The extensive research of two-dimensional layered materials has revealed that valleys, as energy extrema in momentum space, could offer a new degree of freedom for carrying information. Based on this ...concept, researchers have predicted valley-Hall topological insulators that could support valley-polarized edge states at non-trivial domain walls. Recently, several kinds of photonic and sonic crystals have been proposed as classical counterparts of valley-Hall topological insulators. However, direct experimental observation of valley-polarized edge states in photonic crystals has remained difficult until now. Here, we demonstrate a designer surface plasmon crystal comprising metallic patterns deposited on a dielectric substrate, which can become a valley-Hall photonic topological insulator by exploiting the mirror-symmetry-breaking mechanism. Topological edge states with valley-dependent transport are directly visualized in the microwave regime. The observed edge states are confirmed to be fully valley-polarized through spatial Fourier transforms. Topological protection of the edge states at sharp corners is also experimentally demonstrated.
The pore dimension and surface property directly dictate the transport of guests, endowing diverse gas selective adsorptions to porous materials. It is highly relevant to construct metal−organic ...frameworks (MOFs) with designable functional groups that can achieve feasible pore regulation to improve their separation performances. However, the role of functionalization in different positions or degrees within framework on the separation of light hydrocarbon has rarely been emphasized. In this context, four isoreticular MOFs (TKL‐104−107) bearing dissimilar fluorination are rationally screened out and afforded intriguing differences in the adsorption behavior of C2H6 and C2H4. Ortho‐fluoridation of carboxyl allows TKL‐105−107 to exhibit enhanced structural stabilities, impressive C2H6 adsorption capacities (>125 cm3 g−1) and desirable inverse selectivities (C2H6 over C2H4). The more modified ortho‐fluorine group and meta‐fluorine group of carboxyl have improved the C2H6/C2H4 selectivity and adsorption capacity, respectively, and the C2H6/C2H4 separation potential can be well optimized via linker fine‐fluorination. Meanwhile, dynamic breakthrough experiments proved that TKL‐105−107 can be used as highly efficient C2H6‐selective adsorbents for C2H4 purification. This work highlights that the purposeful functionalization of pore surfaces facilitates the assembly of highly efficient MOF adsorbents for specific gas separation.
The C2H6/C2H4 separation potential is successfully optimized by virtue of linker fine‐fluorination within an isoreticular cadmium‐organic framework platform. Due to the integrated balance between adsorption selectivity and capacity, fluorinated TKL‐105−107 exhibit distinct one‐step ethylene purification capabilities from C2H6/C2H4 mixtures, shedding light on the effect of tailor‐made fluorine functionalization on the advanced separation/purification applications.
Objectives
Withanolides are a group of modified C28 ergostane‐type steroids with a C‐22, C‐26 δ‐lactone side chain or a C‐23, C‐26 γ‐lactone side chain. They enjoy a limited distribution in the plant ...kingdom and predominantly occur in several genera of Solanaceae. Of which, the genus Physalis is an important resource for this type of natural molecules. The present review aims to comprehensively illustrate the structural characteristics and classification of withanolides, and particularly focus on the progression on phytochemical and pharmacological aspects of withanolides from Physalis ranging from January 2015 to June 2019.
Key findings
Approximately 351 natural withanolides with novel and unique structures have so far been identified from genus Physalis, mainly isolated from the species of P. angulata and P. peruviana. Withanolides demonstrated diverse biological activity, such as anticancer, anti‐inflammatory, antimicrobial, immunoregulatory, trypanocidal and leishmanicidal activity. Their observed pharmacological functions supported the uses of Physalis species in traditional or folk medicines.
Summary
Due to their unique structure skeleton and potent bioactivities, withanolides are regarded to be promising drug candidates, particularly for developing anticancer and anti‐inflammatory agents. Further investigations for discovering novel withanolides of genus Physalis, exploiting their pharmacological values and evaluating their potency as therapeutic agents are significant work.
Recently, increasing attention has been paid to natural polysaccharides for their low cost, biocompatibility and biodegradability. Quaternization is a modification method to improve the solubility ...and antibacterial ability of natural polysaccharides. Water-soluble derivatives of cellulose, chitin and chitosan offer the prospect of diverse applications in a wide range of fields, such as antibacterial products, drug delivery, wound healing, sewage treatment and ion exchange membranes. By combining the inherent properties of cellulose, chitin and chitosan with the inherent properties of the quaternary ammonium groups, new products with multiple functions and properties can be obtained. In this review, we summarized the research progress in the applications of quaternized cellulose, chitin and chitosan in recent five years. Moreover, ubiquitous challenges and personal perspectives on the further development of this promising field are also discussed.
The formation of zygote is the beginning of mammalian life, and dynamic epigenetic modifications are essential for mammalian normal development. H3K27 di-methylation (H3K27me2) and H3K27 ...tri-methylation (H3K27me3) are marks of facultative heterochromatin which maintains transcriptional repression established during early development in many eukaryotes. However, the mechanism underlying establishment and regulation of epigenetic asymmetry in the zygote remains obscure. Here we show that maternal EZH2 is required for the establishment of H3K27me3 in mouse zygotes. However, combined immunostaining with ULI-NChIP-seq (ultra-low-input micrococcal nuclease-based native ChIP-seq) shows that EZH1 could partially safeguard the role of EZH2 in the formation of H3K27me2. Meanwhile, we identify that EHMT1 is involved in the establishment of H3K27me2, and that H3K27me2 might be an essential prerequisite for the following de novo H3K27me3 modification on the male pronucleus. In this work, we clarify the establishment and regulatory mechanisms of H3K27me2 and H3K27me3 in mouse zygotes.
Conditioned pain modulation (CPM) is impaired in people with chronic pain such as knee osteoarthritis (KOA). The purpose of this randomized, controlled clinical trial was to investigate whether ...strong electroacupuncture (EA) was more effective on chronic pain by strengthening the CPM function than weak EA or sham EA in patients with KOA.
In this multicenter, three-arm parallel, single-blind randomized controlled trial, 301 patients with KOA were randomly assigned. Patients were randomized into three groups based on EA current intensity: strong EA (> 2 mA), weak EA (< 0.5 mA), and sham EA (non-acupoint). Treatments consisted of five sessions per week, for 2 weeks. Primary outcome measures were visual analog scale (VAS), CPM function, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
Three hundred one patients with KOA were randomly assigned, among which 271 (90.0%) completed the study (mean age 63.93 years old). One week of EA had a clinically important improvement in VAS and WOMAC but not in CPM function. After 2 weeks treatment, EA improved VAS, CPM, and WOMAC compared with baseline. Compared with sham EA, weak EA (3.8; 95% CI 3.45, 4.15; P < .01) and strong EA (13.54; 95% CI 13.23, 13.85; P < .01) were better in improving CPM function. Compared with weak EA, strong EA was better in enhancing CPM function (9.73; 95% CI 9.44, 10.02; P < .01), as well as in reducing VAS and total WOMAC score.
EA should be administered for at least 2 weeks to exert a clinically important effect on improving CPM function of KOA patients. Strong EA is better than weak or sham EA in alleviating pain intensity and inhibiting chronic pain.
This study was registered with the Chinese Clinical Trial Registry ( ChiCTR-ICR-14005411 ), registered on 31 October 2014.
In this paper, the finite-time coordination behavior of multiple Euler-Lagrange systems in cooperation-competition networks is investigated, where the coupling weights can be either positive or ...negative. Then, two auxiliary variables about the information exchange among agents are designed, and the finite-time distributed protocol is proposed based on the auxiliary variables and the property of the Euler-Lagrange system. By combining the approach of adding a power integrator with the homogeneous domination method, it is shown that finite-time bipartite consensus can be achieved if the cooperation-competition network is structurally balanced and the parameters of the distributed protocol are chosen appropriately; otherwise, finite-time distributed stabilization can be achieved. Furthermore, from the perspective of network decomposition, the finite-time coordination behavior is further considered, and some sufficient conditions about the cooperation subnetwork and the competition subnetwork are obtained. As an extension, finite-time coordination behavior only with partial state information of the neighbors is discussed, and some similar results are obtained. Finally, four numerical examples are shown for illustration.
Surface-protecting ligands, as a major component of metal nanoclusters (MNCs), can dominate molecular characteristics, performance behaviors, and biological properties of MNCs, which brings diversity ...and flexibility to the nanoclusters and largely promotes their applications in optics, electricity, magnetism, catalysis, biology, and other fields. We report herein the design of a new kind of water-soluble luminescent gold nanoclusters (AuNCs) for enzyme-activatable charge transfer (CT) based on the ligand engineering of AuNCs with 6-mercaptopurine ribonucleoside (MPR). This elaborately designed cluster, Au
5
(MPR)
2
, can form a stable intramolecular CT state after light excitation, and exhibits long-lived color-tunable phosphorescence. After the cleavage by purine nucleoside phosphorylase (PNP), the CT triplet state can be easily directed to a low-lying energy level, leading to a bathochromic shift of the emission band accompanied by weaker and shorter-lived luminescence. Remarkably, these ligand-engineered AuNCs show high affinity towards PNP as well as decent performance for analyzing and visualizing enzyme activity and related drugs. The work of this paper provides a good example for diversifying physicochemical properties and application scenarios of MNCs by rational ligand engineering, which will facilitate future interest and new strategies to precisely engineer solution-based nanocluster materials.
We report herein a new kind of water-soluble gold nanoclusters (AuNCs) for enzyme-activatable charge transfer, based on the ligand engineering of AuNCs with 6-mercaptopurine ribonucleoside (MPR).
Stroke is the most common cerebrovascular disease, the second leading cause of death behind heart disease and is a major cause of long-term disability worldwide. Currently, systemic immunomodulatory ...therapy based on intravenous cells is attracting attention. The immune response to acute stroke is a major factor in cerebral ischaemia (CI) pathobiology and outcomes. Over the past decade, the significant contribution of the spleen to ischaemic stroke has gained considerable attention in stroke research. The changes in the spleen after stroke are mainly reflected in morphology, immune cells and cytokines, and these changes are closely related to the stroke outcomes. Autonomic nervous system (ANS) activation, release of central nervous system (CNS) antigens and chemokine/chemokine receptor interactions have been documented to be essential for efficient brain-spleen cross-talk after stroke. In various experimental models, human umbilical cord blood cells (hUCBs), haematopoietic stem cells (HSCs), bone marrow stem cells (BMSCs), human amnion epithelial cells (hAECs), neural stem cells (NSCs) and multipotent adult progenitor cells (MAPCs) have been shown to reduce the neurological damage caused by stroke. The different effects of these cell types on the interleukin (IL)-10, interferon (IFN), and cholinergic anti-inflammatory pathways in the spleen after stroke may promote the development of new cell therapy targets and strategies. The spleen will become a potential target of various stem cell therapies for stroke represented by MAPC treatment.
Cavernous nerve injury is an important cause of erectile dysfunction (ED). Although protective nerve technology has been widely used in nerve-sparing radical prostatectomy (nsRP), the incidence of ED ...is still very high after surgery. The purpose of our study was to evaluate erectile function (EF) and penile length in the non-erectile state (PLNES) following scheduled phosphodiesterase 5 inhibitor (PDE5i), vacuum erectile device (VED) treatment, and combination therapy after nsRP. One hundred patients with localized prostate cancer and normal EF were randomized to scheduled PDE5i group, VED treatment group, a combined treatment group, and the control group without any intervention. The International Index of Erectile Function-5 (IIEF-5) scores and PLNES were evaluated after 6 months and 12 months of treatment. Sexual Encounter Profile (SEP-Question 2 and SEP-Question 3) were evaluated after 12 months of treatment. Ninety-one of the 100 randomized patients completed the study. We found that the 5 mg tadalafil once a day (OaD) combined with VED can help improve IIEF-5 scores in nsRP patients after both 6 months and 12 months. VED alone or combined with tadalafil OaD can help patients maintain PLNES. VED combined with tadalafil OaD can improve the rate of successful penetration (SEP-Question 2) after 12 months. There were no significant differences in the return to target EF after 12 months among the groups. No significant correlation was noted between the variables and return to target EF (IIEF ≥ 17), and between the variables and effective shortening of the patient's penis (shortening ≥ 1 cm) after 12 months of intervention.
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