Palladium-catalysed fragmentary esterification-induced allylic alkylation of allyl carbonates and cyclic vinylogous anhydrides.

An unprecedented palladium-catalysed fragmentary esterification-induced allylic alkylation (FEAA) of cyclic vinylogous anhydrides (CVAs) and allyl carbonates has been disclosed. The protocol features broad sp3-rich scaffold tolerance, rendering highly functionalized 1,6 and 1,7-dicarbonyls in up to high yields and diastereoselectivities. Three-component FEAA is also well tolerant to generate 1,6-dicarbonyls through the addition of extra O/N-nucleophiles. Furthermore, cyclic allyl carbonate-involved FEAA provides an efficient approach for the synthesis of structurally complex medium-sized rings.

Enantioselective Synthesis of Ten-Membered Lactones via Palladium-Catalyzed [5 + 5] Annulation.

Ten-membered lactones are the core units of many biologically active natural products but with a great synthetic challenge. Based on the principle of vinylogy, novel types of cyclic vinylogous anhydrides have been designed as five-carbon carbonyl synthons, further applied in [5 + 5] annulation with vinylethylene carbonates under chiral palladium catalysis. This strategy features excellent regioselectivity, mild conditions, and broad substrate scope, affording a range of spiro ten-membered lactones bearing oxindole and pyrrolidinone motif in excellent yield (up to 99%) with moderate to high enantioselectivity (up to 89% ee).

High-Frequency Ultrasound and Shear Wave Elastography in Quantitative Differential Diagnosis of High-Risk and Low-Risk Basal Cell Carcinomas.

OBJECTIVES: The purpose of this study was to investigate the value of high-frequency ultrasound and shear wave elastography (SWE) in quantitative differential diagnosis of high-risk and low-risk basal cell carcinomas (BCCs). METHODS: A total of 52 BCCs confirmed by surgical pathology were studied. Taking pathologic subtypes as reference, all the cases were classified as high-risk BCCs or low-risk BCCs. High-frequency ultrasound parameters and SWE parameters recorded preoperatively were retrospectively analyzed. The differences of two groups were compared. RESULTS: There were 12 high-risk BCCs and 40 low-risk BCCs. The maximum infiltration depth (MID) and average Young's modulus (Eave ) of high-risk BCCs were 5.76 ± 2.56 mm and 31.61 ± 12.36 kPa, whereas of low-risk BCCs were 4.29 ± 1.77 mm and 20.04 ± 4.74 kPa, respectively, P < .05. The area under the receiver operator characteristic curve of MID and Eave were 0.714 and 0.811, P > .05. Taking 5.5 mm of MID and 24.45 kPa of Eave as the threshold for the diagnosis of high-risk BCCs, the sensitivity, specificity, and accuracy were 58.3%, 82.5%, 76.9% and 75.0%, 82.5%, 80.8%, P > .05. CONCLUSIONS: The MID and Eave of the lesion can be used to determine the recurrence risk of BCCs and provide a reference for the development of individualized treatment plans.

Estimation of stress distribution and risk of failure for maxillary premolar restored by occlusal veneer with different CAD/CAM materials and preparation designs.

OBJECTIVES: To compare stress distribution and failure probability in maxillary premolars restored by simple occlusal veneer (SOV) and buccal-occlusal veneer (BOV) with 3 different CAD/CAM materials. MATERIALS AND METHODS: A maxillary premolar was digitized by a micro-CT scanner. Three-dimensional dynamic scan data were transformed, and finite element models of 2 different models (SOV and BOV restored teeth) were designed. Three different CAD/CAM materials, including lithium disilicate glass ceramic (LD) IPS e.max CAD, polymer-infiltrated ceramic-network (PICN) Vita Enamic, and resin nano-ceramic (RNC) Lava Ultimate, were designated to both veneers. Maximum principle stresses were determined by applying a 300-N axial load to the occlusal surface. Weibull analyses were performed to calculate the failure probability of the models. RESULTS: LD-restored teeth showed the highest stress in the veneer, lowest stress in substrate teeth, and lowest failure probability for the overall system; RNC-restored teeth showed the lowest stress in the veneer, highest stress in substrate teeth, and highest failure probability. No significant differences were found in the cement layer among the different models. No significant differences of stress and failure probability existed between SOV and BOV preparations. CONCLUSIONS: CAD/CAM composite resin occlusal veneers bear lower maximum stress than ceramic veneers. Teeth restored by composite veneers are more prone to failure than those restored by ceramic veneers. Additional reduction of the buccal surface did not increase the stress on the occlusal veneer under axial load. CLINICAL RELEVANCE: Both occlusal veneers could be used under physiological masticatory force. CAD/CAM glass ceramic was safer than composite resins.

miR-34a inhibits cell proliferation in prostate cancer by downregulation of SIRT1 expression.

MicroRNA-34a (miR-34a) functions as a tumor suppressor gene and inhibits abnormal cell growth by regulating the expression of other genes. The role of miR-34a in regulating sirtuin 1 (SIRT1) in prostate cancer remains unclear. The objective of the present study was to investigate the biological function and molecular mechanisms of miR-34a regulation of SIRT1 in human prostate cancer samples and the human prostate cancer cell line, PC-3. Fresh prostate tissues were obtained from patients, and the miR-34a expression in prostate cancer tissues was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). qPCR and western blotting were performed to assess the effects of miR-34a overexpression on SIRT1 regulation in PC-3 cells, and the cell growth was assessed by Cell Counting Kit-8 (CCK-8). Flow cytometry was used to assess the cell cycle status of the cells. The miR-34a expression levels in prostate cancer tissues were significantly reduced compared with adjacent normal prostate tissues (P<0.05). SIRT1 expression levels in PC-3 cells with over-expression of miR-34a were significantly reduced compared with those in the negative control (P<0.05). The over-expression of miR-34a inhibited PC-3 cells growth and resulted in increased cell cycle arrest compared with the negative control (P<0.05). In conclusion, miR-34a inhibits the human prostate cancer cell proliferation, in part, through the downregulation of SIRT1 expression.

[Effect of different molarity cathepsins specific inhibitor E-64 on dentin-resin bonding durability].

OBJECTIVE: To investigate, in vitro, the effect of cathepsins specific inhibitor N-(trans-epoxysuccinyl)-L-leucine 4-guanidinobutylamide(E-64) on dental endogenous cathepsins and to find its most effective molarity to elevate dentin-resin bonding durability. METHODS: Fifty recently extracted human third molars were divided into five groups according to random number table, and treated with different molarity of E-64 as follow: 0, 2.5, 5.0, 10.0 and 20.0 µmol/L. The group 0 µmol/L was control group. Then 20 specimens of dentin-resin composite were fabricated in each group. Half of the specimens were tested after 24 h water storage(37 °C) and the other half were tested after 90 days water storage(37 °C) followed by 3000 cycles'thermocyling(5-55 °C) as aging treatment. Fractured specimens were analyzed using scanning electron microscopy(SEM). RESULTS: After 24 h water storage, no significant differences were found in micro-tensile bond strength(µTBS) of samples between different groups (P > 0.05). However, after ageing treatment, µTBS of the samples in group 2.5, 5.0, 10.0 and 20.0 µmol/L [(18.7 ± 2.7), (20.8 ± 3.4), (18.3 ± 2.8) and (19.1 ± 2.7) MPa] were significantly higher than that in group 0 µmol/L [(15.1 ± 3.0) MPa] (P < 0.05). Only in the group 5.0 µmol/L no significant difference was found between the original and the decreased value of µTBS(P > 0.05), while the µTBS in other groups decreased significantly after aging treatment(P < 0.05). Failure types were almost adhesive and mixed types. Collagens in hybrid layer were less degraded in the groups using E-64 after aging treatment than control group. CONCLUSIONS: E-64 was effective on inhibiting cathepsins activity in dentin, and induced less collagens degradation in smear layer for better dentin-resin bond durability.

Dark fermentative hydrogen production from neutralized acid hydrolysates of conifer pulp.

Concentrated acid hydrolysis of cellulosic material results in high dissolution yields. In this study, the neutralization step of concentrated acid hydrolysate of conifer pulp was optimized. Dry conifer pulp hydrolysis with 55 % H(2)SO(4) at 45 °C for 2 h resulted in total sugar yields of 22.3-26.2 g/L. The neutralization step was optimized for solid Ca(OH)(2), liquid Ca(OH)(2) or solid CaO, mixing time, and water supplementation. The highest hydrogen yield of 1.75 mol H(2)/mol glucose was obtained with liquid Ca(OH)(2), while the use of solid Ca(OH)(2) or CaO inhibited hydrogen fermentation. Liquid Ca(OH)(2) removed sulfate to below 30 mg SO(4) (2-)/L. Further optimization of the neutralization conditions resulted in the yield of 2.26 mol H(2)/mol glucose.

[Effects of autologous hematopoietic stem cell transplantation on immune function in patient with systemic lupus erythematosus].

To investigate the effects of autologous hematopoietic stem cell transplantation (AHSCT) on immune index in patient with systemic lupus erythematosus (SLE), and evaluate its treatment outcome, the flow cytometry (FCM) and enzyme linked immunosorbent assay (ELISA) were used to detect the leukocyte differentiation antigen, sIL-2R, IL-6, C3, C4, autoantibodies, immunoglobulin for 33 case of SLE before transplantation and at 1, 3, 6, 12 months after transplantation. The results showed that the ratio of CD4(+), CD19(+) cell, the level of sIL-2R, IL-6 and the positive rate of autoantibodies were significantly lower, CD8(+), CD16(+)CD56(+) cell and C3, C4 were higher than those before transplantation. Out of the 33 patients, 26 achieved CR, 3 reached PR and 4 relapsed at 4 - 6 months after transplantation. It is concluded that the immune indexes of patients with SLE changed significantly following AHSCT. These immune indexes may be indications to predict the status of remission in patient with SLE.