Conwayamstrup1816

We further demonstrate that this limitation can be overcome with the introduction of small amounts of tellurium in the precursor. The presence of tellurium allows one to reduce the band gap and increase both the charge carrier concentration and the mobility, especially the cross plane, with a minimal decrease of the Seebeck coefficient. These effects translate into record out of plane ZT values at 800 K.Current technologies for high-throughput single-cell RNA sequencing (scRNA-seq) are based upon stochastic pairing of cells and barcoded beads in nanoliter droplets or wells. They are limited by the mathematical principle of the Poisson statistics such that the utilization of either cells or beads or both is no more than ∼33%. Despite the versatile design of microfluidics or microwells for high-yield loading of beads that beats the Poisson limit, subsequent encapsulation of single cells is still determined by stochastic pairing, representing a fundamental limitation in the field of single-cell sequencing. Here, we present dTNT-seq, an integrated dielectrophoresis (DEP)-trapping-nanowell-transfer (dTNT) approach to perform cell trapping and bead loading both in a sub-Poisson manner to facilitate scRNA-seq. A larger-sized 50 μm microwell array was prealigned precisely on top of the 20 μm DEP nanowell array such that single cells trapped by DEP can be readily transferred into the underneath larger wells by flipping the device, followed by subsequent hydrodynamic bead loading and coisolation with transferred single cells. Using a dTNT device composed of 3600 electroactive DEP-nanowell units, we demonstrated a single-cell trapping rate of 91.84%, a transfer efficiency of 82%, and a routine bead loading rate of >99%, which breaks the Poisson limit for the capture of both cells and beads, thus called double-sub-Poisson distribution, prior to encapsulating them in nanoliter wells for cellular mRNA barcoding. This approach was applied to human (HEK) and mouse (3T3) cells. Comparison with a non-DEP-based method through gene expression clustering and regulatory pathway analysis demonstrates consistent patterns and negligible alternation of cellular transcriptional states by DEP. We envision the dTNT-seq device can be modified for studying cell-cell interactions and enable other applications requiring active manipulation of single cells prior to transcriptome sequencing.Pre-extracting Li+ from Li-rich layered oxides by chemical method is considered to be a targeted strategy for improving this class of cathode material. Understanding the structural evolution of the delithiated material is very important because this is directly related to the preparation of electrochemical performance enhanced Li-rich material. Herein, we perform a high temperature reheat treatment on the quantitatively delithiated Li-rich materials with different amounts of surface defect-spinel phase and carefully investigate the structural evolution of these delithiated materials. It is found that the high temperature reheat treatment could cause the decomposition of the unstable surface defect-spinel structure, followed by the rearrangement of transition metal ions to form the thermodynamically stable phases, More importantly, we find that this process has high correlation with the remaining Li-content in the delithiated material. When the amount of extracted Li+ is relatively small (corresponding to the higher remaining Li-content), the surface defect-spinel phase could be dominantly decomposed into the LiMO2 (M = Ni, Co, and Mn) layered phase along with the significant improvement of electrochemical performance, and continuing to decrease remaining Li-content could lead to the emergence of M3O4-type spinel impurity embedding in the final product. However, when the extracted Li+ further achieves a certain amount, after the high temperature heat-treatment the Mn-rich Li2MnO3 phase (C2/m) could be separated from Ni-rich phases (including R3m, Fd3m, and Fm3m), thus resulting in a sharp deterioration of initial capacity and voltage. These findings suggest that reheating the delithiated Li-rich material to high temperature may be a simple and effective way to improve the predelithiation modification method, but first the amount of extracted Li+ should be carefully optimized during the delithiation process.We report a dual-readout, AuNP-based sandwich immunoassay for the device-free colorimetric and sensitive scanometric detection of disease biomarkers. An AuNP-antibody conjugate serves as a signal transduction and amplification agent by promoting the reduction and deposition of either platinum or gold onto its surface, generating corresponding colorimetric or light scattering (scanometric) signals, respectively. We apply the Pt-based colorimetric readout of this assay to the discovery of a novel monoclonal antibody (mAb) sandwich pair for the detection of an anthrax protective antigen (PA83). The identified antibody pair detects PA83 down to 1 nM in phosphate-buffered saline and 5 nM in human serum, which are physiologically relevant concentrations. Reducing gold rather than platinum onto the mAb-AuNP sandwich enables scanometric detection of subpicomolar PA83 concentrations, over 3 orders of magnitude more sensitive than the colorimetric readout.The current outbreak of the pandemic coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) demands its rapid, convenient, and large-scale diagnosis to downregulate its spread within as well as across the communities. But the reliability, reproducibility, and selectivity of majority of such diagnostic tests fail when they are tested either to a viral load at its early representation or to a viral gene mutated during its current spread. In this regard, a selective "naked-eye" detection of SARS-CoV-2 is highly desirable, which can be tested without accessing any advanced instrumental techniques. selleck chemicals We herein report the development of a colorimetric assay based on gold nanoparticles (AuNPs), when capped with suitably designed thiol-modified antisense oligonucleotides (ASOs) specific for N-gene (nucleocapsid phosphoprotein) of SARS-CoV-2, could be used for diagnosing positive COVID-19 cases within 10 min from the isolated RNA samples. The thiol-modified ASO-capped AuNPs agglomerate selectively in the presence of its target RNA sequence of SARS-CoV-2 and demonstrate a change in its surface plasmon resonance. Further, the addition of RNaseH cleaves the RNA strand from the RNA-DNA hybrid leading to a visually detectable precipitate from the solution mediated by the additional agglomeration among the AuNPs. The selectivity of the assay has been monitored in the presence of MERS-CoV viral RNA with a limit of detection of 0.18 ng/μL of RNA having SARS-CoV-2 viral load. Thus, the current study reports a selective and visual "naked-eye" detection of COVID-19 causative virus, SARS-CoV-2, without the requirement of any sophisticated instrumental techniques.Optofluidic lasers are an emerging technology for the development of miniaturized light sources and biological and chemical sensors. However, most optofluidic lasers demonstrated to date are operated at the single optical cavity level, which limits their applications in high-throughput biochemical sensing, high-speed wavelength switching, and on-chip spectroscopic analysis. Here, we demonstrated an optofluidic droplet laser array on a silicon chip with integrated microfluidics, in which four individual droplet optical cavities are generated and controlled by a 2 × 2 nozzle array. Arrays of droplets with a diameter ranging from 115 to 475 μm can be generated, removed, and regenerated on demand. The lasing threshold of the droplet laser array is in the range of 0.63-2.02 μJ/mm2. An image-based lasing threshold analysis method is developed, which enables simultaneous lasing threshold measurement for all laser units within the laser array using a low-cost camera. Compared to the conventional spectrum-based threshold analysis method, the lasing threshold obtained from the image-based method showed consistent results. Our droplet laser array is a promising technology in the development of cost-effective and integrated coherent light source on a chip for point-of-care applications.Passive radiative cooling includes using the atmospheric window to emit heat energy to the cold outer space and hence reduce the temperature of objects on Earth. In most cases, radiative cooling is required in summer and suppressed in winter for thermal comfort. Recent radiative cooling materials cannot self-adjust cooling capacity according to season and environment, thus limiting their applications. In this study, we have designed a temperature-controlled phase change structure (TCPCS). The TCPCS benefits radiative coolers to adjust their cooling ability according to the ambient temperature. In the outdoor test, the TCPCS can help the cooler to turn off at low temperatures and turn on at high temperatures automatically; the coolers with and without TCPCS have maximal temperature differences of 9.7 and 19.6 °C, respectively, in a whole day. Furthermore, we have further improved and designed a V-shaped TCPCS that can simultaneously achieve the dual functions of cooling in summer and heating in winter. The TCPCS assembled here is a simple, feasible, and scalable structure for self-adaptive cooling.Hierarchical organization plays an important role in the stunning physical properties of natural and synthetic composites. Limits on the physical properties of such composites are generally defined by percolation theory and can be systematically altered using the volumetric filler fraction of the inorganic/organic phase. In natural composites, organic materials such as proteins that interact with inorganic filler materials can further alter the hierarchical order and organization of the composite via topological interactions, expanding the limits of the physical properties defined by percolation theory. However, existing polymer systems do not offer a topological parameter that can systematically modulate the assembly characteristics of composites. Here, we present a composite based on proteins and titanium carbide (Ti3C2Tx) MXene that manifests a topological network that regulates the organization, and hence physical properties, of these biomimetic composites. We designed, recombinantly expressed, and purified synthetic proteins consisting of polypeptides with repeating amino acid sequences (tandem repeats) that have the ability to self-assemble into topologically networked biomaterials. We demonstrated that the interlayer distance between MXene sheets can be controlled systematically by the number of tandem repeat units. We varied the filler fraction and number of tandem repeat units to regulate the in-plane and out-of-plane electrical conductivities of these composites. Once Ti3C2Tx MXene sheets are separated enough to facilitate formation of cross-links in our proteins with the number of tandem repeat units reaching 11, the linear I-V characteristics of the composites switched into nonlinear I-V curves with a distinct hysteresis for out-of-plane electron transport, while the in-plane I-V characteristics remained linear. This highlights the impact of synthetic protein templates, which can be designed to modulate electronic transport in composites both isotropically and anisotropically.