Biomechanics of skin grafts: effect of pattern size, spacing and orientation

Skin graft expansion is the key to the treatment of severe burn injuries requiring skin transplantation. While high expansions have been claimed by a majority of graft manufacturers, the realistic expansions reported to date with skin grafts are much lower. To clarify this discrepancy, we attempted to understand the biomechanics of skin grafts through the study of common graft pattern sizes, spacing, and orientation, and their influence on mesh expansion and induced stress. A novel skin simulant material and additive manufacturing were employed to develop the skin graft models. Tensile testing experiments were conducted to study expansion and overall stresses, and a finite element model (FEM) was used to characterize the local trends. At low strains (i.e., <1), the mesh expansion ratio was reported to be below 1, which increased up to 1.93 at a high strain of 2. The pattern size and spacing were not observed to affect the expansion much (i.e., <10%). With a change in orientation, the expansion decreased across all graft models and strains. High localized induced stresses were reported for high strains, which varied with graft orientation. The novel observations highlight the achievable expansions without overstressing, with standard slit patterning in skin grafts. These findings will not only help achieve better mesh expansion outcomes in burn surgeries but also guide the development of novel graft patterns for enhanced expansion in the future.

Light-induced Patterning of Electroactive Bacterial Biofilms

Electroactive bacterial biofilms can function as living biomaterials that merge the functionality of living cells with electronic components. However, the development of such advanced living electronics has been challenged by the inability to control the geometry of electroactive biofilms relative to solid-state electrodes. Here, we developed a lithographic strategy to pattern conductive biofilms of Shewanella oneidensis by controlling aggregation protein CdrAB expression with a blue light-induced genetic circuit. This controlled deposition enabled S. oneidensis biofilm patterning on transparent electrode surfaces and measurements demonstrated tunable biofilm conduction dependent on pattern size. Controlling biofilm geometry also enabled us, for the first time, to quantify the intrinsic conductivity of living S. oneidensis biofilms and experimentally confirm predictions based on simulations of a recently proposed collision-exchange electron transport mechanism. Overall, we developed a facile technique for controlling electroactive biofilm formation on electrodes, with implications for both studying and harnessing bioelectronics.

Effect of Nanopatterning on Concentration Polarization during Nanofiltration

Membranes used for desalination still face challenges during operation. One of these challenges is the buildup of salt ions at the membrane surface. This is known as concentration polarization, and it has a negative effect on membrane water permeance and salt rejection. In an attempt to decrease concentration polarization, a line-and-groove nanopattern was applied to a nanofiltration (NF) membrane. Aqueous sodium sulfate (Na2SO4) solutions were used to test the rejection and permeance of both pristine and patterned membranes. It was found that the nanopatterns did not reduce but increased the concentration polarization at the membrane surface. Based on these studies, different pattern shapes and sizes should be investigated to gain a fundamental understanding of the influence of pattern size and shape on concentration polarization.

Personal Identification using Odontometry and Palatoscopy: A Pakistani Perspective

Aim: To determine the most common rugae pattern and to find if it has any association with dental arch form or malocclusion. Study Design and setting: It was a retrospective cross-sectional study conducted using the records of 200 patients visiting the Orthodontic Outpatient department of Bahria University Medical and Dental College. Methodology: Number, size, orientation and pattern of palatal rugae were assessed on the plaster models. Dental malocclusion along with dental arch form and width were also evaluated. Descriptive statistics such as frequencies were analyzed. Chi square, Fischer exact test and One Way ANOVA was used to see the significance of differences, p≤0.05 was considered as significant. Results: The sample comprised of class I (n=97), class II(n=87) and class III(n=16).113 cases had inter-molar width >44mm while 87 had ≤44mm. Posterior orientation of the rugae, was pre-dominant for both right (n=100) and left (n=122) first rugae. The most common pattern was curved for both first rugae on right (n=66) and left (n=72) sides. Conclusion: Our study showed that the rugae pattern, size and numbers did not show significant variation in different malocclusion classes. It can be concluded that rugae pattern do not have any significant association with malocclusion class or arch form. Keywords: Arch form, Arch width, Forensic dentistry, Malocclusion, Palatal Rugae

Population, Reproductive and Fishery Dynamics of Spotted Box Crab (Calappa philargius), a New Claw-Only Fishery Species, in the Southern Taiwan Strait, China

The spotted box crab Calappa philargius (Calappidae) is an increasingly consumed species in China, mainly sourced from a claw-only fishery. Being a not well-characterized species in the literature, this study is warranted to inform sustainable management approaches. Here we report on the first in-depth overview on biology and fishery dynamics of C. philargius in the southern Taiwan Strait of China. Whole body crabs (N = 1,009) were collected monthly from January to December 2019 from trawlers, operating in the southern Taiwan Strait; sample collection was absent from May to July because of the national fishing moratorium regulation. Sex ratio, growth pattern, size at maturity and fecundity were estimated. The overall male: female ratio was 1: 1.47, significantly differing from the 1: 1 (p &lt; 0.01); monthly sex ratio variations were also significant (p &lt; 0.01), suggesting possible seasonal sexual segregation. We found the carapace widths (CW) of males were significantly larger than those of females (p &lt; 0.01). Based on the occurrence and percentages of berried females, we identified twin spawning events in January–April and August–October with the overall peak occurring in February. Size at 50% female maturity was 11.47 cm CW. Female absolute fecundity was significantly related to CW via a power function relationship (N = 14, p &lt; 0.01). The estimated average claw yield was 36.28 ± 3.07% of the whole body weight (N = 95), irrespective of sex and size (p &gt; 0.5). Capture and trade data of C. philargius using trawl and trap fishing gears were documented to characterize claw-only fishery dynamics for future research and sustainable use.

Characterisation of Finger Dermatoglyphics Traits and other Biometric Indices among Health Science Undergraduates of the Osun State University, Nigeria

Background: Finger dermatoglyphics has been useful in diagnosing genetically related diseases and detecting crimes. A cross-sectional study was carried out to establish the relationship between fingerprint traits and biometric indices Methods: Finger dermatoglyphics data were obtained using the ink method among the Health Sciences Students of Osun State University, Osogbo, Nigeria. Finger pattern intensity, finger pattern distribution, and finger ridge counts were measured and compared. These were done by counting and classifying ridge patterns and pattern configuration of arches, loops, and whorls and counting their ridge densities. The subject’s height, weight, and colour of the pupil were measured and recorded, respectively Results: The ulnar loops and arches were the most predominant finger patter ns in females, while males showed significantly spiral whorls. The sex differences between these patterns were not statistically significant (P>0.05). Subjects with brown pupils demonstrated higher ulnar loop and elliptical whorl, while those with black pupils possessed significantly well-distributed arches, and were insignificant in pattern width and intensity. Body Mass Index (BMI) polymorphism showed the lowest pattern size (Finger Ridge Counts) demonstrated by significantly reduced total finger ridge count among the subjects with BMI range of 24-26 and predominance of the concentric whorl, radial loop, and arches. However, higher pattern size was observed in subjects with a higher BMI value 27-29 BMI range with corresponding ulanr and spiral whorl respectively. Conclusion: This study demonstrated the prevalent biometrics measure of finger dermatoglyphics traits, in relations to the biometrics distribution of pupillary colour and body mass index among the Health Sciences Students of Osun State University, Osogbo Nigeria

Defining Patterns and Behaviours of Forward Spatter Gunshot Misting

The purpose of this research was to study forward-spatter misting patterns by shooting a firearm through a chamber of blood encased in ballistic gel to determine if there is a relationship between bloodstain pattern size as a function of distance and orientation. There is a lack of research on forward spatter, blood travelling in the direction of a bullet, as most studies focus on back spatter, blood travelling in the opposite direction of a bullet. A bullet was fired through ballistic gel containing a blood chamber, depositing bloodstains onto a large sheet of butcher paper as the target surface. In total, there were 34 trials. The distances observed were 10, 20, 40, and 80 cm, the angles tested were 30°, 60°, and 90°. The orientation between the ballistic gel and paper target varied. A criterion was established to observe the overall area and symmetry of the bloodstain patterns. Statistical analyses indicated a negative linear relation relationship between the bloodstain pattern size and the paper’s angle and distance (R2 = 0.78) and the vertical symmetry of the bloodstain (R2 = 0.87). The orientation between the ballistic gel and paper target can impact the bloodstain pattern’s symmetry and size.

UV Nanoimprint Lithography: Geometrical Impact on Filling Properties of Nanoscale Patterns

Ultraviolet (UV) Nanoimprint Lithography (NIL) is a replication method that is well known for its capability to address a wide range of pattern sizes and shapes. It has proven to be an efficient production method for patterning resist layers with features ranging from a few hundred micrometers and down to the nanometer range. Best results can be achieved if the fundamental behavior of the imprint resist and the pattern filling are considered by the equipment and process parameters. In particular, the material properties and pattern size and shape play a crucial role. For capillary force-driven filling behavior it is important to understand the influencing parameters and respective failure modes in order to optimize the processes for reliable full wafer manufacturing. In this work, the nanoimprint results obtained for different pattern geometries are compared with respect to pattern quality and residual layer thickness: The comprehensive overview of the relevant process parameters is helpful for setting up NIL processes for different nanostructures with minimum layer thickness.

Electrophysiological markers of preclinical diagnosis of glaucomatous optic neuropathy

Purpose: to evaluate the changes in electrophysiological indicators reflecting various aspects of the function of retinal ganglion cells (RGC) and their axons in the early diagnosis of glaucomatous optic neuropathy (GON).Material and methods. Two clinical groups, (1) 35 patients (60 eyes) aged 49 to 70 with suspected glaucoma and (2) 16 patients (30 eyes) aged 43–68 with initial primary open-angle glaucoma (POAG), and a comparison group of 38 relatively healthy subjects (45 eyes) aged 42–70 were tested for pattern-reversed visual evoked potentials (PVEP), transient and stationary pattern-ERGs (PERG) according to ISCEV, and photopic negative response (PhNR).Results. The P100 amplitudes in both clinical groups differed significantly from the norm in PVEP on small and large patterns. The elongation of peak latency (T) of P100 compared with norm was significant for the stimulus 1° in group 2. In both groups of patients, increased variability of the temporal parameters of PERG and PVEP for small patterns was found. In groups 1 and 2, a decrease in the amplitude of P50 and N95 peaks of transient PERG for all stimuli was revealed, which was the most significant for the 0.3° pattern. In group 1, the N95 peak was significantly delayed in PERG for large patterns. A statistically significant reduction in the steady-state PERG's amplitude was found in the groups of suspected glaucoma and initial POAG. The sharpest changes were found for small (0.8° and 0.3°) patterns. The elongation of T compared to the norm was most pronounced for PERG at 0.3°, but due to the high variability of temporary indicators within the group, it had no statistical significance. The amplitude of PhNR was significantly different from the norm in the ERG for a flash of 3.0 cd·sec/m2.Conclusion. In patients with suspected glaucoma, a decrease in the P100 VEP amplitude with the simultaneous elongation of T may be considered as a criteria for the plastic stage at the level of lateral geniculate nucleus. Markers of functional changes in RGCs are the decrease in the amplitude of PhNR in response to bright flash, and P50 and N95 of PERG for pattern size 0.3°. The results indicate a greater vulnerability of the parvocellular system to early events in the development of GON.

A Study on the Activation of Used Market of Hanbok and Hanbok Reform Market

In order to find ways to re-use used Hanbok and activate Hanbok reform, it is necessary to investigate the current status and problems of used Hanbok and Hanbok reform in the domestic Hanbok market. The purpose of this study was to investigate the status and problems of the used Hanbok market and the Hanbok reform market through literature data surveys and in-depth interviews with Hanbok experts, and to study ways to activate used Hanbok and Hanbok reform. Based on the results of this study, as a way to activate the used Hanbok market and the Hanbok reform market, expand opportunities and create a social and cultural atmosphere for wearing Hanbok, and research on design, pattern, size, and materials. It also suggested the establishment of a systematic system for separate collection, reform, sales and management, the establishment of a central institution that manages and operates the re-use of used Hanbok and Hanbok reform, support for education institutions and programs for Hanbok reform, public relations, and changes in Hanbok production methods.