Co 3 O 4 is an attractive earth-abundant catalyst for CO oxidation, and its high catalytic activity has been attributed to Co 3+ cations surrounded by Co 2+ ions. Hence, the majority of efforts for enhancing the activity of Co 3 O 4 have been focused on exposing more Co 3+ cations on the surface. Herein, we enhance the catalytic activity of Co 3 O 4 by replacing the Co 2+ ions in the lattice with Cu 2+ . Polycrystalline Co 3 O 4 nanowires for which Co 2+ is substituted with Cu 2+ are synthesized using a modified hydrothermal method. The Cusubstituted Co 3 O 4 _Cux polycrystalline nanowires exhibit much higher catalytic activity for CO oxidation than pure Co 3 O 4 polycrystalline nanowires and catalytic activity similar to those single crystalline Co 3 O 4 nanobelts with predominantly exposed most active {110} planes. Our computational simulations reveal that Cu 2+ substitution for Co 2+ is preferred over Co 3+ both in the Co 3 O 4 bulk and at the surface. The presence of Cu dopants changes the CO adsorption on the Co 3+ surface sites only slightly, but the oxygen vacancy is more favorably formed in the bonding of Co 3+ −O−Cu 2+ than in Co 3+ −O−Co 2+ . This study provides a general approach for rational optimization of nanostructured metal oxide catalysts by substituting inactive cations near the active sites and thereby increasing the overall activity of the exposed surfaces. ■ INTRODUCTIONCarbon monoxide (CO) emission from transportation and industrial activities is harmful to both human health and the environment. Currently, CO emission is effectively reduced, mainly through catalytic oxidation over catalysts. 1−4 The most active catalysts for CO oxidation are noble metals, but they are expensive and are of limited supply. Co 3 O 4 has emerged as an attractive alternative catalyst for CO oxidation because of its optimal CO adsorption strength, low barrier for CO reaction with lattice O, and excellent redox capacity. 1,5−8 A breakthrough on Co 3 O 4 for catalytic CO oxidation showing that Co 3 O 4 nanorods with predominantly exposed {110} planes exhibit a much higher catalytic activity for CO oxidation and larger resistance to deactivation by water than Co 3 O 4 nanoparticles was reported by Xie et al. 9 The high catalytic activity of Co 3 O 4 {110} planes is attributed to its higher concentration of Co 3+ cations (correspondingly fewer Co 2+ cations) than other crystal planes, since only Co 3+ cations surrounded by Co 2+ ions are active for catalytic oxidation of CO. 10,11 Subsequently, a number of Co 3 O 4 nanostructures, ranging from nanobelts, nanospheres, nanocubes, and nanotubes to nanowires, have been synthesized with the purpose of preferentially exposing Co 3+ cations. 11−14 Nevertheless, regardless of the morphology of the Co 3 O 4 nanostructures, even the highly active Co 3 O 4 {110} planes still contain Co 2+ cations, which have been assumed to be inactive for catalytic oxidation of CO, 9−11 and ultimately limits the catalytic activity of Co 3 O 4 for CO oxidation. Therefore, substituting Co 2+ with...

A new 11 year (2004–2014) monthly 1° gridded Argo temperature and salinity data set with 49 vertical levels from the surface to 1950 m depth (named BOA‐Argo) is generated for use in ocean research and modeling studies. The data set is produced based on refined Barnes successive corrections by adopting flexible response functions based on a series of error analyses to minimize errors induced by nonuniform spatial distribution of Argo observations. These response functions allow BOA‐Argo to capture a greater portion of mesoscale and large‐scale signals while compressing small‐sale and high‐frequency noise relative to the most recent version of the World Ocean Atlas (WOA). BOA‐Argo data set is evaluated against other gridded data sets, such as WOA13, Roemmich‐Argo, Jamestec‐Argo, EN4‐Argo, and IPRC‐Argo in terms of climatology, independent observations, mixed‐layer depth, and so on. Generally, BOA‐Argo compares well with other Argo gridded data sets. The RMSEs and correlation coefficients of compared variables from BOA‐Argo agree most with those from the Roemmich‐Argo. In particular, more mesoscale features are retained in BOA‐Argo than others as compared to satellite sea surface heights. These results indicate that the BOA‐Argo data set is a useful and promising adding to the current Argo data sets. The proposed refined Barnes method is computationally simple and efficient, so that the BOA‐Argo data set can be easily updated to keep pace with tremendous daily increases in the volume of Argo temperature and salinity data.

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ceftazidime-resistant or cefotaxime-resistant nonrepetitive Enterobacter cloacae isolates were collected from 27 patients hospitalized at HuaShan Hospital, Shanghai, People's Republic of China. The Etest did not detect extended-spectrum beta-lactamases (ESBLs) in those 27 isolates; however, screening by the NCCLS ESBL disk test and confirmatory tests detected ESBLs in 4 of 27 isolates and PCR detected ESBLs in 23 of 27 isolates. The majority of ESBL producers exhibited the same repetitive extragenic palindromic PCR pattern but harbored different ESBL genes. CTX-M-3 was the most prevalent ESBL in our study. Interestingly, 12 clonally related E. cloacae isolates possessed a novel bla VEB -type beta-lactamase, bla VEB-3 . Bla VEB-3 was encoded by the chromosome and was located in an integron. Nine of the 12 isolates harbored both the bla VEB-3 and the bla CTX-M-3 -like ESBLs. This is the first report of a VEB-1-like ESBL in China and the first report of the simultaneous presence of VEB-1 and CTX-M-3-like ESBLs in an isolate.Enterobacter cloacae is an important opportunistic pathogen known to cause nosocomial septicemia and urinary tract and respiratory tract infections (9, 25). Reports of multidrug-resistant isolates have increased during the last decade, probably as a result of the extensive use of broad-spectrum antibiotics. In some patient populations, the derepressed production of the AmpC beta-lactamase is a mechanism of beta-lactam resistance in E. cloacae strains (25,28). However, the occurrence of extended-spectrum beta-lactamases (ESBLs) in members of the family Enterobacteriaceae that possess inducible Bush group 1 chromosomal beta-lactamases is also increasingly reported worldwide (1,3,4,5,6,8,12).A 4-month survey was carried out to evaluate the prevalence of diverse ESBLs among E. cloacae isolates in HuaShan Hospital, Shanghai, People's Republic of China. This study identified a novel VEB-type ESBL, VEB-3. This is also the first report of VEB-1-like ESBLs from nosocomial isolates in the People's Republic of China. The first reported VEB-type ESBL, VEB-1, was detected in Pseudomonas aeruginosa strains from Southeast Asia (22). Unlike most of the ESBL genes, bla VEB-1 is part of a gene cassette and is located in class 1 integrons of various structures (10,11,15,16). MATERIALS AND METHODSBacterial isolates. Twenty-seven nonrepetitive ceftazidime-resistant or cefotaxime-resistant E. cloacae clinical isolates were consecutively collected in the bacteriology laboratory of the Center of Laboratory Medicine, Huashan Hospital, Shanghai, from November 2002 to February 2003. During this period, 58 isolates of the species were obtained from patient specimens (22 from sputum, 22 from urine, 6 from blood, and 8 from other specimens). The isolates were identified with the API 20E system (bioMerieux SA, Marcy-1ЈEtoile, France). Escherichia coli ATCC 25922 was used as a negative control. Klebsiella pneumoniae ATCC 700603 was used as an ESBL-positive control. E. cloacae 029 and E. cloacae 029 M were used as control strai...