Accuracy of radiographic techniques in detection of the calcaneofibular ligament calcaneal insertion for lateral ankle ligament complex surgery.

BACKGROUND: Grade III ankle sprains that fail conservative treatment can require surgical management. Anatomic procedures have been shown to properly restore joint mechanics, and precise localization of insertion sites of the lateral ankle complex ligaments can be determined through radiographic techniques. Ideally, radiographic techniques that are easily reproducible intraoperatively will lead to a consistently well-placed CFL reconstruction in lateral ankle ligament surgery. PURPOSE: To determine the most accurate method to locate the calcaneofibular ligament (CFL) insertion radiographically. METHODS: MRIs of 25 ankles were utilized to identify the "true" insertion of the CFL. Distances between the true insertion and three bony landmarks were measured. Three proposed methods (Best, Lopes, and Taser) for determining the CFL insertion were applied to lateral ankle radiographs. X and Y coordinate distances were measured from the insertion found on each proposed method to the three bony landmarks: the most superior point of the postero-superior surface of the calcaneus, the posterior most aspect of the sinus tarsi, and the distal tip of the fibula. X and Y distances were compared to the true insertion found on MRI. All measurements were made using a picture archiving and communication system. The average, standard deviation, minimum, and maximum were obtained. Statistical analysis was performed using repeated measures ANOVA, and a post hoc analysis was performed with the Bonferroni test. RESULTS: The Best and Taser techniques were found to be closest to the true CFL insertion when combining X and Y distances. For distance in the X direction, there was no significant difference between techniques (P = 0.264). For distance in the Y direction, there was a significant difference between techniques (P = 0.015). For distance in the combined XY direction, there was a significant difference between techniques (P = 0.001). The CFL insertion as determined by the Best method was significantly closer to the true insertion compared to the Lopes method in the Y (P = 0.042) and XY (P = 0.004) directions. The CFL insertion as determined by the Taser method was significantly closer to the true insertion compared to the Lopes method in the XY direction (P = 0.017). There was no significant difference between the Best and Taser methods. CONCLUSION: If the Best and Taser techniques can be readily used in the operating room, they would likely prove the most reliable for finding the true CFL insertion.

Ankle Distraction Arthroplasty: A Survivorship Review and Meta-Analysis.

Multiple treatments exist for ankle osteoarthritis. Ankle arthrodesis is the gold standard in late-stage osteoarthritis, but sacrifices range of motion and risks nonunion. Total ankle arthroplasty is typically reserved for low-demand patients as the long-term outcomes are poor. Ankle distraction arthroplasty is a joint sparing procedure which utilizes external fixator frame to unload the joint. This promotes chondral repair and improves function. This study aimed to organize clinical data and survivorship in published papers and direct further research efforts. Thirty-one publications were evaluated and 16 were included in the meta-analysis. The Modified Coleman Methodology Score was used to assess quality of the individual publications. Random effects models were used to estimate the failure risk after ankle distraction arthroplasty. Ankle Osteoarthritis Score (AOS), American Orthopedic Foot and Ankle Score (AOFAS), Van Valburg, and Visual Analog Scores (VAS) all improved postoperatively. Random effects model analysis revealed an overall failure ratio of 11% (95% CI: 7%-15%; p value ≤ .001; I2 = 87.01%) after 46.68 ± 7.17 months follow up, 9% (95% CI: 5%-12%; p value≤0.001 I2=81.59%) with less than 5 years follow-up and 28% (95% CI: 16%-41%; p value≤0.001 I2=69.03%) for patients with more than 5 years follow-up. Ankle Distraction Arthroplasty has promising short to intermediate term outcomes which makes this a reasonable treatment option to delay joint sacrificing surgery. The selection of the optimal candidates and consistent technique would improve research and subsequently outcomes. Based on our meta-analysis, negative prognostic factors include female sex, obesity, ROM < 20°, leg muscle weakness, high activity level, low preoperative pain levels, higher preoperative clinical scores, inflammatory arthritis, septic arthritis, and deformity.

Structural and charge transfer properties of ion intercalated 2D and bulk ice.

Ion trapping at the nanoscale within low-dimensional and bulk ice and their corresponding hydration properties are studied using ab initio techniques. We study the structural and charge transfer properties of ion intercalated two-dimensional (2D) and bulk ice and the corresponding ion hydration properties. We found that (i) the nanochannel size and ionic radius are two important factors that control the spatial distribution of hydrated ions, (ii) the alkali metal and halide ions are located in the center of the graphene-made nanochannel of size ≃6.5 Å, whereas in the nanochannel with size ≃9 Å, large (K+, Rb+, Cl-, Br-, and I-) and small (Li+, Na+, and F-) ions are located in different positions, (iii) the binding energy decreases with increase in the ionic radius, (iv) the hydration of ions decreases for large ions within 2D ice, giving a reduction in coordination number and allowing dehydration of large ions, and (v) the charge transfer mechanism is found to be different for large and small ions.

New strontium titanate polymorphs under high pressure.

We report six new dynamically stable structures of SrTiO3 at various pressures ranging from 0 to 200 GPa. These structures were found by exploring the enthalpy surface with the Minima Hopping structure prediction method. The potential energy surface was generated by a machine learned potential, the charge equilibration via neural network technique (CENT), based on an extensive training data set of highly diverse SrTiO3 periodic and cluster structures. All our CENT structures were validated at the level of density functional theory. For our new structures, we performed phonon calculations and NVT molecular dynamics calculations to investigate their dynamical stability. Finally, X-ray diffraction patterns were simulated to help to identify our predicted structures in experiments.

Adaptable transmitter for discrete and continuous variable quantum key distribution.

We present a versatile transmitter capable of performing both discrete variable and continuous variable quantum key distribution protocols (DV-QKD and CV-QKD, respectively). Using this transmitter, we implement a time-bin encoded BB84 DV-QKD protocol over a physical quantum channel of 47 km and a GG02 CV-QKD protocol with true local oscillator over a 10.5 km channel, achieving secret key rates of 4.1 kbps and 1 Mbps for DV- and CV-QKD, respectively. The reported transmitter scheme is particularly suitable for re-configurable optical networks where the QKD protocol is selected to optimize the performance according to the parameters of the links.

Thermodynamically stable polymorphs of nitrogen-rich carbon nitrides: a C3N5 study.

We have carried out an extensive search for stable polymorphs of carbon nitride with C3N5 stoichiometry using the minima hopping method. Contrary to the widely held opinion that stacked, planar, graphite-like structures are energetically the most stable carbon nitride polymorphs for various nitrogen contents, we find that this does not apply for nitrogen-rich materials owing to the high abundance of N-N bonds. In fact, our results disclose novel morphologies with moieties not previously considered for C3N5. We demonstrate that nitrogen-rich compounds crystallize in a large variety of different structures due to particular characteristics of their energy landscapes. The newly found low-energy structures of C3N5 have band gaps within good agreement with the values measured in experimental studies.

Artificial neural networks for the kinetic energy functional of non-interacting fermions.

A novel approach to find the fermionic non-interacting kinetic energy functional with chemical accuracy using machine learning techniques is presented. To that extent, we apply machine learning to an intermediate quantity rather than targeting the kinetic energy directly. We demonstrate the performance of the method for three model systems containing three and four electrons. The resulting kinetic energy functional remarkably accurately reproduces self-consistently the ground state electron density and total energy of reference Kohn-Sham calculations with an error of less than 5 mHa. This development opens a new avenue to advance orbital-free density functional theory by means of machine learning.

Subtalar distraction arthroplasty with bone marrow aspirate concentrate (BMAC), preliminary results of a new joint preservation technique.

INTRODUCTION: Isolated subtalar osteoarthritis (OA) is a debilitating condition usually occurring after trauma and particularly in the setting of an intraarticular calcaneal fracture. Currently, subtalar (talo-calcaneal joint) fusion surgery is the treatment of choice in managing subtalar OA after failure of conservative treatment. Unfortunately, subtalar fusion eliminates joint motion and increases the load over the adjacent midfoot and ankle joints, which affects the outcome of the surgery over time. Popular in the ankle, distraction arthroplasty offers another joint-preserving option, particularly important for active patients. In contrast to fusion as a salvage procedure, subtalar distraction arthroplasty allows the possibility of maintaining the function of the arthritic subtalar joint while reducing pain and improving the overall function of the foot and ankle. METHODS: We performed subtalar distraction arthroplasty using a circular external fixator combined with BMAC on seven patients with symptomatic and refractory subtalar OA. All these patients were interested in an alternative to fusion. We obtained clinical and radiographic data before and after surgery. Ankle Osteoarthritis Score (AOS) and the Marijnissen Distraction Clinical Score (MDCS) were obtained before surgery, after one year, and at latest follow-up. RESULTS: The average age was 56 years (range 45-69). The mean duration of post-operative follow-up was 35.4 months (range 15.2-53.5). The inversion of the ankle joint changed from 16.9° (10°-25°) pre-operatively to 14.3° (10°-20°) post-operatively (P = 0.28), and the eversion from 5.6° (0°-10°) to 10.0° (0°-20°) (P = 0.17). We found an increase in subtalar joint space from 1.4 mm (0-3) to 2.6 mm (2-4) before and after surgery (P = 0.01), respectively. Finally, Pixel Density Ratio (PDR) increased from 0.87 (0.66-1.30) to 1.01 (0.89-1.18) (P = 0.19). Compared to pre-operative conditions, we observed a decrease in subchondral sclerosis on X-ray in all cases post-operatively. The AOS score for ankle pain improved from 58.8 (47-74) to 15.1 (0-31) (p < 0.01). The AOS score for ankle disability improved from 68.2 (57-81) to 16.1 (0-43.5) (p < 0.001). We found improvement in the MDCS over time for all measured parameters. The clinical condition improved from 1.4 (0-2) to 0.8 (0-2) after one year and to 0.3 (0-2) at the latest follow-up (p < 0.001). Mobility was measured as ROM in the treated ankle relative to each patient's contralateral ankle. This increased from 35% (0-100) to 66% (15-120) to 76% (15-100) (p = 0.059). Function improved from 2.3 (0-3) to 1.3 (0-3) to 0.6 (0-3) (p < 0.001). Pain decreased from 7.4 (2-10) to 4.4 (2-8) to 2.1 (0-7) (p < 0.01). Complications include one patient with sensory neuralgia. CONCLUSIONS: Preliminarily, results of subtalar distraction arthroplasty as a new joint preservation technique are encouraging. Our research suggests the possibility of subtalar distraction arthroplasty as an effective treatment for symptomatic subtalar OA. Furthermore, this new operation does not eliminate the possibility of a future surgery like fusion. Subtalar distraction arthroplasty can be helpful in the management of subtalar OA in active patients who desire preservation of foot and ankle motion.

System reliability analysis of the scoliosis disorder.

BACKGROUND: Scoliosis is a spine abnormal deviation, which is an idiopathic disorder among children and adolescents. As a matter of the fact, distribution of loads on the patient's spine and load-carrying capacity of the vertebral column are both random variables. Therefore, the probabilistic approach may consider as a sophisticated method to deal with this problem. METHOD: Reliability analysis is a probabilistic-based approach to consider the uncertainties of load and resistance of the vertebral column. The main contribution of this paper is to compare the reliability level of a normal and scoliosis spinal. To do so, the numerical analyses associated with the inherent random parameters of bones and applied load are performed. Then, the reliability indices for all vertebrae and discs are determined. Accordingly, as the main innovation of this paper, the system reliability indices of the spinal column for both normal and damaged backbone systems are represented. RESULTS: Based on the required reliability index for normal spinal curvature the target system reliability level for scoliosis disorder is proposed. CONCLUSION: Since the proposed target reliability index is based on the strength limit state of the vertebral column, it can be considered as a reliability level for any proposed treatment approaches.

The Reproducibility of the Jaw Index in the Measurement of Healthy Newborns.

OBJECTIVE: Establish the reliability of the jaw index to objectify the relationship between the maxilla and mandible in healthy newborns. DESIGN: Cohort study. SETTING: Tertiary setting. PATIENTS: A total of 52 healthy newborns were included to detect an inter and intraclass correlation coefficient (ICC) of 0.8 with a 95% confidence interval (95% CI) of width 0.3. Inclusion criteria were children born full term without respiratory or feeding problems, and without congenital malformations or facial deformities due to birth trauma. Uncooperative patients were excluded. INTERVENTIONS: The jaw index, a measuring tool for objectifying micrognathia in children suspected of having Robin sequence, was used. An ICC of greater than 0.8 was considered clinically relevant. MAIN OUTCOME MEASURE(S): Primary outcomes are the reliability of the jaw index expressed as interclass correlation coefficient and ICC. Secondary outcomes are the mean jaw index and mean length of the mandible, maxilla, and the alveolar overjet. RESULTS: An interclass correlation coefficient of 0.74 (95% CI: 0.49-0.86) and an ICC of 0.81 (95% CI: 0.66-0.89) were found. The mandible had an average length of 162.6 mm (standard deviation [SD] 11.1), the maxilla 168.7 mm (SD 9.4), the alveolar overjet 2.0 mm (SD 0.60), and the mean jaw index was 2.1 (SD 0.64). CONCLUSION: The jaw index is a consistent instrument between different observers as well as for one observer measuring consecutively in the same child, to objectify the size of the lower jaw compared to that of the upper jaw in healthy newborns.

Surface reconstructions and premelting of the (100) CaF2 surface.

In this work, surface reconstructions on the (100) surface of CaF2 are comprehensively investigated. The configurations were explored by employing the Minima Hopping Method (MHM) coupled to a machine-learning interatomic potential, that is based on a charge equilibration scheme steered by a neural network (CENT). The combination of these powerful methods revealed about 80 different morphologies for the (100) surface with very similar surface formation energies differing by not more than 0.3 J m-2. To take into account the effect of temperature on the dynamics of this surface as well as to study the solid-liquid transformation, molecular dynamics simulations were carried out in the canonical (NVT) ensemble. By analyzing the atomic mean-square displacements (MSD) of the surface layer in the temperature range of 300-1200 K, it was found that in the surface region the F sublattice is less stable and more diffusive than the Ca sublattice. Based on these results we demonstrate that not only a bulk system, but also a surface can exhibit a sublattice premelting that leads to superionicity. Both the surface sublattice premelting and surface premelting occur at temperatures considerably lower than the bulk values. The complex behaviour of the (100) surface is contrasted with the simpler behavior of other low index crystallographic surfaces.

Optimized symmetry functions for machine-learning interatomic potentials of multicomponent systems.

Current machine-learning methods to reproduce ab initio potential energy landscapes suffer from an unfavorable computational scaling with respect to the number of chemical species. In this work, we propose a new approach by using optimized symmetry functions to explore similarities of structures in multicomponent systems in order to yield linear complexity. We combine these symmetry functions with the charge equilibration via neural network technique, a reliable artificial neural network potential for ionic materials, and apply this method to study alkali-halide materials MX with 6 chemical species (M = {Li, Na, K} and X = {F, Cl, Br}). Our results show that our approach provides good agreement both with experimental and DFT reference data of many physical and structural properties for any chemical combination.

A comparative study of the spatial distribution of HIV prevalence in the metropolis of Kermanshah, Iran, in 1996-2014 using geographical information systems.

OBJECTIVES: Geographical information systems (GISs) have made spatiotemporal understanding of geographical patterns possible and have contributed to the identification and analysis of factors relating to health care behaviours and outcomes. The present study is the first to examine the spatial distribution of HIV prevalence in the metropolis of Kermanshah, Iran, using GISs. METHODS: The research methods were descriptive, analytical and comparative. Additionally, data recorded for HIV-infected patients in 1996-2014 were used and then the loci of HIV infection in the metropolis of Kermanshah were identified and analysed spatially using ArcGIS (Esri, New York, NY, USA). RESULTS: HIV prevalence in the metropolis of Kermanshah increased from 1996 to 2014. Analysis of the spatial distribution of the prevalence of HIV using ArcGIS indicated the presence of clusters of HIV infection. The findings demonstrate that there were many clusters of high HIV prevalence throughout the city of Kermanshah and that these clusters increased in size during the study period. Furthermore, the statistics are indicative of a growing number of HIV-infected women as well as a significant reduction in the mean age of the HIV-infected female population. CONCLUSIONS: The spatial differences in HIV prevalence across the city of Kermanshah, as well as the identification of the resulting spatial clusters in different parts of the city, suggest that measures should be put in place to prevent the growth of these clusters and to reduce the number of women being infected with HIV.

A neural-network potential through charge equilibration for WS2: From clusters to sheets.

In the present work, we use a machine learning method to construct a high-dimensional potential for tungsten disulfide using a charge equilibration neural-network technique. A training set of stoichiometric WS2 clusters is prepared in the framework of density functional theory. After training the neural-network potential, the reliability and transferability of the potential are verified by performing a crystal structure search on bulk phases of WS2 and by plotting energy-area curves of two different monolayers. Then, we use the potential to investigate various triangular nano-clusters and nanotubes of WS2. In the case of nano-structures, we argue that 2H atomic configurations with sulfur rich edges are thermodynamically more stable than the other investigated configurations. We also studied a number of WS2 nanotubes which revealed that 1T tubes with armchair chirality exhibit lower bending stiffness.

Comparison of the effects of Ham'sF10 and αMEM in combination with FBS or BSA in vitrification/warming solution on quality and viability of sheep ovarian follicles.

The aim of this study was to evaluate the effects of the two types of media, namely minimum essential medium (αMEM) and Ham'sF10, supplemented with foetal bovine serum (FBS) or bovine serum albumin (BSA) in vitrification/warming solution on the quality and viability of sheep ovarian follicles. Vitrification method was applied for cryopreservation of sheep ovarian cortex using Ham'sF10 and αMEM supplemented with either BSA or FBS. There were five groups: Fresh, Ham'sF10+ BSA, Ham'sF10+ FBS, αMEM + BSA and αMEM + FBS. Samples were cultured for two weeks after warming. Viability and morphology of follicles and DNA fragmentation in follicles and in tissue stroma cells were analysed before vitrification/warming and following one and two weeks of culture. The Ham'sF10+ FBS and Ham'sF10+ BSA groups showed a significant decrease in follicular viability after one week of culture (p < .05 vs. Fresh). Following two weeks of culture, all groups revealed a considerable fall in the number of viable follicles (p < .05 vs. Fresh). There was an increase in DNA fragmentation of connective tissue cells but not in the follicles (p < .05). Our results showed the better application of αMEM supplemented with BSA as a vitrification solution in improvement of cryopreservation effects and maintenance of follicular survival.

Effect of particle size and partial replacement of alfalfa hay by soya bean hulls on nutrient intake, total tract digestibility and rumen degradability of diets by Holstein steers.

This study examined the effect of alfalfa hay (AH) particle size and the replacement of soya bean hull (SH) for AH within the diet of restricted fed Holstein steers on dry matter intake (DMI), total tract digestion, ruminal digestion, ruminal pH and ammonia nitrogen content, and faecal pH. Four rumen-cannulated Holstein steers averaging 353 ± 9.6 kg of BW were assigned to a 4 × 4 Latin square experiment with four periods and a 2 × 2 factorial arrangement of treatments. Factor A was AH particle size (fine vs. coarse) and factor B was diet SH content (0% vs. 10%; substituted for AH). Steers were fed at 1% of body weight of TMR containing 400 g/kg forage and 600 g/kg concentrate. Chopping of AH to fine particles decreased (p = 0.01) amount of dietary materials retained on the medium sieve (8 mm). The inclusion of SH significantly increased (p = 0.01) materials retained on the 1.18-mm sieve and tended to decrease (p = 0.07) materials on 19-mm sieves. The inclusion of SH increased (p = 0.01) ether extract (EE) intake and increased (p = 0.07) DMI. Inclusion of SH increased (p = 0.01) EE digestion and decreased (p < 0.01) faecal pH. Neither AH particle size nor SH inclusion in diets affected (p > 0.10) the in situ ruminal degradability coefficients of DM ('a', 'b', 'c' or 'a+b'). No interaction of AH×SH was seen on nutrient intake, digestibility and in situ ruminal degradability of Holstein steers.

Cytotoxic effects of Urtica dioica radix on human colon (HT29) and gastric (MKN45) cancer cells mediated through oxidative and apoptotic mechanisms.

Defects in the apoptotic pathways are responsible for both the colorectal cancer pathogenesis and resistance to therapy. In this study, we examined the level of cellular oxidants, cytotoxicity and apoptosis induced by hydroalcoholic extract of U. dioica radix (0-2000 µg/mL) and oxaliplatin (0-1000 µg/mL, as positive control) in human gastric (MKN45) and colon (HT29) cancer, as well as normal human foreskin fibroblast (HFF) cells. Exposure to U. dioica or oxaliplatin showed a concentration dependent suppression in cell survival with IC50 values of 24.7, 249.9 and 857.5 µg/mL for HT29, MKN45 and HFF cells after 72 h treatment, respectively. ROS formation and lipid peroxidation were also concentration-dependently increased following treatment with U. dioica, similar to oxaliplatin. In addition, the number of apoptotic cells significantly increased concomitantly with concentration of U. dioica as compared with control cells, which is similar to oxaliplatin and serum-deprived cancer cells. In conclusion, the present study demonstrated that U. dioica inhibited proliferation of gastric and colorectal cancer cells while posing no significant toxic effect on normal cells. U. dioica not only increased levels of oxidants, but also induced concomitant increase of apoptosis. The precise signaling pathway by which U. dioica induce apoptosis needs further research.

A highly accurate and efficient algorithm for electrostatic interactions of charged particles confined by parallel metallic plates.

We present an accurate and efficient algorithm to calculate the electrostatic interaction of charged point particles with partially periodic boundary conditions that are confined along the non-periodic direction by two parallel metallic plates. The method preserves the original boundary conditions, leading to an exact solution of the problem. In addition, the scaling complexity is quasilinear O(Nln(N)), where N is the number of particles in the simulation box. Based on the superposition principle in electrostatics, the problem is split into two electrostatic problems where each can be calculated by the appropriate Poisson solver. The method is applied to NaCl ultra-thin films where its dielectric response with respect to an external bias voltage is investigated. Furthermore, the total charge induced on the metallic boundaries can be calculated to an arbitrary precision.

A fingerprint based metric for measuring similarities of crystalline structures.

Measuring similarities/dissimilarities between atomic structures is important for the exploration of potential energy landscapes. However, the cell vectors together with the coordinates of the atoms, which are generally used to describe periodic systems, are quantities not directly suitable as fingerprints to distinguish structures. Based on a characterization of the local environment of all atoms in a cell, we introduce crystal fingerprints that can be calculated easily and define configurational distances between crystalline structures that satisfy the mathematical properties of a metric. This distance between two configurations is a measure of their similarity/dissimilarity and it allows in particular to distinguish structures. The new method can be a useful tool within various energy landscape exploration schemes, such as minima hopping, random search, swarm intelligence algorithms, and high-throughput screenings.

Stabilized quasi-Newton optimization of noisy potential energy surfaces.

Optimizations of atomic positions belong to the most commonly performed tasks in electronic structure calculations. Many simulations like global minimum searches or characterizations of chemical reactions require performing hundreds or thousands of minimizations or saddle computations. To automatize these tasks, optimization algorithms must not only be efficient but also very reliable. Unfortunately, computational noise in forces and energies is inherent to electronic structure codes. This computational noise poses a severe problem to the stability of efficient optimization methods like the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm. We here present a technique that allows obtaining significant curvature information of noisy potential energy surfaces. We use this technique to construct both, a stabilized quasi-Newton minimization method and a stabilized quasi-Newton saddle finding approach. We demonstrate with the help of benchmarks that both the minimizer and the saddle finding approach are superior to comparable existing methods.