252 research outputs found

    Scanning tunneling microscopy of deoxyribonucleic acid during replication

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    Scanning tunneling microscopy was used to produce topographic images of uncoated and unlabeled deoxyribonucleic acid (DNA) in air, on a graphite substrate. The images show for the first time a DNA molecule that had been isolated while it was replicating

    Ultrasound-guided laser ablation after excisional vacuum-assisted breast biopsy for small malignant breast lesions: Preliminary results

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    Background: The purpose of this preliminary study is to evaluate the feasibility of the excisional ultrasound (US) guided vacuum-assisted breast biopsy (VAE), followed by US-guided Laser Interstitial Thermal Therapy (LITT) in the treatment of unifocal ductal breast carcinomas ≤ 1 cm and estimate the ablation rate analyzing the final histopathological results after subsequent surgical excision. Methods: In a single session 11 female patients with unifocal less than a centimeter breast cancer underwent 2 different minimally invasive percutaneous US-guided techniques: a VAE breast biopsy with an 8 G needle to remove the lesion and, immediately after, a LITT ablation in the biopsy site. Four weeks later, all patients underwent radiological follow-up. Afterward, a systematic surgery was performed, the ablation rate was calculated, and iconographic and histological features were correlated. Results: Average maximum diameter of the lesions was 7.6 mm (5-10 mm). No patient reported pain or discomfort during procedure. 1/11 patient (9.1%) reported an early minor complication (a small superficial skin burn). After surgical excision, the histopathological evaluation reported in 10/11 cases (90.9%) complete ablation of the target lesion. In only one case (9.1%) residual cancer was detected. The necrotic-hemorrhagic cavities showed a mean maximum diameter of 27.3 mm (20-35 mm). Conclusions: Laser ablation performed after excisional biopsy could be considered a valid alternative to surgical excision for the treatment of lesions ≤ 1 cm, if carried out by expert radiologists. The association of these minimally invasive percutaneous methods has proven to be reliable, fast, and safe with an ablation rate of 90.9% and excellent aesthetic results. RM and CESM are potentially able to quantifying treatment results and to follow-up the ablation effects

    Altered speech-related cortical network in frontotemporal dementia

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    Background: In healthy subjects (HS), transcranial magnetic stimulation (TMS) demonstrated an increase in motor-evoked potential (MEP) amplitudes during specific linguistic tasks. This finding indicates functional connections between speech-related cortical areas and the dominant primary motor cortex (M1). Objective: To investigate M1 function with TMS and the speech-related cortical network with neuroimaging measures in frontotemporal dementia (FTD), including the non-fluent variant of primary progressive aphasia (nfv-PPA) and the behavioral variant of FTD (bv-FTD). Methods: M1 excitability changes during specific linguistc tasks were examined using TMS in 24 patients (15 with nfv-PPA and 9 with bv-FTD) and in 18 age-matched HS. In the same patients neuroimaging was used to assess changes in specific white matter (WM) bundles and grey matter (GM) regions involved in language processing, with diffusion tensor imaging (DTI) and voxel-based morphometry (VBM). Results: During the linguistic task, M1 excitability increased in HS, whereas in FTD patients it did not. M1 excitability changes were comparable in nfv-PPA and bv-FTD. DTI revealed decreased fractional anisotropy in the superior and inferior longitudinal and uncinate fasciculi. Moreover, VBM disclosed GM volume loss in the left frontal operculum though not in the parietal operculum or precentral gyrus. Furthermore, WM and GM changes were comparable in nfv-PPA and bv-FTD. There was no correlation between neurophysiological and neuroimaging changes in FTD. Atrophy in the left frontal operculum correlated with linguistic dysfunction, assessed by semantic and phonemic fluency tests. Conclusion: We provide converging neurophysiological and neuroimaging evidence of abnormal speech-related cortical network activation in FTD

    Electronic structure of the trilayer cuprate superconductor Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta}

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    The low-energy electronic structure of the trilayer cuprate superconductor Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta} near optimal doping is investigated by angle-resolved photoemission spectroscopy. The normal state quasiparticle dispersion and Fermi surface, and the superconducting d-wave gap and coherence peak are observed and compared with those of single and bilayer systems. We find that both the superconducting gap magnitude and the relative coherence-peak intensity scale linearly with TcT_c for various optimally doped materials. This suggests that the higher TcT_c of the trilayer system should be attributed to parameters that simultaneously enhance phase stiffness and pairing strength.Comment: 5 pages, 5 figre

    Engineering the rRNA decoding site of eukaryotic cytosolic ribosomes in bacteria

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    Structural and genetic studies on prokaryotic ribosomes have provided important insights into fundamental aspects of protein synthesis and translational control and its interaction with ribosomal drugs. Comparable mechanistic studies in eukaryotes are mainly hampered by the absence of both high-resolution crystal structures and efficient genetic models. To study the interaction of aminoglycoside antibiotics with selected eukaryotic ribosomes, we replaced the bacterial drug binding site in 16S rRNA with its eukaryotic counterpart, resulting in bacterial hybrid ribosomes with a fully functional eukaryotic rRNA decoding site. Cell-free translation assays demonstrated that hybrid ribosomes carrying the rRNA decoding site of higher eukaryotes show pronounced resistance to aminoglycoside antibiotics, equivalent to that of rabbit reticulocyte ribosomes, while the decoding sites of parasitic protozoa show distinctive drug susceptibility. Our findings suggest that phylogenetically variable components of the ribosome, other than the rRNA-binding site, do not affect aminoglycoside susceptibility of the protein-synthesis machinery. The activities of the hybrid ribosomes indicate that helix 44 of the rRNA decoding site behaves as an autonomous domain, which can be exchanged between ribosomes of different phylogenetic domains for study of function

    Genetic Reconstruction of Protozoan rRNA Decoding Sites Provides a Rationale for Paromomycin Activity against Leishmania and Trypanosoma

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    Aminoglycoside antibiotics target the ribosomal decoding A-site and are active against a broad spectrum of bacteria. These compounds bind to a highly conserved stem-loop-stem structure in helix 44 of bacterial 16S rRNA. One particular aminoglycoside, paromomycin, also shows potent antiprotozoal activity and is used for the treatment of parasitic infections, e.g. by Leishmania spp. The precise drug target is, however, unclear; in particular whether aminoglycoside antibiotics target the cytosolic and/or the mitochondrial protozoan ribosome. To establish an experimental model for the study of protozoan decoding-site function, we constructed bacterial chimeric ribosomes where the central part of bacterial 16S rRNA helix 44 has been replaced by the corresponding Leishmania and Trypanosoma rRNA sequences. Relating the results from in-vitro ribosomal assays to that of in-vivo aminoglycoside activity against Trypanosoma brucei, as assessed in cell cultures and in a mouse model of infection, we conclude that aminoglycosides affect cytosolic translation while the mitochondrial ribosome of trypanosomes is not a target for aminoglycoside antibiotics

    Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study

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    Background: The National Research Council (CNR) prostate cancer monitoring project in Italy (Pros-IT CNR) is an observational, prospective, ongoing, multicentre study aiming to monitor a sample of Italian males diagnosed as new cases of prostate cancer. The present study aims to present data on the quality of life at time prostate cancer is diagnosed. Methods: One thousand seven hundred five patients were enrolled. Quality of life is evaluated at the time cancer was diagnosed and at subsequent assessments via the Italian version of the University of California Los Angeles-Prostate Cancer Index (UCLA-PCI) and the Short Form Health Survey (SF-12). Results: At diagnosis, lower scores on the physical component of the SF-12 were associated to older ages, obesity and the presence of 3+ moderate/severe comorbidities. Lower scores on the mental component were associated to younger ages, the presence of 3+ moderate/severe comorbidities and a T-score higher than one. Urinary and bowel functions according to UCLA-PCI were generally good. Almost 5% of the sample reported using at least one safety pad daily to control urinary loss; less than 3% reported moderate/severe problems attributable to bowel functions, and sexual function was a moderate/severe problem for 26.7%. Diabetes, 3+ moderate/severe comorbidities, T2 or T3-T4 categories and a Gleason score of eight or more were significantly associated with lower sexual function scores at diagnosis. Conclusions: Data collected by the Pros-IT CNR study have clarified the baseline status of newly diagnosed prostate cancer patients. A comprehensive assessment of quality of life will allow to objectively evaluate outcomes of different profile of care

    Long-Lasting Efficacy of Radio Electric Asymmetric Conveyer Neuromodulation Treatment on Functional Dysmetria, an Adaptive Motor Behavior

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    BackgroundFluctuating asymmetry (FA) is widely defined as the deviation from perfect bilateral symmetry and is considered an epigenetic measure of environmental stress. Rinaldi and Fontani hypothesized that the FA morpho-functional changes originate from an adaptive motor behavior determined by functional alterations in the cerebellum and neural circuits, not caused by a lesion, but induced by environmental stress. They called this phenomenon functional dysmetria (FD). On this premise, they developed the radio electric asymmetric conveyer (REAC) technology, a neuromodulation technology aimed at optimizing the best neuro-psycho-motor strategies in relation to environmental interaction.AimsPrevious studies showed that specific REAC neuro postural optimization (NPO) treatment can induce stable FD recovery. This study aimed to verify the duration of the NPO effect in inducing the stable FD recovery over timeMaterials and methodsData were retrospectively collected from a population of 29,794 subjects who underwent a specific semiological FD assessment and received the NPO treatment, regardless of the pathology referred.ResultsThe analysis of the data collected by the various participants in the study led us to ascertain the disappearance of FD in 100% of the cases treated, with a stability of the result detected up to 18 years after the single administration of the REAC NPO treatment.ConclusionsThe REAC NPO neurobiological modulation treatment consisting of a single administration surprisingly maintains a very long efficacy in the correction of FD. This effect can be explained as the long-lasting capacity of the NPO treatment to induce greater functional efficiency of the brain dynamics as proven in previous studies
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