A Search for Exoplanets in Open Clusters and Young Associations based on TESS Objects of Interest

We report the results of our search for planet candidates in open clusters and young stellar associations based on the Transiting Exoplanet Survey Satellite(TESS) Objects of Interest Catalog.We find one confirmed planet,one promising candidate,one brown dwarf and three unverified planet candidates in a sample of 1229 open clusters from the second Gaia data release.We discuss individual planet-star systems based on their basic parameters,membership probability and the observation notes from the ExoFOP-TESS website.We also find ten planet candidates(P> 95%) in young stellar associations by using the BANYAN ∑ Multivariate Bayesian Algorithm.Among the ten candidates,five are known planetary systems.We estimate the rotation periods of the host stars using the TESS light curves and estimate their ages based on gyrochronology.Two candidates with periodic variations are likely to be young planets,but their exact memberships to young stellar associations remain unknown.

Research progress on distribution,sources,identification,toxicity,and biodegradation of microplastics in the ocean,freshwater,and soil environment

Microplastics(MPs)are distributed in the oceans,freshwater,and soil environment and have become major pollutants.MPs are generally referred to as plastic particles less than 5 mm in diameter.They consist of primary microplastics synthesized in microscopic size manufactured production and secondary microplastics generated by physical and environmental degradation.Plastic particles are long-lived pollutants that are highly resistant to environmental degradation.In this review,the distribution and possible sources of MPs in aquatic and terrestrial environments are described.Moreover,the adverse effects of MPs on natural creatures due to ingestion have been discussed.We also have summarized identification methods based on MPs particle size and chemical bond.To control the pollution of MPs,the biodegradation of MPs under the action of different microbes has also been reviewed in this work.This review will contribute to a better understanding of MPs pollution in the environment,as well as their identification,toxicity,and biodegradation in the ocean,freshwater,and soil,and the assessment and control of microplastics exposure.

A novel lytic phage potentially effective for phage therapy against Burkholderia pseudomallei in the tropics

Background:Burkholderia pseudomallei is a tropical pathogen that causes melioidosis.Its intrinsic drug-resistance is a leading cause of treatment failure,and the few available antibiotics require prolonged use to be effective.This study aimed to assess the clinical potential of B.pseudomallei phages isolated from Hainan,China.Methods:Burkholderia pseudomallei strain(HNBPoo1)was used as the isolation host,and phages were recovered from domestic environmental sources,which were submitted to the host range determination,lytic property assays,and stability tests.The best candidate was examined via the transmission electron microscope for classification.With its genome sequenced and analyzed,its protective efficacy against B.pseudomallei infection in A549 cells and Caenorhabditis elegans was evaluated,in which cell viability and survival rates were compared using the one-way ANOVA method and the log-rank test.Results:A phage able to lyse 24/25 clinical isolates was recovered.It was classified in the Podoviridae family and was found to be amenable to propagation.Under the optimal multiplicity of infection(MOl)of o.1,an eclipse period of around 20 min and a high titer(io12 PFU/ml)produced within 1 h were demonstrated.This phage was found stabile at a wide range of temperatures(24,37,40,50,and 60 C)and pH values(3-12).After being designated as vB_BpP_HN01,it was fully sequenced,and the 71,398 bp linear genome,containing 93 open reading frames and a tRNA-Asn,displayed a low sequence similarity with known viruses.Additionally,protective effects of applications of vB_BpP_HNo1(MOl=0.1 and MOl=1)alone or in combination with antibiotics were found to improve viability of infected cells(70.6±6.8%,85.8±5.7%,91.9±1.8%,and 96.8±1.8%,respectively).A significantly reduced mortality(10%)and a decreased pathogen load were demonstrated in infected C.elegans following the addition of this phage.Conclusions:As the frst B.pseudomallei phage was isolated in Hainan,China,phage vB_BpP_HNO1 was characterized by promising lytic property,stability,and effciency of bacterial elimination during the in vitro/vivo experiments.Therefore,we can conclude that it is a potential alternative agent for combating melioidosis.