bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression and purification of listeriolysin O from Listeria monocytogenes harbouring E247M and D320K mutations in Bacillus subtilis
Authors: Ngo Huy Khac , Nguyen Anh Le Tuan , Huynh Phuong Thi Kim , Nguyen Phuc Van , Tran Thuoc Linh , Nguyen Hoang Duc , Phan Trang Thi Phuong
Published: September 2018

Listeriolysin O (LLO) is an important extracellular toxin of Listeria monocytogenes which degrades the phospholipid membranes of the host cells’ phagosomes at low pH during the intracellular survival. In contrast to the natural form, the mutant LLO carrying two replacements of amino acid E247M and D320K possesses stable activity at pH 7.4. In this study, we have constructed vectors that carry the mhlyA gene encoding double-mutated LLOE247M/D320K express in B. subtilis 1012. The target gene was fused to the sequence of LysRN-6xHis-TEV site to enhance the recombinant protein expression in B. subtilis and to ease the acquisition of protein by Ni2+-based affinity chromatography. As results, we have obtained the purified protein LLOE247M/D320K with high purity. The activity measurement with 3 HU hemolytic toxins in the pH range from 5.0 to 8.5 suggested that the activity of LLOE247M/D320K was much better than that of natural LLO at neutral pH and slightly alkaline. These results not only provided important scientific foundations for mutant LLO bases expression in B. subtilis but also supplied purified materials for researche and medical applications based on this protein.
Sarkoma Ewing
Authors: Gozal Fenny , Djakaria H.M
Published: September 2018

Sarkoma Ewing/ Ewing Sarcoma (ES) merupakan keganasan tulang tersering nomor dua pada anak setelah osteosarkoma. Sebagai tumor dengan derajat keganasan tinggi, seringkali ES terdiagnosis dengan kondisi lesi yang ekstensif serta tidak jarang sudah mengalami metastasis sehingga prognosis pasien menjadi buruk. Tata laksana yang tepat untuk ES menjadi tantangan bagi klinisi dalam menangani pasien. Terapi multimodalitas berupa kombinasi antara kemoterapi, pembedahan dan radioterapi menjadi pilihan terbaik dalam tatalaksana ES yang dapat meningkatkan angka 5 year survival dari pasien ES. Radioterapi dalam hal ini memiliki peranan sebagai terapi definitif, pre operatif maupun sebagai terapi adjuvan post operatif.
Neuropharmacological screening of Ficus Carica Linn; Fruit for Anxiolytic and Antidepressant Activity
Authors: Gul Somia , Raza Sabeen , Rashid Zaira , Ayub Maria , Sarwar Ghulam
Published: September 2018

Background: Rutin and polyphenol which are present in ficus carica linn are responsible for anti-depressant and anxiolytics effect.Aims: We have conducted the study to evaluate the anti depressant and anxiolytic effect of ficuscaricalinn on mice and compare its effect with well known prescribed anti depressant and anxiolytic drug alprazolam.Methods: Three groups of mice were marked as Control, Reference and Test. Each group comprise of 5 mice. Control group was on normal diet. Reference group was feeded alprazolam at a dose of 0.5mg/60kg while test group were provided two different dilution of ficuscaricalinn, one dilution is 250mg/ kg/100ml of water and second dilution is 500mg/kg/100ml of water. We used Light/dark box method and Elevated plus maze method to evaluate the anxiolytic effect of ficus carica linn. To determine the anti-depressant effect of ficus carica linn.Results: we was used one method that is Head Dip Method. Results were collected and observed readings and data were clearly indicating the great and pronounced anti depressant and anxiolytic effect of ficus carica linn at a dose of 500mg/kg compare with a widely prescribed drug alprazolam for its anti-depressant and anxiolytic effect.Ficus carica is well known for its numerous biological activities also found to be one of excellent distressing agent. Stress provoking several disorders could be limit by the use of ficus carica fruit in doses 250mg/kg and 500mg/kg. Ficus carica linn as a natural product may prove better therapeutic agent if more study is conducted on it.Conclusion: As this study is confined to the mice, there’s much possibilities to have similar effect in humans but require more work on it.Bangladesh Journal of Medical Science Vol.17(4) 2018 p.606-611
Study of Vitamin D levels in patients with Chronic Kidney Disease
Authors: Mittal SP , Sandhu Harendra Singh , Singh Bant
Published: September 2018

Introduction: Apart from classical functions, vitamin D has autocrine function. Autocrine function of vitamin D has a potential impact on the morbidity and mortality in the Chronic Kidney Disease patients. This study is undertaken to observe probable modality, if present, between post Hemodialysis (HD) decrease in vitamin D levels and clinical deterioration in CKD patients.Method & Material: 63 patients (32 males and 31 females) of Stage – 5 CKD were studied. There vitamin D was estimated before and after HD on first and subsequent maintenance HDs all patients with or without comorbidities.Results: Pre HD total vitamin D levels were ‘deficient’ (58.73%) and ‘sufficient’ in 38.1%, almost equal in patients of both sexes despite intake of supplement containing Calcium and Calcitriol. Post HD vitamin D levels were detected to be markedly low, seems to be ‘washed out’ during HD, in 85.71% of patients (29 males and 27). Vitamin D ‘wash out’ effect was also observed in subsequent maintenance HDs. Females and elderly patients were more prone to vitamin D ‘wash out’. Conventional therapy with vitamin D supplements can replenish but could not prevent its post HD ‘wash out’.Conclusion: It seems, in CKD the deleterious effects of post HD vitamin D deficiency are due to appreciable autocrine dysfunctions resulting in cardio vascular diseases (CVDs) and comorbidities especially diabetes mellitus add to worsening of CVDs, which are the main causes of high morbidity and mortality in these patients.Bangladesh Journal of Medical Science Vol.17(4) 2018 p.652-660
NS-1 antigen positive Dengue Infection and molecular characterization of Dengue Viruses in a private Medical College Hospitalin Dhaka, Bangladesh
Authors: Siddiqua Mahmuda , Alam Ahmed Nawsher , Muraduzzaman AKM , Shirin Tahmina
Published: September 2018

Introduction: Detection of dengue virus infection as soon as possible is critical for management of dengue virus infected patients. Immuno-chromatographic (ICT) tests are easy, cost effective method for dengue virus antigen detection.The sensitivity and specificity of ICT should compare with a gold standard test like RT-PCR. Aim of this study was to compare two test methods (ICT and RT-PCR), observe dengue serotype and seasonal impact on dengue infection.Methodology & result: The patients of Ibn Sina Medical College Hospital from October 2015 to October 2017 were tested for dengue NS1 antigen by ICT method. Out of 3201 sample tested 32.39% were found positive and 89 of which were re-tested for RT-PCR for comparison. Eighty eight of 89 NS1 positive cases showed positive by RT-PCR method giving an accuracy of 98.87%. Among the RT-PCR positive cases 45 were further analyzed for serotype. DEN-1, DEN-2 or both DEN- 1 and DEN-2 were found in 21, 23 and 1cases respectively. No cases of DEN-3 or DEN-4 were detected.Conclusion: This study showed that easily available and cost effective dengue NS1 antigen detection method (ICT) is as effective as molecular test (RT-PCR). DEN-1 and DEN-2 serotype were prevalent during last few years in Bangladesh. Continuous monitoring of dengue virus serotype is important for prevention and control of sudden epidemic by other serotype. Alert to be more during post monsoon when the peak of dengue virus infection was observed.Bangladesh Journal of Medical Science Vol.17(4) 2018 p.669-673
Discharge Coefficients of Ports with Stepped Inlets
Authors: Spencer Adrian
Published: September 2018

Components of aeronautical gas turbines are increasingly being constructed from two layers, including a pressure containing skin, which is then protected by a thermal tile. Between them, pedestals and/or other heat transfer enhancing features are often employed. This results in air admission ports through the dual skin having a step feature at the inlet. Experimental data have been captured for stepped ports with a cross flow approach, which show a marked increase of 20% to 25% in discharge coefficient due to inlet step sizes typical of combustion chamber configurations. In this respect, the step behaves in a fashion comparable to ports with inlet chamfering or radiusing; the discharge coefficient is increased as a result of a reduction in the size of the vena contracta brought about by changes to the flow at inlet to the port. Radiused and chamfered ports have been the subject of previous studies, and empirical correlations exist to predict their discharge coefficient as used in many one-dimensional flow network tools. A method to predict the discharge coefficient change due to a step is suggested: converting the effect of the step into an equivalent radius to diameter ratio available in existing correlation approaches. An additional factor of eccentricity between the hole in the two skins is also considered. Eccentricity is shown to reduce discharge coefficient by up to 10% for some configurations, which is more pronounced at higher port mass flow ingestion fraction.
Leading-Edge Roughness Affecting Diamond-Wing Aerodynamic Characteristics
Authors: Buzica Andrei , Debschütz Lisa , Knoth Florian , Breitsamter Christian
Published: September 2018

Diamond wing configurations for low signature vehicles have been studied in recent years. Yet, despite numerous research on highly swept, sharp edged wings, little research on aerodynamics of semi-slender wings with blunt leading-edges exists. This paper reports on the stall characteristics of the AVT-183 diamond wing configuration with variation of leading-edge roughness size and Reynolds number. Wind tunnel testing applying force and surface pressure measurements are conducted and the results presented and analysed. For the investigated Reynolds number range of 2.1 × 10 6 ≤ R e ≤ 2.7 × 10 6 there is no significant influence on the aerodynamic coefficients. However, leading-edge roughness height influences the vortex separation location. Trip dots produced the most downstream located vortex separation onset. Increasing the roughness size shifts the separation onset upstream. Prior to stall, global aerodynamic coefficients are little influenced by leading-edge roughness. In contrast, maximum lift and maximum angle of attack is reduced with increasing disturbance height. Surface pressure fluctuations show dominant broadband frequency peaks, distinctive for moderate sweep vortex breakdown. The experimental work presented here provides insights into the aerodynamic characteristics of diamond wings in a wide parameter space including a relevant angle of attack range up to post-stall.
Noise-Canceling Office Chair with Multiple Reference Microphones
Authors: Sujbert László , Szarvas Attila
Published: September 2018

Office employees are exposed to acoustic noise, especially in an open office environment. Passive or active headsets sufficiently reduce the level of noise, but their long-time wear is uncomfortable. The paper presents an active headrest system built into a chair. Feedforward control is utilized with multiple reference microphones, and flexible gooseneck microphones serve as error sensors. The reference sensors surround the chair, allowing the suppression of sound waves arriving from any direction. The concept of multiple reference control has been tested by extensive experiments showing that multiple reference signals help to increase the suppression in normal rooms where reverberation occurs, even if only one noise source is present. The preliminary experiments are completed by a series of simulations aiming to explore the zones of quiet at the user’s ears. The paper introduces the construction details of the noise-canceling chair: The two loudspeakers are controlled by the signals of two error microphones and four reference signals. The controller is based on the normalized filtered error least mean squared algorithm, implemented on an Analog Devices ADSP-21262 signal processor-based hardware. Experimental results are reported that show the efficient suppression of tonal, as well as broadband disturbances.
Polymer-Based Chemical Sensors
Authors: Reglero Ruiz José Antonio , Vallejos Saúl , García Félix Clemente , García José Miguel
Published: September 2018

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Optimization of Alachlor Photocatalytic Degradation with Nano-TiO2 in Water under Solar Illumination: Reaction Pathway and Mineralization
Authors: Molla Md. , Furukawa Mai , Tateishi Ikki , Katsumata Hideyuki , Kaneco Satoshi
Published: September 2018

In the present study, the photocatalytic degradation of alachlor was investigated using TiO2 under sunlight irradiation. The effects of some operational parameters, such as photocatalyst concentration, temperature, pH, sunlight intensity and irradiation time, were optimized. The kinetics of photodegradation was found to follow a pseudo-first-order kinetic law, and the rate constant at optimal condition is 0.245 min−1. The activation energy (Ea) is 6.4 kJ/mol. The alachlor mineralization can be completed under sunlight irradiation after 10 h. The formations of chloride, nitrate and ammonium ions are observed during the photocatalytic degradation. The eight photoproducts were identified by the GC–MS technique. The photodegradation reaction pathways are proposed based on the evidence of the detected photoproducts and the calculated frontier electron densities of the alachlor structure. The photocatalytic degradation treatment for the alachlor wastewater under solar irradiation is simple, convenient and low cost.
Comparison of Cost of Protection against Differential Power Analysis of Selected Authenticated Ciphers
Authors: Diehl William , Abdulgadir Abubakr , Farahmand Farnoud , Kaps Jens-Peter , Gaj Kris
Published: September 2018

Authenticated ciphers, which combine the cryptographic services of confidentiality, integrity, and authentication into one algorithmic construct, can potentially provide improved security and efficiencies in the processing of sensitive data. However, they are vulnerable to side-channel attacks such as differential power analysis (DPA). Although the Test Vector Leakage Assessment (TVLA) methodology has been used to confirm improved resistance of block ciphers to DPA after application of countermeasures, extension of TVLA to authenticated ciphers is non-trivial, since authenticated ciphers have expanded input and output requirements, complex interfaces, and long test vectors which include protocol necessary to describe authenticated cipher operations. In this research, we upgrade the FOBOS test architecture with capability to perform TVLA on authenticated ciphers. We show that FPGA implementations of the CAESAR Round 3 candidates ACORN, Ascon, CLOC (with AES and TWINE primitives), SILC (with AES, PRESENT, and LED primitives), JAMBU (with AES and SIMON primitives), and Ketje Jr.; as well as AES-GCM, are vulnerable to 1st order DPA. We then use threshold implementations to protect the above cipher implementations against 1st order DPA, and verify the effectiveness of countermeasures using the TVLA methodology. Finally, we compare the unprotected and protected cipher implementations in terms of area, performance (maximum frequency and throughput), throughput-to-area (TP/A) ratio, power, and energy per bit (E/bit). Our results show that ACORN consumes the lowest number of resources, has the highest TP/A ratio, and is the most energy-efficient of all DPA-resistant implementations. However, Ketje Jr. has the highest throughput.
Impact of Forest Fuels on Gas Emissions in Coal Slurry Fuel Combustion
Authors: Nyashina Galina , Strizhak Pavel
Published: September 2018

Anthropogenic emissions from coal combustion pose a serious threat to human wellbeing. One prospective way to solve this problem is by using slurry fuels instead of coal. The problem is especially pressing in China and Russia, so these countries need reliable experimental data on the SOx and NOx emissions reduction range more than others do. The experiments in this research are based on the components that are typical of Russia. Experimental research was conducted on the way typical forest fuels (ground pine needles, leaves and their mixtures, bark, sawdust, and charcoal) affect the gas emissions from the combustion of slurry fuels based on the wastes. It was established that using forest fuels as additives to coal-water slurries reduces SOx and NOx emissions by 5–91% as compared to coal or to slurries based on used turbine oil. It was revealed that even small concentrations of such additives (7–15%) could result in a several-fold reduction in SOx and NOx. The higher the temperature, the more prominent the role of forest biomass. The calculated complex criterion illustrates that forest fuels increase the performance indicator of fuel suspensions by 1.2–10 times.
Environmentally Friendly Compact Air-Insulated High-Voltage Substations
Authors: Albano Maurizio , Haddad A. Manu , Griffiths Huw , Coventry Paul
Published: September 2018

This paper investigates the possible options for achieving a substantial reduction in a substation footprint using air-insulated switchgear as a more environmentally-friendly alternative to gas-insulated substations that use SF6 gas. Adopting a new approach to surge arrester location and numbers, International Electrotechnical Commission (IEC) minimum clearances can be successfully selected instead of the maximum clearances as currently adopted by many utilities, as is the case in the UK. In addition, innovative alternative compact busbar arrangements using vertical and delta configurations have been proposed by the authors. A further opportunity for compaction is offered by the application of compact and integrated technology offered from several manufacturers. The full overvoltage control within the entire substation under any surge condition is a key aspect of the feasibility of this type of substation. This work demonstrates that the new design option can be an attractive alternative for future substation configuration with minimum footprint.
Cell Wall and Whole Cell Proteomes Define Flocculation and Fermentation Behavior of Yeast
Authors: Kerr Edward D. , McDiarmid Duin C. , Fraser James A. , Schulz Benjamin L.
Published: September 2018

Flocculation is one of the most important characteristics of brewing yeast as it allows for the easy and cheap removal of cells after fermentation. The genes responsible for both the Flo1 and NewFlo flocculation phenotypes are well characterized. However, the relationship between Flo protein abundance and flocculation efficiency is poorly understood. In this present study, we used mass spectrometry proteomics to compare the cell wall and whole cell proteomes of commercial yeast strains with diverse flocculation behaviors. We found that the relative abundance of Flo1/5 or Flo10 in the cell wall was correlated with the ability of these yeast strains to flocculate. Analysis of whole cell proteomes identified differences in the proteomes of yeast strains and identified the potential for high metabolic diversity. Characterization of the cell wall and whole cell proteomes during fermentation showed high levels of Flo10 in cells that settled early during fermentation. Our data reveal the diversity of the cell wall and global proteomes of brewing yeast, highlighting the potential biochemical diversity present in yeast that can be utilized in the production of fermented beverages.
Evolutionary Emergence of Drug Resistance in Candida Opportunistic Pathogens
Authors: Ksiezopolska Ewa , Gabaldón Toni
Published: September 2018

Fungal infections, such as candidiasis caused by Candida, pose a problem of growing medical concern. In developed countries, the incidence of Candida infections is increasing due to the higher survival of susceptible populations, such as immunocompromised patients or the elderly. Existing treatment options are limited to few antifungal drug families with efficacies that vary depending on the infecting species. In this context, the emergence and spread of resistant Candida isolates are being increasingly reported. Understanding how resistance can evolve within naturally susceptible species is key to developing novel, more effective treatment strategies. However, in contrast to the situation of antibiotic resistance in bacteria, few studies have focused on the evolutionary mechanisms leading to drug resistance in fungal species. In this review, we will survey and discuss current knowledge on the genetic bases of resistance to antifungal drugs in Candida opportunistic pathogens. We will do so from an evolutionary genomics perspective, focusing on the possible evolutionary paths that may lead to the emergence and selection of the resistant phenotype. Finally, we will discuss the potential of future studies enabled by current developments in sequencing technologies, in vitro evolution approaches, and the analysis of serial clinical isolates.
Establishing Heat Alert Thresholds for the Varied Climatic Regions of British Columbia, Canada
Authors: McLean Kathleen E. , Stranberg Rebecca , MacDonald Melissa , Richardson Gregory R. A. , Kosatsky Tom , Henderson Sarah B.
Published: September 2018

Following an extreme heat event in 2009, a Heat Alert and Response System (HARS) was implemented for the greater Vancouver area of British Columbia (BC), Canada. This system has provided a framework for guiding public health interventions and assessing population response and adaptation to extreme heat in greater Vancouver, but no other parts of BC were covered by HARS. The objective of this study was to identify evidence-based heat alert thresholds for the Southwest, Southeast, Northwest, and Northeast regions to facilitate the introduction of HARS across BC. This was done based on a national approach that considers high temperatures on two consecutive days and the intervening overnight low, referred to as the high-low-high approach. Daily forecast and observed air temperatures and daily mortality counts for May through September of 2004 through 2016 were obtained. For each date (dayt), dayt−2 forecasts were used to assign high temperatures for dayt and dayt+1 and the overnight low. A range of high-low-high threshold combinations was assessed for each region by finding associations with daily mortality using time-series models and other considerations. The following thresholds were established: 29-16-29 °C in the Southwest; 35-18-35 °C in the Southeast; 28-13-28 °C in the Northwest; and 29-14-29 °C in the Northeast. Heat alert thresholds for all regions in BC provide health authorities with information on dangerously hot temperature conditions and inform the activation of protective public health interventions.
Spatial Assessment of Anthropogenic Impact on Trace Metal Accumulation in Farmland Soils from a Rapid Industrializing Region, East China
Authors: Jiao Wei , Niu Yong , Niu Yuan , Hu Hengyu , Li Ruiping
Published: September 2018

A better understanding of anthropogenic trace metal accumulation in farmland soils is crucial for local food safety and public health, especially for a rapidly industrializing region. In this study, soil samples at two depths were collected from a typical county in East China and analyzed for total concentrations of Fe, Al, Pb, Cd, Cu, Zn, Cr, and Ni. Results showed that trace metals like Pb, Cd, Cu, Zn, Cr, and Ni have accumulated in the regional farmlands, with average topsoil concentrations 1.62–1.77 times higher than their background concentrations in subsoil. However, they were still much lower than the limits of the Chinese Environmental Quality Standard for Soils. By the proper calculation of enrichment factor (EF), it was found that the accumulations of trace metals in the topsoil have been impacted by anthropogenic activities, which could contribute up to 40.83% of total metal concentration. Two principal components were extracted according to the results of principal component analysis (PCA) for EF values, which indicated two important anthropogenic trace metal sources. With the help of spatial distribution maps based on geographical information system (GIS), the anthropogenic sources of Pb, Cr, and Ni were determined to be mostly associated with atmospheric deposition from the central urban area. However, Cd, Cu, and Zn were further confirmed to originate from different agricultural sources. The anthropogenic Cu and Zn inputs were mostly related to pig manure application in the rural northern and southeastern areas, while extensive fertilizer application was identified as the major contributor to anthropogenic Cd accumulation in this region. Overall, the integrated application of EF, PCA, and GIS mapping is an effective approach to achieve the spatial assessment of anthropogenic impact on trace metal accumulation in regional soils.
Sleep Quality and Its Associated Factors among Low-Income Adults in a Rural Area of China: A Population-Based Study
Authors: Wu Wenwen , Wang Wenru , Dong Zhuangzhuang , Xie Yaofei , Gu Yaohua , Zhang Yuting , Li Mengying , Tan Xiaodong
Published: September 2018

Background: There is limited population-based research focusing on sleep quality among low-income Chinese adults in rural areas. This study aimed to assess sleep quality among low-income adults in a rural area in China and identify the association between sleep quality and sociodemographic, lifestyle and health-related factors. Methods: The study was conducted from September to November in 2017 using a cross-sectional survey questionnaire. A total of 6905 participants were recruited via multistage, stratified cluster sampling. Data were collected using the Chinese versions of Pittsburgh Sleep Quality Index and Food Frequency Questionnaire, while we also determined the sociodemographic profiles of the participants. Results: The mean age of the sample was 58.71 ± 14.50 years, with 59.7% being male, while the mean duration of daily sleep was 5.95 ± 1.31 h, with 56.7% reportedly experiencing poor sleep quality. Multiple regression analysis revealed that older age, unemployment, lower income, disability and chronic disease comorbidities were significant factors associated with an increased risk of poor sleep quality for both genders. Moreover, married and higher education level were associated with decreased risk of poor sleep quality for females, while a meat-heavy diet and illness during the past two weeks increased the risk of poor sleep quality for males. Conclusions: Sociodemographic, lifestyle and health-related factors had an impact on the frequently poor sleep quality of low-income Chinese adults in rural areas. Thus, comprehensive measures must be developed to address the modifiable predictive factors that can possibly enhance sleep quality.
Fuzzy Group Consensus Decision Making and Its Use in Selecting Energy-Saving and Low-Carbon Technology Schemes in Star Hotels
Authors: Lu Ping , Yang Xuan , Wang Zhou-Jing
Published: September 2018

Energy-saving and low-carbon technologies play important roles in reducing environmental risk and developing green tourism. An energy-saving and low-carbon technology scheme selection may often involve multiple criteria and sub-criteria as well as multiple stakeholders or decision makers, and thus can be structured as a hierarchical multi-criteria group decision making problem. This paper proposes a framework to solve group consensus decision making problems, where decision makers’ preferences between the alternatives considered with respective to each criterion are elicited by the paired comparison method, and expressed as triangular fuzzy preference relations (TFPRs). The paper first simplifies the existing computation formulas used to determine triangular fuzzy weights of TFPRs. A consistency index is then devised to measure the inconsistency degree of a TFPR and is used to check acceptable consistency of TFPRs. By introducing a possibility degree formula of comparing any two triangular fuzzy weights, an index is defined to measure the consensus level between an individual ranking order and the group ranking order for all alternatives. A consensus model is developed in detail for solving group decision making problems with TFPRs. A case study of selecting energy-saving and low-carbon technology schemes in star hotels is provided to illustrate how to apply the proposed group decision making consensus model in practice.
Hedgehog Signaling in Lung Cancer: From Oncogenesis to Cancer Treatment Resistance
Authors: Giroux-Leprieur Etienne , Costantini Adrien , Ding Vivianne W. , He Biao
Published: September 2018

Hedgehog signaling pathway is physiologically activated during embryogenesis, especially in lung development. It is also reactivated in many solid tumors. In lung cancer, Hedgehog pathway is closely associated with cancer stem cells (CSCs). Recent works have shown that CSCs produced a full-length Sonic Hedgehog (Shh) protein, with paracrine activity and induction of tumor development. Hedgehog pathway is also involved in tumor drug resistance in lung cancer, as cytotoxic chemotherapy, radiotherapy, and targeted therapies. This review proposes to describe the activation mechanisms of Hedgehog pathway in lung cancer, the clinical implications for overcoming drug resistance, and the perspectives for further research.
Beeswax by-Products Efficiently Counteract the Oxidative Damage Induced by an Oxidant Agent in Human Dermal Fibroblasts
Authors: Giampieri Francesca , Gasparrini Massimiliano , Forbes-Hernández Tamara Y. , Manna Piera Pia , Zhang Jiaojiao , Reboredo-Rodríguez Patricia , Cianciosi Danila , Quiles Jose L. , Torres Fernández-Piñar Cristina , Orantes-Bermejo Francisco Josè , Bompadre Stefano , Afrin Sadia , Battino Maurizio
Published: September 2018

The antioxidant capacity and the phytochemical composition of two by-products from beeswax recycling processes were recently investigated. The aim of the present work was to evaluate the efficacy of one of these by-products, MUD1, against the oxidative stress induced by 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) in human dermal fibroblast (HDF) cells. After a preliminary viability assay, the protective effect of MUD1 was investigated through the measurement of apoptosis level, the reactive oxygen species (ROS) and nitrite (NO2−) production, the level of protein and lipid biomarkers (carbonyl groups, total glutathione and thiobarbituric acid-reactive substance) of oxidative damage, and the measurement of antioxidant enzymes activities (glutatione peroxidase, glutathione reductase, glutathione transferase, superoxide dismutase and catalase). The obtained results showed that MUD1 exerted protective effects on HDF, increasing cell viability and counteracted the oxidative stress promoted by AAPH-treatment, and improved mitochondria functionality and wound healing capacities. This work shows the antioxidant effects exerted by beeswax by-products, demonstrating for the first time their potential against oxidative stress in human dermal fibroblast cells; however, further research will be necessary to evaluate their potentiality for human health by more deeply in vitro and in vivo studies.
Vitamin B12 Deficiency Induces Imbalance in Melanocytes Homeostasis—A Cellular Basis of Hypocobalaminemia Pigmentary Manifestations
Authors: Rzepka Zuzanna , Respondek Michalina , Rok Jakub , Beberok Artur , Ó Proinsias Keith , Gryko Dorota , Wrześniok Dorota
Published: September 2018

Vitamin B12 deficiency causes significant changes in cellular metabolism leading to various clinical symptoms, such as hematological, psychiatric, and neurological disorders. We hypothesize that skin pigmentation disorders may be a diagnostically important manifestation of vitamin B12 deficiency, however the cellular and molecular mechanisms underlying these effects remain unknown. The aim of this study was to examine the effect of vitamin B12 deficiency on melanocytes homeostasis. Hypocobalaminemia in vitro model was developed by treating epidermal melanocytes with synthesized vitamin B12 antagonist—hydroxycobalamin(c-lactam). The cells were examined using immunoenzymatic, spectrophotometric, and fluorimetric assays as well as image cytometry. Significant melanogenesis stimulation—the increase of relative melanin content and tyrosinase activity up to 131% and 135%, respectively—has been indicated. Cobalamin-deficient cells displayed the elevation (by 120%) in reactive oxygen species level. Moreover, the redox status imbalance was stated. The study provided a scientific evidence for melanocytes homeostasis disturbance under hypocobalaminemia, thus indicating a significant element of the hyperpigmentation mechanism due to vitamin B12 deficiency. Furthermore, the implication between pigmentary and hematological and/or neuropsychiatric symptoms in cobalamin-deficient patients may be an important issue.
Cement Kiln By-Pass Dust: An Effective Alkaline Activator for Pozzolanic Materials
Authors: Kalina Lukáš , Bílek Vlastimil , Kiripolský Tomáš , Novotný Radoslav , Másilko Jiří
Published: September 2018

Cement kiln by-pass dust (CKD) is a fine-grained by-product of Portland clinker manufacturing. Its chemical composition is not suitable for returning back into feedstock and, therefore, it has to be discharged. Such an increasing waste production contributes to the high environmental impact of the cement industry. A possible solution for the ecological processing of CKD is its incorporation into alkali-activated blast furnace slag binders. Thanks to high alkaline content, CKD serves as an effective accelerator for latent hydraulic substances which positively affect their mechanical properties. It was found out that CKD in combination with sodium carbonate creates sodium hydroxide in situ which together with sodium water glass content increases the dissolution of blast furnace slag particles and subsequently binder phase formation resulting in better flexural and compressive strength development compared to the sample without it. At the same time, the addition of CKD compensates the autogenous shrinkage of alkali-activated materials reducing the risk of material cracking. On the other hand, this type of inorganic admixture accelerates the hydration process causing rapid loss of workability.
Broadband Microwave Absorbing Composites with a Multi-Scale Layered Structure Based on Reduced Graphene Oxide Film as the Frequency Selective Surface
Authors: Ye Fang , Song Changqing , Zhou Qian , Yin Xiaowei , Han Meikang , Li Xinliang , Zhang Litong , Cheng Laifei
Published: September 2018

A broadband microwave absorbing composite with a multi-scale layered structure is proposed, in which a reduced graphene oxide (RGO) film sandwiched between two layers of epoxy glass fiber laminates serves as the frequency selective surface (FSS). RGO films with the desired electrical properties were synthesized directly by hydrothermal reaction, vacuum filtration, and heat treatment without subsequent processing. With the novel layer-by-layer structure ranging from micro to macro scale, the optimized composite exhibits excellent microwave absorption performance with a total thickness of 3.2 mm. Its reflection coefficient (RC) is less than −10 dB in the entire X and Ku band, reaching a minimum value of −32 dB at 10.2 GHz and an average RC of −22.8 dB from 8 to 18 GHz. Enhanced microwave absorption of the composites is achieved through the optimization of layer thickness in the sandwich structure to promote destructive interference. Improved impedance matching by the introduction of FSS along with the polarization and conduction loss of layered graphene films also contribute to the increased absorption.
Accelerated Curing and Enhanced Material Properties of Conductive Polymer Nanocomposites by Joule Heating
Authors: Jang Sung-Hwan , Kim Donghak , Park Yong-Lae
Published: September 2018

Joule heating is useful for fast and reliable manufacturing of conductive composite materials. In this study, we investigated the influence of Joule heating on curing conditions and material properties of polymer-based conductive composite materials consisting of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS). We applied different voltages to the CNT nanocomposites to investigate their electrical stabilization, curing temperature, and curing time. The result showed that highly conductive CNT/PDMS composites were successfully cured by Joule heating with uniform and fast heat distribution. For a 7.0 wt % CNT/PDMS composite, a high curing temperature of around 100 °C was achieved at 20 V with rapid temperature increase. The conductive nanocomposite cured by Joule heating also revealed an enhancement in mechanical properties without changing the electrical conductivities. Therefore, CNT/PDMS composites cured by Joule heating are useful for expediting the manufacturing process for particulate conductive composites in the field of flexible and large-area sensors and electronics, where fast and uniform curing is critical to their performance.
A Semimetal-Like Molybdenum Carbide Quantum Dots Photoacoustic Imaging and Photothermal Agent with High Photothermal Conversion Efficiency
Authors: Dai Wenhao , Dong Haifeng , Zhang Xueji
Published: September 2018

Theranostic platforms integrating imaging diagnostic and therapeutic interventions into a single nanoplatform have attracted considerable attention for cancer-individualized therapies. However, their uncertain stability, complex pharmacokinetics, and intrinsic toxicology of multiple components hinder their practical application in clinical research. In this paper, stable and high-concentration molybdenum carbide quantum dots (Mo2C QDs) with a diameter of approximately 6 nm and a topographic height of about 1.5 nm were synthesized using a facile sonication-assisted liquid-phase exfoliation approach. The prepared Mo2C QDs exhibited a strong near-infrared (NIR) absorbance with a high molar extinction coefficient of 4.424 Lg−1cm−1 at 808 nm, a high photothermal conversion efficiency of 42.9%, and showed excellent performance on photoacoustic imaging. The Mo2C QDs had high stability and highly biocompatibility, with low cytotoxicity. Under NIR irradiation, a remarkable in vitro and in vivo therapeutic effect was obtained. Such a stable and biocompatible all-in-one theranostic nanoagent generated by facile synthesis that combines promising imaging guidance and effective tumor ablation properties may hold great potential for theranostic nanomedicine.
Stress Ratio and Notch Effects on the Very High Cycle Fatigue Properties of a Near-Alpha Titanium Alloy
Authors: Yang Kun , Zhong Bin , Huang Qi , He Chao , Huang Zhi-Yong , Wang Qingyuan , Liu Yong-Jie
Published: September 2018

Ultrasonic fatigue tests up to 1010 cycles were performed on a turbine engine titanium alloy (Ti-8Al-1Mo-1V) at the stress ratio (R) of −1 with smooth specimens and at R = −1, 0.1 and 0.5 with notched specimens. As a result, with increase of fatigue life, the source of reduced fatigue life caused by multi-point surface crack initiation changes from crack propagation stage to crack initiation stage in the high cycle fatigue regime. Notch effect further promotes the degeneration of high cycle and very high cycle fatigue strength at R > −1. The bilinear model, extended from the Goodman method, can better estimate the mean stress sensitivity of this titanium alloy. The fatigue mean stress sensitivity and fatigue-creep mean stress sensitivity of this material increased with the increase of fatigue life. The new model, based on the Murakami model, can provide more appropriate predictions for notch fatigue strength.
Quality Analysis of American Ginseng Cultivated in Heilongjiang Using UPLC-ESI−-MRM-MS with Chemometric Methods
Authors: Xia Yong-Gang , Song Yan , Liang Jun , Guo Xin-Dong , Yang Bing-You , Kuang Hai-Xue
Published: September 2018

American ginseng (Panax quinquefolium) has long been cultivated in China for the function food and medicine. Here, ultra-high performance liquid chromatography was coupled with electrospray ionization and triple quadrupole mass spectrometry (UPLC-ESI−-TQ-MS) for simultaneous detection of 22 ginsenosides in American ginseng cultivated in Mudanjiang district of Heilongjiang. The extraction conditions also were optimized by a Box Behnken design experiment. The optimized result was 31.8 mL/g as ratio of liquid to raw materials, 20.3 min of extraction time, and 235.0 W of extraction powers. The quantitative MS parameters for these 22 compounds were rapidly optimized by single factor experiments employing UPLC-ESI−-multiple reaction monitoring or multiple ion monitoring (MRM/MIM) scans. Furthermore, the established UPLC-ESI−-MRM-MS method showed good linear relationships (R2 > 0.99), repeatability (RSD < 3.86%), precision (RSD < 2.74%), and recovery (94–104%). This method determined 22 bioactive ginsenosides in different parts of the plant (main roots, hairy roots, rhizomes, leaves, and stems) and growth years (one year to four years) of P. quinquefolium. The highest total content of the 22 analytes was in the hairy roots (1.3 × 105 µg/g) followed by rhizomes (7.1 × 104 µg/g), main roots (6.5 × 104 µg/g), leaves (4.2 × 104 µg/g), and stems (2.4 × 104 µg/g). Finally, chemometric methods, hierarchical clustering analysis (HCA) and partial least squares discrimination analysis (PLS-DA), were successfully used to classify and differentiate American ginseng attributed to different growth years. The proposed UPLC-ESI−-MRM-MS coupled with HCA and PLS-DA methods was elucidated to be a simple and reliable method for quality evaluation of American ginseng.
Engineering Surface and Optical Properties of TiO2-Coated Electrospun PVDF Nanofibers Via Controllable Self-Assembly
Authors: Yang Jianming , He Fuan , Wu Huijun , Liang Yuying , Wang Yuxuan , Sun Zhi
Published: September 2018

Understanding the effect of a porous TiO2 nanolayer on the optical scattering and absorption through electrospun fibers is of great importance for the design and development of advanced optical extinction materials. Based on electrospinning and controllable self-assembly techniques, pure electrospun poly(vinylidene fluoride) (PVDF) fibers and TiO2-coated ones with different self-assembly cycles were prepared. The effect of TiO2 self-assembly cycles on surface parameters, e.g., thickness, assembled content, and porosity of the TiO2 nanolayer were determined by scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. With an increase in the self-assembly cycles, the TiO2-coated electrospun PVDF fibers presented rougher surfaces and greater average diameters. According to the characterized surface parameters, the effects of the controllable self-assembly on the optical refractive index, absorption index, and infrared extinction were investigated to increase the optical properties of electrospun PVDF fibers. The results indicated that an increase of almost 120–130 cm−1 in infrared extinction could be achieved through the controllable self-assembly with only 5.7 wt. % assembled TiO2 content. This is highly efficient when compared with other coating modes. We believe that this study could give some positive guidance in the design of TiO2-coated electrospun fibers for improving their surface and optical properties.
The Impact of Management Fees on the Pricing of Variable Annuity Guarantees
Authors: Sun Jin , Shevchenko Pavel V. , Fung Man Chung
Published: September 2018

Variable annuities, as a class of retirement income products, allow equity market exposure for a policyholder’s retirement fund with optional guarantees to limit the downside risk of the market. Management fees andguarantee insurance fees are charged respectively for the market exposure and for the protection from the downside risk. We investigate the pricing of variable annuity guarantees under optimal withdrawal strategies when management fees are present. We consider from both policyholder’s and insurer’s perspectives optimal withdrawal strategies and calculate the respective fair insurance fees. We reveal a discrepancy where the fees from the insurer’s perspective can be significantly higher due to the management fees serving as a form of market friction. Our results provide a possible explanation of lower guarantee insurance fees observed in the market than those predicted from the insurer’s perspective. Numerical experiments are conducted to illustrate the results.
Sub-Diffraction Visible Imaging Using Macroscopic Fourier Ptychography and Regularization by Denoising
Authors: Li Zhixin , Wen Desheng , Song Zongxi , Liu Gang , Zhang Weikang , Wei Xin
Published: September 2018

Imaging past the diffraction limit is of significance to an optical system. Fourier ptychography (FP) is a novel coherent imaging technique that can achieve this goal and it is widely used in microscopic imaging. Most phase retrieval algorithms for FP reconstruction are based on Gaussian measurements which cannot extend straightforwardly to long range, sub-diffraction imaging setup because of laser speckle noise corruption. In this work, a new FP reconstruction framework is proposed for macroscopic visible imaging. When compared with existing research, the reweighted amplitude flow algorithm is adopted for better signal modeling, and the Regularization by Denoising (RED) scheme is introduced to reduce the effects of speckle. Experiments demonstrate that the proposed method can obtain state-of-the-art recovered results on both visual and quantitative metrics without increasing computation cost, and it is flexible for real imaging applications.
Robust Step Counting for Inertial Navigation with Mobile Phones
Authors: Rodríguez Germán , Casado Fernando E. , Iglesias Roberto , Regueiro Carlos V. , Nieto Adrián
Published: September 2018

Mobile phones are increasingly used for purposes that have nothing to do with phone calls or simple data transfers, and one such use is indoor inertial navigation. Nevertheless, the development of a standalone application able to detect the displacement of the user starting only from the data provided by the most common inertial sensors in the mobile phones (accelerometer, gyroscope and magnetometer), is a complex task. This complexity lies in the hardware disparity, noise on data, and mostly the many movements that the mobile phone can experience and which have nothing to do with the physical displacement of the owner. In our case, we describe a proposal, which, after using quaternions and a Kalman filter to project the sensors readings into an Earth Centered inertial reference system, combines a classic Peak-valley detector with an ensemble of SVMs (Support Vector Machines) and a standard deviation based classifier. Our proposal is able to identify and filter out those segments of signal that do not correspond to the behavior of “walking”, and thus achieve a robust detection of the physical displacement and counting of steps. We have performed an extensive experimental validation of our proposal using a dataset with 140 records obtained from 75 different people who were not connected to this research.