Bone density of the cervical, thoracic and lumbar spine measured using Hounsfield units of computed tomography - results of 4350 vertebras.

INTRODUCTION: The assessment of bone density has gained significance in recent years due to the aging population. Accurate assessment of bone density is crucial when deciding on the appropriate treatment plan for spinal stabilization surgery. The objective of this work was to determine the trabecular bone density values of the subaxial cervical, thoracic and lumbar spine using Hounsfield units. MATERIAL AND METHODS: Data from 200 patients who underwent contrast-enhanced polytrauma computed tomography at a maximum care hospital over a two-year period were retrospectively analyzed. HUs were measured with an elliptical measurement field in three different locations within the vertebral body: below the upper plate, in the middle of the vertebral body, and above the base plate. The measured Hounsfield units were converted into bone density values using a validated formula. RESULTS: The mean age of the patient collective was 47.05 years. Mean spinal bone density values decreased from cranial to caudal (C3: 231.79 mg/cm3; L5: 155.13 mg/cm3; p < 0.001), with the highest values in the upper cervical spine. Bone density values generally decreased with age in all spinal segments. There was a clear decrease in values after age 50 years (p < 0.001). CONCLUSIONS: In our study, bone density decreased from cranial to caudal with higher values in the cervical spine. These data from the individual spinal segments may be helpful to comprehensively evaluate the status of the spine and to design a better preoperative plan before instrumentation.

Critical Review on Magnetically Impelled Arc Butt Welding: Challenges, Perspectives and Industrial Applications.

Magnetically Impelled Arc Butt (MIAB) welding is a cutting-edge joining method that replaces the conventional welding procedures such as resistance, friction, flash and butt welding. It is a solid-state process that uses a rotating arc to heat up the butt ends of tubes, being followed by a forging process that completes the joining of the workpieces The magnetic flux density and the current interact to develop the Lorentz force that impels the arc along the faying surfaces. This process is found to produce high tensile strength and defect-free welds in ferrous materials and for this reason, it is predominantly employed in automobile applications for joining metallic tubes. Also, this joining procedure can be applied in the fabrication of boilers, heat exchangers, furnace piping in petrochemical industry and other safety-critical high-pressure machinery parts. The MIAB method has several advantages such as a shorter welding cycle, lower input energy requirement and lower loss of material. Compared to other solid-state welding processes, the MIAB welding has an important advantage in terms of cost-efficient welds with better control and reliability. Moreover, there are researchers who have investigated the joining of non-ferrous dissimilar materials using this welding procedure. The studies have been focused on process parametric analysis that involves optimizing and forecasting the magnetic field and thermal profile distribution. This review article provides competitive insights into various design features, computational methods, tests and material characterization, technical issues and workarounds, as well as automation aspects related to the MIAB-welding process. This work will prove to be a quick reference for researchers, useful to identify the research gaps and conflicting ideas that can be further explored for advancements in joining the similar and dissimilar materials.

Bone density of the axis (C2) measured using Hounsfield units of computed tomography.

INTRODUCTION: The assessment of bone density is of great importance nowadays due to the increasing age of patients. Especially in regard to the surgical stabilization of the spine, the assessment of bone density is important for therapeutic decision making. The aim of this work was to record trabecular bone density values using Hounsfield units of the second cervical vertebra. MATERIAL AND METHODS: The study is a monocentric retrospective data analysis of 198 patients who received contrast-enhanced polytrauma computed tomography in a period of two years at a maximum care hospital. Hounsfield units were measured in three different regions within the C2: dens, transition area between dens and vertebral body and vertebral body. The measured Hounsfield units were converted into bone density values using a validated formula. RESULTS: A total of 198 patients were included. The median bone density varied in different regions of all measured C2 vertebrae: in the dens axis, C2 transition area between dens and vertebral body, and in the vertebral body bone densities were 302.79 mg/cm3, 160.08 mg/cm3, and 240.31 mg/cm3, respectively. The transition area from dens axis to corpus had statistically significant lower bone density values compared to the other regions (p < 0.001). There was a decrease in bone density values after age 50 years in both men and women (p < 0.001). CONCLUSIONS: The transitional area from dens axis to corpus showed statistically significant lower bone density values compared to the adjacent regions (p < 0.001). This area seems to be a predilection site for fractures of the 2nd cervical vertebra, which is why special attention should be paid here in radiological diagnostics after a trauma.

Study on the Weldability of Copper-304L Stainless Steel Dissimilar Joint Performed by Robotic Gas Tungsten Arc Welding.

The welding process of dissimilar metals, with distinct chemical, physical, thermal, and structural properties, needs to be studied and treated with special attention. The main objectives of this research were to investigate the weldability of the dissimilar joint made between the 99.95% Cu pipe and the 304L stainless steel plate by robotic Gas Tungsten Arc Welding (GTAW), without filler metal and without preheating of materials, and to find the optimum welding regime. Based on repeated adjustments of the main process parameters-welding speed, oscillation frequency, pulse frequency, main welding current, pulse current, and decrease time of welding current at the process end-it was determined the optimum process and, further, it was possible to carry out joints free of cracks and porosity, with full penetration, proper compactness, and sealing properties, that ensure safety in operating conditions. The microstructure analysis revealed the fusion zone as a multi-element alloy with preponderant participation of Cu that has resulted from mixing the non-ferrous elements and iron. Globular Cu- or Fe-rich compounds were developed during welding, being detected by Scanning Electron Microscope (SEM). Moreover, the Energy Dispersive X-ray Analysis (EDAX) recorded the existence of a narrow double mixing zone formed at the interface between the fusion zone and the 304L stainless steel that contains about 66 wt.% Fe, 18 wt.% Cr, 8 wt.% Cu, and 4 wt.% Ni. Due to the formation of Fe-, Cr-, and Ni-rich compounds, a hardness increase up to 127 HV0.2 was noticed in the fusion zone, in comparison with the copper material, where the average measured microhardness was 82 HV0.2. The optimization of the robotic welding regime was carried out sequentially, by adjusting the parameters values, and, further, by analyzing the effects of welding on the geometry and on the appearance of the weld bead. Finally, employing the optimum welding regime-14 cm/min welding speed, 125 A main current, 100 A pulse current, 2.84 Hz oscillation frequency, and 5 Hz pulse frequency-appropriate dissimilar joints, without imperfections, were achieved.

Lung cancer mimickers - a case series of seven patients and review of the literature.

BACKGROUND: Lung is the third most frequent identified site of malignancy and lung cancer is the most lethal type of cancer in the world. Several benign lung diseases or proliferations may mimic lung carcinoma in its clinical, pathological, and radiological presentation, which makes the differential diagnosis life changing. This case series was designed to describe the main diagnosis encountered in a multidisciplinary emergency hospital during the last years in Romania. RESULTS: The most challenging cases encountered during the recent years were those of lung hamartoma associated with eosinophilic pneumonia because of the multicentricity of the disease and the suspicion for metastasis in the clinical setting, pulmonary aspergillosis that presented as a cystic lesion with a 9 mm mural nodule, actinomycosis discovered as firm nodule showing aspects of false pleural invasion, cryptococcosis - a hilar mass for which a pneumectomy was prepared, pulmonary parasitosis that presented as a nodule with irregular borders, causing pleural retraction, one case of inflammatory myofibroblastic tumor of the lung, one case of tumorlet type neuroendocrine lesion in a patient with history of melanoma and renal oncocytoma, admitted under the suspicion of lung metastasis. CONCLUSIONS: These are some of the main mimickers of primary or secondary lung cancers and one must be aware of these similitudes to avoid higher cost procedures, psychological stress for the patient and higher mortality.

Chondrosarcoma of the pelvis - case report.

Chondrosarcoma (CHS) is the third most common primary bone tumor after myeloma and osteosarcoma. Histologically, it is made of pure hyaline cartilage differentiation. The tumor itself may have myxoid modification and calcification. It occurs especially after 50 years, with an equal gender distribution. Most CHS are solitary, the etiology is still unclear and most of them are discovered accidentally. Early diagnosis is crucial for a good prognosis. In this paper, we would like to present a case of a female patient with an accidentally discovered CHS of the iliopubic and ischiopubic ramus of the pelvis. The purpose of this report is to highlight the importance of multidisciplinary management of tumor pathology, especially when the site of the tumor is surgically hardly accessible and to underline possible common genetic aspects of benign and malignant tumors.

A rare case of signet-ring cell carcinoma associated with poorly differentiated adenocarcinoma of the non-ampullary duodenum.

Primary duodenal cancer is a rare entity accounting for only 0.3% of all gastrointestinal cancers. Histopathologically, most duodenal cancers are mucin-producing adenocarcinomas, 34% being poorly differentiated. Signet-ring cell (SRC) carcinoma is extremely uncommon in the duodenum. Herein, we report a rare case of SRC carcinoma associated with poorly differentiated adenocarcinoma of the non-ampullary duodenum in a 74-year-old woman. The patient was admitted to the hospital for persistent epigastric pain, significant weight loss and hypochromic microcytic anemia. Esophago-gastro-duodenoscopy revealed a protruded lesion, with ulceration in the second portion of the duodenum, above the papilla. The patient was referred to surgery and pancreatico-duodenectomy with lymph node dissection was performed. The tumor consisted predominately of SRCs, Periodic Acid Schiff (PAS)-Alcian blue positive. The tumor cells were CDX2, cytokeratin (CK) 7 and CK 18/8 positive, which suggested a primary upper gastrointestinal tract site of origin. Immunostaining for mucin (MUC) 2 and MUC5AC was also positive demonstrating the duodenal goblet cells differentiation with a mixed gastric-foveolar and intestinal phenotype. Based on the morphological features and the immunohistochemical profile, a diagnosis of SRC carcinoma associated with poorly differentiated adenocarcinoma of the non-ampullary duodenum was set.

Bilateral serous surface papillary borderline ovarian tumor in 19-year-old patient. Ultrasound, immunohistochemical and therapeutic particularities of reproductive age.

Borderline tumors have a histological aspect of atypical epithelial proliferation without stromal invasion and typically occur in fertile ages, approximately one-third of women diagnosed are younger than 40. Serous borderline tumors are the most encountered and they can present micropapillary features that are associated with a higher rate of recurrence and the possibility of peritoneal implants. We present the case of a serous borderline ovarian tumor in a young patient and the diagnosis and treatment particularities. The patient presented with no symptoms, for a specialist advice, in the context of failure obtaining spontaneous pregnancy over a period of seven months. Paraclinical, the only modified parameter was CA 125, respectively a slight increase of its value. The atypical appearance on abdominal and transvaginal ultrasound indicated a presumptive diagnosis; both ovaries with multiple irregular vegetation, moderately vascular on Doppler examination, with the starting point in epithelial capsule shell, that appeared thick and hyperechogenic. About 7 cm of pelvic fluid was also present. During exploratory laparoscopic intervention, the surrounding tissue of both ovaries was biopsied and the fragments were sent for histopathological and immunohistochemical exam. Immunohistochemical assays correlated with the histopathological analysis and anatomical clinical data confirmed the diagnosis. After informed consent, the patient underwent radical surgery with a quick and uneventful recovery. The series of investigations had the objective to establish the best management of the case and reviewing the possibility of a conservative surgery. Patient clinical aspect matched with the patterns of ovarian borderline tumors by the asymptomatic presence of the bilateral adnexal masses.

Duodenal gastrointestinal stromal tumor presenting as pancreatic head mass - a case report.

Duodenal gastrointestinal stromal tumors (GISTs) are uncommon. Tumors arising from the first and the second part of the duodenum (DI and DII, respectively) can be wrongly diagnosed as pancreatic mass. We present a case of a 59-year-old woman who came with abdominal pain and severe upper gastrointestinal bleeding (hemoglobin 3.5 g÷dL). A solid, heterogeneously enhancing neoplasm in the head of the pancreas was revealed preoperatively by an abdominal computed tomography scan. A diagnosis of GIST was suggested. On exploratory laparotomy, there was a large mass which appeared to be originating from duodenum or from head of pancreas. Intraoperative histopathological diagnosis was GIST. Histopathology showed spindle cell tumor with cytoplasmic eosinophilia and foci of necrosis. The mitotic count was less than 5÷50 high power fields (HPFs). Tumor was involving duodenal muscularis propria, with no infiltration in the duodenal epithelial layer and the pancreas. Immunohistochemical study revealed positive staining for CD117. The tumor was finally diagnosed as GIST arising from the duodenal wall, growing exophytically and attached to the common bile duct and pancreas, without infiltrating the pancreas. Duodenal gastrointestinal stromal tumors can grow exophytically into a large mass and involve the pancreas without infiltrating microscopically and present as pancreatic head mass.

Mesoscopic Transport in Electrostatically Defined Spin-Full Channels in Quantum Hall Ferromagnets.

In this work, we use electrostatic control of quantum Hall ferromagnetic transitions in CdMnTe quantum wells to study electron transport through individual domain walls (DWs) induced at a specific location. These DWs are formed due to the hybridization of two counterpropagating edge states with opposite spin polarization. Conduction through DWs is found to be symmetric under magnetic field direction reversal, consistent with the helical nature of these DWs. We observe that long domain walls are in the insulating regime with a localization length of 4-6 µm. In shorter DWs, the resistance saturates to a nonzero value at low temperatures. Mesoscopic resistance fluctuations in a magnetic field are investigated. The theoretical model of transport through impurity states within the gap induced by spin-orbit interactions agrees well with the experimental data. Helical DWs have the required symmetry for the formation of synthetic p-wave superconductors. The achieved electrostatic control of a single helical domain wall is a milestone on the path to their reconfigurable network and ultimately to a demonstration of the braiding of non-Abelian excitations.

Fraser Syndrome - a Case Report and Review of Literature.

Fraser syndrome is a rare autosomal recessive genetic disorder characterized by major features such as cryptophthalmos, syndactyly, malformations of the larynx and genitourinary tract, craniofacial dysmorphism, orofacial clefting, mental retardation and musculoskeletal anomalies. In total, about 150 affected patients have been described in the literature. The diagnosis of this syndrome can be established after clinical examination. We present the clinical findings of a rare case of Fraser syndrome with lethal phenotype due to bilateral renal agenesis in a female stillborn.

A rare case of osteoma in the frontal sinus: anatomical and histological description.

PURPOSE: The purpose of this paper is to present a rare case of osteoma localized in the left frontal sinus. A 22-year-old woman who arrived at the Department of Neurosurgery of the University Emergency Hospital, Bucharest, Romania, presented a vertical asymmetry of the eyeballs but displayed no clinical signs like pain or diplopia. The computer tomography exam was used for preoperatory diagnostic. Histopathology was performed after surgery using Hematoxylin and Eosin staining. The Nikon Eclipse microscope was used to examine the slides. RESULTS: The histopathology exam shows a compact osteoma with dense and non-Haversian bone tissue and parallel bony trabeculae. A few spaces for the marrow were also found. The osteocytes were small and no fibrous cells were discovered. CONCLUSIONS: The computer tomography and histopathology exam were the investigations that lead us to a true diagnostic of dense osteoma. This tumor was the first case of frontal sinus osteoma histologically described in the Romanian population.

A rare case of uterine myxoid leiomyosarcoma: a case report.

We present the rare case of a 61-year-old female patient who was submitted in the hospital with metrorrhagia and pelvi-abdominal pain. Echographic examination revealed an heterogeneous uterine mass measuring 190/130/110 mm. Therefore, total hysterectomy with bilateral ooforectomy was performed. Grossly, the uterus presented a tumoral mass with areas of hemorrhage, necrosis and abundant mucoid degeneration. On light microscopic examination a malignant neoplastic proliferation with features of myxoid leiomyosarcoma was noted. In this paper, we presented this rare form of leiomyosarcoma with an emphasis on its particularities that have not been mentioned in the literature.