A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury.

JOURNAL/nrgr/04.03/01300535-202502000-00028/figure1/v/2024-05-28T214302Z/r/image-tiff Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI (QK) are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases. However, conventional topical drug delivery often results in a burst release of the drug, leading to transient retention (inefficacy) and undesirable diffusion (toxicity) in vivo. Therefore, a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke. Matrix metalloproteinase-2 (MMP-2) is gradually upregulated after cerebral ischemia. Herein, vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG (TIMP) and customizable peptide amphiphilic (PA) molecules to construct nanofiber hydrogel PA-TIMP-QK. PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro. The results indicated that PA-TIMP-QK promoted neuronal survival, restored local blood circulation, reduced blood-brain barrier permeability, and restored motor function. These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

Magnetic Field-induced Disordered Phase of Spinel Oxides for High Battery Performance.

The disordered phase of spinel LiMn1.5Ni0.5O4 (LNMO) is more appealing as high-voltage cathode due to its superior electrochemical performance compared to its ordered counterpart. Various methods are developed to induce a phase transition. However, the resulting materials often suffer from capacity degradation due to the adverse influence of accompanying Mn3+ ions. This study presents the utilization of local magnetic fields generated by a magnetic Fe3O4 shell to induce a disordered phase transition in LNMO at lower temperature, transitioning it from an order state without significantly increasing the Mn3+ content. The pivotal role played by the local magnetic fields is evidenced through comparisons with samples with nonmagnetic Al2O3 shell, samples subjected to sole heat treatment, and samples heat-treated within magnetic fields. The key finding is that magnetic fields can initiate a radical pair mechanism, enabling the induction of order-disorder phase transition even at lower temperatures. The disordered spinal LNMO with a magnetic Fe3O4 shell exhibits excellent cycling stability and kinetic properties in electrochemical characterization as a result. This innovation not only unravels the intricate interplay between the disordered phase and Mn3+ content in the cathode spinel but also pioneers the use of magnetic field effects for manipulating material phases.

Unveiling the airborne microbial menace: Novel insights into pathogenic bacteria and fungi in bioaerosols from nursery schools to universities.

Bacterial and fungal aerosol pollution is widespread in indoor school environments, and poses potential health risks to students and staff. Understanding the distribution and diversity of microbial communities within aerosols is crucial to mitigate their adverse effects. Existing knowledge regarding the composition of bacterial and fungal aerosols, particularly the presence of potential pathogenic microorganisms in fine particulate matter (PM2.5) from nursery schools to universities, is limited. To bridge this knowledge gap, in the present study, we collected PM2.5 samples from five types of schools (i.e., nursery schools, primary schools, junior schools, and high schools and universities) in China. We used advanced single-molecule real-time sequencing to analyze the species-level diversity of bacterial and fungal components in PM2.5 samples based on 16S and ITS ribosomal genes, respectively. We found significant differences in microbial diversity and community composition among the samples obtained from different educational institutions and pollution levels. In particularly, junior schools exhibited higher PM2.5 concentrations (62.2-86.6 µg/m3) than other schools (14.4-48.4 µg/m3). Moreover, microbial variations in PM2.5 samples were associated with institution type. Notably, the prevailing pathogenic microorganisms included Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Streptococcus pneumoniae, and Schizophyllum commune, all of which were identified as Class II Pathogenic Microorganisms in school settings. Four potentially novel strains of S. commune were identified in PM2.5 samples collected from the university; the four strains showed 92.4 %-94.1 % ITS sequence similarity to known Schizophyllum isolates. To the best of our knowledge, this is the first study to explore bacterial and fungal diversity within PM2.5 samples from nursery schools to universities. Overall, these findings contribute to the existing knowledge of school environmental microbiology to ensure the health and safety of students and staff and impacting public health.

Bi-functional KIT-PR1P peptides combine with VEGF to protect ischemic kidney in rats by targeting to Kim-1.

Introduction: Acute kidney injury (AKI) was a disease with a high mortality mainly caused by renal ischemia/reperfusion injury (I/R). Although the current non-targeted administration of vascular endothelial growth factor (VEGF) for AKI had been revealed to facilitate the recovery of renal I/R, how to targeted deliver VEGF and to retain it efficiently in the ischemic kidney was critical for its clinical application. Methods: In present study, bi-functional KIT-PR1P peptides were constructed which bond VEGF through PR1P domain, and targeted ischemic kidney through KIT domain to interact with biomarker of AKI-kidney injury molecule-1 (Kim-1). Then the targeted and therapeutic effects of KIT-PR1P/VEGF in AKI was explored in vitro and in vivo. Results: The results showed KIT-PR1P exhibited better angiogenic capacity and targeting ability to hypoxia HK-2 cells with up-regulated Kim-1 in vitro. When KIT-PR1P/VEGF was used for the treatment of renal I/R through intravenous administration in vivo, KIT-PR1P could guide VEGF and retain its effective concentration in ischemic kidney. In addition, KIT-PR1P/VEGF promoted angiogenesis, alleviated renal tubular injury and fibrosis, and finally promoted functional recovery of renal I/R. Conclusion: These results indicated that the bi-functional KIT-PR1P peptides combined with VEGF would be a promising strategy for the treatment of AKI by targeting to Kim-1.

Development of Laser Processing Carbon-Fiber-Reinforced Plastic.

Due to its exceptional advantages, such as high specific strength, high specific modulus, and good fatigue resistance, carbon-fiber-reinforced plastic (CFRP) is frequently utilized in aerospace, aviation, automotive, rail transportation, and other areas. Composite components typically need to be joined and integrated. In the equipment manufacturing industry, the most used methods for processing composite components are cutting, drilling, and surface treatment. The quality of CFRP is significantly impacted by traditional mechanical processing, causing flaws like delamination, burrs, and tears. Laser processing technology has emerged as a crucial method for processing CFRP for its high quality, non-contact, simple control, and automation features. The most recent research on the laser processing of CFRP is presented in this paper, supporting scientists and engineers who work in the field in using this unconventional manufacturing technique. This paper gives a general overview of the key features of laser processing technology and the numerous machining techniques available. The concepts and benefits of laser processing technology are discussed in terms of the material properties, mode of operation, and laser characteristics, as well as the methods to achieve high efficiency, low damage, and high precision. This paper reviews the research development of laser processing of carbon-fiber-reinforced plastics, and a summary of the factors affecting the quality of CFRP laser processing. Therefore, the research content of this article can be used as a theoretical basis for reducing thermal damage and improving the processing quality of laser-processed composite materials, while, on this basis, we analyze the development trend of CFRP laser processing technology.

Development of the Cultural Tightness-Looseness Orientation Scale for College Students.

Background: "The cultural tightness-looseness orientation of college students", which involves college students' cognition about tolerance for non-learning-behavior in class, strength of learning-behavior norms in class, and strength of social norms in the generalized macro-context, offers a new perspective to explain college students' psychology and behavior and could effectively promote their all-round development. However, there is severely lack of a reliable and valid instrument. Hence, we seek to develop the Cultural Tightness-Looseness Orientation Scale for College Students (CTLOS-S) in the Chinese context. Methods: We firstly pooled the initial 17 measuring items of CTLOS-S through literature review and the open-ended interview. After conducting questionnaire survey among 264 college students using the initial scale, we did a series of reliability and validity tests to get the formal CTLOS-S, based on which we further administered questionnaire survey among 755 college students to check its reliability, construct validity, criterion validity, content validity, and across-gender invariance. Results: The formal CTLOS-S contains 7-item subscale of tolerance orientation for non-learning-behavior in class, 4-item subscale of strength orientation of learning-behavior norms in class, and 3-item subscale of strength orientation of social norms in the generalized macro-context. The testing results of the second-stage questionnaire survey data (N = 755) demonstrate that the reliability coefficients of CTLOS-S and its three subscales are 0.85, 0.85, 0.83, and 0.76 separately, the internal 3-factor structure validity of CTLOS-S is satisfactorily acceptable with χ 2(74) = 318.76, CFI = 0.94, TLI = 0.93, RMSEA = 0.06, and SRMR = 0.04, and the content validity and criterion validity are satisfactory as the total score of CTLOS-S is positively correlated with each score of its three subscales and the total score of learning engagement scale. Besides, the 3-factor structure of CTLOS-S is invariant across gender. Conclusion: The 14-item CTLOS-S we develop is a reliable and valid instrument for researchers to conduct quantitative studies on college students' cultural tightness-looseness orientation.

Fracture Closure Empirical Model and Theoretical Damage Model of Rock under Compression.

The rock or rock mass in engineering often contains joints, fractures, voids, and other defects, which are the root cause of local or overall failure. In response to most of the current constitutive models that fail to simulate the nonlinear fracture compaction deformation in the whole process of rock failure, especially brittle rocks, a piecewise constitutive model was proposed to represent the global constitutive relation of rocks in this study, which was composed of the fracture compaction empirical model and the damage statistical constitutive model. The fracture empirical compaction model was determined by fitting the expressions of fracture closure curves of various rocks, while the rock damage evolution equation was derived underpinned by the fracture growth. According to the effective stress concept and strain equivalence hypothesis, the rock damage constitutive model was deduced. The model parameters of the fracture compaction empirical model and damage statistical constitutive model were all calculated by the geometrical characteristics of the global axial stress-strain curve to guarantee that the models are continuous and smooth at the curve intersection, which is also simple and ready to program. Finally, the uniaxial compression test data and the triaxial compression test data of different rocks in previous studies were employed to validate the models, and the determination coefficient was used to measure the accuracy. The results showed great consistency between the model curves and test data, especially in the pre-peak stage.

Detrimental Effect of the Characteristic-Human-Capital-Inputs-Based Horizontal Pay Dispersion on Team Member Work Role Performance via Employee Benign and Malicious Envy: An Evidence from China.

Purpose: Pay for employee characteristic human capital inputs, which results in part of horizontal pay dispersion (HPD) and is well acknowledged by organizations and employees, has been greatly ignored by scholars. This study proposes "the characteristic-human-capital-inputs-based HPD" and explores what impact it tends to exert on team member work role performance (TMWRP), why, and when. Drawing on social comparison theory, goal-setting theory, and self-regulatory depletion theory, we develop a dual-mediation model elaborating the detrimental effect of this type of HPD on TMWRP from the perspective of employee benign and malicious envy and test it using objective and subjective data of 364 members coming from 65 Chinese ordinary employee teams. Methods: We on-site collected objective data including each member's pay level, outcome performance, and characteristic human capital inputs. Using five-point Likert rating method, team supervisors were requested to evaluate each member's TMWRP and members were asked to self-rate benign and malicious envy. Hierarchical regression analysis, simple slope analysis, and bootstrapping approach were employed to verify the model. Results: The characteristic-human-capital-inputs-based HPD adversely affects TMWRP by reducing employee benign envy (the mediating effect=-0.053, 95% CI=[-0.111, -0.002], excluding 0) and enhancing employee malicious envy (the mediating effect=-0.025, 95% CI=[-0.059, -0.004], excluding 0). The positive linkage between employee benign envy and TMWRP is only observed in lower-paid employees (the simple slope=0.145, p<0.05). Employee pay level does not moderate the relationship between malicious envy and TMWRP (ß=-0.033, p>0.10). Conclusion: The characteristic-human-capital-inputs-based HPD, which involves the HPD part mainly resulting from employee differences in characteristic human capital inputs, tends to impair TMWRP through inhibiting employee benign envy and promoting employee malicious envy. Employee pay level is an important boundary condition constraining the positive effect of benign envy on TMWRP.

Axonal Transport Impairment and its Relationship with Diffusion Tensor Imaging Metrics of a Murine Model of p301L Tau Induced Tauopathy.

Diffusion Tensor Imaging (DTI) and Manganese Enhanced MRI (MEMRI) are noninvasive tools to characterize neural fiber microstructure and axonal transport. A combination of both may provide novel insights into the progress of neurodegeneration. To investigate the relationship of DTI and MEMRI in white matter of tauopathy, twelve optic nerves of 11-month-old p301L tau mice were imaged and finished with postmortem immunohistochemistry. MEMRI was used to quantify Mn2+ accumulation rates in the optic nerve (ON, termed ONAR) and the Superior Colliculus (SC, termed SCAR), the primary terminal site of ON in mice. We found that both ONAR and SCAR revealed a significant linear correlation with mean diffusion (mD) and radial diffusion (rD) but not with other DTI quantities. Immunohistochemistry findings showed that ONAR, mD, and rD are significantly correlated with the myelin content (Myelin Basic Protein, p < 0.05) but not with the axonal density (SMI-31), tubulin density, or tau aggregates (AT8 staining). In summary, slower axonal transport appeared to have less myelinated axons and thinner remaining axons, associated with reduced rD and mD of in vivo DTI. A combination of in vivo MEMRI and DTI can provide critical information to delineate the progress of white matter deficits in neurodegenerative diseases.

Synthesis, preclinical evaluation, and first-in-human study of Al18F-PSMA-Q for prostate cancer imaging.

PURPOSE: To investigate the potential of a novel Al18F-labeled PSMA-targeted radiotracer for PCa diagnosis through both preclinical and pilot clinical studies. METHODS: Al18F-PSMA-Q was prepared automatically. The binding affinity to PSMA was evaluated in vitro using the 22Rv1 (PSMA +) and PC-3 (PSMA -) cell lines. Pharmacokinetics evaluation, biodistribution study, Micro-PET imaging of Al18F-PSMA-Q in normal mice and tumor-bearing mice, and a comparison with 18F-DCFPyL were performed. PET/CT imaging was performed on 8 healthy volunteers and 20 newly diagnosed PCa patients at 1 h post-injection (p.i.). The biodistribution in human and preliminary diagnostic efficacy of Al18F-PSMA-Q were evaluated, and the radiation dosimetry was estimated using OLINDA/EXM 2.0 software. RESULT: Qualified Al18F-PSMA-Q was efficiently prepared with a non-decay-corrected radiochemical yield (RCY) of 22.0-28.3%, a specific activity (SA) of > 50 GBq/µmol. The hydrophilicity was comparably high with a log P value of - 3.69 ± 0.39. Al18F-PSMA-Q was found to bind to PSMA specifically with a Ki value of 17.05 ± 1.14 nM. The distribution and elimination half-lives of Al18F-PSMA-Q were 3.93 min and 14.22 min, respectively, which were shorter than those of 18F-DCFPyL. Micro-PET imaging of Al18F-PSMA-Q can clearly differentiate 22Rv1 tumors from PC-3 tumors and background with a high SUVmax of 2.17 ± 0.42 and a tumor-to-muscle ratio of 84.37 ± 31.62, which were higher than those of 18F-DCFPyL (1.79 ± 0.39 and 13.25 ± 1.65). The uptake of Al18F-PSMA-Q in 22Rv1 cells and tumors can be substantially blocked by 2-PMPA. High level accumulation of Al18F-PSMA-Q was observed in organs physiologically expressing PSMA. Twenty-six tumor lesions were detected in 20 PCa patients, and the mean SUVmax values of primary tumors, lymph node metastasis, bone metastases, and tumor-muscle ratios were 19.71 ± 16.52, 5.11, 31.30 ± 29.85, and 44.77 ± 22.29, respectively. The mean SUVmax of tumors in patients with PSA > 10 ng/mL was significantly higher than that in patients with PSA ≤ 10 ng/mL (25.97 ± 18.64 vs. 10.33 ± 3.74). Meanwhile, the mean SUVmax of tumors in patients with a Gleason score ≥ 8 was significantly higher than that in patients with a Gleason score < 8 (31.85 ± 22.09 vs. 13.18 ± 11.58). The kidneys received the highest estimated dose of 0.098 ± 0.006 mGy/MBq, and the effective dose was calculated as 0.0128 ± 0.007 mGy/MBq. CONCLUSION: The novel qualified PSMA-targeted radiotracer Al18F-PSMA-Q was conveniently prepared with favorable yield and SA. The results of preclinical and pilot clinical studies exhibited a high specific uptake in PCa lesions and an excellent tumor-to-background ratio with a reasonable radiation exposure, which indicated the great potential of Al18F-PSMA-Q for PCa imaging. TRIAL REGISTRATION: Chinese Clinical trial registry ChiCTR2100053507, Registered 23 November 2021, retrospectively registered.

First complete mitochondrial genome of Antheraea pernyi Guérin-Méneville 1855 (Lepidoptera: Saturniidae) from North Korea.

This study reports the first complete mitochondrial genome of Antheraea pernyi Guérin-Méneville 1855 (Lepidoptera: Saturniidae) strain Dingzhou_1, a silkworm resource serving silk production in North Korea. The mitochondrial genome is circular with 15,573 bp in length encoding 37 typical mitochondrial genes (13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes). The 553-bp A + T-rich region harbors a repeat region composed of 6 ∼ 38 bp tandem repeat units, as found in other known inbred strains from Chinese populations. The phylogenetic analysis clustered Dingzhou_1 from North Korea together with Chinese Liaoning population, suggesting that oak silkworm in North Korea might be introduced from her neighbor China Liaoning.

Cognitive Dissonance of Self-Standards: A Negative Interaction of Green Compensation and Green Training on Employee Pro-Environmental Behavior in China.

PURPOSE: Studies of GHRM practices number in thousands; however, they have failed to provide Chinese contextual evidence for their interactive effects on employee pro-environmental behavior (EPEB). To bridge this research gap as well as to address organizational practitioners' concern in GHRM practices, our study explores the possible interactive effect of green compensation (GC) and green training (GT), which are two core practices of GHRM and are widely employed by Chinese organizations simultaneously, on EPEB drawing on self-determination theory, and unravels the underlying mechanism by introducing employee green self-accountability (EGSA) as a mediator based on the cognitive dissonance theory of self-standards. METHODS: Using on-line survey and five-point Likert rating method, employees (N=847) working in Chinese organizations were requested to self-rate GC, GT, and EGSA; their direct supervisors were invited to evaluate EPEB. The mediated moderation testing procedures with SPSS and the bootstrapping approach with MPLUS were adopted to test the mediated moderation. RESULTS: When being used separately, GC and GT are positively related to EPEB (ß=0.426, p < 0.001; ß=0.368, p < 0.001). When being adopted simultaneously, a negative relationship (the simple slope=-0.454, t=3.671, p=0.000) exists between GC and EPEB at higher-level GT. EGSA partially mediates the negative interaction with 95% bias-corrected confidence intervals [-0.054, -0.018]. CONCLUSION: In the Chinese context, when being used simultaneously with high-high combination, GC and GT negatively interact with each other to engender the squeezed effect of intrinsic motivation by extrinsic motivation, which directly impairs EPEB, and cause employee cognitive dissonance of self-standards, which indirectly weakens EPEB through reducing EGSA. This paper is an attempt to show novelty in identifying negative interactions between GC and GT in EPEB in China and a mediating role of EGSA. Additionally, it addresses organizational practitioners' concern well and provides important implications for decision-making in GHRM practices and EPEB enhancement.

Quasi-solid electrolyte developed on hierarchical rambutan-like γ-AlOOH microspheres with high ionic conductivity for lithium ion batteries.

Upgrading liquid electrolytes with all-solid-state electrolytes (ASEs) or quasi-solid-state electrolytes (QSEs) for solid-state batteries (SBs) have emerged not only to address the intrinsic disadvantages of traditional liquid lithium ion batteries, but also to offer more possibilities for the development of new battery chemistries. In this work, a novel rambutan-like yolk-shell-structured porous γ-AlOOH microsphere with a large specific surface area of 262.92 m2 g-1 was firstly obtained by a simple hydrothermal synthesis route, which was then utilized as a robust framework to assemble QSE via encapsulating abundant liquid electrolyte (LE). The obtained γ-AlOOH-QSE exhibits a high ionic conductivity of 4.0 × 10-3 S cm-1, a large lithium ion transference number (tLi+) of 0.76, as well as a wide electrochemical window of 4.72 V vs. Li/Li+. Moreover, the assembled cell of LiFePO4/γ-AlOOH-QSE/Li could maintain a high specific capacity of 144.4 mA h g-1 even after 120 cycles with almost negligible capacity decay, which could be mainly attributed to the excellent interfacial compatibility, prominent performance in suppressing lithium dendrite growth upon cycling (rigid characteristic), as well as the high ionic conductivity of γ-AlOOH-QSE (intrinsic advantage). This work could not only expand the applications of QSE with cost-effective aluminum-based oxides with facile fabrication strategy, but also will shed light on the construction of SEs with more integrated QSEs and ASEs in the field of advanced energy storage.

The complete mitochondrial genome of the wild silkmoth Antheraea yamamai from Heilongjiang, China (Lepidoptera: Saturniidae).

Here, we reported the complete mitochondrial genome of Antheraea yamamai Guérin-Méneville (1861) collected in Heilongjiang Province, China. The mitochondrial genome is 15,341 bp and encodes 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. Sequence comparison identified 22 SNVs in the A. yamamai mitochondrial genomes between Chinese and Korean populations, indicating a low intraspecific variation between the two populations . Phylogenetic analyses with maximum-likelihood and Bayesian inference methods revealed a close relationship between A. yamamai and Antheraea frithi and supported the relationship among Antheraea species (((A. yamamai + A. frithi) + A. pernyi) + A. assamensis).

Team Member Work Role Performance: The Organizational Benefits From Performance-Based Horizontal Pay Dispersion and Workplace Benign Envy.

In the context of the current uncertain, complex, and interdependent work systems, teams have become organizations' substantial working unit, which in turn challenges the traditional view of employee performance and ultimately results in the emergence of team member work role performance. Employee team-oriented work role behaviors with proficiency, adaptivity, and proactivity, which are integrated by the new construct, are so crucial to team effectiveness that many organizations keenly expect to achieve team member work role performance through implementing a dispersed pay-for-performance plan within a team. This study seeks to address the organizational practitioners' main concern that whether pay dispersion among team members (i.e., horizontal pay dispersion, HPD) could actually help realize team member work role performance and further examines why and when an employee could respond to HPD within a team by engaging in team member work role behaviors from the perspective of the performance-shaping basis and team member's workplace benign envy. Drawing on emotion-related theory, social comparison theory, legitimacy theory, expectation theory, and relative deprivation theory, it proposes that performance-based HPD could not only positively impact team member work role performance via workplace benign envy but also exert a direct-positive effect. Moreover, the activating effect of performance-based HPD on workplace benign envy and the mediating role are much stronger when a team member's pay position is higher. The multi-source data including objective information and subjective perception among 362 ordinary employees within 66 Chinese organizational teams primarily supported the moderated mediation model. Yet, the direct-positive effect was not established.

Zero-Sum Construal of Workplace Success Promotes Initial Work Role Behavior by Activating Prevention Focus: Evidence From Chinese College and University Graduates.

Given that the population of Chinese college and university graduates has become larger and larger year by year since 1999, the problem of individual graduate's employment and workplace adaptability has captured widespread social concern and interest from both scholars and practitioners. Initial work role behavior is essential to an individual graduate's successful adaptation to the workplace and sustainable career development as a new employee. Based on social cognition theory, sense-making theory, and regulatory focus theory, we argue that the individual graduate's zero-sum construal of workplace success is a key factor influencing his or her initial workplace adaptability, which not only directly augments initial work role behavior but also elicits the new employee's inclination toward prevention focus, which in turn enhances initial work role behavior in the context of China's present steady economic development. Moreover, the individual graduate's average pay level moderates the mediating effect of prevention focus, such that the higher the average pay level is, the stronger the positive effect of zero-sum construal on initial work role behavior via prevention focus becomes. Two-stage survey data from 258 Chinese university graduates who have already entered organizations as full-time employees and their direct supervisors provided evidence consistent with our hypothesized first-stage moderated mediation model. Implications, limitations, and future research suggestions are also discussed.

Evaluation of Femoral Head Perfusion by Contrast-Enhanced Ultrasound in a Rabbit Model of Steroid-Induced Osteonecrosis.

OBJECTIVES: To study the technical feasibility of contrast-enhanced ultrasound (CEUS) in evaluating femoral head perfusion in a rabbit model of steroid-induced femoral head osteonecrosis. METHODS: Twenty rabbits were divided randomly into a control group (n = 8) and an experimental group (n = 12). Rabbits in the experimental group were induced by lipopolysaccharide and methylprednisolone to build a model of steroid-induced femoral head osteonecrosis. Contrast-enhanced ultrasound examinations were performed at 3 and 5 weeks after induction. Then, pathologic examinations and microvessel density (MVD) calculations were performed on the excised rabbit femoral heads. RESULTS: The MVD of the experimental group decreased significantly 3 and 5 weeks after induction compared with that of the control group. According to the CEUS examination results, significant differences existed in the ascending slope, descending slope, mean transit time, and time to peak between the groups at 5 weeks (P < .05). A correlation analysis showed that the descending slope had a certain correlation with the MVD (correlation coefficient, 0.376). A receiver operating characteristic curve was used to analyze the capacity of the CEUS parameters to predict the occurrence of osteonecrosis. The areas under the curve for the ascending slope and descending slope were 0.758 and 0.760, respectively (P < .05). CONCLUSIONS: Contrast-enhanced ultrasound can visualize the microcirculation in steroid-induced osteonecrosis of the femoral head in rabbits and may be a useful imaging method for the early monitoring and prediction of femoral head osteonecrosis.

Removing Metal Ions from Water with Graphene⁻Bovine Serum Albumin Hybrid Membrane.

Here we report the fabrication of graphene oxide (GO)-based membranes covalently combined with bovine serum albumin (BSA) for metal ions detection. In this system, BSA acts as a transporter protein in the membrane and endows the membrane with selective recognition of Co2+, Cu2+, AuCl4-, and Fe2+. Combining the metal-binding ability of BSA and the large surface area of GO, the hybrid membrane can be used as a water purification strategy to selectively absorb a large amount of AuCl4- from HAuCl4 solution. Moreover, BSA could reduce the membrane-immobilized AuCl4- by adding sodium borohydride (NaBH4). Interestingly, adsorption experiments on three kinds of metal ions showed that the GO⁻BSA membrane had good selective adsorption of Co2+ compared with Cu2+ and Fe2+. The morphology and composition changes of the membrane were observed with atomic force microscopy (AFM) and Raman spectroscopy, respectively. It is expected that this facile strategy for fabricating large-scale graphene-biomolecule membranes will spark inspirations in the development of functional nanomaterials and wastewater purification.

Hierarchical nanomaterials via biomolecular self-assembly and bioinspiration for energy and environmental applications.

Bioinspired synthesis offers potential green strategies to build highly complex nanomaterials by utilizing the unique nanostructures, functions, and properties of biomolecules, in which the biomolecular recognition and self-assembly processes play important roles in tailoring the structures and functions of bioinspired materials. Further understanding of biomolecular self-assembly for inspiring the formation and assembly of nanoparticles would promote the design and fabrication of functional nanomaterials for various applications. In this review, we focus on recent advances in bioinspired synthesis and applications of hierarchical nanomaterials based on biomolecular self-assembly. We first discuss biomolecular self-assembly towards biological nanomaterials, in which the mechanisms and ways of biomolecular self-assembly as well as various self-assembled biomolecular nanostructures are demonstrated. Secondly, the bioinspired synthesis strategies including molecule-molecule interaction, molecule-material recognition, molecule-mediated nucleation and growth, and molecule-mediated reduction/oxidation are introduced and discussed. Meanwhile, typical examples and discussions on how biomolecular self-assembly inspires the formation of hierarchical hybrid nanomaterials are presented. Finally, the applications of bioinspired nanomaterials in biofuel cells, light-harvesting systems, batteries, supercapacitors, catalysis, water/air purification, and environmental monitoring are presented and discussed. We believe that this review will be very helpful for readers to understand the self-assembly of biomolecules and the biomimetic/bioinspired strategies for synthesizing hierarchical nanomaterials on the one hand, and on the other hand to design novel materials for extended applications in nanotechnology, materials science, analytical science, and biomedical engineering.

Amyloid-beta induced retrograde axonal degeneration in a mouse tauopathy model.

White matter abnormalities, revealed by Diffusion Tensor Imaging (DTI), are observed in patients with Alzheimer's Disease (AD), representing neural network deficits that underlie gradual cognitive decline in patients. However, how DTI changes related to the development of Amyloid beta (Aß) and tau pathology, two key hallmarks of AD, remain elusive. We hypothesized that tauopathy induced by Aß could initiate an axonal degeneration, leading to DTI-detectable white matter abnormalities. We utilized the visual system of the transgenic p301L tau mice as a model system. Aß was injected in Lateral Geniculate Nucleus (LGN), where the Retinal Ganglion Cell (RGC) axons terminate. Longitudinal DTI was conducted to detect changes in the optic tract (OT) and optic nerve (ON), containing the distal and proximal segments of RGC axons, respectively. Our results showed DTI changes in OT (significant 13.2% reduction in axial diffusion, AxD vs. vehicle controls) followed by significant alterations in ON AxD and fractional anisotropy, FA. Histology data revealed loss of synapses, RGC axons and cell bodies resulting from the Aß injection. We further tested whether microtubule-stabilizing compound Epothilone D (EpoD) could ameliorate the damage. EpoD co-treatment with Aß was sufficient to prevent Aß-induced axon and cell loss. Using an acute injection paradigm, our data suggest that EpoD may mediate its protective effect by blocking localized, acute Aß-induced tau phosphorylation. This study demonstrates white matter disruption resulting from localized Aß, the importance of tau pathology induction to changes in white matter connectivity, and the use of EpoD as a potential therapeutic avenue to prevent the axon loss in AD.