Engineering Nanosensitizer to Remodel the TME for Hypoimmunogenic "Cold"-"Hot" Tumor Transformations.

α-PD-L1 therapy has shown encouraging results at harnessing the immune system to combat cancer. However, the treatment effect is relatively low due to the dense extracellular matrix (ECM) and tumor immunosuppressive microenvironment (TIME). Therefore, an ultrasound (US)-responsive nanosensitizer (URNS) is engineered to deliver losartan (LST) and polyethylenimine (PEI) to remolde the TME, driving "cold"-"hot" tumor transformation and enhancing the sensitivity of α-PD-L1 therapy. In the tumor site, noninvasive US can make MTNP generate ROS, which cleave ROS-sensitive bonds to dissociate MTNPtK@LST-PEI, shedding PEI and releasing LST from mesoporous spheres. The results demonstrated that URNS combined with α-PD-L1 therapy effectively inhibited tumor growth with an inhibition rate as high as 90%, which was 1.7-fold higher than that of the α-PD-L1 treatment in vivo. In summary, the URNS improves the sensitivity of α-PD-L1 therapy by remodeling the TME, which provides promising insights for optimizing cancer immunotherapy.

Revealing the Effect of High Ni Content in Li-Rich Cathode Materials: Mitigating Voltage Decay or Increasing Intrinsic Reactivity.

Li-rich layered oxides are considered as one of the most promising cathode materials for secondary lithium batteries due to their high specific capacities, but the issue of continuous voltage decay during cycling hinders their market entry. Increasing the Ni content in Li-rich materials is assumed to be an effective way to address this issue and attracts recent research interests. However, a high Ni content may induce increased intrinsic reactivity of materials, resulting in severe side reactions with the electrolyte. Thus, a comprehensive study to differentiate the two effects of the Ni content on the cell performance with Li-rich cathode is carried out in this work. Herein, it is demonstrated that a properly dosed amount of Ni can effectively suppress the voltage decay in Li-rich cathodes, while over-loading of Ni, on the contrary, can cause structural instability, Ni dissolution, and nonuniform Li deposition during cycling as well as severe oxygen loss. This work offers a deep understanding on the impacts of Ni content in Li-rich materials, which can be a good guidance for the future design of such cathodes for high energy density lithium batteries.

A Self-Disguised Nanospy for Improving Drug Delivery Efficiency via Decreasing Drug Protonation.

Nanoscale drug carriers play a crucial role in reducing side effects of chemotherapy drugs. However, the mononuclear phagocyte system (MPS) and the drug protonation after nanoparticles (NPs) burst release still limit the drug delivery efficiency. In this work, a self-disguised Nanospy is designed to overcome this problem. The Nanospy is composed of: i) poly (lactic-co-glycolic acid)-polyethylene glycol (PLGA-PEG) loading doxorubicin is the core structure of the Nanospy. ii) CD47 mimic peptides (CD47p) is linked to NPs which conveyed the "don't eat me" signal. iii) 4-(2-aminoethyl) benzenesulfonamide (AEBS) as the inhibitor of Carbonic anhydrase IX (CAIX) linked to NPs. Briefly, when the Nanospy circulates in the bloodstream, CD47p binds to the regulatory protein α (SIRPα) on the surface of macrophages, which causes the Nanospy escapes from phagocytosis. Subsequently, the Nanospy enriches in tumor and the AEBS reverses the acidic microenvironment of tumor. Due to above characteristics, the Nanospy reduces liver macrophage phagocytosis by 25% and increases tumor in situ DOX concentration by 56% compared to PLGA@DOX treatment. In addition, the Nanospy effectively inhibits tumor growth with a 63% volume reduction. This work presents a unique design to evade the capture of MPS and overcomes the influence of acidic tumor microenvironment (TME) on weakly alkaline drugs.

Annular Conductive Hydrogel-Mediated Wireless Electrical Stimulation for Augmenting Neurogenesis.

Electrical stimulation (ES) has a remarkable capacity to regulate neuronal differentiation and neurogenesis in the treatment of various neurological diseases. However, wired devices connected to the stimulating electrode and the mechanical mismatch between conventional rigid electrodes and soft tissues restrict their motion and cause possible infections, thereby limiting their clinical utility. An approach integrating the advantages of wireless techniques and soft hydrogels provides new insights into ES-induced nerve regeneration. Herein, a flexible and implantable wireless ES-responsive electrode based on an annular gelatin methacrylate-polyaniline (Gel/Pani) hydrogel is fabricated and used as a secondary coil to achieve wireless ES via electromagnetic induction in the presence of a primary coil. The Gel/Pani hydrogels exhibit favorable biocompatibility, biodegradability, conductivity, and compression resistance. The annular electrode of the Gel/Pani conductive hydrogel (AECH) supports neural stem cell growth, while the applied wireless ES facilitates neuronal differentiation and the formation of functional neural networks in vitro. Furthermore, AECH is implanted in vivo in rats with ischemic stroke and the results reveal that AECH-mediated wireless ES significantly ameliorates brain impairment and neurological function by activating endogenous neurogenesis. This novel flexible hydrogel system addresses wireless stimulation and implantable technical challenges, holding great potential for the treatment of neurodegenerative diseases.

Crocetin Regulates Functions of Neural Stem Cells to Generate New Neurons for Cerebral Ischemia Recovery.

Many neurons undergo apoptosis after ischemic stroke. In the brain, neurogenesis has the potential for neuronal replacement and can be activated by external conditions to repair the injury. Crocetin (CRO), naturally extracted from the plant saffron, acts as a neuroprotective agent for ischemic stroke. However, the underlying mechanism remains unknown. In this work, the effect of CRO on neural stem cell (NSC) behaviors and subventricular zone neurogenesis is investigated. Initially, NSCs are incubated with different concentrations of CRO to detect the cell proliferation and differentiation in vitro. Second, ischemic stroke induced rats are treated with CRO using nimodipine (NMDP) as a comparison. The behavioral functions, infarcted volume, and apoptotic Nissl bodies of rats are noticeably improved after CRO-treatment, comparable to those of NMDP. In addition, the increased regional cerebral blood flow and promoted neuronal differentiation are achieved by CRO-treatment. Brain tissue examination shows significantly increased neuronal regeneration in the focal ischemic injury area. Meanwhile, the length of neurites is prolonged, indicating that CRO could potentially promote neurite extension to enhance cell-cell communication. These findings demonstrate that CRO facilitated the neuronal differentiation of NSCs by activating subventricular zone neurogenesis in damaged cortex and striatum sites to repair ischemic stroke.

Injectable and Degradable POSS-Polyphosphate-Polysaccharide Hybrid Hydrogel Scaffold for Cartilage Regeneration.

The limited self-repair capacity of articular cartilage has motivated the development of stem cell therapy based on artificial scaffolds that mimic the extracellular matrix (ECM) of cartilage tissue. In view of the specificity of articular cartilage, desirable tissue adhesiveness and stable mechanical properties under cyclic mechanical loads are critical for cartilage scaffolds. Herein, we developed an injectable and degradable organic-inorganic hybrid hydrogel as a cartilage scaffold based on polyhedral oligomeric silsesquioxane (POSS)-cored polyphosphate and polysaccharide. Specifically, acrylated 8-arm star-shaped POSS-poly(ethyl ethylene phosphate) (POSS-8PEEP-AC) was synthesized and cross-linked with thiolated hyaluronic acid (HA-SH) to form a degradable POSS-PEEP/HA hydrogel. Incorporation of POSS in the hydrogel increased the mechanical properties. The POSS-PEEP/HA hydrogel showed enzymatic biodegradability and favorable biocompatibility, supporting the growth and differentiation of human mesenchymal stem cells (hMSCs). The chondrogenic differentiation of encapsulated hMSCs was promoted by loading transforming growth factor-ß3 (TGF-ß3) in the hydrogel. In addition, the injectable POSS-PEEP/HA hydrogel was capable of adhering to rat cartilage tissue and resisting cyclic compression. Furthermore, in vivo results revealed that the transplanted hMSCs encapsulated in the POSS-PEEP/HA hydrogel scaffold significantly improved cartilage regeneration in rats, while the conjugation of TGF-ß3 achieved a better therapeutic effect. The present work demonstrated the potential of the injectable, biodegradable, and mechanically enhanced POSS-PEEP/HA hybrid hydrogel as a scaffold biomaterial for cartilage regeneration.

Coronavirus transmissible gastroenteritis virus antagonizes the antiviral effect of the microRNA miR-27b via the IRE1 pathway.

Although the functional parameters of microRNAs (miRNAs) have been explored to some extent, the roles of these molecules in coronavirus infection and the regulatory mechanism of miRNAs in virus infection are still unclear. Transmissible gastroenteritis virus (TGEV) is an enteropathgenic coronavirus and causes high morbidity and mortality in suckling piglets. Here, we demonstrated that microRNA-27b-3p (miR-27b-3p) suppressed TGEV replication by directly targeting porcine suppressor of cytokine signaling 6 (SOCS6), while TGEV infection downregulated miR-27b-3p expression in swine testicular (ST) cells and in piglets. Mechanistically, the decrease of miR-27b-3p expression during TGEV infection was mediated by the activated inositol-requiring enzyme 1 (IRE1) pathway of the endoplasmic reticulum (ER) stress. Further studies showed that when ER stress was induced by TGEV, IRE1 acted as an RNase activated by autophosphorylation and unconventionally spliced mRNA encoding a potent transcription factor, X-box-binding protein 1 (Xbp1s). Xbp1s inhibited the transcription of miR-27 and ultimately reduced the production of miR-27b-3p. Therefore, our findings indicate that TGEV inhibits the expression of an anti-coronavirus microRNA through the IRE1 pathway and suggest a novel way in which coronavirus regulates the host cell response to infection.

An Ultrasound-Induced Self-Clearance Hydrogel for Male Reversible Contraception.

Nearly half of pregnancies worldwide are unintended mainly due to failure of contraception, resulting in negative effects on women's health. Male contraception techniques, primarily condoms and vasectomy, play a crucial role in birth control, but cannot be both highly effective and reversible at the same time. Herein, an ultrasound (US)-induced self-clearance hydrogel capable of real-time monitoring is utilized for in situ injection into the vas deferens, enabling effective contraception and noninvasive recanalization whenever needed. The hydrogel is composed of (i) sodium alginate (SA) conjugated with reactive oxygen species (ROS)-cleavable thioketal (SA-tK), (ii) titanium dioxide (TiO2), which can generate a specific level of ROS after US treatment, and (iii) calcium chloride (CaCl2), which triggers the formation of the hydrogel. For contraception, the above mixture agents are one-time injected into the vas deferens, which can transform from liquid to hydrogel within 160 s, thereby significantly physically blocking the vas deferens and inhibiting movability of sperm. When fertility is needed, a noninvasive remedial ultrasound can make TiO2 generate ROS, which cleaves SA-tK to destroy the network of the hydrogel. Owing to the recanalization, the refertility rate is restored to 100%. Meanwhile, diagnostic ultrasound (D-US, 22 MHz) can monitor the occlusion and recanalization process in real-time. In summary, the proposed hydrogel contraception can be a reliable, safe, and reversible male contraceptive strategy that addresses an unmet need for men to control their fertility.

Tailoring of Gradient Particles of Li-Rich Layered Cathodes with Mitigated Voltage Decay for Lithium-Ion Batteries.

Voltage decay during cycling is still a major issue for Li-rich cathodes in lithium ion batteries. Recently, the increase of Ni content has been recognized as an effective way to mitigate this problem, although it leads to lower-capacity materials. To find a balance between voltage decay and high capacity, particles of Li-rich materials with concentration gradients of transition metals have been prepared. Since voltage decay is caused by oxygen loss and phase transition that occur mainly on the particle surface, the Ni content is designed with a negative gradient of concentration from the surface to the bulk of particles. To do so, microsized Li1.20Ni0.13Co0.13Mn0.54O2 particles are mixed with much smaller LiNi0.8Co0.1Mn0.1O2 particles to form deposits of small particles onto larger particles. The concentration gradient of Ni is achieved as the Ni ions in LiNi0.8Co0.1Mn0.1O2 penetrate into Li1.20Ni0.13Co0.13Mn0.54O2 during a calcination post-treatment. Gradient samples show superior cycling performance and voltage retention as well as improved safety. This systematic study explores a material model combining Li-rich and high-Ni layered cathodes that is shown to be effective in creating a balance between mitigated voltage decay and high energy density.

miR-5089-5p suppresses castration-resistant prostate cancer resistance to enzalutamide and metastasis via miR-5089-5p/SPINK1/ MAPK/MMP9 signaling.

Whether serine protease inhibitor Kazal type 1 (SPINK1) being associated with enzalutamide (Enz) resistance and metastasis of castration-resistant prostate cancer (CRPC) has not been clear. SPINK1 promoted Enz resistance by upregulating Androgen receptor splicing variant 7 (ARv7), and enhanced the invasion/migration of Enz-resistant cells via ERK/p38/ MMP9 signaling. Furthermore, miR-5089-5p suppressed SPINK1 mRNA through direct binding to its 3'UTR, and reversed its pro-proliferative and pro-metastatic effects. Mice bearing SPINK1-knockdown Enz-resistant PCa tumors showed significantly longer survival compared with those bearing wild-type tumors, while treatment with miR-5089-5p inhibitor abrogated the protective effects of SPINK1 knockdown. Taken together, SPINK1 can be used as a biomarker of resistance to Enz, and the miR-5089-5p/SPINK1/MAPK/MMP9 axis is a suitable therapeutic target against Enz-resistant and metastatic CRPC.Methods: The expression of SPINK1 in Enz-resistant prostate cancer (PCa) cell lines was detected through next-generation sequencing data and metastatic PCa patients. In vivo and in vitro experiments were performed to investigate the role of SPINK1 in Enz-resistance and metastasis.

Identification of a six-lncRNA signature based on a competing endogenous RNA network for predicting the risk of tumour recurrence in bladder cancer patients.

Bladder cancer (BC) is the most common malignancy involving the urinary system, and is characterized by a high recurrence rate. It is important to identify potential lncRNA signatures capable of predicting tumour recurrence risk and assessing recurrence prognosis in BC patients. We extracted data from The Cancer Genome Atlas and identified 381 differentially expressed lncRNAs, 855 mRNAs and 70 miRNAs between non-recurrent and recurrent BC tissues. Subsequently, a competing endogenous RNA (ceRNA) network composed of 29 lncRNAs, 13 miRNAs and 4 mRNAs was established. We used univariate and multivariate Cox regression to analyse the relationship between the 29 lncRNAs and recurrence-free survival (RFS) in BC patients. Six lncRNAs had significant prognostic values, and their cumulative risk score indicated that this 6-lncRNA signature independently predicted RFS in BC patients. We applied a receiver operating characteristic (ROC) analysis to assess the efficiency of our prognostic models. High-risk patients exhibited a poorer prognosis than low-risk patients did. Additionally, the 6-lncRNA signature showed a significant correlation with BC clinicopathological characteristics, which indicates that it could be used for effective risk stratification. The current study provides novel insights into the lncRNA-related ceRNA network and this 6-lncRNA signature may be an independent prognostic factor in predicting the recurrence of BC patients.

Amorphous Ni x Co y P-supported TiO2 nanotube arrays as an efficient hydrogen evolution reaction electrocatalyst in acidic solution.

Bimetallic phosphides have been attracting increasing attention due to their synergistic effect for improving the hydrogen evolution reaction as compared to monometallic phosphides. In this work, NiCoP modified hybrid electrodes were fabricated by a one-step electrodeposition process with TiO2 nanotube arrays (TNAs) as a carrier. X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflection spectroscopy, X-ray photoelectron spectroscopy and scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy were used to characterize the physiochemical properties of the samples. The electrochemical performance was investigated by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. We show that after incorporating Co into Ni-P, the resulting Ni x Co y P/TNAs present enhanced electrocatalytic activity due to the improved electron transfer and increased electrochemically active surface area (ECSA). In 0.5 mol L-1 H2SO4 electrolyte, the Ni x Co y P/TNAs (x = 3.84, y = 0.78) demonstrated an ECSA value of 52.1 mF cm-2, which is 3.8 times that of Ni-P/TNAs (13.7 mF cm-2). In a two-electrode system with a Pt sheet as the anode, the Ni x Co y P/TNAs presented a bath voltage of 1.92 V at 100 mA cm-2, which is an improvment of 79% over that of 1.07 V at 10 mA cm-2.

PbTe quantum dots as electron transfer intermediates for the enhanced hydrogen evolution reaction of amorphous MoSx/TiO2 nanotube arrays.

Amorphous molybdenum sulfides (a-MoSx) have been demonstrated as economic and efficient hydrogen evolution catalysts for water splitting. Further improvements of their hydrogen evolution reaction (HER) activities could be achieved by coupling them with appropriate electron transfer intermediates via interfacial engineering. In this study, a novel ternary composite electrode comprising PbTe quantum dots (QDs), a-MoSx and TiO2 nanotube arrays (TNAs) was successfully fabricated by a facile combination of successive ionic layer adsorption and reaction (SILAR) and electrodeposition routes. Investigation of the microstructures and electrocatalytic properties of the a-MoSx/PbTe QD/TNA hybrid material show that PbTe QDs can work as electron temporary storage and electron transfer intermediates between the electrocatalyst a-MoSx and electrode-based material TiO2 that significantly lower the impedance of electrode process, enhance the energy band bending at the interface between the electrolyte and electrode surface, and increase the electrochemically active surface area. The electron interphase crossing from a-MoSx to electrolyte and electron transport inside the electrode are greatly strengthened. The ternary PbTe@MoSx/TNA electrode demonstrates lowered onset potential and Tafel slope and superior electrocatalytic activity and cyclic stability towards HER.

Enhanced hydrogen production of PbTe-PbS/TNAs electrodes modified with ordered mesoporous carbon.

PbTe-PbS/TiO2 nanotube arrays (PbTe-PbS/TNAs) were synthesized by the successive ionic layer adsorption and reaction (SILAR) followed by linear sweep voltammetry (LSV). Using Nafion as a binder, ordered mesoporous carbon was cast on these materials to generate the modified electrodes OMC/PbTe-PbS/TNAs. It was demonstrated that the electrode modification with OMC could enhance the charge transfer between the electrode surface and the electrolyte solution, improve the energy band bending of the electrode/electrolyte interface, increase the active electrochemical surface area of the electrode, and reduce the overpotential of the electrode reactions. Under ambient conditions, the short circuit current density (37.84mAcm-2) and the active electrochemical surface area (29mFcm-2) of the OMC/PbTe-PbS/TNAs electrode were 27.49% and 36.79% higher than that of PbTe-PbS/TNAs (29.68mAcm-2 and 21.2mFcm-2), respectively. A particularly important feature of the OMC modification is that the hot electron extraction capability of the PbTe-PbS/TNAs electrode remained in the new system to provide rapid enhancement of short circuit current density upon increasing temperature. The OMC/PbTe-PbS/TNAs electrode registered a hydrogen generation rate of 11mLcm2h-1, with an energy efficiency of 98.79% and a heat efficiency of 43.03% under cell voltage of 1.0V at 55°C.

Tuning PbS QDs deposited onto TiO2 nanotube arrays to improve photoelectrochemical performances.

The ability to anchor quantum dots (QDs) onto the inner channels of nanotube arrays affords the opportunity to engineer the electron and band structures for a variety of applications. During the successive ionic layer adsorption and reaction (SILAR) preparation, the deposition of PbS QDs had been tuned by adjusting the concentration ratio of sulfur and lead sources onto the TiO2 nanotube array (TNA) support formed via anodic ionization. The photoelectrochemical properties of the PbS QD sensitized TNAs were optimized. The sample microstructure and photoelectrochemical properties were analyzed with X-ray diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRs), photoluminescence (PL), current-voltage characteristics (J-V), electrochemical impedance spectroscopy (EIS), transient photovoltage plots and Mott-Schottky curves. The size and distribution of the PbS QDs were tuned by varying the concentration ratio of sulfur and lead sources during the SILAR process. The band gap structure, flat band potential, lifetime and transport of the photo-induced charge carriers were subsequently modified. With a S/Pb concentration ratio of 5, the samples demonstrated the best photoelectrochemical characteristics with a peak photocurrent density of 8.24mAcm-2 and a corresponding photoconversion efficiency of 7.80%.

Enhanced charge-carrier transfer by CdS and Ag2S quantum dots co-sensitization for TiO2 nanotube arrays.

Thioglycollic acid was employed as a molecular linker to prepare CdS and/or Ag2S quantum dots (QDs) for the co-sensitization of TiO2 nanotube arrays through the successive ionic layer adsorption and reaction (SILAR) method. The microstructure, chemical composition, and photoabsorption of the prepared samples were analyzed by using field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DAS). The interfacial separation and transport of photoinduced charge carries were also examined by applying current-voltage characteristics (J-V), electrochemical impedance spectroscopy (EIS), transient open circuit potential plots, and Mott-Schottky techniques. The sizes of the CdS and Ag2S QDs were found to be 6 and 4 nm, respectively. The co-sensitized samples demonstrate significantly enhanced photo absorption, greatly reduced charge transfer resistance at the semiconductor interfaces, positive shift of the flat band, elongated electron lifetimes, and accelerated interfacial separation and transport of the photoinduced charge carriers. A critical operation sequence is to first carry out the deposition of the CdS QDs that are less mismatched with TiO2 crystal lattice, followed by the deposition of Ag2S QDs. The samples prepared in this manner presented the best optoelectronic characteristics with a short photocurrent density of 9.5 mA·cm(-2). This value is 7.6% higher than 8.83 mA·cm(-2) of the sample prepared by depositing the more mismatched Ag2S QDs followed by deposition of CdS. This value is 18.8% higher than 8 mA·cm(-2) of the Ag2S-only sensitized sample, and 22.6% higher than 7.75 mA·cm(-2) of the CdS-only sensitized sample.

Silver sulfide nanoparticles sensitized titanium dioxide nanotube arrays synthesized by in situ sulfurization for photocatalytic hydrogen production.

Titanium dioxide (TiO2) nanotube arrays (TNAs) sensitized with silver sulfide (Ag2S) nanoparticles (NPs) were synthesized via facile in situ sulfurization. Metallic silver NPs were first loaded on TNAs through a simple electrodeposition process. The as-prepared Ag/TNAs composites were further treated with a solution of acetonitrile containing sulfur (S8) and dried in vacuum to obtain a new nanocomposite material comprising of TNAs sensitized with Ag2S NPs. In these composite nanostructures, ultrafine Ag2S NPs were well-dispersed and assembled on the exterior and interior walls of the TNAs. Owing to sensitizing with a narrow bandgap material like Ag2S and the homogeneous distribution of the Ag2S NP heterojunction structures over the surface of the TNAs, the synthesized nanocomposite samples exhibited remarkable capability to absorb visible light and showed a significant enhancement in the photocatalytic efficiency of hydrogen generation. Under visible light illumination (100mW/cm(2)), a maximum photoconversion efficiency of 1.21% and the highest hydrogen production rate of 1.13mL/cm(2)h were obtained from the TNA electrodes sensitized with Ag2S NPs.

Fabrication of glycopolymer/MWCNTs composite nanofibers and its enzyme immobilization applications.

Glycopolymer (poly(AN-co-OVSEG))/MWCNTs (multiwalled carbon nanotubes) composite nanofibers are fabricated using a facile approach combining enzymatic synthesis, radical polymerization and electrospinning. The structure of the glycopolymer was confirmed by FT-IR and (1)H NMR. Poly(AN-co-OVSEG)/MWCNTs composite nanofibers were prepared using electrospinning and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The hydrophilic properties of the composite nanofibers surfaces were increased since the contact angle of poly(AN-co-OVSEG)/MWCNTs composite was reduced from 65.5° to 37° compared to (PAN). As an enzymatic model catalase (CAT) was loaded (ca. 55.0mg/g) to the poly(AN-co-OVSEG)/MWCNTs nanofibers. The optimum temperature for poly(AN-co-OVSEG)/MWCNTs nanofibers increased from 25°C to 45°C compared to free CAT. The covalently immobilized enzymes conjugate exhibited 60% activity at 60°C, while the free enzyme was entirely inactivity after 5min heat treatment. The immobilized CAT retained 70% of its initial activity after 5 cycles of decomposition of hydrogen peroxide.