269 research outputs found

    Dynamic Stability of a Composite Circular Cylindrical Shell Subjected to Combined Axial and Torsional Loading

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    The dynamic stability of thin, clamped, composite circular cylindrical shells is studied for combined axial and torsional loading. Each load is taken to be har monically varying; the frequencies of the two loads differ, in general. For the case in which the frequencies are commensurate, the applied load function is periodic. The equa tions of motion for the shell are reduced to a system of Hill equations by means of Fourier series expansions. Instability regions of principal and combination parametric resonance are determined by use of the monodromy matrix. Numerical results are generated for boron-epoxy layered shells for various cases of pure axial, pure torsional, and combined loading. The width of the principal instability region is presented as a function of fiber ori entation for a laminate case. Stability diagrams are presented covering about 6 times the lowest natural frequency for various ratios of the applied axial and torsional frequencies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66879/2/10.1177_002199839302701802.pd

    Contralateral prophylactic mastectomies. Correlations between primary tumor and histological findings of controlateral breast

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    Backgound: In Italy in 2015 48,000 new cases of breast carcinomas were diagnosed. Women who are diagnosed with breast cancer have a significant risk of developing contralateral breast cancer during the rest of their lives and this risk is closely associated to the family history, to the onset of breast cancer at a young age and is expressed at about 0.5 to 1% of metachronous tumors per year. The purpose of this work was to evaluate which and how many neoplastic lesions were seen in the contralateral breast that underwent prophylactic mastectomy and to understand what factors predict the appearance of such lesions. Methods: 168 bilateral mastectomies were analyzed in patients with an average age of 47 years, carried out from July 2008 to April 2016, at the Breast Unit of the Sant’Andrea Hospital. We considered women of any age suffering from unilateral breast cancer without either clinical or radiological evidence of a malignant lesion in the contralateral breast and negative for mutations of the BRCA1-BRCA2 genes test. Of the 168 bilateral mastectomies 35 patients were excluded from the study because they underwent neoadjuvant chemotherapy, another 35 patients because they were suffering from a bilateral neoplasia and 7 cases because they had mutated BRCA1 or BRCA2 genes. Therefore the remaining 91 patients were included in the study. Results: Both the histological features of the primary tumor and any lesions found in the contralateral prophylactic breast were analyzed. Histological examination of the main breast showed 59 cases of Invasive Ductal Carcinoma (IDC), 17 cases of Invasive Lobular Carcinoma (ILC), 9 cases of In Situ Ductal Carcinoma (ISDC), 3 microinvasive ductal, 1 invasive tubular carcinoma, 1 in situ lobular and 1 widespread in situ. In the contralateral breast, the definitive histological examination revealed that 47 patients had an occult lesion in the prophylactic contralateral breast; in particular 2 cases of LIN 1, 7 cases of LIN2, 6 cases of lobular carcinoma in situ, 26 between DIN1A/DIN1A-B/DIN1B, 4 cases of carcinoma in situ and 2 cases of Invasive Ductal Carcinoma. The correlation obtained from the observation of the main tumor has shown that in a total of 59 invasive ductal carcinoma 32 have a controlateral occult lesions and in a total of 17 cases of invasive lobular carcinoma 9 have an occult lesion in the prophylactic breast. Of these lesions, the multicentric relationship is that 50% of invasive ductal and invasive lobular carcinoma of the main breast have a contralateral lesion. Conclusion: In conclusion we would like to remind, as demonstrated by our follow-up data and as the literature reiterates, that this surgery does not improve patient survival. Certainly patients with unilateral breast cancer have many surgical therapies to be able to deal with not only having a bilateral mastectomy. The end point of this work is try to understand the risk factors of having a contralateral breast lesion to reduce the probability of a metachronous cance

    Laparoscopic Ist stage orchiopexy using antiadherent sheet for high abdominal testis

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    Abstract High undescended testes with short spermatic vessels are not treated with standard orchiopexy and are currently brought to scrotum prevalently after the section of spermatic vessels, according to the Fowler-Stephens procedure. The ischemic risk of that method is elevated and becomes unbearable in bilateral cases. In 2009 an original staged orchiopexy technique was proposed to elongate the whole cord with anti-adherent sheet preserving the spermatic vessels by which a normal scrotal position was successfully gained without any testis loss. Both stages were performed through inguinotomy. In the present article the successful procedure is updated with implementation of laparoscopy in the first stage in a case of extremely high bilateral 4a type abdominal testis. Laparoscopic access was confirmed as valuable both in terms of extended mobilization and coverage of the entire testis vascular supply. The method of progressive cord elongation by using an anti-adherent sheet avoids the excessive atrophy hazard deriving from the Fowler-Stephens procedure in bilateral high abdominal 4a type testes; based on our findings, the latter can benefit also of a laparoscopic approach in the first stage

    Peer Mentoring: Benefits to First-Time College Students and Their Peer Mentors

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    The experiences of first-year, first-time college students are impacted by a variety of challenges that pose a threat to student success and retention. One intervention universities are implementing to address these challenges are peer mentorship programs. While the benefits to first-time students of peer mentorship programs are well-researched, there is a lack of research on the benefits for mentors themselves. The purpose of this study was to examine the perceived and demonstrable benefits for peer mentors working within a first-year seminar. This mixed-methods study assessed both first-time student achievement outcomes (i.e., first-term GPA and one-year persistence; N = 7,154) as well as the professional and personal development benefits of peer mentors (n = 52). Results showed first-time students who participated in the peer mentor program had significantly higher student achievement and peer mentors themselves had increased academic self-efficacy, improved communication, leadership, and interpersonal presence, and strengthened social and professional networks

    UNIDADES DE MANEJO AMBIENTAL NO NORTE FLUMINENSE

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    Este trabalho é parte integrante de um Projeto mais amplo “Unidade de Manejo Ambiental na Área Costeira do Estado do Rio de Janeiro”, ora em desenvolvimento no Laboratório de Geografia Física do Instituto de Geociência da UFRJ

    ANALISI ECONOMICA RETROSPETTIVA SULLE MISURE DI CONTENIMENTO DELLA SPESA FARMACEUTICA DELL’ASP 1 DI AGRIGENTO RELATIVE AL TRIENNIO 2010/2011/2012

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    Introduzione. Le misure di contenimento della spesa farmaceutica sono state le principali prerogative previste dal Piano di Rientro della Regione Sicilia ( adempimento A.1.2), in tal senso le realtà delle singole ASP si sono adeguate alle direttive regionali mostrando una classifica tra le Asp siciliane che vedono come protagonista virtuosa l’Asp di Agrigento, prima in classifica. La disamina dei dati fa riferimento al triennio 2010/2011/2012. Materiali e metodi. La rilevazione concerne farmaci rimborsati dal SSN ed erogati tramite canale convenzionale privato, farmaci distribuiti direttamente e quelli utilizzati in ambito ospedaliero nel triennio 2010/2011/2012, attraverso report sulla spesa farmaceutica della regione Sicilia. Risultati. Nel 2010 la spesa farmaceutica annua è stata per l’ASP 1 di Agrigento di € 102.942.864,99, questa grazie all’incremento della distribuzione diretta, di cui al PHT D.A.2205/08 attraverso l’introduzione di molecole appartenenti alla categoria N05A (l’11,03 % della spesa totale nell’anno 2011) secondi solo agli antianemici categoria B03X (26,93 % della spesa totale) già presenti nel 2010. La spesa della distribuzione diretta nel 2011 è stata di € 13.973.336,60 mentre la distribuzione attraverso le farmacie private avrebbe fatto lievitare la spesa totale a € 25.006.073,81 nel 2012 invece l’importo è stato di € 14.953.719,04 ed attraverso il canale privato convenzionato avremmo avuto un costo di € 29.530.504,13 . La spesa totale dell’Asp è passata dunque da € 102.942.864,99 nel 2010, a € 92.883.552,99 nel 2011, a € 91.128.889,13 nel 2012. Conclusioni. Le misure adottate per il contenimento della spesa hanno previsto l’introduzione a partire dal 2011 degli antipsicotici atipici, ed il potenziamento del primo ciclo di terapia per il periodo susseguente alla dimissione ospedaliera in base ai criteri dettati dal D.A. 0150/08 portando l’ASP di Ag ad essere tra le più virtuose della regione Sicilia passando dunque dalla sesta posizione in classifica nel 2010 alla prima nel 2012 con un risparmio pari al 11,48 %, il passaggio degli antipsicotici è stato dettato anche dalla necessità dei pazienti che hanno nell’essere sottoposti a controlli periodici da parte degli specialisti ma anche alla valutazione dell’appropriatezza prescrittiva che in quest’ultimo caso è affidato al farmacista ospedaliero. Un altro obiettivo dell’ASP 1 di Agrigento mirato ad un ulteriore contenimento della spesa è quello di estendere la distribuzione diretta anche alla prescrizione successiva ad ogni visita specialistica ambulatoriale

    An Integrated Epidemiological and Economic Model of COVID-19 NPIs in Argentina

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    We added a multi-sectoral economic framework to a SVEIR epidemiological model, combining the economic rationale of the DAEDALUS model with a detailed treatment of lockdown fatigue and declining compliance with Public Health and Social Measures reported in recent empirical work, to quantify the epidemic and economic benefits and costs of alternative lockdown and PHSM policies, both in terms of intensity and length. Our calibration replicates key features of the case and death-curves and economic cost for Argentina in 2021. The model allows us to quantify the short-term policy trade-off between lives and livelihoods and show that it can be significantly improved with targeted pharmaceutical policies such as vaccine rollout to reduce mainly severe disease and the death toll from COVID-19, as has been highlighted by previous studies

    The development of a new international generic measure (EQ-HWB): face validity and psychometric stages in Argentina

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    Objectives This study aimed to present the face validity and psychometric stages performed in Spanish in Argentina, the only Spanish-speaking country of an international collaboration that undertook the construction of a new measure that can be used in economic evaluation across health, social care, and public health, the EQ EQ-HWB (EQ Health and Wellbeing). We also explored the relationship among 3-level version EQ-5D (EQ-5D-3L), 5-level version EQ-5D (EQ-5D-5L), and EQ-HWB. Methods Face validity was based on semistructured face to face interviews of a purposive sample to explore translatability of language and concepts of 97 candidate items, translated into Argentina Spanish. The psychometric evaluation using an online panel assessed the psychometric properties of 64 items that were carried forward (floor and ceiling effects, item correlations, known-group differences in relevant prespecified subgroups by the international and local teams, exploratory and confirmatory factor analysis, and item response theory). EQ-5D-3L, EQ-5D-5L, and EQ-HWB correlations were explored. Results In the face validity stage, 24 interviews with carers, general public, patients, and users of social services were included. Most items showed adequate face validity. In the psychometric assessment, 497 participants were recruited (64% reporting a long-term health condition). Most of the items showed adequate psychometrics in an Argentinian context. EQ-5D-3L and EQ-5D-5L had strong correlations, and EQ-HWB was moderately correlated to EQ visual analog scale. The Argentina team recommended 23 of the final 25 items. Conclusions The assessment of Spanish items contributed to the overall development of EQ-HWB and helped inform the design of an internationally relevant 25-item and a short 9-item measure intended to be used in economic evaluations

    The path from trigeminal asymmetry to cognitive impairment: a behavioral and molecular study

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    Trigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input
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