[Role of mitophagy in diabetes mellitus and its complications and traditional Chinese medicine intervention: a review].

Diabetes mellitus(DM) is a chronic endocrine disease characterized by hyperglycemia caused by carbohydrate or lipid metabolism disorders or insulin dysfunction. Hyperglycemia and long-term metabolic disorders in DM can damage tissues and organs throughout the body, leading to serious complications. Mitochondrial autophagy(mitophagy) is an important mitochondrial quality control process in cells and a special autophagy phenomenon, in which damaged or redundant mitochondria can be selectively removed by autophagic lysosome, which is crucial to maintain cell stability and survival under stress. Studies have confirmed that changes in autophagy play a role in the development and control of DM and its complications. Mitophagy has become a research hotspot in recent years and it is closely associated with the pathogenesis of a variety of diseases. Substantial evidence suggests that mitophagy plays a crucial role in regulating the metabolic homeostasis in the case of DM and its complications. Because the destructive great vessel complications and microvascular complications cause increased mortality, blindness, renal failure, and declined quality of life of DM patients, it is urgent to develop targeted therapies to intervene in DM and its complications. Traditional Chinese medicine(TCM), with a multi-component, multi-target, and multi-level action manner, can prevent the development of drug resistance and have significant therapeutic effects in the prevention and treatment of DM and its complications. Therefore, exploring the mechanisms of TCM in regulating mito-phagy may become a new method for treating DM and its complications. With focus on the roles and mechanisms of mitophagy in DM and its complications, this paper summarizes and prospects the research on the treatment of DM and its complications with TCM via re-gulating mitophagy, aiming to provide new ideas for the clinical practice.

STAT3 promotes migration and invasion of cholangiocarcinoma arising from choledochal cyst by transcriptionally inhibiting miR200c through the c-myb/MEK/ERK signaling pathway.

Signal transducer and activator of transcription 3 (STAT3) have been highlighted in cancer regulation. Its roles in Cholangiocarcinoma (CCA) arising from the choledochal cyst (CC) were unclear. Here, we attempted to elucidate the roles of STAT3 in CCA-CC and explore its mechanism. A total of 20 patients with CCA arising from CC, that underwent CC excision in the infant stage were included. The expressions of STAT3, miR200c and c-Myb in clinical samples were assessed by RT-qPCR and/or western blot. Their expression correlations in tumor tissues were evaluated by Pearson correlation analysis. Their roles in CCA cell migration and invasion were investigated by gene silence using siRNA or miRNA inhibitor mediated approach and MEK activator. The expression levels of EMT, metastasis and MEK/ERK pathway-related proteins were checked by western blot. The high expressions of STAT3 and c-Myb, and low expression of miR200c were detected in CCA samples. We defined the transcription inhibition of STAT3 in miR200c expression and the negative correlation between miR200c and c-Myb expression. Silence of STAT3 increased miR200c expression and retarded the migration and invasion of CCA cells, accompanied by decreased levels of Vimentin, N-cadherin, MMP2 and MMP9, and elevated expression of E-cadherin, resulting in inactivating MEK/ERK pathway. MiR200c inhibitor reversed the changes induced by STAT3 silence, which was restored by si-c-Myb. MEK activator significantly reversed the inactivation of the MEK/ERK pathway induced by si-STAT3+miR200c inhibitor+si-c-Myb. In summary, the silence of STAT3 suppressed metastasis and progression of CCA cells by regulating miR200c through the c-Myb mediated MEK/ERK pathway, suggesting STAT3 is the effective target for CCA arising from CC.

A Microporous MOF Constructed by Cross-Linking Helical Chains for Efficient Purification of Natural Gas and Ethylene.

Natural gas (NG) and ethylene (C2H4) are two raw materials of significant value for manufacturing versatile fine chemicals and/or polymers, and thus the development of solid adsorbing agents such as metal-organic frameworks (MOFs) applied to their depuration is very crucial but remains highly challenging. In this research, we designed and synthesized a ligand containing mixed N and O coordination donors, which was solvothermally assembled with Cu(II) ions to generate a microporous MOF. X-ray crystallography revealed that the title MOF incorporates one-dimensional (1D) homochiral helical chains that are datively cross-linked to form open channels in the three-periodic coordination framework. Furthermore, the behaviors of C1-C2 hydrocarbons and carbon dioxide (CO2) adsorbed in the title MOF were systematically investigated, revealing its promising potential for the purification of both NG and C2H4. At 109 kPa and 298 K, the C2/methane (CH4), CO2/CH4, and acetylene (C2H2)/C2H4 adsorption selectivities are impressive, reaching as high as 62.9, 28.6, and 3.5, respectively. This work represents a unique MOF based on cross-linked homochiral helical chains exhibiting dual-function separation potentials for NG and C2H4 purifications.

Lanthanide-Organic Frameworks Featuring Three-Dimensional Inorganic Connectivity for Multipurpose Hydrocarbon Separation.

Implementation of lanthanide-organic frameworks (LOFs) as solid adsorbents has been frequently handicapped by their permanent porosity being difficult to establish owing to the remarkable flexibility and diversity of lanthanide ions in terms of coordination number and geometry. Construction of robust LOFs with permanent porosity for industrially important hydrocarbon separation will greatly expand their application potential. In this work, by distributing N and O donors into an m-terphenyl skeleton, we rationally synthesized a heterofunctional linker, and constructed a pair of isostructural LOFs. Due to the inclusion of a rarely observed three-dimensional metal-carboxylate backbone serving as a highly connected inorganic secondary building unit, their permanent porosities were successfully established by diverse gas isotherms. They can be applied as separating media not only for natural gas purification and removal of carbon dioxide from C2 hydrocarbons but also more importantly for single-step ethylene (C2H4) purification from a three-component C2Hn mixture during the adsorption process. The latter separation is very challenging and has been less reported in the literature. This work provides a unique example of LOFs featuring three-dimensional inorganic connectivity applied to multipurpose hydrocarbon separations.

Rational Construction and Performance Regulation of an In(III)-Tetraisophthalate Framework for One-Step Adsorption-Phase Purification of C2H4 from C2 Hydrocarbons.

The development of porous materials for ethylene (C2H4) separation and purification, a very important separation process in the chemical industry, is urgently needed but quite challenging. In particular, the realization of selectivity-reversed adsorption (namely, C2H4 is not preferentially adsorbed) and the simultaneous capture of multinary coexisting impurities such as ethane (C2H6) and acetylene (C2H2) will significantly simplify process design and reduce energy and cost consumption, but such porous materials are quite difficult to design and have not yet been fully explored. In this work, by employing an aromatic-rich bithiophene-based tetraisophthalate ligand, we solvothermally fabricated an anionic In(III)-based framework termed ZJNU-115 featuring In(COO)4 as an inorganic secondary building unit as well as one-dimensional channels. Due to the absence of unsaturated metallic sites, together with aromatic-rich channel surface decorated with abundant hydrogen-bonding acceptors of carboxylate oxygen and thiophene sulfur atoms, desolvated ZJNU-115 exhibited an unusual adsorption relationship with respect to C2 hydrocarbons, namely, simultaneous and preferable capture of C2H6 and C2H2 over C2H4 at the temperatures investigated, thus representing a rare metal-organic framework (MOF) with the promising potential for one-step adsorption-phase purification of C2H4 from a trinary C2 hydrocarbon mixture. Compared to a few of the MOFs reported for such an application, ZJNU-115 displayed simultaneously good adsorption selectivities of both C2H2 and C2H6 over C2H4. Furthermore, its separation potential can be postsynthetically tailored by substituting dimethylammonium (Me2NH2+) counterions with tetraalkyl ammonium ions (NR4+; R = Me, Et, or n-Pr). More importantly, ZJNU-115 was stable in various organic solvents as well as aqueous solutions with pH values ranging from 5 to 9, thus laying a solid foundation for its practical applications. The design principle and the performance regulation strategy adopted in this work will offer valuable guidance for the contrapuntal construction of porous MOFs employed for direct multicomponent purification of C2H4 with improved performance.

A Series of Metal-Organic Framework Isomers Based on Pyridinedicarboxylate Ligands: Diversified Selective Gas Adsorption and the Positional Effect of Methyl Functionality.

Solvothermal assembly of copper(II) cations and 5-(pyridine-3-yl)isophthalate linkers bearing different position-substituted methyl groups afforded four ligand-induced metal-organic framework (MOF) isomers as a platform for investigating diverse selective gas adsorption properties and understanding the positional effect of methyl functionality. Single-crystal X-ray diffraction (SCXRD) analyses showed that, when the methyl substituent is at the para position with respect to the pyridinic N atom, the resultant framework compound ZJNU-27 features an eea-type topology, while the other three solids possess an isoreticular structure with an rtl-type topology when the methyl group is situated at the other positions. As revealed by N2 physi-adsorption measurements at 77 K, they exhibit moderate specific surface areas ranging from 584 to 1182 m2 g-1 and distinct degrees of framework flexibility, which are heavily dependent on the methyl position. Comprehensive gas adsorption studies show that they are capable of effectively separating three pairs of binary gas mixtures including C2H2-CH4, CO2-CH4, and CO2-N2 couples. Moreover, their uptake capacities and adsorption selectivities can be tailored by altering the methyl position. In addition, their framework hydro-stability is also influenced by the methyl position. Compared to ZJNU-27 and ZJNU-28, ZJNU-26 and ZJNU-29 exhibit poorer stability against H2O, although the methyl group is more close to inorganic secondary building units (SBUs), which are believed to originate from the steric effect of the methyl group. Overall, the four MOFs display the methyl position-dependent network architectures, framework flexibilities, and selective gas adsorption properties as well as hydrostabilities. The findings observed in this work not only demonstrate the importance of the positional effect of the functional group but also highlight that engineering the substituent position is a potential strategy for achieving the modulation of MOF structures and properties.

Modulation of Topological Structures and Adsorption Properties of Copper-Tricarboxylate Frameworks Enabled by the Effect of the Functional Group and Its Position.

To push forward the structural development and fully explore the potential utility, it is highly desired but challenging to regulate in a controllable manner the structures and properties of MOFs. In this work, we reported the structural and functional modulation of Cu(II)-tricarboxylate frameworks by employing a strategy of engineering the functionalities and their positions. Two pairs of unsymmetrical biaryl tricarboxylate ligands modified with a methyl group and a pyridinic-N atom at distinct positions were logically designed and synthesized, and their corresponding Cu(II)-based MOFs were solvothermally constructed. Diffraction analyses revealed that the variation of functionalities and their positions furnished three different types of topological structures, which we ascribed to the steric effect exerted by the methyl group and the chelating effect involving the pyridinic-N atom. Furthermore, gas adsorption studies showed that three of them are potential candidates as solid separation media for acetylene (C2H2) purification, with the separation potential tailorable by altering functionalities and their locations. At 106.7 kPa and 298 K, the C2H2 uptake capacity varies from 64.1 to 132.4 cm3 (STP) g-1, while the adsorption selectivities of C2H2 over its coexisting components of CO2 and CH4 fall in the ranges of 3.28-4.60 and 14.1-21.9, respectively.

Degradation of Rhodamine B Under Visible-Light by Cu-Doped ZnAl Layered Double Hydroxide.

The Cu-doped ZnAl layered double hydroxides (LDH) were papered by coprecipitation. The prepared samples were characterized by mutiple techniques including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse-reflectance spectroscopy (UV-vis DRS). The doping of Cu2+ into the LDH sheets results in formation of the distorted CuO6 octahedrons which contribute for the excitation of electrons under visible light. The doped Cu2+ also serves as photo-generated charges separator and improves the visible-light-driven photocatalytic activity of ZnAl LDH. A degradation mechanism based on the hydroxyl radical as the active species was proposed.

Improved Visible-Light-Induced Photocatalytic Performance of ZnAl Layered Double Hydroxide by Incorporation of Ni2.

NiZnAl layered double hydroxides (LDH) with Ni/Zn/Al ratios ranging from 0.1/2/1 to 1/2/1 were papered by coprecipitation. The prepared samples were characterized by multiple techniques including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse-reflectance spectroscopy (UV-vis DRS). The incorporation of Ni2+ into the brucite sheets preserves the layered structure of ZnAl LDH. The doped Ni2+ serves as the photogenerated charges separator and improves the visible light photocatalytic activity of ZnAl LDH at a reasonable content. A degradation mechanism based on the hydroxyl radical as the active species was proposed.

[Relationship between XRCC3 gene polymorphisms and lung cancer].

OBJECTIVE: To explore the relationship between XRCC3 and lung cancer after selecting tag SNPs from HapMap database and reconstructing haplotypes. METHODS: Using case-control study design, smoking condition were surveyed by questionare. Peripheral blood of cases and saliva or buccal cell for controls were collected, and then their DNA were extracted. XRCC3 tagSNPs were genotyped by PCR-RFLP. TagSNPs were selected by Haploview, HWE and LD were checked by LDA. Best genetic model and relationship between tagSNPs and lung cancer were analysed by SPSS, and haplotype frequencies and effects were computed by THESIAS. RESULTS: Carriers of rs861537 AG or AA genotype had a statistically significantly increased risk for lung cancer (OR = 1.48, 95% CI: 1.17-1.86). Carriers of rs1799794 per G allele had a statistically significantly decreased risk for lung cancer (OR = 0.83, 95% CI: 0.72-0.97); no significant association was observed between rs861539 and lung cancer. Smoke interacted with rs861537 polymorphism. Compared with CGG haplotype, carriers of CAA had a statistically significantly increased risk for lung cancer (OR = 1.32, 95% CI 1.11-1.57). CONCLUSION: XRCC3 gene polymorphisms were associated with lung cancer.

Engineering ligand conformation by substituent manipulation towards diverse copper-tricarboxylate frameworks with tuned gas adsorption properties.

To expand the structural diversity and optimize the material performance, it is essential but challenging to regulate MOF structures in a predictable and controllable manner. In this work, by manipulating the substituents to engineer the ligand conformations, we designed and synthesized two asymmetric tricarboxylate ligands, and used them to successfully target two copper-tricarboxylate frameworks with diversified topologies depending on the ligand conformations. Besides, the ligand asymmetry induced the formation of two uncommon kinds of copper-carboxylate clusters, thus greatly expanding the library of copper-carboxylate secondary building units. Furthermore, the two compounds also displayed tunable gas adsorption properties pertinent to C2H2 separation and purification. At 298 K and 1 atm, the uptake capacity of C2H2 varies from 79.5 to 104.6 cm3 (STP) g-1, while the adsorption selectivities of C2H2 with respect to CO2 and CH4 are in the range of 2.3-3.8 and 15.3-21.6 for the equimolar components, respectively. Compared to the nitro counterpart, the methoxy MOF features higher C2H2 uptake capacity, larger C2H2/CO2 and C2H2/CH4 adsorption selectivities, and lower regeneration energy. This work demonstrates that simple ligand modification can be used to engineer the structures and tune gas adsorption properties of the resulting MOFs.

Ligand Bent-Angle Engineering for Tuning Topological Structures and Acetylene Purification Performances of Copper-Diisophthalate Frameworks.

To enrich structural chemistry and widen the application prospects of MOFs (metal-organic frameworks), the development of a synthetic strategy to realize structural and functional modulation is highly demanded. By implementation of the linker bent-angle engineering strategy, three banana-like diisophthalate linkers with distinct bent angles were designed and synthesized. The inclusion of the targeted linkers into MOFs through solvothermal assembly with CuCl2·2H2O under identical conditions yielded three crystalline solids featuring diversified topological structures as revealed by X-ray crystallographic studies. Furthermore, functional explorations indicated that they are promising solid adsorbents for acetylene (C2H2) purification application with structurally dependent separation potentials. The results reported in this study illustrated a rare example of modulating the topological structures and separation efficiencies of MOFs by engineering the ligand bent angles.

Improving Ethane/Ethylene Separation Performance of Isoreticular Metal-Organic Frameworks via Substituent Engineering.

The preferential capture of ethane (C2H6) over ethylene (C2H4) presents a very cost-effective and energy-saving means applied to adsorptive separation and purification of C2H4 with a high product purity, which is however challenged by low selectivity originating from their similar molecular sizes and physical properties. Substituent engineering has been widely employed for selectivity regulation and improvement, but its effect on C2H6/C2H4 separation has been rarely explored to date. In this work, four isoreticular coordination framework compounds based on 5-(pyridin-3-yl)isophthalate ligands bearing different substituents were rationally constructed. As revealed by isotherm measurements, thermodynamic studies, and IAST computations, they exhibited promising utility for C2H6/C2H4 separation with moderate adsorption heat and a high uptake amount at a relatively low-pressure domain. Furthermore, the C2H6/C2H4 separation potential can be finely tuned and optimized via purposeful substituent alteration. Most remarkably, functionalization with a nonpolar methyl group yielded an improved separation efficiency compared to its parent compound. This work offers a good reference value for enhancing the C2H6/C2H4 separation efficiency of MOFs by engineering the pore microenvironment and dimensions via substituent manipulation.

Application of Hyperspectral Imaging for Maturity and Soluble Solids Content Determination of Strawberry With Deep Learning Approaches.

Maturity degree and quality evaluation are important for strawberry harvest, trade, and consumption. Deep learning has been an efficient artificial intelligence tool for food and agro-products. Hyperspectral imaging coupled with deep learning was applied to determine the maturity degree and soluble solids content (SSC) of strawberries with four maturity degrees. Hyperspectral image of each strawberry was obtained and preprocessed, and the spectra were extracted from the images. One-dimension residual neural network (1D ResNet) and three-dimension (3D) ResNet were built using 1D spectra and 3D hyperspectral image as inputs for maturity degree evaluation. Good performances were obtained for maturity identification, with the classification accuracy over 84% for both 1D ResNet and 3D ResNet. The corresponding saliency maps showed that the pigments related wavelengths and image regions contributed more to the maturity identification. For SSC determination, 1D ResNet model was also built, with the determination of coefficient (R 2) over 0.55 of the training, validation, and testing sets. The saliency maps of 1D ResNet for the SSC determination were also explored. The overall results showed that deep learning could be used to identify strawberry maturity degree and determine SSC. More efforts were needed to explore the use of 3D deep learning methods for the SSC determination. The close results of 1D ResNet and 3D ResNet for classification indicated that more samples might be used to improve the performances of 3D ResNet. The results in this study would help to develop 1D and 3D deep learning models for fruit quality inspection and other researches using hyperspectral imaging, providing efficient analysis approaches of fruit quality inspection using hyperspectral imaging.

Immobilization of N-oxide functionality into NbO-type MOFs for significantly enhanced C2H2/CH4 and CO2/CH4 separations.

NbO-type MOFs built up from linear diisophthalate ligands and dicopper paddlewheel-based secondary building units offer an excellent platform to perform pore surface chemistry engineering and understand the structure-property relationship. In this work, we designed and synthesized two N-oxide functionalized linear diisophthalate ligands, and employed them to construct under suitable solvothermal conditions their corresponding NbO-type MOFs termed ZJNU-19 and ZJNU-20. Their gas adsorption properties with respect to C2H2, CO2, and CH4 were systematically measured, and adsorption selectivities of C2H2 and CO2 over CH4 were assayed using a well-known ideal adsorbed solution theory, establishing their promising potential for C2H2/CH4 and CO2/CH4 separations in connection with acetylene and natural gas separation and purification, which were found to be less dependent on the methyl position. In particular, at atmospheric pressure, the C2H2 and CO2 uptake capacities reach as high as 214.5 and 114.7 cm3 (STP) g-1 for ZJNU-19, and 210.0 and 111.9 cm3 (STP) g-1 for ZJNU-20 at 295 K, while the IAST-predicted C2H2/CH4 (v/v = 1/1) and CO2/CH4 (v/v = 1/1) adsorption selectivities are up to 42.2 and 6.4 for ZJNU-19, and 42.1 and 6.2 for ZJNU-20 at 298 K. Furthermore, a comparative investigation demonstrated that N-oxide is a powerful chemical functionality that can be utilized to design and construct porous framework compounds for boosting C2H2 and CO2 adsorptions.

A hydrostable cage-based MOF with open metal sites and Lewis basic sites immobilized in the pore surface for efficient separation and purification of natural gas and C2H2.

Design and construction of stable adsorbents for efficient separation and purification of natural gas and C2H2 is fundamentally important in the chemical industry, and hierarchical cage-based MOFs are attractive in this regard due to their intrinsic structural advantages. In this work, a cage-based MOF (termed ZJNU-15) assembled from a tetranuclear Cu4O-based SBU and an amine-functionalized N,O-mixed donor ligand was solvothermally constructed. Single-crystal X-ray diffraction studies showed that the resulting MOF incorporates two different types of polyhedral cages in the entire network and bears incompatible open copper sites and uncoordinated amine groups immobilized in the pore surface. In view of its intriguing structural features, its gas adsorption properties with respect to C2 hydrocarbons, CO2, and CH4 were systematically investigated, revealing that it could achieve efficient removal of C2 hydrocarbons and CO2 from CH4 as well as separation of a binary C2H2-CO2 mixed gas, which is associated with natural gas and C2H2 separation and purification. At 298 K and 1 atm, for equimolar binary components, the IAST-predicted adsorption selectivities for C2 hydrocarbons over CH4 are above 17.7, while the CO2/CH4 and C2H2/CO2 adsorption selectivities are 5.0 and 4.4, respectively. Notably, stability studies showed that the framework maintained its structural integrity after being immersed in HCl/NaOH aqueous solutions within a pH range of 4-11 at ambient temperature for 24 h, indicating its good hydrolytic stability under harsh chemical conditions, which might lay a solid foundation for its practical applications.

An N-oxide-functionalized nanocage-based copper-tricarboxylate framework for the selective capture of C2H2.

The selective capture of C2H2 from C2H2-C2H4 and C2H2-CO2-CH4 mixtures is a very essential but highly challenging process during C2H4 and C2H2 purification in the chemical industry. In this work, by virtue of using oxygen-atom-rich C2H2 recognition sites, we, for the first time, designed and synthesized an N-oxide-functionalized tricarboxylate ligand and utilized it to successfully construct a copper-based MOF. N-Oxide functionalization exerted a significant effect on the ligand conformation, thus resulting in a new topological network that is different from that of the unoxidized parent compound. With a moderate surface area and the immobilization of N-oxide functionality and carboxylate oxygen atoms in two nanocages, the title MOF exhibited promising potential for the multifunctional separation of C2H2/C2H4 and C2H2/CO2/CH4 mixtures under ambient conditions, as shown by pure-composition isotherm measurements, IAST predictions, and molecular modeling studies.

[Meta-analysis on the relationship between alcohol consumption and lung cancer risk].

OBJECTIVE: To study the relationship between alcohol consumption and lung cancer by means of meta-analysis. METHODS: To search the data all about the subjects and process the related data by means of Meta-analysis. RESULTS: 6 prospective studies with 122,288 participants and 3 053 cancer cases, and 15 case-control studies with 8838 cancer cases and 21,591 controls were included. The OR value associated with alcohol were 1.17 (95% CI: 0.96-1.42). The OR values associated with alcohol in men and women were 1.67 (95% CI: 0.61-4.59) and 0.93 (95% CI: 0.51-1.68), respectively. The OR value associated with alcohol from beer in men was 1.46 (95% CI: 1.28-1.67). The OR value associated with alcohol from spirits was 1.34 (95% CI: 1.02-1.74). For those drinking at least seven drinks per week, there was an positive relationship with lung cancer (P < 0.05). CONCLUSION: Consumption of beer, spirits and drinking regularly were associated with lung cancer risk.

[Control Effect of Side Deep Fertilization with Slow-release Fertilizer on Ammonia Volatilization from Paddy Fields].

In order to reduce the ammonia volatilization in paddy fields, seven treatments were evaluated. These included three slow-release nitrogen fertilizers[sulfur-coated urea (SCU); resin-coated urea (RCU); release bulk blending fertilizer (RBB)], two fertilization modes[single base fertilization (B) and combined with panicle fertilizer (BF)], and conventional split fertilization (CN). The effects of side deep fertilization for slow-release nitrogen fertilizers on ammonia volatilization and surface water nitrogen dynamics were examined using a rice transplanter with a fertilizer sowing mechanism in the Taihu Lake region. The results showed that total nitrogen and ammonium nitrogen concentration in the surface water of the SCU treatment in the base period were higher, and those for RCU and RBB were lower than in the CN treatment. The cumulative ammonia volatilization during the whole rice season varied among different types of slow-release nitrogen fertilizers from 3.84% to 28.17% of the total N applied. The nitrogen loss from ammonia volatilization using the three slow-release nitrogen fertilizers was decreased when compared with conventional split fertilization. The ammonia volatilization loss exhibited the following relationship for the treatments:CN, B-SCU > BF-SCU, BF-RBB, BF-RCU, B-RBB, and B-RCU. When the slow-release nitrogen fertilizers were applied in single base fertilization, the total ammonia volatilization for the SCU was significantly higher than those for the RCU and RBB, while no significant differences were detected when these three slow-release fertilizers were combined with panicle fertilizer. Moreover, although the ammonia volatilization of BF-SCU was lower than that of B-SCU, those of BF-RCU and BF-RBB were higher than those with the B-RCU and B-RBB treatments, respectively. There are no significant differences for nitrogen volatilization when any of these three different fertilizers are applied as B or BF. The results for the emissions during ammonia volatilization during different stages indicated that the ammonia volatilization of SCU at the basal-tillering fertilization stage (7.54%) and the tillering-panicle fertilization stage (16.04%) were higher than those of the panicle fertilization-mature stage. The N loss from ammonia volatilization for RBB in the base-tillering fertilization stage (2.91%) increased more than in the tillering-panicle fertilization stage and panicle fertilization-mature stage. For RCU treatment, the highest rate for ammonia volatilization was detected at the panicle fertilization-mature stage (2.75%). Compared with the single base fertilization mode, ammonia volatilization during the panicle fertilization-mature stage was increased when combined with panicle fertilizer (BF) for the slow-release fertilizer. There was no obvious correlation between the N loss with ammonia volatilization for the three slow-release nitrogen fertilizers and the concentration of ammonium nitrogen in surface water during the panicle fertilization-mature stage.

[Effect of Straw Incorporation and Domestic Sewage Irrigation on Ammonia Volatilization from Paddy Fields].

A pot experiment was conducted to study the effect of straw returning and domestic sewage irrigation on the dynamics of NH4+-N concentration and pH in the flood water, and ammonia volatilization of paddy fields. The results showed that the NH4+-N concentration in flood water was significantly increased by wheat straw returning while significantly decreased by domestic sewage irrigation. The cumulative ammonia volatilization in the whole rice season under tap water irrigation and straw removal treatment was 58.29 kg·hm-2, accounting for 24.29% of the total N applied. The N loss ratio of ammonia volatilization was significantly increased to 45.66% by wheat straw returning, while significantly decreased to 17.26% under straw removal and 32.72% under straw returning by domestic sewage irrigation. Significant positive interaction was observed between straw incorporation and domestic sewage irrigation on ammonia volatilization loss. The average N loss from ammonia volatilization during the tillering stage was the highest among the three fertilization stages, accounting for 7.38%-24.44% of the total N applied. In addition, ammonia volatilization fluxes showed a significant positive correlation with the flood water NH4+-N concentration, irrespective of the irrigation water, but had no significant correlation with pH. These results indicated that straw returning increased ammonia volatilization losses, whereas domestic sewage irrigation could effectively reduce ammonia volatilization losses and simultaneously replace 44.41% of chemical nitrogen fertilizer by the N contained in the domestic sewage. The combination of domestic sewage irrigation and straw returning would be an ecological and environmental-friendly measure for rice nitrogen management in Taihu Lake region.