Polycationic Open-Shell Cyclophanes: Synthesis of Electron-Rich Chiral Macrocycles, and Redox-Dependent Electronic States.

π-Conjugated chiral nanorings with intriguing electronic structures and chiroptical properties have attracted considerable interests in synthetic chemistry and materials science. We present the design principles to access new chiral macrocycles (1 and 2) that are essentially built on the key components of main-group electron-donating carbazolyl moieties or the π-expanded aza[7]helicenes. Both macrocycles show the unique molecular conformations with a (quasi) figure-of-eight topology as a result of the conjugation patterns of 2,2',7,7'-spirobifluorenyl in 1 and triarylamine-coupled aza[7]helicene-based building blocks in 2. This electronic nature of redox-active, carbazole-rich backbones enabled these macrocycles to be readily oxidized chemically and electrochemically, leading to the sequential production of a series of positively charged polycationic open-shell cyclophanes. Their redox-dependent electronic states of the resulting multispin polyradicals have been characterized by VT-ESR, UV/Vis-NIR absorption and spectroelectrochemical measurements. The singlet (ΔES-T=-1.29 kcal mol-1) and a nearly degenerate singlet-triplet ground state (ΔES-T(calcd)=-0.15 kcal mol-1 and ΔES-T(exp)=0.01 kcal mol-1) were proved for diradical dications 12+2⋅ and 22+2⋅, respectively. Our work provides an experimental proof for the construction of electron-donating new chiral nanorings, and more importantly for highly charged polyradicals with potential applications in chirospintronics and organic conductors.

Bu-Fei Yi-Shen Granules Reduce Acute Exacerbations in Patients with GOLD 3-4 COPD: A Randomized Controlled Trial.

Purpose: Chronic obstructive pulmonary disease (COPD) is a disease characterized by frequent acute exacerbations (AEs), especially in severe and very severe cases. We aimed to evaluate the efficacy and safety of Bu-fei Yi-shen granules (BYGs) for COPD. Patients and Methods: We conducted a multicenter, randomized, double-blinded, placebo-controlled trial of 348 COPD patients with GOLD 3-4 COPD. The patients were randomly assigned into experimental or control groups in a 1:1 ratio. Patients in the experimental group were prescribed BYG, while those in the control group were administered a placebo, orally, twice daily, with 5 days on and 2 days off per week for 52 weeks. The outcomes included AEs, pulmonary function, clinical signs and symptoms, dyspnea scores (mMRC), quality of life scores, and a 6-minute walk test (6MWT). Results: A total of 280 patients completed the trial, including 135 patients in the experimental group and 145 in the control group. Compared to the control group, significant differences were observed in frequencies of AEs (mean difference: -0.35; 95% CI: -0.61, -0.10; P = 0.006) and AE-related hospitalizations (-0.18; 95% CI: -0.36, -0.01; P = 0.04), 6MWD (40.93 m; 95% CI: 32.03, 49.83; P < 0.001), mMRC (-0.57; 95% CI: -0.76, -0.37; P < 0.001), total symptoms (-2.18; 95% CI: -2.84, -1.53; P < 0.001), SF-36 (11.60; 95% CI: 8.23, 14.97; P < 0.001), and mCOPD-PRO (-0.45; 95% CI: -0.57, -0.33; P < 0.001) after treatment. However, there were no significant differences in mortality, pulmonary function, and mESQ-PRO scores (P > 0.05). No obvious adverse events were observed. Conclusion: BYG, as compared to a placebo, could significantly reduce the frequencies of AEs and AE-related hospitalizations for GOLD 3-4 COPD patients. Clinical symptoms, treatment satisfaction, quality of life, and exercise capacity improved. There was no significant improvement in mortality and pulmonary function.

Synthesis of π-Conjugated Chiral Organoborane Macrocycles with Blue to Near-Infrared Emissions and the Diradical Character of Cations.

Highly emissive π-conjugated macrocycles with tunable circularly polarized luminescence (CPL) have sparked theoretical and synthetic interests in recent years. Herein, we report a synthetic approach to obtain new chiral organoborane macrocycles (CMC1, CMC2, and CMC3) that are built on the structurally chiral [5]helicenes and highly luminescent triarylborane/amine moieties embedded into the cyclic systems. These rarely accessible B/N-doped main-group chiral macrocycles show a unique topology dependence of the optoelectronic and chiroptical properties. CMC1 and CMC2 show a higher luminescence dissymmetry factor (glum) together with an enhanced CPL brightness (BCPL) as compared with CMC3. Electronic effects were also tuned and resulted in bathochromic shifts of their emission and CPL responses from blue for CMC1 to the near-infrared (NIR) region for CMC3. Furthermore, chemical oxidations of the N donor sites in CMC1 gave rise to a highly stable radical cation (CMC1·+SbF6-) and diradical dication species (CMC12·2+2SbF6-) that serve as a rare example of a positively charged open-shell chiral macrocycle.

Expanding new chemistry of aza-boracyclophanes with unique dipolar structures, AIE and redox-active open-shell characteristics.

π-Conjugated macrocycles involving electron-deficient boron species have received increasing attention due to their intriguing tunable optoelectronic properties. However, most of the reported B(sp2)-doped macrocycles are difficult to modify due to the synthetic challenge, which limits their further applications. Motivated by the research of non-strained hexameric bora- and aza-cyclophanes, we describe a new class of analogues MC-BN5 and MC-ABN5 that contain charge-reversed triarylborane (Ar3B) units and oligomeric triarylamines (Ar3N) in the cyclics. As predicted by DFT computations, the unique orientation of the donor-acceptor systems leads to an increased dipole moment compared with highly symmetric macrocycles (M1, M2 and M3), which was experimentally represented by a significant solvatochromic effect with large Stokes shifts up to 12 318 cm-1. Such a ring-structured design also allows the easy peripheral modification of aza-boracyclophanes with tetraphenylethenyl (TPE) groups, giving rise to a change in the luminescence mechanism from aggregation-caused quenching (ACQ) in MC-BN5 to aggregation-induced emission (AIE) in MC-ABN5. The open-shell characteristics have been chemically enabled and were characterized by UV-Vis-NIR spectroscopy and electron paramagnetic resonance (EPR) for MC-BN5. The present study not only showed new electronic properties, but also could expand the research of B/N doped macrocycles into the future scope of supramolecular chemistry, as demonstrated in the accessible functionalization of ring systems.

Bias and Reporting Quality of Clinical Prognostic Models for Idiopathic Pulmonary Fibrosis: A Cross-Sectional Study.

Objective: This study aims to evaluate the risk of bias (ROB) and reporting quality of idiopathic pulmonary fibrosis (IPF) prediction models by assessing characteristics of these models. Methods: The development and/or validation of IPF prognostic models were identified via an electronic search of PubMed, Embase, and Web of Science (from inception to 12 August, 2021). Two researchers independently assessed the risk of bias (ROB) and reporting quality of IPF prediction models based on the Prediction model Risk Of Bias Assessment Tool (PROBAST) and Transparent Reporting of a multivariable prognostic model for Individual Prognosis or Diagnosis (TRIPOD) checklist. Results: Twenty prognostic model studies for IPF were included, including 7 (35%) model development and external validation studies, 8 (40%) development studies, and 5 (25%) external validation studies. According to PROBAST, all studies were appraised with high ROB, because of deficient reporting in the domains of participants (45.0%) and analysis (67.3%), and at least 55% studies were susceptible to 4 of 20 sources of bias. For the reporting quality, none of them completely adhered to the TRIPOD checklist, with the lowest mean reporting score for the methods and results domains (46.6% and 44.7%). For specific items, eight sub-items had a reporting rate ≥80% and adhered to the TRIPOD checklist, and nine sub-items had a very poor reporting rate, less than 30%. Conclusion: Studies adhering to PROBAST and TRIPOD checklists are recommended in the future. The reproducibility and transparency can be improved when studies completely adhere to PROBAST and TRIPOD checklists.

Three Si-substituted polyoxovanadates as efficient catalysts for Knoevenagel condensation and selective oxidation of styrene to benzaldehyde.

Three new Si-substituted polyoxovanadates (POVs), [Cd2(dien)2][Cd(dien)][Cd(Hdien)2][V15Si6O46(OH)2(H2O)]·7H2O (1), [Co(enMe)2]3[Co2(enMe)2(H2O)2][V16Si4O44(OH)2(H2O)]·6H2O (2), and [Co(teta)]4[V16Si4O42(OH)4(H2O)]·10H2O (3) (dien = diethylenetriamine; enMe = 1,2-diaminopropane; teta = triethylenetetramine) were synthesized by the hydrothermal method and characterized. Structural analysis sheds light on the fact that the {V15Si6O48}/{V16Si4O46} clusters of compounds 1-3 were formed by replacing {VO5} square pyramids in the classical {V18O42} cluster with {Si2O7} units. Compound 1 is a 2D bilayer structure formed by the [V15Si6O46(OH)2(H2O)]10- cluster and two types of bridging Cd complexes containing binuclear groups [Cd2(dien)2]4+. Compound 2 is a 3D framework constructed from the [V16Si4O44(OH)2(H2O)]10- cluster and two types of Co complex fragments including binuclear [Co2(enMe)2(H2O)2]4+. In compound 3, the [V16Si4O42(OH)4(H2O)]8- cluster is connected with bridging [Co(teta)]2+ to expand into a 2D network. Compounds 1 and 3 represent the first 2D assemblies based on a vanadosilicate cluster. 1-3 served as heterogeneous catalysts and exhibited highly efficient catalytic activities for the Knoevenagel condensation under mild ambient conditions with low catalyst loading, featuring the open Lewis base {V15Si6O48}/{V16Si4O46} sites and Lewis acid Cd2+/Co2+ sites. The conversion of benzaldehyde was up to 99.3% in 80 min at room temperature using 1 as a heterogeneous catalyst with only 0.37% catalyst loading. Moreover, compounds 1-3 as catalysts for selective oxidation of styrene to benzaldehyde exhibited excellent catalytic performance, high selectivity and could be readily recycled. Most strikingly, compound 1 showed excellent catalytic performance with 97.6% conversion of styrene and 100% selectivity of benzaldehyde in 15 min. In addition, the catalytic activity of catalyst 1 was well maintained after five cycling reactions.

Oligotriarylamine-Extended Organoboranes with Tunable Electron-Donating Strength by Changing the Number of Donor Units.

Triarylborane (Ar3B) and triarylamine (Ar3N) have been widely employed to construct electronically different donor-acceptor (D-A) systems. Herein, we describe a series of A-D-A-type luminescent organoboranes L-B2Nn (n = 1, 3, 5) that show an increased number of Ar3N units as electron donors and two terminal Ar3B as acceptors. When the Ar3N moieties were extended from one to five units, their electron-donating strength was gradually enhanced and the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps could also be tuned, which was further reflected in the red-shifted emissions from blue (λem = 458 nm) to orange (λem = 595 nm) with a decrease in Egap(elect) from 3.19 to 2.61 eV. L-B2N5 showed a huge Stokes shift (∼14 057 cm-1) and a considerably bright emission with an enhanced solid-state quantum efficiency (ΦS = 98%) compared with the other members. L-B2N3 and L-B2N5 exhibited aggregation-induced emissions (AIEs), and an apparent solvatochromic shift was also observed in the emission spectra as the solvent was changed from hexane to tetrahydrofuran (THF) (430 → 595 nm). In addition, the donor-acceptor charge-transfer character in these organoboranes caused a thermally responsive emission over a broad range.

Procalcitonin-guided antibiotic therapy in AECOPD patients: Overview of systematic reviews.

BACKGROUND: Procalcitonin (PCT)-guided antibiotic therapy has emerged as mainstream treatment for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and has been studied in many systematic reviews (SRs), but robust conclusion has not been drawn. Thus, this overview aims to summarize and critically evaluate the methodological and evidence quality of SRs on this topic. METHODS: PubMed, EMBASE, Cochrane library, and Web of science were searched for SRs regarding on PCT-guided antibiotic therapy on AECOPD. Two reviewers assessed the quality of SRs in line with AMSTAR-2 tool and evaluated the strength of evidence quality with the grading of recommendations, assessment, development, and evaluation (GRADE) system for concerned outcomes independently. RESULTS: Six SRs were published from Jun 2011 to Aug 2019, with from 4 (556 patients) to 15 (2571 patients) randomized controlled trials (RCTs) and retrospective studies. All the included SRs were classified as critical low methodology quality according to A MeaSurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) tool. Most of SRs were absented a list of excluded studies (item 7), and adequate investigation of publication bias and discuss its likely impact on the results (item 15). The PCT-guided antibiotic therapy may reduce antibiotic exposure days and antibiotic prescription rate in patients with AECOPD without affecting treatment success rate or causing adverse events (all-cause mortality, re-admission, re-exacerbation), but the results should be study deeper for the low or moderate evidence quality. CONCLUSION: Current SRs show that PCT-guided antibiotic therapy could be employed by clinicians in treatment of AECOPD. However, the high-quality evidence of outcomes is lacking, further intensive exploration should be carried out on the precise role of PCT-guided antibiotic therapy on AECOPD.

Catalyst-free Synthesis of Aminomethylphenol Derivatives in Cyclopentyl Methyl Ether via Petasis Borono-Mannich Reaction.

OBJECTIVE: Aminomethylphenol molecules have wider applications in pharmaceuticals, agrochemicals, plant protection and promising functional materials. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of view. MATERIALS AND METHODS: In order to establish an effective synthetic method for preparing aminomethylphenol derivatives, the Petasis borono-Mannich reaction of salicylaldehyde, phenylboronic acid and 1,2,3,4- tetrahydroisoquinoline was selected as a model reaction. A variety of reaction conditions are investigated, including solvent and temperature. The generality and limitation of the established method were also evaluated. RESULTS AND DISCUSSION: It was found that model reaction can be carried out in cyclopentyl methyl ether at 80 oC under catalyst-free conditions. This protocol, with broad substrate applicability, the reaction of various arylboronic acid, secondary amine and salicylaldehyde proceeded smoothly under optimal reaction conditions to afford various aminomethylphenol derivatives in high yields. A practical, scalable, and high-yielding synthesis of aminomethylphenol derivatives was successfully accomplished. CONCLUSION: A catalyst-free practical method for the synthesis of minomethylphenol derivatives based on Petasis borono-Mannich (PBM) reaction of various arylboronic acid, secondary amine and salicylaldehyde in cyclopentyl methyl ether has been developed. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of cyclopentyl methyl ether as the reaction medium, clean reaction profiles, easy operation, and high to excellent yield.

Moist exposed burn ointment promotes cutaneous excisional wound healing in rats involving VEGF and bFGF.

Cutaneous delayed wounds are a challenging clinical problem, and vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) exhibit key roles in wound healing. Moist exposed burn ointment (MEBO), a Chinese burn ointment with a USA patented formulation, has been reported to promote chronic ischemic and neurogenic ulcer healing in patients; however, the underlying mechanisms remain unclear. In the present study, MEBO significantly promoted the formation of granulation tissue in cutaneous excisional wounds, shortened the time of wound healing, and increased neovascularization and the number of fibroblasts. Furthermore, as well as enhancing the protein expression, MEBO application also increased the gene expression of VEGF and bFGF. The results indicate that MEBO promotes cutaneous excisional wound healing by at least partially enhancing VEGF and bFGF production, implicating the potential uses of MEBO for delayed cutaneous wound healing.