = 0.029), perioperative transfusions (37.9% vs. 27.0%, P = 0.027), and longer hospital stay (7.84 ± 2.40 vs. 7.30 ± 2.32, P = 0.031). CONCLUSIONS: The low level of preoperative LCR can effectively predict 1-year mortality and 30-day total complications after surgery in elderly patients with displaced FNF undergoing hemiarthroplasty.


Assuntos
Fraturas do Colo Femoral , Hemiartroplastia , Humanos , Idoso , Colo do Fêmur/cirurgia , Proteína C-Reativa , Fraturas do Colo Femoral/cirurgia , Estudos Retrospectivos , Linfócitos
19.
Chem Sci ; 13(40): 11792-11797, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36320924

RESUMO

Colloidal superstructures comprising hetero-building blocks often show unanticipated physical and chemical properties. Here, we present a universal assembly methodology to prepare hetero-superstructures. This straightforward methodology allows the assembly of building block materials varying from inorganic nanoparticles to living cells to form superstructures. No molecular linker is required to bind the building blocks together and thus the products do not contain any unwanted adscititious material. The Fourier transform infrared spectra, high resolution transmission electron microscopic images and nanoparticle adhesion force measurement results reveal that the key to self-organization is stripping surface ligands by adding non-polar solvents or neutralizing surface charge by adding salts, which allow us to tune the balance between van der Waals attraction and electrostatic repulsion in the colloid so as to trigger the assembling process. As a proof-of-concept, the superior photocatalytic activity and single-particle surface-enhanced Raman scattering of the corresponding superstructures are demonstrated. Our methodology greatly extends the scope of building blocks for superstructure assembly and enables scalable construction of colloidal multifunctional materials.

20.
Nat Commun ; 13(1): 5845, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195598

RESUMO

Autophagy is crucial for maintaining cellular energy homeostasis and for cells to adapt to nutrient deficiency, and nutrient sensors regulating autophagy have been reported previously. However, the role of eiptranscriptomic modifications such as m6A in the regulation of starvation-induced autophagy is unclear. Here, we show that the m6A reader YTHDF3 is essential for autophagy induction. m6A modification is up-regulated to promote autophagosome formation and lysosomal degradation upon nutrient deficiency. METTL3 depletion leads to a loss of functional m6A modification and inhibits YTHDF3-mediated autophagy flux. YTHDF3 promotes autophagy by recognizing m6A modification sites around the stop codon of FOXO3 mRNA. YTHDF3 also recruits eIF3a and eIF4B to facilitate FOXO3 translation, subsequently initiating autophagy. Overall, our study demonstrates that the epitranscriptome regulator YTHDF3 functions as a nutrient responder, providing a glimpse into the post-transcriptional RNA modifications that regulate metabolic homeostasis.


Assuntos
Autofagia , Autofagia/genética , Códon de Terminação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ativação Transcricional , Regulação para Cima
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