scholarly journals Improvement of Component Flux Estimating Model for Pervaporation Processes

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 418
Author(s):  
Botond Szilagyi ◽  
Andras Jozsef Toth

Separating non-ideal mixtures by pervaporation (hence PV) is a competitive alternative to most traditional methods, such as distillation, which are based on the vapour–liquid equilibrium (VLE). It must be said, in many cases, accurate VLE data are already well known in the literature. They make the method of PV modelling a lot more complicated, and most of the viable models are (semi)empirical and focus on component flux (Ji) estimation. The pervaporation model of Mizsey and Valentinyi, which is based on Rautenbach’s works, is further improved in this work and tested rigorously by statistical means. Until now, this type of exponential modelling was only used for alcohol–water mixtures, but in this work, it was extended to an ethyl acetate–water binary mixture as well. Furthermore, a flowchart of modelling is presented for the first time in the case of an exponential pervaporation model. The results of laboratory-scale experiments were used as the basis of the study and least squares approximation was used to compare them to the different model’s estimations. According to our results, Valentinyi’s model (Model I) and the alternative model (Model III) appear to be the best methods for PV modelling, and there is no significant difference between the models, mainly in organophilic cases. In the case of the permeation component, Model I, which better follows the exponential function, is recommended. It is important to emphasize that our research confirms that the exponential type model seems to be universally feasible for most organic–water binary mixtures. Another novelty of the work is that after PDMS and PVA-based membranes, the accuracy of the semiempirical model for the description of water flux on a PEBA-based membrane was also proved, in the organophilic case.

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 814
Author(s):  
Münir Aktaş ◽  
Sezayi Özübek ◽  
Mehmet Can Uluçeşme

Anaplasma phagocytophilum causes tick-borne fever in small ruminants. Recently, novel Anaplasma variants related to A. phagocytophilum have been reported in ruminants from Tunisia, Italy, South Korea, Japan, and China. Based on 16S rRNA and groEL genes and sequencing, we screened the frequency of A. phagocytophilum and related variants in 433 apparently healthy small ruminants in Turkey. Anaplasma spp. overall infection rates were 27.9% (121/433 analyzed samples). The frequency of A. phagocytophilum and A. phagocytophilum-like 1 infections was 1.4% and 26.5%, respectively. No A. phagocytophilum-like 2 was detected in the tested animals. The prevalence of Anaplasma spp. was comparable in species, and no significant difference was detected between sheep and goats, whereas the prevalence significantly increased with tick infestation. Sequencing confirmed PCR-RFLP data and showed the presence of A. phagocytophilum and A. phagocytophilum-like-1 variant in the sampled animals. Phylogeny-based on 16S rRNA gene revealed the A. phagocytophilum-like 1 in a separate clade together with the previous isolates detected in small ruminants and ticks. In this work, A. phagocytophilum-like 1 has been detected for the first time in sheep and goats from Turkey. This finding revealed that the variant should be considered in the diagnosis of caprine and ovine anaplasmosis.


2019 ◽  
Vol 81 (1-2) ◽  
pp. 81-86
Author(s):  
Pierre Koskas ◽  
Mouna Romdhani ◽  
Olivier Drunat

As commonly happens in epidemiological research, none of the reported studies were totally free of methodological problems. Studies have considered the influence of social relationships on dementia, but the mechanisms underlying these associations are not perfectly understood. We look at the possible impact of selection bias. For their first memory consultation, patients may come alone or accompanied by a relative. Our objective is to better understand the impact of this factor by retrospective follow-up of geriatric memory outpatients over several years. All patients over 70 who were referred to Bretonneau Memory Clinic for the first time, between January 2006 and 2018, were included in the study. The patients who came alone formed group 1, the others, whatever type of relative accompanied them, formed group 2. We compared the Mini-Mental State Examination (MMSE) scores of patients; and for all patients who came twice for consultation with at least a 60-day interval, we compared their first MMSE with the MMSE performed at the second consultation. In total, 2,935 patients were included, aged 79.7 ± 8.4 years. Six hundred and twenty-five formed group 1 and 2,310 group 2. We found a significant difference in MMSE scores between the 2 groups of patients; and upon second consultation in group 2, but that difference was minor in group 1. Our finding of a possible confounding factor underlines the complexity of choosing comparison groups in order to minimize selection bias while maintaining clinical relevance.


2015 ◽  
Vol 26 (3) ◽  
pp. 415-425 ◽  
Author(s):  
Morten Schrøder ◽  
Kirsten A. Boisen ◽  
Jesper Reimers ◽  
Grete Teilmann ◽  
Jesper Brok

AbstractPurposeWe performed a systematic review and meta-analysis of observational studies assessing quality of life in adolescents and young adults born with CHD compared with age-matched controls.MethodsWe carried out a systematic search of the literature published in Medline, Embase, PsychINFO, and the Cochrane Library’s Database (1990–2013); two authors independently extracted data from the included studies. We used the Newcastle–Ottawa scale for quality assessment of studies. A random effects meta-analysis model was used. Heterogeneity was assessed using the I2-test.ResultsWe included 18 studies with 1786 patients. The studies were of acceptable-to-good quality. The meta-analysis of six studies on quality of life showed no significant difference – mean difference: −1.31; 95% confidence intervals: −6.51 to +3.89, I2=90.9% – between adolescents and young adults with CHD and controls. Similar results were found in 10 studies not eligible for the meta-analysis. In subdomains, it seems that patients had reduced physical quality of life; however, social functioning was comparable or better compared with controls.ConclusionFor the first time in a meta-analysis, we have shown that quality of life in adolescents and young adults with CHD is not reduced when compared with age-matched controls.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuai Meng ◽  
Yong Zhu ◽  
Kesen Liu ◽  
Ruofei Jia ◽  
Jing Nan ◽  
...  

Abstract Background Left ventricular negative remodelling after ST-segment elevation myocardial infarction (STEMI) is considered as the major cause for the poor prognosis. But the predisposing factors and potential mechanisms of left ventricular negative remodelling after STEMI remain not fully understood. The present research mainly assessed the association between the stress hyperglycaemia ratio (SHR) and left ventricular negative remodelling. Methods We recruited 127 first-time, anterior, and acute STEMI patients in the present study. All enrolled patients were divided into 2 subgroups equally according to the median value of SHR level (1.191). Echocardiography was conducted within 24 h after admission and 6 months post-STEMI to measure left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD). Changes in echocardiography parameters (δLVEF, δLVEDD, δLVESD) were calculated as LVEF, LVEDD, and LVESD at 6 months after infarction minus baseline LVEF, LVEDD and LVESD, respectively. Results In the present study, the mean SHR was 1.22 ± 0.25 and there was significant difference in SHR between the 2 subgroups (1.05 (0.95, 1.11) vs 1.39 (1.28, 1.50), p < 0.0001). The global LVEF at 6 months post-STEMI was significantly higher in the low SHR group than the high SHR group (59.37 ± 7.33 vs 54.03 ± 9.64, p  = 0.001). Additionally, the global LVEDD (49.84 ± 5.10 vs 51.81 ± 5.60, p  = 0.040) and LVESD (33.27 ± 5.03 vs 35.38 ± 6.05, p  = 0.035) at 6 months after STEMI were lower in the low SHR group. Most importantly, after adjusting through multivariable linear regression analysis, SHR remained associated with δLVEF (beta = −9.825, 95% CI −15.168 to −4.481, p  < 0.0001), δLVEDD (beta = 4.879, 95% CI 1.725 to 8.069, p  = 0.003), and δLVESD (beta = 5.079, 95% CI 1.421 to 8.738, p  = 0.007). Conclusions In the present research, we demonstrated for the first time that SHR is significantly correlated with left ventricular negative remodelling after STEMI.


2016 ◽  
Vol 8 (3) ◽  
pp. 11
Author(s):  
Fereshteh Heydari ◽  
Shohreh Farahani

<p>This study was conducted to compare with the executive function of ADHD versus normal male and female children. To obtain this objective, 30 ADHD children referring a private psychological center for the first time who had taken no medication for this disorder, and 30 normal children from one of the schools of District 14 in Tehran were selected randomly who were of the same age and gender of ADHD children. Wisconsin test was used as a measurement tool. Results showed that there is a significant difference between the average scores of the executive function of normal and ADHD children as well as average scores of the executive function of normal boys and ADHD children at the 0.01 level. In addition, there was a significant difference between the average scores of the executive function of normal girls and ADHD girls at the 0.05 level according to which null hypothesis is rejected. Therefore, ADHD children are of lower executive and cognitive function compared to normal children and have extensive cognitive deficits. Therefore, they require medications along with special training and rehabilitation.</p>


1990 ◽  
Vol 35 (4) ◽  
pp. 395-404 ◽  
Author(s):  
J. F. Morrison ◽  
J. C. Baker ◽  
H. C. Meredith ◽  
K. E. Newman ◽  
T. D. Walter ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1724
Author(s):  
Sylvia Kahwage Sarmento ◽  
Juliana da Silva Ribeiro de Andrade ◽  
Marize Pereira Miagostovich ◽  
Tulio Machado Fumian

Noroviruses are considered an important cause of acute gastroenteritis (AGE) across all age groups. Here, we investigated the incidence of norovirus, genotypes circulation, and norovirus shedding in AGE stool samples from outpatients in Brazil. During a two-year period, 1546 AGE stool samples from ten Brazilian states were analyzed by RT-qPCR to detect and quantify GI and GII noroviruses. Positive samples were genotyped by dual sequencing using the ORF1/2 junction region. Overall, we detected norovirus in 32.1% of samples, with a massive predominance of GII viruses (89.1%). We also observed a significant difference between the median viral load of norovirus GI (3.4×105 GC/g of stool) and GII (1.9×107 GC/g). The most affected age group was children aged between 6 and 24 m old, and norovirus infection was detected throughout the year without marked seasonality. Phylogenetic analysis of partial RdRp and VP1 regions identified six and 11 genotype combinations of GI and GII, respectively. GII.4 Sydney[P16] was by far the predominant genotype (47.6%), followed by GII.2[P16], GII.4 Sydney[P31], and GII.6[P7]. We detected, for the first time in Brazil, the intergenogroup recombinant genotype GIX.1[GII.P15]. Our study contributes to the knowledge of norovirus genotypes circulation at the national level, reinforcing the importance of molecular surveillance programs for future vaccine designs.


2021 ◽  
Vol 20 (1) ◽  
pp. 47-62
Author(s):  
Gildas G.B. Todinanahary ◽  
Nomeniarivelo Hasintantely ◽  
Igor Eeckhaut ◽  
Thierry Lavitra

The distribution of larvae and recruitment of scleractinians in the southwest region of Madagascar were evaluated for the first time between October 2013 and September 2014 at 3 sites. The presence of coral larvae (planulae) was monitored through weekly sampling using a plankton net and the recruitment rate evaluated by monthly sampling of the newly settled corals (<1 year stage) on recruitment tiles and by a monitoring of the recruitment of juveniles (1< Juveniles < 2 years) using the quadrat method. Planulae were present in the plankton for 9 months during the survey. The recorded mean annual density of planula varied from 0.43 ± 0.41 larvae m-3 to 3.23 ± 5.72 larvae m-3 depending on site, with a peak in larval density towards the end of November and the beginning of December. The variability in the occurrence of planula is very high and implied that the density observed in the year does not present a significant difference between the sites (pKW=0.33). The average density of total recruits was 620.13 ± 621.30 recruits m-2, 40.28 ± 50.97 recruits m-2 and 36.34 ± 33.82 recruits m-2, respectively at the sites of Nosy Tafara, Grande Vasque and Rose Garden. Seasonal distribution of coral recruitment was different between the sites. The mean annual density of newly settled recruits (< 1 month stage) was significantly higher at Nosy Tafara with 94.91±101.08 recruits m-2 compared to Grande Vasque and Rose Garden with 18.75±34.32 recruits m-2 and 11.57±18.47 recruits m-2 (pKW<0.001), respectively. The highest density of newly settled recruits was observed between October to December. Higher density of recruits was also observed in March at Nosy Tafara and in May at all three sites. Results of juvenile monitoring showed high rates (> 10 juveniles m-2) compared to other regions and the threshold, but it revealed high mortality among recruits. Coral recruitment in the southwest region of Madagascar was found to be high and could result in increased resilience of the coral reef assemblages.


2019 ◽  
Author(s):  
Noriko Nakayama ◽  
Tetsuya Tsuji ◽  
Makoto Aoyama ◽  
Takafumi Fujino ◽  
Meigen Liu

Abstract Purpose To examine the rates, causes, and impact on quality of life (QOL) of urinary storage symptoms after gynecologic cancer surgery. Methods A questionnaire survey, including Japanese-language versions of the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), Overactive Bladder Symptom Score (OABSS), and Incontinence Impact Questionnaire-7 (IIQ-7), was distributed to gynecologic cancer patients who underwent hysterectomy between 2008 and 2013. Results Of the 145 patients analyzed, 49 (33.8%) had urinary incontinence (UI) pre-surgery and 76 (52.4%) had UI post-surgery, including 34 (35.4%) first-time UI patients, with a significant difference between pre- and post-surgery. Of the 49 subjects with UI pre-surgery, 43 (87.7%) had stress incontinence, while of the 76 patients with UI post-surgery, 44 (57.1%) had stress incontinence, and 24 (31.2%) had mixed incontinence. Seven (4.8%) subjects had overactive bladder (OAB) pre-surgery, whereas 19 (13.1%) had OAB symptoms post-surgery (including 15 first-time OAB patients), with a significant difference between pre- and post-surgery. IIQ-7 scores were markedly higher for patients with mixed incontinence post-surgery than for those with stress incontinence, indicating a lower QOL. Logistic regression analysis identified the number of Cesarean sections and days of urinary bladder catheterization as risk factors for postoperative UI. Conclusions UI and OAB rates were higher after gynecologic cancer surgery than in the general female population. The mixed incontinence rate was markedly higher post-surgery; QOL was low for such patients due to the combination of urgency and stress incontinence. Multiple Cesarean sections and urinary bladder catheterization post-surgery were risk factors for post-surgical UI.


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