15 research outputs found
Development of Food-Luring Baited Traps for Solenopsis invicta (Hymenoptera: Formicidae) Monitoring in the Field in Southern China
Solenopsis invicta Buren (Hymenoptera: Formicidae), a red imported fire ant that originated from South America, is a worldwide invasive pest. This study investigated the efficacy of the newly designed baited trap to detect red imported fire ants, Solenopsis invicta Buren, under field conditions in China. Among the five food lures tested for red imported fire ants, the ants preferred ham sausage and fish powder, followed by mixed powder (50% fish powder + 50% black soldier fly powder) and black soldier fly powder. These lures were compared to sugar water (control) to determine their efficacy in trapping red imported fire ants. Field data revealed that the ham sausage powder trap was more efficient than the fish powder trap based on its ability to trap more red imported fire ants under field conditions and ease of use. Thus, it was concluded that the baited traps are efficient for longterm red imported fire ants monitoring
Preparation of Magnesium Ammonium Phosphate Mortar by Manufactured Limestone Sand Using Compound Defoaming Agents for Improved Strength and Impermeability
Magnesium ammonium phosphate cement (MAPC) mortar has recently risen up as high performance rapid repair material for concrete structures. But high costs of the raw materials limit its restoration and maintenance projects on a wide application range. This study proposes the use of manufactured limestone sand with lower cost and wider range of sources in replacement of quartz sand as fine aggregates to produce MAPC mortar. However, the limestone fines of manufactured sand were initially found to have negative effects on the performance of MAPC mortar, causing significant blistering and volume expansion and decreased compressive strength and interfacial bonding strength. To minimize these negative effects, polyether modified silicone (PMS) defoamer and its compound use with mineral admixtures Portland cement and silica fume were investigated on the effectiveness in reducing expansion and improving other properties of MAPC mortar. Results showed that the compound use of PMS defoamer and Portland cement as a new defoaming formula effectively reduced the volume expansion from 7.92% to 0.91%. The compressive strength and interfacial bonding strength were significantly improved by over 34% and 60% respectively. Moreover, this defoaming formula showed improvements in water-tight performance and resistance to chloride penetration. According to the mercury intrusion porosimetry (MIP) analysis, the total porosity of MAPC mortar after defoaming treatment was decreased by about 40% and the pore structure was also modified to be finer by significantly reducing the harmful macropores. Overall, the use of manufactured limestone sands as fine aggregates turned out to be a feasible and economic approach for promoting the filed application of MAPC mortar.</jats:p
An Experimental Investigation on the Effects of Limestone Fines in Manufactured Sands on the Performance of Magnesia Ammonium Phosphate Mortar
Magnesium ammonium phosphate cement (MAPC) prepared with ammonium dihydrogen phosphate (NH4H2PO4, ADP) and dead-burned Magnesium oxide (MgO) is a new type of rapid patch repair material for concrete structures. In order to reduce the material costs of MAPC mortar, manufactured limestone sands, being a more widely-available resource with lower cost, was investigated in this study as an alternative to quartz sands for the preparation of MAPC mortar. The limestone fines in manufactured sands were found to be the key factor that influences properties of MAPC mortar by causing bubbling and volume expansion before hardening. As a result, the mechanical strength of MAPC mortar decreased with the increasing content of limestone fines due to increased porosity. According to microstructure analysis, the mechanism of these negative effects can be inferred as the reaction between limestone fines and ADP with the gas generation of CO2 and NH3. This reaction mainly occurred during a short period before setting while most limestone fines remained unreactive in the hardened MAPC mortar. Based on the above detailed experimental findings on the effects of limestone fines in manufactured sand on the properties of MAPC mortar, this paper pointed out that effective defoaming methods for inhibiting bubbling was the key to the utilization of manufactured sands in preparation of high performance MAPC mortar.</jats:p
Design, Synthesis, Investigation, and Application of a Macromolecule Photoswitch
Azobenzene (AZO) has attracted increasing interest due to its reversible structural change upon a light stimulus. However, poor fatigue durability and the photobleaching phenomenon restricts its further application. Herein, the AZO domain as a pendent group, was incorporated into copolymers, which was synthesized by radical copolymerization in the research. Structure-properties of synthesized copolymer can be adjusted by monomer ratios. Emphatically, responsive properties of copolymer in different solutions were investigated. In the DMSO solution, copolymer exhibited effective structural change, stable rapid responsive time (1 min) upon UV light at room temperature, stable relative acceptable recovery time (100 min) upon white light at room temperature, and good fatigue resistance property. In an aqueous solution, even more controllable responsive properties and fatigue resistance properties for copolymer were verified by results. More pervasively, the recovery process could be controlled by light density and temperature. In order to clarify reasons for the difference between the AZO molecule and the AZO domain of copolymer, energy barrier or interactions between single atoms or even structural units was calculated using the density functional theory (DFT). Furthermore, the status of copolymer was characterized by dynamic light scattering (DLS) and transmission electron microscope (TEM). Finally, copolymer was further functionalized with bioactive protein (concanavalin, ConA) to reduce the cytotoxicity of the AZO molecule
Fibrinogen-to-prealbumin ratio: A new prognostic marker of resectable pancreatic cancer
BackgroundThe fibrinogen-to-prealbumin ratio (FPR), a novel immune-nutritional biomarker, has been reported to be associated with prognosis in several types of cancer, but the role of FPR in the prognosis of resectable pancreatic cancer has not been elucidated.MethodsA total of 263 patients with resectable pancreatic cancer were enrolled in this study and were randomly divided into a training cohort (n = 146) and a validation cohort (n = 117). Receiver operating characteristic curve (ROC) was used to calculate the cut-off values of immune-nutritional markers. The least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression were performed in the training cohort to identify the independent risk factors, based on which the nomogram was established. The performance of the nomogram was evaluated and validation by the training and validation cohort, respectively.ResultsThe optimal cutoff value for FPR was 0.29. Multivariate analysis revealed that FPR, controlling nutritional status (CONUT), carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), and tumor node metastasis (TNM) stage were independent predictors of overall survival (OS). The nomogram was established by involving the five factors above. The C-index of the training cohort and validation cohort were 0.703 (95% CI: 0.0.646-0.761) and 0.728 (95% CI: 0.671-0.784). Decision curve analysis and time-dependent AUC showed that the nomogram had better predictive and discriminative ability than the conventional TNM stage.ConclusionFPR is a feasible biomarker for predicting prognosis in patients with resectable pancreatic cancer. The nomogram based on FPR is a useful tool for clinicians in making individualized treatment strategies and survival predictions
Preparation of Magnesium Ammonium Phosphate Mortar by Manufactured Limestone Sand Using Compound Defoaming Agents for Improved Strength and Impermeability
Magnesium ammonium phosphate cement (MAPC) mortar has recently risen up as high performance rapid repair material for concrete structures. But high costs of the raw materials limit its restoration and maintenance projects on a wide application range. This study proposes the use of manufactured limestone sand with lower cost and wider range of sources in replacement of quartz sand as fine aggregates to produce MAPC mortar. However, the limestone fines of manufactured sand were initially found to have negative effects on the performance of MAPC mortar, causing significant blistering and volume expansion and decreased compressive strength and interfacial bonding strength. To minimize these negative effects, polyether modified silicone (PMS) defoamer and its compound use with mineral admixtures Portland cement and silica fume were investigated on the effectiveness in reducing expansion and improving other properties of MAPC mortar. Results showed that the compound use of PMS defoamer and Portland cement as a new defoaming formula effectively reduced the volume expansion from 7.92% to 0.91%. The compressive strength and interfacial bonding strength were significantly improved by over 34% and 60% respectively. Moreover, this defoaming formula showed improvements in water-tight performance and resistance to chloride penetration. According to the mercury intrusion porosimetry (MIP) analysis, the total porosity of MAPC mortar after defoaming treatment was decreased by about 40% and the pore structure was also modified to be finer by significantly reducing the harmful macropores. Overall, the use of manufactured limestone sands as fine aggregates turned out to be a feasible and economic approach for promoting the filed application of MAPC mortar
Functional Graphene Oxide Nanocarriers for Drug Delivery
The family of graphene has attracted increasing attention on account of their large specific surface area and good mechanical properties in the biomedical field. However, some characteristics like targeted delivery property and drug delivery capacity could not satisfy the need of a drug carrier. Herein, a graphene oxide (GO) nanocarrier was designed by modification of a folic acid (FA) derivative and a β-cyclodextrin (β-CD) derivative in order to improve two properties, respectively. In the first step, reactive or crosslinkable FA and aldehydic β-CD (β-CD-CHO) were designed and synthesized for further modification. In the second step, synthesized functional molecules were coupled onto GO sheets one by one to obtain the GO nanocarrier. IR spectra and XRD results were used to identify the chemical and structural information before and after modification for the GO nanocarrier. The final GO nanocarrier exhibited a typical thin wrinkled sheet morphology of the GO sheet without any influence by two functional molecules. Finally, in vitro evaluation was used to clarify the drug loading and controlling capacity of the nanocarrier as a drug delivery system. The results revealed that the GO nanocarrier had a better CPT loading capacity and showed better controllability for CPT release
Assessing the Bacterial Communities Composition from Differently Treated Agarwood via 16S rRNA Gene Metabarcoding
Agarwood (Aquilaria sinensis) is one of the most important resin-containing plants used to produce agar around the world and it is a precious herbal medicine usually combined with other herbs. In this study, we used the Illumina sequencing technique to explore the agarwood bacterial community structure from four different incense formations of agarwood, including healthy agarwood, drilling agarwood, liquid fermentation agarwood, and insect attack agarwood. Our results showed that 20 samples of three different incense-formation methods of agarwood and healthy agarwood acquired 1,792,706 high-quality sequences. In-depth investigation showed that when the diversity of agarwood bacterial species was higher, the agarwood incense quality was higher as well. Among healthy agarwood, drilling agarwood, fermentation agarwood, and insect attack agarwood, the bacterial community structure had significant changes. Natural agarwood, such as insect attack agarwood, kept more bacterial community structure, and the incense quality was better. Furthermore, we observed that in the healthy agarwood, Amnibacterium and Delftia were the predominant bacteria. Actinoplanes, Bordetella, and Sphingobacterium were the dominant bacteria in the drilling agarwood. Additionally, Pelagibacterium and Methylovirgula were some of the main bacteria in the fermentation liquid agarwood and the insect attack agarwood, while Cellulomonas and Aeromicrobium were the dominant bacteria. This research provides a basis for further research into the underlying mechanisms of incense production, as well as the bacterial community applications of agarwood production
An Aerial–Wall Robotic Insect That Can Land, Climb, and Take Off from Vertical Surfaces
Insects that can perform flapping-wing flight, climb on a wall, and switch smoothly between the 2 locomotion regimes provide us with excellent biomimetic models. However, very few biomimetic robots can perform complex locomotion tasks that combine the 2 abilities of climbing and flying. Here, we describe an aerial–wall amphibious robot that is self-contained for flying and climbing, and that can seamlessly move between the air and wall. It adopts a flapping/rotor hybrid power layout, which realizes not only efficient and controllable flight in the air but also attachment to, and climbing on, the vertical wall through a synergistic combination of the aerodynamic negative pressure adsorption of the rotor power and a climbing mechanism with bionic adhesion performance. On the basis of the attachment mechanism of insect foot pads, the prepared biomimetic adhesive materials of the robot can be applied to various types of wall surfaces to achieve stable climbing. The longitudinal axis layout design of the rotor dynamics and control strategy realize a unique cross-domain movement during the flying–climbing transition, which has important implications in understanding the takeoff and landing of insects. Moreover, it enables the robot to cross the air–wall boundary in 0.4 s (landing), and cross the wall–air boundary in 0.7 s (taking off). The aerial–wall amphibious robot expands the working space of traditional flying and climbing robots, which can pave the way for future robots that can perform autonomous visual monitoring, human search and rescue, and tracking tasks in complex air–wall environments
Prevalence and Evolutionary Characteristics of Bovine Coronavirus in China
Bovine coronavirus (BCoV), bovine rotavirus, bovine viral diarrhea virus, and bovine astrovirus are the most common intestinal pathogenic viruses causing diarrhea in cattle. We collected 1646 bovine fecal samples from January 2020 to August 2023. BCoV was the major pathogen detected, with a positive rate of 34.02% (560/1646). Of the 670 diarrheal samples and 976 asymptomatic samples, 209 and 351 were BCoV-positive, respectively. Studying the relevance of diarrhea associated with BCoV has shown that the onset of diarrheal symptoms post-infection is strongly correlated with the cattle’s age and may also be related to the breed. We amplified and sequenced the hemagglutinin esterase (HE), spike protein, and whole genomes of the partially positive samples and obtained six complete HE sequences, seven complete spike sequences, and six whole genomes. Molecular characterization revealed that six strains were branched Chinese strains, Japanese strains, and partial American strains from the GⅡb subgroup. Strains HBSJZ2202 and JSYZ2209 had four amino acid insertions on HE. We also analyzed ORF1a and found disparities across various regions within GIIb, which were positioned on separate branches within the phylogenetic tree. This work provides data for further investigating the epidemiology of BCoV and for understanding and analyzing BCoV distribution and dynamics