Reconversions involving hysteria

Thermoelectric generators, which convert heat directly into electrical power, have great potentialities in the energy harvesting field. The exploitation of these potentialities is limited by the materials currently used, characterized by good thermoelectric properties, but also by several drawbacks. This work presents a silicon-based thermoelectric generator, made of a large collection of heavily p-doped silicon nanostructures. This macroscopic device (area of several mm2) collects together the good thermoelectric features of silicon, in terms of high power factor, and a very reduced thermal conductivity, which resulted in being exceptionally low (1.8 W/(m K), close to the amorphous limit). The generated electrical power density is remarkably high for a Si-based thermoelectric generator, and it is suitable for scavenging applications which can exploit small temperature differences. A full characterization of the device (Seebeck coefficient, thermal conductivity, maximum power output) is reported and discussed.Gold nanoparticles (AuNPs) have been widely documented as tumor radiosensitizers via enhanced energy deposition of ionizing radiation. However, the sensitization efficiency of AuNPs is still far from satisfactory owing to the irradiation on nontarget tissues and the tumor radio-resistance. To address these issues, we report herein the rational design and development of hyaluronic acid-modified Au-Ag alloy nanoparticles (Au-Ag@HA NPs) with effective tumor radiosensitization by receptor mediated tumor targeting as well as microenvironment-activated hydroxyl radicals (•OH) generation. In our work, Au-Ag@HA NPs were synthesized by the coreduction of HAuCl4 and AgNO3 in the presence of trisodium citrate, followed by surface modification of HA to the Au-Ag alloy NPs. HA modification affords the alloy NPs with specific targeting to 4T1 breast cancer cells overexpressing CD44 receptor, while the introduction of Ag atom imparts the alloy NPs with superior multienzyme-like activities to the monometallic AuNPs for efficient tumor catalytic therapy. More importantly, the ionizing radiation and peroxidase-like activity of Au-Ag@HA NPs boost the production of •OH and the release of toxic Ag+ in the tumor sites, thereby leading to effective tumor therapeutic outcome. This work provides a promising treatment paradigm for radiation/nanozyme/Ag+ combined therapy against cancer and will advance the design and development of multifunctional nanoplatforms for synergetically enhanced tumor therapy.Single cell manipulation is important in biosensing, biorobotics, and quantitative cell analysis. Although microbeads, droplets, and microrobots have been developed previously, it is still challenging to simultaneously excise, capture, and manipulate single cells in a biocompatible manner. Here, we describe untethered single cell grippers, that can be remotely guided and actuated on-demand to actively capture or excise individual or few cells. We describe a novel molding method to micropattern a thermally responsive wax layer for biocompatible motion actuation. The multifingered grippers derive their energy from the triggered release of residual differential stress in bilayer hinges composed of silicon oxides. A magnetic layer enables remote guidance through narrow conduits and fixed tissue sections ex vivo. Our results provide an important advance in high-throughput single cell scale biopsy tools important to lab-on-a-chip devices, microrobotics, and minimally invasive surgery.The control of acoustic phonons, which are the carriers of sound and heat, has become the focus of increasing attention because of a demand for manipulating the sonic and thermal properties of nanometric devices. In particular, the photoacoustic effect using ultrafast optical pulses has a promising potential for the optical manipulation of phonons in the picosecond time regime. So far, its mechanism has been mostly based on the commonplace thermoelastic expansion in isotropic media, which has limited applicability. In this study, we investigate a conceptually new mechanism of the photoacoustic effect involving a structural instability that utilizes a transition-metal dichalcogenide VTe2 with a ribbon-type charge-density-wave (CDW). Ultrafast electron microscope imaging and diffraction measurements reveal the generation and propagation of unusual acoustic waves in a nanometric thin plate associated with optically induced instantaneous CDW dissolution. Our results highlight the capability of photoinduced structural instabilities as a source of coherent acoustic waves.Uranium(IV) metallocene complexes (CpiPr4)2U(N3)2 (1-N3), (CpiPr)2U(NCO)2 (1-NCO), and (CpiPr4)2U(OTf)2 (1-OTf) containing the bulky CpiPr4 ligand (CpiPr4 = tetra(isopropyl)cyclopentadienyl) were prepared directly from reactions between (CpiPr4)2UI2 or (CpiPr4)2UI and corresponding pseudohalide salts. The mixed-ligand complex (CpiPr4)2U(N3)(OTf) (1-N3-OTf) was isolated after heating a 11 mixture of 1-N3 and 1-OTf. The coordination of 1 equiv B(C6F5)3 to 1-N3 produced the borane-capped azide (CpiPr4)2U(N3)[(μ-η1η1-N3)B(C6F5)3] (2-N3), while the reaction of 1 equiv B(C6F5)3 with 1-NCO yielded (CpiPr4)2U(NCO)[(μ-η1η1-OCN)B(C6F5)3] (2-NCO) in which the borane-capped cyanate ligand had rearranged to become O-bound to uranium. The reaction of (CpiPr4)2UI and NaOCN led to the isolation of the uranium(III) cyanate-bridged "molecular square" [(CpiPr4)2U(μ-η1η1-OCN)]4 (3-OCN). Cyclic voltammetry and UV-vis spectroscopy revealed small differences in the electronic properties between azide and isocyanate complexes, while X-ray crystallography showed nearly identical solid-state structures, with the most notable difference being the geometry of borane coordination to the azide in 2-N3 versus the cyanate in 2-NCO. Reactivity studies comparing 3-OCN to the azide analogue [(CpiPr4)2U(μ-η1η1-N3)]4 (3-N3) demonstrated significant differences in the chemistry of cyanates and azides with trivalent uranium. A computational analysis of 1-NCO, 1-N3, 2-NCO, and 2-N3 has provided a basis for understanding the energetic preference for specific linkage isomers and the effect of the B(C6F5)3 coordination on the bonding between uranium, azide, and isocyanate ligands.A new catalyst system based on Co(OAc)2/bisoxazolinephosphine has been developed to catalyze the direct addition of terminal alkynes to isatins under base-free conditions. Chiral propargyl alcohols with an oxindole skeleton could be prepared in up to 99% yield and 99% ee with the help of the chiral tridentate ligand. A variety of functionalized aliphatic or aromatic alkynes and isatins were utilized in this method, and gram-scale synthesis could be achieved with 1 mol % catalyst.The search for cost-effective and highly active transition-metal-based electrocatalysts is of great importance for overall water splitting to generate clean energy hydrogen. In this work, we present a controllable structural transformation engineering strategy to construct 3D hierarchical CoP porous microscale prism-like superstructure (assembled with nanoflakes) arrays grown on surface-phosphatized Ni foam (CoP/SPNF). Specifically, Zn/Co-based composite arrays with a nanowires@prism hierarchical structure were prepared on Ni foam first. Then, porous Co-based compound arrays with a nanoflakes@prism hierarchical structure were obtained through removing the Zn-based compound by alkaline etching. Finally, CoP arrays were produced through phosphatization of the prepared Co-based array precursor, using NaH2PO2·H2O as the P source. The fabricated CoP/SPNF electrocatalyst exhibits impressive bifunctional performance for the hydrogen evolution reaction (HER, overpotential of 45 mV at 10 mA cm-2) and oxygen evolution reaction (OER, overpotential of 215 mV at 80 mA cm-2) and consequently enables efficient electrolytic water splitting with a low cell voltage of 1.547 V at 30 mA cm-2 and a prominent durability. Versatile CoP with its porous superstructure arrays on surface-phosphatized Ni foam can increase the exposure of electrochemically active sites and render easy contact with the electrolyte, thus facilitating fast electron transport and effective electrolyte diffusion during the electrocatalytic process, as well as promoting the release of product gas bubbles from the electrode. This work provides an effective strategy for the design and preparation of non-noble-metal bifunctional electrocatalysts for overall water splitting electrolysis.A biomarker, such as protein accumulation as an indicator of disease, can be used to predict disease manifestation, determine intervention, and monitor treatment efficacy. Biomarker development frequently focuses on early detection of disease as this is typically considered the only or most pressing need. However, the ideal time point for biomarker use may not always be early in disease but instead, as we will discuss, could be when enough information is available to predict the association between biomarker (protein accumulation) and disease manifestation (symptom severity, progression, prognosis). This Viewpoint highlights the importance of clearly defining the notion of "time" when discussing the development and utility of biomarkers. Using two disease examples, one with a clearly defined starting point (traumatic brain injury) and one with an indistinct starting point (Alzheimer's disease), we explore the concept of timing in biomarker development and utility.The present study tries to validate Hammett's linear free energy relationship (LFER) through an unconventional approach based on density functional reactivity theory (DFRT). Kinetic energy component [〖∆E〗_B(A) ], derived from DFRT based CDASE scheme, is used to verify the linear nature of Hammett's log⁡(k_X/k_H ) vs. σ plot. The study shows that log⁡〖[〖∆E〗_(B(A)) ]_X/[〖∆E〗_(B(A)) ]_H 〗 vs. σ plot (where -X is the atom or group substituted in place of -H) is linear in nature (with reasonably high correlation coefficient values) for different series of reactions.The slopes of the plots also reveal the electrophilic or nucleophilic nature of the transition states as is obtained from conventional log⁡(k_X/k_H ) vs. σ plot. The study thus establishes that DFRT based energy component 〖∆E〗_(B(A)) (which is very easy to compute) can be used, instead of k-values, obtained by either from experiment or from computationally intensive conventional thermochemistry calculations, to generate reliable Hammett's plot.This work introduces a novel methodology for the quantification of uncertainties associated with potential energy surfaces (PESs) computed from first-principles quantum mechanical calculations. The methodology relies on Bayesian inference and machine learning techniques to construct a stochastic PES and to express the inadequacies associated with the ab initio data points and their fit. By combining high fidelity calculations and reduced-order modeling, the resulting stochastic surface is efficiently forward propagated via quasi-classical trajectory and master equation calculations. In this way, the PES contribution to the uncertainty on predefined quantities of interest (QoIs) is explicitly determined. This study is done at both microscopic (e.g., rovibrational-specific rate coefficients) and macroscopic (e.g., thermal and chemical relaxation properties) levels. U0126 mw A correlation analysis is finally applied to identify the PES regions that require further refinement, based on their effects on the QoI reliability.