Publications by authors named "Shubin Liu"

As a major food crop, maize is highly susceptible to pathogenic bacteria, which greatly reduces its yield and quality. Metabolomics reveals physiological and biochemical changes in organisms and aids in analyzing metabolic changes caused by various factors. This study utilized metabolomics to examine maize's metabolic changes after NCLB infestation, aiming to uncover related pathways and potential biomarkers.

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The α-effect is an important concept in chemistry and biochemistry, namely that for a bimolecular nucleophilic substitution (S2) reaction, the nucleophilicity of an atom is increased if its adjacent (α) atom has a lone pair of electrons, lowering the reaction barrier height and increasing the reaction rate. However, exceptions exist, even for very similar structural motifs. We investigate what underlies the α-effect in gas-phase S2 reactions using two total energy decomposition schemes based on density functional theory (DFT) and find that steric effects play an important role, but that there exists a strong linear correlation between the α-effect and electrostatic contribution, suggesting that it is the electrostatic interaction that stabilizes the transition state and leads to the α-effect in gas-phase S2 reactions.

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Covalent bonding and noncovalent interactions are important chemical concepts and how to identify them has been of current interest in the literature. Within the framework of density functional theory (DFT), we recently proposed a few qualitative descriptors to categorize different types of interactions with Pauli energy and its derivatives. In this work, we expand the scope by including the quantities derived from energetic information, which were recently proposed and thoroughly investigated by us from the framework of information-theoretic approach (ITA) in DFT.

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Long-Time Coherent Integration (LTCI) utilizes digital integration to combine multiple coherent cycles, thereby improving the signal-to-noise ratio (SNR). Our previous work introduced single-bit LTCI, an approach optimized for FPGA implementation, but faced challenges of output saturation at high SNR levels and inherent limitations in SNR gain (SNRG), which are insufficient for certain applications. This paper presents a threshold tracking method that improves the performance of single-bit LTCI in high-SNR scenarios.

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Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare lung cancer characterized by early metastasis and invasion. It is predominantly diagnosed at a locally advanced or metastatic stage, hindering the possibility of surgical intervention. However, a standard treatment for advanced PSC remains unestablished.

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We present a fully digital servo optimized for ultra-stable laser frequency stabilization. Experiments such as optical clock experiments can achieve high laser frequency stability, imposing high bandwidth, high precision, and low noise requirements on servo systems. The laser system utilizes the Pound-Drever-Hall method, employing an ultra-stable cavity to generate an error signal for servo input.

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This paper describes the development of a portable neutron-gamma detector for environmental radiation monitoring based on the CLYC crystal. It can function as a gamma spectrometer, gamma dosimeter, and thermal neutron counter. The upper measurement limit of gamma dose rate is approximately 6 mSv/h by using the proposed current mode in CLYC crystal and PMT.

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Article Synopsis
  • Researchers are developing artificial compound eyes (CE) modeled after arthropods to improve imaging technology, but current designs have issues with defocusing when used with standard CMOS cameras.
  • A new compact camera inspired by South American shrimps utilizes a deep learning method to achieve clear wide-field imaging without complex hardware, significantly simplifying its design.
  • The innovative camera, weighing only 5.4g and measuring 3 x 3 cm, shows superior resolution and 3D trajectory tracking, making it suitable for applications in nano-optics, medical endoscopy, and robotics.
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Context: We rationalize the excellent performance of information-theoretic descriptors for predicting atomic and molecular polarizabilities. It seems that descriptors which capture information about the change in valence-shell structure, especially the relative Fisher information measures, are particularly useful. Using this, we can rationalize why the G3 form of the relative Fisher information, which measures the deviation of effective nuclear charge between an atom-in-a-molecule and the reference pro-atom, is especially effective as a predictor of molecular polarizability.

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Context: Electrophilicity and nucleophilicity are two vastly important chemical concepts gauging the capability of atoms in molecules to accept and donate the maximal number of electrons. In our earlier studies, we proposed to simultaneously quantify them using the Kullback-Leibler divergence from the information-theoretic approach in density functional theory. However, several issues with this scheme remain to be clarified such as its general validity, predictability, and relationship with other information-theoretic quantities.

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The steric effect is one of the most widely used concepts for chemical understanding in publications and textbooks, yet a well-accepted formulation of this effect is still elusive. Experimentally, this concept was quantified by the acid-catalyzed hydrolysis of esters, yielding the so-called Taft steric parameter. Theoretically, we recently proposed a density-based scheme to quantify the effect from density functional theory.

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Article Synopsis
  • * The GS115-NTaer vaccine was shown to significantly enhance both the innate and cellular immune responses in the zebrafish, resulting in increased levels of important immune proteins and antibodies.
  • * Additionally, the vaccination altered the gut microbiota composition, contributing to improved survival rates against challenges, with GS115-NTaer vaccinated fish showing better survival compared to control groups, suggesting a valuable approach for enhancing fish immunity.
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Fused-ring electronic acceptors (FREAs) have transformed the field of organic solar cells. However, the prevailing syntheses of FREAs suffer from low yield, difficulty in separation, and high cost. Here, we report new and streamlined syntheses with three distinctive key steps.

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The enantioenriched lactams disclosed in this work are synthesized concisely in four steps. In the penultimate reaction, a benzylamine species complexes with a chiral phosphoric acid to produce benzo-fused δ-lactams equipped with an all-carbon quaternary stereocenter. Partial and full reductions were carried out on the ester and amide moieties, and a Suzuki-Miyaura cross-coupling expanded the molecule from the aromatic ring.

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The Hohenberg-Kohn theorem of density functional theory (DFT) stipulates that energy is a universal functional of electron density in the ground state, so energy can be thought of having encoded essential information for the density. Based on this, we recently proposed to quantify energetic information within the framework of information-theoretic approach (ITA) of DFT (. , 157, 101103).

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Appreciating reactivity in terms of physicochemical effects for chemical processes is one of the most important undertakings in chemistry. While transition state (TS) theory provides the framework enabling the reliable calculation of the barrier height for a given elementary step, analytical tools are necessary to gain insight into key factors governing the different processes during chemical reactions. In this contribution, we partition the potential energy surface of an elementary step along the intrinsic coordinate into three segments, the so-called Pre-TS, TS, and Post-TS regions, and then determine the most important factors dictating each segment.

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Article Synopsis
  • LGG is a type of good bacteria that usually helps keep our intestines healthy and fights bad germs.
  • In an experiment with zebrafish, scientists found that a part of LGG called SpaC can actually hurt the fish's intestines by making their cells die in a specific way.
  • This research shows that probiotics from different creatures, like LGG from humans, might not always be safe for other animals because they can cause problems in their bodies.
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Hot-rolled backup rolls are widely used in steel rolling and usually need to be repaired by arc hardfacing after becoming worn. However, a corrugated-groove defect commonly occurs on the roll surface due to the uneven hardness distribution in the hardfacing layers, affecting the proper usage of the roll. Accordingly, a new swing-arc submerged arc welding (SA-SAW) process is proposed to attempt to solve this drawback.

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This study aimed to elucidate the effects of dietary fermented products of Bacillus velezensis T23 on the growth, immune response and gut microbiota in Pacific white shrimp (Litopenaeus vannamei). Shrimp were fed with diets containing fermentation products of B. velezensis T23 at levels of (0, 0.

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Methods enabling the broad diversification of C(sp)-H bonds from a common intermediate are especially valuable in chemical synthesis. Herein, we report a site-selective (N-phenyltetrazole)thiolation of aliphatic and (hetero)benzylic C(sp)-H bonds using a commercially available disulfide to access N-phenyltetrazole thioethers. The thioether products are readily elaborated in diverse fragment couplings for C-C, C-O, or C-N construction.

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In this work, we have observed that some chiral boron clusters (B16-, B20-, B24-, and B28-) can simultaneously have helical molecular orbitals and helical spin densities; these seem to be the first compounds discovered to have this intriguing property. We show that chiral Jahn-Teller distortion of quasi-planar boron clusters drives the formation of the helical molecular spin densities in these clusters and show that elongation/enhancement in helical molecular orbitals can be achieved by simply adding more building blocks via a linker. Aromaticity of these boron clusters is discussed.

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It is tenable to argue that nobody can predict the future with certainty, yet one can learn from the past and make informed projections for the years ahead. In this Perspective, we overview the status of how theory and computation can be exploited to obtain chemical understanding from wave function theory and density functional theory, and then outlook the likely impact of machine learning (ML) and quantum computers (QC) to appreciate traditional chemical concepts in decades to come. It is maintained that the development and maturation of ML and QC methods in theoretical and computational chemistry represent two paradigm shifts about how the Schrödinger equation can be solved.

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QM/MM methods have been used to study electronic structure properties and chemical reactivity in complex molecular systems where direct electronic structure calculations are not feasible. In our previous work, we showed that non-polarizable force fields, by design, describe intermolecular interactions through pairwise interactions, overlooking many-body interactions involving three or more particles. In contrast, polarizable force fields account partially for many-body effects through polarization, but still handle van der Waals and permanent electrostatic interactions pairwise.

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