Shear wave velocity - SCPTU correlations for sensitive marine clays

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Physiologic compliance in engineered small-diameter arterial constructs based on an elastomeric substrate.

Compliance mismatch is a significant challenge to long-term patency in small-diameter bypass grafts because it causes intimal hyperplasia and ultimately graft occlusion. Current engineered grafts are typically stiff with high burst pressure but low compliance and low elastin expression. We postulated that engineering small arteries on elastomeric scaffolds under dynamic mechanical stimulation would result in strong and compliant arterial constructs. This study compares properties of engineered arterial constructs based on biodegradable polyester scaffolds composed of either rigid poly(lactide-co-glycolide) (PLGA) or elastomeric poly(glycerol sebacate) (PGS). Adult baboon arterial smooth muscle cells (SMCs) were cultured in vitro for 10 days in tubular, porous scaffolds. Scaffolds were significantly stronger after culture regardless of material, but the elastic modulus of PLGA constructs was an order of magnitude greater than that of porcine carotid arteries and PGS constructs. Deformation was elastic in PGS constructs and carotid arteries but plastic in PLGA constructs. Compliance of arteries and PGS constructs were equivalent at pressures tested. Altering scaffold material from PLGA to PGS significantly decreased collagen content and significantly increased insoluble elastin content in constructs without affecting soluble elastin concentration in the culture medium. PLGA constructs contained no appreciable insoluble elastin. This research demonstrates that: (1) substrate stiffness directly affects in vitro tissue development and mechanical properties; (2) rigid materials likely inhibit elastin incorporation into the extracellular matrix of engineered arterial tissues; and (3) grafts with physiologic compliance and significant elastin content can be engineered in vitro after only days of cell culture

Piezocone testing in Nordic soft clays: Comparison of high-quality databases

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Localisation of nitrate-reducing and highly abundant microbial communities in the oral cavity

This is the final version. Available on open access from Public Library of Science via the DOI in this record. Data Availability: All relevant data are within the paper and its Supporting Information filesThe nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing oral bacteria reduce inorganic dietary NO3- to nitrite (NO2-) via the NO3--NO2--NO pathway. Studies of oral NO3--reducing bacteria have typically sampled from either the tongue surface or saliva. The aim of this study was to assess whether other areas in the mouth could contain a physiologically relevant abundance of NO3- reducing bacteria, which may be important for sampling in clinical studies. The bacterial composition of seven oral sample types from 300 individuals were compared using a meta-analysis of the Human Microbiome Project data. This analysis revealed significant differences in the proportions of 20 well-established oral bacteria and highly abundant NO3--reducing bacteria across each oral site. The genera included Actinomyces, Brevibacillus, Campylobacter, Capnocytophaga, Corynebacterium, Eikenella, Fusobacterium, Granulicatella, Haemophilus, Leptotrichia, Microbacterium, Neisseria, Porphyromonas, Prevotella, Propionibacterium, Rothia, Selenomonas, Staphylococcus, Streptococcus and Veillonella. The highest proportion of NO3--reducing bacteria was observed in saliva, where eight of the bacterial genera were found in higher proportion than on the tongue dorsum, whilst the lowest proportions were found in the hard oral surfaces. Saliva also demonstrated higher intra-individual variability and bacterial diversity. This study provides new information on where samples should be taken in the oral cavity to assess the abundance of NO3--reducing bacteria. Taking saliva samples may benefit physiological studies, as saliva contained the highest abundance of NO3- reducing bacteria and is less invasive than other sampling methods. These results inform future studies coupling oral NO3--reducing bacteria research with physiological outcomes affecting human health

In Vivo assessment of a tissue-engineered vascular graft combining a biodegradable elastomeric scaffold and muscle-derived stem cells in a rat model

Limited autologous vascular graft availability and poor patency rates of synthetic grafts for bypass or replacement of small-diameter arteries remain a concern in the surgical community. These limitations could potentially be improved by a tissue engineering approach. We report here our progress in the development and in vivo testing of a stem-cell-based tissue-engineered vascular graft for arterial applications. Poly(ester urethane)urea scaffolds (length=10mm; inner diameter=1.2mm) were created by thermally induced phase separation (TIPS). Compound scaffolds were generated by reinforcing TIPS scaffolds with an outer electrospun layer of the same biomaterial (ES-TIPS). Both TIPS and ES-TIPS scaffolds were bulk-seeded with 10×106 allogeneic, LacZ-transfected, muscle-derived stem cells (MDSCs), and then placed in spinner flask culture for 48h. Constructs were implanted as interposition grafts in the abdominal aorta of rats for 8 weeks. Angiograms and histological assessment were performed at the time of explant. Cell-seeded constructs showed a higher patency rate than the unseeded controls: 65% (ES-TIPS) and 53% (TIPS) versus 10% (acellular TIPS). TIPS scaffolds had a 50% mechanical failure rate with aneurysmal formation, whereas no dilation was observed in the hybrid scaffolds. A smooth-muscle-like layer of cells was observed near the luminal surface of the constructs that stained positive for smooth muscle α-actin and calponin. LacZ+ cells were shown to be engrafted in the remodeled construct. A confluent layer of von Willebrand Factor-positive cells was observed in the lumen of MDSC-seeded constructs, whereas acellular controls showed platelet and fibrin deposition. This is the first evidence that MDSCs improve patency and contribute to the remodeling of a tissue-engineered vascular graft for arterial applications. © 2010 Mary Ann Liebert, Inc

Provider confidence in counseling preconception, pregnant, and postpartum patients regarding COVID‐19 vaccination: A cross‐sectional survey study

Background and Aims Healthcare provider counseling surrounding COVID‐19 vaccine in pregnancy and lactation is essential to vaccination uptake in this population; however, provider knowledge and confidence are not well characterized. We aimed to assess knowledge and confidence in COVID‐19 vaccine counseling among practitioners who provide care to pregnant persons and to describe factors associated with confidence in counseling. Methods A web‐based anonymous survey was distributed via email to a cross‐sectional convenience sample of Obstetrics and Gynecology, Primary Care, and Internal Medicine faculty at three hospitals in a single healthcare network in Massachusetts, United States. Individual demographics and institution‐specific variables were included in the survey along with questions assessing both attitudes toward COVID‐19 illness and confidence in counseling regarding the use of the vaccine in pregnancy. Results Almost all providers (151, 98.1%) reported that they received a COVID‐19 vaccine, and most (111, 72.1%) reported that they believe the benefits of the vaccine in pregnancy outweigh the risks. Forty‐one (26.6%) reported feeling very confident in counseling patients who primarily speak English about the evidence for messenger ribonucleic acid vaccination in pregnancy, and 36 (23%) reported feeling very confident in counseling patients who are not primarily English‐speaking. Forty‐three providers (28.1%) expressed strong confidence in their comfort talking to individuals with vaccine hesitancy based on historic and continued racism and systemic injustices. The sources that survey respondents most used to find information regarding COVID‐19 vaccination in pregnancy were the Centers for Disease Control (112, 74.2%), hospital‐specific resources (94, 62.3%), and the American College of Obstetricians and Gynecologists (82, 54.3%). Conclusion Ensuring that providers feel comfortable bridging the gap between their belief that the vaccine is beneficial for pregnant patients and their comfort with holding conversations with patients regarding vaccination is paramount to ensure equitable access to vaccines for pregnant patients

Space-time Structure of Initial Parton Production in Ultrarelativistic Heavy Ion Collisions

The space and time evolution of initial parton production in ultrarelativistic heavy ion collisions is investigated within the framework of perturbative QCD which includes both initial and final state radiations. Uncertainty principle is used to relate the life time of a radiating parton to its virtuality and momentum. The interaction time of each hard or semihard parton scattering is also taken into account. For central $Au+Au$ collisions at $\sqrt{s}=200$ GeV, most of the partons are found to be produced within 0.5 fm/c after the total overlap of the two colliding nuclei. The local momentum distribution is approximately isotropical at that time. The implication on how to treat correctly the the secondary scattering in an ultimate parton cascading model is also discussed.Comment: 19 pages in REVTEX with 12 figures in separate uuencoded postscript files, LBL-3415

The complex behavior of El Niño winter 2015-2016

This paper examines the outstanding characteristics of the strong 2015-2016 El Nino (EN) winter and its impact over the European region through the stratosphere. Despite being classified as a strong eastern Pacific (EP) EN event, our analysis reveals an anomalous behavior, with some signatures that are more typical of central Pacific (CP) EN events instead. They include (i) a record-breaking value of the CP index, (ii) a stronger polar vortex in early and midwinter, due to reduced upward wave activity and a weakened Aleutian low, and (iii) the occurrence of one of the earliest stratospheric final warmings (SFWs) on record, which are more prone to occur during CP-EN. Following the SFW, a stratospheric influence on the Euro-Atlantic sector is reported in spring, with persistent Greenland blocking resulting in extreme precipitation over some southern European regions. Results highlight the importance of considering early SFWs as mediators of El Nino teleconnections

Multiple Interactions and the Structure of Beam Remnants

Recent experimental data have established some of the basic features of multiple interactions in hadron-hadron collisions. The emphasis is therefore now shifting, to one of exploring more detailed aspects. Starting from a brief review of the current situation, a next-generation model is developed, wherein a detailed account is given of correlated flavour, colour, longitudinal and transverse momentum distributions, encompassing both the partons initiating perturbative interactions and the partons left in the beam remnants. Some of the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure