9 research outputs found

    Seismic stability analysis of landfill

    No full text
    The failure mechanism of a waste containment system is not well understood due to the complexity and the heterogeneity of the system. The recent slope failure of the Kettleman Hills waste landfill (R.B. Seed, 1988) challenges the ability of the geo-environmental engineer to perform stability and failure analysis of a waste containment system. In this paper, an attempt is made to analyze the stability and post-failure conditions of a landfill under cyclic loading using the DDA technique.link_to_subscribed_fulltex

    Divergent Total Syntheses of Aspidospermidine, N-Methylaspidospermidine, N-Acetylaspidospermidine and Aspido-spermine via a Tandem Cyclization of Tryptamine-Ynamide

    No full text
    The divergent total syntheses of aspidospermidine, N-methylaspidospermidine, N-acetylaspidospermidine and aspidosperm-ine were achieved from a common pentacyclic indoline intermediate. The common pentacyclic indoline intermediate was synthesized on a gram scale through a Stork-type alkylation of 1H-pyrrolo[2,3-d]carbazole derivatives, which was prepared based on a BrĂžnsted acid-catalyzed tandem cyclization of tryptamine-ynamide. Scalable synthesis of 1H-pyrrolo[2,3-d]carbazole afforded a facile access and practical approach to the Aspidosperma indole alkaloid family

    High-Frequency Vibration Analysis and Optimization of Irregular Wear of Pantograph Carbon Strips

    No full text
    The irregular wear of carbon current collector pantograph strips increases the railway maintenance costs and introduces safety hazards in the railway operation. This paper presents a method for analyzing the irregular wear of carbon strips with numerical dynamic analyses and modal tests. The carbon strips were studied in laboratory tests, and an equivalent numerical model for the investigation of their irregular wear and performance improvement was established. The results from the computational simulations were evaluated based on the laboratory results, and the correlation between the high-frequency vibration and irregular wear of the carbon strips was studied. The irregular wear contour of the carbon strips coincides with the high-frequency mode shape according to the experimental and numerical results. Moreover, the dynamic design for carbon strips was optimized with the validated computational model. The results suggest that the optimized schemes effectively mitigate the irregular wear of carbon strips

    Genome-wide identification and characterization of Glutathione S-Transferases (GSTs) and their expression profile under abiotic stresses in tobacco (Nicotiana tabacum L.)

    No full text
    Abstract Background Glutathione S-transferases (GSTs) are large and multifunctional proteases that play an important role in detoxification, protection against biotic and abiotic stresses, and secondary metabolite transportation which is essential for plant growth and development. However, there is limited research on the identification and function of NtGSTs. Results This study uses K326 and other six tobacco varieties (Hongda, HG, GDH11, Va116, VG, and GDH88) as materials to conduct comprehensive genome-wide identification and functional characterization of the GST gene in tobacco. A total of 59 NtGSTs were identified and classified into seven subfamilies via the whole-genome sequence analysis, with the Tau type serving as the major subfamily. The NtGSTs in the same branch of the evolutionary tree had similar exon/intron structure and motif constitution. There were more than 42 collinear blocks between tobacco and pepper, tomato, and potato, indicating high homology conservation between them. Twelve segmental duplicated gene pairs and one tandem duplication may have had a substantial impact on the evolution and expansion of the tobacco GST gene family. The RT-qPCR results showed that the expression patterns of NtGSTs varied significantly among tissues, varieties, and multiple abiotic stresses, suggesting that NtGST genes may widely respond to various abiotic stresses and hormones in tobacco, including NtGSTF4, NtGSTL1, NtGSTZ1, and NtGSTU40. Conclusions This study provides a comprehensive analysis of the NtGST gene family, including structures and functions. Many NtGSTs play a critical regulatory role in tobacco growth and development, and responses to abiotic stresses. These findings offer novel and valuable insights for understanding the biological function of NtGSTs and the reference materials for cultivating highly resistant varieties and enhancing the yield and quality of crops

    Interface Engineering with Dynamics‐Mechanics Coupling for Highly Reactive and Reversible Aqueous Zinc‐Ion Batteries

    No full text
    Abstract The practical application of AZIBs is hindered by problems such as dendrites and hydrogen evolution reactions caused by the thermodynamic instability of Zinc (Zn) metal. Modification of the Zn surface through interface engineering can effectively solve the above problems. Here, sulfonate‐derivatized graphene–boronene nanosheets (G&B‐S) composite interfacial layer is prepared to modulate the Zn plating/stripping and mitigates the side reactions with electrolyte through a simple and green electroplating method. Thanks to the electronegativity of the sulfonate groups, the G&B‐S interface promotes a dendrite‐free deposition behavior through a fast desolvation process and a uniform interfacial electric field mitigating the tip effect. Theoretical calculations and QCM‐D experiments confirmed the fast dynamic mechanism and excellent mechanical properties of the G&B‐S interfacial layer. By coupling the dynamics‐mechanics action, the G&B‐S@Zn symmetric battery is cycled for a long‐term of 1900 h at a high current density of 5 mA cm−2, with a low overpotential of ≈30 mV. Furthermore, when coupled with the LMO cathode, the LMO//G&B‐S@Zn cell also exhibits excellent performance, indicating the durability of the G&B‐S@Zn anode. Accordingly, this novel multifunctional interfacial layer offers a promising approach to significantly enhance the electrochemical performance of AZIBs

    Reduced expression of proteolipid protein 2 increases ER stress-induced apoptosis and autophagy in glioblastoma.

    Get PDF
    Proteolipid protein 2 (PLP2) is an integral ion channel membrane protein of the endoplasmic reticulum. The protein has been shown to be highly expressed in many cancer types, but its importance in glioma progression is poorly understood. Using publicly available datasets (Rembrandt, TCGA and CGGA), we found that the expression of PLP2 was significantly higher in high‐grade gliomas than in low‐grade gliomas. We confirmed these results at the protein level through IHC staining of high‐grade (n = 56) and low‐grade glioma biopsies (n = 16). Kaplan‐Meier analysis demonstrated that increased PLP2 expression was associated with poorer patient survival. In functional experiments, siRNA and shRNA PLP2 knockdown induced ER stress and increased apoptosis and autophagy in U87 and U251 glioma cell lines. Inhibition of autophagy with chloroquine augmented apoptotic cell death in U87‐ and U251‐siPLP2 cells. Finally, intracranial xenografts derived from U87‐ and U251‐shPLP2 cells revealed that loss of PLP2 reduced glioma growth in vivo. Our results therefore indicate that increased PLP2 expression promotes GBM growth and that PLP2 represents a potential future therapeutic target

    Attitudes toward COVID-19 Vaccination: A Survey of Chinese Patients with Rheumatic Diseases

    No full text
    The coronavirus disease 2019 (COVID-19) pandemic has imposed enormous morbidity and mortality burdens. Patients with rheumatic diseases (RDs) are vulnerable to the COVID-19 infection, given their immunocompromised status. Ensuring acceptance of the COVID-19 vaccine is important and has attracted attention by health professionals. In this study, we designed an online cross-sectional survey that used an online questionnaire from 8 May 2021 to 4 October 2021. Attitudes toward the COVID-19 vaccination, personal information, current disease activity status, adverse events (AEs), and knowledge sources of vaccines were collected. Descriptive statistics, nonparametric tests, and ordinal logistic regression were used to analyze the data. A total of 1022 questionnaires were received, among which 70.2% (720/1022) of patients with RDs agreed to vaccination, while only 31.6% of patients were actually vaccinated. Male, employed, high-income patients and those with inactive disease showed a more positive attitude. Concerns of AEs and disease flare were the main factors affecting vaccination willingness. Only 29.6% (304/1022) of patients thought they had received enough information about the COVID-19 vaccine from their doctors. In conclusion, most patients with RDs in China intended to get vaccinated, although the vaccination rate in this particular population was low. Rheumatologists should take more responsibility in COVID-19 vaccination education of patients with RDs

    Abrogation of graft ischemia‐reperfusion injury in ischemia‐free liver transplantation

    No full text
    Abstract Background Ischemia‐reperfusion injury (IRI) is considered an inherent component of organ transplantation that compromises transplant outcomes and organ availability. The ischemia‐free liver transplantation (IFLT) procedure has been developed to avoid interruption of blood supply to liver grafts. It is unknown how IFLT might change the characteristics of graft IRI. Methods Serum and liver biopsy samples were collected from IFLT and conventional liver transplantation (CLT) recipients. Pathological, metabolomics, transcriptomics, and proteomics analyses were performed to identify the characteristic changes in graft IRI in IFLT. Results Peak aspartate aminotransferase (539.59 ± 661.76 U/L versus 2622.28 ± 3291.57 U/L) and alanine aminotransferase (297.64 ± 549.50 U/L versus 1184.16 ± 1502.76 U/L) levels within the first 7 days and total bilirubin levels by day 7 (3.27 ± 2.82 mg/dl versus 8.33 ± 8.76 mg/dl) were lower in the IFLT versus CLT group (all p values < 0.001). The pathological characteristics of IRI were more obvious in CLT grafts. The antioxidant pentose phosphate pathway remained active throughout the procedure in IFLT grafts and was suppressed during preservation and overactivated postrevascularization in CLT grafts. Gene transcriptional reprogramming was almost absent during IFLT but was profound during CLT. Proteomics analysis showed that “metabolism of RNA” was the major differentially expressed process between the two groups. Several proinflammatory pathways were not activated post‐IFLT as they were post‐CLT. The activities of natural killer cells, macrophages, and neutrophils were lower in IFLT grafts than in CLT grafts. The serum levels of 14 cytokines were increased in CLT versus IFLT recipients. Conclusions IFLT can largely avoid the biological consequences of graft IRI, thus has the potential to improve transplant outcome while increasing organ utilization
    corecore