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In 1835, the meaning of the cleavage furrows in the division of frog eggs was the cause of a heated argument between the Italian naturalist Mauro Rusconi and Karl Ernst von Baer. These furrows were first described by Prévost and Dumas (Ann Sci Nat 2100-121, 129-149, 1824b) who did not realize they cut the egg into separate masses. Rusconi (Développement de la grenouille comune depuis le moment de sa naissance jusque a son état parfait, Giusti, Milano, 1826) hypothesized a connection between the furrows and a peculiar crystallization of the content of the egg which eventually produced elementary molecules as the building blocks of the embryo. von Baer (Arch Anat Phys Wiss Med 6481-509, 1834) was the first to establish a link between the furrows and an active process of dichotomous division he considered to be the basis for all further development and differentiation. The present paper analyses the theoretical reasons behind these divergent interpretations and focuses attention on their implications for the development of the cell theory and the conceptions of life. Prévost, Dumas and Rusconi interpreted cleavage and the whole embryonic development in the light of eighteenth-century scientific theories and the French materialism of the early nineteenth century, which explained life in terms of ordered molecular movement. Starting from other premises partly rooted in German philosophy von Baer (1834) gave a totally different picture which anticipated the cell theory and modern embryology.

Although hepatitisC virus (HCV) infection remains a major clinical, economic, and societal burden, the development of curative antiviral therapy may accelerate the path toward elimination. This analysis assessed the progress of United States (US) states towards achieving the World Health Organization's (WHO) 2030 HCV elimination targets for incidence, mortality, diagnosis, and treatment.

A previously published Markov model was used to simulate HCV progression over time to estimate the path to HCV elimination in each state based on prevalence, annual treatment, and diagnosis inputs from two large US laboratory datasets from January 2013 to December 2017. State-specific fibrosis stage restrictions on treatment in 2017 were included. The model estimated the year individual states would meet the WHO targets for diagnosing 90% of the HCV-infected population, treating 80% of the eligible population, reducing new HCV infections by 80%, and reducing HCV-related deaths by 65%. The minimum number of annual treatmenet the WHO 2030 elimination targets and 35% are off track by 10 years or more. Strategies must be implemented to reduce overall prevalence by preventing new infections, increasing rates of screening, improving linkage to care, and implementing unfettered access to curative therapy.A new snail-eating leech, Batracobdelloides bangkhenensis sp. n., was discovered at Kasetsart University, Bangkhen Campus, Bangkok, Thailand. This species is found free living in the benthic zone of ponds; feeds on freshwater snails, including Bithynia siamensis siamensis, Indoplanorbis exustus, Radix rubiginosa, Physella acuta, and Pomacea canaliculata; and uses a shell as a shelter during the parental care period, with a colony of 7-15 juvenile individuals held on the venter inside the shell of host. Batracobdelloides bangkhenensis displays distinct morphological characters, including a rice-shaped body showing transparency, cephalization, two eye pairs merged on somite III, an anterior sucker twice as large as the cephalic region, a central mouth in the anterior sucker, seven light brown transverse rows in the neck region, absent dorsal papillae, rich green pigments on the dorsum, a male gonopore on XIIa2/XIIa3 (27-28), a female gonopore on XIIIa1/XIIIa2 (29-30), and diffuse aggregations of minute, spherical salivary glands in the neck region. Comparisons of the COI and COI-ND1 genes showed a monophyletic clade for Batracobdelloides, and the phylogenetic tree of the COI gene also indicated that B. bangkhenensis is distinct from other species in the genus, with strong support values.Because of its widespread distribution in the environment, bisphenol A (BPA) has become a global concern as an endocrine disruptor and a threat to human health through the food chain. Thus an efficient determination method is urgently needed for monitoring the levels of BPA. selleck chemicals Herein, a novel electrochemical technique for the detection of BPA was performed by synchronous extraction and pre-concentration of BPA onto magnetic molecularly imprinted polymer (BMMIP), with subsequent readout on a magneto-actuated glassy carbon electrode (MGCE) by differential pulse voltammetry. Compared to the current methods of BPA determination, this BMMIP-based electrochemical sensor (BMMIPs@MGCE) not only simplifies the sample handling procedures substantially, without filtration, centrifugation, or other complex operations, but also can be easily renewed by a controllable magnetic field. As a sensor component, the core-shell BMMIPs exhibited excellent binding capacity (Qe = 82.5 mg g-1), short adsorption equilibrium time (30 s), and outstanding selectivity (k' = 7.239) towards BPA, as well as stability and recyclability. Importantly, the BMMIPs@MGCE sensor was successfully applied for the on-site monitoring and rapid detection of BPA in complicated real-world specimens, with good recoveries (81.31-119.77%) and a low limit of detection (0.133 μmol L-1). Therefore, the stable and low-cost BMMIPs@MGCE sensor provides a new approach for the rapid determination of BPA in the field of environmental control and food safety. Graphical abstract.A novel electrochemical sensor was constructed for the determination of artemisinin (ART) based on the inhibition of redox for hemin caused by ART. As far as we know, this strategy for ART determination may be proposed for the first time. In this work, untreated multi-walled carbon nanotubes were cast on the glassy carbon electrode (GCE) as conductive carrier. We prepared a bimetallic organic framework named FeGd-MOF and combined it with hemin by a simple physical mixed method. Then, we fabricated the working electrode by layer-by-layer modification and immobilization. The sensor measured by the differential pulse voltammetry (DPV) technique had calibration curves for the determination of ART, which was 0.3-350 μM with the correlation coefficient R2 = 0.9998. Furthermore, the obtained linear range could be practically used in real sample analysis such as dried leaves of Artemisia apiacea. Under the optimized condition, the electrochemical sensor exhibited high sensitivity, good stability, and excellent anti-interference performance.