63 research outputs found

    Towards the Automated Coverlay Assembly in FPCB Manufacturing: Concept and Preliminary Tests

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    AbstractIn modern electronics, flexible and rigid-flex PCBs are largely used due to their intrinsic versatility and performance, allowing to increase the available volume, or enabling connection between unconstrained components. Rigid-flex PCBs consists of rigid board portions with flexible interconnections and are commonly used in a wide variety of industrial applications. However, the assembly process of these devices still has some bottlenecks. Specifically, they require the application of cover layers (namely, coverlays), to provide insulation and protection of the flexible circuits. Due to the variability in planar shape and dimensions, the coverlay application is still performed manually, requiring troublesome manipulation steps and resulting in undetermined time-cycle and precision.This paper aims at the improvement of the industrial process currently performed, by proposing an approach for the automation of Kapton coverlay manipulation and application. Since these products are commercially provided as a film with a protective layer to be removed, the peeling issue is addressed, representing a challenging step of the automated process; the results of a systematic series of tests, performed in order to validate the peeling strategy, are reported in the paper. The overall assembly strategy relies on the development of a customized multi-hole vacuum gripper, whose concept is presented and contextualized in the proposed assembly process by outlining a suitable workcell architecture

    Aberrant crypt foci in colorectal carcinogenesis. Cell and crypt dynamics

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    Aberrant crypt foci (ACF) have been identified on the colonic mucosal surface of rodents treated with colon carcinogens and of humans after methylene-blue staining and observation under a light microscope. Several lines of evidence strongly suggest that ACF with certain morphological, histological, cell kinetics, and genetic features are precursor lesions of colon cancer both in rodents and in humans. Thus, ACF represent the earliest step in colorectal carcinogenesis. This paper has the main purpose of reviewing the evidence supporting this view, with particular emphasis on cell and crypt dynamics in ACF. ACF have been used as intermediate biomarkers of cancer development in animal studies aimed at the identification of colon carcinogens and chemopreventive agents. Recently, evidence has also shown that ACF can be effectively employed in chemopreventive studies also in humans

    Pattern of cell kinetics in colorectal mucosa of patients with different types of adenomatous polyps of the large bowel

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    It is generally accepted that adenomatous polyps represent the natural precursor of many colorectal malignancies. The sequence, however, which leads from a normally appearing mucosa to cancer is complex and involves many steps, including a hyperproliferative mucosa with an upward expansion of the replicative compartment. The current study evaluates cell replication in normal colorectal mucosa of patients with adenomatous polyps of various types and relates the observed findings to the main clinical and morphologic features of adenomas. Forty-four patients with polyps and 27 controls entered the study. Samples of colorectal mucosa were taken at endoscopy and cell replication was evaluated with a standard autoradiographic procedure. Cell replication was expressed as labeling index (LI), in the whole crypt and in each of the five longitudinal compartments in which the crypts were divided. Total LI and LI per crypt compartment were significantly higher (P < 0.02 and P < 0.01, respectively) than in controls. There was no appreciable difference of LI values between patients with single or multiple, tubular or tubulovillous, small or large adenomas, but in all of these subgroups LI was significantly higher than in controls. In conclusion, in normally appearing colorectal mucosa of patients with adenomatous polyps there was a significant increase of cell replication and a marked upward expansion of the proliferative zone; these changes were more evident in the left colon and in the rectum. Finally, cell replication did not seem to be related to the number of polyps, to the most common histotypes, or to the pattern of recurrence

    La consulenza psichiatrica nel trapianto di cuore

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    Il trapianto cardiaco rappresenta attualmente una procedura chirurgica consolidata e costituisce il trattamento di scelta in caso di insufficienza cardiaca terminale refrattaria alle terapie mediche o chirurgiche. Il trapianto di cuore genera questioni psicologiche uniche, che originano dalla complessità del percorso clinico e terapeutico, dal significato simbolico e dalla provenienza dell’organo. Sintomi di disagio psicologico e patologie di interesse psichiatrico, principalmente disturbi d’ansia e dell’umore, sono comuni sia nella fase pre-intervento che nella fase successiva, con tassi di prevalenza del 50% nei pazienti candidati al trapianto e del 20-30% nei riceventi, anche nel lungo periodo. L’individuazione e il trattamento corretto di queste condizioni sono di fondamentale importanza per garantire un risultato ottimale del trapianto nel lungo termine

    Epithelial cell kinetics in the remaining colorectal mucosa after surgery for cancer of the large bowel

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    We used microautoradiography in order to evaluate cell replication of the remaining colorectal mucosa in 20 patients previously operated on for cancer of the large bowel. The results were compared to those of 24 controls without neoplasms or other relevant colorectal disease. Samples of colorectal mucosa were taken during endoscopy. At histological examination each labeled intestinal hemicrypt was divided into 5 longitudinal compartments, from the base to the surface, and S-phase cells in each compartment were counted. Total labeling index (LI, ratio of labeled to total cells x 100) and labeling index per crypt compartment were similar in surgical patients and in controls. In contrast, both total LI and labeling index in the upper portions of the crypt (compartments 3, 4, and 5) were significantly higher in the 9 patients who showed recurrence of polyps than in those (n = 11) without recurrence. The LI in compartments 4 and 5 (the "high crypt region") was 4.37 +/- 0.95 (SEM) in patients with recurrence versus 0.88 +/- 0.21 (P less than 0.001) in patients with negative endoscopy finding and 1.47 +/- 0.22 in controls. Moreover, the fifth compartment was labeled in 8 of 9 individuals in whom polyps recurred but in only 2 of 11 patients without recurrence and 3 of 24 controls. In conclusion, after resection for large bowel cancer colonic epithelial cell proliferation tends to become more quiescent and similar to that of controls. However, in the subgroup of patients in whom polyps reappear, the colorectal mucosa maintains a hyperproliferative state with an expansion of the replicative zone to the most superficial portions of the crypt. These findings support the sequence adenoma-carcinoma and suggest that the evaluation of cell proliferation might be useful in the identification of subjects at increased risk for multiple tumors of the large bowel
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