The Effect of Dimple Insole Design on the Plantar Temperature and Pressure in People with Diabetes and in Healthy Individuals.

An increase in plantar pressure and skin temperature is commonly associated with an increased risk of diabetic foot ulcers. However, the effect of insoles in reducing plantar temperature has not been commonly studied. The aim was to assess the effect of walking in insoles with different features on plantar temperature. Twenty-six (F/M:18/8) participants-13 with diabetes and 13 healthy, aged 55.67 ± 9.58 years-participated in this study. Skin temperature at seven plantar regions was measured using a thermal camera and reported as the difference between the temperature after walking with an insole for 20 m versus the baseline temperature. The mixed analyses of variance indicated substantial main effects for the Insole Condition, for both the right [Wilks' Lambda = 0.790, F(14, 492) = 4.393, p < 0.01, partial eta squared = 0.111] and left feet [Wilks' Lambda = 0.890, F(14, 492) = 2.103, p < 0.011, partial eta squared = 0.056]. The 2.5 mm-tall dimple insole was shown to be significantly more effective at reducing the temperature in the hallux and third met head regions compared to the 4 mm-tall dimple insole. The insoles showed to be significantly more effective in the diabetes group versus the healthy group, with large effect size for the right [Wilks' Lambda = 0.662, F(14, 492) = 8.037, p < 0.000, Partial eta-squared = 0.186] and left feet [Wilks' Lambda = 0.739, F(14, 492) = 5.727, p < 0.000, Partial eta-squared = 0.140]. This can have important practical implications for designing insoles with a view to decrease foot complications in people with diabetes.

Wimpled thin films via multiple motions of a bubble decorated with surface-active molecules.

HYPOTHESIS: Thin liquid films play a crucial role in various systems and applications. Understanding the mechanisms that regulate their morphology is a scientific challenge with obvious implications for application optimization. Thin liquid films trapped between bubbles and air-liquid interface can show various configurations influenced by their deformation history and system characteristics. EXPERIMENTS: The morphology of thin liquid films formed in the presence of surface-active molecules is here studied with interferometric techniques. Three different systems with varying interfacial properties are investigated to understand their influence on film morphology. Specific deformation histories are applied to the films to generate complex film structures. FINDINGS: We achieve the creation of a rather stable wimple by implementing controlled bubble motions against the air-liquid interface. We provide a criterion for wimple formation based on lubrication theory. The long-term stability of the wimple is also investigated, and more complex multi-wimple structures are experimentally produced building upon the achieved wimple stability.

Fibrous hamartoma of infancy of the spinal cord resembling conus and filum, with a coexisting sacral dimple.

Fibrous hamartoma of infancy (FHI) is a rare benign soft tissue lesion of infants and young children. It usually occurs within the first 2 years of life at the superficial layer of the axilla, trunk, upper arm, and external genitalia. FHI in the central nervous system (CNS) is extremely rare. So far, only two spinal cord FHI cases have been reported. We present a case of a 1-month-old girl who presented with a skin dimple in the coccygeal area. Her MRI showed a substantial intramedullary mass in the thoracolumbar area with a sacral soft tissue mass and a track between the skin lesion to the coccygeal tip. Her normal neurological status halted immediate surgical resection. A skin lesion biopsy was first performed, revealing limited information with no malignant cells. A short-term follow-up was performed until the intramedullary mass had enlarged on the 5-month follow-up MRI. Based on the frozen biopsy result of benign to low-grade spindle cell mesenchymal tumor, subtotal resection of the mass was done, minimizing damage to the functioning neural tissue. Both the skin lesion and the intramedullary mass were diagnosed as FHI. Postoperative 5.5-year follow-up MRI revealed minimal size change of the residual mass. Despite being diagnosed with a neurogenic bladder, the patient maintained her ability to void spontaneously, managed infrequent UTIs, and continued toilet training, all while demonstrating good mobility and no motor weakness. This case is unique because the lesion resembled the secondary neurulation structures, such as the conus and the filum, along with a related congenital anomaly of the dimple.

Role of Magnetic Resonance Imaging in the Screening of Closed Spinal Dysraphism.

Closed spinal dysraphism (CSD) encompasses a heterogeneous group of spinal cord deformities, which can be accompanied by several types of skin stigmata. These skin stigmata may include inconspicuous features, such as sacral dimples and deformed gluteal clefts, but the association between such mild skin stigmata and CSD is uncertain. This study aimed to reevaluate the indication for magnetic resonance imaging (MRI) in patients with skin stigmata while considering the indication for surgery. A retrospective analysis was conducted on magnetic resonance images of 1255 asymptomatic children with skin stigmata between 2003 and 2015. Skin stigmata classification was based on medical chart data. All subtypes of CSDs except for filum terminale lipomas (FTL), FTL thicker than 2 mm or with low conus medullaris, were considered to meet the surgical indication. CSD prevalence was estimated while considering the surgical indications and assessed after excluding all FTL cases. Skin stigmata were classified into seven types, dimple, deformed gluteal cleft, hair, subcutaneous mass, appendage, discoloration, and protruding bone, and included 1056 isolated and 199 complex ones. The prevalence of CSD was 19.5%, 6.8%, and 0.5% among patients with isolated dimples (n = 881) and 13.9%, 5.8%, and 0.7% among those with isolated deformed gluteal clefts (n = 136) for all cases, surgical indications, and patients without FTL, respectively. Dimples and deformed gluteal clefts had a low prevalence of CSD requiring surgical intervention, and cases without FTL were rare. Asymptomatic patients with mild skin stigmata may not require immediate MRI.

A precision dimple grinder-polisher produced by 3D printing.

A precision dimple grinder-polisher has been designed and constructed using 3D printing. The purpose of the device is to produce a thin central area in 3 mm round samples for transmission electron microscopy before ion milling to electron transparency. The device can be self-made by any laboratory with a 3D printer for scientific research or teaching, and when combined with recycling and use of biodegradable filaments it can help labs reach their sustainable development goals. A novel sample holder design allows sample alignment without a monocular and thickness detection by light transmission. Novel solutions are developed for aligning the grinding disc and sample rotation motors and for fixing the polishing cloth to the polishing disc. The diameter-depth relationship is investigated for steel and plastic grinding discs. Design principles and materials are discussed, and the tool is evaluated by preparing samples from copper, silicon and tungsten, which are then examined in the transmission electron microscope to evaluate their quality.

Apple-like Shape of Freezing Paraffin Wax Droplets and Its Origin.

Paraffin wax stores energy in the form of latent heat at a nearly constant temperature during melting and releases this energy during solidification. This effect is used in industrial energy storage. At the same time, the possible deformation of even small volumes of material as a result of phase change is insufficiently studied. In this paper, the physical nature of such deformation, probably for the first time, is studied on the example of a droplet of paraffin wax. An unusual change in the shape of a melted droplet of paraffin wax placed on a relatively cold glass plate was observed in the laboratory experiments. As the droplet solidifies, its upper surface becomes nearly flat, and a dimple is formed in the center of this surface, making the droplet look like a fruit (pumpkins are more commonly shaped like this, but the authors prefer apples). A series of experiments, as well as physical and numerical modeling of the droplet's thermal state, taking into account the formation of a mushy zone between liquidus and solidus, made it possible to understand the role of gravity and gradual increase in viscosity and density of paraffin wax on changing the droplet shape and, in particular, to clarify the mechanism of formation of the dimple on its upper. It was shown that the mushy zone between the liquidus and solidus of the paraffin wax is responsible for the dimple formation.

Dimple of Venus Is Associated with the Increased Pelvic Incidence Angle and More Sagittally Oriented Facet Joint.

OBJECTIVES: The present study aims to investigate whether the dimple of Venus affects the anatomy of spinopelvic junction. SUBJECTS AND METHODS: Inclusion criteria were having a lumbar MRI examination in the last 1 year, being older than 18 years of age and being able to radiologically evaluate the whole vertebral colon and pelvic girdle. Exclusion criteria were having congenital diseases of the pelvic girdle/hip/vertebral column and history of fracture or previous surgery in the same anatomic regions. The patients' demographic data and low back pain were noted. At radiological examination, the pelvic incidence angle was measured by lateral lumbar X-ray. The facet joint angle, tropism, facet joint degeneration, intervertebral disc degeneration, and intervertebral disc herniation at the level of L5-S1 were examined on lumbar MRIs. RESULTS: We included 134 male and 236 female patients with a mean age of 47.86 ± 14.50 years and 48.49 ± 13.49 years, respectively. We found that the patients with the dimple of Venus had higher pelvic incidence angle (p < 0.001) and more sagittally oriented facet joint (right facet joint p = 0.017, left facet joint p = 0.001) compared to those without the dimple of Venus. There was no statistically significant relationship between low back pain and the presence of the dimple of Venus. CONCLUSIONS: The dimple of Venus affects the anatomy of the spinopelvic junction and is associated with an increased pelvic incidence angle and a more sagittally oriented facet joint angle.

Management of asymptomatic cutaneous lumbosacral findings in newborns: a neurosurgical perspective.

OBJECTIVE: The purpose of this study was to find areas of agreement among pediatric neurosurgeons with respect to the clinical management of asymptomatic newborns with a variety of lumbosacral skin findings. METHODS: An electronic survey containing 18 clinical images and brief vignettes was sent to pediatric neurosurgeons within the American Academy of Pediatrics Section of Neurological Surgery (AAP SONS). In total, 38% (n = 21) of AAP SONS members submitted complete responses to the survey. Respondents were asked if they would advise routine care, watchful waiting, imaging, or subspecialty consultation for each clinical case. Responses were categorized into two groups: 1) watchful waiting and/or routine care, or 2) imaging and/or subspecialty consultation. Consensus was categorized as good (> 90% of responses in the same group), modest (70%-90%), and poor (< 70%). Demographic information, local factors impacting management, and experiences with local referral patterns were also collected. RESULTS: Among the pediatric neurosurgeons within the AAP SONS network, the authors found high levels (> 90%) of agreement that subcutaneous lipomas, faun tail nevi, large skin tags, and deep/atypical lumbosacral dimples in asymptomatic newborns should prompt an imaging study. Similarly, the authors found high agreement that simple coccygeal dimples do not need imaging. The management of some types of lumbosacral vascular marks and gluteal crease deviations had poor agreement (< 70%). When imaging was recommended, there was preference for spinal MRI in most cases (67%). CONCLUSIONS: Pediatric neurosurgeons generally agree that imaging of the spine is indicated for asymptomatic newborns with subcutaneous lipomas, faun tail nevi, large skin tags, or deep/atypical lumbar dimples (deep or atypical appearing). They also agree that imaging is unnecessary for infants with simple coccygeal dimples. There was a notable lack of consensus on the appropriate management of certain gluteal cleft deviations and cutaneous vascular marks.

Cartilage-inspired surface textures for improved tribological performance of orthopedic implants.

Joint replacements have become one of the most common orthopedic procedures due to the significant demands of retaining functional mobility. While these procedures are of great value to patients, there are some limitations. Durability is the most important limitation associated with joint replacement that needs to be addressed due to the increasing number of younger patients. Titanium is a commonly used implant material which has high biocompatibility, high strength-to-density ratio, and high corrosion resistance. However, current titanium implants have poor wear resistance which shortens their lifespan. In this study, microscale dimples with four different dimple shapes (circular, triangular, square, and star) of similar sizes to the pores found in natural articular cartilage were fabricated on titanium disks to improve implant lubrication and reduce wear. Biotribology tests were performed on dimpled and non-dimpled titanium disks in a condition similar to that inside of a patient's body. It was shown that dimpling the titanium disks optimized the lubricant film formation and decreased the wear rate significantly while also reducing the coefficient of friction (COF). The star-shaped dimples had the lowest COF and almost no detectable wear after 8 h of testing. To investigate whether dimpling increased bacterial colonization due to increased surface area, and to determine whether any increase could be limited by coating with antibacterial materials, bacterial colonization with Staphylococcus aureus was tested with non-dimpled and star-shaped dimpled titanium disks with and without coating with polydopamine (PDA), silver (Ag) nanoparticles (NPs), and PDA + Ag NPs. It was found that dimpling did not increase bacterial colonization, and that coating with PDA, Ag NPs, or PDA + Ag NPs did not decrease bacterial colonization. Nevertheless, we conclude that star-shaped dimpled titanium surfaces have potential utility as more durable orthopedic implants.