Chemoselective Synthesis of Unsymmetrical Dithioacetals through Sequential Carbene Insertion and Acetal Exchange of Acylsilanes and Thiols under Visible Light Irradiation.

Dithioacetals are a frequently used motif in synthetic organic chemistry, and most existing reports discuss only symmetrical dithioacetals. Examples of unsymmetrical dithioacetals are scarce, and few general methods for the selective synthesis of these compounds exists. An intriguing visible-light-induced strategy has been established in this work for sequential reactions of S-H insertion and acetal exchange between acylsilanes and two different thiols that deliver a wide variety of unsymmetrical dithioacetals in moderate yields. The unsymmetrical dithioacetals were obtained with high selectivity, and a great variety of functional groups were tolerated.

[Nitrogen content inversion of wheat canopy leaf based on ground spectral reflectance data]. / åŸºäºŽåœ°é¢è§‚æµ‹å ‰è°±æ•°æ®çš„å†¬å°éº¦å† å±‚å¶ç‰‡æ°®å«é‡åæ¼”æ¨¡åž‹.

Canopy nitrogen content in wheat is a key indicator of wheat grain yield and quality. When using remote sensing technology to predict wheat canopy nitrogen content, a hyperspectral mode with high adaptability and high accuracy is needed to improve the inversion efficiency. We developed a new three-band spectral vegetation index (NEW-NDRE) by combining a two-band spectral index NDRE and the spectral reflectance at 550 nm based on field data collected from different sites, years, with different varieties and nitrogen levels and at multiple growth stages. The NEW-NDRE was compared with 11 traditional spectral vegetation indices in terms of wheat canopy nitrogen content inversion. NEW-NDRE and three traditional indices (NDRE, NDDA and RI-1dB) all closely correlated with wheat canopy nitrogen content. NEW-NDRE displayed the highest correlation with wheat canopy nitrogen content at early grain filling stage, with a coefficient (R2) of 0.9 and a root mean squared error (RMSE) of 0.4. The inversion model developed with the NEW-NDRE was validated with an independent dataset. The relative error (RE) of the model was 9.3%, which was significantly lower than that of NDRE, NDDA and RI-1dB. Generally, NEW-NDRE is a more robust index for wheat canopy nitrogen content inversion than traditional indices through eliminating environmental limitation, and it could be used as a new tool for precise fertilizer application.

[Clinical significance of dynamic monitoring the minimal residual disease in childhood B-lineage acute lymphoblastic leukemia by multiparameter flow cytometry].

This study was aimed to explore the clinical significance of monitoring level of minimal residual disease (MRD) at different time point in B-lineage childhood acute lymphoblastic leukemia (B-ALL). Two hundred and six children with B-ALL were enrolled in this study from Augest 2008 to September 2011 in our hospital. MRD levels were detected by flow cytometry at day 15, 33 and week 12 after initial chemotherapy. The event-free survival (EFS) for patients based on MRD levels measured at different stages of chemotherapy were compared by Kaplan Meier analyses. The results showed that out of 206 cases 196 cases achieved complete remission (CR) after induction therapy (CR rate 95.1%), the 1- and 3-year EFS rate were (92.7 ± 1.8)% and (78.7 ± 3.7)%, respectively, and the 3-year EFS rate was (85.6 ± 4.9)% in standard risk group, (82.1 ± 5.8)% in intermediate risk group and (58.1 ± 9.2)% in high risk group, there was significant statistical difference between above mentioned 3 groups (P < 0.001). The MRD analysis at different time points showed that the higher the MRD level, the lower the 3-year EFS rate of children with ALL, in which the 3-year EFS rate of MRD ≥ 10(-2) at day 15, MRD ≥ 10(-3) at day 33 and MRD ≥ 10(-3) at week 12 were significantly lower. The MRD ≥ 10(-3) at week 12 was proven to be an independent predictor by multivariate Cox proportional-hazards regression model. The 3-year EFS rate for patients with MRD < 10(-3) and MRD ≥ 10(-3) at week 12 were (86.3 ± 4.1)% vs (55.8 ± 9.1)% (P < 0.05); 8 relapsed among 98 cases with negative MRD (MRD < 10(-4)) at day 33, 19 relapsed among 108 cases with positive MRD at day 33 between the two groups for recurrence rate has significant difference (P < 0.05). It is concluded that dynamically monitoring MRD by multi-parameter flow cytometry can precisely evaluate treatment response, judge treatment outcome and predict relapse in childhood B-ALL. The MRD 10(-2) at day 15, MRD 10(-3) at day 33 and MRD 10(-3) at week 12 should be considered as the best cut-off. MRD ≥ 10(-3) at week 12 was proven to be an independent factor of poor prognosis.

[Expression of two subtype molecules of CD133 in childhood with B linage acute lymphoblastic leukemia and its clinical significance].

This study was to explore the expression of two subtype molecules of CD133 and its relationship with clinical prognostic factors in childhood with B linage acute lymphoblastic leukemia (B-ALL) at initial diagnosis and the 33rd day of induction chemotherapy. Expression of CD133-1 and CD133-2 in 48 cases of B-ALL and 25 cases at initial diagnosis and the 33rd day of treatment was detected by flow cytometry. Minimal residual disease (MRD) of B-ALL at 33rd day was evaluated by flow cytometry. The results indicated that the expression of CD133-1 was positive in 18 cases (37.5%), and expression of CD133-2 in 30 cases (62.5%) was positive from 48 cases with newly diagnosed ALL (P < 0.05). At 33rd day of treatment, expression of CD133-1 in 2 cases (8.0%) from 25 cases was positive, and expression of CD133-2 in 23 cases (92.0%) was positive (P < 0.05). After induction chemotherapy in B-ALL, the expression of CD133-1 decreased significantly, but still higher than that in the normal control group. Compared to expression of CD133-1, expression of CD133-2 decreased slowly. It is concluded that there is no relations among expression of CD133 and sex, age, white blood cell count, percentage of bone marrow blast cells, FAB subtype, cytogenetics, leukemia fusion gene, risk stratification and complete remission rate in childhood B-ALL. The positive expression rates and levels of CD133-2 are higher than those of CD133-1 in B-ALL. There is no statistical correlation between expression of CD133 and CD34 in B-ALL. The expression of CD133-2 is significantly related to the level of MRD.

[Analysis of clinical features and prognostic significance of childhood T-lineage acute lymphoblastic leukemia].

This study was aimed to explore the clinical features and prognosis outcome of childhood T-cell acute lymphoblastic leukemia (T-ALL). The clinical data of 38 cases of newly diagnosed T-ALL from Jan 2005 to Aug 2010 were analyzed retrospectively, and 78 cases of B-ALL with intermediate and high risk were collected as control group, then the sensitive rate of patients to prednisone pretreatment, complete remission (CR) rate at day 33 after induction chemotherapy, relapse rate and 3-year event-free survival (EFS) were compared between T-ALL and B-ALL children. The results showed that no significant statistic difference were found in distribution of age, infiltration of liver, spleen and lymph nodes as well as central nervous system disease, chromosome abnormality, expression level of fusion gene and so on between T-ALL and B-ALL groups (p > 0.05), but there were significant differences in sex and number of cases with WBC count ≥ 50 × 10(9)/L between them (p < 0.05). The sensitive rate of T-ALL and B-ALL patients to prednisone pretreatment was 51.9% and 89.3% respectively (p < 0.05). The ratio failed to achieve CR at day 33 after induction chemotherapy was 15.4% and 8.1% in the two groups (p > 0.05). The relapse rate of T-ALL and B-ALL cases was 30.8% (8/26) and 14.9% (11/74) respectively (p > 0.05). The time from CR to relapse was (9.78 ± 3.48) month and (21.28 ± 14.32) month (p < 0.05). The 3 year EFS of T-ALL cases with intermediate and high risk was (37.5 ± 17.1)% and (22.2 ± 9.8)%, while 3 year EFS of B-ALL cases was (66.7 ± 7)% and (51.7 ± 9.3)% respectively (p < 0.05) according to Kaplan-Meier survival curve. It is concluded that as compared with B-ALL cases, the male ratio and initial WBC count are higher, moreover the early response to prednisone pretreatment and 3 year EFS are poor in T-ALL cases, the prognosis outcome is poor also.

[Effects of long-term application of organic fertilizer and superphosphate on accumulation and leaching of Olsen-P in Fluvo-aquic soil].

Based on a 20-year experiment of fertilization with organic and chemical fertilizers on a Fluvo-aquic soil under wheat-corn cropping system, this paper studied the relationships between Olsen-P concentration in plough layer and crop yields as well as the accumulation and vertical translocation of Olsen-P in soil profile. The results showed that when the Olsen-P concentration in plough layer maintained at 10-40 mg x kg(-1), the grain yields of wheat and corn were higher, whereas when the concentration of Olsen-P in plough layer was higher than 40 mg x kg(-1), it started to leach, which meant that in light loam Fluvo-aquic soil, the threshold value for P leaching might be 40 mg x kg(-1). In the treatments of chemical fertilization (NPK) and corn straw returning (SNPK) with the P application rate of 77-90 kg x hm(-2), the Olsen-P concentration in plough layer was increased by 0.63-0.72 mg x kg(-1) per 100 kg x hm(-2) of applied P, with an annual increment of 0.49-0.65 mg x kg(-1) and needed 45-60 years for reaching the threshold value for P leaching. In the treatments of chemical fertilization combined with manure application (MNPK, MNPK2, and 1.5MNPK), the formula of Olsen-P accumulation in 0-20 cm soil layer were Y(MNPK) = 3.1097x + 6.9615 (R2 = 0.8562), Y(MNPK2) = 2.4765x + 13.563 (R2 = 0.9307), and Y1.5MNPK = 4.506x + 6.4464 (R2 = 0.8862). It might take 8 years to reach the threshold value for Olsen-P leaching when the P application rate in treatment 1.5MNPK was 210 kg x hm(-2), 11 years when the P application rate in treatments MNPK2 and MNPK was 125 and 140 kg x hm(-2). Organic fertilization combined with chemical fertilization increased the Olsen-P accumulation rate being 2.5 times higher than chemical fertilization. Excessive application of organic fertilizer could increase the accumulation and leaching of Olsen-P in soil profile.