| 1. |
- Wang, Zhen, et al.
(författare)
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Pendant bases as proton transfer relays in diiron dithiolate complexes inspired by Fe-Fe hydrogenase active site
- 2008
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 693:17, s. 2828-2834
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Tidskriftsartikel (refereegranskat)abstract
- Three dinuclear iron complexes containing pendant nitrogen bases in phosphine ligands with general formular ( l- pdt) [ Fe2( CO) 5L] ( where pdt is SCH2CH2CH2S, L = PPh2NH( CH2) 2N( CH3) 2 ( 5), PPh2NH( 2- NH2C6H4) ( 6), PPh2[ 2- N( CH3) 2CH2C6H4] ( 7)), were prepared as the models of the [ Fe - Fe] hydrogenase active site. The molecular structures of 5 - 7 were characterized by X- ray crystallography. The secondary amine in 6 has weak intramolecular hydrogen bonding with both the terminal nitrogen and sulfur atom, which may suggest a proton transfer pathway from amine in phosphine ligand to the sulfur atom of active site. Protonation of complexes 5 and 6 only occurred at the terminal nitrogen atom. Electrochemical properties of the complexes were studied in the presence of tri. ic acid by cyclic voltammetry.
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| 2. |
- Chen, Zhongsheng, et al.
(författare)
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A Deterministic-Path Routing Algorithm for Tolerating Many Faults on Wafer-Level NoC
- 2019
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Ingår i: 2019 DESIGN, AUTOMATION and TEST IN EUROPE CONFERENCE and EXHIBITION (DATE). - : IEEE. - 9783981926323 - 9781728103310 ; , s. 1337-1342
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Konferensbidrag (refereegranskat)abstract
- Wafer-level NoC has emerged as a promising fabric to further improve supercomputer performance, but this new fabric may suffer from the many-fault problem. This paper presents a deterministic-path routing algorithm for tolerating many faults on wafer-level NoCs. The proposed algorithm generates routing tables using a breadth-first traversal strategy, and stores one routing table in each NoC switch. The switch will then transmit packages according to its routing table online. We use the Tarjan algorithm to dynamically reconfigure the routes to avoid the faulty nodes and develop the deprecated link/node rules to ensure deadlock-free communication of the NoCs. Experimental results demonstrate that the proposed algorithm does not only tolerate the effects of many faults, but also maximizes the available nodes in the reconfigured NoC. The performance of the proposed algorithm in terms of average latency, throughput, and energy consumption is also better than those of the existing solutions.
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| 3. |
- Gao, Weiming, et al.
(författare)
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An azadithiolate bridged Fe2S2 complex as active site model of FeFe-hydrogenase covalently linked to a Re(CO)(3)(bpy)(py) photosensitizer aiming for light-driven hydrogen production
- 2008
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Ingår i: Comptes rendus. Chimie. - : Elsevier BV. - 1631-0748 .- 1878-1543. ; 11:8, s. 915-921
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Tidskriftsartikel (refereegranskat)abstract
- In order to create photoactive catalysts for hydrogen production, a novel trimetallic Re-Fe2S2 complex 4 was synthesized by the coordination of the free -PPh2 group of the ligand of the rhenium photosensitizer 6 to an azadithiolate (ADT)-bridged diiron complex 8 with the assistance of the decarbonylation reagent Me3NO. Complex 4 was characterized by H-1, C-13, P-31 NMR and HRMS spectra. The IR, UV-vis and electrochemical data indicate some interactions between Re and Fe2S2 moieties, and the photo-induced electron transfer from the excited state of the Re moiety to the Fe2S2 catalyst is thermodynamically feasible.
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| 4. |
- Gao, Yan, et al.
(författare)
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Synthesis and photophysical and electrochemical properties of a binuclear Ru(bpy)(3)-Cu(III) corrole complex
- 2007
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Ingår i: Journal of Porphyrins and Phthalocyanines. - 1088-4246 .- 1099-1409. ; 11:06-maj, s. 463-469
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Tidskriftsartikel (refereegranskat)abstract
- A novel binuclear Ru-Cu complex, composed of a copper(III)-corrole and a ruthenium(II) tris(bipyridine) moicty linked by an amide bond, has been synthesized and characterized by H-1 NMR, UV-vis and mass spectrometry. The steady-state emission and the electrochemical properties were investigated. Compared to the parent [Ru(bpy)(3)](2+), the emission-of the desired complex was substantially quenched when the MLCT of [Ru(bpy)(3)](2+) was selectively photoexcited.
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| 5. |
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| 6. |
- Jiang, Fangyuan, et al.
(författare)
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Association between antibiotic use during early life and early-onset colorectal cancer risk overall and according to polygenic risk and FUT2 genotypes
- 2023
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Ingår i: International Journal of Cancer. - : John Wiley & Sons. - 0020-7136 .- 1097-0215. ; 153:9, s. 1602-1611
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Tidskriftsartikel (refereegranskat)abstract
- Early-onset colorectal cancer (EOCRC) has been increasing worldwide. Potential risk factors may have occurred in childhood or adolescence. We investigated the associations between early-life factors and EOCRC risk, with a particular focus on long-term or recurrent antibiotic use (LRAU) and its interaction with genetic factors. Data on the UK Biobank participants recruited between 2006 and 2010 and followed up to February 2022 were used. We used logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) of the associations between LRAU during early life and EOCRC risk overall and by polygenic risk score (constructed by 127 CRC-related genetic variants) and Fucosyltransferase 2 (FUT2), a gut microbiota regulatory gene. We also assessed the associations for early-onset colorectal adenomas, as precursor lesion of CRC, to examine the effect of LRAU during early-life and genetic factors on colorectal carcinogenesis. A total of 113 256 participants were included in the analysis, with 165 EOCRC cases and 719 EOCRA cases. LRAU was nominally associated with increased risk of early-onset CRC (OR = 1.48, 95% CI = 1.01-2.17, P = .046) and adenomas (OR = 1.40, 95% CI = 1.17-1.68, P < .001). When stratified by genetic polymorphisms of FUT2, LRAU appeared to confer a comparatively greater risk for early-onset adenomas among participants with rs281377 TT genotype (OR = 1.10, 95% CI = 0.79-1.52, P = .587, for CC genotype; OR = 1.75, 95% CI = 1.16-2.64, P = .008, for TT genotype; Pinteraction = .089). Our study suggested that LRAU during early life is associated with increased risk of early-onset CRC and adenomas, and the association for adenomas is predominant among individuals with rs281377 TT/CT genotype. Further studies investigating how LRAU contributes together with genetic factors to modify EOCRC risk, particularly concerning the microbiome-related pathway underlying colorectal carcinogenesis, are warranted.
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| 7. |
- Jiang, Shi, et al.
(författare)
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Fe-S complexes containing five-membered heterocycles : novel models for the active site of hydrogenases with unusual low reduction potential
- 2007
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; :8, s. 896-902
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Tidskriftsartikel (refereegranskat)abstract
- Three biomimetic 2Fe2S complexes [{(mu-SCH2)(2)NCH2(2-C4H3O)}](Fe-2(CO)(6)) (6a), [{(mu-SCH2)(2) NCH2(2-C4H3S)}](Fe-2(CO)(6)) (6b) and [{(mu-SCH2)(2)NCH2(5-Br-2-C4H2S)}Fe-2(CO)(6)] (6c) were prepared as models for the active site of Fe-only hydrogenase by the convergent process from [(mu-S-2)Fe-2(CO)(6)] and N,N-bis(hydromethyl)-2-furan and thiophene. The structures of these complexes were identified spectroscopically and crystallographically. The electrochemical behavior of the complexes 6a and 6c was unique as they showed catalytic proton reduction with a low reduction potential at -1.13 and -1.09 V vs Fc/Fc(+), respectively, in the presence of HClO4.
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| 8. |
- Jiang, Shi, et al.
(författare)
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Preparation, characteristics and crystal structures of novel N-heterocyclic carbene substituted furan- and pyridine-containing azadithiolate Fe-S complexes
- 2007
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387 .- 1873-3719. ; 26:7, s. 1499-1504
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Tidskriftsartikel (refereegranskat)abstract
- Two novel N-heterocyclic carbene disubstituted furan- and pyridine-containing azadithiolate Fe-only hydrogenase models (2 and 4) have been synthesized, and characterized by IR and H-1 NMR spectra and X-ray single crystal diffraction. Cyclic voltammetry (CV) experiments indicate that they show more negative reductive potentials at -2.53 V and -2.49 V, respectively versus the ferrocene/ferrocenium couple (Fc/Fc(+)) and are easier to capture proton attributing to the strong electron-donating ligand NHC. After the protonation under F3CCO2H the reductive potentials of 2 and 4 have 1.02 V and 0.77 V shifts, indicating the formation of Fe-H-Fe bond. The results also are confirmed by the data changes in IR spectra and the negative H signals are detected by 1H NMR spectra at -27 ppm and -55 ppm.
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| 9. |
- Jiang, Tao, et al.
(författare)
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Characteristics of dissolved organic matter (DOM) and relationship with dissolved mercury in Xiaoqing River-Laizhou Bay estuary, Bohai Sea, China
- 2017
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 223, s. 19-30
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Because of heterogeneous properties, dissolved organic matter (DOM) is known to control the environmental fate of a variety of organic pollutants and trace metals in aquatic systems. Here we report absorptive and fluorescence properties of DOM, in concurrence with concentrations of dissolved mercury (Hg), along the Xiaoqing River-Laizhou Bay estuary system located in the Bohai Sea of China. A mixing model consisting of the two end-members terrestrial and aquatic DOM demonstrated that terrestrial signatures decreased significantly from the river into the estuary. Quasi-conservative mixing behavior of DOM sources suggests that the variations in the average DOM composition were governed by physical processes (e.g., dilution) rather than by new production and/or degradation processes. In contrast to some previous studies of river-estuary systems, the Xiaoqing River-Laizhou Bay estuary system displayed a non-significant correlation between DOM and Hg quantities. Based on this and the variation of Hg concentration along the salinity gradient, we concluded that Hg showed a non-conservative mixing behavior of suggested end-member sources. Thus, rather than mixing, Hg concentration variations seemed to be controlled by biogeochemical processes.
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| 10. |
- Niu, Guoxiang, et al.
(författare)
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Effects of nitrogen and water addition on soil carbon, nitrogen, phosphorus, sulfur, and their stoichiometry along soil profile in a semi-arid steppe
- 2023
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Ingår i: Journal of Soils and Sediments. - 1439-0108. ; 23:9, s. 3298-3309
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Although past studies have found well-constrained soil carbon (C)/nutrient ratios, the effects of increased nitrogen (N) and water inputs on these ratios across soil depths have rarely been assessed in semi-arid grasslands. Methods: In this study, we evaluated the contents of total C, N, phosphorus (P), sulfur (S), and their stoichiometric ratios in a 0–80 cm soil profile following 13 years of successive N (at rates of 5 and 15 g m−2 yearr−1) and water addition (180 mm per growing season) in a semi-arid grassland of the Mongolian Plateau. Results: In the 0–10 cm soil layer, long-term N addition tended to increase total C and N contents but decreased soil total P and S contents compared to the control. The effects of N addition, as observed in 0–10 cm soil, however, were not consistent with that in the deep 10–80 cm soil layers. Water addition increased the total C, N, and P contents across the entire soil profile but increased total S content only in 0–40 cm soil. Moreover, the combined addition of N and water generally had stronger effects on the four elements across the whole soil profile. For the stoichiometry of the four elements, a low rate of N addition (5 g m−2 year−1) increased soil C:N ratios and decreased soil P:S ratios in the 0–80 cm soils, but a high rate of N addition (15 g m−2 year−1) produced the opposite effect. Both N addition rates resulted in an increase in the soil C:P, C:S, N:P, and N:S ratios. Similarly, in plots that received water, water addition alone decreased the soil C:N ratios, while N addition caused higher fluctuations in these six elemental ratios. However, there was no consistent pattern of change in any one ratio, independent of the addition of water, when taking into account N addition rates and soil depths. Conclusion: Our findings showed that the effects of N addition on soil total C, N, P, and S contents and their stoichiometric ratios were highly influenced by the rate of N addition and the depth of soil, and that these effects could be modulated by increasing precipitation. These results need to be carefully considered while managing the ecological environment in semi-arid steppes.
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