Fluorescent Protein-Based Turn-On Probe through a General Protection–Deprotection Design Strategy

We demonstrated a general protection–deprotection strategy for the design of fluorescent protein biosensors through the construction of a turn-on Hg²⁺ sensor. A combination of fluorescent protein engineering and unnatural amino acid mutagenesis was used. Unlike previously reported fluorescent protein-based Hg²⁺ sensors that relied on the binding of Hg²⁺ to the sulfhydryl group of cysteine residues, a well-established chemical reaction, oxymercuration, was transformed into biological format and incorporated into our sensor design. This novel Hg²⁺ sensor displayed good sensitivity and selectivity both in vitro and in live bacterial cells. Over 60-fold change in fluorescence signal output was observed in the presence of 10 μM Hg²⁺, while such a change was undetectable when nine other metal ions were tested. This new design strategy could expand the repertoire of fluorescent protein-based biosensors for the detection of small-molecule analytes

Improved Photoinduced Fluorogenic Alkene–Tetrazole Reaction for Protein Labeling

The 1,3-dipolar cycloaddition reaction between an alkene and a tetrazole represents one elegant and rare example of fluorophore-forming bioorthogonal chemistry. This is an attractive reaction for imaging applications in live cells that requires less intensive washing steps and/or needs spatiotemporal resolutions. In the present work, as an effort to improve the fluorogenic property of the alkene–tetrazole reaction, an aromatic alkene (styrene) was investigated as the dipolarophile. Over 30-fold improvement in quantum yield of the reaction product was achieved in aqueous solution. According to our mechanistic studies, the observed improvement is likely due to an insufficient protonation of the styrene–tetrazole reaction product. This finding provides useful guidance to the future design of alkene–tetrazole reactions for biological studies. Fluorogenic protein labeling using the styrene–tetrazole reaction was demonstrated both in vitro and in vivo. This was realized by the genetic incorporation of an unnatural amino acid containing the styrene moiety. It is anticipated that the combination of styrene with different tetrazole derivatives can generally improve and broaden the application of alkene–tetrazole chemistry in real-time imaging in live cells

DataSheet_1_Association of overweight, obesity and risk of urinary incontinence in middle-aged and older women: a meta epidemiology study.docx

AimsThe aim of this meta-analysis is to evaluate the potential correlation between obesity and overweight, and the vulnerability to urinary incontinence (UI) in women aged middle-aged and above.MethodsWe searched PubMed, Cochrane Library, and Embase for observational studies published between the inception of the databases and April 25, 2023. A fixed-effects model was used when the P>0.1 and the I2 ≤ 50%. In cases where I2 ≥ 50% (indicating significant heterogeneity), a random-effects model was applied. For the purpose of evaluating publication bias, a funnel plot and Egger’s test were used. Stata 14.0 was used for all statistical analyses.FindingsThis meta-analysis includes 16 observational studies, covering29,618 individuals. The pooled analysis shows that being overweight(25 kg/m2≤BMI2) in middle-aged and elderly women is more likely to develop UI (OR=1.27; 95% CI: 1.17-1.37; I2 = 51.8%, P=0.013). Middle-aged and elderly women with obesity(30 kg/m2≤BMI2) are significantly more likely to develop UI (OR=1.60; 95% CI: 1.42-1.81; I2 = 71.8%, P=0.000). In addition, the results indicated a higher probability of UI in middle-aged and older women with obesity class II (BMI≥35 kg/m2) (OR=1.85; 95% CI: 1.59-2.16; I2 = 48.1%, P=0.103). In subgroup analysis, there is no direct relationship between the obesity in middle-aged and elderly women and an increased risk of stress urinary incontinence (SUI) (OR=1.31; 95% CI: 0.99-1.74; I2 = 63.7%, P=0.011). In middle-aged and elderly women with obesity are more likely to develop urgent urinary incontinence (UUI) (OR=2.11; 95% CI: 1.54-2.89; I2 = 80.2%, P=0.000).ConclusionIn this meta-analysis, overweight and obesity are associated with an increased risk of UI in middle-aged and elderly women. Obesity and overweight are independent risk factors for UI, as demonstrated by this study.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023421986.</p

Dye-Sensitized Solar Cells Employing a Multifunctionalized Hierarchical SnO₂ Nanoflower Structure Passivated by TiO₂ Nanogranulum

We investigated a facile multifunctionalized hierarchical SnO₂ nanoflower photoelectrode passivated by a layer of TiO₂ nanogranulum. The hierarchical SnO₂ nanoflower with thin nanorod and nanosheet has a unique morphology that can afford excellent electron transport propertiesorientation overall, which results in a significant diminution in the charge diffusion route and a rapid collection in FTO substrate. The passivated photoanode not only improved the distribution of dyes in the photoelectrode and reduced the surface defects of SnO₂ photoelectrode to accommodate more dyes, but also suppressed the charge recombination and prolonged electron lifetime by introducing a barrier layer. The microstructure of the sample was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface areas (<i>S</i>_BET) and pore size distribution were detected on BET measurement. The amounts of dye were calculated from UV–vis. The interfacial charge transfer process and the charge recombination were characterized by EIS and IMPS/IMVS measurements. The DSSCs assembled with multifunctionalized photoanode exhibits favorable energy conversion efficiency. The photocurrent increased from 5.44 to 12.74 mA cm², the photovoltage from 440 to 760 mV, and the fill factor from 43.58% to 57.58%. As a result, the cell’s conversion efficiency increased by a factor of 5.3 from 1.05% to 5.60%. The increase in efficiency originates from higher open-circuit potential and higher short-circuit current as well as from superior light scattering effect, long electron lifetime, and slower electron recombination