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Quantum metrology is deeply connected to quantum geometry, through the fundamental notion of quantum Fisher information. Inspired by advances in topological matter, it was recently suggested that the Berry curvature and Chern numbers of band structures can dictate strict lower bounds on metrological properties, hence establishing a strong connection between topology and quantum metrology. In this work, we provide a first experimental verification of such topological bounds, by performing optimal quantum multi-parameter estimation and achieving the best possible measurement precision. By emulating the band structure of a Chern insulator, we experimentally determine the metrological potential across a topological phase transition, and demonstrate strong enhancement in the topologically non-trivial regime. Our work opens the door to metrological applications empowered by topology, with potential implications for quantum many-body systems.

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Peyronie's disease (PD) is a common benign condition characterized by superficial fibrosis and scar formation at the tunica albuginea of the penis, eventually leading to penile curvature. It is believed that penile micro-traumas during intercourse and subsequent activation of inflammatory processes constitute the pathogenetic basis of the disease. Routinely, PD is divided into acute and chronic phases, with pain during erection or flaccid state being the hallmark of the former. Surgical intervention should be avoided during the acute phase, as the risk of recurrence or progression of penile deformity during this stage might affect the optimal outcomes of the procedure. During this stage, many conservative treatment options have been suggested, including oral, topical, and intralesional therapies, extracorporeal shock wave therapy (ESWT), and penile traction therapy (PTT). Currently, the optimal treatment consists of a combined treatment strategy with phosphodiesterase type 5 inhibitors (PDE5Is), ESWT for pain management, PTT, and intralesional therapies. Large, well-designed randomized controlled trials (RCTs) are necessary to further elucidate the most efficient treatment option for acute phase PD.

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DNA is the macromolecule responsible for storing the genetic information of a cell and it has intrinsic properties such as deformability, stability and curvature. DNA Curvature plays an important role in gene transcription and, consequently, in the subsequent production of proteins, a fundamental process of cells. With recent advances in bioinformatics and theoretical biology, it became possible to analyze and understand the involvement of DNA Curvature as a discriminatory characteristic of gene-promoting regions. These regions act as sites where RNAp (ribonucleic acid-polymerase) binds to initiate transcription. This review aims to describe the formation of Curvature, as well as highlight its importance in predicting promoters. Furthermore, this article provides the potential of DNA Curvature as a distinguishing feature for promoter prediction tools, as well as outlining the calculation procedures that have been described by other researchers. This work may support further studies directed towards the enhancement of promoter prediction software.

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Case summary: An 11-year-old neutered male Turkish Angora cat was referred for obstructive feline lower urinary tract disease (FLUTD). On physical examination, the penis was curved at the tip and had a smaller than normal urethral opening proximal to the end, consistent with singular glandular hypospadias with a dorsal penile curvature. Because of its recurrent obstructive FLUTD history and inability to catheterise the urethra, a preputial urethrostomy (PRU) was performed. The PRU resolved the clinical signs with no clinical recurrence and no short- or long-term complications. Relevance and novel information: To the authors' knowledge, this is the first description of singular glandular hypospadias in a cat. In addition, this is the first time feline hypospadias has been reported to occur with obstructive FLUTD and to be treated by preputial urethrostomy.

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The primary objective of this study was to develop a custom algorithm to assess three-dimensional (3D) acetabular coverage of the femoral head based on surface models generated from computed tomography (CT) imaging. The secondary objective was to apply this algorithm to asymptomatic young adult hip joints to assess the regional 3D acetabular coverage variability and understand how these novel 3D metrics relate to traditional two-dimensional (2D) radiographic measurements of coverage. The algorithm developed automatically identifies the lateral- and medial-most edges of the acetabular lunate at one-degree intervals around the acetabular rim based on local radius of curvature. The acetabular edges and the center of a best-fit sphere to the femoral head are then used to compute the mean 3D subchondral arc angles and hip joint coverage angles in five acetabular octants. This algorithm was applied to hip models generated from pelvis/hip CT imaging or abdomen/pelvis CT angiograms of 50 patients between 17 and 25 years of age who had no history of congenital or developmental hip pathology, neuromuscular conditions, or bilateral pelvic and/or femoral fractures. Corresponding 2D acetabular coverage measures of lateral center edge angle (LCEA) and acetabular arc angle (AAA) were assessed on the patients' clinical or digitally reconstructed radiographs. The 3D subchondral arc angle in the superior region (58.0 [54.6-64.8] degrees) was significantly higher (p < 0.001) than all other acetabular subregions. The 3D hip joint coverage angle in the superior region (26.2 [20.7-28.5] degrees) was also significantly higher (p < 0.001) than all other acetabular subregions. 3D superior hip joint coverage angle demonstrated the strongest correlation with 2D LCEA (r = 0.649, p < 0.001), while 3D superior-anterior subchondral arc angle demonstrated the strongest correlation with 2D AAA (r = 0.718, p < 0.001). The 3D coverage metrics in the remaining acetabular regions did not strongly correlate with typical 2D radiographic measures. The discrepancy between standard 2D measures of radiographic acetabular coverage and actual 3D coverage identified on advanced imaging indicates potential discord between anatomic coverage and the standard clinical measures of coverage on 2D imaging. As 2D measurement of acetabular coverage is increasingly used to guide surgical decision-making to address acetabular deformities, this work would suggest that 3D measures of acetabular coverage may be important to help discriminate local coverage deficiencies, avoid inconsistencies resulting from differences in radiographic measurement techniques, and provide a better understanding of acetabular coverage in the hip joint, potentially altering surgical planning and guiding surgical technique.

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PURPOSE OF THE REVIEW: The estimation of penile curvature is an essential component in the assessment of both Peyronie's disease and hypospadias-associated congenital penile curvature, as the degree of curvature can significantly impact treatment decision-making. However, there is a lack of standardization in curvature assessment and current methodologies are prone to inaccuracies. With the rise of artificial intelligence (AI) in urology, new research has explored its applications in penile curvature assessment. This review aims to evaluate the current uses of AI and other automated platforms for assessing penile curvature. RECENT FINDINGS: Several novel and promising tools have been developed to estimate penile curvature, some utilizing AI-driven models and others employing automated computational models. These platforms aim to improve curvature assessment in various settings, including at-home evaluation of Peyronie's disease, in-office assessments using three-dimensional (3D) methodologies, and preoperative evaluations for hypospadias repair. In general, these new platforms produce highly accurate and reproducible angle estimates in non-clinical studies, however their effectiveness and relation to patient outcomes has had limited evaluation in clinical settings. Significant advancements have been made in the assessment and estimation of penile curvature in both Peyronie's and pediatric patients, largely driven by AI and other automated platforms. Continued research is needed to validate these findings in clinical studies, confirm their efficacy, and assess their feasibility for real-world applications.

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This article presents a long-period fiber-grating sensor based on a congruent quasi-helical structure (CQH-LPFG) with the two-parameter measurement of both temperature and curvature. The CQH-LPFG sensor was manufactured using a high-frequency CO2 laser, and an innovative quasi-helical structure was introduced into the two-parameter measurement of the temperature and curvature of the optical fiber sensor with excellent results. The experiment and analysis demonstrate that the curvature sensitivities of the three resonance peaks in the 1440 nm to 1540 nm transmission spectrum were 11.88 nm/m-1, 8.05 nm/m-1, and 11.11 nm/m-1, and the curvature varied ranging from 0.156 m-1 to 0.494 m-1. The three resonance peaks showed temperature responsivities of 29.87 pm/°C, 24.65 pm/°C, and 36.85 pm/°C, respectively, and the linear fit was of excellent quality. In the case of measuring both curvature and temperature changes simultaneously, the resonant peak wavelength of the CQH-LPFG sensor was demodulated through matrix analysis, with dip A and dip C providing superior simultaneous measurements. These features make it a promising candidate for applications such as engineering machinery and the health inspection of buildings.

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HYPOTHESIS: Phospholipids are amphiphilic molecules able to adsorb at oil/water interfaces and thus used to stabilize parenteral emulsions. Yet, their low preferred curvature, which sensitively depends on molecular structures and interactions, favors the formation of lamellar phases and sets constraints on the system formulation. Combining phase studies, structural interfacial characterizations, and stability monitoring for different water/phospholipid/oil systems should shine a light on the mechanisms at play and thus tools to optimize formulations. EXPERIMENTS: Four phase diagrams were established for ternary aqueous systems containing either DOPC or POPC as the phospholipid and hexadecane or miglyol 812 as the oil. Droplet interfaces were probed using small-angle neutron scattering and the amount of adsorbed lipid was determined using separation and Raman spectroscopy. The metastability of both nano and macro emulsions was systematically assessed over weeks using light scattering. FINDINGS: We show that nanoemulsion droplets are stabilized by a lipid monolayer and display excellent metastability if the preferred curvature is positive and large enough, even without any added charges or at high ionic strengths. In contrast, macroemulsion droplets are stabilized with a lipid multilayer, which should possess a positive preferred curvature but also a good enough interfacial anchorage, which is lost upon increasing the preferred curvature. Overall, we provide a rationale for understanding the impact of molecular changes in the formulation on emulsion metastability, through the analysis of the lipid film preferred curvature, layering, and interfacial anchorage.

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AIM: To evaluate the agreement between six currently available periapical radiography-based methods for measuring the root canal curvatures in mesial roots of mandibular first molars, assessed by two examiners with different proficiency levels. METHODOLOGY: Non-endodontically treated mesial roots of 41 human mandibular first molars were radiographed using the parallelling technique. Two independent observers (a specialist in endodontics and radiology and a final-year dental student) assessed their root canal curvature using the methodologies described by Schneider (1971, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 32, 271), Weine (1982, Endodontic therapy), Berbert and Nishiyama (1994, Revista Gaúcha de Odontología, 356), Luiten et al. (1995, Journal of Endodontics, 21, 26), Hankins and ElDeeb (1996, Journal of Endodontics, 22, 123) and Pettiette et al. (1999, Journal of Endodontics, 25, 230). Intra- and inter-examiner reliability was assessed using the intraclass correlation coefficient. The differences in curvature angle measured by the different methods were compared using the one-way anova for repeated measures test, followed by Tukey's post hoc analysis. The effect was calculated using the Cohen's d method. To determine the agreement between methods, the Bland-Altman analysis was used. The significance level was set at 5%. RESULTS: Agreement for the observers was excellent (>0.81) for the six methods considered. For the angle comparisons between methods, the maximum differences were for Schneider versus Weine (35.77°) and Luiten versus Hankins (35.14°), whilst the highest percentage of angles with a difference >10° were Weine versus Luiten and Berbert versus Pettiette (90%) and the comparison Weine versus Hankins presented with the lowest frequency (15%). Excellent agreement was found for five comparisons: Weine versus Luiten (0.940), Berbert versus Pettiette (0.917), Weine versus Pettiette (0.907), Luiten versus Pettiette (0.904) and Berbert versus Luiten (0.812). Compared to Schneider's method, the other methods showed a tendency of increasing difference as the angles became more acute. The other methods exhibited linear differences, remaining constant for smaller and larger angles. CONCLUSIONS: Reliability was excellent for all methods assessed separately. Maximum differences in curvature angles were found when comparing Schneider versus Weine and Luiten versus Hankins. Excellent agreement was found for Weine versus Luiten, Berbert versus Pettiette, Weine versus Pettiette, Luiten versus Pettiette and Berbert versus Luiten. In the presence of dilacerations, the method by Schneider was less sensitive.

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Peyronie's disease (PD) has detrimental effects on the quality of life, mental health, sexual functioning and several other aspects that increase the risk of relationship problems. However, no study to date has assessed the risk of relationship separation in med with PD. Herein, we utilized data from Swedish national registers to examine the risk of relationship separation in men with PD. We conducted a matched cohort study on men born 1933-1992, followed from 1997 to 2013. PD was defined as a physician-assigned diagnosis according to the International Classification of Diseases, Tenth version. Each man with PD (n = 8020) was matched with 10 comparison men. We defined relationship separation as (1) ever separated, and (2) separation rate. We used log-linear regression to estimate the risk ratio, and rate ratio of relationship separation. We adjusted for matching variables (birth year and country of birth), and an indicator of each follow-up year. We found that men with PD had a 13% increased risk of relationship separation (risk ratio 1.13, 95% confidence interval [CI] 1.08-1.17). The rate of relationship separation events, measured on a yearly basis, was increased by 18% (rate ratio 1.18, CI 1.12-1.24), and remained similar when adjusting for follow-up year and socio-economic status.

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The eye lens contains convexly curved fiber cells that align in concentric layers around the lens anterior-posterior pole axis. For lens fiber differentiation at the equator, cells elongate with their apical and basal tips migrating towards the anterior and posterior poles, respectively. At each pole, the fiber tips meet opposing tips of other fiber cells, to form a suture. Although umbilical or point sutures are observed in fish and birds, line, Y- or star-shaped sutures are detected in other vertebrate lenses. Sutures that do not converge at the point are thought to result from intricate movements of the fiber tips, rather than a straightforward migration along a meridional path. The triggers that give rise to these variations are currently not understood. Our findings revealed that in the mouse embryo, the early-stage lens contains only concave curved fibers, and later, a zone of concave-to-convex curve conversion develops. At this point, a nascent suture in a linear shape appears at the posterior pole and subsequently progresses into a V-shape. This V-shape appears to further develop into a Y-shape as a branch extends from the apex of the V-shape. In lens of zebrafish and Xenopus larvae that form point sutures, this curve-conversion zone is not observed. In lens of adult birds (e.g. zebra finch) that form a point suture, these too also lack a curve-conversion zone. In our previous studies, we demonstrated that murine lens fibers undergoing curve conversion extend membrane protrusions, or lamellipodia, at their basal membranes. In line with this, we did not observe protrusions at the basal tips of fibers in the non-mammalian lenses of zebrafish, Xenopus, and zebra finch in which curve conversion does not occur. We propose that the concave-to-convex conversion in rodent lenses introduces defined paths for fiber cell tips, leading to a more elaborate and complex suture formation, compared to the simple point suture of lower vertebrates.

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A gastric rupture resulting from abdominal trauma is a rare occurrence with a frequency of less than 2% of blunt abdominal injuries. Furthermore, gastric perforation secondary to the Heimlich maneuver is even rarer, with only a handful of cases reported in the literature. Here, we present a case of isolated gastric rupture following a successful Heimlich maneuver. Laparotomy revealed a large perforation along the lesser curvature of the stomach. The perforation was repaired by primary closure and reinforced with omental patching.

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Context: Root canal instrumentation is one of the important procedures for successful endodontic therapy. Unexpected fracture of files occurs during root canal instrumentation without any visible signs of deformation compromising the success of root canal treatment. Aims: The aim of the study was to evaluate and compare cyclic fatigue resistance (CFR) of rotary and reciprocating files in simulated canals with 45°, 60°, and 90° angle of curvature. Settings and Design: The study design was an In vitro study. Subjects and Methods: Sixty nickel-titanium files, 30 each of rotary and reciprocating files were selected and divided into four groups (n = 15) of Neoendo Flex, ProTaper Next, WaveOne Gold (WOG), and Reciproc Blue (RPB) files. Each group was further subdivided into three subgroups containing five samples each based on their use in simulated canals with 45°, 60°, and 90° angle of curvature. To simulate root canals with 45°, 60°, and 90° angle of curvature, three artificial canals were designed in a stainless steel metal block. Each file was autoclaved, immersed in 3% sodium hypochlorite (NaOCl), and coated with 17% ethylenediaminetetraacetic acid (EDTA). Each file was tested for CFR using a torque-controlled reduction handpiece by instrumenting in a simulated canal for 10 s until fracture. The cycle of autoclaving, exposure to NaOCl, EDTA, and testing of CFR for 10 s per canal as per groups and subgroups was repeated again and again until the respective file fracture. The time taken to file fracture was recorded using a digital chronometer. The time taken for each file fracture (in minutes) was multiplied by the number of rotations per minute to attain the number of cycles to failure (NCF). Statistical Analysis Used: The obtained results were subjected to statistical analysis using one-way analysis of variance and independent t-test. Results: One-way ANOVA test showed a statistically significant difference between the four groups, P < 0.001. Independent "t"-test between individual subgroups showed a statistically significant difference, as P < 0.05. Conclusions: WOG and RPB reciprocating file systems showed superior CFR, more especially in canals with abrupt 90° angle of curvature compared to both rotary file systems tested. Among rotary file systems tested, Neoendo Flex showed greater CFR than ProTaper Next.

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Background: This study aimed to investigate the potential variance in the prevalence of early-onset scoliosis among children aged 4-7 years and analyze the influencing factors. The goal was to establish a crucial reference point for monitoring and evaluating spinal curvature development in preschoolers, ultimately to reduce the occurrence of adverse health outcomes. Methods: Children aged 4-7 years within the main urban area of Nanjing were selected using a stratified random sampling method. A team of four senior therapists conducted screenings for spinal curvature among children using visual inspection, the Adams forward bending test, and an electronic scoliometer to measure the angle of trunk rotation (ATR) and identify children displaying signs of scoliosis. Children with suspected scoliosis in the initial screening underwent X-ray Cobb angle assessment for confirmation. The prevalence of early-onset scoliosis was then determined from the screening results. R version 4.2.0 software was used to analyze the factors associated with scoliosis among children using partial least squares structural equation modeling. Results: A total of 2281 children were included in this study, consisting of 1211 boys and 1070 girls, with a mean age of 5.44 ± 0.81 years (ranging from 4 to 7 years). Among them, 7.58% exhibited positive signs of scoliosis, 5.87% had early-onset scoliosis, and the positive predictive value was 77.5%. Significant differences in ATR were observed among children in different age groups (Kruskal-Wallis = 15, p = 0.0104) and by sex (t = 3.17, p = 0.00153). Significant variations in ATR were noted in children with scoliosis (t = -22.7, p < 0.001), with a cutoff at ATR = 4.5°, and auxiliary values of 0.947 and 0.990. Children diagnosed with early-onset scoliosis generally exhibited lower body mass index values, with a statistically significant difference (t = 2.99, p = 0.003). Conclusions: Using visual inspection, the Adams test, and an electronic scoliometer to measure the ATR, the present triad method is more sensitive for early scoliosis screening in children with abnormal posture aged 4-7 years. A full spine X-ray is advised in children with an ATR over 4.5° and poor posture.

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Here, we report curvature-induced electron spin catalysis by using solid carbon spheres as catalysts, which were synthesized using positive curvature molecular hexabromocyclopentadiene as a precursor molecule, following a radical coupling mechanism. The curvature spin of carbon is regarded as an overlapping state of σ- and π-radical, which is identified by the inverse Laplace transform of pulse-electron paramagnetic resonance. The growth mechanism of carbon spheres abiding by Kroto's model, is supported by the density functional theory study of thermodynamics and kinetics calculations. The solid carbon spheres present excellent catalytic behaviour of oxidation coupling of amines to form corresponding imines with the conversion of >99%, selectivity of 98.7%, and yield of 97.7%, which is attributed to the predominantly curvature-induced electron spin catalysis of carbon, supported by the calculation of oxygen adsorption energy. This work proposes a view of curvature-induced spin catalysis of carbon, which opens up a research direction for curvature-induced electron spin catalysis.

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The M2 proton channel aids in the exit of mature influenza viral particles from the host plasma membrane through its ability to stabilize regions of high negative Gaussian curvature (NGC) that occur at the neck of budding virions. The channels are homo-tetramers that contain a cytoplasm-facing amphipathic helix (AH) that is necessary and sufficient for NGC generation; however, constructs containing the transmembrane spanning helix, which facilitates tetramerization, exhibit enhanced curvature generation. Here, we used all-atom molecular dynamics (MD) simulations to explore the conformational dynamics of M2 channels in lipid bilayers revealing that the AH is dynamic, quickly breaking the fourfold symmetry observed in most structures. Next, we carried out MD simulations with the protein restrained in four- and twofold symmetric conformations to determine the impact on the membrane shape. While each pattern was distinct, all configurations induced pronounced curvature in the outer leaflet, while conversely, the inner leaflets showed minimal curvature and significant lipid tilt around the AHs. The MD-generated profiles at the protein-membrane interface were then extracted and used as boundary conditions in a continuum elastic membrane model to calculate the membrane-bending energy of each conformation embedded in different membrane surfaces characteristic of a budding virus. The calculations show that all three M2 conformations are stabilized in inward-budding, concave spherical caps and destabilized in outward-budding, convex spherical caps, the latter reminiscent of a budding virus. One of the C2-broken symmetry conformations is stabilized by 4 kT in NGC surfaces with the minimum energy conformation occurring at a curvature corresponding to 33 nm radii. In total, our work provides atomistic insight into the curvature sensing capabilities of M2 channels and how enrichment in the nascent viral particle depends on protein shape and membrane geometry.

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Aim: To determine the influence of biomechanical preparation on various parameters of root canal curvature. Materials and methods: A total of 72 tooth roots with moderate (10-25°) and severe canal curvature (26-75°) were selected and embedded in autopolymerizing acrylic resin for which cone-beam computed tomography (CBCT) image analysis was performed. Schneider angle, canal access angle (CAA), and the radius of curvature were determined preoperatively using auto-computer-aided design (CAD) 2021 software. Protaper gold rotary nickel-titanium (Ni-Ti) files were used to prepare the root canals. All angular and linear values were measured in auto-CAD and compared using postoperative CBCT pictures. The difference in pre- and postoperative values was assessed using paired samples t-test and independent samples t-test. Results: There was a statistically significant difference between the Schneider angle (p = 0.002), (p < 0.001), CAA (p < 0.001), (p = 0.001), and radius of curvature (p = 0.01), (p = 0.001) pre- and postoperatively in both moderate and severe canal curvature groups, respectively. This difference was greater in the severe curvature group (p-value = 0.027) than in the group exhibiting moderate curvature. Among the parameters tested, Schneider angle has shown maximum difference pre- and post before and after mathematical processing (BMP) compared to other parameters. Conclusion: This approach is a new and objective way of measuring root canal geometric changes. The current findings suggest that the Schneider angle, CAA, and the radius of curvature can be used as parameters to evaluate the changes in canal geometry following biomechanical preparation. How to cite this article: Nekkanti H, Enuganti S, Avula JSS, et al. Assessment of Biomechanical Preparation Influence on Various Root Canal Curvatures. Int J Clin Pediatr Dent 2024;17(2):130-135.

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Recently, a variety of microenvironmental biophysical stimuli have been proved to play a crucial role in regulating cell functions. Among them, morpho-physical cues, like curvature, are emerging as key regulators of cellular behavior. Changes in substrate curvature have been shown to impact the arrangement of Focal Adhesions (FAs), influencing the direction and intensity of cytoskeleton generated forces and resulting in an overall alteration of cell mechanical identity. In their native environment, cells encounter varying degrees of substrate curvature, and in specific organs, they are exposed to dynamic changes of curvature due to periodic tissue deformation. However, the mechanism by which cells perceive substrate curvature remains poorly understood. To this aim, a micro-pneumatic device was designed and implemented. This device enables the controlled application of substrate curvature, both statically and dynamically. Employing a combined experimental and simulative approach, human adipose-derived stem cells were exposed to controlled curvature intensity and frequency. During this exposure, measurements were taken on FAs extension and orientation, cytoskeleton organization and cellular/nuclear alignment. The data clearly indicated a significant influence of the substrate curvature on cell adhesion processes. These findings contribute to a better understanding of the mechanisms through which cells perceive and respond to substrate curvature signals. STATEMENT OF SIGNIFICANCE: This work is our contribution to the comprehension of substrate curvature's function as a crucial regulator of cell adhesion at the scale of focal adhesions and cell mechanical identity. In recent years, a large body of knowledge is continuously growing providing comprehension of the role of various microenvironmental biophysical stimuli in regulating cell functions. Nevertheless, little is known about the role of substrate curvature, in particular, when cells are exposed to this stimulus in a dynamic manner. To address the role of substrate curvature on cellular behavior, a micro-pneumatic device was designed and implemented. This device enables the controlled application of substrate curvature, both statically and dynamically. The experiment data made it abundantly evident that the substrate curvature had a major impact on the mechanisms involved in cell adhesion.

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It is well known that Hirshfeld surfaces provide an easy and straightforward way of analysing intermolecular interactions in the crystal environment. The use of atomic Hirshfeld surfaces has also demonstrated that such surfaces carry information related to chemical bonds which allow a deeper evaluation of the structures. Here we briefly summarize the approach of atomic Hirshfeld surfaces while further evaluating the kind of information that can be retrieved from them. We show that the analysis of the metal-centre Hirshfeld surfaces from structures refined via Hirshfeld Atom Refinement (HAR) allow accurate evaluation of contacts of type M...H, and that such contacts can be related to the overall shape of the surfaces. The compounds analysed were tetraaquabis(3-carboxypropionato)metal(II), [M(C4H3O4)2(H2O)4], for metal(II)/M = manganese/Mn, cobalt/Co, nickel/Ni and zinc/Zn. We also evaluate the sensitivity of the surfaces by an investigation of seemingly flat surfaces through analysis of the curvature functions in the direction of C-C bonds. The obtained values not only demonstrate variations in curvature but also show a correlation with the hybridization of the C atoms involved in the bond.

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Chinese Tan sheep lambs are recognised for having tight 'spring-like' curly wool when young, but this phenotype disappears with age. This wool consists of shorter, fine wool fibres (which are usually unmedullated) and heterotypic hair fibres (which are frequently medullated), which are referred to as 'halo hair'. Both the wool and hair fibres consist of α-keratin proteins embedded in a keratin-associated protein (KAP) matrix. Of these KAPs, the KAP20-1 gene (designated KRTAP20-1) and its effect on four fibre traits (mean fibre curvature, mean fibre diameter, fibre diameter standard deviation, and coefficient of variation of fibre diameter) of Tan lambs was studied. Seven previously identified KRTAP20-1 variants (A, B, D, E, F, G, and H) of KRTAP20-1 were revealed, but the previously identified variant C was not present. Of the seven variants detected, only two (A and G) were common and present at frequencies greater than 5%, and the effect of these on the fibre traits of the finer wool fibres was assessed. It was found that variant G was associated with an increased mean fibre curvature in these wool fibres. This suggests that KRTAP20-1 might possibly be expressed differentially in the two fibre types, which may be of future value in breeding.

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