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Objective. To explore the effect of percutaneous coronary intervention (PCI) standardized telephone follow-up service mode on out-of-hospital complications, rehospitalization rate, and life quality of discharged acute coronary syndrome (ACS) patients after PCI. Methods. From August 2020 to March 2022, 218 ACS patients who were discharged after PCI were included. The controls accepted routine nursing care, and the researches accepted PCI standardized telephone follow-up service mode. The nursing satisfaction, rehospitalization rate, out-of-hospital complication rate, blood lipid level, and life quality score were taken as the comparisons. Results. The nursing satisfaction of study group (100.00%) was significantly higher than that of control group (88.07%). The rehospitalization rate was dramatically lower in the study group (3/109; 2.75%) than in the control group (25/109; 22.94%) ( P < 0.05 ). In addition, compared with the control group, the incidence of complications (acute myocardial infarction and angina pectoris) was significantly reduced in the study group outside the hospital ( P < 0.05 ). The blood lipid levels of TCHO, TG, LDL-C, and HDL-C were lower in the study group than in the controls. Further, after nursing, the quality of life score of the two groups was both decreased with a higher quality of life score in the study group ( P < 0.05 ). Conclusion. The application of PCI standardized telephone follow-up service mode in discharged patients with acute coronary syndrome after PCI can reduce out-of-hospital complications and rehospitalization rate and improve blood lipid level and life quality.

Non-enzymatic nanocomposites and their modified electrodes, including carbon nanotubes, graphene, metal nanoparticles, metal oxides, conductive polymers, MOFs and derivatives, molecularly imprinted polymers are discussed in the rapid electrochemical sensing of OPPs.

The citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.

Acyclovir (ACV) is an effective and selective antiviral drug, and the study of its toxicology and the use of appropriate detection techniques to control its toxicity at safe levels are extremely important for medicine efforts and human health. This review discusses the mechanism driving ACV’s ability to inhibit viral coding, starting from its development and pharmacology. A comprehensive summary of the existing preparation methods and synthetic materials, such as 5-aminoimidazole-4-carboxamide, guanine and its derivatives, and other purine derivatives, is presented to elucidate the preparation of ACV in detail. In addition, it presents valuable analytical procedures for the toxicological studies of ACV, which are essential for human use and dosing. Analytical methods, including spectrophotometry, high performance liquid chromatography (HPLC), liquid chromatography/tandem mass spectrometry (LC-MS/MS), electrochemical sensors, molecularly imprinted polymers (MIPs), and flow injection–chemiluminescence (FI-CL) are also highlighted. A brief description of the characteristics of each of these methods is also presented. Finally, insight is provided for the development of ACV to drive further innovation of ACV in pharmaceutical applications. This review provides a comprehensive summary of the past life and future challenges of ACV.

To determine the risk factors of extubation failure and its effect on the prognosis of patients who had successfully passed a spontaneous breathing trial (SBT).The clinical data of patients with mechanical ventilation more than 24 hours who passed SBT admitted to department of intensive care unit (ICU) of First Hospital of Qinhuangdao from November 2018 to November 2019 were retrospectively analyzed. According to the outcome of weaning within 48 hours after weaning, patients were divided into weaning success group and weaning failure group. The baseline data, the presence of basic cardiopulmonary diseases, B-type natriuretic peptide (BNP), fluid balance, albumin and hemoglobin within 24 hours before weaning, the time of mechanical ventilation before weaning, rapid shallow breathing index (RSBI) during SBT, oxygenation index, cough peak flow at the end of SBT, and prognostic indicators were collected. The outcome of weaning was taken as the dependent variable, and the observation factors were taken as the independent variable for univariate analysis. The factors with statistical significance in univariate analysis were analyzed by binary Logistic regression to determine the influencing factors of weaning failure.Of the 204 patients, 167 (81.9%) were successfully weaned, and 37 (18.1%) failed. Compared with the weaning success group, the total duration of mechanical ventilation and the length of ICU stay in the weaning failure group were significantly longer [days: 13.0 (7.5, 23.5) vs. 5.0 (3.0, 8.0), 17.0 (12.5, 31.0) vs. 10.0 (6.0, 15.0), both P0.01], and the tracheotomy rate and mortality were significantly higher (32.4% vs. 0%, 51.4% vs. 0%, both P0.01). Univariate analysis showed that there were significant differences in age, proportion of patients with cardiopulmonary diseases, BNP and cough peak flow between weaning failure group and weaning success group [age (years old): 70.65±15.78 vs. 62.69±15.82, cardiopulmonary diseases: 62.2% vs. 24.6%, BNP (ng/L): 416.87 (32.70, 1 225.80) vs. 45.36 (10.00, 273.60), cough peak flow (L/min): 59.89±9.06 vs. 83.84±16.52, all P0.01]. However, there were no significant differences in gender, acute physiology and chronic health evaluation II (APACHE II) at admission, mechanical ventilation time before weaning, albumin, hemoglobin, oxygenation index, RSBI and fluid balance 24 hours before weaning between weaning failure group and weaning success group [male: 51.4% vs. 68.3%, APACHE II: 16.70±6.65 vs. 15.67±6.28, mechanical ventilation time before weaning (days): 6.0 (2.5, 11.0) vs. 5.0 (3.0, 8.0), albumin (g/L): 27.78±4.15 vs. 27.76±4.46, hemoglobin (g/L): 102.43±15.80 vs. 100.61±17.19, oxygenation index (mmHg, 1 mmHg = 0.133 kPa): 359.33±79.83 vs. 365.75±78.23, RSBI (times×LFor patients who had successfully passed SBT, age ≥ 75 years old, the presence of cardiopulmonary diseases and an increased level of BNP within 24 hours were the risk factors of extubation failure. In addition, the higher the cough peak flow at the end of SBT, the lower the risk of weaning failure will be.

Objective To investigate the effects of tolerogenic dendritic cells (tolDCs) induced by nuclear factor κB oligodeoxynucleotide decoy (NF-κB ODN decoy) on Th1 cells, Th2 cells, Th17 cells and regulatory T cells (Tregs) and the intervention effects on collagen-induced arthritis (CIA) rats. Methods SD female rats used to establish CIA rat models were divided into four groups, including a CIA model group, a bovine type II collagen-decoy-dendritic cell (Col2-decoy DC) treatment group, a blank control group, and a Col2-decoy DC control group. On the 20th days after the first immunization, the rats were injected with tolDCs via the tail vein, and the rats were sacrificed on the 7th weeks. The proportions of Th1 cells, Th2 cells, Th17 cells, and Tregs in the rat spleen were detected by flow cytometry. The ankle joint pathomorphological change was evaluated by HE staining, and the arthritis index (AI) was scored. Results Compared with the CIA model group, the Col2-decoy DC group had lower AI and milder ankle joint pathomorphological change. The percentages of Th1 cells and Th17 cells in the spleen CD4

Neuropsychiatric disorders are major causes of the global burden of diseases, frequently co-occurring with multiple co-morbidities, especially obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease and its various risk factors in the metabolic syndrome. While the determining factors of neuropsychiatric disorders are complex, recent studies have shown that there is a strong link between diet, metabolic state and neuropsychiatric disorders, including anxiety and depression. There is no doubt that rodent models are of great value for preclinical research. Therefore, this article focuses on a rodent model of chronic consumption of high-fat diet (HFD), and/or the addition of a certain amount of cholesterol or sugar, meanwhile, summarising the pattern of diet that induces anxiety/depressive-like behaviour and the underlying mechanism. We highlight how dietary and metabolic risk influence neuropsychiatric behaviour in animals. Changes in dietary patterns, especially HFD, can induce anxiety- or depression-like behaviours, which may vary by diet exposure period, sex, age, species and genetic background of the animals used. Furthermore, dietary patterns significantly aggravate anxiety/depression-like behaviour in animal models of neuropsychiatric disorders. The mechanisms by which diet induces anxiety/depressive-like behaviour may involve neuroinflammation, neurotransmitters/neuromodulators, neurotrophins and the gut–brain axis. Future research should be focused on elucidating the mechanism and identifying the contribution of diet and diet-induced metabolic risk to neuropsychiatric disorders, which can form the basis for future clinical dietary intervention strategies for neuropsychiatric disorders.

Background Non-small cell lung cancer (NSCLC) is a common type of lung cancer. Extracellular vehicles (EVs) are nano-sized particles containing proteins, lipids, and miRNAs secreted by various cells, which play important roles in the development of lung cancer by regulating a wide range of signaling pathways. This study focused on elucidating a potential mechanism by which EVs promote the development of NSCLC. Methods Expression levels of miR-744, SUV39H1, Smad9, and BMP4 in clinical tissue samples of NSCLC patients and cell lines were quantified by RT-qPCR and/or western blot analysis. The interaction between SUV39H1 and miR-744 was identified by dual-luciferase reporter assay. miR-744, SUV39H1, and BMP4 expression levels were modulated in A549 and H460 cells, in order to evaluate their effects on cell proliferation, colony formation and cell cycle. A NSCLC xenograft mouse model was used to verify the in vitro findings. NSCLC cell-derived EVs and normal bronchial epithelial cell-derived EVs were isolated and their roles in NSCLC development were evaluated in vivo and in vitro. Results miR-744 expression was lower in cancer cell-derived derived EVs than in normal lung epithelial cell-derived EVs. Reduced miR-744 expression in EVs upregulated SUV39H1 in NSCLC cells and further increased BMP4 levels to promote NSCLC development. BMP4 was upregulated in NSCLC cells upon suppression of Smad9 mediated by SUV39H1. Reduced miR-744 expression transferred from cancer cell-derived EVs into NSCLC cells enhanced cancer development. Conclusion Overall, our findings unveiled a mechanism whereby miR-744 delivered by NSCLC-derived EVs upregulated SUV39H1, activating the Smad9/BMP9 axis and thus promoted cancer development.

Tolerogenic dendritic cells (tolDCs) are immunosuppressive cells and play an important role in rheumatoid arthritis (RA) as immunotherapeutic tools. We aimed to investigate whether allogeneic tolDCs (allo-tolDCs) and autologous tolDCs (auto-tolDCs) had long-time tolerogenic potential in vivo and improve arthritis in collagen-induced arthritis (CIA) rats. TolDCs were induced by NF-κB Decoy ODN, and loaded with Bovine Type II collagen (CII- loaded tolDCs) and identified by flow cytometry, and labeled with DiR and injected into CIA rats. The biodistribution of DiR-labeled tolDCs was monitored by IVIS imaging at different time points. Major organs were harvested and analyzed by ex-in vivo cell imaging. The tolDCs were successfully constructed, along with expressing low levels of CD80 and CD86 compared to DCs. The fluorescent signals of all DiR (+) groups were observed at least 25 days, and as long as 35 days. DiR (+) CII- loaded allo-and auto-tolDCs at post injection mainly distributed in the chest and abdomen and gradually moved to limb joints over time. The allo- and auto-tolDCs decreased the expression of IFN-γ and IL-2 in CIA rats with different severity compared to CIA rats without tolDCs treatment, while significantly increased the expression of IL-4 and IL-10. Additionally, these tolDCs ameliorated the ankle joints injury in CIA rats with different severity. The both allo- and auto-tolDCs showed long-time tolerogenic potential in vivo and ameliorated arthritis in CIA rats with different severity.

Aptamers are special types of single-stranded DNA generated by a process called systematic evolution of ligands by exponential enrichment (SELEX). Due to significant advances in the chemical synthesis and biotechnological production, aptamers have gained considerable attention as versatile building blocks for the next generation of soft materials. Hydrogels are high water-retainable materials with a three-dimensional (3D) polymeric network. Aptamers, as a vital element, have greatly expanded the applications of hydrogels. Due to their biocompatibility, selective binding, and molecular recognition, aptamer-based hydrogels can be utilized for bioanalytical and biomedical applications. In this review, we focus on the latest strategies of aptamer-based hydrogels in bioanalytical and biomedical applications. We begin this review with an overview of the underlying design principles for the construction of aptamer-based hydrogels. Next, we will discuss some bioanalytical and biomedical applications of aptamer-based hydrogel including biosensing, target capture and release, logic devices, gene and cancer therapy. Finally, the recent progress of aptamer-based hydrogels is discussed, along with challenges and future perspectives.

An electromical sensor based on α-Fe2O3@Co3O4-NRGO composited glass carbon electrode (GCE) was constructed and used for ultrasensitive tyrosine detection. A series of characterization techniques including scanning electron microscopy, X-ray diffraction and electrochemical impedance spectroscopy technique and cyclic voltammetry were employed to investigate the modified electrode. Compared with the bare GCE, the α-Fe2O3@Co3O4-NRGO/GCE exhibited a strong current response to tyrosine because of the synergistic effect of ternary composite. Under optimized conditions, the peak currents that responded to tyrosine concentration had a linear relationship from the scope of 0.01 to 10 µM (R2 = 0.9977) by second derivative linear sweep voltammetry (SDLSV) and 8 nM (S/N = 3) is the detection limit. The sensor showed higher sensitivity, better repeatability, reproducibility and greater sensing stability related advantages over those in previous tyrosine detections. Furthermore, the sensor was successfully applied to trace tyrosine determination in practical samples such as milk and serum.

A novel amaranth electrochemical sensor was produced by electrodepositing a molecularly imprinted polypyrrole film in the presence of amaranth on a multi-walled carbon nanotube (MWCNT) surface. Template molecules were completely eluted through an innovative strategy that only requires the application of a fixed electrical potential in a blank phosphate buffer solution. Obviously, this strategy is much faster and more eco-friendly. The molecularly imprinted polymer (MIP)-based electrochemical sensor was systematically investigated by scanning electron microscopy, atomic force microscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The resultant MIP/MWCNT modified glass carbon electrode (MIP/MWCNT/GCE) shows satisfactory electroactive surface area and charge transfer resistance. As expected, the electrochemical response signals were significantly amplified at the MIP/MWCNT/GCE. Under optimal conditions, the proposed MIP/MWCNT/GCE exhibits extraordinarily good analytical performance for amaranth detection, with two wide detection ranges (0.007 μM to 1.0 μM, and 0.40 μM to 17 μM) and detection possible down to 0.4 nM. Moreover, the polypyrrole MIP films show high binding affinity and specifically identifies amaranth molecules, enabling the robust detection of amaranth in a complicated matrix with excellent selectivity, reproducibility, and stability. The proposed sensor achieves accurate detection of amaranth concentration in various fruit drinks with acceptable recovery.

Two four-wave mixing (FWM) processes with different directions and frequencies can coexist and interfere in a four-level inverted-Y-type atomic system, the generated FWM beams fall into two different electromagnetically induced transparency windows. We report Autler–Townes splitting and dressed suppression and enhancement of two generated FWM beams. In the case of matched slow FWM beams, two FWM processes compete and exchange their energies between them, the forward four-wave beam give its energy to the backward four-wave beam by interaction for long distance. Such studies of two FWM beams can have vital applications in studying the higher-order nonlinear optical processes, generating correlated photon pairs and quantum information processing.

Degradable bioelastomers as porous scaffold materials have great potentials in tissue regeneration due to their compatible mechanical properties to the body’s soft tissues. A citrate-based elastomer is a recently developed bioelastomer possessing good surface affinities toward many cell types, but its insoluble and unmeltable characteristics caused difficulties in fabricating porous scaffolds. Herein, a new method where chitin nanocrystal (ChiNC) supported emulsion-freeze-casting was utilized to fabricate porous scaffolds of thermoset elastomer. ChiNC was initially used as a Pickering emulsifier to stabilize prepolymer latex spheres, then as a supporting agent to prevent ice-templated pores from collapse during thermocuring, and last as a biobased nanofiller to reinforce the porous scaffold. When ChiNC loading was at least 15% or greater, the directional porous structure were facilely obtained via use of a thick-walled Teflon container in a freezer at −40 °C. The nanocomposite elastomer porous scaffold ex...

Chitin nanocrystal (ChiNC) is a promising reinforcing nanofiller for biomedical polymers. However, its self-aggregation characteristics caused processing difficulty in developing ChiNC-based nanocomposites. Herein, a new degradable crosslinked bioelastomer, designated as poly(1,8-octanediol-co-Pluronic F127 citrate) (POFC) was synthesized by melt polycondensation of citric acid, 1,8-octanediol, and Pluronic F127. In comparison to poly(1,8-octanediol citrate) (POC), POFC pre-polymer exhibited self-emulsifying property. Once ChiNC was introduced into the emulsion, a ChiNC stabilized Pickering emulsion was formed. Coupled with a facile green emulsion casting/evaporation method, the ChiNC ultimately reinforced ChiNC/POFC nanocomposite elastomer was fabricated. The presence of F127 segments endowed POFC with better hydrophilicity and shorter degradation time relative to POC. The incorporation of ChiNC into POFC network led to highly increased tensile modulus and strength. In vitro cytotoxicity tests indicated that the ChiNC/POFC elastomer nanocomposite had a good cytocompatibility and it appeared as a potential biomaterial for tissue engineering application.

Objective To yield high-quality tolerogenic dendritic cells (TolDCs) for therapeutic intervention by a refined technique of TolDC preparation from the spleen of modified collagen-induced arthritis (CIA) rats. Methods The refinements took place amid monocellular cell isolation process, including both the preparation of single cell suspension and the adjustment of incubation time after plate seeding of mononuclear cells. TolDCs were induced by administration of NF-κB oligonucleotide (ODN) decoy at the initiation of cell culture. Cell morphology was examined under a microscope and cell viability was revealed by trypan blue staining. Expression of classical cell identity and activation makers, CD103 (OX62), CD80 and CD86 was determined by flow cytometry; meanwhile, DC-stimulated lymphocyte proliferation was measured by MTT assay following mixed lymphocyte reaction (MLR). Results With the established approach, the viability ratio of resulting cells reached over 90% and the proportion of OX62 positive ones was above 87.4%, which altogether confirmed their ideal DC phenotype. Functionally, the tolerogenic nature of the NF-κB ODN-treated DCs was further unveiled by the low expression of costimulatory molecules (CD80 and CD86) and the abrogated capacity of lymphocyte stimulation effect. Conclusion Compared with TolDCs generated by conventional protocol, CIA rat spleen-derived TolDCs isolated by the optimized splenic mononuclear cell preparation procedure and induced by NF-κB ODN decoy show the higher regulatory activity, higher phenotypic stability, higher purity and tolerogenic properties.

A tryptophan (Trp) molecularly imprinted electrochemical sensor was fabricated by drop-coating an imprinted chitosan film on the surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (MIP-MWCNTs/GCE). The surface morphology and electrochemical properties of the MIP-MWCNTs/GCE were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. The electrochemical performance of the MIP-MWCNTs/GCE with Trp showed that the signal of the oxidation current of Trp obtained with MIP-MWCNTs/GCE was significantly enhanced relative to that of the uncovered GCE, indicating that the modified electrode can accelerate electron transfer and has strong selectivity for Trp. The experimental conditions were optimized in parallel, and under the optimal conditions, the MIP-MWCNTs/GCE showed a good linear relationship between the Trp oxidation peak current and Trp concentrations in the ranges of 2.0 nM–0.2 μM, 0.2 μM–10 μM and 10 μM–100 μM The limit of detection (LOD) was 1.0 nM (S/N = 3), and the modified electrode had good reproducibility and stability. Finally, the MIP-MWCNTs/GCE was successfully applied to the determination of Trp in the human serum samples.

In this paper, a tryptophan (Trp) molecularly imprinted chitosan film was prepared on the surface of an acetylene black paste electrode using chitosan as the functional polymer, Trp as the template molecule and sulfuric acid as the crosslinking agent. The surface morphologies of non-imprinted and imprinted electrodes were characterized by scanning electron microscopy (SEM). The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. Some factors affecting the performance of the imprinted electrode such as the concentration of chitosan, the mass ratio of chitosan to Trp, the dropping amount of the chitosan-Trp mixture, the solution pH, and the accumulation potential and time were discussed. The experimental results show that the imprinted electrode exhibit good affinity and selectivity for Trp. The dynamic linear ranges of 0.01&ndash, 4 M, 4&ndash, 20 M and 20&ndash, 100 M were obtained by second derivative linear sweep voltammetry, and the detection limit was calculated to be 8.0 nM. The use of the imprinted electrode provides an effective method for eliminating the interference of potentially interfering substances. In addition, the sensor has high sensitivity, reproducibility and stability, and can be used for the determination of Trp in pharmaceutical preparations and human serum samples.

l-tryptophan is one of the eight kinds of essential amino acids for sustainable human life activity. It is common to detect the concentration of tryptophan in human serum for diagnosing and preventing brain related diseases. Herein, in this study, GCE (glassy carbon electrode) modified by Ta2O5-reduced graphene oxide (-rGO) composite (Ta2O5-rGO-GCE) is synthesized by the hydrothermal synthesis-calcination methods, which is used for detecting the concentration of tryptophan in human serum under the as-obtained optimal detection conditions. As a result, the obtained Ta2O5-rGO-GCE shows larger electrochemical activity area than other bare GCE and rGO-GCE due to the synergistic effect of Ta2O5 NPs and rGO. Meanwhile, Ta2O5-rGO-GCE shows an excellent response to tryptophan during the oxidation process in 0.1 M phosphate buffer solution (pH = 6). Moreover, three wide linear detection range (1.0–8.0 μM, 8.0–80 μM and 80–800 μM) and a low limit of detection (LOD) of 0.84 μM (S/N = 3) in the detection of tryptophan are also presented, showing the larger linear ranges and lower detection limit by employing Ta2O5-rGO-GCE. Finally, the as-proposed Ta2O5-rGO-GCE with satisfactory recoveries (101~106%) is successfully realized for the detection of tryptophan in human serum. The synthesis of Ta2O5-rGO-GCE in this article could provide a slight view for the synthesis of other electrochemical catalytic systems in detection of trace substance in human serum.

In recent years, small-sized electrodes have drawn widespread attraction in electroanalysis due to high sensitivity, rapid response and low cost. Hereby, a sub-millimeter paste electrode with inner diameter of 0.8 mm was prepared by combining the excellent properties of reduced graphene oxide (rGO) and acetylene black (AB), and the electrochemical behavior of tyrosine (Tyr) on the modified electrode (denoted as rGO/ABPE) was investigated in detail. The electrochemical responses obtained on the sub-millimeter rGO/ABPE were compared with that obtained on a conventional size electrode with diameter of 3 mm. The results showed that the 0.8 mm one has better performance than that of 3 mm. Compared with the paste electrode made of graphite powder, the oxidation peak current of Tyr increased significantly due to the synergistic effect of rGO and AB. Under the optimized experimental conditions, the calibration curve of Tyr showed a linear relationship between 0.1 and 100 μM (R = 0.9995) with good sensitivity of 3.314 μA μM−1 cm−2, and the detection limit was 0.06 μM. By comparison with conventional size electrode, the detection of Tyr on the sub-millimeter electrode shows higher sensitivity, wider linear range and lower detection limit. In addition, the excellent reproducibility, stability and selectivity of the sub-millimeter rGO/ABPE make it suitable for Tyr analysis in both food and biological samples.

Citrate-based thermoset bioelastomer has numerous tissue engineering applications. However, its insoluble and unmeltable features restricted processing techniques for fabricating complex scaffolds. Herein, direct ink writing (DIW) was explored for 3D printing of poly(1, 8-octanediol-co-Pluronic F127 citrate) (POFC) bioelastomer scaffolds considering that POFC prepolymer (pre-POFC) was waterborne and could form a stable emulsion. The pre-POFC emulsion couldn't be printed, however, chitin nanocrystal (ChiNC) could be as a rheological modifier to tune the flow behavior of pre-POFC emulsion, and thus DIW printing of POFC scaffolds was successfully realized; moreover, ChiNC was also as a supporting agent to prevent collapse of filaments during thermocuring, and simultaneously as a biobased nanofiller to reinforce scaffolds. The rheological analyses showed the pre-POFC/ChiNC inks fulfilled the requirements for DIW printing. The printed scaffolds exhibited low swelling, and good performances in strength and resilence. Furthermore, the entire process was easily performed and eco-friendly.

In this paper, acetylene black paste electrode (ABPE) was prepared and modified by oxygen-functionalized multi-walled carbon nanotubes (MWCNT-COOH). The fabricated MWCNT-COOH/ABPE was further used for the investigation on the electrochemical behavior of tyrosine by cyclic voltammetry and second-order derivative linear sweep voltammetry. In 0.1 M pH 2.6 phosphate buffer solution, a well-defined anodic peak appeared at 924 mV, which was attributed to the electrooxidation of tyrosine on the modified electrode. The electrochemical parameters of tyrosine on the modified electrode were calculated. Under the optimal conditions, the oxidation peak current of tyrosine varies linearly with its concentration in the range of 0.04−1.0 μ M, 1.0−60 μ M and 60−600 μ M, and the detection limit is 0.02 μM. The MWCNT-COOH/ABPE was applied to the determination of tyrosine in food with satisfactory results.

In this study, batch and column experiments were conducted to evaluate the feasibility of using persulfate oxidation to treat groundwater contaminated by landfill leachate (CGW). In batch experiments, persulfate was compared with H2O2, and permanganate for oxidation of organic compounds in CGW. It was also compared with the potential of biodegradation for contaminant removal from CGW. Persulfate was observed to be superior to H2O2 and permanganate for degradation of total organic carbon (TOC) in the CGW. Conversely, biodegradation caused only partial removal of TOC in CGW. In contrast, persulfate caused complete degradation of the TOC in the CGW or aged CGW, showing no selectivity limitation to the contaminants. Magnetite (Fe3O4) enhanced degradation of leachate compounds in both CGW and aged CGW with limited increase in persulfate consumption and sulfate production. Under dynamic flow condition in 1-D column experiments, both biodegradation and persulfate oxidation of TOC were enhanced by Fe3O4. The enhancement, however, was significantly greater for persulfate oxidation. In both batch and column experiments, Fe3O4 by itself caused minimal consumption of persulfate and production of sulfate, indicating that magnetite is a good persulfate activator for treating CGW in heterogeneous systems The results of the study show that the persulfate-based in-situ chemical oxidation (ISCO) method has great potential to treat the groundwater contaminated by landfill leachate.

Here we report a facile and cost-effective preparation of nickel nanoparticle S/Nitrogen-carbon nanohybrid (Ni NPS/N-C) based on formamide condensation and carbonization, used for highly sensitive and selective electrochemical determination of tryptophan (Trp) in practical samples. The crystallographic phase, surface morphology, elemental distribution, and chemical state of the Ni NPS/N-C nanohybrid were analyzed by XRD, SEM, TEM, EDS, XPS, FTIR, TGA and Raman spectra. The results show that high content of Ni NPs (6.62 wt%) were distributed in the nanohybrid, and a large number of bamboo-like nanotubes were formed during pyrolysis, which dramatically increases the specific surface area, and remarkably promotes the electrical conductivity as well as the catalytic activity of the nanohybrid. The electrochemical behavior of Trp was investigated on the nanohybrid modified carbon paste electrode (Ni NPS/N-C/CPE) and the measurement parameters were optimized. As expected, the modified electrode can remarkably enhance the electrochemical oxidation signal of Trp. Under the optimal experimental conditions, a linear relationship in the range of 0.01–20 μM and 20–80 μM for Trp was established with detection limit of 5.7 nM (S/N = 3). Finally, the proposed sensor was practically applied by evaluation and determination of Trp from various sourcing samples including human serum and pharmaceutical samples.

Vanillin is widely used as a flavoring and fragrance enhancer in foods. Rapid detection of vanillin is of vital significance and necessity for food safety. In this work, a sensitive voltammetric sensor to detect trace vanillin of nanomolarity in food samples was demonstrated by using manganese dioxide nanowires hybridized electrode. Firstly, a modified glassy carbon electrode was prepared using manganese dioxide nanowires functionalized reduced graphene oxide as a modifier (MnO2 NWs-rGO/GCE). Then the MnO2 NWs-rGO/GCE were characterized by scanning electron microscopy, X-ray diffraction (XRD) and cyclic voltammetry (CV). Vanillin's electrochemical behavior in the solution of 0.1 M H2SO4 was studied in detail. The results showed that the modified electrode had an electrocatalytic activity for vanillin oxidation. The adsorption capacity (Γs) and standard rate constant (ks) on the modified electrode were calculated by chronocoulometry (CC). Subsequently, after systematic investigation of second derivative linear sweep voltammetry (SDLSV) under the optimal conditions, the oxidation peak current was linearly correlated with vanillin concentration in the separate ranges of 0.01–20 μM (R2= 0.9808) and 20–100 μM (R2= 0.9964), yielding the detection limit of 6.0 nM (S/N = 3). In addition, MnO2 NWs-rGO/GCE showed the advantages of surface renewal, excellent reproducibility, good stability, and simple preparation. The method was applied to the nanomolarity determination of vanillin in commercial foods with satisfactory results.