Clinical Evidence: a useful tool for promoting evidence-based practice?

Background: Research has shown that many healthcare professionals have problems with guidelines as they would prefer to be given all relevent information relevent to decision-making rather than being told what they should do. This study assesses doctors' judgement of the validity, relevance, clarity and usability of the Italian translation of Clinical Evidence (CE) after its free distribution launched by the Italian Ministry of Health. Methods: Opinions elicited using a standardised questionnaire delivered either by mail or during educational or professional meetings. Results: Twenty percent (n = 1350) doctors participated the study. Most of them found CE's content valid, useful and relevant for their clinical practice, and said CE can foster communications among clinicians, particularly among GPs and specialists. Hospital doctors (63%) more often than GPs (48%) read the detailed presentation of individual chapters. Twenty-nine percent said CE brought changes in their clinical practice. Doctors appreciated CE's nature of an evidence-based information compendium and would have not preferred a collection of practice guidelines. Conclusions: Overall, the pilot initiative launched by the Italian Ministry of Health seems to have been well received and to support the subsequent decision to make the Italian edition of Clinical Evidence concise available to all doctors practising in the country. Local implementation initiatives should be warranted to favour doctor's use of CE

Evidence for acoustic-like plasmons on epitaxial graphene on Pt(111)

The dispersion and the damping of the sheet plasmon in a graphene monolayer grown on Pt(111) have been studied by using angle-resolved electron energy loss spectroscopy. We found that the dispersion relation of the plasmon mode confined in the graphene sheet is linear, as a consequence of the screening by the metal substrate. Present results demonstrate that the presence of an underlying metal substrate could have striking consequences on the plasmon propagation even in the case of a system which exhibits a weak graphene-substrate interaction. Moreover, we found that Landau damping essentially occurs via interband excitations starting above the Fermi wave vector. On the contrary, intraband transitions do not have a significant influence on the collective mod

Pituitary and ovarian hormones: is their plasma concentration affected by litter size in primiparous lactating rabbit does?

[EN] Genetic selection in commercial rabbit lines based on litter size has positively improved the number of kits suckling, presumably to weaning. Although it has been proven that the energetic balance of primiparous does is due to the need to satisfy pregnancy, lactation and growth requirements, litter size adjustment from 7 to 12 kits is applied as a routine in commercial rabbit farms. The suckling stimulus provokes a prolactin (PRL) secretion, which in turn can modulate the preovulatory release of luteinising hormone (LH) and, consequently, the ovulatory and productive responses of the does. This study aimed to determine if litter size of prolific primiparous rabbit does during lactation [Group HL, with high litter density (10-12 kits; n=21) and Group LL, with low litter density (7-9 kits; n=29)] influences plasma concentration of PRL. Blood samples from lactating does were taken weekly throughout lactation starting on day 4 post-partum, until day 32 post-partum, before and immediately after suckling. In addition, the does were re-inseminated after weaning (day 32 post-partum), and sampled at 0 and 60 min after induction of ovulation to determine whether litter size affected the peak of LH, progesterone (P4) concentrations and the main productive parameters of their second pregnancy. All hormones were determined by enzyme immunoassay. Statistical analysis of the results revealed that the PRL concentrations of hyperprolific rabbit does before and immediately after a suckling stimulus from 7-9 or 10-12 kits were significanltly different, as we only detected basal levels, with a rise after weaning in both groups. More studies are necessary, delaying blood sampling to later periods of time after the suckling stimulus, in order to conclude whether the peak release of this hormone is altered or not. There were also no differences in plasma LH and progesterone levels after artificial insemination, or in productive performance of these females after their second pregnancy. In conclusion, the litter size adjustment of prolific primiparous rabbits with 7 to 12 kits determines adequate pituitary, ovarian and reproductive responses at second parturition if the does are inseminated after weaning.This work was supported by the Spanish Ministry of Economy and Competitiveness [Project AGL2015-65572-C2-R1 and Project RTI2018-094404-B-C21].Fernández-Pacheco, C.; Millán, P.; Rodríguez, M.; Formoso-Rafferty, N.; Velasco, B.; Rebollar, PG. (2021). Pituitary and ovarian hormones: is their plasma concentration affected by litter size in primiparous lactating rabbit does?. World Rabbit Science. 29(3):161-168. http://hdl.handle.net/10251/173607OJS16116829

Optimization of pixel size and propagation distance in X-ray phase-contrast virtual histology

X-ray phase-contrast coupled to high-spatial resolution imaging systems provides a high sensitivity for distinguishing soft tissue structures in small samples, thus being suited for X-ray virtual histology. Propagation-based phase-contrast tomography can deliver a considerable gain in signal-to-noise ratio (SNR) at small pixel sizes when it is combined to a suitable phase retrieval filter. We optimized acquisition parameters, namely the propagation distance and the pixel size, with the aim of providing adequate spatial resolution and sensitivity for virtual histology of breast surgery specimens, scanned with a phase-contrast microtomography (mu CT) system employing a commercial sCMOS detector at the SYRMEP beamline of the Italian synchrotron facility Elettra (Trieste, Italy). A pathological breast tissue sample was embedded in paraffin and imaged using a polychromatic synchrotron beam at an average energy of 24 keV. The high numerical optical aperture of the imaging system enabled to adjust the pixel size to 1, 2.5 and 4 mu m. The scans were acquired at five sample-to-detector distances: 4.5, 150, 250, 500 and 1000 mm. SNR was measured in an homogeneous region portion of the mu CT image for each combination of pixel size and propagation distance. Experimental results were compared to a theoretical model taking into account the actual point spread function of the employed imaging system. The measured gain of SNR associated with the application of the phase-retrieval matched the predictions for large Fresnel numbers (N-F > 2). For each pixel size, an optimal range of propagation distances was found. Optimal mu CT reconstructions were then compared with their respective histopatological images, showing an excellent visibility of relevant structures. The optimization performed in this study will allow to select the most appropriate geometrical configurations for future acquisitions of virtual histology images of different specimens via phase-contrast microtomography

Coexistence of halloysite and kaolinite: a study on the genesis of kaolin clays of Campo Alegre Basin, Santa Catarina State, Brazil

Kaolin at Campo Alegre Basin, Santa Catarina State, Brazilwas formed from alteration of volcanic acid rocks. Halloysite clays dominate the clay fraction of the matrix of the kaolin body, whereas a poorly crystalline kaolinite is abundant in veins. Some primary blocky structures have high amounts of illite, in one mine, but in general, only low contents of illite-smectite, illite, chlorite-vermiculite, vermiculite and quartz were identified in the clay fraction of the samples. Toward the top of the mines, hematite and lepidocrocite appear in horizontal red and ochre colored levels and the amount of kaolinite increases compared to halloysite. The vertical zoning of alteration levels, the changes in mineralogy, the positive correlation between depth and Cation Exchange Capacity of the clays, the preservation of different types of rock textures in the kaolin bodies, the dominant tube morphology of the halloysite clays indicate a supergene genesis for the deposits. Criteria to distinguish between supergene and hypogene kaolin are discussed. Transmission Electron Microscopy of the cross sections of halloysite tubes showed polygonal forms that are ascribed to be transitional between kaolinite and halloysite. It is proposed that some of the kaolinite of these deposits be inherited from the dehydration of halloysite tubes

Estudio preliminar comparativo entre los acondicionadores de suelos convencionales y las escorias del proceso Conox para uso agrícola

International audience(Cass. crim. 27 mai 2004, Bull. crim. n° 140 ; D. 2004, IR p. 1933