The PERCIVAL detector: first user experiments

The PERCIVAL detector is a CMOS imager designed for the soft X-ray regime at photon sources. Although still in its final development phase, it has recently seen its first user experiments: ptychography at a free-electron laser, holographic imaging at a storage ring and preliminary tests on X-ray photon correlation spectroscopy. The detector performed remarkably well in terms of spatial resolution achievable in the sample plane, owing to its small pixel size, large active area and very large dynamic range; but also in terms of its frame rate, which is significantly faster than traditional CCDs. In particular, it is the combination of these features which makes PERCIVAL an attractive option for soft X-ray science.

Analysis of laser-proton acceleration experiments for development of empirical scaling laws

Numerous experiments on laser-driven proton acceleration in the MeV range have been performed with a large variety of laser parameters since its discovery around the year 2000. Both experiments and simulations have revealed that protons are accelerated up to a maximum cut-off energy during this process. Several attempts have been made to find a universal model for laser proton acceleration in the target normal sheath acceleration regime. While these models can qualitatively explain most experimental findings, they can hardly be used as predictive models, for example, for the energy cut-off of accelerated protons, as many of the underlying parameters are often unknown. Here we analyze experiments on laser proton acceleration in which scans of laser and target parameters were performed. We derive empirical scaling laws from these parameter scans and combine them in a scaling law for the proton energy cut-off that incorporates the laser pulse energy, the laser pulse duration, the focal spot radius, and the target thickness. Using these scaling laws, we give examples for predicting the proton energy cut-off and conversion efficiency for state-of-the-art laser systems.

Spatially resolved online particle detector using scintillators for laser-driven particle sources

Laser-based particle accelerators have been an active field of research for over two decades moving from laser systems capable of one shot every hour to systems able to deliver repetition rates in the Hz regime. Based on the advancements in laser technology, the corresponding detection methods need to develop from single to multiple use with high readout speed. Here, we present an online compact tracker of particles using scintillators with nine resolvable energy levels and a spatial resolution of 3.6 × 3.6 mm² over the whole active area. This paper describes the design and construction of the detector, which is based on pixellated scintillators embedded inside an absorber matrix. The scintillator pixels are fiberoptically coupled to a camera system for online readout and analysis. Calibration with a radioactive source and first experimental data measuring laser accelerated ions at the PHELIX laser at GSI, Darmstadt, Germany, are presented and discussed.

Abstract PO009: Epigenetic silencing by SETDB1 represses tumor-cell intrinsic immunogenicity

Epigenetic alterations are defining features of many tumor types and have recently been implicated in tumor immunity. However, the epigenetic mechanisms that mediate immune sensitivity or resistance in cancer cells are poorly characterized. To systematically identify epigenetic regulators of immune evasion in cancer, we performed in vivo loss of function CRISPR screens against 936 chromatin regulator genes in syngeneic murine tumor models treated with immune checkpoint blockade. These screens identified SETDB1, an H3K9-methyltransferase, and associated members of the HUSH and KAP1 complexes as intrinsic mediators of immune evasion in cancer cells. We also found that amplification of SETDB1 (1q21) in certain human tumors is associated with immune exclusion and resistance to immune checkpoint blockade. Mechanistically, we find that SETDB1 targets broad domains, hundreds of kilobases in size, that are predominantly located within the open genome compartment “A” (i.e., euchromatin). These SETDB1 domains show strong enrichment for transposable elements (TEs) of the LTR family, and gene loci that arose through segmental duplication events, a key driver of mammalian genome evolution. Setdb1 KO derepresses latent regulatory elements at TEs within these regions and leads to the transcriptional up-regulation of nearby immune genes, including canonical stimulatory ligands of the NKG2D receptor. SETDB1 loss also triggers the activation of hundreds of TEs with the potential to encode retroviral proteins (Gag, Pol, Env), and promotes immune responses dependent on CD8+ T cells and tumor expression of MHC Class I. Our study establishes SETDB1 as an epigenetic checkpoint that represses intrinsic immunogenicity in cancer cells, and thus represents a novel target to enhance the efficacy and scope of immunotherapy.

Citation Format: Jingyi Wu, Arvin Iracheta-Vellve, James Patti, Jeffrey Hsu, Thomas Davis, Deborah Dele-Oni, Peter Du, Jeffrey Ishizuka, Sarah Kim, Susan Klaeger, Nelson Knudsen, Brian Miller, Tung Nguyen, Emily Robitschek, Emily Schneider, Margaret Zimmer, Jacob Jaffe, John Doench, W. Nicholas Haining, Kathleen Yates, Robert Manguso, Bradley Bernstein, Gabriel K. Griffin. Epigenetic silencing by SETDB1 represses tumor-cell intrinsic immunogenicity [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO009.

River ecosystem conceptual models and non-perennial rivers: A critical review

Conceptual models underpin river ecosystem research. However, current models focus on continuously flowing rivers and few explicitly address characteristics such as flow cessation and drying. The applicability of existing conceptual models to nonperennial rivers that cease to flow (intermittent rivers and ephemeral streams, IRES) has not been evaluated. We reviewed 18 models, finding that they collectively describe main drivers of biogeochemical and ecological patterns and processes longitudinally (upstream-downstream), laterally (channel-riparian-floodplain), vertically (surface water-groundwater), and temporally across local and landscape scales. However, perennial rivers are longitudinally continuous while IRES are longitudinally discontinuous. Whereas perennial rivers have bidirectional lateral connections between aquatic and terrestrial ecosystems, in IRES, this connection is unidirectional for much of the time, from terrestrial-to-aquatic only. Vertical connectivity between surface and subsurface water occurs bidirectionally and is temporally consistent in perennial rivers. However, in IRES, this exchange is temporally variable, and can become unidirectional during drying or rewetting phases. Finally, drying adds another dimension of flow variation to be considered across temporal and spatial scales in IRES, much as flooding is considered as a temporally and spatially dynamic process in perennial rivers. Here, we focus on ways in which existing models could be modified to accommodate drying as a fundamental process that can alter these patterns and processes across spatial and temporal dimensions in streams. This perspective is needed to support river science and management in our era of rapid global change, including increasing duration, frequency, and occurrence of drying.

What's in a Name? Patterns, Trends, and Suggestions for Defining Non-Perennial Rivers and Streams

Rivers that cease to flow are globally prevalent. Although many epithets have been used for these rivers, a consensus on terminology has not yet been reached. Doing so would facilitate a marked increase in interdisciplinary interest as well as critical need for clear regulations. Here we reviewed literature from Web of Science database searches of 12 epithets to learn (Objective 1-O1) if epithet topics are consistent across Web of Science categories using latent Dirichlet allocation topic modeling. We also analyzed publication rates and topics over time to (O2) assess changes in epithet use. We compiled literature definitions to (O3) identify how epithets have been delineated and, lastly, suggest universal terms and definitions. We found a lack of consensus in epithet use between and among various fields. We also found that epithet usage has changed over time, as research focus has shifted from description to modeling. We conclude that multiple epithets are redundant. We offer specific definitions for three epithets (non-perennial, intermittent, and ephemeral) to guide consensus on epithet use. Limiting the number of epithets used in non-perennial river research can facilitate more effective communication among research fields and provide clear guidelines for writing regulatory documents.

Application of lectin microarrays for the analysis of seminal plasma glycome

We report application of lectin microarrays, exploiting simultaneous interaction of seminal plasma samples with multiple lectins of different sugar specificities to compare the glycomes of fertile and infertile men. The results indicate reduced lectin reactivity associated with decreased fertility, especially affecting oligozoospermic subjects and probably O-glycosylation. Lectin microarrays may become a potent tool for semen analysis in search of the association of glycosylation and male fertility.

Photophysical dynamics of a binuclear Cu(i)-emitter on the fs to μs timescale, in solid phase and in solution

Understanding subtle aspects of photophysical behavior is the key to design and synthesize new and improved luminescent materials. We contribute to this with an in-depth photophysical characterization of the binuclear copper complex Cu(i)-NHetPHOS-tris-m-tolylphosphine (1), a member of a recently established emitter class for ultra-efficient, printed organic light-emitting diodes (OLEDs). To this end we studied 1 in solution and in solid form, i.e. neat film and KBr-pellet, by means of femtosecond time-resolved transient absorption/reflectivity, time-correlated single photon counting (TCSPC), and nanosecond time-resolved step-scan FTIR spectroscopy. Using these methods, we explore the photoinduced dynamics from ultrafast Franck-Condon state deactivation until the decay of the luminescent states. Upon photoexcitation, we observed multiexponential dynamics in both solution (e.g. acetonitrile 0.8 ps, 59 ps, 3 ns, 11-13 ns) and in solid state (e.g. neat film 0.3 ps, 35 ps, 670 ps, 0.5-1 μs, 3.5-4.5 μs) with four to five time-constants that significantly depend on the type of sample. Quantum chemical calculations at the DFT level in combination with step-scan vibrational spectroscopy provided structural information about the electronic ground state S₀ and the lowest lying excited state T₁, and show that the latter is populated within 1 μs after photoexcitation. We found thermally activated delayed fluorescence (TADF) for this complex, which has been suggested to be the cause for its high efficiency in printed OLED devices. The results suggest that non-radiative processes, lowering the luminescence quantum yield in solution, are active on the ns to μs timescale.

A programmable platform for sub-second multichemical dynamic stimulation and neuronal functional imaging in C. elegans

Caenorhabditis elegans (C. elegans) is a prominent model organism in neuroscience, as its small stereotyped nervous system offers unique advantages for studying neuronal circuits at the cellular level. Characterizing temporal dynamics of neuronal circuits is essential to fully understand neuronal processing. Characterization of the temporal dynamics of chemosensory circuits requires a precise and fast method to deliver multiple stimuli and monitor the animal's neuronal activity. Microfluidic platforms have been developed that offer an improved control of chemical delivery compared to manual methods. However, stimulating an animal with multiple chemicals at high speed is still difficult. In this work, we have developed a platform that can deliver any sequence of multiple chemical reagents, at sub-second resolution and without cross-contamination. We designed a network of chemical selectors wherein the chemical selected for stimulation is determined by the set of pressures applied to the chemical reservoirs. Modulation of inlet pressures has been automated to create robust, programmable sequences of subsecond chemical pulses. We showed that stimulation with sequences of different chemicals at the second to sub-second range can generate different neuronal activity patterns in chemosensory neurons; we observed previously unseen neuronal responses to a controlled chemical stimulation. Because of the speed and versatility of stimulus generated, this platform opens new possibilities to investigate neuronal circuits.

Vinculin is required to maintain glomerular barrier integrity

Cell-matrix interactions and podocyte intercellular junctions are key for maintaining the glomerular filtration barrier. Vinculin, a cytoplasmic protein, couples actin filaments to integrin-mediated cell-matrix adhesions and to cadherin-based intercellular junctions. Here, we examined the role of vinculin in podocytes by the generation of a podocyte-specific knockout mouse. Mice lacking podocyte vinculin had increased albuminuria and foot process effacement following injury in vivo. Analysis of primary podocytes isolated from the mutant mice revealed defects in cell protrusions, altered focal adhesion size and signaling, as well as impaired cell migration. Furthermore, we found a marked mislocalization of the intercellular junction protein zonula occludens-1. In kidney sections from patients with focal segmental glomerulosclerosis, minimal change disease and membranous nephropathy, we observed dramatic differences in the expression levels and localization of vinculin. Thus, our results suggest that vinculin is necessary to maintain the integrity of the glomerular filtration barrier by modulating podocyte foot processes and stabilizing intercellular junctions.

Time-resolved IR spectroscopy of a trinuclear palladium complex in solution

Time-resolved IR spectroscopic methods covering the femto- to microsecond range in combination with (TD-)DFT computations were used to investigate the electronically excited state structure of a trinuclear Pd complex.

Ultrasonographic pattern of spontaneous resolving fetal ovarian cyst: a case report

Fetal ovarian cyst is diagnosed at the rate of one per 2,500 live births and its behaviour in utero may range from spontaneous resolution with no further consequences to torsion, necrosis, and to the necessity of surgical treatment in the postnatal stage. Ovarian cyst torsion in a fetus results in the loss of its reproductive function in adult life. The authors present a case of spontaneous resolving fetal ovarian cyst. The lesion was diagnosed during an ultrasound scan in 30th week of pregnancy. An ultrasound scan performed two weeks later revealed symptoms of cyst torsion; the lesion was 5.7 cm in diameter, heterogeneous, and had a normoechogenic inside. A subsequent ultrasound exam showed a lesion with a diameter of 2.16 cm. An ultrasound exam of the newborn's abdominal cavity performed on the second day showed that the cyst was six mm in diameter. However, the cyst did not show on an ultrasound scan made on the fourth day.

[Effectiveness and safety of a homeopathic drug combination in the treatment of chronic low back pain. A double-blind, randomized, placebo-controlled clinical trial]

BACKGROUND

The homeopathic drug combination Lymphdiaral Basistropfen is established in the treatment of edema and swellings. This is the first time the effectiveness and safety was investigated in the treatment of chronic low back pain.

METHODS

The study is a randomized, double-blind, placebo-controlled trial. From December 2003 to May 2007 248 patients aged 18 to 75 years were screened, 228 were randomized, 221 started therapy, in 192 the progress was measured (103 verum vs. 89 placebo), 137 completed the study (72 verum vs. 65 placebo). They received 10 drops of verum or placebo solution three times daily for 105 days additionally to an inpatient complex naturopathic treatment.

RESULTS

The hannover functional ability questionnaire score (primary outcome measure) tends to increase in the intention-to-treat-analysis (verum: 6.6 vs. placebo: 3.4; p = 0.11) and increases significantly in the per-protocol-analysis (verum: 9.4 vs. placebo: 4.1; p = 0.029). The treatment was well tolerated (92.9% vs. 95.4%). The incidence of adverse reactions and serious adverse reactions was similar in both treatment groups.

CONCLUSIONS

This first randomized, double-blind, placebo-controlled trial shows, that the homeopathic drug combination can improve the treatment of chronic low back pain.

Investigation of promoter variations in dendritic cell-specific ICAM3-grabbing non-integrin (DC-SIGN) (CD209) and their relevance for human cytomegalovirus reactivation and disease after allogeneic stem-cell transplantation

Promoter variations in Toll-like receptor genes (n = 7) and genes encoding pathogen recognition and virus entry receptors (n = 7) were screened to detect any association with human cytomegalovirus (hCMV) reactivation and disease in patients following allogeneic stem-cell transplantation. Two single nucleotide polymorphisms (rs735240, G>A; rs2287886, C>T) in the promoter region of the dendritic cell-specific ICAM3-grabbing non-integrin (DC-SIGN) showed a significant association with an increased risk of development of hCMV reactivation and disease. Furthermore, these genetic markers influenced the expression levels of DC-SIGN on immature dendritic cells, as well as the infection efficiency of immature dendritic cells by hCMV, as determined by hCMV immediate-early antigen staining. Screening of patients following allogeneic stem-cell transplantation for the presence of these defined genetic polymorphisms might help to predict the individual risk of hCMV reactivation and disease.

[Angioedema caused by C1-esterase inhibitor deficiency or ACE inhibitors?]

A 49-year-old woman was admitted to the intensive care ward with increasing shortness of breath due to a massive soft tissue swelling of the neck and face and a marked macroglossia. Similar symptoms were already observed earlier in the patient as well as her father, although such symptoms were never as dramatic as they were on this occasion. The patient was intubated bronchoscopically and treated unsuccessfully with cortisone, fresh plasma und C1-esterase inhibitor. The patient only first reported intake of an ACE inhibitor a few days after the acute episode, which was most probably the causative factor given that serum C1 and C4 complement factors were almost normal.

FZD3 is not a risk gene for schizophrenia: a case-control study in a Caucasian sample

BACKGROUND

Polymorphisms in the human frizzeled-3 (FZD3) gene have been associated with schizophrenia in an Asian population sample. However, this finding could not be confirmed in subsequent studies investigating other populations. Here we attempted to replicate this finding in a sample of 192 German chronically ill schizophrenic subjects.

METHODS

Three single nucleotide polymorphisms in the FZD3 gene have been genotyped by primer extension and MALDI-TOF measurement. Subsequently, associations for single markers as well as haplotypes were tested.

RESULTS

In German patients, neither single markers nor haplotypes in FZD3 were associated with schizophrenia. Further exploratory analyses using a different diagnostic approach did also not yield significant results.

CONCLUSIONS

FZD3 is unlikely to play a role in the genetic predisposition towards schizophrenia in the Caucasian population.

Nitrogen dynamics in a constructed wetland system treating landfill leachate

A pilot scale treatment system was established in 2002 at the Laflèche Landfill in Eastern Ontario, Canada. The system consists of a series of treatment steps: a stabilisation basin (10,000 m3), a woodland peat trickling filter (5,200 m2), a subsurface flow constructed wetland planted in Phragmites sp. (2,600 m2), a surface flow constructed wetland planted in Typha sp. (3,600 m2) and a polishing pond (3,600 m2). The system operates from May to December with leachate being recycled within the landfill during the winter months. Hydraulic loading was increased three-fold over four operating seasons with nitrogen and organic mass loading increasing six-fold. Excellent removal efficiencies were observed with 93% BOD5, 90% TKN and 97% NH4-N removed under the highest loading conditions. Almost complete denitrification was observed throughout the treatment system with NO3-N concentrations never exceeding 5mg L(-1). The peat filter reached treatment capacity at a hydraulic loading of 4cm d(-1) and organic loading rate of 42 kg BOD ha(-1) d(-1), which is consistent with design criteria for vertical flow wetland systems and intermittent sand filters, The first order plug flow kinetic model was effective at describing TKN and ammonium removal in the SSF and FWS wetlands when background concentrations were taken into account. Ammonium removal k-values were consistent with the literature at 52.6 and 57.7 yr(-1) for the SSF and FWS wetlands, respectively, while TKN k-values at 6.9 and 7.7 yr(-1) were almost an order of magnitude lower than literature values, suggesting that leachate TKN could contain refractory organics not found in domestic wastewater.

The last gene of the fla/che operon in Bacillus subtilis, ylxL, is required for maximal sigmaD function

ylxL was found to be the last gene of the fla/che operon in Bacillus subtilis and is cotranscribed with the gene for the flagellum-specific alternate sigma factor, sigma(D). The ylxL gene was disrupted by insertional mutagenesis, and the resultant mutant strain was found to be compromised for sigma(D)-dependent functions.

[Correlation of a computerized SOFA score and derived measures with length of stay at an operative ICU]

OBJECTIVE

The purpose of this study was to assess whether or not the information on progression of illness and therapeutic interventions included in a computerized SOFA (Sequential Organ Failure Assessment) score and derived measures (maximum SOFA, total maximum SOFA and delta SOFA) influences the correlation with length of stay (LOS) at an operative intensive care unit (ICU).

METHODS

During a period of one year 524 patients aging over 18 years who stayed more than 24 hours at an operative ICU were included into this study. Based on SQL scripts (Structured Query Language), a computerized SOFA score and the derived measures "maximum-SOFA", "total-maximum-SOFA" and "delta-SOFA" of all patients were retrospectively calculated for each day at ICU using routine data recorded with the patient data management system ICUData (IMESO GmbH, Hüttenberg, Germany). "Maximum-SOFA" and "total-maximum-SOFA" are measures for the severity of illness or cumulative organ dysfunction. "Delta-SOFA" measures the magnitude of organ dysfunction developing during ICU stay and is therefore potentially influenced by therapeutic measures. Analysis was based on exact LOS in hours.

RESULTS

Mean LOS of the whole collective was 5.2 +/- 6.8 days (median 2.8, range 1 - 51). Correlation of LOS depending on score results increased from "admission-SOFA" (r = 0.280), to "maximum-SOFA" (r = 0.444), "total-maximum-SOFA" (r = 0.503), and "delta-SOFA" (r = 0.576).

CONCLUSION

Therefore, the sum of information on progression of illness and therapeutic interventions included in derived measures improves the correlation with LOS at an ICU compared to the "admission-SOFA".

Computational analysis of Thr203 isomerization in green fluorescent protein

Green fluorescent protein (GFP) is an extensively used fluorescent tag. Photoisomerization between two spectroscopically distinct states in wild-type GFP is responsible for its two visible absorption bands at 398 nm (A) and 475 nm (B). We have used molecular mechanics and database analysis to support the suggestion of other researchers that the anionic form of the GFP chromophore is responsible for the B absorption band, while the phenol form is responsible for band A. The anionic (-Otyr, Nimid, Glu222H) species is the only form that has a low energy pathway allowing for isomerization of Thr203 to a conformation where it stabilizes the phenolate form and is therefore the most likely species responsible for the B absorption band. The rotation of the Thr203 side-chain is restricted; this may be significant in the formation of the intermediate state which is central to the photoisomerization. Our calculations support the most commonly accepted mechanism for photoisomerization, and we have shown that the 201LSTQS205 sequence does not allow a g+ conformation for Thr203.