Fluidic Force Microscopy and Atomic Force Microscopy Unveil New Insights into the Interactions of Preosteoblasts with 3D-Printed Submicron Patterns.

Physical patterns represent potential surface cues for promoting osteogenic differentiation of stem cells and improving osseointegration of orthopedic implants. Understanding the early cell-surface interactions and their effects on late cellular functions is essential for a rational design of such topographies, yet still elusive. In this work, fluidic force microscopy (FluidFM) and atomic force microscopy (AFM) combined with optical and electron microscopy are used to quantitatively investigate the interaction of preosteoblasts with 3D-printed patterns after 4 and 24 h of culture. The patterns consist of pillars with the same diameter (200 nm) and interspace (700 nm) but distinct heights (500 and 1000 nm) and osteogenic properties. FluidFM reveals a higher cell adhesion strength after 24 h of culture on the taller pillars (32 ± 7 kPa versus 21.5 ± 12.5 kPa). This is associated with attachment of cells partly on the sidewalls of these pillars, thus requiring larger normal forces for detachment. Furthermore, the higher resistance to shear forces observed for these cells indicates an enhanced anchorage and can be related to the persistence and stability of lamellipodia. The study explains the differential cell adhesion behavior induced by different pillar heights, enabling advancements in the rational design of osteogenic patterns.

Interventional Radiology in Splenic Trauma: If Not Now, Then When?

Introduction: The treatment of blunt splenic injuries showed major evolutionary changes, from fundamental/ basic splenectomy to nonoperative and endovascular treatment, "catheter surgery". Currently, in Trauma Centers, splenic angioembolization is considered the first-line intervention in trauma. This article presents the Bucharest Emergency Clinical Hospital experience in the use of splenic angioembolization, a therapeutic solution in accordance with contemporary practice and literature. Methods: This retrospective study includes patients with splenic trauma by blunt mechanism, in which diagnostic / therapeutic angiography was performed, hospitalized in the Clinical Emergency Hospital Bucharest between January 2006 and December 2019. The main endpoints of the study were: post-traumatic mortality, the need for surgery (laparoscopic/classic) to resolve splenic bleeding, the number of days of hospitalization, the need for hospitalization for more than 1 day in the intensive care unit, the day when the platelet count began to increase, the evolution of laboratory parameters (hospitalization, preangiography, postangiography/embolization, discharge). A secondary endpoint of the study was the frequency of complications that did not require surgery. Results: During the mentioned period in 64 patients treated nonoperatively, diagnostic angiography was performed (27 cases, group B) or therapeutic angiography (37 cases, group A). 26.56% of cases were 55 years old (55-81 years old), the predominance of males being obvious (62.5%). The mean value of the ISS was 21.7 +- 10.4, and 71.87% of cases presented ISS 16. The mean value of the ISS was 21.7 +- 10.4, and 71.87% of cases presented ISS 16. The degree of splenic injury (American Association for the Surgery of Trauma-Organ Injury Scale) presented the mean value 2.95. The degree of splenic lesion was statistically significantly more severe in group A (p 0.001) and preangiography hemoglobin values were significantly lower compared to hospitalization values (p 0.001) indicating the persistence of hemorrhage. Procedural failures occurred in 4.68% of cases, with zero mortality. Conclusions: Splenic interventional radiology is a safe, effective and rational procedure. The development of therapeutic protocols is necessary to allow maximum use of this procedure.

Broadband nonreciprocal linear acoustics through a non-local active metamaterial.

The ability to create linear systems that manifest broadband nonreciprocal wave propagation would provide for exquisite control over acoustic signals for electronic filtering in communication and noise control. Acoustic nonreciprocity has predominately been achieved by approaches that introduce nonlinear interaction, mean-flow biasing, smart skins, and spatio-temporal parametric modulation into the system. Each approach suffers from at least one of the following drawbacks: the introduction of modulation tones, narrow band filtering, and the interruption of mean flow in fluid acoustics. We now show that an acoustic media that is non-local and active provides a new means to break reciprocity in a linear fashion without these deleterious effects. We realize this media using a distributed network of interlaced subwavelength sensor-actuator pairs with unidirectional signal transport. We exploit this new design space to create a stable metamaterial with non-even dispersion relations and electronically tunable nonreciprocal behavior over a broad range of frequencies.

Y-stenting with braided stents for wide-neck intracranial bifurcation aneurysms. A single-center initial experience.

INTRODUCTION: The treatment of wide-neck bifurcation aneurysms is still challenging despite the use of new techniques, such as Y-stenting, the waffle-cone technique and intrasaccular flow disrupters, in recent years. Moreover, the use of flow diverter stents in bifurcation aneurysms has been proposed by several teams, although the results remain controversial. This study aims to evaluate the feasibility and efficacy of Y-stent assisted coiling of bifurcation aneurysms with braided stents. METHODS: We retrospectively reviewed all patients in whom Y-stenting with braided stents had been performed in our center. Six patients were identified and analyzed. Technical success, complications, angiographic outcomes, procedural data, and follow-up controls are reported here. This study was approved by our local ethical committee. RESULTS: Technical success was achieved in all procedures. Overall procedure-related morbidity and mortality was 0%. In the immediate post-treatment angiography, adequate occlusion (neck remnant or total occlusion) was observed in all patients. Short- and long-term follow-up angiography showed adequate occlusion of the aneurysms. CONCLUSIONS: In this small, retrospective single-center analysis we showed that Y-stent assisted coiling with braided stents is a safe and feasible technique. Moreover, it has a high immediate occlusion rate and very good long-term stability.

Design and experimental demonstration of broadband acoustic pressure enhancing passive metafluids.

This paper presents the design and experimental demonstration of a passive broadband acoustic pressure enhancing metafluid in air. The design is optimized for fabrication via three-dimensional (3D) printing and takes advantage of the property of acoustic pressure to enhance sound as the sound passes with minimal insertion loss from the background medium into a high impedance fluid. Numerical simulations and experimental measurements of the fabricated structure show that the metafluid enhances the sound pressure level by 7 dB in more than one octave without introducing sound distortions. Moreover, the metafluid is subwavelength in size and does not increase the aperture of the sensor. These results provide an excellent path toward improving the sensitivity of compact acoustic sensors without employing active elements.

Single-sensor multispeaker listening with acoustic metamaterials.

Designing a "cocktail party listener" that functionally mimics the selective perception of a human auditory system has been pursued over the past decades. By exploiting acoustic metamaterials and compressive sensing, we present here a single-sensor listening device that separates simultaneous overlapping sounds from different sources. The device with a compact array of resonant metamaterials is demonstrated to distinguish three overlapping and independent sources with 96.67% correct audio recognition. Segregation of the audio signals is achieved using physical layer encoding without relying on source characteristics. This hardware approach to multichannel source separation can be applied to robust speech recognition and hearing aids and may be extended to other acoustic imaging and sensing applications.

Anisotropic acoustic metafluid for underwater operation.

The paper presents a method to design and characterize mechanically robust solid acoustic metamaterials suitable for operation in dense fluids such as water. These structures, also called metafluids, behave acoustically as inertial fluids characterized by anisotropic mass densities and isotropic bulk modulus. The method is illustrated through the design and experimental characterization of a metafluid consisting of perforated steel plates held together by rubber coated magnetic spacers. The spacers are very effective at reducing the effective shear modulus of the structure, and therefore effective at minimizing the ensuing coupling between the shear and pressure waves inside the solid effective medium. Inertial anisotropy together with fluid-like acoustic behavior are key properties that bring transformation acoustics in dense fluids closer to reality.

Highlighted Steps of the Management Algorithm in Acute Lower Gastrointestinal Bleeding - Case Reports and Literature Review.

Acute lower gastrointestinal bleeding is a major problem worldwide, being a rare and life threatening condition, with a mortality rate situated between 2 and 4%. Acute lower gastrointestinal bleeding is solvent for 1 - 2% of the entire hospital emergencies, 15% presenting as massive bleeding and up to 5% requiring surgery. Lower gastrointestinal bleeding can be classified depending on their location in the small or large intestine. The small bowel is the rarest site of lower gastrointestinal bleeding, at the same time being the commonest cause of obscure bleeding. 5% of total lower GI bleeding appears in the small bowel. When endoscopic therapy associated with medical treatment are insufficient, endovascular intervention can be lifesaving. Unfortunately in some rare cases of acute lower gastrointestinal bleeding with hemo-dynamic instability and the angiography performed being unable to locate the source of bleeding, the last therapeutic resource remains surgery. In the following we exemplify two cases of acute lower gastrointestinal bleeding which were resolved in different ways, followed by a thorough description of the different types of available treatment and finally, in the conclusions, we systematize the most important stages of the management algorithm in acute lower gastrointestinal bleeding.

Three-dimensional broadband omnidirectional acoustic ground cloak.

The control of sound propagation and reflection has always been the goal of engineers involved in the design of acoustic systems. A recent design approach based on coordinate transformations, which is applicable to many physical systems, together with the development of a new class of engineered materials called metamaterials, has opened the road to the unconstrained control of sound. However, the ideal material parameters prescribed by this methodology are complex and challenging to obtain experimentally, even using metamaterial design approaches. Not surprisingly, experimental demonstration of devices obtained using transformation acoustics is difficult, and has been implemented only in two-dimensional configurations. Here, we demonstrate the design and experimental characterization of an almost perfect three-dimensional, broadband, and, most importantly, omnidirectional acoustic device that renders a region of space three wavelengths in diameter invisible to sound.

Atypical abnormal pulmonary vein drainage with atrial septal defect: surgical treatment.

Sinus venosus atrial septal defect (SV-ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV-ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio-CT was finally conclusive. This diagnostic approach allowed the surgical planning.

Measurement of a broadband negative index with space-coiling acoustic metamaterials.

We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction.

The Utility of Multimodal Imaging and Artificial Intelligence Algorithms for Overlying Two Volumes in the Decision Chain for the Treatment of Complex Pathologies in Interventional Neuroradiology-A Case Series Study.

3D rotational angiography is now increasingly used in routine neuroendovascular procedures--in particular, for situations where the analysis of two overlayed sets of volume imaging proves useful for planning the treatment strategy or for confirming the optimal apposition of the intravascular devices used. The aim of this study is to identify and describe the decision algorithm for which the overlay function of 3D rotational angiography volumes, high-resolution contrast-enhanced flat panel detector CT adapted for intravascular devices (VasoCT/DynaCT), non-enhanced flat detector C-arm volume acquisition functionality integrated with the angiography equipment (XperCT/DynaCT), and isovolumetric MRI volumes were all used in treatments performed in a series of 29 patients. Two superposed 3DRA volumes were used in the treatment aneurysms located at the junction of two vascular territories and for arteriovenous malformations with compartments fed from different vascular territories. The superposition function of a preoperatively acquired 3DRA volume and a postoperatively acquired VasoCT volume provides accurate information about the apposition of neuroendovascular endoprostheses used in the treatment of aneurysms. The automatic overlay function generated by the 3D workstation is particularly useful, but in about 50% of cases it requires manual operator-dependent correction, requiring a certain level of experience. In our experience, multimodal imaging brings an important benefit, both in the treatment decision algorithm and in the assessment of neuroendovascular treatment efficacy.

Artificial Intelligence-The Rising Star in the Field of Gastroenterology and Hepatology.

Artificial intelligence (AI) is a term that covers a multitude of techniques that are used in a manner that tries to reproduce human intelligence. AI is helpful in various medical specialties that use imaging for diagnostic purposes, and gastroenterology is no exception. In this field, AI has several applications, such as detecting and classifying polyps, detecting the malignancy in polyps, diagnosing Helicobacter pylori infection, gastritis, inflammatory bowel disease, gastric cancer, esophageal neoplasia, and pancreatic and hepatic lesions. The aim of this mini-review is to analyze the currently available studies regarding AI in the field of gastroenterology and hepatology and to discuss its main applications as well as its main limitations.

Design of an acoustic metamaterial lens using genetic algorithms.

The present work demonstrates a genetic algorithm approach to optimizing the effective material parameters of an acoustic metamaterial. The target device is an acoustic gradient index (GRIN) lens in air, which ideally possesses a maximized index of refraction, minimized frequency dependence of the material properties, and minimized acoustic impedance mismatch. Applying this algorithm results in complex designs with certain common features, and effective material properties that are better than those present in previous designs. After modifying the optimized unit cell designs to make them suitable for fabrication, a two-dimensional lens was built and experimentally tested. Its performance was in good agreement with simulations. Overall, the optimization approach was able to improve the refractive index but at the cost of increased frequency dependence. The optimal solutions found by the algorithm provide a numerical description of how the material parameters compete with one another and thus describes the level of performance achievable in the GRIN lens.

COVID-19-associated Parotid Gland Abscess.

BACKGROUND: Human infection with the SARS-CoV-2 virus has caused a pandemic characterized by a plethora of diseases, of which those affecting the internal organs and nervous system can have severe, life-threatening consequences. Among the manifestations of the disease at the viral entry site, diseases in oral mucosa adnexa are rarely reported. This case report describes a COVID-19-associated aggravating parotid gland disease. CASE REPORT: The 47-year-old, SARS-CoV-2-positive male patient, already hospitalized and now in need of ventilation, had been referred for intensive care treatment due to increasing respiratory problems. A unilateral swelling of the cheek was noticed, the cause of which was initially a parotid gland infection. Examination ruled out mechanical causes of the parotid gland. During further treatment, the patient developed a parotid abscess, which was drained extra orally. CONCLUSION: The oral cavity is primarily considered as a reservoir of the pathogen. There is an increasing number of reports detailing inflammation of the major salivary glands associated with SARS-CoV-2 virus. Knowledge of this association facilitates therapeutic decisions.

Magnesium Orotate and the Microbiome-Gut-Brain Axis Modulation: New Approaches in Psychological Comorbidities of Gastrointestinal Functional Disorders.

Magnesium orotate has been cited in the medical literature for the past three years as a possible adjuvant in some pediatric and adult gastroenterological disorders associated with dysbiosis. Studies also focus on the possibility of adding magnesium orotate in psychiatric disorders' treatment, such as major depression and anxiety. The most relevant element in these studies is the efficiency of magnesium orotate therapy in cases with both gastroenterological and psychiatric symptoms. This article proposes a literature review, focused on the studies published in the last three years, targeting magnesium orotate treatment and probiotic supplementation in patients with both digestive and psychiatric symptoms. Moreover, this review will compare the efficiency of magnesium orotate and probiotics within both the pediatric and adult communities, focusing on the possibility of gut-brain axis modulation and its involvement in the clinical evolution of these patients.

Experimental acoustic ground cloak in air.

We present the design, fabrication, and performance analysis for a class of two-dimensional acoustic cloaking coatings in air. Our approach takes advantage of transformation acoustics and linear coordinate transformations that result in shells which are homogeneous, broadband, and compact. The required material parameters are highly anisotropic; however, we show that they are easily achievable in practice in metamaterials made of perforated plastic plates. The good performance of the fabricated design is assessed from measurements of the sound field produced around the cloak by a broadband source. The remarkably low complexity of the device made of perforated plastic plates shows that sound in air can be fully and effectively manipulated using realizable transformation acoustics devices.

Phase conjugation and negative refraction using nonlinear active metamaterials.

We present an experimental demonstration of phase conjugation using nonlinear metamaterial elements. Active split-ring resonators loaded with varactor diodes are demonstrated theoretically to act as phase-conjugating or time-reversing discrete elements when parametrically pumped and illuminated with appropriate frequencies. The metamaterial elements were fabricated and shown experimentally to produce a time-reversed signal. Measurements confirm that a discrete array of phase-conjugating elements act as a negatively refracting time-reversal rf lens only 0.12λ thick.

A Preliminary Evaluation of the Pro-Chondrogenic Potential of 3D-Bioprinted Poly(ester Urea) Scaffolds.

Degeneration of articular cartilage (AC) is a common healthcare issue that can result in significantly impaired function and mobility for affected patients. The avascular nature of the tissue strongly burdens its regenerative capacity contributing to the development of more serious conditions such as osteoarthritis. Recent advances in bioprinting have prompted the development of alternative tissue engineering therapies for the generation of AC. Particular interest has been dedicated to scaffold-based strategies where 3D substrates are used to guide cellular function and tissue ingrowth. Despite its extensive use in bioprinting, the application of polycaprolactone (PCL) in AC is, however, restricted by properties that inhibit pro-chondrogenic cell phenotypes. This study proposes the use of a new bioprintable poly(ester urea) (PEU) material as an alternative to PCL for the generation of an in vitro model of early chondrogenesis. The polymer was successfully printed into 3D constructs displaying adequate substrate stiffness and increased hydrophilicity compared to PCL. Human chondrocytes cultured on the scaffolds exhibited higher cell viability and improved chondrogenic phenotype with upregulation of genes associated with type II collagen and aggrecan synthesis. Bioprinted PEU scaffolds could, therefore, provide a potential platform for the fabrication of bespoke, pro-chondrogenic tissue engineering constructs.