"Matching Rule" for Generation, Modulation and Amplification of Circularly Polarized Luminescence.

ConspectusCircularly polarized luminescence (CPL) generated by chiral luminescent systems has sparked enormous attention in multidisciplinary field as it brings infinite potential for applications, such as 3D optical displays, biological probes, and chiroptical sensors. Satisfying both the conditions of chirality and luminescence (including fluorescence or phosphorescence) is a prerequisite for constructing CPL materials. In this regard, whether in organic, inorganic, or hybrid systems, chiral and luminescent components generally involve effective coupling through covalent or noncovalent bonds. For covalent interactions, such as the copolymerization of chiral and luminescent monomers, although covalent bonds provide high stability for the system, they inevitably involve tedious preparation procedures that connect chirality and luminescence together. For noncovalent bonds, take supramolecular assembly as an example, chiral elements and achiral light-emitting units are chiral transferred through intermolecular interactions, and their advantages include the diversity of luminescent and chiral building blocks, the stimuli responsiveness brought by noncovalent bonds, as well as the potential amplification of CPL signals by coassembly. However, the stability of the assembly system may be poor, and the assembly chiroptical performance and morphology are difficult to predict. Gratifyingly, matching rule that do not rely on covalent together with noncovalent interactions allows for the effortless construction, modulation, as well as amplification of CPL systems.In this Account, we overview different strategies based on matching rule, including fluorescence-selective absorption, circularly polarized reflection, and circularly polarized fluorescence energy transfer (CPF-ET). Examples of these strategies are illustrated with a focus on helical polymers in light of their appealing structures and wide uses. For instance, for fluorescence-selective absorption, chiral helical polymers can convert racemic fluorescence light into a circularly polarized one with specific handedness by simply overlapping the helical polymer's circular dichroism (CD) spectra with the luminophore's emission spectra. For circularly polarized reflection, employing the selective reflection of certain handedness's circularly polarized light, the high helical twisting power (HTP) of the helical polymer in the cholesteric liquid crystals (N*-LCs) gives the system high glum. Additionally, for CPF-ET, only the emission spectrum of the donor and the absorption (or excitation) spectrum of the achiral acceptor are required to overlap, and no covalent or noncovalent interactions between the two are required. An outlook for the CPL materials related to matching rule which will avail the optimization and extension of this intriguing approach concludes the Account. We hope that the Account will offer insightful inspiration for the flourishing progress of chiroptical systems and present exciting opportunities.

Normal reference values for magnetic resonance imaging measurements of the fetal internal jugular veins in middle and late pregnancy.

BACKGROUND: At present, there is a lack of normal magnetic resonance imaging (MRI) morphometric reference values for fetal internal jugular veins during middle and late pregnancy. OBJECTIVE: We used MRI to assess the morphology and cross-sectional area of the internal jugular veins of fetuses during middle and late pregnancy and to explore the clinical value of these parameters. MATERIALS AND METHODS: The MRI images of 126 fetuses in middle and late pregnancy were retrospectively analysed to determine the optimal sequence for imaging the internal jugular veins. Morphological observation of the fetal internal jugular veins in each gestational week was carried out, lumen cross-sectional area was measured and the relationship between these data and gestational age was analysed. RESULTS: The balanced steady-state free precession sequence was superior to other MRI sequences used for fetal imaging. The cross section of fetal internal jugular veins was predominantly circular in both the middle and late stages of pregnancy, however the prevalence of an oval cross section was significantly higher in the late gestational age group. The cross-sectional area of the lumen of the fetal internal jugular veins increased with increasing gestational age. Fetal jugular vein asymmetry was common, with the right jugular vein being dominant in the high gestational age group. CONCLUSION: We provide normal reference values for fetal internal jugular veins measured by MRI. These values may form the basis for clinical assessment of abnormal dilation or stenosis.

Non-3d Metal Modulation of a 2D Ni-Co Heterostructure Array as Multifunctional Electrocatalyst for Portable Overall Water Splitting.

Portable water splitting devices driven by rechargeable metal-air batteries or solar cells are promising, however, their scalable usages are still hindered by lack of suitable multifunctional electrocatalysts. Here, a highly efficient multifunctional electrocatalyst is demonstrated, i.e., 2D nanosheet array of Mo-doped NiCo2 O4 /Co5.47 N heterostructure deposited on nickel foam (Mo-NiCo2 O4 /Co5.47 N/NF). The successful doping of non-3d high-valence metal into a heterostructured nanosheet array, which is directly grown on a conductive substrate endows the resultant catalyst with balanced electronic structure, highly exposed active sites, and binder-free electrode architecture. As a result, the Mo-NiCo2 O4 /Co5.47 N/NF exhibits remarkable catalytic activity toward the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), affording high current densities of 50 mA cm-2 at low overpotentials of 310 mV for OER, and 170 mV for HER, respectively. Moreover, a low voltage of 1.56 V is achieved for the Mo-NiCo2 O4 /Co5.47 N/NF-based water splitting cell to reach 10 mA cm-2 . More importantly, a portable overall water splitting device is demonstrated through the integration of a water-splitting cell and two Zn-air batteries (open-circuit voltage of 1.43 V), which are all fabricated based on Mo-NiCo2 O4 /Co5.47 N/NF, demonstrating a low-cost way to generate fuel energy. This work offers an effective strategy to develop high-performance metal-doped heterostructured electrode.

Pt-Cu Bimetallic Nanoparticles Loaded in the Lumen of Halloysite Nanotubes.

In this study, we demonstrate that Pt-Cu bimetallic nanoparticles with different compositions (Pt3Cu, PtCu, PtCu3) can be loaded in the lumen of halloysite nanotube (HNT) via a simple one-pot reduction. Increasing the pH of metallic precursor (H2PtCl6 and CuCl2)/HNT solutions enhances the dissociation of H2PtCl6, advancing the association of [PtCl6]2- with the positively charged inner surface (Al-OH) of HNT. Moreover, the shrinkage of bond length from Pt-Cl in [PtCl6]2- to Pt-O in [PtCl4(OH)2]2- due to pH-modulated ligand exchange may also assist Pt(IV) being trapped inside the halloysite. In the meantime, Cu(II) cations may complex with Pt(IV) anions via electrostatic force that would help the formation of Pt-Cu bimetallic nanoparticles inside the halloysite. The obtained PtCu3@HNT system shows a significantly enhanced catalytic performance in the reduction of 4-nitrophenol by sodium borohydride, with a mass activity approximating 60 times higher than that of unloaded Pt nanoparticles. The high catalytic efficiency can be maintained after thermal treatment at 200 or 400 °C.

Short- and long-term outcomes of laparoscopic surgery in elderly patients with rectal cancer.

PURPOSE: This study aimed to use propensity score matching (PSM) to compare the short- and long-term outcomes of laparoscopic surgery for the treatment of rectal cancer in elderly and middle-aged patients. METHODS: Data were retrospectively obtained from 588 patients aged ≥60 years when they underwent laparoscopic surgery for rectal cancer in our hospital between January 2009 and December 2016. The patients were divided into an elderly group (≥70 years) or a middle-aged group (60-69 years), and were subsequently matched 1:1 using PSM for sex, body mass index, Charlson comorbidity index (CCI), tumor location, clinical stage, and American Society of Anesthesiologists (ASA) score. A total of 115 patients from each group were matched and included in the study, and their short-term and long-term outcomes were compared. RESULTS: The elderly group had greater intraoperative blood loss and a higher surgical conversion rate, although the other outcomes were similar between the two groups (surgical time, pathology results, 30-day incidence of complications, and incidence of major complications). No patients died intraoperatively or within 30 days after surgery. There were no significant differences in the two groups' rates of tumor recurrence, 5-year overall survival, and 5-year disease-free survival. CONCLUSION: Although elderly patients had greater intraoperative blood loss and a higher surgical conversion rate, laparoscopic surgery for rectal cancer provided similar short-term and long-term outcomes among middle-aged and elderly patients.

Identification of five anti-lipopolysaccharide factors in oriental river prawn, Macrobrachium nipponense.

Anti-lipopolysaccharide factors (ALFs) are a group of antimicrobial peptides (AMPs) with broad-spectrum antimicrobial activities and antiviral activities mainly found in crustaceans and horseshoe crabs. In the present study, we identified 5 ALF expression sequence tags (ESTs) through analysis of the established M. nipponense transcriptome, and cloned their full-length cDNA sequences using rapid amplification of cDNA ends (RACE) method. The 5 ALFs were designated as MnALF1-5, and all of them showed high similarity with their Macrobrachium rosenbergii homologs in the phylogenetic analyses, especially in LPS binding domains. In healthy adult prawns, we found the highest expression of MnALF2 and MnALF4 in haemocytes, and the highest expression of MnALF4 and MnALF3 in intestine. Some isoforms of MnALF were down-regulated but the majority was up-regulated in different prawn tissues upon Aeromonas hydrophila challenge. To conform the expected antimicrobial activities harbored in MnALFs' LPS binding domains, we used a synthesized peptide cMnALF24 that corresponds to the LPS binding domain of MnALF2 as a representative molecule for the antibacterial activity test, and found that cMnALF24 possessed strong and broad-spectrum antibacterial activity against Gram positive and Gram negative bacteria, but no inhibition activity against fungi; Meanwhile, in the hemolytic test, cMnALF24 showed weak hemolysis activities (around 10%) to the rabbit red blood cells at concentrations of 0.67-33.50 µM. This study provides insights into understanding the antibacterial function of ALFs in the innate immunity of freshwater prawn, and reports a peptide that can be a potential drug candidate with good efficacy against bacterial infection and low toxicity to host cells.

Circularly polarized luminescence in quantum dot-based materials.

Quantum dots (QDs) have emerged as fantastic luminescent nanomaterials with significant potential due to their unique photoluminescence properties. With the rapid development of circularly polarized luminescence (CPL) materials, many researchers have associated QDs with the CPL property, resulting in numerous novel CPL-active QD-containing materials in recent years. The present work reviews the latest advances in CPL-active QD-based materials, which are classified based on the types of QDs, including perovskite QDs, carbon dots, and colloidal semiconductor QDs. The applications of CPL-active QD-based materials in biological, optoelectronic, and anti-counterfeiting fields are also discussed. Additionally, the current challenges and future perspectives in this field are summarized. This review article is expected to stimulate more unprecedented achievements based on CPL-active QD-based materials, thus further promoting their future practical applications.

Event-Triggered Multiasynchronous H∞ Control for Markov Jump Systems With Transmission Delay.

In this article, the issue of event-triggered multiasynchronous H∞ control for Markov jump systems with transmission delay is concerned. In order to reduce sampling frequency, multiple event-triggered schemes (ETSs) are introduced. Then hidden Markov model (HMM) is employed to describe multiasynchronous jumps among subsystems, ETSs, and controller. Based on the HMM, the time-delay closed-loop model is constructed. In particular, when triggered data are transmitted over networks, a large transmission delay may cause disorder of transmission data such that the time-delay closed-loop model cannot be developed directly. To overcome this difficulty, a packet loss schedule is presented and the unified time-delay closed-loop system is obtained. By the use of the Lyapunov-Krasovskii functional method, sufficient conditions with the controller design are formulated for guaranteeing the H∞ performance of the time-delay closed-loop system. Finally, the effectiveness of the proposed control strategy is demonstrated by two numerical examples.

Variations of bubble cavitation and temperature elevation during lesion formation by high-intensity focused ultrasound.

High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in both thermal ablations for solid tumor/cancer and soft-tissue fragmentation. Mechanical and thermal effects, which play an important role in the HIFU treatment simultaneously, are dependent on the operating parameters and may vary with the progress of therapy. Mechanical erosion in the shape of a "squid," a "dumbbell" lesion with both mechanical and thermal lesions, or a "tadpole" lesion with mechanical erosion at the center and thermal necrosis on the boundary in the transparent gel phantom could be produced correspondingly with the pulse duration of 5-30 ms, which is much longer than histotripsy burst but shorter than the time for tissue boiling, and pulse repetition frequency (PRF) of 0.2-5 Hz. Meanwhile, variations of bubble cavitation (both inertial and stable cavitation) and temperature elevation in the focal region (i.e., z = -2.5, 0, and 2.5 mm) were measured by passive cavitation detection (PCD) and thermocouples during the therapeutic procedure, respectively. Stable cavitation increased with the pulse duration, PRF, and the number of pulses delivered. However, inertial cavitation was found to increase initially and then decrease with long pulse duration and high PRF. Temperature in the pre-focal region is always higher than those at the focal and post-focal position in all tests. Great variations of PCD signals and temperature elevation are due to the generation and persistence of large bubble, which is resistant to collapse and occurs with the increase of pulse duration and PRF. Similar lesion pattern and variations were also observed in ex vivo porcine kidneys. Hyperechoes in the B-mode ultrasound image were comparable to the shape and size of lesions in the dissected tissue. Thermal lesion volume increased with the increase of pulse duration and PRF, but mechanical erosion reached its maximum volume with the pulse duration of 20 ms and PRF of 1 Hz. Altogether, bubble cavitation and thermal field vary with the progress of HIFU treatment with different sonication parameters, which provide insights into the interaction of ultrasound burst with the induced bubbles for both soft tissue fractionation and enhancement in thermal accumulation. Appropriate synergy and monitoring of mechanical and thermal effects would broaden the HIFU application and enhance its efficiency as well as safety.

Adaptive Neural Event-Triggered Control of Networked Markov Jump Systems Under Hybrid Cyberattacks.

This article is concerned with the neural network (NN)-based event-triggered control problem for discrete-time networked Markov jump systems with hybrid cyberattacks and unmeasured states. The event-triggered mechanism (ETM) is used to reduce the communication load, and a Luenberger observer is introduced to estimate the unmeasured states. Two kinds of cyberattacks, denial-of-service (DoS) attacks and deception attacks, are investigated due to the vulnerability of cyberlayer. For the sake of mitigating the impact of these two types of cyberattacks on system performance, the ETM under DoS jamming attacks is discussed first, and a new estimation of such mechanism is given. Then, the NN technique is applied to approximate the injected false information. Some sufficient conditions are derived to guarantee the boundedness of the closed-loop system, and the observer and controller gains are presented by solving a set of matrix inequalities. The effectiveness of the presented control method is demonstrated by a numerical example.