Residual Problems Research Articles

Comparative effectiveness of biorational pesticides for management of Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams & Granara de Willink in Gymnema sylvestre (Retz.) R.Br. ex Sm

The cotton mealybug, Phenacoccus solenopsis Tinsley and papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) are becoming major threats to the production of Gymnema sylvestre R. Br. (Asclepiadaceae) in India. Management mainly depends on chemical insecticides which cause a serious problem of pesticide residue and insecticide resistance. The use of biorational insecticides such as biopesticides, botanicals, insect growth regulators, and microbial insecticides is important components of an Integrated Pest Management (IPM) program for successful management. We evaluated the bio-efficacy of twelve biorational insecticides, including entomopathogenic fungi (EPF), using the leaf spray method in laboratory conditions at 25 ± 1 °C, 70 % ± 5 % RH. The results revealed that the highest percent mortality was recorded by acetamiprid 20 % SP (100.00 %), followed by azadirachtin (98.27 %), Lecanicillium muscarium (2 × 109 spores/mL) (85.70 %) and Ocimum sanctum leaf extract (76.87 %) at 120 h after treatment (HAT) in P. solenopsis. In P. marginatus, 100.00 %, 96.39 % and 85.67 % and 74.90 % mortalities were achieved by acetamiprid 20 % SP, azadirachtin, L. muscarium (2 × 109 spores/mL) and O. sanctum leaf extract, respectively, at 120 HAT during the first spray. Various biorational insecticides showed a more or less similar trend of percent mortality in both species during the second spray. In both species, the lowest percent mortality was recorded by Andrographis paniculata leaf extract (46.29, 44.54) and (41.03, 46.39) at 120 Hours after treatment in the first and second spray, respectively. It was concluded that all the prescribed treatments are more effective than the control. Overall, azadirachtin recorded the highest percent mortality after acetamiprid and had the shortest LT50 (12.52 h) and (13.87 h) values in P. solenopsis and P. marginatus, respectively. Our study emphasizes that biopesticides like Azadirachtin 1 % EC (10000 ppm), L. muscarium (2 × 109 spores/mL) (5 mL/L) and O. sanctum leaf extract (5 %) may be recommended as alternatives to synthetic insecticides. Botanicals and EPF would be the most effective approach for sustainable integrated management of P. solenopsis and P. marginatus in the G. sylvestre ecosystem.

Antibacterial Activity of Neutral Electrolyzed Water Against Listeria Monocytogenes

Inadequate cleaning and disinfection processes in the food industry are major causes of foodborne infections. Therefore, an effective cleaning process is essential for food production areas. Traditional disinfectants in the food industry have side effects like corrosion, irritation, toxicity, and residue problems. Therefore, electrolyzed water has become increasingly popular as an effective disinfectant in the food industry. Neutral electrolyzed water (NEW) contains hypochlorous acid and hypochlorite to effectively inactivate pathogens and has been proven to be stable. Listeria monocytogenes, a common foodborne pathogen, can be found throughout the food production chain in different points and conditions. This study examined the antimicrobial effect of NEW on Listeria monocytogenes at different concentrations, exposure times, and in vitro conditions. To assess the effectiveness of NEW, 0.1 %, 5 %, 10 %, 50 %, and 90 % concentrations were prepared, and the inactivation treatment was carried out for 30, 60, 90, and 120 min at room temperature. The results showed that at concentrations of 10 %, 50 %, and 90 %, the disinfectant significantly reduced the number of Listeria monocytogenes to undetectable levels within 30 minutes. However, about 1 log10 reduction was achieved at 0.1 % concentration in all applied times. This study reveals that NEW is highly effective for inactivating L. monocytogenes and should be used more in the food industry. In conclusion that NEW is a safe, environmentally friendly, and not harmful to food quality alternative to traditional disinfectants in the food industry, and recommended its increased use.

A hybrid WUDT-NAFnet for simultaneous source data deblending

Simultaneous source technology, which reduces seismic survey time and improves the quality of seismic data by firing more than one source with a narrow time interval, is compromised by the massive blended interference. Therefore, deblending algorithms have been developed to separate this interference. Recently, deep learning (DL) has been proved its great potential in suppressing the interference. The most popular DL method employs neural network as a filter to attenuate the blended noise in an iterative estimation and subtraction framework (IESF). However, there are still amplitude distortion and blended noise residual problems, especially when dealing with weak signal submerged in strong interference. To address these problems, we propose a hybrid WUDT-NAFnet, which contains two sub-networks. The first network is a wavelet based U-shape deblending transformer network (WUDTnet), incorporated into IESF as a robust regularization term to iteratively separate the blended interference. The second network is a nonlinear activate free network (NAFnet) designed to recover the event amplitude and further suppress the weak noise residual in IESF. With the hybrid network, the blended noise can be separated purposefully and accurately. Examples using synthetic and field seismic data demonstrate that the WUDT-NAFnet outperforms traditional curvelet transform (CT) based method and the deblending transformer (DT) model in terms of deblending. Additionally, for field applications, the data augmentation method of bicubic interpolation is applied to mitigate the feature difference between synthetic and field data. Consequently, the trained network exhibits strong signal preservation ability in numerical field example without requiring additional training.

A parallel finite element post-processing algorithm for the damped Stokes equations

This paper presents and analyzes a parallel finite element post-processing algorithm for the simulation of Stokes equations with a nonlinear damping term, which integrates the algorithmic advantages of the two-level approach, the partition of unity method and post-processing technique. The most valuable highlights of the present algorithm are that (1) a global continuous approximate solution is generated via the partition of unity method; (2) by adding an extra coarse grid correction step, the smoothness of the approximate solution is improved; (3) it has a good parallel performance since there requires little communication in solving a series of residual problems in the subdomain of interest. We theoretically derive the L2-error estimates both for the approximate velocity and pressure and H1-error estimate for the velocity under some necessary conditions. Meanwhile, we numerically perform various test examples to validate the theoretically predicted convergence rate and illustrate the high efficiency of the proposed algorithm.

A study of NoSQL query injection in Neo4j

Query injection refers to a class of attack types that involve the insertion of maliciously crafted query parameters in database query operations, and/or API calls. Although these security issues have been studied extensively in relational databases, the possibility and incidence of injection in NoSQL data stores –which are built around fundamentally different data models– has received less attention.In this article, we present the outcomes of an in-depth investigation of the injection-related risks in the Neo4j graph database and its broader ecosystem. This study is based on (i) an investigation of the distributed execution of parameterized queries, from language-specific client connectors, to communication (Bolt protocol) and execution in Neo4j (in query plans), and (ii) identifying residual injection problems in cases where parameterized, static queries will not suffice. The study involves code-centric data flow investigation of the Neo4j code base, and is complemented with a test suite of injection test cases.We found that (i) the mechanism of query parameterization as promoted by Neo4j is effective in mitigating traditional query injection threats, and (ii) traditional query injection attacks however remain possible when this approach is not adopted, which is realistic for applications that necessarily involve dynamic, run-time query construction (e.g., analytics pipelines).

The clinical prognosis of elderly patients with decompensated congestive heart failure greatly improved for 7 years after introduction of our unique clinical pathway

Abstract Background In Japan, especially in rural areas where our facility is located, the number of elderly decompensated congestive heart failure(DCHF) cases is increasing remarkably. Their hospitalization period tends to prolonged due to various complications peculiar to the elderly, and after discharge, they often admit in a short period with DCHF. In August 2015, we introduced the clinical pathway (PATH), which stipulates the efficient medical care for DCHF and comprehensive patient education by multidisciplinary staff. We have previously reported its effect about wide shortening of mean hospitalization period and significant reduction of rehospitalization in CHF patients admitted to our hospital. Purpose In this study, we re-examined the short-term and long-term clinical effects of PATH in elderly DCHF patients for 7 years, and also considered the residual problems about them. Methods We enrolled 929 DCHF cases (1128 admissions) aged 75 years or older who ware admitted to our hospital from April 2014 to July 2022. We divided them into two groups: 152 cases(199 admissions) admitted before the introduction of PATH (N-group) and 667 cases(929 admissions) applied PATH (P-group). About two groups we compared the acute care situation for DCHF, mean hospitalization period(HP), and DCHF readmission rate within 1 year after discharge(RA). Results The mean age of the P-group was slightly older. There were no significant differences between the two groups in the living conditions before admission, the proportion of each underlying disease or clinical data at admission. The performance rate of each treatment procedure in the acute phase was lower, and these performance period ware all shorter in P-group. The introduction rate of cardiac rehabilitation was higher and start timing was earlier in P-group. (Figure1) As a result, HP was significantly shorter), and the RA rate was lower in P-group. However, even in P-group, the cases who could not be discharged from the hospital to home(OTHER-group) took more time to adjust for hospital transfer or nursing home admission, so their HP was longer than that of the cases who could be directly discharged to home(HOME-group). And the RA rate of cases with past history of hospitalization for DCHF(PH-group) was higher than that of cases without history(NPH- group). (Figure2) Conclusion In the 7 years after the introduction of unique clinical pathway for acute phase treatment of decompensated congestive heart failure, even in elderly patients, it confirmed that each acute phase treatment had become more efficient, and the mean hospitalization period had been widely shortened. In addition, comprehensive lifestyle guidance to prevent worsening of their condition has seemed to reduce the rehospitalization rate for heart failure after discharge. However, we also confirmed f a few residual problems to be solved about the cases who could not discharged at home for any reason or repeated re-admission for heart failure.Figure 2

Star polymer soil delivery nanoplatform for applying biological agents in the field to control plant rhizosphere diseases

As the main cause of destructive plant diseases, pathogenic oomycete in plant rhizosphere brings about enormous losses to agricultural production. Although chemical pesticides are still one of the most important prevention and control methods for phytopathogens, the usage of chemical pesticides was limited by the 3R (resistance, residue, and rampant) problem. In the early stage of our research, analysis and comparison of the metabolome of resistance to Phytophthora nicotianae and common strain suggested that naringenin might be a highly efficient potential biogenic antimicrobial agent to prevent and control soil rhizosphere diseases. Unfortunately, the bioactivity and absorption capacity of active ingredients in the environment made it unsuitable for field application; thus, for efficient field application of naringenin, the 24 nm-sized naringenin-loaded nano-star-shaped polymerized (NSPs) were prepared with good loading efficiency 37.3% for naringenin. The soil mobility test indicated that NSPs could effectively reduce the adsorption of active ingredients and enhance the mobility of active ingredients in soil. The bacteriostatic test proved that these NSPs had better antimicrobial activity than the naringenin used alone and could efficiently induce the expression of plant resistance phenylpropanoid compounds. Finally, pot and field experiments showed improved control efficiency of NSPs 41% loaded with naringenin. Transcriptome analysis found that a large number of energy-related genes were downregulated in NSPs nematodes, suggesting that disturbed energy-related genes might lead to the disturbance of energy synthesis and metabolism. Naringenin-loaded nano-carriers were used to prevent and control plant disease-causing pathogens in the rhizosphere, which is of great significance to improve the prevention and control effect and reduce the environmental load of these anti-pathogenic agents.

Recycling of hazardous jarosite residues based on hydrothermal crystal transformation

Jarosite [MeFe3(SO4)2(OH)6] is a typical non-ferrous smelting slag produced in the process of iron removal from hydrometallurgical solution, which contains a large number of valuable and toxic metal elements. Treating the complex and hazardous jarosite residue in an economically and environmentally sound way has always been an urgent problem. A novel one-step hydrothermal treatment method was proposed in this paper for recycling of jarosite residues. It can be seen from the XRD and TEM results that jarosite residues could be completely transformed into hematite crystal particles under hydrothermal conditions at temperature above 220℃. Meanwhile, other valuable metal components (such as nickel sulfate hexahydrate) entrained in the residue will be dissolved in the aqueous solution, which can be reused in the hydrometallurgical process. Through phase composition analysis of the hydrothermal process, it is concluded that jarosite was firstly pyrolyzed to generate Fe3+. The obtained Fe3+ was then hydrolyzed to Fe (OH)3, which was transformed into Fe2O3 through dehydration condensation and directional arrangement. Further roasting the hematite particles, the obtained product contained 62.57 % of Fe, but only 0.21 % of S and 0.04 % of As, which meets the requirements of raw materials for iron making. In addition, compared with the current international standard ISO 1248:2006 (E), the obtained hematite particles with nanometer size and single crystal structure can be used as iron oxide red pigment. Overall, the one-step hydrothermal treatment of jarosite residues followed by reduction roasting not only realizes the economic recycling of the metal resources, but also solves the stacking problem of those hazardous residues.

Preparation of hypercrosslinked porous polymer with manifold functional groups for sensitive determination of phenylurea herbicides in beverages and celtuce samples.

Wide use of phenylurea herbicide has caused serious residue problem and threaten human health. It is important to develop viable method for their sensitive determination. Herein, a multi-functionalized porous polymer was prepared by crosslinking hexafluorobisphenol A with pyromellitic dianhydride. Using the multi-functionalized porous polymer as solid phase extraction sorbent, combined with high performance liquid chromatography, a sensitive method was established for determining phenylurea herbicides in beverages and celtuces. High sensitivity was achieved, with method detection limit (S/N=3) of 0.01---0.025ngmL-1 for beverages, 1.70ngg-1 for celtuce, and quantitation limits of 0.03---0.10ngmL-1 for beverages, 5.00ngg-1 for celtuce. The method recoveries were 80.5---120.0 % with relative standard deviations lower than 6.1%. Adsorption mechanism mainly involved F-π, F-O, π-π, polar interactions and hydrogen-bonding interactions. This study offers a simple protocol to develop multi-functional sorbents for extraction of organic pollutants.

Immunoassay for the detection of cyproconazole in foods: From hapten synthesis to the establishment of a gold immunochromatographic assay

Cyproconazole (CPZ) is extensively used in agricultural production. However, its overuse can lead to high residue problems in crops. Existing detection methods are still dominated by instrumental methods and the development of rapid, sensitive field detection remains a challenge. In this study, we designed a novel hapten synthetic pathway and prepared a monoclonal antibody (mAb) that could specifically recognize CPZ with high sensitivity (half inhibition rate was 0.27 ng/mL). From this, a gold immunochromatographic assay (GICA) for the detection of CPZ was established by combining the mAb with gold nanoparticles, with limits of detection in rice, tomatoes and grapes of 0.02 mg/kg, 0.01 mg/kg and 0.05 mg/kg, respectively. The spiked recoveries ranged from 86.5 % to 115.1 %, and the results showed that the GICA was not significantly different from detection using LC-MS/MS. Therefore, we have successfully developed a GICA method for the reliable in situ, rapid and sensitive detection of CPZ.

Minimal residual methods in negative or fractional Sobolev norms

For numerical approximation the reformulation of a PDE as a residual minimisation problem has the advantages that the resulting linear system is symmetric positive definite, and that the norm of the residual provides an a posteriori error estimator. Furthermore, it allows for the treatment of general inhomogeneous boundary conditions. In many minimal residual formulations, however, one or more terms of the residual are measured in negative or fractional Sobolev norms. In this work, we provide a general approach to replace those norms by efficiently evaluable expressions without sacrificing quasi-optimality of the resulting numerical solution. We exemplify our approach by verifying the necessary inf-sup conditions for four formulations of a model second order elliptic equation with inhomogeneous Dirichlet and/or Neumann boundary conditions. We report on numerical experiments for the Poisson problem with mixed inhomogeneous Dirichlet and Neumann boundary conditions in an ultra-weak first order system formulation.

Patient reported symptoms and disabilities before and after neuroma surgery: a register-based study

Residual problems may occur from neuroma despite surgery. In a 12-month follow-up study using national register data, symptoms, and disabilities related to surgical methods and sex were evaluated in patients surgically treated for a neuroma. Among 196 identified patients (55% men; lower age; preoperative response rate 20%), neurolysis for nerve tethering/scar formation was the most used surgical method (41%; more frequent in women) irrespective of affected nerve. Similar preoperative symptoms were seen in patients, where different surgical methods were performed. Pain on load was the dominating symptom preoperatively. Women scored higher preoperatively at pain on motion without load, weakness and QuickDASH. Pain on load and numbness/tingling in fingers transiently improved. The ability to perform daily activities was better after nerve repair/reconstruction/transposition than after neurolysis. Regression analysis, adjusted for age, sex, and affected nerve, showed no association between surgical method and pain on load, tingling/numbness in fingers, or ability to perform daily activities. Neuroma, despite surgery, causes residual problems, affecting daily life. Choice of surgical method is not strongly related to pre- or postoperative symptoms. Neurolysis has similar outcome as other surgical methods. Women have more preoperative symptoms and disabilities than men. Future research would benefit from a neuroma-specific ICD-code, leading to a more precise identification of patients.

Molecularly imprinted poly(o-phenylenediamine) coated ZIF-5-Ru(bpy)32+ composite for the sensitive and selective ECL detection of tetracycline

The widespread use of tetracycline unavoidably causes residue problems, hence its monitor in foods and environment is important. In this work, a simple but sensitive electrochemiluminescence (ECL) sensor is prepared for tetracycline detection. The sensor is constructed using TiO2 nanoparticle, ZIF-5 loaded Ru(bpy)32+ (Ru@ZIF-5), and molecularly imprinted poly-o-phenylenediamine. The TiO2 NP acts as a co-reaction accelerator for tri-n-propylamine (TPrA) by producing electrons and holes at a certain potential to promote the production of TPrA. ZIF-5 has a large specific surface area and rich functional groups, thus can well immobilize a large amount of illuminant Ru(bpy)32+. The electrodeposited molecularly imprinted polymer acts as a recognition element. Due to the synergic effect of different components, the resulting ECL sensor shows a wide linear range of 10 nM–50 μM, high selectivity, low detection limit, and good stability. It can be used for the detection of tetracycline in food and environmental samples.

The effects of Beauveria bassiana infection on the gene expression profiles of Diaphorina citri adults

The Asian citrus psyllid, Diaphorina citri Kuwayama, is a citrus pest worldwide. This pest transmits the pathogens of Huanglongbing, Candidatus Liberibacter asiaticus (CLas), and has led to huge economic losses. The use of chemical pesticides is the first choice for field pest control, while resistance, resurgence, and residue (3R) problems have received widespread attention. Biological control is an optional and effective method for D. citri management and needs to be developed. In this study, eleven entomopathogenic fungi strains were collected, and their morphologies were recorded. After blasting with the ITS sequences, eight strains were identified as Beauveria bassiana, and three strains were Metarhizium anisopliae. The pathogenicity of these fungi on D. citri adults at 1.0 × 107 conidia/mL was tested, with the LT50 ranging from 4.764 to 8.551. The virulence of B. bassiana strain XM-D1 was further evaluated, and the LC50 was 4.93 × 105 conidia/mL. A total of 155 and 894 differentially expressed genes (DEGs) were identified in the samples after 24 and 48 h of XM-D1 infection, respectively. Further analyses found that the pathways of apoptosis, cholesterol metabolism, fatty acid biosynthesis, and vitamin digestion and absorption could be involved in the response of D. citri adults to 48 h of infection, and DEGs encoding chaperone proteins, cuticle protein 12.5, P450s, and lysozymes may play important roles in immune defense. Our preliminary findings enrich the entomopathogenic fungi repository and shed light on the defense mechanism of D. citri in response to B. bassiana infection at the molecular level.

Neuromas cause severe residual problems at long-term despite surgery

Pain, and disabilities after neuroma surgery, using patient reported outcome measurements (PROMs), were evaluated by QuickDASH and a specific Hand Questionnaire (HQ-8). The 69 responding individuals (response rate 61%; 59% women; 41% men; median follow up 51 months) reported high QuickDASH score, pain on load, cold sensitivity, ability to perform daily activities and sleeping difficulties. Individuals reporting impaired ability to perform daily activities and sleeping problems had higher scores for pain, stiffness, weakness, numbness/tingling, cold sensitivity and QuickDASH. Only 17% of individuals reported no limitations at all. No differences were observed between sexes. Surgical methods did not influence outcome. Symptoms and disabilities correlated moderately-strongly to each other and to ability to perform regular daily activities as well as to sleeping difficulties. Pain, cold sensitivity, sleeping difficulties and limitation to perform daily activities were associated to higher QuickDASH. A weak association was found between follow up time and QuickDASH score as well as pain on load, but not cold sensitivity. A major nerve injury was frequent among those with limitations during work/performing other regular daily activities. Despite surgical treatment, neuromas cause residual problems, which affect the capacity to perform daily activities and ability to sleep with limited improvement in long-term.

Accelerated solutions of convection‐dominated partial differential equations using implicit feature tracking and empirical quadrature

SummaryThis work introduces an empirical quadrature‐based hyperreduction procedure and greedy training algorithm to effectively reduce the computational cost of solving convection‐dominated problems with limited training. The proposed approach circumvents the slowly decaying ‐width limitation of linear model reduction techniques applied to convection‐dominated problems by using a nonlinear approximation manifold systematically defined by composing a low‐dimensional affine space with bijections of the underlying domain. The reduced‐order model is defined as the solution of a residual minimization problem over the nonlinear manifold. An online‐efficient method is obtained by using empirical quadrature to approximate the optimality system such that it can be solved with mesh‐independent operations. The proposed reduced‐order model is trained using a greedy procedure to systematically sample the parameter domain. The effectiveness of the proposed approach is demonstrated on two shock‐dominated computational fluid dynamics benchmarks.

Problems of pesticide residues in grains

Problems of pesticide residues in grains

Photoelectrochemical aptasensing of lincomycin based on a AgI-carboxylated multiwalled carbon nanotubes-BiOI Z-scheme heterojunction

Lincomycin (LIN) is a common antibiotic that is widely used in animal husbandry and other fields, and the residual problem caused by its abuse has attracted widespread attention. Herein, a novel AgI-carboxylated multiwalled carbon nanotubes (cMWCNT)-BiOI Z-scheme heterojunction material was synthesized via a one-pot hydrothermal method, modified on a fluorine-doped tin oxide (FTO) electrode surface, and used for detecting LIN. The photocurrent on the AgI-cMWCNT-BiOI/FTO photoelectrode is 4.6 times that on the control AgI-BiOI/FTO photoelectrode. An amino-functionalized LIN aptamer was fixed on the AgI-cMWCNT-BiOI/FTO photoelectrode by the cross-linking reaction between chitosan and glutaraldehyde, and then Ru(NH3)63+ was electrostatically attached to the LIN aptamer to increase the photocurrent response to the LIN binding. When LIN binds competitively with Ru(NH3)63+ to the aptamer, the photocurrent signal can be quantitatively decreased. Under optimized conditions, the anodic photocurrent at 0 V vs KCl-saturated calomel electrode in 0.1 M phosphate buffer (pH 7.0) containing 0.100 M ascorbic acid was linear with the common logarithm of LIN concentration from 10.0 pM to 500 nM, with a limit of detection of 2.8 pM (S/N = 3). Satisfactory recovery results were obtained in the analysis of cow milk samples.

An "on-off-on" fluorescent switch based on luminous covalent organic framework for the rapid and selective detection of glyphosate.

Glyphosate, the most used herbicide in the world, has a residue problem that cannot be ignored. However, glyphosate itself does not have fluorescence emission and lacks the conditions for fluorescence detection. In this work, a rapid and selective fluorescence detection method of glyphosate was designed by an "on-off-on" fluorescent switch based on luminous covalent organic framework (L-COF). Only the fixed concentration of Fe3+ as intermediate could trigger the fluorescent switch and no incubation step was required. The proposed method showed good accuracy with correlation coefficient of 0.9978. The method's limits of detection and quantitation were 0.88 and 2.93 μmol/L, which were lower than the maximum allowable residue limits in some regulations. Environmental water samples and tomatoes were selected as actual samples to verify the application in complex matrix. A satisfactory mean recovery from 87% to 106% was gained. Furthermore, Fe3+ could induce fluorescence quenching of L-COF through photo-induced electron transfer (PET) effect, while the addition of glyphosate could block PET effect to achieve the detection. These results demonstrated the proposed method had abilities to detect glyphosate, and broadened the application of L-COF.

Bifunctional Y/g-C3N4 promoted cycloaddition of CO2 to epoxide: Halogen-free and acid-base synergistic catalysis

Cycloaddition reaction of CO2 to epoxides is an important procedure for both CO2 conversion and cyclic carbonate synthesis. Homogeneous alkali halide and quaternary ammonium salt are the general catalysts, while they have the problems of halogen corrosion and residue, intricate separation, and catalyst recycling. Here, a series of heterogenous and halogen-free bifunctional yttrium-coordinated g-C3N4 were synthesized and employed to catalyze the cycloaddition of CO2 to butylene oxide. Excellent butylene oxide conversion (94.5%) and butene carbonate selectivity (95.0%) were achieved over the typical Y/g-C3N4-0.5 catalyst without any halogen addition. The characterizations demonstrate that the coordinated Y species function well as the preferred Lewis acid sites for epoxide ring opening and butene carbonate desorption, and the uncondensed amino groups are supplied as Lewis base sites to activate CO2. It is the synergistic effect based on acid-base duality that enhances the catalytic performance of Y/g-C3N4 to cycloaddition of CO2 with epoxide.