Dissolved organic matter quantity and quality response of tropical rainforest headwater rivers to the transition from dry to wet season

Dissolved organic matter (DOM) and its composition in aquatic ecosystems is a key indicator of ecosystem function and an important component of the global carbon cycle. Tropical rainforest headwaters play an important role in global carbon cycling. However, there is a large uncertainty on how DOM sources interact during mobilisation and the potential fate of associated carbon and nutrients. Using field techniques to measure dissolved organic carbon (DOC) concentration and composition, changes in DOM source from headwaters to larger downstream rivers were observed. This study shows that the hydrological connectivity, developed during the transition from dry to wet seasons, changes the DOM supply and transport across a tropical river catchment. The observed variability in the DOC-river discharge relationship provides further evidence of the changes in the DOM supply in a small headwater. This novel insight into the seasonal changes of the dynamics of DOM supply to the river helps understanding the mobilization of terrestrial DOM to tropical headwaters and its export from smaller to larger rivers. It also highlights the data gap in the study of smaller headwaters which may account for uncertainty in estimating the terrestrial carbon transported by inland waters.

Yersinia entomophaga Tc toxin is released by T10SS-dependent lysis of specialized cell subpopulations

Disease-causing bacteria secrete numerous toxins to invade and subjugate their hosts. Unlike many smaller toxins, the secretion machinery of most large toxins remains enigmatic. By combining genomic editing, proteomic profiling and cryo-electron tomography of the insect pathogen Yersinia entomophaga, we demonstrate that a specialized subset of these cells produces a complex toxin cocktail, including the nearly ribosome-sized Tc toxin YenTc, which is subsequently exported by controlled cell lysis using a transcriptionally coupled, pH-dependent type 10 secretion system (T10SS). Our results dissect the Tc toxin export process by a T10SS, identifying that T10SSs operate via a previously unknown lytic mode of action and establishing them as crucial players in the size-insensitive release of cytoplasmically folded toxins. With T10SSs directly embedded in Tc toxin operons of major pathogens, we anticipate that our findings may model an important aspect of pathogenesis in bacteria with substantial impact on agriculture and healthcare.

Structure of the native myosin filament in the relaxed cardiac sarcomere

The thick filament is a key component of sarcomeres, the basic units of striated muscle1. Alterations in thick filament proteins are associated with familial hypertrophic cardiomyopathy and other heart and muscle diseases2. Despite the central importance of the thick filament, its molecular organization remains unclear. Here we present the molecular architecture of native cardiac sarcomeres in the relaxed state, determined by cryo-electron tomography. Our reconstruction of the thick filament reveals the three-dimensional organization of myosin, titin and myosin-binding protein C (MyBP-C). The arrangement of myosin molecules is dependent on their position along the filament, suggesting specialized capacities in terms of strain susceptibility and force generation. Three pairs of titin-α and titin-β chains run axially along the filament, intertwining with myosin tails and probably orchestrating the length-dependent activation of the sarcomere. Notably, whereas the three titin-α chains run along the entire length of the thick filament, titin-β chains do not. The structure also demonstrates that MyBP-C bridges thin and thick filaments, with its carboxy-terminal region binding to the myosin tails and directly stabilizing the OFF state of the myosin heads in an unforeseen manner. These results provide a foundation for future research investigating muscle disorders involving sarcomeric components.

Aurophilic Molecules on Surfaces. Part II. (NapNC)AuCl on Au(111)

Although aurophilicity is a well-known phenomenon in structural gold chemistry and is found in many crystals of Au(I) complexes, its potential for self-assembly in thin films is not yet explored. This paper is Part II of a study, in which we investigated the ultrathin film formation of chlorido(2-naphthyl isonitrile) gold(I) on gold surfaces. Here, we present the data for the growth of (NapNC)AuCl on isotropic Au(111) surfaces. Already during physical vapor deposition, the condensation of ultrathin films is monitored by photoelectron emission microscopy (PEEM) and incremental and spectrally resolved changes in the optical reflectance (DDRS). Additional structural data obtained by scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) reveal that the "crossed swords" packing motif known from the bulk is also present in thin films.

Aurophilic Molecules on Surfaces. Part I. (NapNC)AuCl on Au(110)

Aurophilicity is a well-known phenomenon in structural gold chemistry and is found in many crystals of Au(I) complexes. However, these attractive dispersion forces between and within complexes containing Au(I) moieties have not been well studied in ultrathin films. In this paper, we elucidate the interaction of chlorido(2-naphthyl isonitrile)gold(I) on and with Au(110) surfaces. Already during physical vapor deposition, the condensation of ultrathin films is monitored by photoelectron emission microscopy (PEEM) and by incremental and spectrally resolved changes in the optical reflectance (DDRS). Additional structural data obtained by STM and LEED reveal that the "crossed swords" packing motif known from the bulk is also present in thin films. The molecular arrangement changes several times during thin-film deposition.

Effect of 12-months testosterone replacement therapy on bone mineral density and markers of bone turnover in testicular cancer survivors - results from a randomized double-blind trial

BACKGROUND

Testicular cancer survivors (TCS) are at risk of Leydig cell insufficiency, which is a condition characterized by elevated luteinising hormone (LH) in combination with low levels of testosterone. It has been suggested that this condition is associated with impaired metabolic profile and low bone mineral density (BMD). The primary aim of the randomized double-blind trial NCT02991209 was to evaluate metabolic profile after 12-months testosterone replacement therapy (TRT) in TCS with mild Leydig cell insufficiency. Here we present the secondary outcomes of changes in BMD and markers of bone turnover.

METHODOLOGY

In total, 69 TCS with mild Leydig cell insufficiency were randomized 1:1 to 12 months TRT (n = 35) (Tostran, gel, 2%, applied transdermally, with a maximum daily dose of 40 mg) or placebo (n = 34). BMD and markers of bone turnover were evaluated at baseline, after 6- and 12-months TRT, and 3-months post-treatment. Linear mixed effects models were used to analyse changes in BMD, N-terminal propeptide of type 1 procollagen (P1NP) and C-terminal telopeptide of type I collagen (CTX).

RESULTS

After 12 months treatment, TRT was not associated with a statistically significant difference in BMD compared to placebo; total body BMD: 0.01 g/cm2 (95% confidence interval (CI): -0.01 - 0.02), BMD of the lumbar spine: 0.01 g/cm2, (95% CI: -0.01-0.03), BMD of the left femoral neck: 0.00, (95% CI: -0.01-0.02). TRT was associated with a small but statistically significant increase in P1NP: 11.65 µg/L (95% CI: 3.96, 19.35), while there was no difference in CTX.

CONCLUSION

12 months of TRT did not change BMD, while there was as small and clinically irrelevant increase in P1NP compared to placebo in TCS with mild Leydig cell insufficiency. The findings need validation in a larger cohort.

Actionable reporting versus unwanted advice in PET-CT reports

AIM

To investigate the opinions of clinician referrers on the presence and type of management advice in reports of positron-emission tomography (PET)-computed tomography (CT) examinations.

MATERIALS AND METHODS

Eighteen clinicians were interviewed using a structured questionnaire about their opinions on further management advice in PET-CT reports.

RESULTS

Opinions varied amongst clinicians, but some themes predominated: (1) advice on further imaging tests and areas outside the referrer's area of expertise are more welcome than other types of advice; (2) a differential diagnosis or clinical significance is of greater value than specific management advice; (3) some referrers do not want any further advice.

CONCLUSION

Before advising on further management, reporters should consider clinicians' opinions regarding this. Seeking the opinion of clinicians in other hospitals may be necessary. A review of the Royal College of Radiologists Actionable Reports standard to ensure it is more in line with the opinions of clinicians may be useful.

TomoTwin: generalized 3D localization of macromolecules in cryo-electron tomograms with structural data mining

Cryogenic-electron tomography enables the visualization of cellular environments in extreme detail, however, tools to analyze the full amount of information contained within these densely packed volumes are still needed. Detailed analysis of macromolecules through subtomogram averaging requires particles to first be localized within the tomogram volume, a task complicated by several factors including a low signal to noise ratio and crowding of the cellular space. Available methods for this task suffer either from being error prone or requiring manual annotation of training data. To assist in this crucial particle picking step, we present TomoTwin: an open source general picking model for cryogenic-electron tomograms based on deep metric learning. By embedding tomograms in an information-rich, high-dimensional space that separates macromolecules according to their three-dimensional structure, TomoTwin allows users to identify proteins in tomograms de novo without manually creating training data or retraining the network to locate new proteins.

Disease progression of heart failure in type 2 diabetes patients in Germany; a real world data analysis using health insurance claims data

 

Individuals with Type 2 Diabetes (T2D) show two- to four-fold increased risk of Heart failure (HF). Given the increasing T2D prevalence in Germany, researching the interaction of T2DM and HF is of high importance. HF still progresses rapidly. Left ventricular ejection fraction (LVEF) plays an important role in understanding disease progression. Commonly, LVEF is being distinguished into three categories: HF with preserved LVEF (HFpEF), HF with moderate reduced LVEF (HFmEF) and HF with reduced LVEF (HFrEF). In Germany there are no recent data on disease progression in HF especially according to LVEF categories. Purpose of this study is to a) measure how many T2DM patients acquire HF over two years; b) understand the progression of HF in these patients in a five-year follow-up; and c) visualize disease progression with Sankey plots.

We used insurance claims data from German Statutory Health Insurances (SHI). As LVEF category is not included in these data, a model was used to classify patients into HFrEF or HFpEF (with omitting the HFmEF category due to better statistical performance of a binary model). The model was derived from a set of 34 proxy variables (disease coding, interventions, drug prescriptions). Selection period for T2D patients is 2013. Inclusion period was 2014–2015, follow-up 2016–2020. Baseline characteristics include demographic data, disease stage, comorbidities, and risk factors. Follow-up criteria were MACE (including hospital admission) changes in LVEF category and mortality. 173,195 individuals with T2D were identified in 2013, median age 66 yrs. 6,725 (3.88% of the overall sample) developed HF in 2014 or 2015, median age 74 yrs. As Sankey plot visualizations show, 34.4% of the patients had MACE over the course of five years; 24.5% were still alive and 9.9% died from CV-death. Further 33% died of other causes. Myocardial infarct was the most common MACE, followed by stroke (32%), hospital admission for HF (28%) and CV death (7%). 40% of patients were never admitted to a hospital over the study period. Exploratory analyses identified 5,282 HFpEF patients (78.54%) and 1,443 HFrEF patients (21.46%). Survival after 5 years in HFpEF patients was 71%, in HFrEF patients 29%. After five years 3,430 (90%) surviving patients were still in HFpEF and 399 (10%) in HFrEF.

This analysis provides disease progression insights in T2D patients who developed HF in Germany. The sample is representative for the country and numbers can be extrapolated to the overall German SHI population. A significant number of patients die within 5 years of initial diagnosis. As echo diagrams are not available in German insurance claims, validity of the predicted LVEF cannot be assessed. Further research featuring real world LVEF score validation would be highly desirable. Beyond therapeutic care, digital solutions for closer monitoring of these patients may improve the outcome of these patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi

Accelerated 2D Classification With ISAC Using GPUs

A widely used approach to analyze single particles in electron microscopy data is 2D classification. This process is very computationally expensive, especially when large data sets are analyzed. In this paper we present GPU ISAC, a newly developed, GPU-accelerated version of the established Iterative Stable Alignment and Clustering (ISAC) algorithm for 2D images and generating class averages. While the previously existing implementation of ISAC relied on a computer cluster, GPU ISAC enables users to produce high quality 2D class averages from large-scale data sets on a single desktop machine equipped with affordable, consumer-grade GPUs such as Nvidia GeForce GTX 1080 TI cards. With only two such cards GPU ISAC matches the performance of twelve high end cluster nodes and, using high performance GPUs, is able to produce class averages from a million particles in between six to thirteen hours, depending on data set quality and box size. We also show GPU ISAC to scale linearly in all input dimensions, and thereby capable of scaling well with the increasing data load demand of future data sets. Further user experience improvements integrate GPU ISAC seamlessly into the existing SPHIRE GUI, as well as the TranSPHIRE on-the-fly processing pipeline. It is open source and can be downloaded at https://gitlab.gwdg.de/mpi-dortmund/sphire/cuISAC/

Attenuation of Photoelectron Emission by a Single Organic Layer

We report an in situ study of the thin-film growth of cobalt-phthalocyanine on Ag(100) surfaces using photoelectron emission microscopy (PEEM) and the Anderson method. Based on the Fowler-DuBridge theory, we were able to correlate the evolution of the mean electron yield acquired with PEEM for coverages up to two molecular layers of cobalt-phthalocyanine to the global work function changes measured with the Anderson method. For coverages above two monolayers, the transients measured with the Anderson method and those obtained with PEEM show different trends. We exploit this discrepancy to determine the inelastic mean free path of the low-energy electrons while passing through the third layer of CoPc.

Standard deviation of microscopy images used as indicator for growth stages

Photoelectron emission microscopy (PEEM) and low energy electron microscopy (LEEM) can easily distinguish between organic molecules adsorbed in crystallites or in the wetting layers as well as the bare metal substrate due to their different electronic properties. Already before (and during) the condensation of such solid phases (2D islands or 3D crystallites), there is a dilute 2D gas phase. Such a 2D gas phase consists of molecules, which are highly mobile and diffuse across the surface. The individual molecules are too small to be resolved in PEEM/LEEM images. Here, we discuss, how image features below and above the resolution limit of a PEEM/LEEM affect the mean electron yield and its (normalized) standard deviation. We support our findings with two experimental examples: the deposition of cobalt phthalocyanine (CoPc) on Ag(100) and of perfluoro-pentacene on Ag(110). Our results demonstrate, how a spatial and temporal analysis of image series can be used to obtain information about molecular phases, which cannot be directly resolved in microscopy images.

Structures from intact myofibrils reveal mechanism of thin filament regulation through nebulin

In skeletal muscle, nebulin stabilizes and regulates the length of thin filaments, but the underlying mechanism remains nebulous. In this work, we used cryo-electron tomography and subtomogram averaging to reveal structures of native nebulin bound to thin filaments within intact sarcomeres. This in situ reconstruction provided high-resolution details of the interaction between nebulin and actin, demonstrating the stabilizing role of nebulin. Myosin bound to the thin filaments exhibited different conformations of the neck domain, highlighting its inherent structural variability in muscle. Unexpectedly, nebulin did not interact with myosin or tropomyosin, but it did interact with a troponin T linker through two potential binding motifs on nebulin, explaining its regulatory role. Our structures support the role of nebulin as a thin filament "molecular ruler" and provide a molecular basis for studying nemaline myopathies.

Real-time, large-depth holographic 3D head-up display: selected aspects

Today's state-of-the-art automotive head-up displays (HUD) possess single- or double layer focal planes that limit the observers' eye focus to these planes when crucial information is shown. Other visual 3D cues such as motion parallax also suffer from this limitation. The resulting viewing experience contradicts the natural way of viewing during driving or interaction, when alerts and hints should appear at the correct projection depth where real objects of interest are located. Here we present a real-time holographic HUD with continuous depth that supports the intuitive and natural way of viewing and interacting with virtual environments outside and inside the car. We demonstrate full-color, 3D real-time encoding within a field-of-view of 5^∘×3^∘.

Absence of clinical benefit of FDG PET-CT in staging T1 part-solid lung adenocarcinoma

AIM

To assess the rates of nodal and metastatic disease and change in management when staging part-solid T1 lung adenocarcinomas using integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) in a UK population.

MATERIALS AND METHODS

This was a retrospective review of PET-CT examinations performed to stage radiologically suspected T1 part-solid lung adenocarcinoma (n=58) from two different centres. Rates of detection of nodal and metastatic disease, change in management, and final patient outcome were recorded.

RESULTS

PET-CT changed the stage in one patient from N0 to N1. It did not change final management in any patient.

CONCLUSIONS

In this UK population, PET-CT had minimal additional diagnostic benefit in staging patients with T1 part-solid lung adenocarcinoma. Especially given its cost, the inclusion of PET-CT for this indication in guidelines should be reviewed.

A trigonal coordination of Au(I) phosphane complexes stabilized by O-H ⋯ X (X = Cl-, Br-, I-) interactions

In this work, we show that intramolecular hydrogen bonding can be used to stabilize tri-coordinated phosphane-gold(I) complexes. Two molecular structures of 2-(diphenylphosphino)benzoic acid (L) coordinated to a gold(I) atom were determined by single-crystal X-ray diffraction. The linear L-Au-Br shows a standard linear coordination and dimerizes via hydrogen bonds of the carboxylic acid. Upon addition of two additional phosphane ligands the complex [L3Au]X is formed which is stabilized by three intramolecular -C(O)O-H … X hydrogen bonds as proven by the X-ray structure of the respective chlorido-complex. X-ray powder diffractograms suggest the same structure also for X- = Br- and I-.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00706-021-02843-2.

Unilateral axillary adenopathy following COVID-19 vaccination: a multimodality pictorial illustration and review of current guidelines

We present a multimodality pictorial review of axillary lymphadenopathy in patients recently vaccinated against COVID-19. As the mass vaccination programme continues to be rolled out worldwide in an effort to combat the pandemic, it is important that radiologists consider recent COVID-19 vaccination in the differential diagnosis of unilateral axillary lymphadenopathy and are aware of typical appearances across all imaging methods. We review current guidelines on the management of unilateral axillary lymphadenopathy in the context of recent COVID-19 vaccination.

The molecular basis for sarcomere organization in vertebrate skeletal muscle

Sarcomeres are force-generating and load-bearing devices of muscles. A precise molecular picture of how sarcomeres are built underpins understanding their role in health and disease. Here, we determine the molecular architecture of native vertebrate skeletal sarcomeres by electron cryo-tomography. Our reconstruction reveals molecular details of the three-dimensional organization and interaction of actin and myosin in the A-band, I-band, and Z-disc and demonstrates that α-actinin cross-links antiparallel actin filaments by forming doublets with 6-nm spacing. Structures of myosin, tropomyosin, and actin at ~10 Å further reveal two conformations of the "double-head" myosin, where the flexible orientation of the lever arm and light chains enable myosin not only to interact with the same actin filament, but also to split between two actin filaments. Our results provide unexpected insights into the fundamental organization of vertebrate skeletal muscle and serve as a strong foundation for future investigations of muscle diseases.

[PIMS-a new pediatric challenge]

The boy of Egyptian origin was previously healthy. After a history of fever for 7 days, abdominal pain, vomiting and dry cough resistant to treatment with oral antibiotics, he was admitted to hospital. The clinical examination showed a slightly red throat, a tense abdomen and erythema. The blood tests revealed leukocytosis and significantly increased inflammatory parameters. The abdominal ultrasound showed thickened intestinal loops in the left lower abdomen and the echocardiography showed minimal mitral regurgitation, a narrow pericardial effusion lamella over both ventricles and normal coronary arteries. Accordingly, cardiac enzymes were elevated. The day after admission, the boy developed an increasing rash and was transferred to the PICU because of septic shock refractory to high volume resuscitation, requiring hemodynamic support with noradrenaline and noninvasive respiratory assistance. The initial testing for SARS-CoV‑2 on nasopharyngeal aspirates was negative twice; however, serum IgG antibodies were positive. Other viral and bacterial infections were excluded as the cause of the symptoms.The patient received IVIG, ASS, furosemide and methylprednisolone and the antibiotic treatment was continued. The dosage of the catecholamine could be reduced according to the patient's condition and the serially performed echocardiographic findings. The patient recovered in his general condition and was discharged from the PICU after 8 days. With the help of a detailed family history, we were able to figure out that the whole family, including the patient himself, had symptoms of a cold about 1 month earlier. Hence, SARS-CoV‑2 antibody tests carried out showed a positive result for all of them.Pediatric inflammatory multisystem syndrome (PIMS) can quickly lead to manifest shock symptoms, necessitating close monitoring. A PICU background is crucial to treat possibly occurring symptoms and complications. High-dose steroids are used therapeutically alongside supportive therapies.