21 research outputs found
Hydrothermal Synthesis of 1T-MoS2/Pelagic Clay Composite and Its Application in the Catalytic Reduction of 4-Nitrophenol
Pelagic clay is an emerging marine resource with strong hydrophilicity, fine particles and a large specific surface area. In this work, a 1T-MoS2/pelagic clay composite was fabricated by hydrothermal synthesis. In the composite, 1T-MoS2 nanosheets are evenly dispersed on the surface of the clay minerals, significantly reducing the agglomeration of MoS2. Compared with pure 1T-MoS2, the 1T-MoS2 nanosheets generated on the surface of pelagic clay have significantly smaller lateral dimensions and thicknesses. Moreover, the specific surface area is much larger than that of the pure 1T-MoS2 nanosheets fabricated by the same method, indicating that the active sites of the MoS2 sheets are fully exposed. In addition, the composite exhibited excellent hydrophilicity, leading to a high dispersibility in aqueous solutions. In this work, the composite was used as a catalyst in the reduction of 4-nitrophenol (4-NP), and the conversion of 4-NP reached up to 96.7%. This result shows that the 1T-MoS2/pelagic clay composite is a promising catalyst in a variety of reactions
Efficient algorithm for globally computing the min–max linear fractional programming problem
In this paper, we consider the min–max linear fractional programming problem (MLFP) which is NP-hard. We first introduce some auxiliary variables to derive an equivalent problem of the problem (MLFP). An outer space branch-and-bound algorithm is then designed by integrating some basic operations such as the linear relaxation method and branching rule. The global convergence of the proposed algorithm is proved by means of the subsequent solutions of a series of linear relaxation programming problems, and the computational complexity of the proposed algorithm is estimated based on the branching rule. Finally, numerical experimental results demonstrate the proposed algorithm can be used to efficiently compute the globally optimal solutions of test examples
Three-dimensional visualization of the Autographa californica multiple nucleopolyhedrovirus occlusion-derived virion envelopment process gives new clues as to its mechanism
AbstractBaculoviruses produce two virion phenotypes, occlusion-derived virion (ODV) and budded virion (BV). ODV envelopment occurs in the nucleus. Morphogenesis of the ODV has been studied extensively; however, the mechanisms underlying microvesicle formation and ODV envelopment in nuclei remain unclear. In this study, we used electron tomography (ET) together with the conventional electron microscopy to study the envelopment of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ODV. Our results demonstrate that not only the inner but also the outer nuclear membrane can invaginate and vesiculate into microvesicles and that intranuclear microvesicles are the direct source of the ODV membrane. Five main events in the ODV envelopment process are summarized, from which we propose a model to explain this process
Combined HIF-1α and SHH Up-Regulation Is a Potential Biomarker to Predict Poor Prognosis in Postoperative Hepatocellular Carcinoma
Background Hypoxia-inducible factor-1α (HIF-1α) or sonic hedgehog (SHH) is associated with hepatocellular carcinoma (HCC) progression. Hypoxia inhibits ferroptosis, which induces cancer cell death. However, the correlation between the combined HIF-1α and SHH up-regulation with prognosis, and the association between SHH and ferroptosis remain unclear. This study aimed to investigate them. Methods We detected the expression of HIF-1α and SHH in HCC. Cox regression, clinical data, and Kaplan–Meier analyses were performed. In vitro cell experiments verified the relationship between HIF-1α and SHH, and observed the invasion of hypoxic HCC cells. The correlation between SHH and ferroptosis was also analyzed. Results HIF-1α and SHH expression levels were significantly correlated with HCC (p < 0.0001). HIF-1α and SHH expression levels were found to be associated with TNM stage (p = 0.0121, p = 0.0078, respectively), vascular invasion (p < 0.0001, p < 0.0001, respectively), and recurrence (p = 0.0212, p = 0.0392, respectively). The combined upregulation of HIF-1α and SHH was an independent factor for predicting the overall survival (OS) of patients with HCC (p = 0.003), who had the shortest OS (p = 0.0009). SHH paralleled the increase in HIF-1α expression, which promotes cancer cell invasion. The upregulation of SHH was related to the inhibition of the expression of ferroptosis-related factors (FANCD2, p < 0.0001 and FTH1, p = 0.0009) in HCC. Conclusion Combined HIF-1α and SHH upregulation is a potentially poor prognosis indicator in patients with HCC because the upregulation of SHH inhibits ferroptosis in hypoxic cancer cells
Colored Basalt Fibers Preparation via One-Step Drawing Lubricated by a Composite Sizing Consisted with Rhodamine B
The continuous basalt fibers (BFs) dyed with cationic dyes (RhB) were prepared through one-step drawing strategy using miscible liquids of phosphorylating starch (PS) cross-linked polyvinyl alcohol (PVA) and sodium silicate (SS) as infiltration agents. The new method of dyeing was relied on the residual temperature of melt drawing, and the dye molecules were lubricated onto fibers firmly. Different means were used to characterize the color fibers, and a compact layer was formed on the fiber surface. The prepared composite fibers (PVA-SS-PS-RhB/BF) exhibited stable color fastness (washing and rubbing fastness achieved to 4–5 grade). The crosslinking significantly improved the water resistance with dissolved residue up to 80%, and the heightened glass transition temperature was observed. The breaking force of dyed fibers was observed to be 50.3% higher than that of raw fibers, and the breaking elongation was 71.8% higher than the original fibers
Paleomagnetic constraints on the Mesozoic drift of the Lhasa terrane (Tibet) from Gondwana to Eurasia
The Mesozoic plate tectonic history of Gondwana-derived crustal blocks of the Tibetan Plateau is hotly debated, but so far, paleomagnetic constraints quantifying their paleolatitude drift history remain sparse. Here, we compile existing data published mainly in Chinese literature and provide a new, high-quality, well-dated paleomagnetic pole from the ca. 180 Ma Sangri Group volcanic rocks of the Lhasa terrane that yields a paleolatitude of 3.7°S ± 3.4°. This new pole confirms a trend in the data that suggests that Lhasa drifted away from Gondwana in Late Triassic time, instead of Permian time as widely perceived. A total northward drift of ~4500 km between ca. 220 and ca. 130 Ma yields an average south-north plate motion rate of 5 cm/yr. Our results are consistent with either an Indian or an Australian provenance of Lhasa
Efficacy of Adjuvant Transarterial Chemoembolization after Radical Hepatectomy in Solitary Hepatocellular Carcinoma Patients: A Retrospective Study
Background: More and more studies have suggested that hepatocellular carcinoma (HCC) patients with high-risk recurrence factors can benefit the most from postoperative adjuvant transarterial chemoembolization (PA-TACE) for its potential effect in delaying cancer recurrence. However, it remains unclear if solitary HCC (SHCC) patients particularly those without high-risk recurrence factors should also receive PA-TACE. This study aimed to analyze the efficacy of PA-TACE in them. Methods: Retrospectively, we enrolled 123 SHCC patients who either received radical hepatectomy alone (No TACE group, n = 39) or followed by PA-TACE (PA-TACE group, n = 84) in our institution. Prognostic risk factors, disease-free survival (DFS), and overall survival (OS) were analyzed using the Cox proportional hazard regression model, the Kaplan-Meier method, and the log-rank test. Results: Liver cirrhosis was the only independent risk factor for SHCC patients. Overall, the PA-TACE group had no improved OS (P = 0.977) but worse DFS compared with the No TACE group (P = 0.045). Consistently, in subgroup analysis, SHCC patients with negative microvascular invasion (MVI), tumor size ≤ 5 cm and preoperative alpha-fetoprotein (AFP) < 400 ng/ml had similar OS (P = 0.466, P = 0.864, P = 0.488, respectively) but even worse DFS (P = 0.035, P = 0.040, P = 0.019, respectively) than those in the No TACE group. Besides, there was no significant difference in DFS and OS between the two groups of SHCC patients with liver cirrhosis (P = 0.342, P = 0.941, respectively). Conclusions: PA-TACE may not improve the long-term survival of SHCC patients, but may even potentially promote their postoperative tumor recurrence, especially for those with MVI-negative, tumor size ≤ 5 cm, and preoperative AFP < 400 ng/ml
Critical Role of Groundwater Inflow in Sustaining Lake Water Balance on the Western Tibetan Plateau
It is difficult to quantify the amount of groundwater inflow on the Tibetan Plateau (TP), yet it can be critically important for sustaining lake water balance. Here we show that most endorheic lakes on the western TP exhibited considerable water level increase during the ice-covered period, which contrasts with lakes in other regions of the TP. An analysis of lake water balance attributes this water surplus to significant groundwater inflow, which is estimated to be about 59%–66% of total inflow into lakes. The groundwater inflow occurred after the 2000s, which is consistent with the rapid lake expansion and significant increase in precipitation. We suggest that the groundwater inflow is mainly related to large-scale active faults in the limestone bedrock and sufficient meltwater from high elevations. Our results imply that groundwater may be deeply involved in the water cycle and modify the seasonal and inter-annual lake variations on the western TP
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The early Eocene rise of the Gonjo Basin, SE Tibet: From low desert to high forest
Views differ on the uplift history of the SE Tibetan Plateau and causal geodynamic mechanisms, yet reliable age-constrained paleoaltimetry in this region could test growth models of the entire plateau. Here we apply carbonate clumped isotope thermometry to well-dated carbonate paleosols and marls in the Gonjo Basin, SE Tibet, to reveal the topographic evolution of the basin. The sedimentary ages of carbonates of the lower and upper Ranmugou Formation are constrained to 54-50 Ma and 44-40 Ma, respectively. The temperature derived from carbonate clumped isotope thermometry indicates the mean annual air temperature (MAAT) of the Gonjo Basin in the early Eocene was ∼24 °C, which is consistent with the warm climate indicated by palm fossils. The MAAT of the basin in the middle Eocene was ∼7 °C, 17 °C cooler than in the early Eocene. Carbonate clumped oxygen isotope thermometry-based paleoaltimetry shows the Gonjo Basin experienced a rapid uplift of 3.1 km, from ∼0.7 km in the early Eocene to ∼3.8 km in the middle Eocene. This rise explains the marked cooling. As a cause of this rapid rise, and the associated regional climate change transforming the landscape from desert to forest, we invoke crustal deformation and thickening induced by intracontinental subduction between the Lhasa and Qiangtang terranes that comprise the core of the Tibet
NIR-II fluorescence-guided liver cancer surgery by a small molecular HDAC6 targeting probeResearch in context
Summary: Background: Hepatocellular carcinoma (HCC) is the sixth most common malignancy globally and ranks third in terms of both mortality and incidence rates. Surgical resection holds potential as a curative approach for HCC. However, the residual disease contributes to a high 5-year recurrence rate of 70%. Due to their excellent specificity and optical properties, fluorescence-targeted probes are deemed effective auxiliary tools for addressing residual lesions, enabling precise surgical diagnosis and treatment. Research indicates histone deacetylase 6 (HDAC6) overexpression in HCC cells, making it a potential imaging biomarker. This study designed a targeted small-molecule fluorescent probe, SeCF3-IRDye800cw (SeCF3-IRD800), operating within the Second near-infrared window (NIR-II, 1000–1700 nm). The study confirms the biocompatibility of SeCF3-IRD800 and proceeds to demonstrate its applications in imaging in vivo, fluorescence-guided surgery (FGS) for liver cancer, liver fibrosis imaging, and clinical samples incubation, thereby preliminarily validating its utility in liver cancer. Methods: SeCF3-IRD800 was synthesized by combining the near-infrared fluorescent dye IRDye800cw-NHS with an improved HDAC6 inhibitor. Initially, a HepG2-Luc subcutaneous tumor model (n = 12) was constructed to investigate the metabolic differences between SeCF3-IRD800 and ICG in vivo. Subsequently, HepG2-Luc (n = 12) and HCCLM3-Luc (n = 6) subcutaneous xenograft mouse models were used to assess in vivo targeting by SeCF3-IRD800. The HepG2-Luc orthotopic liver cancer model (n = 6) was employed to showcase the application of SeCF3-IRD800 in FGS. Liver fibrosis (n = 6) and HepG2-Luc orthotopic (n = 6) model imaging results were used to evaluate the impact of different pathological backgrounds on SeCF3-IRD800 imaging. Three groups of fresh HCC and normal liver samples from patients with liver cancer were utilized for SeCF3-IRD800 incubation ex vivo, while preclinical experiments illustrated its potential for clinical application. Findings: The HDAC6 inhibitor 6 (SeCF3) modified with trifluoromethyl was labeled with IRDy800CW-NHS to synthesize the small-molecule targeted probe SeCF3-IRD800, with NIR-II fluorescence signals. SeCF3-IRD800 was rapidly metabolized by the kidneys and exhibited excellent biocompatibility. In vivo validation demonstrated that SeCF3-IRD800 achieved optimal imaging within 8 h, displaying high tumor fluorescence intensity (7658.41 ± 933.34) and high tumor-to-background ratio (5.20 ± 1.04). Imaging experiments with various expression levels revealed its capacity for HDAC6-specific targeting across multiple HCC tumor models, suitable for NIR-II intraoperative imaging. Fluorescence-guided surgery experiments were found feasible and capable of detecting sub-visible 2 mm tumor lesions under white light, aiding surgical decision-making. Further imaging of liver fibrosis mice showed that SeCF3-IRD800's imaging efficacy remained unaffected by liver pathological conditions. Correlations were observed between HDAC6 expression levels and corresponding fluorescence intensity (R2 = 0.8124) among normal liver, liver fibrosis, and HCC tissues. SeCF3-IRD800 identified HDAC6-positive samples from patients with HCC, holding advantages for perspective intraoperative identification in liver cancer. Thus, the rapidly metabolized HDAC6-targeted small-molecule NIR-II fluorescence probe SeCF3-IRD800 holds significant clinical translational value. Interpretation: The successful application of NIR-II fluorescence-guided surgery in liver cancer indicates that SeCF3-IRD800 has great potential to improve the clinical diagnosis and treatment of liver cancer, and could be used as an auxiliary tool for surgical treatment of liver cancer without being affected by liver pathology. Funding: This paper is supported by the National Natural Science Foundation of China (NSFC) (92,059,207, 62,027,901, 81,930,053, 81,227,901, 82,272,105, U21A20386 and 81,971,773), CAS Youth Interdisciplinary Team (JCTD-2021-08), the Zhuhai High-level Health Personnel Team Project (Zhuhai HLHPTP201703), and Guangdong Basic and Applied Basic Research Foundation under Grant No. 2022A1515011244