Base-modified nucleotides mediate immune signaling in bacteria.

Signaling from pathogen sensing to effector activation is a fundamental principle of cellular immunity. While cyclic (oligo)nucleotides have emerged as key signaling molecules, the existence of other messengers remains largely unexplored. Here, we reveal a bacterial anti-phage system that mediates immune signaling through nucleobase modification.

Structural and physicochemical properties and changes in vitro digestion and fermentation of soluble dietary fiber from tea residues modified by fermentation.

The aim of this study was to investigate the structure, physicochemical properties, and changes in vitro digestion and fermentation between unfermented tea residue dietary fiber (UDF) and fermented tea residue soluble dietary fiber (FSDF). The results showed that soluble dietary fiber in FSDF was increased from 2.54 % to 15.

Catalytically inactive long prokaryotic Argonaute systems employ distinct effectors to confer immunity via abortive infection.

Argonaute proteins (Agos) bind short nucleic acids as guides and are directed by them to recognize target complementary nucleic acids. Diverse prokaryotic Agos (pAgos) play potential functions in microbial defense. The functions and mechanisms of a group of full-length yet catalytically inactive pAgos, long-B pAgos, remain unclear.

The trans DNA cleavage activity of Cas12a provides no detectable immunity against plasmid or phage.

Cas12a is a type V-A CRISPR-Cas RNA-guided endonuclease. It cleaves dsDNA at specific site, and then is activated for nonspecific ssDNA cleavage in trans . The immune function of the trans activity is still unknown.

A comparative study of volatile components in Dianhong teas from fresh leaves of four tea cultivars by using chromatography-mass spectrometry, multivariate data analysis, and descriptive sensory analysis.

Dianhong teas produced from fresh leaves of different tea cultivars (YK is Yunkang No. 10, XY is Xueya 100, CY is Changyebaihao, SS is Shishengmiao), were compared in terms of volatile compounds and descriptive sensory analysis. A total of 73 volatile compounds in 16 tea samples were tentatively identified.

The study of fingerprint characteristics of Dayi Pu-Erh tea using a fully automatic HS-SPME/GC-MS and combined chemometrics method.

The quality of tea is presently evaluated by the sensory assessment of professional tea tasters, however, this approach is both inconsistent and inaccurate. A more standardized and efficient method is urgently needed to objectively evaluate tea quality. In this study, the chemical fingerprint of 7 different Dayi Pu-erh tea brands and 3 different Ya'an tea brands on the market were analyzed using fully automatic headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS).

[Comprehensive utilization and sustainable development of Chinese herbal medicinal resource].

The issues concerning protection, comprehensive utilization, sustainable development, and quickening up the modernization of Chinese herbal medicinal resource, as well as how to accelerate the international conjunction of Chinese medicinal industry were discussed in this paper.

[Progress in application of infrared spectroscopy and comparative study of chromatographic fingerprints].

The newest development of applications of IR techniques to the identification of Chinese herbs, the discrimination of folk medicine herbs, Chinese herbs processing and Chinese traditional injection, which involving enhancing computer analysis depth, intensifying the pre-treatment of Chinese herb and using 2D-IR correlation spectroscopy for processing control, was elaborated in the present paper. Meanwhile, the establishment of multi-component determination analysis system of chromatographic fingerprint diagram was shown. And the sameness and difference of the IR spectroscopy and chromatography fingerprint diagram techniques were analyzed, and a comparison was made in terms of quality control of Chinese herbal medicine.