Microstructure and Friction Properties of AlCrTiVNbx High-Entropy Alloys via Annealing Manufactured by Vacuum Arc Melting.

To enhance the friction and wear properties of alloys, AlCrTiVNbx high-entropy alloys (HEAs) with various Nb contents were prepared using the arc melting technique and then annealed at 1000 °C for 2 h. The microstructure and hardness changes in the AlCrTiVNbx (x = 0.3, 0.4, and 0.5) HEAs after casting and annealing were studied via scanning electron microscopy, X-ray diffractometry, optical microscopy and the Vickers hardness test. The MFT-EC400 ball disc reciprocating friction and wear tester was used to investigate the wear resistance of the HEAs before and after annealing. The results show that the annealed AlCrTiVNbx HEAs changed from a single-phase structure to a multi-phase structure, and the content of the face-center cubic (FCC) phase and hexagonal close-packed (HCP) phase further increases with the increase in Nb content. The hardness value of the annealed HEAs is greatly enhanced compared with the casting state, and the hardness of the Nb0.5 HEA is increased from 543 HV to 725 HV after annealing. The wear resistance of the alloys after the annealing treatment is also greatly improved, among which Nb0.5 has the best wear resistance. The average friction coefficient of Nb0.5 is 0.154 and the wear rate is 2.117 × 10-5 mm3/(N·m). We believe that the precipitation strengthening after the annealing treatment and the lubrication effect of the FCC phase are the reasons for the significant improvement in wear resistance. The morphology of the samples indicates that the wear mechanism of the alloy includes adhesive wear, abrasive wear and a certain degree of oxidation wear.

USP25 ameliorates diabetic nephropathy by inhibiting TRAF6-mediated inflammatory responses.

Diabetic kidney disease (DKD) is a common diabetic vascular complication affecting nearly 40% of patients with diabetes. The lack of efficacious therapy for DKD necessitates the in-depth investigation of the molecular mechanisms underlying the pathogenesis and progression of DKD, which remain incompletely understood. Here, we discovered that the expression of USP25, a deubiquitinating enzyme, was significantly upregulated in the kidney of diabetic mice. Ablation of USP25 had no influence on glycemic control in type 1 diabetes but significantly aggravated diabetes-induced renal dysfunction and fibrosis by exacerbating inflammation in the kidney. In DKD, USP25 was mainly expressed in glomerular mesangial cells and kidney-infiltrating macrophages. Upon stimulation with advanced glycation end-products (AGEs), USP25 markedly inhibited the production of proinflammatory cytokines in these two cell populations by downregulating AGEs-induced activation of NF-κB and MAPK pathways. Mechanistically, USP25 interacted with TRAF6 and inhibited its K63 polyubiquitination induced by AGEs. Collectively, these findings identify USP25 as a novel regulator of DKD.

OTUB1 inhibits breast cancer by non-canonically stabilizing CCN6.

BACKGROUND: CCN6 is a matricellular protein that critically regulates the tumourigenesis and progression of breast cancer. Although the tumour-suppressive function of CCN6 has been extensively studied, molecular mechanisms regulating protein levels of CCN6 remain largely unclear. This study aims to investigate the regulation of CCN6 by ubiquitination and deubiquitinating enzymes (DUBs) in breast cancer. METHODS: A screening assay was performed to identify OTUB1 as the DUB for CCN6. Various biochemical methods were applied to elucidate the molecular mechanism of OTUB1 in the regulation of CCN6. The role of OTUB1-CCN6 interaction in breast cancer was studied with cell experiments and the allograft model. The correlation of OTUB1 and CCN6 in human breast cancer was determined by immunohistochemistry and Western blot. RESULTS: We found that CCN6 protein levels were controlled by the ubiquitin-proteasome system. The K48 ubiquitination and degradation of CCN6 was inhibited by OTUB1, which directly interacted with CCN6 through its linker domain. Furthermore, OTUB1 inhibited the ubiquitination of CCN6 in a non-canonical manner. Deletion of OTUB1, concomitant with reduced CCN6 abundance, increased the migration, proliferation and viability of breast cancer cells. Supplementation of CCN6 abolished the effect of OTUB1 deletion on breast cancer. Importantly, OTUB1 expression was downregulated in human breast cancer and positively correlated with CCN6 levels. CONCLUSION: This study identified OTUB1 as a novel regulator of CCN6 in breast cancer.

In-Situ Silica Xerogel Assisted Facile Synthesis of Fe-N-C Catalysts with Dense Fe-Nx Active Sites for Efficient Oxygen Reduction.

In the past decade, atomically dispersed Fe active sites (coordinated with nitrogen) on carbon materials (FeNC) have emerged rapidly as promising single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) to substitute precious group metal (PGM) catalysts, owing to their earth abundance and low cost. Nonetheless, the production of highly active FeNC SACs is largely restricted by material cost, low product yield and difficulty of microstructure design. Herein, the authors demonstrate a facile in-situ xerogel (ISG) assisted synthetic strategy, using cheap materials, to construct FeNC SACs (ISG FeNC). The porous silica xerogel, formed in-situ with the FeNC precursors, encourages the emergence of enormous micropores/mesopores and homogeneous confinement/protection to the precursors during pyrolysis, benefiting to the formation of abundant accessible active sites (27.6 × 1019 sites g-1 ). Correspondingly, the ISG FeNC exhibits excellent ORR activity with a half-wave potential (E1/2  = 0.91 V) in alkaline medium. The Zn-air battery assembled using the ISG FeNC SACs as the bifunctional catalyst of air cathode, demonstrates commendable performance with high peak power density of 249.1 mW cm-2 and superior long-term stability (660 cycles with 220 h). This work offers an economic and efficient way to fabricate PGM-free SACs for diverse applications.

Composition-Dependent Aspect Ratio and Photoconductivity of Ternary (BixSb1-x)2S3 Nanorods.

The chemical composition, size and shape, and surface engineering play key roles in the performance of electronic, optoelectronic, and energy devices. V2VI3 (V = Sb, Bi; VI = S, Se) group materials are actively studied in these fields. In this paper, we introduce a colloidal method to synthesize uniform ternary (BixSb1-x)2S3 (0 < x < 1) nanorods. These nanorods show composition-dependent aspect ratios, enabling their composition, size, and shape control by varying Bi/Sb precursor ratios. It is found that the surface passivation by various thiols (L-SH) efficiently enhances the photoconductivity and optical responsive capability of (BixSb1-x)2S3 nanorods when used as active materials in indium tin oxide (ITO)/(BixSb1-x)2S3/ITO optoelectronic devices. Meanwhile, the increase of Sb content causes a gradual deterioration of photoconductivity of thiol-passivated nanorods. We propose that the thiol passivation is able to reduce the number of S vacancies, which act as the recombination centers (trapped states) for photogenerated electrons and holes, and thus boosts the carrier transport in (BixSb1-x)2S3 nanorods, and in particular that the composition-related conductivity deterioration is attributed to the increase of unpassivated S vacancies and surface oxidation due to the rise of Sb content.

A characterization of structural proteins expressed by Bombyx mori bidensovirus.

Bombyx mori bidensiovirus (BmBDV) is a species of Bidensovirus that has been was placed into a new genus within the new family Bidnaviridae by the International Committee on Taxonomy of Viruses. BmBDV causes fatal flacherie disease in silkworms, which causes large losses to the sericulture industry. BmBDV contains two sets of complementary linear single-stranded DNAs of approximately 6.5kb (viral DNA 1, VD1) and 6.0kb (viral DNA 2, VD2). VD1 and VD2 are encapsidated in separate icosahedral non-enveloped capsids, which are similar in size and shape. However, the strategies used to express BmBDV structural proteins remains unclear. In this work, a total of six structural proteins were separated by two-dimensional electrophoresis and shown to be encoded by the BmBDV VP gene via mass spectrometry. The transmission electron microscopy results showed that co-expression of the BmBDV VP and SP structural proteins in Spodoptera frugiperda sf9 cells resulted in the formation of 22-24nm virus-like particles. Furthermore, a mutation of the major structural protein-encoding VP gene, in which the second in-frame ATG codon was mutated to GCG, abrogated the production of several structural proteins, indicating that this strategy of expressing BmBDV VP is dependent on a leaky scanning translation mechanism.

Morphological synthesis of Prussian blue analogue Zn3[Fe(CN)6]2⋠xH2O micro-/nanocrystals and their excellent adsorption performance toward methylene blue.

Prussian blue analogue Zn3[Fe(CN)6]2⋅xH2O (Zn-PBA) micro-/nanocrystals with well-defined spherical, cubic and polyhedral morphologies have been successfully synthesized by a simple room-temperature solution method. The morphologies and sizes of the micro-/nanocrystals can be easily tuned by HCl dosage and polymer additive. The as-prepared products are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis and Brunauer Emmet Teller adsorption-desorption analysis. The possible formation mechanism for these Zn-PBA micro-/nanocrystals is then proposed. In addtion, adsorption performances of these micro-/nanocrystals toward organic dyes are systematically investigated. It is demonstrated that they exhibit strong adsorption selectivity to methylene blue (MB) with an extraordinary adsorption capacity as high as 1.016gg(-1) due to the proper pore size and large specific surface area (643.2m(2)g(-1)) of the product as well as the strong electrostatic interaction between MB molecules and Zn-PBA particles. It is found that the morphology and size of the micro-/nanocrystals have an important effect on their adsorption performance. Moreover, the adsorbed MB dye can be well released in some organic solvents such as ethanol and trichloromethane. The facile morphology-controlled synthesis and excellent adsorption property afford the materials promising application in adsorption related fields.

Facile synthesis of magnetically separable reduced graphene oxide/magnetite/silver nanocomposites with enhanced catalytic activity.

In this study, the combination of magnetite (Fe3O4) with reduced graphene oxide (RGO) generates a new hybrid substrate for the dispersion of noble metal nanoparticles. Well-dispersed silver (Ag) nanoparticles loaded on the surface of Fe3O4 modified RGO are achieved by an efficient two-step approach. Through reducing Ag(+) ions, highly dispersed Ag nanoparticles are in-situ formed on the RGO/Fe3O4 substrate. It is found that the existence of Fe3O4 nanocrystals can significantly improve the dispersity and decrease the particle size of the in-situ formed Ag nanoparticles. Magnetic study reveals that the as-prepared RGO/Fe3O4/Ag ternary nanocomposites display room-temperature superparamagnetic behavior. The catalytic properties of the RGO/Fe3O4/Ag ternary nanocomposites were evaluated with the reduction of 4-nitrophenol into 4-aminophenol as a model reaction. The as-synthesized RGO/Fe3O4/Ag ternary catalysts exhibit excellent catalytic stability and much higher catalytic activity than the corresponding RGO/Ag catalyst. Moreover, the RGO/Fe3O4/Ag catalysts can be easily magnetically separated for reuse. This study further demonstrates that nanoparticles modified graphene can act as an effective hybrid substrate for the synthesis of multi-component and multifunctional graphene-based composites.

Tuning the morphology of g-C3N4 for improvement of Z-scheme photocatalytic water oxidation.

Solar-driven water oxidation is the key step for overall water splitting that efficiently harvests and converts solar energy into fuels; the development of a highly efficient photocatalyst that can mediate water oxidation has become an appealing challenge. Herein, we report a facile two-step process to decorate silver phosphate (Ag3PO4) particles on different types of graphitic carbon nitrides (g-C3N4) as composite photocatalysts for water oxidation. For all the Ag3PO4/g-C3N4 materials, an in situ Z-scheme is created by the generation of Ag nanoparticles which act as a cross-linking bridge between Ag3PO4 and g-C3N4 in the composite, resulting in better charge separation and higher catalytic performance. A detailed analysis emphasizes the importance of the g-C3N4 on the chemical, photophysical, and catalytic properties of the composite materials. Our results show that the alteration of the morphology dominates the performance of the composite materials.

Porous NiCo2O4 nanosheets/reduced graphene oxide composite: facile synthesis and excellent capacitive performance for supercapacitors.

A composite with porous NiCo2O4 nanosheets attached on reduced graphene oxide (RGO) sheets is synthesized through a facile solution-based method combined with a simple thermal annealing process. The capacitive performances of the as-prepared NiCo2O4/RGO (NCG) composites as electrode materials are investigated. It is found that the NCG composites exhibit a high specific capacitance up to 1186.3 F g(-1) at the current density of 0.5 A g(-1), and superior cycling stability with about 97% of the initial capacitance after 100 cycles. The greatly enhanced capacitive performance of the NCG electrode can be attributed to the existence of RGO support, which serves as both conductive channels and active interface. The approach used in the synthesis provides a facile route for preparing graphene-binary metal oxide electrode materials. The remarkable capacitive performance of NCG composites will undoubtedly make them be attractive for high performance energy storage applications.

[Related research on mechanical property of valve membrane in transcatheter bioprosthesis valve based on the chemical modification and cutting technology].

The aim of this research is to investigate the preparation method of valve membrane in transcatheter bio- prosthetic valve, and to study the effect of chemical modification and cutting technology to tensile property and suture force property of valve membrane. We carried out a series of processes to perform the tests, such as firstly to test the crosslinking degree of valve membrane using ninhydrin method, then to test the tensile property and suture force property by using Instron's biomechanicAl testing equipment, and then to observe the collagen fiber orientation in valve membrane using Instron's biomechanical testing equipment and using field emission scanning electron microscopy. The study indicated that after the chemical modification, the crosslinking degree, tensile strength and suture force strength increasing rate of valve membrane were 93.78% ± 3. 2%, (8.24 ± 0.79) MPa, 102%, respectively. The valve membrane had a better biomechanical property and would be expected to become valve membrane in transcatheter bioprosthesis valve.

Anchoring noble metal nanoparticles on CeO2 modified reduced graphene oxide nanosheets and their enhanced catalytic properties.

The strategy of structurally integrating noble metal, metal oxide, and graphene is expected to offer prodigious opportunities toward emerging functions of graphene-based nanocomposites. In this study, we develop a facile two-step approach to disperse noble metal (Pt and Au) nanoparticles on the surface of CeO2 functionalized reduced graphene oxide (RGO) nanosheets. It is shown that Pt and Au with particle sizes of about 5 and 2nm are well dispersed on the surface of RGO/CeO2. The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 was used as a model reaction to quantitatively evaluate the catalytic properties of the as-synthesized RGO/Pt/CeO2 and RGO/Au/CeO2 ternary nanocomposites. In such triple-component catalysts, CeO2 nanocrystals provide unique and critical roles for optimizing the catalytic performance of noble metallic Pt and Au, allowing them to express enhanced catalytic activities in comparison with RGO/Pt and RGO/Au catalysts. In addition, a possible mechanism for the enhanced catalytic activities of the RGO/Pt/CeO2 and RGO/Au/CeO2 ternary catalysts in the reduction of 4-NP is proposed. It is expected that our prepared graphene-based triple-component composites, which inherit peculiar properties of graphene, metal oxide, and noble metal, are attractive candidates for catalysis and other applications.

Solution-phase catalytic synthesis, characterization and growth kinetics of Ag2S-CdS matchstick-like heteronanostructures.

A facile catalytic growth route was developed for the low-temperature solution synthesis of Ag2S-CdS matchstick-like heteronanostructures in oleylamine, which are composed of a Ag2S spherical head and a CdS rod-like stem. Ag2S nanoseeds acted as an effective catalyst for the growth of CdS nanorods and remained at the tip of the resultant nanorods, leading to the formation of Ag2S-CdS heterostructures with a matchstick shape. The diameter of the Ag2S heads and the length of the CdS stems could be easily controlled by varying the molar ratios of the Ag/Cd precursors. The differential scanning calorimetry (DSC) and variable-temperature X-ray diffraction (XRD) studies confirmed that Ag2S catalytic seeds underwent a phase change, that is, they were in a high-temperature superionic conducting cubic structure during the CdS nanorod growth and then converted to a low-temperature monoclinic crystal structure as the reaction was cooled to room temperature. The influence of synthetic temperature on the product morphology was investigated and the morphological evolution at different growth stages was monitored using transmission electron microscopy (TEM). Furthermore, the growth kinetics of the Ag2S-CdS matchstick-like heteronanostructures, including the dissolution, nucleation and growth of CdS within the Ag2S catalyst, was reasonably discussed on the basis of the structural characteristics of the superionic cubic Ag2S catalyst and the low solubility of CdS in Ag2S derived from the Ag2S-CdS binary phase diagram.

Solution-solid-solid mechanism: superionic conductors catalyze nanowire growth.

The catalytic mechanism offers an efficient tool to produce crystalline semiconductor nanowires, in which the choice, state, and structure of catalysts are active research issues of much interest. Here we report a novel solution-solid-solid (SSS) mechanism for nanowire growth catalyzed by solid-phase superionic conductor nanocrystals in low-temperature solution. The preparation of Ag2Se-catalyzed ZnSe nanowires at 100-210 °C is exampled to elucidate the SSS model, which can be extendable to grow other II-VI semiconductor (e.g., CdSe, ZnS, and CdS) nanowires by the catalysis of nanoscale superionic-phase silver or copper(I) chalcogenides (Ag2Se, Ag2S, and Cu2S). The exceptional catalytic ability of these superionic conductors originates from their structure characteristics, known for high-density vacancies and fast mobility of silver or copper(I) cations in the rigid sublattice of Se(2-) or S(2-) ions. Insights into the SSS mechanism are provided based on the formation of solid solution and the solid-state ion diffusion/transport at solid-solid interface between catalyst and nanowire.

The competition between template growth and catalytic growth of one-dimensional ZnS nanostructures: nanobelts or nanowires.

Template growth and catalytic growth are two typical mechanisms for the solution-chemistry synthesis of one-dimensional (1D) II-VI semiconductor nanomaterials. Here, we systematically demonstrate the competition relationship between them by tuning the synthesis of 1D ZnS nanostructures in different chain-length primary alkyl-amines. The template growth, derived from the coordination effect of amines, produces ZnS nanobelts and will compete with the Ag2S-catalyzed mechanism as AgNO3 is added into these amines. In short-chain n-propylamine and n-butylamine the template growth is much stronger than the catalytic growth, leading to the morphology maintenance of ZnS nanobelts, whereas the latter replaces the former in long-chain n-octylamine and n-dodecylamine due to the decrease of coordination ability of amines, which yields ZnS nanowires instead of nanobelts. A balance of competition is built between these two mechanisms in middle-length n-hexylamine, producing a mixture of ZnS nanobelts and nanowires. The morphology and growth mechanism changes of ZnS nanostructures have been rationally investigated using various characterization techniques. Meanwhile, the optical properties of the products synthesized before and after adding AgNO3 are comparatively studied by UV-vis absorption and photoluminescence (PL) spectra.

Synthesis of reduced graphene oxide/CeO2 nanocomposites and their photocatalytic properties.

With a unique structure and extraordinary properties, graphene has attracted tremendous attention in the preparation of graphene-based composites for various applications. In this study, two different strategies, including in situ growth and a self-assembly approach, have been developed to load CeO2 nanoparticles onto reduced graphene oxide (RGO) nanosheets. The microstructure and morphology of the as-synthesized RGO/CeO2 nanocomposites were investigated by x-ray diffraction, Raman spectroscopy and transmission electron microscopy. The results reveal that CeO2 nanoparticles with well-controlled size and a uniform distribution on RGO sheets with tunable density can be achieved through the self-assembly approach. The significantly enhanced photocatalytic activity of the RGO/CeO2 nanocomposites in comparison with bare CeO2 nanoparticles was revealed by the degradation of methylene blue under simulated sunlight irradiation, which can be attributed to the improved separation of electron-hole pairs and enhanced adsorption performance due to the presence of RGO. A suitable loading content of CeO2 on RGO was found to be crucial for optimizing the photocatalytic activity of the nanocomposites. It is expected that this convenient assembly approach with high controllability can be extended to the attachment of other functional nanoparticles to RGO sheets, and the resultant RGO-supported highly dispersed nanoparticles are attractive for catalysis, sensing and power source applications.

In situ growth of Ni(x)Co(100-x) nanoparticles on reduced graphene oxide nanosheets and their magnetic and catalytic properties.

Ni(x)Co(100-x) (x = 0, 25, 50, 75, and 100) nanoparticles were uniformly in situ grown on reduced graphene oxide (RGO) nanosheets by a coreduction process for the first time. The as-synthesized products were characterized by X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectrometry (ICP-OES), and transmission electron microscopy (TEM). It was found that RGO nanosheets can effectively prevent the aggregation of Ni(x)Co(100-x) nanoparticles. The size and morphology of the Ni(x)Co(100-x) nanoparticles on RGO nanosheets can be slightly adjusted by changing the Ni:Co atomic ratio. The magnetic properties of the RGO-Ni(x)Co(100-x) composites were investigated at 300 and 1.8 K, respectively. The results reveal that the composites have ferromagnetic characteristics and show composition dependent magnetic properties. In addition, these RGO-Ni(x)Co(100-x) nanocomposites also exhibit enhanced catalytic activities toward the reduction of 4-nitrophenol (4-NP) by NaBH(4) as compared with bare Ni(x)Co(100-x) alloy, and the RGO-Ni(25)Co(75) shows the highest catalytic activity among the obtained nanocomposites. This general and facile coreduction route can be extended to synthesize other alloy nanostructures on RGO nanosheets with various morphologies and functions, and provides a new opportunity for the application of graphene-based materials.

Pain reduction of acupoint electrical stimulation for patients with spinal surgery: a placebo-controlled study.

BACKGROUND: Acupoint electrical stimulation (AES) is commonly used for pain management. However, its true or placebo effect to achieve pain relief needs to be verified. OBJECTIVE: This study aimed to examine the true effect of AES to reduce postoperative pain in patients with spinal surgery receiving patient-controlled analgesia (PCA). METHOD: A placebo- and sham-controlled study was conducted. Participants were randomly assigned to intervention with AES at true acupoints (the AES group, n=30), AES at sham acupoints (the sham group, n=30), or no intervention with AES (the control group, n=30). Outcomes were assessed according to the amount of pain experienced and analgesics used. RESULTS: There were significant differences among the three groups in pain relief across time, and the occurrence of PCA button pushed and amount of analgesics used. The beneficial effects of AES were discernible when compared to the sham and the control. CONCLUSIONS: AES at the true acupoints effectively reduced postoperative pain and analgesic usage. AES has now been implemented into healthcare and it is recommended that nurses be provided with the opportunity to earn their AES skills. More studies evaluating the effects of AES over a longer period and on pain after different surgical procedures are suggested.

[Effectiveness of nursing instruction in reducing uncertainty, anxiety and self-care in breast cancer women undergoing initial chemotherapy].

BACKGROUND: Level of uncertainty and anxiety may increase when breast cancer women experience unexpected side effects during chemotherapy. PURPOSE: This longitudinal study explored the effectiveness of nursing instruction in reducing uncertainty, anxiety and self-care in breast cancer women undergoing initial chemotherapy. METHODS: This study used a quasi-experimental design. Convenience sampling was used to recruit 75 women with breast cancer at a medical centre in northern Taiwan between January 2008 and September 2008. Participants were divided into either the control (n=37) or experimental (n=38) group. Control group patients received usual care. Experimental group patients were provided with nursing instructions that followed the evidence-based guidelines prescribed in the "Chemotherapy Self-Care for Breast Cancer" handbook and individualized education. Both groups received repeated questionnaires in the first, third and sixth chemotherapy cycles. Demographic data, Mishel's Uncertainty Illness Scale, Hospital Anxiety and Depression Scale and the Self-Care Scale were used for data collection and analysis. RESULTS: There were no significant differences in demographic data between the two groups. There were moderate to high levels of uncertainty and low levels of anxiety in both groups prior to the first chemotherapy cycle. There was a significant decrease in uncertainty and an elevation in self-care level (p<.05*) in both groups at the sixth chemotherapy cycle. However, the experimental group showed less uncertainty and higher levels of self-care in comparison with the control group. There was a significant decrease in complexity uncertainty in the experimental group (p=.02*) and no significant decrease in the control group. CONCLUSIONS: Study results indicate that nursing instruction can decrease uncertainty and elevate self-care levels. We suggest that nurses provide structured nursing instructions based on evidence-based guidelines to breast cancer women undergoing initial chemotherapy in order to promote self-care level and patient degree of control over their disease and treatment. This intervention may ameliorate patient and family uncertainties with regard to disease and chemotherapy complexity.

Structure and mechanical properties of pincers of lobster (Procambarus clarkii) and crab (Eriocheir Sinensis).

The structure and mechanical properties of the pincer exoskeletons (cuticles) of lobster (Procambarus clarkii) and crab (Eriocheir Sinensis) were investigated, respectively. The microstructures and inorganic materials of the pincer exoskeletons were observed and determined using a scanning electron microscope and X-ray diffraction. The mechanical properties of the pincer exoskeletons were evaluated by nano-indentation tests and tensile tests under different conditions. The results showed that the inorganic materials in the lobster claw exoskeleton exhibited an amorphous structure, while those in the crab claw exoskeleton were crystallized as calcium carbonate with a calcite crystal structure and were stable at the temperature below 250 degrees C. The surfaces of the pincers were biologically unsmooth. Many concave valleys with setae near the tip and many convex domes far off the tip were observed on the surface of the lobster pincer, while many micro-spines were seen on the surface of crab pincer. The microstructures of the pincer exoskeleton exhibited highly mineralized chitin-protein fibers arranged in a twisted plywood structure. The surface hardness and elastic modulus of the crab claws were 0.33 GPa and 8.18 GPa, respectively, higher than those of the lobster claw (0.27 and 5.44 GPa). The transition in the mechanical properties and structure between the exocuticle and the endocuticle was discontinuity. The tensile strength of the crab pincer was two times higher than that of the lobster pincer, and the dry specimen was fractured more easily than the fresh specimen.