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Purpose: The purpose of the present study is to develop a calibration method to account for differences in echo times (TE) and facilitate the use of restriction spectrum imaging restriction score (RSIrs) as a quantitative biomarker for the detection of clinically significant prostate cancer (csPCa). Methods: This study included 197 consecutive patients who underwent MRI and biopsy examination; 97 were diagnosed with csPCa (grade group ≥ 2). RSI data were acquired three times during the same session: twice at minimum TE ~75 ms and once at TE = 90 ms (TEmin1, TEmin2, and TE90, respectively). A linear regression model was determined to match the C‐maps of TE90 to the reference C‐maps of TEmin1 within the interval ranging from 95th to 99th percentile of signal intensity within the prostate. RSIrs comparisons were made at the 98th percentile within each patient's prostate. We compared RSIrs from calibrated TE90 (RSIrsTE90corr) and uncorrected TE90 (RSIrsTE90) to RSIrs from reference TEmin1 (RSIrsTEmin1) and repeated TEmin2 (RSIrsTEmin2). Calibration performance was evaluated with sensitivity, specificity and area under the ROC curve (AUC). Results: Scaling factors for C1, C2, C3, and C4 were estimated as 1.68, 1.33, 1.02, and 1.13, respectively. In non‐csPCa cases, the 98th percentile of RSIrsTEmin2 and RSIrsTEmin1 differed by 0.27 ± 0.86SI (mean ± standard deviation), whereas RSIrsTE90 differed from RSIrsTEmin1 by 1.82 ± 1.20SI. After calibration, this bias was reduced to ‐0.51 ± 1.21SI, representing a 72% reduction in absolute error. For patients with csPCa, the difference was 0.54 ± 1.98SI between RSIrsTEmin2 and RSIrsTEmin1 and 2.28 ± 2.06SI between RSIrsTE90 and RSIrsTEmin1. After calibration, the mean difference decreased to ‐1.03SI, a 55% reduction in absolute error. At the Youden index for patient‐level classification of csPCa (8.94SI), RSIrsTEmin1 has a sensitivity of 66% and a specificity of 72%. Conclusions: The proposed linear calibration method produces similar quantitative biomarker values for acquisitions with different TE, reducing TE‐induced error by 72% and 55% for non‐csPCa and csPCa, respectively. [ABSTRACT FROM AUTHOR]

Introduction: The current work probes the effectiveness of multimodal touch screen tablet electronic devices in conveying science, technology, engineering, and mathematics graphics via vibrations and sounds to individuals who are visually impaired (i.e., blind or low vision) and compares it with similar graphics presented in an embossed format. Method: A volunteer sample of 22 participants who are visually impaired, selected from a summer camp and local schools for blind students, were recruited for the current study. Participants were first briefly (~30 min) trained on how to explore graphics via a multimodal touch screen tablet. They then explored six graphic types (number line, table, pie chart, bar chart, line graph, and map) displayed via embossed paper and tablet. Participants answered three content questions per graphic type following exploration. Results: Participants were only 6% more accurate when answering questions regarding an embossed graphic as opposed to a tablet graphic. A paired-samples t test indicated that this difference was not significant, t(14) = 1.91, p = 0.07. Follow-up analyses indicated that presentation medium did not interact with graphic type, F(5, 50) = 0.43, p =0.83, nor visual ability, F(1, 13) = 0.00, p = 0.96. Discussion: The findings demonstrate that multimodal touch screen tablets may be comparable to embossed graphics in conveying iconographic science and mathematics content to individuals with visual impairments, regardless of the severity of impairment. The relative equivalence in response accuracy between mediums was unexpected, given that most students who participated were braille readers and had experience reading embossed graphics, whereas they were introduced to the tablet the day of testing. Implications for practitioners: This work illustrates that multimodal touch screen tablets may be an effective option for general education teachers or teachers of students with visual impairments to use in their educational practices. Currently, preparation of accessible graphics is time consuming and requires significant preparation, but such tablets provide solutions for offering "real-time" displays of these graphics for presentation in class.

Lower extremity joint kinetic factors are thought to modulate walk-to-run transition (WRT) and run-to-walk transition (RWT). This study aimed to investigate joint stiffness and energetic patterns during the WRT and RWT processes and identify whether gait transitions occur within a single step or not. Ten healthy subjects participated in treadmill WRT (1.8–2.4 m/s) and RWT (2.4–1.8 m/s) tests. We investigated two steps before transition (S–2, S–1), two steps after transition (S1, S2) and the transition step (S0). We found significant differences between S2 and S–2 for ankle joint stiffness during WRT and RWT (p < 0.001); for hip joint stiffness, we found significant differences between S1 and S–1 during WRT and RWT (p ≤ 0.001). Additionally, stance phase mechanical energy generation was observed to transfer from proximal to distal joints at S0 during WRT, and from distal to proximal at S0 during RWT. Transition step ankle kinematic and kinetic patterns were similar to the target locomotion task gait format in both WRT and RWT. Moreover, RWT required longer adaptation time compared with WRT. These findings indicate that WRT and RWT were modulated before and after the actual transitions, not within a single step. Redistribution of joint mechanical work generation was related to gait transition triggers, which modulate the WRT and RWT processes. [ABSTRACT FROM AUTHOR]

Noninvasive assessment of muscle mechanical properties in clinical and performance settings tends to rely on manual palpation and emphasizes examination of musculotendinous stiffness. However, measurement standards are highly subjective. The purpose of the study was to compare musculotendinous stiffness in adult women with varying resistance training history while exploring the use of multiple tissue compliance measures. We identified relationships between tissue stiffness and morphology, and tested the hypothesis that combining objective measures of mor-phology and stiffness would better predict indices of contractile performance. Resistance-trained (RT) women (n = 11) and nontrained (NT) women (n = 10) participated in the study. Muscle echogenicity and morphology were measured using B-mode ultrasonography (US). Vastus lateralis (VL) and patellar tendon (PT) stiffness were measured using digital palpation and US across submaximal isometric contractions. Muscle function was evaluated during maximal voluntary isometric contraction (MVIC) of the knee extensors (KEs). Resistance trained had significantly greater PT stiffness and reduced echogenicity (p < 0.01). Resistance trained also had greater strength per body mass (p < 0.05). Muscle echogenicity was strongly associated with strength and rate of torque development (RTD). Patellar tendon passive stiffness was associated with RTD normalized to MVIC (RTDrel; r = 0.44, p < 0.05). Patellar tendon stiffness was greater in RT young women. No predictive models of muscle function incorporated both stiffness and echogenicity. Because RTDrel is a clinically relevant measure of rehabilitation in athletes and can be predicted by digital palpation, this might represent a practical and objective measure in settings where RTD may not be easy to measure directly. [ABSTRACT FROM AUTHOR]

Objective: To identify vaginal morphology and position factors associated with prolapse recurrence following vaginal surgery. Design: Secondary analysis of magnetic resonance images (MRI) of the Defining Mechanisms of Anterior Vaginal Wall Descent cross‐sectional study. Setting: Eight clinical sites in the US Pelvic Floor Disorders Network. Population or Sample: Women who underwent vaginal mesh hysteropexy (hysteropexy) with sacrospinous fixation or vaginal hysterectomy with uterosacral ligament suspension (hysterectomy) for uterovaginal prolapse between April 2013 and February 2015. Methods: The MRI (rest, strain) obtained 30–42 months after surgery, or earlier for participants with recurrence who desired reoperation before 30 months, were analysed. MRI‐based prolapse recurrence was defined as prolapse beyond the hymen at strain on MRI. Vaginal segmentations (at rest) were used to create three‐dimensional models placed in a morphometry algorithm to quantify and compare vaginal morphology (angulation, dimensions) and position. Main outcome measures: Vaginal angulation (upper, lower and upper–lower vaginal angles in the sagittal and coronal plane), dimensions (length, maximum transverse width, surface area, volume) and position (apex, mid‐vagina) at rest. Results: Of the 82 women analysed, 12/41 (29%) in the hysteropexy group and 22/41 (54%) in the hysterectomy group had prolapse recurrence. After hysteropexy, women with recurrence had a more laterally deviated upper vagina (p = 0.02) at rest than women with successful surgery. After hysterectomy, women with recurrence had a more inferiorly (lower) positioned vaginal apex (p = 0.01) and mid‐vagina (p = 0.01) at rest than women with successful surgery. Conclusions: Vaginal angulation and position were associated with prolapse recurrence and suggestive of vaginal support mechanisms related to surgical technique and potential unaddressed anatomical defects. Future prospective studies in women before and after prolapse surgery may distinguish these two factors. [ABSTRACT FROM AUTHOR]

The editorial in the Journal of Musculoskeletal Research discusses the increasing prevalence of degenerative joint diseases and the limitations of pharmacologic treatments and joint replacements. Regenerative medicine, including techniques like stem cell therapies and platelet-rich plasma injections, offers potential benefits such as tissue repair, pain management, enhanced surgical outcomes, and reduced dependency on opioids. The editorial highlights the role of regenerative medicine in promoting healing and improving outcomes for musculoskeletal conditions, with contributions from researchers in the United States and Taiwan. [Extracted from the article]

Zero-velocity assumption has been used for estimation of foot trajectory and stride length during running from the data of foot-mounted inertial measurement units (IMUs). Although the assumption provides a reasonable initialization for foot trajectory and stride length estimation, the other source of errors related to the IMU's orientation still remains. The purpose of this study was to develop an improved foot trajectory and stride length estimation method for the level ground running based on the displacement of the foot. Seventy-nine runners performed running trials at 5 different paces and their running motions were captured using a motion capture system. The accelerations and angular velocities of left and right feet were measured with two IMUs mounted on the dorsum of each foot. In this study, foot trajectory and stride length were estimated using zero-velocity assumption with IMU data, and the orientation of IMU was estimated to calculate the mediolateral and vertical distance of the foot between two consecutive midstance events. Calculated foot trajectory and stride length were compared with motion capture data. The results show that the method used in this study can provide accurate estimation of foot trajectory and stride length for level ground running across a range of running speeds. [ABSTRACT FROM AUTHOR]

The lower–extremity system acts like a spring in the running stance phase. Vertical stiffness ( K v e r t ) and leg stiffness ( K l e g ) reflect the whole–body center of mass (COM) and leg–spring system loading and response in running, while joint stiffness ( K j o i n t ) represents joint–level dynamic loading and response. This study aimed to investigate whether K j o i n t is associated with K v e r t and K l e g across different running speeds. Twenty healthy subjects were recruited into a treadmill running study (1.8 to 3.8 m/s, with 0.4 m/s intervals). We found that K j o i n t accounted for 38.4% of the variance in K v e r t (p = 0.046) and 42.4% of the variance in K l e g (p = 0.028) at 1.8 m/s; K j o i n t also accounted for 49.8% of the variance in K v e r t (p = 0.014) and 79.3% of the variance in K l e g (p < 0.0001) at 2.2 m/s. K k n e e had the strongest unique association with K v e r t and K l e g at 1.8 and 2.2 m/s. K j o i n t was associated with K l e g at a wider range of speeds. These findings built a connection between joint stiffness and limb stiffness within a certain range of running speeds. K k n e e may need to be considered as an important factor in future limb stiffness optimization and general running performance enhancement. [ABSTRACT FROM AUTHOR]

Simple Summary: Women at high risk for breast cancer are regularly screened using contrast-enhanced magnetic resonance imaging (MRI) to identify potential malignancy. Diffusion-weighted MRI (DW-MRI) is a non-contrast technique that measures the differential movement of water molecules in tissues and is sensitive to cancer cells. In this study, we use a multi-exponential advanced DW-MRI model called restriction spectrum imaging (RSI) to characterize the diffusion characteristics of malignant lesions, benign lesions, and healthy breast tissue to help differentiate benign from malignant disease. In a cohort of patients, we show that cancer exhibits more restricted diffusion compared to benign breast lesions and healthy tissue, whereas benign and healthy tissue are not different from each other. Diffusion-weighted MRI (DW-MRI) offers a potential adjunct to dynamic contrast-enhanced MRI to discriminate benign from malignant breast lesions by yielding quantitative information about tissue microstructure. Multi-component modeling of the DW-MRI signal over an extended b-value range (up to 3000 s/mm2) theoretically isolates the slowly diffusing (restricted) water component in tissues. Previously, a three-component restriction spectrum imaging (RSI) model demonstrated the ability to distinguish malignant lesions from healthy breast tissue. We further evaluated the utility of this three-component model to differentiate malignant from benign lesions and healthy tissue in 12 patients with known malignancy and synchronous pathology-proven benign lesions. The signal contributions from three distinct diffusion compartments were measured to generate parametric maps corresponding to diffusivity on a voxel-wise basis. The three-component model discriminated malignant from benign and healthy tissue, particularly using the restricted diffusion C1 compartment and product of the restricted and intermediate diffusion compartments (C1 and C2). However, benign lesions and healthy tissue did not significantly differ in diffusion characteristics. Quantitative discrimination of these three tissue types (malignant, benign, and healthy) in non-pre-defined lesions may enhance the clinical utility of DW-MRI in reducing excessive biopsies and aiding in surveillance and surgical evaluation without repeated exposure to gadolinium contrast. [ABSTRACT FROM AUTHOR]

Chemistry-driven strategies for modifying, controlling and monitoring protein function in vitro and in vivo have attracted widespread interest among chemists in recent years. Several strategies have now emerged that complement standard genetics-based approaches, and they are being increasingly adopted by biologists to address issues in relevant contexts from cells to animals. With the development of these chemical biology tools, we might be approaching a time when detailed quantitative analysis of protein function, to a degree previously available only in reconstituted systems, is attainable in an in vivo setting.

The development of lightweight portable sensors and algorithms for the identification of gait events at steady-state running speeds can be translated into the real-world environment. However, the output of these algorithms needs to be validated. The purpose of this study was to validate the identification of running gait events using data from Inertial Measurement Units (IMUs) in a semi-uncontrolled environment. Fifteen healthy runners were recruited for this study, with varied running experience and age. Force-sensing insoles measured normal foot-shoe forces and provided a standard for identification of gait events. Three IMUs were mounted to the participant, two bilaterally on the dorsal aspect of the foot and one clipped to the back of each participant's waistband, approximating their sacrum. The identification of gait events from the foot-mounted IMU was more accurate than from the sacral-mounted IMU. At running speeds <3.57 m s−1, the sacral-mounted IMU identified contact duration as well as the foot-mounted IMU. However, at speeds >3.57 m s−1, the sacral-mounted IMU overestimated foot contact duration. This study demonstrates that at controlled paces over level ground, we can identify gait events and measure contact time across a range of running skill levels. [ABSTRACT FROM AUTHOR]