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Nodal line semimetal (NLSM) has become a captivating medium for studying varieties of novel quantum phenomena. Here, based on first-principles calculations, we identify a square compound lattice (SCL) structure, namely C-Me-graphene, featuring a NLSM, wherein the nodal line of this configuration resides precisely at the Fermi energy without any extraneous bands in the vicinity, manifesting the quintessential characteristics of an ideal NLSM. As a corollary, utilizing symmetry analysis, we propose that nodal lines can be generated by exploiting the two-dimensional (2D) SCL of carbon. This is because the SCL not only satisfies time-reversal symmetry and inversion symmetry but also conforms to glide mirror symmetry. Additionally, this structure reveals remarkable mechanical attributes, exemplifying the highest Young's modulus within the realm of 2D materials, second only to graphene. Our work not only identifies an ideal carbon-based NLSM but also advances a scheme for crafting NLSMs, which would greatly enrich topological materials with exotic properties.
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BACKGROUND: Olgotrelvir is an oral antiviral with dual mechanisms of action targeting severe acute respiratory syndrome coronavirus 2 main protease (i.e., Mpro) and human cathepsin L. It has potential to serve as a single-agent treatment of coronavirus disease 2019 (Covid-19). METHODS: We conducted a phase 3, double-blind, randomized, placebo-controlled trial to evaluate the efficacy and safety of olgotrelvir in 1212 nonhospitalized adult participants with mild to moderate Covid-19, irrespective of risk factors, who were randomly assigned to receive orally either 600 mg of olgotrelvir or placebo twice daily for 5 days. The primary and key secondary end points were time to sustained recovery of a panel of 11 Covid-19-related symptoms and the viral ribonucleic acid (RNA) load. The safety end point was incidence of treatment-emergent adverse events. RESULTS: The baseline characteristics of 1212 participants were similar in the two groups. In the modified intention-to-treat population (567 patients in the placebo group and 558 in the olgotrelvir group), the median time to symptom recovery was 205 hours in the olgotrelvir group versus 264 hours in the placebo group (hazard ratio, 1.29; 95% confidence interval [CI], 1.13 to 1.46; P<0.001). The least squares mean (95% CI) changes of viral RNA load from baseline were -2.20 (-2.59 to -1.81) log10 copies/ml in olgotrelvir-treated participants and -1.40 (-1.79 to -1.01) in participants receiving placebo at day 4. Skin rash (3.3%) and nausea (1.5%) were more frequent in the olgotrelvir group than in the placebo group; there were no treatment-related serious adverse events, and no deaths were reported. CONCLUSIONS: Olgotrelvir as a single-agent treatment significantly improved symptom recovery. Adverse effects were not dose limiting. (Funded by Sorrento Therapeutics, a parent company of ACEA Therapeutics; ClinicalTrials.gov number, NCT05716425.).
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Antivirais , Tratamento Farmacológico da COVID-19 , Humanos , Masculino , Método Duplo-Cego , Feminino , Pessoa de Meia-Idade , Antivirais/uso terapêutico , Antivirais/efeitos adversos , Antivirais/administração & dosagem , Adulto , COVID-19/virologia , SARS-CoV-2 , Idoso , Resultado do Tratamento , Compostos OrgânicosRESUMO
As a disease with high morbidity and high mortality, lung cancer has seriously harmed people's health. Therefore, early diagnosis and treatment are more important. PET/CT is usually used to obtain the early diagnosis, staging, and curative effect evaluation of tumors, especially lung cancer, due to the heterogeneity of tumors and the differences in artificial image interpretation and other reasons, it also fails to entirely reflect the real situation of tumors. Artificial intelligence (AI) has been applied to all aspects of life. Machine learning (ML) is one of the important ways to realize AI. With the help of the ML method used by PET/CT imaging technology, there are many studies in the diagnosis and treatment of lung cancer. This article summarizes the application progress of ML based on PET/CT in lung cancer, in order to better serve the clinical. In this study, we searched PubMed using machine learning, lung cancer, and PET/CT as keywords to find relevant articles in the past 5 years or more. We found that PET/CT-based ML approaches have achieved significant results in the detection, delineation, classification of pathology, molecular subtyping, staging, and response assessment with survival and prognosis of lung cancer, which can provide clinicians a powerful tool to support and assist in critical daily clinical decisions. However, ML has some shortcomings such as slightly poor repeatability and reliability.
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The grain boundaries (GBs) composed of pentagons and octagons (558 GBs) have been demonstrated to induce attractive transport properties such as Van Hove singularity (VHS) and quasi-one-dimensional metallic wires. Here, we propose a monolayer carbon allotrope which is formed from the introduction of periodic 558 GBs to decorate intact graphene, termed as PHO-graphene. The calculated electronic properties indicate that PHO-graphene not only inherits the previously superior characteristics such as Van Hove singularity and quasi-one-dimensional metallic wires, but also possesses two twisted Dirac cones near the Fermi level. Further calculation finds that the Berry phase is quantized to ± π at the two Dirac points, which is consistent with the distribution of the corresponding Berry curvature. The parity argument uncovers that PHO-graphene hosts a nontrivial band topology and the edge states connecting the two Dirac points are clearly visible. Our findings not only provide a reliable avenue to realize the abundant and extraordinary properties of carbon allotropes, but also offer an attractive approach for designing all carbon-based devices.
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Two-dimensional (2D) boron nitride (BN) is a promising candidate for aerospace materials due to its excellent mechanical and thermal stability properties. However, its unusually prominent band gap limits its application prospects. In this work, we report a gapless monolayer BN, t-BN, which has four anisotropic Dirac cones in the first Brillouin zone exactly at the Fermi level. To further confirm the semimetallic character, the nontrivial topological properties are proven through the topologically protected edge states and the invariant non-zero Z2. Additionally, the Young's modulus and Poisson ratio characterize the strong mechanical strength of t-BN. Our theoretical predictions provide more possibilities for exploring the Dirac cone in BN, which will enhance the 2D boron derivative materials.
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The effect of substitutional metal dopants in NiOx on the structural and electronic structures is of great interest, particularly for increasing the p-type conductivities as a hole transport layer (HTL) applied in perovskite solar cells (PSCs). In this paper, experimental fabrications and density functional theory calculations have been carried out on Cd-doped NiOx films to examine the effect of divalent doping on the electronic and geometric structures of NiOx. The results indicate that divalent Cd dopants reduced the formation energy of the Ni vacancy (VNi) and created more VNi in the films, which enhanced the p-type conductivity of the NiOx films. In addition, Cd doping also deepened the valence band edge, reduced the monomolecular Shockley-Read-Hall (SRH) recombination losses, and promoted hole extraction and transport. Hence, the PSCs with Cd:NiOx HTLs manifest a high efficiency of 20.47%, a high photocurrent density of 23.00 mA cm-2, and a high fill factor of 79.62%, as well as negligible hysteresis and excellent stability. This work illustrates that divalent elements such as Cd, Zn, Co, etc. may be potential dopants to improve the p-type conductivity of the NiOx films for applications in highly efficient and stabilized PSCs.
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The exploration of carbon phases with intact massless Dirac fermions in the presence of defects is critical for practical applications to nanoelectronics. Here, we identify by first-principles calculations that the Dirac cones can exist in graphene with stacking fault (SF) induced periodic line defects. These structures are width (n)-dependent to graphene nanoribbon and are thus termed as (SF)n-graphene. The electronic properties reveal that the semimetallic features with Dirac cones occur in (SF)n-graphene with n = 3m + 1, where m is a positive integer, and then lead to a quasi-one-dimensional conducting channel. Importantly, it is found that the twisted Dirac cone in the (SF)4-graphene is tunable among type-I, type-II, and type-III through a small uniaxial strain. The further stability analysis shows that (SF)n-graphene is thermodynamic stable. Our findings provide an artificial avenue for exploring Dirac Ffermions in carbon-allotropic structures in the presence of defects.
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The exploration of novel two-dimensional semimetallic materials is always an attractive topic. We propose a series of two-dimensional silicon carbides with a tetragonal lattice. The band structure of silicon carbides with tetragonal carbon rings and silicon rings exhibits Dirac cones. Interestingly, the Dirac cone of tetragonal SiC originates from a "ring coupling" mechanism. This mechanism refers to the mutual coupling between the four carbon atoms in the tetragonal C ring, and the same coupling in the tetragonal Si ring. Additionally, the "ring coupling" mechanism is applicable to other group IV binary compounds such as monolayer GeC and SnC. This work provides reliable evidence for the argument that two-dimensional tetragonal materials can produce Dirac cones.
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Circular RNAs (circRNAs), a group of non-coding RNAs, play an important role in cancer biology, and in the present study, we aimed to clarify the expression profiles and biological functions of circRNA circVANGL1 in non-small cell lung cancer (NSCLC). The results showed that circVANGL1 was overexpressed in human NSCLC tissues and cell lines. circVANGL1 expression was closely associated with tumor size, TNM stage and overall survival of NSCLC patients. Further loss-of-function analysis revealed that knockdown of circVANGL1 inhibited proliferation and induced apoptosis in NSCLC cell lines. The migration and invasion of NSCLC cells were also suppressed by circVANGL1 knockdown. In addition, we predicted that circVANGL1 might serve as a competing endogenous RNA (ceRNA), becoming a sink for miR-195, thereby modulating the expression of Bcl-2 in NSCLC cells. Rescue experiments demonstrated that miR-195 inhibitor abrogated the beneficial role of circVANGL1 knockdown in NSCLC cells. Taken together, we conclude that circVANGL1 functions as an oncogene to promote NSCLC progression partly through miR-195/Bcl-2 axis, which might be a novel therapeutic target for NSCLC patients.
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Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas de Transporte/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Circular/genética , Células A549 , Idoso , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Longo não Codificante/genética , Regulação para CimaRESUMO
The present study aimed to further explore the molecular mechanisms of miRNA-223 in non-small cell lung cancer (NSCLC). Data prospectively collected from NSCLC patients and volunteers from March 2016 to MayMAP2016 at Tsinghua Changgung Hospital were analyzed. Cell proliferation was measured using MTT assay, while cell apoptosis and caspase-3/9 activity were measured using ï¬ow cytometry and caspase-3/9 activity kit. Bax, EGFR, PI3K and p-Akt protein were also investigated using western blotting. The results revealed that the serum levels of miRNA-223 in NSCLC patients were downregulated. In an inMAPvitro model, over-expression of miRNA-223 induced apoptosis while reducing cell proliferation. In contrast, downregulation of the expression of miRNA-223 inhibited apoptosis whereas it increased cell proliferation. Meanwhile, overexpression of miRNA-223 suppressed the protein expression of EGFR, PI3K and p-Akt in NSCLC cells. An EGFR inhibitor promoted the anticancer effects of miRNA-223 in NSCLC cells through the EGFR/PI3K/AKT pathway. Meanwhile, a PI3K inhibitor increased the anticancer effects of miRNA-223 in NSCLC cells through the PI3K/AKT pathway. Thus, a new pathway has been identified in the present study, and application of miRNA-223 may induce the apoptosis of NSCLC through the PI3K/AKT pathway by EGFR.
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Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética , Células A549 , Apoptose/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação para Baixo/genética , Receptores ErbB/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
Proliferating cell nuclear antigen (PCNA) functions as a bridging molecule, which targets proteins that have distinct roles in cell growth. The expression of PCNA is dysregulated in some tumors and takes part in the progression of oncogenesis. However, the roles of PCNA in the progression of non-small cell lung cancer (NSCLC) remain unknown. The present study aimed to investigate the function of PCNA in the occurrence and development of NSCLC and its underlying molecular mechanisms. Western blotting, RT-PCR, and immunohistochemistry assays were used to detect the expression pattern of PCNA in NSCLC tissues and cells. A log rank test was performed to compare the overall survival (OS) of patients with high/low expression of PCNA. Besides, the relationship between PCNA and signal transducer and activator of transcription-3 (STAT3) proteins were evaluated. Then, MTT, flow cytometry, clonal formation, and in vivo xenograft assays were conducted to investigate the effects of PCNA/STAT3 on cell growth, clonal formation, apoptosis, and tumorigenesis. Results showed that PCNA expression was elevated in NSCLC tissues and cells and it could combine with STAT3 and increased its expression and phosphorylation. Moreover, the expression of PCNA showed a positive correlation with the TNM grade and occurrence rate of the lymphatic metastasis and poor prognosis of NSCLC patients. Overexpression of PCNA promoted cell proliferation, clonal formation, and tumorigenesis in lung cancer cells and inhibited cell apoptosis. In contrast, these effects were inhibited when knockdown of STAT3. In conclusion, this study demonstrates that PCNA functions as an oncogene in the progression of NSCLC through up-regulation of STAT3. These findings point to a potentially new therapeutic strategy for NSCLC.