Epidemiology of Cervical Spine Injuries Requiring Surgical Treatment in Plovdiv and Plovdiv Region, Bulgaria.

Objective: Cervical spine injuries (CSI) are associated with high rates of permanent disability and mortality, which increase the socioeconomic burden on healthcare systems worldwide. We aimed to investigate the epidemiology of CSI, frequency of operative treatment, and incidence of associated neurological deficits at regional level. Methods: We performed a retrospective monocentric study of patients with sustained CSI from January 2017 to December 2021, carried out only in a first-level trauma center in the Plovdiv metro region. Demographic, clinical, and imaging data from the medical records were thoroughly analyzed. Based on the assumption that all patients with CSI were hospitalized in single trauma center, the percentage of cases indicated for surgical treatment was calculated based on the population of the entire Plovdiv metro area. Results: One hundred forty-nine patients permanently residing in the Plovdiv metro region were included in this study. Of the 149 patients, 97 (65.1%) were surgically treated and 61 (62.9%) were over 60 years of age. The frequency of operative interventions for CSI was 2.9/100,000 patients. Annually, 10.6 people from the Plovdiv metro region suffer from neurological deficits as a result of neck injuries (1.6/100,000 residents). The number of patients with complete spinal cord injury in the surgically treated group was 11 (11.3%); that is, the regional frequency was 2.2 people per year. Conclusion: In the Plovdiv metro region, a significant annual frequency of neurological deficits requiring surgical intervention for CSI has been established, especially in patients aged >60 years.

Sacral nerve root metastasis in a patient with lung carcinoma resembling neurinoma - a case report and literature review.

Intradural extramedullary metastases from systemic neoplasms are very rare, with an incidence ranging from 2% to 5% of all secondary spinal diseases. We present the case of a 53-year-old man diagnosed with lung adenocarcinoma with symptoms of severe back pain and tibial paresis. The magnetic resonance imaging (MRI) revealed an intradural lesion originating from the right S1 nerve root mimicking neurinoma. Total tumor removal was achieved via posterior midline approach. The histological examination was consistent with lung carcinoma metastasis. Due to the rarity of single nodular nerve root metastases, MRI images may be misinterpreted as nerve sheath tumors, such as schwannomas or neurofibromas. We performed a brief literature review outlining the mainstay of diagnosis, therapeutic approach, and the prognosis of these rare lesions.

Long-term Tractography Evaluation of Corpus Callosum Impairment After Severe Traumatic Brain Injury in Patients With Isolated Intraventricular Hemorrhage on Admission CT: Two Illustrative Cases and a Literature Review.

Severe traumatic brain injury (TBI) is often associated with diffuse axonal injury. Diffuse axonal injury affecting the corpus callosum may present with intraventricular hemorrhage on baseline computed tomography (CT) scan. Posttraumatic corpus callosum damage is a chronic condition that can be diagnosed over the long term using various magnetic resonance imaging (MRI) sequences. Here, we present two cases of severe survivors of TBI with isolated intraventricular hemorrhage detected on an initial CT scan. After acute trauma management, long-term follow-up was performed. Diffusion tensor imaging and subsequent tractography revealed a significant decrease in the fractional anisotropy values and the number of corpus callosum fibers compared with those in healthy control patients. This study presents a possible correlation between traumatic intraventricular hemorrhage on admission CT and long-term corpus callosum impairment detected on MRI in patients with severe head injury by presenting demonstrative cases and conducting a literature review.

Brain abscess caused by Paenibacillus lactis.

We present a case of a 30-year-old male patient who was admitted to our institution with a 4-month history of persistent headache, pain in the left half of the face and the left ear. The initial magnetic resonance imaging detected an inflammatory process in the left pyramid interpreted as petrous apicitis. Subsequently, he developed generalized seizures. Follow-up computed tomography scanning with contrast enhancement demonstrated newly-formed brain abscess in the basal region of the left temporal lobe. The patient underwent microsurgical evacuation and resection of the abscess. Microbiological examination isolated Paenibacillus lactis as a causative microorganism. During the postoperative period, the patient further developed life-threatening meningitis that was successfully managed with prolonged intravenous antimicrobial treatment. Six-months follow-up examination confirmed complete neurological recovery with no signs of recurrence based on Magnetic Resonance Imaging (MRI). To the best of our knowledge, this is the first reported case of brain abscess caused by Paenibacillus lactis in the medical literature.

Nanomechanics of Ultrathin Carbon Nanomembranes.

Ultrathin carbon nanomembranes (CNMs) are two-dimensional materials (2DM) of a few nm thickness with sub-nm intrinsic pores that mimic the biofiltration membranes found in nature. They enable highly selective, permeable, and energy-efficient water separation and can be produced at large scales on porous substrates with tuned properties. The present work reports the mechanical performance of such CNMs produced by p-nitrobiphenyl phosphonic acid (NBPS) or polyvinylbiphenyl (PVBP) and their composite membranes of microporous supporting substrates, which constitute indispensable information for ensuring their mechanical stability during operation. Measuring the nanomechanical properties of the ultrathin material was achieved by atomic force microscopy (AFM) on membranes both supported on flat substrates and suspended on patterned substrates ("composite membrane"). The AFM analysis showed that the CNMs presented Young's modulus in the range of 2.5-8 GPa. The composite membranes' responses were investigated by tensile testing in a micro-tensile stage as a function of substrate thickness and substrate pore density and diameter, which were found to affect the mechanical properties. Thermogravimetric analysis was used to investigate the thermal stability of composite membranes at high temperatures. The results revealed the structural integrity of CNMs, while critical parameters governing their mechanical response were identified and discussed.

Short-term outcome of treatment of elderly patients with epidural hematomas.

INTRODUCTION: There is substantial literature data dedicated to intracranial epidural hematomas affecting young and middle-aged individuals, but studies focusing on their characteristics in elderly patients are scarce, assuming that old age is a poor prognostic factor.

Monoradiculopathy Caused by Sporadic Hemangioblastoma of the Conus Medullaris: Case Report and Literature Review.

Sporadic spinal extramedullary hemangioblastomas of the conus medullaris are extremely rare. We present the case of a 40-year-old male with symptoms of severe back pain and monoradiculopathy. The magnetic resonance imaging (MRI) revealed an intradural extramedullary tumor attached to the conus medullaris. Total tumor removal was achieved via a typical posterior midline approach through laminectomy of L1 and L2 vertebrae, resulting in complete resolution of the preoperative symptoms. The histological examination was consistent with hemangioblastoma. To the best of our knowledge, this is the fifth case reported in the literature. We performed a brief literature review outlining the mainstay of diagnosis and therapeutic approach to these challenging lesions.

Contemporary insight into diffuse axonal injury.

Diffuse axonal injury (DAI) is present in approximately 50% of the cases with severe traumatic brain injury. It is one of the leading causes of morbidity and mortality among children and young individuals worldwide. Generally, DAI occurs as a result of high-velocity accidents. Typically, it presents with loss of consciousness for at least 6 hours and neurological deficit dependent on the brain area that is affected by the injury. The final diagnosis is confirmed by neuroimaging studies such as computed tomography and magnetic resonance imaging. According to the injured brain site, DAI is classified into three grades: Grade I-DAI with axonal lesions in the cerebral hemispheres; Grade II-DAI with focal axonal lesions in the corpus callosum; Grade III-DAI with focal or multiple axonal lesions in the brainstem. Each of the three grades is associated with different outcome.Due to the high disability and mortality rate, DAI represents an important medical, personal and social problem. The aim of the current review is to address the unsolved issues connected with the pathogenesis, diagnostics, treatment and outcome of the diffuse axonal injury.

Imaging of carbon nanomembranes with helium ion microscopy.

Carbon nanomembranes (CNMs) prepared from aromatic self-assembled monolayers constitute a recently developed class of 2D materials. They are made by a combination of self-assembly, radiation-induced cross-linking and the detachment of the cross-linked SAM from its substrate. CNMs can be deposited on arbitrary substrates, including holey and perforated ones, as well as on metallic (transmission electron microscopy) grids. Therewith, freestanding membranes with a thickness of 1 nm and macroscopic lateral dimensions can be prepared. Although free-standing CNMs cannot be imaged by light microscopy, charged particle techniques can visualize them. However, CNMs are electrically insulating, which makes them sensitive to charging. We demonstrate that the helium ion microscope (HIM) is a good candidate for imaging freestanding CNMs due to its efficient charge compensation tool. Scanning with a beam of helium ions while recording the emitted secondary electrons generates the HIM images. The advantages of HIM are high resolution, high surface sensitivity and large depth of field. The effects of sample charging, imaging of multilayer CNMs as well as imaging artefacts are discussed.

Tailoring the mechanics of ultrathin carbon nanomembranes by molecular design.

Freestanding carbon nanomembranes (CNMs) with a thickness between 0.6 and 1.7 nm were prepared from self-assembled monolayers (SAMs) of diverse polyaromatic precursors via low-energy electron-induced cross-linking. The mechanical properties of CNMs were investigated using AFM bulge test, where a pressure difference was applied to the membrane and the resulting deflection was measured by atomic force microscopy. We found a correlation between the rigidity of the precursor molecules and the macroscopic mechanical stiffness of CNMs. While CNMs from rigid and condensed precursors like naphthalene and pyrene thiols prove to exhibit higher Young's moduli of 15-19 GPa, CNMs from nonfused oligophenyls possess lower Young's moduli of ~10 GPa. For CNMs from less densely packed SAMs, the presence of defects and nanopores plays an important role in determining their mechanical properties. The finite element method (FEM) was applied to examine the deformation profiles and simulate the pressure-deflection relationships.

A universal scheme to convert aromatic molecular monolayers into functional carbon nanomembranes.

Free-standing nanomembranes with molecular or atomic thickness are currently explored for separation technologies, electronics, and sensing. Their engineering with well-defined structural and functional properties is a challenge for materials research. Here we present a broadly applicable scheme to create mechanically stable carbon nanomembranes (CNMs) with a thickness of ~0.5 to ~3 nm. Monolayers of polyaromatic molecules (oligophenyls, hexaphenylbenzene, and polycyclic aromatic hydrocarbons) were assembled and exposed to electrons that cross-link them into CNMs; subsequent pyrolysis converts the CNMs into graphene sheets. In this transformation the thickness, porosity, and surface functionality of the nanomembranes are determined by the monolayers, and structural and functional features are passed on from the molecules through their monolayers to the CNMs and finally on to the graphene. Our procedure is scalable to large areas and allows the engineering of ultrathin nanomembranes by controlling the composition and structure of precursor molecules and their monolayers.

Chemisorbed monolayers of corannulene penta-thioethers on gold.

Penta(tert-butylthio)corannulene and penta(4-dimethylaminophenylthio)corannulene form highly stable monolayers on gold surfaces, as indicated by X-ray photoelectron spectroscopy (XPS). Formation of these homogeneous monolayers involves multivalent coordination of the five sulfur atoms to gold with the peripheral alkyl or aryl substituents pointing away from the surface. No dissociation of C-S bonds upon binding could be observed at room temperature. Yet, the XPS experiments reveal strong chemical bonding between the thioether groups and gold. Temperature-dependent XPS study shows that the thermal stability of the monolayers is higher than the typical stability of self-assembled monolayers (SAMs) of thiolates on gold.