Construction of a Bifunctional Redox-Site Conjugated Covalent-Organic Framework for Photoinduced Precision Trapping of Uranyl Ions.

The performance of covalent-organic frameworks (COFs) for the photocatalytic extraction of uranium is greatly limited by the number of adsorption sites. Herein, inspired by electronegative redox reactions, we designed a nitrogen-oxygen rich pyrazine connected COF (TQY-COF) with multiple redox sites as a platform for extracting uranium via combining superaffinity and enhanced photoinduction. The preorganized bisnitrogen-bisoxygen donor configuration on TQY-COF is entirely matched with the typical geometric coordination of hexavalent uranyl ions, which demonstrates high affinity (tetra-coordination). In addition, the presence of the carbonyl group and pyrazine ring effectively stores and controls electron flow, which efficaciously facilitates the separation of e-/h+ and enhances photocatalytic performance. The experimental results show that TQY-COF removes up to 99.8% of uranyl ions from actual uranium mine wastewater under the light conditions without a sacrificial agent, and the separation coefficient reaches 1.73 × 106 mL g-1 in the presence of multiple metal ions, which realizes the precise separation in the complex environment. Importantly, DFT calculations further elucidate the coordination mechanism of uranium and demonstrate the necessity of the presence of N/O atoms in the photocatalytic adsorption of uranium.

Axially chiral dihydrophenanthrene dimers from Pholidota yunnanensis with anti-neuroinflammatory activities.

Axially chiral compounds are well known in medicinal chemistry of natural products, but their absolute configurations and bioactivities are rarely reported and studied. In this study, eleven undescribed axially chiral dihydrophenanthrene dimers, as well as twenty-five known dihydrophenanthrenes, were isolated from the entire plant of Pholidota yunnanensis. Their structures were elucidated by comprehensive spectroscopic analysis. A method for determining the absolute configurations of enantiomers was developed based on the rotational barriers and calculated ECD spectra. Additionally, the activities of all isolated compounds were assessed in LPS-induced BV-2 microglial cells. Most dihydrophenanthrenes exhibited significant NO inhibitory activities, and compound 7 showed the most potent inhibitory effect with an IC50 value of 1.5 µM, compared to the positive control minocycline. The immunofluorescence and western blot results revealed that compound 7 suppressed the expression of Iba-1, iNOS and COX-2 in LPS-stimulated BV-2 microglial cells.

The time-dependent expression of FPR2 and ANXA1 in murine deep vein thrombosis model and its relation to thrombus age.

Thrombus age determination in fatal venous thromboembolism cases is an important task for forensic pathologists. In this study, we investigated the time-dependent expressions of formyl peptide receptor 2 (FPR2) and Annexin A1 (ANXA1) in a stasis-induced deep vein thrombosis (DVT) murine model, with the aim of obtaining useful information for thrombus age timing. A total of 75 ICR mice were randomly classified into thrombosis group and control group. In thrombosis group, a DVT model was established by ligating the inferior vena cava (IVC) of mice, and thrombosed IVCs were harvested at 1, 3, 5, 7, 10, 14, and 21 days after modeling. In control group, IVCs without thrombosis were taken as control samples. The expressions of FPR2 and ANXA1 during thrombosis were detected using immunohistochemistry and double immunofluorescence staining. Their protein and mRNA levels in the samples were determined by Western blotting and quantitative real-time PCR. The results reveal that FPR2 was predominantly expressed by intrathrombotic neutrophils and macrophages. ANXA1 expression in the thrombi was mainly distributed in neutrophils, endothelial cells of neovessels, and fibroblastic cells. After thrombosis, the expressions of FPR2 and ANXA1 were time-dependently up-regulated. The percentage of FPR2-positive cells and the level of FPR2 protein significantly elevated at 1, 3, 5 and 7 days after IVC ligation as compared to those at 10, 14 and 21 days after ligation (p < 0.05). Moreover, the mRNA level of FPR2 were significantly higher at 5 days than that at the other post-ligation intervals (p < 0.05). Besides, the levels of ANXA1 mRNA and protein peaked at 10 and 14 days after ligation, respectively. A significant increase in the mRNA level of ANXA1 was found at 10 and 14 days as compared with that at the other post-ligation intervals (p < 0.01). Our findings suggest that FPR2 and ANXA1 are promising as useful markers for age estimation of venous thrombi.

Hydrogen-Bonded Organic Cocrystal-Encapsulated Perovskite Nanocrystals as Coreactant-Free Electrochemiluminescent Luminophore for the Detection of Uranium.

Lead halide perovskite nanocrystals with excellent photophysical properties are promising electrochemiluminescence (ECL) candidates, but their poor stability greatly restricts ECL applications. Herein, hydrogen-bonded cocrystal-encapsulated CsPbBr3 perovskite nanocrystals (PeNCs@NHS-M) were synthesized by using PeNCs as nuclei for inducing the crystallization of melamine (M) and N-hydroxysuccinimide (NHS). The as-synthesized composite exhibits multiplicative ECL efficiencies (up to 24-fold that of PeNCs) without exogenous coreactants and with excellent stability in the aqueous phase. The enhanced stability can be attributed to the well-designed heterostructure of the PeNCs@NHS-M composite, which benefits from both moiety passivation and protection of the peripheral cocrystal matrix. Moreover, the heterostructure with covalent linkage facilitates charge transfer between PeNCs and NHS-M cocrystals, realizing effective ECL emission. Meanwhile, the NHS and M components act as coreactants for PeNCs, shortening the electron-transport distance and resulting in a significant increase in the ECL signal. Furthermore, by taking advantage of the specific binding effect between NHS-M and uranyl (UO22+), an ECL system with both a low detection limit (1 nM) and high selectivity for monitoring UO22+ in mining wastewater is established. The presence of UO22+ disrupted the charge-transfer effect within PeNCs@NHS-M, weakening the ECL signals. This work provides an efficient design strategy for obtaining stable and efficient ECLs from perovskite nanocrystals, offering a new perspective for the discovery and application of perovskite-based ECL systems.

Hydrogen-Bonded Cocrystals Encapsulating CsPbBr3 Perovskite Nanocrystals with Enhancement of Charge Transport for Photocatalytic Reduction of Uranium.

At present, poor stability and carrier transfer efficiency are the main problems that limit the development of perovskite-based photoelectric technologies. In this work, hydrogen-bonded cocrystal-coated perovskite composite (PeNCs@NHS-M) is easily obtained by inducing rapid crystallization of melamine (M) and N-hydroxysuccinimide (NHS) with PeNCs as the nuclei. The outer NHS-M cocrystal passivates the undercoordinated lead atoms by forming covalent bonds, thereby greatly reducing the trap density while maintaining good structure stability for perovskite nanocrystals. Moreover, benefiting from the interfacial covalent band linkage and long-range ordered structures of cocrystals, the charge transfer efficiency is effectively enhanced and PeNCs@NHS-M displays superior photoelectric performance. Based on the excellent photoelectric performance and abundant active sites of PeNCs@NHS-M, photocatalytic reduction of uranium is realized. PeNCs@NHS-M exhibits U(VI) reduction removal capability of up to 810.1 mg g-1 in the presence of light. The strategy of cocrystals trapping perovskite nanocrystals provides a simple synthesis method for composites and opens up a new idea for simultaneously improving the stability and photovoltaic performance of perovskite.

Cooperation with dynamic asymmetric evaluation in complex networks from a risk perspective.

The choice of strategy exposes individuals to the risk of betrayal. This induces individuals' irrational tendencies in strategy selection, which further influences the emergence of cooperative behavior. However, the underlying mechanisms connecting risk perception and the emergence of cooperation are still not fully understood. To address this, the classic evolutionary game model on complex networks is extended. We depict the interaction between strategy imitation and payoff evaluation from two perspectives: dynamic adjustment and irrational assessment. Specifically, the probability distortion involved in the dynamic selection of imitative reference points, as well as the asymmetric psychological utility associated with reference point dependence, is emphasized. Monte Carlo simulations demonstrate that individual irrational cognition induced by the risk of strategy selection can promote the emergence of cooperative behavior. Among them, the risk sensitivity within psychological utility has the most significant moderating effect. Moreover, the promoting effect of strong heterogeneity and high clustering in the network topology on cooperation under risk scenarios has been clarified. Additionally, the influence of initial states on the emergence of cooperation follows a step-like pattern. This research offers valuable insights for further exploring the cooperation mechanisms among irrational agents, even in scenarios involving the regulation of group cooperation behavior in risky situations.

Correlation between the triglyceride-glucose index and the onset of atrial fibrillation in patients with non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is associated with atrial fibrillation (AF). Insulin resistance (IR) is the main cause of the high prevalence of AF in NAFLD patients. The triglyceride-glucose index (TyG) is a novel IR-related indicator implicated in the incidence and severity of NAFLD. However, the role of TyG in determining the risk for AF in patients with NAFLD remains unclear. METHODS: A retrospective study was conducted on 912 patients diagnosed with NAFLD via ultrasonography. These patients were divided into two groups: (1) NAFLD+ AF and (2) NAFLD+ non-AF. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to assess the correlation between the TyG index and the high risk for AF. A receiver operating characteristic (ROC) curve was constructed to evaluate the predictive value for the TyG index for AF. Restricted cubic splines (RCS) were used to test the linear correlation between TyG and the risk for AF. RESULTS: A total of 204 patients with AF and 708 patients without AF were included in this study. The LASSO logistic regression analysis showed that TyG was an independent risk factor for AF (odds ratio [OR] = 4.84, 95% confidence interval [CI] 2.98-7.88, P < 0.001). The RCS showed that the risk for AF increased linearly with TyG over the entire TyG range; this risk was also evident when the patients were analyzed based on sex (P for nonlinear > 0.05). In addition, the correlation between TyG and AF was a consistent finding in subgroup analysis. Furthermore, ROC curve analysis showed that TyG levels combined with traditional risk factors improved the predictive value for atrial fibrillation. CONCLUSION: The TyG index is useful in assessing the risk for atrial fibrillation in patients with NAFLD. Patients with NAFLD and increased TyG indices have higher risks for atrial fibrillation. Therefore, TyG indices should be assessed when managing patients with NAFLD.

Triglyceride-Glucose Index is Significantly Associated with the Risk of Hyperuricemia in Patients with Nonalcoholic Fatty Liver Disease.

Purpose: The triglyceride-glucose (TyG) index is a new index of insulin resistance (IR), and its association with hyperuricemia (HUA) is unclear. The aim of this study was to investigate whether TyG is an independent risk factor for hyperuricemia (HUA) in patients with nonalcoholic fatty liver disease (NAFLD). Patients and Methods: We retrospectively analyzed 461 patients with ultrasound-confirmed NAFLD and calculated the TyG index. Multivariate logistic regression was used to analyze the relationship between the TyG index and HUA in NAFLD patients. The correlation between the TyG index and HUA was further confirmed by a restricted cubic spline. Furthermore, the stability of the association between TyG index and HUA was examined using subgroup analysis. Receiver operating characteristic (ROC) curves were constructed to evaluate the predictive value of the TyG index on HUA. Multivariate linear regression was used to analyze the linear relationship between the TyG index and serum uric acid. Results: A total of 166 HUA patients and 295 non-HUA patients were included in the study. The results of multivariate logistic regression analysis showed that after controlling the confounding risk factors, TyG was still an independent risk factor for HUA (OR = 2.00, 95% CI: 1.38 -2.91, p < 0.001). Restricted cubic splines showed that HUA risk increased linearly with TyG across the entire TyG range. The ROC curve showed that TyG index was better than triglyceride in predicting HUA in NAFLD patients, with AUC values of 0.62 and 0.59, respectively. Multiple linear regression analysis showed that TyG index was significantly positively correlated with blood uric acid (B = 1.37, 95% CI: 0.67-2.08, p < 0.001). Conclusion: TyG index is an independent risk factor for HUA in patients with NAFLD. The increase of the TyG index level is closely related to the occurrence and development of HUA in patients with NAFLD.

Study on Components with Anti-Neuroinflammatory Activities from Caragana microphylla Lam.

Caragana microphylla Lam., is a perennial herb in the genus Caragana in the Fabaceae family. Two undescribed triterpenoid saponins (1-2), along with thirty-five known components (3-37) were obtained from the roots of C. microphylla Lam. These compounds were identified using physicochemical analyses and various spectroscopic methods. The anti-neuroinflammatory activities were evaluated by measuring the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Compared with positive control minocycline, compounds 10, 19, and 28 exhibited significant effects with IC50 values of 14.04, 19.35 and 10.20 µM, respectively.

Characteristics of the nasal mucosa of commercial pigs during normal development.

The nasal mucosa is constantly exposed to inhaled pathogens and is the first defence against respiratory infections. Here, we investigated the structural and compositional characteristics of the nasal mucosa of commercial pigs at various growth stages. The epithelial thickness, number of capillaries, and secretion function of the nasal mucosa dramatically increased with age; however, underlying lymphoid follicles in the respiratory region were rarely observed across the growth stages. The nasal mucosa was explored at the epithelial, immunological, and biological (commensal microbiota) barriers. In the epithelial barrier, the proliferative capacity of the nasal epithelia and the expression of tight junction proteins were high after birth; however, they decreased significantly during the suckling stage and increased again during the weaning stage. In the immunological barrier, most pattern recognition receptors were expressed at very low levels in neonatal piglets, and the innate immune cell distribution was lower. During the suckling stage, increased expression of Toll-like receptor (TLR) 2 and TLR4 was observed; however, TLR3 expression decreased. TLR expression and innate immune cell quantity significantly increased from the weaning to the finishing stage. In the biological barrier, Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes comprised the dominant phyla in neonatal piglets. A dramatic decrease in nasal microbial diversity was observed during the suckling stage, accompanied by an increase in potentially pathogenic bacteria. Proteobacteria, Bacteroidetes, and Firmicutes were identified as the core phyla of the nasal microbiota; among these, the three dominant genera, Actinobacter, Moraxella, and Bergerella, may be opportunistic pathogens in the respiratory tract. These characteristics comprise an essential reference for respiratory infection prevention at large-scale pig farms.

Lung protective effects of dietary malate esters derivatives from Bletilla striata against SiO2 nanoparticles through activation of Nrf2 pathway.

Objective: To study the protective activities of the dietary malate esters derivatives of Bletilla striata against SiO2 nanoparticles-induced A549 cell lines and its mechanism action. Methods: The components were isolated and elucidated by spectroscopic methods such as 1D NMR and 2D NMR. And MTT assays was used to tested these components on the A549 cell survival rates and ROS or proteins levels were detected by Western blotting. Results: A new glucosyloxybenzyl 2-isobutylmalate (a malate ester derivative), along with 31 known compounds were isolated and identified from n-BuOH extract of EtOH extract of B. striata. Among them, compounds 3, 4, 11, 12 and 13 possessed noteworthy proliferative effects for damaged cells, with ED50 of 14.0, 13.1, 3.7, 11.6 and 11.5 µmol/L, respectively, compared to positive control resveratrol (ED50, 14.7 µmol/L). Militarine (8) prominently inhibited the intracellular ROS level, and increased the expression of Nrf2 and its downstream genes (HO-1 and γ-GCSc). Furthermore, Nrf2 activation mediates the interventional effects of compound 8 against SiO2 nanoparticles (nm SiO2)-induced lung injury. Moreover, treatment with compound 8 significantly reduced lung inflammation and oxidative stress in nm SiO2-instilled mice. Molecular docking experiment suggested that 8 bound stably to the HO-1 protein by hydrogen bond interactions. Conclusion: The dietary malate esters derivatives of B. striata could significantly increase the viability of nm SiO2-induced A549 cells and decrease the finer particles-induced cell damages. Militarine is especially promising compound for chemoprevention of lung cancer induced by nm SiO2 through activation of Nrf2 pathway.

Flexible three-dimensional covalent organic frameworks for ultra-fast and selective extraction of uranium via hydrophilic engineering.

It has been considered challenging to develop ideal adsorbents for efficient and lower adsorption time uranium extraction, especially 3D covalent organic frameworks with interpenetrating topologies and tunable porous structures. Here, a "soft" three-dimensional (3D) covalent organic framework (TAM-DHBD) with a fivefold interpenetrating structure is prepared as a novel porous platform for the efficient extraction of radioactive uranium. The resultant TAM-DHBD appears exceptional crystallinity, prominent porosity and excellent chemical stability. Based on the strong mutual coordination between phenolic-hydroxyl/imine-N on the main chain and uranium, TAM-DHBD can effectively avert the competition of other ions, showing high selectivity for uranium extraction. Impressively, the 3D ultra-hydrophilic transport channels and multi-directional uniform pore structure of TAM-DHBD lay the foundation for the ultra-high-speed diffusion of uranium (the adsorption equilibrium can be reached within 60 min under a high-concentration environment). Furthermore, the utilization of lightweight structure not only increases the adsorption site density, but renders the adsorption process flexible, achieving a breakthrough adsorption capacity of 1263.8 mg g-1. This work not only highlights new opportunities for designing microporous 3D COFs, but paves the way for the practical application of 3D COFs for uranium adsorption.

An ionic vinylene-linked three-dimensional covalent organic framework for selective and efficient trapping of ReO4- or 99TcO4.

The synthesis of ionic olefin linked three-dimensional covalent organic frameworks (3D COFs) is greatly challenging given the hardness of the formation of stable carbon-carbon double bonds (-C = C-). Herein, we report a general strategy for designing porous positively charged sp2 carbon-linked 3D COFs through the Aldol condensation promoted by quaternization. The obtained 3D COFs, namely TFPM-PZI and TAPM-PZI, showed impressive chemical stability. Furthermore, the positively charged frameworks with regular porosity endow 3D ionic COFs with selective capture radioactive ReO4-/TcO4- and great removal efficiency in simulated Hanford waste. This research not only broadens the category of 3D COFs but also promotes the application of COFs as efficient functional materials.

Post-infectious cough of different syndromes treated by traditional Chinese medicines: A review.

The application of traditional Chinese medicines (TCMs) has a history of more than 2000 years, which have the characteristics of multi-component, multi-target, and high safety. Post-infectious cough (PIC) is a respiratory disease with high incidence. It belongs to subacute cough and accounts for as much as 40%-50%. Cough is the main clinical manifestation of PIC. PIC seriously affects people's life quality because of complex etiology, long-term course of disease, treatment difficulties and other characteristics. Western medicines are based on the principle of symptomatic treatment, so they are often difficult to control PIC fundamentally. These factors could due to that PIC is prolonged and unable to heal repeatedly. TCMs have obvious advantages in treating PIC, with accurate curative effects, less side effects and adverse reactions and are effective in improving PIC-related symptoms and indicators, enhancing patients' life quality and reducing pain. TCMs, guided by holistic concept and syndrome differentiation, advocate determine treatment on the basis of pattern types, and have remarkable clinical treatment effects. As for TCMs etiology, pathogenesis and syndrome types of PIC, TCM scholars have not yet reached a unified standard. However, most of them think that wind pathogen can cause PIC alone, or it can be combined with other evils, which might be the main mechanism of PIC. This paper discusses the advantages and limitations of TCMs in PIC treatment from etiology, pathogenesis, distribution of syndrome types and treatment of TCMs. This article focuses on the treatment methods and pharmacodynamic material basis of wind pathogen, providing ideas in treating PIC of TCMs clinically and innovative drug development.

3D Ionic Olefin-Linked Conjugated Microporous Polymers for Selective Detection and Removal of TcO4-/ReO4- from Wastewater.

Technetium (99Tc) is a highly toxic radioactive nuclear wastewater contaminant. Real-time detection of 99Tc is very difficult due to its difficult-to-complex nature. Herein, a novel three-dimensional ionic olefin-linked conjugated microporous polymer (TFPM-EP-Br) is constructed using tetrakis(4-aldehyde phenyl)methane (TFPM) as the central monomer. The unique cationic cavity and highly hydrophobic framework enable TFPM-EP-Br to act as a fluorescent sensor for TcO4-. The fluorophores of TFPM-EP-Br can be quenched due to electron transfer from TFPM-EP-Br to TcO4- and the formation of strongly nonfluorescent complexes. Meanwhile, the regular pore channels are beneficial for the fast mass transfer of TcO4-, resulting in an ultrafast response time (less than 2 s) with an ultralow detection limit (33.3 nM). In addition, the ultrahigh specific surface area enables TFPM-EP-Br to combine the ability to synergistically detect and remove radioactive 99Tc. From this perspective, the novel conjugated microporous polymer has made a breakthrough in the detection and extraction of radioactive contaminants.

Endovascular treatment of extracranial carotid artery aneurysms using self-expandable covered stent grafts: A single center retrospective study.

OBJECTIVES: This study was aimed to evaluate the safety and efficacy of endovascular treatment of extracranial carotid artery aneurysms (ECAAs) using self-expandable covered stent grafts. METHODS: All patients with ECAA at a single institution were reviewed from February 2014 to February 2020. Eight consecutive patients (three men, mean age 64.5 years) treated with endovascular repair with self-expandable covered stent graft were retrospectively reviewed. Patient characteristics, angiographic results, and follow-up outcomes were retrospectively recorded. Access to ECAA was gained via a femoral approach or a direct puncture of common carotid artery after surgical exposure because of kinking of the aortic arch and common carotid artery. A self-expandable covered stent graft (Viabahn; W. L. Gore, Flagstaff, AZ) was deployed to exclude the aneurysm. RESULTS: Based on imaging features, there were five peudoaneurysms and three true aneurysms. The technical success rate was 100%. Cerebral protection devices were not used in all the patients during the procedures. Immediate absolute obliteration of the ECAA with no endoleak was documented in all the patients. Perioperative complications included one internal carotid-cavernous sinus fistula, one bleeding at the puncture site, and one stroke. The mean follow-up period was 35.5 months (range, 9-72 months). All the patients were alive, with an obligation rate of 100%. No transient ischemia attack, stroke, or reoccurrence of symptoms was identified during the follow-up period. Radiological examinations identified patency of the stent grafts and revealed no endoleaks, stent fracture, stent migration, or aneurysm rupture. CONCLUSIONS: Endovascular treatment of ECAAs with self-expandable covered stent grafts appears to be a safe and feasible alternative for traditional open surgery, especially in the challenging anatomy and instable physical conditions. Although cerebrovascular accidents can occur as the result of hemodynamic changes during the perioperative period, the minimal alternative can yield satisfactory midterm follow-up clinical outcomes.

Transbrachial and transfemoral approaches combined with visceral protection for the treatment of juxtarenal aortoiliac occlusive disease: Technical issues and clinical outcomes.

PURPOSE: To evaluate the safety and efficacy of transbrachial and transfemoral approaches combined with visceral protection for the endovascular treatment of juxtarenal aortoiliac occlusive disease (AIOD) over an average 19-month follow-up period. METHODS: In this retrospective analysis, all patients with juxtarenal AIOD at a single institution were reviewed from June 2015 to January 2020. Patient characteristics, angiographic results, and follow-up outcomes were retrospectively recorded. The indications for treatment were critical limb threatening ischemia in 12 patients and bilateral claudication in five patients. Percutaneous access via the left brachial artery was first obtained to recanalize the infrarenal occluded lesions. After that, femoral accesses were achieved. A 4-Fr catheter, a 4 mm balloon, or a 6-Fr 90-cm-long sheath was used to complete visceral artery protection. RESULTS: A total of 17 juxtarenal AIOD patients (14 males; mean age, 63.4 ± 8.1 years) underwent endovascular treatment. The technical success rate was 100%. Complete reconstruction was achieved in 15 (88.2%) patients. The infrarenal aorta was reconstructed with kissing covered stent grafts (n = 7), kissing bare-metal stents (n = 2), covered stent grafts (n = 2), bare-metal stents (n = 1), or the off-label use of iliac limb stent grafts (n = 5). Renal embolization was found in 3 (17.6%) patients during intraoperative angiography. There was 1 (5.9%) case of distal runoff embolization after CDT and 1 (5.9%) case of left iliac artery rupture. One (5.9%) death occurred due to acute myocardial infarction 20 days after the operation. The average follow-up period was 19.3 ± 16.7 months (range, 1-54 months) in the remaining 16 cases. The renal artery patency rate was 100%. The estimated cumulative primary patency rates were 92.3% at 12 months and 59.3% at 36 months according to the Kaplan-Meier method. CONCLUSIONS: Transbrachial and transfemoral approaches combined with visceral protection offer a safe and effective alternative to open revascularization for the endovascular treatment of juxtarenal AIOD.

Dihydrophenanthrenes from medicinal plants of Orchidaceae: A review.

The plants of Orchidaceae are widely distributed in the world, 47 species of which have been used as folk medicines with a long history. The tubers and stems of them exhibit diverse efficacy, including clearing heat and resolving toxin, moistening lung and relieving cough and promoting blood circulation. Since dihydrophenanthrenes were responsible for the medical purposes, the characteristic skeletons, pharmacological effects and clinical applications of dihydrophenanthrenes were summarized in this review, so as to provide a theoretical basis for the comprehensive study, development and application of DPs from medicinal plants of Orchidaceae.

Electronic synergy between ligands of luminol and isophthalic acid for fluorescence ratiometric detection of Hg2.

Stimulus-responsive double-ligand luminol-Eu-IPA infinite coordination polymer nanoparticles (luminol-Eu-IPA CPNPs) were prepared as a ratiometric fluorescence probe for highly selective detecting Hg2+. The CPNPs were constituted of Eu3+ as the nuclear metal coordinated by isophthalic acid (IPA) together with luminol as an auxiliary ligand. The photoinduced electron transfer (PET) occurring from IPA to luminol prevented the antenna effect between IPA and Eu3+, leading to the quench fluorescence of Eu3+ under light excitation. As Hg2+ has a high affinity to N atom of luminol and the spin-orbit coupling effect, spectroscopically and magnetically silent properties, the fluorescence intensity of luminol was quenched. Meanwhile, the PET effect between luminol and IPA was interrupted under the presence of Hg2+. This process resulted in a significant decrease in the fluorescence intensity of luminol and a significant increase in the fluorescence intensity of Eu3+. Therefore, the fluorescence ratiometric detection of Hg2+ was performed by monitoring the ratio of the fluorescence at 617 nm of Eu3+ to that at 430 nm of luminol. The linear range was from 0.05 to 20 µM with a detection limit as low as 13.2 nM Hg2+ (S/N = 3). Due to the fluorescence of luminol be quenched and the effect of PET be disrupted simultaneously, the probe exhibiting excellent detection selectively can avoid false positive signals, which was demonstrated for monitoring mercury ions in real water samples. Precision in positioning ligands in CPNPs is an advantage to achieve high specificity in comparison to traditional organic dendrimers or precious metal nanomaterials.

Enhanced electron transfer on microbial electrosynthesis biocathode by polypyrrole-coated acetogens.

Extracellular electron transfer (EET) is a significant pathway to transport electrons between bacteria and electrode in microbial electrosynthesis systems (MESs). To enhance EET in the MES, a high-conductivity polymer, polypyrrole (PPy), was coated on the surface of mixed culture acetogens in situ and the PPy-coated bacteria were inoculated on the cathode of MES. The charge transfer resistance of PPy-coated biocathode was 33%-70% of that with PPy-uncoated. Acetate production rate and Faradic efficiency in PPy-coated biocathodes increased by 3 to 6 times. After 960 h operation, Acetobacterium, Desulfovibrio, and Acinetobacter dominate the community on the coated and uncoated biocathode. Quinone loop and NADH dehydrogenase to ubiquinone were involved in electron transfer pathway of biocathode and stimulated by PPy coating. Low-level expression of C-type cytochromes on biocathode indicated its less important role in inward EET. The study provided useful information for applications of high-conductivity chemicals in microbial electrosynthesis.