An AIE-Based Probe for Rapid and Ultrasensitive Imaging of Plasma Membranes in Biosystems.

The abnormality of the plasma membrane (PM) is an important biomarker for cell status and many diseases. Hence, visualizing the PM, especially in complex systems, is an emerging field in the life sciences, especially in low-resource settings. Herein, we developed a water-soluble PM-specific probe utilizing electrostatic and hydrophobic interaction strategies with aggregation-induced emission as the signal output. The probe could image the PM with many advanced features (wash-free, ultrafast staining process, excellent PM specificity, and good biocompatibility), which were demonstrated by the PM imaging of neurons. The probe allowed for the first time the imaging of erythrocytes in the complex brain environment through a fluorescence-based method. Moreover, the PM of the epidermal and partial view of the eyeball structure of live zebrafish are also revealed.

Impact on lung function among children exposed to home new surface materials: The seven Northeastern Cities Study in China.

We conducted a cross-sectional study to investigate the associations between recent home renovation exposure and lung function in children. We randomly recruited 7326 school children residing in 24 districts from seven cities in northeastern China. We collected information about home renovations from parents using a questionnaire and lung function measurements from children using spirometer recordings gathered by trained professionals and expressed as the forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), maximal mid-expiratory flow (MMEF), and peak expiratory flow (PEF). We identified higher odds of diminished lung function among these with home renovation in the previous 2 years compared to those without home renovation in the previous 2 years, for FVC (odds ratios [ORs] = 1.84 [95%CI: 1.58, 2.15]; FEV1: ORs = 2.82 [95%CI: 2.36, 3.36]; PEF: ORs = 1.51 [95%CI: 1.24, 1.83]; and MMEF: ORs = 1.90 [95%CI: 1.60, 2.24]). The associations were stronger among children exposed to new polyvinyl chloride (PVC) flooring compared to children exposed to other surface materials. Our results were consistent throughout the analysis of each type of renovation materials. In conclusion, recent home renovation exposure was associated with poor lung function among children. Strategies to protect home owners and their families from respiratory hazards during and after renovation are required.

Pincushion of Tubule Discovery and Tubular Morphology Landscape Establishment of Block Copolymer Self-Assemblies.

Block copolymer (BCP) self-assembly is a versatile technique in the preparation of polymeric aggregates with varieties of morphologies. However, its morphology library is limited. Here, the discovery of pincushion of tubules is reported for the first time, via BCP self-assembly of poly(4-vinylpyridine)-b-polystyrene (P4VP-b-PS) with very high molecular weight (500 kDa) and asymmetry (2 mol% P4VP). The investigation confirms the importance of core-forming block length on morphology control of BCP self-assemblies, especially with respect to tubular structures. The morphology landscape of tubular structures is successfully established, where dumbbell of tubule, tubule, loose clew of tubules, tight clew of tubules, and pincushion of tubules can be prepared by adjusting the core-forming block length. This work therefore expands the structure library of BCP self-assemblies and opens up a new avenue for the further applications of these tubular materials.

Thermo-responsive behavior of borinic acid polymers: experimental and molecular dynamics studies.

The thermo-responsive properties of borinic acid polymers were investigated by experimental and molecular dynamics simulation studies. The homopolymer poly(styrylphenyl(tri-iso-propylphenyl)borinic acid) (PBA) exhibits an upper critical solution temperature (UCST) in polar organic solvents that is tunable over a wide temperature range by addition of small amounts of H2O. The UCST of a 1 mg mL(-1) PBA solution in DMSO can be adjusted from 20 to 100 °C by varying the H2O content from ∼0-2.5%, in DMF from 0 to 100 °C (∼3-17% H2O content), and in THF from 0 to 60 °C (∼4-19% H2O). The UCST increases almost linearly from the freezing point of the solvent with higher freezing point to the boiling point of the solvent with the lower boiling point. The mechanistic aspects of this process were investigated by molecular dynamics simulations. The latter indicate rapid and strong hydrogen-bond formation between BOH moieties and H2O molecules, which serve as crosslinkers to form an insoluble network. Our results suggest that borinic acid-containing polymers are promising as new "smart" materials, which display thermo-responsive properties that are tunable over a wide temperature range.

Dual lignin-derived polymeric system for peptone removal from simulated wastewater.

The long-term existence of peptone can breed a large number of bacteria and cause the eutrophication of municipal wastewater. Thus, removing peptone in the wastewater is a major challenge facing the current industry. This study used cationic and anionic lignin polymers, i.e., kraft lignin-[2-(methacryloyloxy)ethyl] trimethylammonium methyl sulfate (cationic lignin polymer, CLP) and kraft lignin-acrylic acid (anionic lignin polymer, ALP), as flocculants to eliminate peptone from model wastewater in the single and dual component systems. The affinity of peptone for ALP or CLP was assessed by quartz crystal microbalance with dissipation, X-ray photoelectron spectroscopy, contact angle, and vertical scan analyzer. Results illustrated that the adsorption effect of CLP for peptone was significantly superior to that of ALP owing to the stronger vital interaction between cationic polymer and peptone molecules. Based on destabilization and sedimentation analyses, introducing CLP triggered the preliminary flocculation of peptone via bridging action, as indicated by a considerable increment in the destabilization index (from 1.1 to 10.6). Moreover, peptone adsorbed more on the CLP coated surface than on the ALP coated one (14.8 vs 5.4 mg/m2), while ALP facilitated its further adsorption in the dual polymer system. This is because CLP adsorbed a part of peptone molecules on its surface. Then, ALP entrapped the unattached peptone onto the CLP coated surface through electrostatic interaction. Compared with the single polymer system, mixing ALP and CLP subsequently into the peptone solution in the dual system generated larger size aggregates (mean diameter of 6.1 µm) and made the system destabilization (Turbiscan stability index up to 58.1), thereby yielding more flocculation and sedimentation. Finally, peptone was removed successfully from simulated wastewater with a turbidity removal efficiency of 92.5%. These findings confirmed that the dual-component system containing two lignin-derived polymers with opposite charges could be viable for treating peptone wastewater.

Characterization of a novel swollenin from Penicillium oxalicum in facilitating enzymatic saccharification of cellulose.

BACKGROUND: Plant expansins and fungal swollenin that can disrupt crystalline cellulose have great potential for applications in conversion of biomass. Recent studies have been mainly focused on Trichoderma reesei swollenin that show relatively low activity in the promotion of cellulosic hydrolysis. Our aim was to isolate a novel swollenin with greater disruptive activity, to establish an efficient way of producing recombinant swollenin, and to optimize the procedure using swollenin in facilitation of cellulosic hydrolysis. RESULTS: A novel gene encoding a swollenin-like protein, POSWOI, was isolated from the filamentous fungus Penicillium oxalicum by Thermal Asymmetric Interlaced PCR (TAIL-PCR). It consisted of a family 1 carbohydrate-binding module (CBM1) followed by a linker connected to a family 45 endoglucanase-like domain. Using the cellobiohydrolase I promoter, recombinant POSWOI was efficiently produced in T. reesei with a yield of 105 mg/L, and showed significant disruptive activity on crystalline cellulose. Simultaneous reaction with both POSWOI and cellulases enhanced the hydrolysis of crystalline cellulose Avicel by approximately 50%. Using a POSWOI-pretreatment procedure, cellulases can produce nearly twice as many reducing sugars as without pretreatment. The mechanism by which POSWOI facilitates the saccharification of cellulose was also studied using a cellulase binding assay. CONCLUSION: We present a novel fungal swollenin with considerable disruptive activity on crystalline cellulose, and develop a better procedure for using swollenin in facilitating cellulosic hydrolysis. We thus provide a new approach for the effective bioconversion of cellulosic biomass.

Co-pyrolysis of biomass and polyethylene: Insights into characteristics, kinetic and evolution paths of the reaction process.

Investigation on the distribution and mechanism of co-pyrolysis products is vital to the directional control and high-value utilization of agriculture solid wastes. Co-pyrolysis, devolatilization, kinetics characteristics, and evolution paths of corn stalk (CS) and low-density-polyethylene (LDPE) were investigated via thermogravimetric experiments. The co-pyrolysis behaviors could be separated into two stages: firstly, the degradation of CS (150- 400 °C); secondly, the degradation of CS (400- 550 °C). The devolatilization index (DI) increased with the addition of LDPE. Furthermore, a combination of devolatilization chemical analysis with product analysis to analyze the intrinsic mechanism during co-pyrolysis. The results indicated that the yield of alkanes and olefin in gas products increased with the addition of LDPE. Additionally, LDPE pyrolysis maybe abstract hydrogen from CS pyrolysis and evolved into hydrogen, methane, and ethylene. Further, the co-pyrolysis kinetic parameters were computed by using model-free isoconversion methods, which showed promotion of CS pyrolysis and the reduced activation energy. All the activation energy were declined, which indicated a "bidirectional positive effect" during co-pyrolysis. The mean activation energy of P-cellulose (P-CE), P-hemicellulose (P-HM), P-lignin (P-LG), and LDPE decreased by 23.49 %, 12.89 %, 15.36 %, and 27.82 %, respectively. This study further proves the hydrogen donor transfer pathway in the co-pyrolysis process of CS and LDPE, providing theoretical support for the resource utilization of agricultural solid waste.

A biocompatible polyethylene glycol/alginate composite hydrogel with significant reactive oxygen species consumption for promoting wound healing.

In areas of wound inflammation, excessive reactive oxygen species (ROS) may worsen the infection and lead to tissue damage, resulting in a vicious circle. Therefore, many hydrogels with sensitive ROS consumption capabilities and antibacterial properties have been widely developed and applied. These hydrogels usually achieve their ROS consumption capacity by introducing reactive active groups: however, these materials normally require complicated preparation procedures and have high potential toxicity. Inspired by these limitations, an integrated polyethylene glycol/alginate-based hydrogel (itg-PEGDA@SA) has been developed via a simple two-step process, where the inner PEGDA hydrogel (hdg-PEGDA) acts as a ROS scavenger and the outer sodium alginate hydrogel (SA) can be degraded to act as a recombinant human epidermal growth factor (rhEGF)-loaded platform to enhance the functionality of this composite hydrogel. Altogether, the itg-PEGDA@SA hydrogel showed significant ROS consumption and biocompatibility in vitro, and when applied for wound healing, the formation of uniform and ordered collagen fibers (stained using aniline blue) can be achieved. This hydrogel showed favorable attributes in ROS scavenging, and it can be a promising material for use in wound dressings and biomaterial fields.

Production of a bio-magnetic adsorbent via co-pyrolysis of pine wood waste and red mud.

The efficient reduction of accumulated waste biomass and red mud by converting them into a value-added magnetic adsorbent is both difficult and tempting in terms of sustainability. This study focused on investigating the reaction mechanism of co-pyrolysis of different biomasses, including pine wood, cellulose, and lignin, with red mud at 500, 650, and 800 °C, and the comprehensive characterizations of the produced bio-magnetic particles. The performance of biomass and red mud based magnetic adsorbents is also evaluated, and their primary adsorption mechanisms for organic pollutants are revealed by using different organic model compounds. The samples produced at 800 °C showed the best performance. For example, the sample prepared using red mud and pine wood at 800 °C showed the highest adsorption capacity of ibuprofen, which was 21.01 mg/g at ∼pH 4.5, indicating strong π stacking interactions as the dominant adsorption mechanism. When compared to lignin-rich biomass, adsorbents composed of cellulose-rich biomass showed greater adsorption efficacy. The findings show that co-pyrolysis of biomass with red mud can reduce waste while also producing a flexible adsorbent that is magnetically separable and effective at absorbing different organic contaminants from water.

Prenatal exposure to perfluoroalkyl substances is associated with lower hand, foot and mouth disease viruses antibody response in infancy: Findings from the Guangzhou Birth Cohort Study.

BACKGROUND: Perfluoroalkyl substances (PFASs) are synthetic chemicals widely used in industry and for commercial products. Their immunomodulatory effects are a growing health concern in children. Hand, Foot and Mouth Disease (HFMD) is a common childhood viral infection, and increased incidence of which has parallel the rise in PFAS exposure in the Asia-Pacific region. OBJECTIVE: We conducted the first study to assess whether prenatal exposure to PFAS was associated with a reduction in HFMD virus antibodies in infants. METHODS: We enrolled 201 mother-infant pairs from the Guangzhou Birth Cohort Study from July to October 2013. High performance liquid chromatography-mass spectrometry was employed to determine concentrations of specific PFAS isomers in cord blood. Neutralizing antibodies titers were measured against two HFMD viruses, enterovirus 71 (EV71) and coxsackievirus A 16 (CA16), in cord blood serum and blood serum at three months of age. RESULTS: Higher umbilical cord blood PFAS concentrations were associated with lower EV71 and CA16 antibody concentrations. A doubling in the composite sum of cord blood PFASs in three month old infants was associated with significant increase in the risk of HFMD antibody concentration below clinical protection level (≥1:8 titers) for CA16 (odds ratio, OR: 2.74 [95% confidence interval (CI): 1.33, 5.61] and for EV71 (OR = 4.55, 95% CI: 1.45, 4.28). This association was higher in boys at three months of age for CA16. CONCLUSIONS: Our findings suggest that cord blood PFAS exposure is associated with lower HFMD antibody in infancy. Given the widespread nature of PFAS exposures and the high global incidence of HFMD globally, these findings have substantial public health implications and therefore, these associations need to be replicated in a larger study to more definitively address the risk.

Epidermal growth factor receptor-targeted immune magnetic liposomes capture circulating colorectal tumor cells efficiently.

AIM: To compare the capacity of newly developed epidermal growth factor receptor (EGFR)-targeted immune magnetic liposomes (EILs) vs epithelial cell adhesion molecule (EpCAM) immunomagnetic beads to capture colorectal circulating tumor cells (CTCs). METHODS: EILs were prepared using a two-step method, and the magnetic and surface characteristics were confirmed. The efficiency of capturing colorectal CTCs as well as the specificity were compared between EILs and EpCAM magnetic beads. RESULTS: The obtained EILs had a lipid nanoparticle structure similar to cell membrane. Improved binding with cancer cells was seen in EILs compared with the method of coupling nano/microspheres with antibody. The binding increased as the contact time extended. Compared with EpCAM immunomagnetic beads, EILs captured more CTCs in peripheral blood from colorectal cancer patients. The captured cells showed consistency with clinical diagnosis and pathology. Mutation analysis showed same results between captured CTCs and cancer tissues. CONCLUSION: EGFR antibody-coated magnetic liposomes show high efficiency and specificity in capturing colorectal CTCs.

The selective hydrogenolysis of C-O bonds in lignin model compounds by Pd-Ni bimetallic nanoparticles in ionic liquids.

ß-O-4 and α-O-4 linkages can be selectively cleaved by Pd-Ni bimetallic nanoparticles in ionic liquids using hydrogen gas as the hydrogen donor under ambient pressure and neutral conditions. No hydrogenation of the benzene ring takes place in the catalytic system. An obvious improvement in activity is found compared with single nickel and palladium catalysts based on the results of experiments and characterization. After the reaction, the catalytic system still remains in the reactor by simple extraction, which can be reused without further treatment.

[Root canal treatment of mandibular first premolar with 3 root canals: a case].

The occurrence of three canals in mandibular premolars is very rare. This article reported and discussed the treatment of a mandibular first premolar with 3 root canals, specially in aspect of root-detecting and root-shaping.