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1.
Front Plant Sci ; 15: 1378707, 2024.
Article in English | MEDLINE | ID: mdl-38803604

ABSTRACT

Introduction: This study used Bacillus amyloliquefaciens DGL1 isolated from the arid sandy land of the Qinghai-Tibetan Plateau as the research strain and investigated the effects of DGL1 on the biomass, physiology, and metabolites of Medicago sativa under different intensities of drought stress to provide a high-quality bacterial source and a theoretical basis for the research and development of biological fertilizer suitable for arid areas. Methods: The exopolysaccharides (EPS), 1-Aminocyclopropane-1-carboxylate deaminase (ACC), and phosphorus solubilizing capacity of DGL1 were determined. The effects of a DGL1 suspension on alfalfa biomass, physiological indexes, degree of peroxidation of cell membranes, and activity of antioxidant enzymes were determined after irrigating roots under drought stress. The effects on soil physicochemical properties were also evaluated, and metabolomics analysis was performed to explore the effect of DGL1 on the metabolites of alfalfa under drought stress. Results: Strain DGL1 produced extracellular polysaccharide EPS and ACC deaminase and was capable of phosphorus solubilization. Treatment with DGL1 increased the biomass of alfalfa under different degrees of drought stress, significantly increased the activities of alfalfa antioxidant enzymes Super Oxide Dismutase (SOD), Peroxidase (POD), and catalase (CAT), reduced the content of MDA and H2O2, and increased the content of quick-acting phosphorus, quick-acting potassium, ammonium nitrogen, and nitrate nitrogen in the soil, thus improving soil fertility. Through metabolomics analysis, DGL1 was shown to affect amino acid metabolic pathways, such as arginine, leucine, glutamate, and tyrosine, as well as the levels of energy-providing polysaccharides and lipids, in alfalfa under 15% PEG-6000 drought stress, enhancing alfalfa's capacity to resist drought stress. Discussion: Strain DGL1 enhances the drought suitability of alfalfa and has the potential for dryland development as a biological agent.

2.
Insects ; 15(4)2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38667358

ABSTRACT

A comprehensive and precise evaluation of Arthropoda diversity in agricultural landscapes can enhance biological pest control strategies. We used Malaise traps and sweep nets to collect insects from three double-cropping paddy fields. DNA was extracted from the ethanol preservative of the Malaise traps and from tissue samples of selected parasitoid wasps. This was followed by amplification using DNA barcoding primers to prepare high-throughput sequencing libraries. We annotated a total of 4956 operational taxonomic units (OTUs), encompassing 174 genera and 32 families of parasitoid wasps. The ethanol filter method efficiently captured a wide range of information. However, the method has low resolution and may result in a reduced estimate of species abundance. Additional insect species were also identified in the parasitoid samples. This suggests that high throughput sequencing from adult parasitoid wasps can also detect host species, enabling a better understanding of host species and providing insights into food webs.

3.
Front Microbiol ; 15: 1321989, 2024.
Article in English | MEDLINE | ID: mdl-38633698

ABSTRACT

Introduction: Bacillus amyloliquefaciens DGL1, isolated from the arid sandy areas in Dagler, Qinghai Province, China, promotes the growth of Avena sativa variety "Qing Yan 1". Methods: To elucidate the transcriptomic changes in the oat root system following interaction with DGL1 and to reveal the molecular mechanism by which DGL1 promotes oat growth, treatment and control groups of oat roots at 2, 4, 8, and 12 h after inoculation with a suspension of strain DGL1 were analyzed using Illumina high-throughput transcriptome sequencing technology. The differentially expressed genes were determined through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, and the metabolic pathways and key genes were analyzed. Results: The results showed that 7874, 13,392, 13,169, and 19,026 differentially expressed genes were significantly enriched in the glycolysis/gluconeogenesis pathway, amino acid metabolism, nitrogen metabolism, plant hormone signal transduction, and other related metabolic pathways in the oat roots at 2, 4, 8, and 12 h after inoculation with a DGL1 suspension. The GO and KEGG enrichment analyses revealed that the genes encoding plasma membrane ATPase, phosphoglycerate kinase gene PGK, ammonium transporter protein gene AMT, cellulose synthase gene CSLF6, and growth hormone response family gene IAA18 were significantly upregulated. Discussion: It is hypothesized that the pro-growth mechanism of strain DGL1 in oats is the result of the coordination of multiple pathways through the promotion of oat energy metabolism, phytohormone signaling, secondary metabolite synthesis, and amino acid metabolism.

4.
Adv Mater ; : e2313661, 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38499342

ABSTRACT

Petroleum, as the "lifeblood" of industrial development, is the important energy source and raw material. The selective transformation of petroleum into high-end chemicals is of great significance, but still exists enormous challenges. Single-atom catalysts (SACs) with 100% atom utilization and homogeneous active sites, promise a broad application in petrochemical processes. Herein, the research systematically summarizes the recent research progress of SACs in petrochemical catalytic reaction, proposes the role of structural design of SACs in enhancing catalytic performance, elucidates the catalytic reaction mechanisms of SACs in the conversion of petrochemical processes, and reveals the high activity origins of SACs at the atomic scale. Finally, the key challenges are summarized and an outlook on the design, identification of active sites, and the appropriate application of artificial intelligence technology is provided for achieving scale-up application of SACs in petrochemical process.

5.
Front Public Health ; 12: 1343950, 2024.
Article in English | MEDLINE | ID: mdl-38450145

ABSTRACT

Introduction: Although the global COVID-19 emergency ended, the real-world effects of multiple non-pharmaceutical interventions (NPIs) and the relative contribution of individual NPIs over time were poorly understood, limiting the mitigation of future potential epidemics. Methods: Based on four large-scale datasets including epidemic parameters, virus variants, vaccines, and meteorological factors across 51 states in the United States from August 2020 to July 2022, we established a Bayesian hierarchical model with a spike-and-slab prior to assessing the time-varying effect of NPIs and vaccination on mitigating COVID-19 transmission and identifying important NPIs in the context of different variants pandemic. Results: We found that (i) the empirical reduction in reproduction number attributable to integrated NPIs was 52.0% (95%CI: 44.4, 58.5%) by August and September 2020, whereas the reduction continuously decreased due to the relaxation of NPIs in following months; (ii) international travel restrictions, stay-at-home requirements, and restrictions on gathering size were important NPIs with the relative contribution higher than 12.5%; (iii) vaccination alone could not mitigate transmission when the fully vaccination coverage was less than 60%, but it could effectively synergize with NPIs; (iv) even with fully vaccination coverage >60%, combined use of NPIs and vaccination failed to reduce the reproduction number below 1 in many states by February 2022 because of elimination of above NPIs, following with a resurgence of COVID-19 after March 2022. Conclusion: Our results suggest that NPIs and vaccination had a high synergy effect and eliminating NPIs should consider their relative effectiveness, vaccination coverage, and emerging variants.


Subject(s)
COVID-19 , United States/epidemiology , Humans , Bayes Theorem , COVID-19/epidemiology , COVID-19/prevention & control , Vaccination , Vaccination Coverage , Pandemics
6.
BMJ Glob Health ; 9(2)2024 02 06.
Article in English | MEDLINE | ID: mdl-38320803

ABSTRACT

INTRODUCTION: China initialised the expanded hepatitis A vaccination programme (EHAP) in 2008. However, the effectiveness of the programme remains unclear. We aimed to comprehensively evaluate the effectiveness of EHAP in the country. METHODS: Based on the provincial data on the incidence of hepatitis A (HepA), the population and meteorological variables in China, we developed interrupted time series (ITS) models to estimate the effectiveness of EHAP with the autocorrelation, seasonality and the meteorological confounders being controlled. Results were also stratified by economic zones, age groups and provinces. RESULTS: We found a 0.9% reduction (RR=0.991, 95% CI: 0.990 to 0.991) in monthly HepA incidence after EHAP, which was 0.3% greater than the reduction rate before EHAP in China. Across the three economic regions, we found a 1.1% reduction in HepA incidence in both central and western regions after EHAP, which were 0.3% and 1.2% greater than the reduction rates before EHAP, respectively. We found a decreased reduction rate for the eastern region. In addition, we found generally increased reduction rate after EHAP for age groups of 0-4, 5-14 and 15-24 years. However, we found decreased reduction rate among the 25-64 and ≥65 years groups. We found a slight increased rate after EHAP in Shanxi Province but not elsewhere. CONCLUSION: Our finding provides comprehensive evidence on the effectiveness of EHAP in China, particularly in the central and western regions, and among the population aged 0-24 years old. This study has important implications for the adjustment of vaccination strategies for other regions and populations.


Subject(s)
Hepatitis A , Humans , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Young Adult , Adult , Hepatitis A/epidemiology , Hepatitis A/prevention & control , Interrupted Time Series Analysis , Vaccination , China/epidemiology , Incidence
7.
Adv Mater ; 36(11): e2308243, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38102967

ABSTRACT

The development of facile, efficient synthesis method to construct low-cost and high-performance single-atom catalysts (SACs) for oxygen reduction reaction (ORR) is extremely important, yet still challenging. Herein, an atomically dispersed N, S co-doped carbon with abundant vacancy defects (NSC-vd) anchored Fe single atoms (SAs) is reported and a vacancy defects inductive effect is proposed for promoting electrocatalytic ORR. The optimized catalyst featured of stable Fe─N3 S1 active sites exhibits excellent ORR activity with high turnover frequency and mass activity. In situ Raman, attenuated total reflectance surface enhanced infrared absorption spectroscopy reveal the Fe─N3 S1 active sites exhibit different kinetic mechanisms in acidic and alkaline solutions. Operando X-ray absorption spectra reveal the ORR activity of Fe SAs/NSC-vd catalyst in different electrolyte is closely related to the coordination structure. Theoretical calculation reveals the upshifted d band center of Fe─N3 S1 active sites facilitates the adsorption of O2 and accelerates the kinetics process of *OH reduction. The abundant vacancy defects around the Fe─N3 S1 active sites balance the OOH* formation and *OH reduction, thus synergetically promoting the electrocatalytic ORR process.

8.
Structure ; 31(10): 1275-1281.e4, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37527655

ABSTRACT

Focused ion beam (FIB) is widely used for thinning frozen cells to produce lamellae for cryo-electron microscopy imaging and for protein structures study in vivo. However, FIB damages the lamellae and a quantitative experimental analysis of the damage is lacking. We used a 30-keV gallium FIB to prepare lamellae of a highly concentrated icosahedral virus sample. The viruses were grouped according to their distance from the surface of lamellae and reconstructed. Damage to the approximately 20-nm-thick outermost lamella surface was similar to that from exposure to 16 e-/Å2 in a 300-kV cryo-electron microscope at high-resolution range. The damage was negligible at a depth beyond 50 nm, which was reduced to 30 nm if 8-keV Ga+ was used during polishing. We designed extra steps in the reconstruction refinement to maximize undamaged signals and increase the resolution. The results demonstrated that low-energy beam polishing was essential for high-quality thinner lamellae.

9.
Small Methods ; 7(7): e2300121, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37002182

ABSTRACT

This study adopts a facile and effective in situ encapsulation-oxidation strategy for constructing a coupling catalyst composed of atomically dispersed Pt-doped Co3 O4 spinel nanoparticles (NPs) embedded in polyhedron frames (PFs) for robust propane total oxidation. Benefiting from the abundant oxygen vacancies and more highly valent active Co3+ species caused by the doping of Pt atoms as well as the confinement effect, the optimized 0.2Pt-Co3 O4 NPs/PFs catalyst exhibits excellent propane catalytic activity with low T90 (184 °C), superior apparent reaction rate (21.62×108 (mol gcat -1 s-1 )), low apparent activation energy (Ea = 17.89 kJ mol-1 ), high turnover frequency ( 811×107 (mol gcat -1 s-1 )) as well as good stability. In situ diffuse reflectance infrared Fourier transform spectroscopy and density functional theory calculations indicate that the doping of Pt atoms enhances the oxygen activation ability, and decreases the energy barrier required for CH bond breaking, thus improving the deep oxidation process of the intermediate species. This study opens up new ideas for constructing coupling catalysts from atomic scale with low cost to enhance the activation of oxygen molecules and the deep oxidation of linear short chain alkanes at low temperature.

10.
Medicine (Baltimore) ; 102(10): e33218, 2023 Mar 10.
Article in English | MEDLINE | ID: mdl-36897700

ABSTRACT

RATIONALE: Cerebral venous sinus thrombosis (CVST) represents 0.5% to 1% of all strokes. CVST can cause headaches, epilepsy, and subarachnoid hemorrhage (SAH). CVST is easily misdiagnosed because of the variety and non-specificity of symptoms. Herein, we report a case of infectious thrombosis of the superior sagittal sinus with SAH. PATIENT CONCERNS: A 34-year-old man presented to our hospital with a 4-hour history of sudden and persistent headache and dizziness with tonic convulsions of the limbs. Computed tomography revealed SAH with edema. Enhanced magnetic resonance imaging showed an irregular filling defect in the superior sagittal sinus. DIAGNOSES: The final diagnosis was hemorrhagic superior sagittal sinus thrombosis and secondary epilepsy. INTERVENTIONS: He was treated with antibiotic, antiepileptic, fluids to rehydrate, and intravenous dehydration. OUTCOMES: After treatment, the seizures did not recur and the symptoms were relieved. One month after the antibiotic treatment, the muscle strength of the patient's right extremity was restored to level 5, and there was no recurrence of his neurological symptoms. LESSONS: We describe a case of infectious thrombosis of the superior sagittal sinus manifested as SAH, which is easily misdiagnosed, especially when patients present with an infection. Clinicians must therefore take care during the diagnosis and selection of the treatment strategy.


Subject(s)
Sagittal Sinus Thrombosis , Sinus Thrombosis, Intracranial , Subarachnoid Hemorrhage , Thrombosis , Male , Humans , Adult , Subarachnoid Hemorrhage/etiology , Superior Sagittal Sinus , Magnetic Resonance Imaging/adverse effects , Seizures/complications , Headache/diagnosis , Thrombosis/complications , Sinus Thrombosis, Intracranial/complications
11.
Naunyn Schmiedebergs Arch Pharmacol ; 396(6): 1187-1203, 2023 06.
Article in English | MEDLINE | ID: mdl-36692827

ABSTRACT

Buyang Huanwu decoction (BYHWD) is a classical traditional prescription. Glycosides are effective extracts of BYHWD, which have been proven to protect blood vessels and prevent atherosclerosis (AS). However, the mechanism of glycosides in inhibiting abnormal angiogenesis in atherosclerosis is still unclear. The specific amygdalin (AG), paeoniflorin (PF), and astragaloside IV (ASV) contents in the BYHWD-containing serum were detected using mass spectrometry. Network pharmacology and molecular docking are used to screen the targets of glycosides for treating atherosclerosis. The predicted targets were validated in an AS model of rat thoracic aortic endothelial cells (RTAEC) induced by oxidized low-density lipoprotein (ox-LDL). According to the mass spectrometry data, the specific contents of AG, PF, and ASV in the serum were 24.11 ng/ml, 20.94 ng/ml, and 69.87 ng/ml, respectively. Results of bioinformatics analysis show that signal transducer and activator of transcription (STAT)-3, hypoxia-inducible factor (HIF)-1, and vascular endothelial-derived growth factor (VEGF) may be involved in the treatment of AS with glycosides. The results of cell experiments revealed that glycoside combinations could treat atherosclerosis by inhibiting STAT3, HIF-1, and VEGF. AG, PF, and ASV are the effective ingredients of BYHWD. Glycoside combinations significantly ameliorate atherosclerosis by inhibiting STAT3, HIF-1, and VEGF.


Subject(s)
Atherosclerosis , Glycosides , Rats , Animals , Glycosides/pharmacology , Glycosides/therapeutic use , Vascular Endothelial Growth Factor A , Endothelial Cells , Hypoxia-Inducible Factor 1 , Molecular Docking Simulation , Atherosclerosis/drug therapy
12.
Environ Sci Pollut Res Int ; 30(6): 16438-16448, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36184708

ABSTRACT

The rationally designed heterojunction photocatalysts with magnetic semiconductors and easy recyclability have received considerable attention due to their great advantages in practical application. In our work, a series of ZnIn2S4/ZnFe2O4 Z-scheme heterojunction photocatalysts with superior magnetic properties were synthesized by a gentle chemical bath method and utilized for the effective photodegradation and Cr(VI) reduction under irradiation. Systematic evaluation experiments revealed that the derived ZnIn2S4/ZnFe2O4 photocatalysts exhibited enhanced photocatalytic efficiency for RhB degradation and Cr(VI) reduction as compared with pristine ZnIn2S4 and ZnFe2O4, which was primarily due to the close contact interface and the formation of Z - scheme charge transfer mechanism between ZnFe2O4 rods and ZnIn2S4 nanosheets. Moreover, the as-synthesized photocatalyst could be easily recycled with a remarkable photocatalytic performance because of its magnetic separation characteristic. The present work opens up a vast prospect for the design of highly efficient and magnetically separable photocatalysts for environmental remediation.


Subject(s)
Environmental Restoration and Remediation , Wastewater , Chromium , Magnetic Phenomena
13.
Environ Pollut ; 315: 120436, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-36279996

ABSTRACT

The design of visible-light-driven photocatalysts has been rapidly developed due to the great application potential in environmental pollution remediation. The present work focused on the construction of a novel ternary g-C3N4/Bi2MoO6/CeO2 nanocomposite and the application for photocatalytic removal of 4-CP under irradiation. The g-C3N4/Bi2MoO6/CeO2 photocatalysts were successfully synthesized by a facile solid-state thermolysis assisted ultrasonic dispersion to introduce g-C3N4 nanosheets into Bi2MoO6/CeO2 composite. Morphology characterization revealed that the Bi2MoO6/CeO2 spherical structure uniformly dispersed on the g-C3N4 nanosheets and the close interface contact induced the generation of dual Z-scheme heterojunction. The as-prepared photocatalysts shown enhanced catalytic activity in comparison with binary Bi2MoO6/CeO2 composites and the optimal CBC-20% exhibited the highest degradation efficiency of 99.1% for 4-CP under 80 min illumination, which was attributed to the efficient separation of photogenerated e--h+ pairs under the dual Z-scheme charges transfer mode. Additionally, combined with trapping experiments and EPR analysis, 4-CP was decomposed mainly by the active species •O2- and h+ with a marginal assistance of •OH during the photocatalytic process. The intermediates for 4-CP degradation were analyzed and a reasonable degradation pathway was proposed.

14.
J Healthc Eng ; 2022: 9271879, 2022.
Article in English | MEDLINE | ID: mdl-35310191

ABSTRACT

Atherosclerosis is a chronic inflammatory disease of the arterial wall and the main cause of cardiovascular disease and cerebrovascular disease. In recent years, the mortality rate of atherosclerotic diseases has become higher and higher. This article aims to study the dysregulation of atherosclerotic vascular endothelial secretion and smooth muscle cell proliferation, and put forward and practice the pathological research of atherosclerotic disease. This article describes in detail atherosclerosis, endothelial dysfunction, and smooth muscle cell proliferation, and studies the causes of atherosclerosis. Research results indicate that atherosclerotic vascular endothelial dysfunction also has a great influence on the proliferation of smooth muscle cells. Many genes and environmental factors can regulate the functions of endothelial cells, vascular smooth muscle cells, and mononuclear macrophages and affect the formation of atherosclerosis. At the same time, diabetes, hypertension, hyperlipidemia, obesity, etc. are the main causes of atherosclerosis. The number of patients with cardiovascular and cerebrovascular diseases dying from atherosclerosis in the country is increasing, and the proportion is close to 30%.


Subject(s)
Atherosclerosis , Endothelial Cells , Atherosclerosis/pathology , Cell Proliferation , Humans , Myocytes, Smooth Muscle
15.
Nanoscale ; 12(2): 843-850, 2020 Jan 02.
Article in English | MEDLINE | ID: mdl-31830178

ABSTRACT

We demonstrated that heteroatomic nitrogen (N) doping of graphene can significantly enhance the performance of the graphene-palladium nanoparticle composite catalyst (N/G-Pd) in the electrocatalytic hydrodechlorination (EHDC) reaction. Specifically at -0.80 V (vs. Ag/AgCl), the N/G-430-Pd (prepared at 430 °C, pyridinic/pyrrolic-N-rich) and N/G-900-Pd (prepared at 900 °C, pyridinic/graphitic-N-rich) with equivalent total N content delivered the apparent rate constants (kobs) of 0.28 and 0.20 min-1 molPd-1 in removing 2,4-dichlorophenol, much higher than the 0.13 min-1 molPd-1 of the C-Pd. Additionally, we identified the determinant role of pyrrolic-N in boosting EHDC from the linear relationship between kobs-N and the pyrrolic-N content in the catalyst. Combined experimental and DFT analyses revealed that the positive effect of N doping originated from the strong N-Pd interactions, which modulated the Pd electronic structure and its interactions with the reactant and EHDC products (phenol and Cl-). The pyrrolic N-Pd bond was favorable as it could balance the reactant adsorption and the product desorption.

16.
J Hazard Mater ; 389: 121876, 2020 May 05.
Article in English | MEDLINE | ID: mdl-31874754

ABSTRACT

This work exploited one novel power of the Mott-Schottky heterojunction interface in activating the palladium (Pd) in electrocatalytic hydrodechlorination reaction (EHDC, one reaction targeted for the abatement of chlorinated organic pollutants from water). By forming a Mott-Schottky contact with polymer carbon nitride (Pd-PCN), the Pd nanoparticles enable a relatively complete and pseudo-first-order conversion of 2,4-dichlorophenol (2,4-DCP) to phenol and Cl- with the reaction rate constant (kobs) triple that of the conventional Pd-C (0.68 vs. 0.26 min-1 molPd-1). Further comparison in kobs of Pd-PCN and the Pd catalysts reported in literatures revealed that our Pd-PCN was among the top active catalysts for EHDC. The robust performance of Pd-PCN was attributed to the strong metal-support interactions at the Mott-Schottky heterojunction interface, which enriched the electron on Pd and improved its anti-poisoning ability against phenol. The strong support-metal interactions also endowed Pd-PCN with high activity/structure stability in EHDC. The presence of some anions in water body including NO3-, NO2- and Cl- exerted little effect on EHDC, while the reduced sulfur compounds (S2- and SO32-), even in a very low concentration (1 mM), could significantly deactivate the catalyst. This work provides a facile and efficient strategy to activate noble metals in catalytic reactions.

17.
Nanoscale ; 11(34): 15892-15899, 2019 Aug 29.
Article in English | MEDLINE | ID: mdl-31464326

ABSTRACT

Identifying the rate-determining step over the catalysts and clarifying the underlying mechanisms are crucial for maximizing the electrocatalytic hydrodechlorination (EHDC) efficiency for detoxification of the chlorophenol pollutants in water. Here, monodisperse palladium nanoparticles (Pd NPs) separately supported on carbon (C) and titanium nitride (TiN) were synthesized as two model catalysts. The support effects on EHDC efficiency, kinetics and current efficiency towards 2,4-dichlorophenol (2,4-DCP), and the electronic structure of Pd and its binding strengths with 2,4-DCP, phenol and Cl- (the primary EHDC product) were investigated by experimental and density functional theory (DFT) analyses. The low current efficiency (<30%) of both catalysts and the good description of EHDC kinetics by the Langmuir-Hinshelwood model suggest that the 2,4-DCP coverage on Pd, rather than the well-known adsorbed hydrogen generation, determines EHDC efficiency. Furthermore, the superior EHDC efficiency on TiN-Pd (96.4% vs. 80.9% on C-Pd), coupled with the weakened adsorption of 2,4-DCP and phenol on TiN-supported Pd, demonstrates that the 2,4-DCP coverage is largely influenced by phenol due to its poisoning effect by blocking active sites, and phenol desorption is the rate-determining step of EHDC on the catalyst. The support TiN enables alleviation of the phenol poisoning by modulating the electronic structure of Pd. The d band center of Pd can serve as a potential descriptor of EHDC efficiency, and its optimization for balancing 2,4-DCP and phenol adsorption should be an effective strategy to enhance EHDC.

18.
Insects ; 10(2)2019 Feb 03.
Article in English | MEDLINE | ID: mdl-30717472

ABSTRACT

Cold treatment at 0.0 °C with different exposure durations (0⁻12 days) was applied to the Mediterranean fruit fly Ceratitis capitata (Wiedemann) fed on a lab diet. The examined developmental stages were early eggs (<6 h), late eggs (>42 h), first instar, second instar and third instar larvae. Pupation, adult emergence and sex ratios of survived flies were investigated to study the C. capitata responses to this low temperature treatment. Our results showed that exposure time at low temperature has a clear effect on pupation and adult emergence. Based on pupation ratios, the first and third instar are the most cold tolerant stages, with LT99 = 7.3 for both of them. Cold tolerance at both stages are very close and no significant differences were detected. There were no significant differences on C. capitata sex ratios among different stages after treatment. This study improves our understanding of C. capitata responses to cold treatment, which may assist in the improvement of the current treatment strategies to control this destructive horticulture pest species.

19.
Environ Sci Technol ; 50(14): 7650-7, 2016 07 19.
Article in English | MEDLINE | ID: mdl-27322639

ABSTRACT

This work report a facile approach to efficiently separate surfactant-stabilized water (droplet diameter of around 2.0 µm) from water-in-oil emulsion via converting liquid water into solid crystal water followed by removal with centrifugation. The liquid-solid conversion is achieved through the solid-to-solid phase transition of calcium sulfate hemihydrate (CaSO4. 0.5H2O, HH) to dihydrate (CaSO4·2H2O, DH), which could immobilize the water into crystal lattice of DH. For emulsion of 10 mg mL(-1) water, the immobilization-separation process using polycrystalline HH nanoellipsoids could remove 95.87 wt % water at room temperature. The separation efficiency can be further improved to 99.85 wt % by optimizing the HH dosage, temperature, HH size and crystalline structure. Property examination of the recycled oil confirms that our method has neglectable side-effect on oil quality. The byproduct DH was recycled to alpha-HH (a valuable cemetitious material widely used in construction and binding field), which minimizes the risk of secondary pollution and promotes the practicality of our method. With the high separation efficiency, the "green" feature and the recyclability of DH byproduct, the HH-based immobilization-separation approach is highly promising in purifying oil with undesired water contamination.


Subject(s)
Calcium Sulfate/chemistry , Water/chemistry , Emulsions , Particle Size , Surface-Active Agents/chemistry
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