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result(s) for
"Selinger, F."
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Fabrication and validation of an affordable DIY coaxial 3D extrusion bioprinter
by
Selinger, F.
,
Frauenlob, M.
,
Mateos-Timoneda, M. A.
in
Alginates - chemistry
,
Bioink
,
Bioprinting - economics
2025
3D bioprinting has emerged as a promising technology in tissue engineering, allowing for the precise fabrication of complex structures to mimic native tissues. Coaxial bioprinting enhances the complexity of printed structures by extruding multiple materials in concentric layers. However, costly commercial systems and a lack of Do-it-Yourself (DIY) guides for coaxial 3D bioprinting limit the wider adoption of this technology. This study presents a detailed description of modifying a commercial 3D printer to a coaxial 3D bioprinting system that simultaneously drives two syringe pump extruders connected to a coaxial nozzle. The system was validated using a soft alginate-gelatin hydrogel core and a load-bearing methylcellulose-based (MC) hydrogel shell. Shape fidelity of the 3D printed structures was evaluated for core-shell extrusion ratio, coaxial nozzle configuration, and in-situ crosslinking of the hydrogel core. Employing optimized printing settings allowed the fabrication of complex scaffold structures with a gradual transition between the extrusion of core and shell material. Mesenchymal stem cells (MSCs) encapsulated in varying alginate concentrations were printed, maintaining shape fidelity and high cell viability. In conclusion, we developed a cost-effective DIY coaxial 3D bioprinter capable of extruding soft cell-laden hydrogels that are not printable by conventional extrusion bioprinting. This printer presents an easy to build and modify platform to encourage a wider audience to utilize and tailor coaxial bioprinting for their specific requirements.
Journal Article
Fabrication and validation of an affordable DIY coaxial 3D extrusion bioprinter
by
Selinger, F.
,
Frauenlob, M.
,
Mateos-Timoneda, M. A.
in
639/301/54
,
639/301/923/1027
,
Humanities and Social Sciences
2025
3D bioprinting has emerged as a promising technology in tissue engineering, allowing for the precise fabrication of complex structures to mimic native tissues. Coaxial bioprinting enhances the complexity of printed structures by extruding multiple materials in concentric layers. However, costly commercial systems and a lack of Do-it-Yourself (DIY) guides for coaxial 3D bioprinting limit the wider adoption of this technology. This study presents a detailed description of modifying a commercial 3D printer to a coaxial 3D bioprinting system that simultaneously drives two syringe pump extruders connected to a coaxial nozzle. The system was validated using a soft alginate-gelatin hydrogel core and a load-bearing methylcellulose-based (MC) hydrogel shell. Shape fidelity of the 3D printed structures was evaluated for core-shell extrusion ratio, coaxial nozzle configuration, and in-situ crosslinking of the hydrogel core. Employing optimized printing settings allowed the fabrication of complex scaffold structures with a gradual transition between the extrusion of core and shell material. Mesenchymal stem cells (MSCs) encapsulated in varying alginate concentrations were printed, maintaining shape fidelity and high cell viability. In conclusion, we developed a cost-effective DIY coaxial 3D bioprinter capable of extruding soft cell-laden hydrogels that are not printable by conventional extrusion bioprinting. This printer presents an easy to build and modify platform to encourage a wider audience to utilize and tailor coaxial bioprinting for their specific requirements.
Journal Article
Deuterium supersaturated surface layer in tungsten: ion energy dependence
by
Schwarz-Selinger, T.
,
Patino, M.I.
,
Chang, F.
in
Density
,
Deuterium
,
deuterium supersaturated surface layer
2023
Properties of deuterium (D) supersaturated surface layers (DSSLs) formed in tungsten (W), such as thickness, internal microstructures, and D retention, are experimentally investigated as a function of the incident ion energy, E i . W samples were exposed to D plasmas in the PISCES-A linear plasma device in a range of E i ∼ 45–175 eV, while other plasma exposure parameters were fixed: sample temperature, T s , ∼423 K, ion flux, Γ i , ∼1.2 × 10 21 m −2 s −1 , and fluence, Φ i , ∼3.0 × 10 24 m −2 . High-resolution, cross-sectional, transmission electron microscopy observations confirm that (1) a DSSL forms even at the lowest E i ∼ 45 eV, (2) the DSSL thickness, Δ t DSSL , is found to decrease with decreasing E i from ∼11–12 nm at E i ∼ 175 eV to ∼5–6 nm at ∼45 eV, and to agree with approximately the maximum implantation depth calculated using SDTrimSP, and (3) high-density D nanobubbles with a diameter of ∼1 nm or less exist inside the DSSL, which is deemed to validate a theory-predicted vacancy stabilization process due to trapping of a solute D atom(s). Utilizing a D areal density of ∼4.2 × 10 19 m −2 in the first 14 nm from the surface at E i ∼ 75 eV from nuclear reaction analysis and the measured E i dependence of Δ t DSSL , our previous laser-induced breakdown spectroscopy data is updated: both dynamic and static D retention increase with decreasing E i , and the D/W atomic fraction during plasma exposure reaches ∼0.3 at E i ∼ 45 eV. A possible DSSL formation mechanism is proposed.
Journal Article
Microbial preparations (probiotics) for the prevention of Clostridium difficile infection in adults and children: an individual patient data meta-analysis of 6,851 participants
2018
OBJECTIVE. To determine whether probiotic prophylaxes reduce the odds of Clostridium difficile infection (CDI) in adults and children. DESIGN. Individual participant data (IPD) meta-analysis of randomized controlled trials (RCTs), adjusting for risk factors. METHODS. We searched 6 databases and 11 grey literature sources from inception to April 2016. We identified 32 RCTs (n=8,713); among them, 18 RCTs provided IPD (n=6,851 participants) comparing probiotic prophylaxis to placebo or no treatment (standard care). One reviewer prepared the IPD, and 2 reviewers extracted data, rated study quality, and graded evidence quality. RESULTS. Probiotics reduced CDI odds in the unadjusted model (n=6,645; odds ratio [OR] 0.37; 95% confidence interval [CI], 0.25-0.55) and the adjusted model (n=5,074; OR, 0.35; 95% CI, 0.23-0.55). Using 2 or more antibiotics increased the odds of CDI (OR, 2.20; 95% CI, 1.11-4.37), whereas age, sex, hospitalization status, and high-risk antibiotic exposure did not. Adjusted subgroup analyses suggested that, compared to no probiotics, multispecies probiotics were more beneficial than single-species probiotics, as was using probiotics in clinical settings where the CDI risk is 5%. Of 18 studies, 14 reported adverse events. In 11 of these 14 studies, the adverse events were retained in the adjusted model. Odds for serious adverse events were similar for both groups in the unadjusted analyses (n=4,990; OR, 1.06; 95% CI, 0.89-1.26) and adjusted analyses (n=4,718; OR, 1.06; 95% CI, 0.89-1.28). Missing outcome data for CDI ranged from 0% to 25.8%. Our analyses were robust to a sensitivity analysis for missingness. CONCLUSIONS. Moderate quality (ie, certainty) evidence suggests that probiotic prophylaxis may be a useful and safe CDI prevention strategy, particularly among participants taking 2 or more antibiotics and in hospital settings where the risk of CDI is >= 5%.
Journal Article
Reply to Comment on ‘Deuterium supersaturated surface layer in tungsten: ion energy dependence’
2024
We reply to the comment by Li et al (submitted to Nucl. Fusion with this response) on our recent paper Nishijima et al (2023 Nucl. Fusion 63 126003). In this response, we address the existence of an incident ion energy, E i, threshold for the deuterium (D) supersaturated surface layer (DSSL) formation with a newly conducted D plasma exposure experiment at E i ∼ 20 eV. It is also further demonstrated, based on new experiments where the ion flux, fluence, and sample temperature are scanned, that non-kinetic (ballistic) processes play a role in the DSSL formation and growth. In addition, the effect of impurities in our plasma is discussed also with a new analysis of the surface composition made after a D plasma exposure.
Journal Article
Comparative analysis of SET domain proteins in maize and Arabidopsis reveals multiple duplications preceding the divergence of monocots and dicots
by
Kaeppler, S.M
,
Kaeppler, H.F
,
Cone, K.C
in
Amino Acid Sequence
,
amino acid sequences
,
Amino acids
2003
Histone proteins play a central role in chromatin packaging, and modification of histones is associated with chromatin accessibility. SET domain [Su(var)3-9, Enhancer-of-zeste, Trithorax] proteins are one class of proteins that have been implicated in regulating gene expression through histone methylation. The relationships of 22 SET domain proteins from maize (Zea mays) and 32 SET domain proteins from Arabidopsis were evaluated by phylogenetic analysis and domain organization. Our analysis reveals five classes of SET domain proteins in plants that can be further divided into 19 orthology groups. In some cases, such as the Enhancer of zeste-like and trithorax-like proteins, plants and animals contain homologous proteins with a similar organization of domains outside of the SET domain. However, a majority of plant SET domain proteins do not have an animal homolog with similar domain organization, suggesting that plants have unique mechanisms to establish and maintain chromatin states. Although the domains present in plant and animal SET domain proteins often differ, the domains found in the plant proteins have been generally implicated in protein-protein interactions, indicating that most SET domain proteins operate in complexes. Combined analysis of the maize and Arabidopsis SET domain proteins reveals that duplication of SET domain proteins in plants is extensive and has occurred via multiple mechanisms that preceded the divergence of monocots and dicots.
Journal Article
Mutant p53 upregulates alpha-1 antitrypsin expression and promotes invasion in lung cancer
2017
Missense mutations in the
TP53
tumor-suppressor gene inactivate its antitumorigenic properties and endow the incipient cells with newly acquired oncogenic properties that drive invasion and metastasis. Although the oncogenic effect of mutant p53 transcriptome has been widely acknowledged, the global influence of mutant p53 on cancer cell proteome remains to be fully elucidated. Here, we show that mutant p53 drives the release of invasive extracellular factors (the ‘secretome’) that facilitates the invasion of lung cancer cell lines. Proteomic characterization of the secretome from mutant p53-inducible H1299 human non-small cell lung cancer cell line discovered that the mutant p53 drives its oncogenic pathways through modulating the gene expression of numerous targets that are subsequently secreted from the cells. Of these genes, alpha-1 antitrypsin (A1AT) was identified as a critical effector of mutant p53 that drives invasion
in vitro
and
in vivo,
together with induction of epithelial–mesenchymal transition markers expression. Mutant p53 upregulated A1AT transcriptionally through the involvement with its family member p63. Conditioned medium containing secreted A1AT enhanced cell invasion, while an A1AT-blocking antibody attenuated the mutant p53-driven migration and invasion. Importantly, high A1AT expression correlated with increased tumor stage, elevated p53 staining and shorter overall survival in lung adenocarcinoma patients. Collectively, these findings suggest that A1AT is an indispensable target of mutant p53 with prognostic and therapeutic potential in mutant p53-expressing tumors.
Journal Article
RNA expression analysis using a 30 base pair resolution Escherichia coli genome array
by
Lockhart, David J.
,
Johansson, Erik M.
,
Blattner, Frederick R.
in
Agriculture
,
Bacteriology
,
Bioinformatics
2000
We have developed a high-resolution “genome array” for the study of gene expression and regulation in
Escherichia coli
. This array contains on average one 25-mer oligonucleotide probe per 30 base pairs over the entire genome, with one every 6 bases for the intergenic regions and every 60 bases for the 4,290 open reading frames (ORFs). Twofold concentration differences can be detected at levels as low as 0.2 messenger RNA (mRNA) copies per cell, and differences can be seen over a dynamic range of three orders of magnitude. In rich medium we detected transcripts for 97% and 87% of the ORFs in stationary and log phases, respectively. We found that 1,529 transcripts were differentially expressed under these conditions. As expected, genes involved in translation were expressed at higher levels in log phase, whereas many genes known to be involved in the starvation response were expressed at higher levels in stationary phase. Many previously unrecognized growth phase-regulated genes were identified, such as a putative receptor (b0836) and a 30S ribosomal protein subunit (S22), both of which are highly upregulated in stationary phase. Transcription of between 3,000 and 4,000 predicted ORFs was observed from the antisense strand, indicating that most of the genome is transcribed at a detectable level. Examples are also presented for high-resolution array analysis of transcript start and stop sites and RNA secondary structure.
Journal Article
Cause-Specific Mortality and 30-year Relative Survival of Crohn's Disease and Ulcerative Colitis
2013
Data from the northern hemisphere suggest that patients with ulcerative colitis (UC) have similar survival to the general population, whereas mortality in Crohn's disease (CD) is increased by up to 50%. There is a paucity of data from the southern hemisphere, especially in Australia.MethodsA prevalence cohort (1977–1992) of patients with inflammatory bowel disease (IBD) diagnosed after 1970 was studied. Survival status data and causes of death up to December 2010 were extracted from the National Death Index. Relative survival analysis was carried out separately for men and women.ResultsOf 816 cases (384 men, 432 women; 373 CD, 401 UC, 42 indeterminate colitis), 211 (25.9%) had died by December 2010. Median follow-up was 22.2 years. Relative survival of all patients with IBD was not significantly different from the general population at 10, 20, and 30 years of follow-up. Separate analyses of survival in CD and UC also showed no differences from the general population. There was no difference in survival between patients diagnosed earlier (1971–1979) or later (1980–1992). At least 17% of the deaths were caused by IBD. Fatal cholangiocarcinomas were more common in IBD (P < 0.001), and fatal colorectal cancers more common in UC (P = 0.047).ConclusionsIn Australia, IBD patient survival is similar to the general population. In contrast to data from Europe and North America, survival in CD is not diminished in Australia. IBD caused direct mortality in 17%, especially as biliary and colorectal cancers are significant causes of death.
Journal Article
Deuterium supersaturated surface layer in tungsten: ion energy dependence
2023
Abstract
Properties of deuterium (D) supersaturated surface layers (DSSLs) formed in tungsten (W), such as thickness, internal microstructures, and D retention, are experimentally investigated as a function of the incident ion energy, E i . W samples were exposed to D plasmas in the PISCES-A linear plasma device in a range of E i ∼ 45–175 eV, while other plasma exposure parameters were fixed: sample temperature, T s , ∼423 K, ion flux, Γ i , ∼1.2 × 10 21 m −2 s −1 , and fluence, Φ i , ∼3.0 × 10 24 m −2 . High-resolution, cross-sectional, transmission electron microscopy observations confirm that (1) a DSSL forms even at the lowest E i ∼ 45 eV, (2) the DSSL thickness, Δ t DSSL , is found to decrease with decreasing E i from ∼11–12 nm at E i ∼ 175 eV to ∼5–6 nm at ∼45 eV, and to agree with approximately the maximum implantation depth calculated using SDTrimSP, and (3) high-density D nanobubbles with a diameter of ∼1 nm or less exist inside the DSSL, which is deemed to validate a theory-predicted vacancy stabilization process due to trapping of a solute D atom(s). Utilizing a D areal density of ∼4.2 × 10 19 m −2 in the first 14 nm from the surface at E i ∼ 75 eV from nuclear reaction analysis and the measured E i dependence of Δ t DSSL , our previous laser-induced breakdown spectroscopy data is updated: both dynamic and static D retention increase with decreasing E i , and the D/W atomic fraction during plasma exposure reaches ∼0.3 at E i ∼ 45 eV. A possible DSSL formation mechanism is proposed.
Journal Article