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

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

Dynamic response of a rotating beam subjected to an accelerating distributed surface force

A method is given by which the response of a rotating or non-rotating timoshenko beam can be determined, subjected to an accelerating fixed direction distributed surface force. The beam model includes the gyroscopically induced displacement transverse to the direction of the load. The solution for pinned supports is set up using multi-integral transforms, and the inversion is expressed in terms of convulution integrals. These are numerically integrated for a uniformly distributed load having an exponentially varying velocity function. Results are presented for the displacement under the load's center as a function of position and for the displacement of every point on the beam at an instant in time. Comparisons are made between the beam response to a constant velocity load and its response to a load which accelerates to the same velocity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29849/1/0000196.pd

Accurate prediction of PHEMT intermodulation distortion using the nonlinear discrete convolution model

A general-purpose, technology-independent behavioral model is adopted for the intermodulation performance prediction of PHEMT devices. The model can be easily identified since its nonlinear functions are directly related to conventional DC and small-signal differential parameter measurements. Experimental results which confirm the model accuracy at high operating frequencies are provided in the pape

High Prevalence of Anterolateral Ligament Abnormalities on MRI in Knees With Acute Anterior Cruciate Ligament Injuries. A Case-Control Series From the SANTI Study Group

Background: Broad variation in the reported rate of magnetic resonance imaging (MRI)–detected abnormalities of the anterolateral structures of the anterior cruciate ligament (ACL)–injured knee suggests a lack of reliability that has limited the use of MRI in clinical decision making. Purpose/Hypothesis: The aim of this study was to use MRI to determine the prevalence and spectrum of abnormalities of the anterolateral structures in acute ACL-injured knees, using the contralateral uninjured knee as a reference. We hypothesized that MRI evaluation of the acutely injured knee (using the uninjured knee as a reference) would allow reliable identification of abnormalities of the anterolateral structures. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Patients with acute ACL injury underwent MRI scan of both knees. Images were evaluated by 3 observers. Inter- and intraobserver reliabilities were determined for MRI parameters of anterolateral ligament (ALL) injury by use of the kappa (κ) test. Univariate and multivariate analyses were conducted to test associations between ALL abnormality and associated injuries. Results: A total of 34 patients were evaluated. Of these, 30 patients (88.2%) had at least 1 ALL abnormality in the ACL-injured knee (increased signal: n = 27[79.4%]; increased thickness: n = 15[44.1%]; tapering: n = 7[20.6%]; irregularities in the path of the ALL fibers: n = 21[61.7%]). Asymmetries of the genicular vessels were observed in 21 patients (61.7%). ALL abnormality was significantly associated with lateral joint capsular tears (P <.001). No correlation was found between ALL lesions and iliotibial band lesions (P =.49). Inter- and intraobserver reliabilities were very good concerning ALL signal changes and femoral and tibial bone bruises (κ coefficient, 0.81-1). Conclusion: MRI evaluation of the ALL was associated with good and very good inter- and intraobserver reliabilities, and it demonstrated abnormalities of the ALL in the majority of acutely ACL-injured knees. The index of suspicion for ALL injury should be elevated by the presence of lesions of the lateral capsule. This suggests that the ALL is part of a wider area of the lateral capsule that is often injured simultaneously in an acute ACL tear

BRAF exon 15 mutations in papillary carcinoma and adjacent thyroid parenchyma: A search for the early molecular events associated with tumor development

BRAF exon 15 mutations are the most common molecular alterations found in papillary thyroid carcinoma (PTC). To date, there is no information regarding BRAF alterations in the thyroid parenchyma surrounding the tumor. To explore the early events associated with the development of PTC, we used massively parallel sequencing to investigate BRAF exon 15 in 30 PTCs and in 100 samples from the thyroid parenchyma surrounding the tumor. BRAF p.V600E was identified in 19/30 PTCs (63.3%). BRAF p.V600E mutations were identified in the tissue adjacent the PTC only in samples containing psammoma bodies. The other samples were either BRAF wild type (WT) or carried BRAF non p.V600E mutations. Specifically, BRAF p.G593D,-p.A598T,-p.V600M,-p.R603Q,-p.S607F, and-p.S607P were identified in 4 of 36 (11.1%) samples with follicular cell atypia, in 2 of 16 (12.5%) with follicular cell hyperplasia, and in 1 of 33 (3.0%) histologically normal samples\u2014only in tissue surrounding BRAF p.V600E mutated PTCs. These mutations are predicted to affect protein function in silico but, in vitro, have kinase activity and BRAF phosphorylation levels similar to BRAF WT. No BRAF exon 15 mutations were identified in samples adjacent to PTCs that were BRAF WT. A mutagenic process affecting BRAF exon 15 occurs in a subset of thyroid glands that develop BRAF p.V600E mutated PTCs

Post-operative outcomes and predictors of mortality after colorectal cancer surgery in the very elderly patients

Background: The frailty of the very elderly patients who undergo surgery for colorectal cancer negatively influences postoperative mortality. This study aimed to identify risk factors for postoperative mortality in octogenarian and nonagenarian patients who underwent surgical treatment for colorectal cancer. Methods: This is a single institution retrospective study. The primary outcomes were risk factors for postoperative mortality. The variables of the octogenarians and nonagenarians were compared by using t-test, chi-square test, and Fisher exact test. A multivariate logistic regression analysis was carried out on the combined cohorts. Results: we identified 319 octogenarians and 43 nonagenarians (N = 362) who underwent surgery for colorectal cancer at the Sant'Orsola-Malpighi university hospital in Bologna between 2011 and 2015. The 30-day post-operative mortality was 6% (N = 18) among octogenarians and 21% (N = 9) for the nonagenarians. The groups significantly differed in the type of surgery (elective vs. urgent surgery, p < 0.0001), ASA score (p = 0.0003) and rates of 30-day postoperative mortality (6% vs. 21%, p = 0.0003). In the multivariate analysis ASA > III (OR 2.37, 95% CI [1.43\u20133.93], p < 0,001), and urgent surgery (OR 2.17, 95% CI [1.17\u20134.04], p = 0.014) were associated to post-operative mortality. On the contrary, pre-operative albumin 653.4 g/dL (OR 0.14, 95% CI [0.05\u20130.52], p = 0.001) was associated with a protective effect on postoperative mortality. Conclusions: In the very elderly affected by colorectal cancer, preoperative nutritional status and pre-existing comorbidities, rather than age itself, should be considered as selection criteria for surgery. Preoperative improvement of nutritional status and ASA risk assessment may be beneficial for stratification of patients and ultimately for optimizing outcomes

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

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

Typical and atypical COVID-19 computed tomography findings

In December 2019 a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 was identified and the disease associated was named coronavirus disease 2019 (COVID-19). Fever, cough, myalgia, fatigue associated to dyspnea represent most common clinical symptoms of the disease. The reference standard for diagnosis of severe acute respiratory syndrome coronavirus 2 infection is real time reverse-transcription polymerase chain reaction test applied on respiratory tract specimens. Despite of lower specificity, chest computed tomography (CT), as reported in manifold scientific studies, showed high sensitivity, therefore it may help in the early detection, management and follow-up of COVID-19 pneumonia. Patients affected by COVID-19 pneumonia usually showed on chest CT some typical features, such as: Bilateral ground glass opacities characterized by multilobe involvement with posterior and peripheral distribution; parenchymal consolidations with or without air bronchogram; interlobular septal thickening; crazy paving pattern, represented by interlobular and intralobular septal thickening surrounded by ground-glass opacities; subsegmental pulmonary vessels enlargement (> 3 mm). Halo sign, reversed halo sign, cavitation and pleural or pericardial effusion represent some of atypical findings of COVID-19 pneumonia. On the other hand lymphadenopathy's and bronchiectasis' frequency is unclear, indeed conflicting data emerged in literature. Radiologists play a key role in recognition of high suspicious findings of COVID-19 on chest CT, both typical and atypical ones. Thus, the aim of this review is to illustrate typical and atypical CT findings of COVID-19

High prevalence of anterolateral ligament abnormalities on MRI in knees with acute anterior cruciate ligament injuries: a case-control series from the SANTI study group

Background: Broad variation in the reported rate of magnetic resonance imaging (MRI)–detected abnormalities of the anterolateral structures of the anterior cruciate ligament (ACL)–injured knee suggests a lack of reliability that has limited the use of MRI in clinical decision making. Purpose/Hypothesis: The aim of this study was to use MRI to determine the prevalence and spectrum of abnormalities of the anterolateral structures in acute ACL-injured knees, using the contralateral uninjured knee as a reference. We hypothesized that MRI evaluation of the acutely injured knee (using the uninjured knee as a reference) would allow reliable identification of abnormalities of the anterolateral structures. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Patients with acute ACL injury underwent MRI scan of both knees. Images were evaluated by 3 observers. Inter- and intraobserver reliabilities were determined for MRI parameters of anterolateral ligament (ALL) injury by use of the kappa (κ) test. Univariate and multivariate analyses were conducted to test associations between ALL abnormality and associated injuries. Results: A total of 34 patients were evaluated. Of these, 30 patients (88.2%) had at least 1 ALL abnormality in the ACL-injured knee (increased signal: n = 27[79.4%]; increased thickness: n = 15[44.1%]; tapering: n = 7[20.6%]; irregularities in the path of the ALL fibers: n = 21[61.7%]). Asymmetries of the genicular vessels were observed in 21 patients (61.7%). ALL abnormality was significantly associated with lateral joint capsular tears (P < .001). No correlation was found between ALL lesions and iliotibial band lesions (P = .49). Inter- and intraobserver reliabilities were very good concerning ALL signal changes and femoral and tibial bone bruises (κ coefficient, 0.81-1). Conclusion: MRI evaluation of the ALL was associated with good and very good inter- and intraobserver reliabilities, and it demonstrated abnormalities of the ALL in the majority of acutely ACL-injured knees. The index of suspicion for ALL injury should be elevated by the presence of lesions of the lateral capsule. This suggests that the ALL is part of a wider area of the lateral capsule that is often injured simultaneously in an acute ACL tear