The high-quality sequencing of the Brassica rapa‘XiangQingCai’genome and exploration of genome evolution and genes related to volatile aroma

‘Vanilla’(XQC,brassica variety chinensis)is an important vegetable crop in the Brassica family,named for its strong volatile fragrance.In this study,we report the high-quality chromosome-level genome sequence of XQC.The assembled genome length was determined as 466.11 Mb,with an N50 scaffold of 46.20 Mb.A total of 59.50%repetitive sequences were detected in the XQC genome,including 47570 genes.Among all examined Brassicaceae species,XQC had the closest relationship with B.rapa QGC(‘QingGengCai’)and B.rapa Pakchoi.Two whole-genome duplication(WGD)events and one recent whole-genome triplication(WGT)event occurred in the XQC genome in addition to an ancient WGT event.The recent WGT was observed to occur during 21.59-24.40 Mya(after evolution rate corrections).Our findings indicate that XQC experienced gene losses and chromosome rearrangements during the genome evolution of XQC.The results of the integrated genomic and transcriptomic analyses revealed critical genes involved in the terpenoid biosynthesis pathway and terpene synthase(TPS)family genes.In summary,we determined a chromosome-level genome of B.rapa XQC and identified the key candidate genes involved in volatile fragrance synthesis.This work can act as a basis for the comparative and functional genomic analysis and molecular breeding of B.rapa in the future.

Comparative Study on Functional Properties of Mulberry Black Tea Fermented by Phellinus igniarius and Eurotium cristatum

[Objectives]To compare functional properties of mulberry black tea fermented by Phellinus igniarius and Eurotium cristatum.[Methods]The functional components of mulberry black tea fermented by P.igniarius and E.cristatum,the deep processing and health care effects of two probiotic fungi were explored.[Results]The polysaccharide content in the tea fermented by P.igniarius was the highest at 0.410 mg/mL,and the hydroxyl radical scavenging rate was the strongest,reaching 60.31%;the content of flavonoids in the tea fermented by E.cristatum was the highest,reaching 60.65μg/mL,and the content of polysaccharides was 83.17%higher than that of mulberry black tea,reaching 0.279 mg/mL.[Conclusions]The mulberry black tea fermented by P.igniarius and E.cristatum has improved in different functional components,and has its own advantages in aroma and mouthfeel,so it has certain research value and market prospect.

Practicing the concept of “structuring” processing in the manufacture of polymer films

Polymer processing is a technology used to transfer raw materials into products with different shapes and functionalities and is a key step for polymer application.After years of development,the polymer processing task has changed from traditional processing,which mainly addresses the specific shapes of articles and focuses on the effect of processing on the structures and properties of polymers,to modern processing,which directly transforms a“designed structure”into commercial products via processing.It is the so-called“structuring”processing.Owing to the unique long-chain nature and slow topological relaxation,polymers are always driven and frozen into different nonequilibrium conformations,providing an effective way to design a given polymer material with desired structure and tunable performances via processing.Among the endless number of processing techniques,film casting is a prototypical pathway involving high supercooling or/and a strong flow field,based on which diverse thin polymer films have been successfully developed.In this review,taking isotactic polypropylene(i PP)film as an example,we highlight the strategy of“structuring”processing,in which we transform various crystalline structures of i PP into diverse commercial film products.

Increased clonal dissemination of OXA-232-producing ST15 Klebsiella pneumoniae in Zhejiang,China from 2018 to 2021

Background OXA-232-producing Klebsiella pneumoniae was first identified in China in 2016,and its clonal transmission was reported in 2019.However,there are no prevalence and genotypic surveillance data available for OXA-232 in China.Therefore,we investigated the trends and characteristics of OXA-232 type carbapenemase in Zhejiang Province,China from 2018 to 2021.Methods A total of 3278 samples from 1666 patients in the intensive care units were collected from hospitals in Zhejiang Province from 2018 to 2021.Carbapenem-resistant isolates were initially selected by China Blue agar plates supplemented with 0.3μg/ml meropenem,and further analyzed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry identification,immune colloidal gold technique,conjugation experiment,antimicrobial susceptibility testing and whole genome sequencing.Results A total of 79 OXA-producing strains were recovered,with the prevalence increased from 1.8%[95%confidence interval(CI):0.7–3.7%]in 2018 to 6.0%(95%CI:4.4–7.9%)in 2021.Seventy-eight strains produced OXA-232 and one produced OXA-181.The blaOXA-232 gene in all strains was located in a 6141-bp ColKP3-type non-conjugative plasmid and the blaOXA-181 gene was located in a 51,391-bp ColKP3/IncX3-type non-conjugative plasmid.The blaOXA-232-producing K.pneumoniae was dominated(75/76)by isolates of sequence type 15(ST15)that differed by less than 80 SNPs.All OXA-producing strains(100%,95%CI:95.4–100.0%)were multidrug-resistant.Conclusions From 2018 to 2021,OXA-232 is the most prevalent OXA-48-like derivative in Zhejiang Province,and ST15 K.pneumoniae isolates belonging to the same clone are the major carriers.The transmission of ColKP3-type plasmid to E.coli highlighted that understanding the transmission mechanism is of great importance to delay or arrest the propagation of OXA-232 to other species.

Simple,stable and efficient nonlinear pulse compression through cascaded filamentation in air

Nonlinear compression has become an obligatory technique along with the development of ultrafast lasers in generating ultrashort pulses with narrow pulse widths and high peak power.In particular,techniques of nonlinear compression have experienced a rapid progress as ytterbium(Yb)-doped lasers with pulse widths in the range from hundreds of femtoseconds to a few picoseconds have become mainstream laser tools for both scientific and industrial applications.Here,we report a simple and stable nonlinear pulse compression technique with high efficiency through cascaded filamentation in air followed by dispersion compensation.Pulses at a center wavelength of 1040 nm with millijoule pulse energy and 160 fs pulse width from a high-power Yb:CaAlGdO_(4) regenerative amplifier are compressed to 32 fs,with only 2.4% loss from the filamentation process.The compressed pulse has a stable output power with a root-meansquare variation of 0.2% over 1 hour.

Genome-wide identification of endogenous retrovirus elements and their active transcription in mink genome

Mammalian endogenous retroviruses(ERVs)are ancient retroviruses that have been integrated into genomes.ERVs were believed to be inactive until the discovery of ERV transcription in the mouse genome.However,the transcription level and function of ERV elements in mammalian genomes are not well understood.In this study,we performed the first genome‐wide scanning of ERV loci in the American mink(Neogale vison)genome(NeoERV)followed by transcriptomic analysis to detect actively transcribed NeoERV elements.A total of 365,791 NeoERV loci were identified,and161,205(44%)of these loci were found to be actively transcribed based on transcriptomic data from three types of tissues(amygdala,trachea and lung).More than one third of the actively transcribed NeoERV loci were tissue‐specific.Furthermore,some of the active loci were associated with host gene transcription,and the level of NeoERV transcription was positively correlated with that of host genes,specifically when active loci were located in overlapped gene regions.An in‐depth analysis of the envelope protein coding env gene showed that,in general,its transcription level was higher than that of NeoERVs,which is believed to be associated with host immunity.

Traditional Chinese Medicine syndrome-related herbal prescriptions in treatment of malignant tumors

OBJECTIVE: To investigate the distribution characteristics of TCM syndromes and the related herbal prescriptions for malignant tumors (MT). METHODS: A clinical database of the TCM syndromes and the herbal prescriptions in treatment of 136 MT patients were established. The data were then analyzed using cluster and frequency analysis. RESULTS: According to the cluster analysis, the TCM syndromes in MT patients mainly included two patterns: deficiency of both Qi and Yin and internal accumulation of toxic heat. The commonly-prescribed herbs were Huangqi (Astraglus), Nüzhen-zi (Fructus Ligustri Lucidi), Lingzhi (Ganoderma Lucidum), Huaishan (Dioscorea Opposita), Xiakucao (Prunella Vulgaris), and Baihuasheshecao (Herba Hedyotidis). CONCLUSION: Deficiency of Qi and Yin is the primary syndrome of MT, and internal accumulation of toxic heat is the secondary syndrome. The herbs for Qi supplementation and Yin nourishment are mainly used, with the assistance of herbs for heat-clearance and detoxification.

A high-performance potassium-ion capacitor based on a porous carbon cathode originated from the Aldol reaction product

Potassium-ion capacitors(KICs) emerge as a promising substitute for the well-developed lithium-ion capacitors(LICs),however,the energy density of KICs is below expectations because of lacking a suitable electrical double-layer positive electrode.Using chemical activation of the Aldol reaction product of acetone with KOH,we synthesized a porous ca rbon with a Brunauer-Emmett-Teller surface area of up to 2947 m2/g and a narrow pore size distribution ranging from 1 nm to 3 nm.Half-cell(versus potassium metal) test demonstrates that this porous carbon has high capacitive performance in K+ based organic electrolytes.Furthermore,a novel KIC fabricated by this porous carbon as the cathode,yields high values of energy density and power density.The processes used to make this porous carbon are readily low-cost to fabricate metal-ion capacitors.

四丁基溴化铵催化炔基酮的氢化反应

炔丙醇类化合物因其同时具有炔基与羟基两种官能团,在医药、农药及功能分子材料方面有很多的应用,同时也是有机合成中一类用途很广泛的中间体.目前获得炔丙醇类化合物的方法通常依赖于过渡金属催化的氢化反应和羰基化合物的炔基化反应,制备成本较高,基团耐受性差.本文报道了一类四丁基溴化铵催化的炔基酮与频那醇硼烷的氢化反应,以高达94%收率合成了一系列炔丙醇化合物.该反应为炔丙醇类化合物的合成提供了一种便捷、经济、高效的方法.