Universal Probe Research Articles

Luminosity Function of Collapsar Gamma-Ray Bursts: The Progenitor of Long Gamma-Ray Bursts Is Not Singular

Gamma-ray bursts (GRBs) are powerful probes of the high-redshift Universe. However, the proportion of collapsar GRBs among long GRBs and their event rate relative to the star formation rate (SFR) remain contentious issues. We assume that long GRBs with z ≥ 2 are all collapsar GRBs and construct the luminosity function using a high-redshift sample from the Swift satellite spanning 2004 to 2019. We model the luminosity function with a broken power-law form and consider three scenarios: no evolution, luminosity evolution, and density evolution. Our results are as follows: (1) The no-evolution model can be ruled out. (2) The fitting results indicate that to adequately explain the observations, a significant redshift evolution in either luminosity (evolution index δ=1.54−0.22+0.21 ) or density ( δ=2.09−0.26+0.29 ) is required. This excludes the possibility that the evolution of long GRBs with redshift is due to contamination from noncollapsar GRBs. (3) The luminosity evolution model predicts that the number of collapsar GRBs with z < 2 and P ≥ 1 ph cm−2 s−1 is 138.6, accounting for 82.5% of the observed long GRBs with z < 2 and P ≥ 1 ph cm−2 s−1. The density evolution model predicts that the number of collapsar GRBs with z < 2 and P ≥ 1 ph cm−2 s−1 is 80.2, accounting for 47.7% of the observation. Regardless of the model, a substantial portion of the long GRBs are not collapsar GRBs.

From phylogenomics to breeding: Can universal target capture probes be used in the development of SNP markers for kinship analysis?

AbstractPremiseLeveraging DNA markers, particularly single‐nucleotide polymorphisms (SNPs), in parentage analysis, sib‐ship reconstruction, and genomic relatedness analysis can enhance plant breeding efficiency. However, the limited availability of genomic information, confined to the most commonly used species, hinders the broader application of SNPs in species of lower economic interest (e.g., most tree species). We explored the possibility of using universal target capture probes, namely Angiosperms353, to identify SNPs and assess their effectiveness in genomic relatedness analysis.MethodsWe tested the approach in 11 tree species, six of which had a half‐sib family structure. Variants were called within species, and genomic relatedness analysis was conducted in species with two or more families. Scalability via amplicon sequencing was tested by designing primers and testing them in silico.ResultsAdequate SNPs for relatedness analysis were identified in all species. Relatedness values from Angiosperms353‐based SNPs highly correlated with those from thousands of genome‐wide DArTseq SNPs in Cordia africana, one of the species with a family structure. The in silico performance of designed primers demonstrated the potential for scaling up via amplicon sequencing.DiscussionUtilizing universal target capture probes for SNP identification can help overcome the limitations of genomic information availability, thereby enhancing the application of genomic markers in breeding plant species with lower economic interest.

A molecular detection method for HBV pgRNA without RNA extraction based on nucleic acid hybridization

BackgroundEarly diagnosis is critical for patients with chronic hepatitis B. Here, we utilized a sandwich RNA hybridization assay to directly detect HBV pgRNA, thereby avoiding the need for RNA extraction and purification. MethodsWe designed a hybridization cascade reaction on a solid surface using a set of oligonucleotide probes that target several highly conserved regions in pgRNA. The detection performance was validated by concurrently testing serum samples from CHB patients and healthy individuals. ResultsThe optimal detection conditions were: a universal probe coating concentration of 0.003 µg/µl with a coating duration of 2 h; capture probe and detection probe concentrations of 0.1 nM; a hybridization capture duration of 4 h; and an antibody incubation duration of 60 minutes. The sensitivity and specificity were calculated to be 91.47 % and 90.63 %, respectively. ConclusionThis novel detection method is both simple and high-throughput, making it particularly suitable for active CHB infection screening

Fluorescent labeling of live-cell surfaceome and its application in antibody-target interaction analysis

BackgroundCell-surface proteins play key roles in the communication between external stimuli and internal signaling. As protein types and expression levels vary in different cells, in-situ visualization of the whole surface proteome (surfaceome) may facilitate the study of their functions in homeostasis maintenance or response to environmental changes (e.g., drug treatment). However, there lacks easily-prepared and universal labeling probes to visualize them in living cells. ResultsWe designed and synthesized a small-molecule fluorescent probe, SRB-NHS, for one-step labeling of surfaceome. Live-cell imaging results exhibited the plasma membrane localization of the fluorescent signal from SRB-NHS and SDS-PAGE/fluorescence scanning results confirmed the covalent labeling of proteins by SRB-NHS, indicating the suitability of SRB-NHS for surfaceome labeling towards different cell lines. SignificanceUpon labeling by SRB-NHS, the cellular internalization of surfaceome was studied under different stimuli (e.g., nutritional deprivation, drug treatments). Intriguingly, specific monitoring of the interaction between antibody drugs and related cell-surface targets can be achieved when the probe is used in combination with fluorescently labeled antibodies and imaged via Förster resonance energy transfer (FRET), offering a new method compatible with various cell lines to monitor the surfaceome or a specific drug-target interaction in situ.

Novel Mn and Si alloyed complex phase steel for automotive applications

Automotive industries require materials with higher strength, plasticity and crashworthiness, aiming for 3rd generation of advanced high strength steels (AHSS) with medium Mn, Si and minor alloying elements. In this investigation, 3rd generation AHSS were synthesized using a vacuum arc melting furnace with manganese (Mn) and silicon (Si) as major alloying elements as well as minor additions such as Cr, Al, Ni, etc. The steels thus developed were characterized using FE-SEM, XRD, microhardness tester, universal testing machine (UTM) and 3-dimensional Atom Probe Tomography (APT). The alloy steels after casting and homogenization were subjected to hot rolling at 1100 °C, with rolling exit temperature 900 ± 50 °C. The FE-SEM micrographs in SE mode revealed a complex phase microstructure with martensite, ferrite, bainitic ferrite and retained austenite in the specimens obtained after rolling and air cooling. The microhardness of the developed alloys is found in the range of 395–502 VHN in the hot-rolled and air cooled condition of the specimen. The tensile strength of alloys was measured to be in the range of 1412–1614 MPa with elongation of 12.12 %–18.92 %. The analysis of fracture surfaces after tensile tests for developed alloys revealed that Alloy 1 (Fe-4Mn-1.5Si) had dimples indicating ductile fracture while Alloy 2 (Fe-6Mn-1.5Si) has a mixture of dimples and facets, and Alloy 3 (Fe-8Mn-1.5Si) has lower dimples but larger facets, confirming quasi-ductile fracture with a lower ductility limit of 12.12 %. Atom Probe Tomography was performed to study the complex phase structure at nanoscale through re-distribution of carbon and other alloying elements. 3D APT revealed the presence of very fine retained austenite film of thickness ∼4–5 nm and carbon content of 6–8 at.%. This complex phase microstructure obtained after hot rolling and normalizing is made of very fine bainitic ferrite with film type retained austenite providing TRIP effect, in addition martensite and ferrite resulting in high strength.

Truly the best of both worlds: Merging lineage-specific and universal probe kits to maximize phylogenomic inference.

Hybridization capture kits are now commonly used for reduced representation approaches in genomic sequencing, with both universal and clade-specific kits available. Here, we present a probe kit targeting 799 low-copy genes for the plant family Annonaceae. This new version of the kit combines the original 469 genes from the previous Annonaceae kit with 334 genes from the universal Angiosperms353 kit. We also compare the results obtained using the original Angiosperms353 kit with our custom approach using a subset of specimens. Parsimony-informative sites and the results of maximum likelihood phylogenetic inference were assessed for combined matrices using the genera Asimina and Deeringothamnus. The Annonaceae799 genes derived from the Angiosperms353 kit have extremely high recovery rates. Off-target reads were also detected. When evaluating size, the proportion of on- and off-target regions, and the number of parsimony-informative sites, the genes incorporated from the Angiosperms353 panel generally outperformed the genes from the original Annonaceae probe kit. We demonstrated that the new sequences from the Angiosperms353 probe set are variable and relevant for future studies on species-level phylogenomics and within-species studies in the Annonaceae. The integration of kits also establishes a connection between projects and makes new genes available for phylogenetic and population studies.

The Evolution of Massive Binary Stars

Massive stars play a major role in the evolution of their host galaxies and serve as important probes of the distant Universe. It has been established that the majority of massive stars reside in close binaries and interact with their companion stars during their lifetimes. Such interactions drastically alter their life cycles and complicate our understanding of their evolution, but are also responsible for the production of interesting and exotic interaction products. ▪Extensive observation campaigns with well-understood detection sensitivities have enabled the conversion of observed properties into intrinsic characteristics, facilitating a direct comparison to theory.▪Studies of large samples of massive stars in our Galaxy and the Magellanic Clouds have unveiled new types of interaction products, providing critical constraints on the mass transfer phase and the formation of compact objects.▪The direct detection of gravitational waves has revolutionized the study of stellar mass compact objects, providing a new window to study massive star evolution. Their formation processes are, however, still unclear. The known sample of compact object mergers will increase by orders of magnitude in the coming decade, which is vastly outgrowing the number of stellar-mass compact objects detected through electromagnetic radiation.

Rapid and simultaneous detection of common childhood diarrhea viruses by microfluidic-FEN1-assisted isothermal amplification with ultra-high specificity and sensitivity

Rapid and accurate diagnostic methods are crucial for managing viral gastroenteritis in children, a leading cause of global childhood morbidity and mortality. This study introduces a novel microfluidic-Flap endonuclease 1 (FEN1)-assisted isothermal amplification (MFIA) method for simultaneously detecting major viral pathogens associated with childhood diarrhea—rotavirus, norovirus, and adenovirus. Leveraging the specificity-enhancing properties of FEN1 with a universal dspacer-modified flap probe and the adaptability of microfluidic technology, MFIA demonstrated an exceptional detection limit (5 copies/μL) and specificity in the simultaneous detection of common diarrhea pathogens in clinical samples. Our approach addresses the limitations of current diagnostic techniques by offering a rapid (turn around time <1 h), cost-effective, easy design steps (universal flap design), and excellent detection performance method suitable for multiple applications. The validation of MFIA against the gold-standard PCR method using 150 actual clinical samples showed no statistical difference in the detection performance of the two methods, positioning it as a potential detection tool in pediatric diagnostic virology and public health surveillance. In conclusion, the MFIA method promises to transform pediatric infectious disease diagnostics and contribute significantly to global health efforts combating viral gastroenteritis.

A novel mediator probe and universal fluorescence probe (MP-UP) system for highly sensitive and versatile nucleic acid detection

Real-time qPCR and digital PCR are powerful techniques for detecting nucleic acids with high specificity and sensitivity, relying on sequence-specific labeled probes. However, each target requires the design and synthesis of specific probes, incurring significant costs. Therefore, the development of a specific and universal detection technique is both urgent and beneficial. Previously, a universal detection method was developed using a modified mediator probe and a universal hairpin reporter. However, our experiments uncovered that the mediator primers, generated by Taq polymerase cleaving mediator probes, deviate from the expected sequence, indicating a severe compromise in detection ability. Additionally, the high cost of the modified mediator probe and hairpin reporter impedes the practicality of their method. To overcome these challenges, we have developed a novel universal detection method (MP-UP) using Taqman probes, unmodified mediator probes and helper target, enabling the utilization of all mediator primers to produce abundant fluorescence. Enhanced MP-UP qPCR with an increased signal-to-noise ratio, MP-UP ddPCR, and multiplex MP-UP were established, exhibiting remarkable sensitivity, specificity, and precision comparable to specific probe assays or commercial testing kit. The mediator probe and helper target cost only one-tenth of a specific Taqman probe, rendering it feasible to replace the latter in specific nucleic acid detection.

Bladder-resident bacteria associated with increased risk of recurrence after electrofulguration in women with antibiotic-recalcitrant urinary tract infection.

Antibiotic-recalcitrant recurrent urinary tract infection (rUTI) is has become increasingly observed in postmenopausal women. Therefore, when standard antibiotic therapies have failed, some elect electrofulguration (EF) of areas of chronic cystitis when detected on office cystoscopy. EF is thought to remove tissue-resident bacteria that have been previously detected in the bladder walls of postmenopausal women with rUTI. We hypothesized that increased bladder bacterial burden may be associated with incomplete rUTI resolution following EF. Following IRB approval, bladder biopsies were obtained from 34 consenting menopausal women electing EF for the advanced management of rUTI. 16S rRNA FISH was performed using both universal and Escherichia probes and tissue-resident bacterial load was quantified. Time to UTI relapse after EF was recorded during a six-month follow-up period and the association of bladder bacterial burden and clinical covariates with UTI relapse was assessed. We observed bladder-resident Escherichia in 52% of all participants and in 92% of participants with recent E. coli UTI. Time-to-relapse analysis revealed that women with high bladder bacterial burden as detected by the universal probe had a significantly ( p =0.035) higher risk of UTI within six months of EF (HR=3.15, 95% CI: 1.09-9.11). Interestingly, bladder-resident Escherichia was not significantly associated ( p =0.26) with a higher risk of UTI relapse (HR= 2.14, 95% CI: 0.58-7.90). We observed that total bladder bacterial burden was associated with a 3.1x increased risk of rUTI relapse within six months. Continued analysis of the relationship between bladder bacterial burden and rUTI outcomes may provide insight into the management of these challenging patients.

Genomic incongruence accompanies the evolution of flower symmetry in Eudicots: a case study in the poppy family (Papaveraceae, Ranunculales).

Reconstructing evolutionary trajectories and transitions that have shaped floral diversity relies heavily on the phylogenetic framework on which traits are modelled. In this study, we focus on the angiosperm order Ranunculales, sister to all other eudicots, to unravel higher-level relationships, especially those tied to evolutionary transitions in flower symmetry within the family Papaveraceae. This family presents an astonishing array of floral diversity, with actinomorphic, disymmetric (two perpendicular symmetry axes), and zygomorphic flowers. We generated nuclear and plastid datasets using the Angiosperms353 universal probe set for target capture sequencing (of 353 single-copy nuclear ortholog genes), together with publicly available transcriptome and plastome data mined from open-access online repositories. We relied on the fossil record of the order Ranunculales to date our phylogenies and to establish a timeline of events. Our phylogenomic workflow shows that nuclear-plastid incongruence accompanies topological uncertainties in Ranunculales. A cocktail of incomplete lineage sorting, post-hybridization introgression, and extinction following rapid speciation most likely explain the observed knots in the topology. These knots coincide with major floral symmetry transitions and thus obscure the order of evolutionary events.

Choline Phosphate-Grafted Nanozymes as Universal Extracellular Vesicle Probes for Bladder Cancer Detection.

Urinary extracellular vesicles (uEVs) are regarded as highly promising liquid-biopsy biomarkers for the early diagnosis and prognosis of bladder cancer (BC). However, detection of uEVs remains technically challenging owing to their huge heterogeneity and ultralow abundance in real samples. We herein present a choline phosphate-grafted platinum nanozyme (Pt@CP) that acts as a universal EV probe for the construction of a high-throughput and high-sensitivity immunoassay, which allowed multiplex profiling of uEV protein markers for BC detection. With the Pt@CP-based immunoassays, three uEV protein markers (MUC-1, CCDC25, and GLUT1) were identified for BC, by which the BC cases (n = 48), cystitis patients (n = 27), and healthy donors (n = 24) were discriminated with high clinical sensitivity and specificity (area under curve = 98.3%). For the BC cases (n = 9) after surgery, the Pt@CP-based immunoassay could report the postoperative residual tumor that cannot be observed by cystoscopy, which is clinically significant for assessing BC recurrence. This work provides generally high sensitivity for EV detection, facilitating the discovery and clinical use of EV-based biomarkers.

An alternative method for SARS-CoV-2 detection with use modified fluorescent in situ hybridization

The real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR) tests are the gold standard in detecting SARS-CoV-2 virus infection. However, despite high sensitivity and specificity, they have limitations that in some cases may result in false negative results. Therefore, it is reasonable to search for additional tools that could support microbiological diagnosis of SARS-CoV-2. The aim of the study was to develop a highly specific molecular test capable of detecting and visualizing SARS-CoV-2 infection. A universal probe and a set of 18 specific oligonucleotides with a FLAP sequence attached to them on both sides were designed to visualize SARS-CoV-2 virus infection based on the fluorescence in situ hybridization method (FISH). FISH conditions using the developed kit were standardized on the Vero CCL-81 cell line infected by SARS-CoV-2 virus. The method was tested on 290 nasopharyngeal swabs (collected in a doublet) from patients with clinical symptoms of SARS-CoV-2. Each one swab from the doublet was subjected to RNA isolation and amplification by rRT-PCR. From the second swab, a microscopic preparation was performed for FISH. The use of the rRT-PCR allowed obtaining 200 positive and 90 negative results, while our FISH method allowed for 220 positive results and 70 negative results. The differences obtained using both methods were statistically significant (p = 0.008). The obtained results support the use of FISH as an additional method in microbiological diagnostics of SARS-CoV-2.

Gamma-Ray Bursts as Distance Indicators by a Statistical Learning Approach

Gamma-ray bursts (GRBs) can be probes of the early Universe, but currently, only 26% of GRBs observed by the Neil Gehrels Swift Observatory have known redshifts (z) due to observational limitations. To address this, we estimated the GRB redshift (distance) via a supervised statistical learning model that uses optical afterglow observed by Swift and ground-based telescopes. The inferred redshifts are strongly correlated (a Pearson coefficient of 0.93) with the observed redshifts, thus proving the reliability of this method. The inferred and observed redshifts allow us to estimate the number of GRBs occurring at a given redshift (GRB rate) to be 8.47–9 yr−1 Gpc−1 for 1.9 < z < 2.3. Since GRBs come from the collapse of massive stars, we compared this rate with the star formation rate, highlighting a discrepancy of a factor of 3 at z < 1.

A new nuclear phylogeny of the tea family (Theaceae) unravels rapid radiations in genus Camellia

Molecular analyses of rapidly radiating groups often reveal incongruence between gene trees. This mainly results from incomplete lineage sorting, introgression, and gene tree estimation error, which complicate the estimation of phylogenetic relationships. In this study, we reconstruct the phylogeny of Theaceae using 348 nuclear loci from 68 individuals and two outgroup taxa. Sequence data were obtained by target enrichment using the recently released Angiosperm 353 universal probe set applied to herbarium specimens. The robustness of the topologies to variation in data quality was established under a range of different filtering schemes, using both coalescent and concatenation approaches. Our results confirmed most of the previously hypothesized relationships among tribes and genera, while clarifying additional interspecific relationships within the rapidly radiating genus Camellia. We recovered a remarkably high degree of gene tree heterogeneity indicative of rapid radiation in the group and observed cytonuclear conflicts, especially within Camellia. This was especially pronounced around short branches, which we primarily associate with gene tree estimation error. Our analysis also indicates that incomplete lineage sorting (ILS) contributed to gene-tree conflicts and accounted for approximately 14 % of the explained variation, whereas inferred introgression levels were low. Our study advances the understanding of the evolution of this important plant family and provides guidance on the application of target capture methods and the evaluation of key processes that influence phylogenetic discordances.

Development of a Coumarin-derived Fluorescent Probe for Detection of HOCl and its Application in Cells and Zebrafish.

We have prepared a simple, universal and efficient coumarin-derived fluorescent probe (XDS1) to detecting HOCl. The experimental findings revealed that the introduction of HOCl produced an obvious quenching effect on the probe with high selectivity and sensitivity. The calculated limit of detection (LOD) was as low as 0.02μM. Furthermore, an impressive response time of less than 10 s was observed when XDS1 detecting HOCl. Importantly, the probe XDS1 exhibited negligible cytotoxicity, thereby facilitating its application for imaging HOCl within biological environment. The probe XDS1 had been successfully used for specific detection in cells.

Simultaneous detection of seven bacterial pathogens transmitted by flies using the reverse line blot hybridization assay

BackgroundTraditional methods for detecting insect-borne bacterial pathogens are time-consuming and require specialized laboratory facilities, limiting their applicability in areas without access to such resources. Consequently, rapid and efficient detection methods for insect-borne bacterial diseases have become a pressing need in disease prevention and control.MethodsWe aligned the ribosomal 16S rRNA sequences of seven bacterial species (Staphylococcus aureus, Shigella flexneri, Aeromonas caviae, Vibrio vulnificus, Salmonella enterica, Proteus vulgaris, and Yersinia enterocolitica) by DNASTAR Lasergene software. Using DNASTAR Lasergene and Primer Premier software, we designed universal primers RLB-F and RLB-R, two species-specific probes for each pathogen, and a universal probe (catch-all). The PCR products of seven standard strains were hybridized with specific oligonucleotide probes fixed on the membrane for specific experimental procedures. To evaluate the sensitivity of PCR-RLB, genomic DNA was serially diluted from an initial copy number of 1010 to 100 copies/μl in distilled water. These dilutions were utilized as templates for the PCR-RLB sensitivity analysis. Simultaneous detection of seven fly-borne bacterial pathogens from field samples by the established PCR-RLB method was conducted on a total of 1060 houseflies, collected from various environments in Lanzhou, China.ResultsThe established PCR-RLB assay is capable of detecting bacterial strains of about 103 copies/μl for S. aureus, 103 copies/μl for S. flexneri, 105 copies/μl for A. caviae, 105 copies/μl for V. vulnificus, 100 copies/μl for S. enterica, 105 copies/μl for P. vulgaris, and 100 copies/μl for Y. enterocolitica. The results demonstrate that the detection rate of the established PCR-RLB method is higher (approximately 100 times) compared to conventional PCR. This method was applied to assess the bacterial carrier status of flies in various environments in Lanzhou, China. Among the seven bacterial pathogens carried by flies, S. enterica (34.57%), S. flexneri (32.1%), and Y. enterocolitica (20.37%) were found to be the predominant species.ConclusionsOverall, this research shows that the rapid and efficient PCR-RLB detection technology could be a useful for surveillance and therefore effective prevention and control the spread of insect-borne diseases. Meanwhile, the experimental results indicate that urban sanitation and vector transmission sources are important influencing factors for pathogen transmission.Graphical

Establishment of a rapid counting method for lactic acid bacteria and yeast in dairy products

The plate count agar (PCA) method is a common technique used to count microorganisms in dairy products, but this method is time‐consuming and highly selective by the medium. This study adopted Lab158 and PF2 as the universal probes for hybridising lactic acid bacteria and yeasts, respectively, and investigated the effects of fixation time, hybridisation time, hybridisation temperature, probe concentration and propidium iodide (PI) concentration on hybridisation efficiency in the samples. The results showed that the highest hybridisation efficiency for lactic acid bacteria and yeast, along with the best double staining results, was observed under the following conditions: a fixation time of 80 min, a hybridisation time of 180 min, a hybridisation temperature of 48°C, a probe volume of 5 μL for lactic acid bacteria and 3 μL for yeast, and a PI volume of 5 μL for lactic acid bacteria and 3 μL for yeast. The fluorescence in situ hybridisation‐flow cytometry (FISH‐FCM) and PCA counting results showed a significant positive correlation (r &gt; 0.9). The FISH‐FCM and PCA counting results showed a significant positive correlation (r &gt; 0.9). The FISH‐FCM counting method can serve as a quick and accurate method for the counting of lactic acid bacteria and yeast in dairy products.

A63 RESTRAINED STRESS IN MICE INDUCES TRANSLOCATION OF GUT COMMENSAL BACTERIAL INTO DISTAL ORGANS

Abstract Background Bacterial translocation is defined as the migration of bacteria from the intestinal lumen into extraintestinal tissues; this process has been implicated in the pathophysiology of gastrointestinal disorders including irritable bowel syndrome (IBS) and central nervous system disorders. In our recent study, we found that gut bacteria from patients with IBS can disrupt the mucus layer and penetrate into the lamina propria in our microbiota-humanized mouse model. It is well known that psychological stress triggers or exacerbates IBS symptoms. Furthermore, experimental stress models have been able to reproduce some features of IBS and demonstrate that gut bacteria can translocate into the mesenteric lymph node (MLN), liver, and spleen. These studies suggested that bacterial translocation might induce changes in behavior and brain function. However, the direct causal relationship between bacterial translocation and behavioral changes, and the mechanism of bacterial translocation remains unclear. Aims To investigate translocation of commensal bacteria within the gut wall and their migration into distant organs using a mouse stress model. Methods SPF C57BL/6 mice were split into 2 groups: restraint stress group (3 hrs x 7 days, n=9) and non-stress control group (n=8). After the last session of stress, we conducted light/dark preference and tail suspension tests. We collected jejunum, ileum, and colon samples for histology. We also sampled blood, MLN, liver, spleen, and brain for histology and bacterial cultures. The tissues were collected under aseptic conditions. The blood or organ homogenates were plated and incubated in aerobic and anaerobic conditions. Intestinal tissues were submitted to fluorescence in situ hybridization staining with a bacterial universal probe in combination with immunofluorescence to co-stain with e-cadherin and CD103. The images were taken by confocal microscopy. Results The chronic restrain stress-induced anxiety-like, but not depressive behavior, as assessed by the light/dark test. Compared to the controls, bacterial culture was more frequently positive in the stress group: blood (0% vs 25%), MLN (0% vs 50%), spleen (0% vs 25%), liver (0% vs 25%), and brain (25% vs 74%). The histology showed that intestinal bacteria were present within the gut wall and brain in the stress group. Interestingly, these bacteria co-localized with the goblet cells in the jejunum, ileum and colon, and CD103+ dendritic cells in the colon (Fig. 1). Conclusions We found that mice subjected to the restraint stress exhibit abnormal behavior, accompanied by bacterial infiltration into the gut wall, as well as bacterial translocation into distal organs, including brain. Our histology data suggest a potential contribution of goblet cells-dendritic cells pathway in commensal gut bacteria translocation in the restrained stress model. Intestinal bacteria were present within the gut wall in the stress group. Funding Agencies CIHR Farncombe Innovation Fund

Ultrafast photochemical processes in 1,2-dichloroethene measured with a universal XUV probe.

The presence of two chlorine atoms in 1,2-dichloroethene allows for isomerization around the double bond. This isomerization can lead to rich photochemistry. We present a time-resolved pump-probe photoelectron spectroscopy measurement on both the cis- and trans- isomers of 1,2-dichloroethene. A universal XUV probe of 22.3 eV is used allowing observation of photoelectrons formed anywhere on the potential energy surface, even from the ground-state or dissociation products. Following excitation with a 200 nm pump both ultrafast excited state dynamics and product formation are observed within the time resolution of the experiment. Excited state population begins to return to the ground state on an ultrafast time scale (<70 fs) and population of products channels is observed on the same timescale. With the aid of ab initio calculations it is found that population transfer from the excited state is facilitated by vibrational modes involving C-C-H bends.