Green One-Step Strategy of Conductive Ink for Active Health Monitoring in Rehabilitation and Early Care.

Conductive ink deposited on flexible substrates through simple methods such as dyeing or printing is one of the most promising approaches for scalable fabrication of wearable electronics. However, excessive chemical additives or a complex preparation process has limited the practical applications of conductive inks. Herein, a highly stable and antibacterial AgNPs/CNT/rGO (SACR) conductive ink with the only assistance of sustainable silk sericin (SS) is developed through a green one-step strategy. SS functions as not only the reductant of silver ions and GO by donating electrons but also the dispersant and stabilizer of CNTs through strong noncovalent interactions. The universality of SACR ink is demonstrated by depositing on various flexible substrates through handwriting, screen-printing, and dyeing techniques; meanwhile, the mechanical reliability between SACR ink and substrates is validated by peeling, bending, and twisting measurements. In addition, the synergistic effects of the multilevel hierarchical 0D/1D/2D structure and abundant interfacial interactions in SACR ink are advantageous to enhancing sensing performance. An SACR ink-based strain sensor and hydrogen peroxide (H2O2) sensor are fabricated to detect physical and biochemical indicators, demonstrating the enormous potential of SACR ink in intelligent wearables for active health monitoring in early care.

First report of Fusarium solani causing Fusarium wilt of Bletilla striata (hyacinth orchid) in Zhejiang province of China.

Bletilla striata, a member of the family Orchidaceae, is a perennial herbaceous plant used in Chinese medicine. It is a commonly cultivated economic crop in the Yangtze River Basin provinces of China, as its roots are used to treat bleeding and inflammation. In Zhejiang province, Bletilla striata has a planting area of 1400 hectares with a total production of approximately 2.6×106 kg. In October 2021, over 40% of B. striata plants showed severe wilt in a traditional Chinese medicine plantation (ca. 10 ha) in Xianju City, Zhejiang Province, China. In July, leaf curling, crinkling, and leaf-edge browning of the diseased plants were first noticed in the field. Then, necrotic streaks gradually spread to the roots. Stems displayed chlorosis and withering and when they were cut vertically, symptoms such as vascular bundle discoloration, appeared. After October, the individual plants slowly wilted and died, their aboveground parts became filamentous, and the epidermis detached from the corm's fibrous roots. Diseased plants were easily removed as the corm root had fractured. White mycelia were clearly seen in the stem. Three symptomatic leaves and three stems were cut, their surfaces disinfected, and plated on potato dextrose agar (PDA). Six strains were subsequently isolated from all samples. Fungal colonies with white to cream-colored mycelia from all tissues appeared after 3 d of incubation at 26 °C. Pure cultures obtained after monospore isolation were examined for their morphological characteristics. The colonies grew rapidly, were fluffy and appressed, and had cottony white to pale cream coloration. Microconidia were hyaline, oval to reniform, with zero or one-septate (4.0-12.0 × 1.0-5.5 µm), and usually formed on elongated monophialidic conidiogenous cells. Macroconidia were wide, fusiform, or slightly curved with one or three septa (23.0-36.0 × 4.5-7.0 µm). Chlamydospores were spherical and were abundant on carrot agar (CA) medium within 2 wk. Fresh mycelia and conidia that grew at 26 ℃ for 7 d were collected from PDA plates. Next, DNA was extracted using the Ezup Column Fungi Genomic DNA Purification kit (Sangon Biotech, Shanghai, China). We amplified a portion of RNA polymerase II second largest subunit gene (RPB2) using primers 5f2/7cr (O'Donnell et al. 2010), the internal transcribed spacer (ITS) region using primers ITS1F/ITS4 (White et al. 1990), and the partial translation elongation factor-1α gene using primers EF1/ EF2 (O'Donnell et al. 1998) from the genomic DNA and sent the PCR amplicons for sequencing at Tsingke Biotechnology Co., Ltd., Wuhan, China. A BLAST search of the obtained sequences (GenBank accessions OP743920, OP913183, and OP913180) showed 99-100% homology with the respective sequences of the Fusarium solani reference isolate NRRL46702 (O'Donnell et al. 2008). Based on the morphological and molecular characteristics and BLAST search, the fungus was identified as F. solani (Leslie and Summerell 2006). Pathogenicity of the purified F. solani isolate was assessed by inoculateing a F. solani spore suspension of 1×106 conidia/mL (20 mL per seedling) on corm wounds made with a toothpick. Four inoculated and three non-inoculated seedlings (sterilized water as a negative control) were grown in a greenhouse at 26 °C under natural sunlight and covered with plastic bags to maintain humidity for 72 h. After 15 d, leaf browning on leaf edges, new leaf bases, and corm epidermis was observed. Symptoms, similar to those detected in the original sample, developed on the inoculated leaves, whereas the controls remained asymptomatic. Fusarium solani was successfully re-isolated from all four inoculated seedlings, and their identity confirmed by generating partial Tef1 and RPB2 sequences, thereby fulfilling the Koch's postulate. To our knowledge, F. solani has not been previously reported as a pathogen of B. striata.

Quercitrin Is a Novel Inhibitor of Salmonella enterica Serovar Typhimurium Type III Secretion System.

The purpose was to screen type III secretory system (T3SS) inhibitors of Salmonella enterica serovar Typhimurium (S. Typhimurium) from natural compounds. The pharmacological activities and action mechanisms of candidate compounds in vivo and in vitro were systematically studied and analyzed. Using a SipA-ß-lactamase fusion reporting system, we found that quercitrin significantly blocked the translocation of SipA into eukaryotic host cells without affecting the growth of bacteria. Adhesion and invasion assay showed that quercitrin inhibited S. Typhimurium invasion into host cells and reduced S. Typhimurium mediated host cell damage. ß-galactosidase activity detection and Western blot analysis showed that quercitrin significantly inhibited the expression of SPI-1 genes (hilA and sopA) and effectors (SipA and SipC). The results of animal experiments showed that quercitrin significantly reduced colony colonization and alleviated the cecum pathological injury of the infected mice. Small molecule inhibitor quercitrin directly inhibited the function of T3SS and provided a potential antibiotic alternative against S. Typhimurium infection. Importance: T3SS plays a crucial role in the bacterial invasion and pathogenesis of S. Typhimurium. Compared with conventional antibiotics, small molecules could inhibit the virulence factors represented by S. Typhimurium T3SS. They have less pressure on bacterial vitality and a lower probability of producing drug resistance. Our results provide strong evidence for the development of novel inhibitors against S. Typhimurium infection.

First report of Calonectria pseudopteridis causing brown spot on Eriocaulon buergerianum in Zhejiang province, China.

Eriocaulon buergerianum is a traditional Chinese herb, used to treat eye diseases. In July 2020, a severe brown spot disease occurred on E. buergerianuim in Yongjia county (120°19'E, 27°58'N), Zhejiang province, China. Seventy-three plants from a survey of about 150 plants showed brown leaf spots. The spots were yellowish-brown to brown, and primarily affected leaves. As the disease progressed, the spots expanded, and fused. Sixty of the 150 plants wilted (Fig. 1 A-D). Diseased tissues were surface-sterilized in 75% ethanol (30 s), rinsed three times with sterile distilled water, air-dried (5 min), placed on potato dextrose agar (PDA) at 26°C (12-h light/dark cycle), and cultured for 4 days. Hyphal tip technique was used to obtain five isolates, which were transferred to malt extract agar (MEA), oatmeal agar (OA), and PDA. After seven days of growth at 26°C, the colonies had light, yellowish-brown centers with gray-white edges; the reverse sides had reddish- to yellowish-brown centers. Seven-day-old colonies grown on oatmeal agar (OA) produced a sparse aerial mycelium with yellowish-brown centers, and light yellowish-brown centers on the reverse side. Seven-day-old colonies grown on PDA exhibited yellowish-brown, floccose, aerial mycelia with reddish-brown to yellowish-brown pigment on the back (Fig. 1 E-G). The colonies also produced microsclerotia on OA and PDA media. On carnation leaf agar (CLA) and water agar (WA), only macroconidia were produced. Macroconidiophores comprised a stipe bearing penicillate, fertile branches, and a clavate vesicle. Macroconidia were cylindrical, rounded at both ends, colorless, hyaline, 1- to 2-septate, but mainly one, and 71.86 to 96.11 µm (mean = 82.27 µm, n = 50) × 4.13 to 5.21 µm (mean = 4.63 µm, n = 50) (Fig. 1 H-K). Morphological characteristics of the isolate on CLA or WA medium were similar to the Calonectria petridis species complex (Alfenas et al. 2015; Liu et al. 2020). The actin (Act), calmodulin (Cal), internal transcribed spacer (ITS), Histone3 (His3), a fragment of the large subunit nuclear ribosomal DNA (LSU), RNA polymerase II subunit 2 (Rpb2), translation elongation factor 1α (Tef1), and ß-tubulin 2 (Tub2) genes were sequenced. The sequences were deposited in GenBank as: His3: Not detected; Act, OM933603, MZ770831, OM933604-OM933606; Cal, OM933607, MZ770832, OM933608-OM933610; ITS, OM955624, MZ720794, OM955625-OM955627; LSU, OM955640, MZ720792, OM955641-OM955643; Rpb2, OM933615, MZ770834, OM933616-OM933618; Tef1, OM933611, MZ770833, OM933612-OM933614; and Tub2, OM933619, MZ770835, OM933620-OM933622. Sequences of the Act, Cal, ITS, LSU, Rpb2, and Tef1 genes of these strains show a 99% match to the ex-type strain Ca. pteridis CBS111793 and Ca. pseudopteridis CBS163.28 (Act, GQ280494, MT335112; Cal, GQ267413, MT335347; ITS, GQ280616, MT359808; LSU, GQ280738, MT359568; Rpb2, KY653438, MT412640; Tef1, FJ918563, MT412878). The Tub2 sequences showed 99% identity with sequences of the ex-holotype Ca. pteridis CBS111793 (Tub2, DQ190578) (Alfenas et al. 2015; Liu et al. 2020; Lombard et al. 2016). Phylogenetic analysis showed that these strains and Ca. pseudopteridis CBS163.28 were clustered in a high-support bootstrap value clade (bootstrap = 85) (Fig. 2). In August 2020, healthy E. buergerianum plants in the blooming-fruiting stage were used to test the pathogenicity of the isolates. The mycelium of isolate GJC3 was cultured on CLA medium at 26°C (12-h light/dark cycle) for ten days. Eight healthy plants were inoculated by spraying with a conidial suspension (10 mL of 1 × 105 conidia/mL). Another eight plants were sprayed with sterilized water 10 mL of sterilized water as controls. The experiment was repeated three times. Pathogenicity tests were performed in the greenhouse (60% relative humidity, 28 to 20°C day/night, temperature range, and natural sunlight). After 15 days, inoculated plants showed yellowish-brown to brown spots and withering of the leaves, whereas the control plants remained healthy (Fig. 1 L-N). Ca. pseudopteridis was reisolated from the inoculated plants, and its morphology and gene sequences were similar to the original isolate GJC3. Ca. pseudopteridis was not isolated from the control plants. Morphological characteristics, molecular data and pathogenicity test identified these organisms as Ca. pseudopteridis. This report provides a basis for further research on biology and management of this disease.

First report of Curvularia geniculata causing leave spot disease of Bletilla striata in Zhejiang of China.

Bletilla striata, a perennial herbaceous plant belonging to the family Orchidaceae, is native to China and is widely distributed in the Yangtze River basin. In China, B. striata is a popular medicinal plant that is typically used to reduce wound bleeding and inflammation. In September 2021, distinct leaf spot symptoms were observed in more than 50% of B. striata plants in a traditional Chinese medicine plantation (ca. 10 ha) in Xianju City, Zhejiang Province, China. Small, round, pale brown, necrotic spots were first observed on the leaves. Subsequently, these lesions became grayish brown in the center and dark brown with slight protuberances at the margins and eventually enlarged to 5-8 mm on the leaves. Over time, the small spots enlarged and coalesced into necrotic streaks (1-2 cm). Leaves with symptoms of disease were cut, surface-sterilized, and plated on potato dextrose agar (PDA). Fungal colonies (28×28 mm) with grayish-black mycelia from all tissues were produced after 3 days of incubation at 26 °C. The mature colonies eventually turned black in the center, with obvious rings appearing after 10 days of culture. Basal conidia ranged from pale to dark brown, whereas apical ones were pale brown, with central cells being larger and darker than basal cells. Conidia were smooth and either fusiform, cylindrical, or slightly curved with rounded tips. They ranged in length from 22.34 to 36.82 (mean = 28.63) µm with 2-4 septations and slight septal constrictions. Monospore isolation was performed to obtain a pure culture. Strain BJ2Y5 was subsequently stored in the strain Preservation Center of Wuhan University (Wuhan, China) and the strain preservation number CCTCC M 2023123 was obtained. Fresh mycelia and conidia that grew at 26 ℃ for 7 days were collected from PDA plates. DNA was extracted using the Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech Co., Shanghai, China). The phylogenetic position of isolate BJ2-Y5 was clarified based on DNA sequence analysis of three loci, namely glyceraldehyde 3-phosphate dehydrogenase (GAPDH; Berbee et al. 1999), the internal transcribed spacer (ITS) region (White et al. 1990), and partial sequences of the second largest subunit of RNA polymerase II (RPB2; O'Donnell et al. 2007). A BLAST search (GenBank accession nos. OP913168, OP743380, and OP913171) showed 99% homology to the reference isolate CBS 220.52. Based on the morphological and molecular information presented in this study these isolates were identified as C. geniculata (Hosokawa et al. 2003). Furthermore, we evaluated the pathogenicity of B. striata leaves by smearing a conidial suspension (106 conidia/mL) on both sides of leaves with and without wounds. Five inoculated and three non-inoculated leaves (smeared with sterile distilled water as a negative control) were kept in a greenhouse at 26 °C under natural sunlight and covered with plastic bags for 72 h to maintain humidity. After 7 days, small round spots appeared on the wounds. Fifteen days later, the symptoms of disease on the wounded inoculated leaves were similar to those observed in the original sample, whereas the control plants remained healthy. No symptoms of infection were observed in unwounded inoculated leaves. C. geniculata was successfully re-isolated from all five inoculated leaves and was confirmed based on Koch's postulates. To the best of our knowledge, C. geniculata infection has not been previously reported in B. striata.

Discrete unified gas kinetic scheme for continuum compressible flows.

In this paper, a discrete unified gas kinetic scheme (DUGKS) is proposed for continuum compressible gas flows based on the total energy kinetic model [Guo et al., Phys. Rev. E 75, 036704 (2007)1539-375510.1103/PhysRevE.75.036704]. The proposed DUGKS can be viewed as a special finite-volume lattice Boltzmann method for the compressible Navier-Stokes equations in the double distribution function formulation, in which the mass and momentum transport are described by the kinetic equation for a density distribution function (g), and the energy transport is described by the other one for an energy distribution function (h). To recover the full compressible Navier-Stokes equations exactly, the corresponding equilibrium distribution functions g^{eq} and h^{eq} are expanded as Hermite polynomials up to third and second orders, respectively. The velocity spaces for the kinetic equations are discretized according to the seventh and fifth Gauss-Hermite quadratures. Consequently, the computational efficiency of the present DUGKS can be much improved in comparison with previous versions using more discrete velocities required by the ninth Gauss-Hermite quadrature.

Diffuse interface model for a single-component liquid-vapor system.

We elucidate the theoretical relationships among fundamental physical concepts that are involved in the diffuse interface modeling for an isothermal single-component liquid-vapor system, which cover both the equation of state (EOS) and the surface tension force. As an example, a flat surface at equilibrium is discussed both theoretically and numerically by using two different approaches. Particularly, the force structure in the transition region is clearly presented, which demonstrates that the capillary contributions due to the density gradients can suppress the mechanical instability of the thermodynamic pressure and lead to constant hydrodynamic pressure (and chemical potential). Then, by comparing with the van der Waals (vdW) EOS for a flat interface at equilibrium, it is shown that applying the double-well approximation can give qualitative predictions for relatively high density ratio (ρ_{l}/ρ_{g}=7.784) and satisfactory results for relatively low density ratio (ρ_{l}/ρ_{g}=1.774). The main cause for this observation is attributed to the nonlinear variation of the generalized coefficient function in the double-well formulation at different density ratios. In addition, for the latter case, we simulate a droplet impact on a hydrophilic wall by using a recently proposed well-balanced discrete unified gas kinetic scheme (WB-DUGKS), which justifies the applicability of the double-well approximation to complex interfacial dynamics in the low-density-ratio limit. Furthermore, the reason for the inconsistency between the coefficients of the mean-field force expressions in the existing literature is explained.

First report of Calonectria ilicicola causing fruit rot on postharvest Prunus persica in Zhejiang Province, China.

Peach (Prunus persica) is an important economic tree fruit in China, with 15 million tons produced in 2020 (Xu et al. 2022). In September 2021, fruit rot on postharvest P. persica 'Yingqingtao' was observed in an orchard warehouse in Qixing district (120°41'E, 29°15'N), Zhejiang Province. Disease incidence was estimated at 25%, and yield loss was estimated at approximately 20% of the total yield. The naturally infected fruit had water-soaked, light brown lesions that fused, and produced a gray-white, dense mycelium (Fig. 1 A). The mycelia were transferred using a sterilized toothpick to potato dextrose agar (PDA) and cultured for 7 d. Macroconidia were used to produce five single-spore isolates, each from a different fruit. Six-day-old colonies grown on PDA at 26°C had light brown centers with gray-white edges; on the underside the centers were reddish brown and white towards the margin (Fig. 1 D). Isolate TGF2 was selected for further identification. Macroconidia were hyaline, straight, cylindrical, and one-to-three septae, 63.2 to 81.8 × 5.7 to 7.8 µm (mean = 73.9 ± 4.3 × 6.9 ± 0.5, n = 30) (Fig. 1 E). Chlamydospores were produced abundantly on PDA (Fig. 1 F), and measured 11.7 to 19.4 × 8.5 to 16.9 µm (n = 10). Perithecia were reddish orange, globose, and 329.9 to 417.1 µm in diameter on PDA (Fig. 1 G). Asci were hyaline and clavate, 61.2 to 91.8 × 14.4 to 20.7 µm (n = 10); ascospores were hyaline, slightly curved, 1- to 3-septate, mostly 1-septate, and 37.6 to 59.7 × 4.9 to 6.4 µm (mean = 49.9 ± 4.5 × 5.6 ± 0.4, n = 30) (Fig. 1 H-J). Morphological characteristics placed this organism within the Ca. kyotensis species complex (Liu et al. 2020). For molecular identification, the internal transcribed spacer (ITS: OP164807-OP164811), calmodulin (Cal: OP176049-OP176053), histone3 (His3: OP176054-OP176058), and translation elongation factor 1α (Tef1: OP176044-OP176048) genes were sequenced (Liu, et al., 2020). The twenty sequences were deposited in GenBank. A BLAST search of these sequences showed 99% identity with sequences of the ex-holotype Ca. ilicicola CMW 30998 (Liu et al. 2020). Bayes phylogenesis suggested that these strains and Ca. ilicicola CMW 30998 were clustered in the same clade (Bayesian posterior probability = 1) (Fig. 2). Integrating morphology and molecular data, these strains were identified as Ca. ilicicola. For pathogenicity tests, P. persica fruits were surface sterilized in 75% ethanol for 30 s and air-dried for 5 mins to allow the alcohol to volatilize. A conidial suspension (30 mL of 1 × 106 conidia/mL) of TGF2 was sprayed onto ten fruits, and ten fruits sprayed with sterilized water served as controls. The experiment was repeated three times. Fruits were kept on a mist bench at 26°C and 60% relative humidity. After 5 days, inoculated fruits showed necrotic lesions and a dense, gray-white mycelium, however, the control fruits showed no symptoms (Fig. 1 B, C). Ca. ilicicola was reisolated from lesions of inoculated fruits. Ca. ilicicola has been reported from Vaccinium sp., Glycine max, Medicago sativa (Farr and Rossman 2022; Kleczewski et al. 2019; Zhang et al. 2020). To our knowledge, this is the first report of Ca. ilicicola causing fruit rot of P. persica in China. In other research on Ca. ilicicola, we found that continuous light could inhibit its growth, suggesting a method to protect postharvest peaches.

Reactive mixing performance for a nanoparticle precipitation in a swirling vortex flow reactor.

Mixing performance for a consecutive competing reaction system has been investigated in a swirling vortex flow reactor (SVFR). The direct quadrature method of moments combined with the interaction by exchange with the mean (DQMOM-IEM) method was employed to model such reacting flows. This type of reactors is able to generate a strong swirling flow with a great shear gradient in the radial direction. Firstly, mixing at both macroscale and microscale was assessed by mean mixture fraction and its variance, respectively. It is found that macromixing can be rapidly achieved throughout the whole reactor chamber due to its swirling feature. However, micromixing estimated by Bachelor length scale is sensitive to turbulence. Moreover, the additional introduction of ultrasound irradiation can significantly improve the mixing uniformity, namely, free of any stagnant zone presented in the reactor chamber on a macroscale, and little variance deviating from the mean environment value can be observed on a microscale. Secondly, reaction progress variable and the reactant conversion serve as indicators for the occurrence of side reaction. It is found that strong turbulence and a relatively fast micromixing process compared to chemical reaction can greatly reduce the presence of by-product, which will then provide homogenous environment for particle precipitation. Moreover, due to the generation of cavitation bubbles and their subsequent collapse, ultrasound irradiation can further intensify turbulence, creating rather even environment for chemical reactions. Low conversion rate was observed and little by-products were generated consequently. Therefore, it is suggested that the SVFR especially intensified by ultrasound irradiation has the ability to provide efficient mixing performance for the fine-particle synthesis process.

Consistent lifting relations for the initialization of total-energy double-distribution-function kinetic models.

A lifting relation connecting the distribution function explicitly with the hydrodynamic variables is necessary for the Boltzmann equation-based mesoscopic approaches in order to correctly initialize a nonuniform hydrodynamic flow. We derive two lifting relations for Guo et al.'s total-energy double-distribution-function (DDF) kinetic model [Z. L. Guo et al., Phys. Rev. E 75, 036704 (2007)1539-375510.1103/PhysRevE.75.036704], one from the Hermite expansion of the conserved and nonconserved moments, and the second from the O(τ) Chapman-Enskog (CE) approximation of the Maxwellian exponential equilibrium. While both forms are consistent to the compressible Navier-Stokes-Fourier system theoretically, we stress that the latter may introduce numerical oscillations under the recently optimized discrete velocity models [Y. M. Qi et al., Phys. Fluids 34, 116101 (2022)10.1063/5.0120490], namely a 27 discrete velocity model of the seventh-order Gauss-Hermite quadrature (GHQ) accuracy (D3V27A7) for the velocity field combined with a 13 discrete velocity model of the fifth-order GHQ accuracy (D3V13A5) for the total energy. It is shown that the Hermite-expansion-based lifting relation can be alternatively derived from the latter approach using the truncated Hermite-polynomial equilibrium. Additionally, a relationship between the order of CE expansions and the truncated order of Hermite equilibria is developed to determine the minimal order of a Hermite equilibria required to recover any multiple-timescale macroscopic system. Next, three-dimensional compressible Taylor-Green vortex flows with different initial conditions and Ma numbers are simulated to demonstrate the effectiveness and potential issues of these lifting relations. The Hermite-expansion-based lifting relation works well in all cases, while the Chapman-Enskog-expansion-based lifting relation may produce numerical oscillations and a theoretical model is developed to predict such oscillations. Furthermore, the corresponding lifting relations for Qi et al.'s total energy DDF model [Y. M. Qi et al., Phys. Fluids 34, 116101 (2022)10.1063/5.0120490] are derived, and additional simulations are performed to illustrate the generality of our approach.

Impacts of evaporation and inundation on near-surface salinity at a coastal wetland park.

Salinization is one of the main causes of conversion between different ecosystems and landuse functions in coastal wetlands. In this paper, we studied the spatiotemporal dynamics of soil moisture and salinity in a reclaimed national wetland park in Guangdong Province, China. We found that diel evaporation affected soil water up to 40 cm deep. Extreme rainfall only increased topsoil moisture with limited leaching effects on soil salinity. Salt accumulation occurred between 40 and 70 cm depth in rainy season, lasting until the end of monitoring period. Whereas the topsoil was salinized between land-surface to 30 cm deep in dry season, which was recovered after rainfall. This result suggested that the force balance between capillarity and gravity created a relative stable saline layer which was not flushed out during inundation. Therefore, considering these site-specific features could lead to the improved understanding of the migration of salinity in the soil profiles.

First report of Diaporthe gardeniae causing branch blight of Gardenia jasminoides Ellis in Zhejiang Province, China.

Gardenia jasminoides Ellis, an important Chinese medicine, is cultivated on approximately 1,400 hectares in China. From August to October 2016, a severe disease affecting leaves, stems, and fruits of G. jasminoides, occurred in Cangnan (120°39'E, 27°48'N), Zhejiang province. Infected leaves or stems became shriveled, and in severe cases, young fruits presented red-brown or yellow necrotic lesions with numerous black spots. More than thirty diseased fruit and stem samples were collected, ten diseased fruits were surfacedisinfected (70% ethanol for 30 s, 1.5% sodium hypochlorite for 1 min) and kept at about 25℃ for 24 h with 80% humidity. The conidial suspension (105 conidia/ml) made of creamy drops secreted from the lesion black spots was spread onto PDA (Potato-Dextrose-Agar) and incubated at 25℃ in the dark for 7 d. Only one isolate (step01) was suspected to be the target pathogen, and other three isolates were Alternaria sp. The colony of step01 was white to grayish with an irregular edge on the front and a white to brown spiral grain on the back. Black pycnidia, produced after 20 d, were globose to subglobose, individual or overlapped, with an ostiole secreting a creamy conidial suspension. Alpha-conidia were aseptate, hyaline, oval to oblong with two oil balls, 7.4-15.9×2.4-4.5 µm (average 10.2×3.3 µm); beta-conidia were hyaline, aseptate, linetype, straight or slightly curled, 15.3-26.5×1.3-2.5 µm (average 20.8×1.6 µm). This isolate resembled Diaporthe sp. (Hansen and Barrett 1938). For species identification, DNA was extracted (Sangon Biotech Rapid Fungi Genomic DNA Isolation Kit - B518229)，and the internal transcribed spacer region (ITS), elongation factor (EF1-α), ß-Tubulin (TUB), and histone H3 (HIS) of step01 were amplified using the primer pairs ITS1/ITS4, EF1-728F/ EF1-986R, BT-2a /BT-2b and CYLH3F/CYLH3R, respectively (Udayanga et al 2014, Huang et al. 2015).These sequences were submitted to GenBank as KY797655 (ITS), MF158048 (EF1- α), MF158049 (TUB), and MF158050 (HIS). In comparison with the other sequence of Diaporthe sp. using MEGA7.0 (maximum likelihood, bootstrap replications=1,000), step01 showed 100% identity with D. gardeniae. Based on their morphology and molecular identification, step01 was identified as D. gardeniae (syn. Phomopsis gardeniae). Pathogenicity was tested on three one-year-old G. jasminoides plants by stem inoculation. Two or three stems per plant were inoculated by binding a mycelial plug (5 ×12 mm), covered by humid cotton and plastic film, to the tender stem. A total of two plants were treated. Plants were kept at about 25℃ for 4 weeks. Control plants were inoculated with PDA plugs. Leaf blight started from the apex, extended to the stalk, and the leaves finally fell off. Three months after inoculation, symptoms developed on the underlying leaves, the stem was withered with black spots, a pattern like that observed in the field. No symptoms appeared in the control leaves. Five identical colonies were re-isolated from symptomatic tissues and identified again as D. gardeniae, fulfilling the Koch's postulates. Several fungi are associated with canker, leaf spot, and fruit rot in Gardenia throughout China, including Pestalotiopsis sp. (Huang et al. 2006), Botryosphaeria dothidea (Dong et al. 2016), and Phoma sp. (Luo et al. 2016). To the best of our knowledge, this is the first report of D. gardenia infecting G. jasminoides Ellis in Zhejiang Province, China.

First report of Colletotrichum godetiae causing anthracnose fruit rot on Prunus pseudocerasus in Zhejiang province, China.

Prunus pseudocerasus (L.) G. Don is an economically important crop, with 8,420 hm2 of harvested area and 35,000 tons in 2020 (https://www.fao.org/faostat/zh/#data/QCL), and is one of the favorite fruits among consumers. A severe fruit rot disease of P. pseudocerasus cultivar "HeiZhenZhu" was observed in an orchard in Pujiang county (119°42'E, 29°21'N), Zhejiang province in April 2022. Sixty-three plants from a survey of about 200 plants showed anthracnose symptoms, with a disease incidence of more than 30%. Ten diseased fruits were collected from eight different trees. The naturally affected fruits during color changing stage showed initial light brown necrotic lesions, later, the lesions were depressed, and dark brown, the fruits were rotten, and pink conidial masses were produced (Fig. 1 A-F). Conidia were transferred using a sterilized needle into sterile water, diluted to approx. 10 conidia/µL, and spread onto potato dextrose agar (PDA) (Thermo Scientific™) (containing cephalosporin 50 µg/mL). After 24 h, single colonies were transferred, and six single-spore isolates were obtained from different plants. When the strains were grown at 26°C for 7 days, the colonies on PDA were flat with entire margin, surface medium gray-green to white, reverse salmon, light gray-green to white (Fig. 1 G). The conidia of the representative strain YTTJ-JHGS5 were unicellular, hyaline, smooth-walled, cylindrical to fusiform with one end round and one end acute, or both acute ends, 14.4 to 18.9 µm (mean = 16.4 ± 0.9 µm, n = 30) × 4.4 to 5.8 µm (mean = 5.1 ± 0.3 µm, n = 30) (Fig. 1 I). Conidiogenous cells were hyaline, smooth-walled, cylindrical to clavate, 6.5-16.8 µm × 2.6-5.3 µm (n = 30), opening 1.1-2.0 µm (Fig. 1 H). Appressoria were single, light brown to medium brown, elliptical or irregular in shape, the outline entire or undulate, 9.2 to 12.1 µm (mean = 9.2 ± 1.1 µm, n = 30) × 4.6 to 6.7 µm (mean = 5.6 ± 0.4 µm, n = 30) (Fig. 1 J). The morphological characteristics of YTTJ-JHGS5 were consistent with the Colletotrichum acutatum species complex (Damm et al. 2012). To further identify the species, the internal transcribed spacer (ITS), actin (ACT), beta-tubulin (TUB), chitin synthase (CHS-1), calmodulin (CAL) and glyceraldehyde-3-phosphate dehydrogenase (GPD) genes were sequenced (Weir et al. 2012; O'Donnell et al. 2000). The thirty-six sequences had been deposited in GenBank (ITS: ON155427-ON155432; ACT: ON191542-ON191547; CAL: ON191548-ON191553; CHS-1: ON167522-ON167527; GPD: ON191554-ON191559; TUB2: ON191560-ON191565, respectively). A BLAST search of these sequences (ITS, ACT, CHS-1, GPD, and TUB2) showed 99% identity with the sequences of ex-holotype C. godetiae CBS133.44 (ITS: JQ948402; ACT: JQ949723; CHS-1: JQ949063; GPD: JQ948733; TUB2: JQ950053) (Damm et al. 2012); the sequences of CAL genes of these strains showed 99% identity with the sequence of C. godetiae VV-087 (CAL: MK416001) (Varjas et al. 2020). The Bayes phylogenesis showed that six strains and C. godetiae CBS133.44 were clustered in a robust branch (Bayesian posterior probability = 1). Based on the morphological characteristics and phylogenesis, these strains were identified as C. godetiae. To fulfill Koch's postulates, in April 2022, live plant pathogenicity tests were performed in the field, and color-changing-stage fruits of five-year-old trees were disinfected with 75% alcohol and air-dried for 10 min to volatilize excess alcohol. A conidial suspension (50 mL of 1 × 106 conidia/mL) was sprayed on fifteen fruits for each plant, fifteen fruits sprayed with sterilized water served as control. The experiment was repeated four times, each repeat contained ten trees. The daily average temperature and daily average RH in the orchard were 22°C and 67%, respectively. After 6 days, the fruit surfaces were depressed, dark brown, later, the lesions were expanded, and pink conidial masses were observed (Fig. 1, L). Control fruits remain healthy (Fig. 1, K). C. godetiae was re-isolated from the lesions of inoculated fruits. C. godetiae has been reported on Ceanothus sp., Fragaria × ananassa and so on worldwide (Farr and Rossman 2022), in addition, C. fructicola infected cherry (Zhao et al. 2022). To our knowledge, this is the first report of C. godetiae causing anthracnose fruit rot on Prunus pseudocerasus in China. This disease occurs mainly on immature fruits and leads to yield loss in the field, therefore it is necessary to take preventive measures in advance.

Discrete unified gas-kinetic scheme for the conservative Allen-Cahn equation.

In this paper, two discrete unified gas-kinetic scheme (DUGKS) methods with piecewise-parabolic flux reconstruction are presented for the conservative Allen-Cahn equation (CACE). One includes a temporal derivative of the order parameter in the force term while the other does not include temporal derivative in the force term but results in a modified CACE with additional terms. In the context of DUGKS, the continuum equations recovered from the piecewise-linear and piecewise-parabolic reconstructions for the fluxes at cell faces are subsequently derived. It is proved that the resulting equation with the piecewise-linear reconstruction is a first-order approximation to the discrete velocity kinetic equation due to the presence of the force term and the nonconservation property of the momentum of the collision model. To guarantee second-order accuracy of DUGKS, the piecewise-parabolic reconstruction for numerical flux is proposed. To validate the accuracy of the present DUGKS with the proposed flux evaluation, several benchmark problems, including the diagonal translation of a circular interface, the rotation of a Zalesak disk and the deformation of a circular interface, have been simulated. Numerical results show that the accuracy of both proposed DUGKS methods is almost comparable and improved compared with the DUGKS with linear flux reconstruction scheme.

Synergistic Effect of Lithocholic Acid with Gentamicin against Gram-Positive Bacteria but Not against Gram-Negative Bacteria.

Listeria monocytogenes (L. monocytogenes) is an important Gram-positive food-borne pathogen that severely threatens public health. A checkerboard microdilution method was performed to evaluate the synergistic effect of lithocholic acid (LCA) with Gentamicin (Genta) against L. monocytogenes. BacLight LIVE/DEAD staining, scanning electron microscopy and biofilm inhibition assays were further used to explore the bactericidal effect and antibiofilm effect of this combination on L. monocytogenes. Additionally, the synergistic effects of LCA derivatives with Genta were also evaluated against L. monocytogenes, S.aureus and S. suis. The results indicated that a synergistic bactericidal effect was observed for the combined therapy of LCA at the concentration without affecting bacteria viability, with Genta. Additionally, LCA in combination with Genta had a synergistic effect against Gram-positive bacteria (L. monocytogenes, S. aureus and S. suis) but not against Gram-negative bacteria (E. coli, A. baumannii and Salmonella). BacLight LIVE/DEAD staining and scanning electron microscopy analysis revealed that the combination of LCA with Genta caused L. monocytogenes membrane injury, leading to bacteria death. We found that 8 µg/mL LCA treatment effectively improved the ability of Genta to eradicate L. monocytogenes biofilms. In addition, we found that chenodeoxycholic acid, as a cholic acid derivative, also improved the bactericidal effect of Genta against Gram-positive bacteria. Our results indicate that LCA represents a broad-spectrum adjuvant with Genta for infection caused by L. monocytogenes and other Gram-positive pathogens.

First report of Colletotrichum scovillei causing anthracnose fruit rot on Eriobotrya japonicain in Zhejiang province, China.

Loquat (Eriobotrya japonica (Thunb.) Lindl.) is a fruit tree of high economic impotance in China. In May 2021, fruit rot on cv. "Baozhu" was observed in Yuhang district (119°40'E, 30°09'N), Zhejiang province, at an incidence of more than 30% within five orchards (the total affected area were about 121, 000 m2). Early symptoms of naturally affected fruits were dark brown, necrotic lesion (Fig. 1 A). Lesions subsequently expanded, and orange conidia were observed (Fig. 1 B). Conidia were transferred using a sterilized needle into sterile water, diluted to several conidia (approximately 10 conidia/µL) in the field of light microscope, and spread onto potato dextrose agar (PDA). After 24 h, single colonies were transferred, and six single-spore strain isolated from different fruits or locations were obtained. Six-day old colonies grown on PDA at 27°C had gray-green centers with white edges, and on the reverse side, the centers were brown (Fig. 1 C). Isolate PPGS2 was selected for further characterization. Conidia were unicellular, smooth-walled, hyaline, cylindrical with one rounded and one acute end, or with both ends rounded and they (n = 30) measured 11.1 to 16.0 µm (mean = 13.3 µm) × 3.0 to 4.6 µm (mean = 4.1) (Fig. 1 D). Appressoria were single or in smalln groups, light brown to dark brown, ovoid or elliptical with a smooth or undulate outline, and measured (n = 30) 4.6 to 8.7 µm (mean = 6.5 µm) × 4.0 to 5.6 µm (mean = 4.9 µm) (Fig. 1 H). These features of PPGS2 were consistent with species of the Colletotrichum acutatum species complex (Damm et al. 2012). For species identification, the internal transcribed spacer (ITS), beta-tubulin (TUB), chitin synthase (CHS-1), calmodulin (CAL), and actin (ACT) genes were sequenced (O'Donnell et al. 2000; Weir et al. 2012). The five sequences were deposited in GenBank (OK054581, OK077960, OK077987, OK077988 and OK077989, respectively). A BLAST search of these sequences showed 99% identity with sequences of the ex-holotype C. scovillei CBS126529 (Damm et al. 2012). The evolutionary tree shown that PPGS2 and C. scovillei CBS126529 were clustered in a branch (SH-aLRT/approximate Bayes test/bootstrap support = 88.6/0.999/96). Combining morphological characteristics with phylogenetic analysis, PPGS2 was identified as C. scovillei. To fulfill Koch's postulates, E. japonica fruit were disinfected with 75% alcohol and air-dried for 5 mins to allow the alcohol to volatilize. A conidial suspension (10 mL of 1 × 106 conidia/ml) of PPGS2 was sprayed onto six fruits, and six fruit sprayed with sterilized water served as controls. The experiment was repeated three times. Fruits were kept on a mist bench at 27°C and 80% relative humidity for 5 days. Inoculated fruit developed dark brown necrotic lesions that later fused and expanded (Fig. 1, E-G), whereas control fruit remained symptomless. C. scovillei was re-isolated from lesions of inoculated fruit. C. scovillei has been reported from fruit of Capsicum sp., Musa sp., Mangifera indica, and Clausena lansium in China (Farr and Rossman 2021). To our knowledge, this is the first report of C. scovillei causing anthracnose fruit rot of E. japonica in China. This disease results in severe economic losses both in the field and after harvest, and it is necessary to develop more effective prevention and control strategies.

First Report of Aureobasidium pullulans var. pullulans Causing Spot Blight of Pear (Pyrus pyrifolia) in Zhejiang Province of China.

Asian pear (Pyrus pyrifolia Nakai cv. cuiguan), is widely grown in Zhejiang province of China. In April 2019, symptoms consisting of small black, round leaf spots and blight flower petals were observed on over 30 % of 'Cuiguan' pear trees in an orchard (ca. 0.8 ha) near Cixi city, Zhejiang province, China. Initially, leaf spots were observed on leaf petioles, which, with time, enlarged and coalesced into necrotic streaks (1-2 cm) along the length of the petioles. Irregularly, reddish brown spots developed on flower petals, which hastened their senescence. Additional symptoms included round, black spots on leaves (2-3 mm in diameter) and necrosis of shoot tips. Symptomatic tissues from petals, petioles and leaves were plated onto potato dextrose agar (PDA). After five days of incubation at 26 °C, slimy fungal colonies (48×48 mm) with pinkish to orange-colored mycelia and with regular annulations were isolated from all tissues. After 10 days, cultured were shiny and dark brown in the center. The color of conidia ranged from hyaline to dark brown. Hyaline conidia were blastic, unicellular, ellipsoidal, smooth, with lengths that ranged from 11.03 to 27.14 (avg. 18.38) µm, and widths that ranged from 3.45 to 8.86 (avg. 6.04) µm (n = 50). Dark brown conidia were 1 to 2 celled, 10.89 to 26.03 (avg. 17.41) µm in length and 4.26 to 12.15 (avg. 6.94) µm in width (n = 50), and a slight septal constriction. Conidiogenous cells were clavate, hyaline, eseptate and top smoothly with 3-11 spores. Indistinct scars remained when the conidia dislodge from the conidiogenous cells. Single spore isolation was used to obtain pure cultures. Mycelia and conidia were scraped from cultures and DNA was extracted using Ezup Column Fungi Genomic DNA Purification Kit (Sangon Biotech). Amplified PCR products from the internal transcribed spacer (ITS) region ITS1F/ITS4 (White et al. 1990), the partial 28S rDNA (LSU) NL1/NL4 (Boekhout et al. 1995), the ß-tubulin (TUB) gene Bt2a/Bt2b (Glass & Donaldson 1995) and the partial elongase gene (ELO) ELO2-F/ELO2-R (Zalar et al. 2008) were sequenced (Tsingke Biotechnology Co., Hangzhou, Zhejiang). A blast search (GenBank Accession No. MT107050, OK485685, OK631951, OK631950) showed 99% Aureobasidium pullulans reference isolate CBS584.75 and EXF-150, which was consistent with the morphological data (Cene et al. 2014). Three-yr-old seedlings from 'Cuiguan' pears were spray with conidial suspension (106 conidia/ml) on the both sides of leaves without wounding. In a greenhouse (26 °C, natural light), six inoculated plants and three noninoculated plants (sprayed with sterile distilled water) enclosed in plastic bags to maintain humidity for 72 h. At 5 days after inoculation, shoot tips blackened and began to wilt. At 15 days after inoculation, symptoms similar to those on the original sample developed on inoculated petioles and leaves, whereas the control plants remained healthy. No symptoms were observed on leaves that were mature at the time of inoculation. Aureobasidium pullulans var. pullulans was reisolated from all inoculated plant. Overall, this disease shortened the life of pear flowers and reduced fruit set. To our knowledge, A. pullulans var. pullulans has not previously been reported as a pathogen of P. pyrifolia.

Challenges in simulating and modeling the airborne virus transmission: A state-of-the-art review.

Recently, the COVID-19 virus pandemic has led to many studies on the airborne transmission of expiratory droplets. While limited experiments and on-site measurements offer qualitative indication of potential virus spread rates and the level of transmission risk, the quantitative understanding and mechanistic insights also indispensably come from careful theoretical modeling and numerical simulation efforts around which a surge of research papers has emerged. However, due to the highly interdisciplinary nature of the topic, numerical simulations of the airborne spread of expiratory droplets face serious challenges. It is essential to examine the assumptions and simplifications made in the existing modeling and simulations, which will be reviewed carefully here to better advance the fidelity of numerical results when compared to the reality. So far, existing review papers have focused on discussing the simulation results without questioning or comparing the model assumptions. This review paper focuses instead on the details of the model simplifications used in the numerical methods and how to properly incorporate important processes associated with respiratory droplet transmission. Specifically, the critical issues reviewed here include modeling of the respiratory droplet evaporation, droplet size distribution, and time-dependent velocity profile of air exhaled from coughing and sneezing. According to the literature review, another problem in numerical simulations is that the virus decay rate and suspended viable viral dose are often not incorporated; therefore here, empirical relationships for the bioactivity of coronavirus are presented. It is hoped that this paper can assist researchers to significantly improve their model fidelity when simulating respiratory droplet transmission.

Influence of particle-fluid density ratio on the dynamics of finite-size particles in homogeneous isotropic turbulent flows.

In this paper, direct numerical simulations of particle-laden homogeneous isotropic turbulence are performed using lattice Boltzmann method incorporating interpolated bounce-back scheme. Four different particle-fluid density ratios are considered to explore how particles with different particle-fluid density ratios respond to the turbulence. Overall particle dynamics in the homogeneous isotropic turbulence such as the Lagrangian statistics of single particle and the preferential concentration of particles are investigated. Results show that particle acceleration and angular acceleration are more intermittent than velocity and angular velocity for finite-size particles with different particle-fluid density ratios. The preferential concentration of particles is investigated using radial distribution function and Voronoï tessellation, and the preferential concentration is more profound for particles with two intermediate particle-fluid density ratios. The Voronoï analysis indicates that the distribution of Voronoï cells satisfy the log-normal distribution better than the gamma distribution. The mechanism of preferential concentration is analyzed using the sweep-stick mechanism and drift mechanism. Results show that although a higher probability of having particles located near the sticky points is found, the sticky mechanism is very weak for large density ratios. The particle clustering is then found to be better qualitatively described by the drift mechanism.

Visualization of the interaction of water aerosol and nanofiber mesh.

Face masks play a critical role in reducing the transmission risk of COVID-19 and other respiratory diseases. Masks made with nanofibers have drawn increasingly more attention because of their higher filtration efficiency, better comfort, and lower pressure drop. However, the interactions and consequences of the nanofibers and microwater droplets remain unclear. In this work, the evolution of fibers made of polymers with different contact angles, diameters, and mesh sizes under water aerosol exposure is systematically visualized. The images show that capillarity is very strong compared with the elasticity of the nanofiber. The nanofibers coalesce irreversibly during the droplet capture stage as well as the subsequent liquid evaporation stage. The fiber coalescence significantly reduces the effective fiber length for capturing aerosols. The nanofiber mesh that undergoes multiple droplet capture/evaporation cycles exhibits a fiber coalescing fraction of 40%-58%. The hydrophobic and orthogonally woven fibers can reduce the capillary forces and decrease the fiber coalescing fraction. This finding is expected to assist the proper design, fabrication, and use of face masks with nanofibers. It also provides direct visual evidence on the necessity to replace face masks frequently, especially in cold environments.