A Water-Soluble Highly Oxidizing Cobalt Molecular Catalyst Designed for Bioinspired Water Oxidation.

Herein, we present a stable water-soluble cobalt complex supported by a dianionic 2,2'-([2,2'-bipyridine]-6,6'-diyl)bis(propan-2-ol) ligand scaffold, which is a rare example of a high-oxidation species, as demonstrated by structural, spectroscopic and theoretical data. Electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility measurements revealed that the CoIV center of the mononuclear complex in the solid state resides in the high spin state (sextet, S=5/2). The complex can effectively catalyze water oxidation via a single-site water nucleophilic attack pathway with an overpotential of only 360 mV in a phosphate buffer with a pH of 6. The key intermediate toward water oxidation was speculated based on theoretical calculations and was identified by in situ spectroelectrochemical experiments. The results are important regarding the accessibility of high-oxidation state metal species in synthetic models for achieving robust and reactive oxidation catalysis.

[Preoperative location of major language functional cerebral areas using functional magnetic resonance imaging].

OBJECTIVE: To design a set of functional magnetic resonance imaging (fMRI) tasks to activate the major Chinese language functional areas. METHODS: Eight volunteers and 3 patients received fMRI studies with the tasks of semantic judgment, word reading and listening comprehension. Brain activation map of each task was obtained after standard fMRI data processing. RESULTS: The fMRI examination with 3 tasks activated middle frontal gyrus (BA 9), Broca area and Wernicke area respectively. CONCLUSION: A set of fMRI examinations, including semantic judgment, word reading and listening comprehension, can activate the major Chinese language functional areas steadily and may be used as a preoperative localizer of language areas.

A Heterobimetallic AuIII -PtII Photocatalyst for Water Reduction to Hydrogen.

A supramolecular complex, [Au(C^N^C)(C≡CC6 H4 C≡C)Pt(terpy)]+ , has been synthesized as a photocatalyst for water reduction. This compound consists of a cyclometalated alkyne-gold(III) photosensitizer and a platinum(II) terpyridine complex bridged through a central phenylethynyl group.

Visible-Light-Driven Hydrogen Production and Polymerization using Triarylboron-Functionalized Iridium(III) Complexes.

The development of novel iridium(III) complexes has continued as an important area of research owing to their highly tunable photophysical properties and versatile applications. In this report, three heteroleptic dimesitylboron-containing iridium(III) complexes, [Ir(p-B-ppy)2 (N^N)]+ {p-B-ppy=2-(4-dimesitylborylphenyl)pyridine; N^N=dipyrido[3,2-a:2',3'-c]phenazine (dppz) (1), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq) (2), and 1,10-phenanthroline (phen) (3)}, were prepared and fully characterized electrochemically, photophysically, and computationally. Altering the conjugated length of the N^N ligands allowed us to tailor the photophysical properties of these complexes, especially their luminescence wavelength, which could be adjusted from λ=583 to 631 nm in CH2 Cl2 . All three complexes were evaluated as visible-light-absorbing sensitizers for the photogeneration of hydrogen from water and as photocatalysts for the photopolymerization of methyl methacrylate. The results showed that all of them were active in both photochemical reactions. High activity for the photosensitizer (over 1158 turnover numbers with 1) was observed, and the system generated hydrogen even after 20 h. Additionally, poly(methyl methacrylate) with a relatively narrow molecular-weight distribution was obtained if an initiator (i.e., ethyl α-bromophenylacetate) was used. The living character of the photoinduced polymerization was confirmed on the basis of successful chain-extension experiments.

Risk assessment of heavy metals in soils and vegetables around non-ferrous metals mining and smelting sites, Baiyin, China.

A field survey was conducted to investigate the metal and arsenic contamination in soils and vegetables on four villages (Shuichuan (SCH), Beiwan (BWA), Dongwan (DWA) and Wufe (WFE)) located along, Baiyin, China, and to evaluate the possible health risks to local population through foodchain. Results show that the most significantly contaminated soils occurred upstream at SCH where Cd, Cu and As concentrations exceeded maximum allowable concentrations for Chinese agricultural soil. Further downstream the degree of contamination semi-systematically decreased in concentrations of metal. Generally, the leafy vegetables were more heavily contaminated than non-leafy vegetables. Chinese cabbage is the most severely contaminated, the concentrations of Cd exceeded the maximum permit levels (0.05 mg/kg) by 4.5 times. Bio-accumulate factor also shows that an entry of Cd to food chain plants is the greatest potential. Furthermore, the estimated daily intake amounts of the considered toxic elements (Cd, Pb and Cu) from the vegetables grown at SCH and BWA and DWA have exceeded the recommended dietary allowance levels. Thus, the vegetables grown in three villages above, which affected by Baiyin mining and smelting have a health hazard for human consumption.

Three-dimensional Fluoroscopy-based Navigation for the Pedicle Screw Placement in Patients with Primary Invasive Spinal Tumors.

BACKGROUND: Although pedicle screw placement (PSP) is a well-established technique for spine surgery, the treatment of patients with primary invasive spinal tumor (PIST) has high surgical risks secondary to destroyed pedicles. Intraoperative three-dimensional fluoroscopy-based navigation (ITFN) system permits safe and accurate instrumentation of the spine with the advantage of obtaining intraoperative real-time three-dimensional images and automatic registration. The aim of this study is to evaluate the feasibility and accuracy of PSP using ITFN system for patients afflicted with PIST in the thoracic spine. METHODS: Fifty-one patients diagnosed with PISTs were retrospectively analyzed, and 157 pedicles screws were implanted in 23 patients using the free-hand technique (free-hand group) and 197 pedicle screws were implanted in 28 patients using the ITFN system (ITFN group). Modified classification of Gertzbein and Robbins was used to evaluate the accuracy of PSP, and McCormick classification was applied for assessment of neurological function. Demographic data and factors affecting accuracy of screw insertion were compared using independent t-test while comparison of accuracy of screw insertion between the two groups was analyzed with Chi-square test. RESULTS: Of 51 patients, 39 demonstrated improved neurological status and the other 12 patients reported that symptoms remained the same. In the free-hand group, 145 screws (92.4%) were Grade I, 9 screws (5.7%) were Grade II, and 3 screws (1.9%) were Grade III. In the ITFN group, 192 screws (97.4%) were Grade I, 5 screws (2.6%) were Grade II, and no Grade III screw was detected. Statistical analysis showed that the accuracies of pedicle screws in the two groups are significantly different (χ2 = 4.981, P = 0.026). CONCLUSIONS: The treatments of PISTs include total tumor resection and reconstruction of spine stability. The ITFN system provides a high accuracy of pedicle screw placement.

Recurrent intracranial meningioma with multiple pulmonary metastases: A case report.

Meningiomas are slow-growing tumors, which are generally considered to be benign and rarely metastasize. Although cases of extracranial metastatic meningioma have previously been reported, multiple pulmonary metastases from a benign intracranial meningioma is particularly rare. In the present report, a case of recurrent transitional meningioma with multiple lung nodules, which were demonstrated to be metastatic meningioma, is presented. A 54-year-old female patient received surgical resection of the tumor located in the left base of the middle cranial fossa in 2006. Post-surgery pathological examination indicated a transitional meningioma of World Health Organization grade I. The tumor recurred at the original site 1 year and 3 months later and was completely surgically removed once again. Radiotherapy was administered following the second surgery. Gamma Knife was used to remove the recurrent tumor 18 months following the second surgery. Simultaneously, a chest computed tomography scan revealed multiple pulmonary nodules, which were demonstrated to be metastatic meningioma following wedge resection of the superior lobe of the right lung. The clinical behavior of meningioma does not always correlate with the classification of meningioma. A higher rate of cellular proliferation is not essential for extracranial metastasis, and an individual meningioma of any type may metastasize. Comprehensive examinations should be performed for patients with a history of recurrent intracranial meningioma to detect any distant metastases as early as possible, even when the primary tumor is benign.

[Contaminative features of heavy metals for tidal sediment cores in Tianjin Bohai Bay].

Three sediment cores were collected in Nov. of 2003 from Dagu estuary to Qikou estuary. The grain size, TOC and heavy metal contents of core sediments were analyzed in order to study the geochemical characteristics, contamination features and the spatial and vertical distribution characters for heavy metals of tidal zones in Bohai Bay. The grain size of tidal sediments becomes finer from north to south. Ultrafine, fine and power sand are the main compositions in the sediment of Dagu and Duliujian estuary. The sediment of Qikou estuary is mainly composed by power and ultrafine sand. The vertical distribution trends of three sediment cores indicate that the grain-size becomes bigger from the bottom to the upper. The distribution of Fe, Al, Mn contents has distinct negative correlation with the grain-size of sediment, that is to say, the fine-grained sediments have higher contents of Fe, Al, Mn. Pb, Zn and Cd are the dominating contaminative elements in tidal sediments of Bohai Bay. Their contents are higher than the corresponding environmental background values, indicating of the anthropogenic enrichment.