The XYZ states revisited Yuan, Chang-Zheng
International journal of modern physics. A, Particles and fields, gravitation, cosmology,
07/2018, Volume:
33, Issue:
21
Journal Article
Peer reviewed
Open access
The BESIII and the LHCb became the leading experiments in the study of the exotic states after the Belle and BaBar experiments finished their data taking in the first decade of this century. We ...review the progress in the study of the XYZ states at BESIII and LHCb experiments with their unique data samples in
e
+
e
−
annihilation at center-of-mass energies of 3.8–4.6 GeV and in
p
p
collision at center-of-mass energies 7, 8, and 13 TeV, respectively. With these data samples, we have deepened our understanding of the most famous charmonium-like states
X
(
3
8
7
2
)
,
Y
(
4
2
6
0
)
,
Z
c
(
3
9
0
0
)
, and
Z
c
(
4
4
3
0
)
, as well as other similar states like the
Y
(
4
1
4
0
)
and
X
(
3
8
2
3
)
. We review the progress in the study of these states and also discuss perspectives at future experiments.
Dearomatization reactions provide rapid access to structurally complex three-dimensional molecules from simple aromatic compounds. Plenty of reports have demonstrated their utilities in the synthesis ...of natural products, medicinal chemistry, and materials science in the last decades. Recently, visible-light mediated photocatalysis has emerged as a powerful tool to promote many kinds of transformations. The dearomatization reactions induced by visible-light have also made significant progress during the past several years. This review provides an overview of visible-light induced dearomatization reactions classified based on the manner in which aromaticity is disrupted.
An unprecedented highly enantioselective Ru‐catalyzed direct asymmetric reductive amination of α‐keto amides with ammonium salts has been disclosed, efficiently offering valuable enantioenriched ...N‐unprotected unnatural α‐amino acid derivatives bearing a broad range of aryl or alkyl α‐substituents. This protocol features easily accessible substrates, good functional‐group tolerance and excellent enantiocontrol, making it a good complementary approach to the known methods. Moreover, this method is also applicable to the preparation of N‐unprotected unnatural α‐amino acid derivatives containing an additional stereogenic center at the β‐position through a dynamic kinetic resolution (DKR) process. Convenient transformations of the obtained products into chiral N‐unprotected unnatural α‐amino acids, drug intermediates, peptides, and organocatalysts/ligands further showcase the utility of this method.
An unprecedented Ru‐catalyzed direct asymmetric reductive amination of α‐keto amides with ammonium salts has been achieved. This protocol provides an efficient and practical way for the synthesis of diverse enantioenriched α‐aryl‐ or alkyl‐substituted N‐unprotected unnatural α‐amino acids and N‐unprotected β‐branched α‐amino acids. Further follow‐up transformations enable access to drug intermediates, peptides, and organocatalysts/ligands.
Dearomatization of indoles provides efficient synthetic routes for substituted indolines. In most cases, indoles serve as nucleophiles. Reported here is an asymmetric dearomatization reaction of ...indole derivatives that function as electrophiles. The combination of a photocatalyst and chiral phosphoric acid open to air unlocks the umpolung reactivity of indoles, enabling their dearomatization with N‐hydroxycarbamates as nucleophiles. A variety of fused indolines bearing intriguing oxy‐amines were constructed in excellent yields with moderate to high enantioselectivities. Mechanistic studies show that the realization of two sequential single‐electron transfer oxidations of the indole derivatives is key, generating the configurationally biased carbocation species while providing the source of stereochemical induction. These results not only provide an efficient synthesis of enantioenriched indoline derivatives, but also offer a novel strategy for further designing asymmetric dearomatization reactions.
Unlocked: Dearomatization of indoles and their derivatives provides efficient synthetic routes for substituted indolines. For this asymmetric dearomatization reaction the indoles function as electrophiles. The combined utilization of a photocatalyst and chiral phosphoric acid (CPA) open to air unlocks the umpolung reactivity of indoles, enabling enantioselective dearomatization of indoles with N‐hydroxycarbamates as nucleophiles.
Plants face a more volatile environment than other organisms because of their immobility, and they have developed highly efficient mechanisms to adapt to stress conditions. Transcription factors, as ...an important part of the adaptation process, are activated by different signals and are responsible for the expression of stress-responsive genes. MYB transcription factors, as one of the most widespread transcription factor families in plants, participate in plant development and responses to stresses by combining with MYB cis-elements in promoters of target genes. MYB transcription factors have been extensively studied and have proven to be critical in the biosynthesis of secondary metabolites in plants, including anthocyanins, flavonols, and lignin. Multiple studies have now shown that MYB proteins play diverse roles in the responses to abiotic stresses, such as drought, salt, and cold stresses. However, the regulatory mechanism of MYB proteins in abiotic stresses is still not well understood. In this review, we will focus mainly on the function of Arabidopsis MYB transcription factors in abiotic stresses, especially how MYB proteins participate in these stress responses. We also pay attention to how the MYB proteins are regulated in these processes at both the transcript and protein levels.
Benefiting from new materials, innovative structures, advanced techniques, and multiple mechanisms, electromagnetic interference (EMI) shielding materials are developing vigorously. However, in the ...pursuit of high-efficiency EMI shielding performance, the electromagnetic pollution caused by excessive secondary reflection has not received enough attention. Electromagnetic radiation is not only harmful to the human body but also interferes with work and degrades the performance of electronic equipment, which brings a lot of trouble to our life and even threatens national defense security. Therefore, developing green EMI shielding is becoming a new hot topic. In this review, the definition and criterion of green EMI shielding are systematically clarified and summarized, and the regulation strategies of green EMI shielding through dielectric/magnetic “genes” and design philosophy are dissected. Moreover, the existing issues and challenges of green electromagnetic functional materials are summarized, and the applications in multifunctional green electromagnetic devices are prospected, which has important guiding significance for future research.
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Nonadiabatic holonomic quantum computation (NHQC) has been developed to shorten the construction times of geometric quantum gates. However, previous NHQC gates require the driving Hamiltonian to ...satisfy a set of rather restrictive conditions, reducing the robustness of the resulting geometric gates against control errors. Here we show that nonadiabatic geometric gates can be constructed in an extensible way, called NHQC+, for maintaining both flexibility and robustness against certain types of noises. Consequently, this approach makes it possible to incorporate most of the existing optimal control methods, such as dynamical decoupling, composite pulses, and a shortcut to adiabaticity, into the construction of single-looped geometric gates. Furthermore, this extensible approach of geometric quantum computation can be applied to various physical platforms such as superconducting qubits and nitrogen-vacancy centers. Specifically, we performed numerical simulation to show how the noise robustness in recent experimental implementations Phys. Rev. Lett. 119, 140503 (2017); Nat. Photonics 11, 309 (2017) can be significantly improved by our NHQC+.approach. These results cover a large class of new techniques combing the noise robustness of both geometric phase and optimal control theory.
Phthalocyanine (Pc) molecules exhibit high extinction coefficients in near-infrared region, rendering them well-suited for phototherapies, but most of their applications are limited to the field of ...photodynamic therapy (PDT). Herein, for the first time, we illustrate that Pc molecules can be endowed with excellent photothermal properties by means of structural regulation rather than formation of aggregates. Three representative Pc derivatives show efficient activities of photothermal therapy (PTT) against human hepatocellular carcinoma cells. Among them, copper phthalocyanine (PcC1) exhibits a high
PTT efficacy against mice bearing S180 tumors. The unique investigation in this article should light up a perspective of Pc's new applications for PTT, which enable to make up the inherent defects of PDT.
The grass family is one of the largest families in angiosperms and has evolved a characteristic inflorescence morphology, with complex branches and specialized spikelets. The origin and development ...of the highly divergent inflorescence architecture in grasses have recently received much attention. Increasing evidence has revealed that numerous factors, such as transcription factors and plant hormones, play key roles in determining reproductive meristem fate and inflorescence patterning in grasses. Moreover, some molecular switches that have been implicated in specifying inflorescence shapes contribute significantly to grain yields in cereals. Here, we review key genetic and molecular switches recently identified from two model grass species, rice (Oryza sativa) and maize (Zea mays), that regulate inflorescence morphology specification, including meristem identity, meristem size and maintenance, initiation and outgrowth of axillary meristems, and organogenesis. Furthermore, we summarize emerging networks of genes and pathways in grass inflorescence morphogenesis and emphasize their evolutionary divergence in comparison with the model eudicot Arabidopsis thaliana. We also discuss the agricultural application of genes controlling grass inflorescence development.
Water pollution by toxic organic dyes is one of the most critical health and environmental problems worldwide. By means of molecular dynamics method, the present work aims to evaluate the ...applicability of montmorillonite (Mt) modified by hexadecyltrimethylammonium cations (HDTMA+) compared to unmodified Na-Mt for the adsorption of cationic methylene blue (MB) dye. The results showed that the adsorption energy of MB on both HDTMA-Mt and Na-Mt absorbent ranged from − 100 to − 250 kJ/mol, indicating the effectiveness of two types of adsorbents in dye water treatment. The highest adsorption energy was found at w = 50% in each adsorbent system. Adsorption mechanisms of MB depend on molecular orientations, which is influenced by the surfactant and water content. The adsorption mechanism of MB is chemisorption dominated by strong electrostatic interaction between CH3 groups of MB and oxygen atoms of Mt surfaces. Besides, physisorption also plays a minor role in MB orientations. It is found that the existence of cationic surfactants can slightly improve the adsorption capacity of MB only at higher water content through enlarging the interlayer space of Mt and reducing mobility of MB. However, there will be a negative impact on the reduction of adsorption sites for dyes especially at low water content. Our results provide a possible application for swelling clay minerals being a promising adsorbent for dyes-surfactants co-existing wastewater treatment.
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•The dynamic adsorption processes of MB dye on HDTMA-Mt and Na-Mt are simulated.•There is no significant enhancement for the adsorption energy of MB in the presence of surfactants.•MB molecular orientations are influenced by both surfactant and water content.•The adsorption mechanism of MB is chemisorption dominated by strong electrostatic interaction.
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