Martin Hardt

Martin Hardt
Justus-Liebig-Universität Gießen | JLU · Biomedical Research Center BFS - Imaging Unit

Dr. rer. nat.

About

75
Publications
13,676
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2,348
Citations
Citations since 2016
31 Research Items
1279 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250

Publications

Publications (75)
Article
The determination of the electrostatic charge of biological nanoparticles requires a purified, mono-disperse, and concentrated sample. Previous studies proofed an impact of the preparation protocol on the stability and electro-hydrodynamics of viruses, whereas commonly used methods are often complex and do not allow the required sample throughput....
Preprint
Full-text available
Microplastics (MP) represent an anthropogenic surface for bacterial colonization in marine ecosystems. In order to determine if MP act as vectors of specific bacterial communities, which might include non-native and potential pathogens for the marine biota, bacterial assemblages formed on sterile polyethylene MP particles after 12 weeks of incubati...
Article
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The demonstration that spray-induced gene silencing (SIGS) can confer strong disease resistance, bypassing the laborious and time-consuming transgenic expression of double-stranded (ds)RNA to induce the gene silencing of pathogenic targets, was ground-breaking. However, future field applications will require fundamental mechanistic knowledge of dsR...
Preprint
The demonstration that spray-induced gene silencing (SIGS) can confer strong disease resistance bypassing the laborious and time-consuming transgenic expression of double-stranded (ds)RNA to induce gene silencing of pathogenic targets was groundbreaking. However, future field applications will require fundamental mechanistic knowledge on dsRNA upta...
Article
Full-text available
The Alphaproteobacterium Rhizobium radiobacter (syn. Agrobacterium tumefaciens, “A. fa brum”) can live in close association with the sebacinoid fungus Serendipita (syn. Piriformospora) indica that forms a mutualistic Sebacinalean symbiosis with a wide range of host plants. The endobacterial strain R. radiobacter F4 (RrF4), which was originally isol...
Article
The large demand for safe and efficient viral vector-based vaccines and gene therapies against both inherited and acquired diseases accelerates the development of viral vectors. One outstanding example, the Orf virus, has a wide range of applications, a superior efficacy and an excellent safety profile combined with a reduced pathogenicity compared...
Article
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Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that t...
Article
The leaf colonizing bacterial microbiota was studied in a long-term warming experiment of a permanent grassland, which had been continuously exposed to increased surface temperate (+2°C) for more than six years. Two abundant plant species, Arrhenatherum elatius and Galium album, were studied. Surface warming reduced stomata opening and changed leaf...
Preprint
Small (s)RNA molecules are crucial factors in the communication between hosts and their interacting pathogens, where they function as effectors that can modulate both host defense and microbial virulence/pathogenicity through a mechanism termed cross-kingdom RNA interference (ckRNAi). Consistent with this recent knowledge, sRNAs and their double-st...
Article
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Current antibiotics cannot eradicate uropathogenic Escherichia coli (UPEC) biofilms, leading to recurrent urinary tract infections. Here, we show that the insect antimicrobial peptide cecropin A (CecA) can destroy planktonic and sessile biofilm-forming UPEC cells, either alone or when combined with the antibiotic nalidixic acid (NAL), synergistical...
Article
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Cellular specialization and interaction with other cell types in cardiac tissue is essential for the coordinated function of cell populations in the heart. The complex interplay between cardiomyocytes, endothelial cells and fibroblasts is necessary for adaptation but can also lead to pathophysiological remodeling. To understand this complex interpl...
Article
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Introduction: Mitochondria supply cellular energy and are key regulators of intrinsic cell death and consequently affect longevity. The nematode Caenorhabditis elegans is frequently used for lifespan assays. Using paraquat (PQ) as a generator of reactive oxygen species, we here describe its effects on the acceleration of aging and the associated d...
Article
Full-text available
The endocannabinoid (EC) system has been implicated in the pathogenesis of several metabolic diseases, including nonalcoholic fatty liver disease (NAFLD). With the current study we aimed to verify the modulatory effect of endocannabinoid receptor 1 (CB1)-signaling on perilipin 2 (PLIN2)-mediated lipophagy. Here, we demonstrate that a global knockou...
Article
Full-text available
Natural products have moved into the spotlight as possible sources for new drugs in the treatment of helminth infections including schistosomiasis. Surprisingly, insect-derived compounds have largely been neglected so far in the search for novel anthelminthics, despite the generally recognized high potential of insect biotechnology for drug discove...
Data
3D animation of a female ovary stained for EdU-positive proliferating stem cells and Hoechst-positive cells. Still images are shown in Fig 7. (MPG)
Data
Characterization of AChE activity. (A-D) Inhibition of enzymatic activity by the AChE inhibitor physostigmine. Enzymatic activity over time of AChE from electric eel (A) or of protein lysates of paired S. mansoni males (B) after adding different concentrations of physostigmine (0 – 2500 nM). One representative out of two similar experiments is show...
Data
Effect of harmonine on proliferation of gonadal stem cells (conventional CLSM without IMARIS processing). Worms were treated with 5 μM (C, D) or 10 μM (E, F) harmonine or with an equivalent amount of solvent as negative control (A, B) for 72 h, with EdU added for the last 24 h. EdU-positive proliferating stem cells in female ovaries (A, C, E) or ma...
Data
Carboxyl-esterase domains in AChE orthologs of S. mansoni. PFAM domains were revealed by the online-tool SMART (http://smart.embl-heidelberg.de/). (TIF)
Article
Full-text available
Marine sponges thrive in benthic environments despite intense spatial competition and predator pressure. The sessile filter-feeders usually compensate their lack of physical defense and behavioral escape by a high level of bioactivity. In the stinging black sponge (Haliclona cnidata sp. nov.), these chemical defense mechanisms are complemented by “...
Article
A bright-orange-pigmented, Gram-stain-negative, motile, and rod-shaped bacterium, strain MAA42T, was isolated from a marine sponge of the genus Haliclona, which is in long-time culture in a marine aquarium system at the Justus Liebig University Giessen, Germany. The strain grew at 4-34 °C (optimum 28 °C), in the presence of 0.5-9.5 % (w/v) NaCl (op...
Article
Full-text available
Circular RNAs (circRNAs) are a novel class of noncoding RNAs present in all eukaryotic cells investigated so far and generated by a special mode of alternative splicing of pre-mRNAs. Thereby, single exons, or multiple adjacent and spliced exons, are released in a circular form. CircRNAs are cell-type specifically expressed, are unusually stable, an...
Article
Two Gram-stain-negative, facultative anaerobic, motile, rod-shaped strains, S-B4-1UT and JOB-63a, forming small whitish transparent colonies on marine agar, were isolated from a sponge of the genus Haliclona. The strains shared 99.7% 16S rRNA gene sequence identity and a DNA-DNA hybridization value of 100%, but were differentiated by genomic finger...
Article
Full-text available
Coronavirus replication is associated with intracellular membrane rearrangements in infected cells, resulting in the formation of double-membrane vesicles (DMVs) and other membranous structures that are referred to as replicative organelles (ROs). The latter provide a structural scaffold for viral replication/transcription complexes (RTCs) and help...
Article
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A yellow-pigmented, Gram-stain-negative, motile and rod-shaped bacterium, strain M1A16(T), was isolated from the internal tissue of a sponge of the genus Haliclona, which was long-term cultured in the CEMarin aquaria system at Justus Liebig University of Giessen. The strain grew well at 20-32 °C (optimum 25 °C), in the presence of 0-6 % NaCl (optim...
Article
Full-text available
Many ribonucleases (RNases) are considered as promising tools for antitumor therapy because of their selective cytotoxicity toward cancer cells. Binase, the RNase from Bacillus pumilus, triggers apoptotic response in cancer cells expressing RAS oncogene which is mutated in a large percentage of prevalent and deadly malignancies including colorectal...
Chapter
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The nonpathogenic Alphaproteobacterium Rhizobium radiobacter (syn. Agrobacterium tumefaciens) (RrF4) is a subculture of the endobacterium R. radiobacter, which is intricately associated with its host, the beneficial plant-colonizing fungal basidiomycete Piriformospora indica. RrF4 is genetically very similar to the well-studied plant pathogenic R....
Article
Over the last decade there have been increasing efforts to develop 3D scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone m...
Article
Over the last decade there have been increasing efforts to develop adequate 3D scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizi...
Article
Full-text available
The Alphaproteobacterium Rhizobium radiobacter F4 (RrF4) was originally characterized as an endofungal bacterium in the beneficial endophytic Sebacinalean fungus Piriformospora indica. Although attempts to cure P. indica from RrF4 repeatedly failed, the bacterium can easily be grown in pure culture. Here, we report on RrF4's genome and the benefici...
Article
In the emerging era of post-genomic research on schistosomes, new methods are required to functionally analyse genes of interest in more detail. Among other tools, schistosome cell lines are needed to overcome present research constraints. Based on a recently established organ isolation protocol for adult Schistosoma mansoni, we report here on the...
Article
Full-text available
Unlabelled: Influenza A viruses (IAV) replicate their segmented RNA genome in the nucleus of infected cells and utilize caspase-dependent nucleocytoplasmic export mechanisms to transport newly formed ribonucleoprotein complexes (RNPs) to the site of infectious virion release at the plasma membrane. In this study, we obtained evidence that apoptoti...
Article
The genus Origanum is divided in several species and subspecies. Common oregano (Origanum vulgare L. subsp. vulgare) and Greek oregano (Origanum vulgare L. subsp. hirtum) are two important subspecies which are characterized by different content of essential oil synthesized in glandular trichomes. Investigations with light microscopy and scanning el...
Conference Paper
Full-text available
A high number of bacterial species is inhabiting the aboveground part (phyllosphere) of plants. Global climate changes lead to an increasing atmospheric CO 2 concentration which can directly or indirectly (by increasing plant growth) affect the abundance and community structures of the phyllosphere-inhabiting bacteria and in consequence influence p...
Article
Full-text available
Aims Nitrification inhibitors (NI) formulated on granulated ammonium sulphate nitrate (ASN) are an option to minimize nitrate leaching into ground waters and emissions of the greenhouse gas N2O. This paper focuses (a) on the development of an analytic enabling to extract and quantify the NI 3,4-dimethylpyrazolephosphate (DMPP), marketed since 1999....
Article
Full-text available
In order to separate and analyze saliva types secreted during stylet propagation and feeding, aphids were fed on artificial diets. Gel saliva was deposited as chains of droplets onto Parafilm membranes covering the diets into which watery saliva was secreted. Saliva compounds collected from the diet fluid were separated by SDS-PAGE, while non-solub...
Data
Absorption of water by salivary sheath of M. viciae. Salivary sheaths on Parafilm®, were observed with bright field microscopy (40× water immersion objective). Images were taken at t = 0 s (A) and t = 30 s (B). A salivary sheath that dried for approximately 30 minutes (A) swells after addition of water and reaches its final size within a few second...
Data
Solubilisation of salivary sheaths from M. viciae by denaturating solution. Salivary sheaths, attached to the lower side of Parafilm®, were observed with bright field microscopy (40× water immersion objective). Images were taken at t = 0 min (A, D), t = 20 min (B, E) and t = 40 min (C, F) after application of the respective solvent (denaturating so...
Article
The orphan carrier protein Slc10a4 represents a novel member of the so-called "sodium-bile acid co-transporter family," SLC10. Slc10a4 has a close phylogenetic relationship with the liver bile acid carrier Ntcp (Slc10a1), but has no transport activity for bile acids. In a previous study Slc10a4 proved to be predominantly expressed in the rat brain,...
Article
Ganss C, Hardt M, Lussi A, Cocks A-K, Klimek J, Schlueter N. Mechanism of action of tin-containing fluoride solutions as anti-erosive agents in dentine – an in vitro tin-uptake, tissue loss, and scanning electron microscopy study. Eur J Oral Sci 2010; 118: 376–384. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Solutions containing t...
Article
Full-text available
A thin liquid layer covers the lungs of air-breathing vertebrates. Active ion transport processes via the pulmonary epithelial cells regulate the maintenance of this layer. This study focuses on basolateral Cl(-) uptake mechanisms in native lungs of Xenopus laevis and the involvement of the Na(+)/K(+)/2 Cl(-) cotransporter (NKCC) and HCO(3)(-)/Cl(-...
Article
In patients with eating disorders, gastric and pancreatic enzymes could possibly reach the oral cavity during vomiting and could perhaps degrade the organic matrix of eroded dentine. This in vitro study sought to investigate whether pepsin, trypsin or the combination of both, have an influence on erosive mineral loss in dentine and whether they are...
Article
Erosion of dentine causes mineral dissolution, while the organic compounds remain at the surface. Therefore, a determination of tissue loss is complicated. Established quantitative methods for the evaluation of enamel have also been used for dentine, but the suitability of these techniques in this field has not been systematically determined. There...
Article
Tin-containing fluoride solutions can reduce erosive tissue loss, but the effects of the reaction between tin and enamel are still not clear. During a 10-d period, enamel specimens were cyclically demineralized (0.05 M citric acid, pH 2.3, 6 x 5 min d(-1)) and remineralized (between the demineralization cycles and overnight). In the negative-contro...
Article
Eroded dentine has a complex histological structure, and its organic fraction becomes increasingly exposed as a result of the continual action of acids. The present study sought to investigate the effects of brushing forces up to 4 N on mineralized and organic dentine fractions. The study was a cyclic demineralization and remineralization experimen...
Article
The viral and cellular determinants leading to binding and entry of hepatitis B virus (HBV) are still not fully understood. We found that HBV infection of primary hepatocyte cultures is dependent on the presence of cholesterol in the viral envelope. Extraction of cholesterol from HBV purified from plasma of HBV-infected patients with methyl-beta-cy...
Article
The stereotyped response of the female Leptophyes punctatissima Bosc. to a representation of the male call has been taken as a behavioural measure to determine the directional sensitivity of monaurally deafened animals. By using the responses of an auditory interneuron (T-fibre), the directional sensitivity could also be measured neurophysiological...
Article
For successful in vivo infection, Eimeria bovis sporozoites have to traverse the mucosal layer of the ileum to infect lymphatic endothelial cells and may, thereby, be exposed to the interstitial fluid and to the lymph representing potential targets for leukocytes. To mimic this situation in vitro, we exposed E. bovis sporozoites to bovine PMN and f...
Article
The aim of the study was to evaluate the relevance of cations in different fluoride compounds for their effectiveness as anti-erosive agents. Human enamel samples underwent a de- and re-mineralisation procedure for 10 days. Erosive demineralisation was performed with 0.05 M citric acid (pH 2.3) 6 x 2 min daily followed by immersion in the test solu...
Article
It is an established assumption that eroded dental hard tissues are particularly prone to toothbrush abrasion. Only a few studies have aimed to show this for dentine and, if so, disregarded the complex histological structure of this tissue. Therefore, the present study sought (i) to investigate the effects of toothbrushing on eroded dentine and (ii...
Article
In dentine, erosive lesion progression and efficacy of fluoridation measures for symptomatic therapy of dental erosion are both dependent on the presence of the organic matrix. In patients with eating disorders in combination with chronic vomiting, the demineralized organic matrix can be degraded by gastric enzymes. The aim of this study was to inv...
Article
Full-text available
The aim of the present study was the characterization of the subtypes of inositol 1,4,5-trisphosphate receptors (IP3R) in rat colonic epithelium. A monoclonal antibody against IP3R1 did not stain the colonic epithelial cells. In contrast, IP3R2 and IP3R3 were found within the epithelium; however, with a distinct intracellular localization and diffe...
Article
Full-text available
A novel genus and species are proposed for two strains of methanotrophic bacteria isolated from hypersaline lakes in the Crimean Peninsula of Ukraine. Strains 10Ki(T) and 4Kr are moderate halophiles that grow optimally at 1-1.5 M (5.8-8.7%, w/v) NaCl and tolerate NaCl concentrations from 0.2 M up to 2.5 M (1.2-15%). This optimum and upper limit are...
Article
Post-growth treatments, such as annealing, sulfurization, etching as well as ageing, were performed on CuInS2 films prepared by RF reactive sputtering. Their effects on the structural, optical and electrical properties of the films were studied by means of x-ray diffraction (XRD) and scanning electron microscopy (SEM), optical transmission, and Hal...
Article
We asked to what extent Ca(2+) signals in two different domains of Paramecium cells remain separated during different stimulations. Wild-type (7S) and pawn cells (strain d4-500r, without ciliary voltage-dependent Ca(2+)-channels) were stimulated for trichocyst exocytosis within 80 ms by quenched-flow preparation and analysed by energy-dispersive X-...
Article
As a preliminary step towards superstrate-type solar cells, we fabricated films of a CuInS2/ZnO:Al/float glass configuration. A layer of aluminum doped ZnO (ZnO:Al) with a thickness of 320–450 nm was first prepared on float glass at 200 °C by mid-frequency magnetron reactive sputtering. Then, a CuInS2 layer, typically 500 nm thick, was deposited on...
Article
We investigated systematically the influence of the sputter parameters, such as substrate temperature, H2S flow, and sputter power on the structural, optical, and electrical properties of the sputtered CuInS2 films, to optimize the parameters for the one-stage growth of CuInS2 films by radio frequency (R-F) reactive sputtering. When the H2S flow du...
Article
Full-text available
CuInS2 films were deposited on float glass substrates by a one-stage reactive RF sputter process using a Cu-In alloy target and H2S gas. The sputtered films generally have a (112) preferential orientation. X-ray reflectometry was used to measure the thickness, surface density as well as surface roughness of the sputtered films. The surface morpholo...