17,241 research outputs found

    Converging organoids and extracellular matrix::New insights into liver cancer biology

    Get PDF

    ‘When is a hotspot a good nanospot’:review of analytical and hotspot-dominated surface enhanced Raman spectroscopy nanoplatforms

    Get PDF
    Substrate development in surface-enhanced Raman spectroscopy (SERS) continues to attract research interest. In order to determine performance metrics, researchers in foundational SERS studies use a variety of experimental means to characterize the nature of substrates. However, often this process would appear to be performed indiscriminately without consideration for the physical scale of the enhancement phenomena. Herein, we differentiate between SERS substrates whose primary enhancing structures are on the hundreds of nanometer scale (analytical SERS nanosubstrates) and those whose main mechanism derives from nanometric-sized gaps (hot-spot dominated SERS substrates), assessing the utility of various characterization methods for each substrate class. In this context, characterization approaches in white-light spectroscopy, electron beam methods, and scanning probe spectroscopies are reviewed. Tip-enhanced Raman spectroscopy, wavelength-scanned SERS studies, and the impact of surface hydrophobicity are also discussed. Conclusions are thus drawn on the applicability of each characterization technique regarding amenability for SERS experiments that have features at different length scales. For instance, while white light spectroscopy can provide an indication of the plasmon resonances associated with 10 s–100 s nm-scale structures, it may not reveal information about finer surface texturing on the true nm-scale, critical for SERS’ sensitivity, and in need of investigation via scanning probe techniques

    Medical prospects of cryptosporidiosis in vivo control using biofabricated nanoparticles loaded with Cinnamomum camphora extracts by Ulva fasciata

    Get PDF
    Background and Aim: Global efforts are continuing to develop preparations against cryptosporidiosis. This study aimed to investigate the efficacy of biosynthesized Ulva fasciata loading Cinnamomum camphora oil extract on new zinc oxide nanoparticles (ZnONPs shorten to ZnNPs) and silver nanoparticles (AgNPs) as alternative treatments for Cryptosporidium parvum experimental infection in rats. Materials and Methods: Oil extract was characterized by gas chromatography-mass spectrometry, loaded by U. fasciata on ionic-based ZnO and NPs, and then characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Biosafety and toxicity were investigated by skin tests. A total of 105 C. parvum oocysts/rat were used (n = 81, 2–3 W, 80–120 g, 9 male rats/group). Oocysts shedding was counted for 21 d. Doses of each preparation in addition to reference drug were administered daily for 7 d, starting on post-infection (PI) day (3). Nitazoxanide (100 mg) was used as the reference drug. After 3 weeks, the rats were sacrificed for postmortem examination and histopathological examination. Two blood samples/rat/group were collected on the 21st day. Ethylenediaminetetraacetic acid blood samples were also used for analysis of biochemistry, hematology, immunology, micronucleus prevalence, and chromosomal abnormalities. Results: C. camphora leaves yielded 28.5 ± 0.3 g/kg oil and 20 phycocompounds were identified. Spherical and rod-shaped particles were detected at 10.47–30.98 nm and 18.83–38.39 nm, respectively. ZnNPs showed the earliest anti-cryptosporidiosis effect during 7–17 d PI. Other hematological, biochemical, immunological, histological, and genotoxicity parameters were significantly fruitful; hence, normalized pathological changes induced by infestation were observed in the NPs treatments groups against the infestation-free and Nitazoxanide treated group. Conclusion: C. camphora, U. fasciata, ZnNPs, and AgNPs have refluxed the pathological effects of infection as well as positively improved host physiological condition by its anticryptosporidial immunostimulant regenerative effects with sufficient ecofriendly properties to be proposed as an alternative to traditional drugs, especially in individuals with medical reactions against chemical commercial drugs

    Efficient simulation of neural development using shared memory parallelization

    Get PDF
    The Neural Development Simulator, NeuroDevSim, is a Python module that simulates the most important aspects of brain development: morphological growth, migration, and pruning. It uses an agent-based modeling approach inherited from the NeuroMaC software. Each cycle has agents called fronts execute model-specific code. In the case of a growing dendritic or axonal front, this will be a choice between extension, branching, or growth termination. Somatic fronts can migrate to new positions and any front can be retracted to prune parts of neurons. Collision detection prevents new or migrating fronts from overlapping with existing ones. NeuroDevSim is a multi-core program that uses an innovative shared memory approach to achieve parallel processing without messaging. We demonstrate linear strong parallel scaling up to 96 cores for large models and have run these successfully on 128 cores. Most of the shared memory parallelism is achieved without memory locking. Instead, cores have only write privileges to private sections of arrays, while being able to read the entire shared array. Memory conflicts are avoided by a coding rule that allows only active fronts to use methods that need writing access. The exception is collision detection, which is needed to avoid the growth of physically overlapping structures. For collision detection, a memory-locking mechanism was necessary to control access to grid points that register the location of nearby fronts. A custom approach using a serialized lock broker was able to manage both read and write locking. NeuroDevSim allows easy modeling of most aspects of neural development for models simulating a few complex or thousands of simple neurons or a mixture of both.Code available athttps://github.com/CNS-OIST/NeuroDevSim

    Synthesizing Ti–Ni Alloy Composite Coating on Ti–6Al–4V Surface from Laser Surface Modification

    Get PDF
    In This Work, a Ni-Alloy Deloro-22 Was Laser-Deposited on a Ti–6Al–4V Bar Substrate with Multiple Sets of Laser Processing Parameters. the Purpose Was to Apply Laser Surface Modification to Synthesize Different Combinations of Ductile TiNi and Hard Ti2Ni Intermetallic Phases on the Surface of Ti–6Al–4V in Order to Obtain Adjustable Surface Properties. Scanning Electron Microscopy, Energy Dispersion Spectroscopy, and X-Ray Diffraction Were Applied to Reveal the Deposited Surface Microstructure and Phase. the Effect of Processing Parameters on the Resultant Compositions of TiNi and Ti2Ni Was Discussed. the Hardness of the Deposition Was Evaluated, and Comparisons with the Ti–6Al–4V Bulk Part Were Carried Out. They Showed a Significant Improvement in Surface Hardness on Ti–6Al–4V Alloys after Laser Processing, and the Hardness Could Be Flexibly Adjusted by using This Laser-Assisted Surface Modification Technique

    Solidification behavior of high nitrogen stainless steels and establishment of a one-dimensional heat transfer framework

    Get PDF
    Duplex stainless steel (DSS) has excellent corrosion resistance and mechanical properties due to its dual-phase structure. The solidification process is the key to determining the structure of materials, and an in-depth investigation of solidification can help us better understand the properties of materials. The melting and solidification processes of S32101 DSS were investigated using high temperature confocal microscopy (HTCM)

    Genetic and functional analysis of the adaptive immune response

    Get PDF
    The cells of the adaptive immune system rely on somatic recombination of V, D and J genes to obtain a vast range of specificities. T cells use four chains encoded by three genomic loci, to produce alpha/beta or gamma/delta T cell receptors (TCRs). B cell receptors (BCRs) are encoded by three loci, a single heavy chain and two light chain loci, kappa and lambda. Because these genomic regions are highly polymorphic, the germline TCR and BCR repertoires are individual, shaping the elicited response against infections and vaccines in each person. In this thesis, I used a set of specialized tools and analysis pipelines to explore the adaptive immune receptors at the genomic and functional levels in both humans and non-human primates (NHP), highlighting the benefits of integrating individualized TCR/BCR repertoire analysis with functional studies to understand adaptive immune responses. In paper I, we sequence expressed TCR repertoires of 45 individuals from four human populations: African, East Asian, South Asian, and European. Analysis of these repertoires with the germline gene inference tool, IgDiscover, identified 175 novel V and J alleles, most of which were characterized by codon changes or non-functional variants. The germline TCR repertoires were highly diverse between individuals, with some of the novel alleles identified only in specific populations. Furthermore, we report three introgressed regions inherited from Homo neanderthalensis. One of these regions includes a novel variant of TRGV4, frequent in Eurasians populations, which display altered reactivity to the ligand butyrophilin-like molecule 3 (BTNL3). In papers II and III, we analyzed the humoral immune response in NHPs elicited by a series of immunizations with SARS-CoV-2 Spike-derived subunit proteins. In paper II, we observed detectable neutralization titers after priming with ancestral spike (S) protein with very high antibody titers obtained after boosting. The immunization regimen resulted in durable neutralization titers as well as S-specific memory B cells. In paper III, we used a heterotypic boosting strategy with beta-derived receptor binding domain (RBD) to broaden the response to circulating SARS-CoV-2 variants. The boost elicits potent and protective cross-neutralizing humoral immune responses. In paper IV, we analyzed multi-compartmental longitudinal samples from two macaques used in paper II. We combined single cell and next generation sequencing (NGS) of BCR repertoires to characterize S-specific antibodies and S-specific B cell lineages elicited by immunizations with ancestral SARS-CoV-2 S proteins. Lineage tracing analysis identified persistent antibody lineages that were present after priming and were widely disseminated in blood, bone marrow (BM), spleen and different lymph nodes (LN), including a broadly neutralizing RBD-binding lineage. Through structural cryo-EM studies, we showed that this antibody achieved cross-neutralization by targeting conserved RBD residues with crucial interactions through its heavy chain CDR3 (HCDR3)

    Endometrial microbiota in women with and without adenomyosis: A pilot study

    Get PDF
    IntroductionThe endometrial microbiota plays an essential role in the health of the female reproductive system. However, the interactions between the microbes in the endometrium and their effects on adenomyosis remain obscure.Materials and methodsWe profile endometrial samples from 38 women with (n=21) or without (n=17) adenomyosis to characterize the composition of the microbial community and its potential function in adenomyosis using 5R 16S rRNA gene sequencing.ResultsThe microbiota profiles of patients with adenomyosis were different from the control group without adenomyosis. Furthermore, analysis identified Lactobacillus zeae, Burkholderia cepacia, Weissella confusa, Prevotella copri, and Citrobacter freundii as potential biomarkers for adenomyosis. In addition, Citrobacter freundii, Prevotella copri, and Burkholderia cepacia had the most significant diagnostic value for adenomyosis. PICRUSt results identified 30 differentially regulated pathways between the two groups of patients. In particular, we found that protein export, glycolysis/gluconeogenesis, alanine, aspartate, and glutamate metabolism were upregulated in adenomyosis. Our results clarify the relationship between the endometrial microbiota and adenomyosis.DiscussionThe endometrial microbiota of adenomyosis exhibits a unique structure and Citrobacter freundii, Prevotella copri, and Burkholderia cepacia were identified as potential pathogenic microorganisms associated with adenomyosis. Our findings suggest that changes in the endometrial microbiota of patients with adenomyosis are of potential value for determining the occurrence, progression, early of diagnosis, and treatment oadenomyosis
    • …
    corecore