Renormalized One-loop Theory of Correlations in Disordered Diblock Copolymers

A renormalized one-loop theory (ROL) is used to calculate corrections to the random phase approximation (RPA) for the structure factor \Sc(q) in disordered diblock copolymer melts. Predictions are given for the peak intensity $S(q^{\star})$, peak position $q^{\star}$, and single-chain statistics for symmetric and asymmetric copolymers as functions of $\chi N$, where $\chi$ is the Flory-Huggins interaction parameter and $N$ is the degree of polymerization. The ROL and Fredrickson-Helfand (FH) theories are found to yield asymptotically equivalent results for the dependence of the peak intensity $S(q^{\star})$ upon $\chi N$ for symmetric diblock copolymers in the limit of strong scattering, or large $\chi N$, but yield qualitatively different predictions for symmetric copolymers far from the ODT and for asymmetric copolymers. The ROL theory predicts a suppression of $S(q^\star)$ and a decrease of $q^{\star}$ for large values of $\chi N$, relative to the RPA predictions, but an enhancement of $S(q^{\star})$ and an increase in $q^{\star}$ for small $\chi N$ ($\chi N < 5$). By separating intra- and inter-molecular contributions to $S^{-1}(q)$, we show that the decrease in $q^{\star}$ near the ODT is caused by the $q$ dependence of the intermolecular direct correlation function, and is unrelated to any change in single-chain statistics, but that the increase in $q^{\star}$ at small values of $\chi N$ is a result of non-Gaussian single-chain statistics.Comment: 16 pages, 13 figures, submitted to J. Chem. Phy

On data collection time by an electronic nose

We use electronic nose data of odor measurements to build machine learning classification models. The presented analysis focused on determining the optimal time of measurement, leading to the best model performance. We observe that the most valuable information for classification is available in data collected at the beginning of adsorption and the beginning of the desorption phase of measurement. We demonstrated that the usage of complex features extracted from the sensors’ response gives better classification performance than use as features only raw values of sensors’ response, normalized by baseline. We use a group shuffling cross-validation approach for determining the reported models’ average accuracy and standard deviation

Renormalization of the one-loop theory of fluctuations in polymer blends and diblock copolymer melts

Attempts to use coarse-grained molecular theories to calculate corrections to the random-phase approximation (RPA) for correlations in polymer mixtures have been plagued by an unwanted sensitivity to the value of an arbitrary cutoff length, {\it i.e.}, by an ultraviolet (UV) divergence. We analyze the UV divergence of the inverse structure factor $S^{-1}(k)$ predicted by a `one-loop' approximation similar to that used in several previous studies. We consider both miscible homopolymer blends and disordered diblock copolymer melts. We show, in both cases, that all UV divergent contributions can be absorbed into a renormalization of the values of the phenomenological parameters of a generalized self-consistent field theory (SCFT). This observation allows the construction of a UV convergent theory of corrections to SCFT phenomenology. The UV-divergent one-loop contribution to $S^{-1}(k)$ are shown to be the sum of: (i) a $k$-independent contribution that arises from a renormalization of the effective $\chi$ parameter, (ii) a $k$-dependent contribution that arises from a renormalization of monomer statistical segment lengths, (iii) a contribution proportional to $k^{2}$ that arises from a square-gradient contribution to the one-loop fluctuation free energy, and (iv) a $k$-dependent contribution that is inversely proportional to the degree of polymerization, which arises from local perturbations in fluid structure near chain ends and near junctions between blocks in block copolymers.Comment: 35 pages, 2 figure

Wpływ oligomerów procyanidolowych na aktywność antykoagulacyjną osocza

Background. Procyanidolic oligomers (PO) inhibit the degradation of subendothelial connective tissue by collagenase and elastase neutralization. Their efficacy in postphlebitic syndrome and venous insufficiency may suggest an additional systemic action mediated by endothelium. Therefore, the plasma anticoagulant response and the tissue plasma pathway inhibitor (TFPI) release induced by PO was assessed. Material and methods. Twenty-six patients, both surgical and medical, aged 29&#8211;86 years, who required antithrombotic prophylaxis for at least 5 days, were included in the study. The patients with higher thrombotic risk received either unfractionated heparin (UFH; 5000 IU bid, s.c., n = 8) or low molecular weight heparin (LMWH; 2850 IU AXa/0.3 mL o.d, s.c., n = 8). The patients with lower thrombotic risk received PO (150 mg bid, p.o., n = 10). In the control group there were age- and sex-matched healthy volunteers, to whom a placebo was administered. Blood samples were drawn before, on the 1, 4, 8 h, as well as on the days 2, 5 after administration of the study medication. Results. The TFPI concentration did not change significantly from the baseline value at any time, either in patients or in controls. Anti-Xa activity increased at 1 h until day 5 after administration of each study medication. Anti-IIa activity increased at 1 hour and remained elevated until day 5 under UFH and LMWH treatment, but only until day 2 in the PO group. The area under the curve of both anti-Xa and anti-IIa activity was similar in all three study groups but significantly larger as compared to the controls. Conclusions. Procyanidolic oligomers, like heparin and LMWH, induce anticoagulant response in plasma, but do not release TFPI into the blood.Wstęp. Oligomery procyanidolowe (PO) hamują degradację podśródbłonkowej tkanki łącznej poprzez neutralizację kolagenazy i elastazy. Skuteczność PO w zespole pozakrzepowym i niewydolności żylnej może sugerować ich dodatkowe działanie układowe, w którym pośredniczy śródbłonek. Było to przesłanką do oceny odpowiedzi antykoagulacyjnej osocza wywoływanej przez PO i uwalniania inhibitora drogi zewnątrzpochodnej (TFPI). Materiał i metody. Do badania włączono 26 chorych z oddziałów chirurgicznego i internistycznego w wieku 29&#8211;86 lat, u których konieczne było zastosowanie profilaktycznej terapii przeciwzakrzepowej przez co najmniej 5 dni. Chorzy z dużym ryzykiem zakrzepowym otrzymywali albo heparynę niefrakcjonowaną (UFH; 5000 jm. dwa razy dziennie podskórnie, n = 8), albo heparynę drobnocząsteczkową (LMWH; 2850 jm. AXa/0,3 ml raz dziennie podskórnie, n = 8). Pacjenci, u których ryzyko zakrzepowe było małe, otrzymywali PO (150 mg dwa razy dziennie doustnie, n = 10). Grupę kontrolną stanowili zdrowi ochotnicy zaklasyfikowani według wieku i płci, otrzymujący placebo. Krew do badań pobierano przed podaniem leku oraz w 1., 4. i 8. godzinie oraz w 2. i 5. dniu od podania leku. Wyniki. Stężenie TFPI nie zmieniało się w porównaniu z wartością wyjściową zarówno w grupach badanych, jak i kontrolnej. Aktywność anty-Xa zwiększała się od 1. godziny do 5. dnia po podaniu każdego leku. Aktywność anty-IIa była zwiększona od 1. godziny do 5. dnia po podaniu UFH i LMWH, ale tylko do 2. dnia po PO. Całkowita aktywność anty-Xa i anty-IIa, oceniana jako wielkość pola pod krzywą w badanym czasie, była podobna we wszystkich grupach badanych, ale znacząco wyższa w porównaniu z grupą kontrolną. Wnioski. Oligomery procyanidolowe, podobnie jak heparyna niefrakcjonowana i drobnocząsteczkowa, wywołują odpowiedź antykoagulacyjną w osoczu, ale nie powodują uwalniania TFPI do krwi

Life Cycle Assessment of Hydrogen Production from Coal Gasification as an Alternative Transport Fuel

The gasification of Polish coal to produce hydrogen could help to make the country independent of oil and gas imports and assist in the rational energy transition from gray to green hydrogen. When taking strategic economic or legislative decisions, one should be guided not only by the level of CO2 emissions from the production process, but also by other environmental impact factors obtained from comprehensive environmental analyses. This paper presents an analysis of the life cycle of hydrogen by coal gasification and its application in a vehicle powered by FCEV cells. All the main stages of hydrogen fuel production by Shell technology, as well as hydrogen compression and transport to the distribution point, are included in the analyses. In total, two fuel production scenarios were considered: with and without sequestration of the carbon dioxide captured in the process. Life cycle analysis was performed according to the procedures and assumptions proposed in the FC-Hy Guide, Guidance Document for performing LCAs on Fuel Cells and H₂ Technologies by the CML baseline method. By applying the CO2 sequestration operation, the GHG emissions rate for the assumed functional unit can be reduced by approximately 44% from 34.8 kg CO2-eq to 19.5 kg CO2-eq, but this involves a concomitant increase in the acidification rate from 3.64·10−2 kg SO2-eq to 3.78·10−2 kg SO2-eq, in the eutrophication index from 5.18·10−2 kg PO3−4-eq to 5.57·10−2 kg PO3−4-eq and in the abiotic depletion index from 405 MJ to 414 MJ and from 1.54·10−5 kg Sbeq to 1.61·10−5 kg Sbeq

Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

The analysis of Carbon Footprint (CF) for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF) were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ). The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA)

Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

The analysis of Carbon Footprint (CF) for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF) were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ). The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA)

COVID-19 in Memes: The Adaptive Response of Societies to the Pandemic?

COVID-19 expanded rapidly throughout the world, with enormous health, social, and economic consequences. Mental health is the most affected by extreme negative emotions and stress, but it has been an underestimated part of human life during the pandemic. We hypothesized that people may have responded to the pandemic spontaneously with increased interest in and creation of funny internet memes. Using Google and Google Trends, we revealed that the number of and interest in funny internet memes related to COVID-19 exploded during the spring 2020 lockdown. The interest in coronavirus memes was positively correlated with interest in mortality due to COVID-19 on a global scale, and positively associated with the real number of deaths and cases reported in different countries. We compared content of a random sample of 200 coronavirus memes with a random sample of 200 non-coronavirus memes found on the Internet. The sentiment analysis showed that coronavirus memes had a similar proportion of positive and negative words compared to non-coronavirus memes. However, an internet questionnaire revealed that coronavirus memes gained higher funniness scores than a random sample of non-coronavirus memes. Our results confirm that societies may have turned to humor to cope with the threat of SARS-CoV-2

The macroecology of the COVID-19 pandemic in the Anthropocene

Severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19), has expanded rapidly throughout the world. Thus, it is important to understand how global factors linked with the functioning of the Anthropocene are responsible for the COVID-19 outbreak. We tested hypotheses that the number of COVID-19 cases, number of deaths and growth rate of recorded infections: (1) are positively associated with population density as well as (2) proportion of the human population living in urban areas as a proxies of interpersonal contact rate, (3) age of the population in a given country as an indication of that population’s susceptibility to COVID-19; (4) net migration rate and (5) number of tourists as proxies of infection pressure, and negatively associated with (5) gross domestic product which is a proxy of health care quality. Data at the country level were compiled from publicly available databases and analysed with gradient boosting regression trees after controlling for confounding factors (e.g. geographic location). We found a positive association between the number of COVID-19 cases in a given country and gross domestic product, number of tourists, and geographic longitude. The number of deaths was positively associated with gross domestic product, number of tourists in a country, and geographic longitude. The effects of gross domestic product and number of tourists were non-linear, with clear thresholds above which the number of COVID-19 cases and deaths increased rapidly. The growth rate of COVID-19 cases was positively linked to the number of tourists and gross domestic product. The growth rate of COVID-19 cases was negatively associated with the mean age of the population and geographic longitude. Growth was slower in less urbanised countries. This study demonstrates that the characteristics of the human population and high mobility, but not population density, may help explain the global spread of the virus. In addition, geography, possibly via climate, may play a role in the pandemic. The unexpected positive and strong association between gross domestic product and number of cases, deaths, and growth rate suggests that COVID-19 may be a new civilisation disease affecting rich economies

The structure of multimorbidity in older age in residents of long-term care institutions

On the basis of a cross-sectional study among residents of two long-term care centers in the Lubuskie Voivodeship (i.e., Dom Pomocy Społecznej (DPS) - a residential home in Zielona Góra and Zakład Opiekuńczo-Leczniczy - a psychiatric care and treatment institution in Ciborz), the authors determined multimorbidity and polypragmasy in people over 60. The study material consisted of the medical data of persons who had been residents of the two institutions till 2013. The differences between DOS and ZOL in the number of diseases and drugs taken were established by using the Pearson's Chi-squared test and t-test. The most common disorders were: hypertension, circulatory collapse, atherosclerosis, dementing diseases, lesions of joints and bones, COPD, type II diabetes, gastrointestinal lesions, permanent atrial fibrillation, and cancer lesions. Statistically significant differences were revealed between the residents of DPS and ZOL in: the number of diagnosed diseases, taken medications, people with hypertension, circulatory collapse occurrences, dementing diseases, bone diseases, joint diseases, permanent atrial fibrillations, cancers, post-stroke conditions, and people with COPD.Na podstawie badań przekrojowych pensjonariuszy z dwóch różnych ośrodków opieki długoterminowej w województwie lubuskim (Dom Pomocy Społecznej w Zielonej Gó¬rze i Zakład Opiekuńczo-Leczniczym o profilu psychiatrycznym w Ciborzu) określono wielochorobowość i polipragmazje u osób po 60. roku życia. Materiał do badań stanowiły dane dotyczące historii chorób pochodzące od 207 osób przebywających do 2013 roku w dwóch ośrodkach opieki długoterminowej. Różnice w liczbie poszczególnych schorzeń i liczbie przyjmowanych leków pomiędzy dwoma instytucjami opieki długoterminowej oceniano za pomocą testu chi-kwadrat Persona i testu t. Najczęściej występowały następujące schorzenia: nadciśnienie tętnicze, niewydolność krążenia, miażdżyca, choroby otępienne zmiany chorobowe w obrębie stawów i kości, POChP, cukrzyca typu II, zmiany w przewodzie pokarmowym, utrwalone migotanie przedsionków i zmiany nowotworowe. Pomiędzy pensjonariuszami DPS-u i ZOL-u wykazano następujące istotne statystycznie różnice: w liczbie zdiagnozowanych przez lekarza chorób, liczbie przyjmowanych leków, częstości osób z nadciśnieniem tętniczym, częstości występowania niewydolności krążenia, liczbie chorób otępiennych, chorób w obrębie stawów i kości, utrwalonych migotań przedsionków, większej częstości chorób nowotwo¬rowych, większej ilości stanów po udarach mózgu oraz osób z POChP