515 research outputs found

    Microbial respiration and natural attenuation of benzene contaminated soils investigated by cavity enhanced Raman multi-gas spectroscopy

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    Soil and groundwater contamination with benzene can cause serious environmental damage. However, many soil microorganisms are capable to adapt and are known to strongly control the fate of organic contamination. Innovative cavity enhanced Raman multi-gas spectroscopy (CERS) was applied to investigate the short-term response of the soil micro-flora to sudden surface contamination with benzene regarding the temporal variations of gas products and their exchange rates with the adjacent atmosphere. 13C-labeled benzene was spiked on a silty-loamy soil column in order to track and separate the changes in heterotrophic soil respiration – involving 12CO2 and O2 – from the natural attenuation process of benzene degradation to ultimately form 13CO2. The respiratory quotient (RQ) decreased from a value 0.98 to 0.46 directly after the spiking and increased again within 33 hours to a value of 0.72. This coincided with the maximum 13CO2 concentration rate (0.63 μmol m−2 s−1), indicating the highest benzene degradation at 33 hours after the spiking event. The diffusion of benzene in the headspace and the biodegradation into 13CO2 were simultaneously monitored and 12 days after the benzene spiking no measurable degradation was detected anymore. The RQ finally returned to a value of 0.96 demonstrating the reestablished aerobic respiration

    Autonomic cardiac regulation during spontaneous nocturnal hypoglycemia in children with type 1 diabetes

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    Hypoglycemia is the most common complication in insulin treated diabetes. Though mostly mild, it can be fatal in rare cases: It is hypothesized that hypoglycemia related QTc prolongation contributes to cardiac arrhythmia.; To evaluate influence of nocturnal hypoglycemia on QTc and heart rate variability (HRV) in children with T1D.; Children and adolescents with T1D for at least 6 months participated in an observational study using continuous glucose monitoring (CGM) and Holter electrocardiogram for five consecutive nights. Mean QTc was calculated for episodes of nocturnal hypoglycemia (<3.7 mmol/L) and compared to periods of the same duration preceding hypoglycemia. HRV (RMSSD, low and high frequency power LF and HF) was analyzed for different 15 min intervals: before hypoglycemia, onset of hypoglycemia, before/after nadir, end of hypoglycemia and after hypoglycemia.; Mean QTc during hypoglycemia was significantly longer compared to euglycemia (412 ± 15 vs. 405 ± 18 ms, p = 0.005). HRV changed significantly: RMSSD (from 88 ± 57 to 73 ± 43 ms) and HF (from 54 ± 17 to 47 ± 17nu) decreased from before hypoglycemia to after nadir, while heart rate (from 69 ± 9 to 72 ± 12 bpm) and LF (from 44 ± 17 to 52 ± 21 nu) increased (p = 0.04).; A QTc lengthening effect of nocturnal hypoglycemia in children with T1D was documented. HRV changes occurred even before detection of nocturnal hypoglycemia by CGM, which may be useful for hypoglycemia prediction

    Le West African Data and Metadata Repository : une archive de données à long terme pour les ensembles de données écologiques de l'Afrique de l'Ouest

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    Obwohl zunehmend Daten für ökologische Studien gebraucht werden, gehen noch immer viele Daten verloren oder sind mangels geeigneter Datenarchive nicht sichtbar genug. Mit dem West African Data and Metadata Repository stellen wir ein Langzeitdatenarchiv für eine datenarme Region vor, das eine detaillierte Dokumentation mit Metadaten nach dem EML-Standard erlaubt und Datenhaltern die Möglichkeit gibt, Datenzugangsebenen und Nutzungsbedingungen zu bestimmen. Dieser Artikel gibt einen Überblick zu Struktur, Funktionen und Inhalt. Das Repositorium ist online unter der URL http://westafricandata.senckenberg.de.Although there is an increasing need for data in ecological studies, many datasets are still lost or not sufficiently visible due to a lack of appropriate data archives. With the West African Data and Metadata Repository, we present a secure long-term archive for a data-poor region allowing detailed documentation by metadata following the EML standard and giving data holders the opportunity to define levels of data access and conditions of use. This article gives an overview of structure, functions and content. The repository is online at the URL http://westafricandata.senckenberg.de.Bien qu'il existe un besoin croissant de données dans les études écologiques, de nombreux ensembles de données sont encore perdues ou pas suffisamment visibles en raison d'un manque d'archives de données appropriées. Avec le West African Data and Metadata Repository, nous présentons une archive sécurisé à long terme pour une région pauvre en données permettant une documentation détaillée par des métadonnées suivant la norme EML et donnant aux propriétaires de données la possibilité de définir des niveaux de l'accès aux données et les conditions d'utilisation. Cet article donne un aperçu de la structure, des fonctions et du contenu. Le référentiel est en ligne à l'adresse URL http://westafricandata.senckenberg.de

    Creatine synthesis and transport during rat embryogenesis: Spatiotemporal expression of AGAT, GAMT and CT1

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    BACKGROUND: Creatine (Cr) is synthesized by a two-step mechanism involving arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), and is taken up by cells through a specific Cr transporter, CT1. Recently, genetic defects of this pathway have been described, that lead to Cr deficiency, neurological symptoms in early infancy and severe neurodevelopmental delay. To investigate the involvement of Cr synthesis and uptake pathways during embryonic development, we determined the spatiotemporal expression of AGAT, GAMT and CT1 during the rat embryogenesis, at the mRNA and protein level. RESULTS: We show that AGAT and GAMT are expressed in hepatic primordium as soon as 12.5 days, then progressively acquire their adult pattern of expression, with high levels of AGAT in kidney and pancreas, and high levels of GAMT in liver and pancreas. AGAT and CT1 are prominent in CNS, skeletal muscles and intestine, where they appear earlier than GAMT. High levels of CT1 are found in epithelia. CONCLUSION: Our results suggest that de novo synthesis of Cr by AGAT and GAMT, as well as cellular Cr uptake by CT1, are essential during embryonic development. This work provides new clues on how creatine can be provided to developing tissues, and suggests that Cr deficiencies might induce irreversible damages already in utero, particularly on the nervous system

    Kupffer Cells and Blood Monocytes Orchestrate the Clearance of Iron-Carbohydrate Nanoparticles from Serum.

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    Intravenous (IV) iron nanoparticle preparations are widely used to treat iron deficiency. The mechanism of mononuclear phagocyte system-mediated clearance of IV iron nanoparticles is unknown. The early uptake and homeostasis of iron after injection of ferric carboxymaltose (FCM) in mice was studied. An increase in serum iron was observed at 2.5 h followed by a return to baseline by 24 h. An increase in circulating monocytes was observed, particularly Ly6Chi and Ly6Clow. FCM was also associated with a time-dependent decrease in liver Kupffer cells (KCs) and increase in liver monocytes. The increase in liver monocytes suggests an influx of iron-rich blood monocytes, while some KCs underwent apoptosis. Adoptive transfer experiments demonstrated that following liver infiltration, blood monocytes differentiated to KCs. KCs were also critical for IV iron uptake and biodegradation. Indeed, anti-Colony Stimulating Factor 1 Receptor (CSF1R)-mediated depletion of KCs resulted in elevated serum iron levels and impaired iron uptake by the liver. Gene expression profiling indicated that C-C chemokine receptor type 5 (CCR5) might be involved in monocyte recruitment to the liver, confirmed by pharmaceutical inhibition of CCR5. Liver KCs play a pivotal role in the clearance and storage of IV iron and KCs appear to be supported by the expanded blood monocyte population

    Und was ist mit uns? – Ein Vergleich der Situation von Kindern bei einer legalen oder illegalen Substanzabhängigkeit der Eltern

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    Die vorliegende Literaturarbeit mit dem Titel „Und was ist mit uns? - Ein Vergleich der Situation von Kindern bei einer legalen oder illegalen Substanzabhängigkeit der Eltern“ befasst sich mit der Frage, welche Auswirkungen eine legale oder illegale Substanzabhängigkeit der Eltern auf die kindliche Entwicklung hat. In einer Vielzahl der Literatur und in den jeweiligen Interventionen in Bezug auf die Suchtthematik wird der Fokus stark auf die substanzabhängige Person gelegt. Die Kinder der Betroffenen geraten dabei in den Hintergrund. Die Autorinnen Tamara Bachmann, Sabrina Seeholzer und Anne-Joséphine Wildi stellen daher in dieser Arbeit bewusst die Kinder aus suchtbelasteten Familien in den Mittelpunkt. Die Themen Suchtmittelabhängigkeit und kindliche Entwicklung werden aufgrund theoretischer Grundlagen erläutert. Weiter wird das Leben in einer Suchtfamilie thematisiert und aufgezeigt, welche Auswirkungen dies konkret auf die kindliche Entwicklung hat. Die aus der Theorie gewonnenen Erkenntnisse werden anhand eines Vergleiches, inwiefern sich die Auswirkungen auf die Kinder unterscheiden, wenn diese in einer Familie mit einer legalen oder einer illegalen Suchtthematik aufwachsen, verarbeitet. Die Arbeit zeigt unter anderem auf, welche Aufgaben die Profession der Sozialen Arbeit, in Zusammenhang mit den Kindern aus suchtbelasteten Familien, innehat. Anhand von Fallbeispielen werden die wissenschaftlichen Erkenntnisse für die Leserschaft realistisch veranschaulicht

    Regional differences in health care of patients with inflammatory bowel disease in Germany

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    Background: The regional availability of specialized physicians is an important aspect in healthcare of patients with IBD. The association between physician density and healthcare is not yet clear. Most studies did not consider district type, which reflects population density. Our research question was, “Do specialist density and district type influence the healthcare of IBD patients in Germany?” Methods: We combined a claims dataset from a German health insurance fund with population and physician data. Four main aspects were investigated: regular specialist visits, drug therapies, surveillance colonoscopy, and IBD-related hospitalizations. Various regression analyses were performed. Results: The study cohort was comprised of 21,771 individuals, including 9282 patients with Crohn disease and 12,489 patients with ulcerative colitis. Patients who were living in districts with higher specialist densities were more likely to attend specialist visits on a regular basis. No difference in the frequencies of TNF-alpha inhibitor therapies was found. However, individuals from urban areas were more likely to receive a permanent immunosuppressive therapy with continuous specialist support. Conclusions: The results revealed that some aspects had positive effects on the probability of implementing healthcare in accordance with pathways and guidelines. No clear evidence of a general healthcare undersupply in rural areas was found.DF

    Sensors for foetal hypoxia and metabolic acidosis: a review

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    This article reviews existing clinical practices and sensor research undertaken to monitor fetal well-being during labour. Current clinical practices that include fetal heart rate monitoring and fetal scalp blood sampling are shown to be either inadequate or time-consuming. Monitoring of lactate in blood is identified as a potential alternative for intrapartum fetal monitoring due to its ability to distinguish between different types of acidosis. A literature review from a medical and technical perspective is presented to identify the current advancements in the field of lactate sensors for this application. It is concluded that a less invasive and a more continuous monitoring device is required to fulfill the clinical needs of intrapartum fetal monitoring. Potential specifications for such a system are also presented in this paper

    Increased Receptor Affinity and Reduced Recognition by Specific Antibodies Contribute to Immune Escape of SARS-CoV-2 Variant Omicron.

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    In this report, we mechanistically reveal how the Variant of Concern (VOC) SARS-CoV-2 Omicron (B.1.1.529) escapes neutralizing antibody responses, by physio-chemical characterization of this variant in comparison to the wild-type Wuhan and the Delta variant (B.1.617.2). Convalescent sera, as well as sera obtained from participants who received two or three doses of mRNA vaccines (Moderna-mRNA-1273® or Pfizer-BNT162b2®), were used for comparison in this study. Our data demonstrate that both Delta, as well as Omicron variants, exhibit a higher affinity for the receptor ACE2, facilitating infection and causing antibody escape by receptor affinity (affinity escape), due to the reduced ability of antibodies to compete with RBD-receptor interaction and virus neutralization. In contrast, only Omicron but not the Delta variant escaped antibody recognition, most likely because only Omicron exhibits the mutation at E484A, a position associated with reduced recognition, resulting in further reduced neutralization (specificity escape). Nevertheless, the immunizations with RNA-based vaccines resulted in marked viral neutralization in vitro for all strains, compatible with the fact that Omicron is still largely susceptible to vaccination-induced antibodies, despite affinity- and specificity escape

    The Evolving Landscape of Biomarkers for Anti-PD-1 or Anti-PD-L1 Therapy

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    The administration of antibodies blocking the immune checkpoint molecules programmed cell death protein 1 (PD-1) or programmed cell death 1 ligand 1 (PD-L1) has evolved as a very promising treatment option for cancer patients. PD-1/PD-L1 inhibition has significantly enhanced expansion, cytokine secretion, and cytotoxic activity of CD4+ and CD8+ T lymphocytes, resulting in enhanced antitumor responses. Anti-PD-1 or anti-PD-L1 therapy has induced tumor regression and improved clinical outcome in patients with different tumor entities, including melanoma, non-small-cell lung cancer, and renal cell carcinoma. These findings led to the approval of various anti-PD-1 or anti-PD-L1 antibodies for the treatment of tumor patients. However, the majority of patients have failed to respond to this treatment modality. Comprehensive immune monitoring of clinical trials led to the identification of potential biomarkers distinguishing between responders and non-responders, the discovery of modes of treatment resistance, and the design of improved immunotherapeutic strategies. In this review article, we summarize the evolving landscape of biomarkers for anti-PD-1 or anti-PD-L1 therapy
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