Oscillation of Gas Density in the Gas Filament Remained by a Streamer Discharge in Water

When a streamer discharge occurs in water, several luminous plasma filaments will be created in the water during the discharge. After the discharge, these plasma filaments turn into neutral gas phase and remain in water. The gas filament remained in water is a good object for studying the basic processes involved in the streamer propagation. We investigated the evolution of the gas filaments remained in water after a streamer discharge at different experimental conditions. We recorded eight successive images during one discharge pulse. The density of gas in the gas filament and the radius of the gas filament were measured from the obtained images. We found that the radius of the gas filament and the density of gas in the gas filament are almost not influenced by the impulse voltage within the range studied. While the conductivity of water has strong effect on the radius of the gas filament and the density of gas in the gas filament. The radius of the gas filament becomes thicker and expands faster as the conductivity of water becomes larger. The density of gas in the gas filament remained in water oscillates between 400 to 800 kg/m3 with an duration of ~10 μs during the expansion period of 4–39 μs after the HV pulse starts. Both the impulse voltage and the conductivity of water do not affect the oscillation duration of the density of gas in the gas filament.

Impact of Medicaid expansion on pancreatic cancer care: A difference-in-difference analysis.

e18567 Background: The Affordable Care Act (ACA) increased insurance coverage for low-income individuals, which should potentially lead to better access to care and improved oncological outcomes. This study seeks to evaluate the impact of Medicaid expansion (ME) on care for pancreatic ductal adenocarcinoma (PDAC). Methods: Patients who were uninsured or on Medicaid and diagnosed with PDAC between 2004 and 2017 were queried from the National Cancer Database (NCDB). Two different expansion cohorts were included: early expansion states and 2014 expansion states. For early expansion states, the time period of pre-expansion was 2004-2009 and post-expansion was 2010-2017. As for the 2014 expansion states, the pre-expansion period was from 2004-2013 and post-expansion period was from 2014-2017. Patients in non-expansion states formed the control group. A difference-in-difference (DID) analysis was used to assess the association of ME with stage of diagnosis, treatment and survival for each expansion cohort. Results: In both early and January 2014 expansion states, there was an increase in overall Medicaid coverage (Early: DID = 0.29, 2014: DID = 0.37; P < 0.001), in particular for non-Hispanic Black and Hispanic Black patients (Non-Hispanic Black: Early: DID = 0.11, 2014: DID = 0.11; P < 0.001, Hispanic-Black: 2014: DID = 0.20; P = 0.003). There were no differences in early stage diagnosis (Early: DID = 0.02, 2014: DID = -0.02; P > 0.05). There was an increase in the number of patients receiving surgery (Early: DID = 0.05; P = 0.001, 2014: DID = 0.03; P = 0.029) but no difference in time to surgery among patients receiving surgery upfront (Early: DID = 1.75, 2014: DID = 0.38; P > 0.05). There was no difference in 30-day readmission post-surgery (Early: DID = 0.003; 2014: DID = -0.00007; P > 0.05) or 90-day mortality (Early: DID = -0.007, 2014: DID = -0.035; P > 0.05). Moreover, there was no difference in receipt of chemotherapy (Early: DID = 0.01, 2014: DID = 0.005; P > 0.05) or time to chemotherapy for patients receiving neoadjuvant chemotherapy (Early: Early: DID = 9.62, 2014: DID = 0.01; P > 0.05). Finally, there was no difference in receipt of palliative care among stage IV patients in both cohorts (Early: DID = -0.004, 2014: DID = 0.004; P > 0.05). Conclusions: This study suggests that after ME, PDAC patients were more likely to be insured and had increased access to surgical care. Future, studies should evaluate the implications of improved surgical access on clinical outcomes such as mortality.

Impact of Medicaid expansion on two-year mortality among stage IV breast cancer (BC) patients according to race.

6525 Background: Inadequate access to healthcare services is associated with worse outcomes. Disparities in access to cancer care are more frequently seen among racial/ethnic minorities, uninsured patients, and those with low socioeconomic status. A provision in the Affordable Care Act called for expansion of Medicaid eligibility in order to cover more low-income Americans. In this study, we evaluate the impact of Medicaid expansion in 2-year mortality among metastatic BC patients according to race. Methods: Women (aged 40-64) diagnosed with metastatic BC (stage IV de novo) between 01/01/2010 and 12/31/2015 and residing in states that underwent Medicaid expansion in 01/2014 were identified in the National Cancer Database. For comparison purposes, 2010-2013 was considered the pre-expansion period and 2014-2015 the post-expansion period. We calculated 2-year mortality difference-in-difference (DID) estimates between White and non-White patients using multivariable linear regression models. Results are presented as adjusted differences (in % points) between groups in the pre- and post-expansion periods and as adjusted DID with 95%CI. Covariates included age, comorbidity, BC subtype, insurance type, transfer of care, distance to hospital, region, residence area, education, income quartile, facility type and facility volume. In addition, overall survival (OS) was evaluated in pre- and post-expansion periods via Kaplan-Meier method and Cox proportional hazards models; results are presented as 2-year OS estimates, hazard ratios (HRs), and 95% CIs. Results: Among 7,675 patients included, 4,942 were diagnosed in the pre- and 2,733 in the post-expansion period. We observed a reduction in 2-year mortality rates in both groups according to Medicaid expansion. Among Whites 2-year mortality decreased from 42.5% to 38.7% and among non-Whites from 45.4% to 36.4%, resulting in an adjusted DID of -5.2% (95%CI -9.8 to -0.6, p = 0.027). A greater reduction in 2-year mortality was observed among non-Whites in a sub-analysis of patients who resided in the poorest quartile (n = 1372), with an adjusted DID of -14.6% (95%CI -24.8 to -4.4, p = 0.005). In the multivariable Cox model, during the pre-expansion period there was an increased risk of death for non-Whites compared to Whites (HR 1.14, 95% CI 1.03 to 1.26, P = 0.04), however no differences were seen in the post-expansion period between the two groups (HR 0.93, 95% CI 0.80 to 1.07, P = 0.31). Conclusions: Medicaid expansion reduced racial disparities by decreasing the 2-year mortality of non-White patients with metastatic breast cancer and reducing the gap when compared to Whites. These results highlight the positive impact of policies aimed at improving equity and increasing access to health care.

SHR-1701, a bifunctional fusion protein targeting PD-L1 and TGF-β, for advanced NSCLC with EGFR mutations: Data from a multicenter phase 1 study.

9055 Background: Despite the development of targeted therapies for advanced NSCLC harboring EGFR mutations ( EGFR+), acquired resistance remains inevitable. Immune checkpoint inhibitor as monotherapy has limited efficacy. Blockade of the TGF-β pathway which plays a key role in immune suppression may enhance the tumor response to anti-PD-1/PD-L1 antibodies. Here, we assessed SHR-1701, a novel bifunctional fusion protein composed of a mAb against PD-L1 fused with the extracellular domain of TGF-β receptor II, in advanced NSCLC pts including one separate EGFR+ cohort. Methods: This phase 1 study includes a 3+3 dose-escalation and dose-expansion period of pretreated advanced NSCLC and multiple clinical expansion cohorts of different tumor types, genetic aberrations, or prior therapies. During the dose-escalation and dose-expansion period, pathologically confirmed pts received SHR-1701 at 3, 10, or 20 mg/kg Q3W or 20 mg/kg Q2W by intravenous infusion. The primary objectives were to determine the safety profile, maximum tolerated dose (MTD), and recommended phase 2 dose (RP2D) of SHR-1701. In the EGFR+ NSCLC clinical expansion cohort, histologically or cytologically confirmed advanced pts after at least 1L standard EGFR TKI received SHR-1701 at RP2D, and the primary endpoint was objective response rate (ORR). Treatment beyond progression was allowed. Results: During the dose-escalation and dose-expansion period, 30 pts were recruited: all stage IV; 83.3% had ≥2 metastasis sites; 76.7% had received ≥2L prior systemic therapy. One dose-limiting toxicity (immune-mediated pneumonitis) in the 20 mg/kg Q2W group was observed, and the MTD was not reached. Population pharmacokinetics and exposure‐response analysis of SHR-1701 based on this study and another phase 1 study for advanced solid tumors (NCT03710265) demonstrated 30 mg/kg Q3W as the RP2D. In the EGFR+ NSCLC cohort, 27 pts were enrolled: all stage IV; 77.8% had ≥2 metastasis sites; 70.4% had received ≥2L prior systemic therapy; 29.6% had 19-Del, 14.8% 19-Del and T790M, 7.4% 20-ins, 29.6% L858R, 18.5% L858R and T790M. With a median SHR-1701 exposure of 8.7 weeks (range, 3.0-24.0), 4 of the 24 pts who had at least one post-baseline radiographic assessment achieved objective responses, including 3 ongoing confirmed and 1 unconfirmed partial response. ORR was 16.7% (95% CI, 4.7%-37.4%), and disease control rate was 50.0% (95% CI, 29.1%-70.9%). Grade 3 treatment-related adverse events (TRAEs) occurred in 2 (7.4%) pts, including anemia, hypokalemia, and asthenia (1 [3.7%] for each). There were no grade 4 or 5 TRAEs. No pts discontinued treatment due to TRAEs. Conclusions: SHR-1701 monotherapy shows a manageable safety profile and encouraging antitumor activity in advanced EGFR+ NSCLC pts after failure of at least 1L standard EGFR TKI. Further investigation of SHR-1701 combination therapy for EGFR+ NSCLC is warranted. Clinical trial information: NCT03774979.

The modified early age strains development model for the case of two-way restraint conditions

This paper proposes a design model (2D MSDM) for assessment the early-age stress-strain parameters of two-axially restrained expansive concrete elements. The analytical model allows defining the restrained expansion strains and corresponding self-stresses in case of arbitrary restraint conditions in orthogonal directions by taking into consideration the elastic-plastic behavior of concrete during the expansion period. The results of solution according to the proposed model were compared with the experimental results of expansive concrete elements with orthogonal confinement carried out by authors and other researchers.

EMG Signal Feature Extraction, Normalization and Classification for Pain and Normal Muscles Using Genetic Algorithm and Support Vector Machine

Electromyography (EMG) is the process of measuring neuromuscular activities generated during the contraction and expansion period of muscles throughout the body. The potential is recorded by inserting needle or by placing electrodes on the surface of body. In this research, an automatic EMG signal classification system is developed using machine learning oriented Support Vector Machine (SVM). The collected data is selected using Genetic Algorithm (GA). The purpose of GA is to select those rows from the dataset, which contains potential or electrical activities recorded while the patient is in motion. Furthermore, the selected features are neutralized using critic method. To improve the row selection cosine similarity is being used to determine an average value hence also helps for data reduction. Based on the average similarity values, SVM is trained and used for classification during the testing phase. The experiment has been performed in MATLAB tool and the classification accuracy for normal and pain EMG signal of 91.3% and 92.4% respectively is achieved.

The medieval Mongolian roots of Y-chromosomal lineages from South Kazakhstan

Background The majority of the Kazakhs from South Kazakhstan belongs to the 12 clans of the Senior Zhuz. According to traditional genealogy, nine of these clans have a common ancestor and constitute the Uissun tribe. There are three main hypotheses of the clans’ origin, namely, origin from early Wusuns, from Niru’un Mongols, or from Darligin Mongols. We genotyped 490 samples of South Kazakhs by 35 Y-chromosomal SNPs (single nucleotide polymorphism) and 17 STRs (short tandem repeat). Additionally, 133 samples from citizen science projects were included into the study. Results We found that three Uissun clans have unique Y-chromosomal profiles, but the remaining six Uissun clans and one non-Uissun clan share a common paternal gene pool. They share a high frequency (> 40%) of the C2*-ST haplogroup (marked by the SNP F3796), which is associated with the early Niru’un Mongols. Phylogenetic analysis of this haplogroup carried out on 743 individuals from 25 populations of Eurasia has revealed a set of haplotype clusters, three of which contain the Uissun haplotypes. The demographic expansion of these clusters dates back to the 13-fourteenth century, coinciding with the time of the Uissun’s ancestor Maiky-biy known from historical sources. In addition, it coincides with the expansion period of the Mongol Empire in the Late Middle Ages. A comparison of the results with published aDNA (ancient deoxyribonucleic acid) data and modern Y haplogroups frequencies suggest an origin of Uissuns from Niru’un Mongols rather than from Wusuns or Darligin Mongols. Conclusions The Y-chromosomal variation in South Kazakh clans indicates their common origin in 13th–14th centuries AD, in agreement with the traditional genealogy. Though genetically there were at least three ancestral lineages instead of the traditional single ancestor. The majority of the Y-chromosomal lineages of South Kazakhstan was brought by the migration of the population related to the medieval Niru’un Mongols.

Infection surveillance and prevention strategies to detect and prevent postaccess breast tissue expander infections

No standardized surveillance criteria exist for surgical site infection after breast tissue expander (BTE) access. This report provides a framework for defining postaccess BTE infections and identifies contributing factors to infection during the expansion period. Implementing infection prevention guidelines for BTE access may reduce postaccess BTE infections.