In-situ spectroscopic probe of the intrinsic structure feature of single-atom center in electrochemical CO/CO2 reduction to methanol.

While exploring the process of CO/CO2 electroreduction (COxRR) is of great significance to achieve carbon recycling, deciphering reaction mechanisms so as to further design catalytic systems able to overcome sluggish kinetics remains challenging. In this work, a model single-Co-atom catalyst with well-defined coordination structure is developed and employed as a platform to unravel the underlying reaction mechanism of COxRR. The as-prepared single-Co-atom catalyst exhibits a maximum methanol Faradaic efficiency as high as 65% at 30 mA/cm2 in a membrane electrode assembly electrolyzer, while on the contrary, the reduction pathway of CO2 to methanol is strongly decreased in CO2RR. In-situ X-ray absorption and Fourier-transform infrared spectroscopies point to a different adsorption configuration of *CO intermediate in CORR as compared to that in CO2RR, with a weaker stretching vibration of the C-O bond in the former case. Theoretical calculations further evidence the low energy barrier for the formation of a H-CoPc-CO- species, which is a critical factor in promoting the electrochemical reduction of CO to methanol.

Antityrosinase and antioxidant properties of mung bean seed proanthocyanidins: Novel insights into the inhibitory mechanism.

This study investigated the structure, antioxidant activity, antityrosinase activity and mechanism of proanthocyanidins from mung bean seed [Vigna radiata (L.) Wilczek]. The structural composition were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization-full-mass spectrometry (ESI-Full-MS), and high-pressure liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) techniques. The mung bean seed proanthocyanidins were composed of procyanidins, prodelphinidins, and their rhamnosides. According to enzyme kinetic analysis, these compounds were potent, reversible, and mixed-type inhibitors of tyrosinase. They inhibited the enzyme activity by interacting with enzyme as well as substrates. The results of molecular docking showed that the interaction between mung bean seed proanthocyanidins and tyrosinase was driven by hydrogen bond, hydrophobic and electrostatic interactions. In addition, mung bean seed proanthocyanidins were demonstrated as powerful antioxidants. Therefore, this study confirmed a novel tyrosinase inhibitor and would lay a scientific foundation for their utilization in pharmaceutical and food industries.

Condensed Tannins from Longan Bark as Inhibitor of Tyrosinase: Structure, Activity, and Mechanism.

In this study, the content, structure, antityrosinase activity, and mechanism of longan bark condensed tannins were evaluated. The findings obtained from mass spectrometry demonstrated that longan bark condensed tannins were mixtures of procyanidins, propelargonidins, prodelphinidins, and their acyl derivatives (galloyl and p-hydroxybenzoate). The enzyme analysis indicated that these mixtures were efficient, reversible, and mixed (competitive is dominant) inhibitor of tyrosinase. What's more, the mixtures showed good inhibitions on proliferation, intracellular enzyme activity and melanogenesis of mouse melanoma cells (B16). From molecular docking, the results showed the interactions between inhibitors and tyrosinase were driven by hydrogen bond, electrostatic, and hydrophobic interactions. In addition, high levels of total phenolic and extractable condensed tannins suggested that longan bark might be a good source of tyrosinase inhibitor. This study would offer theoretical basis for the development of longan bark condensed tannins as novel food preservatives and medicines of skin diseases.

Inhibition of tyrosinase by cherimoya pericarp proanthocyanidins: Structural characterization, inhibitory activity and mechanism.

In this study, the structure of proanthocyanidins purified from cherimoya (Annona squamosa) pericarp was analyzed by ESI-QTOF-MS and HPLC analyses. The result indicated that these compounds were procyanidin-type proanthocyanidins, consisting mainly of (epi)catechin units linked b y B-type interflavan bonds. The analyses of enzymology showed that the activities of monophenolase and diphenolase of tyrosinase could be powerfully inhibited by the proanthocyanidins. Further researches on the inhibition mechanism demonstrated that they were reversible and competitive inhibitors with the KI value of 27.1±3.1µg/mL. These inhibitors quenched the fluorescence of tyrosinase through a static quenching mechanism and spontaneously formed proanthocyanidins-enzyme complex. Fluorescence changes of proanthocyanidins in the presence of copper ion suggested that the interactions could reduce the fluorescence intensity of these polymers and the molecular docking analysis revealed that copper irons of the enzyme could be chelated by adjacent hydroxyl groups on the B ring of proanthocyanidins. Moreover, proanthocyanidins were proved to be efficient quencher of substrates. These results would lay scientific foundation for their farther application in food and medicine industry.

[Characteristics and Prognostic Significance of Cytogenetic Abnormalities in Diffuse Large B-Cell Lymphoma Patients with Bone Marrow Involvement].

OBJECTIVE: To investigate the cytogenetic abnormalitis in patients with diffuse large B-cell lymphoma(DLBCL) patients with bone marrow involvement and their influence on prognosis. METHODS: Conventional karyotyping was performed on bone marrow specimens in 47 DLBCL patients with histologically confirmed bone marrow involvement(BMI). The karyotyping results of bone marrow, the characteristics and clinical effect of chromosomal abnormalities were analysed. RESULTS: In 47 DLBCL cases with BMI, the chromosomal abnormalities were detected in 25(53%) cases. Among them, complex karyotype was more frequent, being noted in 19(40%) patients. The most frequently involved chromosomes were chromosome 1 and 18(both 26%), others were chromosome 3(23%), 6(19%), 7, 8 and 14(13%). Among all karyotype changes, the most common numerical aberrations, in decreasing order of incidence, were trisomy 3(13%), trisomy 5, trisomy 7, trisomy 12, trisomy 18 and loss of 21(6%,each), and the most predominant structural aberrations, in decreasing order of incidence, were 1q+(17%), 1p+, 6q-, 8q+, 14q+, 18p+, 18q+ and aberrations involving band 2p21-p23 (6%,each). The prognostic impact analysis of both clinical features and cytogenetic aberrations revealed that IPI≥3 (P=0.03) or the presence of chromosomal abnormalities (P=0.005) were significantly related with poor progression free survival(PFS), and IPI≥3 (P=0.024), lactate dehydrogenase(LDH)≥ three times of the upper limit of normal (P=0.027) and the presence of chromosomal abnormalities (P=0.001) predominantly related with poor overall survival(OS). In multivariate analysis, the presence of chromosomal abnormalities was the only independently adverse factor for PFS(P=0.037, HR 2.323) and OS(P=0.015, HR 2.833). The analysis of prognostic effects of specific chromosomal aberrations showed that patients with specific cytogenetic abnormalities of 1q+, 8q+, +12, 12q+, 18p+ and aberrations involving band 2p21-23 had significantly poor PFS, and patients with specific cytogenetic abnormalities of 1q+, +3, +5, +7, 8q+, +12, 12q+ and aberrations involving band 2p21-23 had significantly poor OS. When the above mentioned specific chromosomal aberrations were analyzed with clinical covariate, the presence of chromosomal aberration of 8q+ (P=0.022, HR 2.701) and IPI≥3 (P=0.043, HR 2.949) were independently poor prognostic factors for PFS, and 1q+ (P=0.032, HR 2.973) was the independently poor prognostic factor for OS. CONCLUSION: In DLBCL patients with BMI, the presence of chromosomal abnormalities is the only independently poor factor for PFS and OS, and among them, the specific cytogenetic aberrations of 8q+ or 1q+ have an independently poor prognostic impact on PFS or OS, respectively, which need to be further studied.

Structure and function of chicken interleukin-1 beta mutants: uncoupling of receptor binding and in vivo biological activity.

Receptor-binding and subsequent signal-activation of interleukin-1 beta (IL-1ß) are essential to immune and proinflammatory responses. We mutated 12 residues to identify sites important for biological activity and/or receptor binding. Four of these mutants with mutations in loop 9 (T117A, E118K, E118A, E118R) displayed significantly reduced biological activity. Neither T117A nor E118K mutants substantially affected receptor binding, whereas both mutants lack the IL-1ß signaling in vitro but can antagonize wild-type (WT) IL-1ß. Crystal structures of T117A, E118A, and E118K revealed that the secondary structure or surface charge of loop 9 is dramatically altered compared with that of wild-type chicken IL-1ß. Molecular dynamics simulations of IL-1ß bound to its receptor (IL-1RI) and receptor accessory protein (IL-1RAcP) revealed that loop 9 lies in a pocket that is formed at the IL-1RI/IL-1RAcP interface. This pocket is also observed in the human ternary structure. The conformations of above mutants in loop 9 may disrupt structural packing and therefore the stability in a chicken IL-1ß/IL-1RI/IL-1RAcP signaling complex. We identify the hot spots in IL-1ß that are essential to immune responses and elucidate a mechanism by which IL-1ß activity can be inhibited. These findings should aid in the development of new therapeutics that neutralize IL-1 activity.

Circular permutation of chicken interleukin-1 beta enhances its thermostability.

Interleukin-1ß is a cytokine critically involved in immune and inflammatory responses. To extend its use as a component of avian vaccines, a circularly permuted chicken interleukin-1ß was synthesized that maintains its activity after pre-incubation at high temperatures, unlike wild-type chicken interleukin-1ß, which is irreversibly inactivated at high temperatures.

[Clinical and laboratory features of T-cell prolymphocytic leukemia in China].

OBJECTIVE: To investigate the clinical and laboratory characteristics and survival of Chinese patients with T- cell prolymphocytic leukemia (T-PLL). METHODS: Eleven patients with T-PLL admitted in our hospital from Jan 2006 to Oct 2012 were retrospectively analyzed. RESULTS: Of the 11 patients, nine were males and two females, with the median age of 56.0(19-69) years old. All the patients, except for three, presented with leukocytosis. The incidence of hyperleukocytosis (1/11) was less frequent than that in the British series (75%) (P=0.000). Lymphocyte counts in peripheral blood were increased in 9 of the 11 patients with the median absolute lymphocyte count (ALC) of 17.22(0.58-148.83)×109/L. Superficial lymphadenopathy and splenomegaly were the most common physical signs. It was common that serum lactate dehydrogenase (LDH) and beta 2 microglobulin(ß2-MG)were higher than normal level. All cases were positive for CD2/CD3/CD5/TCRαß, negative for CD1a /HLA-DR and TdT, and most of them were strong positive for CD7 expression. By chromosome analyses, most cases. (9/10) have normal chromosome. This rate is significantly higher than that of the British and American series (3% and 25%, respectively) (P=0.000, P=0.001). The 14q11 abnormality and trisomy 8q, which are common among Western cases, were not observed in any of our cases. With a median follow-up of 23.0 months, three patients died. Two year progress free survival (PFS) and overall survival (OS) were 53.3% and 50%, respectively. There were 3 patients with PFS over a number of years, whether it should be considered as the T-chronic lymphocytic leukemia (T-CLL) is worthy of further studies. CONCLUSION: The common clinical manifestations of T-PLL patients were increased lymphocyte counts and lymphadenopathy as well as splenomegaly. And most cases have high level of blood LDH and ß2- MG and normal chromosome karyotype.

[Treatment of malignant lymphoma by autologous hematopoietic stem cell transplantation combined with high dose radiotherapy and chemotherapy].

OBJECTIVE: To investigate the effects of treatment of malignant lymphoma (ML) by autologous hematopoietic stem cell transplantation (AHSCT) combined with high dose radiotherapy and chemotherapy. METHODS: From June 1991 to October 2002, 56 patients, aged 9 - 65 years, with ML, 44 non-Hodgkin's lymphoma (NHL) and 12 Hodgkin's disease (HD) were treated with AGSCT combined with high dose radiotherapy and chemotherapy. Among them, 12 received autologous bone marrow transplantation (ABMT) and 44 received autologous peripheral blood stem cell transplantation (APBSCT), In the latter the APBSCs were mobilized by carboplatin and etoposide (CE) or CHOP (CTX, ADM, VCR, PDN) plus granulocyte-colony stimulating factor (G-CSF) and/or granulocyte-macrophage colony stimulating factor (GM-CSF) 10 micro g/kg/d. Pretreatment included BEAM (BCNU, Vp-16, AraC, MEL) or MEL 140 mg/m(2) + Vp-16,200 mg/L total body irradiation (TBI) 8 Gy. The patients were flowed up for 40 - 4,310 days with a median of 1,820 days. RESULTS: Hematopoietic reconstruction was observed in all patients. The 1, 2, and 5-year disease-free survival rates were 87.5%, 60.7%, and 57.1% respectively, with the longest survival of 11 years. Fourteen patients developed relapse. No transplantation-related death was seen. CONCLUSION: Autologous hematopoietic stem cell transplantation combined with high dose radiotherapy and chemotherapy is effective on Ml. AHSCT shows a more rapid effect on hematopoietic reconstruction than ABMT.