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Abstract Background Attention to the collection of patient-reported outcomes measures (PROMs) associated with total hip arthroplasty (THA) is growing. The aim of this study was to preoperatively predict failure to achieve the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) between pre- and postoperative PROMs. In addition, we sought to identify factors predictive of failure to achieve MCID and SCB in patients undergoing a THA. Methods A retrospective query of the electronic health record data was performed at a single institution. Outcomes of interest were the anchor-based MCID, the distribution-based MCID, and the SCB for the Hip Disability and Osteoarthritis Outcome Score for Joint Replacement. Several machine learning models were built for each outcome and were evaluated by areas under the receiver operating characteristic curve and the precision-recall curve. Furthermore, logistic regression models were used to identify significant risk factors. Results Of the 857 patients who underwent THA, 350 patients completed both pre- and postoperative surveys. Of the final sample (i.e., 350 patients), 56 (16.0%), 29 (8.3%), and 71 (20.3%) failed to reach the anchor-based (i.e., 17.7 points) and distribution-based (10.6 points) MCIDs and the SCB (i.e., 22.0 points). The machine learning model performances were far beyond the baseline and comparable to the ones in existing studies, suggesting reliability in the prediction. Two shared factors associated with the failure in both the MCIDs and the SCB were highlighted: a patient’s race and pre-existing mental illness. Conclusion Understanding the risk factors of failing to meet MCID and SCB may provide a more objective opportunity to quantify patient and surgeon expectations associated with THA. Our findings call stakeholders' particular attention to patients with preoperative mental disorders, and raise further questions regarding the impact of race, in the care of patients with degenerative hip disease.

Abstract The present study investigates the human haptic perception of 2.5D tactile patterns based on adjective ratings and how physical factors, such as the bump diameter of the pattern or material, affect their tactile perception. We designed fifty tactile patterns by varying the pattern’s bump diameter, pattern uniformity, and material and evaluated the effect of the parameters on haptic perception by conducting a couple of human subject experiments. In Experiment 1, the perceived intensities of the tactile patterns were tested for a total of ten properties (adjective pairs). The experimental results indicate significant effects of the factors, the bump diameter, pattern type, and material on the perceived intensities of the 2.5D patterns. In Experiment 2, a cluster sorting of the tactile patterns was conducted, and a haptic perceptual space was constructed with an MDS (multi-dimensional scaling). The results indicate a grouping of the samples by bump diameter and an effect of sample pattern uniformity for larger 2.5D tactile patterns. Overall, the present study showed that bump diameter, pattern type, and material significantly affected the perception of 2.5D tactile patterns based on the adjective ratings, and the 2.5D patterns could be grouped by the pattern’s bump diameter and uniformity.

Abstract Objective The objective of this study was to examine the causal relationship between the usage of patient portals and patients’ self-care self-efficacy and satisfaction in care outcomes in the context of cancer care. Methods The National Institute’s HINTS 5 Cycle 1–4 (2017–2020) data were used to perform a secondary data analysis. Patients who reported being ever diagnosed with cancer were included in the study population. Their portal usage frequency was considered as an intervention. Patient’s self-care self-efficacy and satisfaction in care were the primary outcomes considered and they were measured by survey respondents’ self-reported information. A set of conditional independence tests based on the causal diagram was developed to examine the causal relationship between patient portal usage and the targeted outcomes. Results A total of 2579 were identified as patients with cancer or cancer survivors. We identified patient portals’ impact on strengthening patients’ ability to take care of their own health (P = .02, for the test rejecting which is necessary for the expected causal relationship, ie, the portal usage impacts the target outcome; P = .06, for the test rejecting which is necessary for the reverse causal relationship), and we identified heterogenous causal relationships between frequent patient portal usage and patients’ perceived quality of care (P = .04 and P = .001, for the tests rejecting both suggests heterogeneous causal relationships). We could not conclusively determine the causal relationship between patient portal usage and patients’ confidence in getting advice or information about health or cancer care related topics (P > .05 for both tests, suggesting inconclusive causal directions). Conclusions The results advocate patient portals and promote the need to provide better support and education to patients. The proposed statistical method exploits the potential of national survey data for causal inference studies.

Background: The International Agency for Research on Cancer (IARC) Monograph conducted a systematic review of the relationship between asbestos and ovarian cancer. However, there may have been information bias due to the undue weight given to few articles. To address this limitation, the present study performed a meta-analysis integrating studies published both before and after the 2012 IARC Monograph on Asbestos, with the aim of investigating the association between asbestos exposure and ovarian cancer. Methods: A comprehensive search of major journal databases was conducted to identify studies examining the relationship between asbestos exposure and ovarian cancer, including those featured in the 2012 IARC Monograph on Asbestos. A meta-analysis on asbestos exposure and cancer risk was performed. Results: The meta-analysis of studies published after the 2012 IARC Monograph on Asbestos found a summary Standardized Mortality Ratio (SMR) of 2.04 (95% CI: 1.03—4.05; p = 0.0123; 5 studies), with a significant degree of heterogeneity among the studies (I2 = 72.99%). The combined analysis of 15 studies before and after the 2012 IARC Monograph showed an overall summary SMR of 1.72 (95% CI: 1.43—2.06; p = 0.0349; 15 studies), with a moderate degree of heterogeneity (I2 = 42.99%). Conclusion: This meta-analysis provides evidence of a significant association between asbestos exposure and ovarian cancer mortality. While the possibility of misdiagnosis in earlier studies cannot be completely ruled out, recent findings suggest a robust correlation between asbestos exposure and ovarian cancer. This highlights the importance of sustained efforts to minimize asbestos exposure and protect public health.

In the present study, we investigate the effect of rendering virtual vibrotactile motion to the perception of lateral force during planar sweeping motion. The virtual vibrotactile motion was rendered by an algorithm to create the sensation of resistive lateral force utilizing illusory haptic effects. The direction of the virtual vibrotactile motion was the opposite of the hand-sweeping motion to create the sensation of resistive force. We conducted two experiments that mapped the lateral resistive haptic feedback rendered by the virtual vibrotactile motion and force feedback to the perceived force magnitude. In Experiment 1, the test was conducted for three reference stimulus force and two maximum signal intensities. The results indicate significant effect of the two experimental parameters. The perceived lateral force was significantly larger with the virtual vibrotactile motion than the force feedback only. Also, the increase in the maximum signal intensity led to a larger perceived lateral force. Experiment 2 tested the effect of vibrotactile signal envelope function on the perceived lateral force by conducting a comparative experiment for linear and logarithmic envelope functions. The experimental results indicate a significantly larger perceived lateral force for the logarithmic signal envelope function than the linear signal envelope function. Overall, this study suggests that rendering virtual vibrotactile motion at the fingertip during swiping motion can create the sensation of additive lateral force and that the perceived intensity can be controlled by modulating the vibrotactile signal intensity and the signal envelope functions.

Background: The Centers for Medicare & Medicaid Services currently incentivizes hospitals to reduce postdischarge adverse events such as unplanned hospital readmissions for patients who underwent total joint arthroplasty (TJA). This study aimed to predict 90-day TJA readmissions from our comprehensive electronic health record data and routinely collected patient-reported outcome measures. Methods: We retrospectively queried all TJA-related readmissions in our tertiary care center between 2016 and 2019. A total of 104-episode care characteristics and preoperative patient-reported outcome measures were used to develop several machine learning models for prediction performance evaluation and comparison. For interpretability, a logistic regression model was built to investigate the statistical significance, magnitudes, and directions of associations between risk factors and readmission. Results: Given the significant imbalanced outcome (5.8% of patients were readmitted), our models robustly predicted the outcome, yielding areas under the receiver operating characteristic curves over 0.8, recalls over 0.5, and precisions over 0.5. In addition, the logistic regression model identified risk factors predicting readmission: diabetes, preadmission medication prescriptions (ie, nonsteroidal anti-inflammatory drug, corticosteroid, and narcotic), discharge to a skilled nursing facility, and postdischarge care behaviors within 90 days. Notably, low self-reported confidence to carry out social activities accurately predicted readmission. Conclusions: A machine learning model can help identify patients who are at substantially increased risk of a readmission after TJA. This finding may allow for health-care providers to increase resources targeting these patients. In addition, a poor response to the “social activities” question may be a useful indicator that predicts a significant increased risk of readmission after TJA.

Background: The aim of this study was to improve understanding of hospital length of stay (LOS) in patients undergoing total joint arthroplasty (TJA) in a high-efficiency, hospital-based pathway. Methods: We retrospectively reviewed 1401 consecutive primary and revision TJA patients across 67 patient and preoperative care characteristics from 2016 to 2019 from the institutional electronic health records. A machine learning approach, testing multiple models, was used to assess predictors of LOS. Results: The median LOS was 1 day; outpatients accounted for 16.5%, 1-day inpatient stays for 38.0%, 2-day stays for 26.4%, and 3-days or more for 19.1%. Patients characteristically fell into 1 of 3 broad categories that contained relatively similar characteristics: outpatient (0-day LOS), short stay (1- to 2-day LOS), and prolonged stay (3 days or greater). The random forest models suggested that a lower Risk Assessment and Prediction Tool score, unplanned admission or hospital transfer, and a medical history of cardiovascular disease were associated with an increased LOS. Documented narcotic use for surgery preparation prior to hospitalization and preoperative corticosteroid use were factors independently associated with a decreased LOS. Conclusions: After TJA, most patients have either an outpatient or short-stay hospital episode. Patients who stay 2 days do not differ substantially from patients who stay 1 day, while there is a distinct group that requires prolonged admission. Our machine learning models support a better understanding of the patient factors associated with different hospital LOS categories for TJA, demonstrating the potential for improved health policy decisions and risk stratification for centers caring for complex patients.

Background: The prevalence of Parkinson’s disease (PD) has grown rapidly compared to that of other neurological disorders. Acupuncture has been used to address the complex symptoms of PD. Recently, similarities in the mechanisms of action between acupuncture and neuromodulation have received considerable attention. This review aims to summarize the evidence regarding these similarities to suggest potential role of acupuncture in the treatment of PD. Methods: The literature from two electronic databases, PubMed and Google Scholar, was searched using the search terms 'Acupuncture', 'Parkinson's disease', 'Vagus nerve stimulation', and 'Brain functional connectivity'. We then explored the evidence for the effectiveness of acupuncture in PD and evaluated the evidence for similarities in the mechanisms of action between acupuncture and neuromodulation. Results: Data suggests that acupuncture treatment is effective for PD symptoms by modulating inflammation and brain functional connectivity (BFC). These acupuncture effects have been shown to be similar to neuromodulation in controlling inflammation and BFC. Based on the shared mechanisms of action, potential acupuncture mechanisms that may ameliorate a wide range of PD symptoms include but are not limited to (1) vagal activation of the anti-inflammatory pathway and (2) BFC enhancement. Conclusion: The development of acupuncture strategies based on shared mechanisms with neuromodulation will provide new treatment options for patients with PD as personalized neuromodulating therapies. Further studies are needed to gather scientific evidence for optimizing parameters in PD patients.

BackgroundDepression is a substantial global health problem, affecting >300 million people and resulting in 12.7% of all deaths. Depression causes various physical and cognitive problems, leading to a 5-year to 10-year decrease in life expectancy compared with the general population. Physical activity is known to be an effective, evidence-based treatment for depression. However, people generally have difficulties with participating in physical activity owing to limitations in time and accessibility. ObjectiveTo address this issue, this study aimed to contribute to the development of alternative and innovative intervention methods for depression and stress management in adults. More specifically, we attempted to investigate the effectiveness of a mobile phone–based physical activity program on depression, perceived stress, psychological well-being, and quality of life among adults in South Korea. MethodsParticipants were recruited and randomly assigned to the mobile phone intervention or waitlist group. Self-report questionnaires were used to assess variables before and after treatment. The treatment group used the program around 3 times per week at home for 4 weeks, with each session lasting about 30 minutes. To evaluate the program’s impact, a 2 (condition) × 2 (time) repeated-measures ANOVA was conducted, considering pretreatment and posttreatment measures along with group as independent variables. For a more detailed analysis, paired-samples 2-tailed t tests were used to compare pretreatment and posttreatment measurements within each group. Independent-samples 2-tailed t tests were conducted to assess intergroup differences in pretreatment measurements. ResultsThe study included a total of 68 adults aged between 18 and 65 years, who were recruited both through web-based and offline methods. Of these 68 individuals, 41 (60%) were randomly assigned to the treatment group and 27 (40%) to the waitlist group. The attrition rate was 10.2% after 4 weeks. The findings indicated that there is a significant main effect of time (F1,60=15.63; P=.003; ηp2=0.21) in participants’ depression scores, indicating that there were changes in depression level across time. No significant changes were observed in perceived stress (P=.25), psychological well-being (P=.35), or quality of life (P=.07). Furthermore, depression scores significantly decreased in the treatment group (from 7.08 to 4.64; P=.03; Cohen d=0.50) but not in the waitlist group (from 6.72 to 5.08; P=.20; Cohen d=0.36). Perceived stress score of the treatment group also significantly decreased (from 2.95 to 2.72; P=.04; Cohen d=0.46) but not in the waitlist group (from 2.82 to 2.74; P=.55; Cohen d=0.15). ConclusionsThis study provided experimental evidence that mobile phone–based physical activity program affects depression significantly. By exploring the potential of mobile phone–based physical activity programs as a treatment option, this study sought to improve accessibility and encourage participation in physical activity, ultimately promoting better mental health outcomes for individuals with depression and stress.

Abstract Background ICU operational conditions may contribute to cognitive overload and negatively impact on clinical decision making. We aimed to develop a quantitative model to investigate the association between the operational conditions and the quantity of medication orders as a measurable indicator of the multidisciplinary care team’s cognitive capacity. Methods The temporal data of patients at one medical ICU (MICU) of Mayo Clinic in Rochester, MN between February 2016 to March 2018 was used. This dataset includes a total of 4822 unique patients admitted to the MICU and a total of 6240 MICU admissions. Guided by the Systems Engineering Initiative for Patient Safety model, quantifiable measures attainable from electronic medical records were identified and a conceptual framework of distributed cognition in ICU was developed. Univariate piecewise Poisson regression models were built to investigate the relationship between system-level workload indicators, including patient census and patient characteristics (severity of illness, new admission, and mortality risk) and the quantity of medication orders, as the output of the care team’s decision making. Results Comparing the coefficients of different line segments obtained from the regression models using a generalized F-test, we identified that, when the ICU was more than 50% occupied (patient census > 18), the number of medication orders per patient per hour was significantly reduced (average = 0.74; standard deviation (SD) = 0.56 vs. average = 0.65; SD = 0.48; p

The in situ small punch (SP) test method is a simple screening technology developed to assess the hydrogen embrittlement (HE) characteristics of structural steels. This method can easily adjust the influencing parameters such as test temperature, gas pressure, and punch velocity depending on the hydrogen service environment. With increased hydrogen consumption, using pipelines for mass hydrogen transportation is being considered. This study evaluated the HE susceptibility of API-X52 and API-X70 steels, considering the hydrogen usage environment. The study investigated the effects of hydrogen pressure and punch velocity on the HE behaviors of each pipe steel at room temperature using the SP energy and relative reduction in thickness (RRT) to determine their effect on HE susceptibility quantitatively. The study found that hydrogen pressure produced a different HE effect; the lower the hydrogen pressure, the more HE was relieved. Particularly, when the punch velocity was high, such as 1 mm/min, the HE effect was significantly relaxed. However, when the punch velocity was below 0.01 mm/min, HE occurred even at low hydrogen pressure conditions, meaning hydrogen diffusion within the specimen during the SP testing reached a critical hydrogen concentration to create a brittle fracture. Both pipeline steels showed similar HE behaviors under a wide range of H2 pressures and punch velocities, showing an inverse S-curve for quantitative factors of SP energy and RRT against the H2 pressure at 1.0 mm/min punch velocity. The study classified the observed HE behaviors into four types based on quantitative and qualitative aspects. These findings confirm that the in situ SP test is a useful screening technique, and the factor RRT can be effectively applied to the HE screening of pipeline steels in low and high-pressure hydrogen environments.

Orientia tsutsugamushi is the causative pathogen of scrub typhus, an acute febrile disease prevalent in the Asia–Pacific region that is spread to people through chigger bites. Despite the emerging threat, there is no currently available vaccine against O. tsutsugamushi. Here, we developed dual-antigen subunit vaccine nanoparticles using recombinant 47 kD and 56 kD proteins, which are immunogenic outer membrane antigens of O. tsutsugamushi. The biocompatible protein vaccine nanoparticles were formed via desolvation of r56 or r47E antigens with acetone, coating with an additional layer of the 56 kD protein, and stabilization with reducible homobifunctional DTSSP and heterobifunctional SDAD crosslinkers. The dual-antigen subunit vaccine nanoparticles significantly improved antigen-specific antibody responses in vaccinated mice. Most importantly, the dual-antigen nanoparticles coated with an additional layer of the 56 kD protein were markedly more immunogenic than soluble antigens or single-antigen nanoparticles in the context of cellular immune responses. Given the significance of cellular immune responses for protection against O. tsutsugamushi, these results demonstrate the potent immunogenicity of dual-layered antigen nanoparticles and their potential as a promising strategy for developing vaccines against scrub typhus.

Abstract As touch screen technologies advanced, a digital stylus has become one of the essential accessories for a smart device. However, most of the digital styluses so far provide limited tactile feedback to a user. Therefore we focused on the limitation and noted the potential that a digital stylus may offer the sensation of realistic interaction with virtual environments on a touch screen using a 2.5D haptic system. Thus, we developed a haptic stylus with SMA (Shape Memory Alloy) and a 2.5D haptic rendering algorithm to provide lateral skin-stretch feedback to mimic the interaction force between fingertip and a stylus probing over a bumpy surface. We conducted two psychophysical experiments to evaluate the effect of 2.5D haptic feedback on the perception of virtual object geometry. Experiment 1 investigated the human perception of virtual bump size felt via the proposed lateral skin-stretch stylus and a vibrotactile stylus as reference. Experiment 2 tested the participants’ ability to count the number of virtual bumps rendered via the two types of haptic styluses. The results of Experiment 1 indicate that the participants felt the size of virtual bumps rendered with lateral skin-stretch stylus significantly sensitively than the vibrotactile stylus. Similarly, the participants counted the number of virtual bumps rendered with the lateral skin-stretch stylus significantly better than with the vibrotactile stylus. A common result of the two experiments is a significantly longer mean trial time for the skin-stretch stylus than the vibrotactile stylus.

Despite their great utility in synthetic and materials chemistry, Diels-Alder and retro Diels-Alder reactions have been vastly unexplored in promoting self-assembly processes. Here the authors show the release of steric bulkiness associated with a bridged bicyclic Diels Alder adduct by the retro Diels-Alder reaction that allowed generation of two building blocks that spontaneously self-assembled to form a supramolecular polymer.

The transmittance of the p-doped hole transporting layer (p-HTL) and the charge generation layer (p-CGL) corresponding to the photoluminescence (PL) of blue dopants in an emitting layer decreases as the ratio of the p-dopant increases due to the absorption of the p-dopant. However, there was little difference in the luminous efficiency of blue top-emitting organic light-emitting diodes using p-HTL or p-CGL at a maximum doping ratio of 20%. p-HTL for a single structure required a 5% doping ratio to ensure sufficient electrical characteristics, but p-CGL for the two-stack tandem structure required more than a 10% doping ratio. The optical simulation showed that the device was affected by the specific absorbance of the p-dopant depending on the doping ratio and thickness. Although there was no significant difference in efficiency depending on the doping ratio at a thickness of 10 nm, the reduction rate of the external quantum efficiency increased from over 20 nm due to the doping ratio.

In the virtual world, people can reconstruct their identity the way they want with avatars. Many expect the high degree of freedom in avatar customization will give new chances to socially marginalized people experiencing discrimination against their physical traits. Accordingly, research on a virtual embodiment of marginalized people has been steady with increased interest in equity and inclusion. However, even discourse alienates people with disabilities. In addition, there are few studies on the virtual representations of people with disabilities. Therefore, this paper explores the shared perception of avatar-based disability representations among people with disability to help understand how they want to construct their disability with avatars. The study also gives direction for a barrier-free virtual world. We conducted semi-structured in-depth interviews with people with physical impairments who used virtual world services and performed a core-periphery analysis of social representations. This study expands the range of academic adoption of the social representations theory and provides insights for stakeholders such as service providers to design an inclusive virtual world.

Reported herein are solution-processed polymer anode electrodes for blue phosphorescent organic light-emitting diodes (PhOLEDs). The highly conductive anodes were made from 10-wt%-methyl-red-(MR)-doped poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (PH1000) films. The red-colored and uniform polymer films demonstrated electrical conductivity values that significantly increased from 0.25 to 50 S·cm−1 after doping. The more than 200-fold enhancement in conductivity indicates that the doped films have a lower sheet resistance and better hole injection and transport properties than the pristine films. The resultant PhOLEDs based on the doped polymer anodes exhibited stable, broad, and intense blue emission at 468 nm with a 2616 cd·m−2 maximum luminance and a 4 V turn-on voltage. The obtained study results confirmed the effectiveness of the MR dye as a dopant for the significant enhancement of the conductivity and effective hole injection of PEDOT:PSS. Efficient future flexible optoelectronic applications can be built using this highly conductive polymer electrode obtained via a simple, solution-processed, and cost-effective doping approach.

Most of the previous haptic interfaces provides tactile feedback directly to the hand, which can impede the operability. Noting the issue, we propose a haptic system that can provide 3D vector information with continuous skin-stretch feedback. We designed the system to render a 3D vector by combining two orthogonally located continuous skin-stretch modules whose orientation could be controlled. To optimize the stimuli, we conducted a psychophysical experiment that measured human sensitivity to the orientation of the continuous skin-stretch feedback. Considering the asymmetry of tactile sensitivity, we collected the data at two locations of the forearm. The results indicate that the participants were more sensitive to the angle change when the skin-stretch feedback was aligned in the proximal-distal direction. Based on the information, we built an algorithm to set the rotation angle of the skin-stretch module to render any target 3D vector. We conducted two experiments for virtual interaction to evaluate our proposed method. In Experiment 1, we tested if adjusting the skin-stretch orientation could improve the human perception of the virtual surface features, and the result indicated a significant improvement in the surface feature perception with the orientation adjustment. Experiment 2 tested a participant's ability to follow a random 3D contour under two conditions, visual cue (V) condition, and visual and continuous skin-stretch (V+CF) cues condition. For the V+CF condition, the skin-stretch interface rendered the error 3D vector to the participant's forearm. The result indicated a significantly lower root-mean-square error for the V+CF condition than the V condition. Thus, the addition of the continuous skin-stretch feedback benefitted the participants to stay closer to the target virtual contour than with visual information only.

In this paper, a computationally efficient implementation technique for optimal precoder selection in spatially multiplexed (SM) multiple-input multiple-output (MIMO) systems with maximum-likelihood detection at the receiver is proposed. The techniques previously developed for suboptimal precoder selection were based on the lower bounds of the free distances of precoders to reduce the processing time. However, the use of these techniques leads to significant declines in error performance when the number of spatial streams approaches the number of receiving antennas. At the same time, to achieve optimal performance, the conventional optimal precoder selection technique can be employed; however, it has a long processing time due to exhaustive search. Thus, in this paper, we propose a precoder selection technique that maintains an optimal performance without the prohibitive processing time of the conventional optimal precoder selection. The processing time can be reduced by the following: (1) exploiting the symmetric structure of quadrature amplitude modulation (QAM) constellations, thereby reducing the search space; (2) adopting the concept of sphere decoding (SD); (3) eliminating the last stage of SD; and (4) performing an SD-like process in a selective manner. Both the optimal performance and reduction in the processing time realized by the proposed technique are confirmed via simulation.

The selection of an appropriate turbulence/transition model is critical when simulating the hypersonic flows based on the Reynolds-averaged Navier–Stokes (RANS) equation. In particular, a deep understanding of the validity, reliability, and limitations of existing models is an essential prerequisite to facilitate their further development. This paper reports on the assessment of two models dedicated to hypersonic boundary layer transition analysis. Both models are compared with two other models that are widely used in this field. The double ramp and shock wave laboratory scramjet intake cases are used for the validation and evaluation of the predictive performance of both models via comparison against experimental data. The results reveal that the appropriate selection of the transition model is critical to the attainment of accurate results. Moreover, the forebody of the scramjet combustion propulsion-01 (SCP-01) flight vehicle, which is a research model, is analyzed as a case study. The air intake performance of the SCP-01, as predicted by four models, is compared and analyzed at different flight altitude and Mach number conditions. The results reveal that the accuracy of the prediction of boundary layer and separated flow transitions significantly affects the flow field and corresponding air intake performance. Furthermore, the uncertainty of results obtained using the two models increases significantly with an increase in altitude. Finally, the reliability and limitations of the transition models considered in this study are examined.

Recent advancements in virtual reality and augmented reality call for light-weight and compliant haptic interfaces to maximize the task-performance interactivity with the virtual or extended environment. Noting this, we propose a haptic glove using a tendon-driven compliant robotic mechanism. Our proposed interface can provide haptic feedback to two fingers of a user, an index finger and a thumb. It can provide both cutaneous and kinesthetic feedback to the fingers by using the tendon-driven system. Each actuator is paired with a force sensor to exert the desired tension accurately. In order to optimize the perception of the kinesthetic feedback, we propose a perception-based kinesthetic feedback distribution strategy. We experimentally measured the force perception weight for peripheral interphalangeal (PIP) and metacarpophalangeal (MCP) joints. We observed no significant difference in the force perception between the two joints. Then, based on the obtained weights, our proposed force distribution method calculates the force for each joint. We also evaluated the effect of additional cutaneous feedback to the kinesthetic feedback, on the force perception at the fingertip. The experimental result has shown that additional cutaneous feedback has significantly increased the sensitivity of the human perception. Finally, we evaluated our proposed system and force distribution algorithm by conducting a human subject test. The experimental result indicates that the availability of the cutaneous feedback significantly improved the perceived realism and acuity of the contact force.

We propose a novel wearable robotic glove or exo-glove design scalable to the variation of the hand kinematics. While most of the traditional robot hand is driven by rotating the joint directly with a rigid body, our exo-glove deforms a robotic finger's skin and, thus, the hand skeleton joints. Multiple tendons woven on the exo-glove's surface can make multi-DOF finger joint motions. We allocated tendons to mimic a hand's intrinsic and extrinsic muscles. Thus, a robotic hand actuated with the exo-glove can perform natural finger motions, including abduction/adduction and flexion/extension of finger joints. Moreover, additional tendons for the thumb enable power grips and the robotic hand's human-like motion. The proposed design approach places all the actuators on the surface without directly actuating any of the hand skeleton's joint. Therefore, a random hand skeleton can work as a robotic hand by putting the wearable robotic glove on it. Thus, the proposed model provides a high degree of freedom on choosing hand skeletons. We expect the aforementioned biomimetic features of our proposed method will benefit not only traditional robotic hands design but also the design of prosthetic hands and robot power-assisted hand glove.

We investigate how different types of haptic feedback to hand affect the perceived size of a virtual object. Multiple haptic interfaces are designed to deliver different types of haptic feedback to hand. In the preliminary experiment, we investigated the effect of cutaneous feedback on the perceived size of the virtual object. The experimental results indicate that the availability of cutaneous feedback resulted in an insignificant effect on the perceived size of the virtual object. On the other hand, the availability of cutaneous feedback led the participants to exert significantly smaller grip force than when there is only force feedback. In the main experiment, we provided haptic feedback to the dorsum of the hand to modulate the hand kinesthesia at the moment of contact with the virtual object. For the reference stimuli, skin-stretch or vibrotactile feedback was provided to a participant's hand along with cutaneous and force feedback to the fingertips. Reference stimuli were rendered only with cutaneous and force feedback to the fingers. The experimental results indicate a significant effect of the type of haptic feedback to the dorsum of a hand. The skin-stretch feedback led the participants to feel virtual objects with a size of 40 mm, larger than without the feedback. The vibrotactile feedback resulted in the perceived size of virtual objects with a size of 20 or 40 mm, smaller than without the vibrotactile feedback.

In this paper, we investigate the requirements for fully asymmetric remote collaboration and present a prototype system. Unlike previously studied asymmetric remote collaboration systems, fully asymmetric remote collaboration handles the cases, where a user of one side is a complete novice having difficulty in explaining his/her problems and unfamiliar with a collaboration system, and thus the remote expert of the other side must locate the local user's problem and teach the local user by having full control of the remote collaboration system. These cases can frequently occur when we collaborate with elderly people. For a fully asymmetric remote collaboration system, there are some requirements which are a little bit different from those of an asymmetric one. We itemize them in the three phases of collaboration: identifying a problem, finding a solution, and showing the solution to a local user. We also design and implement a prototype of a fully asymmetric collaboration system to meet the requirements. Our system consists of a robot with cameras and a projector for a local user and an HMD (head mounted display) with a controller for a remote expert. We also design an efficient HMD-based interaction method for fully asymmetric remote collaboration with our system. We show the efficiency of our prototype system in a fully asymmetric remote collaboration situation by user evaluation.

The demand for realistic haptic feedback actuators has increased as mobile devices have increased in popularity. However, most current haptic actuators provide limited 1-DOF tactile sensations, such as vibrations. This paper presents a 2-DOF haptic impact actuator that can provide planar directional (e.g., x and y directional) and magnitude tactile cues to a user. We built an impact actuator that was designed to be of such a size that a user can grasp it with one hand. Multiple electromagnets of the actuator drive a permanent magnet to hit the actuator housing, creating an impact. For the control of the impact direction, we assumed the direction of a magnetic field vector at the centre of the actuator would follow that of a reference vector formed by voltage heading into the electromagnet array. The results of magnetic field measurements support our assumption by showing that the trend of the magnetic field vector coincided with that of the reference voltage vector. Furthermore, the measurement of the impact acceleration showed the trend that the impact direction follows the reference voltage vector.

This paper introduces a flow simulation-based reservoir modeling study of a two-well pad with long production history and identical completion parameters in the Midland Basin. The study includes building geologic model, history matching, well performance prediction, and finding optimum lateral well spacing in terms of oil volume and economic metrics. The reservoir model was constructed based on a geologic model, integrating well logs, and core data near the target area. Next, a sensitivity analysis was performed on the reservoir simulation model to better understand influential parameters on simulation results. The following history matching was conducted with the satisfactory quality, less than 10% of global error, and after the model calibration ranges of history matching parameters have substantially reduced. The population-based history matching algorithm provides the ensemble of the history-matched model, and the top 50 history-matched models were selected to predict the range of Estimate Ultimate Recovery (EUR), showing that P50 of oil EUR is within the acceptable range of the deterministic EUR estimates. With the best history-matched model, we investigated lateral well spacing sensitivity of the pad in terms of the maximum recovery volume and economic benefit. The results show that, given the current completion design, the well spacing tighter than the current practice in the area is less effective regarding the oil volume recovery. However, economic metrics suggest that the additional monetary value can be realized with 150% of current development assumption. The presented workflow provides a systematic approach to find the optimum lateral well spacing in terms of volume and economic metrics per one section given economic assumptions, and the workflow can be readily repeated to evaluate spacing optimization in other acreage.

In the Earth's magnetosphere, sunspots and magnetic cusp fusion devices, the boundary between the plasma and the magnetic field is marked by a diamagnetic current layer with a rapid change in plasma pressure and magnetic field strength. First principles numerical simulations were conducted to investigate this boundary layer with a spatial resolution beyond electron gyroradius while incorporating a global equilibrium structure. The boundary layer thickness is discovered to be on the order of electron gyroradius scale due to a self-consistent electric field suppressing ion gyromotion at the boundary. Formed at the scale of the electron gyroradius, the electric field plays a critical role in determining equilibrium structure and plasma transport. The discovery highlights the necessity to incorporate electron gyroradius scale physics in studies aimed at advancing our understanding of fusion devices, the magnetosphere and sunspots.

Purpose: The goal of this study was to investigate the association between hypercholesterolemia and the time required for progression to castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy (ADT). Materials and Methods: Data from 154 patients with prostate cancer between 2005 and 2012 were reviewed retrospectively. ADT was employed as a treatment modality for these patients either due to multiple bone metastases at the time of diagnosis or due to old age in combination with other morbidities. Serum cholesterol levels and statin use were reviewed. We analyzed the factors associated with the development of CRPC after ADT treatment. The mean follow-up period was 34.8 months. Results: The mean age of the patients was 71.3 years old and their mean prostate-specific antigen level was 141.8±212.6 ng/mL. Their mean cholesterol level was 175.9±37.7 mg/dL, and 14 patients (9.1%) were statin users. CRPC developed in 44 patients (28.6%), and the mean duration from ADT treatment to CRPC was 24.1 months. In a multivariate analysis, hypercholesterolemia was associated with the development of CRPC (hazard ratio [HR]=1.017, p＜0.001), depending on clinical T stage (p=0.005) and the presence of bone metastasis (p＜0.001). A subanalysis showed that hypercholesterolemia was associated with the development of CRPC in patients with bone metastasis (HR=1.032, p＜0.001), but not in patients without bone metastasis. Conclusions: Hypercholesterolemia may be associated with the development of CRPC after ADT in patients with bone metastasis. Further studies with longer follow-up periods and larger samples are needed to validate this finding.

In this paper, a novel unequal error protection (UEP) technique is proposed for video streaming over multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. Based on the concept of hierarchical quadrature amplitude modulation (HQAM) UEP and multi-antenna UEP, the proposed technique combines the relative protection levels (PLs) of constellation symbols and the differentiated PLs of the transmit antennas. In the proposed technique, standard square quadrature amplitude modulation (QAM) constellations are used instead of HQAM so that the QAM mapper at the transmitter side and the soft decision calculation at the receiver side remain unchanged, but the UEP benefit of HQAM is retained. The superior performance of the proposed technique is explained by the improved connections between data with various priorities and data paths with various PLs. The assumed video compression method is H.264/AVC, which is known to be commercially successful. The IEEE802.16m system is adopted as a data transmission system. With the aid of realistic simulations in strict accordance with the standards of IEEE802.16m systems and H.264/AVC video compression systems, the proposed technique HQAM-multi-antenna UEP is shown to improve the video quality significantly for a given average bit error rate when compared with previous techniques.

With the current biotherapeutic market dominated by antibody molecules, bispecific antibodies represent a key component of the next-generation of antibody therapy. Bispecific antibodies can target two different antigens at the same time, such as simultaneously binding tumor cell receptors and recruiting cytotoxic immune cells. Structural diversity has been fast-growing in the bispecific antibody field, creating a plethora of novel bispecific antibody scaffolds, which provide great functional variety. Two common formats of bispecific antibodies on the market are the single-chain variable fragment (scFv)-based (no Fc fragment) antibody and the full-length IgG-like asymmetric antibody. Unlike the conventional monoclonal antibodies, great production challenges with respect to the quantity, quality, and stability of bispecific antibodies have hampered their wider clinical application and acceptance. In this review, we focus on these two major bispecific types and describe recent advances in the design, production, and quality of these molecules, which will enable this important class of biologics to reach their therapeutic potential.

An area-efficient non-volatile flip flop (NVFF) is proposed. Two minimum-sized Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) and two magnetic tunnel junction (MTJ) devices are added on top of a conventional D flip-flop for temporary storage during the power-down. An area overhead of the temporary storage is minimized by reusing a part of the D flip-flop and an energy overhead is reduced by a current-reuse technique. In addition, two optimization strategies of the use of the proposed NVFF are proposed: (1) A module-based placement in a design phase for minimizing the area overhead; and (2) a dynamic write pulse modulation at runtime for reducing the energy overhead. We evaluated the proposed NVFF circuit using a compact MTJ model targeting an implementation in a 10 nm technology node. Results indicate that area overhead is 6.9 % normalized to the conventional flip flop. Compared to the best previously known NVFFs, the proposed circuit succeeded in reducing the area by 4.1 × and the energy by 1.5 × . The proposed placement strategy of the NVFF shows an improvement of nearly a factor of 2−18 in terms of area and energy, and the pulse duration modulation provides a further energy reduction depending on fault tolerance of programs.

We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when β (plasma pressure/magnetic field pressure) is of order unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high β a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. While not able to confirm the details of Grad’s work, the current experiment does validate, for the first time, the conjecture that confinement is substantially improved at high β. This represents critical progress toward an understanding of the plasma dynamics in a high-β cusp system. We hope that these results will stimulate a renewed interest in the cusp configuration as a fusion confinement candidate. In addition, the enhanced high-energy electron confinement resolves a key impediment to progress of the Polywell fusion concept, which combines a high-β cusp configuration with electrostatic fusion for a compact, power-producing nuclear fusion reactor.