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1.
Biochem Pharmacol ; 201: 115070, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35526597

RESUMO

Given the essential role of Epigenetic regulation in many biological processes, targeted epigenetic drugs have been gradually applied to the treatment of tumors. Histone deacetylases (HDACs) are a class of epigenetic enzymes, which play key roles in chromosome structural modification and gene expression regulation. Targeted microtubules drugs have achieved great success in clinical application for decades. Development of novel agents with multitargeting capabilities specially dual-target has become a popular research field for the treatment of human cancers, which may provide synergistic anticancer effects. Here, we reported a novel aromatic amide derivative SY-65 co-targeted tubulin and histone deacetylase 1 with potent anticancer activity in vitro and in vivo. Compound SY-65 was identified as a dual inhibitor of tubulin/HDAC1 (IC50 = 3.64 and 0.529 µM, respectively) with excellent antiproliferative activity against MGC-803, HCT-116, KYSE-450, HGC-27, SGC-7901 and MKN-45 cells. Especially, compound SY-65 exhibited potent antiproliferative activity against MGC-803, HGC-27 and SGC-7901 cells with IC50 values <55 nM, which was better than that of Colchicine, MS-275 and SAHA. Compound SY-65 effectively inhibited tubulin polymerization and bound to the colchicine binding site of tubulin, as well as inhibited HDAC1 activity both intra/extracellularly. Molecular docking results suggested there were the well-defined binding modes of compound SY-65 in HDAC1 and tubulin. In addition, compound SY-65 inhibited colony formation, interfered with the cell cycle distribution, induced cell cycle arrest at the G2/M phase and apoptosis in MGC-803 and HGC-27 cells. Compound SY-65 also exhibited a good tumor inhibitory effect in vivo without obvious toxicity. Therefore, compound SY-65 could be developed as a novel tubulin/HDAC1 candidate inhibitor for future cancer therapeutics.

2.
Brain Commun ; 4(2): fcac069, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35441136

RESUMO

Amyotrophic lateral sclerosis is a rapidly progressive neurodegenerative disease that affects 1/350 individuals in the United Kingdom. The cause of amyotrophic lateral sclerosis is unknown in the majority of cases. Two-sample Mendelian randomization enables causal inference between an exposure, such as the serum concentration of a specific metabolite, and disease risk. We obtained genome-wide association study summary statistics for serum concentrations of 566 metabolites which were population matched with a genome-wide association study of amyotrophic lateral sclerosis. For each metabolite, we performed Mendelian randomization using an inverse variance weighted estimate for significance testing. After stringent Bonferroni multiple testing correction, our unbiased screen revealed three metabolites that were significantly linked to the risk of amyotrophic lateral sclerosis: Estrone-3-sulphate and bradykinin were protective, which is consistent with literature describing a male preponderance of amyotrophic lateral sclerosis and a preventive effect of angiotensin-converting enzyme inhibitors which inhibit the breakdown of bradykinin. Serum isoleucine was positively associated with amyotrophic lateral sclerosis risk. All three metabolites were supported by robust Mendelian randomization measures and sensitivity analyses; estrone-3-sulphate and isoleucine were confirmed in a validation amyotrophic lateral sclerosis genome-wide association study. Estrone-3-sulphate is metabolized to the more active estradiol by the enzyme 17ß-hydroxysteroid dehydrogenase 1; further, Mendelian randomization demonstrated a protective effect of estradiol and rare variant analysis showed that missense variants within HSD17B1, the gene encoding 17ß-hydroxysteroid dehydrogenase 1, modify risk for amyotrophic lateral sclerosis. Finally, in a zebrafish model of C9ORF72-amyotrophic lateral sclerosis, we present evidence that estradiol is neuroprotective. Isoleucine is metabolized via methylmalonyl-CoA mutase encoded by the gene MMUT in a reaction that consumes vitamin B12. Multivariable Mendelian randomization revealed that the toxic effect of isoleucine is dependent on the depletion of vitamin B12; consistent with this, rare variants which reduce the function of MMUT are protective against amyotrophic lateral sclerosis. We propose that amyotrophic lateral sclerosis patients and family members with high serum isoleucine levels should be offered supplementation with vitamin B12.

3.
Oxid Med Cell Longev ; 2022: 1012509, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35368874

RESUMO

Transplant oncology is a newly emerging discipline integrating oncology, transplant medicine, and surgery and has brought malignancy treatment into a new era via transplantation. In this context, obtaining a drug with both immunosuppressive and antitumor effects can take into account the dual needs of preventing both transplant rejection and tumor recurrence in liver transplantation patients with malignancies. Capecitabine (CAP), a classic antitumor drug, has been shown to induce reactive oxygen species (ROS) production and apoptosis in tumor cells. Meanwhile, we have demonstrated that CAP can induce ROS production and apoptosis in T cells to exert immunosuppressive effects, but its underlying molecular mechanism is still unclear. In this study, metronomic doses of CAP were administered to normal mice by gavage, and the spleen was selected for quantitative proteomic and phosphoproteomic analysis. The results showed that CAP significantly reduced the expression of HSP90AB1 and SMARCC1 in the spleen. It was subsequently confirmed that CAP also significantly reduced the expression of HSP90AB1 and SMARCC1 and increased ROS and apoptosis levels in T cells. The results of in vitro experiments showed that HSP90AB1 knockdown resulted in a significant decrease in p-Akt, SMARCC1, p-c-Fos, and p-c-Jun expression levels and a significant increase in ROS and apoptosis levels. HSP90AB1 overexpression significantly inhibited CAP-induced T cell apoptosis by increasing the p-Akt, SMARCC1, p-c-Fos, and p-c-Jun expression levels and reducing the ROS level. In conclusion, HSP90AB1 is a key target of CAP-induced T cell apoptosis via Akt/SMARCC1/AP-1/ROS axis, which provides a novel understanding of CAP-induced T cell apoptosis and lays the experimental foundation for further exploring CAP as an immunosuppressant with antitumor effects to optimize the medication regimen for transplantation patients.


Assuntos
Proteínas Proto-Oncogênicas c-akt , Fator de Transcrição AP-1 , Animais , Apoptose , Capecitabina/farmacologia , Capecitabina/uso terapêutico , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP90 , Humanos , Camundongos , Proteômica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T/metabolismo , Fatores de Transcrição
4.
Open Life Sci ; 17(1): 189-201, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35415238

RESUMO

Traumatic brain injury (TBI) is a predominant cause of death and permanent disability globally. In recent years, much emphasis has been laid on treatments for TBI. Increasing evidence suggests that human umbilical cord mesenchymal stem cells (HUCMSCs) can improve neurological repair after TBI. However, the clinical use of HUCMSCs transplantation in TBI has been limited by immunological rejection, ethical issues, and the risk of tumorigenicity. Many studies have shown that HUCMSCs-derived exosomes may be an alternative approach for HUCMSCs transplantation. We hypothesized that exosomes derived from HUCMSCs could inhibit apoptosis after TBI, reduce neuroinflammation, and promote neurogenesis. A rat model of TBI was established to investigate the efficiency of neurological recovery with exosome therapy. We found that exosomes derived from HUCMSCs significantly ameliorated sensorimotor function and spatial learning in rats after TBI. Moreover, HUCMSCs-derived exosomes significantly reduced proinflammatory cytokine expression by suppressing the NF-κB signaling pathway. Furthermore, we found that HUCMSC-derived exosomes inhibited neuronal apoptosis, reduced inflammation, and promoted neuron regeneration in the injured cortex of rats after TBI. These results indicate that HUCMSCs-derived exosomes may be a promising therapeutic strategy for TBI.

5.
Front Chem ; 10: 860398, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35433628

RESUMO

New multilayer 3D chiral molecules have been designed and synthesized asymmetrically through the strategy of center-to-multilayer folding chirality control and double Suzuki couplings. Individual diastereoisomers were readily obtained and separated via flash column chromatography. The key diastereoisomer was further converted into corresponding enantiomers. These enantiomers possess electron-deficient aromatic bridges layered with top and bottom aromatic scaffolds. X-ray structural analysis has unambiguously confirmed the configuration, and intermolecular packing results in regular planar patterns in solid crystals. The synthesis was achieved in a total of ten steps starting from commercially available starting materials.

6.
Arch Gynecol Obstet ; 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35411411

RESUMO

OBJECTIVE: To better understand the risk stratification and outcomes of gynecologic PEComas. METHODS: Clinicopathological features and outcomes of gynecologic PEComas cases reported in both English and Chinese literature before September, 2020 were evaluated. The efficacy of three proposed criteria were compared to verify their practicability in gynecologic PEComas. The Chi-square test and Cox proportional hazard model were performed for statistical analysis. RESULTS: A total of 210 cases were retrieved: 95 from English literature and 115 from Chinese literature. The Flope criterion achieved an accuracy of 47% for detecting malignancy of gynecologic PEComas, 64.2% for the Schoolmeester criterion, and 63.8% for the WHO criterion. Both Chi-square test and uni-variate analysis showed that tumor size ≥ 5 cm, infiltrative growth pattern, mitotic rate ≥ 1/50 high per filed (HPF), high nuclear grade and cellularity, necrosis, and vascular invasion were significantly related to recurrence and/or metastasis (R/M) of gynecologic PEComas. Still only high mitotic rate (≥ 1/50 HPF), high nuclear grade and cellularity, and necrosis significantly influenced the long-term survival. Multi-variate analysis showed high nuclear grade and cellularity was an independent risk factor for R/M of gynecologic PEComas. No model was fitted for the death rate due to a small number of events. When defined malignant PEComas cases as meeting three or more out of six clinicopathologic features, the accuracy of such attempt was 62%, but the false-negative rate dropped by 37-55%. CONCLUSIONS: Gynecologic PEComas with three or more high-risk factors may be considered as malignant. Further efforts should be invested to look for new potential prognostic factors.

8.
Insect Biochem Mol Biol ; 144: 103764, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35367588

RESUMO

A highly sensitive olfactory system is required for various insect behaviors, including oviposition site selection, host location, and mate recognition. Odorant receptors (ORs) play a critical role in odorant detection. In this study, we cloned four OR genes referred to as AlucORs (AlucOR4, AlucOR39, AlucOR43, and AlucOR47) from the green mirid bug, Apolygus lucorum, and used Real-time quantitative PCR to show that expression of all four ORs was considerably biased to antennae. Functional analysis, performed using a Xenopus oocyte expression system, revealed that AlucOR47 was robustly and sensitively tuned to the important plant volatile, linalool, and its analogs, linalyl acetate and linalool tetrahydride. Electroantennogram recordings showed that all three ligands elicited obvious responses in male and female mirid bug antennae, with the response to linalool being the strongest. In behavioral assays, male and female mirid bugs displayed significant aversions to linalool. Additionally, the repellent behavior effect of A. lucorum in response to linalool disappeared after knocking down AlucOR47 by RNA interference (RNAi). Taken together, these results indicate that AlucOR47 is necessary for linalool perception in A. lucorum. Our results suggest that AlucOR47 may play a role in plant-insect interactions and provide insight into potential means of biological control against mirid bugs.


Assuntos
Heterópteros , Receptores Odorantes , Monoterpenos Acíclicos , Animais , Feminino , Heterópteros/metabolismo , Masculino , Odorantes , Receptores Odorantes/genética , Receptores Odorantes/metabolismo
9.
Pest Manag Sci ; 2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35420250

RESUMO

BACKGOUND Sex pheromones of the fall armyworm, Spodoptera frugiperda, show differences in composition and proportions in different geographical populations, but always contain Z9-14:OAc as the major component. Odorant receptor neurons (ORNs) housed in the long trichoid sensilla (TS) of male antennae are essential to detect female-released sex pheromones in moths. RESULTS: In this study, we identified seven components from pheromone gland extracts of female S. frugiperda in the Yunnan population from China, including (Z)-7-dodecen-1-yl acetate (Z7-12:OAc), (Z)-9-tetradecenal (Z9-14:Ald), (Z)-9-dodecen-1-yl acetate (Z9-12:OAc), (Z)-9-tetradecen-1-yl acetate (Z9-14:OAc), (E)-11-tetradecen-1-yl acetate (E11-14:OAc), (Z)-11-tetradecen-1-yl acetate (Z11-14:OAc) and (Z)-11-hexadecen-1-yl acetate (Z11-16:OAc) at a ratio of 1.2:4:0.8:79.1:1.6:1.6:11.7 by gas chromatography coupled with mass spectrometry. Gas chromatography-electroantennographic detection showed that Z9-14:OAc, Z7-12:OAc and Z11-16:OAc are the male antennal active components. Peripheral coding of pheromones in males was investigated by single sensillum recording. Five functional neurons housed in three types of TS were identified based on profiles of neuronal responses, which are responsible for attractive component Z9-14:OAc, synergistic components Z7-12:OAc, Z11-16:OAc, interspecific pheromones (Z)-9-tetradecen-1-ol (Z9-14:OH) and (Z,E)-9,12-tetradecadien-1-yl acetate (Z9,E12-14:OAc), respectively. Wind tunnel and field tests demonstrated that a ternary combination of Z9-14:OAc, Z7-12:OAc and Z11-16:OAc at a ratio of 88:1:11 shows the strongest attractiveness to males. CONCLUSION: An optimized pheromone blend of Z9-14:OAc, Z7-12:OAc and Z11-16:OAc in an 88:1:11 ratio was identified for monitoring the invasive pest S. frugiperda in China. Five functional ORNs encoding intra- and interspecific pheromones were identified in male antennae, of which three neurons encode attractive component Z9-14:OAc, synergistic components Z7-12:OAc and Z11-16:OAc, respectively, and the other two neurons encode interspecific pheromones Z9-14:OH and Z9,E12-14:OAc, separately. © 2022 Society of Chemical Industry.

10.
J Org Chem ; 87(9): 5976-5986, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35442684

RESUMO

Asymmetric synthesis of new atropisomerically multilayered chiral targets has been achieved by taking advantage of the strategy of center-to-multilayer chirality and double Suzuki-Miyaura couplings. Diastereomers were readily separated via flash column chromatography and well characterized. Absolute configuration assignment was determined by X-ray structural analysis. Five enantiomerically pure isomers possessing multilayer chirality were assembled utilizing anchors involving electron-rich aromatic connections. An overall yield of 0.69% of the final target with hydroxyl attachment was achieved over 11 steps from commercially available starting materials.

11.
Appl Opt ; 61(9): 2213-2218, 2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35333236

RESUMO

We investigated and fabricated 1×8 and 1×16 traditional/saddle arrayed waveguide grating (AWG) wavelength division multiplexing devices on flexible substrates. The core layer was made of the negative epoxy photoresist SU-8, and polydimethylsiloxane (PDMS) material was selected for the cladding based on the high refractive index difference. A chemical modification method of PDMS was proposed to enhance the film-forming characteristics of the SU-8 core layer on PDMS substrates. After fabricating and characterizing the optical properties of the AWGs, the dimensions of the proposed 1×8 and 1×16 AWGs were 0.9×0.8cm2 and 1.1×0.9cm2, respectively. Experimental results showed that the saddle-type 1×8 and 1×16 AWGs had good signal transmission characteristics, and the insertion losses were only 5.1 dB and 6.8 dB, respectively, which were lower than those of traditional-type AWGs with the same dimensions and number of waveguides.

12.
bioRxiv ; 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35291294

RESUMO

New therapeutic targets are a valuable resource in the struggle to reduce the morbidity and mortality associated with the COVID-19 pandemic, caused by the SARS-CoV-2 virus. Genome-wide association studies (GWAS) have identified risk loci, but some loci are associated with co-morbidities and are not specific to host-virus interactions. Here, we identify and experimentally validate a link between reduced expression of EXOSC2 and reduced SARS-CoV-2 replication. EXOSC2 was one of 332 host proteins examined, all of which interact directly with SARS-CoV-2 proteins; EXOSC2 interacts with Nsp8 which forms part of the viral RNA polymerase. Lung-specific eQTLs were identified from GTEx (v7) for each of the 332 host proteins. Aggregating COVID-19 GWAS statistics for gene-specific eQTLs revealed an association between increased expression of EXOSC2 and higher risk of clinical COVID-19 which survived stringent multiple testing correction. EXOSC2 is a component of the RNA exosome and indeed, LC-MS/MS analysis of protein pulldowns demonstrated an interaction between the SARS-CoV-2 RNA polymerase and the majority of human RNA exosome components. CRISPR/Cas9 introduction of nonsense mutations within EXOSC2 in Calu-3 cells reduced EXOSC2 protein expression, impeded SARS-CoV-2 replication and upregulated oligoadenylate synthase ( OAS) genes, which have been linked to a successful immune response against SARS-CoV-2. Reduced EXOSC2 expression did not reduce cellular viability. OAS gene expression changes occurred independent of infection and in the absence of significant upregulation of other interferon-stimulated genes (ISGs). Targeted depletion or functional inhibition of EXOSC2 may be a safe and effective strategy to protect at-risk individuals against clinical COVID-19.

13.
Research (Wash D C) ; 2022: 9847949, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35265849

RESUMO

A novel class of polymers and oligomers of chiral folding chirality has been designed and synthesized, showing structurally compacted triple-column/multiple-layer frameworks. Both uniformed and differentiated aromatic chromophoric units were successfully constructed between naphthyl piers of this framework. Screening monomers, catalysts, and catalytic systems led to the success of asymmetric catalytic Suzuki-Miyaura polycouplings. Enantio- and diastereochemistry were unambiguously determined by X-ray structural analysis and concurrently by comparison with a similar asymmetric induction by the same catalyst in the asymmetric synthesis of a chiral three-layered product. The resulting chiral polymers exhibit intense fluorescence activity in a solid form and solution under specific wavelength irradiation.

14.
Genomics ; 114(3): 110319, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35227836

RESUMO

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have been proposed as a promising strategy for myocardial infarction (MI). This study aims to explore the mechanism of human umbilical cord MSCs (hucMSCs)-derived EVs loaded with miR-223 on MI. Inflammation, cell biological functions, and fibrosis in vitro were measured. Furthermore, MI rat models were established to verify the role of EVs-miR-223 in vivo. The binding relationship between miR-223 and P53 was confirmed. ChIP assay was utilized to observe the combination of P53 and S100A9. The suppressed fibrosis of cardiomyocytes occurred with cells overexpressing miR-223. MiR-223 contributed to the angiogenesis of HUVECs. P53 was a target gene of miR-223. In vivo, miR-223 relieved myocardial fibrosis and inflammation infiltration, and promoted the angiogenesis in MI rats. HucMSC-derived EVs loaded with miR-223 mitigates MI and promotes myocardial repair through the P53/S100A9 axis, manifesting the underlying therapy values of hucMSC-derived EVs loaded with miR-223 in MI.

15.
J Soc Psychol ; : 1-16, 2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35152848

RESUMO

Blood donation anxiety is a major psychological obstacle for blood donation. However, it remains unclear what the mechanism underlying the relationship between anxiety and blood donation intention is and what factor(s) will buffer the negative effects of anxiety. Based on social cognitive theory, we theorized a model delineating the mechanism with which blood donation anxiety was related to blood donation intention. Data were collected in a three-wave online survey including 425 individuals and was analyzed using hierarchical multiple regression with SPSS 24.0 software. The results indicated that the negative relationship between blood donation anxiety and blood donation intention was mediated by moral disengagement. Meanwhile, mindfulness was found to play a buffering role in the relationship between blood donation anxiety and moral disengagement as well as the indirect relationship between blood donation anxiety and blood donation intention via moral disengagement. Our findings advanced the understanding of the detrimental consequences of blood donation anxiety and demonstrated that while blood donation anxiety came at a high cost, it can be managed.

16.
Int J Med Sci ; 19(1): 1-12, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34975294

RESUMO

As a rare type of gestational trophoblastic disease, placental site trophoblastic tumor (PSTT) is originated from intermediate trophoblast cells. Long noncoding RNAs (lncRNAs) regulate numerous biological process. However, the role of lncRNAs in PSTT remains poorly understood. In the present study, expression levels of lncRNAs and mRNAs in four human PSTT tissues and four normal placental villi were investigated. The results of microarray were validated by the reverse transcription and quantitative real-time polymerase reaction (RT-qPCR) and immunohistochemistry analyses. Furthermore, GO and KEGG pathway analyses were performed to identify the underlying biological processes and signaling pathways of aberrantly expressed lncRNAs and mRNAs. We also conducted the coding-non-coding gene co-expression (CNC) network to explore the interaction of altered lncRNAs and mRNAs. In total, we identified 1247 up-regulated lncRNAs and 1013 down-regulated lncRNAs as well as 828 up-regulated mRNAs and 1393 down-regulated mRNAs in PSTT tissues compared to normal villi (fold change ≥ 2.0, p < 0.05). GO analysis showed that mitochondrion was the most significantly down-regulated GO term, and immune response was the most significantly up-regulated term. A CNC network profile based on six confirmed lncRNAs (NONHSAT114519, NR_103711, NONHSAT003875, NONHSAT136587, NONHSAT134431, NONHSAT102500) as well as 354 mRNAs was composed of 497 edges. GO and KEGG analyses indicated that interacted mRNAs were enriched in the signal-recognition particle (SRP)-dependent cotranslational protein targeting to membrane and Ribosome pathway. It contributes to expand the understanding of the aberrant lncRNAs and mRNAs profiles of PSTT, which may be helpful for the exploration of new diagnosis and treatment of PSTT.


Assuntos
Perfilação da Expressão Gênica , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Tumor Trofoblástico de Localização Placentária/genética , Neoplasias Uterinas/genética , Proteínas ADAMTS/genética , Feminino , Humanos , Imuno-Histoquímica , Gravidez , Proteínas/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Mitochondrial DNA B Resour ; 7(1): 68-69, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34993313

RESUMO

Schima superba is the dominant species of subtropical evergreen broad-leaved forest which has the characteristics of ecological fire prevention function. In this study, we report the complete chloroplast genome sequence of S. superba. The cp genome was 157,205 bp in length with a GC content of 37.40%, including a large single-copy (LSC 87,161 bp), a small single-copy (SSC 18,092 bp), and a pair of inverted repeats (IR 25,976 bp). The genome encoded 133 functional genes, including 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic analysis showed that S. superba was closely related to Schima sinensis, Schima multibracteata, Schima crenata, and Schima remotisertata.

18.
Org Lett ; 24(4): 1060-1065, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-35080390

RESUMO

The first example of divergent N-heterocycle syntheses through a copper-catalyzed three-component reaction of α,ß-unsaturated ketoximes, paraformaldehyde, and amines has been documented. In particular, this divergent synthetic strategy was achieved by controlling the reaction conditions to afford the corresponding imidazoles and dihydroimidazoles in moderate to good yields with a broad substrate scope and good functional group compatibility.

19.
Micromachines (Basel) ; 13(1)2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35056263

RESUMO

Capacitive micromachined ultrasound transducers (CMUTs) have broad application prospects in medical imaging, flow monitoring, and nondestructive testing. CMUT arrays are limited by their fabrication process, which seriously restricts their further development and application. In this paper, a vacuum-sealed device for medical applications is introduced, which has the advantages of simple manufacturing process, no static friction, repeatability, and high reliability. The CMUT array suitable for medical imaging frequency band was fabricated by a silicon wafer bonding technology, and the adjacent array devices were isolated by an isolation slot, which was cut through the silicon film. The CMUT device fabricated following this process is a 4 × 16 array with a single element size of 1 mm × 1 mm. Device performance tests were conducted, where the center frequency of the transducer was 3.8 MHz, and the 6 dB fractional bandwidth was 110%. The static capacitance (29.4 pF) and center frequency (3.78 MHz) of each element of the array were tested, and the results revealed that the array has good consistency. Moreover, the transmitting and receiving performance of the transducer was evaluated by acoustic tests, and the receiving sensitivity was -211 dB @ 3 MHz, -213 dB @ 4 MHz. Finally, reflection imaging was performed using the array, which provides certain technical support for the research of two-dimensional CMUT arrays in the field of 3D ultrasound imaging.

20.
Chemistry ; 28(7): e202200183, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35092103

RESUMO

Invited for the cover of this issue are Guigen Li's groups at Texas Tech University and Nanjing University. The cover artwork shows that chirality patterns exist from universal to molecular levels showing light emission properties. Read the full story of multilayer 3D chirality and its asymmetric catalytic synthesis at 10.1002/chem.202104102.


Assuntos
Polímeros , Catálise , Humanos
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