Continuum Field Theory for the Deformations of Planar Kirigami.

Mechanical metamaterials exhibit exotic properties that emerge from the interactions of many nearly rigid building blocks. Determining these properties theoretically has remained an open challenge outside a few select examples. Here, for a large class of periodic and planar kirigami, we provide a coarse-graining rule linking the design of the panels and slits to the kirigami's macroscale deformations.

The detection matrix as a model-agnostic tool to estimate the number of degrees of freedom in mechanical systems and engineering structures.

Estimating the number of degrees of freedom of a mechanical system or an engineering structure from the time-series of a small set of sensors is a basic problem in diagnostics, which, however, is often overlooked when monitoring health and integrity. In this work, we demonstrate the applicability of the network-theoretic concept of detection matrix as a tool to solve this problem. From this estimation, we illustrate the possibility to identify damage.

Shape-morphing architected sheets with non-periodic cut patterns.

We investigate the out-of-plane shape morphing capability of single-material elastic sheets with architected cut patterns that result in arrays of tiles connected by flexible hinges. We demonstrate that a non-periodic cut pattern can cause a sheet to buckle into three-dimensional shapes, such as domes or patterns of wrinkles, when pulled at specific boundary points. These global buckling modes are observed in experiments and rationalized by an in-plane kinematic analysis that highlights the role of the geometric frustration arising from non-periodicity.

Neural stem cells and glioblastoma.

Glioblastoma multiforme represents one of the most common brain cancers with a rather heterogeneous cellular composition, as indicated by the term "multiforme". Recent reports have described the isolation and identification of cancer neural stem cells from human adult glioblastoma multiforme, which possess the capacity to establish, sustain, and expand these tumours, even under the challenging settings posed by serial transplantation experiments. Our study focused on the distribution of neural cancer stem cells inside the tumour.

Papillary glioneuronal tumor. Case report and literature review.

Objective And Importance: Papillary glioneuronal tumor is a recently described neoplasm composed of gliovascular pseudopapillae associated with intervening neuronal cells ranging from neurocytes to ganglion cells. This tumor is not currently included in the WHO classification of tumors of the central nervous system. We describe a new case of papillary glioneuronal tumor and analyze the data for a series of further 15 patients from international literature.

Activating PTPN11 mutations play a minor role in pediatric and adult solid tumors.

The PTPN11 gene encodes SHP-2, a widely expressed cytoplasmic protein tyrosine phosphatase functioning as a signaling transducer. Germ-line PTPN11 mutations cause Noonan syndrome (NS), a developmental disorder characterized by an increased risk of malignancies. Recently, a novel class of activating mutations in PTPN11 has been documented as a somatic event in a heterogeneous group of leukemias.

Extrathecal intraradicular nerve sheath tumor.

Object: The purpose of this study was to analyze the clinical profile of patients harboring extrathecal and intraradicular nerve sheath tumors (NSTs), located inside the sleeve of an extrathecal nerve root and very often within the proximal portion of the spinal nerve, and to evaluate the incidence of long-term dysfunction of the tumor-affected roots if resected. These tumors have not received particular attention in the literature.

Methods: A single-institution series of 16 patients who had undergone surgery for intraradicular NSTs during a 50-year period was selected retrospectively.

Spinal extradural schwannoma.

Object: The authors endeavor to define the clinical and surgery-related profile of spinal nerve sheath tumors located in the extradural space outside both the dural sac and, apparently, the nerve roots' sleeve.

Methods: A series of 24 extradural schwannomas was retrospectively selected after reviewing the notes of spinal nerve sheath tumors surgically treated at La Sapienza University of Rome. Clinical data, tumor-related characteristics, and outcome were analyzed.

Idiopathic intracranial hypertrophic pachymeningitis: two case reports and review of the literature.

In 1949, Naffziger et al. first described idiopathic intracranial hypertrophic pachymeningitis (IIHP) as an aseptic, diffuse inflammatory disease that causes thickening of the dura mater and often headache and progressive multiple nerve palsies due to fibrous entrapment or ischemic damage of neurovascular structures. Pachymeningeal thickening can be diffuse or nodular.

Intradural lumbar disc herniations: the role of MRI in preoperative diagnosis and review of the literature.

The goal of this article is to report our experience on intradural lumbar disc herniation, consider the causes of this pathology, and analyze it from clinical, diagnostic, and therapeutic perspectives with a particular emphasis on the role of MRI in preoperative diagnosis. We analyzed nine patients treated surgically for intradural lumbar disc hernia. All of them underwent surgery, and hemilaminectomy was performed.

Surgical treatment of pituitary tumors in the elderly: clinical outcome and long-term follow-up.

Pituitary adenomas in the elderly represent an increasing proportion of pituitary tumors, making the surgical management of these patients of special importance. We therefore decided to review our experience with transsphenoidal surgery (TSS) in this age group, in order to better evaluate its efficacy, safety and outcome. A retrospective study was performed on 39 patients aged more than 70 years at the time of surgery (mean age 74.

Treatment of relevant nerve roots involved in nerve sheath tumors: removal or preservation?

Objective: Surgery for the treatment of patients with spinal nerve sheath tumors can require complete resection of the nerve roots involved in the tumor. The purpose of the present study is to analyze the risks of resection of eloquent roots as compared with the risks of incomplete tumor removal.

Methods: The pertinent literature on spinal nerve sheath tumors was reviewed.

Cyst of the medullary conus: malformative persistence of terminal ventricle or compressive dilatation?

The ventriculus terminalis is a cavity situated at the level of the conus medullaris, enclosed by ependymal tissue and normally present as a virtual cavity or as a mere ependymal residue. In rare cases, and almost exclusively in pediatric age, the ventriculus terminalis may be visualized by radiological investigations, either by sonography or MRI, and represents a transient finding in children under 5 years of age. In pathological conditions, a cyst of the conus medullaris is probably the result of a persistent ventriculus terminalis and is usually described in children in association with a tethered cord; in a very limited number of cases, it has been described in adults whose clinical symptoms consist of neurological and/or sphincter disturbances not associated with other pathologies.