This work evaluates the ability of various lipid-based amphiphilic small molecules (ASMs) to modulate the mechanical and rheological properties of oleogels principally structured by ethyl cellulose (EC). Six ASMs varying in the chemical structure of their polar headgroups were used to produce EC-ASM oleogels. Stearic acid (StAc), monoacylglycerol (MAG), sodium stearoyl lactylate (SSL), and citric acid esters of monoglycerides (CITREM) all provided a dramatic enhancement in gel strength, while lactic acid (LACTEM) and acetic acid (ACETEM) esters produced only a marginal increase. Those additives which crystallized above 20 °C displayed pronounced changes in their network organization and crystal morphology in the presence of EC. Differences in the solid/liquid phase change behavior were also observed in select samples using differential scanning calorimetry. Both the small and large amplitude oscillatory shear responses were dependent on the ASM which was dependent on the chemistry of the headgroup, crystal network organization, and ability to plasticize the polymer network. The extent of thixotropic recovery was largely dependent on the polarity of functional groups in the ASMs, but was also influenced by the formation of a secondary crystal network. In general, ASMs which formed larger, system-spanning crystal networks (MAG, StAc) produced more brittle gels, while the highly hydrophilic, charged headgroup of SSL promoted a homogeneous distribution of small crystals, resulting in a tougher material. In the absence of a crystal network, stronger polar species in the ASM headgroup produced higher gel strength and increased elasticity. Thus, both ASM chemical structure and crystallization properties strongly contribute to the functionality of the resulting combined oleogelator systems.
Prior work has suggested that visual working memory as measured in change detection tasks can be based on recollection, whereby participants consciously identify a specific feature of a stimulus that has changed, or on familiarity, whereby participants sense that a change has occurred but are unable to consciously access what has changed. Whether recollection and familiarity also contribute to auditory working memory is unclear. The present study aims to address that gap in knowledge by having participants make confidence judgments in change detection tests for speech sounds and pure tones. The results indicated that both recollection and familiarity contribute to auditory working memory across a variety of conditions, and showed that these two processes are functionally dissociable. With speech sounds, subjects were better able to detect syllable changes compared to tone or location changes, and this benefit reflected a selective increase in recollection rather than familiarity. Moreover, for pure tones, both recollection and familiarity also contributed to performance, but recollection was found to be selectively eliminated under stimulus-limited test conditions (i.e., noise-masked, brief dichotic presentations). The results indicate that recollection and familiarity contribute to auditory working memory in a manner that is functionally similar to that observed in visual working memory.
Although deep autoencoders excel at extracting intricate features, their application in process monitoring is limited by the requirement for large sample sizes and interpretability of latent representations. This work presents a special deep learning structure named Siamese network to detect abnormal deviations in nonlinear dynamic processes. By leveraging the capability of Siamese architecture to process multiple inputs simultaneously, the training sample size expands exponentially, which enhances the learning potential of the model. Furthermore, a long short-term memory unit is integrated to enable the capture of long-term process dynamics. To refine the distribution of latent features extracted from diverse data types, a contrastive loss function is proposed, which strengthens the model's fault detection capabilities and enhances its interpretation of latent representations. Then T2 statistic is established on the latent space to perform fault detection. The effectiveness of the method is demonstrated through case studies on simulation processes and an industrial process.
Axially loaded piles in liquefiable soils can undergo severe settlement due to an earthquake event. During shaking, the settlement is caused by the decreased shaft and tip capacity from excess pore pressures (ue) generated around the pile. Post shaking, soil settlement from the reconsolidation of liquefied soil surrounding the pile results in the development of additional load (known as drag load), causing downdrag settlement of the pile. Estimating the axial load distribution and pile settlement is essential for designing and evaluating the performance of axially loaded piles in liquefiable soils. In practice, a simplified neutral plane solution method is used, where the liquefied soils are modeled as a consolidating layer without considering the effect of ue generation/dissipation. A TzQzLiq analysis models the load and settlement response of axially loaded piles in liquefiable soils by accounting for the effect of excess pore pressure (ue) generation/dissipation on the shaft and tip capacity. This paper presents the deficiencies of the simplified neutral plane method in predicting the drag load as well as the downdrag settlement by comparing it with the TzQzLiq analysis validated with hypergravity model tests. The results show that the drag load and the downdrag settlement predicted by the neutral plane method might be over- or under-estimated depending on the pile load, the rate of ue dissipation, and the soil settlement. For the cases studied, it was found that most of the pile settlement occurs during shaking due to the decrease in the pile's tip resistance from the development of ue in the soil surrounding it. While large drag loads develop during reconsolidation, the resulting downdrag settlement is small. While the neutral plane method generally predicted a downdrag settlement comparable to that of the TzQzLiq analysis, it overpredicted drag load and could not predict co-seismic settlement. Finally, the study advocates for the development and use of a displacement-based procedure (accounting for all the mechanisms occurring during and after an earthquake event) such as based on TzQzLiq analysis in accurately evaluating the performance of the pile (i.e., the pile settlement and the maximum load), thus providing an overall safe, efficient, and optimized design.
PURPOSE: To evaluate the feasibility and safety of intravitreal injection of autologous CD34+ stem cells from bone marrow (BMSCs) in eyes with vision loss from retinitis pigmentosa (RP). DESIGN: Phase I prospective, open-label, single-center study. PARTICIPANTS: Seven eyes (7 patients) with RP with best-corrected visual acuity (BCVA) of 20/60 to 20/400 or visual field constriction to within 10°. METHODS: A comprehensive examination with ETDRS BCVA, macular OCT, perimetry, and fluorescein angiography was performed at baseline, 1 to 3 months, and 6 months after study treatment. Bone marrow aspiration, isolation of CD34+ BMSCs under good manufacturing practice conditions, and intravitreal cell injection were performed on the same day. The CD34+ cells were isolated from bone marrow using a Ficoll gradient and the Miltenyi CliniMACS system. Isolated CD34+ cells were released for clinical use if viability, sterility, and purity met the release criteria accepted by the United States Food and Drug Administration for this clinical study. MAIN OUTCOME MEASURES: Number of CD34+ cells isolated for injection and adverse events associated with study treatment during follow-up. Secondary outcome measures are changes in BCVA and perimetry. RESULTS: All isolated CD34+ cells passed the release criteria. A mean of 3.26 ± 0.66 million viable CD34+ cells (range 1.6 to 7.05 million) were injected intravitreally per eye. No adverse event was noted during the study follow-up except for 1 participant who was noted with transient cells in the anterior chamber with mild elevation in intraocular pressure at 18 hours after study injection which normalized by 24 hours. Best-corrected visual acuity remained within 2 lines of baseline or improved in all participants at 6 months follow-up. Perimetry was stable or improved in all eyes during study follow-up except 1 eye with transient improvement at 1 month and worsening of both eyes at 6 months. CONCLUSIONS: Intravitreal injection of autologous CD34+ BMSCs is feasible and appears to be well tolerated in eyes with vision loss from RP. A larger randomized prospective study would be needed to evaluate further the safety and potential efficacy of this cell therapy for vision loss associated with RP. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
CONTEXT: Precision weeding, a sector of agricultural technology in which drones and/or automated weeders use chemical, mechanical, or thermal means to eradicate weeds, has moved from academic research settings to commercialization. Because of labor shortage pressures, the push to gain competitive advantages, and the environmental impacts of excessive chemical inputs, many California growers have been interested in adopting precision weeding technologies in their operations. OBJECTIVE: Using semi-structured qualitative interviews, this study investigated the viewpoints of three key stakeholder groups involved in the diffusion and adoption of precision weeding technologies: California growers, precision weeding startups, and agricultural technology venture capital firms. With the supplemental viewpoints of large agricultural firms and their corporate venture capital arms and government agencies, this study seeks to understand the compatible motivations between stakeholders, current collaborative models between stakeholders and their limitations, and the user journey for growers adopting precision weeding technology. METHODS: We conducted 17 semi-structured qualitative interviews with diverse stakeholders in the precision weeding sector to gather textual data and gain high data saturation. Data collection balanced rigorous criteria for participant selection with adaptive interview questions to ensure depth and relevance. The analysis procedure involved coding and thematic framework development, complemented by grounded theory for iterative data examination and stakeholder map creation for distilling cross-organizational insights and stakeholder dynamics. RESULTS AND CONCLUSIONS: The results indicated that compatible motivations include addressing current labor issues, reducing costs, and the potential of precision weeding to transform agriculture. Less cited but still popular motivations included having more weeding options, meeting specific field needs, and environmental sustainability. The individual and stakeholder group cognitive maps demonstrated that concerns such as startup longevity, the high expenses of precision weeding machinery, and some startups lacking a direct connection to growers commonly limit the growers' adoption of precision weeding technologies. SIGNIFICANCE: The procedure and cognitive mapping presented in this study can be applied to other emerging agtech technologies and ecosystems.
Exposure to social adversity has been associated with cortisol dysregulation during pregnancy and in later childhood; less is known about how prenatal exposure to social stressors affects postnatal cortisol of infants. In a secondary analysis of data from a longitudinal study, we tested whether a pregnant woman's reports of social adversity during the third trimester were associated with their infant's resting cortisol at 1, 6, and 12 months postnatal. Our hypothesis was that prenatal exposure to social adversity would be associated with elevation of infants' cortisol. Measures included prenatal survey reports of social stressors and economic hardship, and resting cortisol levels determined from infant saliva samples acquired at each postnatal timepoint. Data were analyzed using linear mixed effects models. The final sample included 189 women and their infants (46.56% assigned female sex at birth). Prenatal economic hardship was significantly associated with infant cortisol at 6 months postnatal; reports of social stressors were not significantly associated with cortisol at any time point. Factors associated with hardship, such as psychological distress or nutritional deficiencies, may alter fetal HPA axis development, resulting in elevated infant cortisol levels. Developmental changes unique to 6 months of age may explain effects at this timepoint. More work is needed to better comprehend the complex pre- and post-natal physiologic and behavioral factors that affect infant HPA axis development and function, and the modifying role of environmental exposures.
INTRODUCTION: Student-run free clinics (SRFCs) offer medical students a unique opportunity to develop their clinical, diagnostic, and social skills while providing care to medically underserved communities. This study aims to evaluate the value of SRFC involvement on students self-reported confidence in various clinical domains and satisfaction with their medical education. METHODS: We conducted a single-center retrospective pre-post assessment at an urban academic institution among second- to fourth-year medical students. We administered a 25-item questionnaire capturing the scope of clinic involvement and assessing self-reported confidence in multiple clinical domains following a one-year-long participation in student-run free clinics. RESULTS: Fifty-six students completed the survey. Participation in SRFCs significantly increased self-reported confidence in patient history-taking (p < 0.001), performing oral presentations (p < 0.001) and physical exams (p < 0.001). Students also reported significantly greater confidence in working with translators (p < 0.001) or as part of an interprofessional team (p < 0.001) and understanding the needs of the population served (p < 0.001). Students also found SRCs to significantly improve their confidence in preparedness for clerkships (p < 0.001). SRFC involvement can improve medical students confidence in their clinical and interpersonal skills and enhance preparedness for clerkships and working with diverse patient groups. CONCLUSION: SRFCs are a useful tool in the medical school curriculum that help bridge the gap between classroom learning and clinic and may encourage practice in medically underserved communities. SRFCs also integrate classroom material and clinical practice, although standardized evaluation metrics need to be developed. SRFCs should be incorporated as a learning experience by medical schools nationwide.
Bile acids (BA) are among the most abundant metabolites produced by the gut microbiome. Primary BAs produced in the liver are converted by gut bacterial 7-α-dehydroxylation into secondary BAs, which can differentially regulate host health via signaling based on their varying affinity for BA receptors. Despite the importance of secondary BAs in host health, the regulation of 7-α-dehydroxylation and the role of diet in modulating this process is incompletely defined. Understanding this process could lead to dietary guidelines that beneficially shift BA metabolism. Dietary fiber regulates gut microbial composition and metabolite production. We tested the hypothesis that feeding mice a diet rich in a fermentable dietary fiber, resistant starch (RS), would alter gut bacterial BA metabolism. Male and female wild-type mice were fed a diet supplemented with RS or an isocaloric control diet (IC). Metabolic parameters were similar between groups. RS supplementation increased gut luminal deoxycholic acid (DCA) abundance. However, gut luminal cholic acid (CA) abundance, the substrate for 7-α-dehydroxylation in DCA production, was unaltered by RS. Further, RS supplementation did not change the mRNA expression of hepatic BA producing enzymes or ileal BA transporters. Metagenomic assessment of gut bacterial composition revealed no change in the relative abundance of bacteria known to perform 7-α-dehydroxylation. P. ginsenosidimutans and P. multiformis were positively correlated with gut luminal DCA abundance and increased in response to RS supplementation. These data demonstrate that RS supplementation enriches gut luminal DCA abundance without increasing the relative abundance of bacteria known to perform 7-α-dehydroxylation.
