(2R*,6S*)-tert-Butyl 2,6-bis­(hydroxy­meth­yl)morpholine-4-carboxyl­ate

In the title compound, C11H21NO5, the H atoms of the hydr­oxy groups are disordered over two positions, each in a 1:1 ratio. In the crystal, inter­molecular O—H⋯O hydrogen bonds link pairs of mol­ecules into centrosymmetric dimers. Weak inter­molecular O—H⋯O inter­actions further link these dimers into chains extended in the [100] direction

(S)-tert-Butyl 3-(3-phenyl-1,2,4-oxa­diazol-5-yl)piperidine-1-carboxyl­ate

The title compound, C18H23N3O3, crystallized with two independent mol­ecules (A and B) in the asymmetric unit. The phenyl ring and the 1,2,4-oxadiazole ring are inclined to one another by 19.9 (3)° in mol­ecule A and 7.3 (3)° in mol­ecule B. The absolute structure of the title compound was referred to the transfered chiral center (S) of one of the starting reacta­nts. In the crystal, A mol­ecules are linked by C—H⋯N inter­actions involving the two oxadiazole N atoms

(2R,6S)-tert-Butyl 2-(benzhydrylcarbamoyl)-6-methylmorpholine-4-carboxylate

The title compound, C24H30N2O4, was obtained by the reaction of (2R,6S)-4-(tert-butoxycarbonyl)-6-methylmorpholine-2-carboxylic acid with diphenylmethanamine in dimethylformamide solution. The morpholine ring is in a chair conformation. In the crystal, weak intermolecular C—H...O hydrogen bonds link molecules into chains along the b axis

Response of Water Resources to Future Climate Change in a High-Latitude River Basin

Global water resources are affected by climate change as never before. However, it is still unclear how water resources in high latitudes respond to climate change. In this study, the water resource data for 2021–2050 in the Naoli River Basin, a high-latitude basin in China, are calculated by using the SWAT-Modflow Model and future climate scenarios RCP4.5 and RCP8.5. The results show a decreasing trend. When compared to the present, future streamflow is predicted to decrease by 2.73 × 108 m3 in 2021–2035 and by 1.51 × 108 m3 in 2036–2050 in the RCP4.5 scenario, and by 8.16 × 108 m3 in 2021–2035 and by 0.56 × 108 m3 in 2036–2050 in the RCP8.5 scenario, respectively. Similarly, groundwater recharge is expected to decrease by −1.79 × 108 m3 in 2021–2035 and −0.75 × 108 m3 in 2036–2050 in the RCP 4.5 scenario, and by −0.62 × 108 m3 in 2021–2035 and −0.12 × 108m3 in 2036–2050 in the RCP 8.5 scenario, respectively. The worst impact of climate change on water resources in the basin could be frequent occurrences of extremely wet and dry conditions. In the RCP 4.5 scenario, the largest annual streamflow is predicted to be almost 14 times that of the smallest one, while it is 18 times for the groundwater recharge. Meanwhile, in the RCP 8.5 scenario, inter-annual fluctuations are expected to be more severe. The difference is 17 times between the largest annual streamflow and the lowest annual one. Moreover, the value is 19 times between the largest and lowest groundwater recharge. This indicates a significant increase in conflict between water use and supply

ClRTL1 Encodes a Chinese Fir RNase III–Like Protein Involved in Regulating Shoot Branching

Identification of genes controlling shoot branching is crucial for improving plant architecture and increasing crop yield or biomass. A branching mutant of Chinese fir named “Dugansha” (Cunninghamia lanceolata var. dugan.) has been isolated in our laboratory. We chose the cDNA-AFLP technique and an effective strategy to screen genes that potentially regulate shoot branching in Chinese fir using this mutant. An RNase III-like1 cDNA fragment named ClRTL1 was identified as a potential positive regulator. To investigate the function of ClRTL1 in regulating shoot branching, we cloned the full-length cDNA sequence from C. lanceolata (Lamb.) Hook, deduced its secondary structure and function, and overexpressed the coding sequence in Arabidopsis. The ClRTL1 cDNA is 1045 bp and comprises an open reading frame of 705 bp. It encodes a protein of 235 amino acids. The deduced secondary structure of the ClRTL1 indicates that it is a mini-RNase III-like protein. The expression analysis and phenotypes of 35S: ClRTL1 in A. thaliana implies that ClRTL1 plays a role in promoting shoot branching in Chinese fir

A New Triterpenoid from Teucrium viscidum

molecule

Improved LC/MS/MS Quantification Using Dual Deuterated Isomers as the Surrogates: A Case Analysis of Enrofloxacin Residue in Aquatic Products

Extensive and high residue variations in enrofloxacin (ENR) exist in different aquatic products. A novel quantitative method for measuring ENR using high-performance liquid chromatography–tandem mass spectrometry was developed employing enrofloxacin-d5 (ENR-d5) and enrofloxacin-d3 (ENR-d3) as isotope surrogates. This reduced the deviation of detected values, which results from the overpass of the linear range and/or the large difference in the residue between the isotope standard and ENR, from the actual content. Furthermore, high residue levels of ENR can be directly diluted and re-calibrated by the corresponding curve with the addition of high levels of another internal surrogate without repeated sample preparation, avoiding the overflow of the instrument response. The validation results demonstrated that the method can simultaneously determine ENR residues from MQL (2 µg/kg) to 5000 × MQL (method quantification limit) with recoveries between 97.1 and 106%, and intra-precision of no more than 2.14%. This method realized a wide linear calibration range with dual deuterated isomers, which has not been previously reported in the literature. The developed method was successfully applied to the analysis of ENR in different aquatic products, with ENR residue levels varying from 108 to 4340 μg/kg and an interval of precision in the range of 0.175~6.72%. These results demonstrate that batch samples with a high variation in ENR residues (over the linear range with a single isotope standard) can be detected by the dual isotope surrogates method in a single sample preparation process