Modification of 3D-Printed PLA Structures Using Photo-Iniferter Polymerization: Toward On-Demand Antimicrobial Water Filters.

Water filtration is an important application to ensure the accessibility of clean drinking water. As requirements and contaminants vary on a local level, adjustable filter devices and their evaluation with contaminants are required. Within this work, modular filter devices are designed featuring an adjustable surface functionalization. For this purpose, 3D-printed structures are created consisting of bio-based poly(lactic acid) (PLA) that are manufactured by extrusion printing. The surface of PLA is activated with amino groups that are used to install xanthates as chain transfer agents. Subsequently, photo-iniferter (PI) polymerization is used to create cationic polymer brushes on the surface of PLA substrates. Multiple surface characterization techniques are employed to prove successful growth of polymer brushes on PLA. After initial optimization studies on flat surfaces, filter devices are printed, functionalized, and used to remove bacteria from contaminated water. Significant reduction of the number of microorganisms is detected after filtration (single filtration or cycling) and contaminating organism can also be removed from freshwater samples by simple incubation with a 3D-printed filter. The herein developed setup for producing functional filter devices and probing their performance in affinity filtration is a useful platform technology, enabling the rapid testing of polymer brushes for such applications.

PEATmoss (Physcomitrella Expression Atlas Tool): a unified gene expression atlas for the model plant Physcomitrella patens.

Physcomitrella patens is a bryophyte model plant that is often used to study plant evolution and development. Its resources are of great importance for comparative genomics and evo-devo approaches. However, expression data from Physcomitrella patens were so far generated using different gene annotation versions and three different platforms: CombiMatrix and NimbleGen expression microarrays and RNA sequencing. The currently available P. patens expression data are distributed across three tools with different visualization methods to access the data. Here, we introduce an interactive expression atlas, Physcomitrella Expression Atlas Tool (PEATmoss), that unifies publicly available expression data for P. patens and provides multiple visualization methods to query the data in a single web-based tool. Moreover, PEATmoss includes 35 expression experiments not previously available in any other expression atlas. To facilitate gene expression queries across different gene annotation versions, and to access P. patens annotations and related resources, a lookup database and web tool linked to PEATmoss was implemented. PEATmoss can be accessed at https://peatmoss.online.uni-marburg.de.

Characterization of Phytochrome Interacting Factors from the Moss Physcomitrella patens Illustrates Conservation of Phytochrome Signaling Modules in Land Plants.

Across the plant kingdom, phytochrome (PHY) photoreceptors play an important role during adaptive and developmental responses to light. In Arabidopsis thaliana, light-activated PHYs accumulate in the nucleus, where they regulate downstream signaling components, such as phytochrome interacting factors (PIFs). PIFs are transcription factors that act as repressors of photomorphogenesis; their inhibition by PHYs leads to substantial changes in gene expression. The nuclear function of PHYs, however, has so far been investigated in only a few non-seed plants. Here, we identified putative target genes of PHY signaling in the moss Physcomitrella patens and found light-regulated genes that are putative orthologs of PIF-controlled genes in Arabidopsis. Phylogenetic analyses revealed that an ancestral PIF-like gene was already present in streptophyte algae, i.e., before the water-to-land transition of plants. The PIF homologs in the genome of P. patens resemble Arabidopsis PIFs in their protein domain structure, molecular properties, and physiological effects, albeit with notable differences in the motif-dependent PHY interaction. Our results suggest that P. patens PIFs are involved in PHY signaling. The PHY-PIF signaling node that relays light signals to target genes has been largely conserved during land plant evolution, with evidence of lineage-specific diversification.

Large-scale gene expression profiling data for the model moss Physcomitrella patens aid understanding of developmental progression, culture and stress conditions.

The moss Physcomitrella patens is an important model organism for studying plant evolution, development, physiology and biotechnology. Here we have generated microarray gene expression data covering the principal developmental stages, culture forms and some environmental/stress conditions. Example analyses of developmental stages and growth conditions as well as abiotic stress treatments demonstrate that (i) growth stage is dominant over culture conditions, (ii) liquid culture is not stressful for the plant, (iii) low pH might aid protoplastation by reduced expression of cell wall structure genes, (iv) largely the same gene pool mediates response to dehydration and rehydration, and (v) AP2/EREBP transcription factors play important roles in stress response reactions. With regard to the AP2 gene family, phylogenetic analysis and comparison with Arabidopsis thaliana shows commonalities as well as uniquely expressed family members under drought, light perturbations and protoplastation. Gene expression profiles for P. patens are available for the scientific community via the easy-to-use tool at https://www.genevestigator.com. By providing large-scale expression profiles, the usability of this model organism is further enhanced, for example by enabling selection of control genes for quantitative real-time PCR. Now, gene expression levels across a broad range of conditions can be accessed online for P. patens.

Molecular evidence for convergent evolution and allopolyploid speciation within the Physcomitrium-Physcomitrella species complex.

BACKGROUND: The moss Physcomitrella patens (Hedw.) Bruch & Schimp. is an important experimental model system for evolutionary-developmental studies. In order to shed light on the evolutionary history of Physcomitrella and related species within the Funariaceae, we analyzed the natural genetic diversity of the Physcomitrium-Physcomitrella species complex. RESULTS: Molecular analysis of the nuclear single copy gene BRK1 reveals that three Physcomitrium species feature larger genome sizes than Physcomitrella patens and encode two expressed BRK1 homeologs (polyploidization-derived paralogs), indicating that they may be allopolyploid hybrids. Phylogenetic analyses of BRK1 as well as microsatellite simple sequence repeat (SSR) data confirm a polyphyletic origin for three Physcomitrella lineages. Differences in the conservation of mitochondrial editing sites further support hybridization and cryptic speciation within the Physcomitrium-Physcomitrella species complex. CONCLUSIONS: We propose a revised classification of the previously described four subspecies of Physcomitrella patens into three distinct species, namely Physcomitrella patens, Physcomitrella readeri and Physcomitrella magdalenae. We argue that secondary reduction of sporophyte complexity in these species is due to the establishment of an ecological niche, namely spores resting in mud and possible spore dispersal by migratory birds. Besides the Physcomitrium-Physcomitrella species complex, the Funariaceae are host to their type species, Funaria hygrometrica, featuring a sporophyte morphology which is more complex. Their considerable developmental variation among closely related lineages and remarkable trait evolution render the Funariaceae an interesting group for evolutionary and genetic research.

Skeletal stability and complications in transantral maxillary distraction in patients with cleft lip and palate.

The current prospective study aimed at assessing skeletal stability and complications arising from transantral maxillary distraction adopted for advancements of less than 12 mm in patients with cleft lip, alveolus, and palate malformations.The recruited patients with cleft lip, alveolus, and palate were followed up for 12 months. Lateral skull radiographs were obtained before surgery (T0), at the end of the activation period of the distractors (T1), and after completion of the follow-up interval (T2). Length and height of the maxilla were assessed at the different points of time. The relapse rate of maxillary advancement was calculated. Complications such as infections, distractor breakage and loosening, nonunions, and the need for reoperation were documented.Seven patients were included in this study (mean [SD] age, 19.5 [2.6] y). The length of the maxilla significantly increased by 6.4 ± 1.1 mm at T1 (P = 0.018) but showed a significant relapse by 7.5% at T2 (P = 0.018). As a complication, a case of infection of the cheek occurred during the consolidation period, which could be treated conservatively. In an additional patient, there was a loosening of a distractor at the end of the distraction period, which required reoperation with conventional fixation of the maxilla in the intended position. At the time of removal of the distractors and the conventional osteosynthesis plates, no cases of nonunion could be identified.It seems that the low horizontal relapse rate of transantral maxillary distraction in patients with cleft lip and palate outweighs the possible complications of this procedure in cases of limited distances of advancement of less than 12 mm.

Agricultural intensification and cereal aphid-parasitoid-hyperparasitoid food webs: network complexity, temporal variability and parasitism rates.

Agricultural intensification (AI) is currently a major driver of biodiversity loss and related ecosystem functioning decline. However, spatio-temporal changes in community structure induced by AI, and their relation to ecosystem functioning, remain largely unexplored. Here, we analysed 16 quantitative cereal aphid-parasitoid and parasitoid-hyperparasitoid food webs, replicated four times during the season, under contrasting AI regimes (organic farming in complex landscapes vs. conventional farming in simple landscapes). High AI increased food web complexity but also temporal variability in aphid-parasitoid food webs and in the dominant parasitoid species identity. Enhanced complexity and variability appeared to be controlled bottom-up by changes in aphid dominance structure and evenness. Contrary to the common expectations of positive biodiversity-ecosystem functioning relationships, community complexity (food-web complexity, species richness and evenness) was negatively related to primary parasitism rates. However, this relationship was positive for secondary parasitoids. Despite differences in community structures among different trophic levels, ecosystem services (parasitism rates) and disservices (aphid abundances and hyperparasitism rates) were always higher in fields with low AI. Hence, community structure and ecosystem functioning appear to be differently influenced by AI, and change differently over time and among trophic levels. In conclusion, intensified agriculture can support diverse albeit highly variable parasitoid-host communities, but ecosystem functioning might not be easy to predict from observed changes in community structure and composition.

Effects of enamel sealing on shear bond strength and the adhesive remnant index : Study of three fluoride-releasing adhesives in combination with metal and ceramic brackets.

OBJECTIVES: Selected combinations of materials were used to create tooth-adhesive-bracket complexes to evaluate shear bond strength (SBS) and the adhesive remnant index (ARI) with regard to enamel sealing. METHODS: Four adhesive systems also appropriate for use as enamel sealants were combined with four bracket types, resulting in 16 adhesive-bracket combinations, each of which was tested on 15 permanent bovine incisors. Sealant-adhesives included two recently introduced fluoride-releasing systems (Riva bond LC® and go!®), one established primer (Opal® Seal™), and one commonly used adhesive as control (Transbond™ XT). Brackets included two metal (discovery® by Dentaurum and Sprint®) and two ceramic (discovery® pearl and GLAM®) systems. After embedding the bovine teeth, bonding the brackets to their surface, and storing the resultant samples as per DIN 13990-2 with modifications, an SBS test was performed by applying the shear force directly at the bracket base in an incisocervical direction. Then the ARI scores were determined. RESULTS: Discovery® + Transbond™ XT yielded the highest (47.2 MPa) and GLAM® + go!® the lowest (17.0 MPa) mean SBS values. Significant differences (p < 0.0001) were found between metal and ceramic brackets of the same manufacturers (Dentaurum and Forestadent). Our ratings of the failure modes upon debonding predominantly yielded ARI 0 or 1. The high SBS values and low ARI scores observed with discovery® + Transbond XT™ were reflected in a high rate of enamel fracture, which occurred on 11 of the 15 tooth specimens in this group. CONCLUSIONS: All sealant-bracket combinations were found to yield levels of SBS adequate for clinical application. SBS values and ARI scores varied significantly depending on which sealant-brackets were used.

Shear bond strength of brackets on restorative materials: Comparison on various dental restorative materials using the universal primer Monobond® Plus.

OBJECTIVE: The purpose of this work was to analyze surfaces consisting of different restorative materials for shear bond strength (SBS) and failure patterns of metal and ceramic brackets. Bonding involved the use of a universal primer (Monobond® Plus, Ivoclar Vivadent). MATERIALS AND METHODS: Six restorative materials were tested, including one composite resin (Clearfil Majesty™ Posterior, Kuraray Noritake Dental), one glass-ceramic material (IPS Empress® Esthetic, Ivoclar Vivadent), one oxide-ceramic material (CORiTEC Zr transpa Disc, imes-icore), two base-metal alloys (remanium® star, Dentaurum; Colado® CC, Ivoclar Vivadent), and one palladium-based alloy (Callisto® 75 Pd, Ivoclar Vivadent). Bovine incisors served as controls. Both metal and ceramic brackets (discovery®/discovery® pearl; Dentaurum) were bonded to the restorative surfaces after sandblasting and pretreatment with Monobond® Plus. A setup modified from DIN 13990-2 was used for SBS testing and adhesive remnant index (ARI)-based analysis of failure patterns. RESULTS: The metal brackets showed the highest mean SBS values on the glass-ceramic material (68.61 N/mm(2)) and the composite resin (67.58 N/mm(2)) and the lowest mean SBS on one of the base-metal alloys (Colado® CC; 14.01 N/mm(2)). The ceramic brackets showed the highest mean SBS on the glass-ceramic material (63.36 N/mm(2)) and the lowest mean SBS on the palladium-based alloy (38.48 N/mm(2)). Significant differences between the metal and ceramic brackets were observed in terms of both SBS values and ARI scores (p < 0.05). Under both bracket types, fractures of the composite-resin and the glass-ceramic samples were observed upon debonding. Opaque restorative materials under metal brackets were found to involve undercuring of the adhesive. CONCLUSIONS: Monobond® Plus succeeded in generating high bond strengths of both bracket types on all restorative surfaces. Given our observations of cohesive fracture (including cases of surface avulsion) of the composite-resin and the glass-ceramic samples, we recommend against using these material combinations in clinical practice.

Warmth and competence in your face! Visual encoding of stereotype content.

Previous research suggests that stereotypes about a group's warmth bias our visual representation of group members. Based on the stereotype content model (SCM) the current research explored whether the second big dimension of social perception, competence, is also reflected in visual stereotypes. To test this, participants created typical faces for groups either high in warmth and low in competence (male nursery teachers) or vice versa (managers) in a reverse correlation image classification task, which allows for the visualization of stereotypes without any a priori assumptions about relevant dimensions. In support of the independent encoding of both SCM dimensions hypotheses-blind raters judged the resulting visualizations of nursery teachers as warmer but less competent than the resulting image for managers, even when statistically controlling for judgments on one dimension. People thus seem to use facial cues indicating both relevant dimensions to make sense of social groups in a parsimonious, non-verbal and spontaneous manner.

Network theory inspired analysis of time-resolved expression data reveals key players guiding P. patens stem cell development.

Transcription factors (TFs) often trigger developmental decisions, yet, their transcripts are often only moderately regulated and thus not easily detected by conventional statistics on expression data. Here we present a method that allows to determine such genes based on trajectory analysis of time-resolved transcriptome data. As a proof of principle, we have analysed apical stem cells of filamentous moss (P. patens) protonemata that develop from leaflets upon their detachment from the plant. By our novel correlation analysis of the post detachment transcriptome kinetics we predict five out of 1,058 TFs to be involved in the signaling leading to the establishment of pluripotency. Among the predicted regulators is the basic helix loop helix TF PpRSL1, which we show to be involved in the establishment of apical stem cells in P. patens. Our methodology is expected to aid analysis of key players of developmental decisions in complex plant and animal systems.

3D CT based rating of unilateral impacted canines.

OBJECTIVE: The aim of this study was to develop a reference system for multislice computed tomography (MSCT) images to determine of the location of impacted teeth in metric terms. STUDY DESIGN: The CT data of 17 patients with unilateral impacted maxillary canines were selected retrospectively from existing MSCT data sets. In a reference coordinate system, defined by anterior nasal spine (ANS), posterior nasal spine (PNS), and A-point, the axis length and the inclination of the canines were determined and impacted and non-impacted canines were compared. RESULTS: There were significant differences between the impacted and non-impacted canines (p ≤ 0.0003) for all inclinations and the lengths in the x- and z-axes. The measurement of the inclination and sections of the impacted and non-impacted canine tooth axes showed sufficient repeatability and reproducibility. CONCLUSION: The coordinate system proved to be suitable for the exact metric localization of impacted teeth.

Prediction and validation of promoters involved in the abscisic acid response in Physcomitrella patens.

Detection of cis-regulatory elements, such as transcription factor binding sites (TFBS), through utilization of ortholog conservation is possible only if genomic data from closely related organisms are available. An alternative approach is the detection of TFBS based on their overrepresentation in promoters of co-regulated genes. However, this approach usually suffers from a high rate of false-positive prediction. Here, we have conducted a case study using promoters of genes known to be strongly induced by the phytohormone abscisic acid (ABA) in the model plant Physcomitrella patens, a moss. Putative TFBS were detected using three de novo motif detection tools in a strict consensus approach. The resulting motifs were validated using data from microarray expression profiling and were able to predict ABA-induced genes with high specificity (90.48%) at mediocre sensitivity (33.33%). In addition, 27 genes predicted to contain ABA-responsive TFBS were validated using real-time PCR. Here, a total of 37% of the genes could be shown to be induced upon ABA treatment, while 70% were found to be regulated by ABA. We conclude that the consensus approach for motif detection using co-regulation information can be used to identify genes that are regulated under a given stimulus. In terms of evolution, we find that the ABA response has apparently been conserved since the first land plants on the level of families involved in transcriptional regulation.

Targeted gene knockouts reveal overlapping functions of the five Physcomitrella patens FtsZ isoforms in chloroplast division, chloroplast shaping, cell patterning, plant development, and gravity sensing.

Chloroplasts and bacterial cells divide by binary fission. The key protein in this constriction division is FtsZ, a self-assembling GTPase similar to eukaryotic tubulin. In prokaryotes, FtsZ is almost always encoded by a single gene, whereas plants harbor several nuclear-encoded FtsZ homologs. In seed plants, these proteins group in two families and all are exclusively imported into plastids. In contrast, the basal land plant Physcomitrella patens, a moss, encodes a third FtsZ family with one member. This protein is dually targeted to the plastids and to the cytosol. Here, we report on the targeted gene disruption of all ftsZ genes in P. patens. Subsequent analysis of single and double knockout mutants revealed a complex interaction of the different FtsZ isoforms not only in plastid division, but also in chloroplast shaping, cell patterning, plant development, and gravity sensing. These results support the concept of a plastoskeleton and its functional integration into the cytoskeleton, at least in the moss P. patens.