3 research outputs found

    Supersaturation-Controlled Shape Evolution of α‑Fe<sub>2</sub>O<sub>3</sub> Nanocrystals and Their Facet-Dependent Catalytic and Sensing Properties

    No full text
    Surface engineering of crystals at nanoscale level by precisely and rationally exposing specific facets proved to be highly effective in enhancing the performance of inorganic functional nanocrystals. To do so, a comprehensive understanding of the growth mechanism was of great importance. By using hematite (α-Fe<sub>2</sub>O<sub>3</sub>) as an example, in this paper we demonstrated high effectiveness of controlling supersaturation of growth monomers in engineering the exposed facets of nanocrystals. Under surfactant-free hydrothermal conditions, a series of morphology evolution of α-Fe<sub>2</sub>O<sub>3</sub> nanocrystals from {012} faceted pseudocubes to {113} faceted hexagonal bipyramids and {001} faceted nanoplates were successfully activated through concentration-, reaction time-, and solvent-dependent hydrolysis of ferric acetylacetonate. High supersaturation was eventually proven to be conducive to the formation of facets with high surface energy. Furthermore, the α-Fe<sub>2</sub>O<sub>3</sub> nanocrystals enclosed with facets of high surface energy exhibited excellent catalytic activity and gas-sensing ability. The present work will deepen our understanding of thermodynamics and kinetic control over the morphology of nanocrystals as well as our understanding of surface-related performance of inorganic functional nanocrystals

    The Role of the Active Site Flap in Streptavidin/Biotin Complex Formation

    No full text
    Obtaining a detailed description of how active site flap motion affects substrate or ligand binding will advance structure-based drug design (SBDD) efforts on systems including the kinases, HSP90, HIV protease, ureases, etc. Through this understanding, we will be able to design better inhibitors and better proteins that have desired functions. Herein we address this issue by generating the relevant configurational states of a protein flap on the molecular energy landscape using an approach we call MT<sub>Flex‑b</sub> and then following this with a procedure to estimate the free energy associated with the motion of the flap region. To illustrate our overall workflow, we explored the free energy changes in the streptavidin/biotin system upon introducing conformational flexibility in loop<sub>3–4</sub> in the biotin unbound (<i>apo</i>) and bound (<i>holo</i>) state. The free energy surfaces were created using the Movable Type free energy method, and for further validation, we compared them to potential of mean force (PMF) generated free energy surfaces using MD simulations employing the FF99SBILDN and FF14SB force fields. We also estimated the free energy thermodynamic cycle using an ensemble of closed-like and open-like end states for the ligand unbound and bound states and estimated the binding free energy to be approximately −16.2 kcal/mol (experimental −18.3 kcal/mol). The good agreement between MT<sub>Flex‑b</sub> in combination with the MT method with experiment and MD simulations supports the effectiveness of our strategy in obtaining unique insights into the motions in proteins that can then be used in a range of biological and biomedical applications

    Data_Sheet_1_Effect of various hepatectomy procedures on circulating tumor cells in postoperative patients: a case-matched comparative study.docx

    No full text
    BackgroundThe objective of this study is to elucidate the prevalence of systemic circulating tumor cells (CTCs) prior to and following resection of hepatocellular carcinoma (HCC), and to compare the disparities in postoperative CTCs in terms of quantity and classifications between the open liver resection (OPEN) and laparoscopic liver resection (LAP) cohorts.Patients, materials, and methodsFrom September 2015 to May 2022, 32 consecutive HCC patients who underwent laparoscopic liver resection at Southwest Hospital were retrospectively enrolled in this study. The clinicopathological data were retrieved from a prospectively collected computer database. Patients in the OPEN group matched at a 1:1 ratio with patients who underwent open liver resection during the study period on age, gender, tumor size, number of tumors, tumor location, hepatitis B surface antigen (HBsAg) positivity, alpha-fetoprotein (AFP) level, TNM and Child-Pugh staging from the database of patients to form the control group. The Can-Patrol CTC enrichment technique was used to enrich and classify CTCS based on epithelial-mesenchymal transformation phenotypes. The endpoint was disease-free survival (DFS), and the Kaplan–Meier method and multiple Cox proportional risk model were used to analyze the influence of clinicopathological factors such as total CTCs and CTC phenotype on prognosis.ResultsThe mean age of the 64 patients with primary liver cancer was 52.92 years (23–71), and 89.1% were male. The postoperative CTC clearance rate was more significant in the OPEN group. The total residual CTC and phenotypic CTC of the LAP group were significantly higher than those of the OPEN group (p = 0.017, 0.012, 0.049, and 0.030, respectively), which may increase the possibility of metastasis (p = 0.042). In Kaplan–Meier analysis, DFS was associated with several clinicopathological risk factors, including Barcelona Clinical Liver Cancer (BCLC) stage, tumor size, and vascular invasion. Of these analyses, BCLC Stage [p = 0.043, HR (95% CI) =2.03(1.022–4.034)], AFP [p = 0.007, HR (95% CI) =1.947 (1.238–3.062)], the number of positive CTCs [p = 0.004, HR (95% CI) =9.607 (2.085–44.269)] and vascular invasion [p = 0.046, HR (95% CI) =0.475 (0.22–1.023)] were significantly associated with DFS.ConclusionIn comparison to conventional OPEN technology, LAP technology has the capacity to augment the quantity of epithelial, mixed, and mesenchymal circulating tumor cells (CTCs). Following the surgical procedure, there was a notable increase in the total CTCs, epithelial CTCs, and mixed CTCs within the LAP group, indicating a potential drawback of LAP in facilitating the release of CTCs.</p
    corecore