Lateral Surface Research Articles

Does Ovariectomy Affect the Mechanics of the Mandibular Alveolar Bone Structure of Wistar Rats Subjected to Tooth Loss and Modified Diet?—A FEA Study

The aim of this study was to evaluate the mechanical effect of ovariectomy, diet, and tooth extraction on the bone structure of the mandible of Wistar rats. Mandibles from 40 female Wistar rats were used, divided into rats with ovariectomy surgery or surgical simulation. Half of the rats had the right upper incisor extracted and a soft diet was introduced for half of the animals for 30 days. After euthanasia, microtomography of the mandibles was performed for bone segmentation to construct three-dimensional models. Each mandible was subjected to a three-point bending test. The simulation by finite element method was configured according to the protocol for positioning the part on the support and force action by the load cell defined in the mechanical tests. Stress dissipation was described qualitatively on a color scale distributed in ranges of stress values. All models showed a higher concentration of stresses in the regions of force action and in the support regions, with differences in stress values and locations. Diet and dental condition interfered in the distribution of stresses, with the lateral surface of the mandible being more influenced by diet and the medial surface of the mandible by diet and dental condition.

Management of Plaque Psoriasis with Multimodal Treatment of Ayurveda - A Case Report

Psoriasis is the immune system problem that causes skin to revitalize at faster rate. It’s the chronic disease that has psychological and social impact on patient’s life. This condition had been narrated many decennium ago but proper aetiology and its cure remain under researched. In Ayurveda this multifaceted etiology disease needs multimodal treatment. The modern treatment provides only temporary relief with too many serious side effects. The treatment embraced here was in accordance with ayurvedic Samprapti. This case report details the successful management of plaque psoriasis in a 32-year-old female patient using a multimodal treatment approach, which incorporated Panchakarma, a traditional Ayurvedic detoxification therapy. The patient presented with erythematous plaques on forehead, neck region, lateral surface of legs and at arms along with itchy and burning skin. Auspitz sign and Koebner phenomenon was positive. Diagnosis made on the basis of Sign and Symptoms. After a thorough evaluation of the patient's constitution and the nature of the disease, a customized Panchakarma protocol was devised involving Virechana (Purgation) followed by Basti (medicated enema) along with Shamana Chikitsa (Internal Medication). The results revealed a remarkable improvement in the patient's psoriasis lesions, with a significant reduction in PASI scores, reduction in scaling, erythema, and in duration. The patient reported a substantial reduction in itching and discomfort. This case report emphasizes the potential of Panchakarma as an adjunctive therapy for plaque psoriasis, highlighting the holistic and personalized approach of Ayurveda in managing chronic skin conditions. Further research and larger-scale studies are warranted to confirm the effectiveness of Panchakarma in the treatment of psoriasis and to observe its long-term benefits and safety profile.

Gunshot Defense Wounds: Three Case Reports and a Literature Review

Defense wounds generally occur when a victim attempts to protect vital organs and blood vessels during an assault, and are therefore typically located on the forearms or hands. Gunshot-induced defense wounds are less frequent compared to stab wounds, which have been extensively described in the literature. We present three cases where victims unsuccessfully attempted to defend themselves from gunshots, and where the detailed description of injuries played a key role in the reconstruction of the crime scenes. In the first case, a man was shot with a smooth-bore shotgun, presenting a “through-and-through” gunshot wound on the lateral surface of the left forearm and a large gaping wound on the posterior surface of the same forearm. The second and third cases involved two men who were shot with handguns. The first displayed an entrance wound on the dorsal surface of the right hand, with burned edges and smoke soiling, and an exit wound on the palmar surface. The second case involved two wounds on the left hand: one on the dorsum and the other on the palm. To the best of our knowledge, few studies in the literature emphasize the role of gunshot defense wounds in aiding the reconstruction of crime dynamics. The cases presented in this study highlight the importance of precisely defining the pathological and morphological features of the wounds, as well as the bullet trajectories, to accurately identify defense wounds. These findings are valuable for reconstructing the dynamics of the assault and providing critical information to the public prosecutor.

Damage features and mechanism of prestressed hollow square piles subjected to non-contact underwater explosion

Critical hydraulic structures are increasingly vulnerable to underwater explosion attacks, with the supporting piles being prime targets for terrorist activities. This study investigates the damage effects and mechanisms of prestressed concrete hollow square (PCHS) piles under non-contact underwater explosions. A series of underwater explosion experiments was conducted on four PCHS piles. The dynamic response of PCHS piles throughout the underwater explosion process was simulated using a coupled fluid-solid numerical model. The mechanisms of dynamic damage to the PCHS piles were elucidated through an integrated analysis of both experimental and numerical results. The research indicates that the damage characteristics of PCHS piles include longitudinal and oblique cracks on the lateral surfaces, transverse cracks on the rear side, and localized fragmentation of concrete. Three primary damage modes have been identified: bending failure(L¯c= 0.59 m/kg1/3), combined bending-shear failure(L¯c= 0.36 m/kg1/3), and punching failure(L¯c= 0.24 m/kg1/3). The local and global responses induced by shock waves are the primary causes of structural damage. Furthermore, as the stand-off distance decreases, the impact of explosive bubbles increases the magnitude of the overall response. A comparative analysis also examined the impact of prestress and axial load on the damage behavior of hollow square piles.

A Customized Distribution of the Coefficient of Friction of the Porous Coating in the Short Femoral Stem Reduces Stress Shielding

Stress shielding and aseptic loosening have been identified as adverse effects of short-stem total hip arthroplasty resulting in hardware failure. However, there is a gap in research regarding the impact of stress shielding in customized porous coatings. The purpose of this study was to optimize the distribution of the coefficients of friction in the porous coating of a metaphyseal femoral stem to minimize stress shielding. Static structural analysis of an implanted short, tapered-wedge stem with a titanium porous coating was performed with the use of Analysis System Mechanical Software under axial loading. To limit computational time, we randomly sampled only 500 of the possible combinations of coefficients of friction. Results indicate that the coefficient of friction in the distal lateral porous coating significantly affected the mid-distal medial femoral surface and lateral femoral surface. The resultant increased proximal strains resulted from an increased coefficient of friction in lateral porous coating and a reduction in the coefficient of friction in medial mid-distal coating. These findings suggest that a customized porous coating distribution may produce strain patterns that are biomechanically closer to intact bone, thereby reducing stress shielding in short femoral stems.

Does the Scenario of Connection Between the Positive Leader Tip and the Lateral Surface of the Negative Leader Exist?

AbstractBased on the high‐speed video observations obtained at the Tall‐Object Lightning Observatory in Guangzhou (TOLOG), the attachment processes of three lightning flashes seem to belong to the connections between “the lateral surface of negative leader and positive leader tip” which had never been reported before were investigated. The leader connection processes of these flashes were examined in detail, and a mechanism behind connecting behavior between the lateral surface of negative leader and positive leader tip was discussed. Observation shows that negative leaders usually have abundant branches. Although some may extinguish, they still maintain a certain conductivity. When the positive leader tip comes close to the lateral surface of the negative leader (usually a few tens of meters), the previously disappeared short branch can be reactivated. It is easier for the positive leader tip to connect the tips of these branches (whether they have been extinguished or not).

Analysis of the three‐dimensional elasticity theory problem for a radially inhomogeneous cylinder

AbstractIn this paper an axisymmetric problem of elasticity theory for a radially inhomogeneous cylinder of small thickness is studied. It is assumed that homogeneous mixed boundary conditions are specified on lateral surfaces of the cylinder, and boundary conditions that leave the cylinder in equilibrium are specified on the ends of the cylinder. It is considered that elastic moduli are arbitrary continuous functions of a variable along the radius of the cylinder. The formulated boundary value problem is reduced to a spectral problem containing a small parameter characterizing the thinness of the cylinder walls. To determine its solution, the method of asymptotic integration is used, based on three iteration processes. All solutions of the equilibrium equation are constructed, satisfying the specified homogeneous boundary conditions on lateral surfaces. It is obtained that the solution of the problem consists of a penetrating solution and a solution of the nature of the boundary layer. An analysis of stress‐strain states corresponding to different types of solutions is carried out. Based on the constructed asymptotic solutions, a connection is found between the solutions obtained by the equation of elasticity theory and by the applied theory of shells. It is shown that the penetrating solution determines the internal stress‐strain state of a radially inhomogeneous cylinder. The stress state determined by the penetrating solution is equivalent to the principal vector of stress acting in a cross section perpendicular to the axis of the cylinder.The first terms of asymptotic expansions of the penetrating solution in a small parameter coincide with solutions in the applied theory of shells. New classes of solutions are defined as the character of a boundary layer, which are localized at the ends of the cylinder and decrease exponentially with distance from the ends. These solutions are absent in the applied theories of shells. The first terms of the asymptotic expansion of the solution, having the nature of a boundary layer, are equivalent to the Saint‐Venant edge effect in the theory of heterogeneous plates. Asymptotic formulas for displacement and stresses are constructed, allowing one to calculate the three‐dimensional stress‐strain state of a radially heterogeneous cylinder of small thickness with any predetermined accuracy. Based on the obtained asymptotic expansions, one can estimate the applicability areas of applied theories and construct a refined applied theory for radially heterogeneous cylindrical shells.

Ultrabroadband Photodetection with MoS2 and Gold Nanorod Using Gap-Mode Plasmon Effect.

Plasmon resonance using metal nanostructures enables the realization of high-performance optoelectronic devices via field enhancements in the vicinity of the metal nanostructure. This study proposes an ultrabroadband MoS2 photodetector based on the gap-mode plasmon of gold nanorods. The use of MoS2 as a gap spacer for the gap-mode plasmon effect and as a channel material for the photodetector is demonstrated. The proposed photodetector demonstrates superior performance, a high photoresponsivity of 2.8 A/W at a near-infrared wavelength of 1100 nm, and a fast response time of 17 μs. In addition to the gap-mode plasmon effect of the gold nanorod enhancing the photoresponsivity from 1.13 to 8.7 A/W, the lateral surface plasmon resonance of the gold nanorods enhances the absorption of the longitudinal mode of the gold nanorods (near-infrared to infrared range). Further, the gap-mode plasmon effect of the gold nanorods enhances the absorption of the transverse mode of the gold nanorods (visible range), thus realizing ultrabroadband photodetection. Therefore, the proposed device design strategy contributes significantly to overcoming the trade-off between photoresponsivity and response time.

Determination of Load Forces on the Upper Part of Orthopedic and Postoperative Shoes

Determined patterns of force load on the sole and upper of orthopedic and postoperative shoes when bending the foot while walking. To determine the force of the load on the top of the postoperative orthopedic shoes, the frictional forces between the lateral surfaces of the shoes and the outer lateral sides of the foot can be neglected. Thus, the task will be reduced to the compilation of equilibrium equations of a plane system of forces. As can be seen from the load diagram of the top of the shoe, we have a flat arbitrarily located system of forces. To determine the unknown forces, it is necessary to compile a system of two equilibrium equations, which will represent the algebraic sums of the projections of all forces on the horizontal and vertical axes. To automate the design process of orthopedic and postoperative shoes, a computer program was developed that allows you to perform calculations of the corresponding forces and tension depending on the design and types of material of individual elements, as well as obtain regression equations for determining the effect of tension on the magnitude of the detachment force.

Metabolic pathways regulated by strigolactones foliar spraying enhance osmoregulation and antioxidant defense in drought-prone soybean

BackgroundDrought stress is a significant abiotic stressor that hinders growth, development, and crop yield in soybeans. Strigolactones (SLs) positively regulate plant resistance to drought stress. However, the impact of foliar application of SLs having different concentrations on soybean growth and metabolic pathways related to osmoregulation remains unknown. Therefore, to clarify the impact of SLs on soybean root growth and cellular osmoregulation under drought stress, we initially identified optimal concentrations and assessed key leaf and root indices. Furthermore, we conducted transcriptomic and metabolic analyses to identify differential metabolites and up-regulated genes.ResultsThe results demonstrated that drought stress had a significant impact on soybean biomass, root length, root surface area, water content and photosynthetic parameters. However, when SLs were applied through foliar application at appropriate concentrations, the accumulation of ABA and soluble protein increased, which enhanced drought tolerance of soybean seedlings by regulating osmotic balance, protecting membrane integrity, photosynthesis and activating ROS scavenging system. This also led to an increase in soybean root length, lateral root number and root surface area. Furthermore, the effects of different concentrations of SLs on soybean leaves and roots were found to be time-sensitive. However, the application of 0.5 µM SLs had the greatest beneficial impact on soybean growth and root morphogenesis under drought stress. A total of 368 differential metabolites were screened in drought and drought plus SLs treatments. The up-regulated genes were mainly involved in nitrogen compound utilization, and the down-regulated metabolic pathways were mainly involved in maintaining cellular osmoregulation and antioxidant defenses.ConclusionsSLs enhance osmoregulation in soybean plants under drought stress by regulating key metabolic pathways including Arachidonic acid metabolism, Glycerophospholipid metabolism, Linoleic acid metabolism, and Flavone and flavonol biosynthesis. This study contributes to the theoretical understanding of improving soybean adaptability and survival in response to drought stress.

Basolateral Mechanics Prevents Rigidity Transition in Epithelial Monolayers.

The mechanics of epithelial tissues, which is governed by forces generated in various cell regions, is often investigated using two-dimensional models that account for the apically positioned actomyosin structures but neglect basolateral mechanics. We employ a more detailed three-dimensional model to study how lateral surface tensions affect the structure and rigidity of such tissues. We find that cells are apicobasally asymmetric, with one side appearing more ordered than the other depending on target cell apical perimeter. In contrast to the 2D model, which predicts a rigidity transition at large target perimeters, tissues in the 3D model remain solidlike across all parameter space.

A human monoclonal antibody targeting the monomeric N6 neuraminidase confers protection against avian H5N6 influenza virus infection

The influenza neuraminidase (NA) is a potential target for the development of a next-generation influenza vaccine, but its antigenicity is not well understood. Here, we isolate an anti-N6 human monoclonal antibody, named 18_14D, from an H5N6 avian influenza virus (AIV) infected patient. The antibody weakly inhibits enzymatic activity but confers protection in female mice, mainly via ADCC function. The cryo-EM structure shows that 18_14D binds to a unique epitope on the lateral surface of the N6 tetramer, preventing the formation of tightly closed NA tetramers. These findings contribute to the molecular understanding of protective immune responses to NA of AIVs in humans and open an avenue for the rational design of NA-based vaccines.

Improving the Supraalar Groove Aesthetic Subunit and Lateral Crura Convex-Concave Deformity.

Lateral crura surface problems are one of the most difficult challenges in nose tip surgery. Closed Preservation Rhinoplasty (CPR) is a revolutionary concept keeping nose tip flexibility and elasticity. Solving lateral crura surface problems and keeping tip flexibility the surgeon will accomplish a sharper supraalar groove transition between the dorsum and the tip. The convex-concave lateral crura deformity (CCLCD) or S shape lateral crura is one of the biggest constraints to accomplish a beautiful tip and dorsum-tip transition (DTT). This deformity is the reason of commonly said parenthesis deformity of cephalic malposition. This LLC convexityconcavity shape creates a C shape shadow. This DTT is one of the key areas to accomplish natural results and it depends on different nose structures, not just the lower lateral cartilages (LLC). A total 560 rhinoplasty cases were studied retrospectively between September and December 2023. Three hundred and twenty patients had at least 1 year of follow-up. Patients had follow-up at 2 weeks, 1 month, 3 months, 6 months and 1 year after surgery. No secondary rhinoplasty was included. Just 2 secondary septoplasty cases were included without any nose skin undermining in the previous surgery. Surgical details were documented, including the 6 fundamental steps of this technique (1) mucosal lower lateral incision, (2) dorsum subperichondral dissection and vertical scroll release, (3) lateral crura tail caudal release, lateral crura steal and slide under flap lateralization, (4) upper laterals caudal resection, (5) vertical scroll reconstruction, and (6) turning point extension graft. Three hundred and twenty patients had at least 1 year of follow-up. 516 underwent a closed approach and 47 patients an open approach. All patients had subperichondral dissection of the hump envelope. All patients who underwent a closed approach had a low strip let down dorsal preservation technique. All patients who underwent an open approach had structural technique with spreader flaps or grafts at the keystone area. All the patients underwent their osteotomies with a piezoelectric device. Twenty-three revision surgeries were necessary. CPR taught us how important ligament and soft tissue preservation are. It taught the less damage you do to the nose soft tissues and scaffold the less support you need on it. Surgeons have been over grafting the lateral crura to solve postoperative problems mainly due to dissection problems and lack of lateral crura support. This paper shows how to solve lateral crura surface problems keeping the tip flexible and elastic creating also a nice and natural supraalar groove transition by applying 6 surgical manoeuvres.

New linear stapled semimechanical esophagogastric anastomosis with invagination

Objective. Development and implementation esophagogastric linear stapled semimechanical anastomosis with invagination. Material and methods. Seromuscular stitches are applied over 4 cm on both sides to the lateral surfaces of the esophagus posterior wall and gastric graft posterior wall, towards their edges. The posterior wall of the anastomosis is sutured and cutted with a linear stapler on 30–40 mm deep. The anterior wall sutured with a linear stapler. The next layer of sutures on the anastomosis anterior wall invaginates the anastomos and the esophageal stump into the gastric graft. Results. There was no early postoperative mortality. Average I. Lewis minimally invasive esophagectomy time was 353 minutes (245–470 minutes). The average volume of blood loss was 114 mL (50–200 mL). No patient faced an anastomotic leak. Anastomotic stricture occurred in 5 patients (19.2%) during 21 days to 6 months of follow-up. There were no anastomosis-related complications above Clavien-Dindo grade II. Conclusions. Linear stapled semimechanical anastomosis with invagination has proven both clinical and technical advantages of its use.

Classification, angioarchitecture and treatment outcomes of medullary bridging vein-draining dural arteriovenous fistulas in the foramen magnum region: a multicenter study.

This study aimed to classify medullary bridging vein-draining dural arteriovenous fistulas (MBV-DAVFs) located around the foramen magnum (FM) according to their location and characterize their angioarchitecture and treatment outcomes. Patients with MBV-DAVFs diagnosed between January 2013 and October 2022 were included. MBV-DAVFs were classified into four groups. Jugular vein-bridging vein (JV-BV) DAVF: located in proximity to jugular fossa, Anterior condylar vein (ACV)-BV DAVF: proximity to anterior condylar canal, Marginal sinus (MS)-BV DAVF: lateral surface of FM and Suboccipital cavernous sinus (SCS)-BV DAVF: proximity to dural penetration of vertebral artery. Twenty patients were included, three JV-BV, four ACV-BV, three MS-BV and ten SCS-BV DAVFs, respectively. All groups showed male predominance. There were significant differences in main feeders between JV (jugular branch of ascending pharyngeal artery) and SCS group (C1 dural branch). Pial feeders from anterior spinal artery (ASA) or lateral spinal artery (LSA) were visualized in four SCS and one MS group. Drainage pattern did not differ between groups. Transarterial embolization (TAE) was performed in three, two, one and two cases and complete obliteration was obtained in 100%, 50%, 100% and 0% in JV, ACS, MS and SCS group, respectively. Successful interventions without major complications were finally obtained in 100%, 75%, 100%, and 40% in JV, ACS, MS and SCS group, respectively. JV-BV DAVFs were successfully treated using TAE alone. SCS-BV DAVFs were mainly fed by small C1 dural branches of vertebral artery often with pial feeders from ASA or LSA, and difficultly treated by TAE alone.

Clinical Anatomy of Vessels of Popliteal Region

INTRODUCTION: A modern standard for noninvasive diagnostics of the vascular system is duplex scanning. The knowledge of variability of vascular anatomy is essential for ultrasound doctors. AIM: To clarify variants of the clinical anatomy of vessels of the popliteal region using duplex scanning and anatomical preparation. MATERIALS AND METHODS: The work used data of duplex scanning of the arteries and veins of the lower extremities of patients without pathology of the vascular system of the lower extremities, who underwent examination of the vascular system: 200 patients aged from 18 to 92 years. As control, the data of anatomical preparation of 50 amputated lower extremities were taken, with preliminary filling the venous system with a blue synthetic gel. RESULTS: In the course of anatomical preparation, two trunks of the popliteal vein were identified in the distal popliteal region in 86.0% of observations. A typical drain of the small saphenous vein with formation of the saphenopopliteal junction was encountered in 60.0% of cases. In duplex scanning, a high bifurcation of the popliteal artery was detected in 1.9% of observations. The two trunks of the popliteal vein in the distal part of the popliteal region were encountered in 82.4% of cases, and the medial trunk was almost always larger than the lateral one. The small saphenous vein drained into the popliteal vein in 63.0% of cases. In 7.2% of observations, it drained into one of the intramuscular veins. In 0.95% of observations, a perforator vein was identified in the popliteal region. The sural veins were identified in all the patients — two on the medial and lateral surface positioned at the sides of the two trunks of the sural arteries, forming a single trunk before confluence with the popliteal vein. CONCLUSIONS: TThe study revealed the following anatomic variants of vessels of the popliteal region: two trunks of the popliteal vein below the knee joint cleft in 85.7% to 86.0% of observations; a high bifurcation of the popliteal artery in 1.9%; saphenopopliteal junction in 60.0% to 63.0%; perforator veins of the popliteal region in 0.95% of observations; upon that, the small saphenous vein does not form the saphenopopliteal junction.

Topographic anatomy of the lateral surface of the parietal lobe and its relationship with white matter tracts.

Aim of this study was to define sulcal and gyral variations of the lateral parietal cortex and underlying white matter tracts and emphasize the importance of relationship between topographic anatomy of parietal lobe and white matter tracts underlying it in approaches to deep parietal and atrial lesions. Twenty-eight formalin-fixed cerebral hemispheres of 14 adult cadavers were used. Ten hemispheres were dissected from lateral to medial by fiber dissection and all stages were photographed. Our anatomic findings were supported by MRI tractography. Postcentral sulcus and intraparietal sulcus were continuous in most of the cadavers (71% in right, 64% in left side). Intermediate sulcus of Jensen was in bayonet shape in 86 and 50 percent of cadavers at right and left side, respectively. The range of perpendicular distance between the meeting point and interhemispheric fissure was 2.5-4.9 cm in right and 2.8-4.2 cm in left hemisphere whereas the range of distance between meeting point and the sylvian fissure was 3-6 cm and 2.5-5.6 in left and right hemispheres, respectively. When the meeting point was located more laterally, the probability of damaging the arcuate fasciculus and superior longitudinal fasciculus II during dissection was increased. We also found that the intraparietal sulcus and intermediate sulcus of Jensen were associated with the superior longitudinal fasciculus II, middle longitudinal fasciculus, inferior frontooccipital fasciculus, tapetum, and optic radiation. These variations and their relation to subcortical tracts should be considered in atrium and deep parietal lobe surgeries.

Optimisation of Beam Member Loading

Introduction. The I-beams are deemed to have the highest load-bearing capacity. However, in practice, due to wide spreading and affordability of pipe-rolling products, the tubular beams are being used quite often. The load-bearing capacity of these beams should be compared under the condition of their equal mass per running meter. An I-beam according to the GOST R 57837-2017 with the mass of running meter equal to 194 kg and a pipe according to the GOST 33228-2015 with the mass of 194 kg/m have been compared. The load-bearing capacity of an I-beam was almost twice as high as that of a tubular beam. The data about the concrete filled steel tubular (CFST) beams, including the ones with the prestressed concrete core at the bottom, is also provided. In such beams, a steel pipe works as an external reinforcement — exo-reinforcement. The load-bearing capacity of the CFST beams is quite considerable taking into account their low cost and good processability. The present research aims at increasing the load-bearing capacity of the tubular beams, which will expand the range of the construction products.Materials and Methods. The geometric optimisation and mental experiment methods have been used. The idea of using the fluid filling material for a tubular beam is based on the well-known property of fluid — its almost complete incompressibility. The maximum volume of a geometric long body with the rectilinear generatrix of lateral surface (for a given lateral surface) is reached if its cross-section has the shape of a circle, which corresponds to a round pipe.Results. A tubular beam with the fluid filling material (a hydraulic beam) is a round pipe blanked off at both ends, completely filled with fluid (without air pockets). When a hydraulic beam is loaded, its lateral surface tends to deform. Consequently, the internal volume of the pipe tends to decrease. However, since fluid is incompressible, its volume doesn’t decrease, which, in turn, prevents the pipe from deformation.Discussion and Conclusion. In a hydraulic beam, due to fluid, the entire load is distributed relatively evenly over the whole internal surface of a beam. The load-bearing capacity of a hydraulic beam has been estimated, which is five times higher than that of an I-beam and ten times higher than that of a tubular beam.

Reduced-dimensional modelling for nonlinear convection-dominated flow in cylindric domains

The aim of the paper is to construct and justify asymptotic approximations for solutions to quasilinear convection–diffusion problems with a predominance of nonlinear convective flow in a thin cylinder, where an inhomogeneous nonlinear Robin-type boundary condition involving convective and diffusive fluxes is imposed on the lateral surface. The limit problem for vanishing diffusion and the cylinder shrinking to an interval is a nonlinear first-order conservation law. For a time span that allows for a classical solution of this limit problem corresponding uniform pointwise and energy estimates are proven. They provide precise model error estimates with respect to the small parameter that controls the double viscosity-geometric limit. In addition, other problems with more higher Péclet numbers are also considered.

Anterior Distal Femoral Hemiepiphysiodesis Using Coronally Oriented 8-plates for the Correction of Fixed Knee Flexion Deformities in Children-Preliminary Results.

The original technique for guided growth of the distal femur for correction of pediatric fixed knee flexion deformities (FKFDs) involves the utilization of two 8-plates inserted on either side of the trochlear groove, a technique that has been frequently linked to the development of persistent postoperative knee pain and crepitus. The present study aimed to assess the preliminary results of a novel technique where the two 8-plates are fixed in the coronal plane, one on each of the medial and lateral surfaces, so that they occupy the anterior part of the distal femur. Our study was a prospective case series that included cases with FKFD of >10 degrees in children with at least 12 months of predicted growth remaining. The preoperative knee flexion contracture angle was documented. The surgical procedure entailed the insertion of 2 coronally oriented 8-plates on the medial and lateral surfaces of the distal femur as anterior as possible to the axis of the femur without encroachment on the trochlear groove. The duration of time required to attain full knee extension and any complications encountered were recorded. Wilcoxon signed-rank was used to compare the preoperative and final contracture angles. The level of statistical significance was set at P <0.05. Thirteen knees in 8 patients (6 boys and 2 girls) were included. The median age was 11 years (6 to 14). There was a significant improvement in the FKFD for the whole cohort from 25 degrees (14 to 42) to 0 degrees (-9 to 8), P <0.05. The median rate of correction was 2.0 degrees/month (0.9 to 5.8). The time till full correction was 14 months (4 to 25). Postoperative knee pain and metalware-related complications were not reported by any patient during follow-up. Guided growth of the distal femur using coronally oriented 8-plates is an effective procedure for the treatment of FKFDs in children. This modified technique may achieve faster correction while minimizing the risk of postoperative knee pain compared with the conventional technique. Level IV-case series.