81 research outputs found

    Hingeless arm for space robotics actuated through shape memory alloys

    Get PDF
    Operating outside the spacecraft via remotely controlled structures is an important opportunity in different space applications. The research in this area is focused on designing robots that are sufficiently flexible to allow inspection in locations where access is difficult or impossible for astronauts, while minimizing weight and bulk. The purpose of the research is to design a borescope for space applications with no hinges or other mechanisms, exploiting biomimetic design concepts. This is pursued by giving to the borescope a backbone exoskeleton provided by a continuous structure made of fibre reinforced composite material and using NiTi wires as tendons, taking advantage of their low weight and dimensions, which allow them to be embedded between the composite layers during the lamination process. After a study of the state of the art of flexible structures, concentrated in the medical and robotic fields, the research work unfolded in two phases. In the first design phase, several composite layup solutions were considered and analysed using finite element models, leading to the definition of the borescope geometrical parameters and to an initial estimate of the displacements that can be achieved. In the second experimental phase, seven prototypes were produced and tested, with one or more wires, to validate the design and to search for a configuration that can be actuated in different directions. The borescope prototypes resulted flexible enough to achieve an extended degree of bending and at the same time sufficiently rigid to allow complete rearm of the NiTi wires. The numerical and experimental study led to the definition of the design parameters, the number of wires, and the manufacturing technique to integrate NiTi actuators

    MagnetoPlasmonic Waves/HOMO-LUMO Free π-Electron Transitions Coupling in Organic Macrocycles and Their Effect in Sensing Applications

    Get PDF
    Optical and magneto-optical surface plasmon resonance (MOSPR) characterization and preliminary sensing test onto single- and multi-layers of two organic macrocycles have been performed; TbPc2(OC11H21)8 phthalocyanine and CoCoPo2 porphyrin were deposited by the Langmuir-Schäfer (LS) technique onto proper Au/Co/Au magneto-optical transducers. Investigations of the MOSPR properties in Kretschmann configuration by angular modulation, gives us an indication about the potential discrimination of two organic macrocycles with absorption electronic transition in and out of the propagating plasmon energy spectral range. An improved molecular vapors sensitivity increase by the MOSPR sensing probe can be demonstrated depending on the overlap between the plasmonic probe energy and the absorption electronic transitions of the macrocycles under investigation. If the interaction between the plasmon energy and molecular HOMO-LUMO transition is preserved, a variation in the complex refractive index takes place. Under this condition, the magneto-plasmonic effect reported as 1/|MOSPR| signal allows us to increase the detection of molecules deposited onto the plasmonic transducer and their gas sensing capacity. The detection mechanism appears strongly enhanced if the Plasmon Wave/HOMO-LUMO transitions energy are in resonance. Under coupling conditions, a different volatile organic compounds (VOC) sensing capability has been demonstrated using n-butylamine as the trial molecule

    Myxoid Liposarcoma: Prognostic Factors and Metastatic Pattern in a Series of 148 Patients Treated at a Single Institution

    Get PDF
    Objectives: The authors reported a retrospective study on myxoid liposarcomas (MLs), evaluating factors that may influence overall survival (OS), local recurrence-free survival (LRFS), metastasis-free survival (MFS), and analyzing the metastatic pattern. Methods: 148 MLs were analyzed. The sites of metastases were investigated. Results: Margins (p = 0.002), grading (p = 0,0479), and metastasis (p < 0,0001) were significant risk factors affecting overall survival (OS). Type of presentation (p = 0.0243), grading (p = 0,0055), margin (p = 0.0001), and local recurrence (0.0437) were risk factors on metastasis-free survival (MFS). Authors did not observe statistically significant risk factors for local recurrence-free survival (LRFS) and reported 55% extrapulmonary metastases and 45% pulmonary metastases. Conclusion: Margins, grading, presentation, local recurrence, and metastasis were prognostic factors. Extrapulmonary metastases were more frequent in myxoid liposarcoma

    Clinical Features and Outcome of 79 Dogs With Digital Squamous Cell Carcinoma Undergoing Treatment: A SIONCOV Observational Study

    Get PDF
    In dogs, digit squamous cell carcinoma (SCC) is uncommon. Clinical signs are frequently underestimated, leading to a diagnostic delay. The purpose of this retrospective study was to report our experience regarding the clinical presentation, diagnostic work-up, treatment and outcome of 79 client-owned dogs with SCC of the digit. The greatest majority (84.8%) of dogs was dark-coated. Schnauzers represented approximately one third of the study population, and had a poorer outcome compared with other breeds. The majority of SCCs occurred in the front limbs (61%), and bone lysis was frequently observed (92.4%). Approximately 9% of dogs had involvement of multiple digits, and this was associated with a shorter time to progression (TTP; P = 0.047). Similarly, a duration of clinical signs &gt;90 days was associated with a shorter TTP (P = 0.02). Regional lymph node metastases were documented in 17.7% of dogs at admission and were significantly associated with tumor-related death (P &lt; 0.001). At presentation, none of the dogs had evidence of distant metastasis. Digit amputation achieved adequate local tumor control in the majority of cases. Adjuvant chemotherapy and radiation therapy were carried out in 21.5% of cases, with uncertain benefit. Due to the relatively non-aggressive clinical behavior of digit SCC, chemotherapy should only be offered in the case of metastatic disease. Approximately one fourth of dogs developed de novo SCCs during the follow-up. Careful examination of the digits should be encouraged in breeds considered at high risk and in dogs with a previous history of digital SCC

    Impact of mercaptopurine metabolites on disease outcome in the AIEOP-BFM 2009 protocol for acute lymphoblastic leukemia

    Get PDF
    : In the maintenance phase of AIEOP-BFM acute lymphoblastic leukemia (ALL) 2009 protocol, mercaptopurine (MP) is given at the planned dose of 50 mg/m2/day; however, dose adjustments are routinely performed to target patients' white blood cells to the optimal range of 2000-3000 cells/μl. ALL pediatric patients (n=290, age: median (1st-3rd quartile): 4.8 (3.0-8.1) years; male: 56.9%) were enrolled mainly in four medium-large Italian pediatric hospitals; 14.1% of patients relapsed after a median (1st-3rd quartile) follow-up time of 4.43 (3.82-5.46) years from maintenance beginning. MP metabolites (thionucleotide (TGN) and methyl-derivatives (MMPN)) were measured in the erythrocytes of 387 blood samples of 200 patients by HPLC-UV. SNPs (rs1800462, rs1800460 and rs1142345 in TPMT gene, rs116855232 in NUDT15, rs1127354, rs7270101, rs6051702 in ITPA and rs2413739 in PACSIN2) were characterized by Taqman SNP genotyping assays. Cox proportional hazard models did not show an impact TGN levels and variability on relapse. In contrast, after multivariate analysis, relapse hazard ratio (HR) increased in ALL children of the intermediate risk arm compared to those in standard risk arm (3.44, 95% confidence interval (CI), 1.31-9.05, p= 0.012), and in carriers of the PACSIN2 rs2413739 T allele compared to those with the CC genotype (heterozygotes CT: HR, 2.32; 95% CI, 0.90-5.97; p=0.081; homozygous TT: HR, 4.14; 95% CI, 1.54-11.11; p=0.005). Future studies are needed to confirm the lack of impact of TGN levels and variability on relapse in the AIEOP-BFM ALL trials, and to clarify the mechanism of PACSIN2 rs2413739 on outcome

    Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries

    Get PDF
    IMPORTANCE: Limited information exists about the epidemiology, recognition, management, and outcomes of patients with the acute respiratory distress syndrome (ARDS). OBJECTIVES: To evaluate intensive care unit (ICU) incidence and outcome of ARDS and to assess clinician recognition, ventilation management, and use of adjuncts-for example prone positioning-in routine clinical practice for patients fulfilling the ARDS Berlin Definition. DESIGN, SETTING, AND PARTICIPANTS:The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents. EXPOSURES:Acute respiratory distress syndrome. MAIN OUTCOMES AND MEASURES: The primary outcome was ICU incidence of ARDS. Secondary outcomes included assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS. RESULTS: Of 29,144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0% (95% CI, 28.2%-31.9%); of moderate ARDS, 46.6% (95% CI, 44.5%-48.6%); and of severe ARDS, 23.4% (95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4% (95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5% (95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1% (95% CI, 38.2-42.1), whereas 82.6% (95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3% (95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% (95% CI, 31.4%-38.5%) for those with mild, 40.3% (95% CI, 37.4%-43.3%) for those with moderate, and 46.1% (95% CI, 41.9%-50.4%) for those with severe ARDS. CONCLUSIONS AND RELEVANCE: Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS

    Clinical Features and Outcome of 79 Dogs With Digital Squamous Cell Carcinoma Undergoing Treatment: A SIONCOV Observational Study

    Get PDF
    In dogs, digit squamous cell carcinoma (SCC) is uncommon. Clinical signs are frequently underestimated, leading to a diagnostic delay. The purpose of this retrospective study was to report our experience regarding the clinical presentation, diagnostic work-up, treatment and outcome of 79 client-owned dogs with SCC of the digit. The greatest majority (84.8%) of dogs was dark-coated. Schnauzers represented approximately one third of the study population, and had a poorer outcome compared with other breeds. The majority of SCCs occurred in the front limbs (61%), and bone lysis was frequently observed (92.4%). Approximately 9% of dogs had involvement of multiple digits, and this was associated with a shorter time to progression (TTP; P = 0.047). Similarly, a duration of clinical signs &gt;90 days was associated with a shorter TTP (P = 0.02). Regional lymph node metastases were documented in 17.7% of dogs at admission and were significantly associated with tumor-related death (P &lt; 0.001). At presentation, none of the dogs had evidence of distant metastasis. Digit amputation achieved adequate local tumor control in the majority of cases. Adjuvant chemotherapy and radiation therapy were carried out in 21.5% of cases, with uncertain benefit. Due to the relatively non-aggressive clinical behavior of digit SCC, chemotherapy should only be offered in the case of metastatic disease. Approximately one fourth of dogs developed de novo SCCs during the follow-up. Careful examination of the digits should be encouraged in breeds considered at high risk and in dogs with a previous history of digital SCC

    Medicamentos opioides: revisão literária de aspectos farmacológicos de relevância

    Get PDF
    A dor é que uma percepção empírica sensorial nociceptiva, de conotação afetiva e desagradável, oposta ao prazer. O fenômeno da dor é resultado da ativação dos receptores nociceptivos, os quais captam estímulos nocivos ao organismo via SNC, o qual proporciona a detecção e sinalização do dano tecidual, exteriorizado como sensação dolorosa. Os receptores opioides são acoplados à proteína G na membrana celular, de tal forma que quando os mesmos sofrem estímulo farmacológico específico, ocorre inibição da enzima adenilato ciclase, com consequente queda da concentração intracelular de monofosfato cíclico de adenosina

    Uso do teste LF-LAM para diagnóstico de Tuberculose ativa em paciente que vive com HIV

    Get PDF
    A tuberculose (TB) é uma doença infectocontagiosa granulomatosa, de alta infectividade e baixa patogenicidade, de tropismo primariamente respiratório, mas que pode afetar outros órgãos, como linfonodos, pele, rins, intestino e cérebro. É imperativo excluir o diagnóstico de TB em pacientes diagnosticados com HIV. Este estudo se trata do relato de caso de um paciente de 30 anos, gênero masculino, sem comorbidades prévias, que comparece à Unidade de Pronto Atendimento (UPA) queixando-se de desconforto respiratório aos pequenos esforços, tosse seca, febrícula aferida diariamente, diaforese, disfagia e perda ponderal de 15 kg. Feita a suspeição clínica de tuberculose, optou-se pela solicitação do teste rápido molecular para TB, no entanto, o paciente não conseguiu produzir a amostra necessária para análise. Assim, foi solicitado o teste de antígeno urinário lipoarabinomanano, que foi positivo, permitindo o tratamento precoce dessa grave infecção. Confirmou-se, também, o diagnóstico de HIV. O desconhecimento de métodos diagnósticos alternativos para pacientes de alto risco para TB é um complexo desafio em saúde pública, dada a elevada taxa de morbimortalidade nos portadores dessa doença, sobretudo, naqueles coinfectados com o vírus HIV
    corecore