Highly Efficient Electrocatalytic CO2 Reduction to C2+ Products on a Poly(ionic liquid)-Based Cu0 -CuI Tandem Catalyst.

Electroreduction of CO2 on a polymer-modified Cu-based catalyst has shown high multi-electron reduction (>2 e- ) selectivity, however, most of the corresponding current densities are still too small to support industrial applications. In this work, we designed a poly(ionic liquid) (PIL)-based Cu0 -CuI tandem catalyst for the production of C2+ products with both high reaction rate and high selectivity. Remarkably, a high C2+ faradaic efficiency (FE C 2 + ) of 76.1 % with a high partial current density of 304.2 mA cm-2 is obtained. Mechanistic studies reveal the numbers and highly dispersed Cu0 -PIL-CuI interfaces are vital for such reactivity. Specifically, Cu nanoparticles derived Cu0 -PIL interfaces account for high current density and a moderate C2+ selectivity, whereas CuI species derived PIL-CuI interfaces exhibit high activity for C-C coupling with the local enriched *CO intermediate. Furthermore, the presence of the PIL layer promotes the C2+ selectivity by lowering the barrier of C-C coupling.

Cobalt-Catalyzed Chemoselective Transfer Hydrogenative Cyclization Cascade of Enone-Tethered Aldehydes.

The ligand-free Co-catalyzed chemoselective reductive cyclization cascade of enone-tethered aldehydes with i-PrOH as the environmentally benign hydrogen surrogate is developed by this study. Mechanistic studies disclosed that such a protocol is initiated by an ortho-enone-assisted Co(I)-catalyzed reduction of the aldehyde functionality with i-PrOH. Meanwhile, the selectivity from the Michael-Aldol cycloreduction cascade to the oxa-Michael cascade is feasible and readily adjusted by the addition of steric Lewis bases, such as TEMPO and DABCO, delivering substituted 1H-indenes and dihydroisobenzofurans, respectively.

Dehydrative Formation of Isosorbide from Sorbitol over Poly(ionic liquid)-Covalent Organic Framework Hybrids.

In this study, the covalent bonding of linear poly(ionic liquid)s (PILs) with covalent organic frameworks (COFs) was accessed by copolymerization of a vinyl-decorated COF with 4-vinylbenzyl chloride, followed by quaternization with tertiary amines. The resultant PIL-COF composite by anchoring a proper content of vinyl sites on the COF-based comonomer retains the crystallinity and porosity, thereby facilitating access of the reactants to the catalytic active sites. As a proof of concept, the dehydrative transformation of sorbitol into isosorbide was selected as a benchmark reaction, whose rate improved significantly in the presence of PIL-COF-0.33 compared with those of individual components and the mesoporous PIL counterpart due to uniform pore sizes and flexible linear catalytic chains. In addition, the hybrids bearing a chemical cross-linkage between PILs and COFs are robust, and PIL-COF-0.33 can be recovered and reused for 10 runs without significant reactivity loss. These findings provide the basis for a novel design concept for achieving both efficient and stable IL catalysis.

Boosting the hole transport of conductive polymers by regulating the ion ratio in ionic liquid additives.

Poly(3,4-ethylenedioxythiophene) (PEDOT) has aroused great interest in organic electrics because of its high electrical conductivity and mechanical flexibility. To improve the charge transport, it can act as an ionic liquid (IL) additive due to its ion characteristics and high electrical conductivity. Herein, we investigated the hole-transport performance of PEDOT treated by ILs featuring specific ion ratios (4 : 1, 3 : 1, 2 : 1, 1 : 1, 1 : 2, 1 : 3, and 1 : 4) of the cation and anion through classical dynamics simulations and quantum mechanics computations. The hole mobility of the amorphous PEDOT, constituting nine EDOT monomers, could be improved to 16.81, 18.03, and 10.14 cm2 V-1 s-1 when synergistically regulating the ion ratio to 2 : 1, 3 : 1, and 4 : 1. Consequently, these ratios potentially achieved nearly a 100-fold improvement in the electrical conductivity with respect to the pristine system. The improvements mainly stemmed from the fact that decreasing the amount of anions in ILs and prolonging the chain length of PEDOT yielded an ordered face-to-face π-π stacking. The electronic coupling and charge excitation further confirmed that the anions play an active role in tunneling the hole transport in ILs/heterogeneous PEDOT, and the highest occupied molecular orbital (HOMO) energy level of PEDOT was up-shifted significantly after treatment by the ratios of 2 : 1, 3 : 1, and 4 : 1, which favored the electron-donating ability and was in line with the extraordinary enhancement of the hole mobility. Our results imply that regulating the ion ratio in ILs is a novel strategy for modulating the electronic properties and π-stacked morphology of PEDOT.

Tris(pyrazolyl)borate Cobalt-Catalyzed Hydrogenation of C═O, C═C, and C═N Bonds: An Assistant Role of a Lewis Base.

The combination of tris(pyrazolyl)borate cobalt complexes and Lewis base is developed as an efficient catalyst precursor in the homogeneous hydrogenation. A broad substrate scope including carbonyls, alkenes, enamines, and imines is reduced with 60 atm of H2 at 60 °C. Mechanistic studies support the hydrogenation operates through a frustrated Lewis pair (FLP)-like reduction process. These results highlight the development of novel non-noble metal catalytic processes, when combined with the diverse small molecule activation chemistry associated with FLPs.

N-Hydroxyphthalimide/benzoquinone-catalyzed chlorination of hydrocarbon C-H bond using N-chlorosuccinimide.

The direct chlorination of C-H bonds has received considerable attention in recent years. In this work, a metal-free protocol for hydrocarbon C-H bond chlorination with commercially available N-chlorosuccinimide (NCS) catalyzed by N-hydroxyphthalimide (NHPI) with 2,3-dicyano-5,6-dichlorobenzoquinone (DDQ) functioning as an external radical initiator is presented. Aliphatic and benzylic substituents and also heteroaromatic ones were found to be well tolerated. Both the experiments and theoretical analysis indicate that the reaction goes through a process wherein NHPI functions as a catalyst rather than as an initiator. On the other hand, the hydrogen abstraction of the C-H bond conducted by a PINO species rather than the highly reactive N-centered radicals rationalizes the high chemoselectivity of the monochlorination obtained by this protocol as the latter is reactive towards the C(sp3)-H bonds of the monochlorides. The present results could hold promise for further development of a nitroxy-radical system for the highly selective functionalization of the aliphatic and benzylic hydrocarbon C-H.

A metal-free direct C (sp3)-H cyanation reaction with cyanobenziodoxolones.

A metal-free protocol of direct C(sp3)-H cyanation with cyanobenziodoxolones functioning as both cyanating reagents and oxidants was developed. Unactivated substrates, such as alkanes, ethers and tertiary amines, were thereby transformed to the corresponding nitriles in moderate to high yields. Mechanistic studies indicated that the cyanation proceeded with two potential pathways, which is highly dependent on the substrates: (1) a free radical case for alkanes and ethers and (2) an oxidative case for tertiary amines.

Oxidation of Aromatic Aldehydes to Esters: A Sulfate Radical Redox System.

A mild oxidative esterification of various aromatic aldehydes by sulfate radical redox system was presented. In the reaction pathway exploration, the transiency of MeOSO3- was disclosed, which was generated from esterification between the in situ generated HSO4- and MeOH, a rate-limiting step in the process. More importantly, the selectivity-controlling step was represented by the subsequent nucleophilic displacement between MeOSO3- and aldehydes. The ionic oxidant 1a ((NH4)2S2O8) with more N-H numbers in the cation, as compared with 1c ((n-Bu4N)2S2O8) and 1d ((PyH)2S2O8), has better performance in the oxidative esterification of aldehydes.

Experimental and theoretical studies on hydrogen bond-promoted fixation of carbon dioxide and epoxides in cyclic carbonates.

The hydrogen bond donor-promoted fixation of CO(2) and epoxides into cyclic carbonates was investigated through experimental and density functional theory studies. A highly effective homogeneous system of 1,2-benzenediol-tetrabutyl ammonium bromide (TBAB) and heterogeneous poly-ionic liquids were developed for the fixation of CO(2) into cyclic carbonates via hydrogen bond activation, based on the understanding of the reaction mechanism and catalyst design. The work hence provides a molecular level understanding of the reaction process and forms the basis for the rational design of catalytic systems for the fixation of CO(2) into useful organic compounds.

Synthesis of bimagnetic ionic liquid and application for selective aerobic oxidation of aromatic alcohols under mild conditions.

The first bimagnetic ionic liquid based on Fe and TEMPO with cooperative functionalities not only exhibited strong paramagnetic behaviour at room temperature under an applied magnetic field of 5000 Oe but also proved to be an effective catalyst for selective aerobic oxidation of aromatic alcohols under mild and clean conditions.

[Clinicopathologic study on 61 cases of uterine papillary serous carcinoma with or without adjuvant therapy].

OBJECTIVE: To study the clinicopathologic features of uterine papillary serous carcinoma (UPSC) and the roles of adjuvant therapy. METHODS: Sixty-one cases of UPSC with operation done and followed up for a period of 4 to 9 years were enrolled into the study. The histology of slides specimens were reviewed and immunohistochemical study was performed. The follow-up and survival data were analyzed. RESULTS: All of the 61 patients were post-menopausal, with a median age of 68 years. The clinical presentations included abnormal vaginal bleeding, abdominal symptoms and abnormal Pap smears. The median size of the tumors was 7.5 cm (range=1.2 to 14.8 cm). There were 27.9% cases in FIGO stage I (8.2% in stage IA, 14.8% in stage IB and 4.9% in stage IC), 9.8% in stage II, 32.8% in stage III and 29.5% in FIGO stage IV. The histologic features were similar to those of the ovarian counterpart, with tumor cells containing the high-grade nuclei and arranged in complex papillae. Psammoma bodies were identified in 24.6% of the cases. Immunohistochemical study showed that the tumor cells demonstrated diffuse and strong nuclear staining for p53 and Ki-67. They were negative for estrogen receptor and progesterone receptor. Fifteen of the 61 cases (24.6%) showed no evidence of myometrial invasion. However, ten of the 15 cases had extrauterine disease, with peritoneal (6/15) and nodal (9/15) involvement. Tumors with deep myometrial invasion, lymphovascular permeation and nodal metastasis were associated with worse prognosis by univariate analysis. Fifty-six patients received adjuvant therapy. The number of patients receiving adjuvant chemotherapy alone, adjuvant radiotherapy alone and combined adjuvant chemotherapy/radiotherapy were 42, 24 and 10, respectively. The median survivals of the chemotherapy group and non-chemotherapy group (with or without radiotherapy) were 66.4 months and 32.8 months, respectively. CONCLUSIONS: UPSC has distinctive clinical and pathologic features. The tumor stage, lymph node status, lymphovascular permeation and depth of myometrial invasion were important prognostic factors. Adjuvant chemotherapy for stage III/IV tumors or recurrent UPSC may have survival benefit.

[Clonality analysis and mutational status of IgVH gene in Hodgkin variant of Richter syndrome].

OBJECTIVE: To detect the clonal relationship, the rearrangement, and the mutational status of IgVH gene; the influence of these molecular characteristics on the clinical outcome in Hodgkin variant of Richter syndrome; and the possible molecular pathogenesis in this transformation. METHODS: The clonal rearrangements and mutational status of IgVH genes were analyzed in Hodgkin variant of Richter syndrome and B-CLL with Reed-Stemberg (R-S)-like cells by GeneScan analysis and sequencing. Semi-nest PCR based on laser capture microdissection was utilized to compare the clonal relationship between B-CLL and R-S/R-Slike cells. Immunohistochemical staining was used to detect the different expressions of ZAP70, p53, IRF-4 and LMP1 in the two components. RESULTS: (1) 5/6 B-CLL cases transformed to Hodgkin lymphoma (HL)/R-S-like cells carried the mutated IgVH genes; (2) 2 cases of R-S cells and 1 case of R-S-like cells were clonally distinct from B-CLL clone and express LMP1, whereas 1 case of R-S-like cells was relating to the surrounding B-CLL cells and did not express LMP1; (3) 2/6 B-CLL cases transformed to HL convey VH4-34 and VH3-48 respectively. CONCLUSIONS: (1) Richter transformation to HL/R-S-like cells evolves from the B-CLL which originates from the germinal center or post germinal center B cells, indicating that different lymphoma cells of different subtypes in Richter syndrome come from different B cell lineage and possibly involve a different pathogenesis and pathway; (2) HL and R-S-like cells evolve from either the B-CLL clone or may develop as a clonally unrelated lymphoma, the independent secondary malignancies are appear to be EBV-positive, possibly as a consequence of the underlying immunodeficiency; (3) The biased usage of IgVH genes suggested a role of antigens involved in the HL variant of Richter syndrome.

[Clonality analysis and mutation status of IgVH genes in classic Richter's syndrome].

OBJECTIVE: To study the clonal rearrangements and mutation status of IgVH genes in classic Richter's syndrome, the relationship between molecular findings of IgVH gene and clinical outcome, and to deciper the possible molecular mechanism of transformation. METHODS: The clonal rearrangements and mutation status of IgVH genes were analyzed in cases of classic Richter's syndrome by Genescan and sequencing. Immunohistochemical study for zeta-chain associated protein kinase 70 kDa (ZAP70), p53 and interferon regulation factor 4 (IRF-4) was also performed. RESULTS: Samples of 18 cases of B-chronic lymphocytic leukemia (B-CLL)/ diffuse large B-cell lymphoma (DLBCL,78. 3%) had identical tumor cell clones, whereas DLBCL developed as a clonally independent neoplasm in 5 patients (21.7%). Among the clonally related group, 12 cases carried unmutated VH genes in both B-CLL and DLBCL components and VH3-23, VH3-74 and VH1-2 were accounted for the B-CLL transformation to DLBCL. Immunohistochemical study showed that the transformed DLBCL expressed CD5 in 32.1% of cases, CD23 in 14.3%, ZAP70 in 23.8%, p53 in 80.6% and IRF-4 in 82.6% of the cases respectively. Follow-up data were available in 17 patients with classic Richter's syndrome. The median survival period was 7 months. No significant difference in survival rate was obtained between the clonally related or unrelated groups, between IgVH gene mutated or unmutated groups, and between the groups with or without expression of ZAP70, p53 and IRF-4. CONCLUSIONS: The ratio of clonally related transformed DLBCL from B-CLL to clonally unrelated DLBCL is 2:1. Clonal transformation to DLBCL predominantly occurs in B-CLL patients carrying unmutated IgVH genes. The biased IgVH gene usage suggests antigens are involved in classic Richter's syndrome. Molecular differences of IgVH genes and very poor clinical outcome of this group of transformed DLBCL indicate that there cases may be regarded as a distinct subset of DLBCL.

[Analysis of autopsy cases in 50 years].

OBJECTIVE: To evaluate the changing rate for autopsy and the reason during 50 years, and to study the disagreement between pathological and clinical diagnosis in 3162 autopsy cases. METHODS: To retrospectively analyses 3162 autopsy cases in School of Medicine of Zhejiang University from 1950 to 1999. RESULTS: (1) The most autopsy cases is 1037 cases during 1960 - 1970, while the lowest is 102 cases during 1990 - 1999. (2) The total clinical mis-diagnosis rate is 36.24%, while the highest one is 43.19% in 1970 - 1979 group, and 41.80% in 1990 - 1999; The highest diagnostic inaccuracy rate is for tumor (62.42%), second circulation disease (61.81%), third parasitic disease (49.18%); Invasive fungal infection rate in 3162 autopsy is 2.28%, while the diagnostic inaccuracy rate is as high as 86.10%. (3) In disease spectrum, the common diseases are respiratory disease (32.29%), infectious disease (11.61%) and digestive disease (11.07%) respectively. CONCLUSION: The autopsy rate was decreased gradually over 50 years, while the diagnostic inaccuracy rate is still high.

[Study of dual rearrangements of lymphocytic antigen receptor genes in non-Hodgkin lymphoma].

OBJECTIVE: To investigate the rate of dual rearrangements of lymphocytic antigen receptor genes in non-Hodgkin lymphomas (NHL) and its pathogenesis and pathologic significance. METHODS: PCR analysis of monoclonal, polyclonal and dual rearrangements of IgH and TCR gamma, TCR beta genes was carried out in 125 cases of NHL to evaluate the rate of dual rearrangements, immunohistochemistry was performed for a Ki67 protein expression in 117 cases and the proliferation index was calculated. The relationship between antigen receptor gene rearrangements and proliferation index was analyzed. RESULTS: Combination of the two pairs of IgH gene primers with the multiplex PCR for TCR gamma and TCR beta gene revealed dual rearrangements in 8% (8/96) of B-NHL, 17% (5/29) of T-NHL. In B cell NHL, IgH gene monoclonal, dural and polyclonal rearrangements were identified in 65, 8 and 15 cases respectively, while in T-cell NHL, they were in 15, 5 and 9 cases, respectively. There was no significant difference between proliferation index and monoclonal, dual, polyclonal rearrangements in both B-NHL and T-NHL by One-way test. CONCLUSION: Dual rearrangements in NHL are not rare and have no relationship with proliferation index.

Involvement of ATM/ATR-p38 MAPK cascade in MNNG induced G1-S arrest.

AIM: To understand the effect of low concentration of N-methyl-N'-nitro-nitrosoguanidine (MNNG), which is a widely distributed environmental mutagen and carcinogen especially for human gastric cancer, on DNA damage and to study its possible pathway in regulating cell cycle arrest. METHODS: The DNA damage effect was measured by Comet assay. A specific phospho-(Ser/Thr) ATM/ATR substrate antibody was used to detect the damage sensor by Western blot. p38 kinase activity was measured by direct kinase assay, and immunoprecipitation for the possible connection between ATM/ATR and p38 MAPK. Flow cytometry analysis and p38 MAPK specific inhibitor SB203580 were combined to detect the possible cell cycle arrest by p38 MAPK. RESULTS: With the same low concentration MNNG exposure (0.2 microM 2.5 h), Comet assays indicated that strand breaks accumulated, Western blot and kinase assay showed ATM/ATR and p38 kinase activated, immunoprecipitation showed phospho-ATM/ATR substrate antibody combined with both p38 MAPK antibody and phospho-p38 MAPK antibody. p38 MAPK pathway was involved in the G1-S arrest. CONCLUSION: Activation of ATM/ATR by MNNG induced DNA damage leads to activation of p38 MAPK, which involves in the G1 checkpoint in mammalian cells.

[Effects of power frequency magnetic field on gap junction intercellular communication of astrocytes].

OBJECTIVE: In order to explore if power frequency magnetic field (PFMF) can act as cancer promoter or be synergistic with phorbol 12-myristate 13-acetate (TPA) in cancer promotion, the effects of 50 Hz MF on gap junction intercellular communication (GJIC) of astrocytes were observed. METHODS: Fluorescence redistribution after photobleaching (FRAP) was adopted to observe the recovery of fluorescence intensity in the bleached cells thus to estimate intercellular communication by gap junction. Comparative fluorescence intensity recovery rate (CFIRR) was as evaluation index. The effects of 50 Hz MF alone or with TPA on GJIC of astrocytes were studied. RESULTS: After 3 ng/ml TPA treatment for 1 hour, M(d) of CFIRR was 4.53%/min, whereas that in the control group was 9.74%/min (H = 12.084, P < 0.005). After exposure to 0.8 and 1.6 mT magnetic field for 24 hours respectively, M(d) of CFIRR was 8.25%/min and 6.68%/min respectively, no significant difference from that of control (H = 32.617, P > 0.05). After exposure to 0.8 and 1.6 mT magnetic field for 23 hours then combined with 3 ng/ml TPA treatment for 1 hour, M(d) of CFIRR was 3.32%/min and 2.85%/min respectively, also no significant difference from that in the group treated with 3 ng/ml TPA alone (H = 2.589, P > 0.05). CONCLUSION: 50 Hz MF (within 0 - 1.6 mT) alone could not inhibit GJIC of astrocytes; with TPA, could not enhance the inhibition of TPA on GJIC of astrocytes. But with MF intensity increasing, the inhibition of MF on GJIC showed elevated tendency.