Two-photon excitation fluorescence microspectroscopy protocols for examining fluorophores in fossil plants.

Fluorescence emission is common in plants. While fluorescence microscopy has been widely used to study living plants, its application in quantifying the fluorescence of fossil plants has been limited. Fossil plant fluorescence, from original fluorophores or formed during fossilization, can offer valuable insights into fluorescence in ancient plants and fossilization processes.

Suberin, the hallmark constituent of bark, identified in a 45-million-year-old monkeyhair tree (Coumoxylon hartigii) from Geiseltal, Germany.

Suberin, a complex biopolymer, forms a water- and gas-insoluble barrier that protects the inner tissues of plants. It is abundant in tree bark, particularly in the cork oak Quercus suber. Anatomically, fossil bark has been described since the Devonian.

Traces of calcium oxalate biomineralization in fossil leaves from late Oligocene maar deposits from Germany.

Calcium oxalate (CaOx) is one of the most common bio-mineral in extant plants and is believed to serve a variety of functions such as calcium storage and herbivore defense. However, traces of CaOx crystals have rarely been identified in fossil plants, and they are primarily known from fossil gymnosperms, where empty cavities of former CaOx crystals or ghost crystals have been reported from leaf cuticles of some Late Cretaceous and Cenozoic conifers. Here we investigate fossil angiosperm leaves from the late Oligocene Rott Fossil Lagerstätte and report ghost crystals of various shapes, sizes and topology (distribution patterns), and cavities.

Cervical Visual Inspection with Acetic Acid (VIA) and Oncogenic Human Papillomavirus Screening in Rural Indigenous Guatemalan Women: Time to Rethink VIA.

Single-visit "screen-and-treat" strategies using visual inspection with acetic acid (VIA) and cryotherapy (liquid nitrous oxide ablation) in low-resource settings are commonly used to detect and treat precancerous lesions for cervical cancer prevention. This study compared VIA sensitivity and specificity in rural indigenous Guatemalan communities, to that of oncogenic human papillomavirus (HPV) testing for detection of precancerous changes, using cytology as the reference standard. Between 3-8 September 2017, trained nurses examined 222 women aged 23-58 years with VIA.

The complex role of microbial metabolic activity in fossilization.

Bacteria play an important role in the fossilization of soft tissues; their metabolic activities drive the destruction of the tissues and also strongly influence mineralization. Some environmental conditions, such as anoxia, cold temperatures, and high salinity, are considered widely to promote fossilization by modulating bacterial activity. However, bacteria are extremely diverse, and have developed metabolic adaptations to a wide range of stressful conditions.