Advances of Strategies to Increase the Surface Charge Density of Triboelectric Nanogenerators: A Review

Triboelectric nanogenerators (TENGs) have manifested a remarkable potential for harvesting environmental energy and have the prospects to be utilized for various uses, for instance, self-powered sensing devices, flexible wearables, and marine corrosion protection. However, the potential for further development of TENGs is restricted on account of their low output power that in turn is determined by their surface charge density. The current review majorly focuses on the selection and optimization of triboelectric materials. Subsequently, various methods capable of enhancing the surface charge density of TENGs, including environmental regulation, charge excitation, charge pumping, electrostatic breakdown, charge trapping, and liquid-solid structure are comprehensively reviewed. Lastly, the review is concluded by highlighting the existing challenges in enhancing the surface charge density of TENGs and exploring potential opportunities for future research endeavors in this area.

Perforated Carcinoid Tumor of the Appendix: Need for Guidelines for Management With Respect to Prognostic Factors

Carcinoid tumors, one of the most common malignant lesions involving the appendix, are typically found incidentally during routine appendectomies. While up to 20% of acute appendicitis cases present with perforation, the incidence of perforation among patients with undiagnosed carcinoid tumors of the appendix is unknown. In addition, there is no consensus on the management of carcinoid tumors in the perforated appendix or its impact on prognosis. We present a case of a 42-year-old woman presented with perforated appendicitis. Final pathology demonstrated the presence of a 1.1 cm, well-differentiated grade 1 neuroendocrine tumor at the tip of the appendix extending into the subserosa, without evidence for lymphovascular invasion. Given the depth of tumor invasion and the relatively young age of the patient, the decision was made to perform an interval completion right hemicolectomy for lymph node sampling. Only a few cases have been reported in the available literature, and it remains unclear whether appendiceal perforation represents an independent negative prognostic factor for patient survival. Additional data from cohort studies are needed to determine the true incidence, prognosis, and optimal management of newly diagnosed carcinoid tumors in the perforated appendix. Furthermore, clear consensus guidelines are needed to identify the subgroup of patients who would benefit from interval or primary right hemicolectomy.

Neonatal Hypocalcemia: Common, Uncommon, and Rare Etiologies

Calcium homeostasis in the neonatal period is a reflection of the transition from placental regulation to hormonal maturation in the newborn. Hypocalcemia occurring within the first 72 hours after birth, termed early-onset hypocalcemia (EOH), is more common and often asymptomatic. Hypocalcemia occurring beyond 72 hours of age is termed late-onset hypocalcemia (LOH). LOH is less common than EOH, and affected patients are more likely to be symptomatic. To prevent and treat hypocalcemia in the newborn, neonatal clinicians should be familiar with the common, uncommon, and rare etiologies of EOH and LOH, as summarized in this review.

A107 VISCERAL ADIPOSE TISSUE VOLUME DIFFERENTIATES BETWEEN FIBROSTENOTIC AND INFLAMMATORY CROHN’S DISEASE

Background

Creeping fat, a form of visceral adipose tissue (VAT) that wraps the intestinal wall, influences the formation of Crohn’s disease (CD) strictures. The degree of fat wrapping from intestinal stricture resections is correlated with the extent of chronic inflammation, fibrosis, stricture formation, and response to biologic therapy. VAT and subcutaneous adipose tissue (SAT) ratios from CTE (computed tomography) scans are elevated in CD strictures. However, the definition of strictures in these studies has been poorly defined and not included current well-recognized criteria: 1) bowel wall thickness (BWT), 2) narrowed luminal diameter, and 3) pre-stenotic dilation. (PSD).

Purpose

The objective of this pilot study was to assess the relationship of 2D and 3D VAT:SAT ratios with CT stricture parameters in patients with terminal ileal (TI) CD strictures.

Method

2D VAT:SAT ratios from CT’s of CD patients with TI strictures defined as increased BWT, narrowed luminal diameter (< 50% relative to normal adjacent distended loop), and PSD greater than the stricture diameter were retrospectively obtained from a database and chart review. CT’s from fibrostenotic CD patients were sex and BMI matched to patients with only TI inflammatory behaviour. Patient demographics, medication, smoking, and surgical history were also obtained. Analyses were adjusted for age, sex, and BMI covariates. Unpaired t-tests and multi-variable logistic regression analyses were conducted.

Result(s)

Twenty-eight patients with stricturing CD had a significantly greater mean VAT:SAT volume ratio than 29 non-stricturing CD (41.5 cm³ vs 34.2 cm³, p=0.03). Thirty-six percent (10/28) of CD stricture patients had prior ileocolic resection with a mean disease duration of 13.5 years (range 0-48). The median ileal BWT (7.0 mm, range 4.0-13.0 mm) for the stricturing group was significantly greater than those with inflammatory behaviour (BWT 2.0 mm, p<0.0001). The median luminal diameter and PSD for the stricture group was 2.0 mm (range 0 - 14.0 mm), and 3.0 cm (range 1.0 - 7.3 cm), respectively.

Image

Conclusion(s)

Fibrostenotic TI CD patients have increased VAT:SAT ratios in comparison to those with only inflammatory behaviour. These pilot VAT:SAT results provide an initial foundation for further studies to assess its predictive role in responsiveness of medical or surgical therapies in stricturing CD.

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Disclosure of Interest

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Multifunctional Photothermal Phase-Change Superhydrophobic Film with Excellent Light-Thermal Conversion and Thermal-Energy Storage Capability for Anti-icing/De-icing Applications

The accumulation of ice may cause serious safety problems in numerous fields. A photothermal superhydrophobic surface is considered to be useful for preventing ice formation because of its environmentally friendly, energy-saving, and excellent anti-icing/de-icing properties. However, it easily fails to work in the absence of sunlight. To improve its anti-icing property without sunlight irradiation, a multifunctional photothermal phase-change superhydrophobic film (MPPSF) consisting of phase-change microcapsules (PCMs) and carbon nanotubes (CNTs) was fabricated using a facile spraying method. Benefitting from the excellent light-thermal conversion effect of CNTs, the surface temperature could increase from -20 to 130.1 °C within 180 s under 808 nm near-infrared laser irradiation of 1 W/cm², thus realizing high-efficiency de-icing. Meanwhile, a portion of the light-thermal energy was stored in the MPPSF because of the phase change of the PCMs. Without sunlight irradiation, the latent heat of the PCMs was released when the external temperature approached the phase-transition temperature. The synergistic effects of the phase-transition latent heat release and superhydrophobicity allowed the MPPSF to effectively hinder the formation of ice for 10.1 min at -20 °C. Therefore, this MPPSF with outstanding anti-icing and de-icing performances is expected to achieve ice prevention and removal in all-days.

The gut microbiome: an overview of current trends and risks for paediatric populations

PURPOSE OF REVIEW

Gut health is an increasingly popular topic of discussion among scientists and the general population alike. As interest surrounding the gut microbiome grows, the accessibility to misinformation and unfounded gut health trends to youth is likely to emerge as a public health concern. The purpose of this review is to provide paediatricians with current information about the gut microbiome, as well as explanations and possible risks of the multitude of gut health trends that adolescents may be exposed to.

RECENT FINDINGS

The gut microbiome is implicated in overall health by playing roles in digestion, immunity and mental health. Novel microbiome-related therapies, such as faecal microbiota transplants, and the gut-brain link show the therapeutic potential of the gut microbiome. However, unproven dietary fads and trends on social media are rampant as well, such as ginger juice shots. In addition, paediatric supplements meant to target gut health are unregulated, yet are highly marketed. Improperly applying these trends and diets may result in risks of malnutrition and body image issues for impressionable children.

SUMMARY

Increased familiarity regarding the types of gut health trends and diets among young people will allow paediatricians to more effectively advise their patients about potential risks and good gut health practices. Paediatricians and caregivers serve as role models and educators with regard to children's perceptions and management of their gut and overall health.

Evaluation of intraperitoneal vancomycin in peritoneal dialysis-associated peritonitis

BACKGROUND

Intraperitoneal (IP) vancomycin is recommended as one of the treatment options for gram-positive coverage in the management of peritoneal dialysis (PD)-associated peritonitis. There is a lack of literature supporting the optimal dose and approach to vancomycin therapeutic drug-level monitoring.

METHODS

A retrospective chart review was conducted using the BC Renal Agency PROMIS Database and our hospital records from 1 June 2011 to 1 July 2019. Adult patients with PD-associated peritonitis who received IP vancomycin and had at least one serum vancomycin level drawn were included. All patients received a loading dose of 30 mg/kg, which was repeated every 3-5 days depending on PD modality. Serum vancomycin levels were drawn prior to the second vancomycin dose, then at the discretion of the prescriber. The primary end point was the rate of therapeutic serum vancomycin levels ≥15 mg/L.

RESULTS

Twenty-three episodes of PD-associated peritonitis in 20 patients met the eligibility criteria. Only 15/23 serum vancomycin levels were drawn appropriately after the first dose. Sixty per cent of these levels were subtherapeutic at <15 mg/L. All subsequent serum vancomycin levels were above the therapeutic target. Most peritonitis episodes (78%) achieved resolution of infection. Residual kidney function was not significantly correlated with serum vancomycin levels (p = 0.19).

CONCLUSIONS

An IP vancomycin regimen of 30 mg/kg every 3-5 days resulted in subtherapeutic serum vancomycin levels in most patients following the loading dose but therapeutic levels thereafter. A large percentage of vancomycin levels were drawn inappropriately due to misalignment of outpatient follow-up visits and timing of blood work.

Nano-Gaps Fabricated by Thermal Evaporation and Stripping Techniques

The fabrication of inexpensive nano-gaps is vitally important for the research and application of nanochannel-based devices. This study presents a low-cost and simple method for the fabrication of nano-gaps using thermal evaporation and stripping techniques. The structural morphology of metal films deposited on the convex structures of photoresist by sputtering and thermal evaporation was studied. The effect of angles of thermal evaporation on the width of nano-gaps was investigated. The characteristics of metal film deposited on the convex structures of photoresist and spaces between these convex structures after stripping were investigated, and the adhesive force between the metal film and silicon substrate was also analyzed. Finally, a metal film of Cu was deposited on the convex structures of photoresist by thermal evaporation. After stripping, nano-gaps with a width of 187 nm were fabricated. The method proposed in this paper can be employed to mass-produce two-dimensional nanochannels based devices at low cost.

Differential cytokine and chemokine expression during rejection and infection following intestinal transplantation

BACKGROUND/OBJECTIVES

Rejection and infectious enteritis in intestinal transplant (ITx) patients present with virtually identical symptoms. Currently, the gold standard for differentiating between these two conditions is endoscopy, which is invasive and costly. Our primary aim was to identify differences in peripheral blood cytokines during episodes of acute cellular rejection (ACR) and infectious enteritis in patients with intestinal transplants.

METHODS

This was a prospective, cross-sectional study involving ITx patients transplanted between 2000 and 2016. We studied 63 blood samples collected from 29 ITx patients during periods of normal (n = 24) and abnormal (n = 17) allograft function. PBMCs from whole blood samples were cultured under unstimulated or stimulated conditions with phytohemagglutinin (PHA). The supernatant from these cultures were collected to measure cytokine and chemokine levels using a 38-plex luminex panel.

RESULTS

Our study found that cytokines and chemokines are differentially expressed in normal, ACR, and infectious enteritis samples under unstimulated conditions based on heatmap analysis. Although each cohort displayed distinctive signatures, only MDC (p = 0.037) was found to be significantly different between ACR and infectious enteritis. Upon stimulation of PBMCs, patients with ACR demonstrated increased immune reactivity compared to infectious enteritis; though this did not reach statistical significance.

CONCLUSIONS

To our knowledge, this is the first comprehensive study comparing cytokine expression during acute rejection and infectious enteritis in intestinal transplant recipients. Our results suggest that cytokines have the potential to be used as clinical markers for risk stratification and/or diagnosis of ACR and infectious enteritis.

The Fabrication of Polymethyl Methacrylate Nozzles for Electrohydrodynamic Printing

Electrohydrodynamic (EHD) jet printing enables rapid prototyping high-resolution and low-cost lines with width of micrometer or even nanometer. However, EHD printing always suffers from nozzle clogging when the nozzle inner-diameter decrease to micro-scale. Thus fabrication of low cost nozzles becomes significantly important. In this work, 50 μm wide and 12.5 μm deep PMMA (Polymethyl Methacrylate) nozzles were fabricated without using traditional expensive glass capillary pulling approach. To replicate PMMA nozzle with high precision, the embossing condition was optimized according to replication precision, the deformation rate, and maximum stress. To nearly fully bond PMMA nozzle with intact PMMA microchannel, the bonding condition was optimized according the bonding rate and dimension loss of PMMA microchannel. The availability of the fabricated PMMA nozzle was finally verified by EHD printing experiments.

Patient experiences of sleep in dialysis: systematic review of qualitative studies

RATIONALE AND OBJECTIVE

Sleep problems affect more than half of patients receiving dialysis and are associated with increased risk of mortality, cardiovascular events, depression and impaired functioning and quality of life. Symptoms such as fatigue and exhaustion may be attributed to sleep problems or sleep disorders, as well as the burden of kidney disease and treatment. This study aims to describe the patient perspectives on the reasons, impact and management of sleep problems in dialysis.

STUDY DESIGN

Systematic review and thematic synthesis of qualitative studies that report patient experience and perspectives on sleep in dialysis.

SETTING AND POPULATION

Patients receiving dialysis.

SEARCH STRATEGY AND SOURCES

MEDLINE, Embase, PsycINFO, CINAHL, reference lists and PhD dissertations were searched from inception to August 2019.

DATA EXTRACTION

All text from the results/conclusion of the primary studies.

ANALYTICAL APPROACH

Thematic synthesis.

RESULTS

We included 48 studies involving 1156 participants from 16 countries. We identified six themes: dominating demands of treatment (with subthemes of: demanding and relentless schedule, regret for wasted time); scheduling and control (managing sleep routines, napping and nocturnal sleep disruption, meditative aids); disruptions due to dialysis (unsettled sleep, hypervigilance and worry); symptoms depriving sleep (difficulty falling asleep, constant waking); overwhelmed and without choice (futility of sleep, uncontrollable exhaustion, restlessness is irrepressible); and as a coping mechanism (avoiding anxiety, alleviating symptoms, combating boredom).

LIMITATIONS

Most studies were conducted in high-income, English-speaking countries.

CONCLUSION

The treatment and symptom burden of dialysis disrupts and deprives patients of sleep, which leads to overwhelming and uncontrollable exhaustion. Better management of symptoms and effective strategies to manage sleep routines may improve sleep quality for better overall health in patients receiving dialysis.

Characterization of Sub-Regional Variation in Saccharomyces Populations and Grape Phenolic Composition in Pinot Noir Vineyards of a Canadian Wine Region

Wine is a product of grape juice fermentation by yeast. Terroir is a term that encompasses all environmental factors and interactions at a specific geographical site, resulting in the development of regional-specific microbial strains and grape metabolites. In this study we determine the distribution of vineyard-associated wine yeast strains and characterize the flavonoid profile of Pinot Noir grapes among 3 sub-regions in the Okanagan Valley (OV), a major wine region in British Columbia, Canada. Pinot Noir grape samples were collected from 13 vineyards among 3 sub-regions of the OV, namely Kelowna (KE), Naramata-Penticton (NP) and Oliver-Osoyoos (OO), within a week prior to the winery harvesting date in 2016 and 2017. A total of 156 spontaneous Pinot Noir fermentations were conducted and vineyard-associated Saccharomyces strains were isolated from fermentations that reached two-thirds sugar depletion. Using microsatellite genotyping, we identified 103 Saccharomyces cerevisiae strains and 9 Saccharomyces uvarum strains. We also identified Saccharomyces paradoxus in one vineyard using ITS sequencing. We developed a microsatellite database of 160 commercial S. cerevisiae strains to determine the identity of the isolated strains and we include the database herein. Commercial strains were widely distributed across the three sub-regions. Forty-two of our 103 S. cerevisiae strains were equivalent or highly similar to commercial strains whereas the remaining 61 were considered as ‘unknown’ strains. Two S. uvarum strains were previously isolated in other OV studies and none matched the S. uvarum commercial strain BMV58. S. cerevisiae population structure was driven by sub-region, although S. cerevisiae populations did not differ significantly across vintages. S. uvarum and S. paradoxus were only identified in the 2017 vintage, demonstrating dynamic wine yeast populations between vintages. We found that the flavonoid profile of Pinot Noir grapes from the same 13 vineyards was also affected by sub-regional terroir. The anthocyanin content was lower and the proportion of methoxylated anthocyanins and flavonols was higher in Pinot Noir grapes from OO, the warmer sub-region as compared to KE, the cooler sub-region. Our study demonstrates that both yeast populations and metabolites associated with the Pinot Noir variety have sub-regional variation within a viticultural area.

Nano-Patterns of Photoresist Fabricated by Ultraviolet Lithography Technology

Nanofluidics devices with two-dimensional nano-structures have attracted extensive interests for biological and chemical applications. The fabrication of nanoscale mask patterns with controllable line width is an indispensable process for manufacturing two-dimensional nano-structures. However, a simple and low-cost method for fabricating two-dimensional nano-patterns is still a challenge. In this work, a novel simple and low-cost method for fabricating nanoscale mask patterns with controllable line width, based on the ultraviolet exposure is presented. In the experiment, a layer of AZ5214 reversal photoresist was exposed to the ultraviolet light through the photomask with microscale patterns. After the lithography, nanoscale photoresist mesas patterns instead of microscale patterns were produced. The photoresist mesas with 400~800 nm width were fabricated. Meanwhile, by adjusting the parameters of exposure time, various nanoscale dimensions of photoresist mesas can be obtained. The proposed method overcomes limitations of the conventional ultraviolet lithography technology without the need to the expensive nanolithography equipment. Our novel fabrication method should be a useful tool for two-dimensional nano-structures fabrication due to its advantages of simple fabrication process, well controllability, and low-cost.

The protocol-guided rapid evaluation of veterans experiencing new transient neurological symptoms (PREVENT) quality improvement program: rationale and methods

BACKGROUND

Transient ischemic attack (TIA) patients are at high risk of recurrent vascular events; timely management can reduce that risk by 70%. The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) developed, implemented, and evaluated a TIA quality improvement (QI) intervention aligned with Learning Healthcare System principles.

METHODS

This stepped-wedge trial developed, implemented and evaluated a provider-facing, multi-component intervention to improve TIA care at six facilities. The unit of analysis was the medical center. The intervention was developed based on benchmarking data, staff interviews, literature, and electronic quality measures and included: performance data, clinical protocols, professional education, electronic health record tools, and QI support. The effectiveness outcome was the without-fail rate: the proportion of patients who receive all processes of care for which they are eligible among seven processes. The implementation outcomes were the number of implementation activities completed and final team organization level. The intervention effects on the without-fail rate were analyzed using generalized mixed-effects models with multilevel hierarchical random effects. Mixed methods were used to assess implementation, user satisfaction, and sustainability.

DISCUSSION

PREVENT advanced three aspects of a Learning Healthcare System. Learning from Data: teams examined and interacted with their performance data to explore hypotheses, plan QI activities, and evaluate change over time. Learning from Each Other: Teams participated in monthly virtual collaborative calls. Sharing Best Practices: Teams shared tools and best practices. The approach used to design and implement PREVENT may be generalizable to other clinical conditions where time-sensitive care spans clinical settings and medical disciplines.

TRIAL REGISTRATION

clinicaltrials.gov: NCT02769338 [May 11, 2016].

Birth outcomes in women with gestational diabetes managed by lifestyle modification alone: The PANDORA study

AIMS

To assess outcomes of women in the Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) cohort with gestational diabetes mellitus (GDM) managed by lifestyle modification compared with women without hyperglycaemia in pregnancy.

METHODS

Indigenous (n = 97) and Europid (n = 113) women managed by lifestyle modification were compared to women without hyperglycaemia (n = 235). Multivariate linear and logistic regressions assessed whether GDM-lifestyle women had poorer outcomes compared to women without hyperglycaemia.

RESULTS

Women with GDM-lifestyle had higher body mass index and lower gestational weight gain than women without hyperglycaemia. On univariate analysis, gestational age at delivery was lower and induction rates were higher in women with GDM-lifestyle than without hyperglycaemia. On multivariable regression, GDM-lifestyle was associated with lower gestational age at delivery (by 0.73 weeks), lower birthweight z-score (by 0.26, p = 0.007), lower likelihood of large for gestational age (LGA) [OR (95% CI): 0.55 (0.28, 1.02), p = 0.059], and greater likelihood of labour induction [2.34 (1.49, 3.66), p < 0.001] than women without hyperglycaemia.

CONCLUSION

Women with GDM managed by lifestyle modification had higher induction rates and their offspring had lower birthweight z-scores, with a trend to lower LGA than those without hyperglycaemia in pregnancy. Further studies are indicated to explore reasons for higher induction rates.

Prognostic implications of residual disease tumor-infiltrating lymphocytes and residual cancer burden in triple-negative breast cancer patients after neoadjuvant chemotherapy

BACKGROUND

For primary triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), higher pretreatment tumor-infiltrating lymphocytes (TILs) correlates with increased pathologic complete response (pCR) rates, and improved survival. We evaluated the added prognostic value of residual disease (RD) TILs to residual cancer burden (RCB) in predicting survival post-NAC.

PATIENTS AND METHODS

We combined four TNBC NAC patient cohorts who did not achieve pCR. RD TILs were investigated for associations with recurrence-free survival (RFS), and overall survival (OS) using Cox models with stromal TILs as a continuous variable (per 10% increment). The likelihood ratio test was used to evaluate added prognostic value of RD TILs.

RESULTS

A total of 375 RD TNBC samples were evaluable for TILs and RCB. The median age was 50 years, with 62% receiving anthracycline/taxane chemotherapy. The RCB class after NAC was 11%, 50%, and 39% for I, II, and III, respectively. The median RD TIL level was 20% (IQR 10-40). There was a positive correlation between RD TIL levels and CD8+ T-cell density (ρ = 0.41). TIL levels were significantly lower with increasing post-NAC tumor (P = 0.005), nodal stage (P = 0.032), but did not differ by RCB class (P = 0.84). Higher RD TILs were significantly associated with improved RFS (HR: 0.86; 95% CI 0.79-0.92; P < 0.001), and improved OS (HR: 0.87; 95% CI 0.80-0.94; P < 0.001), and remained significant predictors in multivariate analysis (RFS P = 0.032; OS P = 0.038 for OS). RD TILs added significant prognostic value to multivariate models including RCB class (P < 0.001 for RFS; P = 0.021 for OS). The positive prognostic effect of RD TILs significantly differed by RCB class for RFS (PInt=0.003) and OS (PInt=0.008) with a greater magnitude of positive effect observed for RCB class II than class III.

CONCLUSIONS

TIL levels in TNBC RD are significantly associated with improved RFS and OS and add further prognostic information to RCB class, particularly in RCB class II.

Human Umbilical Cord Perivascular Cells and Human Bone Marrow Mesenchymal Stromal Cells Transplanted Intramuscularly Respond to a Distant Source of Inflammation

Intravenously administered mesenchymal stromal cells (MSCs) are rapidly entrapped in the lungs, where they display an anti-inflammatory phenotype. Intramuscular (IM) delivery provides an increased MSC dwell-time, which could result in a sustained modulation of an inflammatory milieu. We studied the therapeutic effects of IM delivered MSCs to treat a distant (contralateral) inflammation, and compared the efficacy of neonatal (umbilical cord) and adult bone marrow MSCs (BMMSCs). Inflammation decreased over 48 h, but neonatal cells showed an earlier response than BMMSCs. Tumor necrosis factor-induced gene-6 (TSG-6) was released at the site of MSC delivery, while neutrophil infiltration was abrogated and inflammation reduced at the contralateral site. MSCs did not distribute to the organs or to the site of inflammation. Thus, IM delivery presents a promising alternative for the treatment of inflammation, and neonatal MSCs may represent a stronger candidate than those derived from adult BM to treat inflammatory diseases.

Fast Microfluidic Chip Fabrication Technique by Laser Erosion and Sticky Tape Assist Bonding Technique

Disposable microfluidic chips are becoming increasingly important for biological and chemical researches. Future advances in their commercial applications depends on the mass fabrication of low cost microfluidic chip. In this study we are presenting a simple, low cost and fast way of fabricating PMMA microfluidic chips based on laser erosion. The influence of the width and depth of PMMA microchannels on erosion current and erosion times was analyzed. To bond the open PMMA microchannels at low pressure and temperature, sticky tape assist bonding method was proposed. By this method, the microfluidic chip can be fully sealed without using any equipment. The leakage test indicated that the bonded microfluidic chip can endure an pressure up to 0.82 MPa.

Temperament Is Associated With Outdoor Free Play in Young Children: A TARGet Kids! Study

OBJECTIVE

Outdoor free play is important for preschoolers' physical activity, health, and development. Certain temperamental characteristics are associated with obesity, nutrition, and sedentary behaviors in preschoolers, but the relationship between temperament and outdoor play has not been examined. This study examined whether there is an association between temperament and outdoor play in young children.

METHODS

Healthy children aged 1 to 5 years recruited to The Applied Research Group for Kids (TARGet Kids!), a community-based primary care research network, from July 2008 to September 2013 were included. Parent-reported child temperament was assessed using the Childhood Behavior Questionnaire. Outdoor free play and other potential confounding variables were assessed through validated questionnaires. Multivariable linear regression was used to determine the association between temperament and outdoor play, adjusted for potential confounders.

RESULTS

There were 3393 children with data on outdoor play. The association between negative affectivity and outdoor play was moderated by sex; in boys, for every 1-point increase in negative affectivity score, mean outdoor play decreased by 4.7 minutes per day. There was no significant association in girls. Surgency was associated with outdoor play; for every 1-point increase in surgency/extraversion, outdoor play increased by 4.6 minutes per day.

CONCLUSIONS

Young children's temperamental characteristics were associated with their participation in outdoor free play. Consideration of temperament could enhance interventions and strategies to increase outdoor play in young children. Longitudinal studies are needed to elucidate the relationship between children's early temperament and physical activity.

Abstract P4-06-05: Treatment of ESR1 mutant and PIK3CA mutant patient-derived breast cancer xenograft models reveals differential anti-tumor responses to estrogen receptor degraders and PI3K inhibitors in vivo

The phosphoinositide 3-kinase (PI3K) pathway is a key driver of hormone receptor (HR)–positive breast cancer growth and survival. It is estimated that 40-45% of HR+ breast cancers harbor oncogenic mutations in the PIK3CA gene, which encodes the p110α isoform of PI3K. Taselisib (GDC-0032) is a mutant-selective PI3K inhibitor that demonstrates enhanced potency in PIK3CA mutant breast cancer cells and is being developed as a treatment for metastatic breast cancer that targets PIK3CA-mutant, HR-positive, HER2-negative patients. Activating mutations in the ESR1 gene were recently described in metastatic breast cancer. These mutations confer hormone independent growth and may be associated with resistance to aromatase inhibitors. Drugs that selectively bind and antagonize the Estrogen Receptor alpha (ERα) protein and target it for degradation, such as fulvestrant, are referred to as selective estrogen receptor degraders (SERDs). Preclinical activity of the orally bioavailable SERD, GDC-0810, has not been well characterized in ESR1 mutant PDX models. Therefore, our aim was to evaluate the efficacy and pharmacodynamic responses to agents that target ERα and PI3K as monotherapies and in combination, in ESR1 and PIK3CA mutant HR+ breast cancer patient-derived xenograft (PDX) models. We hypothesized that mutational status of ESR1 and PIK3CA may predict the responsiveness of HR+ PDX models to SERDs and PI3K inhibitors in vivo. Characterization of seven PDX models included authentication of hormone receptor status by immunohistochemistry (IHC) and determination of ESR1 and PIK3CA genotype and allele frequency by exome sequencing. For a subset of models that utilize estrogen for growth, mice were supplemented with 17β-estradiol, and cells or tumor fragments were implanted into the fat pad of intact female NOD-SCID or NOD-SCID-IL2Rgamma null mice and treated with fulvestrant, GDC-0810, or taselisib. Both fulvestrant and GDC-0810 were efficacious in ESR1 wild type (WT) and mutant PDX models but to variable degrees ranging from tumor stasis to growth delay, with GDC-0810 resulting in superior single agent activity at relevant clinical exposure in the WHIM20 and WHIM43 ESR1 mutant models. PIK3CA mutations (E542K, E545K, M1004V, and H1047R) were confirmed in six PDX models and PI3K pathway activation verified by strong pS6RP IHC staining. Taselisib induced tumor growth inhibition and tumor regressions in models harboring PIK3CA mutations, and models with no detectable expression of WT p110α were the most sensitive. In the WHIM43 (ESR1 D538G, PIK3CA M1004V), HCI-011 (ESR1 WT, PIK3CA E545K) and HCI-013 (ESR1 Y537S, PIK3CA H1047R) PDX models, combining fulvestrant and taselisib treatment further enhanced tumor growth inhibition with respect to either treatment alone. Our studies demonstrate the diverse anti-tumor responses of HR+ PDX models to SERDs and the PI3K inhibitor taselisib in the context of clinically relevant ESR1 and PIK3CA mutations. Pharmacological and genomic characterization of additional PDX models may aid in strengthening associations between genotype, drug sensitivity and predictive biomarkers of response.

Citation Format: Young A, Crocker L, Cheng E, Lacap J, Hamilton P, Oeh J, Ingalla E, Arrazate A, Hager J, Nannini M, Friedman L, Daemen A, Giltnane J, Sampath D. Treatment of ESR1 mutant and PIK3CA mutant patient-derived breast cancer xenograft models reveals differential anti-tumor responses to estrogen receptor degraders and PI3K inhibitors in vivo [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-06-05.

Exome sequencing identifies recurrent mutations in NF1 and RASopathy genes in sun-exposed melanomas

We report on whole-exome sequencing (WES) of 213 melanomas. Our analysis established NF1, encoding a negative regulator of RAS, as the third most frequently mutated gene in melanoma, after BRAF and NRAS. Inactivating NF1 mutations were present in 46% of melanomas expressing wild-type BRAF and RAS, occurred in older patients and showed a distinct pattern of co-mutation with other RASopathy genes, particularly RASA2. Functional studies showed that NF1 suppression led to increased RAS activation in most, but not all, melanoma cases. In addition, loss of NF1 did not predict sensitivity to MEK or ERK inhibitors. The rebound pathway, as seen by the induction of phosphorylated MEK, occurred in cells both sensitive and resistant to the studied drugs. We conclude that NF1 is a key tumor suppressor lost in melanomas, and that concurrent RASopathy gene mutations may enhance its role in melanomagenesis.

Two dimensional PMMA nanofluidic device fabricated by hot embossing and oxygen plasma assisted thermal bonding methods

A method for obtaining a low-cost and high-replication precision two-dimensional (2D) nanofluidic device with a polymethyl methacrylate (PMMA) sheet is proposed. To improve the replication precision of the 2D PMMA nanochannels during the hot embossing process, the deformation of the PMMA sheet was analyzed by a numerical simulation method. The constants of the generalized Maxwell model used in the numerical simulation were calculated by experimental compressive creep curves based on previously established fitting formula. With optimized process parameters, 176 nm-wide and 180 nm-deep nanochannels were successfully replicated into the PMMA sheet with a replication precision of 98.2%. To thermal bond the 2D PMMA nanochannels with high bonding strength and low dimensional loss, the parameters of the oxygen plasma treatment and thermal bonding process were optimized. In order to measure the dimensional loss of 2D nanochannels after thermal bonding, a dimension loss evaluating method based on the nanoindentation experiments was proposed. According to the dimension loss evaluating method, the total dimensional loss of 2D nanochannels was 6 nm and 21 nm in width and depth, respectively. The tensile bonding strength of the 2D PMMA nanofluidic device was 0.57 MPa. The fluorescence images demonstrate that there was no blocking or leakage over the entire microchannels and nanochannels.

Core-shell hydrogel beads with extracellular matrix for tumor spheroid formation

Creating multicellular tumor spheroids is critical for characterizing anticancer treatments since they may provide a better model of the tumor than conventional monolayer culture. Moreover, tumor cell interaction with the extracellular matrix can determine cell organization and behavior. In this work, a microfluidic system was used to form cell-laden core-shell beads which incorporate elements of the extracellular matrix and support the formation of multicellular spheroids. The bead core (comprising a mixture of alginate, collagen, and reconstituted basement membrane, with gelation by temperature control) and shell (comprising alginate hydrogel, with gelation by ionic crosslinking) were simultaneously formed through flow focusing using a cooled flow path into the microfluidic chip. During droplet gelation, the alginate acts as a fast-gelling shell which aids in preventing droplet coalescence and in maintaining spherical droplet geometry during the slower gelation of the collagen and reconstituted basement membrane components as the beads warm up. After droplet gelation, the encapsulated MCF-7 cells proliferated to form uniform spheroids when the beads contained all three components: alginate, collagen, and reconstituted basement membrane. The dose-dependent response of the MCF-7 cell tumor spheroids to two anticancer drugs, docetaxel and tamoxifen, was compared to conventional monolayer culture.

Fabrication of two dimensional polyethylene terephthalate nanofluidic chip using hot embossing and thermal bonding technique

We present in this paper a method for obtaining a low cost and high replication precision 2D (two dimensional) nanofluidic chip with a PET (polyethylene terephthalate) sheet, which uses hot embossing and a thermal bonding technique. The hot embossing process parameters were optimized by both experiments and the finite element method to improve the replication precision of the 2D nanochannels. With the optimized process parameters, 174.67 ± 4.51 nm wide and 179.00 ± 4.00 nm deep nanochannels were successfully replicated into the PET sheet with high replication precision of 98.4%. O2 plasma treatment was carried out before the bonding process to decrease the dimension loss and improve the bonding strength of the 2D nanofluidic chip. The bonding parameters were optimized by bonding rate of the nanofluidic chip. The experiment results show that the bonding strength of the 2D PET nanofluidic chip is 0.664 MPa, and the total dimension loss of 2D nanochannels is 4.34 ± 7.03 nm and 18.33 ± 9.52 nm, in width and depth, respectively. The fluorescence images demonstrate that there is no blocking or leakage over the entire micro- and nanochannels. With this fabrication technology, low cost polymer nanochannels can be fabricated, which allows for commercial manufacturing of nano-components.

A novel hybrid patterning technique for micro and nanochannel fabrication by integrating hot embossing and inverse UV photolithography

Nanofluidic devices with micro and nanostructures are becoming increasingly important for biological and chemical applications. However, the majority of the present fabrication methods suffer from a low pattern transfer quality during the simultaneous embossing of the microscale and nanoscale patterns into a thermoplastic polymer due to insufficient polymer flow. In this work, a novel hybrid patterning technique, integrating hot embossing and inverse ultraviolet (UV) photolithography, is developed to fabricate micro and nanochannels with a high replication precision of the SU-8 layer. The influence of embossing temperature and time on the replication precision was investigated. The effect of UV lithography parameters on the micro and nanochannel pattern was analyzed. To improve the SU-8 bonding strength, the influence of the O2 plasma treatment parameters on the water contact angles of the exposed and unexposed SU-8 layer were studied. A complete SU-8 nanofluidic chip with 130 nm wide and 150 nm deep nanochannels was successfully fabricated with a replication precision of 99.5%. Compared with most of the current processing methods, this fabrication technique has great potential due to its low cost and high pattern transfer quality of the SU-8 micro and nanochannels.

Identification of PLX4032-resistance mechanisms and implications for novel RAF inhibitors

BRAF inhibitors improve melanoma patient survival, but resistance invariably develops. Here we report the discovery of a novel BRAF mutation that confers resistance to PLX4032 employing whole-exome sequencing of drug-resistant BRAF^V600K melanoma cells. We further describe a new screening approach, a genome-wide piggyBac mutagenesis screen that revealed clinically relevant aberrations (N-terminal BRAF truncations and CRAF overexpression). The novel BRAF mutation, a Leu505 to His substitution (BRAF^L505H), is the first resistance-conferring second-site mutation identified in BRAF mutant cells. The mutation replaces a small nonpolar amino acid at the BRAF-PLX4032 interface with a larger polar residue. Moreover, we show that BRAF^L505H, found in human prostate cancer, is itself a MAPK-activating, PLX4032-resistant oncogenic mutation. Lastly, we demonstrate that the PLX4032-resistant melanoma cells are sensitive to novel, next-generation BRAF inhibitors, especially the ‘paradox-blocker’ PLX8394, supporting its use in clinical trials for treatment of melanoma patients with BRAF-mutations.

Organ Procurement and Transplantation Network/Scientific Registry of Transplant Recipients 2014 Data Report: Intestine

As of September 19, 2014, 2441 cases of intestinal transplantation have been performed in 46 centers (2400 deceased, 41 living). Eight centers did more than 100 transplants. Annual case numbers peaked in 2007 (N = 198) and steadily decreased to 109 cases in 2013. Short gut syndrome (68%) and functional bowel problems (15%) are two major indications for intestinal transplantation. The 3 major types of transplants involving the intestine include: isolated intestine transplant (I); simultaneous intestine, liver, and pancreas transplant (I+L+P); and, combined intestine and liver (I+L) transplant. Graft survival has significantly improved in recent years, mainly due to improved first year graft survival. The 1-, 5-, and 10-year graft survivals were: 74%, 42%,and 26%, respectively (I); 70%, 50%, and 40%, respectively (I+L+P); and 61%, 46%, and 40%, respectively (I+L). The longest graft survivals for I, l+L+P, and l+L were 19 years, 16 years, and 23 years, respectively. Steroids, Thymoglobulin, and rituximab are 3 major induction agents used in recent years. Prograf, steroids, and Cellcept are 3 major maintenance agents. Induction recipients (68% of all patients) had a significantly lower acute rejection rate than nonrecipients before discharge (60% versus 75%, p < 0.001). Most of the patients received 2 (53%) or 3 (25%) maintenance immunosuppressants. Acute rejection episodes were usually treated with one (60%) or two agents (27%). Steroids were most commonly used (50-60%). OKT3 has been replaced with antithymocyte globulin (since 1999) and rituximab (since 2006). During 1990-2000, 94% (N = 445) of patients received ABO identical intestinal transplants, while 6% (N = 29) received ABO compatible transplants. ABO identical transplant recipients had a significantly higher 5-year graft survival rate than ABO compatible recipients (39% versus 21%, p < 0.0001). In recent years (2001- 2012), more patients received ABO compatible (N = 188, 11%) than in the early decade (p < 0.01). 5-year graft survival rates of ABO compatible transplants were lower than those of ABO identical transplants. However, the difference did not reach statistical significance (46% versus 49%, p = 0.07). The effect of ABO compatibility on graft outcome was further confirmed by Cox Analysis. ABO incompatible transplants are still rarely performed (N = 4) in intestine. In conclusion, annual case numbers of intestinal transplants have been decreasing, regardless of improved graft survival. ABO compatible intestinal transplants previously had a significantly lower graft survival rate than ABO identical transplants. However, the graft survival difference became less significant in recent years, possibly due to, or at least partly due to the use of new immunosuppressive agents.

Renal allograft outcomes following early corticosteroid withdrawal in Hispanic transplant recipients

BACKGROUND

Renal transplant outcomes in Hispanics have been conflicting regarding acute rejection (AR) and allograft survival. Additionally, the feasibility of early corticosteroid withdrawal (ECW) regimens among Hispanics has not been adequately addressed. The purpose of this study is to report outcomes following ECW among Hispanic renal transplant recipients.

METHODS

We retrospectively reviewed 498 consecutive renal transplants performed at our institution between July 2005 and October 2007, including 73 Hispanic and 146 white recipients who had ECW (median follow-up 49 months). Demographics, transplant data, and outcomes of Hispanic and white recipients (WR) were analyzed.

RESULTS

Hispanics had a higher incidence of diabetes mellitus and hypertension (p = 0.007), a higher proportion of blood type O (p = 0.006), and a higher serum panel reactive antibody at the time of transplantation (p = 0.02) compared with WR. Additionally, Hispanics were on dialysis longer than WR prior to transplantation (p = 0.03). Nevertheless, the incidence of AR, patient, and graft survival rates was similar (p > 0.05) between Hispanics and WR. Ethnicity was not an independent predictor of inferior patient and graft outcomes in multivariate analyses.

CONCLUSION

Our single-center experience indicates that ECW can be performed in Hispanic renal transplant recipients, with patient and allograft outcomes comparable with those observed in WR.

Cecal diverticulitis as a continuing diagnostic and management dilemma: a report of two cases in children

Right-sided diverticulitis remains an exceedingly rare condition in the pediatric population. The clinical presentation mimics acute appendicitis, and the correct diagnosis is often difficult to make prior to operative exploration. We report two cases of cecal diverticulitis, and discuss the diagnosis and management of this disease, with a review of the literature.

Transafe

An earlier version of this paper was presented at the 2011 IEEE International Symposium on Technology and Society (ISTAS) at Saint Xavier University in Chicago, Illinois (and printed in the 2011 ISTAS proceedings).

This paper describes a proposed mobile platform, Transafe , that captures and analyses public perceptions of safety to deliver 'crowdsourced' collective intelligence about places in the City of Melbourne, Australia, and their affective states at various times of the day. Public perceptions of crime on public transport in Melbourne are often mismatched with actual crime statistics and such perceptions thus can act as social barriers to visitors and locals traversing within and through the city. Using interactive mobile applications and social media, the visualization of this crowdsourced safety perception information will increase the commuter's awareness of various situations in the City of Melbourne. In addition, through social behavioral analysis and ethnographic research, the collective public intelligence will also help inform the stakeholders of the city for future policy-making and policing strategies for safety perception management. At the centre of the proposed platform is the design and development of a mobile phone application that can contribute to people feeling safer by supporting users to report crimes and misdemeanors that they witness, and provide information about transportation and emergency services around where the users are located. The proposed application can also act as a crime deterrent with one feature that enables user tracking by up to three nominated friends if the user opts to activate tracking when feeling unsafe while roaming the city.

Detecting copy number status and uncovering subclonal markers in heterogeneous tumor biopsies

Background

Genomic aberrations can be used to determine cancer diagnosis and prognosis. Clinically relevant novel aberrations can be discovered using high-throughput assays such as Single Nucleotide Polymorphism (SNP) arrays and next-generation sequencing, which typically provide aggregate signals of many cells at once. However, heterogeneity of tumor subclones dramatically complicates the task of detecting aberrations.

Results

The aggregate signal of a population of subclones can be described as a linear system of equations. We employed a measure of allelic imbalance and total amount of DNA to characterize each locus by the copy number status (gain, loss or neither) of the strongest subclonal component. We designed simulated data to compare our measure to existing approaches and we analyzed SNP-arrays from 30 melanoma samples and transcriptome sequencing (RNA-Seq) from one melanoma sample.

We showed that any system describing aggregate subclonal signals is underdetermined, leading to non-unique solutions for the exact copy number profile of subclones. For this reason, our illustrative measure was more robust than existing Hidden Markov Model (HMM) based tools in inferring the aberration status, as indicated by tests on simulated data. This higher robustness contributed in identifying numerous aberrations in several loci of melanoma samples. We validated the heterogeneity and aberration status within single biopsies by fluorescent in situ hybridization of four affected and transcriptionally up-regulated genes E2F8, ETV4, EZH2 and FAM84B in 11 melanoma cell lines. Heterogeneity was further demonstrated in the analysis of allelic imbalance changes along single exons from melanoma RNA-Seq.

Conclusions

These studies demonstrate how subclonal heterogeneity, prevalent in tumor samples, is reflected in aggregate signals measured by high-throughput techniques. Our proposed approach yields high robustness in detecting copy number alterations using high-throughput technologies and has the potential to identify specific subclonal markers from next-generation sequencing data.

Bacterial Breakaway

Peptides produced by Staphylococcus epidermidis promote dissemination of this bacterium from biofilms, leading to systemic infection in catheterized patients.

Too Much of a Good Thing?

Antibiotics alter the normal intestinal flora and increase susceptibility to infection by highly resistant bacteria.

Steroid avoidance in two-haplotype-matched living donor renal transplants with basiliximab induction therapy

BACKGROUND

Induction therapy and haplotype matching are utilized to mitigate immunologic risk in renal transplantation. The incidence of acute rejection (AR) of renal allografts has been reported to be as low as 9.3% within the first year among two-haplotype-matched siblings with no induction and triple-drug maintenance immunosuppression. We report our use of basiliximab induction in a series of two-haplotype-matched living donor renal transplants (LDRT).

METHODS

We retrospectively reviewed 25 patients who received a two-haplotype-matched LDRT with basiliximab induction therapy. The primary endpoints were acute rejection (AR) episodes at 6 and 12 months and 1-year patient and graft survival rates. The secondary endpoints were the incidence of delayed graft function (DGF), cytomegalovirus (CMV), and BK virus (BKV).

RESULTS

The rate of AR at 6 months was 0% (0/25) and 4% (1/25) at 12 months. The 1-year graft and patient survival rates were 100%. The incidence of DGF was 4% (1/25), while the incidences of CMV and BKV were 0%.

CONCLUSION

Basiliximab induction therapy with a steroid-sparing regimen yields favorable results in two-haplotype-matched LDRT, including a notable reduction in the rates of AR as compared to triple-drug maintenance immunosuppression without induction. These patients have excellent graft survival with no increased incidences of secondary infections.

Scar Tactics

Targeted delivery of antifibrotic compounds stems scar formation.

The Closer

Growth hormone–releasing hormone directly stimulates fibroblasts to accelerate wound healing.

Licensed to Enter

A protein transduction domain peptide enhances the cellular uptake of Foxp3 protein for the treatment of autoimmune and allergic disorders.

Bridging the Gap in Spinal Cord Injury

Valproic acid coaxes transplanted neural stem cells to differentiate into neurons that boost repair of spinal cord injury in mice.