Copper(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of 1,3-enynes and azomethine ylides.

Herein, we report a copper(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides and 1,3-enynes, which provides a series of chiral poly-substituted pyrrolidines in high regio-, diastereo-, and enantioselectivities. Both 4-aryl-1,3-enynes and 4-silyl-1,3-enynes serve as suitable dipolarophiles while 4-alkyl-1,3-enynes are inert. Moreover, the method is successfully applied in the construction of both tetrasubstituted stereogenic carbon centers and chiral spiro pyrrolidines. The DFT calculations are also conducted, which imply a concerted mechanism rather than a stepwise mechanism. Finally, various transformations started from the pyrrolidine bearing a triethylsilylethynyl group and centered on the alkyne group are achieved, which compensates for the inertness of 4-alkyl-1,3-enynes in the present reaction.

[Relationship between Effect of Induction Chemotherapy and Prognosis in AML Patients].

OBJECTIVE: To explore the relationship between effect of induction chemotherapy and prognosis in acute myeloid leukemia (AML) patients. METHODS: The clinical data of 146 adult AML patients treated in Affiliated Hospital of Chifeng University from March 2015 to March 2018 were enrolled and retrospectively analyzed. Day 14 bone marrow biopsy (D14BM) cellularity and blast proportion, daily peripheral blood blast (PBB) clearance rate, time to PBB clearance and etc. were primarily observed after induction chemotherapy. All the patients were divided into Non-relapse survival group, Relapse survival group, Non-relapse death group and Relapse death group according to survival and recurrence situation during 2-year follow-up. The survival of the patients was analyzed by Kaplan-Meier. Univariate analysis of prognostic factors were performed by ordinal Logistic regression, and ROC curve was used to assess the prediction efficiency of those factors for the 2-year overall survival (OS) and relapse of the patients. RESULTS: A total of 138 patients were included since 8 cases failed to be assessed clinically. Their 2-year OS rate was 65.94%. Age of the patients in Non-relapse survival group was lower than that in Relapse death group. The D14BM cellularities in Non-relapse survival group and Relapse survival group were lower than those in Relapse death group (P<0.05). Daily PBB clearance rates in Non-relapse survival group and Relapse survival group were higher than those in Non-relapse death group and Relapse death group (P<0.05). There was a statistical difference among the four groups in the number of cycles of induction chemotherapy (P<0.05). The survival rate within 2 years in the patients with D14BM cellularity≤10% was higher than that in patients with cellularity >10%, while it was higher in patients with daily PBB clearance rate >20% than those with clearance rate≤20% (P<0.05). Age (HR=1.102, P=0.000), D14BM cellularity (HR=1.252, P=0.000) and the cycles of induction chemotherapy≥3 (HR=1.703, P=0.000) were the risk factors affecting the prognosis of AML patients, while daily PBB clearance rate was a protective factor (HR=0.799, P=0.000). The AUC of age, daily PBB clearance rate and D14BM cellularity in predicting 2-year OS of AML patients was 0.738, 0.817 and 0.807, respectively, whereas in predicting relapse within 2 years it was 0.691, 0.647 and 0.711, respectively. There was no statistical difference among the three factors in the sensitivity of 2-year OS (68.11%, 85.12%, 74.49%) and 2-year relapse (50.00%, 64.13%, 61.60%) (P>0.05). CONCLUSION: Bone marrow biopsy results and PBB clearance rate are related to prognosis in AML patients, which can offer certain predictive value in assessing 2-year OS of patients.

Novel Nanofluidic Cells Based on Nanowires and Nanotubes for Advanced Chemical and Bio-Sensing Applications.

Since the first introduction of one-dimensional nanochannels for single-molecule detection, there has been increasing interest in modern nanofluidic systems, such as chemical and biological sensing applications. Recently developed nanowires (NWs) and nanotubes (NTs) have received tremendous attention due to their unique geometrical, physical and chemical properties, which are very attractive in this field. Here, we review the recent research activities in the field of novel nanofluidic cells based on NWs and NTs. First, we give a brief introduction of this field. Then the common synthesis methods of NWs and NTs are summarized. After that, we discuss the working principle and sensing mechanism of nanofluidic devices, which is fundamental to the interaction between these nanostructures and small molecules. Finally, we present the NW- and NT-based devices for chemical and bio-sensing applications, such as gas sensing, pathogen detection, DNA sequencing, and so forth.

[Effects of increased planting density with reduced nitrogen fertilizer application on greenhouse gas emission in double-season rice fields under water saving and simple cultivation mode]. / èŠ‚æ°´è½»ç®€æ ½åŸ¹æ¨¡å¼ä¸‹å¢žå¯†å‡æ°®å¯¹åŒå­£ç¨»ç”°æ¸©å®¤æ°”ä½“æŽ’æ”¾çš„å½±å“.

To clarify the effects of increased density and reduced nitrogen on greenhouse gas emission in double-season paddy fields under the water-saving and simple cultivation mode, we used Luliangyou 996 (early rice) and Fengyuanyou 299 (late rice) as materials to collect greenhouse gas by closed static box method, monitored the dynamics of CH4 and N2O emissions from different combinations of increased density and reduced nitrogen for early and late rice, and explored changes in cumulative CH4 and N2O emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) as affected by different combinations of increased density and reduced nitrogen from double-season rice fields. The results showed that the cumulative emissions of CH4 and N2O from different combinations were significantly different. Compared with the control (CK), cumulative CH4 emission, GWP and GHGI in the two seasons decreased by 50.8%, 37.3%, and 42.9% for the combination of increased density and reduced nitrogen IR2(the amount of nitrogen applied of early rice was 86.4 kg·hm-2, the density was 360000 holes·hm-2; the amount of nitrogen applied of late rice was 108 kg·hm-2, the density was 320000 holes·hm-2), respectively. IR2 of early rice had the lowest N2O cumulative emission, being 33.7% lower than CK. IR1(the amount of nitrogen applied of early rice was 103.2 kg·hm-2, the density was 320000 holes·hm-2; the amount of nitrogen applied of late rice was 129 kg·hm-2, the density was 280000 holes·hm-2) of late rice had the lowest N2O cumulative emission, being decreased by 94.9%. IR2 had the lowest annual total GWP and GHGI of double-season paddy fields. Compared with other treatments of increased density and reduced nitrogen, the IR2 treatment, where nitrogen fertilizer in both early and late rice was reduced by 28.0%, the density of early rice was increased by 28.6%, and the density of late rice was increased by 33.3%, was an effective and safe option for simultaneously ensuring high yield and reducing greenhouse gas emissions.

Copper-Catalyzed Vinylogous Aerobic Oxidation of Unsaturated Compounds with Air.

A mild and operationally simple copper-catalyzed vinylogous aerobic oxidation of ß,γ- and α,ß-unsaturated esters is described. This method features good yields, broad substrate scope, excellent chemo- and regioselectivity, and good functional group tolerance. This method is additionally capable of oxidizing ß,γ- and α,ß-unsaturated aldehydes, ketones, amides, nitriles, and sulfones. Furthermore, the present catalytic system is suitable for bisvinylogous and trisvinylogous oxidation. Tetramethylguanidine (TMG) was found to be crucial in its role as a base, but we also speculate that it serves as a ligand to copper(II) triflate to produce the active copper(II) catalyst. Mechanistic experiments conducted suggest a plausible reaction pathway via an allylcopper(II) species. Finally, the breadth of scope and power of this methodology are demonstrated through its application to complex natural product substrates.

[Plant metabolomics approach for age discrimination of mountain cultivated ginseng using UPLC-Q-TOF/MS].

Growth year is one of the important factors for the quality of mountain cultivated ginseng (MCG). For age differentiation of MCG, rhizome extracts of ginseng aged from 11 to 15 years were analyzed using a non-targeted approach with ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based on plant metabolomics technique. Multivariate statistical methods such as principal component analysis (PCA) and orthogonal partial least squared discrimination analysis (OPLS-DA) were used to compare the derived patterns among the samples. The results showed that the chemical constituents of MCG rhizome extracts of ginseng aged from 11 to 15 years were different. The data set was subsequently applied to metabolite selection by variable importance in the projection (VIP) for sophisticated classification with the optimal number of metabolites. The OPLS-DA model of MCG has a high interpretability and predictive capability, which established by selecting metabolites of MCG aged from 11 to 15 years. By this approach, MCG samples aged from 11 to 15 years, which are the most in demand in the Chinese ginseng market, can be precisely differentiated on the basis of selected metabolites. This proposed analytical method is fast, accurate, and reliable for discriminating the growth year of MCG. Moreover, this study supplies a new method for the age discrimination of other Chinese medicinal materials.