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Chondroitin sulfate-mediated albumin corona nanoparticles were readily prepared without any chemical reaction, and their active tumor targeting and therapeutic effects were examined. Negatively charged chondroitin sulfate (CS) and positively charged doxorubicin (DOX) self-assembled into nanoparticles (CS-DOX-NPs) via electrostatic interactions. Bovine serum albumin (BSA) was then adsorbed on the surface of CS-DOX-NPs to form albumin corona nanoparticles (BC-DOX-NPs) protected from endogenous proteins. Due to the dual effect of BSA and CS, BC-DOX-NPs interacted with the gp60, SPARC and CD44 receptors on tumor cells, facilitating their rapid and efficient transcytosis and improving their accumulation and uptake within tumor tissues. The simultaneous presence of BSA and CS also allowed BC-DOX-NPs to target CD44 efficiently, leading to greater cellular uptake and cytotoxicity against 4T1 cells than CS-DOX-NPs or free DOX. Intravenous injection of BC-DOX-NPs into orthotopic 4T1 tumor-bearing mice led to greater drug accumulation at the tumor site than with CS-DOX-NPs or free DOX, resulting in significant inhibition of tumor growth and lower exposure of major organs to the drug., Graphical abstract Albumin corona can enhance the anti-tumor effect of chondroitin sulfate-mediated nanoparticles through BSA-gp60-SPARC pathway, which helps nanoparticles pass through the vascular endothelial barrier faster and accumulate more in tumor tissues.Image, graphical abstract

A new triarylindanone, namely selagindanone A (1), and a new isobenzofuranone (2), 3,4-bis(4-hydroxyphenyl)isobenzofuran-1(3H)-one, were isolated from Selaginella tamariscina. Their structures were elucidated by comprehensive spectroscopic and mass spectrometric analyses, including 1 D-, 2 D-NMR and HR-ESI-MS. Compound 1 possesses a unique structural feature of triaryl-substituted in the skeleton of 1-indanone. In addition, compound 2 showed weak cytotoxicity against human hepatocellular carcinoma SMMC-7721 and HepG2 cell lines.

Ten compounds (1–10) were obtained from soil-derived Penicillium cremeogriseum W1-1 with the antimicrobial guided isolation procedure. Among them, 4 presented broad-spectrum antimicrobial activities and its preliminary mechanisms were evaluated. Compound 4 showed growth inhibition on drug-resistant pathogenic strains Escherichia coli and Candida albicans with post-contact effect (PCE), changed the morphology and membrane structure, killed cells with leakage, inhibited the growth of C. albicans by eradicating biofilms. Interestingly, the fraction containing 4 presented in vivo anti-pathogenic activities in mice, indicating this indole diterpenoid alkaloid could been used as potential antimicrobial agent.

Integrating electrochromism into supercapacitors can provide multifunctional electrochromic supercapacitors (ESCs) for smart windows and portable and wearable electronics. Polyaniline (PANI) as the most promising electrode material for ESCs is limited by its poor solution processability and inferior cycling stability. The strategy we propose here is to add 1,3,6,8-pyrenetetrasulfonic acid (1,3,6,8-Psas) as an anchored dopant during the polymerization of PANI. Its large steric hindrance can play a role in inter-chain support and reduce the effect of inter-chain interaction for obtaining excellent solution processability. In addition, 1,3,6,8-Psas can also act as a crosslinking agent, which can adjust the morphology of PANI to provide a composite electrode with a rich pore structure for increased contact area with electrolyte and thus improved ion transmission. The area specific capacitance of the original PANI-WO3/FTO composite electrode calculated from the CV curve at 100 mV s−1 is 38.71 mF cm−2, while the 1,3,6,8-Psas doped PANI-WO3/FTO composite electrode is 72.11 mF cm−2, which indicates that the introduction of 1,3,6,8-Psas could greatly improve the electrochemical properties of the solution processed PANI. The capacitance retention rate of the composite electrode with 1,3,6,8-Psas as the anchor doping agent is 70.12% after 1000 cycles, while the capacitance retention rate of the PANI-WO3/FTO electrode with 1000 cycles is only 43.34%, which indicates that the anchoring effect of 1,3,6,8-Psas can support the linking of PANI and prevent the impact failure of the PANI chain skeleton.

The dense extracellular matrix (ECM) in tumor tissue severely hinders the penetration and enrichment of antitumor nanomedicines, which could significantly affect their efficiency. In this study, we used pH-sensitive nanocarriers loaded with collagenase (Col) to remold the tumor microenvironment (TME). Furthermore, we combined the collagenase delivery system with a nanomedicine to improve its penetration and enrichment in the tumor, thereby improving efficacy. We synthesized acetalated dextran (Ace-DEX) with an ideal pH-sensitivity as the carrier material of collagenase. Under mild preparation conditions, collagenase was loaded into Ace-DEX nanoparticles (NPs) with a high loading capacity (>4%) and remained highly active (>90%). Col-carrying NPs (Col-NPs) significantly reduced the tumor collagen content by 15.1%. Pretreatment with Col-NPs increased the accumulation of doxorubicin (DOX)-loaded liposome (DOX-Lipo) in the tumor by 2.8-fold. There were no safety concerns as the Col-NP showed no significant toxicity and reduced Col-induced damage to healthy tissues. Additionally, the number of circulating tumor cells remained unchanged after Col-NP treatment, suggesting no increased risk of tumor metastasis. Because the Col-NP acts essentially independent of the subsequent treatment, it has considerable potential for enhancing many existing delivery systems and drugs for cancer treatment. It may also be used for treating other collagen-related diseases.

Submergence tolerance is crucial when thinking in promising species for restoration of ecosystems prone to suffer extreme flooding events. In this study, two-year-old seedlings of Distylium chinense were subjected to one field study and five controlled experiments: unsubmerged and watered daily as controls (CK) and completely submerged for 30, 60, 90 and 120 days, respectively followed by a 60-day recovery period to test the submergence tolerance. The results showed that the survival decreased with the increasing flooding duration. Different submergence duration treatments affected dry mass accumulation and carbohydrate content of roots, stems and leaves. Flooding stress affected the activities of pyruvate decarboxylase (PDC), ethanol dehydrogenase (ADH) and lactic dehydrogenase (LDH) enzymes, which indicated the roots and leaves adapt to long-term flooding by reinforcing their anaerobic respiration and activities of ADH were higher than those of LDH for roots and leaves with stronger alcoholic fermentation mainly. After de-submergence, the recovery patterns of carbohydrate were coincided with those of dry mass accumulation of the roots, stems and leaves. A significant regression equation analysis showed root starch content and dry mass accumulation were the major factors affecting the seedling survival. And D. chinense accumulated substantial amounts of carbohydrate before submergence and invested more in roots and stems than in leaves, which enhances long-term survival under submergence. Carbohydrate storage is a key functional trait that can explain high survival under submergence. D. chinense may have adopted a suite of growth and respiratory metabolic adaptation strategies to survive long-term submergence.

Because rapid, convenient, and selective methods for HIV detection are urgently needed, herein, a simple label-free and enzyme-free strategy is constructed for sensitive fluorescence detection of HIV DNA using the fluorescent intercalating dye thioflavin T (THT) as the detection signal source. This strategy utilizes a hairpin DNA sequence (H1) and two assistant strands. H1 is wisely designed with a G-quadruplex sequence in the stem. Target DNA, when present in solution, will hybridize with H1 to form H1/target duplexes and release the G-quadruplexes. Additionally, the assistant probes hybridize with the unfolded H1 to form a stable DNA double strand, resulting in the displacement of the target to participate in another similar reaction cycle. Consequently, many G-quadruplex structures are generated, leading to a significantly amplified fluorescence signal of THT. The linear range is from 0.1 nM to 50.0 nM with a limit of detection of 13 pM. Results can be achieved within 40 min, because the cyclic amplification involves only one DNA hairpin and two auxiliary chains. Furthermore, this platform exhibited good selectivity with one base mismatch or other DNA sequences. This strategy could be used as a simple, sensitive, and selective tool to detect other DNA biomarkers.

A molecular beacons (MBs) loaded on molybdenum disulfide (MoS2) nanosheets as fluorescence probes for sensitive and versatile detection of microRNAs (miRNAs) through hybridization chain reaction (HCR) has been designed. MoS2 was used as a adsorbent to capture the MBs and a selective fluorescence quencher to reduce the background signal. In the absence of miRNAs, HCR could not be triggered due to the stability of MB probes. The probes attached to the MoS2 surface, efficiently quenching fluorescence of the G-quadruplex/Thioflavin T. However, the presence of target miRNAs triggers the HCR process to generate large amount of HCR products. Meanwhile, the HCR products of long nanowires chain with abundant G-quadruplexes could not be adsorbed on the surface of MoS2, and therefore detach from the MoS2. Consequently, Thioflavin T could be embedded in G-quadruplexes and produced strong fluorescence signal. This fluorescence emission signal could achieve detection of miRNA as low as 4.2 pM and a wide linear ranges from 0.1 to 100 nM. In addition, a versatile fluorescence probe has been developed for detection of miRNA-21 by changing the miRNA-recognition domain of MB. Thus, the fluorescent probe would be a potential alternative tool for biomedical research and clinical molecular diagnostics.

In this work, an improved mathematical model was proposed for simulation of the diffusion of dibenzothiophene (DBT) molecules inside the porous materials in liquid phase. The experimental data of the diffusion were obtained in some silica adsorbents with uniform pore structure. The intrinsic pore diffusivity and intrinsic surface diffusivity of molecules were obtained through optimizing the parameters in the mathematical model with the experimental data. The bulk diffusivity of molecules in solution was obtained when the pore size of the silica adsorbents was large enough. The correlation of the intrinsic pore diffusivity with the ratio of diffusion molecular size to pore size of porous materials was established. In addition, the effect of pore size on the ratio of surface mass transfer to total mass transfer was studied and it was found that the smaller the pore size of porous materials, the higher the ratio of surface mass transfer to total mass transfer.

Sulfate radical-based advanced oxidation process (SR-AOPs) has great promise in water treatment, there is thereby a pressing need yet still a significant challenge to rationally design an efficient and green catalyst for heterogeneous catalytic reactions. In this study, deep eutectic solvents (DESs) were prepared and employed to simultaneously achieve structural engineering of fibrils separation and surface modifying of nitrogen doping on biochar derived from filaments biomass (NRBF) of Ramie (Boehmeria nivea (L.) Gaud). The more regular structure and pure carbon with reasonable configuration, and the N doped in hexatomic ring of NRBF were great impetus to improve the catalytic performance for peroxydisulfate (PDS) activation, with 4.5 times higher degradation rate of tetracycline than pristine biochar. The in-depth mechanistic study of PDS activation confirmed that dominated pathway was in transition from original reactive species (1O2) in pristine biochar system to a direct electron-shuttle pathway in NRBF system. Moreover, the non-radical dominated NRBF/PDS system showed good potential for bacteria (Escherichia coli) inactivation in disinfection application. Therefore, this work provides the underlying insights to guide the design of a functional and green biochar converting from Ramie filaments by an environmentally friendly facile protocol to achieve multiple purposes of wastewater decontamination and disinfection.

Objective To observe the brain protective effect of Leonuri Herba Total Alkali (LHA) on cerebral ischemia reperfusion injury in rats, so as to provide basis for clinical research. Methods Adult male SD rats were randomly assigned into sham group, middle cerebral artery occlusion/reperfusion (MCAO/R) group, and LHA + MCAO/R group (25 mg/kg, 50 mg/kg, and 100 mg/kg). Fourteen days before MCAO/R surgery, the rats in treatment groups were orally administered with LHA in ultrapure water once daily for 14 days, while rats in the sham and MCAO groups were given the same amount of saline in advance. After 1 h of administration on the 14th day, MCAO surgery was subjected. The neurological deficits, brain infarct volume, histopathology, immunofluorescence, inflammation indicators and the gene/protein expressions of BDNF-TrKB-PI3K/Akt signaling pathway in the rat brain tissue were evaluated 24 h after the MCAO/R-injury. Results It was found that rats in LHA pre-administration group showed significantly reduced neurological deficit scores, infarction volume, the serum levels of NSE and S100β. Meanwhile, the content of Evans Blue (EB) in brain tissue from LHA group was decreased, as well as the levels of inflammatory cytokines and their gene levels. Moreover, LHA pre-administration inhibited the expression of CD44, GFAP, FOXO1 and promoted the expression of BDNF and NeuN. In addition, LHA pre-administration could up-regulate the protein expression of TrkB, p-PI3K, p-Akt, Bcl-2, and down-regulate the protein expression of Bax, and increase the level of Bcl-2/Bax. Conclusions The study demonstrated that LHA pre-administration could regulate the PI3K/Akt pathway by increasing BDNF levels, and play a neuroprotective role in cerebral ischemia-reperfusion injury.

Systematic study of the surface chemical properties of uranium minerals is necessary to improve the uranium ore extracting process. The presented work aims to argue geochemistry and acid hydrometallurgy accessibility of uraninite from the Mianhuakeng (MHK) granite-hosted uranium deposit, South China, which provides insight on this ore extracting domain. Mineralogy, geochemical composition, U&ndash, Th&ndash, Pb chemical age, and uranium deportment of the uraninite were systematically analyzed by using scanning electron microscope with energy dispersion spectrum (SEM-EDS), an electron probe microanalyzer (EPMA), and x-ray photoelectron spectroscopy (XPS). The results showed that uraninite was intergrowth with coffinite, probably due to uraninite being partly metasomatized into coffinite along the fissures. The major element content of uraninite such as for UO2, SiO2, and CaO were 79.46 &plusmn, 2.03 wt%, 6.19 &plusmn, 1.36 wt%, and 5.09 &plusmn, 0.80 wt%, respectively. Single-point U&ndash, Pb chemical ages for uraninite grains were calculated with the EPMA data, and the results showed ages ranging from a few million to dozens of million years, indicating Pb loss after uraninite formed. Uranium deportment in uraninite generally existed in the forms of UO2, U3O8, and UO3, and mostly showed high valence states suggested by XPS. Uranium on the surface of the uraninite grain was partially oxidized by sulfuric acid leaching, which led to tetravalent uranium converting to hexavalent uranium, suggesting uraninite in the MHK uranium deposit is accessible to be leached by sulfuric acid.

Brown tides caused by Aureococcus anophagefferens have occurred along the Qinhuangdao coastline in the Bohai Sea (BS) in recent years. Little is known about the spatio-temporal distribution of A. anophagefferens, particularly its profile distribution and the effects of environmental controls. In this study, four surveys were conducted in Qinhuangdao coastal waters during the brown tide from June to July 2013; another survey was conducted to cover a larger region in the BS in May 2016. Temperature, salinity, nutrients, and chlorophyll a were analyzed; and the density of A. anophagefferens was detected by a sensitive qPCR method. The intensive brown tide only occurred in Qinhuangdao inshore waters at temperatures ranging from 21.5 to 23.2 °C and relatively high salinity (> 29). Redundancy analysis indicated that the low dissolved inorganic nitrogen limited the growth of other pico- and nano-algal species; high dissolved organic nitrogen and low inorganic nutrients were suitable for the development of brown tides in Qinhuangdao coastal waters, which also contained a thermocline during the brown tide. At the early stage of the brown tide, a high abundance of A. anophagefferens appeared at the bottom of offshore waters characterized by low temperature and high salinity. The A. anophagefferens cells were speculated to originate from water mass located in a depression between the central ridge and the Qinhuangdao coastal area. In brief, this study reported the spatio-temporal variation of brown tides based on the abundance of A. anophagefferens and environmental forces and implied that A. anophagefferens could be transported from the bottom of offshore waters to promote brown tides in inshore waters of Qinhuangdao.

Ischemic stroke is one of the most common causes of mortality worldwide and is a primary cause of disability and mortality in adults. There is an unmet need for drugs that can effectively treat ischemic stroke. Hence, the present study explored the neuroprotective effects of andrographolide (Andro) in a mouse model of bilateral common carotid artery occlusion, and systematically evaluated the potential mechanisms underlying its effects. The effects of Andro on mouse brain tissue following cerebral ischemia-reperfusion injury (CIRI) were evaluated by histopathological (H&E and Nissl) and immunofluorescence [glial fibrillary acidic protein (GFAP) and neuronal nuclei (NeuN)] staining. A traditional Chinese medicine-based network pharmacology method was performed to establish and analyze compound-target-disease and function-pathway networks in order to elucidate the possible mechanisms responsible for the protective role of Andrographis paniculata in CIRI. In addition, western blot analysis and RT-qPCR was performed to evaluate the expression and activation of signaling proteins predicted to be involved in this mechanism. The amelioration of histopathological alterations was observed in mice pre-treated with Andro. Immunofluorescence staining revealed that Andro decreased the expression of GFAP and increased the expression of NeuN, and significantly decreased the levels of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α). Network pharmacology analysis revealed that neuroinflammatory response and apoptosis were associated with the effects of Andrographis paniculata on CIRI. Western blot analysis revealed that the mice pre-treated with Andro exhibited an upregulated protein expression of tropomyosin receptor kinase B (TrkB), p-PI3K and p-Akt, as well as a decrease in the expression of GFAP and an increase in the expression of NeuN. In addition, the data of RT-qPCR indicated that the mice pre-treated with Andro exhibited a significantly decreased expression of encoding IL-1β mRNA, IL-6 mRNA and TNF-α mRNA in the brain compared to the untreated mice following CIRI. On the whole, the findings of the present study suggest that pre-treatment with Andro exerts a protective effect against CIRI, which may be partly related to its potential to reduce neuroinflammatory response and apoptosis in patients with stroke.

The present study investigated the effectiveness of a Carisolv III + 0.5% sodium hypochlorite (NaOCl)-based root canal irrigant for smear layer removal.Forty maxillary incisors were randomly divided into 4 groups (n = 10 per group). The canals in group A (experimental) were prepared with 0.5% NaOCl, and Carisolv III and 0.5% NaOCl was used for the final washing; groups B and C (positive controls) used 2% and 5.25% NaOCl, respectively; and group D (negative control) used phosphate-buffered saline (PBS). Ethylenediaminetetraacetic acid (EDTA) was used for all of the groups. A 5-point scoring scale and scanning electron microscopy were used to evaluate the effectiveness of the irrigants. The canals were consistently cleaner in the coronal and middle thirds than in the apical thirds (P .05).For cleaning the root canals, 5.25% NaOCl was more effective than 2% NaOCl, 0.5% NaOCl + Carisolv III, and phosphate-buffered saline , respectively (P .05). The 2% NaOCl solution showed similar results to 0.5% NaOCl + Carisolv III (P .05). The combination of 5.25% NaOCl and 17% EDTA remains the most effective irrigant for removal of the root canal smear layer.A combination of Carisolv III + 0.5% NaOCl (with 17% EDTA) showed a cleaning ability similar to that of 2% NaOCl (with 17% EDTA).

The newly emerging aggregation-induced emission (AIE) theory provides a striking perspective to synthesize luminescent liquid crystal (LLC) materials with outstanding solid-state luminescence properties which have showed potential applications as semiconductor materials, liquid crystal displays and organic light-emitting diodes. However, to date, all the known AIE-active LLC molecules are based on very limited AIE fluorophores including cyanostilbene, tolane, tetraphenylethene and metallomesogen cores, which greatly impede the wide applications of these materials, while on the other hand leave us with plenty of opportunities to develop novel AIE-based LLC materials. In this work, we design and synthesize two categories of tetraphenylthiophene-core disk-like molecules, TPTn bearing one tetraphenylthiophene-core and eight peripheral alkoxyl chains, and TPTEn bearing one tetraphenylthiophene-core and four 3,4,5-trialkoxybenzoate groups, which can form square, rectangular or hexagonal columnar phases depending on the mesogenic core structures and the chain length of aliphatic tails. Meanwhile, these tetraphenylthiophene-core LLC molecules exhibit obvious AIE characteristics, the fluorescence emission intensity values measured in the aggregated state were hundred times higher than those values measured in benign solvents. Furthermore, these AIE-active tetraphenylthiophene core LLC materials showed narrow band gap energies and excellent gelation ability in appropriate solvents, due to which they might have potential applications as organic semiconductor materials and sensors.

In this study, we designed a set of SARS‐CoV‐2 enrichment probes to increase the capacity for sequence‐based virus detection and obtain the comprehensive genome sequence at the same time. This universal SARS‐CoV‐2 enrichment probe set contains 502 120nt ssDNA biotin‐labeled probes designed based on all available SARS‐CoV‐2 viral sequences and it can be used to enrich for SARS‐CoV‐2 sequences without prior knowledge of type or subtype. Following the CDC health and safety guidelines, marked enrichment was demonstrated in a virus strain sample from a cell culture, three nasopharyngeal swab samples (cycle threshold [Ct] values: 32.36, 36.72, and 38.44) from patients diagnosed with COVID‐19 (positive control) and four throat swab samples from patients without COVID‐19 (negative controls), respectively. Moreover, based on these high‐quality sequences, we discuss the heterozygosity and viral expression during coronavirus replication, and its phylogenetic relationship with other selected high‐quality samples from The Genome Variation Map (GVM). Therefore, this universal SARS‐CoV‐2 enrichment probe system can capture and enrich SARS‐CoV‐2 viral sequences selectively and effectively in different samples, especially clinical swab samples with a relatively low concentration of viral particles. This article is protected by copyright. All rights reserved.

This manuscript is based on the method we developed urgently to deal with the research requirement in the conflict between achieving a complete genome sequence for the evolutionary history of SARS-CoV-2 study and the low viral RNA concentration. Here, in this manuscript, we developed a set of SARS-CoV-2 enrichment probes to increase the sensitivity of sequence-based virus detection and characterization via obtaining the comprehensive genome sequence. Following the CDC health and safety guidelines, we test the concept using the culturing supernatant contain SARS-CoV-2 particles, and its full-length sequence was used for further analysis. The fraction of SARS-CoV-2 endogenous DNA was 93.47% with Cluster Factor about 1.1, which demonstrate that the numbers of mapped reads to SARS-CoV-2 reference sequence significantly increased, compared to metagenomic sequencing technology, following SARS-CoV-2 probe enrichment. Moreover, based on the high-quality sequence, we discussed the heterozygosity and viral expression during replication of coronavirus, and its phylogenetic relationship with other selected high-quality samples from The Genome Variation Map (GVM) (on 2020/03/22). We believe this manuscript is valuable for all the researchers who are interested in using clinical warp samples to obtain the high coverage of SARS-CoV-2 genome sequence with a relatively low concentration of viral particles. This would allow the clinician to correlate the diagnostic data with molecular monitoring in viral evolutional, the most importantly, to track the functional mutation of SARS-CoV-2.

The synthesis and self-assembly studies of DNA/RNA-mimic artificial polymers have drawn extensive scientific attention since synthetic chemists can manipulate the functions of these modified nucleic acid molecules by varying their macromolecular backbone and nucleoside unit structures. In this paper, we report two types of modified nucleic acids with olefin bridges prepared by acyclic diene metathesis polymerization (ADMET). The 3′-OH and 5′-OH groups of deoxythymidine and deoxyadenosine analogue monomers are functionalized with either two terminal allyl units or allyl and acryloyl units, respectively. The consequent ADMET approaches provide either regio-uncontrolled oligodeoxynucleosides with poor E/Z selectivity or well-defined oligodeoxynucleosides built in a highly ordered head-to-tail addition manner. These two different macromolecular structures markedly influence the self-assembly morphologies of the corresponding oligodeoxynucleosides, which show spherical and filamentous helix nanostructures, res...

Hydrocracking of 1-methylnaphthalene to light aromatic hydrocarbons, such as benzene (B), toluene (T) and xylene (X), at 420 °C and 6 MPa was studied over a series of sulfided Metals/Beta catalysts (Metals = NiMo, NiW, CoMo, CoW, Mo, W). Based on reaction results, a six-lump reaction kinetic model was proposed and a mathematic kinetic model was established which agreed well with the experimental data. All the kinetic constants of every step reaction in the reaction model were obtained. Hydrogenation activity of catalysts not only be affected by metal species and their contents, but also be influenced by metal-zeolite interaction. Strong acidity resulting strong interaction between acid centers and metal centers decreased the hydrogenation activity of catalysts. When the amount of loaded metal oxides increases, the Bronsted acid concentration of zeolite decreases. Selective-hydrogenation activity is a key factor to BTX yield and W-based catalysts showed higher selective hydrogenation activity than other catalysts. Both experiments and the kinetic model showed that 25W/Beta catalyst had the highest BTX yield (53 wt%), attributed to its relatively high selective-hydrogenation activity of W and suitable metal-zeolite interaction.

In this manuscript, we describe a photo-responsive dual-layer polysiloxane-based liquid crystal elastomer (LCE) soft actuator with switchable handedness of helical curling motions. Benefite...

New generation spacecraft technology requires more and more deployable, light-weight, thin polymer films, in particular novel polyimide materials with high optical transparency, excellent foldability and superior flexibility. In this work, we develop a highly transparent, ultra-foldable, ultra-flexible and ultra-processable polyimide composite material by incorporating 5–8 wt% of ionic liquid 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide into colorless polyimide matrices. This 23-μm-thick polyimide composite film exhibits a high optical transmittance of 90.4% even at 450 nm wavelength and an incredibly low cutoff wavelength of 273 nm. It is an extremely strong and flexible material, with a tensile modulus of 844.6 MPa, a tensile strength of 48.2 MPa, a high elongation at break of 108.4%, and an extraordinary minimum bend radius of 1 μm. It can be easily folded in half 4 times or twisted by 900° without any crack damages. Moreover, it has a low expense cost and good film processability for industrialization manufacturing. All of these superior performances render this ionic liquid/polyimide composite an ideal structural material for solar sails, solar arrays and thin-film photovoltaics, etc.

In this paper, an electrochemical sensor was developed for detecting heavy metal ions by using contains O, S and N atoms polymer hollow nanosphere materials for the electrochemical simultaneous detection of Pb2+ and Cu2+. poly(2,5-bis-(2,3-dihydrothieno[3,4-b][1,4]dioxyin-5-yl)pyridine) hollow nanosphere (poly(BPE)HNs) and poly(3,6-bis(3,4-ethylenedioxythienylpyridazine) hollow nanosphere (poly(EPE)HNs) were prepared by via chemical oxidative polymerization method. And the resulting products were characterized by FT-IR, UV–vis, TGA, XRD, TEM and SEM. The results indicated that two kinds of polymers were prepared successfully. Furthermore, the electrochemical sensors were applied for the electrochemical determination of Pb2+ and Cu2+ using DPV method. And the results indicated that poly(BPE)HNs modified glassy carbon electrode (poly(BPE)HNs/GCE) exhibited linear detection range from 0.012–4 μM and 0.016–4 μM for the Pb2+ and Cu2+, with the sensitivity of 19.51 μA/μM and 4.87 μA/μM. The detection limits (S/N = 3) of 0.005 μM and 0.012 μM, respectively. The real sample analysis suggested that the poly(BPE)HNs modified electrode can be applied for the detection of the Pb2+ and Cu2+ ions in tap water samples.

Objectives Edaravone, a free radical scavenger, alleviates blood-brain barrier disruption in conjunction with suppression of the inflammatory reaction in acute cerebral infarction. Thrombolysis with recombinant tissue plasminogen activator (rtPA) is an established therapy for acute cerebral infarction patients. The purpose of this study was to assess the effects of edaravone on outcomes in acute cerebral infarction patients treated with ultra-early thrombolysis of iv-rt-PA. Patients and Methods We conducted a retrospective cohort study using the database of Ningbo First Hospital. We identified patients who were admitted with a primary diagnosis of acute cerebral infarction and treated with intravenous rtPA(iv-rtPA) within 3 h of symptom onset from March 1st in 2014 to October 31st in 2016.Thenceforth,the patients were divided into 2 groups by treatment with(edaravone group) or without edaravone(non-edaravone group). Glasgow Coma Scale (GCS) scores and mRS score at admission were used. Clinical background, risk factors for acute cerebral infarction hemorrhagic transformation, 7-day mortality, recanalization rate, bleeding complications and blood rheology indexes were collected. We also collected the following factors: National Institutes of Health Stroke Scale scores, barthel index. Results 136 patients treated without edaravone during hospitalization were selected in non-edaravone group while edaravone group included 132 patients treated with edaravone during hospitalization. The patient baseline distributions were well balanced between non-edaravone group and edaravone group. The rate of hemorrhagic transformation in non-edaravone group was higher than that in edaravone group (P ＜ 0.05). The NIHSS scores 7 days and 14 days after symptom onset were higher in non-edaravone group than in edaravone group (both P ＜ 0.05). Edaravone group showed a higher recanalization rate and a lower bleeding complications rate at discharge than the non-edaravone group (both P ＜ 0.05). The differences of all the blood rheology indexes between the two groups were statistically significant (all P ＜ 0.05). Conclusions Edaravone may improve outcomes of acute cerebral infarction patients treated with ultra-early thrombolysis of iv-rt-PA.

Polycyclic aromatic hydrocarbons (PAHs) accumulated in agricultural soils are likely to threaten human health and ecosystem though the food chain, therefore, it is worth to pay more attention to soil contamination by PAHs. In this study, the presence, distribution and risk assessment of 16 priority PAHs in rice-wheat continuous cropping soils close to industrial parks of Suzhou were firstly investigated. The concentrations of the total PAHs ranged from 125.99 ng/g to 796.65 ng/g with an average of 352.94 ng/g. Phenanthrene (PHE), fluoranthene (FLT), benzo [a] anthracene (BaA) and pyrene (PYR) were the major PAHs in those soil samples. The highest level of PAHs was detected in the soils around Chemical plant and Steelworks, followed by Printed wire board, Electroplate Factory and Paper mill. The composition of PAHs in the soils around Chemical plant was dominated by 3-ring PAHs, however, the predominant compounds were 4, 5-ring PAHs in the soils around other four factories. Meanwhile, the concentration of the total PAHs in the soils close to the factories showed a higher level of PAHs in November (during rice harvest) than that in June (during wheat harvest). Different with other rings of PAHs, 3-ring PAHs in the soils around Chemical plant and Steelworks had a higher concentration in June. The results of principal component analysis and isomeric ratio analysis suggested that PAHs in the studied areas mainly originated from biomass, coal and petroleum combustion. The risk assessment indicated that higher carcinogenic risk was found in those sites closer to the industrial park.

Ancient DNA obtained from ancient samples, such as sediments, bones, and teeth, is an important genetic resource that can be used to reconstruct an evolutional history of humans, animals, and plants. The application of high-throughput sequencing enables the research of ancient DNA to be conducted in a whole genome scale. However, post-mortem DNA damage mainly caused by deamination of cytosine to uracil (or methylated cytosine to thymine) may confound the variant calling and downstream analysis. In this article, we develop a Python program to implement a new variant caller, "AntCaller", which extracts the information on nucleotide substitutions from sequencing data and calculates the probability of each genotype based on a Bayesian rule. Through both simulation studies and real data analyses, it was shown that our method reduced the false discovery rate caused by nucleotide misincorporations and outperformed two mainstream variant callers (i.e., GATK and SAMtools) in terms of calling accuracy. In a real application with serious DNA damage, AntCaller still outperformed GATK and SAMtools combined with quality score recalling.

Parkinson's disease (PD) is the second most common neurodegenerative disease. Eigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, is known to exert a beneficial effect on PD patients. Although some mechanisms were suggested to underlie this intervention, it remains unknown if the EGCG-mediated protection was achieved by remodeling gut microbiota. In the present study, 0.1 mM or 0.5 mM EGCG was administered to the Drosophila melanogaster with PINK1 (PTEN induced putative kinase 1) mutations, a prototype PD model, and their behavioral performances, as well as neuronal/mitochondrial morphology (only for 0.5 mM EGCG treatment) were determined. According to the results, the mutant PINK1B9 flies exhibited dopaminergic, survival, and behavioral deficits, which were rescued by EGCG supplementation. Meanwhile, EGCG resulted in profound changes in gut microbial compositions in PINK1B9 flies, restoring the abundance of a set of bacteria. Notably, EGCG protection was blunted when gut microbiota was disrupted by antibiotics. We further isolated four bacterial strains from fly guts and the supplementation of individual Lactobacillus plantarum or Acetobacter pomorum strain exacerbated the neuronal and behavioral dysfunction of PD flies, which could not be rescued by EGCG. Transcriptomic analysis identified TotM as the central gene responding to EGCG or microbial manipulations. Genetic ablation of TotM blocked the recovery activity of EGCG, suggesting that EGCG-mediated protection warrants TotM. Apart from familial form, EGCG was also potent in improving sporadic PD symptoms induced by rotenone treatment, wherein gut microbiota shared regulatory roles. Together, our results suggest the relevance of the gut microbiota-TotM pathway in EGCG-mediated neuroprotection, providing insight into indirect mechanisms underlying nutritional intervention of Parkinson's disease.

A widely applicably method is described for fluorometric determination of targets such as microRNA and viral DNA. It is making use of a Mg(II)-dependent DNAzyme and a G-quadruplex. In the absence of analyte, an inactive DNAzyme is formed by the hybridization of split DNAzymes and substrate. On addition of target analyte, the end of each strand of the split DNAzymes bind the analyte. This leads to the generation of an active DNAzyme. In the presence of Mg(II), the activated DNAzyme is formed and can cleave the substrate strand. Hence, the caged G-quadruplex sequences will be released. These released G-quadruplexes combine with thioflavin T to generate a G-quadruplex/thioflavin T complex and thereby cause amplified fluorescence. The method shows a 70 pM detection limit for H5N1 and works over a wide linear range 1 nM to 400 nM. Conceivably, this detection scheme has a wide scope in that it may be applied to other assays for microRNAs and DNAs by variation of the type of DNAzyme. Graphical abstract Schematic presentation of target detection: the DNAzyme cannot cleave the substrate strand when target is absent. Once the target is added, the active DNAzyme can cleave the substrate strand in the presence of Mg

A tetranuclear cluster {[(Tp)Fe(CN)3]Co(pp)H2O}2·[(Tp)Fe(CN)3]2 ⋅ 6H2O (1; Tp = hydrotris(pyrazoly)borate, pp = 2,6-bis(N-pyrazolyl)pyridine) and a hexanuclear cluster {[(pzTp)Fe(CN)3]2Co(pp)}2·2H2O (2; pzTp = tetrakis(pyrazoly)borate) have been synthesized via rational assembly of the same (ppCoII)2 + unit and different tricyanometalate building blocks with varying proportions of sterically hindered groups. Magnetic measurements reveal that 1 exhibits the dominant antiferromagnetic interactions between Fe(III) and Co(II) ions, while 2 exhibits the dominant ferromagnetic interactions.

Monodomain liquid crystalline elastomers (LCEs) with anisotropic, loosely crosslinked polymeric matrices have attracted intense scientific attention due to their widespread applications in stimuli-responsive soft actuators. However, traditional synthetic pathways towards monodomain LCEs require complicated procedures, elevated reaction temperatures, and a prolonged preparation time ranging from several hours to even several days. In this manuscript, we report a fast room-temperature one-pot, two-stage thiol–ene photoaddition method to synthesize monodomain polysiloxane-based LCE films. The first stage is a partial thiol–ene photo-crosslinking of poly(3-mercaptopropylmethylsiloxanes) and vinyl-terminated mesogens and crosslinkers in solution, the second stage is a complete thiol–ene photo-crosslinking of the uniaxially-stretched pre-crosslinked LCE film. Starting from mesogenic monomers, the whole preparation process can be finished in less than 30 minutes, and all the preparation experiments are performed at room temperature, in open air. We believe that this facile one-pot, two-stage thiol–ene photoaddition method can open a new route for the fast and robust production of monodomain LCE shape memory materials.

Recognition of melamine is not only of importance for the food industry but also an interesting scientific research topic. The objective of this work is to screen suitable hydrogen-bonding complementary compounds for the construction of melamine-core supramolecular discotic liquid crystal (LC) materials which might provide a LC perspective for detection and separation of melamine in the future. We design and synthesize five categories of long-alkyl-tailed compounds bearing different hydrogen-bonding complementary functional groups, including benzoic acid, cyanuric acid, homophthalimide, succinimide and thymine derivatives. The experimental results demonstrate that the imidodicarbonyl unit is the best hydrogen-bonding complementary functional group of melamine. Furthermore, the heterocyclic ring size markedly influences the hydrogen-bonding strength of the melamine-imidodicarbonyl unit complex. Most importantly, liquid crystallinity can be generated from these hydrogen-bonding supramolecular complexes. In particular, a variety of columnar mesomorphic orders (such as hexagonal columnar, rectangular columnar, and square columnar phases) can be effectively achieved by functionalization of thymine or succinimide units and modulation of the molar ratios of melamine and these hydrogen-bonding complementary compounds.

The detailed procedure and mechanistic analysis for the synthesis of polymethylhydrosiloxane-based semi-interpenetrating networks (PMHS-SIPNs) with Si−H and other functional groups under mild reaction conditions was presented in this work. And the Si−H –containing organosilicon materials was proved to be a useful support in the construction of nanosilver catalyst according to the previous reported strategy that with the concept of titanium-promoted reduction of ester with hydrosilane for well-distributed dispersion of titanium and nanosilver on cross-linked PMHS-SIPNs supporter (Ag@TiO2@PMHSIPN). Furthermore, a highly efficient method for the synthesis of primary propargylic alcohols has been developed using PMHS-based semi-interpenetrating networks –supported nanosilver (Ag@TiO2@PMHSIPN) as catalyst.

In this work, we report the first example of uniaxial aligned conjugated polymer (CP)/liquid crystalline elastomer (LCE) composite material by doping polyaniline nanoparticles into a classical monodomain polysiloxane-based LCE matrix. A series of comparative experiments are performed to investigate the photoresponsive properties of these polyaniline/LCE samples in correspondence to the two different conjugation forms (emeralidine salt (ES) or emeralidine base (EB)) and the varied doping concentrations (0.5 or 1.0 wt %) of the incorporated polyaniline nanoparticles. Taking advantage of the excellent photothermal conversion efficiency, these novel polyaniline/LCE composite materials can lift up ca. 200 times their own weights under the NIR illumination driving force, and such a photostimulated muscle-like actuation behavior is fully reversible after NIR light is removed.

Ethnopharmacological relevance Herbaceous peony (Paeonia lactiflora Pall.) flower has been used widely in dietotherapy in China and other countries. It has good ethnopharmacological value in the treatment of various metabolic diseases. However, the molecular mechanisms by which it lowers serum uric acid are unknown. The development of pharmaceutical resources is very important. Here, we sought to elucidate the mode of action of herbaceous peony in terms of reducing uric acid levels. Aim of the study: In the present research, the effects of the total glucosides of herbaceous peony flower were investigated in a rat hyperuricaemia model. Another aim of the study was to clarify the mechanism by which herbaceous peony flower (TGPF) lowers serum uric acid levels. Materials and methods A hyperuricaemic rat model was induced via intragastric administration of 100 mg/kg adenine and 250 mg/kg ethambutol hydrochloride (EH) for 23 d. Then TongFengShu 600 mg/kg, allopurinol 42 mg/kg, or TGPF (50 mg/kg, 100 mg/kg, or 200 mg/kg) was administered 1 h after the adenine and EH treatments. Results TGPF improved weight loss and decreased serum UA, XOD, MCP-1, TNF-α, Cr, and BUN in the rats with hyperuricaemic nephropathy. TGPF downregulated renal URAT1 and GLUT9, upregulated renal OAT1, and ameliorated histopathological changes in the thymus, spleen, and kidney. Conclusion TGPF is promising as a therapeutic agent against hyperuricaemia. It regulates the uric acid transporters and diminished serum uric acid levels, and alleviates renal pathology associated with hyperuricaemia.

An efficient amplification strategy based on the G-triplex DNA structure was developed for label- and enzyme-free fluorescence detection of human immunodeficiency virus (HIV) DNA. In this system, three hairpin molecules (H1, H2, and H3) were used to detect the target and amplify the signal. Fluorescence enhancement was achieved by producing more G-triplexes to bind with Thioflavine T. A detection limit of 33 pM with good linearity in the range from 400 pM to 110 nM was observed. This method avoided using of enzyme and cumbersome labeling procedures and was relatively superior to previous G-quadruplex-based approaches, which often encounter some difficulties in control and excitation. Moreover, the application for detecting HIV-DNA in biological fluids indicates that further applications for clinical diagnosis are expected.

Datura metel L. is a widely used traditional herbal medicine, and withanolides and amides are the two groups of main bioactive constituents in Datura metel seeds. This study aimed to elucidate the metabolism of four representative bioactive compositions containing daturataturin A (1), daturametelin I (2), N-trans-feruloyltyramine (3), and cannabisin F (4) in rats. After separately oral administration of 20 mg/kg withanolides (1, 2) and amides (3, 4) to rats, a total of 12, 24, and 21 metabolites were detected in the plasma, urine, and fecal samples, respectively. Among them, three hydroxylated metabolites, 1-M3, 2-M2, and 3-M5, were detected in plasma and rat liver microsome incubation system in high abundance. Two metabolites of 1 and 2 were unambiguously identified by comparing with reference standards. Particularly, the methylated metabolite 27α-methoxy-(22R)-22,26-epoxy-27-[(β-D-glucopyranosyl)oxy]ergosta-2,4,6,24-tetraene-1,26-dione (daturametelin L) is a new compound. The withanolides could readily get hydroxylation or methylation metabolism. Meanwhile, the phase II metabolism (glucuronidation or sulfation) was the major reaction for the amides. This is the first study on in vivo metabolism of these active compounds in seeds of Datura metel.

In this article, novel chitosan-g-poly (acrylic acid) hydrogel elastomers were successfully sythesised by grafting chitosan (CTS) onto poly acrylic acid (PAA) through radical polymerization in the presence/absence of direct current electric field. Their structure and electro-response were evaluated through scanning electron microscopy (SEM), infrared spectroscopy (IR), and dynamic mechanical analyser (DMA), respectively. Stress-strain test showed that the toughness of the chitosan-g-PAA elastomer is higher than the PAA gel. The result demonstrates the elastomers obtained in the presence/absence of electric field with similar chemical composition possess different microstructure. The positive electro responsive effect appeared on the elastomers, and both of storage modulus increment and increment sensitivity yielded maximum value at the AA concentration of 14.09 wt% under the applied electric field of 1.5 kV/mm. Thermo gravimetry and differential scanning calorimetry (TG-DSC) showed the elastomers cured under an applied electric field have stronger intramolecular bonding and higher cross-linking density.

In this work, aiming to combine thermal-induced LC-to-isotropic phase transition effect, azobenzene’s trans–cis tautomerization effect and the photothermal effect into one liquid crystalline elastomer (LCE) system to prepare a heat/UV/near-infrared(NIR) triple-stimuli-responsive LCE material, we design and synthesize a polysiloxane-based side-chain side-on azobenzene-containing LCE matrix embedded with 1 wt % single-walled carbon nanotubes, through Finkelmann’s two-step cross-linking process coupled with a uniaxial stretching technique. The multistimuli responsive behaviors of this LCE/CNT composite film are investigated under different external stimuli (heat, UV, NIR). The composite film can realize a reversible deformation between contraction and extension under heating/cooling cycles. Moreover, the composite film can perform an impressive three-dimensional deformation (bending) under UV-light irradiation. On the contrary, long wavelength light (NIR laser) forces the composite film into shrinking instea...

In recent years, side chain engineering has been proven to play a critical role in the development of high performance conjugated polymers for organic electronics. Here, we report a new strategy to improve charge transport property through side chain functionalization. A series of carbazole–diketopyrrolopyrrole based conjugated polymers P1, P2 and P3 with different side chains have been designed and synthesized. For P2 and P3, a pyrene and carbazole unit were incorporated into the terminal of the alkyl side chain, respectively. Thermal properties, crystallinities, UV-vis absorptions, electrochemical properties as well as charge transport properties of the polymers were investigated in detail. Interestingly, results showed that incorporation of the fused aromatic ring into the side chain terminal not only changed the absorption and electrochemical properties, but also affected the charge transport properties. The pyrene and carbazole group in the side chain terminal significantly promoted aggregation of the polymer chains, which would provide short-range order for improved charge carrier mobility. Compared to the hole mobility (0.019 cm2 V−1 s−1) for polymer P1 with the whole alkyl chains, increased hole mobilities of 0.081 cm2 V−1 s−1 and 0.052 cm2 V−1 s−1 were achieved for polymer P2 and polymer P3, respectively. It is worthy to note that our strategy gives rise to no increment of the crystallinity of the polymer, being beneficial for the practical application of soft electronics since high crystallinity of the material usually leads to poor thin film uniformity and weak mechanical resilience. In this respect, we offer a promising tool to aid rational polymer design for enhanced charge transport property.

The known synthetic methods of preparing main-chain liquid crystalline polymers (MCLCPs) are rather limited to several polycondensation reactions. However, the nature of step-growth polycondensation endows the corresponding MCLCPs with relatively low molecular weights and broad molecular weight distributions. In this manuscript, an entropy-driven ring-opening metathesis polymerization (ED-ROMP) approach is for the first time applied in producing a MCLCP by polymerizing a macrocyclic olefin monomer containing one cyclohexanecarboxylic acid phenyl ester group as a mesogenic core and one icos-10-enedicarbonyl group as a flexible aliphatic chain. For comparison, Yamaguchi macrolactonization and ring-closing metathesis (RCM) methods are used to synthesize the macrocyclic olefin monomer, and it turns out that although the macrolactonization method can prepare a pure macrocyclic monomer, the RCM strategy is advantageous in providing a much higher overall reaction yield. Furthermore, compared with a traditional acyclic diene metathesis (ADMET) polymerization of mesogenic α,ω-diene, the ED-ROMP approach starting with the same monomer-to-catalyst ratio, releases no heat or volatiles during the reaction, and can efficiently provide MCLCPs with much higher molecular weights over a shorter reaction time.

The matrix polymer PTBCHNB bearing o-nitrobenzyl group was successfully synthesized by copolymerization of tertiary-butyl methacrylate (TBMA), cyclohexyl methacrylate (CHMA) and o-nitrobenzyl methacrylate (NBMA) via reversible addition fragmentation chain transfer (RAFT) polymerization method. PTBCHNB was characterized by FTIR, 1HNMR, GPC and DSC. After UV irradiation, the o-nitrobenzyl groups of PTBCHNB were photocleaved and the resulting carboxyl groups were highly alkali soluble, and PTBCHNB was converted to PCHIBMA bearing carboxyl groups. So, the matrix polymer could be etched by mild alkali solution with no requirements of photoacid generators and other diverse additives. The photocleavable behaviors of PTBCHNB were determined by FTIR, 1H NMR and TGA analysis. The resist formulated with PTBCHNB and cast in THF solution showed square pattern of 10 μm×10 μm using a mercury-xenon lamp in a contact printing mode and tetramethyl-ammonium hydroxide aqueous solution as a developer.

The preparation, single-crystal X-ray crystallography and magnetic properties are reported for two single-zigzag chain complexes {[W(CN)8][Ni(imi)4]}·Bu4N·CH3OH·2H2O (1) and {[Mo(CN)8][Ni(imi)4]}·Bu4N·2H2O (2) (imi = imidazole, Bu = normal-butyl). The structure studies reveal that both complexes feature one-dimension anion chains linked by [W(CN)8]3 − units in 1 or [Mo(CN)8]3 − units in 2. Magnetic studies show that strong ferromagnetic exchange is operative within the WV(μ-CN)NiII units for (1) and MoV(μ-CN)NiII units for (2).

Poly(glycidyl methacrylate) (PGMA) with pendant iron(II)-triazoles groups was synthesized through the grafting method. The structure was characterized by 1H NMR, FTIR and XRD. Meanwhile, SQUID and DSC were conducted to measure the spin crossover property of the composite. The Fe(II) complexes modified by PGMA not only display an evident spin crossover performance, but also have excellent processability.

A series of donor-acceptor conjugated polymers incorporating benzodithiophene (BDT) as donor unit and phenanthrenequnioxaline as acceptor unit with different side chains have been designed and synthesized. For polymer P1 featuring the BDT unit and alkoxy chains substituted phenanthrenequnioxaline unit in the backbone, serious steric hindrance resulted in quite low molecular weight. The implementation of thiophene ring spacer in polymer P2 greatly suppressed the interannular twisting to extend the effective conjugation length and consequently gave rise to improved absorption property and device performance. In addition, utilizing the alkylthienyl side chains to replace the alkyl side chains at BDT unit in polymer P3 further enhanced the photovoltaic performance due to the increased conjugation length. For polymer P4, translating the alkoxy side chains at the phenanthrenequnioxaline ring into the alkyl side chains at thiophene linker group enhanced molecular planarity and strengthened π−π stacking. Consequently improved absorption property and increased hole mobility were achieved for polymer P4. Our results indicated that side chain engineering not only can influence the solubility of polymer but also can determine the polymer backbone planarity and hence the photovoltaic properties. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1915–1926

This manuscript describes a facile method to prepare a series of novel crosslinked gemini lyotropic liquid crystal (LLC) materials. In comparison with previously reported crosslinkable LLC monomers requiring lengthy, harsh and expensive synthetic protocols, herein this new acrylate-type LLC monomer can be conveniently prepared in two steps and is highly stable at ambient temperatures. This new LLC monomer predominantly forms lamellar lyotropic mesophase, and meanwhile when mixed with 17–22 wt% water at 55 – 79°C, it presents an unidentified X phase which is quite similar to bicontinuous cubic phase. The corresponding UV-crosslinked LLC membrane containing a mixture of LLC monomer, H2O, butyl rubber (BR) and a photo-initiator can retain the original mesophase and build hydrophilic nanochannels. To test the water permeability, the LLC/BR mixtures are further coated onto a polyethersulfone (PES)-supported membrane by hot-pressing and photo-crosslinking. The average water vapour flux of an X-phase LLC/BR-PES ...

The development of a simple and efficient analytical method for determination of enantiomeric purity of 2-(aminomethyl)-1-ethylpyrrolidine was presented. The method was based on pre-column derivatization of 2-(aminomethyl)-1-ethylpyrrolidine with 4-nitrobenzoic acid completing separation of the enantiomers on high performance liquid chromatographic (HPLC) chiral stationary phase (CSP). After optimizing all the effective parameters, the best performances were achieved on a Chiralcel OD-H analytical column (250 × 4.6 mm) using n-hexane: ethanol (98:2, v/v) containing 0.2% triethylamine as mobile phase with a flow rate of 1.0 mL min-1 at 25°C. Online UV and optical rotation (OR) detection was performed at 254 nm. The parameters which have an effect on chiral separation were investigated, including mobile phase additive, organic modifier type and concentration, column temperature and flow rate. The method was tested for precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness. The present method is expected to be accurate, stable, rapid and sensitive and can be used for the determination of the enantiomeric purity of 2-(aminomethyl)-1-ethylpyrrolidine in bulk samples.

This manuscript presents a facile thiol–ene photo-click chemistry method to prepare magnetic stir bar-encapsulated polysiloxane-based organocatalyst gels under benign conditions, and develops a Stir Bar-Encapsulated Catalysis (SBEC) technique. Through thiol–ene addition chemistry, we graft olefin-terminated organocatalysts (i.e. MacMillan catalyst, proline catalyst, and N-heterocyclic carbene catalyst) onto poly[3-mercaptopropylmethylsiloxane], which is further photo-crosslinked to coat the embedded magnetic stir bar. The prepared magnetic stir bar-encapsulated polysiloxane-based organocatalyst gels can be put into reaction flasks to perform stirring and catalysis functions at the same time. The most important benefit of SBEC technique is to infinitely simplify the catalyst/product separation procedure by using a simple stir-bar-retriever, even without any precipitation/filtration steps. The catalytic performances of three different organocatalyst gels applied in asymmetric Diels–Alder reaction, asymmetric aldol reaction and benzoin condensation reaction respectively are also examined herein.

Most of the traditional chiral side-chain liquid crystalline polymers (SCLCPs) depend on pendant chiral mesogenic units to introduce chirality into their structure, with the polymer backbones being usually achiral. In this work, we asymmetrically synthesize several enantiomerically pure norbornene monomers functionalized with achiral mesogenic units, and further apply a ring-opening metathesis polymerization technique to prepare a series of side-on and end-on SCLCPs with an optically active polynorbornene main chain and achiral mesogens. Their physical properties are fully characterized by NMR, UV, CD, GPC, TGA, DSC, polarimetry, polarized optical microscopy and small-angle X-ray scattering. The obtained side-on SCLCPs display the tendency to form nematic, i.e. achiral mesophases, in strong contrast to the chiral nematic (cholesteric) mesophase exhibited by their comparative end-on analogues. The proposed explanation for this phenomenon is that the chiral backbones and the laterally attached mesogens of side-on SCLCPs can concurrently exist in a parallel arrangement so that the mesogenic directors might not be affected by the chirality information, while the mesogenic directors of end-on SCLCPs always tilt to the backbone orientation so that the twisting power of chiral main chains might force the terminally attached mesogens to form helical structures.

In a bulk-heterojunction (BHJ) polymer solar cell, film morphology of the active layer plays a significant role in determining the device performance. For lots of polymers, optimization of BHJ morphology can be achieved by employing high boiling solvent additive such as 1-chloronaphthalene (1-CN). However, the additive process significantly increases the device fabrication complexity and leads to poor reproducibility of the device performance, which is not beneficial to large-scale manufacturing. In this paper, we show that well-organized film morphology can be achieved by systematic modification of the polymer structure. First, a new diketopyrrolopyrrole based monomer with a naphthalene group introduced to the terminal of the alkyl side chain was synthesized. The naphthalene group was incorporated to improve the miscibility of the polymer with a fullerene derivative and help the polymer chains self-assemble into an ordered microstructure for defined film morphology. By simply varying the monomers' ratio in copolymerization, we prepared a series of indacenodithiophene-diketopyrrolopyrrole based polymers namely, P1, P2, P3 and P4, with different contents of naphthalene group functionalized side chains. The influences of naphthalene modification on the optical and electrochemical properties of polymers, film morphology and photovoltaic properties were investigated in detail. As expected, we observed better miscibility without any significant effects on the electronic and optical properties of the polymer for 25% molar percentage of the naphthalene linked monomer employed during polymerization. However, further enhancement of the naphthalene content may decrease π–π stacking, hence leading to reduced optical property and hole mobility. When 50% molar percentage of the naphthalene linked monomer was contained in polymerization, an optimum device efficiency of 4.01% can be achieved, which was much higher than 2.92% for the 1-CN additive optimized non-naphthalene side chain counterpart based device.

Previously reported polymer backbone structures of mesogen-jacketed liquid crystalline polymers (MJLCPs) are still limited to polyacrylate, polystyrene, polyacetylene, polysiloxane, polythiophene and polynorbornene. In this manuscript, we describe a new system of MJLCPs with poly(vinyl benzoate)-backbone (PVBnB), which were synthesized by solution polymerization and bulk photo-polymerization methods. Due to the low reactivity of the vinylbenzoate group, we cannot achieve a high degree of polymerization. Ironically, benefiting from this low reactivity, we successfully prepared several loosely cross-linked MJLCP (xPVBnB) films with homogeneous- or homeotropic-alignment, for the first time by using UV-illumination on a unidirectional oriented mixture of vinylbenzoate monomers, crosslinkers and photo-initiators to perform polymerization and cross-linking at the same time, which are however extremely difficult for the much more reactive acrylate-type or styrene-type MJLCPs’ precursor monomers due to the spontaneous thermal-polymerization reactions occurring at high temperatures. Experimental results show that PVBnB can form nematic or smectic phases depending on the alkyl chain length, xPVBnB films present very small elastomeric transformations (i.e. shrinkage/wrinkle) during the LC-to-isotropic phase transition.