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1.
Chem Sci ; 15(12): 4504-4509, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38516076

RESUMO

The Simons process is an electrochemical fluorination method to prepare organofluorine compounds. Despite the wide application, the underlying mechanism is still unclear. We report the investigation of the black film formed on the surface of the anodes in aHF by an in situ Ni K-edge X-ray absorption near edge structure (XANES) investigation. An electrochemical cell for in situ X-ray absorption spectroscopy (XAS) is presented.

2.
Semin Arthritis Rheum ; : 152328, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38042621

RESUMO

BACKGROUND: B-cell activation is triggered by the B-cell receptor, but is also controlled by inhibitory receptors, which limit the BCR signaling. CD22 (Siglec-2) and Siglec-G are such inhibitory receptors expressed on B cells. CD22- or Siglec-G deficient mice show enhanced B cell activation. OBJECTIVES: It was the objective of our study to investigate the role of these inhibitory receptors in autoimmune disease and leukemia. RESULTS: Ageing Siglec-G deficient or CD22 x Siglec-G deficient mice develop an SLE-like autoimmune disease with autoantibodies and kidney nephritis. In a mouse model for chronic lymphocytic leukemia (CLL), Siglec-G deficient mice show an earlier and more severe disease. AUTHOR'S CONCLUSIONS: These results show that Siglec-G and CD22 are both involved in preventing autoimmune diseases and leukemia delevopment and could therefore be attractive new targets.

3.
EMBO Rep ; 24(8): e56420, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37424400

RESUMO

Chronic Lymphocytic Leukemia (CLL) is the most common leukemia in adults in the Western world. B cell receptor (BCR) signaling is known to be crucial for the pathogenesis and maintenance of CLL cells which develop from mature CD5+ B cells. BCR signaling is regulated by the inhibitory co-receptor Siglec-G and Siglec-G-deficient mice have an enlarged CD5+ B1a cell population. Here, we determine how Siglec-G expression influences the severity of CLL. Our results show that Siglec-G deficiency leads to earlier onset and more severe course of the CLL-like disease in the murine Eµ-TCL1 model. In contrast, mice overexpressing Siglec-G on the B cell surface are almost completely protected from developing CLL-like disease. Furthermore, we observe a downmodulation of the human ortholog Siglec-10 from the surface of human CLL cells. These results demonstrate a critical role for Siglec-G in disease progression in mice, and suggest that a similar mechanism for Siglec-10 in human CLL may exist.


Assuntos
Leucemia Linfocítica Crônica de Células B , Camundongos , Animais , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/genética , Camundongos Transgênicos , Proteínas Proto-Oncogênicas , Linfócitos B/metabolismo , Receptores de Antígenos de Linfócitos B/genética
4.
J Chem Phys ; 158(24)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37352425

RESUMO

With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. The BAMline, a real-life sample materials research beamline, provides unique insights into materials' electronic and chemical structure at different time and length scales. The beamline specializes in x-ray absorption spectroscopy, x-ray fluorescence spectroscopy, and tomography experiments. This enables real-time optimization of material properties and performance for various applications, such as energy transfer, energy storage, catalysis, and corrosion resistance. This paper gives an overview of the analytical methods and sample environments of the BAMline, which cover non-destructive testing experiments in materials science, chemistry, biology, medicine, and cultural heritage. We also present our own synthesis methods, processes, and equipment developed specifically for the BAMline, and we give examples of synthesized materials and their potential applications. Finally, this article discusses the future perspectives of the BAMline and its potential for further advances in sustainable materials research.


Assuntos
Síncrotrons , Espectrometria por Raios X/métodos
5.
Biosensors (Basel) ; 13(4)2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37185530

RESUMO

Cardiac vascular diseases, especially acute myocardial infarction (AMI), are one of the leading causes of death worldwide. Therefore cardio-specific biomarkers such as cardiac troponin I (cTnI) play an essential role in the field of diagnostics. In order to enable rapid and accurate measurement of cTnI with the potential of online measurements, a chemiluminescence-based immunosensor is presented as a proof of concept. A flow cell was designed and combined with a sensitive CMOS camera allowing sensitive optical readout. In addition, a microfluidic setup was established, which achieved selective and quasi-online cTnI determination within ten minutes. The sensor was tested with recombinant cTnI in phosphate buffer and demonstrated cTnI measurements in the concentration range of 2-25 µg/L. With the optimized system, a limit of detection (LoD) of 0.6 µg/L (23 pmol/L) was achieved. Furthermore, the selectivity of the immunosensor was investigated with other recombinant proteins, such as cTnT, and cTnC, at a level of 16 µg/L. No cross-reactivity could be observed. Measurements with diluted blood plasma and serum resulted in an LoD of 60 µg/L (2.4 nmol/L) and 70 µg/L (2.9 nmol/L), respectively.


Assuntos
Técnicas Biossensoriais , Infarto do Miocárdio , Humanos , Troponina I , Luminescência , Imunoensaio , Infarto do Miocárdio/diagnóstico , Biomarcadores
6.
Faraday Discuss ; 241(0): 178-193, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36169080

RESUMO

Mechanochemistry offers a unique opportunity to modify and manipulate crystal forms, often providing new products as compared with conventional solution methods. While promising, there is little known about how to control the solid form through mechanochemical means, demanding dedicated investigations. Using a model organic cocrystal system (isonicotinamide:glutaric acid), we here demonstrate that with mechanochemistry, polymorphism can be induced in molecular solids under conditions seemingly different to their conventional thermodynamic (thermal) transition point. Whereas Form II converts to Form I upon heating to 363 K, the same transition can be initiated under ball milling conditions at markedly lower temperatures (348 K). Our results indicate that mechanochemical techniques can help to reduce the energy barriers to solid form transitions, offering new insights into controlling polymorphic forms. Moreover, our results suggest that the nature of mechanochemical transformations could make it difficult to interpret mechanochemical solid form landscapes using conventional equilibrium-based tools.


Assuntos
Cristalização , Niacinamida , Temperatura , Termodinâmica , Niacinamida/química , Glutaratos/química
7.
Risk Anal ; 34(7): 1270-85, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24444356

RESUMO

A major issue in all risk communication efforts is the distinction between the terms "risk" and "hazard." The potential to harm a target such as human health or the environment is normally defined as a hazard, whereas risk also encompasses the probability of exposure and the extent of damage. What can be observed again and again in risk communication processes are misunderstandings and communication gaps related to these crucial terms. We asked a sample of 53 experts from public authorities, business and industry, and environmental and consumer organizations in Germany to outline their understanding and use of these terms using both the methods of expert interviews and focus groups. The empirical study made clear that the terms risk and hazard are perceived and used very differently in risk communication depending on the perspective of the stakeholders. Several factors can be identified, such as responsibility for hazard avoidance, economic interest, or a watchdog role. Thus, communication gaps can be reduced to a four-fold problem matrix comprising a semantic, conceptual, strategic, and control problem. The empirical study made clear that risks and hazards are perceived very differently depending on the stakeholders' perspective. Their own worldviews played a major role in their specific use of the two terms hazards and risks in communication.


Assuntos
Comunicação , Risco , Pesquisa Empírica , Grupos Focais , Alemanha
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