A colorimetric and fluorescent merocyanine-based probe for biological thiols

A new "dual-mode" chromogenic and fluorescent turn-on probe (2) for the selective sensing of biological thiols is reported. In MeOH-H2O cosolvent at physiological pH 7.40 (MeOH-H2O = 3:7), biological thiols cleave the 2,4-dinitrobenzenesulfonyl group to release the chromo-and fluorophore merocyanine (3).National Natural Science Foundation of China [20675067, 20835005]; NCET of Fujian Province of Chin

Memory-enhancing effect of Rhodiola rosea L extract on aged mice

Purpose: The memory-enhancing effects of Rhodiola rosea L. extract (RRLE) on normal aged mice were assessed.Methods: In the open-field test, the effect of RRLE (150 and 300 mg/kg) on mouse locomotive activities was evaluated by investigating the extract’s influence on CAT and AchE activities in the brain tissue of mice.Results: Compared with aged group, high dose of RRLE reduced the total distance (3212.4 ± 123.1 cm, p < 0.05) significantly, increased catalase (CAT) activity (101.4 ± 12.2 U/mg pro, p < 0.05), and inhibited acetyl cholinesterase (AChE) activity (0.94 ± 0.12 U/mg pro, p < 0.05) in the brain tissue of aged mice.Conclusion: The results show that RRLE improves the memory functions of aged mice probably by increasing CAT activity while decreasing AChE activity.Keywords: Rhodiola rosea, Memory function, Catalase, Acetyl cholinesterase, Open-field tes

A heterozygous moth genome provides insights into herbivory and detoxification

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants1, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood2. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.Minsheng You … Simon W Baxter … et al

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

In situ boron isotopic analyses of tourmalines from Neogene magmatic rocks in the northern and southern margins of Tibet: Evidence for melting of continental crust and sediment recycling

Sediment recycling has important impacts on the differentiation of the continental crust, and is considered to mainly occur in arc settings. In collisional orogenic belts, however, sediment recycling processes are comparatively less well understood. In general, sedimentary rocks or tourmaline with continental affinities have boron (B) isotope compositions that differ from marine sedimentary rocks, magmatic rocks undergoing seawater alteration or tourmaline originating from these rocks or fluids. This study uses laser-ablation multi-collector, inductively coupled plasma-mass spectrometry (LA-MC-ICPMS) for in-situ B isotope analyses of tourmaline from the northern and southern margins of Tibet. Tourmalines from the Hudongliang Pliocene two mica rhyolites in the Songpan-Gangzi block and the Cuonadong Miocene two mica granites in the Himalayan Block have δ11B values of −10.47 ± 0.54‰ and −12.48 ± 1.04‰, respectively. Combined with petrological and Nd–Sr isotope data, we suggest that these strongly peraluminous magmatic rocks from the northern and southern margins of Tibet were mainly generated by partial melting of subducted or overridden metasedimentary rocks with continental affinities due to the contraction caused by the collision between the Indian and Asian plates. Given the widespread occurrences of strongly peraluminous Neogene magmatic rocks in the southern and northern margin of Tibet, we suggest that the recycling of sediments with continental affinity played an important role in the evolution of continental crust during the collisional orogenic process

Cost-effectiveness analysis of chemotherapy for advanced gastric cancer in China

AIM: To assess the economics of various chemotherapeutic regimens for advanced gastric cancer (AGC), and to select the best cost-effective regimen for the common Chinese patients