Hasil untuk "Chemical technology"

A. Verma, R. Dash, P. Bhunia

V. Gupta, I. Ali, T. Saleh et al.

C. Barrera-Díaz, Violeta Lugo-Lugo, B. Bilyeu

G. Olah, G. Prakash, Alain Goeppert

L. Gold, Deborah Ayers, Jennifer Bertino et al.

BACKGROUND The interrogation of proteomes ("proteomics") in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology and medicine. METHODOLOGY/PRINCIPAL FINDINGS We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 µL of serum or plasma). Our current assay measures 813 proteins with low limits of detection (1 pM median), 7 logs of overall dynamic range (~100 fM-1 µM), and 5% median coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding signature of DNA aptamer concentrations, which is quantified on a DNA microarray. Our assay takes advantage of the dual nature of aptamers as both folded protein-binding entities with defined shapes and unique nucleotide sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to rapidly discover unique protein signatures characteristic of various disease states. CONCLUSIONS/SIGNIFICANCE We describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine.

G. Rayment, D. J. Lyons

M. Shannon, P. Bohn, M. Elimelech et al.

M. Aresta, A. Dibenedetto

D. McQuade, A. E. Pullen, T. Swager

K. Choy

J. Banks, Hege S. Beard, Yixiang X. Cao et al.

M. Smanski, Hui Zhou, J. Claesen et al.

Yun Zhang, Yiwen Guo, Kaibo Sun et al.

Zn-doped carbon dots (Zn@C-210 calcination temperature at 210 °C and Zn@C-260 calcination temperature at 260 °C) were synthesized via an in situ calcination method using zinc citrate complexes as precursors, aiming to investigate the mechanisms of their distinctive fluorescence properties. A range of analytical methods were employed to characterize these nanomaterials. The mechanism study revealed that the coordination structure of Zn-O, formed through zinc doping, can induce a metal–ligand charge-transfer effect, which significantly increases the probability of radiative transitions between the excited and ground states, thereby enhancing the fluorescence intensity. The Zn@C-210 in a solid state and Zn@C-260 in water exhibited approximately 71.50% and 21.1% quantum yields, respectively. Both Zn@C-210 and Zn@C-260 exhibited excitation-independent luminescence, featuring a long fluorescence lifetime of 6.5 μs for Zn@C-210 and 6.2 μs for Zn@C-260. Impressively, zinc-doped CDs displayed exceptional biosafety, showing no acute toxicity even at 1000 mg/kg doses. Zn@C-210 has excellent fluorescence in a solid state, showing promise in anti-photobleaching applications; meanwhile, the dual functionality of Zn@C-260 makes it useful as a folate sensor and cellular imaging probe. These findings not only advance the fundamental understanding of metal-doped carbon dot photophysics but also provide practical guidelines for developing targeted biomedical nanomaterials through rational surface engineering and doping strategies.

Georgiy A. Ivanov, Dmitry P. Shornikov, Nikolay N. Samotaev et al.

A technique has been proposed and experimentally tested for measuring the hydrogen concentration in an inert atmosphere within a closed system. This method utilizes a metal-oxide-semiconductor field-effect capacity-type (MOSFEC) sensor under harsh conditions such as exposure to inert gases, pressure fluctuations, and varying temperatures. The measurement is performed during the thermal decomposition of metal hydrides in a liquid sodium environment. The developed measurement technique for determining hydrogen concentration released from metal hydride samples in a system with a closed gas path is cost-effective compared to standardized, resource-intensive open-volume flow measurement methods. The use of the developed MOSFEC sensor technique allows for rapid and efficient investigation of the in situ real-time dynamics of gas release from various metal hydride materials differing in their hydrogen content within a small closed volume. Additionally, this approach enables precise determination of the specific gas release temperatures.

Haixu Chen, Zhengbin Han, Shengliang Wang et al.

Abstract Liquid-liquid phase separation plays an important role in many natural and technological processes. Herein, we implement lateral microphase separation at the surface of oil micro-droplets suspended in water to prepare a range of discrete floating protein/polymer continuous two-dimensional (2D) heterostructures with variable interfacial domain structures and dynamics. We show that gel-like domains of bovine serum albumin (BSA) co-exist with fluid-like polyvinyl alcohol (PVA) regions at the oil droplet surface to produce floating heterostructures comprising a 2D phase-separated protein mesh or an array of discrete mobile protein rafts depending on the conditions employed. Enzymes are embedded in the discontinuous BSA domains to produce droplet-supported microphase-separated 2D reaction scaffolds that can be tuned for interfacial catalysis. Taken together, our work has general implications for the structural and functional augmentation of oil droplet interfaces and contributes to the surface engineering and functionality of droplet-based micro-reactors.

M. Aresta, A. Dibenedetto, E. Quaranta

Mohammad Abubakr, Suhaib Shahid, Iram Arman

Hydrogen production is a vital process in the quest for decarbonization and a sustainable future. This conversation explores the various technologies used in hydrogen production, such as steam methane reforming, electrolysis, and biomass gasification. These methods have different applications and efficiencies, but all contribute to the production of hydrogen gas. The future of hydrogen production looks promising, as it offers a clean and versatile energy source that can be used in various sectors, including transportation, industry, and power generation. The increasing demand for hydrogen in these sectors, coupled with the global push for decarbonization, highlights the importance of advancing hydrogen production technologies and infrastructure. This paper focuses broadly on different methods of hydrogen production like steam methane reforming, electrolysis, and biomass gasification. Steam methane reforming is currently the most common method, accounting for about 95% of global hydrogen production. Electrolysis is another method that uses electricity to split water into hydrogen and oxygen. Biomass gasification involves converting organic materials into hydrogen gas through a thermochemical process. The renewable energy sources considered are water and biomass and the methods considered are Electrolysis (grid), thermolysis, thermochemical water splitting, photoelectrochemical water splitting, and gasification. Electrolysis of water to produce hydrogen accounts for about 5% of the total hydrogen production. Statistically, global hydrogen production reached about USD 155.35 billion in 2022, with the majority of it being used in the petroleum refining and ammonia production industries. As for applications, hydrogen can be used as a fuel for fuel cell vehicles, as a feedstock for chemical processes, and as a storage medium for renewable energy.

Soichi Shirai, Takahiro Horiba, Hirotoshi Hirai

Quantum chemical calculations have attracted much attention as a practical application of quantum computing. Quantum computers can prepare superpositions of electronic states with various numbers of electrons on qubits. This special feature could be used to construct an efficient method for analyzing the structural variations of molecules and chemical reactions involving changes in molecular charge. The present work demonstrates a variational quantum eigensolver (VQE) algorithm based on a cost function ($L_{cost}$) having the same form as the grand potential of the grand canonical ensemble of electrons. The chemical potential of the electrons ($w$) is used as an input to these VQE calculations, whereas the molecular charge is not specified in advance but rather is a physical quantity that results from the calculations. Calculations involving model systems are carried out to show the viability of this new approach. Calculations for typical electron-donating and electron-accepting molecules using this technique yielded cationic, neutral or anionic species depending on the value of $w$. Models representing the adsorption of water or ammonia on copper-based catalysts predicted that oxidation would be associated with such adsorption. The molecular structures in which such reactions occurred were found to be dependent on the catalyst model, the adsorbed molecular species, and the value of $w$. These results arise because the electronic state that gives the lowest $L_{cost}$ value depends on the value of $w$ and the molecular structure. This behaviour was successfully simulated by the present VQE calculations.

Recep Vural, Aymen Khaleel, Ertugrul Basar

Reconfigurable intelligent surface (RIS)-assisted communication is a key enabling technology for next-generation wireless communication networks, allowing for the reshaping of wireless channels without requiring traditional radio frequency (RF) active components. While their passive nature makes RISs highly attractive, it also presents a challenge: RISs cannot actively identify themselves to user equipments (UEs). Recently, a new method has been proposed to detect and identify RISs by letting them modulate their identities in the signals reflected from their surfaces. In this letter, we first propose a new and simpler modulation method for RISs and then validate the concept of RIS detection and identification (RIS-ID) using a real-world experimental setup. The obtained results validate the RIS-ID concept and show the effectiveness of our proposed modulation method over different operating scenarios and systems settings.

Malik Hassanaly, Nicholas T. Wimer, Anne Felden et al.

The Quasi-Steady State Approximation (QSSA) can be an effective tool for reducing the size and stiffness of chemical mechanisms for implementation in computational reacting flow solvers. However, for many applications, stiffness remains, and the resulting model requires implicit methods for efficient time integration. In this paper, we outline an approach to formulating the QSSA reduction that is coupled with a strategy to generate C++ source code to evaluate the net species production rate, and the chemical Jacobian. The code-generation component employs a symbolic approach enabling a simple and effective strategy to analytically compute the chemical Jacobian. For computational tractability, the symbolic approach needs to be paired with common subexpression elimination which can negatively affect memory usage. Several solutions are outlined and successfully tested on a 3D multipulse ignition problem, thus allowing portable application across a chemical model sizes and GPU capabilities. The implementation of the proposed method is available at https://github.com/AMReX-Combustion/PelePhysics under an open-source license.