Humic substances mediated superior photochemical pollutant conversion on defective TiO2 in environmentally relevant matrices: The key roles of oxygen vacancy in surface interactions, oxidant activation and radical generation

Ubiquitous humic substances usually exhibit strong interfering effects on target pollutant removal in advanced water purification. This work aims to develop a photochemical conversion system on the nonstoichiometric TiO2 for pollutant removal in environmentally relevant matrices. In this synergistic reaction system, the redox-reactive humic substances and defective oxygen vacancies can serve as the organic electron transfer mediator and the key surface reactive sites, respectively. This system achieves a superior pollutant degradation in real surface water at low oxidant concentrations. Reactive oxygen vacancies on the TiO2 surface and sub-surface are of considerable interest for this photochemical reaction system. By engineering defective oxygen vacancies on high-energy {001} polar facet, the surface and electronic interactions between tailored TiO2 and humic substances are greatly strengthened for the promoted electron transfer and oxidant activation. Rendered by the strong surface affinity and molecular activation, defective oxygen vacancies thermodynamically and dynamically promote reactive chain reactions for free radical formation, including the selective O2 reduction to ·O2- and the H2O2 activation to ·OH. Our findings take new insights into environmental geochemistry, and provide an effective strategy to in-situ boost the humic substances-mediated water purification without secondary pollution. ENVIRONMENTAL IMPLICATION: Humic substances are widely distributed in aquatic environment, thus playing important roles in environmental geochemistry. For example, humic substances can achieve good surface adsorption through electrostatic adsorption, ligand exchange and electronic interactions with typical TiO2 to form reactive ligand-metal charge transfer complexes for pollutant degradation. Inspired by the unique properties of surface and sub-surface oxygen vacancies, the defective TiO2 was designed to refine the humic substances-mediated photochemical reactions. A superior reactivity was measured for pollutant degradation. Our findings provide an effective strategy to boost naturally photochemical decontamination in environmentally relevant matrices.

Slow-release synthesis of Cu single-atom catalysts with the optimized geometric structure and density of state distribution for Fenton-like catalysis

Single-atom Fenton-like catalysis has attracted significant attention, yet the quest for controllable synthesis of single-atom catalysts (SACs) with modulation of electron configuration is driven by the current disadvantages of poor activity, low selectivity, narrow pH range, and ambiguous structure-performance relationship. Herein, we devised an innovative strategy, the slow-release synthesis, to fabricate superior Cu SACs by facilitating the dynamic equilibrium between metal precursor supply and anchoring site formation. In this strategy, the dynamics of anchoring site formation, metal precursor release, and their binding reaction kinetics were regulated. Bolstered by harmoniously aligned dynamics, the selective and specific monatomic binding reactions were ensured to refine controllable SACs synthesis with well-defined structure-reactivity relationship. A copious quantity of monatomic dispersed metal became deposited on the C3N4/montmorillonite (MMT) interface and surface with accessible exposure due to the convenient mass transfer within ordered MMT. The slow-release effect facilitated the generation of targeted high-quality sites by equilibrating the supply and demand of the metal precursor and anchoring site and improved the utilization ratio of metal precursors. An excellent Fenton-like reactivity for contaminant degradation was achieved by the Cu1/C3N4/MMT with diminished toxic Cu liberation. Also, the selective ·OH-mediated reaction mechanism was elucidated. Our findings provide a strategy for regulating the intractable anchoring events and optimizing the microenvironment of the monatomic metal center to synthesize superior SACs.

Recycling chestnut shell for superior peroxymonosulfate activation in contaminants degradation via the synergistic radical/non-radical mechanisms

The efficient recycling of agricultural chestnut shell waste is of considerable interest due to its large availability and economic feasibility. Herein, an alkaline-activated biochar was thermally prepared using chestnut shell by finely regulating main conditions; its morphological, structural and physic-chemical properties were well characterized. Fenton-like capacity to trigger peroxymonosulfate activation for superior pollutant degradation with high efficiency and good selectivity was validated in different water matrix. Both radical formation and electron transfer were identified as reaction pathways, while the selective non-radical mechanism played the major role in pollutant degradation. Surface ketonic groups were identified as the main reactive sites for non-selective radical production, while crystal edges and structural defects on sp²/sp³ carbon network could smoothly mediate the selective electron transfer from pollutant to oxidant in the non-radical Fenton-like catalysis. The two-mixed radical/non-radical pathways exhibited important advantages for environmental decontamination, in comparison with the one-single radical or non-radical mechanism. Our study provided a promising recycling strategy for agricultural chestnut shell, as well as an environment-friendly catalyst for heterogeneous Fenton-like catalysis in green water purification rendered by the synergistic radical/non-radical reaction pathways.

Superior degradation of phenolic contaminants in different water matrices via non-radical Fenton-like mechanism mediated by surface-disordered WO3

Heterogeneous Fenton-like catalysis mediated by solid catalyst is a promising oxidation technology for water purification. The redox reactivity, cost-effectiveness, and environmental compatibility of solid catalyst play governing roles in oxidant activation, radical generation, and pollutant degradation. Herein, the surface-disordered WO₃ (D-WO₃) functionally engineered by the unique crystalline-amorphous core-shell structure is proven to be a superior solid catalyst of heterogeneous Fenton-like catalysis for peroxymonosulfate (PMS) activation and pollutant degradation in various water matrices. Six typical phenolic and dye pollutants are effectively and selectively degraded in the D-WO₃/PMS system with much reduced matrix effects. Both radical identifying and scavenging tests elucidate the important role of non-radical ¹O₂ and mediated electron transfer during PMS activation on the D-WO₃ surface. The superior Fenton-like activity of D-WO₃ can be mainly attributed to the surface and sub-surface distorted lattice sites with finely tailored atomic and electronic structures and surface chemistry. These distorted lattice sites can thermodynamically serve as the key reactive centers of dissociative adsorption and catalytic activation for both PMS and pollutant, with high adsorption energy, strong structural activation, and smooth electron transfer. Our findings provide a new chance for heterogeneous Fenton-like catalysis mediated by transition metal oxides with high capacity, low cost, and no toxicity for promising water purification.

Reusing Sulfur-Poisoned Palladium Waste as a Highly Active, Nonradical Fenton-like Catalyst for Selective Degradation of Phenolic Pollutants

Recycling of deactivated palladium (Pd)-based catalysts can not only lower the economic cost of their industrial use but also save the cost for waste disposal. Considering that the sulfur-poisoned Pd (Pd_xS_y) with a strong Pd-S bond is difficult to regenerate, here, we propose a direct reuse of such waste materials as an efficient catalyst for decontamination via Fenton-like processes. Among the Pd_xS_y materials with different poisoning degrees, Pd₄S stood out as the most active catalyst for peroxymonosulfate activation, exhibiting pollutant-degradation performance rivaling the Pd and Co²⁺ benchmarks. Moreover, the incorporated S atom was found to tune the surface electrostatic potentials and charge densities of the Pd active site, triggering a shift in catalytic pathway from surface-bound radicals to predominantly direct electron transfer pathway that favors a highly selective oxidation of phenols. The catalyst stability was also improved due to the formation of strong Pd-S bond that reduces corrosion. Our work paves a new way for upcycling of Pd-based industrial wastes and for guiding the development of advanced oxidation technologies toward higher sustainability.

Stable Electrochemical Determination of Dopamine by a Fluorine-Terminated {001}-Exposed TiO2 Single Crystal Sensor

Photochemical oxidation is able to effectively regenerate the fouled electrode in electrochemical pollutant monitoring, while its regeneration capacity is limited by the surface-bound hydroxyl radical speciation with low activity and mobility, which is attributed to the dissociated water adsorption on hydrophilic metal oxides. In this work, fluorine-terminated {001}-exposed TiO₂ single crystals (F-TiO₂) are rationally designed to construct an Au-based electrochemical sensor (Au/F-TiO₂) for dopamine (DA) detection in different matrices. The Au/F-TiO₂ sensor exhibits an efficient and stable detection capacity in both environmental and biological samples. A superior photochemical regeneration capacity is obtained on the Au/F-TiO₂ electrode with much reduced matrix effects under UV irradiation. Spectral observation, crystallographic analysis, pollutant degradation performance, radical inhibition, and surface enhanced Raman scattering tests reveal that both the fluorine-terminated surface chemical features and the bulk-free radical speciation are mainly responsible for the superior photochemical regeneration capacity of the Au/F-TiO₂ electrode. Even for the real biological samples, a stable electrochemical DA detection is also achieved on the Au/F-TiO₂ sensor. Our work establishes a new approach to refine electrochemical sensors for stable monitoring and provides a robust photoactive electrode substrate with high efficiency and low cost for practical applications.

Photochemical pollutant degradation on facet junction-engineered TiO2 promoted by organic arsenical: Governing roles of arsenic-terminated surface chemistry and bulk-free radical speciation

Photochemical oxidation based on semiconducting metal oxides is an efficient strategy to remove environmental pollutants in water, air and soil. The fine manipulation of photo-carriers separation, surface chemistry and radical speciation is of considerable interest for environmental remediation. In this work, the morphology- and structure-tailored TiO₂ single crystals with epitaxial {101}/{001} facet junction were designed, prepared and tested for photochemical pollutant oxidation in the presence of organic arsenicals, the main component in swine wastewater from livestock industry, although they have been forbidden for several years. The facet junction-tailored TiO₂ deserved an efficient photo-carriers separation with high quantum efficiency. The photochemical oxidation of 4-chlorophenol (4-CP), phenol and bisphenol A (BPA) was substantially improved by roxarsone (ROX). ROX-enhanced photochemical activity of TiO₂ was mainly attributed to the in-situ arsenic-terminated surface chemistry by Ti-OAs^VO₃/-OAs^IIIO₂. This surface played governing roles in water/TiO₂ interactions, and changed water adsorption from dissociative to molecular configuration. Furthermore, ·OH was finely regulated from low-activity surface-bound to high-activity bulk-free speciation between as-generated photo-holes with free water molecules. Our findings provided a new chance to refine the TiO₂-based photochemical oxidation, and a modifying technology to treat swine wastewater from livestock industry with much reduced secondary pollution.

Non-radical activation of H2O2 by surface-disordered WO3 for efficient and selective pollutant degradation with weak matrix effects

Heterogeneous catalysis is promising for water treatment. Solid catalysts play governing roles. Herein, the surface-disordered WO₃, D-WO₃, engineered with surface and sub-surface defective sites from NaBH₄ reduction was proven to be an effective catalyst for H₂O₂ activation. The defective degree and defects amount on WO₃ were regulated by NaBH₄. More than 95% of two typical azo dyes, RhB and MG, were selectively degraded in D-WO₃/H₂O₂ system during 3.0 h, while no significant activity was observed for MO as well as bisphenol A, roxarsone, phenol, 4-chlorophenol, p-nitrophenol, o-aminophenol, urea, and 2,4-dichlorophenol in comparison under the identical conditions (mainly less than 20%). Both ESR and radical scavenging tests indicated the minor role of ·OH from H₂O₂ activation on D-WO₃. The superior activity of D-WO₃ could be mainly attributed to the surface and sub-surface defects with finely tailored local atomic configurations and electronic structures of central metal sites. Surface and sub-surface defective sites could serve as the reactive sites of interfacial adsorption, dissociative activation, and catalytic decomposition for both oxidant and pollutants, with high adsorption energy, strong structural activation, and superior catalytic activity. Our findings provided a new chance for non-selective radical catalysis based on transition metal oxides and a promising catalyst with high performance, low cost, and no toxicity for pollutant degradation with weak matrix effects in wastewater and surface water.

Electrochemical treatment of phenol-containing wastewater by facet-tailored TiO2: Efficiency, characteristics and mechanisms

Electrochemical oxidation is widely used for water and wastewater treatment. Anodic material is crucial and the shape-tailored {001}-exposed TiO₂ has been proven to be an ideal electrode material for pollutant oxidation. In this work, the electrochemical treatment of wastewater containing typical p-substituted phenols by facet-tailored TiO₂ is studied in terms of efficiency, characteristics and mechanisms. Experimental results demonstrate that the anodic oxidation of p-substituted phenols becomes more difficult with the increasing Hammett's constant (σ) of phenols, while their degradation rates (k) increase continuously with the initial surface concentration (Γ). Phenols are degraded mainly by surface-bound ·OH and direct electron transfer on the TiO₂/Ti electrode, rather than by bulk-free ·OH suspended in the aqueous phase. Theoretical calculations reveal that the surface-bound ·OH-mediated oxidation mechanism is attributed mainly to the strong surface bond strength between shape-tailored TiO₂ and water molecule as well as the reactive ·OH. Such strong interactions are associated with the higher density of atomic steps, edges and kinks of low-coordinate surface atoms with a large number dangling bonds on the high-energy {001} polar facet. For practical treatment of real wastewater with different matrixes, the facet-tailored TiO₂/Ti electrode exhibits both a high efficiency and a fast kinetics. Our findings provide a new chance to degrade phenolic pollutants in wastewater and offer atomic-scale insights into the preparation, modification and application of TiO₂-based anodic materials for electrochemical water treatment.

Photochemical Protection of Reactive Sites on Defective TiO2- x Surface for Electrochemical Water Treatment

The electrode is the key in electrochemical process for water and wastewater treatment. Many nonstoichiometric metal oxides are active electrode materials but have poor stability under strong anodic polarization due to their susceptible nature of the oxygen vacancies on surface and subsurface as defective reactive sites. In this work, a novel photochemical protecting strategy is proposed to stabilize the defective reactive sites on the TiO_{2- x} surface and subsurface for long-term anodic oxidation of pollutants. With this strategy, a novel photoassisted electrochemical system at low anodic bias is further constructed. Such a system exhibits a high protecting capacity at a low operation cost for electrochemical degradation of bisphenol A (BPA), a typical persistent organic pollutant. Its excellent photochemical protecting capacity is found to be mainly attributed to the mild non-band-gap excitation pathways on the defective TiO_{2- x} electrode under both visible-light irradiation and moderate anodic polarization. Under real sunlight irradiation, a 20 run cyclic test for BPA degradation demonstrates the excellent performance and stability of the constructed system at low bias without significant oxygen evolution. Our work provides a new opportunity to utilize the defective and reactive TiO_{2- x} for efficient, stable, and cost-effective electrochemical water treatment with the aid of its photo- and electrochemical bifunctional properties.

Photo-assisted electrochemical detection of bisphenol A in water samples by renewable {001}-exposed TiO2 single crystals

Bisphenol A (BPA) is a semi-persistent environmental endocrine disrupter and widely present in aqueous environments. Electrochemical detection is an effective method to monitor pollutants like BPA in aqueous environments. However, the electrode fouling from anodic polymeric products is one main barrier of electrochemical sensors for their practical applications. In this work, a renewable electrochemical sensor was rationally designed, constructed and tested for efficient BPA detection. The TiO₂ anodic material was surface-engineered by inorganic-framework molecular imprinting sites with tailored morphological shape, exposed facet and crystal structure. This electrode could be activated mainly as an electrochemical catalyst and partially as a photochemical catalyst. The developed TiO₂-based sensor exhibited a good detection reliability and cyclic stability for determining BPA in water samples, with an electrochemical signal decrease of less than 5.0% in 10-run cyclic tests. By virtue of the bi-functional properties of the tailored TiO₂ anodic material, a unique photo-assisted electrochemical sensor was further developed, in which analyte digestion and analytical signal originated mainly from anodic conversion. Such a synergistic digesting mechanism distinguishes it from the reported electro-assisted photochemical TiO₂ sensors. Our work provides a robust sensor for monitoring pollutants in aqueous environments and a new opportunity to develop renewable electrode materials with good reusability.

Author Correction: Chemotherapy with radiotherapy influences time-to-development of radiation-induced sarcomas: a multicenter study

Since the publication of this paper, the authors noticed an error in Fig. 1. The X-axis on all the figure panels should read 'Time (years)', not 'Time (months)'. The corrected Fig. 1 is shown below.

A prospective multicentre phase III validation study of AZGP1 as a biomarker in localized prostate cancer

Background

Prostate cancers (PCs) with similar characteristics at the time of diagnosis can have very different disease outcomes. Conventional biomarkers of PC still lack precision in identifying individuals at high risk of PC recurrence. While many candidate biomarkers are proposed in the literature, few are in clinical practice as they lack rigorous validation. This study prospectively enrolled an independent phase III cohort to evaluate the clinical utility of zinc-alpha 2-glycoprotein (AZGP1) as a prognostic biomarker in localized PC.

Patients and methods

In our multicentre, prospective phase III study, AZGP1 status in 347 radical prostatectomy specimens was assayed by immunohistochemistry in a NATA-accredited laboratory. The AZGP1 score was assessed in a multivariable model incorporating established prognostic factors. We also report extended outcomes from our previous phase II study. The primary endpoint was biochemical relapse-free survival (BRFS). Secondary endpoints were metastasis-free survival (MFS) and PC-specific survival (PCSS).

Results

In the phase II cohort, with a median follow-up of 15.8 years, low/absent AZGP1 expression was an independent predictor of poor BRFS (HR, 1.4; 95% CI, 1.1-1.9; P = 0.03), MFS (HR, 2.8; 95% CI, 1.2-6.6; P = 0.02) and PCSS (HR, 3.8; 95% CI, 1.5-9.5; P = 0.005). These results were validated in our prospective phase III cohort. Low/absent AZGP1 expression independently predicted for BRFS (HR, 1.9; 95% CI, 1.1-3.3; P = 0.02), with shorter MFS (HR, 2.0; 95% CI, 1.1-3.4; P = 0.02). AZGP1 improved the discriminatory value when incorporated into existing prognostic risk models.

Conclusion

Our study provides prospective phase III validation that absent/low AZGP1 expression provides independent prognostic value in PC. This study provides robust evidence for the incorporation of this biomarker into clinical practice.

Photochemical Anti-Fouling Approach for Electrochemical Pollutant Degradation on Facet-Tailored TiO2 Single Crystals

Electrochemical degradation of refractory pollutants at low bias before oxygen evolution exhibits high current efficiency and low energy consumption, but its severe electrode fouling largely limits practical applications. In this work, a new antifouling strategy was developed and validated for electrochemical pollutant degradation by photochemical oxidation on facet-tailored {001}-exposed TiO₂ single crystals. Electrode fouling from anodic polymers at a low bias was greatly relieved by the free ·OH-mediated photocatalysis under UV irradiation, thus efficient and stable degradation of bisphenol A, a typical environmental endocrine disrupter, and treatment of landfill leachate were accomplished without remarkable oxygen evolution in synergistic photoassisted electrochemical system. Electrochemical and spectroscopic measurements indicated a clean electrode surface during cyclic pollutant degradation. Such a photochemical antifouling strategy for low-bias anodic pollutants degradation was mainly attributed to the improved electric conductivity and excellent electrochemical and photochemical activities of tailored TiO₂ anodic material, whose unique properties originated from the favorable surface atomic and electronic structures of high-energy {001} polar facet and single-crystalline structure. Our work opens up a brand new approach to develop catalytic systems for efficient degradation of refractory contaminants in water and wastewater.

A simple strategy to refine Cu2O photocatalytic capacity for refractory pollutants removal: Roles of oxygen reduction and Fe(II) chemistry

Visible-light-driven photocatalysis is a promising technology for advanced water treatment, but it usually exhibits a low efficiency. Cu₂O is a low-cost semiconductor with narrow band gap, high absorption coefficient and suitable conduction band, but suffers from low charge mobility, poor quantum yield and weak catalytic performance. Herein, the Cu₂O catalytic capacity for refractory pollutants degradation is drastically improved by a simple and effective strategy. By virtue of the synergistic effects between photocatalysis and Fenton, a novel and efficient photocatalysis-driven Fenton system, PFC, is originally proposed and experimentally validated using Cu₂O/Nano-C hybrids. The synergistic PFC is highly Nano-C-dependent and exhibits a significant superiority for the removal of rhodamine B and p-nitrophenol, two typical refractory pollutants in wastewater. The PFC superiority is mainly attributed to: (1) the rapid photo-electron transfer driven by Schottky-like junction, (2) the selective O₂ reduction mediated by semi-metallic Nano-C for efficient H₂O₂ generation, (3) the specific H₂O₂ activation and large OH generation catalyzed by Haber-Weiss Fenton mechanism, and (4) the accelerated Fe²⁺/Fe³⁺ cycling and robust Fe²⁺ regeneration via two additional pathways. Our findings might provide a new chance to overcome the intrinsic challenges of both photocatalysis and Fenton, as well as develop novel technology for advanced water treatment.

Heterogeneous activation of H2O2 by defect-engineered TiO(2-x) single crystals for refractory pollutants degradation: A Fenton-like mechanism

The heterogeneous catalyst plays a key role in Fenton-like reaction for advanced oxidation of refractory pollutants in water treatment. Titanium dioxide (TiO2) is a typical semiconductor with high industrial importance due to its earth abundance, low cost and no toxicity. In this work, it is found that TiO2 can heterogeneously activate hydrogen peroxide (H2O2, E°=1.78 eV), a common chemical oxidant, to efficiently generate highly-powerful hydroxyl radical, OH (E(0)=2.80 eV), for advanced water treatment, when its crystal shape, exposed facet and oxygen-stoichiometry are finely tuned. The defect-engineered TiO2 single crystals exposed by high-energy {001} facets exhibited an excellent Fenton-like activity and stability for degrading typical refractory organic pollutants such as methyl orange and p-nitrophenol. Its defect-centered Fenton-like superiority is mainly attributed to the crystal oxygen-vacancy, single-crystalline structure and exposed polar {001} facet. Our findings could provide new chance to utilize TiO2 for Fenton-like technology, and develop novel heterogeneous catalyst for advanced water treatment.

Efficient Electrochemical Reduction of Nitrobenzene by Defect-Engineered TiO2-x Single Crystals

TiO2 is a typical semiconductor and has been extensively used as an effective photocatalyst for environmental pollution control. But it could not be used as an electrochemical reductive catalyst because of its low electric conductivity and electrocatalytic activity. In this work, however, we demonstrate that TiO2 can act as an excellent cathodic electrocatalyst when its crystal shape, exposed facet and oxygen-stoichiometry are finely tailored by the local geometric and electronic structures. The defect-engineered TiO2-x single crystals dominantly exposed by high-energy {001} facets exhibits a high cathodic activity and great stability for electrochemical reduction of nitrobenzene, a typical refractory pollutant with high toxicity in environment. The single crystalline structure, the high-energy {001} facet and the defective oxygen vacancy of the defect-engineered TiO2-x single crystals are found to be mainly responsible for their cathodic superiority. With the findings in this work, a more practical non-Pd cathodic electrocatalyst could be prepared and applied for electrocatalytic reduction of refractory pollutants in water and wastewater, and extend the promising applications of TiO2 in the fields of environmental science.

Protective effect of the polarity of macrophages regulated by IL-37 on atherosclerosis

As an anti-inflammatory cytokine, interleukin-37 (IL-37) provides certain protective effects against inflammatory and autoimmune diseases. Recent reports indicate that IL-37 is expressed in foam cells of atherosclerotic plaques in both the coronary and carotid arteries of humans, suggesting the possible involvement of IL-37 in the pathogenesis and progression of atherosclerosis. Current evidence supports the protective role that IL-37 plays against atherosclerosis via the regulation of different subtypes of macrophage. Atherosclerosis was induced in apolipoprotein E -/- mice through diet, and the mice were then given IL-37 to observe patterns in the aorta plaque. Furthermore, human peripheral blood-derived monocytes were cultured for seven days to induce the differentiation of macrophages. Specifically, we observed the effect of IL-37 on oxygenated low density lipoprotein (ox-LDL)-induced macrophage polarity, in addition to conducting an expressional assay of the M1 cell markers tumor necrosis factor (TNF)-α and CD86 and the M2 marker CD206. IL-37 effectively decreased the area ratio between the aorta plaque and vascular cavity. We also observed that M1 macrophages can be induced from peripheral monocytes by ox-LDL, with significant elevation of marker molecules TNF-α and CD86. The co-stimulation of IL-37 and ox-LDL, however, inhibited the induction of M1 cells and facilitated the transformation of macrophages into M2 cells, as supported by the elevation of cell-specific marker CD206. These results indicate that IL-37 can prevent atherosclerosis by modulating macrophage polarity.

Degradation of refractory pollutants under solar light irradiation by a robust and self-protected ZnO/CdS/TiO2 hybrid photocatalyst

Photocatalyst plays a vital role in the photochemical water treatment. To improve the visible-light photoactivity of TiO2 for refractory pollutant degradation, CdS/TiO2 hybrids with different nanostructures have been prepared, but usually suffer from a low photocatalytic degradation efficiency and a rapid photocorrosion. In this work, we developed a synergistic ZnO/CdS/TiO2 hybrid, which could act as a robust and self-protected photocatalyst for water purification without additional sacrificial reagents. This was attributed to the two different junction mechanisms in one single hybrid. Photons were selectively adsorbed by ZnO and CdS, then, the electrons with a low reductive activity in ZnO recombined directly with the holes with a low oxidative activity in CdS, whereas the holes with a high oxidative activity in ZnO and the electrons with a high reductive activity in CdS were captured for catalytic reaction. The superiority of the novel ZnO/CdS/TiO2 hybrid over the traditional CdS/TiO2 hybrid in both photocatalytic activity and anti-photocorrosion capacity was demonstrated in the degradation of Atrazine and Rhodamine B, two typical refractory organic pollutants, and the treatment of real textile wastewater under solar light irradiation. The developed ZnO/CdS/TiO2 hybrid exhibited an excellent potential for the degradation of refractory pollutants, and provided a new way to advance intrinsically solar-susceptible catalyst for photochemical wastewater treatment.

Defective titanium dioxide single crystals exposed by high-energy {001} facets for efficient oxygen reduction

The cathodic material plays an essential role in oxygen reduction reaction for energy conversion and storage systems. Titanium dioxide, as a semiconductor material, is usually not recognized as an efficient oxygen reduction electrocatalyst owning to its low conductivity and poor reactivity. Here we demonstrate that nano-structured titanium dioxide, self-doped by oxygen vacancies and selectively exposed with the high-energy {001} facets, exhibits a surprisingly competitive oxygen reduction activity, excellent durability and superior tolerance to methanol. Combining the electrochemical tests with density-functional calculations, we elucidate the defect-centred oxygen reduction reaction mechanism for the superiority of the reductive {001}-TiO_2−x nanocrystals. Our findings may provide an opportunity to develop a simple, efficient, cost-effective and promising catalyst for oxygen reduction reaction in energy conversion and storage technologies.

Titanium dioxide is not generally considered to be an effective oxygen reduction catalyst. Here, the authors show that nanostructured titanium dioxide, self-doped with oxygen vacancies and with exposed high-energy {001} facets, exhibits competitive oxygen reduction catalytic activity and durability.

Electrochemical degradation of refractory pollutants using TiO2 single crystals exposed by high-energy {001} facets

Anodic material plays a vital role in electrochemical water treatment. Titanium dioxide (TiO2) has been widely recognized as an excellent semiconductor photocatalyst, rather than an efficient electrocatalyst, due to its relatively low electric conductivity and poor electrochemical activity. In this work, it is found that TiO2 can actually become a superior electrocatalyst when its crystal shape and exposed facet are finely tuned. The shape-engineered TiO2 single crystals with {001} facets exhibit an excellent electro-catalytic activity and stability for degrading typical organic pollutants such as rhodamine B and bisphenol A, and treating complex landfill leachate. Its electro-catalytic superiority is mainly attributed to the single-crystalline structure and exposed polar {001} facet. Our findings could provide new possibility of utilizing TiO2 for efficient electrochemical water treatment because of its high activity, great stability, low cost and no toxicity.

A green approach for preparing doped TiO(2) single crystals

Doped TiO2 with metal, nonmetal, and rare earth elements has shown a great potential in energy and environmental applications, but it is difficult to dope well-defined TiO2 single crystals (SCs) with {001} exposed facet due to their high crystallinity. In this work, we developed a green and general approach to prepare the {001}-exposed TiO2 SCs doped with various elements, on the basis of recycling the wasted ethylene glycol electrolyte from the anodic oxidation for TiO2 nanotube preparation. All six representative elements (i.e., metal, nonmetal, and rare earth types) could be successfully doped into the TiO2 SCs without breaking their single-crystalline structure and exposed high-energy facet. The electronic properties of the doped TiO2 SCs were significantly improved. All the doped TiO2 SCs exhibited a superior photoactivity under visible-light irradiation for degrading rhodamine B, a typical organic pollutant. The prepared doped TiO2 SCs have a promising potential in environmental and energy applications.

Gene expression analysis of Dupuytren's disease: the role of TGF-beta2

Dupuytren's disease is characterised by nodular fibroblastic proliferation of the palmar fascia leading to contracture of the hand. Transforming growth factor beta (TGF-beta) is thought to play a role in its pathogenesis. We performed a cDNA microarray analysis of Dupuytren's diseased cord tissue with an emphasis on TGF-beta isoforms. Normal-appearing transverse ligament of the palmar fascia from adjacent to the diseased cord and palmar fascia from patients undergoing carpal tunnel release were used as controls. TGF-beta gene expression was confirmed by quantitative real-time polymerase chain reaction. Over 20 unique genes were found to be significantly up-regulated, including several previously reported genes. A dominant increase in TGF-beta2 expression was seen in the cord tissue, whereas TGF-beta1 and TGF-beta3 were found not to be significantly up-regulated. Quantitative real-time polymerase chain reaction confirmed these findings. This gene expression profile allows for further experiments that may eventually lead to gene therapy to block the development and progression of Dupuytren's disease clinically.

Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats

Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.

Cultural correlates of self perceived health status among Chinese elderly

This study examines self-perceived physical and mental health among 213 Chinese elderly who visited the Geriatric Outpatient Clinic of Beijing Hospital, the People's Republic of China. The study hypothesizes that cultural factors, specified by family relations, along with demographic factors, number of diseases, economic well-being, and living conditions have a significant impact on subjects self-perceived health status. Pearson correlation, linear and logistic regression analyses are performed. Results indicate that age, number of diseases, perceived family respect, neighborhood relations, and percentage of income spent on rent are significant predictors of self-perceived physical health. These same factors plus preference to live with a son and personal monthly income are significant predictors of self-perceived mental health. Socio-cultural implications of these findings are examined.

Life satisfaction among Chinese elderly in Beijing

The present study examined correlates of life satisfaction among 350 Chinese elderly aged 65 or older. Subjects consisted of a clinic sample (n = 200) and a randomly selected community sample (n = 150) recruited from the same area in Beijing. Linear regression analysis was performed, using health, financial status, and family support as independent variables. Results showed that the regression model explained 38 percent of the variance in life satisfaction in the total sample, 34 percent and 43 percent of the variance respectively in the clinical and community samples. Life satisfaction was significantly predicted by health and financial status among community elderly and by health, financial status, as well as family support among outpatient elderly. Findings suggest that the socio-cultural context has exerted important impacts on the Chinese elderly's life satisfaction.

Anthropophobia: its meaning and concomitant experiences

This study investigated the essential feature and concomitant experiences of anthropophobia, a culturally specific phobic disorder in China and Japan. One hundred and fifty subjects, including 50 anthropophobic, 50 neurasthenic and 50 normal subjects, were recruited from hospitals and downtown residential areas in Beijing. Measures of anthropophobic symptoms and DSM-III-R depressive and anxiety symptoms were administered to all subjects. Nonparametric analysis of variance, analysis of variance (ANOVA and MANOVA) and Fisher's exact test were performed to examine group differences on each symptomatic item of the three measures. Results indicate that the core anthropophobic symptoms include a fear of making eye contact with others and a fear of being watched by others, which essentially express fears of others' judgement or opinion of oneself. Anxiety and depression are associated features of anthropophobia. However, these concomitants are experienced more cognitively and less somatically in the case of anthropophobia than neurasthenia.

Sociocultural contexts of anthropophobia: a sample of Chinese youth

BACKGROUND

Anthropophobia, a subtype of social phobia, is prevalent in Chinese and Japanese societies. This study investigated sociocultural influences on the course of this culturally specific mental disorder.

METHOD

One hundred and fifty subjects, including 50 anthropophobic, 50 neurasthenic, and 50 community subjects, were interviewed in Beijing, China for the assessment of their early life experiences (child-parent relationships and sexual experiences), collectivism disposition, sexual attitudes, and communication behaviors. Logistic and linear regression analyses were performed to examine significant predictors of the occurrence and the symptom level of anthropophobia.

RESULTS

Regression models explained 69% of variance in the diagnosis and 57% of variance in the symptom level of anthropophobia among anthropophobic and community subjects. They also explained 48% and 47% of variance respectively in the diagnosis and the level of symptoms among anthropophobic and neurasthenic subjects. Anthropophobic subjects had more problematic relationships with parents than did community and neurasthenic subjects. They also exhibited significantly stronger characteristics of collectivism than did community subjects. Sexual contact with a non-family member prior to age 19 and a feeling of discomfort when interacting with the opposite sex were significantly associated with the diagnosis and symptom level of anthropophobia.

CONCLUSIONS

It was concluded that anthropophobic subjects' early sexual experiences and need for parental approval shaped their conformity to social norms and negative sexual attitudes, which were reinforced by the collective-orientated cultural environment, and contributed to the development of anthropophobia.

Ethnic characteristics of mental disorders in five U.S. communities

The study examined the ethnic ratio of 16 DSM-III mental disorders among White, Black, Hispanic, and Asian Americans. A total of 18,126 residents from 5 sites and 2,939 residents from the Epidemiological Catchment Area's Los Angeles site were studied separately. Logistic regression analysis was performed. Results showed that Blacks were significantly less likely than Whites to have major depressive episode, major depression, dysthymia, obsessive-compulsive disorder, drug and alcohol abuse or dependence, antisocial personality, and anorexia nervosa, but they were significantly more likely than Whites to have phobia and somatization. Lifetime prevalence rates of schizophrenia, obsessive-compulsive disorder, panic, and drug abuse or dependence were significantly lower among Hispanics than among Whites. Asians also had significantly lower rates than Whites of schizophreniform, manic episode, bipolar disorder, panic, somatization, drug and alcohol abuse or dependence, and antisocial personality. Compared with the overall findings, ethnic differences at the Los Angeles site were lessened between Blacks and Whites, enhanced between Hispanics and Whites, and basically unchanged between Asians and Whites.

Family and cultural correlates of depression among Chinese elderly

This study hypothesized that depressive experiences of the elderly could be aggravated by universal factors such as low social status, poor health, financial strain, and unhealthy lifestyle, as well as by factors specific to an indigenous socio-cultural environment (stressful family dynamics) of a given population. Three hundred and fifty Chinese subjects aged 65 or older were interviewed either at their homes or in the geriatric out-patient clinic of Beijing Hospital. Hierarchical logistic regression was used to examine significant predictors of depression. Results showed that certain social status, poor physical health, financial strain, unhealthy lifestyle, and stressful family situation explained 47 percent of the variance in depression. However, stressful family situation alone explained 13 percent of the variance in depression, indicating that family factors were important predictors of depression for Chinese elderly. Furthermore, this study demonstrated for the first time that verbal abuse within Chinese families is a significant correlate of depression among the elderly. Cultural implications of these findings are discussed.

The association between breast cancer and diet and other factors

To explore the effects of diet and other factors on breast cancer development, a case-control study was conducted in Tianjin between 1986-87. After adjusting for confounding factors, it was found that factors associated with increased risk of breast cancer included --early age at menarche; late age at menopause; late age at first birth; high Qutelet's index; histories of breast wound, disease and benign tumor; and a family history of malignant tumor, high fat, high calorie, low vegetable intake; elevated serum cholesterol and LDL-cholesterol; and lower levels of serum HDL-cholesterol and whole blood selenium.

[Risk factors of breast cancer among women in Tianjin, China and Adelaide, Australia]

In order to study the possible explanation of the marked difference in the incidences of breast cancer between Chinese and Australian women, the authors have compared and analysed the results of two case-control studies completed recently in Tianjin, China and Adelaide, Australia. Of 9 potential risk factors studied, 8 are significantly higher in Adelaide (Ad) women than in Tianjin women. Women in Ad were much taller, heavier, more obese, earlier at menarche, later at first full-term pregnancy, more nulliparous, less parity, more in history of breast cancer in first degree relatives. In addition, they were well educated. The findings obtained by analysis of logistic regression model indicated that increased risk for breast cancer was associated with early menarche, late first full-term pregnancy, less parity, nulliparity, histories of benign breast diseases and breast cancer in first degree relatives in the Tianjin study, but not in Ad study. Late menopause and history of oral contraceptive were not associated with the increased risk in both studies. These factors being not associated with breast cancer in Ad women was unexpected. The explanation of the indefinite findings in Ad study was due to the fact that the level of the risk factor is higher, more uniform, and lack of stratum. The difference in the level of the risk factor will not appear among cases and controls in case-control study, and significance of the risk factor therefore may not be found. According to data on diet survey in these two cities, the amount of fat intake was significantly higher in Ad women than in Tianjin women.(ABSTRACT TRUNCATED AT 250 WORDS)