Analytical Modeling of a New Compliant Microsystem for Atherectomy Operations

This work offers a new alternative tool for atherectomy operations, with the purpose of minimizing the risks for the patients and maximizing the number of clinical cases for which the system can be used, thanks to the possibility of scaling its size down to lumen reduced to a few tenths of mm. The development of this microsystem has presented a certain theoretical work during the kinematic synthesis and the design stages. In the first stage a new multi-loop mechanism with a Stephenson’s kinematic chain (KC) was found and then adopted as the so-called pseudo-rigid body mechanism (PRBM). Analytical modeling was necessary to verify the synthesis requirements. In the second stage, the joint replacement method was applied to the PRBM to obtain a corresponding and equivalent compliant mechanism with lumped compliance. The latter presents two loops and six elastic joints and so the evaluation of the microsystem mechanical advantage (MA) had to be calculated by taking into account the accumulation of elastic energy in the elastic joints. Hence, a new closed form expression of the microsystem MA was found with a method that presents some new aspects in the approach. The results obtained with Finite Element Analysis (FEA) were compared to those obtained with the analytical model. Finally, it is worth noting that a microsystem prototype can be fabricated by using MEMS Technology classical methods, while the microsystem packaging could be a further development for the present investigation

Grasping and releasing agarose micro beads in water drops

The micromanipulation of micro objects is nowadays the focus of several investigations, specially in biomedical applications. Therefore, some manipulation tasks are required to be in aqueous environment and become more challenging because they depend upon observation and actuation methods that are compatible with MEMS Technology based micromanipulators. This paper describes how three grasping-releasing based tasks have been successfully applied to agarose micro beads whose average size is about 60 \u3bcm: (i) the extraction of a single micro bead from a water drop; (ii) the insertion of a single micro bead into the drop; (iii) the grasping of a single micro bead inside the drop. The success of the performed tasks rely on the use of a microgripper previously designed, fabricated, and tested

GPM-DPR Observations on TGFs Producing Storms

Unique spaceborne measurements of the three-dimensional structure of convective clouds producing terrestrial gamma ray flashes (TGFs) were performed using both active and passive microwave sensors on board the Global Precipitation Measurement (GPM)-Core Observatory satellite, finding coherent features for nine TGF-producing storms. The delineation of cloud structure using the radar reflectivity factor shows convective cells with significant vertical development and thick layers with high ice content. Compared to other cumulonimbus clouds in the tropics, the TGFs counterparts have higher reflectivity values above 3 and 8 km altitude showing in all cases a cumulonimbus tower and the TGFs locations are very close, or coincident, to these high Z columns, where reflectivity exceeds 50dBz. Using the GPM Microwave Imager radiometer, most thunderstorms show a very strong depression of polarization corrected temperature (PCT) at channel 89GHz, indicating a strong scattering signal by ice in the upper cloud layers. At channel 166GHZ, the difference between vertical and horizontal brightness temperature signal always returns positive values, from 0.2 up to 13.7K indicating a complex structure with randomly/vertically oriented ice particles. The PCT was used to characterize the analyzed storms in terms of hydrometeor types, confirming in 7/9 cases a high likelihood of hail/graupel presence. To perform analysis on the TGFs parent flashes, radio atmospherics data from the Earth Networks Total Lightning Network lightning network were used. Waveform data indicate that all cases are intra-cloud events and TGFs typically take place during the peak of flash rate production. Finally, the analysis of the most intense event is shown

Further evidence to justify reassignment of Mycoplasma mycoides subspecies mycoides Large Colony type to Mycoplasma mycoides subspecies capri

Analysis, using the polymerase chain reaction (PCR), restriction enzyme endonuclease analysis (REA), protein profile patterns, random amplification of polymorphic DNA (RAPD) fingerprinting, 16S rRNA gene sequencing and antisera growth inhibition tests, of 22 strains of Mycoplasma mycoides subsp. mycoides Large Colony type (MmmLC) and eight strains of M. mycoides subsp. capri (Mmc) are presented, along with a summary of comparative data from the literature for over 100 strains, all of which supports the reclassification of the MmmLC and Mmc strains into the single subspecies, M. mycoides subspecies capri

Fournier's gangrene and intravenous drug abuse. An unusual case report and review of the literature

Fournier's gangrene is a potentially fatal emergency condition characterized by necrotizing fasciitis and supported by an infection of the external genital, perineal and perianal region, with a rapid and progressive spread from subcutaneous fat tissue to fascial planes.In this case report, a 52-year-old man, with a history of hepatitis C-virus (HCV)-related chronic liver disease and cocaine use disorder for which he was receiving methadone maintenance therapy, was admitted to the Emergency Department with necrotic tissue involving the external genitalia.Fournier's gangrene is usually due to compromised host immunity, without a precise cause of bacterial infection; here it is linked to a loco-regional intravenous injection of cocaine. A multimodal approach, including a wide surgical debridement and a postponed skin graft, was needed. Here we report this case, with a narrative review of the literature

Renal artery embolization before radical nephrectomy for complex renal tumour: Which are the true advantages?

Introduction: Renal artery embolization is performed before radical nephrectomy (RN) for renal mass in order to induce preoperative infarction and to facilitate surgical intervention through decrease of intraoperative bleeding. Moreover, in metastatic renal cancer it seems to stimulate tumour-specific antibodies, even if no established benefits in clinical response or survival have been reported. The role of preoperative renal artery embolization (PRAE) in management of renal masses has been often debated and its real benefits are still unclear. Nevertheless, in huge and complex renal masses, which are often characterized by a high and anarchic blood supply and rapid local invasion, radical nephrectomy can be challenging even for skilled surgeons. The aim of this prospective randomized study was to evaluate the effectiveness and safety of PRAE in complex masses by comparing perioperative outcomes of RN with and without PRAE.Materials and methods: From December 2015 to May 2018 we enrolled prospectively 64 patients who underwent RN for localized (T2a-b) or locally advanced (T3 and T4) or advanced (N+, M+) renal cancers. Patients were divided in two groups. The first group included 30 patients who underwent PRAE; in the second group we enrolled 34 patients who did not undergo RN without PRAE. Perioperative outcomes in terms of operative time, blood loss, transfusion rate and length of hospitalization were evaluated. Statistical analysis was performed using GraphPad Prism 6.0 software.Results: Median blood loss was 250 ml (50-500) and 400 ml (50-1000) in the first and second group, respectively, with a statistically significant difference (p=0.0066). Median surgical time was 200 min (90-390) and 240 min (130-390) in PRAE and No-PRAE group (p=0.06), respectively. No major complications occurred after embolization. Overall complication rate in Group 1 and 2 was 46.7% (14/30) and 50% (17/34), respectively (p=0.34). No major complications occurred in both groups. The mean follow up was 21,5 months.Conclusions: Our results prove PRAE to be a safe procedure with low complications rate. To our experience, PRAE seems to be a useful tool in surgical management of a large mass and advanced disease

Impact of intrauterine growth restriction on cerebral and renal oxygenation and perfusion during the first 3 days after birth

Intrauterine growth restriction (IUGR) is associated with a higher incidence of perinatal complications as well as cardiovascular and renal diseases later on. A better insight into the disease mechanisms underlying these sequalae is important in order to identify which IUGR infants are at a higher risk and find strategies to improve their outcome. In this prospective case–control study we examined whether IUGR had any effect on renal and cerebral perfusion and oxygen saturation in term neonates. We integrated near-infrared spectroscopy (NIRS), echocardiographic, Doppler and renal function data of 105 IUGR infants and 105 age/gender-matched controls. Cerebral and renal regional oxygen saturation values were measured by NIRS during the first 12 h after birth. Echocardiography alongside Doppler assessment of renal and anterior cerebral arteries were performed at 6, 24, 48 and 72 h of age. Glomerular and tubular functions were also assessed. We found a left ventricular dysfunction together with a higher cerebral oxygen saturation and perfusion values in the IUGR group. IUGR term infants showed a higher renal oxygen saturation and a reduced oxygen extraction together with a subclinical renal damage, as indicated by higher values of urinary neutrophil gelatinase-associated lipocalin and microalbumin. These data suggest that some of the haemodynamic changes present in growth-restricted foetuses may persist postnatally. The increased cerebral oxygenation may suggest an impaired transition to normal autoregulation as a consequence of intra-uterine chronic hypoxia. The higher renal oxygenation may reflect a reduced renal oxygen consumption due to a subclinical kidney damage

Role of serum-free light chain assay for defining response and progression in immunoglobulin secretory multiple myeloma

The International Myeloma Working Group (IMWG) guidelines recommend using electrophoresis and immunofixation to define response and progressive disease (PD) in immunoglobulin (Ig) secretory multiple myeloma (Ig-MM), whereas the role of serum-free light chain (sFLC) is controversial. We retrospectively analyzed the value of adding sFLC assays in the definition of response and PD according to IMWG criteria in 339 Ig-MM patients treated with a first-line novel agent-based therapy (median follow-up 54 months). sFLC PD was defined according to conventional criteria plus increased sFLC levels, or sFLC escape (sFLCe); progression/sFLCe-free survival (ePFS) was the time from the start of treatment to the date of first PD or sFLCe, or death; overall survival after PD/sFLCe (OS after Pe) was the time from first PD or sFLCe to the date of death. 148 (44%) patients achieved a complete response and 198 (60%) a normal sFLC ratio (sFLCR). sFLCR normalization was an independent prognostic factor for extended PFS (HR = 0.46, p = 0.001) and OS (HR = 0.47, p = 0.006) by multivariable analysis. 175 (52%) patients experienced PD according to the IMWG criteria, whereas 180 (53%) experienced PD or sFLCe. Overall, a sFLCe was observed in 31 (9%) patients. Median PFS and ePFS were both equal to 36 (95% CI = 32–42, and 32–40, respectively) months. sFLC PD adversely affected the OS after Pe compared to PD with increasing monoclonal Ig only (HR = 0.52, p = 0.012). Our results support the inclusion of the sFLC assay for defining response and PD in Ig-MM

AGILE Observations of GRB 220101A: A "new Year's Burst" with an Exceptionally Huge Energy Release

We report the AGILE observations of GRB 220101A, which took place at the beginning of 2022 January 1 and was recognized as one of the most energetic gamma-ray bursts (GRBs) ever detected since their discovery. The AGILE satellite acquired interesting data concerning the prompt phase of this burst, providing an overall temporal and spectral description of the event in a wide energy range, from tens of kiloelectronvolts to tens of megaelectronvolts. Dividing the prompt emission into three main intervals, we notice an interesting spectral evolution, featuring a notable hardening of the spectrum in the central part of the burst. The average fluxes encountered in the different time intervals are relatively moderate, with respect to those of other remarkable bursts, and the overall fluence exhibits a quite ordinary value among the GRBs detected by MCAL. However, GRB 220101A is the second farthest event detected by AGILE, and the burst with the highest isotropic equivalent energy of the entire MCAL GRB sample, releasing Eiso = 2.54 × 1054 erg and exhibiting an isotropic luminosity of Liso = 2.34 × 1052 erg s−1 (both in the 400 keV–10 MeV energy range). We also analyzed the first 106 s of the afterglow phase, using the publicly available Swift-XRT data, carrying out a theoretical analysis of the afterglow, based on the forward shock model. We notice that GRB 220101A is with high probability surrounded by a wind-like density medium, and that the energy carried by the initial shock shall be a fraction of the total Eiso, presumably near ∼50%.publishedVersio