Secondary Protrusions Research Articles

Вторинні порушення форми грудної клітки після корекції лійкоподібної деформації за методом Nuss

Aim - studying the influence of the elasticity of the chest on the formation of secondary pectus carinatum and secondary protrusion of costal arches after Nuss procedure in order to determine the risk groups for the occurrence of data of secondary postoperative deformations in order to optimize a surgical intervention in these groups . Materials and methods. We analysed the data of 6 patients with pectus carinatum and 5 children with rib arches protrusion, which were formed as a result of Nuss funnel chest correction. The elasticity of the chest was studied by determining the ratio of its circumference during maximum inhalation and exhalation (mobility index - MI) as well as the ratio of the distance between the support plane in the supine position and the front surface of the chest in a neutral position and at the moment of compression (compliance index - CI). To calibrate the indicators, the data were calculated in a group of 30 healthy children. Depending on the obtained values, 3 degrees of chest elasticity are distinguished: high, medium and rigid chest. Results. 3 degrees of chest elasticity were determined in children without chest deformity: high (MI - 9.1±0.9%; CI - 28.1±1.8%), medium (MI - 6.8±0.2%; CI - 22.7±2.1%) and a low or rigid chest (MI - 4.9±0.2%; CI - 15.6±1.8%). The following data were recorded in patients with secondary deformities: 80% of patients with secondary pectus carinatum had a high degree of elasticity of the chest, 20% - average degree. In 83.33% of cases, patients with secondary rib arches protrusion had a high degree of elasticity of the chest, and 16.67% had an average degree. Secondary rib arches protrusion in 80% of cases is combined with the use of one horizontal bar. All cases of occurrence of secondary deformations are associated with a symmetric local type of funnel chest with or without deformations of costal arches or with an asymmetric local type. Conclusions. Using the Nuss operation technique with short plates in patients in the period of rapid growth with a high degree of elasticity of the chest with type IA and IIA1 of funnel chest can reduce the risk of secondary pectus carinatum; and in cases of high level risk of secondary protrusion of the rib arches the "flare buster" technique can help avoid this complication. The vast majority of secondary deformations are prone to spontaneous regression. The research was adhered to the principles of the Declaration of Helsinki. The research protocol was agreed by the Local Ethics Committee of the mentioned institution. The patients' informed consent was obtained for the study. No conflict of interests was declared by the authors.

Numerical investigation of thermal performance factor in dimpled-solar air heater (SAH)

ABSTRACT A novel solar air heater design with dimples in a rectangular channel with a 7:1 aspect ratio was examined mathematically by ANSYS FLUENT 14.0. Four different cases of dimples configuration namely A (a spherical dimple), B (hemispherical symmetric protrusion is made in the center), C (secondary protrusion is present at an angle of 26.5o) and D (secondary protrusion is made tangent to the upstream) were simulated over the Reynolds number range of 10,000 to 30,000. CFD simultaions were performed for the inlet mass flow rate corresponding to the Reynolds number value of 10,000 and constant wall temperature of 320K. After turbulnec model selection and grid independence study, the numerical results are validated with the experimental data within the error band of ±15%. Secondary protrusion inside the dimple, an improvement in heat transfer and reduced flow recirculation was observed. The maximum thermal performance factor for the B, C, and D cases was found at Reynolds numbers of 10,000, 15,000, and between 20,000 and 30,000, respectively. Over the spectrum of Reynolds numbers, case D exhibits the most promising design overall with an increase of 37.5% in thermal performance factor. These design scenarios demonstrate an encouraging improvement in thermal performance factor.

Protective effect of vitamin D against hyperoxia-induced bronchopulmonary dysplasia in newborn mice

To investigate the protective effect of vitamin D (VD) against hyperoxia-induced bronchopulmonary dysplasia (BPD) in newborn mice and explore the mechanism. Thirty-six newborn mice were randomly divided into air + VD group, air + saline group, hyperoxia + VD group, and hyperoxia + saline group. In all the groups, saline or VD was administered on a daily basis via intramuscular injection. After 3 weeks of treatment, the mice were weighed and cardiac blood was collected for measurement of serum VD level using ELISA, and histological examination of the lungs was performed. Radial alveolar counting (RAC) and alveolar secondary interval volume density were measured using image analysis software. The expression levels of vascular endothelial cell growth factor (VEGF) and VEGF receptor 2 (VEGFR2) in the lung tissues were detected using Western blotting. The weight gain rate of the mice and the weight of the lungs were significantly higher in air + saline group and air + VD group than in the hyperoxia + saline group. The RAC was significantly lower in hyperoxic+saline group than that in hyperoxia+VD group (P < 0.001), and was significantly higher in hyperoxic+VD (125 times) than in hyperoxia + VD (1250 times) group (P < 0.01). The alveolar secondary protrusion count was significantly higher in hyperoxic+VD (1250 times) group than in hyperoxic+saline group (P < 0.001), and was significantly higher in hyperoxia+VD (125 times) group than in hyperoxia + VD (1250 times) group (P < 0.01). Compared with that in air + saline group, VEGFR2 expression was significantly lowered in hyperoxia+saline group (P < 0.05) and in air+VD group (P < 0.05); VEGFR2 expression was significantly higher in hyperoxia+VD (1250 times) group than in hyperoxia+saline group (P < 0.001) and hyperoxia+VD (125 times) group (P < 0.001); VEGFR2 expression was significantly higher in hyperoxia+VD (125 times) group than in hyperoxia+ saline group (P < 0.05). In newborn mice with BPD, VD supplement can increase the weight of the lungs and promote lung maturation, and a higher concentration of VD can better protect the lungs and promote the growth of pulmonary blood vessels.

Numerical Analysis of Flow Structure and Heat Transfer Characteristics in Dimpled Channels With Secondary Protrusions

Dimple structure is an effective heat transfer augmentation approach on coolant channel due to its advantage on pressure penalty. The implication of secondary protrusion, which indicates protrusion with smaller dimension than dimple, will intensify the Nusselt number Nu inside dimple cavity without obvious extra pressure penalty. The objective of this study is to numerically analyze the combination effect of dimples and secondary protrusion. Different protrusion–dimple configurations including protrusion print-diameter Dp, protrusion–dimple gap P, and staggered angle α are investigated. From the results, it is concluded that the implication of secondary protrusion will considerably increase the heat transfer rates inside dimple cavity. Cases 4 and 6 possess the highest Nusselt number enhancement ratio Nu/Nu0 reaching up to 2.1–2.2. The additional pressure penalty brought by the protrusion is within 15% resulting in total friction ratio f/f0 among the range of 1.9–2.1. Dimpled channels with secondary protrusions possess higher thermal performance factor TP, defined as (Nu/Nu0)/(f/f0)1/3, among which cases 4 and 6 are the optimal structures. Besides this, the TP of protrusion–dimple channels are comparable to the other typical heat transfer devices, and higher TP can be speculated after a more optimal dimple shape or combination with ribs and fins.

Numerical modeling flow and heat transfer in dimpled cooling channels with secondary hemispherical protrusions

Flow characteristics and heat transfer performances of rectangular dimpled channels with secondary protrusions are numerically analyzed and compared in this research work. The special arrangement is a conventional dimpled cavity with a small-size secondary protrusion placed upstream of the dimple. The objective is to determine the most optimal configuration for augmenting heat transfer rates with minimized pressure drop penalties, and providing flow details of secondary protrusions with different arrangements or geometries. The main considered parameters are the height ratios and relative location of the secondary protrusions placed upstream of the dimple. All turbulent fluid flows and surface heat transfer results are obtained using computation fluid dynamics with a validated k–ε RNG (Re-Normalization Group) turbulence model in eight rectangular channels with different secondary protrusion arrangements. From this investigation, it is found that secondary protrusions cause downward flows and reduce the extent of the recirculating flows in the adjacent primary dimple and then greatly improve the averaged local heat transfer of the corresponding primary dimple surface. In addition, secondary protrusions can improve the reattachment and strengthen the shedded vortex structures from the dimple. The heat transfer is enhanced with increasing height of the secondary protrusions but the pressure drop is also increased significantly. The largest Nu/Nu0/(f/f0) factor is obtained by a depth ratio of 0.1 and the largest Nu/Nu0/(f/f0)1/3 factor is provided by a depth ratio of 0.2. The vortex structure formed downstream of the secondary protrusions remains to take effect and develop in the primary dimple if the secondary protrusions are located near the centerline area as in Case C1. The acting vortex structures can improve the spanwise flow and improve the turbulent mixing downstream of the dimple. With a secondary protrusion located away from the centerline, the heat transfer enhancement is weakened. The heat transfer augmentation and overall thermal performance advantages of a dimpled channel with secondary protrusions are evident compared with conventional dimpled channels.

Numerical Prediction of Flow Structure and Heat Transfer in Square Channels with Dimples Combined with Secondary Half-Size Dimples/Protrusions

The present study employs square cross-section dimpled channels with different arrangements of upstream secondary half-size dimples or protrusions to determine the optimal configurations for augmenting heat transfer rates with minimized pressure drop penalties. Five dimpled channels with and without upstream secondary dimples or protrusions are investigated (simple dimpled channel [case A]; dimpled channels with secondary dimples upstream each dimple [cases B1 and B2, respectively]; and dimpled channels with secondary protrusions upstream each dimple [cases C1 and C2, respectively]). All turbulent fluid flow and surface heat transfer results are obtained using computation fluid dynamics with a k-ϵ RNG turbulence model. Numerical results are qualified using grid-independent predictions of experimental data for one baseline dimple array arrangement. The channel inlet Reynolds number ranges from 8,000 to 24,000. From this study, secondary protrusions can bring forward flow separations and reduce the scope of recirculating flows in adjacent primary dimples and then greatly improve averaged local heat transfer of primary dimple surface. The result does not apply to secondary dimples which hinder flow reattachment in primary dimples and go against heat transfer enhancement. For averaged heat transfer on all the middle heated surfaces, heat transfer enhancement by secondary protrusions is not evident especially at high Reynolds numbers and the uniformity of roughness arrangements as dimples and protrusions makes a dominant role in the averaged heat transfer efficiency, while the dimple structure exhibits heat transfer advantage over protrusions at high Reynolds numbers. For the studied cases, case C1 obtains the best overall thermal performance at low Reynolds numbers, while case B2 is the best one at high Reynolds numbers. It is also recommend that case A can be effectively designed to exhibit the relatively good overall thermal performance with minimizing the blade weight and stress.

The Arp2/3 complex mediates multigeneration dendritic protrusions for efficient 3‐dimensional cancer cell migration

Arp2/3 is a protein complex that nucleates actin filament assembly in the lamellipodium in adherent cells crawling on planar 2-dimensional (2D) substrates. However, in physiopathological situations, cell migration typically occurs within a 3-dimensional (3D) environment, and little is known about the role of Arp2/3 and associated proteins in 3D cell migration. Using time resolved live-cell imaging and HT1080, a fibrosarcoma cell line commonly used to study cell migration, we find that the Arp2/3 complex and associated proteins N-WASP, WAVE1, cortactin, and Cdc42 regulate 3D cell migration. We report that this regulation is caused by formation of multigeneration dendritic protrusions, which mediate traction forces on the surrounding matrix and effective cell migration. The primary protrusions emanating directly from the cell body and prolonging the nucleus forms independent of Arp2/3 and dependent on focal adhesion proteins FAK, talin, and p130Cas. The Arp2/3 complex, N-WASP, WAVE1, cortactin, and Cdc42 regulate the secondary protrusions branching off from the primary protrusions. In 3D matrices, fibrosarcoma cells as well as migrating breast, pancreatic, and prostate cancer cells do not display lamellipodial structures. This study characterizes the unique topology of protrusions made by cells in a 3D matrix and show that these dendritic protrusions play a critical role in 3D cell motility and matrix deformation. The relative contribution of these proteins to 3D migration is significantly different from their role in 2D migration.

Comparative morphological studies on the stereo structure of the lingual papillae of selected primates using scanning electron microscopy

A scanning electron microscope was used to observe the lingual papillae and their connective tissue cores (CTCs) in five primates (tupai, tamarin, crab-eating monkey, mandrill, and human). There were some slender protrusions rising from the top of the filiform papilla in all five types of primate. After removing the epithelium the filiform CTC from the tupai, tamarin and crab-eating monkey displayed a U-shaped arrangement of rod-shaped protrusions. The filiform CTC from the crab-eating monkey also had a columnar base. The human filiform CTC consisted of a primary columnar base, numerous short rod-shaped secondary protrusions from its upper periphery, and a few central protrusions. The filiform CTC from the Mandrill was fundamentally similar to that of the human, however, its base was shorter. The fungiform CTC from the tupai was column shaped, with several depressions for taste buds on the top. There were three vallate papillae in the tupai, tamarin, and mandrill, approximately four in the monkey, and between five and twelve in the human. Moderately developed foliate papillae were found in the tamarin, monkey, mandrill and human. The tupai, however, possessed a finger-like lateral organ instead. The lingual root area of the tupai, tamarin, crab-eating monkey and mandrill was relatively small with a smooth surface. Only the human had a tonsil-structure, which was located on the surface of its larger lingual root.

Size and shape of human cranial sutures–A new scoring method

A method for the differentiation of sutural patterns of the human cranial vault is introduced. Three criteria of differentiation are considered, one for size and two for shape: 1) maximal shape extension; 2) basic configuration; 3) secondary protrusion. The method is illustrated here for the coronal and lambdoid sutures of 70 recent Italian skulls (35 adult males and 35 adult females). Differences between coronal and lambdoid sutural size and shape can be detected analytically; for example, the coronal suture commonly shows lesser degrees of shape extension, a simpler basic configuration, and an absence of secondary protrusion. Heterogeneity within each suture, as well as a relationship among corresponding sections and between the three criteria adopted, have been also observed; symmetry predominates for both the sutures, and sexual differences are slight.

Ultrastructure of the epidermal-dermal junction and cutaneous basal lamina in Bowen's disease.

Ten tissue sections from 10 examples of Bowen's disease were excised from paraffin blocks, rehydrated, and incubated in 90% formic acid at 45 degrees C for 18 h. The epidermis was gently removed with the aid of a dissecting microscope, and the remaining dermis with attached basal lamina was processed for scanning electron microscopy. This surface showed a well-preserved basal lamina. The dermal papillae in the areas of Bowen's disease were elongated and had frequent secondary protrusions. The normal 0.5 mu interconnecting corrugations were often replaced by either broad, coarse corrugations or by large areas of smooth-to-undulating basal lamina. This study demonstrates marked alterations in spatial interactions between neoplastic epidermis and underlying dermis in Bowen's disease.

Microanalysis of TiNb carbonitrides in HSLA steels

The microchemistry and morphology of Ti- and Nb-rich carbonitrides formed during continuous casting in some HSLA steels, differing only in their Nb content, have been investigated in order to characterize the effect of Nb on the nucleation and growth process of these particles. Precipitates were extracted using the carbon extraction replica technique and analyzed in a VG-HB 5 STEM by EDS. They exhibit large composition gradients and their morphology is roughly correlated to their size. A model based on the formalism of ternary solubility products in liquid iron and in austenite is developed to explain satisfactorily these composition gradients, and gives the composition of newly formed nuclei in austenite and that of the last deposited layer of precipitates. Nuclei appear as spherical particles, grow by interface instability to polyhedral particles, then to dendrites, with secondary protrusions developed from the primary arms also as a result of an interface instability process.

Otto's Disease and other forms of Protrusio Acetabuli: Primary juvenile osteo-asthenic protrusion and secondary protrusions

Otto's Disease and other forms of Protrusio Acetabuli: Primary juvenile osteo-asthenic protrusion and secondary protrusions