Initial Fill Research Articles

Experimental research on the two-phase explosive boiling mechanism of superheated liquid under different leakage conditions

In this study, a 17 L cube vessel was designed to simulate the explosive boiling of high-pressure liquefied gas after the leakage of the storage tank. The influence of leakage conditions such as crack position, crack diameter, and initial liquid fill level were investigated. Results indicate that when the crack is at the gas phase and gas-liquid interface, the rapid boiling of the liquid is caused by the leakage and significant pressure rebound is occurred. What’s more, cracks located under the gas-liquid phase may also cause a significant rebound in pressure. As the crack diameter increases, the two-phase flow boiling intensity first increases and then decreases, and it reaches the maximum when the diameter is 30 mm. Furthermore, a concept of the critical liquid level difference was proposed, and its influencing factors were studied. Under the experimental conditions in this article, BLEVE will not occur if the height between the liquid level and the crack is above the critical liquid level difference.

Fuel–shell mix and yield degradation in kinetic shock-driven inertial confinement fusion implosions

Fuel–shell mix in kinetic plasma conditions is probed using nuclear and x-ray self-emission in shock-driven, D3He-gas-filled inertial confinement fusion implosions. As initial gas fill density decreases, measured nuclear yields and ion temperatures are lower than expected as compared to radiation-hydrodynamic simulations. Spatially and temporally resolved x-ray emissions indicate significant mixing at the fuel–shell interface in implosions with low initial gas fill density. This observed fuel–shell mix introduces a substantial amount of shell ions into the center of the implosion prior to and during shock flash and is the key mechanism needed in the kinetic-ion simulations to match experimental nuclear yields.

CLIMFILL v0.9: a framework for intelligently gap filling Earth observations

Abstract. Remotely sensed Earth observations have many missing values. The abundance and often complex patterns of these missing values can be a barrier for combining different observational datasets and may cause biased estimates of derived statistics. To overcome this, missing values in geoscientific data are regularly infilled with estimates through univariate gap-filling techniques such as spatial or temporal interpolation or by upscaling approaches in which complete donor variables are used to infer missing values. However, these approaches typically do not account for information that may be present in other observed variables that also have missing values. Here we propose CLIMFILL (CLIMate data gap-FILL), a multivariate gap-filling procedure that combines kriging interpolation with a statistical gap-filling method designed to account for the dependence across multiple gappy variables. In a first stage, an initial gap fill is constructed for each variable separately using state-of-the-art spatial interpolation. Subsequently, the initial gap fill for each variable is updated to recover the dependence across variables using an iterative procedure. Estimates for missing values are thus informed by knowledge of neighbouring observations, temporal processes, and dependent observations of other relevant variables. CLIMFILL is tested using gap-free ERA-5 reanalysis data of ground temperature, surface-layer soil moisture, precipitation, and terrestrial water storage to represent central interactions between soil moisture and climate. These variables were matched with corresponding remote sensing observations and masked where the observations have missing values. In this “perfect dataset approach” CLIMFILL can be evaluated against the original, usually not observed part of the data. We show that CLIMFILL successfully recovers the dependence structure among the variables across all land cover types and altitudes, thereby enabling subsequent mechanistic interpretations in the gap-filled dataset. Correlation between original ERA-5 data and gap-filled ERA-5 data is high in many regions, although it shows artefacts of the interpolation procedure in large gaps in high-latitude regions during winter. Bias and noise in gappy satellite-observable data is reduced in most regions. A case study of the European 2003 heatwave shows how CLIMFILL reduces biases in ground temperature and surface-layer soil moisture induced by the missing values. Furthermore, in idealized experiments we see the impact of fraction of missing values and the complexity of missing value patterns to the performance of CLIMFILL, showing that CLIMFILL for most variables operates at the upper limit of what is possible given the high fraction of missing values and the complexity of missingness patterns. Thus, the framework can be a tool for gap filling a large range of remote sensing observations commonly used in climate and environmental research.

The Impact of Preoperative Breast Volume on Development of Mastectomy Skin Flap Necrosis in Immediate Breast Reconstruction.

Mastectomy skin flap necrosis (MSFN) can significantly impact outcome after immediate breast reconstruction. Several techniques exist to predict MSFN, but these may require additional testing and information, and they are often not available before surgery. We aim to identify whether breast volume, as calculated from preoperative mammography, can be used as a preoperative predictor of MSFN. A retrospective chart review from 2010 to 2020 resulted in 378 patients who underwent immediate implant-based breast reconstruction. Complete imaging data were available for 278 patients and 441 reconstructed breasts. Demographic, perioperative, and outcomes data were collected. Measurements from preoperative diagnostic mammograms were used to calculate breast volume. Univariate and multivariate analyses were used to evaluate the association of variables available preoperatively, including breast volume from mammogram and MSFN. Secondary analyses were performed for need for reoperation and loss of reconstruction. On univariate analysis of MSFN development, demographic variables found to be significantly associated with MSFN included body mass index (P = 0.04), diabetes (P = 0.03), and breast volume calculated from routine mammography (P ≤ 0.0001). Average preoperative breast volume via mammography without and with MSFN was 970.6 mL (95% confidence interval [CI], 908.9-1032.3) and 1298.3 mL (95% CI, 1140.0-1456.5) (P < 0.0001), respectively. Statistically significant intraoperative variables for MSFN development included prolonged operative time (P = 0.005), greater initial tissue expander fill volumes (P ≤ 0.001), and prepectoral implant location (P = 0.02). Higher initial tissue expander fill volumes in implant-based reconstructions were associated with increased rates of MSFN, 264.1 mL (95% CI, 247.2-281.0) without MSFN and 349.9 mL (95% CI, 302.0-397.8) in the group with MSFN, respectively (P < 0.001). On multivariate analysis, preoperative imaging volume (P = 0.02) was found to be significant, whereas body mass index and diabetes lost significance (P = 0.40) in association with MSFN. The results of this study establish an association between larger breast volume on preoperative imaging and development of MSFN. This may be useful as a tool for more appropriate patient selection and guidance in the setting of immediate breast reconstruction.

Hospitalization rate differences among cancer patients on biologics and biosimilars.

e13530 Background: Febrile neutropenia (FN), a severe adverse effect of many cancer treatments, often results in emergency hospitalizations. Granulocyte colony-stimulating factors (G-CSF; filgrastim and pegfilgrastim) have proven efficacy in the prophylaxis of chemotherapy-induced neutropenia and are associated with reducing FN and hospitalizations. Clinical studies have shown that biosimilars are comparable to their originator products; however, no real-world studies on the impact of biosimilar G-CSF on FN hospitalizations exist. We hypothesize that no difference in FN-related hospitalizations between biosimilar and originator biologic G-CSF will occur. Methods: This was a retrospective cohort study of adult patients receiving either biologic G-CSF or biosimilar G-CSF from 5/1/2018 through 4/30/2021. Patients were followed from their initial G-CSF fill during the study period until 30 days following the last dose received. Patients were excluded if they switched exposure groups during the study period or did not maintain eligibility for the duration of follow-up. The primary outcome was FN hospital admission rate between the two groups, defined as any inpatient claims with the primary diagnosis ICD-10 code D70.1 or R50.2. Descriptive statistics and logistic regression were conducted to account for confounding between the groups. Incidence rates were calculated per 1000 person-years of exposure (PY); p-values &lt; 0.05 were considered significant. Results: A total of 13,670 patients met the inclusion criteria, with 6,939 (50.8%) receiving biologic G-CSF. Biosimilar patients were younger (Mean [standard deviation (SD)]: 63.8 [13.4] vs. 65.5 [13.0] p &lt; 0.05), male (40.0% vs. 37.2%; p &lt; 0.05), had more G-CSF claims (Mean [SD]: 5.6 [6.8] vs. 4.5 [4.3]; p &lt; 0.05) and were more likely to utilize a specialty pharmacy (10.1% vs. 4.7%; p &lt; 0.05). Pegfilgrastim was the most common G-CSF medication overall (73.5%); however, filgrastim use was significantly more common in biosimilar patients (43.2% vs. 10.4%; p &lt; 0.05). FN hospitalizations were rare, with 1.1% of patients experiencing an event. No difference in hospitalizations were noted (biosimilars: 1.1%, biologics: 1.0%; p = 0.39). After regression, no factors analyzed were associated with FN-related hospitalizations. Crude FN incidence rates were 45.9 cases per 1000 PY (95% Confidence Interval [CI]: 35.6-56.1 per 1000 PY) among biosimilar patients compared to 37.5 cases per 1000 PY (95% CI: 28.6-46.4 per 1000 PY) among biologic patients, resulting in a rate difference of 8.3 cases per 1000 PY (95% CI: 5.2-22.0 cases per 1000 PY; p = 0.22). Conclusions: In a large real-world analysis, biosimilar G-CSF demonstrated similar effectiveness in preventing FN hospitalization as originator biologic G-CSF agents.

Measurements of the imploding plasma sheath in triple-nozzle gas-puff z pinches

Gas-puff z-pinch implosions are characterized by the formation of a dense annular plasma shell, the sheath, that is driven to the axis by magnetic forces and therefore subject to the magneto-Rayleigh–Taylor instability. Here, the conditions within these sheaths are measured on the 1-MA COBRA generator at Cornell University [Greenly et al., Rev. Sci. Instrum. 79, 073501 (2008)] for various gas species and initial fill densities. The gas-puff loads are initialized by a 7 cm diameter triple-nozzle gas valve assembly with concentric outer and inner annular nozzles and a central gas jet. Thomson scattering and laser interferometry provide spatially resolved flow, temperature, and electron density profiles midway through the implosion, while extreme ultraviolet pinhole cameras record the evolution of the plasma column and photoconducting diodes measure x-ray emission. Analysis of the scattering spectra includes a means of discriminating between thermal and non-thermal broadening to test for the presence of hydrodynamic turbulence. Two types of sheath profiles are observed, those with sharp discontinuities at the leading edge and those with smooth gradients. In both cases, non-thermal broadening is generally peaked at the front of the sheath and exhibits a characteristic decay length that roughly scales with the sheath ion mean free path. We demonstrate that this non-thermal broadening term is inconsistent with laminar velocity gradients and is more consistent with dissipative turbulence driven by unstable plasma waves in a collisionless shock. The resulting differences in sheath profile are then set by the sheath ion collisionality in a manner consistent with recent 1D kinetic simulations [Angus et al., Phys. Plasmas 28, 010701 (2021)].

Numerical analysis of die filling with a forced feeder using GPU-enhanced discrete element methods

Understanding die filling behaviour of powders is critical in developing optimal formulation and processes in various industries, such as pharmaceuticals and fine chemicals. In this paper, forced die filling is analysed using a graphics processing unit (GPU) based discrete element method (DEM), for which a powder feeder equipped with a wired stirrer is considered. The influences of operating parameters, such as the initial powder bed height, the filling speed, and the stirrer speed, on the die filling performance are systematically explored. It is shown that a larger initial powder bed height leads to a higher filling ratio, which can be attributed to a higher filling intensity; while the deposited particle mass in the die is almost independent of the powder bed height, when the initial fill level is larger than a critical bed height. Additionally, the filling ratio slightly increases with the increase of stirrer speed for cases with a stirrer, while the filling ratios are lower than that without a stirrer, which is attributed to the stirrer occupying some space above the die and reducing the effective discharge area. The obtained results can provide useful information for optimising the feeder system design and the operating condition.

The Port Delivery System with ranibizumab: a new paradigm for long-acting retinal drug delivery

The Port Delivery System with ranibizumab (PDS) is an innovative intraocular drug delivery system designed for the continuous delivery of ranibizumab into the vitreous for 6 months and beyond. The PDS includes an ocular implant, a customized formulation of ranibizumab, and four dedicated ancillary devices for initial fill, surgical implantation, refill-exchange, and explantation, if clinically indicated. Ranibizumab is an ideal candidate for the PDS on account of its unique physicochemical stability and high solubility. Controlled release is achieved via passive diffusion through the porous release control element, which is tuned to specific drug characteristics to accomplish a therapeutic level of ranibizumab in the vitreous. To characterize drug release from the implant, release rate was measured in vitro with starting concentrations of ranibizumab 10, 40, and 100 mg/mL, with release of ranibizumab 40 and 100 mg/mL found to remain quantifiable after 6 months. Using a starting concentration of 100 mg/mL, active release rate at approximately 6 months was consistent after the initial fill and first, second, and third refills, demonstrating reproducibility between implants and between multiple refill-exchanges of the same implant. A refill-exchange performed with a single 100-µL stroke using the refill needle was shown to replace over 95% of the implant contents with fresh drug. In vitro data support the use of the PDS with fixed refill-exchange intervals of at least 6 months in clinical trials.

Air versus Saline: The Effect of Tissue Expander Fill on Outcomes of Prepectoral Breast Reconstruction.

Traditionally, saline is used for intraoperative/postoperative expansion in two-stage alloplastic breast reconstruction. Recently, intraoperative expansion with air has been proposed, to reduce pressure on the mastectomy skin flap in the immediate postoperative setting. The authors examined whether the intraoperative tissue expansion medium (i.e., air versus saline) affected postmastectomy complications in two-stage prepectoral reconstruction. This was a retrospective cohort study of 87 patients (144 breasts) undergoing prepectoral breast reconstruction at the authors' institution. Patient data were abstracted from medical records. Stepwise, multivariable-adjusted logistic regression using robust variances was used to identify predictors of postmastectomy complications. Statistical and power analyses were completed. Of the 87 study patients, 29 (33.3 percent) received intraoperative saline fill and 58 (66.7 percent) received air fill. Demographic/clinical data were well-matched between cohorts. Median follow-up was 165 days, and average patient age was 46.7 years. Initial tissue expander fill volumes were similar between study cohorts ( p = 0.2). The crude association between air versus saline fill on overall complication rates suggested that air-filled tissue expanders may be protective (OR = 0.4; p = 0.03), and the suggested protective effect was maintained with borderline significance even after potential confounders (i.e., American Society of Anesthesiologists class III or higher, body mass index, diabetes, mastectomy specimen weight, smoking status) were added to the model (OR = 0.4; p = 0.05). In addition, fewer complications requiring salvage reoperation were observed with air-filled tissue expanders (adjusted OR = 0.3; p = 0.02). The medium used for immediate intraoperative tissue expansion impacted postmastectomy outcomes in patients undergoing two-stage prepectoral breast reconstruction. The results demonstrated that air-filled tissue expanders were associated with fewer postoperative complications/salvage reoperations relative to saline-filled tissue expanders. Therapeutic, III.

PD05-01 ASSOCIATION BETWEEN ON-TREATMENT FOLLOW-UP TESTING AND MEDICATION ADHERENCE AMONG PATIENTS PRESCRIBED PREVENTIVE PHARMACOLOGIC THERAPY FOR URINARY STONE DISEASE

You have accessJournal of UrologyCME1 May 2022PD05-01 ASSOCIATION BETWEEN ON-TREATMENT FOLLOW-UP TESTING AND MEDICATION ADHERENCE AMONG PATIENTS PRESCRIBED PREVENTIVE PHARMACOLOGIC THERAPY FOR URINARY STONE DISEASE Joseph Crivelli, Phyllis Yan, Ryan Hsi, Vahakn Shahinian, Brian Denton, and John Hollingsworth Joseph CrivelliJoseph Crivelli More articles by this author , Phyllis YanPhyllis Yan More articles by this author , Ryan HsiRyan Hsi More articles by this author , Vahakn ShahinianVahakn Shahinian More articles by this author , Brian DentonBrian Denton More articles by this author , and John HollingsworthJohn Hollingsworth More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002524.01AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Guidelines on medical management for urinary stone disease (USD) recommend that clinicians obtain a 24-hour urine specimen within six months of initiating preventive pharmacological therapy (PPT) to assess therapeutic response. We examined whether there are beneficial spillover effects associated with this testing, specifically increased PPT adherence. METHODS: Using claims data from working-age, commercially insured adults with USD (2008 to 2019), we identified those who were prescribed PPT (i.e., a thiazide diuretic, alkali citrate therapy, or allopurinol). Next, we sorted patients into three groups: 1) those who did not complete any 24-hour urine testing, 2) those who completed only a baseline 24-hour urine collection prior to initiating PPT, and 3) those who completed both baseline testing and on-treatment follow-up testing within six months of initiating PPT. We defined PPT adherence based on percentage days covered using pharmacy claims and assessed this over 0 to 180 days and 180 to 360 days following the initial prescription fill. Finally, we fit multivariable logistic regression models to evaluate the association between on-treatment follow-up testing and PPT adherence. RESULTS: Among a cohort of 5,072 patients receiving PPT for USD, 3,517 (69.3%) did not complete 24-hour urine testing, 1,214 (23.9%) completed a baseline collection only, and 341 (6.7%) completed both baseline and on-treatment follow-up testing. Adjusted adherence rates based on results from multivariable logistic regression are shown in the Figure. There were no significant differences in adherence rates between patients without any 24-hour urine testing and those who performed a baseline urine collection only; however, compared to patients without any 24-hour urine testing, rates of PPT adherence were significantly higher for those who completed both baseline and on-treatment follow-up testing (45.9% vs. 24.7% at 0 to 180 days [P<0.01] and 29.5% vs. 15.7% at 180 to 360 days [P<0.01]). CONCLUSIONS: On-treatment follow-up testing for patients with USD managed with PPT was associated with higher rates of medication adherence. Further research is needed to understand how the timing of on-treatment follow-up testing can be optimized to maximize PPT adherence. Source of Funding: NIH 5R01DK121709 (JH) © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e86 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joseph Crivelli More articles by this author Phyllis Yan More articles by this author Ryan Hsi More articles by this author Vahakn Shahinian More articles by this author Brian Denton More articles by this author John Hollingsworth More articles by this author Expand All Advertisement PDF DownloadLoading ...

Fill dynamics and sample mixing in the AirCore

Abstract. The AirCore is a long coiled tube that acts as a “tape recorder” of the composition of air as it is slowly filled or flushed. When launched by balloon with one end of the tube open and the other closed, the initial fill air flows out during ascent as the outside air pressure drops. During descent atmospheric air flows back in. I describe how we can associate the position of an air parcel in the tube with the altitude it came from by modeling the dynamics of the fill process. The conditions that need to be satisfied for the model to be accurate are derived. The extent of the mixing of air parcels that enter at different times is calculated so that we know how many independent samples are in the tube upon landing and later when the AirCore is analyzed.

Impact of Empirical Antibiotic Therapy on Outcomes of Outpatient Urinary Tract Infection Due to Nonsusceptible Enterobacterales.

ABSTRACTResistance to oral antibiotics commonly used to treat outpatient urinary tract infections (UTIs) is increasing, but the implications of empirical treatment of resistant pathogens are not well described. Using an electronic records database, we reviewed the outcomes of patients >18 years of age who developed an outpatient UTI and had an outpatient urine culture result showing a member of the order Enterobacterales along with prescription data for an oral antibiotic filled on the day before, day of, or day after the culture was collected. Linear probability models were used to estimate partial effects of select clinical and demographic variables on the composite outcome. In all, 4,792 patients had 5,587 oral antibiotic prescriptions. Of 5,395 evaluable episodes, 22% of patients received an antibiotic to which the pathogen was resistant in vitro, and those patients were almost twice as likely to require a second prescription (34% versus 19%) or be hospitalized (15% versus 8%) within 28 days of the initial prescription fill compared to patients who received an antibiotic to which the pathogen was susceptible. Approximately 1% of Enterobacterales isolates were resistant to all commonly available classes of oral antibiotics. A greater risk of treatment failure was seen in patients over 60 years of age, patients with diabetes mellitus, men, and those treated with an antibiotic when prior culture identified an organism resistant to that class. The increasing resistance among members of Enterobacterales responsible for outpatient UTIs is limiting the effectiveness of empirical treatment with existing antibiotics, and consequently, outpatients with UTI are more likely to require additional courses of therapy or be hospitalized.IMPORTANCE Resistance rates for bacteria that cause urinary tract infections (UTIs) have increased dramatically. Regional rates of resistance to commonly prescribed antibiotics now exceed 20%, which is the threshold at which the Infectious Diseases Society of America recommends therapy be guided by culture. Our goals were to describe outcomes for outpatients with UTIs caused by bacteria resistant to empirically chosen antibiotics and to create a simple stratification schema for clinicians to identify UTI patients at increased risk of treatment failure due to antibiotic mismatch. These data are relevant to clinicians, given how common uncomplicated UTIs are, and highlight the need for clinicians to understand local resistance rates and the importance of culture-guided treatment, especially in vulnerable patients. These findings also showed that 1% of bacteria were resistant to all major classes of oral antibiotics, underscoring the need for new antibiotics to treat patients with UTIs due to resistant bacteria.

Experimental investigation of the creep behaviour of remoulded loess under different levels of compactness.

Generally, a loess high fill project will undergo a time-dependent deformation and settlement process for a long time after the initial fill. Understanding the creeping behaviour of compacted loess is an important part of determining the stability of a compacted loess foundation. To study the creep behaviour of remoulded loess under different levels of compactness, we performed triaxial shear and triaxial creep tests using Q2 loess specimens obtained from the new district of Yan’an city. Based on laboratory test results, the triaxial shear and creep characteristics of remoulded loess under different levels compactness are summarised. The regularity of instantaneous strain, creep strain, total accumulated strain and initial shear modulus were analysed and the relationship between the compactness and long-term strength of remoulded loess is provided. It was found that the remoulded loess becomes harder and its long-term strength increases with an increase in compactness. Furthermore, we propose a new creep model (HD), based on the hardening-damage mechanism, and have derived one-dimensional (1D) and three-dimensional (3D) creep equations based on this new creep model. This new creep model is flexible enough to fit the typical creep test curves of remoulded loess, while perfectly describing the tertiary creep stage. Finally, the sensitivity of the HD creep model parameters was analysed; the results indicate that the parameters denoted as α, γ, and β significantly affect the morphological changes and various stage characteristics are represented by the creep curve.

Wildfires and Monsoons: Cryptic Drivers for Highly Variable Provenance Signals within a Carboniferous Fluvial System

Sediment delivery and supply are explicitly controlled by variations in broad-scale processes such as climate, tectonics and eustasy. These in turn influence fluvial processes and hinterland evolution. A bespoke multi-proxy approach (integrating apatite and zircon U-Pb geochronology, trace elements in apatite, and Pb-in-K-feldspar provenance tools) coupled with outcrop investigation is used to constrain the temporal trends in sediment delivery to channel sandstones of the fluvio-estuarine mid-Viséan Mullaghmore Sandstone Formation, Ireland. Provenance data indicate unique detrital signatures for all sampled horizons, indicating the fluctuating nature of sediment supply to this medium-sized basin. Tectonism and/or abrupt relative sea-level fall likely caused fluvial rejuvenation, resulting in local basement sourcing of the initial fill. Older and more distal sources, such as the Nagssugtoqidian Belt of East Greenland, become more prominent in stratigraphically younger channel sandstones suggesting catchment expansion. Paleoproterozoic to Mesoproterozoic sources are most dominant, yet the detrital grain cargo varies in each channel sandstone. Proximal sources such as the Donegal Batholith and Dalradian Supergroup are variable and appear to switch on and off. These signal shifts are likely the result of channel migration and paleoclimatic fluctuation. A monsoonal climate and large-scale wildfire events (evidenced by fusain) likely contributed to modify plant cover, intensify erosion, and increase run-off and sediment delivery rates from specific areas of the hinterland.

Predicting Nipple–Areolar Complex Necrosis in Nipple-sparing Mastectomy with a Machine Learning Model

BACKGROUND & OBJECTIVES: Necrosis of the nipple-areolar complex (NAC) is the Achilles’ heel of Nipple Sparing Mastectomy (NSM).1 Our goal was to create a user-friendly, validated technology platform that surgeons could utilize preoperatively to predict which patients are at risk of NAC necrosis and aid in shared decision-making. This prediction would be based on patient characteristics and intraoperative variables. METHODS: We conducted a retrospective review of all NSM with immediate reconstruction performed at our institution between January 2015 and July 2019. Preoperative clinical characteristics, operative variables, and postoperative complications were collected and linked to NAC outcomes. These results were utilized to train a Random Forest machine learning model to predict necrosis when given preoperative patient characteristics, including age, BMI, smoking status, medical history, previous breast incisions, breast size, and planned implant or tissue expander (TE) size. Our model was subsequently validated by predicting NAC outcomes in a prospective cohort. The prospective cohort included all therapeutic and prophylactic NSM performed at our institution from May 2020 through October 2020. RESULTS: 305 breasts in 181 patients were included in the retrospective dataset which served as the foundation for our machine learning model. Full-thickness skin necrosis including part or all of the NAC occurred in 46 cases (15.1%). The strongest predictors of NAC necrosis were implant weight (P < 0.001) and weight of the mastectomy specimen (P < 0.001). When controlling for implant volume in our model, fill weight maintained a strong association with NAC necrosis. Rates of NAC necrosis among TE reconstructions using air only were lower at equivalent volumes compared with TE using saline fill and direct to implant reconstructions. Other influential factors included diabetes (P = 0.005), smoking (P = 0.04), and hypertension (= 0.03). With a prospective cohort of 27 patients, our predictive machine learning model achieved 96% accuracy (P = 0.02) with high positive predictive value and specificity for NAC necrosis. The model correctly predicted 4 of 5 cases of NAC necrosis and all 22 cases without necrosis. CONCLUSIONS: Implant weight is an independent risk factor for NAC necrosis following NSM, indicating that lower implant volumes, or using air-only initial TE fill, may mitigate the risk of NAC necrosis. The findings of our predictive Random Forest machine learning model also provide a basis for utilizing artificial intelligence to predict cases with a high probability of NAC necrosis. We created an easy-to-use interface for our model, which allows a user to input patient characteristics and receive a prediction which includes a binary outcome: “NAC Necrosis” or “No NAC Necrosis” and the predicted probability of necrosis. The instrument also provides a description of each variable’s effect on the prediction. Such models may be developed using institutional data and utilized to inform patient decision-making prior to mastectomy. REFERENCE: 1. Wapnir I, Dua M, Kieryn A, et al. Intraoperative imaging of nipple perfusion patterns and ischemic complications in nipple-sparing mastectomies. Ann Surg Oncol. 2014;21(1):100–106.

Tissue Expansion after Non-Skin-Sparing Mastectomy: A Comparative Study of Expansion Courses of Prepectoral and Subpectoral Tissue Expander Placement with Acellular Dermal Matrix

Although skin- or nipple-sparing mastectomy has been popular in the treatment of breast cancer, the radical excision of breast tissue is unavoidable in certain circumstances. However, the ability of an acellular dermal matrix (ADM) to expand remains questionable, and this situation may further hinder tissue expansion. From October 2017 to January 2020, patients who underwent immediate breast reconstruction with tissue expander placement using ADM whose initial fill volume was less than 50 mL were retrospectively reviewed. The primary outcomes were the number of visits and number of days required to complete the expansion, and the secondary outcomes were the amount of postoperative expansions, expander fill ratio and expander volume. Between the prepectoral group (n = 26) and subpectoral group (n = 39), the mean number of days (81.46 days versus 88.64 days, p = 0.365) and mean number of visits (5.08 versus 5.69, p = 0.91) required to complete expansion exhibited no significant differences. Additionally, there were no significant differences in the mean amount of postoperative expansion (314.23 mL versus 315.38 mL, p = 0.950), the mean final volume (353.08 mL versus 339.62 mL, p = 0.481) or the mean final volume ratio (0.89 versus 0.86, p = 0.35) between the two groups. Therefore, we suggest that prepectoral tissue expander placement after conventional mastectomy can be a valid option.

On spherical shock wave focusing in air — A computational study

A detailed numerical study on the phenomenon of Shock Wave focusing in air is carried out. The focusing phenomenon is achieved with the help of a shock tube and a converging section attached to it. The planar shock generated inside the shock tube is converted to a spherical shock with the help of the converging section and is focused to a point. High-temperature effects like temperature-dependent Cp variation and chemical reactions corresponding to dissociated air are included in the simulation. The chemical reactions includes the dissociation, recombination and ionization of nine species of air including three ions (N2, O2, N, O, NO, Ar, NO+, O+, and Ar+) are monitored throughout the simulation. The effect of driven section filling conditions such as initial pressure and temperature on focusing parameters is studied. The variation in the initial fill temperature is found to affect the flow properties much more as compared to the change in initial fill pressure while maintaining the same shock strength. The effect of incident shock strength on shock wave focusing is also investigated. It is observed that as the strength of the shock increases, the conditions like temperature and pressure at the focusing point increase and thereby increasing the reaction rate of all the reactions.

The Impact of Opioid Safety Edits on Opioid Utilization.

Objective To evaluate the impact of opioid safety edits on opioid utilization. Design Retrospective review. Setting Senior Care Action Network (SCAN) Health Plan, a Medicare Advantage Prescription Drug Plan. Patients, Participants The opioid safety edits reviewed included edits for the following: initial opioid fill more than 7 days' supply (DS), cumulative opioid doses 90 or greater and 240 or greater morphine milligram equivalent (MME), concurrent opioid and benzodiazepine (COB) use. Members with prescription drug claims meeting these criteria pre- and postedit implementation and those with prescription drug claim rejections resulting from the edits were included in the review. Results 15,232 members experienced claim rejections resulting from the edits. Comparison of utilization pre and postedit implementation revealed the following results (P < 0.001): 41% decrease in the proportion of members with an initial opioid fill for more than 7 DS; 18% decrease in the proportion of members on opioid doses 90 MME or more; 26% decrease in the proportion of members on opioid doses 240 MME or more; 18% decrease in the proportion of members with COB. Conclusion Opioid safety edits are an effective way to combat overuse and misuse. They serve as a means for increasing collaboration between plans, prescribers, pharmacists, and members which improves care coordination, reduces adverse risks, and helps keep members safe.

Performance of low-cost stainless-steel beverage kegs for long-term storage integrity and easy dispensing of water isotope (δ18 O, δ2 H) reference materials.

A widespread problem observed in global water isotope (δ18 O, δ2 H) proficiency tests is compromised working reference materials due to storage-dispensing evaporation effects. Proper storage requires no evaporation or leakage, which causes isotopic drift and bias. Surveys by the International Atomic Energy Agency (IAEA) show most isotope laboratories use glass or plastic bottles to store working reference materials, with frequent opening and closings that pose evaporation risks. Practical small (ca. 2-5 L) storage-dispensing solutions free of air exposure, evaporation, and leakage are needed. We also tested several smaller-scale bottles for day-to-day aliquots. We tested low-cost, conveniently sized (4 L) adaptations of a common stainless-steel beverage keg with a liquid dispenser, with minor modifications to facilitate low-flow dispensing and pressurization (1-2bar) with Ar or N2 . We tested three kegs (100%, 75%, 50% initial fills) for a 2-year period along with monthly dispensing to assess long-term storage viability for maintaining δ18 O and δ2 H integrity and dispensing, and day-to-day aliquot bottles for 6months. Test results showed these small keg storage systems fully maintained the isotopic integrity of water over the 2-year testing period with no trend in the isotopic data that would reveal evaporative loss or leakage (e.g., pressure or mass loss) regardless of starting fill level. However, evaporated water in the outlet tube assembly must be eliminated by discarding 15-20 mL before dispensing into appropriate daily-use laboratory standard bottles (30-100 mL). Glass bottles for daily aliquots showed good integrity properties, but only if their fill level was >50%. The use of a low-cost pressurized metal beverage keg dispensing system provides a robust solution to enable laboratories to maintain the integrity of their water isotope working reference materials over several years.

Control of substrate strain transfer to thin film photovoltaics via interface design

Brittle thin film photovoltaics (PV) that are integrated with load-bearing structures can be subjected to large strains that lead to fragmentation and performance degradation. Such adverse effects can be mitigated, or altogether eliminated, by mechanically isolating a thin PV module from the underlying load-bearing structure. We developed an effective and efficient strain attenuation strategy to eliminate strain transfer from a stiff unidirectional Carbon Fiber Reinforced Polymer (CFRP) laminate to an integrated thin amorphous Si PV module. An analytical model of the three-layer material system (CFRP laminate, interface layer and PV module) was employed to create strain attenuation maps that depend on the length of the PV module and capture the coupled effects of the shear modulus and the thickness of the interface layer (G2, t2), and the Young’s modulus and the thickness of the PV module (E3, t3) through the terms G2/t2 and E3t3, respectively. Based on these strain attenuation maps, polydimethylsiloxane (PDMS) was identified as an effective and versatile interface material, which provided up to 100% strain attenuation between the CFRP laminate and the PV module. After accounting for confinement effects on the effective modulus of the PDMS interface layer, a very good agreement was achieved between the measured and the predicted strain attenuation. Importantly, the PDMS interfacial layer preserved the initial fill factor of the PV module until CFRP laminate failure at 1.7% strain, while in the absence of the PDMS interface the fill factor decreased when the CFRP laminate strain exceeded 0.80%.