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1.
Molecules ; 29(11)2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38893384

RESUMO

Analysis of the heavy fractions in crude oil has been important in petroleum industries. It is well known that heavy fractions such as vacuum gas oils (VGOs) include heteroatoms, of which sulfur and nitrogen are often characterized in many cases. We conducted research regarding the molecular species analysis of VGOs. Further refine processes using VGOs are becoming important when considering carbon recycling. In this work, we attempted to classify compounds within VGOs provided by Kuwait Institute for Scientific Research. Two VGOs were priorly distillated from Kuwait Export crude and Lower Fars crude. Quantitative analysis was performed mainly using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOFMS). MALDI-TOF-MS has been developed for analyzing high-molecular-weight compounds such as polymer and biopolymers. As matrix selection is one of the most important aspects in MALDI-TOFMS, the careful selection of a matrix was firstly evaluated, followed by analysis using a Kendrick plot with nominal mass series (z*). The objective was to evaluate if this work could provide an effective classification of VGOs compounds. The Kendrick plot is a well-known method for processing mass data. The difference in the Kendrick mass defect (KMD) between CnH2n-14S and CnH2n-20O is only 0.0005 mass units, which makes it difficult in general to distinguish these compounds. However, since the z* value showed effective differences during the classification of these compounds, qualitative analysis could be possible. The analysis using nominal mass series showed the potential to be used as an effective method in analyzing heavy fractions.

2.
Res Sq ; 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36778230

RESUMO

Cell-generated mechanical forces drive many cellular and tissue-level movements and rearrangements required for the tissue or organ to develop its shape1, 2, 3, 4, 5. The prevalent view of tissue morphogenesis relies on epithelial folding resulting in compressed epithelial monolayers, overlooking the involvement of stroma in morphogenesis1, 4, 6, 7. Here, we report a giant web-like network formation of stromal cells in the epithelium-stroma interface, resulting from a multi-scale mechano-reciprocity between migrating cells and their extracellular environment. In multi-layered tissues, surface wrinkles form by a stromal cell-mediated tensional force exerted at the basement membrane. The topographical cue is transmitted to the stromal cell, directing its protrusion and migration along the wrinkles. This inductive movement of the cells conveys traction forces to its surrounding extracellular matrix, remodeling the local architectures of the stroma. In this manner, stromal cells and wrinkles communicate recursively to generate the cellular network. Our observation provides a rational mechanism for network formation in living tissues and a new understanding of the role of cellular-level tensional force in morphogenesis.

3.
Korean J Neurotrauma ; 19(4): 496-501, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38222830

RESUMO

Few cases of injuries caused by wild boars have been reported in the literature. Here, we present the case of a 64-year-old male patient who was attacked by a wild boar. The patient had a laceration to the right forehead and a penetrating wound in the area before the right auricle. Computed tomography scan revealed traumatic subarachnoid hemorrhage, subdural hemorrhage, right temporal lobe contusion hemorrhage, pneumocephalus, right zygomatic arch and temporal bone fracture, and right coronal process fracture of the mandible. Prophylactically, 2,000 mg of ceftriaxone and 400 mg of moxifloxacin were intravenously administered every 24 hours. An emergency craniectomy was performed because the skull fracture was an open fracture and control of the increased intracranial pressure was necessary. Inactivated Rabies Virus Vaccine was also administered postoperatively. We concluded that, unlike typical wounds from other traumatic causes, the risk of wound infection is higher. In order to reduce morbidity and mortality due to wild boar attacks, rapid stabilization of the patient's vital signs, prevention of infection with appropriate antibiotics, and surgical intervention at the appropriate time and method are necessary.

4.
J Nanosci Nanotechnol ; 21(3): 1961-1965, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33404476

RESUMO

The paper introduces the mechanical and microstructural evolution of Mg-B powders/Nb/Cu claddings fabricated using only drawing process and hydrostatic extrusion plus drawing process. We found that the Mg-B powder of the claddings during the latter process was more densified than that of the former process because of larger reduction rate in the process of hydrostatic extrusion. The claddings created by the latter process exhibited a little higher Vickers hardness values and lower grain size than those of the former process in Nb tubes. The refined microstructure of Nb tube by the latter process had higher image quality (IQ) value corresponding to lower dislocation density due to higher misorientation angles between grains than that of the former process, thereby demonstrating the broadly distributed (110) fiber texture.

5.
ACS Appl Bio Mater ; 3(7): 4294-4301, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35025429

RESUMO

Spontaneous activation of macrophages in response to inflammation is a key part of innate immunity and host defense. Macrophages represent a heterogeneous population of cells with different phenotypic profiles performing distinct functions in host defense. Although a spectrum of macrophage activation stages exists in an inflamed region, the effect of local physical conditions on the heterotypic activation of macrophages is unknown. Here, we introduce an in vivo fluid-matrix interface analogous culture platform, an asymmetric microenvironment, facilitating the formation of macrophage aggregates (MAs). Macrophages were self-assembled to form MAs of ∼100 µm diameter at the collagen matrix-medium interface upon phorbol-12-myristate-13-acetate treatment. The macrophages within the half-embedded MAs into the matrix were heterogeneously activated, resulting in inhomogeneous cell-cell and cell-matrix interactions within the aggregates. Our demonstration may aid in a better understanding of the acquisition of macrophage heterogeneity in response to tissue-specific microenvironments.

6.
J Nanosci Nanotechnol ; 20(1): 599-602, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383218

RESUMO

Al6061/Cu and Al6063/Cu cladding materials have been produced by the caliber-rolling process at 298 K. The prepared specimen was post-annealed at a temperature of 773 K for various time durations, and the effects of annealing conditions have been investigated. Vickers hardness of Al6061, Al6063 and Cu decreases as annealing time decreases; however, that of the interface between Al alloys and Cu increases with an annealing time of 1 h, and then decreases as annealing time increases further. The growth of a diffusion layer in Al6063/Cu is larger than that in Al6061/Cu, because the activation energy in the Al6063/Cu is lower than that in Al6061/Cu during the annealing process. Cracking of the diffusion layer occurs by annealing for extended periods of time in both materials, which contributes to the decrease in hardness.

7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 5241-5244, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441520

RESUMO

This paper proposes a method to generate grids to render realistic X-ray images of the narrow blood vessels in real-time angiography simulation. The vertexes of the narrow blood vessels are projected onto the image-rendering plane. The grids aligned in the vessel direction are generated using the projected boundary vertexes on the image-rendering plane. The average computation time of the entire simulation is reduced by 80.17% compared to the simulation using the uniform grids. The results of the questionnaire survey show that the rendered X-ray images are realistic and useful to be applied to the angiography simulation.


Assuntos
Angiografia , Sistemas Computacionais , Simulação por Computador , Raios X
8.
J Korean Neurosurg Soc ; 60(1): 1-7, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28061484

RESUMO

OBJECTIVE: The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. METHODS: We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. RESULTS: The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. CONCLUSION: Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

9.
J Nanosci Nanotechnol ; 15(11): 8589-92, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26726557

RESUMO

Al/Cu clad composed of Al core and Cu sheath has been produced by hydrostatic extrusion at 523 K, at an extrusion rate of 27. The prepared specimen was post-annealed at temperatures of 673 K and 773 K for various time durations, and the effect of annealing conditions have been analyzed. The hardness at the interface between Al and Cu matrix of the Al/Cu bimetal clad increases because of annealing. Results indicate that the hardness is more sensitive to annealing temperature than the annealing time. Three kinds of intermetallic compounds (IMC), namely, CuAl, Cu3Al2, and CuAl2, are formed at the Al-Cu interface, upon annealing at 673 K. On the other hand, four kinds of IMCs, namely, Cu4Al3, CuAl, Cu3Al2, CuAl2, are formed at the annealing temperature of 773 K. The growth of each IMC follows the parabolic law as a function of annealing times at certain annealing temperature. The growth rate of each IMC is limited to its interdiffusion rate constant. The IMC Cu4Al3 appears upon annealing at 773 K, and not during annealing at 673 K, because of the higher value of activation energy associated with its formation, when compared to other IMCs.


Assuntos
Alumínio/química , Cobre/química , Nanopartículas Metálicas/química , Ligas/química , Cristalização/métodos , Dureza , Calefação/métodos , Pressão Hidrostática , Teste de Materiais , Propriedades de Superfície
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