Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 46
Filter
1.
World J Clin Cases ; 12(5): 995-1003, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38414609

ABSTRACT

BACKGROUND: A solitary fibrous tumor (SFT) is often located in the pleura, while SFT of the pancreas is extremely rare. Here, we report a case of SFT of the pancreas and discuss imaging, histopathology, and immunohistochemistry for accurate diagnosis and treatment. CASE SUMMARY: A 54-year-old man presented to our hospital with pancreatic occupancy for over a month. There were no previous complaints of discomfort. His blood pressure was normal. Blood glucose, tumor markers, and enhanced computed tomography (CT) suggested a malignant tumor. Because the CT appearance of pancreatic cancer varies, we could not confirm the diagnosis; therefore, we performed endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). Pathology and immunohistochemistry were consistent with SFT of the pancreas. The postoperative pathology and immunohistochemistry were consistent with the puncture results. The patient presented for a follow-up examination one month after discharge with no adverse effects. CONCLUSION: Other diseases must be excluded in patients with a pancreatic mass that cannot be diagnosed. CT and pathological histology have diagnostic value for pancreatic tumors. Endoscopic puncture biopsy under ultrasound can help diagnose pancreatic masses that cannot be diagnosed preoperatively. Surgery is an effective treatment for SFT of the pancreas; however, long-term follow-up is strongly recommended because of the possibility of malignant transformation of the tumor.

2.
Bioresour Technol ; 382: 129189, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37196744

ABSTRACT

The ammonium and nitrate removal performance and metabolic pathways of a biocontrol strain, Pseudomonas fluorescens 2P24, were investigated. Strain 2P24 could completely remove 100 mg/L ammonium and nitrate, with removal rates of 8.27 mg/L/h and 4.29 mg/L/h, respectively. During these processes, most of the ammonium and nitrate were converted to biological nitrogen via assimilation, and only small amounts of nitrous oxide escaped. The inhibitor allylthiourea had no impact on ammonium transformation, and diethyl dithiocarbamate and sodium tungstate did not inhibit nitrate removal. Intracellular nitrate and ammonium were detectable during the nitrate and ammonium transformation process, respectively. Moreover, the nitrogen metabolism functional genes (glnK, nasA, narG, nirBD, nxrAB, nirS, nirK, and norB) were identified in the strain. All results highlighted that P. fluorescens 2P24 is capable of assimilatory and dissimilatory nitrate reduction, ammonium assimilation and oxidation, and denitrification.


Subject(s)
Ammonium Compounds , Pseudomonas fluorescens , Nitrates/metabolism , Ammonium Compounds/metabolism , Pseudomonas fluorescens/metabolism , Denitrification , Nitrogen , Metabolic Networks and Pathways
3.
Chaos ; 33(4)2023 Apr 01.
Article in English | MEDLINE | ID: mdl-37097939

ABSTRACT

Collective risk social dilemmas are at the heart of the most pressing global challenges we are facing today, including climate change mitigation and the overuse of natural resources. Previous research has framed this problem as a public goods game (PGG), where a dilemma arises between short-term interests and long-term sustainability. In the PGG, subjects are placed in groups and asked to choose between cooperation and defection, while keeping in mind their personal interests as well as the commons. Here, we explore how and to what extent the costly punishment of defectors is successful in enforcing cooperation by means of human experiments. We show that an apparent irrational underestimation of the risk of being punished plays an important role, and that for sufficiently high punishment fines, this vanishes and the threat of deterrence suffices to preserve the commons. Interestingly, however, we find that high fines not only avert freeriders, but they also demotivate some of the most generous altruists. As a consequence, the tragedy of the commons is predominantly averted due to cooperators that contribute only their "fair share" to the common pool. We also find that larger groups require larger fines for the deterrence of punishment to have the desired prosocial effect.


Subject(s)
Cooperative Behavior , Punishment , Humans , Game Theory , Altruism , Carbon
4.
Nutrients ; 15(4)2023 Feb 20.
Article in English | MEDLINE | ID: mdl-36839407

ABSTRACT

Cardiac ischaemia/reperfusion (I/R) injury causes cardiomyocyte apoptosis and mitochondrial dysfunction. Ursolic acid (UA), as a pentacyclic triterpenoid carboxylic acid, exerts several bioactivities in animal models of different diseases, but the preventive role of UA in I/R-induced myocardial dysfunction remains largely unknown. Male wild-type mice were pre-administered with UA at a dosage of 80 mg/kg i.p. and then subjected to cardiac I/R injury for 24 h. Cardiac function and pathological changes were examined by echocardiography and histological staining. The protein and mRNA levels of the genes were determined using qPCR and immunoblotting analysis. Our results revealed that UA administration in mice significantly attenuated the I/R-induced decline in cardiac function, infarct size, myocyte apoptosis, and oxidative stress. Mechanistically, UA increased three immunoproteasome catalytic subunit expressions and activities, which promoted ubiquitinated PP2A degradation and activated AMPK-PGC1α signalling, leading to improved mitochondrial biosynthesis and dynamic balance. In vitro experiments confirmed that UA treatment prevented hypoxia/reperfusion (H/R)-induced cardiomyocyte apoptosis and mitochondrial dysfunction through activation of AMPK signalling. In summary, our findings identify UA as a new activator of the immunoproteasome that exerts a protective role in I/R-induced myocardial dysfunction and suggest that UA supplementation could be beneficial for the prevention of cardiac ischaemic disease.


Subject(s)
Myocardial Reperfusion Injury , Male , Mice , Animals , Myocardial Reperfusion Injury/prevention & control , AMP-Activated Protein Kinases/metabolism , Signal Transduction/physiology , Mitochondria/metabolism , Apoptosis , Myocytes, Cardiac/metabolism , Ursolic Acid
5.
Front Microbiol ; 13: 982674, 2022.
Article in English | MEDLINE | ID: mdl-36312953

ABSTRACT

It is unknown whether nirBDs, which conventionally encode an NADH nitrite reductase, play other novel roles in nitrogen cycling. In this study, we explored the role of nirBDs in the nitrogen cycling of Pseudomonas putida Y-9. nirBDs had no effect on organic nitrogen transformation by strain Y-9. The △nirBD strain exhibited higher ammonium removal efficiency (90.7%) than the wild-type strain (76.1%; P < 0.05) and lower end gaseous nitrogen (N2O) production. Moreover, the expression of glnA (control of the ammonium assimilation) in the △nirBD strain was higher than that in the wild-type strain (P < 0.05) after being cultured in ammonium-containing medium. Furthermore, nitrite noticeably inhibited the ammonium elimination of the wild-type strain, with a corresponding removal rate decreasing to 44.8%. However, no similar impact on ammonium transformation was observed for the △nirBD strain, with removal efficiency reaching 97.5%. In conclusion, nirBDs in strain Y-9 decreased the ammonium assimilation and increased the ammonium oxidation to nitrous oxide.

6.
Comput Math Methods Med ; 2022: 3654181, 2022.
Article in English | MEDLINE | ID: mdl-35844443

ABSTRACT

Objective: To investigate the effect of a home care model on coping style and quality of life of patients with postcranial surgery complicated by epilepsy. Methods: One hundred and forty-four patients with postcranial surgery complicated by epilepsy admitted to our hospital from July 2017 to April 2018 were selected as study subjects and randomly divided into 63 cases each in the observation group and the control group. The control group was given nursing interventions including health education, psychological intervention, medication guidance, complication prevention, and follow-up management, while the observation group was jointly given collaborative family nursing interventions. At a follow-up of 6 months, indicators such as coping style, treatment compliance, and quality of life were compared between the two groups. Results: Patients in the observation group had significantly higher problem solving, help seeking, and rationalization scores and significantly lower self-blame scores than the control group (P < 0.01); significantly higher treatment compliance than the control group (P < 0.01); and significantly higher social functioning, emotional well-being, and energy/fatigue scores than the control group (P < 0.01). Conclusion: The home care model helps to promote the development of positive coping styles, improve treatment compliance, and improve the quality of life of patients after cranial surgery.


Subject(s)
Craniocerebral Trauma , Epilepsy , Home Care Services , Adaptation, Psychological , Epilepsy/therapy , Humans , Quality of Life/psychology
7.
Anal Chem ; 94(14): 5707-5714, 2022 04 12.
Article in English | MEDLINE | ID: mdl-35348336

ABSTRACT

An electrochemiluminescence (ECL) sensor provides a sensitive and convenient method for early diagnosis of diseases; however, it is still a challenge to develop simple and sensitive sensing platforms based on efficient ECL signals and luminophore groups. Porphyrin-based metal-organic frameworks (MOFs) show great potential in ECL sensing; however, the mechanism and structure-activity relationship, as well as application, are rarely reported. Herein, hydrothermal reactions obtained porphyrin Zr-MOFs (PCN-222) with different specific surface areas, pore sizes, structures, and surface charge states by tuning the reaction time were developed, which served both as the ECL luminophore, coreaction promoter for S2O82-, and a connection in the ECL immunoassay. By progressively controlling the condition of the hydrothermal reaction, PCN-222 with large surface area-abundant micropores can be obtained, which has good conductivity and positively charged surfaces, obtaining excellent ECL performance. The ECL performance and the enhancement mechanism were investigated in detail. Using PCN-222-6h with the best ECL intensity as the immobilization matrix for the aptamer, a highly sensitive and selective assay for thrombin was developed. The decrease of the ECL signal was logarithmically linear with the concentration of thrombin in the range from 50 fg mL-1 to 100 pg mL-1 with a low detection limit of 2.48 fg/mL. This proposed strategy provides a brand new approach for tuning of the structures of MOFs as effective ECL signal probes, thus providing wider possibilities for effective ECL immunoassays in the detection of other biomarkers in diagnosis of diseases.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , Metal-Organic Frameworks , Porphyrins , Electrochemical Techniques , Limit of Detection , Luminescent Measurements , Metal-Organic Frameworks/chemistry , Thrombin , Zirconium/chemistry
8.
IEEE Trans Neural Netw Learn Syst ; 32(10): 4374-4388, 2021 Oct.
Article in English | MEDLINE | ID: mdl-32903188

ABSTRACT

Composite function optimization problem often arises in machine learning known as regularized empirical minimization. We introduce the acceleration technique to the Newton-type proximal method and propose a novel algorithm called accelerated proximal subsampled Newton method (APSSN). APSSN only subsamples a small subset of samples to construct an approximate Hessian that achieves computational efficiency. At the same time, APSSN still keeps a fast convergence rate. Furthermore, we obtain the scaled proximal mapping by solving its dual problem using the semismooth Newton method instead of resorting to the first-order methods. Due to our sampling strategy and the fast convergence rate of the semismooth Newton method, we can get the scaled proximal mapping efficiently. Both our theoretical analysis and empirical study show that APSSN is an effective and computationally efficient algorithm for composite function optimization problems.

9.
Sci Rep ; 10(1): 10460, 2020 06 26.
Article in English | MEDLINE | ID: mdl-32591589

ABSTRACT

We aimed to reveal clinicopathological features and explore survival-related factors of colorectal signet ring cell carcinoma (SRCC). A population-based study was carried out to investigate colorectal SRCC by using data extracted from the surveillance, epidemiology and end results (SEER) database between 2004 and 2015. In total, 3,278 patients with colorectal SRCC were identified, with a median age of 63 (12-103) years old. The lesions of most patients (60.49%) were located in the cecum-transverse colon. In addition, 81.27% patients had advanced clinical stage (stage III/IV), and 76.69% patients had high pathological grade. The 3-, 5-year cancer-specific survival and overall survival rate was 35.76%, 29.32% and 32.32%, 25.14%. Multivariate analysis revealed that primary site in cecum-transverse colon, married, received surgery, lymph node dissections ≥ 4 regional lymph nodes were independent favorable prognostic. Meanwhile, aged ≥ 65 years, higher grade, tumor size ˃5 cm and advanced AJCC stage were associated with poor prognosis. Patient age, tumor grade, marital status, tumor size, primary tumor location, AJCC stage, surgery and number of dissected lymph node had significant correlation with prognosis of colorectal SRCC.


Subject(s)
Carcinoma, Signet Ring Cell/mortality , Carcinoma, Signet Ring Cell/pathology , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Lymphatic Metastasis/pathology , Male , Middle Aged , Neoplasm Grading/methods , Prognosis , Retrospective Studies , SEER Program , Survival Rate , Young Adult
10.
Viruses ; 12(4)2020 04 01.
Article in English | MEDLINE | ID: mdl-32244654

ABSTRACT

High-throughput approaches have opened new opportunities for understanding biological processes such as persistent virus infections, which are widespread. However, the potential of persistent infections to develop towards pathogenesis remains to be investigated, particularly with respect to the role of host metabolism. To explore the interactions between cellular metabolism and persistent/pathogenic virus infection, we performed untargeted and targeted metabolomic analysis to examine the effects of Cricket paralysis virus (CrPV, Dicistroviridae) in persistently infected silkworm Bm5 cells and acutely infected Drosophila S2 cells. Our previous study (Viruses 2019, 11, 861) established that both glucose and glutamine levels significantly increased during the persistent period of CrPV infection of Bm5 cells, while they decreased steeply during the pathogenic stages. Strikingly, in this study, an almost opposite pattern in change of metabolites was observed during different stages of acute infection of S2 cells. More specifically, a significant decrease in amino acids and carbohydrates was observed prior to pathogenesis, while their abundance significantly increased again during pathogenesis. Our study illustrates the occurrence of diametrically opposite changes in central carbon mechanisms during CrPV infection of S2 and Bm5 cells that is possibly related to the type of infection (acute or persistent) that is triggered by the virus.


Subject(s)
Bombyx/metabolism , Carbon/metabolism , Dicistroviridae/pathogenicity , Drosophila/metabolism , Host-Pathogen Interactions , Metabolome , Animals , Bombyx/cytology , Bombyx/virology , Cell Line , Cytopathogenic Effect, Viral , Dicistroviridae/physiology , Drosophila/cytology , Drosophila/virology , Virus Replication
11.
Chemosphere ; 242: 125203, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31678848

ABSTRACT

Insect glutathione S-transferases (GSTs) are important in insecticide detoxification and Insect-specific GSTs, Epsilon and Delta, have largely expanded in insects. In this study, we functionally expressed and characterized an epsilon class GST gene (BdGSTe8), predominant in the adult Malpighian tubules of Bactrocera dorsalis. This gene may be associated with malathion resistance based on transcriptional studies of resistant and susceptible strains. RNA interference-mediated knockdown of this gene significantly recovered malathion susceptibility in the adults of a malathion-resistant strain, and overexpression of BdGSTe8 enhanced resistance in transgenic Drosophila. Analysis of BdGSTe8 polymorphism showed that several point mutations may be associated with metabolic resistance to malathion. A cytotoxicity assay in Escherichia coli indicated that both of the recombinant BdGSTe8 proteins may play a functional role in protecting cells from toxicity. The allele of BdGSTe8-B conferred higher levels of malathion detoxification capability. Liquid chromatography and ultra-performance liquid chromatography-tandem mass spectrometry analysis showed that the BdGSTe8-A allele did not metabolize malathion directly. However, the BdGSTe8-B allele was involved in the direct metabolism of malathion, which was caused by a mutation in V128A. Further analysis of the sequence suggests that BdGSTe8 evolved rapidly. It maybe play the role of a backup gene and could become a new gene in the future in order to retain the ability of detoxification of malathion, which was driven by positive selection. These results suggest that divergent molecular evolution in BdGSTe8 has played a role in metabolic resistance to malathion in B. dorsalis.


Subject(s)
Evolution, Molecular , Glutathione Transferase/metabolism , Insecticide Resistance/genetics , Malathion/pharmacology , Tephritidae/drug effects , Animals , Animals, Genetically Modified , Drosophila/drug effects , Drosophila/genetics , Drosophila/physiology , Glutathione Transferase/genetics , Inactivation, Metabolic/genetics , Insecticides/pharmacology , Malathion/metabolism , Tephritidae/genetics , Tephritidae/physiology
12.
Viruses ; 11(9)2019 09 16.
Article in English | MEDLINE | ID: mdl-31527462

ABSTRACT

How a host metabolism responds to infection with insect viruses and how it relates to pathogenesis, is little investigated. Our previous study observed that Cricket paralysis virus (CrPV, Dicistroviridae) causes short term persistence in silkworm Bm5 cells before proceeding to acute infection. In this study, a metabolomics approach based on high resolution mass spectrometry was applied to investigate how a host metabolism is altered during the course of CrPV infection in Bm5 cells and which changes are characteristic for the transition from persistence to pathogenicity. We observed that CrPV infection led to significant and stage-specific metabolic changes in Bm5 cells. Differential metabolites abundance and pathway analysis further identified specific metabolic features at different stages in the viral life cycle. Notably, both glucose and glutamine levels significantly increased during CrPV persistent infection followed by a steep decrease during the pathogenic stages, suggesting that the central carbon metabolism was significantly modified during CrPV infection in Bm5 cells. In addition, dynamic changes in levels of polyamines were detected. Taken together, this study characterized for the first time the metabolic dynamics of CrPV infection in insect cells, proposing a central role for the regulation of both amino acid and carbohydrate metabolism during the period of persistent infection of CrPV in Bm5 cells.


Subject(s)
Bombyx/virology , Dicistroviridae/pathogenicity , Host-Pathogen Interactions , Metabolomics , Amino Acids/metabolism , Animals , Bombyx/cytology , Carbohydrate Metabolism , Carbon/metabolism , Cell Line , Glucose/metabolism , Glutamine/metabolism , Mass Spectrometry , Polyamines/metabolism , Viral Proteins/genetics , Virus Replication
13.
Elife ; 82019 05 14.
Article in English | MEDLINE | ID: mdl-31084703

ABSTRACT

Early adverse experiences often have devastating consequences. However, whether preweaning paternal deprivation (PD) affects emotional and social behaviors and their underlying neural mechanisms remain unexplored. Using monogamous mandarin voles, we found that PD increased anxiety-like behavior and attenuated social preference in adulthood. PD also decreased the number of oxytocin (OT)-positive neurons projecting from the paraventricular nucleus (PVN) and reduced the levels of the medial prefrontal cortex OT receptor protein in females and of the OT receptor and V1a receptor proteins in males. Intra-prelimbic cortical OT injections reversed the PD-induced changes in anxiety-like behavior and social preferences. Optogenetic activation of the prelimbic cortex OT terminals from PVN OT neurons reversed the PD-induced changes in emotion and social preference behaviors, whereas optogenetic inhibition was anxiogenic and impaired social preference in naive voles. These findings demonstrate that PD increases anxiety-like behavior and attenuates social preferences through the involvement of PVN OT neuron projections to the prelimbic cortex.


Subject(s)
Anxiety , Neural Pathways/anatomy & histology , Paraventricular Hypothalamic Nucleus/anatomy & histology , Paternal Deprivation , Social Behavior , Animals , Arvicolinae , Female , Male , Neurons/chemistry , Receptors, Oxytocin/analysis , Receptors, Vasopressin/analysis
14.
Sci Rep ; 8(1): 14180, 2018 09 21.
Article in English | MEDLINE | ID: mdl-30242291

ABSTRACT

The aim is to determine whether there is an independent association between Hp infection and carotid intima-media thickness (CIMT) in a cross-section observational study. Among of 14588 routine health check-up participants, 13770 subjects underwent the 13C-urea breath test (13C-UBT) and ultrasound measurement of CIMT. Traditional atherosclerotic risk factors were also recorded. The ratio of increased CIMT in Hp positive group (28.6%) was not significant difference compared with Hp negative group (29.7%) (p = 0.164). The HP infection rates was no significant difference between increased CIMT (38.4%) and non- increased CIMT (39.7%) patients. However, all the traditional atherosclerotic risk factors including age, gender, BMI, waistline, total cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, free fatty acid, homocysteine, systolic and diastolic blood pressure, fasting plasma glucose and C reactive protein were different between increased CIMT and non- increased CIMT participants. The odds of Hp infection for CIMT risk (OR 0.948; 95% CI 0.879-1.022; P = 0.164) was not higher in binary logistic regression analysis even after adjustment for traditional risk factors (OR 1.118; 95% CI 0.958-1.306; P = 0.157). Our study found no evidence of association between CIMT and HP infection.


Subject(s)
Carotid Artery Diseases/etiology , Carotid Artery Diseases/physiopathology , Helicobacter Infections/complications , Helicobacter Infections/physiopathology , Atherosclerosis/blood , Atherosclerosis/etiology , Atherosclerosis/metabolism , Atherosclerosis/physiopathology , C-Reactive Protein/metabolism , Carotid Artery Diseases/blood , Carotid Artery Diseases/metabolism , Carotid Intima-Media Thickness , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Cholesterol, VLDL/blood , Cross-Sectional Studies , Female , Helicobacter Infections/blood , Helicobacter Infections/metabolism , Helicobacter pylori/pathogenicity , Humans , Male , Middle Aged , Risk Factors , Triglycerides/blood
15.
Article in English | MEDLINE | ID: mdl-28697978

ABSTRACT

There are many evidences that insect carboxylesterase possess important physiological roles in xenobiotic metabolism and are implicated in the detoxification of organophosphate (OP) insecticides. Despite the ongoing resistance development in the oriental fruit fly, Bactrocera dorsalis (Hendel), the molecular basis of carboxylesterase and its ability to confer OP resistance remain largely obscure. This study was initiated to provide a better understanding of carboxylesterase-mediated resistance mechanism in a tephritid pest fly. Here, we narrow this research gap by demonstrating a well-conserved esterase B1 gene, BdB1, mediates malathion resistance development via gene upregulation with the use of a laboratory selected malathion-resistant strain (MR) of B. dorsalis. No sequence mutation of BdB1 was detected between MR and the susceptible strain (MS) of B. dorsalis. BdB1 is predominantly expressed in the midgut, a key insect tissue for detoxification. As compared with transcripts in MS, BdB1 was significantly more abundant in multiple tissues in the MR. RNA interference (RNAi)-mediated knockdown of BdB1 significantly increased malathion susceptibility. Furthermore, heterologous expression along with cytotoxicity assay revealed BdB1 could probably have the function of malathion detoxification.


Subject(s)
Esterases/metabolism , Insecticide Resistance/genetics , Malathion/pharmacology , Tephritidae/enzymology , Amino Acid Sequence , Animals , Esterases/genetics , Gene Expression Regulation, Enzymologic , Insecticides/pharmacology , Phylogeny , RNA Interference
16.
Waste Manag ; 67: 20-26, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28578857

ABSTRACT

Surface treatment with Fenton was applied to flotation separation of acrylonitrile-butadienestyrene (ABS) and polyvinylchloride (PVC). After treatment, the floatability of ABS has a dramatic decrease, while the floatability of PVC is not affected. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra were recorded to ascertain the mechanism of Fenton treatment. FT-IR and XPS analysis confirms that the introduction of oxygen-containing group occurs on the surface of ABS. The optimum conditions are molar ration (H2O2:Fe2+) 10000, H2O2 concentration 0.4M/L, pH 5.8, treatment time 2min and temperature 25°C, frother concentration 15mg/L and flotation time 3min. Particle sizes and mixing ratios were also investigated. Plastic mixtures of ABS and PVC with different particle sizes and mixing ratios can be effectively separated. The purity of ABS and PVC are up to 100% and 99.78%, respectively; the recovery of ABS and PVC are up to 99.89% and 100%, respectively. A practical, environmentally friendly and effective reagent, namely Fenton, was originally applied to surface treatment of ABS and PVC waste plastics for flotation separation of their mixtures.


Subject(s)
Acrylonitrile , Butadienes , Plastics , Styrene , Hydrogen Peroxide , Refuse Disposal , Spectroscopy, Fourier Transform Infrared
17.
Waste Manag ; 65: 3-10, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28400158

ABSTRACT

A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO4) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO4 concentration 2mmolL-1, treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL-1. Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO4 solution is feasible, enabling the process greener.


Subject(s)
Plastics , Polyvinyl Chloride , Polycarboxylate Cement , Polymethyl Methacrylate , Water Purification
19.
Pestic Biochem Physiol ; 130: 44-51, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27155483

ABSTRACT

Extensive use of insecticides in many orchards has prompted resistance development in the oriental fruit fly, Bactrocera dorsalis (Hendel). In this study, a laboratory selected strain of B. dorsalis (MR) with a 21-fold higher resistance to malathion was used to examine the resistance mechanisms to this organophosphate insecticide. Carboxylesterase (CarE) was found to be involved in malathion resistance in B. dorsalis from the synergism bioassay by CarE-specific inhibitor triphenylphosphate (TPP). Molecular studies further identified a previously uncharacterized α-esterase gene, BdCarE2, that may function in the development of malathion resistance in B. dorsalis via gene upregulation. This gene is predominantly expressed in the Malpighian tubules, a key insect tissue for detoxification. The transcript levels of BdCarE2 were also compared between the MR and a malathion-susceptible (MS) strain of B. dorsalis, and it was significantly more abundant in the MR strain. No sequence mutation or gene copy changes were detected between the two strains. Functional studies using RNA interference (RNAi)-mediated knockdown of BdCarE2 significantly increased the malathion susceptibility in the adult files. Furthermore, heterologous expression of BdCarE2 combined with cytotoxicity assay in Sf9 cells demonstrated that BdCarE2 could probably detoxify malathion. Taken together, the current study bring new molecular evidence supporting the involvement of CarE-mediated metabolism in resistance development against malathion in B. dorsalis and also provide bases on functional analysis of insect α-esterase associated with insecticide resistance.


Subject(s)
Carboxylesterase/genetics , Genes, Insect/genetics , Insecticide Resistance/genetics , Malathion/metabolism , Tephritidae/genetics , Animals , Carboxylesterase/metabolism , Gene Knockdown Techniques , Phylogeny , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Tephritidae/drug effects , Tephritidae/enzymology
20.
Sci Rep ; 6: 23952, 2016 Apr 11.
Article in English | MEDLINE | ID: mdl-27063294

ABSTRACT

The network control problem has recently attracted an increasing amount of attention, owing to concerns including the avoidance of cascading failures of power-grids and the management of ecological networks. It has been proven that numerical control can be achieved if the number of control inputs exceeds a certain transition point. In the present study, we investigate the effect of degree correlation on the numerical controllability in networks whose topological structures are reconstructed from both real and modeling systems, and we find that the transition point of the number of control inputs depends strongly on the degree correlation in both undirected and directed networks with moderately sparse links. More interestingly, the effect of the degree correlation on the transition point cannot be observed in dense networks for numerical controllability, which contrasts with the corresponding result for structural controllability. In particular, for directed random networks and scale-free networks, the influence of the degree correlation is determined by the types of correlations. Our approach provides an understanding of control problems in complex sparse networks.

SELECTION OF CITATIONS
SEARCH DETAIL
...