Path Planning for 3-D In-Hand Manipulation of Micro-Objects Using Rotation Decomposition

Robotic manipulation and assembly of micro and nanocomponents in confined spaces is still a challenge. Indeed, the current proposed solutions that are highly inspired by classical industrial robotics are not currently able to combine precision, compactness, dexterity, and high blocking forces. In a previous work, we proposed 2-D in-hand robotic dexterous manipulation methods of arbitrary shaped objects that considered adhesion forces that exist at the micro and nanoscales. Direct extension of the proposed method to 3-D would involve an exponential increase in complexity. In this paper, we propose an approach that allows to plan for 3-D dexterous in-hand manipulation with a moderate increase in complexity. The main idea is to decompose any 3-D motion into a 3-D translation and three rotations about specific axes related to the object. The obtained simulation results show that 3-D in-hand dexterous micro-manipulation of arbitrary objects in presence of adhesion forces can be planned in just few seconds.

A finite deformation electro-mechanically coupled computational multiscale formulation for electrical conductors

Motivated by the influence of deformation-induced microcracks on the effective electrical properties at the macroscale, an electro-mechanically coupled computational multiscale formulation for electrical conductors is proposed. The formulation accounts for finite deformation processes and is a direct extension of the fundamental theoretical developments presented by Kaiser and Menzel (Arch Appl Mech 91:1509–1526, 2021) who assume a geometrically linearised setting. More specifically speaking, averaging theorems for the electric field quantities are proposed and boundary conditions that a priori fulfil the extended Hill–Mandel condition of the electro-mechanically coupled problem are discussed. A study of representative boundary value problems in two- and three-dimensional settings eventually shows the applicability of the proposed formulation and reveals the severe influence of microscale deformation processes on the effective electrical properties at the macroscale.

Observables in inhomogeneous ground states at large global charge

As a sequel to previous work, we extend the study of the ground state configuration of the D = 3, Wilson-Fisher conformal O(4) model. In this work, we prove that for generic ratios of two charge densities, ρ1/ρ2, the ground-state configuration is inhomogeneous and that the inhomogeneity expresses itself towards longer spatial periods. This is the direct extension of the similar statements we previously made for ρ1/ρ2 ≪ 1. We also compute, at fixed set of charges, ρ1, ρ2, the ground state energy and the two-point function(s) associated with this inhomogeneous configuration on the torus. The ground state energy was found to scale (ρ1 + ρ2)3/2, as dictated by dimensional analysis and similarly to the case of the O(2) model. Unlike the case of the O(2) model, the ground also strongly violates cluster decomposition in the large-volume, fixed-density limit, with a two-point function that is negative definite at antipodal points of the torus at leading order at large charge.

Surgical Resection of Atypical Metastatic Melanoma to the Atriocaval Junction: A Case Report

Metastatic tumors to the heart include lymphomas, sarcoma, leukemia, and melanoma. Of these, metastatic melanoma is the most common, and are usually hematogenous, where metastatic lesions can be present in the left ventricle, right atrium, and/ or the right ventricle. We present an atypical metastatic melanoma pattern, where cardiac metastasis originated by direct extension from the adjacent gastric mesentery. We also present our trans-cardiac resection approach, which was the safest way to access the cardiac metastasis intra-operatively without disrupting the tumor.

Bilateral Schneiderian (sinonasal) papilloma: An uncommon rare entity

Sinonasal papilloma is a benign surface mucosal neoplasm with variable growth pattern and cytological features. It is a rare benign tumor with tendency to recur and also malignant transformation. The most common sites of inverting papillomata are lateral nasal wall and middle meatus and are usually unilateral. Rarely Bilateral disease can occur, which may be due to direct extension of the tumour, but can also occur as two distinct lesions. The etiology still remains unclear, eventhough the morphology and clinical behavior of this lesion has been well described. Here we report a case of recurrent bilateral nasal polyposis, histologically diagnosed as Inverted sinonasal papilloma, which is a rare entity.

Intraorbital Abscess: A Rare Cause of Orbit Compression

Introduction: Intraorbital abscess is a rare complication of rhinosinusitis that affects most commonly the pediatric population. It is thought to be caused by direct extension or venous spread of infections from contiguous sites and can lead to life-threatening complications, like permanent visual loss and cerebral abscesses. Objectives: Intraorbital abscess is a rare condition that requires prompt diagnosis and treatment to avoid serious complications. Our objectives are to provide an overview of this rare disease process and its management including our successful treatment experience. Case Description: We present a 2 case report of a 13-year-old pediatric male and a 66-year-old male with history of chronic sinusitis who presented with a right intraorbital abscess successfully treated with external drainage with decompression of the orbit. Conclusion: When intraorbital abscess is encountered, a high index of suspicion is needed to allow prompt and accurate diagnosis for this infrequent condition. Timely surgical drainage of the abscess is needed to prevent the development of fatal complications.

Asymptotic behavior of repeated eigenvalues of perturbed self-adjoint elliptic operators

A variational characterization for the shift of eigenvalues caused by a general type of perturbation is derived for second order self-adjoint elliptic differential operators. This result allows the direct extension of asymptotic formulae from simple eigenvalues to repeated ones. Some examples of particular interest are presented theoretically and numerically for the Laplacian operator for the following domain perturbations: excision of a small hole, local change of conductivity, small boundary deformation.

Chronic Sphenoiditis With Deep Neck Space Extension: Case Report With Review of the Literature and Postulated Mechanisms for Extracranial Extension

Isolated primary sphenoid sinusitis is a rare occurrence, estimated to make up less than 3% of sinus infections. The posterior anatomic location of the sphenoid makes treatment challenging when it becomes infected. Complications involving intracranial extension to surrounding structures often result in cranial nerve deficits due to their proximity. A single case of chronic sphenoiditis with direct extracranial extension into the prevertebral space is reported with a discussion on clinical presentation, diagnosis, and management. A 46-year-old female patient with diffuse headaches radiating into the neck and throat was evaluated in the office. Computed tomography demonstrated sphenoiditis with direct extension into the prevertebral space. Imaging revealed a purported route of direct extension through the clinoid and directly into the clivus to form an abscess in the longus colli muscle. The patient underwent endoscopic surgical management including drainage of the prevertebral abscess and has since made a full recovery. This is the first reported case of direct extension of sphenoiditis into the prevertebral space. The findings highlight the importance of aggressive treatment of chronic sphenoid infections to prevent detrimental complications. Computed tomography imaging proved an advantageous imaging modality to demonstrate bony erosion and sinus tracts from the skull base to the deep neck space.

Electrochemotherapy Modulates Mammary Tumor Growth in Rats on a Western Diet Supplemented with Curcumin

In the US, every 12 min, six women are diagnosed with breast cancer and one dies. This highlights a critical need for developing alternate therapies using natural compounds, which are cost effective and with less side effects. Curcumin, the yellow pigment of turmeric has been found to suppress initiation, progression, and metastasis of a variety of tumors. Multiple clinical trials highlight the efficacy of curcumin in treating breast cancer and other diseases. Our in vitro studies have demonstrated that the electrical pulse (EP) application can further enhance the effectiveness of curcumin against breast cancer cells in a therapy called electrochemotherapy (ECT). In a direct extension of these results, we studied the effect of ECT coupled with intratumoral curcumin administration (EP+Cur) on N-methyl-N-nitrosourea (MNU) induced mammary tumors in female Sprague Dawley rats. Beginning at the weaning and throughout the study, rats were fed either western diet (West) or western diet, supplemented with 1% curcumin (W+Cur). Our results showed that EP+Cur treatment led to a reduced growth rate in rats fed with W+Cur diet compared to West diet (57.14% vs. 16.67% in West diet). These results provide a foundation for further studies towards utilizing it in clinical practice.