Shaft Thickness Research Articles

Baseline trichoscopic values for afro-textured hair in indigenous South Africans show lower density and unique features.

Afro-textured hair exhibits distinct physicochemical properties with possible variations in measurable hair parameters. Standardized documentation of trichoscopic norms of afro-textured hair in indigenous Africans is notably lacking. A cross-sectional study involving 122 South Africans of both genders of African ancestry (mean age 20.9 ± 3.3 years) with natural afro-textured hair was performed to establish trichoscopic norms. Standard images, one overview, and five microimages (one 20× and four 50× magnifications) were captured with the FotoFinder Medicam1000V2 videodermoscope. Hair density (HD; N/cm2); hair shaft thickness (HST; μm); the proportion of thin, mid, and thick hairs (%); cumulative hair thickness (mm/cm2); and follicular units (FU; N/cm2) were assessed. The average HD was 139.1 ± 33.88 hairs/cm2 with significant variations across different scalp areas. The average hair thickness was 62.59 ± 8.45 μm with the frontal scalp showing the greatest HST, the proportion of thick hairs, cumulative hair thickness, and FU densities; the temporal had the greatest proportion of thin hairs, whereas the occipital showed the highest proportion of triple hair FU. Male participants exhibited significantly greater average hair thickness, more thick hairs, and more double and triple FU, whereas females had higher cumulative hair thickness density, more thin and intermediate hairs, and more single follicular units. Baseline trichoscopic values for natural afro-textured hair in indigenous South Africans reveal lower hair densities, variations in shaft diameters, and follicular unit patterns compared to other racial groups. Significant gender-based differences are evident in some of the measured parameters. Tailored reference values are essential for accurate clinical evaluations and hair transplant planning.

ВЛИЯНИЕ ВАКУУМНОЙ ТЕРАПИИ НА ДИНАМИКУ КЛЕТОЧНЫХ РЕАКЦИЙ ПРИ МОДЕЛИРОВАНИИ ГНОЙНОГО ВОСПАЛИТЕЛЬНОГО ПРОЦЕССА У КРЫС

Relevance. Vacuum therapy is used worldwide to treat acute trauma, thermal injuries, osteomyelitis, purulent wounds, urological pathology, etc. The sanogenetic effect of vacuum therapy is associated with the effect of altered barometric pressure on the tone of microvessels. However, specific mechanisms of vacuum action on the course of typical pathological processes have been poorly studied. Objective. To determine the degree of influence of barometric therapy on the severity of cellular reactions in the focus of experimental purulent inflammation. Material and methods. The study was conducted on 2 series of outbred white male rats (control and experimental). To simulate purulent inflammation, diffusion chambers of our own design filled with an aqueous suspension of a one-day culture of staphylococcus aureus were implanted under the skin of the thigh of animals. Vacuum therapy was carried out in a pressure chamber where the pressure was maintained from 0.03 to 0.05 atmospheres. The procedure was carried out every day with an exposure of 10 minutes. The material was fixed in a 10% solution of neutral formalin. Results. The following data on the development of inflammation were obtained: the thickness of the cellular shaft, the ratio of neutrophils and macrophages, the structure of cellular structures on the 1st, 3rd, 5th, 7th, 10th, 15th, 20th day after implantation. Conclusion. Modeling of experimental microbial inflammation against the background of vacuum therapy resulted in a significant reduction in the duration of cellular reactions compared to the staphylococcal inflammatory process, improvement of the migratory, phagocytic, synthetic capabilities of cells implementing the inflammation process, which prevented the inflammation from protracted. Reduced barometric pressure increased the phagocytic activity of leukocytes, the rate of their migration to the inflammation site, collagen synthesis by fibroblasts, the interaction of cells in the inflammation site, and, therefore, reduced the duration of the process phases and inflammation as a whole, preventing the inflammation from becoming chronic and generalizing.

A Case Report of Microifusion of Drugs Into the Skin (MMP<sup>®</sup>) with Minoxidil in Chronic Telogen Effluvium

Introduction: Telogen effluvium (TE) is a common cause of diffuse, non-scarring hair shedding, particularly affecting women. Chronic telogen effluvium (CTE), although less common than the acute form, presents as gradual hair loss that persists for more than six months and can last for years. Current treatment options are limited, and while topical minoxidil is often used, there is insufficient evidence to fully support its effectiveness in CTE. This has led to the exploration of innovative treatment methods, such as Microinfusion of drugs into the skin (MMP®), a form of microneedling. Case Presentation: A 28-year-old female patient with a three-year history of hair loss underwent MMP® combined with 0.5% minoxidil on the right side of the scalp, targeting the frontal, parietal, and vertex areas. The treatment was administered over 3 monthly sessions, followed by the daily application of 5% minoxidil at home on both sides of the scalp. Six weeks after the final session, a trichoscopic reassessment using TrichoLAB® revealed the following results: In the frontal region, hair density increased slightly by 1 hair (from 206 to 207), while hair shaft thickness decreased by 2 µm (from 61 to 59 µm). In the parieto-vertex region, there was a more notable increase of 47 hairs (from 223 to 270), with a slight decrease in hair shaft thickness by 3 µm (from 67 to 64 µm). Conclusions: The patient reported a modest improvement in hair volume, supported by trichoscopic data, particularly in the parieto-vertex region. The combination of MMP® and minoxidil shows potential as a treatment for CTE, emphasizing the need for further research in larger, controlled trials to confirm its efficacy.

A SYSTEMATIC REVIEW OF LASER-BASED TREATMENTS FOR HAIR FALL

Objective: Hair loss, or alopecia, is a common condition affecting both men and women. Various treatment options exist, including medications, hair replacement, and more recently, laser therapies. This systematic review aims to compare the efficacy of different laser treatments for hair loss, including low-level laser therapy (LLLT), excimer laser, erbium glass laser, erbium YAG laser, and CO2 laser. Methodology: A comprehensive literature search was conducted using Google Scholar to identify relevant studies on laser treatments for hair loss. Inclusion criteria encompassed English-language original research articles and clinical trials reporting quantitative or qualitative outcomes of laser treatment for hair loss.. Twenty nine studies meeting the inclusion criteria were synthesized narratively and presented in a tabular format. Results: The review found that various laser treatments showed promising results in promoting hair regrowth. LLLT demonstrated consistent improvements in hair count and density across multiple studies, with increases ranging from 35% to 120% depending on the treatment area and patient sex. Excimer lasers showed hair regrowth in 41.5% to 60% of treated patches. Erbium glass, erbium YAG, and CO2 lasers also exhibited positive outcomes, improving hair density, shaft thickness, and inducing the anagen phase of hair growth. Conclusion: This systematic review suggests that laser treatments, particularly LLLT and excimer lasers, show efficacy in treating hair loss. However, the small sample sizes in many studies indicate a need for larger clinical trials to further validate these findings. Future research should focus on optimizing treatment parameters, comparing the efficacy of different laser types and potentially exploring visible light therapy to provide more targeted and cost-effective treatment options for patients suffering from hair loss.

Does low-energy fractional carbon dioxide laser therapy improve hair regrowth in female-pattern hair loss?

Background Female-pattern hair loss (FPHL) has the potential to impact the quality of life, physical attractiveness, and interpersonal relationships of many patients. In recent years, lasers and light therapy have been used as alternatives or supplementary therapy for hair loss. Objective To evaluate the efficacy of ablative fractional carbon dioxide (CO2) laser therapy alone in improving hair growth in FPHL. Patients and methods Thirty patients presenting with FPHL were included in a split-scalp prospective interventional study. Two areas of the scalp were studied. One area was treated with fractional CO2 laser and the second was injected with intradermal saline as control. The sessions were scheduled every 2 weeks for four sessions then monthly for 2 months. Patients were evaluated after each session and 2 months after the last session. Results were evaluated by clinical photography, trichoscopic, and folliscopic examination regarding the count of terminal and vellus hair, the thickness and density of hair shafts, and the patient’s satisfaction score. Results Fractional CO2 laser therapy alone was found to be effective in improving hair growth in FPHL. Conclusion Fractional CO2 laser therapy would have potential mechanisms in inducing hair regrowth in FPHL. However, the detailed mechanisms underlying hair regrowth and injury induced by the laser need further clarification.

The high-bone-mass phenotype of novel transgenic mice with LRP5 A241T mutation

Gain-of-function mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) can cause high-bone-mass (HBM) phenotype, with 19 identified mutations so far. The A242T mutation in LRP5 has been found in 9 families, making it one of the most prevalent mutations. However, the correlation between the A242T mutation and HBM phenotype remains unverified in animal models. This study aimed to investigate the bone properties in a new transgenic mouse model carrying the LRP5 A241T missense mutation, equivalent to A242T in humans. Heterozygous Lrp5A241T mice were generated using CRISPR/Cas9 genome editing. Body weight increased with age from 4 to 16 weeks, higher in males than females, with no difference between Lrp5A241T mice and wild-type control. Micro-CT showed slightly longer femur and notably elevated trabecular bone mass of the femur and fifth lumbar spine with higher bone mineral density, bone volume fraction, and trabecular thickness in Lrp5A241T mice compared to wild-type mice. Additionally, increased cortical bone thickness and volume of the femur shaft and skull were observed in Lrp5A241T mice. Three-point bending tests of the tibia demonstrated enhanced bone strength properties in Lrp5A241T mice. Histomorphometry confirmed that the A241T mutation increased bone formation without affecting osteoblast number and reduced resorption activities in vivo. In vitro experiments indicated that the LRP5 A241T mutation enhanced osteogenic capacity of osteoblasts with upregulation of the Wnt signaling pathway, with no significant impact on the resorptive activity of osteoclasts. In summary, mice carrying the LRP5 A241T mutation displayed high bone mass and quality due to enhanced bone formation and reduced bone resorption in vivo, potentially mediated by the augmented osteogenic potential of osteoblasts. Continued investigation into the regulatory mechanisms of its bone metabolism and homeostasis may contribute to the advancement of novel therapeutic strategies for bone disorders.

Fractional CO2 laser, platelet rich plasma and combination of both in treatment of female pattern hair loss

Background Female pattern hair loss (FPHL) is one of the most common chronic problems seen by dermatologists worldwide. Hair loss has a significant influence on the quality of life and is associated with low self-esteem and depression. The treatment modalities vary from medical approaches to surgical interventions. However, limited perceived efficacy of a therapeutic regimen may lead to premature stoppage of treatment. Objective To evaluate the efficacy of platelet rich plasma (PRP), fractional CO2 laser and combination of both in treatment of FPHL. Patients and methods This is a split-scalp prospective interventional study in which thirty patients presenting with FPHL received PRP in one area, fractional CO2 in another one, combined fractional CO2 and PRP in a third one and saline intradermal injection in the fourth area in frontal and mid scalp region of scalp. The sessions were scheduled every 2 weeks for 4 sessions, then monthly for 2 months. Patients were evaluated after each session and 3months after the last session. The results were evaluated by trichoscopic and folliscopic examination in the four examined areas. Assessment of treatment response was done according to the count of terminal and vellus hair, the thickness and density of hair shafts and the percentage of change, determined by folliscopic examination. Patients’ satisfaction and side effects were evaluated. Results There was significant difference between the studied groups as regards percentage of change of terminal hair, vellus hair, hair thickness and hair density after treatment. Pairwise comparisons showed that the combined group was statistically better than either PRP, fractional CO2, or saline group as regards all studied parameters (P value was <0.05 for each). Conclusion Combination of fractional CO2 laser and topical PRP application would have a synergistic effect in treatment of FPHL. The technique would be an excellent alternative to injections in order to stimulate hair growth in patients with FPHL.

Influence of the process time on a self-piercing riveting process with tumbling kinematic

The increasing significance of ecological responsibility, stricter political regulations and economic objectives are driving innovation in research fields such as lightweight construction. One of the most important popular methods is the use of multi-material systems. Due to the different geometric and mechanical properties of the various materials used, resource efficient applications and utilizations are possible. Great challenges arise for the joining processes to realize these multi-material systems, since conventional joining processes reach their limits. In the field of mechanical joining processes, there are continuously new approaches, such as superimposing the punch in a self-piercing riveting process with a tumbling kinematic, to increase the number of adaptable process parameters and enhance the process control. Through various preliminary tests, a good understanding of the process has been developed, which allows to directly control the geometric joint parameters by configuring the tumbling strategy. A major challenge, particularly with regard to future industrial applications, is the process time, which is comparatively high due to the tumbling kinematics. In the investigations, a reduction of approximately 90% of the process time is targeted by adapting the joining and tumbling strategy. Therefore, the correlation of the traverse velocity and the tumbling velocity are examined in a gradual series of experiments. To represent realistic applications, the experiments are carried out with a dual-phase steel and a precipitation-hardening aluminum alloy. For identifying the influence of the process parameters on the joining process, a constant rivet–die combination is applied. Further, the examination of force–displacement curves is conducted. Moreover, the determination of geometric joint parameters is reliant upon macrographs to assess the influence of the joining time on the geometric joint formation. The test results show that a significant increase in joining speed with a resulting reduction in process time is feasible. Although the joining properties are affected, reliable joining is possible. In particular, the shaft thickness of the rivet is influenced by the varying proportion of the tumbling process in the joining operation and increases with higher joining speeds.

Morphological heterogeneity of neurons in the human central amygdaloid nucleus.

The central amygdaloid nucleus (CeA) has an ancient phylogenetic development and functions relevant for animal survival. Local cells receive intrinsic amygdaloidal information that codes emotional stimuli of fear, integrate them, and send cortical and subcortical output projections that prompt rapid visceral and social behavior responses. We aimed to describe the morphology of the neurons that compose the human CeA (N = 8 adult men). Cells within CeA coronal borders were identified using the thionine staining and were further analyzed using the "single-section" Golgi method followed by open-source software procedures for two-dimensional and three-dimensional image reconstructions. Our results evidenced varied neuronal cell body features, number and thickness of primary shafts, dendritic branching patterns, and density and shape of dendritic spines. Based on these criteria, we propose the existence of 12 morphologically different spiny neurons in the human CeA and discuss the variability in the dendritic architecture within cellular types, including likely interneurons. Some dendritic shafts were long and straight, displayed few collaterals, and had planar radiation within the coronal neuropil volume. Most of the sampled neurons showed a few to moderate density of small stubby/wide spines. Long spines(thin and mushroom) were observed occasionally. These novel data address the synaptic processing and plasticity in the human CeA. Our morphological description can be combined with further transcriptomic, immunohistochemical, and electrophysiological/connectional approaches.It serves also to investigate how neurons are altered in neurological and psychiatric disorders with hindered emotional perception, in anxiety, following atrophy in schizophrenia, and along different stages of Alzheimer's disease.

Effectiveness and safety of alcohol-free minoxidil in the management of treatment-naive patients with androgenetic alopecia

Background: Androgenetic alopecia (AGA) is a common dermatological condition in India, with potentially adverse psychosocial consequences. Here, we assess the effectiveness and safety of an alcohol-free, procapil-based formulation of minoxidil 5% in patients with AGA. Methods: Treatment-naïve, male patients (aged 18 to ≤45 years) with AGA were enrolled in this open-label, single-arm, non-comparative, investigator-initiated study. The change in anagen/telogen ratio (ATR), hair density, and hair shaft thickness from baseline to days 45, 90, 135 and 180, investigator and patients’ global assessment for effectiveness and tolerability, and safety were assessed. A total of 53 men were enrolled. Results: The mean (standard deviation [SD]) age of the study population was 28.3 (6.0) years. The mean (SD) ATR improvement post-treatment with minoxidil 5% was seen from day 90 (mean change: 0.4; p=0.009; 95% confidence interval [CI]: 0.1-0.7) till Day 180 (mean change: 0.4; p=0.011; 95% CI: 0.1-0.6). Improvement in hair density (p<0.01) and hair shaft thickness (p<0.01) across frontal, temporal, and occipital regions was also evident. The investigator assessment for effectiveness was ‘excellent’/’good’/’satisfactory’ for 90% of patients, which corroborated with patients’ assessment (90%) at day 180. All the investigators and patients indicated that minoxidil had ‘good’ tolerability for all patients. No adverse events were reported during the study. Conclusions: Alcohol-free minoxidil 5% was found to have a good safety profile and was efficacious in Indian male patients with AGA, with a high level of patient acceptance.

Evaluation of the efficacy of microneedling without and with minoxidil 5% and autologous platelet-rich plasma for androgenetic alopecia in men.

Androgenetic alopecia is the most common form of non-cicatricial hair loss in men. The condition also affects young adults and can cause significant psychological distress. In addition to widely accepted methods, clinicians have at their disposal a number of therapies for which there are no established treatment algorithms. The study was conducted on a selected group of 92 men aged between 20 and 50 years. The patients were divided into three groups, each with a different therapeutic algorithm: group A - three microneedling treatments 1 month apart, group B - three microneedling treatments 1 month apart and daily topical application of 5% minoxidil, group C - three platelet-rich plasma treatments 1 month apart. Each group showed an increase in mean hair number and density. However, only group C demonstrated a statistically significant increase in hair shaft thickness. Currently, there is no clear consensus in the literature regarding algorithms for microneedling and platelet-rich plasma treatment of the scalp. For the study, we selected a minimum effective algorithm that yielded satisfactory results.

Beyond Traditional Treatments: Exploring Cutting-Edge Approaches for Androgenetic Alopecia

Androgenetic Alopecia is a genetically predetermined disorder resulting in hair loss from an excessive sensitivity to androgens. Several treatment options have been investigated for androgenetic alopecia, yet only topical minoxidil and finasteride have received approval from the US Food and Drug Administration. This review article examines and evaluates the efficacy of new, cutting-edge techniques for treating AGA, including Low-Level Laser Therapy, Platelet Rich Plasma Therapy, Micro needling, and Topical Growth Factors and Peptides. Several essential factors are stimulated by minoxidil, including vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and insulin-like growth factor (IGF)-1. IGF-1 also plays a significant role in regulating follicular differentiation, which makes it a vital regulator of hair follicle development and function. Low-level laser therapy (LLLT) uses low-intensity light at red or near-infrared wavelengths to induce changes in cellular activity, which improves blood circulation, reduces inflammation, and boosts cellular energy, ultimately leading to improved hair follicle density and diameter. Platelet-rich plasma therapy (PRP) is used in dermatology for acne scar treatment, lipid transplantation, wound healing, and hair regeneration. It involves a centrifugation process that increases the platelet concentration and reduces the red blood cell ratio. Micro needling is a minimally invasive procedure that stimulates the production of collagen, growth factors, and neovascularization, which promotes tissue rejuvenation. It is most utilized for individuals who are unable to achieve successful results using medical therapy. These approaches have shown positive outcomes in terms of hair regrowth, improved hair density, increased hair shaft thickness, and patient satisfaction.

Minoxidil oral en alopecias no androgénicas

For several years minoxidil has been used in medicine and trichology. Its mechanism of action remains unclear, it prolongs anagen, modulates angiogenesis and increases hair shaft thickness. New research suggests an antiandrogenic and immunomodulatory role. Low-dose oral minoxidil has proven to be an alternative for alopecia. The optimal dose for this purpose has not been established, it is probably different for children, women and men. Androgenic alopecia has been the most widely studied condition, there are other pathologies such as telogen effluvium, traction alopecia, alopecia areata, chemotherapy-induced alopecia, loose anagen hair syndrome, monilethrix, and scarring alopecia (fibrosing frontal alopecia and lichen planus pilaris). This literature review aims to expose the mechanism of action, pharmacokinetics, safety and efficacy of oral minoxidil in different types of non-androgenic alopecia.

Androgenetic Alopecia in Children and Adolescents: From Trichoscopy to Therapy

Introduction: Pediatric androgenetic alopecia is a product of hormonal and genetic factors. The diagnosis depends on recognizing the hair loss pattern in the context of a positive family history and a typical trichoscopy. Methods: A multicenter retrospective study assessing medical data from January 2008 to January 2023 of two reference centers – one public and one private in west Mexico. Patients under 18 years old were included. The clinical features, trichoscopic findings, associated conditions, and treatment received were documented and analyzed. Results: We found 145 patients, with a mean age of 16.08 ± 1.30 years, predominantly comprising males (72%). Trichoscopy was performed on 33 patients. The main trichoscopic findings were hair shaft thickness variability in 100% of the cases, vellus hair in 85%, and single-hair units in 79%. Vitamin D deficiency was found in 84% of the cases with laboratory determination, insulin resistance in 33%, and hyperandrogenemia in 12.5%. Topical minoxidil emerged as the main treatment modality in 24% of cases, demonstrating both efficacy and tolerability. Conclusion: Pediatric androgenetic alopecia could be more prevalent than commonly perceived, potentially explained by the lower level of suspicion among medical practitioners. Distinctive trichoscopic findings offer valuable guidance for therapeutic strategies and ongoing management.

Vitamin C Deficiency Deteriorates Bone Microarchitecture and Mineralization in a Sex-Specific Manner in Adult Mice.

Vitamin C (VitC) is essential for bone health, and low VitC serum levels increase the risk for skeletal fractures. If and how VitC affects bone mineralization is unclear. Using micro-computed tomography (μCT), histologic staining, as well as quantitative backscattered electron imaging (qBEI), we assessed the effects of VitC on femoral structure and microarchitecture, bone formation, and bone mineralization density distribution (BMDD) in the VitC incompetent Gulo-/- mouse model and wild-type mice. In particular, VitC-supplemented, 20-week-old mice were compared with age-matched counterparts where dietary VitC intake was excluded from week 15. VitC depletion in Gulo-/- mice severely reduced cortical thickness of the diaphyseal shaft and bone volume around the growth plate (eg, bone volume of the primary spongiosa -43%, p < 0.001). Loss of VitC also diminished the amount of newly formed bone tissue as visualized by histology and calcein labeling of the active mineralization front. BMDD analysis revealed a shift to higher calcium concentrations upon VitC supplementation, including higher average (~10% increase in female VitC deficient mice, p < 0.001) and peak calcium concentrations in the epiphyseal and metaphyseal spongiosa. These findings suggest higher bone tissue age. Importantly, loss of VitC had significantly more pronounced effects in female mice, indicating a higher sensitivity of their skeleton to VitC deficiency. Our results reveal that VitC plays a key role in bone formation rate, which directly affects mineralization. We propose that low VitC levels may contribute to the higher prevalence of bone-degenerative diseases in females and suggest leveraging this vitamin against these conditions. © 2023 American Society for Bone and Mineral Research (ASBMR).

Hair-to-Hair Trichoscopy: An Objective Method to Assess Effectiveness of Botulinum Toxin in a Clinical Trial for Androgenetic Alopecia

Introduction: Androgenetic alopecia (AGA) is the most common alopecia affecting both genders leading to a potential decrease in quality of life and self-esteem. A current concern in trichology is how to accurately measure clinical response in both daily medical practice and academic research. Hair-to-hair (H2H)-matching technology™ has recently emerged as a technique to evaluate variations in follicular units, hair shaft number, and thickness. This study aimed to describe the methodology employed in a clinical trial using this technology to test the efficacy of botulinum toxin (BT) for male AGA. Methods: This pilot study is a triple-blind, randomized, split scalp, placebo-controlled clinical trial. Patients enrolled were submitted to injections half of the scalp with 50 IU of BT and the other half with 1 mL of normal saline as a control. The trial involved three visits (weeks 0, 12, and 24) and 8 global clinical photographs followed by H2H-matching trichoscopy were captured before the injections at each visit. Paired t test analysis was employed for matched pairs of the following parameters: total hair count, the total number of terminal hair strands, average shaft thickness, and the number of hairs lost or gained during each visit. Then, the software compared the differences between the two sides (BT vs. placebo) per scalp zone and a long time. Conclusion: The combination of manually corrected image processing, follicular map, and H2H-matching technology™ appears to be the most precise way to evaluate changes in hair count and thickness over time. The design is reproducible and can help other researchers and dermatologists in their clinical practice to obtain reliable results in similar scientific research.

Assessment of Occipital Involvement Among a Large Population of Females with Pattern Hair Loss in Saudi Arabia.

Cumulative evidence suggests the involvement of the occipital region in female pattern hair loss (FPHL). However, most of the studies that have been published so far concerned relatively small samples of patients. To assess the occipital involvement in FPHL and analyze its correlation with disease severity among a large sample of patients. A retrospective study involved 1000 adult women with FPHL, between January 2020 and August 2022. Occipital involvement was defined as more than 10% of thin hairs (<0.03 mm). Baseline trichometry parameters in the frontal and occipital regions were analyzed. Occipital involvement was observed in 32.4% of the patients. Positive correlations between frontal and occipital regions were observed for all trichometry parameters; the strongest concerned average hair shaft thickness (Pearson's coefficient r=0.708), cumulative hair thickness (r=0.673), and trichometry-derived Sinclair scale (r=0.656). The risk of occipital involvement increased independently with the disease severity in frontal region; however, the disease progression was slower in the occipital compared to frontal region. One-third of females in our study with FPHL had occipital involvement. This has a major impact on the methods used to diagnose pattern hair loss in females and their treatment plan including hair restoration surgery.

Investigation of The Effect of Reduced Shank Thickness of Friction Welded Yoke Shaft on Strength

Usage of friction welding method on the joints provides many advantages such as cost reduction, weight reduction and higher quality. The yoke shaft produced by rotary friction welding (RFW) involves a yoked part and a hollow round bar which are welded to each other. And so, no additional drilling method used in the way of removing material from the centre of the yoke shaft, is required to reduce the weight. The weight is inherently reduced thanks to hollow round bar used in RFW method. It is possible to use a friction welded yoke shaft in a wide range of wall thickness by removing material from the shank diameter for different applications. At this point, the key factor is strength of the friction welded yoke shaft with reduced wall thickness on the shank diameter. The aim of this study is investigation the effect of the reduced wall thickness of a yoke shaft produced by RFW on the strength. For this purpose, yoke shafts were manufactured by using RFW and consecutive processes such as turning and millings to reduce the wall thickness. The specimens in different wall thickness were tested to determine the strength. Additionally finite element analyses (FEAs) were implemented for each variation of the specimens and compared with the test results. As a result, it was determined that yoke shafts with reduced wall thicknesses, which were produced by RFW and then consecutively machining operations to obtain a specific wall thickness, can be used in drive shaft manufacturing securely.

Intake and growth histories modulate bone morphology, microarchitecture, and mineralization in juvenile green turtles (Chelonia mydas)

Abstract Compensatory growth (CG) is accelerated growth that occurs when food availability increases after food restriction. This rapid growth may be associated with sublethal consequences. In this study, we investigated the effects of food restriction and subsequent realimentation and CG on bone structure in juvenile green turtles (Chelonia mydas). Turtles were fed ad libitum food for 12 weeks (AL), restricted food for 12 weeks (R), or restricted food for 5 weeks followed by ad libitum food for 7 weeks (R-AL). R-AL turtles demonstrated partial CG via enhanced food conversion efficiency (FCE) upon realimentation. After the 12th week, gross morphology (GM), microarchitecture, and mineralization of the right humerus of each turtle were analyzed. Many GM measurements (including proximal and maximal bone lengths, bone widths, and shaft thickness), most measurements of bone microarchitecture (excluding cortical and trabecular thickness and trabecular separation), and all mineralization measurements were labile in response to intake. We examined the possibility that changes in nutrient allocation to bone structure during realimentation facilitated CG in previously food-restricted turtles. Restoration of bone lengths was prioritized over restoration of bone widths during CG. Furthermore, restoration of trabecular number, connectivity density, and bone volume fraction was prioritized over restoration of cortical bone volume fraction. Finally, diaphyseal bone mineralization was partially restored, whereas no restoration of epiphyseal bone mineralization occurred during CG. Shifts in nutrient allocation away from certain bone attributes during food restriction that were not rectified when food availability increased probably provided an energy surplus that enhanced the conversion of food to growth and thus powered the CG response. Our study revealed how resource allocation to various bone attributes is prioritized as nutritional conditions change during development. These “priority rules” may have detrimental consequences later in life, indicating that conservation of green turtle foraging grounds should be given high priority.

Improving chatter performance of a lathe spindle through grapho-optimization

Structural modifications to spindle systems have been demonstrated in previous studies to improve their dynamical performance. The aim of this study is to improve the performance of a lathe spindle system in terms of chatter occurrence, while maintaining the same overall mass of the system. The design of the spindle system is optimized using the grapho-optimization method, employing the Kuhn-Tucker optimality criterion to evaluate the design parameters. Specifically, the thickness of the spindle shaft and the diameter of the shaft next to the chuck are varied. The optimized spindle system shows a significant improvement in the first natural frequency value compared to the original design; the first natural frequency is increased by 59.7 %.