Construction of Dual-Active Sites by Interfacing with Polyhydroxy Fullerene on Nickel Hydroxide Surfaces to Promote CO2 Deep Photoreduction to CH4.

Due to the complex series of elementary steps involved, achieving deep photoreduction of CO2 to multielectron products such as CH4 remains a challenging task. Therefore, it is crucial to strategically design catalysts that facilitate the controlled formation of the crucial intermediates and provide precise control over the reaction pathway. Herein, we present a pioneering approach by employing polyhydroxy fullerene (PHF) molecules to modify the surface of Ni(OH)2, creating stable and effective synergistic sites to enhance the formation of CH4 from CO2 under light irradiation. As a result, the optimized PHF-modified Ni(OH)2 cocatalyst achieves a CH4 production rate of 455 µmol g-1 h-1, with an electron-based selectivity of approximately 60%. The combination of in situ characterizations and theoretical calculations reveals that the hydroxyl species on the surface of PHF can participate in stabilizing crucial intermediates and facilitating water activation, thereby altering the reaction pathway to form CH4 instead of CO. This study provides a novel approach to regulating the selectivity of photocatalytic CO2 reduction by exploring molecular surface modification through interfacing with functionalized carbon clusters.

New insight into biodegradable macropore filler on tuning mechanical properties and bone tissue ingrowth in sparingly dissolvable bioceramic scaffolds.

Structural parameters of the implants such as shape, size, and porosity of the pores have been extensively investigated to promote bone tissue repair, however, it is unknown how the pore interconnectivity affects the bone growth behaviors in the scaffolds. Herein we systematically evaluated the effect of biodegradable bioceramics as a secondary phase filler in the macroporous networks on the mechanical and osteogenic behaviors in sparingly dissolvable bioceramic scaffolds. The pure hardystonite (HT) scaffolds with ∼550 & 800 µm in pore sizes were prepared by digital light processing, and then the Sr-doped calcium silicate (SrCSi) bioceramic slurry without and with 30 % organic porogens were intruded into the HT scaffolds with 800 µm pore size and sintered at 1150 °C. It indicated that the organic porogens could endow spherical micropores in the SrCSi filler, and the invasion of the SrCSi component could not only significantly enhance the compressive strength and modulus of the HT-based scaffolds, but also induce osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The pure HT scaffolds showed extremely slow bio-dissolution in Tris buffer after immersion for 8 weeks (∼1 % mass decay); in contrast, the SrCSi filler would readily dissolve into the aqueous medium and produced a steady mass decay (>6 % mass loss). In vivo experiments in rabbit femoral bone defect models showed that the pure HT scaffolds showed bone tissue ingrowth but the bone growth was impeded in the SrCSi-intruded scaffolds within 4 weeks; however, the group with higher porosity of SrCSi filler showed appreciable osteogenesis after 8 weeks of implantation and the whole scaffold was uniformly covered by new bone tissues after 16 weeks. These findings provide some new insights that the pore interconnectivity is not inevitable to impede bone ingrowth with the prolongation of implantation time, and such a highly biodegradable and bioactive filler intrusion strategy may be beneficial for optimizing the performances of scaffolds in bone regenerative medicine applications.

Comparison of osteogenic capability of 3D-printed bioceramic scaffolds and granules with different porosities for clinical translation.

Pore parameters, structural stability, and filler morphology of artificial implants are key factors influencing the process of bone tissue repair. However, the extent to which each of these factors contributes to bone formation in the preparation of porous bioceramics is currently unclear, with the two often being coupled. Herein, we prepared magnesium-doped wollastonite (Mg-CSi) scaffolds with 57% and 70% porosity (57-S and 70-S) via a 3D printing technique. Meanwhile, the bioceramic granules (57-G and 70-G) with curved pore topography (IWP) were prepared by physically disrupting the 57-S and 70-S scaffolds, respectively, and compared for in vivo osteogenesis at 4, 10, and 16 weeks. The pore parameters and the mechanical and biodegradable properties of different porous bioceramics were characterized systematically. The four groups of porous scaffolds and granules were then implanted into a rabbit femoral defect model to evaluate the osteogenic behavior in vivo. 2D/3D reconstruction and histological analysis showed that significant bone tissue production was visible in the central zone of porous granule groups at the early stage but bone tissue ingrowth was slower in the porous scaffold groups. The bone tissue regeneration and reconstruction capacity were stronger after 10 weeks, and the porous architecture of the 57-S scaffold was maintained stably at 16 weeks. These experimental results demonstrated that the structure-collapsed porous bioceramic is favorable for early-stage osteoconduction and that the 3D topological scaffolds may provide more structural stability for bone tissue growth for a long-term stage. These findings provide new ideas for the selection of different types of porous bioceramics for clinical bone repair.

Application of case-based learning in psychology teaching: a meta-analysis.

BACKGROUND: Case-based learning (CBL) has been found to be effective for many subjects, but there is currently a lack of evidence regarding its utility in psychology education. The present study investigated whether CBL pedagogy can improve students' academic performance in psychology courses compared to the traditional teaching methods. METHODS: A systematic review and meta-analysis were conducted to investigate the effectiveness of CBL in psychology teaching. Databases including PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), the VIP database, and Wanfang data were searched to find eligible randomized controlled trials. Pooled effect estimates were calculated using Hedges' g under the random effects model, and a subgroup analysis was carried to investigate the heterogeneity among studies. RESULTS: Fifteen studies with 2172 participants, 1086 in the CBL group and 1086 in the traditional lecture-based teaching group, were included in the meta-analysis. Students in the CBL group scored significantly higher on exams than those in the lecture-based group [Hedges' g = 0.68, 95%CI (0.49, 0.88), p < 0.00]. Relatively high heterogeneity was noted among the included studies. Publication bias was examined by the funnel plot and Egger's test, but did not significantly influence the stability of the results. A subsequent evaluation using the trim-and-fill method confirmed that no single study was skewing the overall results. A qualitative review of the included studies suggested that most students in the CBL group were satisfied with the CBL teaching mode. CONCLUSIONS: This meta-analysis indicated that the CBL pedagogy could be effective in psychology education, and might help increase students' academic scores, while encouraging a more engaging and cooperative learning environment. At present, the application of CBL in psychology education is in its initial stage. Problems related to the curriculum itself, research methodology, and challenges faced by both teachers and learners have confined its practice. Fully tapping into the strengths of CBL in psychology teaching will require additional work and advancing research.

Usage of Cell-Free Protein Synthesis in Post-Translational Modification of µ-Conopeptide PIIIA.

The post-translational modifications of conopeptides are the most complicated modifications to date and are well-known and closely related to the activity of conopeptides. The hydroxylation of proline in conopeptides affects folding, structure, and biological activity, and prolyl 4 hydroxylase has been characterized in Conus literatus. However, the hydroxylation machinery of proline in conopeptides is still unclear. In order to address the hydroxylation mechanism of proline in µ-PIIIA, three recombinant plasmids encoding different hybrid precursors of µ-PIIIA were constructed and crossly combined with protein disulfide isomerase, prolyl 4 hydroxylase, and glutaminyl cyclase in a continuous exchange cell-free protein system. The findings showed that prolyl 4 hydroxylase might recognize the propeptide of µ-PIIIA to achieve the hydroxylation of proline, while the cyclization of glutamate was also formed. Additionally, in Escherichia coli, the co-expression plasmid encoding prolyl 4 hydroxylase and the precursor of µ-PIIIA containing pro and mature regions were used to validate the continuous exchange cell-free protein system. Surprisingly, in addition to the two hydroxyproline residues and one pyroglutamyl residue, three disulfide bridges were formed using Trx as a fusion tag, and the yield of the fusion peptide was approximately 20 mg/L. The results of electrophysiology analysis indicated that the recombinant µ-PIIIA without C-terminal amidate inhibited the current of hNaV1.4 with a 939 nM IC50. Our work solved the issue that it was challenging to quickly generate post-translationally modified conopeptides in vitro. This is the first study to demonstrate that prolyl 4 hydroxylase catalyzes the proline hydroxylation through recognition in the propeptide of µ-PIIIA, and it will provide a new way for synthesizing multi-modified conopeptides with pharmacological activity.

A Chiral Metal-Organic Framework Prepared on Large-Scale for Sensitive and Enantioselective Fluorescence Recognition.

MOF-based luminescent sensors have garnered considerable attention due to their potential in recognition and discrimination with high sensitivity, selectivity, and fast response in the last decades. Herein, this work describes the bulk preparation of a novel luminescent homochiral MOF, namely, [Cd(s-L)](NO3)2 (MOF-1), from an enantiopure pyridyl-functionalized ligand with rigid binaphthol skeleton under mild synthetic condition. Except for the features of porosity and crystallinity, the MOF-1 has also been characterized with water-stability, luminescence, and homochirality. Most important, the MOF-1 exhibits highly sensitive molecular recognition toward the4-nitrobenzoic acid (NBC) and moderate enantioselective detection of proline, arginine, and 1-phenylethanol.

A triphasic biomimetic BMSC-loaded scaffold for osteochondral integrated regeneration in rabbits and pigs.

Osteochondral tissue involves cartilage, calcified cartilage and subchondral bone. These tissues differ significantly in chemical compositions, structures, mechanical properties and cellular compositions. Therefore, the repairing materials face different osteochondral tissue regeneration needs and rates. In this study, we fabricated an osteochondral tissue-inspired triphasic material, which was composed of a poly(lactide-co-glycolide) (PLGA) scaffold loaded with fibrin hydrogel, bone marrow stromal cells (BMSCs) and transforming growth factor-ß1 (TGF-ß1) for cartilage tissue, a bilayer poly(L-lactide-co-caprolactone) (PLCL)-fibrous membrane loaded with chondroitin sulfate and bioactive glass, respectively, for calcified cartilage, and a 3D-printed calcium silicate ceramic scaffold for subchondral bone. The triphasic scaffold was press-fitted into the osteochondral defects in rabbit (cylindrical defects with a diameter of 4 mm and a depth of 4 mm) and minipig knee joints (cylindrical defects with a diameter of 10 mm and a depth of 6 mm). The µ-CT and histological analysis showed that the triphasic scaffold was partly degraded, and significantly promoted the regeneration of hyaline cartilage after they were implanted in vivo. The superficial cartilage showed good recovery and uniformity. The calcified cartilage layer (CCL) fibrous membrane was in favor of a better cartilage regeneration morphology, a continuous cartilage structure and less fibrocartilage tissue formation. The bone tissue grew into the material, while the CCL membrane limited bone overgrowth. The newly generated osteochondral tissues were well integrated with the surrounding tissues too.

Industrial applications of sol-gel derived coatings.

Sol-gel derived coatings have many practical applications in different industries. In this paper, HI-GARD® hard coat, multi-layer antireflective coatings, and an anti-glare coating with organic particles are described. Optical and mechanical performances of these coatings are discussed in addition to adhesion properties. The HI-GARD® hard coat was dip or spin coated from a sol by hydrolyzing alkoxysilanes with water in an acidic condition. The hard coat acts as a protective coating for optical lenses with excellent optical properties with a Bayer ratio of 4.8 and an adhesion of 5B. The multi-layer antireflective coatings were prepared by incorporating titanium oxide sol into the HI-GARD® hard coat solution to obtain different layers by spin-coating with tunable refractive index. These two-layer or three-layer antireflective coatings increase transmittance by at least 3% compared to an uncoated glass substrate. Anti-glare coatings were spray-coated at room temperature on glass substrates by embedding cationic or anionic polystyrene particles in an acid-hydrolyzed silane sol. The anti-glare coating with organic particles can provide a significant glare reduction with a haze value of up to 13% for display surface without sparkling. In addition to these transparent coatings, non-transparent sol-gel derived coatings such as a sol-gel non-stick coating for cookware and bakeware, and two zinc-silicate protective coatings hydrolyzed from a silane with addition of zinc dusts for corrosion protection are also discussed briefly. The schematic structures of the hard coat on CR-39® substrate, three-layer AR coatings on glass substrate, and organic particle embedded anti-glare coatings on glass substrate, and their respective transmittance or reflective curves.

Integrating pore architectures to evaluate vascularization efficacy in silicate-based bioceramic scaffolds.

Pore architecture in bioceramic scaffolds plays an important role in facilitating vascularization efficiency during bone repair or orbital reconstruction. Many investigations have explored this relationship but lack integrating pore architectural features in a scaffold, hindering optimization of architectural parameters (geometry, size and curvature) to improve vascularization and consequently clinical outcomes. To address this challenge, we have developed an integrating design strategy to fabricate different pore architectures (cube, gyroid and hexagon) with different pore dimensions (∼350, 500 and 650 µm) in the silicate-based bioceramic scaffolds via digital light processing technique. The sintered scaffolds maintained high-fidelity pore architectures similar to the printing model. The hexagon- and gyroid-pore scaffolds exhibited the highest and lowest compressive strength (from 15 to 55 MPa), respectively, but the cube-pore scaffolds showed appreciable elastic modulus. Moreover, the gyroid-pore architecture contributed on a faster ion dissolution and mass decay in vitro. It is interesting that both µCT and histological analyses indicate vascularization efficiency was challenged even in the 650-µm pore region of hexagon-pore scaffolds within 2 weeks in rabbit models, but the gyroid-pore constructs indicated appreciable blood vessel networks even in the 350-µm pore region at 2 weeks and high-density blood vessels were uniformly invaded in the 500- and 650-µm pore at 4 weeks. Angiogenesis was facilitated in the cube-pore scaffolds in comparison with the hexagon-pore ones within 4 weeks. These studies demonstrate that the continuous pore wall curvature feature in gyroid-pore architecture is an important implication for biodegradation, vascular cell migration and vessel ingrowth in porous bioceramic scaffolds.

Chloramphenicol-activated electro-chemiluminescent behavior of BNQDs-Ru(phen)32+ system for ultra-sensitive sensing of chloramphenicol in pharmaceutical and milk samples.

To improve the sensitivity for electro-chemiluminescent (ECL) detection of chloramphenicol (CAP), a common broad-spectrum antibiotic, boron nitride quantum dots (BNQDs) were prepared with excellent photoelectric property and low toxicity. After its structure and electrochemical property were investigated in detail, it was noted that the ECL signal of Ru(Phen)32+could be strengthened by the proposed BNQDs, which was further activated by ten's times in the presence of CAP. Under the optimized conditions, there was an excellent linear relationship between ΔECL and lgcCAPin a wide linear range from 1.0 × 10-10to 1.0 × 10-6mol l-1CAP. The detection limit was super-low to be 3.3 × 10-11mol l-1(S/N = 3). When applied for CAP detection in real pharmaceutical and food samples, the recoveries were between 97.8% and 105.7% with R.S.D. less than 3.3%. A possible CAP-activated ECL mechanism of BNQDs-Ru(phen)32+was also proposed. This work will offer a great potential for efficient monitoring of CAP pollution and clinical diagnosing of CAP-related diseases in future.

Chloramphenicol-activated electro-chemiluminescent behavior of BNQDs-Ru(phen)32+ system for ultra-sensitive sensing of chloramphenicol in pharmaceutical and milk samples.

To improve the sensitivity for electro-chemiluminescent (ECL) detection of chloramphenicol (CAP), a common broad-spectrum antibiotic, boron nitride quantum dots (BNQDs) were prepared with excellent photoelectric property and low toxicity. After its structure and electrochemical property were investigated in detail, it was noted that the ECL signal of Ru(Phen)32+ could be strengthened by the proposed BNQDs, which was further activated by ten's times in the presence of CAP. Under the optimized conditions, there was an excellent linear relationship between △ECL and lgcCAP in a wide linear range from 1.0×10-10 to 1.0×10-6 mol/L CAP. The detection limit was super-low to be 3.3×10-11 mol/L (S/N=3). When applied for CAP detection in real pharmaceutical and food samples, the recoveries were between 97.8 and 105.7 % with R.S.D. less than 3.3%. A possible CAP-activated ECL mechanism of BNQDs-Ru(phen)32+ was also proposed. This work will offer a great potential for efficient monitoring of CAP pollution and clinical diagnosing of CAP-related diseases in future.

Fully arthroscopic treatment of medial Hoffa fracture associated with anterior cruciate ligament tear: case report and surgical technique.

A Hoffa fracture is a rare intra-articular injury consisting of a coronal plane fracture of one or both of the distal femoral condyles. Because of the rarity of medial Hoffa fractures, only a few reports have described this injury and its arthroscopic management. In this article, we present a rare case involving a 32-year-old man with a displaced medial Hoffa fracture associated with a proximal anterior cruciate ligament tear. He was treated by a single-stage fully all-inside arthroscopic technique. Arthroscopic-assisted internal fixation ensured fragment stability and enabled us to visualize the fracture reduction, monitor the screw insertion, and reconstruct the anterior cruciate ligament tear at the same time. This technique is a novel but demanding treatment method for medial Hoffa fractures and is particularly useful for properly selected patients with associated intra-articular knee injuries.

Artificial osteochondral interface of bioactive fibrous membranes mediating calcified cartilage reconstruction.

Calcified cartilage is a mineralized osteochondral interface region between the hyaline cartilage and subchondral bone. There are few reported artificial biomaterials that could offer bioactivities for substantial reconstruction of calcified cartilage. Herein we developed new poly(L-lactide-co-caprolactone) (PLCL)-based trilayered fibrous membranes as a functional interface for calcified cartilage reconstruction and superficial cartilage restoration. The trilayered membranes were prepared by the electrospinning technique, and the fibrous morphology was maintained when the chondroitin sulfate (CS) or bioactive glass (BG) particles were introduced in the upper or bottom layer, respectively. Although 30% BG in the bottom layer led to a significant decrease in tensile resistance, the inorganic ion release was remarkably higher than that in the counterpart with 10% BG. The in vivo studies showed that the fibrous membranes as osteochondral interfaces exhibited different biological performances on superficial cartilage restoration and calcified cartilage reconstruction. All of the implanted host hyaline cartilage enabled a self-healing process and an increase in the BG content in the membranes was desirable for promoting the repair of the calcified cartilage with time. The histological staining confirmed the osteochondral interface in the 30% BG bottom membrane maintained appreciable calcified cartilage repair after 12 weeks. These findings demonstrated that such an integrated artificial osteochondral interface containing appropriate bioactive ions are potentially applicable for osteochondral interface tissue engineering.

One-dimensional nitrogen doped porous carbon nano-array arranged by carbon nanotubes for electrochemical sensing ascorbic acid, dopamine and uric acid simultaneously.

In this work, one-dimensional nitrogen doped porous carbon nano-arrays arranged by carbon nanotube (1D CNTs@NPC) were first constructed, using a coating technology at room temperature and followed by high temperature carbonization. It was expected that the resulting glassy carbon electrodes modified by 1D CNTs@NPC (CNTs@NPC/GCE) could express different electrochemical responses to ascorbic acid (AA), dopamine (DA), uric acid (UA), by virtue of the synergistic-improved effect between CNTs and NPC. Under the optimized conditions, there were excellent analytical parameters for CNTs@NPC/GCE to detect AA, DA and UA, i.e. a wide linear range of 40-2100µM for AA, 0.5-49µM for DA and 3-50µM for AA with low detection limits of 0.36µM, 0.02µmol l-1and 0.57µM respectively. Importantly, the proposed CNTs@NPC/GCE was efficiently applied to determine AA, DA and UA in some real samples with high stability, reproducibility and selectivity. This work will offer an efficient potential for diagnosing ascorbic acid, dopamine or uric acid-related diseases on clinical testing in future.

Concurrent arthroscopic meniscal repair during open-wedge high tibial osteotomy is not clinically beneficial for medial meniscus posterior root tears.

PURPOSE: This prospective study aimed to investigate the clinical benefits of meniscal repair during open-wedge high tibial osteotomies (OWHTOs) in patients with medial meniscus posterior root tears (MMPRTs) and to identify potential risk factors for meniscal healing. METHODS: Ninety patients with degenerative MMPRTs were included in the final cohort and randomized into three groups. The patients in Group A (n = 30) underwent OWHTO and arthroscopic all-inside meniscal repair concurrently, those in Group B (n = 34) underwent OWHTO only, and those in Group C (n = 26) underwent arthroscopic partial meniscectomy. Clinical and radiological outcomes were recorded, and meniscal healing was evaluated during second-look arthroscopy. Logistic regression analysis was performed to identify risk factors for meniscal healing. RESULTS: After a minimum follow-up of 24 months, no significant differences between Groups A and B regarding the final Lysholm (p = 0.689) or Hospital for Special Surgery (HSS) scores (p = 0.256) were observed. There were significant differences among the three groups regarding the hip-knee-ankle angle (HKA), weight-bearing line (WBL) ratio, medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) (p < 0.001, respectively), but the differences between Groups A and B were not significant. During second-look arthroscopy, the healing rate of the MMPRTs was significantly higher in Group A (63.3%) than in Group B (35.3%). Concurrent meniscal repair and changes in the HKA, and MPTA were risk factors for meniscal healing. CONCLUSION: Concurrent arthroscopic meniscal repair during OWHTO did not lead to significant clinical benefits in the treatment of MMPRTs, except for an increased rate of meniscal healing, which was not associated with clinical outcomes. LEVEL OF EVIDENCE: II, prospective comparative study.

α-Conotoxin as Potential to α7-nAChR Recombinant Expressed in Escherichia coli.

α7 nicotinic acetylcholine receptors (nAChR) is an important nicotinic acetylcholine receptors subtype and closely associated with cognitive disorders, such as Alzheimer's and schizophrenia disease. The mutant ArIB (V11L, V16A) of α-conotoxin ArIB with 17-amino acid residues specifically targets α7 nAChR with no obvious effect on other nAChR subtypes. In the study, the synthetic gene encoding mature peptide of ArIB and mutant ArIB (V11L, V16A) carried a fusion protein Trx and 6 × His-tag was separately inserted in pET-32a (+) vector and transformed into Escherichia coli strain BL21(DE3) pLysS for expression. The expressions of Trx-ArIB-His6 and Trx-ArIB (V11L, V16A)-His6 were soluble in Escherichia coli, which were purified by Ni-NTA affinity chromatography column and cleaved by enterokinase to release rArIB and rArIB (V11L, V16A). Then, rArIB and rArIB (V11L, V16A) were purified by high-performance liquid chromatography (HPLC) and identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Bioactivity of rArIB and rArIB (V11L, V16A) was assessed by two-electrode voltage-clamp electrophysiology in Xenopus laevis oocytes expressing human nAChR subtypes. The results indicated that the yield of the fusion proteins was approximately 50 mg/L and rArIB (V11L, V16A) antagonized the α7 nAChR subtype selectively with 8-nM IC50. In summary, this study provides an efficient method to biosynthesize α-conotoxin ArIB and rArIB (V11L, V16A) in Escherichia coli, which could be economical to obtain massively bioactive disulfide-rich polypeptides at fast speed.

Risk factors for iliopsoas impingement after total hip arthroplasty using a collared femoral prosthesis.

BACKGROUND: The relationship between collar design of a femoral component and iliopsoas impingement (IPI) after total hip arthroplasty (THA) is still underrecognized. The purpose of our study was to determine the possible risk factors for IPI related to the femoral component, when using a collared femoral prosthesis. METHODS: A total of 196 consecutive THA patients (206 hips) using a collared femoral prosthesis were reviewed retrospectively after exclusion of the factors related to acetabular component and femoral head. The patients were divided into +IPI and -IPI group according to the presence of IPI. Radiological evaluations were performed including femoral morphology, stem positioning, and collar protrusion length (CPL). Multivariate regression analysis was performed to assess the risk factors for IPI. RESULTS: At a minimum follow-up of 1 year, IPI was observed in 15 hips (7.3%). Dorr type C proximal femur was found in nine hips (60%) in the +IPI group and in 28 hips in the -IPI group (14.7%, p < 0.001). The mean stem anteversion in the +IPI group was significantly greater than that in the -IPI group (19.1° vs. 15.2°, p < 0.001), as well as the mean CPL (2.6 mm vs. - 0.5 mm, p < 0.001). The increased stem anteversion (OR = 1.745, p = 0.001) and CPL (OR = 13.889, p = 0.001) were potential risk factors for IPI. CONCLUSIONS: The incidence of IPI after THA is higher than expected when using a collared femoral prosthesis. Among the factors related to collared femoral prosthesis, excessively increased stem anteversion and prominent collar protrusion are independent predictors for IPI. In addition, high risk of IPI should be carefully considered in Dorr type C bone, despite that femoral morphology is not a predictive factor. LEVEL OF EVIDENCE: Level IV, clinical cohort study.

Electrocatalytic oxygen evolution with a cobalt complex.

The development of an earth-abundant, first-row water oxidation catalyst that operates at a high TOF and a low overpotential remains a fundamental chemical challenge. Cobalt complexes are important members of water oxidation catalysts. Herein, we report a cobalt-based robust homogeneous water oxidation catalyst, which can electrocatalyze water oxidation at a high pH and a low overpotential (η = 520 mV) in phosphate buffer. This homogeneous system exhibits a high turnover frequency (about 5 s-1) of catalyzing water oxidation to produce oxygen at η = 720 mV. We speculate the mechanism of the reaction that O-O bond formation prefers a HO-OH coupling in catalytic water oxidation.

Localization of Phosphoproteins within the Barnacle Adhesive Interface.

Barnacles permanently adhere to nearly any inert substrate using proteinaceous glue. The glue consists of at least ten major proteins, some of which have been isolated and sequenced. Questions still remain about the chemical mechanisms involved in adhesion and the potential of the glue to serve as a platform for mineralization of the calcified base plate. We tested the hypothesis that barnacle glue contains phosphoproteins, which have the potential to play a role in both adhesion and mineralization. Using a combination of phosphoprotein-specific gel staining and Western blotting with anti-phosphoserine antibody, we identified multiple phosphorylated proteins in uncured glue secretions from the barnacle Amphibalanus amphitrite The protein composition of the glue and the quantity and abundance of phosphoproteins varied distinctly among individual barnacles, possibly due to cyclical changes in the glue secretion over time. We assessed the location of the phosphoproteins within the barnacle glue layer using decalcified barnacle base plates and residual glue deposited by reattached barnacles. Phosphoproteins were found throughout the organic matrix of the base plate and within the residual glue. Staining within the residual glue appeared most intensely in regions where capillary glue ducts, which are involved in cyclical release of glue, had been laid down. Lastly, mineralization studies of glue proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that proteins identified as phosphorylated possibly induce mineralization of calcium carbonate (CaCO3). These results contribute to our understanding of the protein composition of barnacle glue, and provide new insights into the potential roles of phosphoproteins in underwater bioadhesives.

Chemiluminescence determination of sulphite using a cyclometalated iridium complex as chemiluminescence reagent.

A simple, fast and accurate chemiluminescence (CL) method for the determination of sulphite has been developed, based on its sensitizing effect on the CL reaction between a novel water-soluble iridium complex, [(dpci)2Ir(bvbbi)](PF6) (dpci = 3,4-diphenylcinnoline; bvbbi = N,N'-bivinylester-(1)H,(1')H-[2,2'] bibenzimidazole) and cerium(IV). Under the optimal experimental conditions, the increased CL response was linear, with the concentration of sulphite over the range 5.0 × 10(-7)-5.0 × 10(-4) mol/L. The detection limit of the method was 1.6 × 10(-7) mol/L, with a relative standard deviation (RSD) of 2.7% for nine repetitive determination of 1.0 × 10(-4) mol/L sulphite. The method was successfully applied to the quantitative analysis of sulphite in sugar samples. The possible reaction mechanism of sulphite on the [(dpci)2Ir(bvbbi)](PF6)-cerium(IV) system is also briefly discussed.