Reproduction of a fossil rhinoceros from 18 mya and origin of litter size in perissodactyls.

Reproductive strategy is among the most important characteristics of organism. Here, we report reproductive strategy of singleton pregnancy of a fossil rhinoceros, Plesiaceratherium gracile, from 18 mya of the Shanwang Basin, China. Dental and body development data revealed that after birth, the calf of P. gracile is breastfed for 2-3 years; at approximately 5 years of age, when the M2 tooth is slightly worn, the female has already reached sexual maturity and attained a size close to that of an adult and could give birth to the first calf. Furthermore, given litter size is phylogenetically conservative and closely correlates with body size, we conclude that the litter size of perissodactyls is determined by the singleton pregnancy since the Eocene. By contrast, other reproductive traits are highly variable and have a different pace of evolution, and traits observed in living rhinoceroses have been evolving at least since 18 mya.

Effects of Nitro-Oxidative Stress on Biomolecules: Part 1-Non-Reactive Molecular Dynamics Simulations.

Plasma medicine, or the biomedical application of cold atmospheric plasma (CAP), is an expanding field within plasma research. CAP has demonstrated remarkable versatility in diverse biological applications, including cancer treatment, wound healing, microorganism inactivation, and skin disease therapy. However, the precise mechanisms underlying the effects of CAP remain incompletely understood. The therapeutic effects of CAP are largely attributed to the generation of reactive oxygen and nitrogen species (RONS), which play a crucial role in the biological responses induced by CAP. Specifically, RONS produced during CAP treatment have the ability to chemically modify cell membranes and membrane proteins, causing nitro-oxidative stress, thereby leading to changes in membrane permeability and disruption of cellular processes. To gain atomic-level insights into these interactions, non-reactive molecular dynamics (MD) simulations have emerged as a valuable tool. These simulations facilitate the examination of larger-scale system dynamics, including protein-protein and protein-membrane interactions. In this comprehensive review, we focus on the applications of non-reactive MD simulations in studying the effects of CAP on cellular components and interactions at the atomic level, providing a detailed overview of the potential of CAP in medicine. We also review the results of other MD studies that are not related to plasma medicine but explore the effects of nitro-oxidative stress on cellular components and are therefore important for a broader understanding of the underlying processes.

Molecular dynamics simulation of the transmembrane transport process of reactive species under the synergistic effect of plasma oxidation and an electric field.

Cold atmospheric pressure plasma (CAP)-assisted cancer therapy has become a popular topic in plasma biomedical research. Membrane lipid oxidation and local electric fields are two important factors in plasma-cell interactions, and the study of their synergistic effect is highly significant for optimizing the regulatory mechanism of the plasma-induced apoptosis of cancer cells. In this paper, a model of oxidized phospholipids was established, and the transmembrane process of reactive species was simulated by the classical molecular dynamics (MD) method under the conditions of oxidation and an electric field. The results showed that hydrophilic reactive oxygen species could not penetrate the membrane lipids through oxidation. The formation of electroporation provided a new channel for reactive species to penetrate the membrane, and the oxidation effect reduced the electric field threshold of membrane electroporation. Our simulation could provide theoretical support for the plasma-induced apoptosis of cancer cells at the microscopic level, provide mechanistic guidance for the practical application of plasma-induced cancer therapy, and promote the development of CAP in the field of cancer therapy.

Blockage of Osteopontin-Integrin ß3 Signaling in Infrapatellar Fat Pad Attenuates Osteoarthritis in Mice.

The knowledge of osteoarthritis (OA) has nowadays been extended from a focalized cartilage disorder to a multifactorial disease. Although recent investigations have reported that infrapatellar fat pad (IPFP) can trigger inflammation in the knee joint, the mechanisms behind the role of IPFP on knee OA progression remain to be defined. Here, dysregulated osteopontin (OPN) and integrin ß3 signaling are found in the OA specimens of both human and mice. It is further demonstrated that IPFP-derived OPN participates in OA progression, including activated matrix metallopeptidase 9 in chondrocyte hypertrophy and integrin ß3 in IPFP fibrosis. Motivated by these findings, an injectable nanogel is fabricated to provide sustained release of siRNA Cd61 (RGD- Nanogel/siRNA Cd61) that targets integrins. The RGD- Nanogel possesses excellent biocompatibility and desired targeting abilities both in vitro and in vivo. Local injection of RGD- Nanogel/siRNA Cd61 robustly alleviates the cartilage degeneration, suppresses the advancement of tidemark, and reduces the subchondral trabecular bone mass in OA mice. Taken together, this study provides an avenue for developing RGD- Nanogel/siRNA Cd61 therapy to mitigate OA progression via blocking OPN-integrin ß3 signaling in IPFP.

The crosslink between the hyaluronic acid and drugs treated by reactive oxygen species produced in plasma based on the molecular dynamics simulation.

Hyaluronic Acid (HA)-based pre-drugs can enable targeted drug delivery to cancer cells with CD44-high expressing, thus, it is essential to design an efficient, target specific drug delivery system based on HA. Plasma, as a simple and clean tool, has been widely used in the modification and crosslinking of biological materials in recent years. In this paper, we used the Reactive Molecular Dynamic (RMD) to explore the reaction between reactive oxygen species (ROS) in plasma and HA with drugs (PTX, SN-38, and DOX), in order to examine possible drug-coupled systems. The simulation results indicated the acetylamino groups in HA could be oxidized to unsaturated acyl groups, which offers the possibility of crosslinking. Three drugs also exposed the unsaturated atoms under the impact of ROS, which can cross-link directly to HA through CO and CN bonds, forming a drug coupling system with better release. This study revealed the exposure of active sites on HA and drugs by ROS impact in plasma, allowing us to study the crosslinking mechanism between HA and drugs at molecular level deeply, and also provided a new light for establishment of HA-based targeted drug delivery system.

Reactive Molecular Dynamics Simulation on Degradation of Tetracycline Antibiotics Treated by Cold Atmospheric Plasmas.

The abuse of tetracycline antibiotics (TCs) has caused serious environmental pollution and risks to public health. Degradation of TCs by cold atmospheric plasmas (CAPs) is a high efficiency, low energy consumption and environmentally friendly method. In this study, a reactive molecular dynamics (MD) simulation is applied to study the interactions of reactive oxygen species (ROS) produced in CAPs and TCs (including tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC) and demeclocycline (DMC)). As revealed by the simulation data at the atomic level, the main reaction sites on TCs are the C2 acylamino, the C4 dimethylamine, the C6 methyl group, the C8 site on the benzene ring and the C12a tertiary alcohol. The interaction between ROS and TCs is usually initiated by H-abstraction, followed by the breaking and formation of the crucial chemical bonds, such as the breaking of C-C bonds, C-N bonds and C-O bonds and the formation of C=C bonds and C=O bonds. Due to the different structures of TCs, when the ROS impact OTC, CTC and DMC, some specific reactions are observed, including carbonylation at the C5 site, dechlorination at the C7 site and carbonylation at the C6 site, respectively. Some degradation products obtained from the simulation data have been observed in the experimental measurements. In addition, the dose effects of CAP on TCs by adjusting the number of ROS in the simulation box are also investigated and are consistent with experimental observation. This study explains in detail the interaction mechanisms of degradation of TCs treated by CAPs with the final products after degradation, provides theoretical support for the experimental observation, then suggests optimization to further improve the efficiency of degradation of TCs by CAPs in applications.

Injectable spontaneous hydrogen-releasing hydrogel for long-lasting alleviation of osteoarthritis.

Excessive production of reactive oxygen species (ROS) amplifies pro-inflammatory pathways and exacerbates immune responses, and is a key factor in the progression of osteoarthritis (OA). Therapeutic hydrogen gas (H2) with antioxidative and anti-inflammatory effects, has a potential for OA alleviation, but the targeted delivery and sustained release of H2 are still challenging. Herein, we develop an injectable calcium boride nanosheets (CBN) loaded hydrogel platform (CBN@GelDA hydrogel) as a high-payload and sustainable H2 precursor for OA treatment. The CBN@GelDA hydrogel could maintain constant physiological pH conditions which further promotes more H2 release than the CBN alone and lasts more than one week. The biocompatibility of this hydrogel with macrophages and chondrocytes is effectively enhanced. The experiments show that the CBN@GelDA hydrogel holds the ROS scavenging ability, reducing the expression of related inflammatory cytokines, lessening M1 macrophages but stimulating M2 phenotype, and thereby decreasing chondrocyte apoptosis, which facilitates to breaking of the vicious circle of OA progression. Furthermore, a single-time injection of the CBN@GelDA hydrogel markedly reduces joint destruction in OA rats. From what has been discussed above, this injectable spontaneous H2-releasing hydrogel is promising for OA treatment. STATEMENT OF SIGNIFICANCE: Oxidative stress and inflammation play the key role in the occurrence and development of osteoarthritis (OA). The system of a hydrogel loaded with H2 precursor calcium boride nanosheet (CBN), which is the first to use as an H2 precursor, integrates superior injectable and biocompatible of hydrogel and the selection of antioxidant properties of H2. This system can improve H2 release behavior and achieve a single injection into the articular cavity to alleviate the progression of OA in rats. This study of the combination of a convenient long-acting injectable hydrogel and a safe therapeutic gas is of great value for improving the quality of life of clinical patients.

Atomic-scale simulations of the deoxynivalenol degradation induced by reactive oxygen plasma species.

Deoxynivalenol (DON) is one of the most widely distributed and toxicologically dangerous mycotoxins. Cold atmospheric plasma (CAP) experiments have indicated a considerable degrading effect on DON, but the underlying interaction mechanism of plasma species and DON remains unknown. In this paper, a Reactive Molecular Dynamics (RMD) simulation is carried out to investigate the DON detoxification pathways induced by reactive oxygen species (ROS). The simulation results indicate that the given ROS (O atoms, OH radicals, H2O2 molecules, and O3 molecules) can modify toxicologically important functional groups through the processes of the ring-opening reaction of the 12,13-epoxide ring and the scission of double C9 = C10 bond to reduce the toxicity of DON. The formation of aldehyde and ketone groups by the hydrogen atom abstraction reaction can also be observed in the simulation, which agrees well with the experimental measurements. Furthermore, the dose effects described by the number density of ROS are examined to provide experimental guidance on plasma discharge parameter settings. The chemical pathways and statistical data reveal DON's atomic-scale degradation mechanism and give a theoretical understanding of the optimal strategy for degrading mycotoxins in future applications.

Fabrication of Ga2O3 Schottky Barrier Diode and Heterojunction Diode by MOCVD.

In this article, we reported on a Ga2O3-based Schottky barrier diode and heterojunction diode from MOCVD. The Si-doped n-type Ga2O3 drift layer, grown by MOCVD, exhibited high crystal quality, flat surfaces, and uniform doping. The distribution of unintentional impurities in the films was studied. Then nickel Schottky barrier diode and p-NiO/n-Ga2O3 heterojunction diode were fabricated and measured. Without any electric field management structure, the Schottky barrier diode and heterojunction diode have specific resistances of 3.0 mΩ·cm2 and 6.2 mΩ·cm2, breakdown voltages of 380 V and 740 V, thus yielding power figures of merit of 48 MW·cm-2 and 88 MW·cm-2, respectively. Besides, both devices exhibit a current on/off ratio of more than 1010. This shows the prospect of MOCVD in power device manufacture.

Development of a Novel Inflammatory-Associated Gene Signature and Immune Infiltration Patterns in Intervertebral Disc Degeneration.

Background: Both inflammatory factors and immune response play important roles in the pathogenesis of intervertebral disc degeneration (IDD). However, a comprehensive analysis of interaction between inflammatory response-associated genes (IRGs) and immune microenvironment in patients with IDD remains lacking. Hence, the current research is aimed at investigating the correlations between IRG signatures and immune cells in the progression of IDD. Methods: The expression profiles (GSE27494 and GSE41883) and IRGs were downloaded from the Gene Expression Omnibus (GEO) database and Molecular Signature Database (MSigDB), respectively. Weighted gene coexpression network analysis (WGCNA) and differential expression analysis were used to identify the pivotal modules and common differentially expressed genes (DEGs) associated with IDD. Subsequently, we retrieved differentially expressed IRGs (DE-IRGs) by intersecting IRGs and DEGs for enrichment analysis. Next, LASSO regression analyses were performed to screen optimal marker genes for IDD prediction. Additionally, we validated differences DE-IRGs between IDD patients and controls in GSE150408. Finally, the infiltration alteration of immune cells was evaluated by the CIBERSORT, and the correlation between diagnostic markers and infiltrating immune cells was analyzed. Results: A total of 10 upregulated differentially expressed inflammatory genes were identified that were obviously related to progression of IDD. Functional analysis results revealed that DE-IRGs were mainly enriched in signaling pathways TNF, IL-17, NOD-like receptor, and NF-kappa B pathway. A five-gene signature that consisted of IL-1ß, LIF, LYN, NAMPT, and SLC7A2 was constructed by the LASSO Cox regression. IL1B, LYN, and NAMPT were further validated as optimal candidate genes in the pathophysiology of IDD. In addition, there was a remarkable immune cell infiltration difference between the healthy and IDD groups. The proportions for dendritic cells activated, mast cells activated, and neutrophils in the IDD group were significantly higher than those in the normal group, while the proportion of some cells was lower than that of the normal group, such as T cell CD4 memory resting, NK cells activated, and macrophage M0. Furthermore, correlation analysis indicated IL-1ß, LYN, and NAMPT were closely implicated with immune cell infiltration in IDD development. Conclusions: We explored an association between inflammatory response-associated signature and immune infiltration in IDD and validated that IL-1ß, LYN, and NAMPT might serve as biomarkers and therapeutic targets for IDD in the future.

Performance enhancement of nitrogen-polar GaN-based light-emitting diodes prepared by metalorganic chemical vapor deposition.

Nitrogen-polar (N-polar) III-nitride materials have great potential for application in long-wavelength light-emitting diodes (LEDs). However, the poor quality of N-polar nitride materials hinders the development of N-polar devices. In this work, we report the enhanced performance of N-polar GaN-based LEDs with an optimized InGaN/GaN double quantum well (DQW) structure grown by metalorganic chemical vapor deposition. We improved the quality of the N-polar InGaN/GaN DQWs by elevating the growth temperature and introducing hydrogen as the carrier gas during the growth of the quantum barrier layers. N-polar LEDs prepared based on the optimized InGaN/GaN DQWs show significantly enhanced (by over 90%) external quantum efficiency and a weakened droop effect compared with a reference LED. More importantly, the optimized N-polar DQWs show a significantly longer emission wavelength than Ga-polar DQWs grown at the same QW growth temperature. This work provides a feasible approach to improving the quality of the N-polar InGaN/GaN QW structure, and it will promote the development of N-polar GaN-based long-wavelength light-emitting devices for micro-LED displays.

Analysis of the correlation between the severity of neonatal hypoxic ischemic encephalopathy and multiple organ dysfunction.

OBJECTIVE: To evaluate the hypoxic ischemic encephalopathy (HIE) and multiple organ dysfunction (MOD) in neonates and analyze the correlation between the two disorders. METHODS: From January 2018 to January 2020, infants with HIE who were born in our hospital at or above 37 weeks of gestation, and those with ischemic hypoxic encephalopathy at or above 2000 grams were selected as study subjects. HIE and MOD monitoring were performed for three days. HIE severity was graded according to reported scores including amplitude integrated EEG. Multiple organ dysfunction was also assessed. The correlation between neonatal hypoxic ischemic encephalopathy and multiple organ dysfunction was analyzed. RESULTS: Children with HIE were divided into three grades: mild, moderate and severe. There were statistically significant differences among the three groups in emergency caesarean section, Apgar 5 minutes, systemic hypothermia and neonatal mortality. Differences in MOD scores were found in three HIE stages per day from Day 1 to Day 3. Among children with mild HIE grading, the most common mildly affected organ systems are pH, electrolyte imbalance and liver system, and the least affected organs are kidney and blood systems. Among children with HIE grade of mild and severe, there was no significant difference in moderate-severe organ involvement, and the number of severely affected children was small. CONCLUSION: With the increase of HIE severity, multi-organ involvement is aggravated. The organ involvement of HIE children with different degrees of severity is different.

Performance enhancement of an N-polar nitride deep-ultraviolet light-emitting diode with compositionally graded p-AlGaN.

Highly efficient hole injection into a AlGaN quantum well is desirable in nitride deep-ultraviolet light-emitting diodes (DUV LEDs) for high optical performance. In this work, we report the observation of enhanced hole injection in the N-polar AlGaN-based DUV LEDs with compositionally graded p-AlxGa1-xN (x = 0.65-0.75) by simulation and show that the enhanced hole injection leads to the increase of the peak internal quantum efficiency (IQE) and the significant reduction of efficiency droop at high current density. This work might activate researchers to realize the efficient polarization p-type doping of N-polar AlGaN with high Al content and thus to achieve high performance DUV LEDs experimentally.

Plasma-induced destruction of Candida albicans cell wall components: A reactive molecular dynamics simulation.

Cold atmospheric plasma (CAP) has attracted significant attention and has been widely used to inactivate pathogens based on its excellent effect; however, the mechanisms underlying the interactions between plasma-generated species and organisms have not yet been fully elucidated. In this paper, the interactions of reactive oxygen plasma species (O, OH and H2O2) with chitin polymer (the skeletal component of the Candida albicans cell wall) were investigated by means of reactive molecular dynamics simulations from a microscopic point of view. Our simulations show that O and OH species can break important structural bonds (e.g., N-H bonds, O-H bonds and C-H bonds) of chitin. This is followed by a cascade of bond cleavage and double bond formation events. This simulation study aimed to improve the understanding of the micromechanism of plasma-inactivated Candida albicans at the atomic level.

Demonstration of epitaxial growth of strain-relaxed GaN films on graphene/SiC substrates for long wavelength light-emitting diodes.

Strain modulation is crucial for heteroepitaxy such as GaN on foreign substrates. Here, the epitaxy of strain-relaxed GaN films on graphene/SiC substrates by metal-organic chemical vapor deposition is demonstrated. Graphene was directly prepared on SiC substrates by thermal decomposition. Its pre-treatment with nitrogen-plasma can introduce C-N dangling bonds, which provides nucleation sites for subsequent epitaxial growth. The scanning transmission electron microscopy measurements confirm that part of graphene surface was etched by nitrogen-plasma. We study the growth behavior on different areas of graphene surface after pre-treatment, and propose a growth model to explain the epitaxial growth mechanism of GaN films on graphene. Significantly, graphene is found to be effective to reduce the biaxial stress in GaN films and the strain relaxation improves indium-atom incorporation in InGaN/GaN multiple quantum wells (MQWs) active region, which results in the obvious red-shift of light-emitting wavelength of InGaN/GaN MQWs. This work opens up a new way for the fabrication of GaN-based long wavelength light-emitting diodes.

Stromal cell-derived factor-1 may play pivotal role in distraction-stimulated neovascularization of diabetic foot ulcer.

Diabetic foot ulcer (DFU) has become a major medical, social and economic concern worldwide. It is highly desirable to develop promising new solutions to effectively and appropriately treat DFU. In recent years, investigators have used an innovative technology called proximal tibial cortex transverse distraction (PTCTD) to treat DFU and have achieved satisfactory results in terms of improved wound healing and circumvention of amputation as a consequence of enhanced neovascularization and perfusion of the ulcerated feet after the operation, but the underlying mechanism has not been explored. Previous studies have suggested that in addition to stimulating osteogenesis, bone distraction also facilitates neovascularization, which may be associated with the chemokine stromal cell-derived factor-1 (SDF-1). As an important member of the chemokine family, SDF-1 is primarily responsible for the homing and migration of endothelial progenitor cells (EPCs) or bone marrow-derived mesenchymal stem cells (BMSCs), and plays a central role in the process of neovascularization. In vivo or in vitro experiments show that bone distraction can induce the expression of SDF-1 and increase its plasma concentration. Moreover, some researchers have found that an insufficient level of SDF-1 in the circulation and wounds of patients with DFU can lead to impaired neovascularization. Therefore, we believe that SDF-1 plays an important role in promoting neovascularization of DFU as a result of bone distraction. We summarize the currently relevant literature to put forward an undisclosed but meaningful mechanism of bone distraction in the treatment of DFU.

The miRNA-15b/USP7/KDM6B axis engages in the initiation of osteoporosis by modulating osteoblast differentiation and autophagy.

Osteoporosis is a metabolic disease that results from oxidative stress or inflammation in renal disorders. microRNAs (miRNAs) are recently implicated to participate in osteoporosis, but the mechanism remains largely unexplored. Herein, we aimed to explore the potential role of miR-15b in osteoblast differentiation and autophagy in osteoporosis. We established osteoporosis models through ovariectomy and determined that miR-15b was highly expressed whereas USP7 and KDM6B were poorly expressed in tissue of osteoporosis mice. Treatment of silenced miR-15b resulted in the elevation of decreased bone mineral density (BMD), the maximum elastic stress and the maximum load of osteoporosis mice. In osteoblasts, miR-15 overexpression decreased proliferation but suppressed the cell differentiation and autophagy, accompanied with decreased expression of USP7. Mechanistically, miR-15 bound and inhibited USP7 expression, while overexpression of USP7 promoted autophagy of osteoblasts. USP7, importantly, strengthened the stability of KDM6B and promoted KDM6B expression. MG132 protease inhibitor increased KDM6B and USP7 expression in osteoblasts. Silencing of KDM6B reversed the promoting effect on autophagy and proliferation induced by overexpression of USP7. Taken altogether, miR-15b inhibits osteoblast differentiation and autophagy to aggravate osteoporosis by targeting USP7 to regulate KDM6B expression.

Hexagonal BN-Assisted Epitaxy of Strain Released GaN Films for True Green Light-Emitting Diodes.

Epitaxial growth of III-nitrides on 2D materials enables the realization of flexible optoelectronic devices for next-generation wearable applications. Unfortunately, it is difficult to obtain high-quality III-nitride epilayers on 2D materials such as hexagonal BN (h-BN) due to different atom hybridizations. Here, the epitaxy of single-crystalline GaN films on the chemically activated h-BN/Al2O3 substrates is reported, paying attention to interface atomic configuration. It is found that chemical-activated h-BN provides B-O-N and N-O bonds, where the latter ones act as effective artificial dangling bonds for following GaN nucleation, leading to Ga-polar GaN films with a flat surface. The h-BN is also found to be effective in modifying the compressive strain in GaN film and thus improves indium incorporation during the growth of InGaN quantum wells, resulting in the achievement of pure green light-emitting diodes. This work provides an effective way for III-nitrides epitaxy on h-BN and a possible route to overcome the epitaxial bottleneck of high indium content III-nitride light-emitting devices.

Ultrastable Lead-Free Double Perovskite Warm-White Light-Emitting Devices with a Lifetime above 1000 Hours.

Recently, white light-emitting devices (WLEDs) based on halide perovskites has been extensively studied. However, the lead toxicity and poor stability of conventional lead halide perovskites severely hinder their commercial applications. In this study, lead-free double perovskite Cs2AgInCl6 with a broadband emission was fabricated by a heat-assisted solution evaporation method, in which a compositional engineering by sodium (Na+) alloying and bismuth (Bi3+) doping was performed. The photoluminescence quantum yield was promoted from ∼1.1 to 46.4% and then to 87.2% by Na+ alloying and subsequent Bi3+ doping. In addition, the theory calculation reveals that the diffusion barrier of Cl- vacancy in Cs2AgInCl6 can be increased by Na+ alloying, which would contribute to the stability of the material. Experimentally, the resulting Cs2Ag0.7Na0.3InCl6:Bi products demonstrate a remarkable stability under heat, ultraviolet light, and moisture conditions. The above advantages make it possible for this material to be used as solid-state phosphors for WLED applications, and the Commission International de I'Eclairage color coordinates at (0.38, 0.44), correlated color temperature of 4347 K, and high color rendering index of 87.8 were achieved. More importantly, the WLED demonstrates a remarkable operation stability in air ambient, and only 4.5% emission decay occurs after a long working time for 1000 h, the longest lifetime for perovskite-based WLEDs as far as we know.

Accurate Monitoring Platform for the Surface Catalysis of Nanozyme Validated by Surface-Enhanced Raman-Kinetics Model.

Surface-enhanced Raman scattering (SERS) is a supersensitive technique for monitoring catalytic reactions. However, building a SERS-kinetics model to investigate catalytic efficiency on the surface or interface of the catalyst remains a great challenge. In the present study, we successfully obtained an excellent semiconducting SERS substrate, reduced MnCo2O4 (R-MnCo2O4) nanotubes, whose favorable SERS sensitivity is mainly related to the promoted interfacial charge transfer caused by the introduction of oxygen vacancies as well as the electromagnetic enhancement effect. Furthermore, the R-MnCo2O4 nanotubes showed a favorable oxidase-like activity toward oxidation with the aid of molecular oxygen. It was also showed the oxidase-like catalytic process could be monitored using the SERS technique. A new SERS-kinetics model to monitor the catalytic efficiency of the oxidase-like reaction was developed, and the results demonstrate that the Vm values measured by the SERS-kinetics method are close to that obtained by the UV-vis approach, while the Km values measured by the SERS-kinetics method are much lower, demonstrating the better affinity between the enzyme and the substrate from SERS results and further confirming the high sensitivity of the SERS-kinetics approach and the actual enzyme-like reaction on the surface of nanozymes, which provides guidance in understanding the kinetics process and catalytic mechanism of natural enzymatic and other artificial enzymatic reactions. This work demonstrated the improved SERS sensitivity of defective semiconductors for the application of enzyme mimicking, providing a new frontier to construct highly sensitive biosensors.