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Despite the ubiquity and complexity of atmospheric polycyclic aromatic compounds (PACs), many of these compounds are largely unknown and lack sufficient toxicity data for comprehensive risk assessments. In this study, nontarget screening assisted by in-house and self-developed spectra databases was, therefore, employed to identify PACs in atmospheric particulate matter collected from multiple outdoor settings. Additionally, absorption, distribution, metabolism, excretion, and toxicity properties were evaluated to indicate PAC’s overall abilities to cause adverse outcomes and incorporated into a novel health risk assessment model to assess their inhalation risks. Here, except for target PACs, 98 PAC analogues across eight categories were identified in the outdoor samples of atmospheric particulate matter. Their concentrations were source-specific and correlated to that of the total 16 priority polycyclic aromatic hydrocarbons (PAHs). Virtual high-throughput screening results suggested that metabolism disruption and endocrine disruption might be significant non-carcinogenic effects caused by the PACs. However, PAHs and oxygenated PAHs exhibited stronger overall abilities to induce non-carcinogenic adverse outcomes in human body when compared to the other PACs. Among PACs, total PAHs exhibited the highest carcinogenic and non-carcinogenic risks, while emerging PAHs accounted for 47% and 27% of total carcinogenic and non-carcinogenic risks, respectively. This study advances our understanding of the potential harmful effects of PACs and provides insights into mitigating the inhalation risks from complex PAC exposures based on classified risk levels.

Erythromycin (ERY) is a typical macrolide antibiotic with large production and extensive use on a global scale. Detection of ERY in both freshwaters and coaster seawaters, as well as relatively high ecotoxicity of ERY have been documented. Notably, hormesis has been reported on several freshwater algae under ERY stress, where growth was promoted at relatively lower exposures but inhibited at higher treatment levels. On the contrary, there is limited information of ERY toxicity in marine algae, hampering the risk assessment on ERY in the coaster waters. The presence of hormesis may challenge the current concept of dose-response adopted in chemical risk assessment. Whether and how exposure to ERY can induce dose-dependent toxicity in marine algae remain virtually unknown, especially at environmentally relevant concentrations. The present study used a model marine diatom Thalassiosira weissflogii (T. weissflogii) to reveal its toxicological responses to ERY at different biological levels and decipher the underlying mechanisms. Assessment of multiple apical endpoints shows an evident growth promotion following ERY exposure at an environmentally relevant concentration (1 µg/L), associated with increased contents reactive oxygen species (ROS) and chlorophyll-a (Chl-a), activated signaling pathways related to ribosome biosynthesis and translation, and production of total soluble protein. By contrast, growth inhibition in the 750 and 2500 µg/L treatments was attributed to reduced viability, increased ROS formation, reduced content of total soluble protein, inhibited photosynthesis, and perturbed signaling pathways involved in xenobiotic metabolism, ribosome, metabolism of amino acid, and nitrogen metabolism. Measurements of multiple apical endpoints coupled with de novo transcriptomics analysis applied in the present study, a systems biology approach, can generate detailed mechanistic information of chemical toxicity including dose-response and species sensitivity difference used in environmental risk assessment.

The bio-inertness of titanium (Ti) and accompanying severe inflammation can extremely inhibit the coupled osteogenesis-angiogenesis regulation and result in an undesirable osseointegration of peri-implant during the implantation process. Herein, three types of TiO2 nanotubes (TNT) were prepared on native Ti substrate using an anodic oxidation approach, including TNT with a diameter of 30 nm (TNT-30), 70 nm (TNT-70), or 110 nm (TNT-110). Among the four substrates, TNT-70 was the most prominent to induce the differentiation of macrophages to the pro-healing M2 phenotype via significant down-regulation of pro-inflammation genes (CD86, iNOS, CD11c) and cytokines (TNF-α, IL-6), as well as up-regulation of anti-inflammation genes (CD206, Arg-1, IL-10) and cytokines (TGF-β, IL-10). Furthermore, TNT-70 could stimulate the osteogenic potential of mesenchymal stem cells (MSCs) and the angiogenic ability of human umbilical vein endothelial cells (HUVECs) via multiple paracrine signaling. In vivo experiments suggested that TNT-70 significantly relieved early inflammatory response around the implant, facilitated coupled osteogenesis and angiogenesis, and effectively promoted the osseointegration of peri-implant. This study provided a reference for fabricating surface topography on Ti implant for improving osseointegration and relieving associated excessive inflammatory response.

Lithium doping has been widely employed to modulate the photoluminescence of lanthanide-doped crystals. Despite its effectiveness, the underlying mechanism remains debatable. Using cubic sodium yttrium fluoride as a model crystal, first-principles calculations indicate that neutral substitution of host sodium with lithium ions can occur, irrespective of synthesis conditions. Unlike lithium substitution, the formation of lithium interstitials is likely accompanied by the substitution of F- with O2- ions. The lithium substitution shows negligible influence on the electronic structures of the host crystal and the 4f orbital energies of lanthanide ions. By comparison, the lithium-oxygen defect pairs could induce self-absorption losses in lanthanide luminescence or produce ligand-to-metal charge transfer states that could populate lanthanide 4f states.

Abdominal aortic aneurysm (AAA) is a progressive focal dilatation and weakening of the abdominal aorta, causing 1.3% of all deaths among men aged 65–85 years worldwide. The formation of AAA is a complex process with multiple risk factors. Therefore, this study aimed to determine the relationship of disease severity and physiological factors, and gut microbiota structures in AAA patients. Physiological indicators and fecal 16S rRNA gene sequences from healthy controls and patients with AAA were collected. The correlations between the diameter of the AAA and clinical parameters, and gut microbiota composition were then analyzed separately using multivariable analysis. The diameter of AAA was extremely positively correlated with smoking index, alkaline phosphatase, blood glucose, and blood triglycerides and negatively correlated with prealbumin and Cystatin C. As the diameter of AAA increased, the α-diversity, including Chao 1, Shannon, and Simpson indices, of the gut microbiota decreased and presented a negative linear relationship. Patients with AAA with more severe disease had significantly increased relative abundance of Enterobacteriaceae and decreased relative abundance of Veillonellaceae. A strong correlation was observed between the diameter and physiological data, as well as between diameter and gut microbiota composition. This study could improve the understanding of AAA, and gut microbiota may be a potential target to prevent and treat this deadly disease.

Gelatin-based hydrogels have a broad range of biomedical fields due to their biocompatibility, convenience for chemical modifications, and degradability. However, gelatin-based hydrogels present poor antibacterial ability that hinders their applications in treating infected wound healing. Herein, a series of multifunctional hydrogels (Gel@Zn) were fabricated through free-radical polymerization interaction based on gelatin methacrylate (GelMA) and dopamine methacrylate (DMA), and then immersed them into zinc nitrate solutions based on the metal coordination and ionic bonding interaction. These designed hydrogels wound dressings show strong antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by increasing intracellular reactive oxygen species (ROS) level and changing bacterial membrane permeability. Meanwhile, the hydrogels exhibit good cytocompatibility, enhance the adhesion, proliferation, and migration of NIH-3T3 cells. Furthermore, Gel@Zn-0.08 (0.08 ​M Zn2+ immersed with Gel sample) presents a good balance between antibacterial effect, cell viability, and hemolytic property. Compared with 3 ​M commercial dressings, Gel@Zn-0.04, and Gel@Zn-0.16, the Gel@Zn-0.08 could significantly improve the healing process of S. aureus-infected full-thickness wounds via restrained the inflammatory responses, enhanced epidermis and granulation tissue information, and stimulated angiogenesis. Our study indicates that the Zn-incorporated hydrogels are promising bioactive materials as wound dressings for infected full-thickness wound healing and skin regeneration.

CYP1A is the most commonly used biomarker and transgenic fish which carrying a cyp1a promoter to drive a reporter gene can be used as reliable way to monitor dioxin/dioxin-like compounds (DLCs) in the environment. Here, we cloned the cyp1a promoter of Gambusia affinis and this promoter showed stronger transcriptional activity than that of zebrafish. Then, a Tg(GAcyp1a:eGFP/Luc) transgenic zebrafish line was first constructed with the G. affinis cyp1a promoter driving eGFP expression using meganuclease I-SceI mediated transgenesis technology. The Tg(GAcyp1a:eGFP/Luc) larvae at 72 h post-fertilization (hpf) were tested by exposing to TCDD for 72 h, and induced GFP was mainly expressed in the liver with low background. The Tg(GAcyp1a:eGFP/Luc) zebrafish showed high sensitivity (limit of detection of 0.322 ng/L TCDD and 0.7 TEQ-ng/L PCDD/Fs) and specificity (insensitive to responses to PAHs and PCBs). In addition, the transgenic line showed a low detection concentration of the DLCs contaminated environmental samples (as low as 1.8 TEQ-ng/L), and the eGFP fluorescence intensity and the chemical-TEQ values were closely correlated. In conclusion, a sensitively and specifically transgenic zebrafish line was established to convenient and effective to detect DLCs in the environment.

Objectives: The aim of this study was to investigate the effects of low-intensity pulsed ultrasound (LIPUS) in a post-traumatic osteoarthritis (OA) rat model and in vitro. Methods: Thirty-eight male, four-month-old Sprague Dawley rats were randomly assigned to Sham, Sham ​+ ​US, OA, and OA ​+ ​US. Sham surgery was performed to serve as a negative control, and anterior cruciate ligament transection was used to induce OA. Three days after the surgical procedures, Sham ​+ ​US and OA ​+ ​US animals received daily LIPUS treatment, while the rest of the groups received sham ultrasound (US) signals. Behavioral pain tests were performed at baseline and every week thereafter. After 31 days, the tissues were collected, and histological analyses were performed on knees and innervated dorsal root ganglia (DRG) neurons traced by retrograde labeling. Furthermore, to assess the activation of osteoclasts by LIPUS treatment, RAW264.7 ​cells were differentiated into osteoclasts and treated with LIPUS. Results: Joint degradation in cartilage and bone microarchitecture were mitigated in OA ​+ ​US compared to OA. OA ​+ ​US showed improvements in behavioral pain tests. A significant increase of large soma-sized DRG neurons was located in OA compared to Sham. In addition, a greater percentage of large soma-sized innervated neurons were calcitonin gene-related peptide-positive. Daily LIPUS treatment suppressed osteoclastogenesis in vitro, which was confirmed via histological analyses and mRNA expression. Finally, lower expression of netrin-1, a sensory innervation-related protein, was found in the LIPUS treated cells. Conclusion: Our findings demonstrate that early intervention using LIPUS treatment has protective effects from the progression of knee OA, including reduced tissue degradation, mitigated pain characteristics, improved subchondral bone microarchitecture, and less sensory innervation. Furthermore, daily LIPUS treatment has a suppressive effect on osteoclastogenesis, which may be linked to the suppression of sensory innervation in OA. The translational potential of this article: This study presents a new potential for early intervention in treating OA symptoms through the use of LIPUS, which involves the suppression of osteoclastogenesis and the alteration of DRG profiles. This intervention aims to delay joint degradation and reduce pain.

Noninvasive diagnosis of bone density and mechanical properties using non-radiation imaging modality is an emerging area with promising in early prediction of osteopenia and treatment effectiveness in the clinic and functional disuse, i.e., long-term bedrest and space mission. Advances in quantitative ultrasound have shown advantages in measuring both bone density and mechanical strength, non-radiation, imaging capability, and easy to use. The challenge that remained is the poor penetration of ultrasound signals passing through trabecular and cortical bones and acoustic energy scattering. A new scanning confocal ultrasound technology is developed in this lab to detect the alteration of bone to provide diagnostic results in bone density and structure properties. A software-controlled flexible ultrasound system with 2-D dual array transducer is developed and proposed for the purpose of noninvasive bone density diagnosis and assessment of bone loss. Transmitting (Tx) transducer elements are divided into sub-blocks to excite the ultrasound signals in sequence to decrease the system complexity while maintaining beam pattern properties by the signal processing procedure at receiving (Rx) side. Apodization is also applied to reduce acoustic side lobes and to make the resolution in the ultrasound field of view (FOV) more uniform. This study may provide basic understanding of modulated confocal ultrasound beam forming for tissue characterization, such as trabecular bone structual and strength properties.

Background: Osteoporosis parallels aging and functional mechanical unloading (e.g., space flight and bed rest), jeopardizing mineral density, microstructure, and integrity of bone and leading to an increased risk of fracture. A way to combat this deterioration is to harness the sensitivity of bone to mechanical signals. Objective: This study evaluates the longitudinal effect of a dynamic mechanical loading through the heel on human bone in vivo during 90-day bed rest, monitored by quantitative ultrasound (QUS) imaging and dual-energy X-ray absorptiometry (DXA) in localized regions of interests, i.e., calcaneus. Methods: A total of 29 bed rest individuals were evaluated (11 control and 18 treatment) with a brief (10-minute) daily low-intensity (0.3g), high-frequency (30Hz) dynamic mechanical stimulation countermeasure through vibrational inhibition bone erosion (VIBE). Both QUS and DXA detected longitudinal bone density and quality changes. Results: Ultrasound velocity (UV) decreased in the control group and increased in the group treated with low-intensity loading. The UV increased by 1.9% and 1.6% at 60- and 90-day bed rest (p=0.01) in VIBE over control groups. A trend was found in broadband ultrasound attenuation (BUA), with a VIBE benefit of 1.8% at day 60 and 0.5% at day 90 in comparison with control (p=0.5). Bone mineral density (BMD) assessed by DXA decreased -4.50% for control individuals and -2.18% for VIBE individuals, showing a moderate effect of the mechanical intervention (p=0.19). Significant correlations between QUS and DXA were observed, with a combined BUA and UV vs. BMD: r2=0.70. Conclusion: These results indicated that low-intensity, high-frequency loading has the potential to mitigate regional bone loss induced by long-term bed rest and that QUS imaging may be able to assess the subtle changes in bone alteration. Translational potential of this article: Quantitative ultrasound has shown the efficacy of noninvasively assessing bone mass and structural properties in cadaver and isolated trabecular bone samples. While its ability in measuring in vivo bone quality and density is still unclear, a scanning confocal ultrasound imaging is developed and can perform an instant assessment for the subtle changes of such bone loss. This ultrasound imaging modality can potentially be used in the clinical assessment of bone mass. Moreover, physical stimulation has shown the ability to prevent bone loss induced by functional disuse and estrogen deficiency in animal models. However, its treatment capability is unclear. This study has shown that low-magnitude mechanical signals, introduced using low-intensity vibration (LIV), can mitigate regional bone loss caused by functional disuse. Thus localized mechanical treatment, and the quantitative ultrasound imaging have shown translational potential to noninvasively attenuate bone loss, and assess bone mass in the clinic, e.g., in an extreme condition such as long-term space mission, and long-term bedrest such as in case of spinal cord injury. Keywords: Bed rest, Bone remodelling, Confocal acoustic navigation, Osteoporosis and osteopenia, Ultrasound imaging, Whole-body vibration

Background/Objective: The participation of sensory neural regulation in bone metabolism has been widely studied. However, the physiological role of sensory neural regulation in the functional adaptation to weight bearing is not clear. This study was conducted to investigate the effect of capsaicin-induced sensory neuron lesions on cancellous architecture properties in a hindlimb suspension (HLS) model. Methods: Thirty-two female rats were randomly assigned to four groups. Groups b and d underwent systemic capsaicin treatment, whereas Groups a and c were treated with vehicle. Then, Groups c and d were subjected to HLS, whereas Groups a and b were allowed hindlimbs full loading. The proximal trabecular and mid-shaft cortical bone structure were evaluated via microcomputed tomography, and the biomechanical properties of the tibial mid-shaft were assessed using the four-point bending test. Results: The trabecular bone volume was reduced by 40% and 50% in Groups b and c, respectively, and was also reduced significantly in Group d. Trabecular thickness and trabecular separation in Group b were not significantly different from those of Group a. The cortical bone area fraction showed no significant difference among all groups. Compared with Group a, the ultimate strength in Group b decreased by 20.3%, whereas it did not change significantly in Group c. Conclusion: The results suggest that capsaicin-sensitive sensory neurons play an important role in bone modelling. The effect of capsaicin is similar to HLS. However, HLS has no add-on effect to capsaicin in the reduction of bone density and mechanical properties. Translational potential of this article: This study gives clues to the function of sensory neurons in bone modelling.

Intraspecific male polymorphism exhibiting extreme differences in morphology, behavior and life history presents good opportunities to explore adaptation mechanisms to different environments. In this study, we examined the transcriptomic differences between wingless and winged morphs of a fig wasp species Philotrypesis tridentata to investigate molecular basis to maintain polymorphisms. The winged male adults fly outside fig syconia to mate, while the wingless only stay and mate inside fig syconia where they have developed. We identified 2,391 differentially expressed genes (DEGs) with 1,396 highly expressed in winged morphs and 995 in wingless morphs. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses on the DEGs and differential alternative splicing genes and analyzed the top ten DEGs with the highest differential expression in each morph. The results showed that genes related to biosynthesis processes, lipid metabolism, energy production, flight and defense of the complex environments outside fig syconia were up-regulated in winged morphs. Genes involved in substance and energy metabolism and chemical reception were up-regulated in wingless morphs which might relate to their living inside fig syconia. The differences in highly expressed genes between two morphs prove adaptation of P. tridentata male polymorphism to different living environments., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)