Colonoscopic Treatment of a Fecaloma at the Anastomotic Site after Colectomy

Fecalomas most commonly occur in constipated patients and are rarely reported after colectomy. A 55-year-old Japanese female presented with a fecaloma after colectomy, which was impacted at a functional end-to-end anastomosis (FEEA) site. Four and a half years ago, she underwent sigmoidectomy for colon cancer. A follow-up computed tomography (CT) scan revealed an 11 cm incidental fecaloma. The patient was advised to undergo surgery, but she desired nonoperative management because of minimal symptoms, and was referred to our institution. On the day of admission (day 1), mechanical fragmentation of the fecaloma was attempted during the first colonoscopy. Although a large block of stool was evacuated after a second colonoscopic fragmentation on day 8, the third colonoscopy on day 21 and CT scan on day 22 showed no significant change in the fecaloma. Frequent colonoscopic fragmentation was performed, with a fourth, fifth, and sixth colonoscopy on days 24, 29, and 31, respectively. After the size reduction was confirmed at the sixth colonoscopy, the patient was discharged home on day 34. The fecaloma completely resolved after the seventh colonoscopic fragmentation on day 44. Sixteen months after treatment, there is no evidence of recurrent fecaloma. According to the literature, risk factors for fecaloma after colectomy include female gender, left-side colonic anastomosis, and FEEA. FEEA might not be recommended for anastomoses in the left colon, particularly in female patients, to avoid this complication. Colonoscopic fragmentation is recommended for fecalomas at an anastomotic site after colectomy in patients without an absolute indication for surgery.

Experimental Evaluation of the Effectiveness of Aspiration-Based Techniques to Treat Different Types of Acute Thromboembolic Occlusions in the Femoropopliteal Vascular System Using an In Vitro Flow Model

Purpose In this in vitro study, the effectiveness and safety of four aspiration-based techniques for thrombectomy are evaluated for three types of thrombi in a flow model simulating the femoropopliteal segment. Material and Methods Red, white, and mixed thrombi were produced in a standardized manner and used to simulate occlusion of a superficial femoral artery using a pulsatile flow model. Four techniques were compared: aspiration alone, aspiration + stent retriever, exposing thrombus to laser by an excimer laser system and a laser catheter + aspiration, and aspiration + mechanical fragmentation by a separator. Rate of first-pass recanalization, embolic events, and number of embolized fragments > 1 mm were compared. Results Aspiration alone, stent retriever, laser, and separator differed in rates of first-pass recanalization (53.3%; 86.6%; 20%; and 100%) and embolic events (40%; 93.3%; 73.3%; and 60%). Number of embolized fragments was lowest with aspiration and higher with separator, laser, and stent retriever. Rates of first-pass-recanalization (75%; 75%; and 45%) and embolic events (65%; 60%; and 75%) differed for red, white, and mixed thrombi. The mixed thrombus caused the highest number of embolized fragments, which was particularly high using the stent retriever. Conclusion Additional use of mechanical techniques significantly enhances the effectiveness of thrombectomy but simultaneously provokes more embolism. Laser seems to negatively alter the structure of a thrombus and thus diminishes the effectiveness, while provoking embolism. All techniques had lowest effectiveness, but highest embolism with the mixed thrombus. This was particularly striking when a stent retriever was used with the mixed thrombus.

COMPUTATIONAL MICROSTRUCTURE-BASED ANALYSIS OF RESIDUAL STRESS EVOLUTION IN METAL-MATRIX COMPOSITE MATERIALS DURING THERMOMECHANICAL LOADING

A technique for computer simulation of three-dimensional structures of materials with reinforcing particles of complex irregular shapes observed in the experiments is proposed, which assumes scale invariance of the natural mechanical fragmentation. Two-phase structures of metal-matrix composites and coatings of different spatial scales are created, with the particles randomly distributed over the matrix and coating computational domains. Using the titanium carbide reinforcing particle embedded into the aluminum as an example, plastic strain localization and residual stress formation along the matrix-particle interface are numerically investigated during cooling followed by compression or tension of the composite. A detailed analysis is performed to evaluate the residual stress concentration in local regions of bulk tension formed under all-round and uniaxial compression of the composite due to the concave and convex interfacial asperities.

A Different Protein Corona Cloaks “True-to-Life” Nanoplastics with Respect to Synthetic Polystyrene Nanobeads

Given the complexity of separating nanoplastics from environmental samples, studies have usually been conducted using synthetic polystyrene nanobeads. By mechanical fragmentation in cryogenic conditions of daily-life plastic items, we produced “true-to-life” nanoplastics (T2LNPs), that promises to give a true insight into the interaction with biological systems. T2LNPs have been fully characterized by Fourier transform Infrared spectroscopy and by Atomic Force Microscopy. They result in populations of spheroidal nanoparticles with a broad multimodal size distribution. The mandatory need for a representative sample to evaluate the potential effects of nanoparticles on human health and the environment is demonstrated by the different protein corona identified on T2LNPs and synthetic polystyrene nanobeads upon incubation with human plasma.

A Different Protein Corona Cloaks “True-to-Life” Nanoplastics with Respect to Synthetic Polystyrene Nanobeads

Given the complexity of separating nanoplastics from environmental samples, studies have usually been conducted using synthetic polystyrene nanobeads. By mechanical fragmentation in cryogenic conditions of daily-life plastic items, we produced “true-to-life” nanoplastics (T2LNPs), that promises to give a true insight into the interaction with biological systems. T2LNPs have been fully characterized by Fourier transform Infrared spectroscopy and by Atomic Force Microscopy. They result in populations of spheroidal nanoparticles with a broad multimodal size distribution. The mandatory need for a representative sample to evaluate the potential effects of nanoparticles on human health and the environment is demonstrated by the different protein corona identified on T2LNPs and synthetic polystyrene nanobeads upon incubation with human plasma.

Systematic decay analysis of 202Po∗ compound nucleus using Dynamical Cluster-decay Model

The decay analysis of [Formula: see text]Po[Formula: see text] compound nucleus (CN), formed via [Formula: see text]Ca+[Formula: see text]Gd reaction, with inclusion of additional degrees-of-freedom, i.e., the higher multipole deformations, the octupole ([Formula: see text]) and hexadecupole ([Formula: see text]), the corresponding “compact” orientations ([Formula: see text]), and noncoplanarity degree-of-freedom ([Formula: see text]0), is investigated within the collective clusterization approach. The Quantum Mechanical Fragmentation Theory (QMFT)-based Dynamical Cluster-decay Model (DCM), wherein the point of penetration [Formula: see text], fixed via the in-built neck-length parameter [Formula: see text] in [Formula: see text] (equivalently, the “barrier lowering” [Formula: see text]), is used to best fit the channel cross-section ([Formula: see text]) and predict the quasi-fission (qf)-like nCN cross-section [Formula: see text], if any, and the fusion–fission ([Formula: see text]) cross-sections. We also look for other target-projectile (t-p) combinations for the synthesis of CN [Formula: see text]Po[Formula: see text].