Two sample cells designed specifically for sum-frequency-generation (SFG) measurements at the solid/liquid interface were developed: one thin-layer analysis cell allowing measurement of films on reflective metallic surfaces through a micrometer layer of solution and one spectroelectrochemical cell allowing investigation of processes at the indium tin oxide/solution interface. Both sample cells are described in detail and data illustrating the capabilities of each are shown. To further improve measurements at solid/liquid interfaces, the broadband SFG system was modified to include a reference beam which can be measured simultaneously with the sample signal, permitting background correction of SFG spectra in real time. Sensitivity tests of this system yielded a signal-to-noise ratio of 100 at a surface coverage of 0.2 molecules/nm(2). Details on data analysis routines, pulse shaping methods of the visible beam, as well as the design of a purging chamber and sample stage setup are presented. These descriptions will be useful to those planning to set up a SFG spectrometer or seeking to optimize their own SFG systems for measurements of solid/liquid interfaces.
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ACS Nano
January 2025
Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France.
Atomic force microscopy (AFM) has reached a significant level of maturity in biology, demonstrated by the diversity of modes for obtaining not only topographical images but also insightful mechanical and adhesion data by performing force measurements on delicate samples with a controlled environment (e.g., liquid, temperature, pH).
View Article and Find Full Text PDFAdv Biotechnol (Singap)
June 2024
MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, 510275, China.
Autosomal dominant polycystic kidney disease (ADPKD) is a dominant genetic disorder caused primarily by mutations in the PKD1 gene, resulting in the formation of numerous cysts and eventually kidney failure. However, there are currently no gene therapy studies aimed at correcting PKD1 gene mutations. In this study, we identified two mutation sites associated with ADPKD, c.
View Article and Find Full Text PDFInflamm Res
January 2025
Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, 1005 D.B. Todd Jr. Blvd, Nashville, TN, USA.
Background: The aberrant expression of α defensin 5 (DEFA5) protein in colonic inflammatory bowel diseases (IBDs) underlies the distinct pathogenesis of Crohn's colitis (CC). It can serve as a biomarker for differentiating CC from Ulcerative colitis (UC), particularly in Indeterminate colitis (IC) cases into UC and CC. We evaluated the specificity of commercially available anti-DEFA5 antibodies, emphasizing the need to further validate their appropriateness for a given application and highlighting the necessity for novel antibodies.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Molecular Reaction Dynamics, CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Directly probing the heterogeneous conformations of intracellular proteins within their native cellular environment remains a significant challenge in mass spectrometry (MS). Here, we establish an in-cell MS and ultraviolet photodissociation (UVPD) strategy that directly ejects proteins from living cells into a mass spectrometer, followed by 193 nm UVPD for structural analysis. Applying this approach to calmodulin (CaM), we reveal that it adopts more extended conformations within living cells compared with purified samples , highlighting the unique influence of intracellular environments on protein folding.
View Article and Find Full Text PDFHealth Promot Int
January 2025
School of Health Systems and Public Health, University of Pretoria, HW Snyman Building, Bophelo Road, Pretoria 0084, South Africa.
Cervical cancer is the second most common malignancy among South African women and the load of abnormal cervical smears has clinical, programmatic and policy implications. This cross-sectional study of women who presented for cervical cancer screening aimed to determine the prevalence of abnormal cervical smears and associated factors in primary health care (PHC) facilities in Gauteng-the most densely populated province in South Africa. A questionnaire collected data on socio-demography, tobacco use, sexual behaviours, HIV status, past treatment for sexually transmitted infections (STI) and cervical cancer screening in the past 10 years.
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