NaClO4 Solutions Research Articles

Transformation behavior of the ultraviolet absorbent 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) in polyethylene plastic under chlorination

In plastic, a 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) ultraviolet light absorber is a common additive. When using sodium hypochlorite (NaClO) to disinfect plastic, UV328 may react with NaClO. For this work, we investigated the transformation behavior of UV328 in polyethylene (PE) plastic by NaClO. The reaction rate increased with the initial free active chlorine (OCl−) concentration and the decrease of the initial UV328 concentration. At room temperature (25 °C) to lower temperatures (0 °C), OCl− could transform UV328, and the reaction activation energy was fitted as 31.10 kJ/mol. Replacement of the plastic carrier (change to polypropylene) had no effect on the reaction process. A total of 12 intermediates were identified, and calculations based on density functional theory (DFT) were used to assist in rationalizing the product structure. Chlorination, hydroxylation, coupling, and bond cleavage were speculated as the main transformation pathways. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were the only two measured disinfection by-products in the system, and their concentration were 18.33 and 18.19 μg/g, respectively. The toxicity prediction by Toxicity Estimation Software Tool (T.E.S.T) illustrated that the toxicity of the transformation products was higher overall than that of UV328 during the reaction. This work can help to deepen the understanding of the transformation behavior of UV328 in PE plastic in NaClO solution.

Understanding the interactions of NaClO oxidant with coal for intensified hydraulic fracturing effectiveness

The efficacy of hydraulic fracturing coalbeds to enhance methane production suffers from a reduction of the effective permeability due to formation damage. To address this practical challenge, this paper explores the feasibility of applying the oxidative treatment to coals in the post-hydraulic fracturing period. Experimental methodologies are utilized to reveal the fundamental interactions of coal with the oxidative in the context of a combined treatment of hydraulic fracturing and NaClO solution injection. Anthracite and bituminous coals are experimented to account for the effect of coal rank. A comprehensive package of techniques, i.e., ultrasonic wave velocity and hardness (for mechanical properties), scanning electron microscopy (for microstructure and morphology), contact angle (for wettability), and FTIR spectroscopy (for functional groups) were employed to comprehensively investigate the impacts of fracturing fluid and NaClO solution on the chemical and physical properties of the coal samples. The results show that the fracturing fluid exerts varying degrees of harm to the permeability of the two coals, while the effects of oxidative treatment are rank specific in dissolving the blockage and smoothening the fracture surface. It is further unveiled that NaClO solution promotes aromatic structure decomposition at the coal surface to form oxygen-containing functional groups, and its effects on coal permeability evolve in multiple stages. The findings of this study shed light upon implementing oxidative treatment to aid hydraulic fracturing performance in CBM for clean coal production in a carbon-constrained world.

Highly selective and permeable β-cyclodextrin based polyester nanofiltration membranes maintaining good chlorine resistance

Possessing high chlorine resistance is an important consideration for membranes to be applied for water treatment. In this study, the superior chlorine resistant β-cyclodextrin (β-CD) based polyester membranes were developed via interfacial polymerization (IP) with the β-CD and glycerol or mannitol as the aqueous phase monomers. By adjusting the compositions of the aqueous phase, the pore size and distribution of the resultant membranes were accurately controlled, thus improving the separation efficiency of the membranes. The optimized membrane (β-CD/Ma3) had the higher water flux (60.4 L‧m-2‧h-1 at 2.0 bar) and Na2SO4 retention (95.6%). After immersed in 10 ppm sodium hypochlorite (NaClO) solution for 360 h, the membrane performance in terms of water flux and salt retention was almost unaltered, mirroring a good long-term stability. In another test, the Na2SO4 retention of membrane remained at 91.7%, which was only 4.1% lower than the original value, after exposure to a high concentrated NaClO solution (2000 ppm) for 72 h. Fouling cycling test was also performed, and the flux was maintained as high as 97.2% of the original value after examination of three cycles. All these observations clearly indicate that the optimized membrane has outstanding chlorine resistance and superior antifouling property.

First Report of Leaf Tip Blight Caused by Epicoccum sorghinum on Phoebe bournei in Fujian, China.

Phoebe bournei, belonging to the family Lauraceae, is indigenous to China, where it is a protected species. In March 2022, ca. 90% of 20,000 P. bournei saplings suffered from leaf tip blight in a sapling nursery with an area of 200 m2 in Fuzhou, China. Initially, brown discoloration appeared on the tips of young leaves. The symptomatic tissue continued to expand as the leaf grew. To isolate the pathogen, 10 symptomatic leaves were randomly sampled from the nursery, and surface-sterilized in 75% alcohol for 30 s, followed by a 5% NaClO solution for 3 min, and then rinsed 3 times with sterile water. Twenty small pieces (0.3 x 0.3 cm) were excised from the margin of diseased and healthy tissue and transferred to five PDA plates amended with 50 μg/ml ampicillin. The plates were incubated at 25°C for 5 days. Finally, 17 isolates were obtained, and nine isolates with the highest isolation frequency shared the same morphological characteristics. On PDA, these colonies had aerial hyphae, white in the beginning, and became pale brown with the pigment production. Chlamydospores were observed after incubation for 7 days at 25°C, pale brown and nearly spherical, unicellular, or multicellular. Conidia were unicellular or bicellular, hyaline, and ellipsoidal, 5.15 to 9.89× 3.46 to 5.87 µm, n=50. The 9 fungi were identified as Epicoccum sp (Khoo et al. 2022a, b, c). Furthermore, strain MB3-1 was chosen randomly as the representative of the 9 isolates, and ITS, LSU, TUB sequences were amplified using the primers ITS1/ITS4, LR0R/LR5, Bt2a/Bt2b respectively (Raza et al. 2019). The sequences were submitted to NCBI and analyzed using BLAST. Results of BLAST showed that ITS (OP550308), LSU (OP550304), TUB (OP779213) sequences had 99.59% (490bp out of 492bp), 99.89% (870bp out of 871bp), 100% (321bp out of 321bp) identity to Epicoccum sorghinum sequences MH071389, MW800361, MW165323, respectively. ITS, LSU, TUB sequences were concatenated for phylogenetic analysis using the maximum likelihood method with 1000 bootstrap replicates in MEGA 7.0 software. The phylogenetic tree showed that MB3-1 was clustered together with E. sorghinum. Pathogenicity tests were performed on young leaves of healthy P. bournei saplings in vivo by inoculating with fungal conidia suspension. The conidia were eluted from the colony of MB3-1 and adjusted to 1×106 spores/ml. An amount of 20 μl conidia suspension (0.1% tween-80) was evenly sprayed on three leaves of one P. bournei sapling, 20 μl sterile water was sprayed on three other leaves of the same sapling as control, and three saplings were treated. All the treated saplings were kept at 25°C. MB3-1 caused leaf tip blight symptoms similar to those observed in nature at 6 days post inoculation (dpi). The pathogen was reisolated from inoculated leaves and identified as E. sorghinum. The experiment was repeated twice with the same results. Recently, E. sorghinum has been reported in Brazil (Gasparetto et al. 2017), Malaysia (Khoo et al. 2022a, b, c), and the United States (Imran et al. 2022). To our knowledge, this is the first report of E. sorghinum causing leaf tip blight on P. bournei. Wood from P. bournei is used to produce high-quality furniture due to its vertical grain and durability (Chen et al. 2020). And the demand for wood requires numerous saplings for afforestation. But this disease has the risk of causing insufficient saplings, which would affect the development of the P. bournei timber industry.

First report of Diplodia mutila causing canker and branch dieback of walnut trees in Xinjiang, China.

Walnut (Juglans regia L.) has become an important economic fruit tree in China. In April 2022, branch dieback was observed in 15-year-old walnut trees (cv Wen 185) in a commercial orchard in Aksu, Xinjiang, China (40°21'55''N, 80°1'48''E), with an incidence of 2% (4 out of 200 trees) of affected trees. The symptoms observed, included depressed and shrunken cankers, twigs and branches dieback. Cross-sections of diseased branches revealed dark-brown wedge-shaped lesions. To isolate the potential causal pathogen, four specimens were isolated from diseased branches, and small pieces taken from the edge of canker samples (0.5 × 0.5 cm), were disinfected by immersion in 75% ethanol for 30 s and 2% NaClO solution for 3 min, and rinsed three times with sterile water. The disinfected wood samples were then placed on potato dextrose agar (PDA) and incubated in the dark at 25°C for 2-3 days. Then, we applied the mycelial tip purification method and repeated this purification process until a single colony was formed. Four pure isolates (3-1-51A, W-2-54, K-1-43A, K-1-43B) developed white to white-gray fast-growing colonies with abundant aerial mycelium after seven days at 25°C on PDA and gradually became dark olive green over subsequent growth stages. Conidia production was then induced on 2% w/v water agar containing sterilized pine needles under near-U/V light (Alves et al., 2004). The conidia were initially hyaline, thick-walled, oblong to ovoid with one septum and a size range of 19.47-24.16 × 9.78-13.51 µm (n = 40). Based on morphological characteristics these isolates were tentatively identified as Diplodia mutila (Fr.) Mont. (Alves et al., 2004).To confirm the pathogen identified, the representative isolate 3-1-51A was amplified and sequenced using specific primer pairs (ITS1/ITS4, EF1-986/EF1-728E, BT2a/BT2b) to the internal transcribed spacer (ITS), translation elongation factor 1-alpha (TEF1-α), and beta-tubulin (TUB) (White et al. 1990; Carbone and Kohn 1999; O' Donnell and Cigelnik 1997), respectively. The sequences showed 100% similarity to two D. mutila strains CBS230.30 and CBS112553. Maximum likelihood analysis was performed based on a concatenated dataset (ITS + TEF1-α + TUB) gene using MEGA 11. 0 and isolate 3-1-51A formed a single clade with the reference ex-type of D. mutila. The isolate 3-1-51A was deposited into GenBank as OP006733, OP373140, and OP373139 for ITS, TEF1-α, and TUB, respectively. To fulfill Koch's postulates, pathogenicity tests were performed using isolate 3-1-51A on one-year-old healthy walnut branches cv. Wen 185 of walnut trees (n=5). Five twigs of healthy walnut branches were cleaned, submerged in 1% NaClO for 15 minutes and then dried. Then, a sterile hole punch (5mm in diameter) was used to create a wound in the middle of each walnut branch, and placing mycelial plugs(3 days old; 5 mm in diameter) and sealed with parafilm. An equal number of twigs inoculated with sterile agar plugs served as controls. On the 7th day after inoculation, dark brown coloration was developed on the branches with symptoms of shrinkage dryness, and dieback. D. mutila isolate was re-isolated only from the inoculated branches. In negative control twigs, lesions and re-isolated were absent, thus fulfilling Koch's postulates. D. mutila has been previously reported causing canker and branch dieback in walnut trees in Chile (Díaz et al. 2018) and California (Chen et al. 2014). Previously, D. seriata (Zhang et al. 2017), Botryosphaeria dothidea (Guo et al. 2016), Lasiodiplodia pseudotheobromae (Guo et al. 2016), Dothiorella gregaria (Liu et al. 1986) and Neofusicoccum parvum (Yu et al. 2015) have been identified on walnut trees in China. To our knowledge, this is the first report of canker and branch dieback caused by D. mutila in walnut trees in Xinjiang, China. Further studies are now required to better understand the etiology of canker and branch dieback on walnut trees from different areas in China.

First Report of Root Rot caused by Coniella fragariae on Paeoniae radix Rubra in China.

Paeoniae radix Rubra is a traditional Chinese herbal medicine, which has the effect of clearing heat and cooling blood, activating blood and removing stasis. It has become popular in the Chinese market in recent years due to its extremely high medicinal value and showy flower color. In May 2021, typical symptoms of root rot were observed in a field (35°7'12″ N, 103°58'48″ E) in Dingxi, Gansu province, China. Approximately 10% of the plants in the field had typical root rot symptoms, and the root of each affected plant is at least 5% severe. The roots of the naturally infected plants in the field discolored and decayed with black brown spots on the surface of the root bark, the root bark detached from the phloem，and some leaves were chlorosis, shrunken and smaller, and the branches were dead and underdeveloped. In the transverse section, the xylem was black diffusion and abnormal odor. Three diseased plants with typical symptoms were chosen at random and brought back to the lab. Small pieces cut from the margins of lesions were surface disinfested with 75% ethanol for 15 s, and 0.5% NaClO solution for 30 s, rinsed three times in sterile distilled water, dried on sterile filter paper, plaed onto potato dextrose agar (PDA), and incubated at 25 ± 1℃ for 7 days in the dark. The pure cultures were obtained by single-spore isolation. All isolates produced wavy on the surface, radial from the inside out, initially white or milky white to orange colonies with abundant black brown oily conidiomata pycnidia on PDA at 25 ± 1℃ after 15 days in the dark. The conidiomata pycnidia is spherical to irregularly spherical, 231.5 to 512.4 μm, initially transparent with age turning brown, with a dark brown internal conidial mass inside, and with a 13.1 to 45.4 μ m wide ostiole central. Young conidia (n=100) developed from conidiogenous cells, which were simple, tapering, hyaline, smooth, and 12.3 to 18.0 × 2.5 to 4.6 μm, 1.0 to 1.5 µm wide at apex. Mature conidia (n=100) were ellipsoid, apices tapering, subobtusely rounded, brown, and 6.5 to 11.0 × 4.1 to 7.5 µm. The morphological characteristics of the isolates were consistent with previous descriptions of the genus Coniella (Crous et al., 2014). A representation isolate CS-1 was deposited in the Institute of Plant Protection, Gansu Academy of Agricultural Sciences and used for further studies. To confirm the identity of the causal fungus, the internal transcribed spacer (ITS), 28S large subunit of nuclear ribosomal RNA (LSU) and partial translation elongation factor 1-alpha (TEF1-α) gene of the representative isolate CS-1 were amplified and sequenced using primers ITS1/ITS4 (White et al., 1990), LROR/LR7 (Chethan et al., 2017) and EF1-728F/EF1-986R (Carbone and Kohn, 1999), respectively, and deposited on GenBank with accession numbers OP824764 (ITS), OP824767 (LSU)/span>and OP903926 (TEF1-α). Blastn analysis of all sequences resulted in E-value of 0.0 (ITS and LSU) and nearly 0.0 (TEF1-α), with Query cover values of 90% to 99% identity with C. fragariae, confirming the hypothesis based on morphological features examination. To conduct a pathogenicity test, three root segments of healthy plants were wounded using sterilized needles and inoculated by pipetting 10 μL of conidial suspension (1×107 conidia/mL) onto each wound, and controls were inoculated with 10 μL sterile distilled water. These root segments were kept in a moist chamber at 25°C in the dark. The experiment was repeated three times. After 14 days, root rot symptoms were observed on all of the inoculated root segments and identical to those observed in the field, whereas control root segments did not develop symptoms. The pathogen was re-isolated from the lesions of inoculated root segments, fulfilling Koch's postulates. To the best of our knowledge, this is the first report of C. fragariae causing root rot on P. radix Rubra in China. This identification can aid in the selection of appropriate management measures for this disease.

Improvement of membrane-forming ability and separation performance of hydroxylated BN membrane by GO via π-π interaction

Two-dimensional hydroxylated boron nitride (OH-BN) nanosheets were prepared using a new approach of ball milling and monoethanolamine (MEA) assisted sonication. OH-BN/graphene oxide (GO) hybrid nanofiltration membranes were developed for the improvement of the membrane-forming ability of OH-BN nanosheets by π-π interaction between GO and OH-BN nanosheets. The membrane-forming ability of OH-BN nanosheets were improved significantly after the introduction of GO nanosheets, and typical layered structure and enhanced separation performances were achieved for OH-BN/GO hybrid membrane with 40 wt% of GO (OH-BN40GO). OH-BN40GO membrane with a thickness of 500 nm possessed a favorable water permeance of 162.3 L/m2·h·bar and a pleasant rejection rate of 97.7 % for Methyl Blue (MB). Moreover, OH-BN40GO hybrid membrane exhibited an excellent anti-swelling ability in aqueous solution, and kept almost unchanged after soaking in water for 3 months. The flux recovery ratio of OH-BN40GO membrane reached to 85.8 % after BSA contamination and NaClO solution rinse, revealing a suitable anti-fouling property of OH-BN40GO membrane.

First Report of Colletotrichum siamense Causing Leaf Spot on Jasminum sambac in China.

Jasmine (Jasminum sambac (L.) Aiton) is cultivated as a commercial floricultural crop in many countries around the world (Gao et al., 2020). From June to August 2020, leaf spots on jasmine were observed on a jasmine plantation in Hengzhou of Guangxi province. Over 40% of the plants in 6 ha fields were infected. This disease was prevalent in jasmine production area of China (Chen et al., 2012; Du et al., 2020). Symptoms began as chlorotic regions (from 5 to 10 mm in diameter) with light brown necrotic centers, which gradually expanded to the entire leaf. Eventually, the disease leaded to defoliation and dieback. The edges of the affected parts from diseased leaves were cut into pieces (3 mm2). Pieces were treated with 75% ethanol for 10 s, soaked in 2% NaClO solution for 1 min, washed three times with sterile water, and then incubated on potato dextrose agar (PDA) plates at 28℃ for 5 days in the dark. Fungal cultures that showed similar morphological characteristics were isolated, and three representative isolates (HL6-1 to HL6-3) were purified following Mo et al. (2018). The cultures on PDA changed from white to dark grey after 7 days and produced conidiomata after 14 days. Conidia were hyaline, one-celled, guttulate, cylindrical, of 12.07 to 18.09 × 4.04 to 8.05 μm, 13.17 to 16.35 × 4.22 to 6.13 μm and 10.11 to 22.17 × 3.65 to 8.1 μm for HL6-1, HL6-2 and HL6-3, respectively. Gray-brown or dark brown appressoria formed from conidia were subglobose or elliptical. Conidial appressoria and mycelial appressoria were 5.53 to 13.96 × 3.58 to 13.95 μm and 4.24 to 14.01 × 2.4 to 10.86 μm. Genomic DNA was extracted from three isolates and the partial internal transcribed spacer (ITS) regions, intergenic region of apn2 and MAT1-2-1 (ApMAT), and fragments of actin (ACT), glyceraldehydes-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-1), and β-tubulin (TUB2) genes were amplified, sequenced and submitted to GenBank (ITS, ON115173 to ON115175; ApMat, ON156517 to ON156519; ACT, ON146469 to ON146471; GAPDH, ON156502 to ON156504; CHS-1, ON156507 to ON156509; TUB-2, ON156512 to ON156514). Phylogenetic tree was constructed with MrBayes v. 3.2.6 and MEGA v. 10.1.5 based on the concatenation of multiple sequences. Three isolates were grouped with strain C. siamense ICMP 18578. Results indicated three isolates were identified as Colletotrichum siamense Prihastuti, L. Cai & K.D. Hyde. To confirm the pathogenicity of the three isolates, four sets (five plants per set) of 160 healthy leaves of 2-year-old plants (J. sambac, eight leaves per plant) were slightly scratched with a sterilized toothpick at each of eight locations. Conidial suspension (1×106 conidia/mL) in 0.1% Tween 20 were inoculated onto each wounded spot of three sets as the treatment groups, while wounded leaves treated with sterile water as the control. All plants were covered with plastic bags and cultivated in phytotron (12 h/12 h light/dark, 28°C). After 7 days, irregular chlorotic regions with brown lesions were observed on inoculated leaves while no symptoms on controls. The same fungi were reisolated from inoculated leaves and confirmed by morphological and molecular identification, fulfilling Koch's postulates. Colletotrichum siamense has been associated with leaf anthracnose of J. sambac in Vietnam (Wikee et al., 2011) and J. mesnyi in China (Zhang et al., 2019). To our knowledge, this is the first report of C. siamense causing jasmine anthracnose in China, which provides a reference for the management of this disease.

First Report of Fusarium citri Causing Postharvest Fruit Rot of Chayote in Mexico.

In November 2018, symptoms of brown rot were observed on chayote (Sechium edule) var. nigrum spinosum with a 20% disease incidence of 120 harvested fruits in the National Germplasm Bank of Sechium edule, located in the Centro Regional Universitario Oriente (CRUO) from the Chapingo Autonomous University (Huatusco, Veracruz, Mexico). For fungal isolation, pieces from symptomatic fruits were surface disinfected by immersion in a 1.5% NaClO solution for 2 min, rinsed in sterile distilled water, placed in Petri plates containing potato dextrose agar (PDA) amended with kanamycin sulfate, and incubated at 25ºC. Fusarium-like colonies were consistently isolated on PDA and five monoconidial isolates were obtained. A representative isolate was selected for morphological characterization, phylogenetic analysis, and pathogenicity tests. On PDA, colonies exhibited white and fluffy aerial mycelia, with diffused pale brown pigment in the center at 7 days of incubation at 25℃ in darkness. Macroconidia (n= 100) were hyaline, falcate, with 4 to 5 septa, measuring 23.9 to 31.9 × 2.9 to 4.2 μm, and foot-shaped basal cells. Microconidia and chlamydospores were absent. Morphological features were consistent with the description of the Fusarium incarnatum-equiseti species complex (Xia et al. 2019). The isolate was deposited as FUS2 in the Culture Collection of Phytopathogenic Fungi of the Laboratory of Plant Pathology at the Colegio de Postgraduados. For molecular identification, genomic DNA was extracted, and the internal transcribed spacer (ITS) region, partial sequences of translation elongation factor 1-alpha (EF1-α), and the second-largest subunit of RNA polymerase II (rpb2) genes were amplified, and sequenced with the primer sets ITS5/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and RBP2-5F/RPB2-7R (Liu et al. 1999), respectively. DNA sequences were edited in BioEdit 7.2 and compared with those in the NCBI nucleotide database. Alignments were implemented in MEGA X using reference sequences from Fusarium spp. A phylogenetic tree, including published ITS, EF1-α, and rpb2 sequence data, was constructed for the Fusarium incarnatum-equiseti species complex (FIESC) based on Maximum Likelihood. The sequences were deposited in GenBank (accession nos. ON878083, ON890421, and ON890420). The phylogenetic analysis grouped the isolate FUS2 within the F. citri clade. Pathogenicity of the fungus was verified on 10 healthy chayote fruits var. nigrum spinosum previously disinfested by immersion in a 1% NaClO solution for 3 min and washed in sterile water. A total of 5 mL of a conidial suspension (1 × 106 spores/ml) was sprayed on each whole fruit. Ten control fruit were sprayed with sterile distilled water. The fruits were kept in a moist plastic chamber at 25°C and 12 h light/dark for 30 days. All inoculated fruits developed water-soaked brown lesions (3 to 5 cm in diameter) covered with white mycelium at 15 days after inoculation, whereas no symptoms were observed on the control fruits. The fungus was consistently re-isolated only from the diseased fruits and found to be morphologically identical to the isolate used for inoculation, fulfilling Koch´s postulates. Fusarium citri has been associated with Capsicum sp. and mandarin orange in China, Triticum sp. in Iran, alfalfa in Denmark, and lettuce in the Czech Republic and Italy (Farr and Rossman 2022). To our knowledge, this is the first report of F. citri causing postharvest fruit rot of chayote in Mexico and worldwide.

Dissolution of Ruthenium Metal by Combined Oxidizing and Reducing Action of Sodium Hypochlorite and HCl Solution

ABSTRACT Ruthenium (Ru) is an important platinum group metal for the manufacture of advanced materials owing to its chemical and physical properties. Generally, it is extremely difficult to dissolve Ru metal by using acidic solutions containing strong oxidizing agents. Therefore, pretreatments like alkali fusion roasting at high temperature are practiced to render the Ru metal soluble in aqueous solution. In this work, a simple procedure was proposed to dissolve Ru metal at room temperature without any pretreatments. The dissolution procedure consisted of two steps: (i) oxidation of Ru metal to RuO4 – by using pure NaClO solution; (ii) reduction of RuO4 – to stable Ru2OCl10 4– by using HCl as a reducing agent. The role of NaClO and HCl in the dissolution of Ru metal was discussed on the basis of the potential-pH diagram and the corresponding oxidation and reduction reactions. The effect of several parameters like the concentration of NaClO and HCl, temperature, time, and pulp density was investigated. Optimum conditions were obtained to completely dissolve Ru metal by using NaClO and HCl solution without alkali fusion.

Bonding properties of polyurethan enhanced by branched polyamine and wood interfacial activation

Developing formaldehyde-free and excellent water resistance has constantly been at the center of attention of wood adhesives. In addition to enhancing the adhesive itself, the modification of wood interface can also improve its bonding strength and water resistance. In this study, aqueous solutions of NaIO4 and NaClO2 have been sprayed onto the surface of poplar veneer evenly. An activated wood interface equipped with -CHO and -COOH was prepared. Traditional polyurethane adhesives are primarily two-component, with excessive manufacturing cost, complicated production and use procedures. In this study, a single component high branched polyurethane adhesive (GI) was synthesized via a A2 +B3 oligomerization method by using glycerol and isophorone diisocyanate (IPDI). Using branched polyamine (PA4 N) as a modifier, GI was modified to GI-PA4 N, which was used as an adhesive and then hot pressed with the activated wood to make three-layer plywood. The bonding interface was equipped with urethane bonds, urea-based chemical bonds, amide bonds, Schiff bonds and hydrogen bond, which considerably enhanced the stability and water resistance of the bonding interface. FT-IR and XPS confirmed the existence of -CHO and -COOH at the interface of the activated wood, and characterized the synthesis mechanism and bonding mechanism of GI-PA4 N. The results indicated that when the mass ratio of polyurethane to polyamine was 4:1, the overall performance of the adhesive was the best. The dry bonding strength increased from 1.92 MPa to 3.63 MPa, and the wet bonding strength increased from 1.77 MPa to 3.13 MPa, much higher than the minimum requirement of GB/T 17657–2013 (0.7 MPa). A formaldehyde-free, high-performance plywood with excellent water resistance was successfully prepared using wood interfacial activation and branched polyamine modification.

Leptosphaerulina americana causing holing disease on tobacco in China.

Leptosphaerulina americana causing holing disease on tobacco in China.

The evaluation effect of fusarium verticillioides on seed quality in new high-yielding maize vareties

Fusarium verticillioides can cause a decrease in the yield and quality of corn due to the mycotoxins produced. 10 seeds high yielding maize varieties were sterilized using a 5.15% NaClO solution and sterile water. Inoculated seeds for 72 hours, grown on straw paper and polybags. Observation of germination, plant growth, incidence and severity of disease as well as the identification of Koch’s Postulates method, were observed macroscopically and microscopically at the Laboratory, Hasanuddin University. The results showed that F. verticillioides caused the germination of maize seeds in the Pertiwi and NK sumo varieties to only 33.3%, while the highest germination occurred in the Sukmaraga variety at 91.7%. The growth of corn plants showed differences in height and number of leaves in each of the 10 varieties. Severity of the disease in the vegetative phase occurred in the variety Pertiwi and Pioneer27 by 35% and the varieties with the lowest severity occurred in Zakarin variety by. Selection of varieties that are resistant to the F. verticillioides pathogen greatly influences F. verticillioides infection because they can be a source of inoculum.

A new absorbent system for reducing chlorine gas escape and enhancing pollutants removal during ship exhaust wet scrubbing

Using chlorine-containing oxidants to remove pollutants in the exhaust gas of ships is normally accompanied by Cl2 escape, which poses a significant threat to the environment and the health of the crew. This paper proposes a method to solve the problem of Cl2 escape in a single NaClO solution system using BAD (a new amide absorbent, C12H25NO). The electrostatic potential (ESP) theoretical calculations, FT-IR and UV–vis spectra tests showed that the strong field effect interaction between BAD and Cl2, which can form a stable symmetrical structure similar to a “sandwich”, results in a strong binding ability of BAD to Cl2. The effects of the initial pH, the concentration of NaClO solution, aeration time, and some operating parameters on the loss of active chlorine (AC) components were studied. Under the same conditions, a two-phase composite absorbent system with the addition of BAD can reduce the loss of AC components by 32.67% on average and up to 56.12%. It also can effectively capture the Cl2 escaping with the gas flow and keep it in the system, which enhances the oxidation of NO by Cl2 at the gas–liquid interface. It also has a strong ability to remove pollutants for a long period, as the removal efficiencies of SO2, NO, and NOx within 20 mins were 97.84%, 77.98%, and 76.01%, respectively. The results show that the BAD-NaClO two-phase composite absorbent system can effectively reduce Cl2 escape, and it is a sustainable wet treatment scheme for ship exhaust gas with great application prospects.

Leaf spot of Alnus cremastogyne Caused by Colletotrichum gloeosporioides in Sichuan, China.

Alnus cremastogyne Burk, a broad-leaved tree endemic to south-western China, has both ecological and economic value. The tree is widely used in furniture, timber, windbreaks and sand fixation, and soil and water conservation (Tariq et al. 2018). In December 2020, a new leaf spot disease was discovered on A. cremastogyne in two plant nurseries in Bazhong City (31°15' to 32°45N, 106°21' to 107°45'E), with 77.53% disease incidence. Among the infected trees, 69.54% of the leaves were covered with symptoms of the disease. The typical symptoms initially appeared as irregular brown necrotic lesions, while some lesions were surrounded by a light yellow halo. As the disease progressed, the number of necrotic lesions increased, and lesions gradually expanded and coalesced (Fig. 1). Finally, the disease caused the leaves of A. cremastogyne to wither, curl, die, and fall off. Ten symptomatic leaves were collected from 5 different trees in the two plant nurseries. The leaves with symptoms of leaf spot disease were collected and cut from the junction between the diseased and the healthy tissues. The infected tissues from 10 samples were cut into small 2.5 × 2.5 mm pieces. Infected tissues was sterilized in 3% NaClO solution for 60 s followed by 75% ethanol for 90 s, rinsed three times in sterile water, blot-dried with autoclaved paper towels, and then cultured on potato dextrose agar (PDA) at 25℃ for 4 to 8 days in 12 h/12 h light/dark conditions. After 8 days, the colony diameter reached 71.2 to 79.8 mm. The colonies were initially light pink, and then turned white with pale orange beneath. The conidia were single-celled, aseptate, colorless, cylindrical, straight, bluntly rounded at both ends, and measured 11.6 to 15.9 × 4.3 to 6.1 μm (n = 100). These morphological characteristics were consistent with the description of Colletotrichum gloeosporioides (Pan et al. 2021). For molecular identification, the genomic DNA of a representative isolate, QM202012, was extracted using a fungal genomic DNA extraction kit (Solarbio, Beijing). The internal transcribed spacer (ITS), actin (ACT), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified with primers ITS1/ITS4 (White et al. 1990), ACT-512F/ACT-783R (Carbone & Kohn, 1999) and GDF/GDR (Templeton et al. 1992), respectively. Sequences were deposited in GenBank (ITS: OL744612, ACT: OL763390, and GAPDH: OL799166). BLAST results indicated that the ITS, ACT, and GAPDH sequences showed >99% identity with C. gloeosporioides sequences in NCBI (GenBank NR160754, MG561657, and KP145407). Identification was confirmed by Bayesian inference using Mr Bayer (Fig 2) A conidial suspension (1 × 106 conidia/ml) was used to test pathogenicity on the leaves of 4-year-old A. cremastogyne plants (10 plants). Fifteen leaves of each plant (10 pots in total) were inoculated with the spore suspension on the leaves. The same number of control leaves was sprayed with sterilized distilled water as a control. Finally, all potted plants were placed in a greenhouse at 25°C under 16 h/8 h photoperiod and 67 to 78% relative humidity. The symptoms observed on the inoculated plants were similar to those of the original diseased plants, with 100% of the inoculated plants being infested with brown leaf spots, but the controls remained symptom-free. C. gloeosporioides was re-isolated from the infected leaves and identified by both morphological characteristics and DNA sequence analysis. The pathogenicity test was repeated three times, showing similar results each time, confirming Koch's postulates. To our knowledge, this is the first report of leaf spot on A. cremastogyne caused by C. gloeosporioides in China. This finding indicates that C. gloeosporioides may become a serious threat to A. cremastogyne production in Bazhong City and helps to further examine and prevent leaf spot disease in A. cremastogyne growing areas in Bazhong City.

Nigrospora musae Causing Taxus chinensis var. mairei stem blight in Sichuan, China.

Taxus chinensis var. mairei is the endemic, endangered, and first-class protected tree species in China. This species is considered as an important resource plant because it can produce Taxol which is an effective medicinal compound against various cancers (Zhang et al., 2010). Stem blight was observed in two plant nurseries in Ya'an (102°44'E,30°42'N), Sichuan province in April 2021. The symptoms first appeared as round brown spots on the stem. As the disease progressed, the damaged area gradually expanded into an oval or irregular shape, which was dark brown. About 800 square meters of planting area were investigated and the disease incidence was up to approximately 64.8%. Twenty obviously symptomatic stems which exhibited the same symptoms as above were collected from 5 different trees in the nursery. To isolate the pathogen, the symptom margin was cut into small blocks (5 x 5 mm), and the blocks were surface sterilized in 75% ethanol for 90 s and 3% NaClO solution for 60 s . Finally incubated on Potato Dextrose Agar (PDA) at 28℃ for 5 days. Ten pure cultures were isolated by transferring hyphal and the three strains (HDS06, HDS07 and HDS08) were selected as representative isolates for further study. Initially, colonies on the PDA of three isolates were white and cotton-like, and then gradually turned gray-black from the center. After 21 days, conidia were produced and were smooth-walled, single-celled, black, oblate, or spherical, measuring 9.3 to 13.6 × 10.1 to 14.5 μm in size (n = 50). Conidia were present at the tip of conidiophores on hyaline vesicles. These morphological features were generally consistent with those of N. musae (Wang et al., 2017). To validate the identification, DNA were extracted from the three isolates, followed by the amplification of transcribed spacer region of rDNA (ITS), the translation elongation factor EF-1 (TEF-1), and the Beta-tubulin (TUB2) sequences with the respective primer pairs ITS1/ITS4 (White et al., 1990), EF-728F/EF-986R (Vieira et al., 2014) and Bt2a/Bt2b (O'Donnell et al., 1997) .The sequences were deposited in GenBank with the accession numbers ON965533, OP028064, OP028068, OP060349, OP060353, OP060354, OP060350, OP060351 and OP060352, respectively. Phylogenetic analysis of combined ITS, TUB2, and TEF genes using the Mrbayes inference method showed that the three isolates clustered with Nigrospora musae as a distinct clade (Fig. 2). Combine with morphological characteristics and phylogenetic analysis, three isolates were identified as N. musae. 30 2-year-old healthy potted plants of T. chinensis were used for pathogenicity test. 25 of these plants were inoculated by injecting 10 μL of the conidia suspension (1 × 106 conidia/mL) into stems and then wrap around the seal to moisturize. The remaining 5 plants were injected with the same amount of sterilized distilled water as a control. Finally, all potted plants were placed in a greenhouse at 25°C and 80% relative humidity. After 2 weeks, the inoculated stems developed lesions similar to those observed in the field, whereas controls were asymptomatic. N. musae was re-isolated from the infected stem and identified by both morphological characteristics and DNA sequence analysis. The experiments repeated three times showed similar results. As far as we know, this is the first report of N. musae causing T. chinensis stem blight in the world. The identification of N. musae could provide a certain theoretical basis for field management and further research of T. chinensis.

Effect of Sodium Hypochlorite 0.05% on MMP-9 Extracellular Release in Chronic Wounds.

In chronic wounds, high concentrations of matrix metalloproteinases (MMPs) can cause excessive proteolysis and slow wound healing. Consequently, restoring a proper MMP balance can help reduce the risk of a chronic wound. An antiseptic solution containing 0.05% sodium hypochlorite (Amukine Med 0.05%, Angelini S.p.A.; hereafter termed NaClO solution) is available on the market. The NaClO solution was proven effective and safe in managing infected skin wounds. To further characterize its activity, this study evaluated the in vitro activity of the NaClO solution on the monocyte release of MMPs. Human monocytic THP-1 (ATCC® TIB-202™) cell lines were differentiated into macrophages and treated with different concentrations of NaClO (from 0.05% to 5 × 10-7%). In addition, the THP-1 cell line was stimulated with wound fluid (WF) from patients with active venous leg ulcers in the inflammatory phase. The effect of NaClO (0.025-0.0062%) was also evaluated on healthy human peripheral blood serum samples. The effects of treatments on the gelatinolytic activity of MMP-9 were evaluated by gelatin zymography. The effects on MMPs release were evaluated through the Pro™ Human MMP 9-plex Assay. An exploratory scratch wound healing assay was also performed. The NaClO solution reduced the gelatinolytic activity of MMP-9 and its activated form. The downregulation of MMP-9 gelatinolytic activity was also observed in peripheral blood serum. The MMPs profile showed a reduction in MMP-1 release (p < 0.05) and a slight reduction of the release of MMP-9 and MMP-12 after the treatment with LPS and the NaClO solution. A slight improvement in wound healing was observed after macrophage activation and treatment with the NaClO solution. The results obtained suggest a possible ability of the NaClO solution to modulate the proteolytic pathways in the wound microenvironment, further characterizing its activity and use in clinical practice during wound care.

Base-activated persulfate strategy for ceramic membrane cleaning after treatment of natural surface water

The natural organic matters (NOM) have been proved to form the hydraulically irreversible membrane fouling, which limit the application of the membrane in water treatment processes. To solve the membrane fouling caused by NOM, a novel one-step chemical cleaning method for the ceramic membrane derived from the base-activated persulfate oxidation process was developed in this study. When the SiC ceramic membranes was used to filtrate practical river water, the permeate flux dropped 65% as ΔTMP reached 30 kPa. After 2 h immersion of the fouled membrane in the cleaning solution (2 mM PMS and 8 mM NaOH), the flux recovery rate nearly reached 100%. Direct backwash of the membrane by the above cleaning solution further reduced the cleaning time to 25 mins, while achieving similar cleaning effect. Then the cleaned membranes were immersed in NaClO solution to release all the residual foulants, but the fluorescence excitation-emission matrix spectra (EEM) and total organic carbon (TOC) of the solution were found insignificant, which demonstrated the base-activated persulfate strategy had effectively removed the irreversible membrane fouling. Free radical quenching experiments were carried out and·O2- was identified as the dominant ROS responsible for the removal of the membrane foulants. The permeate flux and filtration efficiency of the SiC membrane were stable after 5 consecutive fouling-cleaning cycles, and the membrane structure was not damaged. In summary, the base-activated persulfate strategy is an efficient and cleaner method for SiC membrane cleaning, which is potential to be applied in practical membrane water treatment process.

Chlorine-Resistant Loose Nanofiltration Membranes Fabricated via Interfacial Polymerization Using Sulfone Group-Containing Amine Monomer for Dye/Salt Separation

Fabrication of high-dye/salt-separation-performances and chlorine-resistant nanofiltration (NF) membranes are crucial for dye desalination. In this study, a thin-film composite NF membrane (PES–DPS) was prepared through the interfacial polymerization of 3,3′-diaminodiphenyl sulfone (DPS) and trimesoyl chloride. Because of the low reactivity and the presence of the sulfone group (O=S=O) of DPS, the prepared PES–DPS membrane provided a relatively loose polyamide layer and exhibited excellent chlorine resistance, enhancing the membrane water flux and dye/salt separation performances. Furthermore, the influence of DPS concentration was systematically investigated. The optimal membrane PES–DPS–1 exhibited high direct Blue 71 rejection (99.1%) and low NaCl rejection (8.7%). Meanwhile, the PES–DPS–1 membrane displayed highly pure water flux (49.4 L·m−2·h−1·bar−1) even at a low-operating pressure (2 bar). Moreover, no significant difference in dye rejection was observed when the membrane was immersed in NaClO solution (pH = 4.0, 2000 ppm) for 12 h, thereby demonstrating its outstanding chlorine stability. In summary, this work provided a new monomer for the preparation of novel polyamide membranes to achieve excellent separation performances and chlorine resistances.

Chemical digestion method to promote activated sludge cell wall breaking and optimize the polyhydroxyalkanoate (PHA) extraction process

A novel protocol for the recovery of PHA from mixed-cultures proposed. In this experiment, activated sludge for PHA synthesis was investigated and a two-stage chemical digestion method was used for activated sludge to improve the yield of PHA. The highest PHA extraction combination that could be obtained in this experiment was sodium hypochlorite(NaClO) plus sodium dodecyl sulfate (SDS), and the optimal concentration of NaClO solution was 25 % (v/v), and the ratio of the dry weight of activated sludge to SDS was 1:2. The recovery and purity of PHA were 72.14 % and 54.47 %, respectively. The reaction time between NaClO and activated sludge affects the recovery of PHA, and the optimal reaction time of NaClO was experimentally obtained as 30 min. The purity of the PHA extract obtained after purification using methanol was improved.