Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 145
Filtrar
1.
J Med Chem ; 67(7): 5437-5457, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38564512

RESUMO

The mitogen-activated protein kinase-interacting protein kinases (MNKs) are the only kinases known to phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at Ser209, which plays a significant role in cap-dependent translation. Dysregulation of the MNK/eIF4E axis has been found in various solid tumors and hematological malignancies, including diffuse large B-cell lymphoma (DLBCL). Herein, structure-activity relationship studies and docking models determined that 20j exhibits excellent MNK1/2 inhibitory activity, stability, and hERG safety. 20j exhibits strong and broad antiproliferative activity against different cancer cell lines, especially GCB-DLBCL DOHH2. 20j suppresses the phosphorylation of eIF4E in Hela cells (IC50 = 90.5 nM) and downregulates the phosphorylation of eIF4E and 4E-BP1 in A549 cells. In vivo studies first revealed that ibrutinib enhances the antitumor effect of 20j without side effects in a DOHH2 xenograft model. This study provided a solid foundation for the future development of a MNK inhibitor for GCB-DLBCL treatment.


Assuntos
Linfoma , Proteínas Serina-Treonina Quinases , Humanos , Fator de Iniciação 4E em Eucariotos/metabolismo , Células HeLa , Fosforilação , Linfoma/tratamento farmacológico
2.
Vet Sci ; 11(3)2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38535849

RESUMO

Pubertal genetic variations between the indigenous Chinese Wanyue Black pig breed and the imported Yorkshire breed significantly impact their reproductive capacity. In order to identify the differentially expressed genes, gene networks, and metabolic pathways in ovary transcriptome of gilts, the serum hormone levels were analyzed by ELISA, and RNA-seq was performed to analyze ovarian genes. Our results reveal higher estradiol (E2) levels in Wanyue black gilts compared to Yorkshire gilts, while Yorkshire gilts exhibit elevated progesterone (P4) and GnRH levels. We identified a total of 154 differentially expressed genes (DEGs), with 87 up-regulated and 67 down-regulated genes in the Wanyue black gilts ovaries compared to the Yorkshire gilts. GO enrichment analysis unveiled the participation of DEGs in processes such as "Reproduction", "Reproductive system development", and "Ovarian follicle development". Moreover, KEGG enrichment analysis revealed the involvement of DEGs in multiple signaling pathways associated with hormone biosynthesis and puberty, encompassing "Steroid hormone biosynthesis", "Estrogen signaling pathway", and "Prolactin signaling pathway". The subsequent bioinformatics analysis identified nine functional genes that potentially contribute to the disparity in ovaries between Wanyue black gilts and Yorkshire gilts. This study offers significant insights into the endocrine and genetic aspects of pubertal development in gilts.

3.
ChemMedChem ; : e202300716, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38426720

RESUMO

The eukaryotic initiation factor 2B (eIF2B) is a key regulator in protein-regulated signaling pathways and is closely related to the function of the central nervous system. Modulating eIF2B could retard the process of neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and vanishing white matter disease (VWM) et al. Here, we designed and synthesized a series of novel eIF2B activators containing oxadiazole fragments. The activating effects of compounds on eIF2B were investigated through testing the inhibition of ATF4 expression. Of all the targeted compounds, compounds 21 and 29 exhibited potent inhibition on ATF4 expression with IC50 values of 32.43 nM and 47.71 nM, respectively, which were stronger than that of ISRIB (IC50=67.90 nM). ATF4 mRNA assay showed that these two compounds could restore ATF4 mRNA to normal levels in thapsigargin-stimulated HeLa cells. Protein Translation assay showed that both compounds were effective in restoring protein synthesis. Compound potency assay showed that both compounds had similar potency to ISRIB with EC50 values of 5.844 and 37.70 nM. Cytotoxicity assay revealed that compounds 21 and 29 had low toxicity and were worth further investigation.

4.
Dyslexia ; 30(2): e1765, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38497366

RESUMO

Given the rapid growth in educational policies targeting educators' knowledge of dyslexia, this study explored the technical adequacy of a common instrument for measuring that knowledge. The responses of 1141 preservice teachers were scored in three ways: polytomously with the original 4-point Likert scale, dichotomously as true-false, and dichotomously as though the options were multiple choice. An exploratory factor analysis suggested at least one-third of the items needed to be removed. Confirmatory factor analyses suggested a one-factor model with polytomous scoring had the best fit to the data, but only six items loaded. All models demonstrated unacceptable internal consistency reliability (<0.70). Because no technically adequate version of the measure was identified, questions remain about basing policy on scores from these instruments. However, the findings indicated ways this type of measure might be improved.


Assuntos
Dislexia , Humanos , Dislexia/diagnóstico , Reprodutibilidade dos Testes , Professores Escolares , Escolaridade , Conhecimentos, Atitudes e Prática em Saúde
5.
Mol Divers ; 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498082

RESUMO

Mitogen-activated protein kinase (MAPK)-interacting kinases (MNKs) can regulate cellular mRNA translation by controlling the phosphorylation of the eukaryotic translation initiation factor 4E (eIF4E), which plays an important role in tumor initiation, development, and metastasis. Although small-molecule MNK inhibitors have made significant breakthroughs in the treatment of various malignancies, their clinical application can be limited by drug resistance, target selectivity and other factors. The strategy of MNK-PROTACs which selectively degrades MNK kinases provides a new approach for developing small-molecule drugs for related diseases. In this study, DS33059, a small-molecule compound modified based on the ongoing clinical trials drug ETC-206, was chosen as the target protein ligand. A series of novel MNK-PROTACs were designed, synthesized and evaluated biological activity. Several compounds showed good inhibitory activities against MNK1/2. Besides, compounds exhibited moderate to excellent anti-proliferative activity in A549 and TMD-8 cells in vitro. In particular, compound II-5 significantly inhibited A549 (IC50 = 1.79 µM) and TMD-8 (IC50 = 1.07 µM) cells. The protein degradation assay showed that compound II-5 had good capability to degrade MNK1. The MNK-PROTACs strategy represents a new direction in treating tumors and deserves further exploration.

6.
Glia ; 72(6): 1150-1164, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38436489

RESUMO

Ischemic stroke is the leading cause of adult disability. The rewiring of surviving neurons is the fundamental process for functional recovery. Accumulating evidence implicates astrocytes in synapses and neural circuits formation, but few studies have further studied how to enhance the effects of astrocytes on synapse and circuits after stroke and its impacts on post-stroke functional recovery. In this study, we made use of chemogenetics to specifically activate astrocytic Gi signaling in the peri-infarcted sensorimotor cortex at different time epochs in a mouse model of photothrombotic stroke. We found that early activation of astrocytic hM4Di after stroke by CNO modulates astrocyte activity and upregulates synaptogenic molecules including thrombospondin-1 (TSP1) as revealed by bulk RNA-sequencing, but no significant improvement was observed in dendritic spine density and behavioral performance in grid walking test. Interestingly, when the manipulation was initiated at the subacute phase of stroke, the recovery of spine density and motor function could be effectively promoted, accompanied by increased TSP1 expression. Our data highlight the important role of astrocytes in synapse remodeling during the repair phase of stroke and suggest astrocytic Gi signaling activation as a potential strategy for synapse regeneration, circuit rewiring, and functional recovery.


Assuntos
Astrócitos , Acidente Vascular Cerebral , Camundongos , Animais , Astrócitos/metabolismo , Acidente Vascular Cerebral/metabolismo , Transdução de Sinais , Neurônios/metabolismo , Sinapses/metabolismo
7.
J Hazard Mater ; 467: 133659, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38350314

RESUMO

Arsenic is a harmful associated element in antimony ore, which might bring out the risk of leakage during complex industrial production of high-purity antimony. Herein, we reported a novel and efficient way to remove the trace arsenic impurity from acidic SbCl3 solution by utilizing copper-system bimetallic particles. Specifically, galvanically coupled Cu2Sb/Cu was in-situ synthesized by introducing precursor copper powder to the specific SbCl3 solution. DFT studies revealed that Sb(III) was easily reduced by Cu to form Cu2Sb due to the strong adsorption of Sb(III) on Cu (111) crystal plane. The Cu2Sb/Cu coupling exhibited excellent activity for As(III) reduction, over 99.4% arsenic were removed under optimal conditions and residual arsenic concentration dropped to only 2.7 mg L-1. Crucially, Sb(III) concentration changes could be neglected. Besides, the dearsenization residues were extensively characterized to analyze the evolvement and cause in the reaction process. The results confirmed that the arsenic removal mechanisms by Cu2Sb/Cu particles were multi-affected, including adsorption, displacement, and precipitation. And the strong electrostatic attraction of AsO+ under high HCl conditions was identified as a key step to achieving dearsenization. This research will provide a theoretical guidance for the green synthesis of high-purity antimony and related products.

8.
Eur J Med Chem ; 267: 116211, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38359537

RESUMO

The cancer immunotherapies involved in cGAS-STING pathway have been made great progress in recent years. STING agonists exhibit broad-spectrum anti-tumor effects with strong immune response. As a negative regulator of the cGAS-STING pathway, ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) can hydrolyze extracellular 2', 3'-cGAMP and reduce extracellular 2', 3'-cGAMP concentration. ENPP1 has been validated to play important roles in diabetes, cancers, and cardiovascular disease and now become a promising target for tumor immunotherapy. Several ENPP1 inhibitors under development have shown good anti-tumor effects alone or in combination with other agents in clinical and preclinical researches. In this review, the biological profiles of ENPP1 were described, and the structures and the structure-activity relationships (SAR) of the known ENPP1 inhibitors were summarized. This review also provided the prospects and challenges in the development of ENPP1 inhibitors.


Assuntos
Neoplasias , Diester Fosfórico Hidrolases , Pirofosfatases , Humanos , Diester Fosfórico Hidrolases/metabolismo , Nucleotidiltransferases/metabolismo , Imunoterapia
9.
Adv Healthc Mater ; 13(3): e2302117, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37922499

RESUMO

Prostate-specific antigen (PSA) is the common serum-relevant biomarker for early prostate cancer (PCa) detection in clinical diagnosis. However, it is difficult to accurately diagnose PCa in the early stage due to the low specificity of PSA. Herein, a new solution-gated graphene field transistor (SGGT) biosensor with dual-gate for dual-biomarker detection is designed. The sensing mechanism is that the designed aptamers immobilized on the surface of the gate electrodes can capture PSA and sarcosine (SAR) biomolecules and induce the capacitance changes of the electric double layers of SGGT. The limit of detections of PSA and SAR biomarkers can reach 0.01 fg mL-1 , which is three-to-four orders of magnitude lower than previously reported assays. The detection time of PSA and SAR is ≈4.5 and ≈13 min, which is significantly faster than the detection time (1-2 h) of conventional methods. The clinical serum samples testing demonstrates that the biosensor can distinguish the PCa patients from the control group and the diagnosis accuracy can reach 100%. The SGGT biosensor can be integrated into the portable platform and the diagnostic results can directly display on the smartphone/Pad. Therefore, the integrated portable platform of the biosensor can distinguish cancer types through the dual-biomarker detection.


Assuntos
Técnicas Biossensoriais , Grafite , Neoplasias da Próstata , Masculino , Humanos , Antígeno Prostático Específico , Neoplasias da Próstata/diagnóstico , Eletrodos , Técnicas Biossensoriais/métodos
10.
Small ; 20(2): e2305625, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37658509

RESUMO

Highly symmetrical and streamlined nanostructures possessing unique electron scattering, electron-phonon coupling, and electron confinement characteristics have attracted a lot of attention. However, the controllable synthesis of such a nanostructure with regulated shapes and sizes remains a huge challenge. In this work, a peanut-like MnO@C structure, assembled by two core-shell nanosphere is developed via a facile hydrogen ion concentration regulation strategy. Off-axis electron holography technique, charge reconstruction, and COMSOL Multiphysics simulation jointly reveal the unique electronic distribution and confirm its higher dielectric sensitive ability, which can be used as microwave absorption to deal with currently electromagnetic pollution. The results reveal that the peanut-like core-shell MnO@C exhibits great wideband properties with effective absorption bandwidth of 6.6 GHz, covering 10.8-17.2 GHz band. Inspired by this structure-induced sensitively dielectric behavior, promoting the development of symmetrical and streamlined nanostructure would be attractive for many other promising applications in the future, such as piezoelectric material and supercapacitor and electromagnetic shielding.

11.
Small ; : e2308129, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38037491

RESUMO

Engineering phase transition in micro-nanomaterials to optimize the dielectric properties and further enhance the electromagnetic microwave absorption (EMA) performance is highly desirable. However, the severe synthesis conditions restrict the design of EMA materials featuring controllable phases, which hinders the tunability of effective absorption bandwidth (EAB) and leads to an unclear loss mechanism. Herein, a seed phase decomposition-controlled strategy is proposed to induct nickel sulfide (NiSx ) absorbers with controllable phases and hollow sphere nature. Transmission electron microscopy holography and theoretical calculations evidence that the reconstruction of atoms in phase transition induces numerous heterogeneous interfaces and lattice defects/sulfur vacancies to cause varied work functions and local electronic redistribution, which contributes to reinforced dielectric polarization. As a result, the optimized NiS2 /NiS heterostructure enables enhanced EM attenuation capability with a wide EAB of 5.04 GHz at only 1.6 mm, compared to that of NiS2 and NiS. Moreover, the correlation between EAB and NiS phase content is demonstrated as the "volcano" feature. This study on the concept of phase transition of micro-nanomaterials can offer a novel approach to constructing highly efficient absorbers for EMA and other functionalities.

12.
Arch Gynecol Obstet ; 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38032412

RESUMO

PURPOSE: The implementation of the universal two-child policy contributes to adverse pregnancy outcomes, but how the policy change leads to adverse pregnancy outcomes is not well elaborated. In this study, we aimed to compare maternal characteristics and complications, accessed the change in the proportion of maternal characteristics and maternal complications, and evaluated the mediation of maternal characteristics on maternal complications. METHODS: Demographic and clinical data of three-level sample facilities were extracted from China's National Maternity Near Miss Obstetrics Surveillance System from Jan 1, 2012 to May 31, 2021. The associations between the universal two-child policy and maternal risk factors, the universal two-child policy and maternal complications, and maternal risk factors and maternal complications were evaluated using multivariate logistic regression analyses, with odds ratios (ORs) and 95% confidence intervals (CIs). Mediation analysis was used to estimate the potential mediation effects on the associations between the policy and maternal complications. Population-attributable fractions (PAF) were conducted to quantify the maternal complications burden attributable to the implementation of the universal two-child policy. RESULTS: In the context of the universal two-child policy, the incidence of maternal near miss, antepartum or intrapartum complication, and post-partum complication increased at municipal- and county-level sample facilities. After adjusting for covariables, there were significant associations between the universal two-child policy and maternal risk factors (P < 0.001), the universal two-child policy and an increased risk of maternal complications (P < 0.001), and maternal risk factors and maternal complications(P < 0.001). The effects of the universal two-child policy on maternal near miss and medical disease were significantly mediated by maternal risk factors with mediation proportions of 19.77% and 4.07% at the municipal-level sample facility, and mediation proportions for 2.72% at the county-level sample facility on medical disease. The universal two-child policy contributed 19.34%, 5.82%, 8.29%, and 46.19% in the incidence of the maternal near miss, antepartum or intrapartum complication, post-partum complication, and medical disease at municipal-level sample facility, respectively. The corresponding PAF% at county-level sample facility was 40.49% for maternal near miss, 32.39% for the antepartum or intrapartum complication, 61.44% for post-partum complication, and 77.72% for medical disease. For provincial-level sample facility, the incidence of maternal near miss, antepartum or intrapartum complications, and medical diseases decreased (P < 0.05) and no statistically significant difference occurred in the incidence of post-partum complications. CONCLUSIONS: In the context of the universal two-child policy, the incidence of maternal near miss, antepartum or intrapartum complication, and post-partum complication increased at municipal- and county-level sample facility. Maternal risk factors may play a mediating role in the effect of policy change and maternal complications. Provincial hospitals have been able to improve the quality of perinatal health care and reduce adverse pregnancy outcomes by adjusting their obstetric service strategies in the context of the new birth policy.

13.
Adv Healthc Mater ; 12(25): e2300563, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37377126

RESUMO

The persistent infection of high-risk-human papillomavirus type 16 (HPV16) is considered an essential element for suffering cervical cancer. Despite polymerase chain reaction, loop-mediated amplification, and microfluidic chips are used to detect the HPV16, these methods still exist some drawbacks including time-consuming and false positive results. The CRISPR-Cas system is widely used in the region of biological detection due to its precise targeted recognition capability. In this contribution, the novel solution-gated graphene transistor sensor is designed to realize the unamplified and label-free detection of HPV16 DNA. Using the precise recognition of the CRISPR-Cas12a system and the gate functionalization, HPV16 DNA can be precisely identified without need the amplification and labeling. The limit of detection of the sensor can be up to 8.3 × 10-18  m and the detection can be within 20 min. Additionally, the heat-Inactivated clinical samples can be clearly distinguished by the sensor the diagnosis results have a high degree of agreement with q-PCR detection.


Assuntos
Sistemas CRISPR-Cas , Grafite , Humanos , Papillomavirus Humano 16/genética , DNA/genética , Técnicas de Amplificação de Ácido Nucleico
14.
Genes (Basel) ; 14(6)2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37372346

RESUMO

(1) Background: Piglet diarrhea is one of the most serious diseases in pigs and has brought great economic losses to the pig industry. Alteration of the gut microbiota is an important factor in the etiology of piglet diarrhea. Therefore, this study aimed to analyze the differences in the gut microbial structures and fecal metabolic profile between post-weaning diarrhea and healthy Chinese Wannan Black pigs. (2) Methods: An integrated approach of 16S rRNA gene sequencing combined with LC/MS-based metabolomics was employed in this study. (3) Results: We found an increase in the relative abundance of the bacterial genus Campylobacter and a decrease in phylum Bacteroidetes and the species Streptococcus gallolyticus subsp. macedonicus. (S. macedonicus) in piglet diarrhea. Meanwhile, obvious changes in the fecal metabolic profile of diarrheic piglets were also detected, particularly higher levels of polyamines (spermine and spermidine). Moreover, there were substantial associations between the disturbed gut microbiota and the altered fecal metabolites, especially a strong positive relationship between spermidine and Campylobacter. (4) Conclusions: These observations may provide novel insights into potential etiologies related to post-weaning diarrhea and further enhance our understanding of the role of gut microbiota in host homeostasis and in modulating gut microbial structure.


Assuntos
Diarreia , Espermidina , Animais , Suínos , RNA Ribossômico 16S/genética , Fezes/microbiologia , Diarreia/veterinária , Metaboloma
15.
Eur J Med Chem ; 256: 115453, 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37163947

RESUMO

Interleukin-1 receptor associated kinase 4 (IRAK4) is a critical mediator of MYD88 L265P-induced NF-κB activation, indicating it is a promising therapeutic target for diffuse large B-cell lymphoma (DLBCL). Herein we report the discovery of a series of 2,3-dihydrobenzofuran IRAK4 inhibitors through structure-based drug design. The representative compound 22 exhibited strong IRAK4 inhibitory potency (IRAK4 IC50 = 8.7 nM), favorable kinase selectivity and high antiproliferative activity against the MYD88 L265P DLBCL cell line (OCI-LY10 IC50 = 0.248 µM). Compound 22 also exhibited the ability to inhibit the activation of IRAK4 signaling pathway and induce apoptosis in MYD88 L265P DLBCL cell line. In combination with Bruton's tyrosine kinase (BTK) inhibitor ibrutinib, 22 showed enhanced apoptosis-inducing effect and antiproliferative potency. The most advanced compound 22 in this inhibitor series holds promise for further development into efficacious and selective IRAK4 inhibitors for the treatment of DLBCL.


Assuntos
Quinases Associadas a Receptores de Interleucina-1 , Linfoma Difuso de Grandes Células B , Humanos , Fator 88 de Diferenciação Mieloide/metabolismo , Linhagem Celular Tumoral , Linfoma Difuso de Grandes Células B/metabolismo
16.
Front Cell Dev Biol ; 11: 1169745, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37250898

RESUMO

MicroRNAs (miRNAs) are small, noncoding RNAs that play a crucial role in the complex and dynamic network that regulates the apoptosis of porcine ovarian granulosa cells (POGCs). Resveratrol (RSV) is a nonflavonoid polyphenol compound that is involved in follicular development and ovulation. In previous study, we established a model of RSV treatment of POGCs, confirming the regulatory effect of RSV in POGCs. To investigate the miRNA-level effects of RSV on POGCs to reveal differentially expressed miRNAs, a control group (n = 3, 0 µM RSV group), a low RSV group (n = 3, 50 µM RSV group), and a high RSV group (n = 3, 100 µM RSV group) were created for small RNA-seq. In total, 113 differentially expressed miRNAs (DE-miRNAs) were identified, and a RT-qPCR analysis showed a correlation with the sequencing data. Functional annotation analysis revealed that DE-miRNAs in the LOW vs. CON group may be involved in cell development, proliferation, and apoptosis. In the HIGH vs. CON group, RSV functions were associated with metabolic processes and responses to stimuli, while the pathways were related to PI3K24, Akt, Wnt, and apoptosis. In addition, we constructed miRNA-mRNA networks related to Apoptosis and Metabolism. Then, ssc-miR-34a and ssc-miR-143-5p were selected as key miRNAs. In conclusion, this study provided an improved understanding of effects of RSV on POGCs apoptosis through the miRNA modulations. The results suggest that RSV may promote POGCs apoptosis by stimulating the miRNA expressions and provided a better understanding of the role of miRNAs combined with RSV in ovarian granulosa cell development in pigs.

17.
Adv Sci (Weinh) ; 10(10): e2206877, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36727817

RESUMO

Electromagnetic (EM) wave pollution is harmful to human health and environment, thus it is absolutely important to develop new electromagnetic wave absorbing materials. MAX phases have been attracted more attention as a potential candidate for electromagnetic wave absorbing materials due to their high conductivity and nanolaminated structure. Herein, two new magnetic MAX phases with multiprincipal elements ((Ti1/3 Nb1/3 Ta1/3 )2 FeC and (Ti0.2 V0.2 Nb0.2 Ta0.2 Zr0.2 )2 FeC) in which Fe atoms replace Al atoms in the A sites are successfully synthesized by an isomorphous replacement reaction of multiprincipal (Ti1/3 Nb1/3 Ta1/3 )2 AlC and (Ti0.2 V0.2 Nb0.2 Ta0.2 Zr0.2 )2 AlC MAX phases with Lewis acid salt (FeCl2 ). (Ti1/3 Nb1/3 Ta1/3 )2 FeC and (Ti0.2 V0.2 Nb0.2 Ta0.2 Zr0.2 )2 FeC exhibit ferromagnetic behavior, and the Curie temperature (Tc ) are 302 and 235 K, respectively. The dual electromagnetic absorption mechanisms that include dielectric and magnetic loss, which is realized in these multiprincipal MAX phases. The minimum reflection loss (RL) of (Ti1/3 Nb1/3 Ta1/3 )2 FeC is -44.4 dB at 6.56 GHz with 3 mm thickness, and the effective bandwidth is 2.48 GHz. Additionally, the electromagnetic wave absorption properties of the magnetic MAX phases indicate that magnetic loss also plays an important role besides dielectric loss. This work shows a promising composition-design strategy to develop MAX phases with good EM wave absorption performance via simultaneously regulating dielectric and magnetic loss together.

18.
Sensors (Basel) ; 23(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36772120

RESUMO

This study proposes a high-temperature superconducting (HTS) bandpass filter with a continuously tunable bandwidth and center frequency. The proposed filter combines several gallium arsenide varactors and a dual-mode resonator (DMR). The even and odd modes of the DMR can be tuned simultaneously using a single bias voltage. The capacitive value of varactors in the circuit is tuned continuously under continuous voltage and frequency tunability. External couplings and the interstage can be realized using an interdigital coupling structure; a fixed capacitor is added to the feeder to improve its coupling strength. A low-insertion loss within the band is obtained using HTS technology. Additionally, the proposed filter is etched on a 0.5 mm-thick MgO substrate and combined with YBCO thin films for demonstration. For the as-fabricated device, the tuning frequency range of 1.22~1.34 GHz was 9.4%; the 3-dB fractional bandwidth was 12.95~17.39%, and the insertion loss was 2.28~3.59 dB. The simulation and experimental measurement results were highly consistent.

19.
Bioorg Med Chem ; 78: 117153, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36621179

RESUMO

Several small-molecule covalent inhibitors of KRASG12C have made breakthrough progress in the treatment of KRAS mutant cancer. However, the clinical application of KRASG12C small-molecule inhibitors may be limited by adaptive resistance. Emerging PROTAC strategy can achieve complementary advantages with small molecule inhibitors and improve anti-tumor efficacy. Based on AMG-510, a series of novel KRASG12C-PROTACs were designed and synthesized. The protein degradation assay showed that PROTACs I-1, II-1, III-2 and IV-1 had binding and degradation ability to KRASG12C. III-2 and IV-1 showed potent inhibitory effect on downstream p-ERK and were more potent than AMG-510. Mechanistic studies demonstrated that PROTACs exerted degradation effects through the ubiquitin-proteasome pathway. Using cell lines sensitive to KRASG12C, anti-proliferative activities of compounds were assessed. PROTACs tested showed overall anti-proliferative activities. Besides,the structure-activity relationships (SARs) of KRASG12C-PROTACs were summarized. These results supported the use of the PROTAC strategy to degrade oncogene KRASG12C and provided clues for structural optimization of KRASG12C-PROTACs.


Assuntos
Neoplasias , Quimera de Direcionamento de Proteólise , Humanos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteólise , Neoplasias/tratamento farmacológico
20.
Adv Sci (Weinh) ; 10(4): e2205886, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36480308

RESUMO

The incidence of prostate cancer (PCa) in men globally increases as the standard of living improves. Blood serum biomarker prostate-specific antigen (PSA) detection is the gold standard assay that do not meet the requirements of early detection. Herein, a solution-gated graphene transistor (SGGT) biosensor for the ultrasensitive and rapid quantification detection of the early prostate cancer-relevant biomarker, miRNA-21 is reported. The designed single-stranded DNA (ssDNA) probes immobilized on the Au gate can hybridize effectively with the miRNA-21 molecules targets and induce the Dirac voltage shifts of SGGT transfer curves. The limit of detection (LOD) of the sensor can reach 10-20  M without amplification and any chemical or biological labeling. The detection linear range is from 10-20 to 10-12  M. The sensor can realize real-time detection of the miRNA-21 molecules in less than 5 min and can well distinguish one-mismatched miRNA-21 molecule. The blood serum samples from the patients without RNA extraction and amplification are measured. The results demonstrated that the biosensor can well distinguish the cancer patients from the control group and has higher sensitivity (100%) than PSA detection (58.3%). Contrastingly, it can be found that the PSA level is not directly related to PCa.


Assuntos
Grafite , MicroRNAs , Neoplasias da Próstata , Masculino , Humanos , Antígeno Prostático Específico/genética , Grafite/química , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Biomarcadores Tumorais/genética , DNA de Cadeia Simples , MicroRNAs/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...