(Benzoato-κO)(benzoic acid-κO)(4,4′-dimethyl-2,2′-bipyridine-κ2 N,N′)hydroxidocopper(II) monohydrate

In the structure of the title complex, [Cu(C7H5O2)(OH)(C12H12N2)(C7H6O2)]·H2O, the CuII ion is penta­coordinated in a tetra­gonal-pyramidal geometry with one O atom of a hydroxide group, one O atom of a benzoate anion and two N atoms of a 4,4′-dimethyl-2,2′-bipyridine ligand occupying the basal plane, and one O atom of a benzoic acid mol­ecule located at the apical site. The title complex was refined with a metal-coordinated OH group and a ‘free’ benzoic acid molecule, although it can be assumed that the proton is delocalized between the OH and the COOH group. The uncoordinated water mol­ecule is equally disordered over two positions. The structure displays O—H⋯O hydrogen bonding

Dibenzoato-κO;κ2 O,O′-(6,6′-dimethyl-2,2′-bipyridine-κ2 N,N′)zinc(II)–benzoic acid (1/1)

In the crystal structure of the title compound, [Zn(C6H5COO)2(C12H12N2)]·C6H5COOH, the Zn atom is penta­coordinated in distorted square-pyramidal geometry by two O atoms of a benzoate anion and two N atoms of a 6,6′-dimethyl-2,2′-bipyridine ligand occupying the basal plane and an O atom of another benzoate anion located at the apical site. In the crystal structure, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π inter­actions are present

Vasorelaxation Effect of Estrone Derivate EA204 in Rabbit Aorta

Estrogen and its derivatives exert vascular protective effects, but the underlying mechanisms remain to be studied fully. Objective. To investigate the vasorelaxation effect and related mechanisms of an estrone derivate EA204[3-(2-piperidin-1-yl)-ethoxy-estra-1, 3, 5 (10)-trien-17-one] on isolated arterial preparation from rabbit thoracic aorta. Methods. Aortic rings from rabbit thoracic aorta were prepared and held in small organ bath filled with Krebs solution; tension change was recorded by a multichannel physiological signal collection and handling system. Results. EA204 (10−5 to 10−3 M) induced a concentration-dependent relaxation of aortic rings with endothelium and without endothelium. In denuded arterial preparations, EA204 had a potent relaxing effect on isolated arterial preparations contracted with phenylephrine, norepinephrine, and high-K+ solution or BaCl2. Mechanism study indicates that EA204 relaxes aortic rings by inhibiting Ca2+ channels (both receptor-operating Ca2+ channels and the voltage-dependent Ca2+ channels were involved) to decrease extracellular Ca2+ influx and intracellular Ca2+ release. EA204 is different from verapamil, which is a noncompetitive inhibitor of Ca2+ channels. In addition, K+ channels opening may contribute to this vasorelaxation effect. Conclusion. EA204 had a potent endothelium-independent relaxing effect on isolated arterial preparation by inhibiting Ca2+ channels and opening K+ channels. The results suggest that EA204 is a potential compound for treatment of cardiovascular diseases in postmenopausal women

Randomness-enhanced expressivity of quantum neural networks

As a hybrid of artificial intelligence and quantum computing, quantum neural networks (QNNs) have gained significant attention as a promising application on near-term, noisy intermediate-scale quantum (NISQ) devices. Conventional QNNs are described by parametrized quantum circuits, which perform unitary operations and measurements on quantum states. In this work, we propose a novel approach to enhance the expressivity of QNNs by incorporating randomness into quantum circuits. Specifically, we introduce a random layer, which contains single-qubit gates sampled from an trainable ensemble pooling. The prediction of QNN is then represented by an ensemble average over a classical function of measurement outcomes. We prove that our approach can accurately approximate arbitrary target operators using Uhlmann's theorem for majorization, which enables observable learning. Our proposal is demonstrated with extensive numerical experiments, including observable learning, R\'enyi entropy measurement, and image recognition. We find the expressivity of QNNs is enhanced by introducing randomness for multiple learning tasks, which could have broad application in quantum machine learning.Comment: 6 pages, 4 figure

Integrating the impacts of vegetation coverage on ecosystem services to determine ecological restoration targets for adaptive management on the Loess Plateau, China

Achieving sustainable resource management is essential to address the rising demand for ecosystem services. The absence of targeted vegetation restoration based on ecological function positioning has, nevertheless, made it challenging to effectively combat the ecological decline. This study attempted to classify four dominant ecological function areas based on the assessment of water conservation, soil retention, habitat quality, and food supply and determined the vegetation coverage threshold by exploring the trade-offs among ecosystem services and constraint effects between ecosystem services and vegetation coverage. The results highlighted the impacts of ecosystem services on vegetation coverage across the years 1990, 2000, 2010, and 2020 and established differentiated ecological restoration targets. The optimal vegetation coverage in the water conservation area was found to be 58%–63%, in the soil retention area was 52%–56%, in the food supply area was 34%–40%, and in the habitat quality area was 65%–70%. Finally, the study identified the subwatersheds with reasonable vegetation coverage, excessive restoration, and those that failed to reach the optimal vegetation coverage to develop targeted restoration strategies for each subwatershed according to its unique vegetation conditions. This study provides valuable insights into the specification of differentiated vegetation coverage targets and serves as a useful tool for more effective ecosystem planning and management.</p

Preparation of an antitumor and antivirus agent: chemical modification of α-MMC and MAP30 from Momordica Charantia L. with covalent conjugation of polyethyelene glycol

Background: Alpha-momorcharin (α-MMC) and momordica anti-HIV protein (MAP30) derived from Momordica charantia L. have been confirmed to possess antitumor and antivirus activities due to their RNA-N-glycosidase activity. However, strong immunogenicity and short plasma half-life limit their clinical application. To solve this problem, the two proteins were modified with (mPEG)[subscript 2]-Lys-NHS (20 kDa). Methodology/principal findings: In this article, a novel purification strategy for the two main type I ribosome-inactivating proteins (RIPs), α-MMC and MAP30, was successfully developed for laboratory-scale preparation. Using this dramatic method, 200 mg of α-MMC and about 120 mg of MAP30 was obtained in only one purification process from 200 g of Momordica charantia seeds. The homogeneity and some other properties of the two proteins were assessed by gradient SDS-PAGE, electrospray ionization quadruple mass spectrometry, and N-terminal sequence analysis as well as Western blot. Two polyethylene glycol (PEG)ylated proteins were synthesized and purified. Homogeneous mono-, di-, or tri-PEGylated proteins were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry. The analysis of antitumor and antivirus activities indicated that the serial PEGylated RIPs preserved moderate activities on JAR choriocarcinoma cells and herpes simplex virus-1. Furthermore, both PEGylated proteins showed about 60%–70% antitumor and antivirus activities, and at the same time decreased 50%–70% immunogenicity when compared with their unmodified counterparts. Conclusion/significance: α-MMC and MAP30 obtained from this novel purification strategy can meet the requirement of a large amount of samples for research. Their chemical modification can solve the problem of strong immunogenicity and meanwhile preserve moderate activities. All these findings suggest the potential application of PEGylated α-MMC and PEGylated MAP30 as antitumor and antivirus agents. According to these results, PEGylated RIPs can be constructed with nanomaterials to be a targeting drug that can further decrease immunogenicity and side effects. Through nanotechnology we can make them low-release drugs, which can further prolong their half-life period in the human body

Chemical differences among collapsing low-mass protostellar cores

Organic features lead to two distinct types of Class 0/I low-mass protostars: hot corino sources, and warm carbon-chain chemistry (WCCC) sources. Some observations suggest that the chemical variations between WCCC sources and hot corino sources are associated with local environments, as well as the luminosity of protostars. We conducted gas-grain chemical simulation in collapsing protostellar cores, and found that the fiducial model predicts abundant carbon-chain molecules and COMs, and reproduces WCCC and hot corino chemistry in the hybrid source L483. By changing values of some physical parameters, including the visual extinction of ambient clouds ($A_{\rm V}^{\rm amb}$), the cosmic-ray ionization rate ($\zeta$), the maximum temperature during the warm-up phase ($T_{\rm max}$), and the contraction timescale of protostars ($t_{\rm cont}$), we found that UV photons and cosmic rays can boost WCCC features by accelerating the dissociation of CO and CH$_4$ molecules. On the other hand, UV photons can weaken the hot corino chemistry by photodissociation reactions, while the dependence of hot corino chemistry on cosmic rays is relatively complex. The $T_{\rm max}$ does not affect WCCC features, while it can influence hot corino chemistry by changing the effective duration of two-body surface reactions for most COMs. The long $t_{\rm cont}$ can boost WCCC and hot corino chemistry, by prolonging the effective duration of WCCC reactions in the gas phase and surface formation reactions for COMs, respectively. Subsequently, we ran a model with different physical parameters to reproduce scarce COMs in prototypical WCCC sources. The scarcity of COMs in prototypical WCCC sources can be explained by insufficient dust temperature in the inner envelopes to activate hot corino chemistry. Meanwhile, the High $\zeta$ and the long $t_{\rm cont}$ favors the explanation for scarce COMs in these sources.Comment: Accepted for publication in A&A, 18 pages, 10 figure