8,659 research outputs found

    Topological jamming of spontaneously knotted polyelectrolyte chains driven through a nanopore

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    The advent of solid state nanodevices allows for interrogating the physico-chemical properties of a polyelectrolyte chain by electrophoretically driving it through a nanopore. Salient dynamical aspects of the translocation process have been recently characterized by theoretical and computational studies of model polymer chains free from self-entanglement. However, sufficiently long equilibrated chains are necessarily knotted. The impact of such topological "defects" on the translocation process is largely unexplored, and is addressed in this study. By using Brownian dynamics simulations on a coarse-grained polyelectrolyte model we show that knots, despite being trapped at the pore entrance, do not "per se" cause the translocation process to jam. Rather, knots introduce an effective friction that increases with the applied force, and practically halts the translocation above a threshold force. The predicted dynamical crossover, which is experimentally verifiable, is of relevance in applicative contexts, such as DNA nanopore sequencing.Comment: 6 pages; 7 figure

    Effects of parity and type of kidding on the quantitative and qualitative milk characteristics of "Rossa Mediterranea" goats

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    AbstractThe "Rossa Mediterranea " goat, also called "Derivata di Siria " has become much more widespread in Sicily over the last ten years. It is a goat characterised by its robustness and ability ..

    Killing two birds with one stone. Is the COVID-19 vaccination campaign an opportunity to improve adherence to cancer screening programmes? The challenge of a pilot project in a large local health authority in Rome

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    The COVID-19 pandemic has affected health services worldwide. The suspension of cancer screening programs during the lockdown period, coupled with the other measures taken to limit the SARS-CoV-2 spread, contributed to the idea that cancer preventive interventions are deferrable. In this opinion paper, we present some data on cancer screening coverage in one of the largest Local Health Authorities in Italy in recent years. Within this context, we introduce the benefits of a pilot project in which we took advantage of the great attention on the COVID-19 vaccination campaign to improve screening uptake. In this project, we offered men and women eligible for cancer screening the opportunity to book appointments while waiting to be vaccinated. In addition, trained healthcare personnel were available on-site to discuss any barriers to participation with the attendees. Despite the project having only just started, preliminary results are encouraging, with positive feedback from the attendees. In conclusion, we advocate for the need to adopt a comprehensive approach when it comes to population health, and we use this project as an example to discuss how it is possible to contribute to minimizing the long-term impact of the COVID-19 pandemic with resources already in place

    Diversity of cervical microbiota in asymptomatic chlamydia trachomatis genital infection: a pilot study

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    Chlamydia trachomatis genital infection continues to be an important public health problem worldwide due to its increasing incidence. C. trachomatis infection can lead to severe sequelae, such as pelvic inflammatory disease, obstructive infertility, and preterm birth. Recently, it has been suggested that the cervico-vaginal microbiota may be an important defense factor toward C. trachomatis infection as well as the development of chronic sequelae. Therefore, the investigation of microbial profiles associated to chlamydial infection is of the utmost importance. Here we present a pilot study aiming to characterize, through the metagenomic analysis of sequenced 16s rRNA gene amplicons, the cervical microbiota from reproductive age women positive to C. trachomatis infection. The main finding of our study showed a marked increase in bacterial diversity in asymptomatic C. trachomatis positive women as compared to healthy controls in terms of Shannon's diversity and Shannon's evenness (P = 0.031 and P = 0.026, respectively). More importantly, the cervical microbiota from C. trachomatis positive women and from healthy controls significantly separated into two clusters in the weighted UniFrac analysis (P = 0.0027), suggesting that differences between the two groups depended entirely on the relative abundance of bacterial taxa rather than on the types of bacterial taxa present. Furthermore, C. trachomatis positive women showed an overall decrease in Lactobacillus spp. and an increase in anaerobes. These findings are part of an ongoing larger epidemiological study that will evaluate the potential role of distinct bacterial communities of the cervical microbiota in C. trachomatis infection

    Lactoferrin's anti-cancer properties. Safety, selectivity, and wide range of action

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    Despite recent advances in cancer therapy, current treatments, including radiotherapy, chemotherapy, and immunotherapy, although beneficial, present attendant side effects and long-term sequelae, usually more or less affecting quality of life of the patients. Indeed, except for most of the immunotherapeutic agents, the complete lack of selectivity between normal and cancer cells for radio- and chemotherapy can make them potential antagonists of the host anti-cancer self-defense over time. Recently, the use of nutraceuticals as natural compounds corroborating anti-cancer standard therapy is emerging as a promising tool for their relative abundance, bioavailability, safety, low-cost effectiveness, and immuno-compatibility with the host. In this review, we outlined the anti-cancer properties of Lactoferrin (Lf), an iron-binding glycoprotein of the innate immune defense. Lf shows high bioavailability after oral administration, high selectivity toward cancer cells, and a wide range of molecular targets controlling tumor proliferation, survival, migration, invasion, and metastasization. Of note, Lf is able to promote or inhibit cell proliferation and migration depending on whether it acts upon normal or cancerous cells, respectively. Importantly, Lf administration is highly tolerated and does not present significant adverse effects. Moreover, Lf can prevent development or inhibit cancer growth by boosting adaptive immune response. Finally, Lf was recently found to be an ideal carrier for chemotherapeutics, even for the treatment of brain tumors due to its ability to cross the blood-brain barrier, thus globally appearing as a promising tool for cancer prevention and treatment, especially in combination therapies

    Morphological traits of the "Pantesco" donkey

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    The Pantelleria donkey is mentioned in prestigious zootechnical texts and treatises of the late 19th and early 20th century Authors such as Chiari, Mascheroni, Dechambre and others. In ancient times, when the Arab colonial extension in the Mediterranean reached its peak, a number of donkeys was transferred to the isle of Pantelleria southwest from Sicily. They served as draft animals and means of locomotion. In this environment scarcely suitable for the breeding of farm animals, considering the geo-morphological conditions of the island one of the most precious and valued donkey races of the Mediterranean basin has its origins: the Pantelleria donkey. Unfortunately, during World War II, Pantelleria was transferred in one of the most important theatres of war in the Mediterranean and the few remaining subjects of the race, once highly esteemed and frequently exported, were almost extirpated. Since then, various efforts have been made to recover the "Pantesco" donkey, but only in 1989 the Regional Forest Administration launched a project to reconstitute this particular population. Owing to comprehensive and accurate research, three males and six females with a percentage of 80 to 90% of "Pantesco" blood could be recovered. The aim of this recovery plan was to prevent the loss of a genotype of great historical and biological value in Sicily no less than in other European and Asian regions. Currently the "Pantesco" donkey population finally registered at the general index of equine races and populations consists of 51 subjects. The objective of our study was to determine the morphological type of this donkey population in order to provide useful data for its ethnic identification. The most significant morphometric traits of the thirty "Pantesco" donkeys examined (15 brood-mares, 13 stallions and 2 colts; those born after 2004 -15 subjects were excluded from measurements ) were measured in an erect position, using Lydtin's stick, calliper and flexible meter, and the most significant morphometric indices were calculated in order to provide for a reliable identification of the morphological type. The data obtained mean values ± sd (withers height:123.35±4.28cm; rump height: 129.43±4.43cm; chest height: 51.88±3.38cm; chest breadth: 28.61±6.66cm; body length: 124.82±8.86cm; lateral conformation body index :99.12±4.71; longitudinal thoracic section index: 41.65±2.42; body proportion index: 84.58±3.79; thorax height index: 42.05±2.07; pelvic index: 27.82±4.16; head length index: 42,28±1.53 and dactylo-thoracic index: 11.28±0.85 ), suggest that the "Pantesco" population can be assigned to the dolichomorphic type

    Resonant electron heating and molecular phonon cooling in single C60_{60} junctions

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    We study heating and heat dissipation of a single \c60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the fullerene cage. The power for decomposition varies with electron energy and reflects the molecular resonance structure. When the STM tip contacts the fullerene the molecule can sustain much larger currents. Transport simulations explain these effects by molecular heating due to resonant electron-phonon coupling and molecular cooling by vibrational decay into the tip upon contact formation.Comment: Accepted in Phys. Rev. Let

    Hyaluronic Acid Inhibits Polycation Induced Cellular Responses

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    Positively charged macromolecules cause a variety of pathological events through their electrostatic interaction with anionic sites present on the membrane of target cells. In the present study we have investigated the effect of hyaluronic acid, a negatively charged molecule, on rat paw oedema induced by poly-L-lysine as well as on histamine release from rat mast cells and nitric oxide formation from rabbit aorta, both induced by this polycation. The results indicate that hyaluronic acid is able to suppress these poly-L-lysine induced effects with a mechanism which possibly depends on its negative charges which may balance the effects of positively charged polycations
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