Treatment of Advanced Gingival Recession Secondary to Surgical Failure with Large Size Deepithelized Gingival Graft Associated with a Modified Tunnel Flap.

Objective: To describe the use of a large size deepithelized gingival graft (DGG) associated with full-split tunnel technique in a clinical case of advanced gingival recession secondary to surgical failure (GRSF). Clinical Considerations. The presented case report helped to achieve satisfactory root coverage, ideal keratinized tissue gain, improvement in soft tissue quality and esthetics, scar deformity correction, and vestibular depth deepening with a one-step procedure of large size DGG associated with full-split tunnel technique for a condition of deep gingival recessions of 7-11 mm caused by a failed bone implantation surgery. Conclusions: The large size DGG associated with full-split tunnel technique provided a versatile one-step procedure to obtain ideal results for advanced GRSF. Clinical Significance. GRSF that is generally associated with inadequate keratinized tissue and scar formation could be rather difficult to deal with. The large size DGG associated with full-split tunnel technique, as a one-step procedure, provided a predictable and practical treatment modality.

Molecular mechanisms of Phytophthora sojae avirulence effectors escaping host recognition.

Phytophthora sojae is a well-known destructive oomycete pathogen, which causes soybean stem and root rot and poses a serious threat to global food security. Growing soybean cultivars with the appropriate resistance to P. sojae (Rps) genes are the primary management strategy to reduce losses. In most Phytophthora pathosystems, host resistance protein encoded by a specific R gene in the plant recognizes corresponding RxLR effector protein, encoded by an avirulence gene. This gene-for-gene relationship has been exploited to help breeders and agronomists deploy soybean cultivars. To date, 6 Rps genes have been incorporated into commercial soybean germplasm and trigger plant immunity in response to 8 P. sojae avirulence effectors. The incorporation of Rps genes in the soybean population creates selection pressure in favor of novel pathotypes of P. sojae. The 8 avirulence genes evolved to evade the host immune system, driven by genetic selection pressures. Understanding the evading strategies has important reference value for the prevention and control of Phytophthora stem and root rot. This investigation primarily highlights the research on the strategies of P. sojae avirulence effector evasion of host recognition, looking forward to creating durable resistance genes and thereby enabling successful disease management.

Chemical oxygen demand and nitrogen removal from real membrane-manufacturing wastewater by a pilot-scale internal circulation reactor integrated with partial nitritation-anammox.

A pilot-scale system integrating internal circulation and partial nitritation-anammox successfully treated real high-strength membrane-manufacturing wastewater in this study. With this pilot-scale system, a high chemical oxygen demand (COD) removal efficiency of 85 % and a nitrogen removal of 90 % are achieved at an organic loading rate of 6.0 kg COD/m3/d. The nitrogenous organic matters in the internal circulation zone are degraded into ammonia nitrogen. In the partial nitrification zone, nitrite accumulation is achieved, providing a suitable NH4+-N/NO2--N ratio for anammox reaction. Partial nitritation is achieved by maintaining an operational temperature at 30-35 °C, free ammonia concentration at 5-7 mg/L and dissolved oxygen at 0.4-0.7 mg/L with a reflux ratio of 150 %. The COD to nitrogen ratio in the internal circulation effluent is maintained below 3.0 to inhibit nitrite oxidizing bacteria. This study demonstrates that a pilot-scale system can efficiently remove organic matters and nitrogen from wastewater of membrane-manufacturing industry.

Nestedness and underlying processes of bird assemblages in Nanjing urban parks.

Nestedness is an important pattern frequently reported for species assemblages on islands or fragmented systems. However, to date, there are few studies that comprehensively investigated faunal nestedness and underlying processes in urbanized landscapes. In this study, we examined the nestedness of bird assemblages and its underlying causal mechanisms in 37 urban parks in Nanjing, China. We used the line-transect method to survey birds from April 2019 to January 2020. We used the Weighted Nestedness metric based on Overlap and Decreasing Fill (WNODF) to estimate the nestedness of bird assemblages. We applied spearman partial correlation test to examine the relationships between nestedness ranks of sites and park characteristics (area, isolation, anthropogenic noise, number of habitat types, and building index), as well as between nestedness ranks of species and their ecological traits (body size, geographic range size, clutch size, minimum area requirement, dispersal ratio, and habitat specificity). We found that bird assemblages in urban parks were significantly nested. Park area, habitat diversity, building index, habitat specificity, and minimum area requirement of birds were significantly correlated with nestedness. Therefore, the nestedness of bird assemblages was caused by selective extinction, habitat nestedness, and urbanization. However, the nestedness of bird assemblages did not result from passive sampling, selective colonization, or human disturbance. Overall, to maximize the number of species preserved in our system, conservation priority should be given to parks with large area, rich habitat diversity, and less building index. From a species perspective, we should focus on species with large area requirement and high habitat specificity for their effective conservation.

Lauric Acid Is a Potent Biological Control Agent That Damages the Cell Membrane of Phytophthora sojae.

Sustainable management of plant pathogens is becoming more challenging, and novel solutions are needed. Plant biologically active secondary metabolites are important sources of novel crop protection chemistry. Effective individual compounds of these natural products have the potential to be successful new agrochemicals. In this study, we identified lauric acid (LA) from soybean defense leaf volatiles. LA inhibited the growth of Phytophthora sojae, the causal agent of soybean root rot. It influenced mycelial development, sporangium formation, and zoospore generation and germination by damaging the P. sojae cell membrane. Additionally, we showed that LA and several of its derivatives, such as glycerol monolaurate (GML), had similar biological activities. Both LA and GML were safe to soybean plants when used at less than 0.3 g a.i./plant and could promote soybean growth, implying their potential as eco-friendly biological control agents.

A Conserved Glycoside Hydrolase Family 7 Cellobiohydrolase PsGH7a of Phytophthora sojae Is Required for Full Virulence on Soybean.

Phytopathogens deploy glycoside hydrolases (GHs) to disintegrate plant cell walls for nutrition and invasion. However, the pathogenic mechanisms of the majority of GHs in virulence remain unknown, especially in oomycetes. In this study, a Phytophthora sojae gene encodes a GH7 family cellobiohydrolase, named PsGH7a, was identified. PsGH7a was highly induced during the cyst germination and infection stages. PsGH7a is conserved in oomycetes, and shares a high amino acid sequence identity (>85%) within Phytophthora genus. The recombinant PsGH7a catalyzes the hydrolysis of ß-1,4-glucan and avicel, which represent the major components of cellulose in plant cell wall. The mutation of catalytic residue Glu236 to alanine resulted in a lower catalytic activity. In addition, the PsGH7a promotes Phytophthora invasion, while the mutant can not. Notably, PsGH7a protein triggers hypersensitive cell death in diverse plants. PsGH7a knockout mutants were generated via CRISPR/Cas9 system, to investigate its biological function. Compared to wild-type strain P6497, the mutants showed reduced virulence on susceptible soybean, indicates PsGH7a is indispensable to P. sojae virulence.

Highly efficient and low-energy nitrogen removal of sludge reduction liquid by coupling denitrification- partial nitrification-Anammox in an innovative auto-recycling integration device with different partitions.

The denitrification (DN), partial nitrification (PN) and Anammox processes were coupled in an auto-recycling integration device to remove nitrogen from the supernatant of sludge reduction pretreatment. The nitrogen removal performance of the device and the effect of organic matter concentration on the nitrogen transformation were discussed. The results showed that DN, PN and Anammox are well coupled and total nitrogen (TN) removal rate reached 0.85 kg/(m3·d). The pre-DN process can achieve the removal of NO3--N produced by the back-end PN-Anammox process without the need of reflux pump drive. When the influent NH4+-N concentration was approximately 400 mg/L, the effluent TN concentration was less than 20 mg/L. The fluctuation of organic matter led to changes of nitrogen transformation in the system, and the best ratio of influent CODbio/TN was 0.7-0.9. Nitrosomonas and Candidatus Brocadia played important roles in the nitrogen removal process as the main functional microorganisms of PN and Anammox, respectively.

[Influence of Substrate Exposure Level on ANAMMOX Microbial Activity and Biomass].

Substrate exposure levels are vital for the growth and metabolism of ANAMMOX microorganisms, and their effects on growth characteristics of ANAMMOX sludge during the enrichment process have been rarely reported. Using two continuous flow stirred reactors and the process of a gradually developing nitrogen load, the changes in biomass and activity, as well as nitrogen removal efficiency of the reactors were investigated under high substrate exposure level culture mode (R1:effluent NH4+-N and NO2--N concentrations were 40-60 mg·L-1) and low substrate exposure level culture mode (R2:effluent NH4+-N and NO2--N concentrations were 0-20 mg·L-1). The results showed that the high substrate exposure level culture mode was more beneficial to the improvement of nitrogen removal performance of the ANAMMOX reactor. For comparison, the NLR (nitrogen load rate), which was 0.69 kg·(m3·d)-1, and the NRR (nitrogen remove rate), which was up to 0.41 kg·(m3·d)-1, was obtained in the high substrate exposure culture mode. These values were twice as high as those obtained in the low substrate exposure culture mode. Under the culture mode with high substrate exposure level, the sludge concentration (in VSS) and the total gene copy numbers of ANAMMOX reached 1805 mg·L-1 and 4.81×1012 copies, respectively, which was conducive to the rapid enrichment of ANAMMOX microorganisms. In the low substrate exposure level culture mode, ANAMMOX sludge was more active,in N/VSS, 0.27 g·(g·d)-1, which was conducive to the cultivation of ANAMMOX sludge with higher biological activity.