Research on Delamination Damage Quantification Detection of CFRP Bending Plate Based on Lamb Wave Mode Control.

The carbon-fiber-reinforced polymer (CFRP) bending structure is widely used in aviation. The emergence and spread of delamination damage will decrease the safety of in-service bending structures. Lamb waves can effectively identify delamination damage as a high-damage-sensitivity detection tool. For this present study, the signal difference coefficient (SDC) was introduced to quantify delamination damage and evaluate the sensitivity of A0-mode and S0-mode Lamb waves to delamination damage. The simulation results show that compared with the S0-mode Lamb wave, the A0-mode Lamb wave exhibits higher delamination damage sensitivity. The delamination damage can be quantified based on the strong correlation between the SDC and the delamination damage size. The control effect of the linear array PZT phase time-delay method on the Lamb wave mode was investigated by simulation. The phase time-delay method realizes the generation of a single-mode Lamb wave, which can separately excite the A0-mode and S0-mode Lamb wave to identify delamination damage of different sizes. The A0-mode Lamb wave was excited by the developed one-dimensional miniaturized linear comb transducer (LCT), which was used to conduct the detection experiment on the CFRP bending plate with delamination damage sizes of Φ6.0 mm, Φ10.0 mm, and Φ15.0 mm. The experimental results verify the correctness of the simulation. According to the Hermite interpolation results of the finite-element simulation data, the relationship between the delamination damage size and the SDC was fitted by the Gaussian function and Rational function, which can accurately quantify the delamination damage. The absolute error of the delamination damage quantification with Gaussian and Rational fitting expression does not exceed 0.8 mm and 0.7 mm, and the percentage error is not more than 8% and 7%. The detection and signal processing methods employed in the present research are easy to operate and implement, and accurate delamination damage quantification results have been obtained.

Optimizing Trilobatin Production via Screening and Modification of Glycosyltransferases.

Trilobatin (TBL) is a key sweet compound from the traditional Chinese sweet tea plant (Rubus suavissimus S. Lee). Because of its intense sweetness, superior taste profile, and minimal caloric value, it serves as an exemplary natural dihydrochalcone sweetener. It also has various health benefits, including anti-inflammatory and glucose-lowering effects. It is primarily produced through botanical extraction, which impedes its scalability and cost-effectiveness. In a novel biotechnological approach, phloretin is used as a precursor that is transformed into TBL by the glycosyltransferase enzyme ph-4'-OGT. However, this enzyme's low catalytic efficiency and by-product formation limit the large-scale synthesis of TBL. In our study, the enzyme Mdph-4'-OGT was used to screen 17 sequences across species for TBL synthesis, of which seven exhibited catalytic activity. Notably, PT577 exhibited an unparalleled 97.3% conversion yield within 3 h. We then optimized the reaction conditions of PT577, attaining a peak TBL bioproduction of 163.3 mg/L. By employing virtual screening, we identified 25 mutation sites for PT577, thereby creating mutant strains that reduced by-products by up to 50%. This research enhances the enzymatic precision for TBL biosynthesis and offers a robust foundation for its industrial-scale production, with broader implications for the engineering and in silico analysis of glycosyltransferases.

Moroidin, a Cyclopeptide from the Seeds of Celosia cristata That Induces Apoptosis in A549 Human Lung Cancer Cells.

Interference of microtubule dynamics with tubulin-targeted drugs is a validated approach for cancer chemotherapy. Moroidin (1) is an Urticaceae-type cyclopeptide having a potent inhibitory effect on purified tubulin polymerization. So far, moroidin has not been chemically synthesized, and its effect on cancer cells remains unknown. Herein, the cyclopeptide moroidin was isolated and identified from the seeds of Celosia cristata, and a revised assignment of its NMR data was presented. For the first time, moroidin (1) was demonstrated as having cytotoxic effects for several cancer cells, especially A549 lung cancer cells. The cellular evidence obtained showed that moroidin disrupts microtubule polymerization and decreases ß-tubulin protein levels, but is not as potent as colchicine. Molecular docking indicated that 1 has a high binding potential to the vinca alkaloid site on tubulin. Moreover, moroidin arrested A549 cells in the G2/M phase and induced cell apoptosis. The intrinsic mitochondrial pathway and AKT were involved in the moroidin-induced cell apoptosis. In addition, moroidin (1) inhibited the migration and invasion of A549 cells at sublethal concentrations.

The legume-specific transcription factor E1 controls leaf morphology in soybean.

BACKGROUND: The leaf is a determinate organ essential for photosynthesis, whose size and shape determine plant architecture and strongly affect agronomic traits. In soybean, the molecular mechanism of leaf development is not well understood. The flowering repressor gene E1, which encodes a legume-specific B3-like protein, is known to be the gene with the largest influence on soybean flowering and maturity. However, knowledge of its potential other functions remains poor. RESULTS: Here, we identified a novel function of E1 protein in leaf development. Unifoliolate leaves of E1-overexpression (E1-OE) lines were smaller and curlier than those of wild type DongNong 50 (DN50) and Williams 82 (W82). Transverse histological sections showed disorganized cells and significantly elevated palisade tissue number, spongy tissue number, and bulliform cell number in E1-OE lines. Our results indicate that E1 binds to the promoters of the leaf- development-related CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factor genes to negatively regulate their expression. CONCLUSIONS: Our findings identify E1 as an important new factor in soybean leaf development.

Determination of immunosuppressive drugs in human urine and serum by surface-assisted laser desorption/ionization mass spectrometry with dispersive liquid-liquid microextraction.

A rapid and sensitive method for the determination of immunosuppressive drugs through surface-assisted laser desorption/ionization mass spectrometric detection (SALDI/MS) was developed. Colloidal Pd and α-cyano-4-hydroxycinnamic acid (CHCA) were used as the SALDI co-matrix. To eliminate interference and enhance the sensitivity, dispersive liquid-liquid microextraction (DLLME) was employed to extract the immunosuppressive drugs from the aqueous solutions. Under optimal extraction and detection conditions, calibration curves for cyclosporine and everolimus in aqueous solutions were linear over a concentration range from 0.01 to 1.20 µM. For sirolimus, the linear concentration range of the calibration curve was from 0.05 to 2.00 µM. The limits of detection (LODs) were calculated to be 3, 3, and 14 nM for cyclosporine, everolimus, and sirolimus, respectively. The enrichment factors of DLLME were calculated to be 108, 122, and 101 for cyclosporine, everolimus, and sirolimus, respectively. This novel method was successfully applied for the determination of immunosuppressive drugs in human urine and serum samples.

Rapid determination of rivaroxaban in human urine and serum using colloidal palladium surface-assisted laser desorption/ionization mass spectrometry.

RATIONALE: Rivaroxaban is a new anticoagulant drug that has recently been introduced for clinical applications. To ensure optimum efficacy while minimizing the risk of toxicity and other adverse effects, a simple and sensitive analytical procedure for monitoring the concentration of rivaroxaban in biological fluids is required. METHODS: Rivaroxaban was extracted from aqueous solutions by dispersive liquid-liquid microextraction (DLLME). Detection of rivaroxaban was achieved through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using colloidal palladium as the SALDI matrix. RESULTS: The calibration curve for rivaroxaban in aqueous solutions was linear over the concentration range from 5 to 500 nM. The limit of detection (LOD) for rivaroxaban at a signal-to-noise ratio of 3 was 2 nM. With a sample-to-extract volume ratio of 200, the enrichment factors were calculated to be 141. This method was successfully applied for the determination of rivaroxaban in human urine and serum samples. The LODs for rivaroxaban in urine and serum were calculated to be 6 nM and 60 nM, respectively. CONCLUSIONS: The analysis speed, together with the ease of operation and high sensitivity, allows SALDI-MS method to be particularly suitable for the high-throughput screening of rivaroxaban levels in human urine and serum samples.

Positive emotion up-regulation is resistant to working memory load: An electrocortical investigation of reappraisal and savoring.

Studies of emotion regulation to-date have mostly focused on negative emotion down-regulation, leaving positive emotion up-regulation poorly understood, particularly regarding factors that may modulate its success. While reappraisal and savoring have been shown to be effective at increasing electrocortical and subjective response to pictures in controlled laboratory settings, it remains unclear whether individuals can effectively enact these techniques to willfully increase positive emotions in everyday life when faced with other concurrent distractions/demands. Here, we used the late positive potential (LPP), an electrocortical measure that is larger for emotional compared to neutral stimuli, to assess the effect of working memory (WM) load on individuals' ability to reappraise or savor positive pictures. Seventy-six participants were randomly assigned to use either reappraisal or savoring to up-regulate positive emotion to pictures. Following training, participants engaged in a positive emotion up-regulation task interspersed with high and low WM load trials, while EEG was recorded. Frequentist and Bayesian statistics showed that although high WM load seemed to consume resources and reduced picture processing overall, it did not interfere with the enhancement of the LPP via positive emotion up-regulation. Nonetheless, WM performance (especially on high-load trials) was worse when participants were engaged in positive emotion up-regulation. Therefore, while both techniques appear to be effective under concurrent WM load, positive emotion up-regulation may interfere with other ongoing tasks.

The association between SGLT2 inhibitors and new-onset acute coronary syndrome in the elderly: a population-based longitudinal cohort study.

BACKGROUND: Several observational cohorts and meta-analytical studies on humans have shown that users of sodium-glucose cotransporter-2 inhibitors (SGLT2is) have a lower risk for new-onset acute coronary syndrome (ACS) than nonusers. However, some studies, including randomized clinical trials, reported the opposite results. This study aimed to investigate the impacts of a SGLT2i on new-onset ACS in a population. METHODS: We conducted a retrospective population-based cohort study involving 56,356 subjects who received SGLT2i therapy and 112,712 patients who did not receive SGLT2i therapy between May 1, 2016 and December 31, 2019. The outcome was the risk of new-onset ACS. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals for associations between SGLT2i use and ACS risk. RESULTS: A total of 670 and 1408 ACS events occurred in SGLT2i users and nonusers, respectively, during a follow-up of 3.7 years. SGLT2i use was associated with a nonsignificantly lower risk of ACS (adjusted HR 0.95, 95%confidence intervals (CI 0.87-1.04, P = 0.3218). We confirmed the robustness of these results through a propensity score 1:1 matching analysis. The results of the subgroup analysis of the subtype of the SGLT2i treatments were consistent with the main findings. An increased risk for the incidence of ACS in male and older (> 70 years) patients were also found. CONCLUSIONS: In this population-based cohort study, we found that SGLT2i use is associated with a nonsignificantly decreased risk of ACS. No difference in the SGLT2i subtype was observed in subgroup analyses. However, the results of this study indicated an increased risk for the incidence of ACS in male and older (> 70 years) patients.

A pragmatic feasibility trial of the Primary Care Intervention for PTSD: A health service delivery model to reduce health disparities for low-income and BIPOC youth.

OBJECTIVE: This study is a non-randomized pragmatic trial to assess the feasibility and acceptability of the Primary Care Intervention for Posttraumatic stress disorder (PCIP) (Srivastava et al., 2021), an Integrated Behavioral Health Care treatment for PTSD in adolescents. METHOD: Following routine clinic procedures, youth who were suspected of having trauma-related mental health symptoms were referred by their primary care providers to integrated care social workers for evaluation. The integrated care social workers referred the first 23 youth whom they suspected of having PTSD to the research study. Twenty youth consented to the study and 19 completed the pre-assessment (17 female; mean age = 19.32, SD = 2.11; range 14-22 years). More than 40% identified as Black and a third as Hispanic/Latinx. PCIP mechanisms and clinical outcomes were assessed pre- and post-treatment, and at one-month follow-up. Participants and therapists completed post-treatment qualitative interviews to assess feasibility and acceptability, and treatment sessions were audio recorded to assess fidelity. RESULTS: Findings suggest high acceptability, satisfaction, and feasibility of the PCIP delivered in "real-life" safety net pediatric primary care. Integrated care social workers had high treatment fidelity. Despite the small sample size, there was significant improvement in symptom scores of anxiety (g = 0.68, p = 0.02) and substance use (g = 0.36, p = 0.04) from pre to post, and depression symptoms (g = 0.38, p = 0.04) from pre to follow-up. Qualitative data from patients who completed exit interviews and integrated social workers indicated high satisfaction with the treatment, with some participants reporting that the integrated intervention was more acceptable and less stigmatizing than seeking mental health care outside of primary care. CONCLUSIONS: The PCIP may improve treatment engagement and access for vulnerable youth. Promising findings of high acceptability, feasibility, and initial clinical effectiveness suggest that PCIP warrants larger-scale study as part of routine care in pediatric integrated care.

Modulation of threat extinction by working memory load: An event-related potential study.

Distraction is typically discouraged during exposure therapy for anxiety, because it is thought to interfere with extinction learning by diverting attention away from anxiety-provoking stimuli. Working memory load is one form of distraction that might interfere with extinction learning. Alternatively, working memory load might reduce threat responding and benefit extinction learning by engaging prefrontal brain regions that have a reciprocal relationship with brain circuits involved in threat detection and processing. Prior work examining the effect of working memory load on threat extinction has been limited and has found mixed results. Here, we used the late positive potential (LPP), an event-related potential that is larger for threatening compared to non-threatening stimuli to assess the effect of working memory load on threat extinction. After acquisition, 38 participants performed three blocks of an extinction task interspersed with low and high working memory load trials. Results showed that overall, the LPP was reduced under high compared to low working memory load, and that working memory load slowed extinction learning. Results provide empirical evidence in support of limiting distraction during exposure therapy in order to optimize extinction learning efficiency.

Generalization of reappraisal to novel negative stimuli as evidenced by the LPP.

Cognitive reappraisal is a well-studied emotion regulation technique that involves changing the meaning of stimuli. To be useful in everyday life, reappraisal's effects would ideally generalize from previously reappraised stimuli to novel, but similar stimuli, saving individuals from needing to generate novel interpretations for similar stimuli. Here, 41 participants were asked to use reappraisal to down-regulate their response to negative pictures from one category (e.g., snakes), and to view negative pictures from another category (e.g., guns) as well as neutral pictures (e.g., plants). In a subsequent task, participants passively viewed novel pictures from all three categories (e.g., snakes, guns, and plants). EEG and subjective ratings of valence and arousal were collected in both tasks. In the reappraisal task, we did not find an effect of reappraisal on the LPP or arousal ratings, but reappraisal reduced ratings of picture unpleasantness. In the second task, negative pictures from the previously reappraised category elicited smaller LPPs than negative pictures from the previously viewed category, though there was no evidence that reappraisal generalized to subjective ratings of pictures. Therefore, at the electrocortical level, cognitive reappraisal may generalize to similar but novel stimuli encountered outside of the reappraisal context. Moreover, meaning change might be more effective in modulating electrocortical response following a delay and in the absence of deliberate attempts to down-regulate emotional response. Nonetheless, reappraisal's effects appear to differ across levels of affective response when similar stimuli are encountered in the absence of willful attempts at reappraisal.

Genome-Wide Analysis of DREB Genes Identifies a Novel Salt Tolerance Gene in Wild Soybean (Glycine soja).

Salt stress is a major factor limiting the growth and yield of soybean (Glycine max). Wild soybeans (Glycine soja) contain high allelic diversity and beneficial alleles that can be re-introduced into domesticated soybeans to improve adaption to the environment. However, very few beneficial alleles have been identified from wild soybean. Here, we demonstrate that wild soybean is more salt tolerant than cultivated soybean and examine dehydration responsive element-binding (DREB) family transcription factor genes to look for advantageous alleles that might improve drought tolerance in cultivated soybean. Our genome-wide analysis identified 103 DREB genes from the Glycine max genome. By combined RNA-sequencing and population genetics of wild, landrace, and cultivated soybean accessions, we show that the natural variation in DREB3a and DREB3b is related to differences in salt tolerance in soybean accessions. Interestingly, DREB3b, but not DREB3a, appears to have undergone artificial selection. Soybean plants carrying the wild soybean DREB3b allele (DREB3b39Del ) are more salt tolerant than those containing the reference genome allele (DREB3bRef ). Together, our results suggest that the loss of the DREB3b39Del allele through domestication of cultivated soybean may be associated with a reduction in salt tolerance. Our findings provide crucial information for improving salt tolerance in soybean through molecular breeding.

Healthy lifestyles among military active duty service members, and associations with body-building and weight-loss supplement use.

PURPOSE: The purpose of this study was to characterize health behavior profiles among active duty service members and associate these profiles with body-building and weight-loss dietary supplement (DS) use. METHODS: Based on U.S. active duty service members who completed the 2011 Health-Related Behavior Survey (n = 39,877), we used latent class analysis to place respondents into latent classes (using healthy/unhealthy food consumption, aerobic activity, strength training, and sleep) and examined associations between latent class and DS use. RESULTS: We identified seven health behavior classes that could be classified by physical activity and diet. Three classes with high activity were further characterized by healthy diet (24%); few unhealthy foods (18%); and unrestricted diet (9%). Three classes with low activity were further characterized by restricted diet (15%), healthy diet (15%), and unhealthy diet (6%). The last class (13%) reported moderate levels of all behaviors. The classes did not vary by sleep. Participant characteristics across most classes were relatively homogenous along demographics and military branch. The active classes had relatively higher usage of body-building and weight-loss DSs. CONCLUSIONS: Latent classes from health behavior indicators might be considered "market segments", which can be targeted with distinct messaging. Service members appear to consume DSs as part of an otherwise healthy lifestyle.

Traumatic events and posttraumatic stress disorder in individuals with severe mental illness in a non-western setting: Data from rural Ethiopia.

Traumatic events and ensuing stress are not widely studied in individuals with severe mental illness (SMI) despite their increased vulnerability to both. Far less is known about traumatic events and posttrauma reactions in people with SMI in low-resourced settings. OBJECTIVE: To address this gap in knowledge, our study focused on trauma and its effects for individuals with SMI and their caregivers in rural Ethiopia. Study aims were to identify events that were considered traumatic by stakeholders; characterize the mental health effects of such events; and discern events and posttrauma symptoms most relevant for SMI. METHOD: Qualitative interviews were gathered from 48 participants in Ethiopia who included individuals with SMI, their caregivers, health care providers, and community and religious leaders. RESULTS: Based on a combined emic and etic approach, major traumatic events included those commonly experienced in rural Ethiopia (e.g., lost property, forced marriage) and endorsed by individuals with SMI (e.g., restraining or chaining, SMI illness in a low-resourced setting). In addition, traumatic events were identified consistent with Western medical criteria (e.g., physical assault, sexual assault). Posttrauma symptoms that were commonly reported included emotions like anger and sadness; thinking too much; crying; and somatic (e.g., burning sensation) and physiological (e.g., shortness of breath) symptoms. As for symptoms consistent with the Diagnostic and Statistical Manual, we found the presence of all four symptom clusters. CONCLUSIONS: Overall, results point to the common occurrence of traumatic events and trauma-linked symptoms for individuals with SMI and their caregivers, including as a result of SMI. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Psychotherapy in a resource-constrained setting: Understanding context for adapting and integrating a brief psychological intervention into primary care.

Low- and middle-income countries have few mental health professionals, and efforts to increase access to treatment are a global priority. A key gap is the lack of integration of psychotherapy interventions as a part of accessible evidence-based care. Current recommendations suggest that the integration of mental health treatments, including psychotherapy, into existing primary care pathways may serve as a means to address this disparity. Understanding the cultural and contextual factors that affect this process is a critical step in identifying necessary adaptations. The aim of this qualitative study was to identify contextual factors associated with integrating psychotherapy in primary care in a predominantly rural district in south-central Ethiopia. Purposive sampling was used to recruit 48 mental health service users, caregivers, health care providers, and community leaders. Semistructured interviews were conducted, recorded, and transcribed in Amharic and translated into English. Although challenges (e.g., stigma, job strain, lack of belief in formal treatments) are present, other existing strengths (e.g., openness to seeking treatment, increasing knowledge about mental health treatment, familiarity with practices similar to therapy) support subsequent psychotherapy adaptation and implementation. These findings suggest possible mechanisms to improve delivery and adaptation in the effort to lower the existing global treatment gap. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The association between work related factors and breastfeeding practices among Chinese working mothers: a mixed-method approach.

Background: Breastfeeding rates remain low in China and some mothers stop breastfeeding shortly after returning to work. Our study aimed to investigate the association between breastfeeding practices of working mothers and their employment status (formal versus informal) and occupational fields (agriculture related, industry related, and business and white collar). We also identified key work-related factors that influence breastfeeding practices in Chinese working mothers. Methods: This is a mixed-method research consisted of two components. We conducted a cross-sectional study of 10,408 breastfeeding mothers with children under 12 months old from 12 regions in China from July 2017 to January 2018. Multiple logistic regression was used to calculate adjusted odds ratios (AdjORs) and 95% confidence intervals (CIs) for breastfeeding practices. For the qualitative component, semi-structured interviews were conducted with 84 breastfeeding mothers in the study areas from July to December 2017, Content analysis was used for the qualitative component. Results: Agriculture related occupations were positively associated with early initiation of breastfeeding (AdjOR 1.32, 95% CI 1.15, 1.51), current breastfeeding (AdjOR 1.76, 95% CI 1.41, 2.20), ever breastfed (AdjOR 1.69, 95% CI 1.09, 2.62), exclusive breastfeeding (AdjOR 1.30, 95% CI: 1.04, 1.62), and predominant breastfeeding (AdjOR 1.72, 95% CI 1.44, 2.05). Business and white collar occupations were positively associated with early initiation (AdjOR1.38, 95% CI 1.23, 1.56) and ever breastfed (AdjOR 1.64, 95% CI 1.12, 2.39), and inversely associated with predominant breastfeeding (AdjOR 0.81, 95% CI 0.68, 0.95). For industry related and business and white collar occupations, informal employment was negatively related to current breastfeeding. In qualitative analysis, four main themes were developed to identify key work-related factors that influence breastfeeding practices: 1) employment benefits; 2) commute time; 3) workplace environment; 4) labor intensity. Mothers who experienced difficulties in one or more of the above would choose to lower breastfeeding frequency or stop breastfeeding. Conclusions: Having flexible work schedules and proximity of workplace to home can assist continuance of breastfeeding. Policies promoting supportive breastfeeding environment at work ought to be implemented. Additionally, informally employed mothers require more attention due to limited legal protection.

The Usage Behavior and Intention Stability of Nurses: An Empirical Study of a Nursing Information System.

BACKGROUND: Many prior studies of technology adoption treat user intention as the single predictor of actual usage behavior. However, as many researchers of behavioral science have pointed out, multiple factors mediate the relationship between user intention and usage behavior. PURPOSE: The present article explores the factors that mediate the relationship between intention and actual behavior. We develop a conceptual framework that is based on the Technology Acceptance Model III and behavior theory to further elicit system usage behavior and to confirm "intention stability" and "past experience" as two significant mediating factors in this relationship. METHODS: The target system was a nursing information system that had been recently adopted by a medical center in central Taiwan. Data were collected using a questionnaire survey conducted in two rounds. Two hundred forty-five valid questionnaires were returned (response rate: 49%). Mediated moderation was analyzed to explore the presence of mediators or moderators between intention and behavior. RESULTS: The results support that intention stability is a mediated moderator and that prior experience is a moderator of the relationship between intention and behavior. These two factors increased by over 13.6% the explanatory power of intention on actual behavior. Furthermore, this study expanded the scope of prior research by confirming intention stability as a moderating variable between intention and behavior. Finally, this study identified the moderating effect of past experience on the intention-behavior relationship, indicating that past experience enhances the predictive power of intention on behavior. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: The findings of this study may assist hospital managers to better understand the nursing information system usage behaviors of nursing staff and to develop ways to enhance the intention stability of these staff. Managers may improve the familiarity of nursing staff with the system by increasing their system-related practice time. More experience should enhance staff system skills and resolve problems such as the need for extra work hours or overtime because of initial system unfamiliarity. Improved work efficiency should then allow nurses to divert more time from administrative work to patient care and training. This positive circle of support is expected to increase the willingness of nurses to accept and take advantage of the system.

A Novel Nitinol Spherical Occlusion Device for Liver Cancer.

Liver cancer or hepatic cancer is a cancer that originates in the liver. It is formed from either the liver itself or from structures within the liver, including blood vessels or the bile duct. Liver cancer can be a life-threatening condition, but it may be cured if found early. Hepatic artery embolization is one of the treatment options involving the injection of substances to reduce the blood flow to cancer cells in the livers of patients with tumors that cannot be removed by surgery; however, this treatment has some limitations. In this paper, we propose a novel nitinol "spherical occlusion device" concept, the first of its kind in the world. Our proposed spherical occlusion device is able to reduce the blood flow to cancer cells by deploying it in the upstream hepatic artery supplying blood to the liver. Moreover, it could carry multiple chemotherapy or radioactive drugs for delivery directly to the target site. Nitinol alloy was chosen as the device material due to its excellent super-elastic property. Computational models were developed to predict the mechanical response of the device during manufacturing and deployment procedures, as well as its hemodynamic behavior. Simulation results showed that the presence of the spherical occlusion device with 14%-27% metal density deployed at the upstream location of the right hepatic artery had significant occlusion effects, with the average blood flow rate cut down by 30%-50%. A pulsed fiber laser and a series of expansions and heat treatments were developed to make the first prototype of the spherical occlusion device for the demonstration of our novel concept.

Investigation of fibrous cap stresses on vulnerable plaques leading to heart attacks.

Rupture-prone plaques in the coronary arteries, called ``vulnerable plaques'', are recognized as the key factor in acute myocardial infarction. Vulnerable plaques have a thin fibrous cap over a large fatty core and are highly susceptible to rupture. In general, this type of plaque rupture is mainly associated with stress concentrated on the fibrous cap. Fibrous cap stresses are counted among the most important factors in the plaque rupture process and must be taken into consideration when assessing the plaque vulnerability leading to heart attacks. The objective of this paper was to investigate the effects of nitinol stent deployment on the morphological changes of vulnerable plaques and then to propose a new stent design concept for effectively reducing fibrous cap stresses and the associated rupture risk. The deployment of a self-expanding nitinol stent was modeled, and the resulting stress distribution on the fibrous cap was investigated. The fibrous cap stresses were more uniformly distributed and the maximum stress was reduced by 13% when the crown number of the stent was increased. This study demonstrates an excellent approach to stent design that could effectively reduce the risk of a vulnerable plaque rupturing and causing a heart attack.

Investigation of fibrous cap stresses on vulnerable plaques leading to heart attacks.

Rupture-prone plaques in the coronary arteries, called ``vulnerable plaques'', are recognized as the key factor in acute myocardial infarction. Vulnerable plaques have a thin fibrous cap over a large fatty core and are highly susceptible to rupture. In general, this type of plaque rupture is mainly associated with stress concentrated on the fibrous cap. Fibrous cap stresses are counted among the most important factors in the plaque rupture process and must be taken into consideration when assessing the plaque vulnerability leading to heart attacks. The objective of this paper was to investigate the effects of nitinol stent deployment on the morphological changes of vulnerable plaques and then to propose a new stent design concept for effectively reducing fibrous cap stresses and the associated rupture risk. The deployment of a self-expanding nitinol stent was modeled, and the resulting stress distribution on the fibrous cap was investigated. The fibrous cap stresses were more uniformly distributed and the maximum stress was reduced by 13% when the crown number of the stent was increased. This study demonstrates an excellent approach to stent design that could effectively reduce the risk of a vulnerable plaque rupturing and causing a heart attack.