Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Food Chem ; 456: 140035, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38870824

RESUMEN

This study examines the food safety risk of organophosphate esters (OPEs) by analyzing data from 23 studies with 14,915 data points. We found EDP contamination highest in cereals, dairy, and meats, and TEHP most prevalent in vegetables and fruits, with contamination levels reaching 4.54 ng/g and 1.46 ng/g, respectively. Food processing influences OPE contamination through complex and multifaceted, akin to a "double-edged sword.", as meta-analysis and Principal Component Analysis (PCA) revealed. Estimated Dietary Intakes (EDI) identified vegetables and cereals as primary OPE sources, contributing 33.3% and 23.8% of total intake, with EDI values of 44.74 ng/kg bw/day and 32.25 ng/kg bw/day, respectively. Current exposure levels are within U.S. EPA safety thresholds (HQ < < 1), but the heightened risk to infants and children necessitates revising safety standards and ongoing monitoring.

2.
Talanta ; 275: 126065, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38663061

RESUMEN

In practical applications, the rapid and efficient detection of universal organophosphorus pesticides (OPs) can assist inspectors in quickly identifying the presence of OPs in samples. However, this presents a challenge for most well-established methods, typically designed to detect only a specific type of organophosphorus molecule at a time. In this proof-of-concept study, we draw inspiration from the structural similarities among OPs to develop innovative peptide-based fluorescence probes for the first time, which could efficiently detect a broad range of OPs within a mere 3 min. Analysis of fluorescence curve fitting reveals a clear linear correlation between the fluorescent intensity of the peptide probes and the concentration of OPs. Additionally, the selectivity analysis indicates that these peptide fluorescent probes exhibit an excellent response to various OPs while maintaining sufficient selectivity for detecting other pesticide types. Accurate sample analysis has also highlighted the potential of these peptide probes as practical tools for the rapid detection of OPs in actual vegetable samples. In summary, this proof-of-concept study presents an innovative approach to designing and developing ultrafast, universally peptide-based OP probes. These custom-designed peptide probes may facilitate rapid sample screening and offer initial quantification for OPs, potentially saving valuable time and effort in practical OP detection.


Asunto(s)
Colorantes Fluorescentes , Compuestos Organofosforados , Péptidos , Plaguicidas , Colorantes Fluorescentes/química , Plaguicidas/análisis , Péptidos/química , Compuestos Organofosforados/análisis , Compuestos Organofosforados/química , Espectrometría de Fluorescencia/métodos , Verduras/química
3.
Stem Cell Res Ther ; 15(1): 16, 2024 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-38229108

RESUMEN

BACKGROUND: Intestinal epithelial cells derived from human pluripotent stem cells (hPSCs) are generally maintained and cultured as organoids in vitro because they do not exhibit adhesion when cultured. However, the three-dimensional structure of organoids makes their use in regenerative medicine and drug discovery difficult. Mesenchymal stromal cells are found near intestinal stem cells in vivo and provide trophic factors to regulate stem cell maintenance and proliferation, such as BMP inhibitors, WNT, and R-spondin. In this study, we aimed to use mesenchymal stromal cells isolated from hPSC-derived intestinal organoids to establish an in vitro culture system that enables stable proliferation and maintenance of hPSC-derived intestinal epithelial cells in adhesion culture. METHODS: We established an isolation protocol for intestinal epithelial cells and mesenchymal stromal cells from hPSCs-derived intestinal organoids and a co-culture system for these cells. We then evaluated the intestinal epithelial cells and mesenchymal stromal cells' morphology, proliferative capacity, chromosomal stability, tumorigenicity, and gene expression profiles. We also evaluated the usefulness of the cells for pharmacokinetic and toxicity studies. RESULTS: The proliferating intestinal epithelial cells exhibited a columnar form, microvilli and glycocalyx formation, cell polarity, and expression of drug-metabolizing enzymes and transporters. The intestinal epithelial cells also showed barrier function, transporter activity, and drug-metabolizing capacity. Notably, small intestinal epithelial stem cells cannot be cultured in adherent culture without mesenchymal stromal cells and cannot replaced by other feeder cells. Organoid-derived mesenchymal stromal cells resemble the trophocytes essential for maintaining small intestinal epithelial stem cells and play a crucial role in adherent culture. CONCLUSIONS: The high proliferative expansion, productivity, and functionality of hPSC-derived intestinal epithelial cells may have potential applications in pharmacokinetic and toxicity studies and regenerative medicine.


Asunto(s)
Células Madre Pluripotentes , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas , Humanos , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Diferenciación Celular , Células Madre Pluripotentes/metabolismo , Organoides/metabolismo , Células Epiteliales/metabolismo , Proliferación Celular , Mucosa Intestinal/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo
4.
Food Chem X ; 20: 101014, 2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-38144849

RESUMEN

The worldwide demand for organophosphorus pesticides (OPs) in food production has raised concerns about pesticide residues. Meta-analysis, proven effective in assessing contaminants like aflatoxins and organotin compounds, is applied here to comprehensively study OP contamination in fresh fruits and vegetables. Employing Comprehensive Meta-Analysis V3.0 software, we meticulously examined 24 relevant articles encompassing 69,467 data points. Our findings revealed that while the residual concentrations of OPs (such as chlorpyrifos and profenofos) in most fruits and vegetables have typically met international or national safety standards, including Codex Alimentarius Commission, European Union, British, and Chinese standards, there are some instances in which the maximum residue limits have been exceeded, posing safety risks. Therefore, significant efforts are required to maintain residual OP contamination at safe concentrations.

5.
BMC Surg ; 23(1): 192, 2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37407952

RESUMEN

BACKGROUND: Considering the high reoperation rate in degenerative lumbar spondylolisthesis (DLS) patients undergoing lumbar surgeries and controversial results on the risk factors for the reoperation, we performed a systematic review and meta-analysis to explore the reoperation rate and risk factors for the reoperation in DLS patients undergoing lumbar surgeries. METHODS: Literature search was conducted from inception to October 28, 2022 in Pubmed, Embase, Cochrane Library, and Web of Science. Odds ratio (OR) was used as the effect index for the categorical data, and effect size was expressed as 95% confidence interval (CI). Heterogeneity test was performed for each outcome effect size, and subgroup analysis was performed based on study design, patients, surgery types, follow-up time, and quality of studies to explore the source of heterogeneity. Results of all outcomes were examined by sensitivity analysis. Publication bias was assessed using Begg test, and adjusted using trim-and-fill analysis. RESULTS: A total of 39 cohort studies (27 retrospective cohort studies and 12 prospective cohort studies) were finally included in this systematic review and meta-analysis. The overall results showed a 10% (95%CI: 8%-12%) of reoperation rate in DLS patients undergoing lumbar surgeries. In surgery types subgroup, the reoperation rate was 11% (95%CI: 9%-13%) for decompression, 10% (95%CI: 7%-12%) for fusion, and 9% (95%CI: 5%-13%) for decompression and fusion. An increased risk of reoperation was found in patients with obesity (OR = 1.91, 95%CI: 1.04-3.51), diabetes (OR = 2.01, 95%CI: 1.43-2.82), and smoking (OR = 1.51, 95%CI: 1.23-1.84). CONCLUSIONS: We found a 10% of reoperation rate in DLS patients after lumbar surgeries. Obesity, diabetes, and smoking were risk factors for the reoperation.


Asunto(s)
Diabetes Mellitus , Fusión Vertebral , Estenosis Espinal , Espondilolistesis , Humanos , Reoperación/métodos , Espondilolistesis/cirugía , Estudios Retrospectivos , Estudios Prospectivos , Resultado del Tratamiento , Estenosis Espinal/cirugía , Descompresión Quirúrgica/métodos , Fusión Vertebral/métodos , Factores de Riesgo , Vértebras Lumbares/cirugía , Diabetes Mellitus/epidemiología , Diabetes Mellitus/cirugía , Obesidad/cirugía
6.
Chem Commun (Camb) ; 59(63): 9626-9629, 2023 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-37464814

RESUMEN

Electrochemical nitrite (NO2-) reduction to ammonia (NH3) can not only remove harmful NO2- in wastewater, but also produce valuable NH3. Herein, a CoFe nanoalloy encapsulated in nitrogen-doped carbon (CoFe-NC) electrocatalyst was fabricated for nitrite reduction, which achieved a high NH3 Faraday efficiency of 94.5%, and a large NH3 yield of 4050.6 µg h-1 cm-2 in a neutral electrolyte.

7.
Environ Sci Pollut Res Int ; 30(15): 45209-45230, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36705827

RESUMEN

This study constructs a mixed oligopoly model that includes a public enterprise and two private enterprises. Game theory was adopted to explore the effects of carbon emission reduction policies. In addition, this study analyzes the optimal carbon emission trading prices and privatization decisions. The results show that the proportion of state-owned shares and the equity efficiency gap affect the equilibrium results for different carbon emission policies. Privatization increases the profits of public firms but does not necessarily increase social welfare. Different carbon emission reduction policies have different effects on the equilibrium results. Moreover, the emission reduction target is not completely consistent with the maximum social welfare target and should be comprehensively considered. The government can intervene by setting carbon emission trading prices and making privatization decisions. Full and partial privatization may be optimal decisions.


Asunto(s)
Carbono , Privatización , Políticas , Gobierno , Sector Público , China
8.
Nanomaterials (Basel) ; 11(11)2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34835811

RESUMEN

Silver nanowire (AgNW) conductive film fabricated by solution processing was investigated as an alternative to indium tin oxide (ITO) in flexible transparent electrodes. In this paper, we studied a facile and effective method by electrodepositing Al2O3 on the surface of AgNWs. As a result, flexible transparent electrodes with improved stability could be obtained by electrodepositing Al2O3. It was found that, as the annealing temperature rises, the Al2O3 coating layer can be transformed from Al2O3·H2O into a denser amorphous state at 150 °C. By studying the increase of electrodeposition temperature, it was observed that the transmittance of the AgNW-Al2O3 composite films first rose to the maximum at 70 °C and then decreased. With the increase of the electrodeposition time, the figure of merit (FoM) of the composite films increased and reached the maximum when the time was 40 s. Through optimizing the experimental parameters, a high-stability AgNW flexible transparent electrode using polyimide (PI) as a substrate was prepared without sacrificing optical and electrical performance by electrodepositing at -1.1 V and 70 °C for 40 s with 0.1 mol/L Al(NO3)3 as the electrolyte, which can withstand a high temperature of 250 °C or 250,000 bending cycles with a bending radius of 4 mm.

9.
Mar Drugs ; 19(4)2021 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-33806230

RESUMEN

Macrolides are a significant family of natural products with diverse structures and bioactivities. Considerable effort has been made in recent decades to isolate additional macrolides and characterize their chemical and bioactive properties. The majority of macrolides are obtained from marine organisms, including sponges, marine microorganisms and zooplankton, cnidarians, mollusks, red algae, bryozoans, and tunicates. Sponges, fungi and dinoflagellates are the main producers of macrolides. Marine macrolides possess a wide range of bioactive properties including cytotoxic, antibacterial, antifungal, antimitotic, antiviral, and other activities. Cytotoxicity is their most significant property, highlighting that marine macrolides still encompass many potential antitumor drug leads. This extensive review details the chemical and biological diversity of 505 macrolides derived from marine organisms which have been reported from 1990 to 2020.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Organismos Acuáticos/metabolismo , Macrólidos/farmacología , Animales , Antiinfecciosos/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Humanos , Macrólidos/aislamiento & purificación , Estructura Molecular , Relación Estructura-Actividad
10.
Micromachines (Basel) ; 12(1)2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-33466688

RESUMEN

Nickel oxide (NiO) is a wide band gap semiconductor material that is used as an electrochromic layer or an ion storage layer in electrochromic devices. In this work, the effect of annealing temperature on sol-gel NiO films was investigated. Fourier transform infrared spectroscopy (FTIR) showed that the formation of NiO via decomposition of the precursor nickel acetate occurred at about 300 °C. Meanwhile, an increase in roughness was observed by Atomic force microscope (AFM), and precipitation of a large number of crystallites was observed at 500 °C. X-ray Diffraction (XRD) showed that the NiO film obtained at such a temperature showed a degree of crystallinity. The film crystallinity and crystallite size also increased with increasing annealing temperature. An ultraviolet spectrophotometer was used to investigate the optical band gap of the colored NiO films, and it was found that the band gap increased from 3.65 eV to 3.74 eV with the increase in annealing temperature. An electrochromic test further showed that optical modulation density and coloring efficiency decreased with the increase in crystallite size. The electrochromic reaction of the nickel oxide film is more likely to occur at the crystal interface and is closely related to the change of the optical band gap. An NiO film with smaller crystallite size is more conducive to ion implantation and the films treated at 300 °C exhibit optimum electrochromic behavior.

11.
Pediatr Neurosurg ; 55(4): 188-196, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33040067

RESUMEN

INTRODUCTION: White matter injury (WMI) is the most common brain injury in preterm infants and can result in life-long neurological deficits. The main cause of WMI is damage to the oligodendrocyte precursor cells (OPC) in the brain that results in delayed myelin sheath formation, or the destruction of existing myelin sheaths. OPC undergo highly regulated and strictly timed developmental changes that result in their transformation to mature oligodendrocytes capable of myelin production. OBJECTIVE: Studies have shown that clobetasol strongly promotes differentiation of OPC into myelin sheaths. Therefore, we hypothesized that clobetasol may be a therapeutic option for the treatment of preterm WMI. METHODS: We induced a WMI rat model and observed white matter damage under an optical microscope. Rats subjected to WMI were injected intraperitoneally with clobetasol (2 or 5 mg/kg daily) from day 1 to day 5 in the early treatment groups, or from day 6 to day 10 in the late treatment groups. After 17 days, the rats were sacrificed and the expression of myelin basic protein (MBP) was visualized using immunofluorescence. In addition, we evaluated myelin sheath formation using electron microscopy. The rats were also subjected to the suspension test, ramp test, and open field test to evaluate neurobehavioral functions. RESULTS: A rat model of WMI was successfully induced. It was found that clobetasol significantly induced MBP expression and myelin sheath formation and improved neurobehavioral function in the rats subjected to WMI. CONCLUSIONS: Our results indicate that clobetasol attenuates WMI by promoting OPC differentiation, and it may be an effective therapeutic agent for the treatment of preterm WMI.


Asunto(s)
Lesiones Encefálicas , Células Precursoras de Oligodendrocitos , Sustancia Blanca , Animales , Animales Recién Nacidos , Diferenciación Celular , Clobetasol , Humanos , Recién Nacido , Recien Nacido Prematuro , Vaina de Mielina , Oligodendroglía , Ratas
12.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(7): 716-720, 2020 Jul.
Artículo en Chino | MEDLINE | ID: mdl-32669167

RESUMEN

OBJECTIVE: To study the role of interleukin-33 (IL-33) in the development and progression of bronchopulmonary dysplasia (BPD) in preterm infants. METHODS: A prospective cohort study was performed on 128 preterm infants with a gestational age of ≤32 weeks and/or a birth weight of ≤1 500 g. They were classified to a non-BPD group with 50 infants, a mild BPD group with 32 infants, a moderate BPD group with 30 infants, and a severe BPD group with 16 infants. Related data were collected, including antepartum factors of mothers (antepartum hormone and chorioamnionitis), intrapartum factors of preterm infants (sex, gestational age, birth weight, mode of birth, and birth asphyxia), treatment after birth (pulmonary surfactant, duration of invasive ventilation, duration of noninvasive ventilation, duration of parenteral nutrition, and length of hospital stay). The high-risk factors for BPD were analyzed. ELISA was used to measure the serum level of IL-33 in preterm infants on days 1, 14, and 28 after birth. The serum level of IL-33 was compared between groups at different time points after birth. The preterm infants with moderate or severe BPD were treated with conventional corticosteroid therapy (DART regimen), and the serum level of IL-33 was measured before and after treatment. RESULTS: There were significant differences between the preterm infants with BPD and those without BPD in the incidence of maternal chorioamnionitis, gestational age, birth weight, the incidence of birth asphyxia, duration of invasive ventilation, duration of noninvasive ventilation, duration of parenteral nutrition, and total length of hospital stay (P<0.05). There were significant differences in the above indices among the preterm infants with different severities of BPD (P<0.05). On days 1, 14, and 28 after birth, the infants with BPD had a significantly higher serum level of IL-33 than those without BPD, and the serum level of IL-33 tended to increase with the severity of BPD and over the time after birth (P<0.05). The preterm infants with moderate or severe BPD had a significant reduction in the serum level of IL-33 after the treatment with DART regimen (P<0.05). CONCLUSIONS: Serum IL-33 is closely associated with the development and severity of BPD. Anti-inflammatory therapy with DART regimen can decrease the serum level of IL-33.


Asunto(s)
Displasia Broncopulmonar , Interleucina-33/sangre , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Embarazo , Estudios Prospectivos , Respiración Artificial
13.
Micromachines (Basel) ; 11(3)2020 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-32188131

RESUMEN

Tungsten trioxide (WO3) is a wide band gap semiconductor material, which is commonly not only used, but also investigated as a significant electrochromic layer in electrochromic devices. WO3 films have been prepared by inorganic and sol-gel free ammonium tungstate ((NH4)2WO4), with the modification of glycerol using the spin coating technique. The surface tension, the contact angle and the dynamic viscosity of the precursor solutions demonstrated that the sample solution with a 25% volume fraction of glycerol was optimal, which was equipped to facilitate the growth of WO3 films. The thermal gravimetric and differential scanning calorimetry (TG-DSC) analysis represented that the optimal sample solution transformed into the WO3 range from 220 °C to 300 °C, and the transformation of the phase structure of WO3 was taken above 300 °C. Fourier transform infrared spectroscopy (FT-IR) spectra analysis indicated that the composition within the film was WO3 above the 300 °C annealing temperature, and the component content of WO3 was increased with the increase in the annealing temperature. The X-ray diffraction (XRD) pattern revealed that WO3 films were available for the formation of the cubic and monoclinic crystal structure at 400 °C, and were preferential for growing monoclinic WO3 when annealed at 500 °C. Atomic force microscope (AFM) images showed that WO3 films prepared using ammonium tungstate with modification of the glycerol possessed less rough surface roughness in comparison with the sol-gel-prepared films. An ultraviolet spectrophotometer (UV) demonstrated that the sample solution which had been annealed at 400 °C obtained a high electrochromic modulation ability roughly 40% at 700 nm wavelength, as well as the optical band gap (Eg) of the WO3 films ranged from 3.48 eV to 3.37 eV with the annealing temperature increasing.

14.
Pest Manag Sci ; 76(8): 2609-2618, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32083388

RESUMEN

BACKGROUND: Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are two families of small water-soluble proteins involved in odor detection and subsequent signal transmission. Determination of their binding mechanisms and specificity towards different odorants is important for developing OBPs/CSPs as targets in pest control management. RESULTS: We re-annotated genes encoding putative OBPs and CSPs in the Asian citrus psyllid (Diaphorina citri) draft genome using various bioinformatic tools. Genes encoding nine OBPs (seven Classic and two Plus-C) and 12 CSPs were identified, consistent with our previous transcriptomic results. Tissue-specific and developmental expression analyses suggested that genes encoding six OBPs and four CSPs were predominantly expressed in antennae, and displayed various expression patterns in different development stages, suggesting potential involvement in olfactory perception. Competitive fluorescence binding assays with 13 candidate ligands, including known host plant volatiles, sex pheromone components and repellents, showed that DcitOBP3 could bind to various odorants, whereas DcitOBP6, 8 and 9 bound specifically to host plant terpenoids. DcitCSP1 and 12 could also bind to certain terpenoids with high binding specificity. CONCLUSION: OBP- and CSP-encoding genes were systematically identified by annotating the draft D. citri genome and those potentially involved in odorant detection and signal transmission were identified by analyzing their tissue-expression profiles and odorant-binding affinities, particularly to the peripheral molecular perception of host plant terpenoids. The identified genes may provide potential targets for efficient pest control. © 2020 Society of Chemical Industry.


Asunto(s)
Hemípteros , Animales , Antenas de Artrópodos , Citrus , Perfilación de la Expresión Génica , Proteínas de Insectos , Odorantes , Receptores Odorantes
15.
Micromachines (Basel) ; 11(3)2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32106449

RESUMEN

The urgent demand for transparent flexible electrodes applied in wide bandgap devices has promoted the development of new materials. Silver nanoring (AgNR), known as a special structure of silver nanowire (AgNW), exhibits attractive potential in the field of wearable electronics. In this work, an environmentally friendly glycerol-based cosolvent polyol method was investigated. The Taguchi design was utilized to ascertain the factors that affect the yield and ring diameter of AgNRs. Structural characterization showed that AgNR seeds grew at a certain angle during the early nucleation period. The results indicated that the yield and ring diameter of AgNRs were significantly affected by the ratio of cosolvent. Besides, the ring diameter of AgNRs was also tightly related to the concentration of polyvinylpyrrolidone (PVP). The difference of reducibility between glycerol, water, and ethylene glycol leads to the selective growth of (111) plane and is probably the main reason AgNRs are formed. As a result, AgNRs with a ring diameter range from 7.17 to 42.94 µm were synthesized, and the quantity was increased significantly under the optimal level of factors.

16.
Rev Sci Instrum ; 90(9): 095005, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31575246

RESUMEN

A novel sensor based on the interdigitated structure is presented to detect surface defects in film-coated metals and measure coating thickness. The detection and measurement are based on monitoring the shift of resonance frequency which is caused by the perturbation of electromagnetic field around the interdigitated structure. A 200-µm-wide defect was successfully detected in the experiment. In addition, the numerical simulations show that the designed sensor can detect a 50-µm-wide defect with a 220 MHz shift in the resonance frequency. The sensor is sensitive, inexpensive, portable, and can detect both defects and measure coating thickness.

17.
Biomimetics (Basel) ; 4(3)2019 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-31500140

RESUMEN

Animals and plants have numerous active protections for adapting to the complex and severe living environments, providing endless inspiration for extending the service life of materials and machines. Conch, a marine animal living near the coast and chronically suffering from the erosion of sand in water, has adapted to the condition through its anti-erosion conch shell. Romanesco broccoli, a plant whose inflorescence is self-similar in character, has a natural fractal bud's form. Coupling the convex domes on the conch shell and the fractal structure of Romanesco broccoli, a novel valve core structure of a water hydraulic valve was designed in this paper to improve the particle erosion resistance and valve core's service life. Three models were built to compare the effect among the normal structure, bionic structure, and multi-source coupling bionic structures, and were coined using 3D printing technology. A 3D printed water hydraulic valve was manufactured to simulate the working condition of a valve core under sand erosion in water flow, and capture the experimental videos of the two-phase flow. Furthermore, based on the water hydraulic platform and one-camera-six-mirror 3D imaging subsystem, the experiment system was established and used to compare the performance of the three different valve cores. As a result, the results showed that the coupling bionic structure could effectively improve the anti-erosion property of the valve core and protect the sealing face on the valve core from wear. This paper presents a novel way of combining advantages from both animal (function bionic) and plant (shape bionic) in one component design.

18.
Org Lett ; 21(17): 7060-7064, 2019 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-31436432

RESUMEN

Phosphine-catalyzed divergent [4+3] domino annulations of fluorinated imidoyl chlorides with MBH carbonates were developed. Two classes of perfluoroalkylated benzazepines were obtained in moderate to good yields via an interesting dearomatization/rearomatization sequence. Remarkably, the fluorinated imidoyl chlorides could be utilized for the first time as a new four-atom building block in phosphine catalysis. Moreover, the proposed mechanism is supported by capturing the intermediate.

19.
BMC Genomics ; 20(1): 646, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31412763

RESUMEN

BACKGROUND: The males of many Bactrocera species (Diptera: Tephritidae) respond strongly to plant-derived chemicals (male lures) and can be divided into cue lure/raspberry ketone (CL/RK) responders, methyl eugenol (ME) responders and non-responders. Representing a non-responders, Bactrocera minax display unique olfactory sensory characteristics compared with other Bactrocera species. The chemical senses of insects mediate behaviors that are associated with survival and reproduction. Here, we report the generation of transcriptomes from antennae and the rectal glands of both male and female adults of B. minax using Illumina sequencing technology, and annotated gene families potentially responsible for chemosensory. RESULTS: We developed four transcriptomes from different tissues of B. minax and identified a set of candidate genes potentially responsible for chemosensory by analyzing the transcriptomic data. The candidates included 40 unigenes coding for odorant receptors (ORs), 30 for ionotropic receptors (IRs), 17 for gustatory receptors (GRs), three for sensory neuron membrane proteins (SNMPs), 33 for odorant-binding proteins (OBPs), four for chemosensory proteins (CSPs). Sex- and tissue-specific expression profiles for candidate chemosensory genes were analyzed via transcriptomic data analyses, and expression profiles of all ORs and antennal IRs were investigated by real-time quantitative PCR (RT-qPCR). Phylogenetic analyses were also conducted on gene families and paralogs from other insect species together. CONCLUSIONS: A large number of chemosensory genes were identified from transcriptomic data. Identification of these candidate genes and their expression profiles in various tissues provide useful information for future studies towards revealing their function in B. minax.


Asunto(s)
Perfilación de la Expresión Génica , Genes de Insecto/genética , Tephritidae/genética , Animales , Anotación de Secuencia Molecular , Olfato/genética
20.
Org Lett ; 20(21): 6715-6718, 2018 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-30350677

RESUMEN

Divergent domino annulation reactions of sulfur ylides and azadienes were developed. A wide range of functionalized benzofuran-fused six- and seven-membered nitrogen-heterocyclic compounds were prepared in moderate to excellent yields under mild conditions. It is worth noting that the crotonate-derived sulfur ylides could be used as a novel C2 synthon or C3 synthon selectively by simply transforming the base.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...