Amplified detection of SARS-COV-2 B.1.1.529 (Omicron) gene oligonucleotides based on exonuclease III-aided MoS2/AIE nanoprobes

The coronavirus disease-2019 pandemic reflects the underdevelopment of point-of-care diagnostic technology. Nuclei acid (NA) detection is the “gold standard” method for the early diagnosis of the B.1.1.529 (Omicron) variant of severe acute respiratory syndrome-coronavirus disease-2. Polymerase chain reaction is the main method for NA detection but requires considerable manpower and sample processing taking ≥ 3 h. To simplify the operation processes and reduce the detection time, exonuclease III (Exo III)-aided MoS₂/AIE nanoprobes were developed for rapid and sensitive detection of the oligonucleotides of Omicron. Molybdenum disulfide (MoS₂) nanosheets with excellent optical absorbance and distinguishable affinity to single-strand and duplex DNAs were applied as quenchers, and aggregation-induced emission (AIE) molecules with high luminous efficiency were designed as donor in fluorescence resonance energy transfer-based nanoprobes. Exo III with catalytic capability was used for signal amplification to increase the sensitivity of detection. The composite nanoprobes detected the mutated nucleocapsid (N)-gene and spike (S)-gene oligonucleotides of Omicron within 40 min with a limit of detection of 4.7 pM, and showed great potential for application in community medicine.     

Megasporogenesis,Microsporogenesis and Development of Female and Male Gametophyte in Siraitia grovenorii

1. The ovule is anatropous, bitegument and crassinucellate. 2. Embryo sac belongs to Polygonum type. Mature embryo sac has 7 cells. 3. In the course of rnegasporogenesis callose appears. 4 Microspore mother cell meiosis is simultaneous type; Tetrad is tetrahedral. 5. Pollen grains are 2-celled. 6. Tapetum consists of 1-3 layers. Cells of inner layer are large, and of outer layer smaller.     

青海省癿扎林区森林植被调查初报

位于青藏高原东南部的癿扎林区,是高山暗针叶林分布的边缘。其植物种类单纯,结构简单。本林区是森林植被向高寒灌丛、草甸的过渡地带,在一定意义上反映出青藏高原植被从森林一草甸中间过渡的一些特点。本文采取典型调查和路线踏查相结合的方法,在7300余公顷林地中共选出20×20m2典型样地8块。在8块样地的野外调查基础上,参考有关资料,首次对癿扎林区高寒常绿针叶林的生态环境、主要类型及其分布规律等问题作初步论述。     

Study on the Airborne Pollen and Its Allergy in Nanning,Guangxi

Guangxi Zhuang Autonomous Region is a subtropic monsoon climate. Plants are various and their blossom period are long. To prevent and cure the respiratory allergic diseases, we made an investigation on the diffusion patterns of airborne allergic pollen grains and spores and their allergization as well in Nanning. Our work paves a way for further similar researches in the south of our country. The relationship between airborne pollen quantity and the climate, the diffution patterns of various pollen grains and the pollen quantity of higher level and lower level are discussed in the present paper.