11 research outputs found

    Large-Scale Surface Shape Sensing with Learning-Based Computational Mechanics

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    Proprioception, the ability to perceive one's own configuration and movement in space, enables organisms to safely and accurately interact with their environment and each other. The underlying sensory nerves that make this possible are highly dense and use sophisticated communication pathways to propagate signals from nerves in muscle, skin, and joints to the central nervous system wherein the organism can process and react to stimuli. In a step forward to realize robots with such perceptive capability, a flexible sensor framework that incorporates a novel modeling strategy, taking advantage of computational mechanics and machine learning, is proposed. The sensor framework on a large flexible sensor that transforms sparsely distributed strains into continuous surface is implemented. Finite element (FE) analysis is utilized to determine design parameters, while an FE model is built to enrich the morphological data used in the supervised training to achieve continuous surface reconstruction. A mapping between the local strain data and the enriched surface data is subsequently trained using ensemble learning. This hybrid approach enables real time, robust, and high‐order surface reconstruction. The sensing performance is evaluated in terms of accuracy, repeatability, and feasibility with numerous scenarios, which has not been demonstrated on such a large‐scale sensor before

    Interactive Multi-Stage Robotic Positioner for Intra-Operative MRI-Guided Stereotactic Neurosurgery

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    Magnetic resonance imaging (MRI) demonstrates clear advantages over other imaging modalities in neurosurgery with its ability to delineate critical neurovascular structures and cancerous tissue in high-resolution 3D anatomical roadmaps. However, its application has been limited to interventions performed based on static pre/post-operative imaging, where errors accrue from stereotactic frame setup, image registration, and brain shift. To leverage the powerful intra-operative functions of MRI, e.g., instrument tracking, monitoring of physiological changes and tissue temperature in MRI-guided bilateral stereotactic neurosurgery, a multi-stage robotic positioner is proposed. The system positions cannula/needle instruments using a lightweight (203 g) and compact (Ø97 × 81 mm) skull-mounted structure that fits within most standard imaging head coils. With optimized design in soft robotics, the system operates in two stages: i) manual coarse adjustment performed interactively by the surgeon (workspace of ±30°), ii) automatic fine adjustment with precise (<0.2° orientation error), responsive (1.4 Hz bandwidth), and high-resolution (0.058°) soft robotic positioning. Orientation locking provides sufficient transmission stiffness (4.07 N/mm) for instrument advancement. The system's clinical workflow and accuracy is validated with lab-based (<0.8 mm) and MRI-based testing on skull phantoms (<1.7 mm) and a cadaver subject (<2.2 mm). Custom-made wireless omni-directional tracking markers facilitated robot registration under MRI

    Controversy and consensus on indications for sperm DNA fragmentation testing in male infertility: a global survey, current guidelines, and expert recommendations.

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    PURPOSE: Sperm DNA fragmentation (SDF) testing was recently added to the sixth edition of the World Health Organization laboratory manual for the examination and processing of human semen. Many conditions and risk factors have been associated with elevated SDF; therefore, it is important to identify the population of infertile men who might benefit from this test. The purpose of this study was to investigate global practices related to indications for SDF testing, compare the relevant professional society guideline recommendations, and provide expert recommendations. MATERIALS AND METHODS: Clinicians managing male infertility were invited to take part in a global online survey on SDF clinical practices. This was conducted following the CHERRIES checklist criteria. The responses were compared to professional society guideline recommendations related to SDF and the appropriate available evidence. Expert recommendations on indications for SDF testing were then formulated, and the Delphi method was used to reach consensus. RESULTS: The survey was completed by 436 experts from 55 countries. Almost 75% of respondents test for SDF in all or some men with unexplained or idiopathic infertility, 39% order it routinely in the work-up of recurrent pregnancy loss (RPL), and 62.2% investigate SDF in smokers. While 47% of reproductive urologists test SDF to support the decision for varicocele repair surgery when conventional semen parameters are normal, significantly fewer general urologists (23%; p=0.008) do the same. Nearly 70% would assess SDF before assisted reproductive technologies (ART), either always or for certain conditions. Recurrent ART failure is a common indication for SDF testing. Very few society recommendations were found regarding SDF testing. CONCLUSIONS: This article presents the largest global survey on the indications for SDF testing in infertile men, and demonstrates diverse practices. Furthermore, it highlights the paucity of professional society guideline recommendations. Expert recommendations are proposed to help guide clinicians

    Impact of varicocele repair on semen parameters in infertile men: a systematic review and meta-analysis

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    Purpose: Despite the significant role of varicocele in the pathogenesis of male infertility, the impact of varicocele repair (VR) on conventional semen parameters remains controversial. Only a few systematic reviews and meta-analyses (SRMAs) have evaluated the impact of VR on sperm concentration, total motility, and progressive motility, mostly using a before-after analytic approach. No SRMA to date has evaluated the change in conventional semen parameters after VR compared to untreated controls. This study aimed to evaluate the effect of VR on conventional semen parameters in infertile patients with clinical varicocele compared to untreated controls. Materials and Methods: A literature search was performed using Scopus, PubMed, Embase, and Cochrane databases following the Population Intervention Comparison Outcome (PICOS) model (Population: infertile patients with clinical varicocele; Intervention: VR [any technique]; Comparison: infertile patients with clinical varicocele that were untreated; Outcome: sperm concentration, sperm total count, progressive sperm motility, total sperm motility, sperm morphology, and semen volume; Study type: randomized controlled trials and observational studies). Results: A total of 1,632 abstracts were initially assessed for eligibility. Sixteen studies were finally included with a total of 2,420 infertile men with clinical varicocele (1,424 patients treated with VR vs. 996 untreated controls). The analysis showed significantly improved post-operative semen parameters in patients compared to controls with regards to sperm concentration (standardized mean difference [SMD] 1.739; 95% CI 1.129 to 2.349; p<0.001; I2 =97.6%), total sperm count (SMD 1.894; 95% CI 0.566 to 3.222; p<0.05; I2 =97.8%), progressive sperm motility (SMD 3.301; 95% CI 2.164 to 4.437; p<0.01; I 2 =98.5%), total sperm motility (SMD 0.887; 95% CI 0.036 to 1.738; p=0.04; I2 =97.3%) and normal sperm morphology (SMD 1.673; 95% CI 0.876 to 2.470; p<0.05; I2 =98.5%). All the outcomes showed a high inter-study heterogeneity, but the sensitivity analysis showed that no study was sensitive enough to change these results. Publication bias was present only in the analysis of the sperm concentration and progressive motility. No significant difference was found for the semen volume (SMD 0.313; 95% CI -0.242 to 0.868; I2 =89.7%). Conclusions: This study provides a high level of evidence in favor of a positive effect of VR to improve conventional semen parameters in infertile men with clinical varicocele. To the best of our knowledge, this is the first SRMA to compare changes in conventional semen parameters after VR with changes in parameters of a control group over the same period. This is in contrast to other SRMAs which have compared semen parameters before and after VR, without reference to a control group. Our findings strengthen the available evidence and have a potential to upgrade professional societies’ practice recommendations favoring VR to improve conventional semen parameters in infertile men

    PrevalĂȘncia e fatores associados a fogachos em mulheres climatĂ©ricas e pĂłs-climatĂ©ricas Prevalence and factors associated with hot flashes in climacteric and post-climacteric women

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    Com o objetivo de determinar a prevalĂȘncia de fogachos e fatores associados, em mulheres entre 40 e 69 anos de idade, provenientes de uma amostra representativa da população da cidade de Pelotas, Rio Grande do Sul, Brasil, realizou-se um estudo transversal. O processo de amostragem foi em mĂșltiplos estĂĄgios, e a coleta de dados, realizada atravĂ©s de entrevista e questionĂĄrio auto-aplicado. Foram incluĂ­das 879 mulheres. A prevalĂȘncia ponto e a prevalĂȘncia de episĂłdio de fogachos foram, respectivamente, de 30,1% e 53,2%. Os fatores estatisticamente associados a fogachos atuais foram a categoria menopausal de prĂ©-menopausa (RP = 2,33) e pĂłs-menopausa (RP = 2,66); idade de 45 a 49 anos (RP = 1,34) e de 50 a 54 anos (RP = 1,42); status sĂłcio-econĂŽmico mais baixo (RP = 2,16); nĂŁo uso de anticoncepção hormonal apĂłs os 40 anos (RP = 1,40); obesidade (RP = 1,39); sobrepeso (RP = 1,32) e viver sem companheiro (RP = 0,80). Dada a alta prevalĂȘncia do sintoma, Ă© necessĂĄrio que os serviços de saĂșde se organizem para lidar com a mulher climatĂ©rica.<br>A cross-sectional study was conducted on the prevalence of hot flashes and associated factors among women from 40 to 69 years old, from a population-based sample in the city of Pelotas, southern Brazil. A multi-stage sampling process was used, and data were collected through an interview and a self-applied questionnaire. A total of 879 women were included. Point prevalence and lifetime prevalence were 30.1% and 53.2%, respectively. Factors associated with hot flashes were: pre-menopausal status (RP = 2.33) and post-menopausal status (RP = 2.66); age 45-49 years (RP = 1.34) and 50-54 years (RP = 1.42); lower social class (RP = 2.16); no use of a hormonal contraception method after 40 years of age (RP = 1.40); obesity (RP = 1.39) and overweight (RP = 1.32); and not having a partner (RP = 0.80). High prevalence of this symptom indicates that health facilities should be prepared to deal with problems encountered by climacteric women

    Hologenomic adaptations underlying the evolution of sanguivory in the common vampire bat.

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    Adaptation to specialized diets often requires modifications at both genomic and microbiome levels. We applied a hologenomic approach to the common vampire bat (Desmodus rotundus), one of the only three obligate blood-feeding (sanguivorous) mammals, to study the evolution of its complex dietary adaptation. Specifically, we assembled its high-quality reference genome (scaffold N50?=?26.9?Mb, contig N50?=?36.6?kb) and gut metagenome, and compared them against those of insectivorous, frugivorous and carnivorous bats. Our analyses showed a particular common vampire bat genomic landscape regarding integrated viral elements, a dietary and phylogenetic influence on gut microbiome taxonomic and functional profiles, and that both genetic elements harbour key traits related to the nutritional (for example, vitamin and lipid shortage) and non-nutritional (for example, nitrogen waste and osmotic homeostasis) challenges of sanguivory. These findings highlight the value of a holistic study of both the host and its microbiota when attempting to decipher adaptations underlying radical dietary lifestyles

    Hormonal and Metabolic Response to Operative Stress in the Neonate

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141075/1/jpen0215.pd
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