Comparison of commonly used retrograde tracers in rat spinal motor neurons

The purpose of this study was to investigate the effect of four fluorescent dyes, True Blue（TB）, Fluoro-Gold（FG）, Fluoro-Ruby（FR）, and 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate（Di I）, in retrograde tracing of rat spinal motor neurons. We transected the muscle branch of the rat femoral nerve and applied each tracer to the proximal stump in single labeling experiments, or combinations of tracers（FG-Di I and TB-Di I） in double labeling experiments. In the single labeling experiments, significantly fewer labeled motor neurons were observed after FR labeling than after TB, FG, or Di I, 3 days after tracer application. By 1 week, there were no significant differences in the number of labeled neurons between the four groups. In the double-labeling experiment, the number of double-labeled neurons in the FG-Di I group was not significantly different from that in the TB-Di I group 1 week after tracer application. Our findings indicate that TB, FG, and Di I have similar labeling efficacies in the retrograde labeling of spinal motor neurons in the rat femoral nerve when used alone. Furthermore, combinations of Di I and TB or FG are similarly effective. Therefore, of the dyes studied, TB, FG and Di I, and combinations of Di I with TB or FG, are the most suitable for retrograde labeling studies of motor neurons in the rat femoral nerve.

An ultrasonic humidification fluorescent tracing method for detecting unsaturated atmospheric water absorption by the aerial parts of desert plants

Atmospheric water absorption by plants has been explored for more than two centuries, and the aerial parts of plants, particularly the leaves of certain species, have been demonstrated to have an ability to absorb and utilize saturated atmospheric water such as fog, dew and condensed water. So far, however, there have been few studies on the aerial parts of desert plants in their absorption of unsaturated water from the atmosphere. This study presents an ultrasonic humidification fluorescent tracing method of detecting unsaturated atmospheric water absorption by the aerial parts of desert plants. We constructed an organic glass room based on the sizes of field plants. Then, the aboveground parts of the plants were humidified in the sealed glasshouse using an ultrasonic humidifier containing fluorescent reagents. The humidity and wetting time were controlled by turning on or off the humidifier according to the reading of a thermo-hygrometer suspended in the glasshouse. Fluorescence microscopy was employed to observe these plant samples. This method can generate unsaturated atmospheric water vapor and incorporate other fluorescent reagents or water-soluble chemical reagents for gasified humidification. In addition, it can identify plant parts that absorb unsaturated atmospheric water from the air, detect water absorption sites on the surface of leaves or tender stems, and determine the ability of tissues or microstructure of aerial parts to absorb water. This method provides a direct visual evidence for the inspection of leaf or tender stem microstructure in response to unsaturated atmospheric water absorption. Moreover, this method shows that aqueous pores in the cuticles of leaves or tender stems of desert plants are large enough to allow the passage of ionic fluorescent brightener with a molecular weight of up to 917 g/mol. Thus, this paper provides an important approach that explores the mechanism by which desert plants utilize unsaturated atmospheric water.

Exploring non-curative endoscopic submucosal dissection:Current treatment optimization and future indication expansion

The increasing popularity of endoscopic submucosal dissection(ESD)as a treatment for early gastric cancer has highlighted the importance of quality assessment in achieving curative resections.This article emphasizes the significance of evaluating ESD quality,not only for curative cases but also for non-curative ones.Postoperative assessment relies on the endoscopic curability(eCura)classification,but management strategies for eCuraC-1 tumour with a positive horizontal margin are unclear.Current research primarily focuses on comparing additional surgical procedures in high-risk patients,while studies specifically targeting eCuraC-1 patients are limited.Exploring management strategies and follow-up outcomes for such cases could provide valuable insights.Furthermore,the application of molecular imaging using near-infrared fluorescent tracers holds promise for precise tumour diagnosis and navigation,potentially impacting the management of early-stage gastric cancer patients.Advancing research in these areas is essential for improving the overall efficacy of endoscopic techniques and refining treatment indications.

Recent developments,challenges,and prospects of carbon dots(CDs)for fluid flow investigation in porous media

Carbon nanostructures exhibit unique physicochemical properties and play a significant role in modern and advanced technologies.Carbon dots(CDs)are a subset of carbon-based particles less than 20 nm in size.In this study,a comprehensive review was performed on the applications of CDs for fluid flow investigations in porous media.CD technology provides precious information about the heterogeneity and permeability of the rock and the existence of a sealed part between the wells in the hydrocarbon reservoir.Studying the volume and flow potential of aquifers is another application of CD in fluid flow study.CDs can be used as an additive in the fluid to modify the chemical or physical properties.Adding CD to injected fluid in the reservoir can change the rheological properties of the fluid and reduce its viscosity.CD injection as a nanofluid in the reservoir rock increases the oil recovery factor and decreases injection pressure due to the change in the wettability of rock from oil-wet to water-wet and the reduction of interfacial tension between the fluids.The mobility and performance of CDs in pore scale are related to some parameters including ionic strength,pH,pore size distribution,and type of fluids in porous media.

Quantitative Determination of Glymphatic Flow Using Spectrophotofluorometry

Following intrathecal injection of fluorescent tracers,ex vivo imaging of brain vibratome slices has been widely used to study the glymphatic system in the rodent brain.Tracer penetration into the brain is usually quantified by image-processing,even though this approach requires much time and manual operation.Here,we illustrate a simple protocol for the quantitative determination of glymphatic activity using spectrophotofluorometry.At specific time-points following intracisternal or intrastriatal injection of fluorescent tracers,certain brain regions and the spinal cord were harvested and tracers were extracted from the tissue.The intensity of tracers was analyzed spectrophotometrically and their concentrations were quantified from standard curves.Using this approach,the regional and dynamic delivery of subarachnoid CSF tracers into the brain parenchyma was assessed,and the clearance of tracers from the brain was also determined.Furthermore,the impairment of glymphatic influx in the brains of old mice was confirmed using our approach.Our method is more accurate and efficient than the imaging approach in terms of the quantitative determination of glymphatic activity,and this will be useful in preclinical studies.