ABSTRACT
4H-silicon carbide (4H-SiC) possesses a high Baliga figure of merit, making it a promising material for power electronics. However, its applications are limited by low hole mobility. Herein, we found that the hole mobility of 4H-SiC is mainly limited by the strong interband electron-phonon scattering using mode-level first-principles calculations. Our research indicates that applying compressive strain can reverse the sign of crystal-field splitting and change the ordering of electron bands close to the valence band maximum. Therefore, the interband electron-phonon scattering is severely suppressed and the electron group velocity is significantly increased. The out-of-plane hole mobility of 4H-SiC can be greatly enhanced by â¼200% with 2% uniaxial compressive strain applied. This work provides new insights into the electron transport mechanisms in semiconductors and suggests a strategy to improve hole mobility that could be applied to other semiconductors with hexagonal crystalline geometries.
ABSTRACT
To investigate the clinical characteristics and risk factors of specific human leukocyte antigen loss (HLA loss) in relapsed acute myeloid leukaemia (AML)/myelodysplastic syndrome (MDS) patients after allogeneic haematopoietic stem cell transplantation (allo-HSCT), and compare the responses of patients with HLA loss relapse with those without HLA loss (non-HLA loss) to different treatment regimens. Clinical data of traceable patients with AML/MDS after myeloablative allo-HSCT in our centre between January 2010 and June 2021, who experienced disease relapse after the transplantation, were collected. The patients were divided into the HLA loss relapse group and the non-HLA loss relapsed group based on HLA loss gene test findings by next-generation sequencing. The patients' median overall survival (OS) after the relapse were compared, and univariate and multivariate analyses were performed using the Kaplan-Meier survival curve and Cox proportional hazard model to explore the responses to different treatments after relapse. A total of 2359 patients were selected. Retrospective HLA gene loss gene detection was performed for the deoxyribonucleic acid in 179 relapsed patients, including 47 patients in the HLA loss group (27.2%), 126 patients in the non-HLA loss group (72.8%) and 6 patients were excluded due to a lack of confirmed results. There was no significant statistical difference in the baseline characteristics of patients between the two groups, but as to transplantation-related characteristics, the donor-recipient relationship and HLA mismatched loci were statistically different between the two groups (both p < 0.001). Multivariate Cox analysis showed that more HLA mismatched loci ≥3 (HR = 3.66; 95% CI: 1.61-8.31; p = 0.002), time (≤6 months) from HSCT to relapse (HR = 7.92; 95% CI: 3.35-18.74; p < 0.001) and donor chimerism (CD3) in bone marrow at relapse (HR = 1.02; 95% CI: 1.00-1.03; p = 0.036) were independent factors affecting HLA loss relapse. The ratio of negative conversion of FLT3-ITD or CEBPA mutation was significantly lower in patients with post-transplantation HLA loss relapse than in the non-HLA loss group (0.0% vs. 45.5%, p = 0.003; 0.0% vs. 80.0%, p = 0.035), with none of the patients with FLT3-ITD or CEBPA mutation turned negative in the HLA loss group. The number of gene mutations turned negative when relapse in the non-HLA loss group was remarkably higher than that in the HLA loss group (p = 0.001). Using donor lymphocyte infusion (DLI) could not prolong OS for the HLA loss group (p = 0.42). Nevertheless, second transplantation had a significant positive impact on OS in the HLA loss group (p = 0.017), although only five patients in the HLA loss group underwent second transplantation. However, patients in the non-HLA loss group using DLI had a relatively longer OS time than those without DLI (p = 0.017). Second transplantation could also prolong OS in the non-HLA loss group, but the effect was not as significant as in the HLA loss group (p = 0.053). In summary, HLA loss detection is essential for patients with recurrence after transplantation, especially for those with more HLA mismatched loci and non-sibling donor. Furthermore, the detection of HLA loss has a guiding role in choosing subsequent therapy when relapsed, as secondary transplantation is more suitable than DLI for those with HLA loss.
Subject(s)
Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Humans , Retrospective Studies , Neoplasm Recurrence, Local , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/therapy , Hematopoietic Stem Cell Transplantation/methods , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/therapy , HLA Antigens/genetics , Risk Factors , Histocompatibility Antigens Class II , Proportional Hazards Models , RecurrenceABSTRACT
Mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma, undergo large-cell transformation (LCT) in the late stage, manifesting aggressive behavior, resistance to treatments, and poor prognosis, but the mechanisms involved remain unclear. To identify the molecular driver of LCT, we collected tumor samples from 133 MF patients and performed whole-transcriptome sequencing on 49 advanced-stage MF patients, followed by integrated copy number inference and genomic hybridization. Tumors with LCT showed unique transcriptional programs and enriched expressions of genes at chr7q. Paternally expressed gene 10 (PEG10), an imprinted gene at 7q21.3, was ectopically expressed in malignant T cells from LCT, driven by 7q21.3 amplification. Mechanistically, aberrant PEG10 expression increased cell size, promoted cell proliferation, and conferred treatment resistance by a PEG10/KLF2/NF-κB axis in in vitro and in vivo models. Pharmacologically targeting PEG10 reversed the phenotypes of proliferation and treatment resistance in LCT. Our findings reveal new molecular mechanisms underlying LCT and suggest that PEG10 inhibition may serve as a promising therapeutic approach in late-stage aggressive T-cell lymphoma.
Subject(s)
Apoptosis Regulatory Proteins/genetics , Cell Transformation, Neoplastic/genetics , DNA-Binding Proteins/genetics , Lymphoma, T-Cell, Cutaneous/genetics , RNA-Binding Proteins/genetics , Skin Neoplasms/genetics , Animals , Cell Line, Tumor , Cell Transformation, Neoplastic/pathology , Female , Gene Amplification , Gene Expression Regulation, Neoplastic , Genomic Imprinting , Humans , Lymphoma, T-Cell, Cutaneous/pathology , Mice, Inbred NOD , Mice, SCID , Mycosis Fungoides/genetics , Mycosis Fungoides/pathology , Skin Neoplasms/pathologyABSTRACT
OBJECTIVE: Antiphospholipid syndrome (APS) is an autoimmune disease mainly affecting young individuals. Testing for antiphospholipid antibodies is recommended for young patients who are suspected to have APS. Yet, it is hard to differentiate APS from other acquired thrombophilia disorders in elderly-onset APS patients. This study aim to investigate the characteristics and prognosis of elderly-onset APS. METHODS: This is an observational cohort study. Thrombotic APS patients who underwent follow-ups between 2009 and 2022 were included. Elderly-onset APS patients (onset age ≥60 years) were compared to non-elderly-onset APS patients (onset age <60 years) and matched cases of elderly non-APS patients (age ≥60 years with thrombosis). RESULTS: A total of 161 APS patients were included in this study, 45 (28.0%) were elderly-onset APS. Stroke (35.6% vs. 18.1%, p = .018) was more common at disease onset in elderly-onset APS patients. Compared to non-elderly-onset patients, elderly-onset APS patients were associated with a higher number of cardiovascular risk factors. Elderly-onset APS patients showed significantly lower positive rate (51.1% vs. 71.6%, p = .014) and ratios [1.24 (1.01-1.38) vs. 1.37 (1.16-1.77), p = .004] of lupus anticoagulant. Elderly-onset APS patients had a significantly higher 10-years cumulative all-cause mortality (p < .001) and APS-related mortality than non-elderly-onset patients (p = .002) and elderly non-APS patients (p = .040). CONCLUSIONS: Elderly-onset APS patients have unique disease characteristics with higher 10-years cumulative all-cause mortality and APS-related mortality. Early recognition and control of comorbidities may reduce the recurrence of thrombosis and mortality in elderly-onset APS patients.
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Photothermal materials generally suffer from challenges such as low photothermal conversion efficiency and inefficient full-spectrum utilization of solar energy. This paper proposes gradient refractive index transparent ceramics (GRITCs) integrated with subwavelength nanostructure arrays and simulates the synergistic anti-reflection effect by an admittance recursive model. An innovative subwavelength structure, possessing a superior light-trapping capability, is initially crafted based on this model. Subsequently, various intelligent optimization algorithms including genetic algorithm, particle swarm optimization, and simulated annealing are employed to optimize the structure of gradient refractive index films respectively. Finally, the photothermal conversion efficiencies of devices based on different photothermal materials are calculated. The simulations and finite-difference time-domain calculations demonstrate that the three-layer GRITCs integrated with an optimal SNA exhibit outstanding full-spectrum and omnidirectional anti-reflection performance. The solar transmittance of the devices can exceed 97% for light wavelengths ranging from 300 to 2500 nm over the full angle of incidence. Our results reveal that the synergistic anti-reflection effect in the SNAs and GRITCs can enhance the photothermal conversion efficiency by more than 20%.
ABSTRACT
An amorphous layer is commonly found at the interfaces of heterostructures due to lattice and thermal mismatch between dissimilar materials. While existing research has explored the impact of these layers on interfacial thermal transport, a comprehensive understanding of the underlying microscopic mechanisms remains essential for advancing thermal nanodevice development. Through phonon wave packet simulations, we investigated the dynamic behaviors of phonons crossing the amorphous interlayer at the GaN/AlN interface from the mode level. Our results highlight the amorphous layer's capability to notably adjust the polarization properties of incoming phonons, culminating in phonon localization. By examining transmission outcomes on a per-mode basis, we demonstrate the amorphous layer's impediment on phonon transport. Notably, this resistance escalates with an increase in the amorphous layer thickness (L), with certain high-frequency TA phonons showing unexpectedly high transmissivity due to polarization conversion and inelastic scattering at the amorphous interface. In addition, we observe that the amorphous layer prompts multiple reflections of incident phonons, instigating discernible from the two-beam interference equation. Finally, in pursuit of enhanced phonon transport, we employ annealing techniques to optimize the interface morphology, leading to the recrystallization of the amorphous layer. This optimization yields a substantial enhancement of interfacial thermal conductance by up to 38% for L = 3 nm.
ABSTRACT
Numerous small molecules exert antitumor effects by interacting with DNA, thereby influencing processes, such as DNA replication, transcription, meiosis, and gene recombination. Benzophenanthridine and protoberberine alkaloids are known to bind DNA and exhibit many pharmacological activities. In this study, we conducted a comparative analysis of the interactions between these two classes of alkaloids with G-quadruplex (G4) DNA and double-stranded DNA (dsDNA). Protoberberine alkaloids showed a greater affinity for binding with G4s than with dsDNA, while benzophenanthridine alkaloids exhibited a significantly stronger binding capacity for dsDNA, especially in regions that are rich in AT base pairs. Benzophenanthridine alkaloids also exhibited much stronger toxicity to various cancer cells. Compared with protoberberine alkaloids, benzophenanthridine alkaloids displayed much stronger activity in inhibiting cellular DNA and RNA synthesis, arresting the cell cycle in the G2/M phase, inducing cell apoptosis, and leading to intracellular DNA damage. Given that dsDNA constitutes the predominant form of DNA within cells for the majority of the cell cycle, the significant antiproliferative activity of benzophenanthridine alkaloids could be attributed, in part, to their higher binding affinity for dsDNA, thereby exerting a more significant impact on cellular proliferation. These findings have valuable implications for understanding the biological activities of isoquinoline alkaloids and their antitumor applications.
ABSTRACT
Deoxyribonucleotide (DNA) is uniquely programmable and biocompatible, and exhibits unique appeal as a biomaterial as it can be precisely designed and programmed to construct arbitrary shapes. DNA hydrogels are polymer networks comprising cross-linked DNA strands. As DNA hydrogels present programmability, biocompatibility, and stimulus responsiveness, they are extensively explored in the field of biomedicine. In this study, we provide an overview of recent advancements in DNA hydrogel technology. We outline the different design philosophies and methods of DNA hydrogel preparation, discuss its special physicochemical characteristics, and highlight the various uses of DNA hydrogels in biomedical domains, such as drug delivery, biosensing, tissue engineering, and cell culture. Finally, we discuss the current difficulties facing DNA hydrogels and their potential future development.
Subject(s)
Biocompatible Materials , DNA , Hydrogels , Tissue Engineering , Hydrogels/chemistry , DNA/chemistry , Humans , Tissue Engineering/methods , Biocompatible Materials/chemistry , Animals , Drug Delivery Systems/methods , Biomedical Engineering/methods , Biosensing Techniques/methods , Cell Culture Techniques/methodsABSTRACT
In this study, a new polyionic polymer inhibitor, TIL-NH2, was developed to address the instability of shale gas horizontal wells caused by water-based drilling fluids. The structural characteristics and inhibition effects of TIL-NH2 on mud shale were comprehensively analyzed using infrared spectroscopy, NMR spectroscopy, contact angle measurements, particle size distribution, zeta potential, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results demonstrated that TIL-NH2 significantly enhances the thermal stability of shale, with a decomposition temperature exceeding 300 °C, indicating excellent high-temperature resistance. At a concentration of 0.9%, TIL-NH2 increased the median particle size of shale powder from 5.2871 µm to over 320 µm, effectively inhibiting hydration expansion and dispersion. The zeta potential measurements showed a reduction in the absolute value of illite's zeta potential from -38.2 mV to 22.1 mV at 0.6% concentration, highlighting a significant decrease in surface charge density. Infrared spectroscopy and X-ray diffraction confirmed the formation of a close adsorption layer between TIL-NH2 and the illite surface through electrostatic and hydrogen bonding, which reduced the weakly bound water content to 0.0951% and maintained layer spacing of 1.032 nm and 1.354 nm in dry and wet states, respectively. Thermogravimetric analysis indicated a marked reduction in heat loss, particularly in the strongly bound water content. Scanning electron microscopy revealed that shale powder treated with TIL-NH2 exhibited an irregular bulk shape with strong inter-particle bonding and low hydration degree. These findings suggest that TIL-NH2 effectively inhibits hydration swelling and dispersion of shale through the synergistic effects of cationic imidazole rings and primary amine groups, offering excellent temperature and salt resistance. This provides a technical foundation for the low-cost and efficient extraction of shale gas in horizontal wells.
ABSTRACT
Cell-SELEX is a powerful tool to generate aptamers that specifically bind the native molecules on living cells. Here, we report an aptamer ZAJ4a generated by cell-SELEX. The molecular target of ZAJ4a was pulled down by the enriched cell-SELEX pool and identified to be the receptor-type tyrosine-protein phosphatase F (PTPRF) through a stable isotope labeling using amino acids in cell culture (SILAC)-based quantitative proteomic method. ZAJ4a showed high binding affinity with nanomolar range to cancer cells expressing PTPRF. Meanwhile, PTPRF was proven to highly express on several cancer cell lines using ZAJ4a as a molecular probe and to highly express in many kinds of cancer samples using gene expression profiling interactive analysis (GEPIA2) from the TCGA and GTEx databases. These results indicate that the aptamer generated by cell-SELEX showed good specificity at the molecular level. This cell-SELEX and target identification strategies show great potential for identifying biomarkers on the cell surface.
Subject(s)
Aptamers, Nucleotide , Aptamers, Nucleotide/chemistry , Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics , Proteomics , Biomarkers , Molecular Probes , SELEX Aptamer Technique/methodsABSTRACT
Cellular prion protein (PrPC) is highly expressed in a variety of tumor cells and plays a crucial role in neurodegenerative diseases. Its N-terminal domain contains a conserved octapeptide (PHGGGWGQ) repeat sequence. The number of repeats has been correlated with the species as well as the development of associated diseases. Herein, PrPC was identified to be the molecular target of a high-affinity DNA aptamer HA5-68 obtained by cell-SELEX. Aptamer HA5-68 was further optimized to two short sequences (HA5-40-1 and HA5-40-2), and its binding site to PrPC was identified to be located in the loop-stem-loop region of the head of its secondary structure. HA5 series aptamers were demonstrated to bind the octapeptide repeat region of PrPC, as well as the synthesized peptides containing different numbers of octapeptide repeats. The PrPC expression on 42 cell lines was measured by using aptamer HA5-68 as a molecular probe. The clear understanding of the molecular structure and binding mechanism of this set of aptamers will provide information for the design of diagnostic methods and therapeutic drugs targeting PrPC.
Subject(s)
Aptamers, Nucleotide , Prion Diseases , Prions , Humans , Prion Proteins , Aptamers, Nucleotide/chemistry , Protein Binding , Prions/genetics , Binding Sites , Prion Diseases/metabolismABSTRACT
Laryngopharynx epithelium neoplasia induced by HPV6/11 infection in juvenile-onset recurrent respiratory papillomatosis (JO-RRP) causes a great health issue characteristic of frequent relapse and aggressive disease progression. Local cell-mediated immunity shaped by the recruitment and activation of cytotoxic effector cells is critical for viral clearance. In this study, we found that NK cells in the papillomas of aggressive JO-RRP patients, in contrast to massive infiltrated T cells, were scarce in number and impaired in activation and cytotoxicity as they were in peripheral blood. Data from cell infiltration analysis indicated that the migration of NK cell to papilloma was restricted in aggressive JO-RRP patients. Further study showed that the skewed chemokine expression in the papillomas and elevated ICAM-1 expression in hyperplastic epithelia cells favored the T cell but not NK cell recruitment in aggressive JO-RRP patients. In parallel to the increased CD3+ T cells, we observed a dramatical increase in Tregs and Treg-promoting cytokines such as IL-4, IL-10 and TGFß in papillomas of aggressive JO-RRP patients. Our study suggested that likely initialized by the intrinsic change in neoplastic epithelial cells with persistent HPV infection, the aggressive papillomas built an entry barrier for NK cell infiltration and formed an immunosuppressive clump to fend off the immune attack from intra-papillomas NK cells. IMPORTANCE Frequent relapse and aggressive disease progression of juvenile-onset recurrent respiratory papillomatosis (JO-RRP) pose a great challenge to the complete remission of HPV 6/11 related laryngeal neoplasia. Local immune responses in papillomas are more relevant to the disease control considering the locale infected restriction of HPV virus in epitheliums. In our study, the restricted NK cell number and reduced expression of activating NKp30 receptor suggested one possible mechanism underlying impaired NK cell defense ability in aggressive JO-RRP papillomas. Meanwhile, the negative impact of HPV persistent infection on NK cell number and function represented yet another example of a chronic pathogen subverting NK cell behavior, affirming a potentially important role for NK cells in viral containment. Further, the skewed chemokine/cytokine expression in the papillomas and the elevated adhesion molecules expression in hyperplastic epithelia cells provided important clues for understanding blocked infiltration and antiviral dysfunction of NK cells in papilloma.
Subject(s)
Killer Cells, Natural , Papilloma , Papillomavirus Infections , Respiratory Tract Infections , Disease Progression , Human papillomavirus 11 , Humans , Intercellular Adhesion Molecule-1/metabolism , Interleukin-10/immunology , Interleukin-4/immunology , Killer Cells, Natural/immunology , Natural Cytotoxicity Triggering Receptor 3/metabolism , Neoplasm Recurrence, Local , Papilloma/immunology , Papilloma/virology , Papillomavirus Infections/immunology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/virology , Transforming Growth Factor beta/immunologyABSTRACT
Accurate interatomic force fields are of paramount importance for molecular dynamics simulations to explore the thermal transport at the GaN/AlN heterogenous interface, which is a key factor hindering heat dissipation and limiting the performance of GaN power electronic devices. In this work, an interatomic potential (force field) based on a deep neural network technique and first-principles calculations is developed for N-Ga-Al semiconductors to predict the elastic and thermodynamic properties. Using our deep neural network potential (NNP), the precise structural features, elastic constants, and thermal conductivities of GaN, AlN, and their alloy are obtained, which are well consistent with those from experiments and first-principles calculations. The interfacial thermal conductance of GaN/AlN heterostructures with different interfacial morphologies are further studied using molecular dynamics simulations with the NNP. It is found that atomic interdiffusion and disorder at the interfaces dramatically reduces the interfacial thermal conductance. The developed NNP exhibits a larger effective dimension with respect to classical empirical potentials and reaches competitive performances, thus pointing towards attractive advantages in the study of GaN heterostructures and devices with the NNP.
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BACKGROUND: The relationship between preoperative frailty and pulmonary complications after cardiac surgery in elderly patients is unclear. This study was designed to evaluate the relationship between frailty and postoperative pulmonary complications (PPCs) in elderly patients undergoing cardiac surgery and to provide a basis for their prevention and treatment. AIMS: This study aimed to investigate the predictive value of preoperative frailty on pulmonary complications after cardiac surgery in elderly patients. METHODS: Frailty was assessed using the CAF. The diagnosis of PPCs was based on the criteria defined by Hulzebos et al., and patients were classified into a PPCs group and a non-PPCs group. Factors with clinical significance and P < 0.05 in univariate regression analysis were included in multivariate logistic regression analysis to determine the relationship between preoperative frailty and PPCs. The area under the receiver operating characteristic (ROC) curve (AUC) was used to compare the predictive effects of the CAF, EuroSCORE II, and ASA + age on the occurrence of PPCs. RESULTS: A total of 205 patients were enrolled in this study, 31.7% of whom developed PPCs. Univariate logistic regression analysis showed that frailty, ASA grade, EuroSCORE II, hemoglobin concentration, FVC, time of operation, and postoperative AKI were associated with the development of PPCs. However, after adjustments for all possible confounding factors, multivariate logistic regression results showed that frailty, prolonged operation time, and postoperative AKI were risk factors for PPCs, and the risk of postoperative PPCs in frail patients was approximately 4.37 times that in nonfrail patients (OR = 4.37, 95%CI: 1.6-11.94, P < 0.05). The predictive efficacy of the traditional perioperative risk assessment tools EuroSCORE II and ASA + age was lower than that of CAF. CONCLUSIONS: Frailty before surgery, prolonged operation time, and postoperative AKI were independent risk factors for pulmonary complications after heart surgery in elderly individuals, and CAF was more effective than the traditional risk predictors EuroSCORE II and ASA + age.
Subject(s)
Acute Kidney Injury , Cardiac Surgical Procedures , Frailty , Humans , Aged , Frailty/epidemiology , Prospective Studies , Risk Factors , Cardiac Surgical Procedures/adverse effects , Postoperative Complications/etiologyABSTRACT
The L1 cell adhesion molecule (L1CAM) plays important roles in the development and plasticity of the nervous system as well as in tumor formation, progression, and metastasis. New ligands are necessary tools for biomedical research and the detection of L1CAM. Here, DNA aptamer yly12 against L1CAM was optimized to have much stronger binding affinity (10-24 fold) at room temperature and 37 °C via sequence mutation and extension. This interaction study revealed that the optimized aptamers (yly20 and yly21) adopted a hairpin structure containing two loops and two stems. The key nucleotides for aptamer binding mainly located in loop I and its adjacent area. Stem I mainly played the role of stabilizing the binding structure. The yly-series aptamers were demonstrated to bind the Ig6 domain of L1CAM. This study reveals a detailed molecular mechanism for the interaction between yly-series aptamers and L1CAM and provides guidance for drug development and detection probe design against L1CAM.
Subject(s)
Aptamers, Nucleotide , Neoplasms , Neural Cell Adhesion Molecule L1 , Humans , Aptamers, Nucleotide/chemistry , Neural Cell Adhesion Molecule L1/metabolism , Neoplasms/metabolismABSTRACT
Expansion microscopy (ExM) is a newly developed technology in recent years that enables nanoscale imaging under conventional microscopes. Herein, we report an aptamer-based ExM imaging strategy. A nucleus-targeting aptamer Ch4-1 was chemically labeled with a dye and an acrydite at each end to perform the functions of molecular recognition, fluorescence reporting, and gel anchoring. After binding cell nucleus, the dual labeled aptamer Ac-Ch4-1-FAM directly participated in gelation and anchored in polyacrylamide gel. After expanding the gel, high-resolution imaging was achieved by confocal microscopy. Multicolor ExM imaging was also realized by combining Ac-Ch4-1-FAM, antibodies and fluorescent dyes. This aptamer-based ExM could clearly image the chromatin morphology at different mitotic stages. The expansion process is simple and the aptamer labeling is easy. The aptamer-based ExM holds great promise in super-resolution imaging of cells and tissues.
Subject(s)
Fluorescent Dyes , Oligonucleotides , Antibodies/chemistry , Cell Nucleus/metabolism , Fluorescent Dyes/chemistry , Microscopy, Fluorescence/methodsABSTRACT
Edge termination plays a vital role in determining the properties of 2D materials. By performing compelling ab initio simulations, a lowest-energy U-edge [ZZ(U)] reconstruction is revealed in the bilayer phosphorene. Such reconstruction reduces 60% edge energy compared with the pristine one and occurs almost without an energy barrier, implying it should be the dominating edge in reality. The electronic band structure of phosphorene nanoribbon with such reconstruction resembles that of an intrinsic 2D layer, exhibiting nearly edgeless band characteristics. Although ZZ(U) changes the topology of phosphorene nanoribbons, simulated transmission electron microscope, scanning transmission electron microscope and scanning tunneling microscope images indicate it is very hard to be identified. One possible identified method is infrared/Raman analyses because the ZZ(U) edge alters vibrational modes dramatically. In addition, it also increases the thermal conductivity of PNR 1.4 and 2.3 times than the pristine and Klein edges.
ABSTRACT
Grain boundaries (GBs) widely exist in black phosphorene (BP), which plays a vital role in determining the properties of 2D materials. Significant GB effect on the thermal boundary resistance in BP structures is found by using molecular dynamics calculations and lattice dynamic analysis. A remarkably high interface thermal resistance is observed. By analyzing the strain distribution and phonon vibrational spectra, we reveal this high thermal resistance originates from phonon localization and strong phonon boundary scattering induced by the local stress at the GB area. Particularly, it is interesting to find that the partial phonon modes display weak localization when GBs present. The fraction of atoms participating in a particular phonon vibrational mode has been quantified through the calculation of phonon participation ratio. In addition, the thermal boundary resistance is found size-dependent, which further induces interesting thermal rectification effect in the BP structures. A high rectification ratio is obtained by adjusting the structural length and temperature bias. These findings provide a through insight into the GB effects on individual phonon mode transmission across the GBs, and highlight that the GB effect is an important factor and should be taken into account for the applications of BP-based phononic devices.
ABSTRACT
ABSTRACT: We aimed to evaluate the quality of life of Chinese patients after immediate reconstruction surgery on individuals with oral cavity cancer. In addition, we compared the differences between radial forearm free flap and pectoralis major myocuta- neous flap. Using the University of Washington quality of life v4 questionnaire, 1:1 matched research was performed on patients received PMM or RFF flap. Chi-square test was used to analyze the variables. One hundred twenty four of 179 questionnaires were returned (69.3%). Age, N stage, and postoperative radiotherapy were similar for both groups. However, there were significant differences between two groups in gender, T stage, operation duration, and complication rate. Oral cavity cancer patients reconstructed with radial forearm free flap had better shoulder and speech functions but worse appearance domains. The results of our research provide important information for patients and physicians during their discussion of treatment programs for oral cavity cancers.
Subject(s)
Free Tissue Flaps , Mouth Neoplasms , Myocutaneous Flap , Plastic Surgery Procedures , Forearm/surgery , Free Tissue Flaps/surgery , Humans , Mouth Neoplasms/surgery , Myocutaneous Flap/surgery , Quality of Life , Plastic Surgery Procedures/methodsABSTRACT
Cutaneous T cell lymphoma is a generally indolent disease derived from skin-homing mature T cells. However, in advanced stages, cutaneous T cell lymphoma may manifest aggressive clinical behaviour and lead to a poor prognosis. The mechanism of disease progression in cutaneous T cell lymphoma remains unknown. This study, based on a large clinical cohort, found that IKZF2, an essential transcription factor during T cell development and differentiation, showed stage- dependent overexpression in the malignant T cells in mycosis fungoides lesions. IKZF2 is specifically over- expressed in advanced-stage mycosis fungoides lesions, and correlates with poor prognosis. Mechanistically, overexpression of IKZF2 promotes cutaneous T cell lymphoma progression via inhibiting malignant cell apoptosis and may contribute to tumour immune escape by downregulating major histocompatibility complex II molecules and up-regulating the production of anti-inflammatory cytokine interleukin-10 by malignant T cells. These results demonstrate the important role of IKZF2 in high-risk cutaneous T cell lymphoma and pave the way for future targeted therapy.