Role of ferroptosis in chronic kidney disease.

Chronic kidney disease (CKD) has historically been a significant global health concern, profoundly impacting both life and well-being. In the process of CKD, with the gradual loss of renal function, the incidence of various life-threatening complications, such as cardiovascular diseases, cerebrovascular accident, infection and stroke, is also increasing rapidly. Unfortunately, existing treatments exhibit limited ability to halt the progression of kidney injury in CKD, emphasizing the urgent need to delve into the precise molecular mechanisms governing the occurrence and development of CKD while identifying novel therapeutic targets. Renal fibrosis, a typical pathological feature of CKD, plays a pivotal role in disrupting normal renal structures and the loss of renal function. Ferroptosis is a recently discovered iron-dependent form of cell death characterized by lipid peroxide accumulation. Ferroptosis has emerged as a potential key player in various diseases and the initiation of organ fibrosis. Substantial evidence suggests that ferroptosis may significantly contribute to the intricate interplay between CKD and its progression. This review comprehensively outlines the intricate relationship between CKD and ferroptosis in terms of iron metabolism and lipid peroxidation, and discusses the current landscape of pharmacological research on ferroptosis, shedding light on promising avenues for intervention. It further illustrates recent breakthroughs in ferroptosis-related regulatory mechanisms implicated in the progression of CKD, thereby providing new insights for CKD treatment. Video Abstract.

Constructing a Photocatalyst for Selective Oxidation of Benzyl Alcohol to Benzaldehyde by Photo-Fenton-like Catalysis.

A photoactive metal-organic framework (MOF), [K(H2O)][Cu(DPNDI)][Cu(DPNDI)(CH3CN)(H2O)] [Cu1.5(DPNDI)1.5H1.5P2W18O62]·2H2O (Cu(Ι)W-DPNDI), was prepared by combining a functional photosensitizer N, N'-bis(4-pyridylmethyl)naphthalene diimide (DPNDI), copper(I) ions, and an oxidation catalyst [P2W18O62]6- into a single framework via a hydrothermal process. Cu(Ι)W-DPNDI exhibited a stable structure, strong light absorption capacity, a suitable band gap, and photoelectric properties, which provided favorable conditions for photocatalysis. In the confined space, the well-aligned Cu(I) ions and POM polyanions played a synergetic effect in the electron-transfer process and reactive oxygen species generation. By coupling photocatalysis and heterogeneous Fenton-like catalysis, Cu(Ι)W-DPNDI displayed high efficiency for the selective oxidation of aromatic alcohols, with up to >99% selectivity and 75% yield.

Designing a Polyoxometalate-Incorporated Metal-Organic Framework for Reduction of Nitroarenes to Anilines by Sequential Proton-Coupled Electron Transfers.

Developing new photocatalysts for reduction of nitroarenes to anilines under mild conditions is very significant. Herein, a new polyoxometalate-based metal-organic framework (POMOF), {[Co(H2O)]2[Co2(H2O)6(TPT)][Co(TPT)PW11O39]}·3H2O·TPT (namely, CoW-TPT, TPT = 2,4,6-tri(4-pyridyl)-1,3,5-triazine), was prepared by incorporating Co(II)-substituted Keggin-type anions [PCoW11O39]5- and a photosensitizer (TPT) into a framework. In this structure, the direct coordination bond between [PCoW11O39]5- and TPT ligand and π···π interactions between TPT molecules are beneficial for the separation and migration of photogenerated carriers, thus improving the photocatalytic activity of CoW-TPT. The combination of both photosensitizer TPT and the electron-storable component [PCoW11O39]5- in a cooperative photocatalysis fashion is conducive to the photocatalytic multielectron reduction of nitroarenes. CoW-TPT provided a high conversion of 94.71% in the photocatalytic reduction of nitroarenes to anilines utilizing triethanolamine as the proton source and electron donor by sequential proton-coupled electron transfers.

Design of a Polyoxometalate-Based Metal-Organic Framework for Photocatalytic C(sp3)-H Oxidation of Toluene.

A powerful and promising route for developing novel photocatalysts for light-driven toluene oxidation in water under mild conditions is presented. Herein, a novel polyoxometalate-based metal-organic framework (POMOF), {Co4W22-DPNDI}, is prepared by incorporating the unusual Co4-sandwiched POM anion [Co4(µ-OH)2(SiW11O39)2]10- ({Co4W22}) and the photoactive organic bridging link N,N'-bis(4-pyridylmethyl)naphthalene diimide (DPNDI) into a framework. {Co4W22} is a good candidate for photocatalytic water oxidation. DPNDI is easily excited to form the radical species DPNDI* in the presence of an electron donor, which is beneficial for activation of the inert O2. Anion···π interactions and covalent bonds between {Co4W22} and DPNDI facilitate electron-hole separation and electron transfer. {Co4W22-DPNDI} displays high catalytic activity for the activation of the C(sp3)-H bond of toluene using light as a driving force and inexpensive water as an oxygen source under mild conditions. In particular, the yield and selectivity are improved by replacing oxygen with water, which may be ascribed to the release of protons during the water oxidation process that facilitate the generation of •OH.

Constructing a Redox-Active Cu(I)-Pyridyltriazine Framework for Catalytic Photoreduction of Nitrobenzenes and Carboxylic Cyclization of Alkynol with CO2.

A redox-active metal-organic framework, Cu(I)-TPT, was synthesized by combination of Cu(I), the halogenoid cyanide group (CN), and redox-active organic bridging ligand 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) into one single framework. Cu(I)-TPT displays a two-dimensional (2D) plane structure by 1D -Cu(I)-CN- chains connected with TPT ligands. Cu(I)-TPT exhibits intrinsic semiconductive features with a moderate bandgap energy (1.97 eV). Under irradiation, Cu(I)-TPT has an electrical conductivity of 2 × 10-7 S cm-1 in the presence of the sacrificial electron donor ethanol under the ambient test conditions, which is owing to the π-π stacking interactions between TPT moieties, the d-π conjugation between the Cu(I) ion and the CN ligands, and the permanent microporosity. Cu(I)-TPT displayed highly efficient hole-electron separation and ordered electron transfer, which is beneficial for the photoreduction of nitrobenzene. In addition, Cu(I)-TPT displays high efficiency in carboxylic cyclization of alkynol with CO2 because it possesses highly decentralized Cu(I) catalytic sites to the active C≡C bond of alkynol and affluent N atoms on the 2D sheets to facilitate the trapping and activation of CO2.

An Isopolymolybdate-Incorporated Metal-Organic Framework with Sulfite Oxidase-Mimicking Activity for Photocatalytic Oxidation of Sulfides Utilizing In Situ-Generated Singlet Oxygen.

Developing new photocatalysts for sulfide oxidation utilizing in situ-generated 1O2 is very significant. Inspired by natural enzymatic processes, we synthesized a mimic sulfite oxidase (SO), {[Co(Mo4O13)(TPT)2]} (CoMo-TPT), by incorporating an isopolymolybdate anion [Mo4O13]2- into a 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT)-based metal-organic framework under mild hydrothermal conditions. In this structure, {Mo4O13} units with intrinsic SO-like catalytic sites are beneficial for the selective oxidation of sulfite and thioether. The ultraviolet-visible spectra of CoMo-TPT exhibited strong absorption from 250 to 650 nm and potential application in the utilization of solar energy. Mott-Schottky measurements indicated that CoMo-TPT is an n-type semiconductor with a LUMO value of -0.70 V (vs NHE) and a HOMO value of 1.39 V. The transient photocurrent responses with strong current density cycles with visible light indicated CoMo-TPT has a high photochemical activity. The lower resistance indicated that CoMo-TPT has a higher efficiency of photoinduced electron and hole separation. CoMo-TPT displayed a high efficiency of 99% and a selectivity of 97.3% in photocatalytic oxidation of sulfides by utilizing in situ-generated 1O2 through a tandem process of formation of H2O2 from O2 followed by catalyzed disproportionation of H2O2.

Visible-Light-Driven C-N Bond Formation by a Hexanickel Cluster Substituted Polyoxometalate-Based Photocatalyst.

A powerful and attractive route to develop novel photocatalysts for C-N bond formation involves the use of pyrrolidine as the substrate and cocatalyst simultaneously. Herein, a new polyoxometalate (POM)-based metal-organic framework, namely, [Ni6(OH)3(H2O)9(DPNDIH)(SiW9O34)]2·2H2O (SiW9Ni6-DPNDI) (DPNDI = N,N'-di(4-pyridyl)-1,4,5,8-naphthalenediimide), was prepared by incorporating a Ni6 cluster-substituted POM anion and a photosensitizer (DPNDI) into a framework. The anion···π interactions and covalent bonds between SiW9Ni6 and DPNDI are beneficial for the consecutive electron separation and transfer. Under visible-light irradiation, DPNDI can be easily excited to generate radical species DPNDI* that could be further excited in the presence of the electron donor pyrrolidine for the inert O2 activation. SiW9Ni6-DPNDI showed a high efficiency in the photocatalysis of C-N bond formation under a mild condition by the synergy of DPNDI and SiW9Ni6. The results of the reaction were confirmed by gas chromatography and 1H NMR. In addition, SiW9Ni6-DPNDI exhibited a high sustainability without an obvious change in yields after five cycles.

A Polyoxometalate-Based Inorganic Porous Material with both Proton and Electron Conductivity by Light Actuation: Photocatalysis for Baeyer-Villiger Oxidation and Cr(VI) Reduction.

Two-dimensional (2D) crystalline porous materials with designable structures and high surface areas are currently a hot research topic in the field of proton- and electron-conducting materials, which provide great opportunities to orderly accommodate carriers in available spaces and to accurately understand the conducting path. The 2D dual-conductive inorganic framework [Co(H2O)6]2{[Co(H2O)4]4[WZn3(H2O)2(ZnW9O34)2]}·8H2O (Co6Zn5W19) is synthesized by combining [WZn3(H2O)2(ZnW9O34)2]12- (Zn5W19) and a Co(II) ion via a hydrothermal method. Due to the presence of a consecutive H-bonding network, electrostatic interactions, and packing effects between the framework and guest molecules, Co6Zn5W19 displays a high proton conductivity (3.55 × 10-4 S cm-1 under 98% RH and 358 K) by a synergistic effect of the combined components. Additionally, a photoactuated electron injection into the semiconducting materials is an important strategy for switching electronic conductivity, because it can efficiently reduce the frameworks without destroying the crystallinity. I-V curves of a tablet of Co6Zn5W19 in the reduced and oxidized states yield conductivities of 1.26 × 10-6 and 5 × 10-8 S cm-1, respectively. Moreover, Co6Zn5W19 is also successfully applied in the photocatalytic reduction of the toxic Cr(VI) metal ion by utilizing its excellent electronic storage capacity and Baeyer-Villiger (BV) oxidation in a molecular oxygen/aldehyde system.

Polyoxometalate-Supported Aminocatalyst for the Photocatalytic Direct Synthesis of Imines from Alkenes and Amines.

Developing efficient photocatalysts for direct oxidative coupling of alkenes and amines with O2 under mild conditions is very significant. Herein, ZnW-PYI is well-designed by assembling a [PZnW11O39(H2O)]5- photooxidation catalyst and chiral aminocatalyst pyrrolidine-2-ylimidazole (PYI) via a coordination model. ZnW-PYI efficiently catalyzed the synthesis of imines from alkenes and amines using O2 as the oxidant through nucleophilic catalysis by employing pyrrolidine as an organocatalyst. Combining a polyoxometalate and PYI within one single framework is an effective approach not only for stabilization and heterogenization of the redox-active catalyst and aminocatalyst but also for realization of compatibility between the reaction intermediates and synergy of multiple catalytic cycles.

Facile Preparation and Photocatalytic Properties of TiO2 Fiber Membrane with Wrinkle Structure.

Herein, TiO2 fiber membrane with wrinkle structure was fabricated by an electrospinning technique in combination with a sol-gel process. The as-prepared TiO2 membranes were interwoven with interconnected nanofibers. The surfacial and morphological features of the obtained TiO2 fiber membrane could be tuned by varying the content of the precursor, titanium (IV) n-butoxide. The nature of wrinkle structure and high surface area demonstrates an impact on the electron-hole separation and charge transfer during photocatalytic tests, thereby leading to an obvious enhancement in the photocatalytic performance. The results revealed the resultant TPNs-20 sample displayed the best photocatalytic performance toward the removal of methyl orange (MO), and its degradation degree was up to 97% within 70 min. Furthermore, a photocatalytic mechanism is proposed on the basis of results and analysis, which indicates that ˙OH and ˙O-2 radicals are the main reactive species responsbile for the enhanced photocatalytic activity. We anticipate that controllable synthesis of promising TiO2 fiber membranes in this study provides new insight into the development of efficient photocatalysts for high-performance environmental remediation.

Effects of healthcare reform on health resource allocation and service utilization in 1110 Chinese county hospitals: data from 2006 to 2012.

The central government of China launched a large-scale, expensive health reform in April 2009 because of the serious health-related problems in the country. This reform aims to re-establish a universal healthcare system, which is expected to provide affordable basic healthcare. Independent two-sample t-test, one-way ANOVA and chi-squared test were conducted to analyze the effect of the health reform on health resource allocation and service utilization in Chinese county hospitals. First, we described the hospitals' financial performance in terms of funding sources, balances and fiscal compensations (for personnel expenditure). Second, we discussed the total number of health personnel as well as the structure (number of medical personnel per thousand population and ratio of doctors and nurses) and quality of the health personnel. Lastly, we investigated the county hospitals' health resource utilization, bed occupancy and average medical expense per visit. Then, we probed different reasons and provided multiple approaches to existing problems. Copyright © 2016 John Wiley & Sons, Ltd.

Beat over the old ground with new strategy: engineering As···As interaction in arsenite-based Dawson cluster ß-[W18O54(AsO3)2(6-.

By reaction of [As2W19O67(H2O)](14-), NiCl2·6H2O, and phen under hydrothermal conditions, a new organic-inorganic tungstoarsenate hybrid [Ni(phen)3]4[As2W18O60]{[Ni(phen)2][H2As2W18O60]}·12H2O (where phen = 1,10-phenanthroline) (1) was obtained via self-assembly and characterized by elemental analysis, infrared (IR) spectroscopy, solid UV-vis absorption spectrum, and single-crystal X-ray diffraction (XRD). An unprecedented 18-tungstoarsenate Dawson cluster, ß-[W18O54(AsO3)2](6-), encapsulating two pyramidal arsenite AsO3(3-) anions as templates and exhibiting interesting intramolecular As···As interaction is first achieved. 1 displays a one-dimensional (1D) chain architecture constructed by alternating ß-[W18O54(AsO3)2](6-) and nickel(II) complexes [Ni(phen)2)](2+). The resulting hybrid can act as a photocatalyst to prompt the degradation of Rhodamine B (RhB) with excellent efficiency.

Novel isopolyoxotungstate [H2W11O38]8- based metal organic framework: as Lewis acid catalyst for cyanosilylation of aromatic aldehydes.

A novel polyoxometalate-based metal organic framework (POMOF) constructed from isolated isopolyoxotungstate [H2W11O38](8-) cluster, {[Cu2(bpy)(H2O)5.5]2[H2W11O38]·3H2O·0.5CH3CN} (1, where bpy = 4,4'-bpydine), has been synthesized under solvothermal conditions and charaterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction. In 1, {W11} clusters are alternately linked by two [Cu(2)(H2O)1.5(Ot)3(N)](2+) cations in an unexpected end-to-end fashion leading to a one-dimensional (1D) chain. Adjacent 1D chains are linked through Cu(1)-bpy-Cu(2) in an opposite direction to form a two-dimensional (2D) wavelike sheet along the ab plane. These 2D sheets are further stacked in a parallel fashion giving rise to the 1D channels with copper(II) cations aligned in the channels. The resulting POMOF acted as a Lewis acid catalyst through a heterogeneous manner to prompt cyanosilylation with excellent efficiency.

Engineering chiral polyoxometalate hybrid metal-organic frameworks for asymmetric dihydroxylation of olefins.

Chiral metal-organic frameworks (MOFs) with porous and tunable natures have made them feasible for performing a variety of chemical reactions as heterogeneous asymmetric catalysts. By incorporating the oxidation catalyst [BW12O40](5-) and the chiral group, L- or D-pyrrolidin-2-ylimidazole (PYI), into one single framework, the two enantiomorphs Ni-PYI1 and Ni-PYI2 were obtained via self-assembly, respectively. The channels of Ni-PYIs were enlarged through a guest exchange reaction to remove the cationic chiral templates and were well modulated with hydrophilic/hydrophobic properties to allow molecules of both H2O2 and olefin ingress and egress. The coexistence of both the chiral directors and the oxidants within a confined space provided a special environment for the formation of reaction intermediates in a stereoselective fashion with high selectivity. The resulting MOF acted as an amphipathic catalyst to prompt the asymmetric dihydroxylation of aryl olefins with excellent stereoselectivity.

Hydroxyl radical-dominated selective oxidation of ethylbenzene over a photoactive polyoxometalate-based metal-organic framework.

Realizing photo-promoted saturated C-H functionalization is a significant challenge. [CuI3(H2O)6(TPT)2][H2BW12O40]·28H2O was assembled by combining electron reservoir [BW12O40]5- with photosensitizer TPT. The continuous coordination bonds and π-π stacking interactions facilitate hole-electron separation and electron transfer, and allow it to exhibit high photocatalytic activity toward ethylbenzene oxidation with O2/H2O as oxidants.

Mean Platelet Volume/Platelet Count Ratio as a Predictor of Both Incidence and Prognosis of Acute Ischemic Stroke in Hemodialysis Patients.

Purpose: This study aimed to explore whether the mean platelet volume/platelet count ratio (MPR) has predictive value for the occurrence and prognosis of acute ischemic stroke (AIS) in hemodialysis patients. Patients and Methods: A total of 402 patients undergoing maintenance hemodialysis were screened and 259 were enrolled in this study. The receiver operating characteristic curve and area under the curve (AUC) were used to evaluate the predictive power of the models. The patients enrolled in this study were divided into three groups based on the tertiles of the MPR value (Q1, Q2, and Q3). Kaplan-Meier curves were used to investigate the association between the MPR and AIS-free survival in hemodialysis patients. Chi-square analysis was performed to explore the association between the MPR and AIS outcomes in hemodialysis patients. And the AIS outcome was assessed using the modified Rankin Scale (mRS). Results: MPR had a predictive value for the occurrence of AIS (AUC=0.814) in hemodialysis patients with a high sensitivity and specificity. AIS-free survival rates in the MPR Q1, MPR Q2, and MPR Q3 groups were 0.930, 0.701, and 0.360, respectively. The proportion of patients with good outcomes (mRS 0-2) was significantly greater among patients in the MPR Q1-Q2 group than in the MPR Q3 group (0.844 vs 0.745, p <0.001). Conclusion: The MPR can be used as a good predictor of AIS in patients undergoing hemodialysis. Patients on hemodialysis with increased MPR levels had a higher incidence of AIS and poorer functional outcomes than those with low MPR levels.

Insights into autotrophic carbon fixation strategies through metagonomics in the sediments of seagrass beds.

Seagrass beds contributes up to 10% ocean carbon storage. Carbon fixation in seagrass bed greatly affect global carbon cycle. Currently, six carbon fixation pathways are widely studied: Calvin, reductive tricarboxylic acid (rTCA), Wood-Ljungdahl (WL), 3-hydroxypropionate (3HP), 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) and dicarboxylate/4-hydroxybutyrate (DC/4-HB). Despite the knowledges about carbon fixation increase, the carbon fixation strategies in seagrass bed sediment remain unexplored. We collected seagrass bed sediment samples from three sites with different characteristics in Weihai, a city in Shandong, China. The carbon fixation strategies were investigated through metagenomics. The results exhibited that five pathways were present, of which Calvin and WL were the most dominant. The community structure of microorganisms containing the key genes of these pathways were further analyzed, and those dominant microorganisms with carbon fixing potential were revealed. Phosphorus significantly negatively corelated with those microorganisms. This study provides an insight into the strategies of carbon fixation in seagrass bed sediments.

Metal-organic frameworks with phosphotungstate incorporated for hydrolytic cleavage of a DNA-model phosphodiester.

Five phosphotungstate-incorporated metal-organic frameworks {[Eu(4)(dpdo)(9)(H(2)O)(16)PW(12)O(40)]}(PW(12)O(40))(2)·(dpdo)(3)·Cl(3) (1); {ZnNa(2)(µ-OH)(dpdo)(4)(H(2)O)(4)[PW(12)O(40)]}·3H(2)O (2); {Zn(3)(dpdo)(7)}[PW(12)O(40)](2)·3H(2)O (3); and [Ln(2)H(µ-O)(2)(dpdo)(4)(H(2)O)(2)][PW(12)O(40)]·3H(2)O (Ln = Ho for 4 and Yb for 5) (dpdo = 4,4'-bipyridine-N,N'-dioxide) have been synthesized through a one-step hydrothermal reaction and characterized by elemental analyses, infrared (IR) spectroscopy, photoluminescence, and single-crystal X-ray diffraction (XRD). The structural analyses indicate that 1-5 display diversity structure from one-dimensional (1D) to three-dimensional (3D) series of hybrids. Kinetic experiments for the hydrolytic cleavage of DNA-model phosphodiester BNPP (bis(p-nitrophenyl)phosphate) were followed spectrophotometrically for the absorbance increase at 400 nm in EPPS (4-(2-hydroxyethyl)piperazine-1-propane sulfonic acid) buffer solution, because of the formation of p-nitrophenoxide with 1-5 under conditions of pH 4.0 and 50 °C. Ultraviolet (UV) spectroscopy indicate that the cleavage of the phosphodiester bond proceeds with the pseudo-first-order rate constant in the range of 10(-7)-10(-6) s(-1), giving an inorganic phosphate and p-nitrophenol as the final products of hydrolysis. The results demonstrate that 1-5 have good catalytic activity and reusability for hydrolytic cleavage of BNPP.

Microalgal bioremediation of heavy metal pollution in water: Recent advances, challenges, and prospects.

With the rapid economy development and population surge, the water resources available for direct use on the earth have been in shortage. Therefore, water pollution remediation inevitably becomes the focus of global attention. Aside from their capacity to fix and effectively control the emission of carbon dioxide thus achieve negative carbon emission, microalgae and its products modified by genetic engineering and other technologies also have a broad prospect in sewage treatment such as efficiently removing all kinds of pollutants in water and producing high-quality biofuels after use. Therefore, research on these organisms has gradually deepened in recent years. This paper summarizes the bioremediation mechanism of heavy metal ions in water by using microalgae and their modified products. The relevant research progresses since 2015 are critically reviewed and discussed. Challenges and prospects are also put forward for their industrial implementation.

Photocatalytic Multielectron Reduction of Nitroarenes to Anilines by Utilizing an Electron-Storable Polyoxometalate-Based Metal-Organic Framework.

A powerful approach to generate photocatalysts for the highly selective reduction of nitrobenzene using light as the driving force is a combination of photosensitizers and electron-storable components in a cooperative photocatalysis fashion. Herein, a new precious metal-free photocatalyst, {ZnW-TPT}, was prepared by incorporating a Zn-substituted monovacant Keggin polyanion [SiZnW11O39]6- and a photoactive organic bridging link 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT) into a framework. In this structure, the direct coordination bond between [SiZnW11O39]6- and the TPT ligand and the π-π interactions between TPT molecules help separate and migrate photogenerated carriers, which improves the photocatalytic activity of {ZnW-TPT}. The photoelectrochemical properties of {ZnW-TPT} were well studied by solid UV-vis absorption, fluorescence, transient photocurrent response, and electrochemical impedance spectroscopy tests. {ZnW-TPT} efficiently converts using hydrazine hydrate with 99% conversion and 99% selectivity for anilines under mild conditions.