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The aim of this article is to help clinicians and allied professionals understand problems that may arise with use of external fixators in limb reconstruction and trauma, and in particular describe how preventative strategies can be implemented. The indications for splinting and orthotic use with external fixators can be broadly subdivided into those that facilitate functional loading and those that maintain joint integrity and function. Specific techniques to accompany use of external fixators in fracture management and limb reconstruction are described. In particular, problems concerning knee, ankle and foot support together with leg length issues are covered and proposals for dealing with joint subluxation, forefoot deformity and toe clawing, regenerate deformity after fixator removal and oedema control are discussed. The solutions described and illustrated are intended to assist those who use external fixators but do not have regular therapist input for support in the after-care of their patients. [ABSTRACT FROM AUTHOR]

The introduction of cadaveric dissection of cerebral vasculature as a part of the neurosurgical training module would help the neurosurgical residents to understand the complex neuroanatomy of the brain vasculature and help gain confdence during the surgical procedure.To the best of our knowledge microsurgical anatomical studies of theMCA have not been done among the Northwest Indian population. Anatomical variations of MCA that have not been described before may come in as a surprise during any surgical intervention. Hence, we intend to record the anatomical variations of the MCA anatomy and its implications in contemporary vascular surgery and neurosurgical practice. The objective of this work was to study and compare the microsurgical anatomy and variations of MCA in Northwest Indian cadavers with the available literature. [ABSTRACT FROM AUTHOR]

Introduction: Revision hip arthroplasty in the presence of complex acetabular deficiencies is challenging. Cement, allograft, reconstruction rings and porous trabecular metal now provide versatile options for acetabular fixation and restoration of acetabular offset. We compare acetabular impaction bone grafting (AIBG) and trabecular metal (TM) cups at long-term follow-up. Methods: 53 patients who underwent revision hip arthroplasty were retrospectively reviewed from local joint registry data. 36 patients were revised using AIBG and 17 with TM. Median clinical follow-up was 9.57 (2.46–18.72) years and 9.65 (7.22–12.46) years, respectively. 82% of the TM group and 63% of the AIBG group were ⩾ Paprosky 2C. Re-revision was considered failure. Radiographs demonstrating 5 mm of femoral head migration and 5° of acetabular component inclination change were considered loose. Results: Patients receiving AIBG were younger (68 vs. 74 years) with a longer interval from initial arthroplasty to revision (17 vs. 13 years). Revisions in both groups were indicated most commonly for failed cementing (AIBG 88.9% vs. TM 70.5%). No TM reconstructions underwent re-revision, with only 1 failing at 6.3 years, compared with 9 AIBG re-revisions. When revising for sepsis, 33% of AIBG revisions failed. Conclusions: AIBG demonstrated high failure rates at long-term follow-up when compared to TM constructs. We recommend the use of AIBG in small cavitary defects only. We strongly advise against its use in the setting of significant bony defects and for prosthetic joint infection. [ABSTRACT FROM AUTHOR]

We have evaluated Sramek's method of impedance cardiography as a non-invasive way of detecting the cardiovascular effects of drugs. We made cardiovascular measurements using the method during passive tilting and exercise 2 h after the oral administration of atenolol (50 and 100 mg), propranolol (40 and 80 mg), pindolol (5 and 10 mg), and placebo in seven separate studies involving eight healthy male volunteers. Equivalent doses of the pure antagonists atenolol (β) and propranolol (β, β) produced similar reductions in heart rate, systolic blood pressure, and cardiac index, and increases in stroke volume and total peripheral resistance, particularly during exercise. In contrast the partial agonist pindolol produced increases in heart rate and cardiac index, and reductions in peripheral resistance at rest. During passive tilting and exercise pindolol reduced heart rate, but cardiac output and total peripheral resistance were unchanged except at the highest levels of exercise. The similar cardiovascular effects of atenolol and propranolol, but differing effects of pindolol, are consistent with reports using other methods of measurement. This suggests that impedance cardiography may have a place in the non-invasive assessment of the cardiovascular effects of drugs. [ABSTRACT FROM AUTHOR]

The expression of receptors for complement and the Fc region of immunoglobulin by alveolar macrophages (AM) constitutes a valuable aid to effector function of these cells. However, during HIV infection such expression may also act to increase binding of immune complexes, thus facilitating viral infection of these cells. This study was designed to determine whether changes in the expression of these receptors occurs in situ during HIV infection. Lung macrophages were isolated by bronchoalveolar lavage in groups of HIV+ subjects segregated on the basis of peripheral CD4 count. A group of normal subjects was also investigated. Expression of CR1 and FcγRI was quantified by measuring the optical density of reaction product following controlled immunoperoxidase staining with MoAbs CD35 and CD64. Both CR1 and FcγRI were increased over normal in all HIV+ subjects. This increase was progressive with advancing disease as determined by correlation with declining peripheral CD4 count. Comparison of asymptomatic and symptomatic subjects with HIV infection showed no difference in CR1 expression but a rise in FcγRI expression in the latter group. An overall inverse correlation was also found between peripheral CD4 count and FcγRI expression, but not CRI expression. These data demonstrate a significant increase in the expression of these receptors on AM from HIV+ subjects, and show that this increase may occur before any symptoms in these patients. [ABSTRACT FROM AUTHOR]

In this computational study, we describe a self-consistent trajectory simulation approach to capture the effect of neutral gas pressure on ion–ion mutual neutralization (MN) reactions. The electron transfer probability estimated using Landau–Zener (LZ) transition state theory is incorporated into classical trajectory simulations to elicit predictions of MN cross sections in vacuum and rate constants at finite neutral gas pressures. Electronic structure calculations with multireference configuration interaction and large correlation consistent basis sets are used to derive inputs to the LZ theory. The key advance of our trajectory simulation approach is the inclusion of the effect of ion-neutral interactions on MN using a Langevin representation of the effect of background gas on ion transport. For H+ − H− and Li+ − H(D)−, our approach quantitatively agrees with measured speed-dependent cross sections for up to ∼105 m/s. For the ion pair Ne+ − Cl−, our predictions of the MN rate constant at ∼1 Torr are a factor of ∼2 to 3 higher than the experimentally measured value. Similarly, for Xe+ − F− in the pressure range of ∼20 000–80 000 Pa, our predictions of the MN rate constant are ∼20% lower but are in excellent qualitative agreement with experimental data. The paradigm of using trajectory simulations to self-consistently capture the effect of gas pressure on MN reactions advanced here provides avenues for the inclusion of additional nonclassical effects in future work. [ABSTRACT FROM AUTHOR]

High-temperature annealing (HTA) is one of the most promising techniques to produce high-quality, cost-efficient AlN templates for further epitaxial growth of AlGaN devices. Unfortunately, the yield of this process seems to be limited due to the restricting face-to-face configuration that is typically used, in which contaminations of the template surface can occur easily. A high yield is crucial for process transfer into industry. Indeed, templates that are annealed in open-face configuration suffer from surface degradation due to excessive AlN evaporation during the course of the annealing process. To highlight the physics that are restricting the open-face approach of the process, sublimation behavior of AlN at temperatures and atmospheres typically used in HTA processes has to be examined. In this study, we use the Knudsen effusion mass spectrometry technique to confirm the previously published results on equilibrium partial pressures of species above AlN. Based on the experimentally determined data and further AlN sublimation experiments, the apparent sublimation coefficient of AlN in N2 and Ar atmospheres at HTA process conditions can be derived. Despite N2 having a stabilizing effect on AlN during HTA, the still high decomposition rates of several hundred nanometers per hour can explain the excessive damage that is typically observed if AlN/sapphire templates are annealed in an open-face configuration. Finally, based on theoretical considerations, a strategy to reduce the sublimation of AlN during HTA in open-face configuration is suggested. [ABSTRACT FROM AUTHOR]

Aims: Following Failed Internal Fixation of Intertrochanteric Fractures (FIF-ITF), the choice of treatment remains a clinical challenge. This study introduces a novel classification system to guide the selection of femoral prostheses in hip arthroplasty (HA) and validates its clinical efficacy. Methods: Retrospectively, we analyzed 108 cases from three university-affiliated hospitals between December 2012 and February 2023 involving patients who underwent hip arthroplasty due to Failed Internal Fixation of Intertrochanteric Fractures (FIF-ITF). Patients were classified into three categories based on fracture healing, proximal femoral support, and the severity of femoral cortical defects, with subtypes identified. Surgical outcomes and complication rates were compared between the Classification-based Decision Group and the Non-classification Decision Group. Results: The Classification-based Decision Group did not differ significantly from the Non-classification Decision Group in operation time, blood loss, or the use of cemented stems. However, the classification system markedly reduced the risk of periprosthetic fractures intraoperatively from 22.5 to 4.4% and postoperatively from 10 to 1.4%. The Classification-based Decision Group also demonstrated higher postoperative Harris Hip Score (HHS) and Visual Analog Scale (VAS) scores. Conclusion: The proposed classification system serves as an innovative clinical tool for femoral prosthesis selection in hip arthroplasty post-FIF-ITF, effectively reducing complications and enhancing hip function in the Classification-based Decision Group, underscoring its significant clinical utility. [ABSTRACT FROM AUTHOR]

Background: There is wide variation in premature mortality rates in adults with severe mental illness (SMI) across London, with Tower Hamlets (a highly deprived and ethnically diverse area) scoring the highest. Objective: To identify examples of best practice and co‐design recommendations for improving physical health checks and follow‐up care amongst people with SMI in Tower Hamlets. Methods: Data were collected through online questionnaires (using SMI physical health best practice checklists), one‐on‐one interviews (n = 7) and focus groups (n = 3) with general practices, secondary mental health services, commissioners and leads of community services and public health programmes, experts by experience and community, voluntary and social enterprise organisations in Tower Hamlets. Data were analysed using deductive and inductive thematic analysis. Results: Twenty‐two participants representing 15 general practices (out of 32), secondary mental health services, commissioners and public health leads completed the online questionnaires. Twenty‐one participants took part in interviews and focus groups. Examples of best practice included cleaning and validating the SMI register regularly by general practices, knowing the number of patients who had been offered and/or received physical health checks, having clear pathways to community and specialist care services, using various communication methods and having a key performance indicator (KPI) for tailored smoking cessation services for people with SMI. Recommendations included adopting evidence‐informed frameworks for risk stratification and utilising the wider primary care workforce with specific training to follow up on results, offer interventions and support navigating pathways and taking up follow‐up care. Incentivising schemes were needed to deliver additional physical health check components such as oral health, cancer screening, Covid‐19 vaccination and sexual health checks. Including KPIs in other community services' specifications with reference to SMI people was warranted. Further engagement with experts by experience and staff training were needed. Conclusion: The present initiative identified best practice examples and co‐designed recommendations for improving physical health checks and follow‐up care in deprived and ethnically diverse people with SMI. Patient or Public Contribution: This initiative was supported by three experts with experience, and two community organisations, who were involved in data curation and interpretation, development of recommendations and/or dissemination activities including writing this manuscript. [ABSTRACT FROM AUTHOR]

Background: Displaced diaphyseal fractures can be reduced using the push-pull technique, wherein a plate is affixed to the distal fragment of the fracture, a post screw is placed proximal to the plate, and a lamina spreader creates distraction. This study evaluated the load to failure and mechanism of failure of bicortical and unicortical post screws during reduction. Materials and Methods: Four matched pairs of cadaver legs were subjected to a 2-cm oblique osteotomy simulating a displaced, oblique diaphyseal fracture. A 6-hole compression plate was affixed to the distal fragment with 2 unicortical locking screws, and a 12-mm unicortical or 20-mm bicortical screw was inserted as a post screw proximal to the plate. A lamina bone spreader was used to exert a distraction force between the plate and the post screw. A mechanical actuator simulated the distraction procedure until failure. Maximum applied load, displacement, and absorbed energy were recorded and compared across unicortical and bicortical groups by paired t tests. Results: At maximum load, we found statistically significant differences in displacement (P=.003) and energy absorbed (P=.022) between the two groups. All unicortical screws failed through screw toggle and bone cut-out. Bicortical screws failed through bending, with no visible damage to the bone at the screw site. Conclusion: When diaphyseal fractures are significantly shortened and require a greater distraction force to achieve reduction, bicortical screws demonstrate a higher mechanical load to failure and increased bone loss from the screw-removal site. A unicortical post screw may be used if minimal distraction is needed. [Orthopedics. 2024;47(5):308–312.] [ABSTRACT FROM AUTHOR]

A time-dependent global model is developed for deep oscillation magnetron sputtering (DOMS) with a Cr target to characterize the plasma using the working Ar gas at a pressure of 0.8 Pa. An input of the global model is the target voltage and current waveforms at charging voltages from 260 to 400 V. The plasma densities vary synchronously with the oscillations of target power. During the on-time of a micropulse, the gas atoms are ionized first to ignite the plasma and subsequently the metal ions follow to sustain the discharge. During the off-time, the gas ions dominate the afterglow. The DOMS possesses a characteristic of alternating gas/metal discharge in the time domain. The peak values of plasma densities increase linearly with charging voltages, which is mainly attributed to the higher Cr+ ion density. The discharge transits from gas dominated to metal dominated at high charging voltage. The working gas rarefaction in DOMS discharge is enhanced at higher charging voltages. At charging voltages higher than 360 V, the metal self-sputtering comes into the runaway regime temporarily as indicated by the self-sputtering parameters exceeding unity, generating the dense and metal-rich plasma. The metal self-sputtering is promoted by gas rarefaction. The electrons tend to ionize the metal atoms after the gas atoms are depleted. The decreased grain size and elevated nano-hardness of the Cr thin films are explained by structure transition from zone I to zone T due to the efficient metal ion bombardment to the growing thin films as the charging voltage increases. [ABSTRACT FROM AUTHOR]

The paper presents the results of a theoretical study of the electron- impact ionization of the 6p, 6s, and 5d shells of the Pb and Bi atoms. Calculations are performed using three relativistic approximations, namely distorted waves, Coulomb-Born, and binary-encounter-dipole, in a wide range of collision energies from thresholds to 700 eV. The ionization cross sections of the sub valent 5d shell of the Pb and Bi atoms are calculated for the first time. It is established that this shell contributes to the total direct ionization cross section twice as much as the 6s shell (up to 26% for Pb and up to 38% for Bi), which shows the importance of taking this process into account in modeling different types of plasma. We analyzed the behavior of the partial ionization cross sections of these atoms calculated using various approximations. Comparison of the resultant full direct ionization cross sections with the data of other authors shows that they satisfactorily describe the process of direct ionization. However, for a more detailed analysis and comparison with experimental data additional calculations of the main process of indirect ionization, namely excitation of autoionization, for the Pb and Bi atoms are required. Analysis of the influence of the third valence electron of the Bi atom compared to the Pb atom on the core-valence interaction shows that this influence is the most significant in the case of the distorted waves approximation. The difference in the behavior of the direct ionization cross sections is caused, in our opinion, by the interaction of valence electrons among themselves. [ABSTRACT FROM AUTHOR]

Background and Aims: Traditional apprenticeship‐based surgical training presents with challenges, especially in acute scenarios. Simulation provides the current standard of facilitating surgical training in a low‐risk environment but is restricted by limited accessibility and high costs. Virtual reality (VR) offers immersive three‐dimensional computer‐generated training scenarios and can connect users from various locations. We aimed to compare the performance of junior doctors to manage an acute surgical scenario using VR and mannequin‐based simulation. We hypothesised that VR would be as effective as mannequin‐based simulation in performance outcomes. Methods: This multicentre, randomised controlled pilot study was conducted with eighteen junior doctor volunteers (Foundation and Core Trainee Year 1). Ten were randomly allocated to VR and eight to mannequin‐based simulation. Participants completed questionnaires and a 15‐min pneumothorax scenario. Quantitative metrics included overall score, time‐to‐critical decisions, and academic buoyancy scores (ABS). Qualitative metrics included participants' likes and dislikes of their allocated simulation modality. Results: VR participants scored significantly higher than mannequin‐based simulation participants in overall scores (74.30% (SD ± 5.08%) vs. 59.75% (SD ± 10.14) (p = 0.04)), and technical skills aspects (77.20% (SD ± 8.01%) vs. 65.00% (SD ± 8.21%) (p = 0.01)). Mannequin‐based simulation participants initiated critical decisions faster and demonstrated a trend towards a faster mean time‐to‐completion (p = 0.06). ABS scores increased for both study groups, though was only significant for VR participants (p ≤ 0.01). VR participants liked how VR fostered independent learning but disliked the formulaic content and impaired communication‐learning compared to mannequin‐based simulation. Conclusion: Both VR and mannequin‐based simulation training are effective in training junior doctors in acute surgical scenarios but present different educational benefits. Future research should recruit a larger sample size for a full comparative randomised controlled trial. [ABSTRACT FROM AUTHOR]

Genome-wide association studies (GWAS) have identified many genetic loci associated with complex traits and diseases in the past 20 years. Multiple heritable covariates may be added into GWAS regression models to estimate direct effects of genetic variants on a focal trait, or to improve the power by accounting for environmental effects and other sources of trait variations. When one or more covariates are causally affected by both genetic variants and hidden confounders, adjusting for them in GWAS will produce biased estimation of SNP effects, known as collider bias. Several approaches have been developed to correct collider bias through estimating the bias by Mendelian randomization (MR). However, these methods work for only one covariate, some of which utilize MR methods with relatively strong assumptions, both of which may not hold in practice. In this paper, we extend the bias-correction approaches in two aspects: first we derive an analytical expression for the collider bias in the presence of multiple covariates, then we propose estimating the bias using a robust multivariable MR (MVMR) method based on constrained maximum likelihood (called MVMR-cML), allowing the presence of invalid instrumental variables (IVs) and correlated pleiotropy. We also established the estimation consistency and asymptotic normality of the new bias-corrected estimator. We conducted simulations to show that all methods mitigated collider bias under various scenarios. In real data analyses, we applied the methods to two GWAS examples, the first a GWAS of waist-hip ratio with adjustment for only one covariate, body-mass index (BMI), and the second a GWAS of BMI adjusting metabolomic principle components as multiple covariates, illustrating the effectiveness of bias correction. Author summary: Genome-wide association studies (GWAS) are powerful in identifying genetic variants influencing complex traits and diseases. However, adjusting for heritable covariates in GWAS may introduce collider bias when both genetic variants and confounders may causally influence these covariates. In this study, for the first time we derived the analytical form of the bias term in GWAS with multiple covariates, enabling bias estimation and correction using any MVMR method. On the other hand, many existing MVMR methods may not be robust to invalid IVs and are designed for independent samples. Since GWAS data of multiple traits are needed, overlapping samples become inevitable. Hence, while investigating the performance of many MVMR methods, we mainly adopt MVMR-cML, a novel MVMR approach robust to invalid IVs and sample overlap. Our simulations underscore that most MVMR methods effectively reduce collider bias across various scenarios. Furthermore, by accounting for correlations among GWAS statistics, as well as the linkage disequilibrium (LD) between the target SNP and IVs, we establish the consistency and asymptotic normality of the bias-corrected estimator based on MVMR-cML. The application of our bias-correction approach to two published GWAS data examples illustrates its utility and efficacy. [ABSTRACT FROM AUTHOR]

Introduction: The hands are the most common site of disability in leprosy. Hand dysfunction could result in difficulty performing activities of daily living. Therefore, hand function should be regularly assessed to ensure that any decrease in hand function could be diagnosed earlier. Methods: This study included 110 patients with leprosy from Likupang and Lembata, Indonesia. Hand function was assessed using the modified Jebsen test to measure hand function respective of the dominance. The grip and pinch strength were used as objective measures of clinical arm function. The World Health Organization (WHO) hand disability grade were used to determine the degree of impairment. Other factors such as age, sex and the type of leprosy were also considered. All factors were analysed using backward logistic regression. Results: Among the 110 participants, a decrease in the dominant (48.2%) and non-dominant (50.9%) hand functions were found. Pinch strength (OR: 3.39; 95% CI: 1.13-10.19) and age (OR: 4.91; 95% CI: 1.72-14.03) were significantly associated with hand function irrespective of the dominance. Conversely, the WHO hand disability grade (OR: 2.97; 95% CI: 1.10-8.04) and type of leprosy (OR: 0.34; 95% CI: 0.12-0.97) were significantly associated with only function of the dominant hand. Conclusion: There is a significant association of age and pinch strength with hand function regardless of the hand dominance. In contrast, the WHO hand disability grade and type of leprosy are significantly associated with the function of the dominant hand only. [ABSTRACT FROM AUTHOR]

The detrimental health effects of smoking are well-known, but the impact of regular nicotine use without exposure to the other constituents of tobacco is less clear. Given the increasing daily use of alternative nicotine delivery systems, such as e-cigarettes, it is increasingly important to understand and separate the effects of nicotine use from the impact of tobacco smoke exposure. Using a multivariable Mendelian randomisation framework, we explored the direct effects of nicotine compared with the non-nicotine constituents of tobacco smoke on health outcomes (lung cancer, chronic obstructive pulmonary disease [COPD], forced expiratory volume in one second [FEV-1], forced vital capacity [FVC], coronary heart disease [CHD], and heart rate [HR]). We used Genome-Wide Association Study (GWAS) summary statistics from Buchwald and colleagues, the GWAS and Sequencing Consortium of Alcohol and Nicotine, the International Lung Cancer Consortium, and UK Biobank. Increased nicotine metabolism increased the risk of COPD, lung cancer, and lung function in the univariable analysis. However, when accounting for smoking heaviness in the multivariable analysis, we found that increased nicotine metabolite ratio (indicative of decreased nicotine exposure per cigarette smoked) decreases heart rate (b = -0.30, 95% CI -0.50 to -0.10) and lung function (b = -33.33, 95% CI -41.76 to -24.90). There was no clear evidence of an effect on the remaining outcomes. The results suggest that these smoking-related outcomes are not due to nicotine exposure but are caused by the other components of tobacco smoke; however, there are multiple potential sources of bias, and the results should be triangulated using evidence from a range of methodologies. Author summary: Although we know that smoking tobacco negatively impacts health, we know relatively little about whether nicotine plays a role in causing poor health outcomes. When used for short periods of time, nicotine appears to have little impact on health. However, until recently, nicotine has rarely been used for long periods without accompanying exposure to tobacco smoke, so it is hard to disentangle the effects of regular nicotine use from the effects of tobacco smoke exposure. In this study, we aimed to dissect the effects of nicotine versus non-nicotine constituents of tobacco smoke on heart and lung health using multivariable Mendelian randomisation and data from a range of sources (including UK Biobank). We found that nicotine does not appear to be an independent cause of poor lung function, lung cancer, chronic obstructive pulmonary disease, or coronary heart disease, but does increase heart rate. These results support previous evidence which suggests that nicotine on its own does not directly cause poor health outcomes, with the exception of increasing heart rate. [ABSTRACT FROM AUTHOR]

Historically, total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been associated with significant perioperative blood loss and a relatively high rate of allogeneic blood transfusions. However, in recent years, tranexamic acid (TXA), a competitive inhibitor of tissue plasminogen activator, inhibiting fibrinolysis of existing thrombi, has substantially decreased the need for blood transfusion in THA and TKA. Various administration strategies have been studied, but there remains a lack of consensus on an optimal route and dosing regimen, with intravenous and topical regimens being widely used. A growing body of literature has demonstrated the safety and efficacy of TXA in primary and revision THA and TKA to reduce blood loss, allogeneic transfusions, and complications; it is associated with lowered lengths of stay, costs, and readmission rates. [ABSTRACT FROM AUTHOR]

Background: Flexible bronchoscopy procedures require detailed anatomical knowledge and advanced technical skills. Simulation-based training offers a patient-safe training environment that can be more efficient than patient-based training. Physical models are cheaper than virtual reality simulators and allow trainees to be acquainted with the equipment used in the clinic. The choice of a physical model for training depends on the local context. The aim of this study was to compare four different bronchoscopy models for flexible bronchoscopy training. Methods: The BronchoBoy manikin, the Koken manikin, a human cadaver, and a preserved porcine lung were included in the study. Seven physicians experienced in bronchoscopy performed a bronchoscopic airway inspection, bronchoalveolar lavage (BAL), and tissue sampling on all four models with performance evaluated by observation and participant evaluation of models by questionnaire. Results: Nineteen segments were identified in all human anatomy models, and the only significant difference found was that only the Thiel embedded cadaver allowed all participants to enter RB1 with an instrument in the working channel (p = 0.001). The Thiel embedded cadaver and the BronchoBoy manikin had low fluid return on BAL (22 and 52 ml), whereas the Koken manikin and the preserved porcine lung had high return (132 and 134 ml), (p = 0.017). Tissue samplings were only completed in the preserved porcine lung and the Thiel embedded cadaver (p < 0.001). Conclusions: An anatomically correct bronchoscopy is best simulated with the Koken manikin or the Thiel embedded cadaver. Bronchoalveolar lavage should be simulated with the Koken manikin or the preserved porcine lung. Tissue sampling procedures are best simulated using the Thiel embedded cadaver or the preserved porcine lung. [ABSTRACT FROM AUTHOR]

State-selective single-electron-capture in collisions of dressed and bare projectiles with helium atoms are investigated by means of the prior-version of the four-body formalism of the target continuum distorted-wave approximation with a long-range Coulomb effects arising from the relative motion of the scattering aggregates. Here, we choose H e 2 + and C 4 + ions as bare and dressed projectiles due to the availability of experimental data in the literature and impact energy varies from 10 to 600 keV/amu. For a dressed projectile, the passive electron plays the role of screening to the projectile nucleus. In the initial channel, the perturbation potential due to the interaction between the dressed projectile and the active electron(s), is approximated by a model potential that contains both the short-range and long-range parts. Coulomb continuum states of the active electron in the field of residual target ion as well as long-range Coulomb effects for the relative motion are incorporated in the final state wavefunction. State-selective total and projectile angular-differential cross sections for single-electron-capture have been calculated. Numerical results for state-selective total cross sections show good agreement with the available theoretical and experimental findings. Moreover, a prominent maxima and minima are observed in the projectile angular differential cross sections as impact energy decreases and its position moves to lower projectile scattering angle. Finally, the validity of the present model is critically assessed in comparison with the existing experimental data. [ABSTRACT FROM AUTHOR]

Platelet count has been associated with blood pressure, but whether this association reflects causality remains unclear. To strengthen the evidence, we conducted a traditional observational analysis in the Lifelines Cohort Study (n = 167,785), and performed bi-directional Mendelian randomization (MR) with summary GWAS data from the UK Biobank (n = 350,475) and the International Consortium of Blood Pressure (ICBP) (n = 299,024). Observational analyses showed positive associations between platelet count and blood pressure (OR = 1.12 per SD, 95% CI: 1.10 to 1.14 for hypertension; B = 0.07, 95% CI: 0.07 to 0.08 for SBP; B = 0.07 per SD, 95% CI: 0.06 to 0.07 for DBP). In MR, a genetically predicted higher platelet count was associated with higher SBP (B = 0.02 per SD, 95% CI = 0.00 to 0.04) and DBP (B = 0.03 per SD, 95% CI = 0.01 to 0.05). IVW models and sensitivity analyses of the association between platelet count and DBP were consistent, but not all sensitivity analyses were statistically significant for the platelet count-SBP relation. Our findings indicate that platelet count has modest but significant effects on SBP and DBP, suggesting causality and providing further insight into the pathophysiology of hypertension. [ABSTRACT FROM AUTHOR]

Background: Suture button fixation is frequently used to stabilize the distal tibiofibular syndesmosis in athletes sustaining an isolated ligamentous syndesmosis injury. Purpose: To report on a series of periprosthetic fibula fractures adjacent to the lateral suture button after a subsequent unrelated ankle injury or progressive stress injury after initial ankle syndesmosis stabilization using the knotless TightRope (Arthrex). Study Design: Case series; Level of evidence, 4. Methods: Eight elite athletes with periprosthetic fibula fractures and stress injuries around the lateral suture buttons were evaluated. In all athletes, the knotless TightRope had been used to stabilize an isolated ligamentous ankle syndesmotic injury, after which all patients recovered and returned to professional sports at their preinjury level. The athletes subsequently developed an acute fibula fracture or a fibula stress fracture related to the 3.7-mm drill hole in the fibula adjacent to the lateral suture buttons after a mean of 14.1 months (range, 5-29 months). The management of these complications was analyzed. Results: Five athletes sustained a periprosthetic fibula fracture in the form of undisplaced spiral Weber B injuries after a subsequent, unrelated injury. Poor healing response was noted with initial nonoperative treatment for the first 2 athletes, and surgical intervention was performed with successful union of the fracture and return to sports. The subsequent 3 athletes had early surgery with uneventful recovery. Another 3 athletes developed stress injuries adjacent to the fibula suture button without a history of acute trauma. In 2 of the 3 athletes, the position of lateral suture buttons was in the anterior third of the fibula. Initial nonoperative management yielded poor healing response, and subsequent surgical intervention was required to enable healing and return to sports. Conclusion: Nonoperative management of fractures adjacent to the fibula suture button of a knotless TightRope may lead to a delay in union. Therefore, early surgical intervention should be considered in elite athletes, whose return-to-sports time is critical. Care is needed to ensure that the fibula hole for the suture button is centrally located because the eccentric placement of the fibula hole in the anterior third of the fibula may contribute to the development of a stress reaction or stress fracture. Surgical intervention for a periprosthetic fibula stress fracture leads to satisfactory resolution of symptoms. [ABSTRACT FROM AUTHOR]

Target poisoning is prevalent in reactive magnetron sputtering and causes deleterious effects, especially in deposition using metal targets. Both the deposition rate and the stoichiometry ratio of the coatings will be compromised because of the quicker coverage of the poisoning materials on the target relative to removal by sputtering. Continuous high-power magnetron sputtering (C-HPMS) possesses merits such as more rapid sputtering than high-power impulse magnetron sputtering and better target poisoning resistance. In this work, the discharge and plasma characteristics of C-HPMS for an Al metal target in reactive O2/Ar atmospheres are investigated by modeling and alumina deposition. At a constant oxygen partial pressure, larger discharge power increases target etching significantly compared to surface combination with O2, leading to reduced surface poisoning. Besides, a higher temperature is produced near the target to produce more intense rarefaction effects and decrease the risk of target poisoning. In Al discharge, the stable deposition window in the O2/Ar ratio under 120 W/cm2 is 5 times of that under 20 W/cm2. Moreover, a large deposition rate of 112 nm/min is achieved at the poisoning-saturated point and a target/substrate distance can be increased to larger than 40 cm, thus providing more flexibility in the design of deposition parameters and hardware requirement. Our results show that high discharge intensity improves plasma density and ionization rates of reactive particles boding well for the deposition of under-stoichiometric and higher-quality amorphous Al2O3 films. The reactive C-HPMS technique has large potential in the commercial production of functional coatings and thin films. [ABSTRACT FROM AUTHOR]

Metal vapor vacuum arcs (VAs) are widely used in various fields of industry, such as circuit breakers, ion sources, electrical thrusters, and deposition systems. VAs usually originate from metal vapors eroding from the surface of a cathode, where they burn as tiny bright points, hence their name "cathode spots" (CS). Due to their high plasma density, short life span, and micrometer scale, the in situ and non-intrusive diagnostics of CS are a challenge. Numerical simulation is one method used to study CS with the aid of high-performance computing. The well-established particle-in-cell method provides solutions for the spatial-temporal electromagnetic field and the microscopic distribution functions of plasma species in phase space from which the macroscopic parameters of the plasma can be calculated. This Perspective reviews the progress in particle modeling of VAs with an emphasis on the non-stationary and non-local physical processes that are not reproduced by fluid models. Furthermore, a personal outlook on future challenges is provided: the physical modeling of plasma–electrode interactions, the collection and evaluation of collision cross sections, the trade-off between heavy computation cost and predictive ability, and the verification and validation of the simulation code. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to an article on new methods for medical diagnosis published in the June 1992 issue.

Background: Blount's disease is a growth disorder of the proximal tibia that causes progressive genu varum in children. Surgical treatment is recommended if the deformity worsens, but which intervention is best remains controversial. This study aims to identify factors influencing outcomes and determine the most effective surgical approach. Methods: A systematic review was conducted of studies published before January 2022. Results: In total, 63 retrospective studies with CEBM IIIb/IV levels were included (1672 knees in 1234 patients). The most commonly reported treatment was acute correction via osteotomy (47%), followed by hemiepiphysiodesis (22%) and gradual correction (18%). Combined procedures were reported in 13% of cases. The overall recurrence rate was 18%, with a significant difference when comparing the recurrence rates after gradual correction with those after hemiepiphysiodesis (7% and 29%, respectively). Major complications beyond recurrence were observed in 5% of cases. A meta-analysis of the available raw data showed a significantly increased recurrence rate (39%) among treated children who were between 4.5 and 11.25 years of age and were followed for a minimum follow-up of 2.5 years. Conclusions: Overall, poor evidence with which to establish an optimal treatment for Blount's disease was found. This study remarked on the need for early diagnosis, classification, and treatment of infantile tibia vara, since a significant rate of recurrence was found in neglected cases. [ABSTRACT FROM AUTHOR]

BACKGROUND Previous studies have found associations of red blood cell (RBC) traits (hemoglobin and RBC count) with blood pressure; whether these associations are causal is unknown. METHODS We performed cross-sectional analyses in the Lifelines Cohort Study (n = 167,785). Additionally, we performed bidirectional 2 sample Mendelian randomization (MR) analyses to explore the causal effect of the 2 traits on systolic (SBP) and diastolic blood pressure (DBP), using genetic instrumental variables regarding hemoglobin and RBC identified in UK Biobank (n = 350,475) and International Consortium of Blood Pressure studies for SBP and DBP (n = 757,601). RESULTS In cross-sectional analyses, we observed positive associations with hypertension and blood pressure for both hemoglobin (odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.16–1.20 for hypertension; B = 0.11, 95% CI: 0.11–0.12 for SBP; B = 0.11, 95% CI: 0.10–0.11 for DBP, all per SD) and RBC (OR = 1.14, 95% CI: 1.12–1.16 for hypertension; B = 0.11, 95% CI: 0.10–0.12 for SBP; B = 0.08, 95% CI: 0.08–0.09 for DBP, all per SD). MR analyses suggested that higher hemoglobin and RBC cause higher DBP (inverse-variance weighted B = 0.11, 95% CI: 0.07–0.16 for hemoglobin; B = 0.07, 95% CI: 0.04–0.10 for RBC, all per SD). Reverse MR analyses (all per SD) suggested causal effects of DBP on both hemoglobin (B = 0.06, 95% CI: 0.03–0.09) and RBC (B = 0.08, 95% CI: 0.04–0.11). No significant effects on SBP were found. CONCLUSIONS Our results suggest bidirectional causal relationships of hemoglobin and RBC with DBP, but not with SBP. [ABSTRACT FROM AUTHOR]

The ionization potentials and total ionization cross sections of glucose and ribose monosaccharide molecules were measured by electron impact at energies up to 70 eV. Using two methods, Hartree–Fock (HF) and density functional theory (DFT), the structure of d- and l-forms of glucose and ribose molecules were calculated using Gaussian. The energy characteristics of the molecular orbitals (MOs) were used to calculate the summarized single ionization cross sections (CS) based on the MOs by the Binary–Encounter–Bethe (BEB) and Gryzinsky (Gryz) models. By normalizing to Gryz-DFT cross sections at thresholds, at 11 eV (Glucose) and 12.65 eV (Ribose), the absolute values of the measured total ionization cross sections of these molecules were obtained. The ionization potentials of glucose and ribose molecules were evaluated from binding HOMO MOs energies and compared with the measured values: 12.25 ± 0.25 eV (Glucose) and 10.46 ± 0.25 eV (Ribose). The contributions of the higher orbitals HOMO, HOMO-1, HOMO-2 to the Gryz-DFT cross section were evaluated. [ABSTRACT FROM AUTHOR]

The single-center convergent close coupling (CCC) method has been applied to positron scattering from the oxygen atom. Cross sections have been calculated for total, elastic, momentum transfer, total ionization, inelastic, and excitation scattering processes from threshold to 5000 eV. Due to their relevance in transport studies, we also present stopping power and mean excitation energy results. Low-energy studies have been conducted to calculate scattering length, the hidden Ramsauer–Townsend minimum, and the energy of the positron virtual state. CCC-scaled complex optical potential calculations are utilized to calculate positronium-formation, direct ionization, and values between the positronium-formation and ionization thresholds. Good agreement is generally observed at high energies with past theory, electron-atomic oxygen experiment, and halved electron/positron O 2 experiment. Large discrepancies, however, have been found between current and previous calculations for positronium-formation cross section and for low-energy elastic scattering cross section. [ABSTRACT FROM AUTHOR]

Introduction: Several studies have reported good to excellent outcomes of revision total hip arthroplasty (rTHA) using allografts for treating severe acetabular bone defects. However, precise information on the impact of allograft type and reconstruction method is not available. Material and methods: Systematic literature search was performed in Medline and Web of Science including patients with acetabular bone loss classified according to the Paprosky classification who underwent rTHA involving the use of allografts. Studies with a minimum follow-up of 2 years published between 1990 and 2021 were included. Kendall correlation was applied to determine the relationship between Paprosky grade and allograft type use. Proportion meta-analyses with 95% confidence interval (CI) were performed to summarize the success of various reconstruction options, including allograft type, fixation method, and reconstruction system. Results: Twenty-seven studies met the inclusion criteria encompassing 1561 cases from 1491 patients with an average age of 64 years (range 22–95). The average follow-up period was 7.9 years (range 2–22). Structural bulk and morselized grafts were used in equal proportions for all Paprosky acetabular defect types. Their use increased significantly with the type of acetabular defect (r = 0.69, p = 0.049). The overall success rate ranged from 61.3 to 98.3% with a random effect pooled estimate of 90% [95% CI 87–93]. Trabecular metal augments (93% [76–98]) and shells (97% [84–99]) provided the highest success rates. However, no significant differences between reconstruction systems, allograft types and fixation methods were observed (p > 0.05 for all comparisons). Conclusion: Our findings highlight the use of bulk or morselized allograft for massive bone loss independent of Paprosky classification type and indicate similar good mid- to long-term outcomes of the different acetabular reconstruction options using allografts. Clinical trial registration: PROSPERO: CRD42020223093. [ABSTRACT FROM AUTHOR]

Minimally invasive esophagectomy (MIE) has been shown to be superior to open esophagectomy with reduced morbidity, mortality, and comparable lymph node (LN) harvest. However, MIE is technically challenging. This study aims to perform a pooled analysis on the number of cases required to surmount the learning curve (LC), i.e. NLC in MIE. PubMed, Embase, Scopus, and the Cochrane Library were systematically searched for articles from inception to June 2022. Inclusion criteria were articles that reported LC in video-assisted MIE (VAMIE) and/or robot-assisted MIE (RAMIE). Poisson means (95% confidence interval [CI]) was used to determine NLC. Negative binomial regression was used for comparative analysis. There were 41 articles with 45 data sets (n  = 7755 patients). The majority of tumors were located in the lower esophagus or gastroesophageal junction (66.7%, n  = 3962/5939). The majority of data sets on VAMIE (n  = 16/26, 61.5%) used arbitrary analysis, while the majority of data sets (n  = 14/19, 73.7%) on RAMIE used cumulative sum control chart analysis. The most common outcomes reported were overall operating time (n  = 30/45) and anastomotic leak (n  = 28/45). Twenty-four data sets (53.3%) reported on LN harvest. The overall NLC was 34.6 (95% CI: 30.4–39.2), 68.5 (95% CI: 64.9–72.4), 27.5 (95% CI: 24.3–30.9), and 35.9 (95% CI: 32.1–40.2) for hybrid VAMIE, total VAMIE, hybrid RAMIE, and total RAMIE, respectively. NLC was significantly lower for total RAMIE compared to total VAMIE (incidence rate ratio: 0.52, P  = 0.032). Studies reporting NLC in MIE are heterogeneous. Further studies should clearly define prior surgical experiences and assess long-term oncological outcomes using non-arbitrary analysis. [ABSTRACT FROM AUTHOR]

State-selective non-dissociative electron capture and ionisation cross sections are calculated for collisions between bare helium-ions and molecular hydrogen. The two-centre wave-packet convergent close-coupling approach is used and the hydrogen molecule is represented as an effective one-electron target. For the electron-capture cross section, our results are in good agreement with experimental measurements at energies above 100 keV/u. However, near the peak of the cross section, they are larger than the experimental data. The total ionisation cross section is also in good agreement with experiment, particularly at low and high energies. The results for the state-selective electron-capture cross section are generally in good agreement with the limited experimental measurements. However, we find that our results appear to consistently overestimate the experimental data for electron capture into the s states at intermediate energies. The present results are the first calculations capable of producing electron capture and ionisation cross sections over a wide incident energy range within a single unified theoretical framework. [ABSTRACT FROM AUTHOR]

Objective: To explore the use of multivariable instrumental variables to resolve the "damned if you do, damned if you don't" adjustment problem created for Mendelian randomisation (MR) analysis using the smoking or lung function related phenotypes in the UK Biobank (UKB). Result: "damned if you do, damned if you don't" adjustment problems occur when both adjusting and not-adjusting for a variable will induce bias in an analysis. One instance of this occurs because the genotyping chip of UKB participants differed based on lung function/smoking status. In simulations, we show that multivariable instrumental variables analyses can attenuate potential collider bias introduced by adjusting for a proposed covariate, such as the UKB genotyping chip. We then explore the effect of adjusting for genotyping chip in a multivariable MR model exploring the effect of smoking on seven medical outcomes (lung cancer, emphysema, hypertension, stroke, heart diseases, depression, and disabilities). We additionally compare our results to a traditional univariate MR analysis using genome-wide analyses summary statistics which had and had not adjusted for genotyping chip. This analysis implies that the difference in genotyping chip has introduced only a small amount of bias. [ABSTRACT FROM AUTHOR]

The consecutive transients (CT) method is a plasma diagnostic technique of charge breeder electron cyclotron resonance ion source plasmas. It is based on the short-pulse injection of singly charged ions and the measurement of the resulting transients of the extracted multi-charged ion beams. Here, we study the origin of the large uncertainty bounds yielded by the method to reveal avenues to improve its accuracy. We investigate effects of the assumed electron energy distribution (EED) and the uncertainty inherited from the ionization cross section data of K 4 + – K 12 + ions on the resulting plasma electron density ne, average energy ⟨ E e ⟩ , and the characteristic times of ion confinement τq, electron impact ionization τ inz q , and charge exchange τ cx q provided by the CT method. The role of the EED was probed with Kappa and double-Maxwellian distributions, the latter resulting in a shift of the ne and ⟨ E e ⟩ distributions. The uncertainty of the ionization cross section σ q → q + 1 inz was artificially curtailed to investigate its impact on values and uncertainties of the plasma parameters. It is demonstrated that the hypothetical perfect knowledge of σ q → q + 1 inz significantly reduces the uncertainties of τq, τ inz q , and τ cx q , which motivates the need for improved cross section data. [ABSTRACT FROM AUTHOR]

The microbiota‐gut‐brain axis (MGBA) has been the subject of much research over the past decade, offering an exciting new paradigm for the treatment of psychiatric disorders. In this review, the MGBA is extended to include skeletal muscle and the potential role of an expanded "muscle‐gut‐brain axis" (MuGBA) in conditions such as anxiety and depression is discussed. There is evidence, from both preclinical and human studies, of bidirectional links between the gut microbiome and skeletal muscle function and structure. The therapeutic role of exercise in reducing depressive and anxiety symptoms is widely recognised, and the potential role of the gut microbiota‐skeletal muscle link is discussed within this context. Potential pathways of communication involved in the MuGBA including the tryptophan‐kynurenine pathway, intestinal permeability, immune modulation, and bacterial metabolites such as short‐chain‐fatty‐acids are explored. [ABSTRACT FROM AUTHOR]

Background: Changing healthcare and social scenarios are reducing the learning opportunities of surgical postgraduates in our country. Majority of surgical training centers in the developed world use laboratory training as an integral part of their curricula. However, in India, most of surgical residents are still trained by traditional apprenticeship model. Aims: To describe the role of laboratory training in improving the competency of surgical postgraduates. Settings and Design: Laboratory dissection was used as an educational intervention for postgraduates in tertiary care teaching hospital. Methods and Material: Thirty-five (35) trainees from various surgical subspecialties performed cadaveric dissection led by senior faculty members. The perceived knowledge and operative confidence of trainees were assessed before and three weeks after the course using a five-point Likert scale. A structured questionnaire was administered to explore the experience of training. Results were tabulated in percentage and proportion. Wilcoxon signed-rank test was applied to find any difference between pre and post perception of knowledge and operative competence of participants. Results: Thirty four (34/35; 96%) were males; 65.7% (23/35) trainees demonstrated improvement in knowledge level after dissection (p < 0.0001) and 74.3% (26/35) in operative confidence (p < 0.0001). Majority believe that cadaveric dissection helps to improve knowledge of procedural anatomy (33/35; 94.3%) and enhances technical skill (25/35; 71.4%). Thirty participants (86%) rated cadaveric dissection as the best tool for surgical training of postgraduates better than operative manuals, surgical videos, and virtual simulators. Conclusions: Laboratory training including cadaveric dissection is feasible, relevant, effective, and acceptable to postgraduate surgical trainees with few disadvantages, which can be taken care of. Trainees felt it should be made part of curriculum. [ABSTRACT FROM AUTHOR]

Introduction: The use of Tranexamic Acid (TXA) in primary unilateral Total Hip Arthroplasty (THA) is well documented. However, considering the potential side effects including deep vein thrombosis and pulmonary embolism, the ideal route of administration of TXA to patients undergoing THA is still not known. Aim: To compare the efficacy of single dose intravenous (i.v.) TXA administration versus combined intravenous and local infiltration of TXA in reducing the perioperative blood loss in primary unilateral THA patients. Materials and Methods: This prospective, randomised clinical study, was conducted in the Department of Anaesthesiology and Critical Care at Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India, between October 2020 to May 2021. 60 patients were randomly allocated into two groups: the combined group C (i.v. administration of 10 mg/kg of TXA combined with local infiltration of 600 mg TXA diluted to 60 mL with normal saline) and the single i.v. group S (i.v. administration of 10 mg/kg of TXA). The perioperative blood loss was calculated in terms of three variables-intraoperative blood loss, drainage blood loss and total blood loss. The number of postoperative blood transfusions noted. Student's t-test and Fischer's-exact tests were applied for statistical analysis. Results: A total of 60 patients scheduled to have primary unilateral THA. Both the groups were similar in demographic features, baseline biochemical values and procedural distribution. There was a statistically significant reduction in the (mean±SD) intraoperative blood loss (697.26±221.43 mL), drain blood volume (254.66±81.36 mL) and total blood loss (952.26±263.57 mL) in the combined group C when compared to the single group S. There was no statistically significant difference (p-value=0.671) in the postoperative blood transfusion rate between the two groups. Conclusion: Intravenous combined with local infiltration of TXA significantly reduced the perioperative blood loss in patients undergoing primary unilateral THA when compared to single dose intravenous administration of TXA. [ABSTRACT FROM AUTHOR]

Purpose: Endoscopy implies high demanding procedures, and their practice requires structured formation curricula supported by adequate training platforms. Physical platforms are the most standardised solution for surgical training, but over the last few years, virtual platforms have been progressively introduced. This research work presents a new hybrid, physic-virtual, endoscopic training platform that exploits the benefits of the two kind of platforms combining realistic tools and phantoms together with the capacity of measuring all relevant parameters along the execution of the exercises and of providing an objective assessment performance. Methods: The developed platform, EndoTrainer, has been designed to train and assess surgical skills in hysteroscopy and cystoscopy following a structured curricula. The initial development and validation is focused on hysteroscopic exercises proposed in the Gynaecological Endoscopic Surgical Education and Assessment (GESEA) Certification Programme from The Academy and European Society for Gynaecological Endoscopy (ESGE) and analyses the obtained results of an extensive study with 80 gynaecologists executing 30 trials of the standard 30 degree endoscope navigation exercise. Results: The experiments demonstrate the benefits of the presented hybrid platform. Multi-variable statistical analysis points out that all subjects have obtained statistically significant improvement in all relevant parameters: shorter and safer trajectories, improved 30-degree endoscope navigation, accurate positioning over the targets and reduction of the execution time. Conclusion: This paper presents a new hybrid approach for training, and evaluating whether it provides an objectivable improvement of camera navigation endoscopic basic skills. The obtained results demonstrate the initial hypothesis: all subjects have improved their camera handling and navigation skills. [ABSTRACT FROM AUTHOR]

The relative performance of three- and four-body perturbation methods is evaluated for one-electron transfer in proton–helium collisions in a large interval of impact energies from 10 to 11000 keV. The four-body boundary-corrected continuum intermediate state (BCIS-4B) method and the three-body continuum distorted wave (CDW-3B) method are used to compute the state-selective and state-summed total cross sections for the first four principal quantum number levels of the formed atomic hydrogen. Detailed comparisons of the obtained results with the corresponding experimental data are exploited to establish the lowest energy limit of applicability of the perturbation theories. As is well known, the CDW-3B method strongly departs from the experimental data below about 80 keV. On the other hand, the BCIS-4B method is presently found to successfully describe the measured cross sections at 20–10500 keV. Moreover, in sharp contrast to the CDW-3B method, in all the considered cases, the BCIS-4B method systematically predicts the experimentally observed Massey peaks at the expected positions of matching of the incident velocity and the electron orbital velocity. [ABSTRACT FROM AUTHOR]

Systematic analysis of discharge processes is needed for a good understanding of the physical mechanism that enables optimal coating deposition, especially pulsed discharges sustained by high voltages and large currents. Owing to the temporal and complex characteristics of the discharge process and relatively simplistic analytical methods, the discharge process and particle evolution in high-power impulse magnetron sputtering (HiPIMS) are still not well understood. In this work, a cylindrical cathode is introduced to restrict the discharge and delay plasma loss, and a global model is established to simulate the discharge on a Cr target in N2/Ar. Particles with different reaction energies appearing successively produce an asynchronous discharge phenomenon, and a series of inflection points corresponding to different physical processes including excitation, sputtering, ionization, and diffusion are observed from the particle density evolution curves. High-precision and time-resolved spectrometry (400 ns) is utilized to monitor the evolution of particles with time, and inflection points predicted by the model are observed experimentally to verify the particle behavior in the HiPIMS discharge. [ABSTRACT FROM AUTHOR]

Background: Gastrointestinal perforation is commonly seen in emergency departments. The perforation of the stomach is an emergency situation that requires immediate surgical treatment. The necessary surgical skills require regular practical training. Owing to patient`s safety, in vivo training opportunities in medicine are restricted. Animal tissue especially porcine tissue, is commonly used for surgical training. Due to its limiting factors, artificial training models are often to be preferred. Many artificial models are on the market but to our knowledge, none that mimic the haptic- and sewing properties of a stomach wall at the same time. In this study, an open source silicone model of a gastric perforation for training of gastric sewing was developed that attempts to provide realistic haptic- and sewing behaviour. Methods: To simulate the layered structure of the human stomach, different silicone materials were used to produce three different model layups. The production process was kept as simple as possible to make it easily reproducible. A needle penetration setup as well as a systematic haptic evaluation were developed to compare these silicone models to a real porcine stomach in order to identify the most realistic model. Results: A silicone model consisting of three layers was identified as being the most promising and was tested by clinical surgeons. Conclusions: The presented model simulates the sewing characteristics of a human stomach wall, is easily reproducible at low-costs and can be used for practicing gastric suturing techniques. Trial registrations: Not applicable. [ABSTRACT FROM AUTHOR]

Processes of multiple electron-impact ionization of ions in a plasma and a beam passing through the plasma have been considered. Using experimental data and theoretical calculations of the cross sections for n-electron ionization , the contribution from many-electron ionization rates to the total ionization rate has been determined as a function of the electron temperature of the plasma T. It has been shown that the total contribution of many-electron ionization rates to the total ionization rate in ion beams passing through the plasma is determined by the relation between the velocity of an ion beam and the thermal velocity of electrons in the plasma . Many-electron ionization rates have been numerically calculated for W+ ions for electron temperatures of the plasma from 1 eV to 10 keV and velocities of the ion beam = 0–30 a.u., where 1 a.u. ≈ 2.2 × 108 cm/s is the atomic unit of velocity. [ABSTRACT FROM AUTHOR]

The absolute densities of O and O 3 in the effluent of a kINPen, an atmospheric pressure plasma jet, are determined by molecular beam mass spectrometry. A nitrogen gas curtain surrounding the effluent provides a stable environment and prevents interactions with the ambient air. Both He and Ar were used as feed gas with admixtures of O 2 up to 1%. Measurements are performed at discharge voltages from 1600 to 3000 V pp and at distances from 5.5 to 10.5 mm from the nozzle of the gas shielding device to the orifice of the mass spectrometer. The measured O atom densities are in the order of 1 × 10 14 cm - 3 to 2 × 10 15 cm - 3 , whereas the O 3 molecule densities are in the order of 1 × 10 14 cm - 3 to 5 × 10 14 cm - 3 , respectively, when operated in argon the plasma generates higher densities of reactive species. Additionally, a novel molecular beam chopper design with linear movement has been successfully tested in the mass spectromerty setup as an alternative to a rotating chopper. [ABSTRACT FROM AUTHOR]

Introduction: Implant loosening is the most common indication for revision after total hip arthroplasty and is associated with progressive bone destruction. Contained defects can be treated with impaction bone grafting (IBG). Segmental defects are successfully restored with metal augmentation. Considering the increasing number of hip arthroplasty cases in young patients, it would appear sensible to reconstruct the bone stock for future revisions by biological bone defect reduction. The data on the treatment of segmental defects with IBG without additional stabilization are lacking. Materials and methods: Paprosky type IIB defects were milled into 15 porcine hemipelves with segmental defect angles of 40°, 80° and 120°. Contained defects without segmental defects (Paprosky type I) and acetabula without defects served as controls. After IBG, a cemented polyethylene cup (PE) was implanted in each case. Cup migration, rotational stiffness and maximum rupture torque were determined under physiological loading conditions after 2500 cycles. Results: Compared with the control without defects, IBG cups showed an asymptotic migration of 0.26 mm ± 0.11 mm on average. This seating was not dependent on the size of the defect. The maximum rupture moment was also not dependent on the defect size for cups after IBG. In contrast, the torsional stiffness of cups with an 120° segmental defect angle was significantly lower than in the control group without defects. All other defects did not differ in torsional stiffness from the control without defects. Conclusions: IBG did not show inferior biomechanical properties in segmental type IIB defect angles up to 80°, compared to cups without defects. [ABSTRACT FROM AUTHOR]