scholarly journals Shock induced aerobreakup of a droplet

2021 ◽  
Vol 929 ◽  
Author(s):  
Shubham Sharma ◽  
Awanish Pratap Singh ◽  
S. Srinivas Rao ◽  
Aloke Kumar ◽  
Saptarshi Basu

The multiscale dynamics of a shock–droplet interaction is crucial in understanding the atomisation of droplets due to external airflow. The interaction phenomena are classified into wave dynamics (stage I) and droplet breakup dynamics (stage II). Stage I involves the formation of different wave structures after an incident shock impacts the droplet surface. These waves momentarily change the droplet's ambient conditions, while in later times they are mainly influenced by shock-induced airflow. Stage II involves induced airflow interaction with the droplet that leads to its deformation and breakup. Primarily, two modes of droplet breakup, i.e. shear-induced entrainment and Rayleigh–Taylor piercing (RTP) (based on the modes of surface instabilities) were observed for the studied range of Weber numbers $(We\sim 30\text{--}15\,000)$ . A criterion for the transition between two breakup modes is obtained, which successfully explains the observation of RTP mode of droplet breakup at high Weber numbers $(We\sim 800)$ . For $We > 1000$ , the breakup dynamics is governed by the shear-induced surface waves. After formation, the Kelvin–Helmholtz waves travel on the droplet surface and merge to form a liquid sheet near the droplet equator. Henceforth, the liquid sheet undergoes breakup processes via nucleation of several holes. The breakup process is recurrent until the complete droplet disintegrates or external drag acting on the droplet is insufficient for further disintegration. At lower Weber numbers, the droplet undergoes complete deformation like a flattened disk, and a multibag mode of breakup based on RTP is observed.

2020 ◽  
Vol 15 ◽  
Author(s):  
Athira K ◽  
Vrinda C ◽  
Sunil Kumar P V ◽  
Gopakumar G

Background: Breast cancer is the most common cancer in women across the world, with high incidence and mortality rates. Being a heterogeneous disease, gene expression profiling based analysis plays a significant role in understanding breast cancer. Since expression patterns of patients belonging to the same stage of breast cancer vary considerably, an integrated stage-wise analysis involving multiple samples is expected to give more comprehensive results and understanding of breast cancer. Objective: The objective of this study is to detect functionally significant modules from gene co-expression network of cancerous tissues and to extract prognostic genes related to multiple stages of breast cancer. Methods: To achieve this, a multiplex framework is modelled to map the multiple stages of breast cancer, which is followed by a modularity optimization method to identify functional modules from it. These functional modules are found to enrich many Gene Ontology terms significantly that are associated with cancer. Result and Discussion: predictive biomarkers are identified based on differential expression analysis of multiple stages of breast cancer. Conclusion: Our analysis identified 13 stage-I specific genes, 12 stage-II specific genes, and 42 stage-III specific genes that are significantly regulated and could be promising targets of breast cancer therapy. That apart, we could identify 29, 18 and 26 lncRNAs specific to stage I, stage II and stage III respectively.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
P Milani ◽  
L Obici ◽  
R Mussinelli ◽  
M Basset ◽  
G Manfrinato ◽  
...  

Abstract Background Cardiac wild type transthyretin (ATTRwt) amyloidosis, formerly known as senile systemic amyloidosis, is an increasingly recognized, progressive, and fatal cardiomyopathy. Two biomarkers staging systems were proposed based on NT-proBNP (in both cases) and troponin or estimated glomerular filtration rate, that are able to predict survival in this population. The availability of novel effective treatments requires large studies to describe the natural history of the disease in different populations. Objective To describe the natural history of the disease in a large, prospective, national series. Methods Starting in 2007, we protocolized data collection in all the patients diagnosed at our center (n=400 up to 7/2019). Results The referrals to our center increased over time: 5 cases (1%) between 2007–2009, 33 (9%) in 2010–2012, 90 (22%) in 2013–2015 and 272 (68%) in 2016–2019. Median age was 76 years [interquartile range (IQR): 71–80 years] and 372 patients (93%) were males. One hundred and seventy-three (43%) had atrial fibrillation, 63 (15%) had a history of ischemic cardiomyopathy and 64 (15%) underwent pacemaker or ICD implantation. NYHA class was I in 58 subjects (16%), II in 225 (63%) and III in 74 (21%). Median NT-proBNP was 3064 ng/L (IQR: 1817–5579 ng/L), troponin I 0.096 ng/mL (IQR: 0.063–0.158 ng/mL), eGFR 62 mL/min (IQR: 50–78 mL/min). Median IVS was 17 mm (IQR: 15–19 mm), PW 16 mm (IQR: 14–18 mm) and EF 53% (IQR: 45–57%). One-hundred and forty-eight subjects (37%) had a concomitant monoclonal component in serum and/or urine and/or an abnormal free light chain ratio. In these patients, the diagnosis was confirmed by immunoelectron microscopy or mass spectrometry. In 252 (63%) the diagnosis was based on bone scintigraphy. DNA analysis for amyloidogenic mutations in transthyretin and apolipoprotein A-I genes was negative in all subjects. The median survival of the whole cohort was 59 months. The Mayo Clinic staging based on NT-proBNP (cutoff: 3000 ng/L) and troponin I (cutoff: 0.1 ng/mL) discriminated 3 different groups [stage I: 131 (35%), stage II: 123 (32%) and stage III: 127 (33%)] with different survival between stage I and II (median 86 vs. 81 months, P=0.04) and between stage II and III (median 81 vs. 62 months, P<0.001). The UK staging system (NT-proBNP 3000 ng/L and eGFR 45 mL/min), discriminated three groups [stage I: 170 (45%), stage II: 165 (43%) and stage III: 45 (12%)] with a significant difference in survival: between stage I and stage II (86 vs. 52 months, P<0.001) and between stage II and stage III (median survival 52 vs. 33 months, P=0.045). Conclusions This is one of the largest series of patients with cardiac ATTRwt reported so far. Referrals and diagnoses increased exponentially in recent years, One-third of patients has a concomitant monoclonal gammopathy and needed tissue typing. Both the current staging systems offered good discrimination of staging and were validated in our independent cohort. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 8 ◽  
pp. 2333794X2110104
Author(s):  
Débora de Fátima Camillo Ribeiro ◽  
Frieda Saicla Barros ◽  
Beatriz Luci Fernandes ◽  
Adriane Muller Nakato ◽  
Percy Nohama

Short binasal prongs can cause skin and mucosal damage in the nostrils of preterm infants. The objective of this study was to investigate the incidence and severity of nasal injuries in preterm infants during the use of short binasal prongs as non-invasive ventilation (NIV) interfaces. A prospective observational study was carried out in the public hospital in a Southern Brazil. The incidence and severity of internal and external nasal injuries were evaluated in 28 preterm infants who required NIV using short binasal prongs for more than 24 hours. In order to identify possible causes of those nasal injuries, the expertise researcher physiotherapist has been carried empirical observations, analyzed the collected data, and correlated them to the literature data. A cause and effect diagram was prepared to present the main causes of the nasal injury occurred in the preterm infants assessed. The incidence of external nasal injuries was 67.86%, and internal ones 71.43%. The external nasal injuries were classified as Stage I (68.42%) and Stage II (31.58%). All the internal injuries had Stage II. The cause and effect diagram was organized into 5 categories containing 17 secondary causes of nasal injuries. There was a high incidence of Stage II-internal nasal injury and Stage I-external nasal injury in preterm infants submitted to NIV using prongs. The injuries genesis can be related to intrinsic characteristics of materials, health care, neonatal conditions, professional competence, and equipment issues.


2021 ◽  
Vol 11 (11) ◽  
pp. 5281
Author(s):  
Marcin Spychała ◽  
Tadeusz Nawrot ◽  
Radosław Matz

The aim of the study was to verify two morphological forms (“angel hair” and “scraps”) of xylit as a trickling filter material. The study was carried out on two types of polluted media: septic tank effluent (STE) and seminatural greywater (GW). The basic wastewater quality indicators, namely, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), ammonium nitrogen (NNH4), and total phosphorus (Ptot) were used as the indicators of treatment efficiency. Filtering columns filled with the investigated material acted as conventional trickling filters at a hydraulic load of 376–472 cm3/d during the preliminary stage, 198–245 cm3/d during stage I, and 184–223 cm3/d during stage II. The removal efficiency of the two morphological forms of xylit did not differ significantly. The average efficiencies of treatment were as follows: for COD, over 70, 80, and 85% for preliminary stage, stage I and stage II, respectively; for BOD5, 77–79% (preliminary stage); for TSS, 42% and 70% during the preliminary stage, and 88, 91, and 65% during stage I; for NNH4, 97–99% for stage I and 36–49% for stage II; for Ptot, 51–54% for stage I and 52–56% for stage II. The study demonstrated that xylit was a material highly effective in wastewater quality indicators removal, even during the initial period of its use.


2020 ◽  
Vol 28 (1) ◽  
pp. 138-151
Author(s):  
Kelly A. Stahl ◽  
Elizabeth J. Olecki ◽  
Matthew E. Dixon ◽  
June S. Peng ◽  
Madeline B. Torres ◽  
...  

Gastric cancer is the third most common cause of cancer deaths worldwide. Despite evidence-based recommendation for treatment, the current treatment patterns for all stages of gastric cancer remain largely unexplored. This study investigates trends in the treatments and survival of gastric cancer. The National Cancer Database was used to identify gastric adenocarcinoma patients from 2004–2016. Chi-square tests were used to examine subgroup differences between disease stages: Stage I, II/III and IV. Multivariate analyses identified factors associated with the receipt of guideline concordant care. The Kaplan–Meier method was used to assess three-year overall survival. The final cohort included 108,150 patients: 23,584 Stage I, 40,216 Stage II/III, and 44,350 Stage IV. Stage specific guideline concordant care was received in only 73% of patients with Stage I disease and 51% of patients with Stage II/III disease. Patients who received guideline consistent care had significantly improved survival compared to those who did not. Overall, we found only moderate improvement in guideline adherence and three-year overall survival during the 13-year study time period. This study showed underutilization of stage specific guideline concordant care for stage I and II/III disease.


2019 ◽  
Vol 10 (2) ◽  
pp. 164-170 ◽  
Author(s):  
Valdano Manuel ◽  
Humberto Morais ◽  
Aida L. R. Turquetto ◽  
Gade Miguel ◽  
Leonardo A. Miana ◽  
...  

Introduction: Single ventricle physiology management is challenging, especially in low-income countries. Objective: To report the palliation outcomes of single ventricle patients in a developing African country. Methods: We retrospectively studied 83 consecutive patients subjected to single ventricle palliation in a single center between March 2011 and December 2017. Preoperative data, surgical factors, postoperative results, and survival outcomes were analyzed. The patients were divided by palliation stage: I (pulmonary artery banding [PAB] or Blalock–Taussig shunt [BTS]), II (Glenn procedure), or III (Fontan procedure). Results: Of the 83 patients who underwent palliation (stages I-III), 38 deaths were observed (31 after stage I, six after stage II, and one after stage III) for an overall mortality of 45.7%. The main causes of operative mortality were multiple organ dysfunction due to sepsis, shunt occlusion, and cardiogenic shock. Twenty-eight survivors were lost to follow-up (22 after stage I, six after stage II). Thirteen stage II survivors are still waiting for stage III. The mean follow-up was 366 ± 369 days. Five-year survival was 28.4 % for PAB and 30.1% for BTS, while that for stage II and III was 49.8% and 57.1%, respectively. Age (hazard ratio, 0.61; 95% confidence interval: 0.47-0.7; P = .000) and weight at surgery (hazard ratio, 0.45; 95% confidence interval: 0.31-0.64; P = .002) impacted survival. Conclusion: A high-mortality rate was observed in this initial experience, mainly in stage I patients. A large number of patients were lost to follow-up. A task force to improve outcomes is urgently required.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Chang-Ming Huang ◽  
Jian-Xian Lin ◽  
Chao-Hui Zheng ◽  
Ping Li ◽  
Jian-Wei Xie ◽  
...  

Objectives. To investigate the prognostic impact of the number of dissected lymph nodes (LNs) in gastric cancer after curative distal gastrectomy.Methods. The survival of 634 patients who underwent curative distal gastrectomy from 1995 to 2004 was retrieved. Long-term surgical outcomes and associations between the number of dissected LNs and the 5-year survival rate were investigated.Results. The number of dissected LNs was one of the most important prognostic indicators. Among patients with comparable T category, the larger the number of dissected LNs was, the better the survival would be (). The linear regression showed that a significant survival improvement based on increasing retrieved LNs for stage II, III and IV (). A cut-point analysis yields the greatest variance of survival rate difference at the levels of 15 LNs (stage I), 25 LNs (stage II) and 30 LNs (stage III).Conclusion. The number of dissected LNs is an independent prognostic factor for gastric cancer. To improve the long-term survival of patients with gastric cancer, removing at least 15 LNs for stage I, 25 LNs for stage II, and 30 LNs for stage III patients during curative distal gastrectomy is recommended.


2011 ◽  
Vol 38 (3) ◽  
pp. 221 ◽  
Author(s):  
Tom A. Porteus ◽  
Suzanne M. Richardson ◽  
Jonathan C. Reynolds

Context Sampling methods to estimate animal density require good survey design to ensure assumptions are met and sampling is representative of the survey area. Management decisions are often made based on these estimates. However, without knowledge of true population size it is not possible for wildlife biologists to evaluate how biased the estimates can be if survey design is compromised. Aims Our aims were to use distance sampling to estimate population size for domestic sheep free-ranging within large enclosed areas of hill country and, by comparing estimates against actual numbers, examine how bias and precision are impaired when survey design is compromised. Methods We used both line and point transect sampling to derive estimates of density for sheep on four farms in upland England. In Stage I we used limited effort and different transect types to compromise survey design. In Stage II we increased effort in an attempt to improve on the Stage I estimates. We also examined the influence of a walking observer on sheep behaviour to assess compliance with distance sampling assumptions and to improve the fit of models to the data. Key results Our results show that distance sampling can lead to biased and imprecise density estimates if survey design is poor, particularly when sampling high density and mobile species that respond to observer presence. In Stage I, walked line transects were least biased; point transects were most biased. Increased effort in Stage II reduced the bias in walked line transect estimates. For all estimates, the actual density was within the derived 95% confidence intervals, but some of these spanned a range of over 100 sheep per km2. Conclusions Using a population of known size, we showed that survey design is vitally important in achieving unbiased and precise density estimation using distance sampling. Adequate transect replication reduced the bias considerably within a compromised survey design. Implications Management decisions based on poorly designed surveys must be made with an appropriate understanding of estimate uncertainty. Failure to do this may lead to ineffective management.


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