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Halide perovskites are of great interest due to their exceptional optical and optoelectronic properties. However, thermal conductivity of many halide perovskites remains unexplored. In this study, an ultralow lattice thermal conductivity κL (0.24 W m-1 K-1 at 300 K) is reported and its weak temperature dependence (≈T-0.27) in an all-inorganic vacancy-ordered halide perovskite, Cs3Bi2Br9. The intrinsically ultralow κL can be attributed to the soft low-lying phonon modes with strong anharmonicity, which have been revealed by combining experimental heat capacity and Raman spectroscopy measurements, and first-principles calculations. It is shown that the highly anharmonic phonons originate from the Bi 6s2 lone pair expression with antibonding states of Bi 6s and Br 4p orbitals driven by the dynamic BiBr6 octahedral distortion. Theoretical calculations reveal that these low-energy phonons are mostly contributed by large Br motions induced dynamic distortion of BiBr6 octahedra and large Cs rattling motions, verified by the synchrotron X-ray pair distribution function analysis. In addition, the weak temperature dependence of κL can be traced to the wave-like tunneling of phonons, induced by the low-lying phonon modes. This work reveals the strong anharmonicity and wave-like tunneling of low-energy phonons for designing efficient vacancy-ordered halide perovskites with intrinsically low κL.
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Grain boundary plays a vital role in thermoelectric transports, leading to distinct properties between single crystals and polycrystals. Manipulating the grain boundary to realize good thermoelectric properties in polycrystals similar as those of single crystals is a long-standing task, but it is quite challenging. Herein, we develop a liquid-phase sintering strategy to successfully introduce Mg2Cu nano-sintering-aid into the grain boundaries of Mg3(Bi, Sb)2-based materials. The nano-aid helps to enlarge the average grain size to 23.7 µm and effectively scatter phonons, leading to excellent electrical transports similar as those of single crystals and ultralow lattice thermal conductivity as well as exceptional thermoelectric figure of merit (1.5 at 500 K) and conversion efficiency (7.4% under temperature difference of 207 K). This work provides a simple but effective strategy for the fabrication of high-performance polycrystals for large-scale applications.
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Ductile inorganic thermoelectric (TE) materials open a new approach to develop high-performance flexible TE devices. N-type Ag2(S,Se,Te) and p-type AgCu(Se,S,Te) pseudoternary solid solutions are two typical categories of ductile inorganic TE materials reported so far. Comparing with the Ag2(S,Se,Te) pseudoternary solid solutions, the phase composition, crystal structure, and physical properties of AgCu(Se,S,Te) pseudoternary solid solutions are more complex, but their relationships are still ambiguous now. In this work, via systematically investigating the phase composition, crystal structure, mechanical, and TE properties of about 60 AgCu(Se,S,Te) pseudoternary solid solutions, the comprehensive composition-structure-property phase diagrams of the AgCuSe-AgCuS-AgCuTe pseudoternary system is constructed. By mapping the complex phases, the "ductile-brittle" and "n-p" transition boundaries are determined and the composition ranges with high TE performance and inherent ductility are illustrated. On this basis, high performance p-type ductile TE materials are obtained, with a maximum zT of 0.81 at 340 K. Finally, flexible in-plane TE devices are prepared by using the AgCu(Se,S,Te)-based ductile TE materials, showing high output performance that is superior to those of organic and inorganic-organic hybrid flexible devices.
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Mode converters, crucial elements within photonic integrated circuits (PICs) designed for multimode optical transmission and switching systems, present a challenge due to their bulky structures in thin-film lithium niobate (TFLN) integrated platforms, which are incompatible with the compact and efficient nature desired for dense PICs. In this work, we propose TE1-TE0, TE2-TE0, and TE3-TE0 mode converters in shallowly etched TFLN, within small footprints. The experimental results show that the insertion loss is 0.4 dB, 0.6 dB, and 0.5 dB for the compact TE1-TE0, TE2-TE0, and TE3-TE0 mode converters, respectively, and these devices can be operated within a wide 1 dB bandwidth (BW) over 100 nm. This work facilitates the development of low-loss, broadband, and compact monolithically integrated photonic devices for future multimode communication networks in TFLN integrated platforms.
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Cu-based liquid-like thermoelectric materials have garnered tremendous attention due to their inherent ultralow lattice thermal conductivity. However, their practical application is hampered by stability issues under a large current or temperature gradient. It has been reported that introduction of copper vacancies can enhance the chemical stability, whereas the micromechanism behind this macroscopic improvement still remains unknown. Here, we have established a quasi in situ TEM method to examine and compare the structural evolution of Cu2-xS0.2Se0.8 (x = 0, 0.05) under external electric fields. It is then found that the preset Cu vacancies could favor the electric-induced formation of a more stable intermediate phase, i.e., the hexagonal CuSe-type structure in the form of either lamellar defects (majorly) or long-range order (minorly), in which ordering of S and Se also occurred. Thereby, copper and chalcogen atoms could largely be solidified into the matrix, and the elemental deposition and evaporation process is mitigated under an electric field.
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Searching for new high-performance thermoelectric (TE) materials that are economical and environmentally friendly is an urgent task for TE society, but the advancements are greatly limited by the time-consuming and high cost of the traditional trial-and-error method. The significant progress achieved in the computing hardware, efficient computing methods, advance artificial intelligence algorithms, and rapidly growing material data have brought a paradigm shift in the investigation of TE materials. Many electrical and thermal performance descriptors are proposed and efficient high-throughput (HTP) calculation methods are developed with the purpose to quickly screen new potential TE materials from the material databases. Some HTP experiment methods are also developed which can increase the density of information obtained in a single experiment with less time and lower cost. In addition, machine learning (ML) methods are also introduced in thermoelectrics. In this review, the HTP strategies in the discovery of TE materials are systematically summarized. The applications of performance descriptor, HTP calculation, HTP experiment, and ML in the discovery of new TE materials are reviewed. In addition, the challenges and possible directions in future research are also discussed.
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Critical phenomena are one of the most captivating areas of modern physics, whereas the relevant experimental and theoretical studies are still very challenging. Particularly, the underlying mechanism behind the anomalous thermoelectric properties during critical phase transitions remains elusive, i.e., the current theoretical models for critical electrical transports are either qualitative or solely focused on a specific transport parameter. Herein, we develop a quantitative theory to model the electrical transports during critical phase transitions by incorporating both the band broadening effect and carrier-soft TO phonon interactions. It is found that the band-broadening effect contributes an additional term to Seebeck coefficient, while the carrier-soft TO phonon interactions greatly affects both electrical resistivity and Seebeck coefficient. The universality and validity of our model are well confirmed by experimental data. Furthermore, the features of critical phase transitions are effectively tuned. For example, alloying S in Cu2Se can reduce the phase transition temperature but increase the phase transition parameter b. The maximum thermoelectric figure of merit zT is pushed to a high value of 1.3 at the critical point (377 K), which is at least twice as large as those of normal static phases. This work not only provides a clear picture of the critical electrical transports but also presents new guidelines for future studies in this exciting area.
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The recently discovered plastic/ductile inorganic thermoelectric (TE) materials open a new avenue for the fabrication of high-efficiently flexible TE devices, which can utilize the small temperature difference between human body and environment to generate electricity. However, the maximum power factor (PF) of current plastic/ductile TE materials is usually around or less than 10 µW cm-1 K-2 , much lower than the classic brittle TE materials. In this work, a record-high PF of 18.0 µW cm-1 K-2 at 375 K in plastic/ductile bulk SnSe2 -based crystals is reported, superior to all the plastic inorganic TE materials and flexible organic TE materials reported before. The origin of such high PF is from the modulation of material's stacking forms and polymorph crystal structures via simultaneously doping Cl/Br at Se-site and intercalating Cu inside the van der Waals gap, leading to the significantly enhanced carrier concentrations and mobilities. An in-plane fully flexible TE device made of the plastic/ductile SnSe2 -based crystals is successfully developed to show a record-high normalized maximum power density to 0.18 W m-1 under a temperature difference of 30 K. This work indicates that the plastic/ductile material can realize high TE power factor to achieve large output electric power density in flexible TE technology.
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BACKGROUND: Triple-negative breast cancer (TNBC) is associated with a dismal prognosis. Immune checkpoint inhibitors have shown promising antitumor activity in neoadjuvant settings. This single-arm, phase II trial aimed to evaluate the efficacy and safety of camrelizumab plus chemotherapy as the neoadjuvant therapy (NAT) in early TNBC. METHODS: Patients received eight cycles of camrelizumab plus nonplatinum-based chemotherapy. The primary endpoint was total pathological complete response (pCR). Secondary endpoints included the breast pathological complete response (bpCR), adverse events (AEs). Multiomics biomarkers were assessed as exploratory objective. RESULTS: Twenty of 23 TNBC patients receiving NAT underwent surgery, with the total pCR rate of 65% (13/20) and bpCR rate of 70% (14/20). Grade ≥3 treatment-related AEs were observed in 14 (60.9%) patients, with the most common AE being neutropenia (65.2%). Tumor immune microenvironment was analyzed between pCR and non-pCR samples before and after the NAT. Gene expression profiling showed a higher immune infiltration in pCR patients than non-pCR patients in pre-NAT samples. Through establishment of a predictive model for the NAT efficacy, TAP1 and IRF4 were identified as the potential predictive biomarkers for response to the NAT. Gene set enrichment analysis revealed the glycolysis and hypoxia pathways were significantly activated in non-pCR patients before the NAT, and this hypoxia was aggravated after the NAT. CONCLUSION: Camrelizumab plus nonplatinum-based chemotherapy shows a promising pCR rate in early-stage TNBC, with an acceptable safety profile. TAP1 and IRF4 may serve as potential predictive biomarkers for response to the NAT. Aggravated hypoxia and activated glycolysis after the NAT may be associated with the treatment resistance.
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Anticorpos Monoclonais Humanizados , Neoplasias de Mama Triplo Negativas , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Hipóxia/tratamento farmacológico , Hipóxia/etiologia , Terapia Neoadjuvante , Projetos Piloto , Resultado do Tratamento , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Microambiente Tumoral , FemininoRESUMO
The flexible thermoelectric technique, which can convert heat from the human body to electricity via the Seebeck effect, is expected to provide a peerless solution for the power supply of wearables. The recent discovery of ductile semiconductors has opened a new avenue for flexible thermoelectric technology, but their power factor and figure-of-merit values are still much lower than those of classic thermoelectric materials. Herein, we demonstrate the presence of morphotropic phase boundary in Ag2Se-Ag2S pseudobinary compounds. The morphotropic phase boundary can be freely tuned by adjusting the material thermal treatment processes. High-performance ductile thermoelectric materials with excellent power factor (22 µWcm-1 K-2) and figure-of-merit (0.61) values are realized near the morphotropic phase boundary at 300 K. These materials perform better than all existing ductile inorganic semiconductors and organic materials. Furthermore, the in-plane flexible thermoelectric device based on these high-performance thermoelectric materials demonstrates a normalized maximum power density reaching 0.26 Wm-1 under a temperature gradient of 20 K, which is at least two orders of magnitude higher than those of flexible organic thermoelectric devices. This work can greatly accelerate the development of flexible thermoelectric technology.
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Information security has gained increasing attention in the past decade, leading to the development of advanced materials for anti-counterfeiting, encryption and instantaneous information display. However, it remains challenging to achieve high information security with simple encryption procedures and low-energy stimuli. Herein, a series of strain/temperature-responsive liquid crystal elastomers (LCEs) are developed to achieve dual-modal, multi-level information encryption and real-time, rewritable transient information display. The as-prepared polydomain LCEs can change from an opaque state to a transparent state under strain or temperature stimuli, with the transition strains or temperatures highly dependent on the concentration of long-chain flexible spacers. Information encrypted by different LCE inks can be decrypted under specific strains or temperatures, leading to multi-level protection of information security. Furthermore, with the combination of the phase transition of polydomain LCEs and the photothermal effect of multi-walled carbon nanotubes (MWCNTs), we achieved a repeatable transient information display by using near-infrared (NIR) light as a pen for writing. This study provides new insight into the development of advanced encryption materials with versatility and high security for broad applications.
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OBJECTIVE: Internal mammary nodes are important in breast cancer prognosis, but their diagnosis is often missed in clinical practice, leading to inaccurate staging and treatment. We developed a validated nomogram to predict the presence of internal mammary sentinel nodes (IMSN) metastasis. METHODS: A total of 864 sequential IMSN biopsy procedures from a prospective studies database of 1505 cases were used for model development and validation. Multivariable logistic regression was performed on 519 sequential IMSN biopsy procedures from multi-center data between August 2018 and July 2022 to predict the presence of IMSN metastasis. A nomogram was developed based on the logistic regression model and subsequently applied to 345 sequential IMSN biopsy procedures from single-center data between November 2011 and July 2018. The model's discrimination was assessed using the area under the receiver operating characteristic curve. RESULTS: The overall frequency of IMSN metastasis was 17.0% in our study. A predictive model for IMSN metastasis was constructed using tumor size, tumor location, lymphovascular invasion, the number of positive axillary nodes (P < 0.05 for all variables in multivariate analysis), and histological grade (P < 0.05 only in univariate analysis). The nomogram was accurate, with a concordance index of 0.84 in the bootstrapping analysis and an area under the receiver operating characteristic curve of 0.80 in the validation population. CONCLUSION: Our nomogram provides an accurate and validated multivariable predictive model for estimating the individual likelihood of having IMSN metastasis. This may be useful for personalized treatment decisions regarding internal mammary radiotherapy in breast cancer patients.
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Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/cirurgia , Nomogramas , Metástase Linfática/patologia , Estudos Prospectivos , Linfonodos/patologia , Biópsia de Linfonodo SentinelaRESUMO
Calcium peroxide (CP) is an oxidizing agent that can gradually release hydrogen peroxide (HP) to achieve selective killing of cyanobacteria in water blooms, and reduce the phosphorus content in the water column. Despite the potential of CP for use in cyanobacterial water bloom disposal, there is a lack of research on the mechanism of oxidative damage on cyanobacterial cells by calcium peroxide. Further studies are required to comprehend the underlying scientific principles and potential risks and benefits of applying this approach to cyanobacteria disposal. In this investigation, we employed varying doses of CP for the treatment of Microcystis aeruginosa (M. aeruginosa), which resulted in the following findings: (1) the HP released from CP can damage the photosystem II of M. aeruginosa, reduce cell photosynthetic pigment content, intensify the degree of membrane lipid peroxidation, and increase the extracellular protein content; (2) CP significantly increased the soluble extracellular polysaccharide (sEPS) and bound extracellular polysaccharide (bEPS) content of cells (p < 0.05), causing the cells to exist as agglomerates and effectively allowing them to flocculate and precipitate, reducing the turbidity of the water body; (3) The increased dose elevated the pH and calcium ions significantly decreased the orthophosphate content, resulting in an increase in extracellular alkaline phosphatase activity, but possibly increasing the total extracellular nitrogen content. These results suggested that CP is an effective chemical algaecide for cyanobacteria, and has the potential to be applied to dispose of cyanobacterial blooms while reducing the phosphorus content of the water column and further inhibiting the growth and proliferation of cells.
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Microcystis , Peróxido de Hidrogênio , Oxidantes , FósforoRESUMO
Chronic stress refers to continuous emotional changes and psychological pressure that individuals experience when they are unable to adjust and stabilize the internal environment over an extended period. It can increase the pressure on endocrine mediators and cytokines in the circulation, as well as tissues throughout the hypothalamic-pituitary-adrenaline (HPA) axis and sympathetic nervous system (SNS); thus, evolving the internal environment of the tumor. This review assesses several key issues, involving psychosocial factors, and integrates clinical, cellular, and molecular studies-as well as the latest research progress-to provide a mechanistic understanding regarding breast oncopsychology. We propose that chronic stress contributes to large individual diferences in the prognosis of breast cancer survivors because they change the basic physiological processes of the endocrine and immune systems, which in turn regulate tumor growth. The study of psychological and physiological reactions of breast cancer patients suggests a new idea for psychological intervention and clinical treatment for breast cancer patients.
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Materials with low thermal conductivity have received significant attention across various research fields, including thermal insulation materials, thermal barrier coatings, and thermoelectric materials. Exploring novel materials with intrinsically low thermal conductivity and investigating their phonon transport properties, chemical bonding, and atomic coordination are crucial. In this study, a novel ternary sulfide is successfully discovered, Cu2 ZrS3 , which is achieved by introducing copper ions into both the interlayer and intralayer of ZrS2 . The resulting structure encompasses various coordination forms within each layer, such as [CuS4 ], [ZrS6 ], and [CuS3 ], leading to pronounced phonon anharmonicity induced by the asymmetric bonding of tri-coordinated Cu atoms within the [ZrS6 ] layer. As a result, Cu2 ZrS3 exhibits intrinsically low lattice thermal conductivity (κL ) of about 0.83 W m-1 K-1 at 300 K and 0.35 W m-1 K-1 at 683 K, which are in the exceptionally low level among sulfides. In comparison to the conventional approach of inserting guests between layers, the substitution of atoms within layers provides a novel and effective strategy for designing low κL materials in transition metal dichalcogenides (TMDCs).
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Ge-Sb-Te compounds (GST), the well-known phase-change materials, are considered to be promising thermoelectric (TE) materials due to their decent thermoelectric performance. While Ge2Sb2Te5 and GeSb2Te4 have been extensively studied, the TE performance of GeSb4Te7 has not been well explored. Reducing the excessive carrier concentration is crucial to improving TE performance for GeSb4Te7. In this work, we synthesize a series of Se-alloyed GeSb4Te7 compounds and systematically investigate their structures and transport properties. Raman analysis reveals that Se alloying introduces a new vibrational mode of GeSe2, enhancing the interatomic interaction forces within the layers and leading to the reduction of carrier concentration. Additionally, Se alloying also increases the effective mass and thus improves the Seebeck coefficient of GeSb4Te7. The decrease in carrier concentration reduces the carrier thermal conductivity, depressing the total thermal conductivity. Finally, a maximum zT value of 0.77 and an average zT value of 0.48 (300-750 K) have been obtained in GeSb4Te5.5Se1.5. This work investigates the Raman vibration modes and the TE performance in Se-alloyed GeSb4Te7 sheddinglight on the performance optimization of other GST materials.
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PURPOSE: We aimed to identify effectiveness-associated indicators and evaluate the optimal tumor reduction rate (TRR) after two cycles of neoadjuvant chemotherapy (NAC) in patients with invasive breast cancer. METHODS: This retrospective case-control study included patients who underwent at least four cycles of NAC at the Department of Breast Surgery between February 2013 and February 2020. A regression nomogram model for predicting pathological responses was constructed based on potential indicators. RESULTS: A total of 784 patients were included, of whom 170 (21.68%) reported pathological complete response (pCR) after NAC and 614 (78.32%) had residual invasive tumors. The clinical T stage, clinical N stage, molecular subtype, and TRR were identified as independent predictors of pCR. Patients with a TRR > 35% were more likely to achieve pCR (odds ratio, 5.396; 95% confidence interval [CI], 3.299-8.825). The receiver operating characteristic (ROC) curve was plotted using the probability value, and the area under the ROC curve was 0.892 (95% CI, 0.863-0.922). CONCLUSION: TRR > 35% is predictive of pCR after two cycles of NAC, and an early evaluation model using a nomogram based on five indicators, age, clinical T stage, clinical N stage, molecular subtype, and TRR, is applicable in patients with invasive breast cancer.
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Neoadjuvant therapy (NAT) is currently recommended to patients with human epidermal growth factor receptor 2-positive breast cancer (HER2+ BC) that typically exhibit a poor prognosis. The tumor immune microenvironment profoundly affects the efficacy of NAT. However, the correlation between tumor-infiltrating lymphocytes or their specific subpopulations and the response to NAT in HER2+ BC remains largely unknown. In our study, the immune infiltration status of 295 patients was classified as "immune-rich" or "immune-poor" phenotypes. The "immune-rich" phenotype was significantly positively related to pathological complete response (pCR). Ten genes were correlated with both pCR and the immune phenotype based on the results of spline and logistic regression. We constructed a generalized non-linear model combining linear and non-linear gene effects and successfully validated its predictive power using an internal and external validation set (AUC = 0.819, 0.797; respectively) and a clinical set (accuracy = 0.75).
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OBJECTIVE: Neoadjuvant therapy (NAT) has been widely implemented as an essential treatment to improve therapeutic efficacy in patients with locally-advanced cancer to reduce tumor burden and prolong survival, particularly for human epidermal growth receptor 2-positive and triple-negative breast cancer. The role of peripheral immune components in predicting therapeutic responses has received limited attention. Herein we determined the relationship between dynamic changes in peripheral immune indices and therapeutic responses during NAT administration. METHODS: Peripheral immune index data were collected from 134 patients before and after NAT. Logistic regression and machine learning algorithms were applied to the feature selection and model construction processes, respectively. RESULTS: Peripheral immune status with a greater number of CD3+ T cells before and after NAT, and a greater number of CD8+ T cells, fewer CD4+ T cells, and fewer NK cells after NAT was significantly related to a pathological complete response (P < 0.05). The post-NAT NK cell-to-pre-NAT NK cell ratio was negatively correlated with the response to NAT (HR = 0.13, P = 0.008). Based on the results of logistic regression, 14 reliable features (P < 0.05) were selected to construct the machine learning model. The random forest model exhibited the best power to predict efficacy of NAT among 10 machine learning model approaches (AUC = 0.733). CONCLUSIONS: Statistically significant relationships between several specific immune indices and the efficacy of NAT were revealed. A random forest model based on dynamic changes in peripheral immune indices showed robust performance in predicting NAT efficacy.