bluuebunny/crossref_metadata_2025 huggingface dataset:
Fully-distributed Load Frequency Control Strategy in an Islanded Microgrid Considering Plug-In Electric Vehicles
Authors: Qi Xiao , Bai Yan , Luo Huanhuan , Zhang Yiqing , Zhou Guiping , Wei Zhonghua
Published: June 2018

With large-scale integration of electric vehicles, this paper investigates the load frequency control problem in an islanded microgrid with plug-in electric vehicles (PEVs), which can be regarded as mobile battery energy storages to provide a valuable contribution to frequency regulation. A novel fully-distributed control strategy is proposed to achieve fast frequency regulation of islanded microgrids and effective coordination control of distributed energy sources. Firstly, distributed control based on an improved linear active disturbance rejection algorithm is realized through a multi-agent system, and it greatly enhances the anti-disturbance capability of the microgrid. Then, in order to guarantee the effectiveness of PEVs in frequency regulation, PEVs are controlled following the controllable power rate (CPR) calculated from the consensus-based multi-agent system. Furthermore, the system control construction in this paper is well designed to avoid the negative effects caused by system communication time delay. Finally, numerical simulations under different disturbances are carried out to demonstrate the effectiveness of the proposed control strategy in comparison with other previous control strategies.
Strip Clear-Cutting Application and Logging Typologies for Renaturalization of Pine Afforestation—A Case Study
Authors: Picchio Rodolfo , Mercurio Roberto , Venanzi Rachele , Gratani Loretta , Giallonardo Tommaso , Lo Monaco Angela , Frattaroli Anna Rita
Published: June 2018

Renaturalization treatment in black pine afforestation is an important topic that should be considered. There is a need to favor the evolution of artificial pine forests toward natural forest systems. Overall, this study focused on pine forests, and suggests one typology of clear-cutting (dismantling cutting) on strips, which is associated with different extraction management techniques. Some ecological and environmental aspects associated with renaturalization treatments that have been applied by different mechanizations in black pine afforestation have been highlighted, as well as how renaturalization and the active ecological management of these stands could affect soil and vegetation. The main objectives of this research were to: (1) analyze the impact of silvicultural treatment and logging activities on forest soil, and (2) assess tree regeneration and floristic biodiversity in an ecological management system, in terms of both quantity and quality characteristics. These analyses were planned to obtain an overview of the environmental impact related to a multifunctional approach to the forest management of black pine afforestation. Essentially, the answers to the main research questions are: (1) less invasive extraction systems seem to use a cable yarder and forest winch; (2) a clear soil recovery trend with good capabilities is visible, in particular for the two extraction systems by cable; however, over a three-year period, only a partial but substantial recovery has been shown; (3) in general, silvicultural treatment showed qualitative and quantitative improvement in terms of tree regeneration; in particular, the extraction systems by forest winch and cable yarder showed better results; (4) silvicultural treatment seems not to have led to improvement at the level of the herbaceous and shrubby layers; however, clear differences are shown among the different harvesting systems. Significant recovery after use of the cable yarder was observed.
Litterfall Production Prior to and during Hurricanes Irma and Maria in Four Puerto Rican Forests
Authors: Liu Xianbin , Zeng Xiucheng , Zou Xiaoming , González Grizelle , Wang Chao , Yang Si
Published: June 2018

Hurricanes Irma and Maria struck Puerto Rico on the 6th and 20th of September 2017, respectively. These two powerful Cat 5 hurricanes severely defoliated forest canopy and deposited massive amounts of litterfall in the forests across the island. We established a 1-ha research plot in each of four forests (Guánica State Forest, Río Abajo State Forest, Guayama Research Area and Luquillo Experiment Forest) before September 2016, and had collected one full year data of litterfall production prior to the arrival of Hurricanes Irma and Maria. Hurricane-induced litterfall was collected within one week after Hurricane Irma, and within two weeks after Hurricane Maria. Each litterfall sample was sorted into leaves, wood (branches and barks), reproductive organs (flowers, fruits and seeds) and miscellaneous materials (mostly dead animal bodies or feces) after oven-drying to constant weight. Annual litterfall production prior to the arrival of Hurricanes Irma and Maria varied from 4.68 to 25.41 Mg/ha/year among the four forests, and annual litterfall consisted of 50–81% leaffall, 16–44% woodfall and 3–6% fallen reproductive organs. Hurricane Irma severely defoliated the Luquillo Experimental Forest, but had little effect on the other three forests, whereas Hurricane Maria defoliated all four forests. Total hurricane-induced litterfall from Hurricanes Irma and Maria amounted to 95–171% of the annual litterfall production, with leaffall and woodfall from hurricanes amounting to 63–88% and 122–763% of their corresponding annual leaffall and woodfall, respectively. Hurricane-induced litterfall consisted of 30–45% leaves and 55–70% wood. Our data showed that Hurricanes Irma and Maria deposited a pulse of litter deposition equivalent to or more than the total annual litterfall input with at least a doubled fraction of woody materials. This pulse of hurricane-induced debris and elevated proportion of woody component may trigger changes in biogeochemical processes and soil communities in these Puerto Rican forests.
Room for Rivers: Risk Reduction by Enhancing the Flood Conveyance Capacity of The Netherlands’ Large Rivers
Authors: Klijn Frans , Asselman Nathalie , Wagenaar Dennis
Published: June 2018

The Netherlands has just finished implementing the Room for the Rivers program along the Rhine and Meuse Rivers in response to increasing river discharges. Recently, making more room for the river is, however, being challenged for future application because the flood defenses are assessed to be too weak and will need reinforcement anyway. To be able to decide on the most desirable policy for the remainder of the century, we require knowledge of all benefits and costs of individual interventions and strategic alternatives for flood mitigation. In this paper, we quantify some benefits of making more room for the rivers. We recognize and quantify two risk-reducing effects and provide results of analyses for the Rhine and Meuse Rivers in The Netherlands. Making room for rivers was originally advocated because it (1) reduces the consequences of flooding, as well as (2) reduces the probability of failure of the embankments. We have now quantified these effects allowing translation into risk reduction proper. Moreover, larger floodplain surface area may influence the relationship between discharge and flood level, which implies that rivers with widened floodplains are less sensitive to uncertainties about future river discharges. This does not reduce risk proper, but makes the river system more robust, as we shall argue in the discussion where we present risk reduction and robustness as complementary perspectives for assessing strategic alternatives for flood risk management.
Differences in the Perception of Social Support Among Rural Area Seniors—A Cross-Sectional Survey of Polish Population
Authors: Chruściel Paweł , Kulik Teresa , Jakubowska Klaudia , Nalepa Dorota
Published: June 2018

Introduction and objective: Social support constitutes an important determinant of an elderly person’s health and of functioning in his or her living environment. It depends on available support networks and the type of help received. Measurement of social support should encompass both its structure and the functions it fulfills, which enables detailed assessment of the phenomenon. The aim of the study was to compare the perception of social support among rural area seniors provided with institutional care with those living in a home setting. Material and method: Using the diagnostic survey method and the technique of the distribution of a direct questionnaire, 364 respondents from rural areas were examined: those living in an institutional environment (n = 190) and those living in their home (natural) environment (n = 174). The respondents were selected on the basis of a combined sampling method: proportionate, stratified, and systematic. Variables were measured with the following questionnaires: Courage Social Network Index (CSNI) and Social Support Scale (SSS). Results: The living environment has been proved to differentiate average values of support both in the structural and functional dimensions in a statistically significant way (p < 0.001). An untypical phenomenon was higher average values pertaining to emotional bonds, frequency of direct contacts, and help received in the group of respondents living in an institutional environment. Conclusions: The living environment and demographic variables affect the perception of social support among elderly people. Full-time institutional care of a senior citizen leads to the deterioration of social support; therefore, keeping an elderly person in a home environment should be one of the primary goals of the senior policy.
Red-Light-Running Crashes’ Classification, Comparison, and Risk Analysis Based on General Estimates System (GES) Crash Database
Authors: Zhang Yuting , Yan Xuedong , Li Xiaomeng , Wu Jiawei , Dixit Vinayak V.
Published: June 2018

Red-light running (RLR) has been identified as one of the prominent contributing factors involved in signalized intersection crashes. In order to reduce RLR crashes, primarily, a better understanding of RLR behavior and crashes is needed. In this study, three RLR crash types were extracted from the general estimates system (GES), including go-straight (GS) RLR vehicle colliding with go-straight non-RLR vehicle, go-straight RLR vehicle colliding with left-turn (LT) non-RLR vehicle, and left-turn RLR vehicle colliding with go-straight non-RLR vehicle. Then, crash features within each crash type scenario were compared, and risk analyses of GS RLR and LT RLR were also conducted. The results indicated that for the GS RLR driver, the speed limit displayed the highest effects on the percentages of GS RLR collision scenarios. For the LT RLR driver, the number of lanes displayed the highest effects on the percentages of LT RLR collision scenarios. Additionally, the drivers who were older than 50 years, distracted, and had a limited view were more likely to be involved in LT RLR accidents. Furthermore, the speeding drivers were more likely to be involved in GS RLR accidents. These findings could give a comprehensive understanding of RLR crash features and propensities for each RLR crash type.
Inter-Individual Variability in Acute Toxicity of R-Pulegone and R-Menthofuran in Human Liver Slices and Their Influence on miRNA Expression Changes in Comparison to Acetaminophen
Authors: Zárybnický Tomáš , Matoušková Petra , Lancošová Bibiána , Šubrt Zdeněk , Skálová Lenka , Boušová Iva
Published: June 2018

Monoterpenes R-pulegone (PUL) and R-menthofuran (MF), abundant in the Lamiaceae family, are frequently used in herb and food products. Although their hepatotoxicity was shown in rodent species, information about their effects in human liver has been limited. The aim of our study was to test the effects of PUL, MF and acetaminophen (APAP, as a reference compound) on cell viability and microRNA (miRNA) expression in human precision-cut liver slices. Slices from five patients were used to follow up on the inter-individual variability. PUL was toxic in all liver samples (the half-maximal effective concentration was 4.0 µg/mg of tissue), while MF and surprisingly APAP only in two and three liver samples, respectively. PUL also changed miRNA expression more significantly than MF and APAP. The most pronounced effect was a marked decrease of miR-155-5p expression caused by PUL even in non-toxic concentrations in all five liver samples. Our results showed that PUL is much more toxic than MF and APAP in human liver and that miR-155-5p could be a good marker of PUL early hepatotoxicity. Marked inter-individual variabilities in all our results demonstrate the high probability of significant differences in the hepatotoxicity of tested compounds among people.
Studies of Microbiota Dynamics Reveals Association of “Candidatus Liberibacter Asiaticus” Infection with Citrus (Citrus sinensis) Decline in South of Iran
Authors: Passera Alessandro , Alizadeh Hamidreza , Azadvar Mehdi , Quaglino Fabio , Alizadeh Asma , Casati Paola , Bianco Piero A.
Published: June 2018

Citrus Decline Disease was recently reported to affect several citrus species in Iran when grafted on a local rootstock variety, Bakraee. Preliminary studies found “Candidatus Phytoplasma aurantifoliae” and “Candidatus Liberibacter asiaticus” as putative etiological agents, but were not ultimately able to determine which one, or if an association of both, were causing the disease. The current study has the aim of characterizing the microbiota of citrus plants that are either asymptomatic, showing early symptoms, or showing late symptoms through amplification of the V1–V3 region of 16S rRNA gene using an Illumina sequencer in order to (i) clarify the etiology of the disease, and (ii) describe the microbiota associated to different symptom stages. Our results suggest that liberibacter may be the main pathogen causing Citrus Decline Disease, but cannot rule out the possibility of phytoplasma being involved as well. The characterization of microbiota shows that the leaves show only two kinds of communities, either symptomatic or asymptomatic, while roots show clear distinction between early and late symptoms. These results could lead to the identification of bacteria that are related to successful plant defense response and, therefore, to immunity to the Citrus Decline Disease.
Integrity of the DNA and Cellular Ultrastructure of Cryptoendolithic Fungi in Space or Mars Conditions: A 1.5-Year Study at the International Space Station
Authors: Onofri Silvano , Selbmann Laura , Pacelli Claudia , De Vera Jean Pierre , Horneck Gerda , Hallsworth John E. , Zucconi Laura
Published: June 2018

The black fungi Cryomyces antarcticus and Cryomyces minteri are highly melanized and are resilient to cold, ultra-violet, ionizing radiation and other extreme conditions. These microorganisms were isolated from cryptoendolithic microbial communities in the McMurdo Dry Valleys (Antarctica) and studied in Low Earth Orbit (LEO), using the EXPOSE-E facility on the International Space Station (ISS). Previously, it was demonstrated that C. antarcticus and C. minteri survive the hostile conditions of space (vacuum, temperature fluctuations, and the full spectrum of extraterrestrial solar electromagnetic radiation), as well as Mars conditions that were simulated in space for a 1.5-year period. Here, we qualitatively and quantitatively characterize damage to DNA and cellular ultrastructure in desiccated cells of these two species, within the frame of the same experiment. The DNA and cells of C. antarcticus exhibited a higher resistance than those of C. minteri. This is presumably attributable to the thicker (melanized) cell wall of the former. Generally, DNA was readily detected (by PCR) regardless of exposure conditions or fungal species, but the C. minteri DNA had been more-extensively mutated. We discuss the implications for using DNA, when properly shielded, as a biosignature of recently extinct or extant life.
1-[5-(4-Ethoxyphenyl)-3-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one
Authors: Karanth Sangeetha , Narayana Badiadka , Avvadukkam Jayashree , Sarojini Balladka
Published: June 2018

The cyclization reaction of 3-(4-ethoxyphenyl)-1-(naphthalen-1-yl)prop-2-en-1-one (1) using hydrazine hydrate in acetic acid medium culminates, resulting in the title compound 1-[5-(4-ethoxyphenyl)-3-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one (2). The structure of the newly synthesized compound is determined by IR, 1H-NMR, 13C-NMR and mass spectral data. In order to evaluate the putative molecular interactions, the title compound (2) is docked against the active site of Cytochrome P450 14α-sterol demethylase (CYP51) from Mycobacterium tuberculosis.
Single Step Laser Transfer and Laser Curing of Ag NanoWires: A Digital Process for the Fabrication of Flexible and Transparent Microelectrodes
Authors: Zacharatos Filimon , Karvounis Panagiotis , Theodorakos Ioannis , Hatziapostolou Antonios , Zergioti Ioanna
Published: June 2018

Ag nanowire (NW) networks have exquisite optical and electrical properties which make them ideal candidate materials for flexible transparent conductive electrodes. Despite the compatibility of Ag NW networks with laser processing, few demonstrations of laser fabricated Ag NW based components currently exist. In this work, we report on a novel single step laser transferring and laser curing process of micrometer sized pixels of Ag NW networks on flexible substrates. This process relies on the selective laser heating of the Ag NWs induced by the laser pulse energy and the subsequent localized melting of the polymeric substrate. We demonstrate that a single laser pulse can induce both transfer and curing of the Ag NW network. The feasibility of the process is confirmed experimentally and validated by Finite Element Analysis simulations, which indicate that selective heating is carried out within a submicron-sized heat affected zone. The resulting structures can be utilized as fully functional flexible transparent electrodes with figures of merit even higher than 100. Low sheet resistance (<50 Ohm/sq) and high visible light transparency (>90%) make the reported process highly desirable for a variety of applications, including selective heating or annealing of nanocomposite materials and laser processing of nanostructured materials on a large variety of optically transparent substrates, such as Polydimethylsiloxane (PDMS).
Elucidating the Photocatalytic Behavior of TiO2-SnS2 Composites Based on Their Energy Band Structure
Authors: Kovacic Marin , Katic Jozefina , Kusic Hrvoje , Loncaric Bozic Ana , Metikos Hukovic Mirjana
Published: June 2018

TiO2-SnS2 composite semiconducting photocatalysts with different building component ratios were prepared by hydrothermal synthesis (TiO2-SnS2-HT) and by immobilization of commercial TiO2 and SnS2 particles (TiO2-SnS2-COMM). The band gap values, which determine the catalysts’ photoactivity, were examined by diffuse reflectance spectroscopy and Kubelka–Munk transformations. The catalysts’ surface properties: specific surface area, charge and adsorption capacitance at the solid–solution interface were characterized using BET analysis, potentiometric titration and electrochemical impedance spectroscopy, respectively. The electronic band structure of TiO2-SnS2 photocatalyst, as the key property for the solar-driven photocatalysis, was deduced from the thermodynamic data and the semiconducting parameters (type of semiconductivity, concentration of the charge carriers, flat band potential) obtained by Mott–Schottky analysis. The photoactivity of both composites was studied in photocatalytic treatment of diclofenac (DCF) under simulated solar irradiation and was compared to the benchmark photocatalyst (TiO2 P25) activity. The influence of process parameters, such as pH, H2O2, and composite formulation on the effectiveness of DCF removal and conversion was investigated and discussed by employing response surface modeling (RSM) approach. The photocatalytic efficiency of both composite materials was discussed on the basis of the hetereojunction formation that facilitated the photoelectron transfer, promoting more efficient photocatalytic degradation of DCF.
Study on the Preparation of Plasma-Modified Fly Ash Catalyst and Its De–NOX Mechanism
Authors: Zhang Lei , Wen Xin , Zhang Lei , Sha Xiangling , Wang Yusu , Chen Jihao , Luo Min , Li Yonghui
Published: June 2018

Fly ash and bentonite were mixed in a certain proportion as raw materials to prepare a denitration catalyst. In previous studies, it has been concluded that fly ash-type catalysts can provide significant catalytic activity for denitrification after being modified with oxygen. In this study, the effect of plasma conditions on the denitration performance of the catalyst was investigated from the aspects of plasma modification power, modification time, and the flow rate of the gas. Boehm titration and infrared analysis systems were used to characterize the performance of the catalyst. The experimental results show that the optimal modification power is 60 W, the optimal modification time is 20 min, and the optimal gas flow rate is 40 mL/min.
Effect of Methionine Oxidation and Substitution of α-Conotoxin TxID on α3β4 Nicotinic Acetylcholine Receptor
Authors: Ren Jie , Li Rui , Ning Jiong , Zhu Xiaopeng , Zhangsun Dongting , Wu Yong , Luo Sulan
Published: June 2018

α-Conotoxin TxID was discovered from Conus textile by gene cloning, which has 4/6 inter-cysteine loop spacing and selectively inhibits α3β4 nicotinic acetylcholine receptor (nAChR) subtype. However, TxID is susceptible to modification due to it containing a methionine (Met) residue that easily forms methionine sulfoxide (MetO) in oxidative environment. In this study, we investigated how Met-11 and its derivatives affect the activity of TxID using a combination of electrophysiological recordings and molecular modelling. The results showed most TxID analogues had substantially decreased activities on α3β4 nAChR with more than 10-fold potency loss and 5 of them demonstrated no inhibition on α3β4 nAChR. However, one mutant, [M11I]TxID, displayed potent inhibition at α3β4 nAChR with an IC50 of 69 nM, which only exhibited 3.8-fold less compared with TxID. Molecular dynamics simulations were performed to expound the decrease in the affinity for α3β4 nAChR. The results indicate replacement of Met with a hydrophobic moderate-sized Ile in TxID is an alternative strategy to reduce the impact of Met oxidation, which may help to redesign conotoxins containing methionine residue.
Survival rate of patients with ascending aorta aneurysm and aortic valve regurgitation in the late postoperative period
Authors: Čypienė Rasa , Grebelis Arimantas , Semėnienė Palmyra , Zakarkaitė Diana , Nogienė Giedrė , Uždavinys Giedrius , Sirvydis Vytautas
Published: June 2018

The aim of the study was to evaluate the long-term survival in patients undergoing surgical treatment for chronic aortic aneurysms with aortic regurgitation. Material and methods. We analyzed survival data of 188 patients during follow-up period of 1 month to 20 years postoperatively. The patients were divided into the following groups according to the clinical course: Group 1 – chronic dissecting aneurysm of ascending aorta with aortic regurgitation (42 patients, 22.3%); Group 2 – chronic nondissecting aneurysm of ascending aorta with aortic regurgitation (146 patients, 77.7%). Mean NYHA functional class of the patients was 3.5±0.06. In the Group 1, 64.3% of the patients were in NYHA functional class IV; 35.7% of the patients were in NYHA class III. In the Group 2, the majority of the patients (58.2%) were in class III; in class IV – 41.8%. The most common etiological factors in both groups were atherosclerosis, arterial hypertension, and Marfan’s syndrome. Results. No differences in overall and long-term survival rates between the groups were found. However, the patients who were in class III before the operation showed significantly higher overall and long-term survival rates in comparison with the survival rate of the patients who were in NYHA class IV preoperatively (overall survival rate, 91.4±3.0% vs 62.9±6.9%; and long-term survival rate, 93.2±2.7% vs 72.9±5.6; respectively). There were 24 deaths (12.8%) during the late postoperative period. The main causes of death were progressive heart failure and infective prosthetic endocarditis (Group 2), chronic heart failure and dysfunction of the conduit (Group 1). Conclusions. The analysis of patients’ long-term survival demonstrated the efficacy of surgical treatment of such a complex pathology as chronic aneurysm of the ascending aorta with aortic valve regurgitation. The survival rate in the late postoperative period was higher in NYHA class III patients. The main causes of death were chronic heart failure and infective prosthetic endocarditis.
Prevalence of the use of psychoactive substances among students during 2005–2006
Authors: Goštautas Antanas , Povilaitis Romualdas , Pilkauskienė Ina , Jakušovaitė Irayda , Statkevičienė Svetlana
Published: June 2018

The aim of this study was to determine the prevalence of addictive substance use among students during one-year period, to evaluate the present situation, and to substantiate the necessity of prevention. Material and methods. The participants of the study were students of the Lithuanian University of Agriculture: 1475 students were inquired in 2005 and 1575 in 2006. The study was performed by applying a questionnaire consisting of 26 standard questions for the evaluation of respondents’ health and health-related behavior. The obtained results showed the stability of addictive substance usage among students during oneyear period: on the average, 33.6% of males and 20.4% of females were daily smokers. No changes were found in the number of nonsmokers, but the number of students who quit smoking was increased. There were no changes in the pattern of ethanol use during one-year period: the highest percentage of male students used alcoholic beverages once or several times per week (38.5%) and several times per month (39.5%). The highest percentage of female students used ethanol several times per month (55.9%). Ethanol and tobacco consumption per day was high, and there were no changes during one year. The rates of drug use were 35.9% among male students, and 17.7% among female. The amount of psychoactive substances used by students (ethanol per one evening and tobacco per one day) did not change and remained dangerously high. Male students consumed 400 mL of vodka, 280 mL of other strong alcoholic beverages, and 2 liters of beer per one evening, while the mean consumption of wine decreased from 383 mL to 308 mL. The respective findings for female students were as follows: 200 mL of vodka, 150 mL of other strong alcoholic beverages, 300 mL of wine, and 750 mL of beer. Male students smoked 11 and females 7 cigarettes per day, on the average. Conclusions. It seems that the stability of addictive substance use among students demonstrates that high risk of chronic diseases is related to the balance between social supply of these substances, and prevention of their distribution and usage.
Professional biological risk factors of health care workers
Authors: Gailienė Greta , Cenenkienė Regina
Published: June 2018

Health care workers are attributed to the group at highest risk of biological factors, as they are daily exposed to fluids of the human body. The risk of sharps injuries and exposure to blood is associated with bloodborne infections. The aim of this study was to determine the frequency and type of professional biological risk factors, to evaluate the use of personal protective devices, application of immunoprophylaxis to health care workers in the surgical departments. Methods. A retrospective study was carried out from January to June 2006. Data were collected in the surgical departments of Hospital of Kaunas University of Medicine. An anonymous questionnaire survey was performed. Results. More than half (51.4%) of the respondents experienced sharps injuries, 62.1% were exposed to biological fluids, and 39.6% of the workers experienced both injury and exposure. In all cases, the hands were injured during sharps injuries. Exposure of healthy skin and eyes to biological fluids occurred in 63% and 20% of the cases, respectively. Majority of exposures were blood splashes (60%). Physicians most frequently experienced sharps injury during the surgery (79.3%), nurses – during the preparation of instruments (35.1%), supporting staff – disposing the waste (75.8%). Commonly physicians were injured by surgical needles (72.4%), nurses – by needlestick (72.4%), and supporting staff – by glass waste (60.6%). Majority of the respondents (86%) were not vaccinated with HB vaccine. No personal protective equipment was used by 14.5% of the respondents during sharps injuries and 5% during exposures. Conclusions. More than half of the respondents experienced sharps injury or exposure to biological fluids during the study period. Physicians and nurses experience sharps injury and exposure to biological fluids more commonly as compared to supporting staff. Hepatitis B vaccination is insufficient among health care workers.
Associations between physical activity of primary school first-graders during leisure time and family socioeconomic status
Authors: Dregval Liudmila , Petrauskienė Aušra
Published: June 2018

In 2008, an international survey on obesity among first-graders and its risk factors was performed in Lithuania. The objective of this study was to assess physical activity of first-graders during leisure time according to family socioeconomic status. The study was performed in Šiauliai region schools selected randomly in 2008. The anonymous questionnaires were distributed among 630 first-graders and filled out by 515 parents (response rate was 81.8%). It was showed that physical activity of first-graders during leisure time is insufficient. More than half of them (60.4%) did not attend sports or dancing clubs; children spent much time passively watching TV or playing on a computer. Mostly children watched TV for 2 hours on workdays (45.1%) and for 3 hours or more on weekends (41.4%). Mostly children spent about an hour per day playing on a computer: one-third of first-graders spent it on workdays; during weekends, the percentage of children spending about an hour per day playing on a computer was lower (28.5%). One-third of first-graders (36.9%) spent their leisure time outside for 3 or more hours on workdays and 87.1% on weekends independently of parents’ educational level, income, and place of residence. The associations between family socioeconomic status and physical activity of children were observed. The lowest percentage of children attending sports or dancing clubs and playing computer games was seen in low-income families and families where parents had low educational level. They spent more time outside (on workdays) compared with those children whose parents had university education and high income. Fewer first-graders from families living in villages than those living in cities attended sports or dancing clubs and played on a computer, but more of them spent leisure time outside.
Self-rated health among physicians
Authors: Baubinas Algirdas , Gurevičius Romualdas , Jankauskienė Konstancija , Sąlyga Jonas , Kairys Jonas , Jurkštienė Vilma , Kėvelaitis Egidijus
Published: June 2018

The aim of the study was to analyze self-rated health among physicians depending on their sex, age, workplace (hospital or polyclinic), and specialty. Material and methods. The studied group consisted of 377 26–70-year-old physicians randomly selected from various county hospitals and polyclinics of Lithuania. There were 85 men and 292 women. The inquiry was performed using the complemented (by the authors of the study) version of the WHO anonymous questionnaire of the quality of life (1995). Responses were evaluated based on physicians’ evaluation of their own health, which was rated as very good, good, satisfactory, poor, and very poor. Results. Only 8.2% of males and 5.8% of females evaluated their health as very good (P>0.05). More men, compared to women, evaluated their health as good (62.3% and 53.1%, respectively; P<0.05), whereas more females evaluated their health as satisfactory, compared to males (36.0% and 25.9%, respectively; P<0.05); 2.4% of males and 5.1% of females (p>0.05) stated that their health was poor. In most cases, physicians of different age groups presented equal evaluations of their health except for physicians in the age groups of 26–37 and 38–43 years – those who evaluated their health as very good comprised a significantly higher percentage (P<0.05), compared to other age groups. As expected, a higher percentage of older physicians evaluated their health as satisfactory. In addition to that, more hospital physicians, compared to those working in polyclinics, evaluated their health as good (12.8% and 1.8%, respectively; P<0.05) and vice versa – significantly more physicians working in polyclinics evaluated their health as satisfactory, compared to those working in hospitals (38.1% and 26.8%, respectively; P<0.05). A significantly higher percentage of surgeons, compared to general practitioners or therapists, evaluated their health as very good (15.8%, 4.5%, and 6.1%, respectively; P<0.05) and a significantly lower percentage – as satisfactory (P<0.05). Conclusions. Irrespectively of sex, 6.4% of the studied physicians evaluated their health as very good; 55.2%, as good; 33.7%, as satisfactory; 4.7%, as poor; and 0.3%, as very poor. A higher percentage of physicians who evaluated their health as very good or good were 26–37 and 38–43 years of age, whereas more physicians in older age groups evaluated their health as satisfactory. A higher percentage of physicians working in hospital evaluated their health as very good, whereas more physicians who worked in polyclinics evaluated their health as satisfactory. Compared to general practitioners and therapists, surgeons more frequently evaluated their health as very good and significantly less frequently – as satisfactory.
Application of Novel Anion-Exchange Blend Membranes (AEBMs) to Vanadium Redox Flow Batteries
Authors: Cho Hyeongrae , Krieg Henning M. , Kerres Jochen A.
Published: June 2018

Both cation-exchange membranes and anion-exchange membranes are used as ion conducting membranes in vanadium redox flow batteries (VRFBs). Anion-exchange membranes (AEMs) are applied in vanadium redox flow batteries due to the high blocking property of vanadium ions via the Donnan exclusion effect. In this study, novel anion-exchange blend membranes (AEBMs) were prepared, characterized, and applied in VRFBs. Bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide), poly[(1-(4,4′-diphenylether)-5-oxybenzimidazole)-benzimidazole] (PBI-OO) and sulfonated polyether sulfone polymer were combined to prepare 3-component AEBMs with 1,2,4,5-tetramethylimidazole (TMIm) for quaternization. 3-component AEBMs showed significantly enhanced chemical and mechanical properties compared with those of 2-component AEBMs, resulting in an improved performance in VRFBs. The compositions of the anion-exchange polymers in 3-component AEBMs were systematically varied to optimize the AEBMs for the redox-flow battery application. While the 3-component AEBMs showed comparable efficiencies with Nafion® 212 membranes, they displayed improved vanadium ions cross-over as was confirmed by open circuit voltage tests and capacity fade tests conducted in VRFBs. In addition, one of the synthesized 3-component AEBM had a superior coulombic efficiency and capacity retention in a charging–discharging test over 300 cycles at a current density of 40 mA/cm2. It can thus be concluded that 3-component AEBMs are promising candidates for long-term operation in VRFBs.
Understanding the Recovery of Rare-Earth Elements by Ammonium Salts
Authors: Hunter Jamie P. , Dolezalova Sara , Ngwenya Bryne T. , Morrison Carole A. , Love Jason B.
Published: June 2018

While the recovery of rare earth elements (REEs) from aqueous solution by ionic liquids (ILs) has been well documented, the metal compounds that are formed in the organic phase remain poorly characterized. Using spectroscopic, analytical, and computational techniques, we provide detailed chemical analysis of the compounds formed in the organic phase during the solvent extraction of REEs by [(n-octyl)3NMe][NO3] (IL). These experiments show that REE recovery using IL is a rapid process and that IL is highly durable. Karl-Fischer measurements signify that the mode of action is unlikely to be micellar, while ions of the general formula REE(NO3)4(IL)2− are seen by negative ion electrospray ionization mass spectrometry. Additionally, variable temperature 139La nuclear magnetic resonance spectroscopy suggests the presence of multiple, low symmetry nitrato species. Classical molecular dynamics simulations show aggregation of multiple ILs around a microhydrated La3+ cation with four nitrates completing the inner coordination sphere. This increased understanding is now being exploited to develop stronger and more selective, functionalized ILs for REE recovery.
Self-Assembled Mucin-Containing Microcarriers via Hard Templating on CaCO3 Crystals
Authors: Balabushevich Nadezhda G. , Sholina Ekaterina A. , Mikhalchik Elena V. , Filatova Lyubov Y. , Vikulina Anna S. , Volodkin Dmitry
Published: June 2018

Porous vaterite crystals of CaCO3 are extensively used for the fabrication of self-assembled polymer-based microparticles (capsules, beads, etc.) utilized for drug delivery and controlled release. The nature of the polymer used plays a crucial role and discovery of new perspective biopolymers is essential to assemble microparticles with desired characteristics, such as biocompatibility, drug loading efficiency/capacity, release rate, and stability. Glycoprotein mucin is tested here as a good candidate to assemble the microparticles because of high charge due to sialic acids, mucoadhesive properties, and a tendency to self-assemble, forming gels. Mucin loading into the crystals via co-synthesis is twice as effective as via adsorption into preformed crystals. Desialylated mucin has weaker binding to the crystals most probably due to electrostatic interactions between sialic acids and calcium ions on the crystal surface. Improved loading of low-molecular-weight inhibitor aprotinin into the mucin-containing crystals is demonstrated. Multilayer capsules (mucin/protamine)3 have been made by the layer-by-layer self-assembly. Interestingly, the deposition of single mucin layers (mucin/water)3 has also been proven, however, the capsules were unstable, most probably due to additional (to hydrogen bonding) electrostatic interactions in the case of the two polymers used. Finally, approaches to load biologically-active compounds (BACs) into the mucin-containing microparticles are discussed.
Fatigue Assessment by Blink Detected with Attachable Optical Sensors of Dye-Sensitized Photovoltaic Cells
Authors: Horiuchi Ryogo , Ogasawara Tomohito , Miki Norihisa
Published: June 2018

This paper demonstrates fatigue assessment based on eye blinks that are detected by dye-sensitized photovoltaic cells. In particular, the sensors were attached to the temple of eyeglasses and positioned at the lateral side of the eye. They are wearable, did not majorly disturb the user’s eyesight, and detected the position of the eyelid or the eye state. The optimal location of the sensor was experimentally investigated by evaluating the detection accuracy of blinks. We conducted fatigue assessment experiments using the developed wearable system, or smart glasses. Several parameters, including the frequency, duration, and velocity of eye blinks, were extracted as fatigue indices. Successful fatigue assessment by the proposed system will be of great benefit for maximizing performance and maintenance of physical/mental health.
Frequency Tuning of Graphene Nanoelectromechanical Resonators via Electrostatic Gating
Authors: Mei Tengda , Lee Jaesung , Xu Yuehang , Feng Philip X.-L.
Published: June 2018

In this article, we report on a comprehensive modeling study of frequency tuning of graphene resonant nanoelectromechanical systems (NEMS) via electrostatic coupling forces induced by controlling the voltage of a capacitive gate. The model applies to both doubly clamped graphene membranes and circumference-clamped circular drumhead device structures. Frequency tuning of these devices can be predicted by considering both capacitive softening and elastic stiffening. It is shown that the built-in strain in the device strongly dictates the frequency tuning behavior and tuning range. We also find that doubly clamped graphene resonators can have a wider frequency tuning range, while circular drumhead devices have higher initial resonance frequency with same device characteristic parameters. Further, the parametric study in this work clearly shows that a smaller built-in strain, smaller depth of air gap or cavity, and larger device size or characteristic length (e.g., length for doubly clamped devices, and diameter for circular drumheads) help achieve a wider range of electrostatic frequency tunability. This study builds a solid foundation that can offer important device fabrication and design guidelines for achieving radio frequency components (e.g., voltage controlled oscillators and filters) with the desired frequencies and tuning ranges.
Cytotoxic Triterpenes from Salacia crassifolia and Metabolite Profiling of Celastraceae Species
Authors: Espindola Laila S. , Dusi Renata G. , Demarque Daniel P. , Braz-Filho Raimundo , Yan Pengcheng , Bokesch Heidi R. , Gustafson Kirk R. , Beutler John A.
Published: June 2018

The new pentacyclic triterpene 11β-hydroxypristimerin (1), along with the known metabolites pristimerin (2), 6-oxopristimerol (3) and vitideasin (4), were isolated from a Salacia crassifolia root wood extract, following a bioassay-guided fractionation approach. Both the extract and the purified triterpenes displayed pronounced cytotoxic activity against human cancer cell lines. The NCI-60 cell line screen revealed that compound 2 was the most active, with a mean GI50 of 0.17 μM, while compound 1 had a mean GI50 of 8.7 μM. A COMPARE analysis of the screening results showed that pristimerin is likely to be the main compound responsible for the cytotoxic activity of the extract (mean GI50 of 0.3 μg·mL−1). A targeted search for pristimerin and related derivatives using LC-MS/MS revealed the presence of pristimerin (2) and 6-oxopristimerol (3) in all Celastraceae species examined and in all plant parts tested, while vitideasin (4) was only detected in the genus Salacia.
Measuring the Density of States of the Inner and Outer Wall of Double-Walled Carbon Nanotubes
Authors: Chambers Benjamin A. , Shearer Cameron J. , Yu LePing , Gibson Christopher T. , Andersson Gunther G.
Published: June 2018

The combination of ultraviolet photoelectron spectroscopy and metastable helium induced electron spectroscopy is used to determine the density of states of the inner and outer coaxial carbon nanotubes. Ultraviolet photoelectron spectroscopy typically measures the density of states across the entire carbon nanotube, while metastable helium induced electron spectroscopy measures the density of states of the outermost layer alone. The use of double-walled carbon nanotubes in electronic devices allows for the outer wall to be functionalised whilst the inner wall remains defect free and the density of states is kept intact for electron transport. Separating the information of the inner and outer walls enables development of double-walled carbon nanotubes to be independent, such that the charge transport of the inner wall is maintained and confirmed whilst the outer wall is modified for functional purposes.
Protective Effects of Salvianolic Acid A against Dextran Sodium Sulfate-Induced Acute Colitis in Rats
Authors: Wang Kai , Yang Qinqin , Ma Quanxin , Wang Bei , Wan Zhengrui , Chen Minli , Wu Liming
Published: June 2018

Salvianolic acid A (SAA) is an active phenolic acid derived from Salvia miltiorrhiza Bunge (Danshen). To explore whether SAA has a therapeutic effect against inflammatory bowel disease (IBD), an acute colitis model was induced in rats by administering 3% dextran sodium sulphate (DSS) for one week. SAA in doses of 4 and 8 mg/kg/day was given by tail vein injection during DSS administration. Both dosages of SAA ameliorated the colitis symptoms, with decreases observed in the disease activity index. A high dosage of SAA (8 mg/kg/day) promoted a longer colon length and an improved colonic tissue structure, compared with the DSS-treated rats not receiving SAA. SAA dose-dependently decreased colonic gene expression of pro-inflammatory cytokines (IL-1β, MCP-1 and IL-6). Moreover, a high dosage of SAA protected against DSS-induced damage to tight junctions (TJ) in the rats’ colons, by increasing TJ-related gene expression (ZO-1 and occuldin). Finally, using 16S rRNA phylogenetic sequencing, we found that SAA modulated gut microbiota imbalance during colitis by increasing the gut microbial diversity as well as selectively promoting some probiotic populations, including Akkermansia spp. Our study suggests that SAA is a promising candidate for the treatment of IBD.
Modular Synthesis of Bioreducible Gene Vectors through Polyaddition of N,N′-Dimethylcystamine and Diglycidyl Ethers
Authors: Si Guoying , Elzes M. Rachèl , Engbersen Johan F. J. , Paulusse Jos M. J.
Published: June 2018

Bioreducible, cationic linear poly(amino ether)s (PAEs) were designed as promising gene vectors. These polymers were synthesized by the reaction of a disulfide-functional monomer, N,N′-dimethylcystamine (DMC), and several different diglycidyl ethers. The resulting PAEs displayed a substantial buffer capacity (up to 64%) in the endosomal acidification region of pH 7.4–5.1. The PAEs condense plasmid DNA into 80–200 nm sized polyplexes, and have surface charges ranging from +20 to +40 mV. The polyplexes readily release DNA upon exposure to reducing conditions (2.5 mM DTT) due to the cleavage of the disulfide groups that is present in the main chain of the polymers, as was demonstrated by agarose gel electrophoresis. Upon exposing COS-7 cells to polyplexes that were prepared at polymer/DNA w/w ratios below 48, cell viabilities between 80–100% were observed, even under serum-free conditions. These polyplexes show comparable or higher transfection efficiencies (up to 38%) compared to 25 kDa branched polyethylenimine (PEI) polyplexes (12% under serum-free conditions). Moreover, the PAE-based polyplexes yield transfection efficiencies as high as 32% in serum-containing medium, which makes these polymers interesting for gene delivery applications.
Efficient Shielding of Polyplexes Using Heterotelechelic Polysarcosines
Authors: Klein Philipp Michael , Klinker Kristina , Zhang Wei , Kern Sarah , Kessel Eva , Wagner Ernst , Barz Matthias
Published: June 2018

Shielding agents are commonly used to shield polyelectrolyte complexes, e.g., polyplexes, from agglomeration and precipitation in complex media like blood, and thus enhance their in vivo circulation times. Since up to now primarily poly(ethylene glycol) (PEG) has been investigated to shield non-viral carriers for systemic delivery, we report on the use of polysarcosine (pSar) as a potential alternative for steric stabilization. A redox-sensitive, cationizable lipo-oligomer structure (containing two cholanic acids attached via a bioreducible disulfide linker to an oligoaminoamide backbone in T-shape configuration) was equipped with azide-functionality by solid phase supported synthesis. After mixing with small interfering RNA (siRNA), lipopolyplexes formed spontaneously and were further surface-functionalized with polysarcosines. Polysarcosine was synthesized by living controlled ring-opening polymerization using an azide-reactive dibenzo-aza-cyclooctyne-amine as an initiator. The shielding ability of the resulting formulations was investigated with biophysical assays and by near-infrared fluorescence bioimaging in mice. The modification of ~100 nm lipopolyplexes was only slightly increased upon functionalization. Cellular uptake into cells was strongly reduced by the pSar shielding. Moreover, polysarcosine-shielded polyplexes showed enhanced blood circulation times in bioimaging studies compared to unshielded polyplexes and similar to PEG-shielded polyplexes. Therefore, polysarcosine is a promising alternative for the shielding of non-viral, lipo-cationic polyplexes.