Research on a Sound Source Localization Method for UAV Detection Based on Improved Empirical Mode Decomposition.

To address the challenge of accurately locating unmanned aerial vehicles (UAVs) in situations where radar tracking is not feasible and visual observation is difficult, this paper proposes an innovative acoustic source localization method based on improved Empirical Mode Decomposition (EMD) within an adaptive frequency window. In this study, the collected flight signals of UAVs undergo smoothing filtering. Additionally, Robust Empirical Mode Decomposition (REMD) is applied to decompose the signals into Intrinsic Mode Function (IMF) components for spectrum analysis. We introduce a sliding frequency window with adjustable bandwidth, which is automatically determined using a Grey Wolf Optimizer (GWO) with a sliding index. This window is used to lock and extract specific frequencies from the IMFs. Based on predefined criteria, the extracted IMF components are reconstructed, and trigger signal times are analyzed and recorded from these reconstructed IMFs. The time differences between sensor receptions are then calculated. Furthermore, this study introduces the Chan-Taylor localization algorithm based on weighted least squares. This advanced algorithm takes sensor time delay parameters as input and solves a set of nonlinear equations to determine the target's location. Simulations and real-world signal tests are used to validate the robustness and performance of the proposed method. The results indicate that the localization error remains below 5% within a 15 m × 15 m measurement area. This provides an efficient and real-time method for detecting the location of small UAVs.

First Report of Alternaria alternata Causing White Leaf Spot on Allium tuberosum in China.

Puding County is the major Allium tuberosum growing area in Guizhou Province of China. In 2019, white leaf spots were observed on Allium tuberosum in Puding County (26.31°N, 105.64°E). The white spots, ranging from elliptic to irregular in shape, first appeared on leaf tips. With disease aggravation, spots gradually coalesced, forming necrotic patches with yellow margins causing leaf necrosis; sometimes there was gray mold on dead leaves. The incidence of the diseased leaf rate was estimated to be 27-48%. To identify the pathogenic agent, 150 leaf tissues (5 mm × 5 mm) were obtained from disease-healthy junctions of 50 diseased leaves. Leaf tissues were disinfected in 75% ethanol for 30 s, soaked in 0.5% sodium hypochlorite for 5 min, and flushed three times with sterile water, before being placed on potato dextrose agar (PDA) in the dark at 25 °C. When colonies appeared, the mycelial tips were picked and placed on new PDA. Purified fungus was obtained after repeating this last step several times. The colonies were grayish-green with white round margins. Conidiophores (2.7-4.5 µm × 27-81 µm) were brown, straight, or flexuous with branches and septa. Conidia (8-34 µm × 5-16 µm) were brown, with 0-5 transverse septa and 0-4 longitudinal septa. The 18S nuclear ribosomal DNA (nrDNA; SSU), 28S nrDNA (LSU), RNA polymerase II second largest subunit (RPB2), internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and translation elongation factor 1-alpha (TEF-α) (Woudenberg et al. 2013) were amplified and sequenced. The sequences were deposited in GenBank (ITS: OP703616, LSU: OP860684, SSU: OP860685, GAPDH: OP902372, RPB2: OP902373, TEF1-α: OP902374). According to BLAST analysis, the ITS, LSU, GAPDH, RPB2, SSU, and TEF1-α of the straishowed 100% (689 of 731 base pairs; bp), 100% (916 of 938 bp), 100% (579 of 600 bp), 100% (946 of 985 bp), 100% (1093 of 1134 bp), and 100% (240 of 240 bp) sequence identity to those of Alternaria alternata (ITS: LC440581.1, LSU: KX609781.1, GAPDH: MT109295.1, RPB2: MK605900.1, SSU: ON055699.1 and TEF1-α: OM220081.1). A phylogenetic tree was constructed using PAUP4 and the maximum parsimony method with 1000 replicas of bootstrapping for all datasets. According to morphological characteristics and phylogenetic analysis, FJ-1 was identified as Alternaria alternata (Simmons 2007, Woudenberg et al. 2015). The strain was preserved in the Agricultural Culture Collection of China (preservation number: ACC39969). To determine the pathogenicity of Alternaria alternata against Allium tuberosum, wounded healthy leaves were inoculated with a conidial suspension (106 conidial/mL) and round mycelial plugs (4mm). Sterile agar PDA plugs with no mycelium or sterile water were inoculated as negative controls. Three days later, white spots appeared on the wounded leaves inoculated with mycelial plugs or conidial suspension. However, the symptoms caused by conidial suspensions were weaker than those caused by mycelial plugs. No symptoms were observed in the control group. The experimental symptoms were consistent with the phenomena observed in the field. The same fungus was reisolated from necrotic lesions and identified as Alternaria alternata using the method described above. To our knowledge, this is the first report of Alternaria alternata causing white leaf spots on Allium tuberosum in China, a disease seriously affected the yield and quality of Allium tuberosum and caused economic losses to farmers. Reference: Simmons EG (2007) Alternaria: an identification manual. CBS Fungal Biodiversity Centre, Utrecht, the Netherlands. Woudenberg JHC, Groenewald JZ, Binder M, Crous PW ( 2013) Alternaria redefined. Stud Mycol, 75: 171-212. https://doi.org/10.3114/sim0015. Woudenberg JHC, Seidl MF, Groenewald JZ, Vries M de, Stielow JB, Thomma BPHJ, Crous PW (2015) Alternaria section Alternaria: Species, formae speciales or pathotypes? Stud Mycol, 82:1-21. https://doi.org/10.1016/j.simyco.2015.07.001.

Bean-Pod-Inspired 3D-Printed Phase Change Microlattices for Solar-Thermal Energy Harvesting and Storage.

Effective and reliable encapsulation of phase change materials (PCMs) is essential and critical to the high-performance solar-thermal energy harvesting and storage. However, challenges remain pertaining to manufacturing scalability, high efficiency in energy storage/release, and anti-leakage of melted PCMs. Herein, inspired by natural legume, a facile and scalable extrusion-based core-sheath 3D printing strategy is demonstrated for directly constructing bean-pod-structured octadecane (OD)/graphene (BOG) phase change microlattices, with regular porous configuration as well as individual and effective encapsulation of OD "beans" into highly interconnected graphene network wrapping layer built by closely stacked and aligned graphene sheets. The unique architectural features enable the ready spreading of light into the interior of phase change microlattice, a high transversal thermal conductivity of 1.67 W m-1 K-1 , and rapid solar-thermal energy harvesting and transfer, thereby delivering a high solar-thermal energy storage efficiency, and a large phase change enthalpy of 190 J g-1 with 99.1% retention after 200 cycles. Most importantly, such encapsulated PCMs feature an exceptional thermal reliability and stability, with no leakage and shape variation even at 1000 thermal cycles and partial damage of BOG. This work validates the feasibility of scalably printing practical encapsulated PCMs, which may revolutionize the fabrication of composite PCMs for solar-thermal energy storage devices.

Highly aligned welding of ultrathin graphene layer to robust carbon nanotube film for significantly enhanced thermal conductivity.

Carbon nanotube (CNT) films have demonstrated great potential for highly efficient thermal management materials. However, how to enable a combined feature of excellent thermal conductivity and structural robustness, which is crucial for the high-performance realization, still remains challenging. Herein, an effective and facile strategy to solve the problem was proposed by developing a graphene (G)/CNT film with highly aligned welding of ultrathin G layer to robust CNT film. The unique architectural features of the obtained composite film enabled a high tensile strength (116 MPa) and electric conductivity (1.7 × 103S cm-1). Importantly, the thermal conductivity was significantly improved compared to neat CNT film, and reached as high as 174 W m-1K-1. In addition, the G/CNT film featured a superior electromagnetic shielding performance. This work provides useful guidelines for designing and fabricating the composite CNT film with prominent thermal conductivity, as well as excellent mechanical and electrical properties.

Modification of nanocrystalline TiO2 coatings with molecularly imprinted TiO2 for uric acid recognition.

Combining the surface modification and molecular imprinting technique, a novel piezoelectric sensing platform with excellent molecular recognition capability was established for the detection of uric acid (UA) based on the immobilization of TiO2 nanoparticles onto quartz crystal microbalance (QCM) electrode and modification of molecularly imprinted TiO2 (MIT) layer on TiO2 nanoparticles. The performance of the fabricated biosensor was evaluated, and the results indicated that the biosensor exhibited high sensitivity in UA detection, with a linear range from 0.04 to 45 µM and a limit of detection of 0.01 µM. Moreover, the biosensor presented high selectivity towards UA in comparison with other interferents. The analytical application of the UA biosensor confirmed the feasibility of UA detection in urine sample.

Is preoperative MRCP necessary for patients with gallstones? An analysis of the factors related to missed diagnosis of choledocholithiasis by preoperative ultrasound.

BACKGROUND: The diagnosis of associated choledocholithiasis prior to cholecystectomy for patients with gallstones is important for the surgical decision and treatment efficacy. However, whether ultrasound is sufficient for preoperative diagnosis of choledocholithiasis remains controversial, with different opinions on whether routine magnetic resonance cholangiopancreatography (MRCP) is needed to detect the possible presence of common bile duct (CBD) stones. METHODS: In this study, a total of 413 patients with gallstones who were admitted to the Department of General Surgery of the First Affiliated Hospital of Harbin Medical University in China for a period of 3 years and underwent both ultrasound and MRCP examinations were retrospectively analysed. After reviewing and screening these cases according to the literature, 11 indicators including gender, age, alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, indirect bilirubin, alkaline phosphatase, γ-aminotransferase, CBD diameter, and concurrent acute cholecystitis were selected and comparatively analysed. RESULTS: Among the 413 patients, a total of 109 cases showed concurrent gallstones and choledocholithiasis, accounting for 26.39 % of all cases. Among them, 60 cases of choledocholithiasis were revealed by ultrasound examination, accounting for 55.05 %, while 49 cases of choledocholithiasis were not detected by ultrasound examination but were confirmed by MRCP instead (the missed diagnosis rate of ultrasound was 44.95 %). The results of statistical analysis suggested that alanine aminotransferase, acute cholecystitis, and CBD diameter were the three most relevant factors for missed diagnosis by ultrasound. CONCLUSION: The accuracy of preoperative ultrasonography for the diagnosis of associated CBD stones for patients with gallstones is not high. However, elevated alanine aminotransferase, concurrent acute cholecystitis, and CBD diameter were identified as key factors that may affect the accuracy of the diagnosis. Thus, routine preoperative MRCP examination is suggested for patients with gallstones to rule out possible concomitant CBD stones.

Database screening of herbal monomers regulating autophagy by constructing a "disease-gene-drug" network.

BACKGROUND: Studies suggest an important role of autophagy as a target for cancer therapy. We constructed a "disease-gene-drug" network using the modular approach of bioinformatics and screened herbal monomers demonstrating functions related to autophagy regulation. METHODS: Based on the microarray results of the gene expression omnibus (GEO) database (GSE2435 and GSE31040, starvation-induced autophagy model), we used the human protein reference database (HPRD) to obtain the protein-protein interaction (PPI) network. In addition, we used the CFinder software to identify several functional modules, performed gene ontology-biological process (GO-BP) functional enrichment analysis using the DAVID software, constructed a herbal monomer-module gene regulatory network using literature search and the Cytoscape software, and then analyzed the relationships between autophagy, genes, and herbal monomers. RESULTS: We screened 544 differentially expressed genes related to autophagy, 375 pairs of differentially expressed genes, and 7 gene modules, wherein the functions of module 3 (composed of 7 genes) were enriched in "cell death". Using the constructed herbal monomer-module gene regulatory network, we found that 30 herbal monomers can simultaneously regulate these 7 genes, indicating a potential regulatory role in autophagy. CONCLUSIONS: Database screening using the disease-gene-drug network can provide new strategies and ideas for the application of herbal medicines in cancer therapy.

ZNF692 Promotes the Progression of Colon Adenocarcinoma by Regulating HSF4 Expression.

Background: Colon adenocarcinoma (COAD) is one of the most common cancer happened in gastrointestinal tract, with the overall incidence rate of 4%-5% among human beings. Like most malignancies, we uncovered the exact mechanisms of the pathogenesis of colorectal cancer yet. Therefore, there is an urgent need to explore the molecules that can be used as diagnostic maker at early stage. In addition, we also need to define the essential factors that related to the prognosis and treatment of the colon carcinoma. Methods: The study was conducted at the Third Affiliated Hospital of Qiqihar Medical University, Qiqihar, China in September 2020. The R language was used to identify the differentially expressed genes. We performed receiver operating characteristic curve analysis to determine the diagnostic markers for COAD. The machine learning strategy was used to assess the effectiveness of genes in the diagnosis of COAD. The molecular mechanism and prognostic value of genes were explored by bioinformatics analysis and molecular experiments. Results: The expression level of heat shock factor 4 (HSF4) was significantly elevated in COAD patients (P=1.89×10-29), according to The Cancer Genome Atlas (TCGA) database. Additionally, survival analysis showed the higher expression level of the HSF4 was correlated with the poor prognosis in COAD. Conclusion: The HSF4 was the target gene of zinc finger protein 692(ZNF692). HSF4 might promote the progression of COAD through the apoptosis pathway. It was diagnostic and prognosis maker of COAD. Furthermore, the upstream gene of HSF4, ZNF692, promotes the progression of colorectal cancer by regulating HSF4 expression.

Priming methods affected deterioration speed of primed rice seeds by regulating reactive oxygen species accumulation, seed respiration and starch degradation.

Introduction: Seed priming is a pre-sowing seed treatment that is beneficial for rice seed germination and seedling growth, but the reduced seed longevity after seed priming greatly limited its adoption. The deterioration of primed seeds showed large differences among different studies, and the priming method might play an important role in regulating the deterioration speed of primed seeds. However, whether and how the priming method affected the deterioration of primed rice seeds during storage remains unknown. Methods: In this study, two typical seed priming methods, namely hydropriming (HP) and osmopriming (PEG) were compared under artificially accelerated aging conditions, the changes in germination performance, starch metabolism, seed respiration and reactive oxygen species accumulation before and after accelerated aging were determined. Results and discussion: Hydroprimed rice seeds exhibited significantly faster deterioration speed than that of PEG-primed seeds in terms of germination speed and percentage. Meanwhile, α-amylase activity and total soluble sugar content in hydroprimed seeds were reduced by 19.3% and 10.0% respectively after aging, as compared with PEG-primed seeds. Such effects were strongly associated with the increased reactive oxygen generation and lipid peroxidation, as the content of superoxide anion, hydrogen peroxide and malondialdehyde in hydroprimed seeds were 4.4%, 12.3% and 13.7% higher than those in PEG-primed seeds after aging, such effect could be attributed to the increased respiratory metabolism in hydroprimed seeds. In addition, the simultaneous use of N-acetylcysteine with HP and PEG priming greatly inhibited the deterioration of primed rice seeds, suggesting that the ability to scavenge reactive oxygen species may be the key factor affecting the speed of deterioration in primed rice seeds during storage.

Piezoelectric detection of bilirubin based on bilirubin-imprinted titania film electrode.

A novel quartz crystal microbalance (QCM) sensor with a high selectivity and sensitivity has been developed for bilirubin determination, based on the modification of bilirubin-imprinted titania film onto a quartz crystal by molecular imprinting and surface sol-gel techniques. The performance of the developed bilirubin biosensor was evaluated and the results indicated that a sensitive bilirubin biosensor could be fabricated. The obtained bilirubin biosensor presents high-selectivity monitoring of bilirubin, better reproducibility, shorter response time (30 min), wider linear range (0.1-50 µM), and lower detection limit (0.05 µM). The analytical application of the bilirubin biosensor confirms the feasibility of bilirubin determination in serum sample.

3D-Printed Flexible Phase-Change Nonwoven Fabrics toward Multifunctional Clothing.

Functional phase-change fabrics hold great promise as wearable clothing. However, how to enable a phase-change fabric with the combined features of excellent structural flexibility and robustness, integrated multifunctionality, superior stability, and durability, as well as facile and scalable manufacturing, still remains a significant challenge. Herein, we demonstrated a scalable and controllable three-dimensional (3D) printing strategy for manufacturing flexible, thin, and robust phase-change nonwoven fabric (PCNF), with abundant and regular breathable pores as well as uniform and tight embedment of highly interconnected single-walled carbon nanotubes (SWNTs) into hydrophobic filaments built by intertwining solid-solid phase-change polymer chains together. The remarkable architectural features enabled an integral whole of the fabric, ready air exchange, superior water impermeability, highly efficient heat harvesting and storage, and effective absorption and reflection of electromagnetic waves, thereby delivering an exceptional combined function of breathability, waterproofness, thermal regulation, and radiation resistance, and meanwhile featuring superior thermal stability and outstanding resistance to stretching/folding fatigue even at cycles up to 2000. This work sheds light on effective strategies for manufacturing wearable phase-change fabrics with multifunctionality and high stability in a scalable manner toward future uses.

Spontaneous Salt-Preventing Solar-Thermal Water Evaporator with a High Evaporation Efficiency through Dual-Mode Water Transfer.

Benefiting from the abundant solar energy and the emergence of photothermal conversion equipment, solar-driven water evaporation has shown great potential in seawater desalination. One common problem for solar-thermal evaporation is that the salt crystallized on the surface of solar absorbers during the seawater evaporation process will significantly deteriorate the continuity and efficiency of the evaporation process. In most reports, efforts have been made to transfer the accumulated salts, while the studies on preventing salt crystallization, which leads to better continuity of the production, are limited. Herein, a spontaneous salt-preventing solar-thermal water evaporator was designed, utilizing a dual-mode water transfer structure consisting of in-plane diffusion and in-tube migration. The dual-mode structural system gave rise to uniform and continuous water transfer, efficiently suppressing the salt concentration in the evaporator. As a result, salt crystallization was scarcely found on the surface of the evaporator under 1 sun irradiation for an ultralong time (200 h), demonstrating its high efficiency in inhibiting salt crystallization. In addition, the small contact area between the water and the evaporator could reduce the heat loss during the solar-thermal evaporation process, which further improved the water evaporation rate (1.64 kg m-2 h-1).

Sieve-Like CNT Film Coupled with TiO2 Nanowire for High-Performance Continuous-Flow Photodegradation of Rhodamine B under Visible Light Irradiation.

Continuous-flow photoreactors hold great promise for the highly efficient photodegradation of pollutants due to their continuity and sustainability. However, how to enable a continuous-flow photoreactor with the combined features of high photodegradation efficiency and durability as well as broad-wavelength light absorption and large-scale processing remains a significant challenge. Herein, we demonstrate a facile and effective strategy to construct a sieve-like carbon nanotube (CNT)/TiO2 nanowire film (SCTF) with superior flexibility (180° bending), high tensile strength (75-82 MPa), good surface wettability, essential light penetration and convenient visible light absorption. Significantly, the unique architecture, featuring abundant, well-ordered and uniform mesopores with ca. 70 µm in diameter, as well as a homogenous distribution of TiO2 nanowires with an average diameter of ca. 500 nm, could act as a "waterway" for efficient solution infiltration through the SCTF, thereby, enabling the photocatalytic degradation of polluted water in a continuous-flow mode. The optimized SCTF-2.5 displayed favorable photocatalytic behavior with 96% degradation of rhodamine B (RhB) within 80 min and a rate constant of 0.0394 min-1. The continuous-flow photodegradation device made using SCTF-2.5 featured exceptional photocatalytic behavior for the continuous degradation of RhB under simulated solar irradiation with a high degradation ratio (99.6%) and long-term stability (99.2% retention after working continuously for 72 h). This work sheds light on new strategies for designing and fabricating high-performance continuous-flow photoreactors toward future uses.

P4HA1 regulates human colorectal cancer cells through HIF1α-mediated Wnt signaling.

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy that is associated with high levels of mortality. CRCs are often associated with an aberrant wingless-type mouse mammary tumor virus integration site family (Wnt) signaling pathway known to be responsible for tumorigenesis and cancer progression. Other factors that contribute to CRC pathology include hypoxia, extracellular matrix and cellular microenvironment. In the present study, modulation of Wnt, a common molecular progenitor for CRC-associated pathology was evaluated. CRC tissues and specific cell lines were found to exhibit increased expression levels of prolyl 4-hydroxylase subunit α1 (P4HA1). P4HA1 expression was found to stabilize hypoxia inducible factor-1α (HIF1α). The silencing of P4HA1 resulted in decreased cell proliferation, cell cycle arrest in the G1 phase, decreased tumorsphere formation, decreased tumorsphere volume, increased susceptibility to 5-fluorouracil and increased caspase-3 activity. However, P4HA1 silencing resulted in the activation and thus proteasomal degradation of ß-catenin, indicative of the abrogation of Wnt signaling pathway. Wnt is a critical signaling pathway and is activated in most CRCs. HIF1α is a poor prognostic marker in CRC. The present study provided preliminary evidence that HIF1α and the Wnt signaling pathway in CRC are modulated through P4HA1. P4HA1 may serve not just as a biomarker for CRC prognosis but may also be targeted for potential therapeutic intervention.

Magnetic single-enzyme nanoparticles with high activity and stability.

Magnetic single-enzyme nanoparticles (SENs) encapsulated within a composite inorganic/organic polymer network were fabricated via the surface modification and in situ aqueous polymerization of separate enzyme molecule. The resultant nanoparticles were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectrometer and X-ray diffraction (XRD). These particles are almost spherical in shape and have a unique size of about 50 nm in diameter. Electrical and magnetic measurements reveal that the magnetic SENs have a conductivity of 2.7 x 10(-3)Scm(-1), and are superparamagnetic with a saturation magnetization of 14.5e microg(-1) and a coercive force of 60Oe. Compared with free enzyme, encapsulated enzyme exhibits a strong tolerance to the variation of solution pH, high temperature, organic solvent and long-term storage, thus showing significantly enhanced enzyme performance and stability.

Mechanism and kinetics of apatite formation on nanocrystalline TiO2 coatings: a quartz crystal microbalance study.

Apatite (Ca5(PO4)3OH) has long been considered as an excellent biomaterial to promote bone repairs and implant. Apatite formation induced by negatively charged nanocrystalline TiO2 coatings soaked in simulated body fluid (SBF) was investigated using in situ quartz crystal microbalance (QCM), scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) techniques, and factors affecting its formation such as pH, size of TiO2 particles and thickness of TiO2 coatings, were discussed in detail. Two different stages were clearly observed in the process of apatite precipitation, indicating two different kinetic processes. At the first stage, the calcium ions in SBF were initially attracted to the negatively charged TiO2 surface, and then the calcium titanate formed at the interface combined with phosphate ions, consequently forming apatite nuclei. After the nucleation, the calcium ions, phosphate ions and other minor ions (i.e. CO3(2-) and Mg2+) in supersaturated SBF deposited spontaneously on the original apatite coatings to form apatite precipitates. In terms of the in situ frequency shifts, the growth-rate constants of apatite (K1 and K2) were estimated, respectively, at two different stages, and the results were (1.96+/-0.14)x10(-3)s(-1) and (1.28+/-0.10)x10(-4)s(-1), respectively, in 1.5 SBF solution. It was found that the reaction rate at the first stage is obviously higher than that at the second stage.

Polyurethane/Red Mud Composites with Flexibility, Stretchability, and Flame Retardancy for Grouting.

Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a "flexible, stretchable, and flame retardant" way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H2O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.

Role of the c-Jun N-terminal kinase signaling pathway in the activation of trypsinogen in rat pancreatic acinar cells.

Bile acid causes trypsinogen activation in pancreatic acinar cells through a complex process. Additional research is required to further elucidate which signaling pathways affect trypsinogen activation when activated. the changes in the whole­genome expression profile of AR42J cells under the effect of taurolithocholic acid 3­sulfate (TLC­S) were investigated. Furthermore, gene groups that may play a regulatory role were analyzed using the modular approach of biological networks. The aim of the present study was to improve our understanding of the changes in TLC­S­stimulated AR42J cells through a genetic functional modular analysis. whole­genome expression profile chip arrays were applied to detect genes that were differentially expressed in pancreatic acinar AR42J cells treated with TLC­S for 20 min. Based on the human protein reference database, a protein­protein interaction network was obtained, which was then processed by CFinder software to derive 14 modules. Among these 14 modules, the gene ontology biological processes enrichment analysis identified two as modules of interest. Kyoto encyclopedia of genes and genomes map analysis revealed that MAP2K4, MAPK8 and FLNA are part of the c-Jun N-terminal kinase (JNK) pathway. The JNK signaling pathway is involved in regulating trypsinogen activation in rat pancreatic AR42J cells. Next, a regulatory network of seven kinase inhibitors was constructed. SP600125 is an ATP­competitive, efficient, selective and reversible inhibitor of JNK. the results were verified by four sets of experiments and demonstrated that trypsinogen activation is mediated by the JNK signaling pathway in the pathogenesis of acute pancreatitis (AP). The present study provided a useful reference for better understanding the pathogenesis of AP and identifying new targets to regulate trypsinogen activation, in addition to providing valuable information for the treatment of AP.

Piezoelectric urea biosensor based on immobilization of urease onto nanoporous alumina membranes.

The urease was immobilized onto nanoporous alumina membranes prepared by the two-step anodization method, and a novel piezoelectric urea sensing system with separated porous alumina/urease electrode has been developed through measuring the conductivity change of immobilized urease/urea reaction. The process of urease immobilization was optimized and the performance of the developed urea biosensor was evaluated. The obtained urea biosensor presented high-selectivity monitoring of urea, better reproducibility (S.D.=0.02, n=6), shorter response time (30s), wider linear range (0.5 microM to 3mM), lower detection limit (0.2 microM) and good long-term storage stability (with about 76% of the enzymatic activity retained after 30 days). The clinical analysis of the urea biosensor confirmed the feasibility of urea detection in urine samples.

Quartz crystal microbalance studies on bilirubin adsorption on self-assembled phospholipid bilayers.

Bilirubin adsorption on self-assembled phospholipid bilayers was studied using quartz crystal microbalance, and factors influencing its adsorption such as pH, temperature, and solution ionic strength were discussed in detail. The results show the amount of adsorbed bilirubin on self-assembled phospholipid bilayers is small at higher temperature and large at higher pH and solution ionic strength, and the adsorption kinetic parameter estimated from the in situ frequency measurement is (1.8+/-0.27)x10(6) M(-1) (mean +/- S.D.). With the present method, the desorption of adsorbed bilirubin caused by human serum albumin and the photoinduced decomposition of adsorbed bilirubin under light illumination were also examined. QCM measurement provides a useful method for monitoring the adsorption/desorption process of bilirubin on self-assembled phospholipid bilayers.