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N-type polycrystalline SnSe is considered as a highly promising candidates for thermoelectric applications due to facile processing, machinability, and scalability. However, existing efforts do not enable a peak ZT value exceeding 2.0 in n-type polycrystalline SnSe. Here, we realized a significant ZT enhancement by leveraging the synergistic effects of divacancy defect and introducing resonance level into the conduction band. The resonance level and increased density of states resulting from tungsten boost the Seebeck coefficient. The combination of the enhanced electrical conductivity (achieved by increasing carrier concentration through WCl6 doping and Se vacancies) and large Seebeck coefficient lead to a high power factor. Microstructural analyses reveal that the co-existence of divacancy defects (Se vacancies and Sn vacancies) and endotaxial W- and Cl-rich nanoprecipitates scatter phonons effectively, resulting in ultralow lattice conductivity. Ultimately, a record-high peak ZT of 2.2 at 773 K is achieved in n-type SnSe0.92 + 0.03WCl6.
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During the coronavirus disease 2019 (COVID-19) pandemic, clinical prevention, early diagnosis, and hematological monitoring were challenging areas. This study aims to compare risk factors and hematological and biochemical data in non-survivor group patients with COVID-19 versus survivor group patients. A total of 204 patients with COVID-19 were selected as research subjects from December 2022 to January 2023. We analyzed the age, sex, time from onset to admission, and laboratory test indicators upon admission. The differences between surviving and deceased patients and mortality-related risk factors were examined. Among the 204 patients, 168 survived, whereas 36 died during hospitalization. Significant differences were observed between the two groups with COVID-19 across various factors, including age (p < 0.0001), WBC count (p < 0.0001), RBC count (p < 0.05), neutrophils (p < 0.0001), lymphocytes (p < 0.05), mean corpuscular hemoglobin concentration (MCHC) (p < 0.0001), RBC distribution width-standard deviation (RDW-SD) (p < 0.0001), RBC distribution width coefficient of variation (RDW-CV) (p < 0.0001), aspartate aminotransferase (AST) (p < 0.05), albumin (ALB) (p < 0.0001), creatinine (CR) (p < 0.0001), uric acid (UA) (p < 0.0001), blood urea nitrogen (BUN) (p < 0.0001), plasma thrombin time (TT) (p < 0.05), prothrombin time (PT) (p < 0.0001), and D-dimer (p < 0.0001). Multivariate logistic analysis revealed that older age, CR, UA, and ALB were independent factors associated with death (p < 0.05). Elderly patients with underlying diseases, abnormal routine blood test indices, and abnormal renal function and coagulation indices are at an increased worse prognosis and should be identified early. Age, UA, CR, and ALB can be used as predictors to assess the worse prognosis in the hospital.
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Here, we combined Cd and In codoping with a simple hydrothermal synthesis method to prepare SnSe powders composed of nanorod-like flowers. After spark plasma sintering, its internal grains inherited well the morphological features of the precursor, and the multiscale microstructure included nanorod-shaped grains, high-density dislocations, and stacking faults, as well as abundant nanoprecipitates, resulting in an ultralow thermal conductivity of 0.15 W m-1 K-1 for the synthesized material. At the same time, Cd and In synergistically regulated the electrical conductivity and Seebeck coefficient of SnSe, leading to an enhanced power factor. Among them, Sn0.94Cd0.03In0.03Se achieved a peak ZT of 1.50 parallel to the pressing direction, representing an 87.5% improvement compared with pure SnSe. Notably, the material possesses isotropic ZT values parallel and perpendicular to the pressing direction, overcoming the characteristic anisotropy in thermal performance observed in previous polycrystalline SnSe-based materials. Our results provide a new strategy for optimizing the performance of thermoelectric materials through structural engineering.
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Novel materials displaying multiple exceptional properties are the backbone of the advancement of various industries. In the field of carbon materials, the combination of different properties has been extensively developed to satisfy diverse application scenarios, for instance, conductivity paired with exceptional hardness, outstanding toughness coupled with super-hardness, or heat resistance combined with super-hardness. In this work, a new carbon allotrope, bcc-C40 carbon, was predicted and investigated using first-principles calculations based on density functional theory. The allotrope exhibits unique structural features, including a combination of sp3 hybridized diatomic carbon and four-fold carbon chains. The mechanical and dynamic stability of bcc-C40 carbon has been demonstrated by its elastic constants and phonon spectra. Additionally, bcc-C40 carbon exhibits remarkable mechanical properties, such as zero homogeneous Poisson's ratio, superhardness with a value of 58 GPa, and stress-adaptive toughening. The analysis of the electronic properties demonstrates that bcc-C40 carbon is a semiconductor with an indirect band gap of 3.255 eV within the HSE06 functional, which increases with the increase in pressure. At a pressure of 150 GPa, bcc-C40 carbon transforms into a direct band gap material. These findings suggest the prospective use of bcc-C40 carbon as a superhard material and a novel semiconductor.
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Here, a high peak ZT of ≈2.0 is reported in solution-processed polycrystalline Ge and Cd codoped SnSe. Microstructural characterization reveals that CdSe quantum dots are successfully introduced by solution process method. Ultraviolet photoelectron spectroscopy evinces that CdSe quantum dots enhance the density of states in the electronic structure of SnSe, which leads to a large Seebeck coefficient. It is found that Ge and Cd codoping simultaneously optimizes carrier concentration and improves electrical conductivity. The enhanced Seebeck coefficient and optimization of carrier concentration lead to marked increase in power factor. CdSe quantum dots combined with strong lattice strain give rise to strong phonon scattering, leading to an ultralow lattice thermal conductivity. Consequently, high thermoelectric performance is realized in solution-processed polycrystalline SnSe by designing quantum dot structures and introducing lattice strain. This work provides a new route for designing prospective thermoelectric materials by microstructural manipulation in solution chemistry.
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Carbon materials have received great attention owing to their numerous allotropes and rich properties. Structure design and property tuning of carbon materials is one of the tremendous challenges in the field of materials science research. Here we carried out a bottom-up approach and identified a series of carbon allotropes with similar structures but distinct properties. The structures designed in this work had comparable energy stability to those previously predicted using the top-down global structure search method. Theoretical property calculations demonstrated that the three carbon structures with pure sp3 hybridization possessed semiconductive and superhard properties, while the carbon structure with sp2 + sp3 hybridization exhibited metallic features. Also, they differed significantly in the anisotropy of the mechanical properties. These carbon structures had some match to the unidentified phases in the detonation soot and could hopefully be synthesized by thermal "degassing" of high-pressure Na-C products. Our results propose a strategy to regulate properties through structural tuning, thus paving a way for the design and synthesis of materials with desirable properties.
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MnTe emerges as an enormous potential for medium-temperature thermoelectric applications due to its lead-free nature, high content of Mn in the earth's crust, and superior mechanical properties. Here, it is demonstrate that multiple valence band convergence can be realized through Pb and Ag incorporations, producing large Seebeck coefficient. Furthermore, the carrier concentration can be obviously enhance by Pb and Ag codoping, contributing to significant enhancement of power factor. Moreover, microstructural characterizations reveal that PbTe nanorods can be introduced into MnTe matrix by alloying Pb. This can modify the microstructure into all-scale hierarchical architectures (including PbTe nanorods, enhances point-defect scattering, dense dislocations and stacking faults), strongly lowering lattice thermal conductivity to a record low value of 0.376 W m-1 K-1 in MnTe system. As a result, an ultra-high ZT of 1.5 can be achieved in MnTe thermoelectric through all-scale hierarchical structuring, optimized carrier concentration, and valence band convergence, outperforming most of MnTe-based thermoelectric materials.
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AIMS: Interleukin-34 (IL-34) and macrophage colony-stimulating factor (CSF-1) have similar functions, such as promoting the formation of liver fibrosis. This study aimed to evaluate and compare the diagnostic value of serum IL-34 and CSF-1 for significant liver fibrosis in patients with chronic hepatitis B (CHB). METHODS: A total of 369 CHB patients, consisting of 208 HBeAg-negative patients and 161 HBeAg-positive patients, were enrolled in this study. Additionally, 72 healthy individuals served as healthy controls (HCs). Serum levels of IL-34 and CSF-1 were measured using the enzyme-linked immunosorbent assay method. Liver fibrosis grades were assessed using the modified Scheuer scoring system. RESULTS: Serum IL-34 and CSF-1 levels exhibited significant elevation in both HBeAg-negative and HBeAg-positive patients in comparison to HCs (p < 0.001). IL-34 emerged as an independent factor linked to significant liver fibrosis, whereas CSF-1 did not exhibit such an association. Receiver operating characteristic (ROC) analysis indicated higher areas under the curves (AUCs) for IL-34 (0.814, p < 0.001 and 0.673, p < 0.001) when diagnosing significant liver fibrosis in HBeAg-negative and HBeAg-positive patients, respectively, as opposed to CSF-1 (0.602, p < 0.001; 0.619, p = 0.385). Within the HBeAg-negative patient subgroup, the AUC for IL-34 surpassed that of FIB-4 (p = 0.009) and APRI (p = 0.045). CONCLUSION: Serum IL-34 has the potential to be a straightforward and practical biomarker that demonstrates superior performance to serum CSF-1 in the diagnosis of significant liver fibrosis in CHB patients, especially within the HBeAg-negative patients.
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Hepatite B Crônica , Interleucinas , Cirrose Hepática , Humanos , Antígenos E da Hepatite B , Hepatite B Crônica/complicações , Interleucinas/sangue , Cirrose Hepática/diagnóstico , Fator Estimulador de Colônias de Macrófagos/sangue , Curva ROCRESUMO
As a kind of endocrine-disrupting chemicals, BPA may affect the human placenta. Due to consumer unease about BPA, many manufacturers are using alternatives to BPA, such as BPS. However, some reports suggest that BPS may produce similar results to BPA. To understand how BPA/BPS leads to reduced synthesis of placental estradiol (E2), we conducted studies using a human choriocarcinoma cell (JEG-3) model for research. In this study. Elisa assay revealed that both BPA/BPS exposures decreased E2 synthesis in JEG-3 cells. The results of RT-PCR showed that both BPA and BPS could reduce the mRNA expression of CYP19A1, a key enzyme for E2 synthesis in JEG-3 cells. In addition, Western blot assay showed that BPA/BPS-induced ER-stress PERK/eIF2α/ATF4 signaling protein expression was increased. The expression of ROS in cells after exposure to BPA/BPS was detected using the 2,7-dichlorodihydrofluorescein diacetate (DCF-DA) method. The results of this experiment showed that BPA/BPS significantly induced an inhibition of ROS in JEG-3 cells. The present study concluded that, firstly, BPS exposure induced almost the same effect as BPA in reducing E2 synthesis in JEG-3 cells. Second, BPA/BPS exposure may reduce E2 synthesis in JEG-3 cells by increasing ROS levels and thus activating endoplasmic reticulum stress.
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Estradiol , Placenta , Gravidez , Feminino , Humanos , Estradiol/farmacologia , Placenta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Compostos Benzidrílicos/farmacologia , Transdução de Sinais , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismoRESUMO
The timely diagnosis and treatment of elevated intracranial pressure (ICP) reduces morbidity rates and prevents mortality. The aim of the present systematic review and meta-analysis was to determine the diagnostic accuracy of optic nerve sheath diameter (ONSD) vs. standard invasive ICP measurements in patients with traumatic brain injury (TBI). The PubMed, Embase, Web of Science and Cochrane Library databases were systematically searched for studies including adult patients with TBI with suspected elevated ICP, and the sonographic ONSD measurements were compared with those from a standard invasive method. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool by two independent authors. A bivariate random effects model was used to summarize the pooled sensitivity, specificity and diagnostic odds ratio (DOR). A total of eight prospective studies with 222 patients with TBI were included. The pooled sensitivity was 0.82 [95% confidence interval (CI), 0.75-0.88], the specificity was 0.82 (95% CI, 0.71-0.90) and the DOR was 17.75 (95% CI, 7.02-44.83) with partial evidence of heterogeneity. The accuracy of the area under the summary ROC was 0.87. An ultrasound-determined elevated ICP has reasonable performance indicators with high sensitivity and specificity in patients with TBI. As such, this method may be a useful complementary monitoring tool in acute care.
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Three novel hexagonal Si-C-N structures, namely SiC3N3, SiC7N6, and SiC13N14, were constructed on the basis of the α-Si3N4 crystal structure. The stability of the three structures is demonstrated by analyzing their elastic constants and phonon dispersion spectra and by calculating their formation energies. The calculated band structures and partial densities of states suggest that the SiC3N3 and SiC7N6 structures possess hole conductivity. The electron orbital analyses indicate that the SiC3N3 and SiC7N6 crystals possess three-dimensional and one-dimensional conductivity, respectively. SiC13N14 is a semiconductor with a wide bandgap of 4.39 eV. Based on two different hardness models and indentation shear stress calculations, the Vickers hardness values of SiC3N3, SiC7N6, and SiC13N14 are estimated to be 28.04/28.45/16.18 GPa, 31.17/34.19/20.24 GPa, and 40.60/41.59/36.40 GPa. This result indicates that SiC3N3 and SiC7N6 are conductive hard materials while SiC13N14 is a quasi superhard material.
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Compared with traditional structure prediction methods, the purposeful bottom-up approach is better able to obtain structures with specified performance. In this study, we established two novel carbon phases in purely sp2-bonded networks, termed H61-carbon and H62-carbon, using a self-assembling approach. These carbyne-connected carbon allotropes had helix chains joined by cumulative double-bond chains. We certified the new carbon allotropes to be dynamically and mechanically stable. Both of these carbon allotropes exhibited excellent mechanical properties, and they had metallic and superconductive characteristics featuring superconducting transition temperatures of 10 K (H61-carbon) and 7.4 K (H62-carbon), respectively. These results provide an important strategy for the design of novel carbon allotropes with specified properties.
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OBJECTIVE: We aimed to explore the mechanisms underlying paraquat (PQ)-induced damage using cell lines (NCTC1469, TC-1, TCMK-1) and bioinformatic analysis of the GSE153959 dataset. Assessment of changes in the expression of ferroptosis-related genes in cellular damage due to paraquat poisoning and the important value of these genes in the pathogenesis. METHODS: Data were retrieved from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) related to ferroptosis were identified by Venn plots and analyzed for enrichment. Proteins encoded by these DEGs were studied for interactions. qRT-PCR and western blotting analyses of cultured cells were used to determine the expression of ferroptosis-related DEGs and their corresponding protein levels. RESULTS: We identified 25 DEGs primarily involved in epidermal growth factor receptor signaling, apoptotic signaling pathways, endoplasmic reticulum (ER) stress, and ferroptosis. From these, we uncovered eight ferroptosis-related DEGs, four of which were involved in ER response and regulators of ferroptosis-Chac1 (ChaC glutathione specific gamma-glutamylcyclotransferase 1), Atf3 (activating transcription factor 3), Tfrc (transferrin receptor), and Slc7a11 (solute carrier family 7 member 11). Significant changes in mRNA and protein levels of CHAC1, ATF3, TFRC, and SLC7A11 were confirmed in PQ-exposed cells. CONCLUSION: ER stress and ferroptosis are critical for PQ-induced cell damage. CHAC1, ATF3, TFRC, and SLC7A11 are essential molecules implicated in PQ-induced ferroptosis that may serve as therapeutic targets for the amelioration of PQ poisoning.
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Ferroptose , Paraquat , Paraquat/toxicidade , Ferroptose/genética , Apoptose , Células Cultivadas , Linhagem CelularRESUMO
Traditional ceramics or metals cannot simultaneously achieve ultrahigh strength and high electrical conductivity. The elemental carbon can form a variety of allotropes with entirely different physical properties, providing versatility for tuning mechanical and electrical properties in a wide range. Here, by precisely controlling the extent of transformation of amorphous carbon into diamond within a narrow temperature-pressure range, we synthesize an in situ composite consisting of ultrafine nanodiamond homogeneously dispersed in disordered multilayer graphene with incoherent interfaces, which demonstrates a Knoop hardness of up to ~53 GPa, a compressive strength of up to ~54 GPa and an electrical conductivity of 670-1,240 S m-1 at room temperature. With atomically resolving interface structures and molecular dynamics simulations, we reveal that amorphous carbon transforms into diamond through a nucleation process via a local rearrangement of carbon atoms and diffusion-driven growth, different from the transformation of graphite into diamond. The complex bonding between the diamond-like and graphite-like components greatly improves the mechanical properties of the composite. This superhard, ultrastrong, conductive elemental carbon composite has comprehensive properties that are superior to those of the known conductive ceramics and C/C composites. The intermediate hybridization state at the interfaces also provides insights into the amorphous-to-crystalline phase transition of carbon.
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The traditional hardness-toughness tradeoff poses a substantial challenge for the development of superhard materials. Due to strong covalent bonds and intrinsic brittleness, the full advantage of microstructure engineering for enhanced mechanical properties requires further exploration in superhard materials. Here heterogeneous diamond-cBN composites were synthesized from a carefully prepared precursor (hBN microflakes uniformly wrapped by onion carbon nanoparticles) through phase transitions under high pressure and high temperature. The synthesized composites inherit the architecture of the precursors: cBN regions with an anisotropic profile that spans several micrometers laterally and several hundred nanometers in thickness are embedded in a nanograined diamond matrix with high-density nanotwins. A significantly high fracture toughness of 16.9 ± 0.8 MPa m1/2 is achieved, far beyond those of single-crystal diamond and cBN, without sacrificing hardness. A detailed TEM analysis revealed multiple toughening mechanisms closely related to the microstructure. This work sheds light on microstructure engineering in superhard materials for excellent mechanical properties.
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Superhard materials other than diamond and cubic boron nitride have been actively pursued in the past two decades. Cubic silicon carbide, i.e., ß-SiC, is a well-known hard material with typical hardness <30 GPa. Although nanostructuring has been proven to be effective in enhancing materials' hardness by virtue of the Hall-Petch effect, it remains a significant challenge to improve hardness of ß-SiC beyond the superhard threshold of 40 GPa. Here, the fabrication of nanocrystalline ß-SiC bulks is reported by sintering nanoparticles under high pressure and high temperature. These ß-SiC bulks are densely sintered with average grain sizes down to 10 nm depending on the sintering conditions, and the Vickers hardness increases with decreasing grain size following the Hall-Petch relation. Particularly, the bulk sintered under 25 GPa and 1400 °C shows an average grain size of 10 nm and an asymptotic Vickers hardness of 41.5 GPa. Boosting the hardness of ß-SiC over the superhard threshold signifies an important progress in superhard materials research. A broader family of superhard materials is in sight through successful implementation of nanostructuring in other hard materials such as BP.
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The aim of this study was to compare the diagnostic values of red blood cell distribution width-coefficient of variation (RDW-CV) and red blood cell distribution width-standard deviation (RDW-SD) in mid-pregnancy women with iron deficiency anemia (IDA). To obtain the results, 115 mid-pregnancy women with IDA, defined as the IDA group, and 142 healthy mid-pregnancy women, selected as the control group, were enrolled in this study. Hematological parameters and ferritin concentrations in the serum were analyzed. The efficiency of RDW-CV and RDW-SD to distinguish IDA from mid-pregnancy women was evaluated using receiver operating characteristic (ROC) curves. The RDW-SD value in the IDA group was significantly higher than that in the control group (p < 0.05), while the RDW-CV value did not differ between them (p = 0.84). Significantly negative correlations were found between RDW-CV (r = -0.297, p = 0.001), RDW-SD (r = -0.404, p = 0.000), and serum ferritin in the IDA group but not in the control group. For the diagnosis of IDA, RDW-CV and RDW-SD produced areas under the ROC curves of 0.58 and 0.84. To conclude, our results suggest that RDW-SD, but not RDW-CV, can be used as a diagnostic index of IDA for mid-pregnancy women.
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Mechanical properties of covalent materials can be greatly enhanced with strategy of nanostructuring. For example, the nanotwinned diamond with an isotropic microstructure of interweaved nanotwins and interlocked nanograins shows unprecedented isotropic mechanical properties. How the anisotropic microstructure would impact on the mechanical properties of diamond has not been fully investigated. Here, we report the synthesis of diamond from superaligned multiwalled carbon nanotube films under high pressure and high temperature. Structural characterization reveals preferentially oriented diamond nanotwin bundles with an average twin thickness of ca. 2.9 nm, inherited from the directional nanotubes. This diamond exhibits extreme mechanical anisotropy correlated with its microstructure (e.g., the average Knoop hardness values measured with the major axis of the indenter perpendicular and parallel to nanotwin bundles are 233 ± 8 and 129 ± 9 GPa, respectively). Molecular dynamics simulation reveals that, in the direction perpendicular to the nanotwin bundles, the dense twin boundaries significantly hinder the motion of dislocations under indentation, while such a resistance is much weaker in the direction along the nanotwin bundles. Current work verifies the hardening effect in diamond via nanostructuring. In addition, the mechanical properties can be further tuned (anisotropy) with microstructure design and modification.
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This publisher's note contains corrections to Opt. Lett.46, 1478 (2021)OPLEDP0146-959210.1364/OL.418996.
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Thin-film lithium-niobate-on-insulator (LNOI) is a very attractive platform for optical interconnect and nonlinear optics. It is essential to enable lithium niobate photonic integrated circuits with low power consumption. Here we present an edge-coupling Mach-Zehnder modulator on the platform with low fiber-chip coupling loss of 0.5 dB/facet, half-wave voltage Vπ of 2.36 V, electro-optic (EO) bandwidth of 60 GHz and an efficient thermal-optic phase shifter with half-wave power of 6.24 mW. In addition, we experimentally demonstrate single-lane 200 Gbit/s data transmission utilizing a discrete multi-tone signal. The LNOI modulator demonstrated here shows great potential in energy-efficient large-capacity optical interconnects.