3D Printable Composite Biomaterials Based on GelMA and Hydroxyapatite Powders Doped with Cerium Ions for Bone Tissue Regeneration

The main objective was to produce 3D printable hydrogels based on GelMA and hydroxyapatite doped with cerium ions with potential application in bone regeneration. The first part of the study regards the substitution of Ca²⁺ ions from hydroxyapatite structure with cerium ions (Ca_10-xCe_x(PO₄)₆(OH)₂, xCe = 0.1, 0.3, 0.5). The second part followed the selection of the optimal concentration of HAp doped, which will ensure GelMA-based scaffolds with good biocompatibility, viability and cell proliferation. The third part aimed to select the optimal concentrations of GelMA for the 3D printing process (20%, 30% and 35%). In vitro biological assessment presented the highest level of cell viability and proliferation potency of GelMA-HC5 composites, along with a low cytotoxic potential, highlighting the beneficial effects of cerium on cell growth, also supported by Live/Dead results. According to the 3D printing experiments, the 30% GelMA enriched with HC5 was able to generate 3D scaffolds with high structural integrity and homogeneity, showing the highest suitability for the 3D printing process. The osteogenic differentiation experiments confirmed the ability of 30% GelMA-3% HC5 scaffold to support and efficiently maintain the osteogenesis process. Based on the results, 30% GelMA-3% HC5 3D printed scaffolds could be considered as biomaterials with suitable characteristics for application in bone tissue engineering.     

Pesticide measurements from the first national environmental health survey of child care centers using a multi-residue GC/MS analysis method

The U.S. Department of Housing and Urban Development, in collaboration with the U.S. Consumer Product Safety Commission and the U.S. Environmental Protection Agency, characterized the environments of young children (<6 years) by measuring lead, allergens, and pesticides in a randomly selected nationally representative sample of licensed institutional child care centers. Multi-stage sampling with clustering was used to select 168 child care centers in 30 primary sampling units in the United States. Centers were recruited into the study by telephone interviewers. Samples for pesticides, lead, and allergens were collected at multiple locations in each center by field technicians. Field sampling was conducted from July through October 2001. Wipe samples from indoor surfaces (floors, tabletops, desks) and soil samples were collected at the centers and analyzed using a multi-residue GC/MS analysis method. Based on the questionnaire responses, pyrethroids were the most commonly used pesticides among centers applying pesticides. Among the 63% of centers reporting pesticide applications, the number of pesticides used in each center ranged from 1 to 10 and the frequency of use ranged from 1 to 107 times annually. Numerous organophosphate and pyrethroid pesticides were detected in the indoor floor wipe samples. Chlorpyrifos (0.004-28 ng/cm2), diazinon (0.002-18 ng/cm2), cis-permethrin (0.004-3 ng/cm2), and     

Cytochrome P450 OxyBtei Catalyzes the First Phenolic Coupling Step in Teicoplanin Biosynthesis

Bacterial cytochrome P450s form a remarkable clade of the P450 superfamily of oxidative hemoproteins, and are often involved in the biosynthesis of complex natural products. Those in a subgroup known as “Oxy enzymes” play a crucial role in the biosynthesis of glycopeptide antibiotics, including vancomycin and teicoplanin. The Oxy enzymes catalyze crosslinking of aromatic residues in the non‐ribosomal antibiotic precursor peptide while it remains bound to the non‐ribosomal peptide synthetase (NRPS); this crosslinking secures the three‐dimensional structure of the glycopeptide, crucial for antibiotic activity. We have characterized OxyB_tei, the first of the Oxy enzymes in teicoplanin biosynthesis. Our results reveal that OxyB_tei possesses a structure similar to those of other Oxy proteins and is active in crosslinking NRPS‐bound peptide substrates. However, OxyB_tei displays a significantly altered activity spectrum against peptide substrates compared to its well‐studied vancomycin homologue.     

Imaging of Small Animal Peripheral Artery Disease Models: Recent Advancements and Translational Potential

Peripheral artery disease (PAD) is a broad disorder encompassing multiple forms of arterial disease outside of the heart. As such, PAD development is a multifactorial process with a variety of manifestations. For example, aneurysms are pathological expansions of an artery that can lead to rupture, while ischemic atherosclerosis reduces blood flow, increasing the risk of claudication, poor wound healing, limb amputation, and stroke. Current PAD treatment is often ineffective or associated with serious risks, largely because these disorders are commonly undiagnosed or misdiagnosed. Active areas of research are focused on detecting and characterizing deleterious arterial changes at early stages using non-invasive imaging strategies, such as ultrasound, as well as emerging technologies like photoacoustic imaging. Earlier disease detection and characterization could improve interventional strategies, leading to better prognosis in PAD patients. While rodents are being used to investigate PAD pathophysiology, imaging of these animal models has been underutilized. This review focuses on structural and molecular information and disease progression revealed by recent imaging efforts of aortic, cerebral, and peripheral vascular disease models in mice, rats, and rabbits. Effective translation to humans involves better understanding of underlying PAD pathophysiology to develop novel therapeutics and apply non-invasive imaging techniques in the clinic.     

Hemlock Woolly Adelgid and Elongate Hemlock Scale Induce Changes in Foliar and Twig Volatiles of Eastern Hemlock

Eastern hemlock (Tsuga canadensis) is in rapid decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; ‘HWA’) and, to a lesser extent, the invasive elongate hemlock scale (Fiorinia externa; ‘EHS’). For many conifers, induced oleoresin-based defenses play a central role in their response to herbivorous insects; however, it is unknown whether eastern hemlock mobilizes these inducible defenses. We conducted a study to determine if feeding by HWA or EHS induced changes in the volatile resin compounds of eastern hemlock. Young trees were experimentally infested for 3 years with HWA, EHS, or neither insect. Twig and needle resin volatiles were identified and quantified by gas chromatography/mass spectrometry. We observed a suite of changes in eastern hemlock’s volatile profile markedly different from the largely terpenoid-based defense response of similar conifers. Overall, both insects produced a similar effect: most twig volatiles decreased slightly, while most needle volatiles increased slightly. Only HWA feeding led to elevated levels of methyl salicylate, a signal for systemic acquired resistance in many plants, and benzyl alcohol, a strong antimicrobial and aphid deterrent. Green leaf volatiles, often induced in wounded plants, were increased by both insects, but more strongly by EHS. The array of phytochemical changes we observed may reflect manipulation of the tree’s biochemistry by HWA, or simply the absence of functional defenses against piercing-sucking insects due to the lack of evolutionary contact with these species. Our findings verify that HWA and EHS both induce changes in eastern hemlock’s resin chemistry, and represent the first important step toward understanding the effects of inducible chemical defenses on hemlock susceptibility to these exotic pests.     

Neuronal correlates of sensorimotor association in stimulus–response compatibility.

Neuronal mechanisms underlying stimulus–response (S-R) associations in S-R compatibility tasks were identified in 2 experiments with monkeys. Visual stimuli were presented on the left and right calling for left–right movements under congruent and incongruent S-R mapping instructions. High- and low-pitched tones calling for left–right movements were presented to the left and right ear, and the stimulus side was irrelevant. Single neurons sensitive to the S-R mapping rule were found in the primary motor cortex. The large overlap between the neuronal populations sensitive to the stimulus side, the S-R mapping rule, and the response side, respectively, is consistent with the idea that sensory-to-motor transformation is a continuous rather than a discrete process. Results partly support the hypothesis that the increase in reaction time with incongruent mapping is caused by the automatic activation of the congruent, but erroneous, response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

设计信息提高SEM缺陷检测取样效率

基于设计的分级将来自设计数据的版图信息与检测到的每个缺陷的相对位置结合起来,利用这种方法可提高缺陷帕雷托质量。通过对系统缺陷和有害缺陷进行分级,可以改进SEM检测。     

Retinal Pigment Epithelium Expressed Toll-like Receptors and Their Potential Role in Age-Related Macular Degeneration

(1) Background: Inflammation is a major pathomechanism in the development and progression of age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) may contribute to retinal inflammation via activation of its Toll-like receptors (TLR). TLR are pattern recognition receptors that detect the pathogen- or danger-associated molecular pattern. The involvement of TLR activation in AMD is so far not understood. (2) Methods: We performed a systematic literature research, consulting the National Library of Medicine (PubMed). (3) Results: We identified 106 studies, of which 54 were included in this review. Based on these studies, the current status of TLR in AMD, the effects of TLR in RPE activation and of the interaction of TLR activated RPE with monocytic cells are given, and the potential of TLR activation in RPE as part of the AMD development is discussed. (4) Conclusion: The activation of TLR2, -3, and -4 induces a profound pro-inflammatory response in the RPE that may contribute to (long-term) inflammation by induction of pro-inflammatory cytokines, reducing RPE function and causing RPE cell degeneration, thereby potentially constantly providing new TLR ligands, which could perpetuate and, in the long run, exacerbate the inflammatory response, which may contribute to AMD development. Furthermore, the combined activation of RPE and microglia may exacerbate neurotoxic effects.     

The moderating effects of personal reputation on accountability-strain relationships.

Although felt accountability has predicted positive outcomes in some studies, it has demonstrated anxiety-provoking properties in others. This inconsistency has led researchers to search for moderating variables that explain why felt accountability promotes or impedes favorable outcomes. Building on these studies, the authors examine the moderating effects of personal reputation on the felt accountability-strain relationship. As hypothesized, the results indicate that a positive personal reputation ameliorated the strain reactions caused by felt accountability. In particular, as felt accountability increased, individuals with strong personal reputations experienced less job tension and depressed mood at work, as well as more job satisfaction, but individuals with weak personal reputations experienced the opposite outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)