Construction of zirconium/hafnium-oxo clusters based on a new protection-calix[8]arene.

Calix[8]arene has been used as a promising type of macrocyclic ligand for the construction of multinuclear metal-oxo clusters (MOCs), but not for zirconium/hafnium-oxo clusters (Zr/HfOCs). In this paper, we report the first series of ZrOCs (HfOCs) based on calix[8]arene: Zr4, Zr8, Hf4, and Hf8. Zr8/Hf8 has a rhombohedral conformation and can be regarded as a derivative of the octahedral Zr6 cluster. Remarkably, I2 adsorption experiments indicate that Zr4 (Zr8) adsorbs much faster than Hf4 (Hf8). Density functional theory (DFT) calculations show that metallic Zr atoms interact more strongly with I2 than metallic Hf atoms. The successful application of calix[8]arene for the synthesis of well-defined ZrOCs (HfOCs) shows a bright future for MOCs protected by macrocyclic ligands.

NaYF4 :Yb/Er@Mn3 O4 @GOX Nanocomposite for Upconversion Fluorescence Imaging and Synergistic Cascade Cancer Therapy by Apoptosis and Ferroptosis.

The cell elimination strategy based on reactive oxygen species (ROS) is a promising method for tumor therapy. However, its efficacy is significantly limited by ROS deficiency caused by H2 O2 substrate deficiency and up-regulation of cellular antioxidant defense induced by high glutathione (GSH) content in tumor cells. To overcome these obstacles, a multifunctional self-cascaded nanocomposite: glucose oxidase (GOX) loaded NaYF4 :Yb/Er@Mn3 O4 (UC@Mn3 O4 , labeled as UCMn) is constructed. Only in tumor microenvironment, it can be specifically activated through a series of cascades to boost ROS production via a strategy of open source (H2 O2 self-supplying ability). The increased ROS can enhance lipid peroxidation and induce tumor cell apoptosis by activating the protein caspase. More importantly, the nanozyme can consume GSH to inhibit glutathione peroxidase 4 (GPX4) activity, which limits tumor cell resistance to oxidative damage and triggers the tumor cell ferroptosis. Therefore, this strategy is expected to overcome the resistance of tumor to oxidative damage and achieve efficient oxidative damage of tumor. Further, degradation of the Mn3 O4 layer induced by GSH and acidic environment can promote the fluorescence recovery of UC fluorescent nuclear for tumor imaging to complete efficient integration of diagnosis and treatment for tumor.

Electron delocalization of robust high-nuclear bismuth-oxo clusters for promoted CO2 electroreduction.

The integration of high activity, selectivity and stability in one electrocatalyst is highly desirable for electrochemical CO2 reduction (ECR), yet it is still a knotty issue. The unique electronic properties of high-nuclear clusters may bring about extraordinary catalytic performance; however, construction of a high-nuclear structure for ECR remains a challenging task. In this work, a family of calix[8]arene-protected bismuth-oxo clusters (BiOCs), including Bi4 (BiOC-1/2), Bi8Al (BiOC-3), Bi20 (BiOC-4), Bi24 (BiOC-5) and Bi40Mo2 (BiOC-6), were prepared and used as robust and efficient ECR catalysts. The Bi40Mo2 cluster in BiOC-6 is the largest metal-oxo cluster encapsulated by calix[8]arenes. As an electrocatalyst, BiOC-5 exhibited outstanding electrochemical stability and 97% Faraday efficiency for formate production at a low potential of -0.95 V vs. RHE, together with a high turnover frequency of up to 405.7 h-1. Theoretical calculations reveal that large-scale electron delocalization of BiOCs is achieved, which promotes structural stability and effectively decreases the energy barrier of rate-determining *OCHO generation. This work provides a new perspective for the design of stable high-nuclear clusters for efficient electrocatalytic CO2 conversion.

Co-modified polyoxovanadoborates derived Co/BN-CNT/VN based bifunctional electrocatalysts for rechargeable zinc-air batteries.

Rational design of high-performance bifunctional electrocatalysts to accelerate the sluggish oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) in rechargeable Zn-air batteries remain an enduring challenge. The construction of multicomponent catalysts is a promising solution to achieve this goal. Herein, B and N co-doped interconnecting graphite carbon and carbon nanotube with the decoration of Co and vanadium nitride (VN) nanoparticles (Co/BN-CNT/VN) are synthesized using Co-modified polyoxovanadoborates as precursors. The optimized composite achieves superior bifunctional oxygen electrocatalytic activity and stability, which is comparable to noble metal catalysts and reported bifunctional electrocatalysts. Specifically, the half-potential of ORR reaches 0.85 V, and the overpotential of OER is low to 296 mV at a current density of 10 mA cm-2. Strikingly, zinc-air batteries assembled based on Co/BN-CNT/VN demonstrate a small charge-discharge voltage gap of 0.873 V, a remarkable peak-power density of 156.3 mW cm-2, and outstanding cycling durability (∼1000 cycles at 10 mA cm-2). This work affords a new alternative strategy to create cost-effective and high-potency bifunctional oxygen electrocatalysts for advanced air batteries.

High-nuclear polyoxovanadates assembled from pentagonal building blocks.

The design and synthesis of high-nuclear polyoxometalates (POMs) constructed from pentagonal molecular building blocks (MBBs) are attractive and challenging. Herein, three new high-nuclear polyoxovanadates, including {V20W2P20} (1), {V18W4P14} (2), and {V26W6P16} (3), have been successfully synthesized under solvothermal conditions. All these structures are assembled from pentagonal MBB {WV5(PhPO3)5} with different configurations. Compound 1 exhibits efficient, stable, and versatile catalytic activity for sulfide oxidation.

Face-Directed Construction of a Metal-Organic Isohedral Tetrahedron for the Highly Efficient Capture of Environmentally Toxic Oxoanions and Iodine.

Geometric analysis has been guiding the design and construction of metal-organic polyhedra. Here, a series of isohedral tetrahedra ZrIT-1 and -2 and VIT-1 and -2 were synthesized by a one-pot method relying on trivalent molecular building blocks. Structural analysis shows that the isohedral tetrahedra constructed with {V6(SO4)(CO2)3} have three different sets of prism lengths, while those constructed with {Zr3O(CO2)3} have two different sets of prism lengths. Comparison of two types of polyhedra reveals that the different sizes and coordination flexibilities of the two MBBs result in different cavity volumes. The environmentally toxic oxoanion trapping ability of ZrIT-1 was explored due to its structural stability and cation cage properties. The results show that ZrIT-1 can capture permanganate and dichromate anions in water with high efficiency and selectivity. Notably, the permanganate adsorption capacity can reach ∼276.6 mg/g, which exceeds those of most metal-organic framework materials. In addition, the adsorption and desorption of iodine showed that ZrIT-1 has a reversible adsorption capacity for iodine.

Organic Supramolecular Zippers with Ultralong Organic Phosphorescence by a Dexter Energy Transfer Mechanism.

Ultralong organic phosphorescence (UOP) materials glow persistently in the dark, which offers new exciting possibilities in the fields of anti-counterfeiting, photoelectric devices and biological imaging. However, the development of single-component UOP materials remains a great challenge. Herein, we develop a single component organic supramolecular zipper system with a lifetime up to 0.77 s. Owing to the introduction of a pyrazole ring into the diphenylsulfone group, the "V" shaped molecules were artfully self-assembled into supramolecular zippers via π-π and C-H⋅⋅⋅π interactions, that is not only of significance in highly efficient generation of triplet excitons but also facilitates a Dexter energy transfer process within supramolecular zippers, that are responsible for alleviating radiative and non-radiative deactivation decay of triplet excitons, to finally boost the UOP. This finding not only gives a new set of guidelines for the design of single-component UOP molecules but also reveals the UOP mechanism from a new perspective.

Bimetallic Metal-Organic Framework-Derived Graphitic Carbon-Coated Small Co/VN Nanoparticles as Advanced Trifunctional Electrocatalysts.

The rational design and construction of multifunctional electrocatalysts with high activity, low cost, and outstanding stability are highly desirable for the development of renewable energy but are still a big challenge. Bimetallic catalysts are a kind of promising candidates, like the hybrids of Co and VN nanoparticles (Co/VN). However, the inevitable aggregation during the preparation and electrochemical process lowers their reactivity and durability. Herein, small Co/VN nanoparticles (4-8 nm) embedded in porous graphitic carbon layers (Co/VN NPs@C) were obtained through the pyrolysis of metal-organic frameworks (MOFs). The synergistic effect of in situ generated Co and VN NPs together with fast electron transfer from graphitic carbon layers renders this catalyst to possess excellent trifunctional performance. More attractively, Co/VN NPs@C as both the anode and the cathode shows a low voltage of 1.58 V when the current density is up to 10 mA cm-2, exceeding most electrocatalysts based on non-noble metals. The rechargeable Zn-air batteries constructed by Co/VN NPs@C deliver high round-trip efficiency together with a peak power density of 130 mW cm-2, a specific capacity of 757 mAh g-1, and desirable stability, outperforming the traditional Zn-air batteries based on the Pt/C and RuO2 pair. This work opens a promising avenue toward constructing highly effective multifunctional electrocatalysts by designing small-sized nanoparticles with various active sites derived from MOFs.

A thiol-functionalized zirconium metal-organic cage for the effective removal of Hg2+ from aqueous solution.

The mercury ions in waste water have threatened public health and environmental protection. In this sense, novel materials with outstanding performances for removal of Hg2+ are imperative. Herein, we demonstrate a thiol-functionalized zirconium metal-organic cage (MOC-(SH)2) with excellent dispersion displays ideal properties for Hg2+ capture. MOC-(SH)2 exhibits the ability of removing Hg2+ in aqueous solutions with a capacity of 335.9 mgHg2+/gMOC-(SH)2, which surpasses that of classical Zr-based metal-organic framework Uio-66-(SH)2 by 1.89 folds. The higher loading capacity of MOC-(SH)2 is probably owing to the excellent dispersion of the discrete cage, which makes the accessibility of binding sites (thiol) easier. Additionally, 99.6% of Hg2+ can be effectively captured by MOC-(SH)2 with the concentration decreased from 5 to 0.02 ppm reaching the permissible limit for Hg2+, outperforming the performance of Uio-66-(SH)2. The excellent absorption property of MOC-(SH)2 is also achieved in terms of superior selectivity under the presence of competitive metal ions. Meanwhile, the regenerated MOC-(SH)2 can be reused without apparent loss of Hg2+ loading capacity. UV-vis absorption spectra, IR spectra and emission spectra further verified the strong chemical affinity between Hg2+ and the thiol of MOC-(SH)2. The study lays the groundwork for using Zr-MOCs in the removal of toxic metal ions and environmental sustainability.

A Novel Magnesium Metal-Organic Framework as a Multiresponsive Luminescent Sensor for Fe(III) Ions, Pesticides, and Antibiotics with High Selectivity and Sensitivity.

Iron(III) ions play a vital role in living biological systems, while organic pollutants including pesticides and antibiotics pose a great threat to the ecological environment. Effective detection for these species is crucial for human health and environmental protection. In this work, we designed and synthesized a new amino-decorated bridging ligand H2APDA and employed it to react with the environmentally friendly Mg(II) ions to construct a novel magnesium luminescent metal-organic framework (Mg-LMOF), namely [Mg2(APDA)2(H2O)3]·5DMA·5H2O (Mg-APDA). The as-synthesized Mg-LMOF is a three-dimensional framework with one-dimensional hexagonal channels. These microporous channels are decorated with Lewis-base amino sites and uncoordinated O atoms, which facilitate the Mg-APDA to anchor and recognize various analytes. Mg-APDA can be used as a multiresponsive luminescent sensor to detect Fe(III) ions, pesticides, and antibiotics effectively. To the best of our knowledge, this work represents the first amino-decorated Mg-LMOF as an efficient fluorescent sensor for detecting metal ions, pesticides, and antibiotics simultaneously.

[Glutathione and male reproduction].

Reduced glutathione (GSH) , the most abundant non-protein thiol in mammalian cells, exists extensively in the human body and plays a key role in many biological processes, including the synthesis of proteins and DNA and the transport of amino acids, especially in protecting cells against oxidation. GSH also shows its important clinical value in the treatment of many diseases. It has been reported that GSH also widely exists in the male reproductive system and has a therapeutic role in male infertility. The objective of this review is to summarize the distribution of GSH in the male reproductive system and its therapeutic value for male infertility.

[Determination of uric acid in the expressed prostatic secretion of chronic prostatitis patients and its clinical significance].

OBJECTIVE: To determine the level of uric acid (UA) in the expressed prostatic secretion (EPS) of chronic prostatitis patients and explore its clinical significance. METHODS: A total of 91 patients with chronic prostatitis diagnosed by NIH standard were divided into a III A (n = 48) and a III B (n = 43) group, and healthy volunteers were selected as the control. The scores on the NIH-Chronic Prostatitis Symptom Index (CPSI) and the WBC count, pH value and UA level in EPS were evaluated for all the three groups. RESULTS: The EPS UA concentration was (257.02 +/- 144.84) micromol/L in Group III B, significantly higher than in Group III A, (159. 73 +/- 121.49) micromol/L, (P < 0.01), and the control, (78.55 +/- 44.53) micromol/L, (P < 0.01). The level of EPS UA was correlated negatively with pH value (r = -0.398, P = 0.000), but positively with CPSI-P, CPSI-U and CPSI-T (r = 0.436, 0.316 and 0.403, P < 0.01). CONCLUSION: Backflow of urine into prostatic ducts might cause chemical inflammation reaction by increasing UA concentration. There is a close relationship between the UA level in EPS and chronic prostatitis symptoms. Determination of the UA level in EPS is of great significance for the diagnosis and treatment of chronic prostatitis.

[Evaluation of sperm mitochondrial membrane potential by JC-1 fluorescent staining and flow cytometry].

OBJECTIVE: To investigate the feasibility and clinical significance of detecting sperm mitochondrial membrane potential (MMP) by JC-1 fluorescent staining and flow cytometry, and to explore the relationship between the results of JC-1 staining and seminal parameters. METHODS: Sixty-three semen samples were divided into a fertile (n = 31) and an infertile group (n = 32) and underwent computer-assisted semen analysis (CASA). All the samples were washed, followed by JC-1 staining and evaluation of sperm MMP by flow cytometry. The percentage of normal sperm MMP was indicated as the percentage of sperm emitting orange-red fluorescence (JC-1 + %). RESULTS: The JC-1 + % was significantly higher in the fertile group than in the infertile one ([75.89 +/- 15.69]% vs [54.04 +/- 22.21] %, P = 0.000), correlated positively with sperm motility (r = 0.610, P = 0.000) and the percentage of grade a + b sperm (r = 0.614, P = 0.000) and negatively with grade d sperm (r = -0.504, P = 0.000). There was a significant positive correlation between the results of JC-1 staining (JC-1 + %) and that of Rh123 /PI dual fluorescent staining (Rh123 + / PI (-)%) (r = 0.938, P = 0.000). CONCLUSION: JC-1 staining and flow cytometry could readily and quickly detect sperm MMP and the sperm JC-1 + % could be an auxiliary marker for the diagnosis of male infertility.

[Clinical, molecular and cytogenetic studies on 4 patients with 46, XX (SRY positive) male syndrome].

OBJECTIVE: To analyze the clinical, molecular and cytogenetic features of 46, XX (SRY positive) male syndrome. METHODS: The clinical features of 4 patients with 46, XX (SRY positive) male syndrome were analyzed retrospectively. Karyotyping, FISH, PCR amplification of the SRY gene, and Y-chromosome microdeletion were performed to study their molecular cytogenetic features. RESULTS: The Four patients were all sociopsychologically males of short stature and came to hospital for infertility. Physical examination revealed that their testes were small in volume and soft in texture, but their penes were normal. Semen analyses showed complete azoospermia. Detection of serum sexual hormone suggested hypergonadotropic hypogonadism. All were karyotyped as 46, XX. Molecular analyses revealed the presence of the SRY gene and absence of AZFa, b and c of the Y chromosome. FISH analysis showed that SRY genes were translocated to Xp in 3 of the patients. CONCLUSION: Phenotypically 46, XX (SRY positive) male patients are males generally, for the presence of the SRY gene in the whole genome and azoospermia due to the deletion of AZF. The clinical characteristics of the patient include testis dysgenesis, infertility and short stature. The long arm of the Y chromosome might contain the gene associated with body height. Extensive molecular and cytogenetic studies on 46, XX male syndrome may help to elucidate its genotype-phenotype relation.