149 research outputs found
Endoglin Is Essential for the Maintenance of Self-Renewal and Chemoresistance in Renal Cancer Stem Cells.
Renal cell carcinoma (RCC) is a deadly malignancy due to its tendency to metastasize and resistance to chemotherapy. Stem-like tumor cells often confer these aggressive behaviors. We discovered an endoglin (CD105)-expressing subpopulation in human RCC xenografts and patient samples with a greater capability to form spheres in vitro and tumors in mice at low dilutions than parental cells. Knockdown of CD105 by short hairpin RNA and CRISPR/cas9 reduced stemness markers and sphere-formation ability while accelerating senescence in vitro. Importantly, downregulation of CD105 significantly decreased the tumorigenicity and gemcitabine resistance. This loss of stem-like properties can be rescued by CDA, MYC, or NANOG, and CDA might act as a demethylase maintaining MYC and NANOG. In this study, we showed that Endoglin (CD105) expression not only demarcates a cancer stem cell subpopulation but also confers self-renewal ability and contributes to chemoresistance in RCC
Simplified Boundary Element Method for Kinematic Response of Single Piles in Two-Layer Soil
A simple approach is formulated to predict the elastic, kinematic pile bending during harmonic or transient excitation for a circular pile (rather than a simplified thin strip). The kinematic response of a pile embedded in two-layer soil is resolved in the frequency domain caused by the upward propagation of shear waves from the underlying bedrock. The simplified approach is generally valid to nonhomogeneous soil profiles, in light of the good comparison with the dynamic FE method and BDWF solution. It employs the soil-displacement-influence coefficients Is to consider the pile-soil interaction (resembling the spring constant kx in the BDWF) and provides conservative estimations of maximum kinematic bending moments at the soil-layer interface (with a sharper stiffness contrast). The accuracy of the approach may be improved by incorporating the interaction of soil into the soil-displacement-influence coefficients Is for such cases with Vb/Va<3
Simplified Boundary Element Method for Kinematic Response of Single Piles in Two-Layer Soil
A simple approach is formulated to predict the elastic, kinematic pile bending during harmonic or transient excitation for a circular pile (rather than a simplified thin strip). The kinematic response of a pile embedded in two-layer soil is resolved in the frequency domain caused by the upward propagation of shear waves from the underlying bedrock. The simplified approach is generally valid to nonhomogeneous soil profiles, in light of the good comparison with the dynamic FE method and BDWF solution. It employs the soil-displacement-influence coefficients to consider the pile-soil interaction (resembling the spring constant in the BDWF) and provides conservative estimations of maximum kinematic bending moments at the soil-layer interface (with a sharper stiffness contrast). The accuracy of the approach may be improved by incorporating the interaction of soil into the soil-displacementinfluence coefficients for such cases with / < 3
Clinical observation of different dosages of dexmedetomidine combined with a target-controlled infusion of propofol in hysteroscopic submucosal myomectomy
ObjectiveThis study aimed to explore the clinical effects of different dosages of dexmedetomidine (Dex) combined with a target-controlled infusion of propofol in hysteroscopic submucosal myomectomy.MethodsNinety patients who underwent hysteroscopic submucosal myomectomy between September 2021 and March 2022 were enrolled and randomly divided into three groups, with 30 patients in each group. Patients in Groups A, B, and C received injections of 0.25, 0.5, or 0.75 µg/kg of Dex, respectively, by intravenous pump over 10 min. After this time, a maintenance dosage of 0.5 µg/kg/h was administered by intravenous infusion until the end of the surgery. Anesthesia was induced using 1.5 mg/kg of propofol and 0.3 µg/kg of sufentanil that were introduced through a laryngeal mask. The plasma concentration of propofol was maintained at 3 µg/ml by target-controlled infusion until the end of the surgery. The mean arterial pressure (MAP), heart rate (HR), and electroencephalographic bispectral index (BIS) were observed when the patient entered the operating room (T0), after catheter indwelling for anesthesia (T1), at the time of cervical dilation (T2), at the time of hysteroscopic surgery (T3), and at the end of the surgery (T4) in all three groups. The total dosage of propofol for induction and maintenance, anesthesia awakening time, orientation recovery time, Visual Analog Scale (VAS) score of the post-awakening uterine contraction pain, and adverse reactions were recorded.ResultsThe intraoperative reductions of MAP and HR in patients were significant in Group C when compared with those in Groups A and B (P < 0.05), and BIS was significantly lower in Group C at T2 and T3 when compared with the baseline measurement at T0 (P < 0.05). The dosage of propofol was significantly higher for Group A than for Groups B and C (P < 0.05). The anesthesia awakening time and orientation recovery time were significantly longer for patients in Group C when compared with patients in Groups A and B (P < 0.05). Within 5–30 min after awakening, the VAS scores in Groups B and C were significantly lower than those for Group A (P < 0.05). The incidence of adverse reactions in Group B was significantly less than that for Groups A and C (P < 0.05).ConclusionThe continuous pumping of 0.5 µg/kg of Dex combined with a target-controlled infusion of propofol in hysteroscopic submucosal myomectomy resulted in positive anesthetic and analgesia effects and fewer adverse reactions. It therefore has high clinical significance
Preparation and Investigation of the Microtribological Properties of Graphene Oxide and Graphene Films via Electrostatic Layer-by-Layer Self-Assembly
Graphene oxide (GO) films with controlled layers, deposited on single-crystal silicon substrates, were prepared by electrostatic self-assembly of negatively charged GO sheets. Afterward, graphene films were prepared by liquid-phase reduction of as-prepared GO films using hydrazine hydrate. The microstructures and microtribological properties of the samples were studied using X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, UV-vis absorption spectroscopy, water contact angle measurement, and atomic force microscopy. It is found that, whether GO films or graphene films, the adhesion force and the coefficients of friction both show strong dependence on the number of self-assembled layers, which both allow a downward trend as the number of self-assembled layers increases due to the interlayer sliding and the puckering effect when the tip slipped across the top surface of the films. Moreover, in comparison with the GO films with the same self-assembled layers, the graphene films possess lower adhesion force and coefficient of friction attributed to the difference of surface functional groups
fault gouge graphitization as evidence of past seismic slip
One moderate- to large-magnitude earthquake (M > 6) nucleates in Earth's crust every three days n average, but the geological record of ancient fault slip at meters-per-second seismic velocities (as opposed to subseismic slow-slip creep) remains debated because of the lack of established fault-zone evidence of seismic slip. Here we show that the irreversible temperature-dependent transformation of carbonaceous material (CM, a constituent of many fault gouges) into graphite is a reliable tracer of seismic fault slip. We sheared CM-bearing fault rocks in the laboratory at just above subseismic and at seismic velocities under both water-rich and water-deficient conditions and modeled the temperature evolution with slip. By means of micro-Raman spectroscopy and focused-ion beam transmission electron microscopy, we detected graphite grains similar to those found in the principal slip zone of the A.D. 2008 Wenchuan (Mw 7.9) earthquake (southeast Tibet) only in experiments conducted at seismic velocities. The experimental evidence presented here suggests that high-temperature pulses associated with seismic slip induce graphitization of CM. Importantly, the occurrence of graphitized fault-zone CM may allow us to ascertain the seismogenic potential of faults in areas worldwide with incomplete historical earthquake catalogues
Algal blooms: how are they harming models used for climate management?
18th International Conference on Harmful Algae (ICHA 2018), 21-26 October 2018, Nantes, France.-- 4 pages, 2 figuresMicroalgae blooms are generally associated with bacterial secondary producers. They produce organic matter (OM), some of which associates with the sea surface microlayer (SML). OM in the SML below the actual surface reduces fluxes of energy, including heat and momentum, and substances, including greenhouse gases, aerosols, algae, bacteria and viruses. In addition to the SML-associated OM, another OM fraction, foam (including whitecaps), often lies above the primary SML when windspeeds exceed about 5 m s-1, trapping gas bubbles. Such foam also dramatically increases albedo, reflecting solar radiation back into space, thus reducing solar heating and penetration of photosynthetically active radiation. Mean coverage of the ocean surface by foam has been measured to range between 1-6%, particularly in zones of Trade Winds. Different types of OM, and particularly their mechanical properties, depend on ambient algal abundance, as well as on taxonomic composition, as do the dynamics of foam formation and decay. Air-sea fluxes may thus be influenced by genomic control through the blooming microalgae and Darwinian-type evolution. Bacteria may also play a role. In addition, foam patches on the ocean’s surface serve as a unique microbial habitat. Such blooms, particularly when their taxonomic composition changes unpredictably, are likely to be harming the usefulness of climate models. Some of this harm might be mitigated by studying the relevant effects of these blooms on fluxes, and incorporating these effects into climate modelsJS is supported by National Nature Science Foundation of China grant (41876134) and the Changjiang Scholar Program of Chinese Ministry of Educatio
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