bluuebunny/crossref_metadata_2025 huggingface dataset:
In Silico Analysis of Hepatitis B Virus Occult Associated Mutations in Botswana Using a Novel Algorithm
Authors: Anderson Motswedi , Choga Wonderful T. , Moyo Sikhulile , Bell Trevor Graham , Mbangiwa Tshepiso , Phinius Bonolo B. , Bhebhe Lynette , Sebunya Theresa K. , Makhema Joseph , Marlink Richard , Kramvis Anna , Essex Max , Musonda Rosemary M. , Blackard Jason T. , Gaseitsiwe Simani
Published: August 2018

Occult hepatitis B infections (OBI) represent a reservoir of undiagnosed and untreated hepatitis B virus (HBV), hence the need to identify mutations that lead to this phenotype. Functionally characterizing these mutations by in vitro studies is time-consuming and expensive. To bridge this gap, in silico approaches, which predict the effect of amino acid (aa) variants on HBV protein function, are necessary. We developed an algorithm for determining the relevance of OBI-associated mutations using in silico approaches. A 3 kb fragment of subgenotypes A1 and D3 from 24 chronic HBV-infected (CHB) and 24 OBI participants was analyzed. To develop and validate the algorithm, the effects of 68 previously characterized occult-associated mutations were determined using three computational tools: PolyPhen2, SNAP2, and PROVEAN. The percentage of deleterious mutations (with impact on protein function) predicted were 52 (76.5%) by PolyPhen2, 55 (80.9%) by SNAP2, and 65 (95.6%) by PROVEAN. At least two tools correctly predicted 59 (86.8%) mutations as deleterious. To identify OBI-associated mutations exclusive to Botswana, study sequences were compared to CHB sequences from GenBank. Of the 43 OBI-associated mutations identified, 26 (60.5%) were predicted by at least two tools to have an impact on protein function. To our knowledge, this is the first study to use in silico approaches to determine the impact of OBI-associated mutations, thereby identifying potential candidates for functional analysis to facilitate mechanistic studies of the OBI phenotype.
Human Age Prediction Based on DNA Methylation Using a Gradient Boosting Regressor
Authors: Li Xingyan , Li Weidong , Xu Yan
Published: August 2018

All tissues of organisms will become old as time goes on. In recent years, epigenetic investigations have found that there is a close correlation between DNA methylation and aging. With the development of DNA methylation research, a quantitative statistical relationship between DNA methylation and different ages was established based on the change rule of methylation with age, it is then possible to predict the age of individuals. All the data in this work were retrieved from the Illumina HumanMethylation BeadChip platform (27K or 450K). We analyzed 16 sets of healthy samples and 9 sets of diseased samples. The healthy samples included a total of 1899 publicly available blood samples (0–103 years old) and the diseased samples included 2395 blood samples. Six age-related CpG sites were selected through calculating Pearson correlation coefficients between age and DNA methylation values. We built a gradient boosting regressor model for these age-related CpG sites. 70% of the data was randomly selected as training data and the other 30% as independent data in each dataset for 25 runs in total. In the training dataset, the healthy samples showed that the correlation between predicted age and DNA methylation was 0.97, and the mean absolute deviation (MAD) was 2.72 years. In the independent dataset, the MAD was 4.06 years. The proposed model was further tested using the diseased samples. The MAD was 5.44 years for the training dataset and 7.08 years for the independent dataset. Furthermore, our model worked well when it was applied to saliva samples. These results illustrated that the age prediction based on six DNA methylation markers is very effective using the gradient boosting regressor.
Selective Aggregation Experiments on Planetesimal Formation and Mercury-Like Planets
Authors: Wurm Gerhard
Published: August 2018

Much of a planet’s composition could be determined right at the onset of formation. Laboratory experiments can constrain these early steps. This includes static tensile strength measurements or collisions carried out under Earth’s gravity and on various microgravity platforms. Among the variety of extrasolar planets which eventually form are (Exo)-Mercury, terrestrial planets with high density. If they form in inner protoplanetary disks, high temperature experiments are mandatory but they are still rare. Beyond the initial process of hit-and-stick collisions, some additional selective processing might be needed to explain Mercury. In analogy to icy worlds, such planets might, e.g., form in environments which are enriched in iron. This requires methods to separate iron and silicate at early stages. Photophoresis might be one viable way. Mercury and Mercury-like planets might also form due to the ferromagnetic properties of iron and mechanisms like magnetic aggregation in disk magnetic fields might become important. This review highlights some of the mechanisms with the potential to trigger Mercury formation.
Lake Nyos, a Multirisk and Vulnerability Appraisal
Authors: Tchindjang Mesmin
Published: August 2018

Situated at the northern flank of the Oku Massif, Lake Nyos crater epitomizes landscape features originating from volcanic explosions during the Quaternary. The Cameroon Volcanic Line (CVL), to which it belongs, constitutes the most active volcanic region in Cameroon. In 1986, an outgas explosion occurred from beneath the lake and killed 1746 people in several neighbouring villages. The event influenced a radial area of 25 to 40 km wide, particularly in eastern and western direction. This was mainly due to: (1) the rugged nature of the landscape (fault fields), which enabled the heavier gas to follow valleys framed by faults corridors without affecting elevated areas; and (2) the seasonal dominating western wind direction, which channeled the gas along tectonic corridors and valleys. This paper assesses the geological risk and vulnerability in the Lake Nyos before and after several proposal to mitigate future outgas events. Remotely sensed data, together with GIS tools (topographic maps, aerial photographs), helped to determine and assess lineaments and associated risks. A critical grid combining severity and frequency analysis was used to assess the vulnerability of the local population. There is evidence that along the main fault directions (SW–NE), anthropogenic activities are most intensive and they may play an aggravating role for disasters. This requires the local population’s consciousness-raising. The results also show that population around Lake Nyos still remains vulnerable to volcanic hazards and floods. However, the area has been safe since the last degassing and jet grouting through multiple procedures and actions proposed in the National Contingency Plan, and equally by the relief organization plan (DROP or ORSEC plan) for the Menchum Division. Another issue is that the local population is concerned with the idea of returning to the affected areas in order to stay close to their ancestors or the deceased. Therefore, even after jet grouting and degassing, the problem of risk minimization for local residents remains.
CCR6–CCL20-Mediated Immunologic Pathways in Inflammatory Bowel Disease
Authors: Ranasinghe Ranmali , Eri Rajaraman
Published: August 2018

Inflammatory bowel disease (IBD) has evoked significant interest in human immunobiology given its tactical immune evasion methodologies resulting in acute immune destabilization. IBD comprising Crohn’s disease and Ulcerative colitis manifests as chronic inflammation in the gut mucosa, leading to complexities involving immune dysregulation in the T helper lymphocyte arm, effecting disease pathogenicity. The mucosa of the alimentary canal is constantly exposed to a myriad of food antigens and luminal microorganisms for which a consistent host-protective mechanism is operative in healthy people. Lowered mucosal immune expression which allows penetration of the epithelial barrier by infective pathogenic microbes elicits both innate and adaptive immune responses in the gut, culminating in aberrant intestinal inflammation. Interestingly, the IBD leukocyte repertoire is significantly entwined with chemokine-assisted chemotactic navigation into the sites of inflammation, which is also thought to generate favorable immune-suppressive responses. The functions of the cognate chemokine receptor, CCR6, which binds with its unique ligand CCL20, are expected to tilt the balance between upregulation of homeostatic tolerance and inflammatory pathophysiology. This review aims to critically examine the CCR6-driven immune pathways: TH1/TH2, TH1/TH17, TH17/Treg, IL-23/IL-17, Akt/ERK-1/2, ILC3, and TH9/TH2 for systematic investigation of its underlying mechanisms in the future and to underpin its importance in resolving IBD pathology. Thus, CCR6 occupies an exclusive position in gut immunology which renders it an invaluable therapeutic tool for the production of novel medicaments to treat IBD.
Exogenous Glycinebetaine Promotes Soil Cadmium Uptake by Edible Amaranth Grown during Subtropical Hot Season
Authors: Yao Wei-Qing , Lei Yong-Kang , Yang Ping , Li Qu-Sheng , Wang Li-Li , He Bao-Yan , Xu Zhi-Min , Zhou Chu , Ye Han-Jie
Published: August 2018

Exogenous glycinebetaine treatment is an effective measure for preventing crops from being exposed to drought and high temperature; however, the effects of this approach on the soil Cd uptake and accumulation by crops remain unclear. Pot experiments were conducted in this study to analyze the effect of glycinebetaine on the soil Cd uptake and accumulation by edible amaranth cultivated in Cd-contaminated soil. Results revealed that after exogenous glycinebetaine treatment on amaranth leaves during the vigorous growth period, the plant biomass, the Cd concentrations in the roots and shoots, and the Cd translocation factor (TF) were significantly higher than those of the control group. The highest Cd concentrations in the roots and shoots and the TF were higher by 91%, 96% and 23.8%, respectively, than the corresponding values in the control group. In addition, exogenous glycinebetaine treatment significantly increased leaf chlorophyll content and promoted the photosynthesis of edible amaranth. Consequently, the contents of soluble sugar, dissolved organic carbon, and low-molecular-weight organic acids significantly increased in the rhizosphere, resulting in Cd mobilization. Significant positive correlations were observed among the contents of leaf chlorophyll, Mg, Fe, pectin and Ca. Given that Cd shares absorption and translocation channels with these elements, we speculated that the increased leaf chlorophyll and pectin contents promoted the absorption and accumulation of Mg, Fe and Ca, which further promoted the absorption and translocation of Cd. These results indicated that exogenous glycinebetaine treatment during hot season would aggravate the health risks of crops grown in Cd-contaminated soils.
The Influence of Adolescents’ Social Networks on Alcohol Consumption: A Descriptive Study of Spanish Adolescents Using Social Network Analysis
Authors: Quiroga Enedina , Pinto-Carral Arrate , García Isaías , Molina Antonio J. , Fernández-Villa Tania , Martín Vicente
Published: August 2018

In adolescence, friends are important due to their influence on the acquisition of habits such as alcohol consumption. However, there is a lack of studies that describe the structural context of adolescents, which would be useful to implement prevention strategies. Therefore, our research question was how adolescent friendship networks influence alcohol consumption. Our goal was to determine the structural profile of adolescent at-risk alcohol users and their relational context in the classroom. We designed a descriptive cross-sectional study based on social network analysis to analyze structural patterns. We recruited 195 students. Social-network and alcohol-consumption variables were analyzed using the UCINET and STATA programs. Some 86.67% of participants had consumed alcohol at some time in their lives and the prevalence of at-risk alcohol use was higher in females (50.48% vs. 49.52%; OR: 1.84; CI 95%: 0.99–3.43%; p = 0.036). The lower the intensity of friendship, the more contacts adolescent at-risk alcohol users had within the network, and the easier it was for them to access their peers. Consequently, we conclude that the structure of a class is a key factor that merits further research.
Reversing the Trends toward Shorter Lives and Poorer Health for U.S. Women: A Call for Innovative Interdisciplinary Research
Authors: Schweinhart April , Clayton Janine Austin
Published: August 2018

The United States (U.S.) is a leader and innovator in biomedicine, yet trails behind for many key health indicators, especially for women. This paper highlights key evidence indicating that not only is the state of women’s health in the U.S. lagging, but it is at risk for falling off the curve. Women’s health care remains fragmented; research in the field can be disconnected and difficult to integrate across disciplines—silos prevail. Structural obstacles contribute to this lack of cohesion, and innovative, interdisciplinary research approaches which integrate the multidimensional aspects of sex and gender, and race and ethnicity, with a life course perspective are sorely needed. Such synergistic, scientific strategies have the potential to reverse the trend towards shorter life expectancy and poorer health for women in the U.S. The National Institute for Health (NIH) seeks to raise the bar for the health of all women by tackling these issues through enhancing the relevance of biomedical research to the health of women and driving the sustained advancement of women in biomedical careers.
Differences in Metabolic Syndrome Prevalence by Employment Type and Sex
Authors: Cho Duk Youn , Koo Jung-Wan
Published: August 2018

Workers may sometimes do the same work, but differ in their risk of health-related problems depending on whether the employment type is standard or non-standard. Furthermore, even with similar job and employment types, there may be differences in risk factors for health-related problems depending on sex. This study aimed to determine the prevalence of metabolic syndrome (MetS) by employment type and sex using data from the Fifth Korean National Health and Nutrition Examination Survey (KNHANES Ⅴ) (2010–2012) and KNHANES Ⅵ (2013–2015) conducted by the Korea Centers for Disease Control and Prevention. Overall, 9523 adult wage workers (5523 standard workers and 4000 non-standard workers) aged ≥ 19 years were analyzed. To determine MetS prevalence odds ratios according to employment type, logistic regression analysis was performed disaggregated by sex. The prevalence of MetS significantly increased with age (p < 0.001), being married (p < 0.05), current smoking status (p < 0.05), and high-risk drinking (p < 0.001) among male subjects. The prevalence of MetS significantly increased among female manual workers (p < 0.001), those with lower educational level and household income (p < 0.001). Non-standard workers of either sex showed higher MetS prevalence than standard workers; only females showed significant difference (p < 0.001). Female non-standard workers showed 1.44, 1.33, and 1.34 (all p < 0.001) times higher odds of MetS prevalence in Models 1, 2, and 3, respectively, compared to standard workers, suggesting a difference in risk factors of MetS according to sex. Also, that employment type affects MetS prevalence suggests that employment pattern is an important risk factor especially in females. Therefore, to manage MetS in female non-standard workers, individual health care as well as social effort may be necessary.
An Augmented Risk Information Seeking Model: Perceived Food Safety Risk Related to Food Recalls
Authors: Liao Chuanhui , Zhou Xiaomei , Zhao Dingtao
Published: August 2018

Food safety is of worldwide concern. As an effective mechanism governing food safety, food recalls are widely applied around the world. Though it is well known that food recalls can have substantial, negative impacts on corporate reputation and marketing, we know relatively little related to what factors motivate people to seek related information after the recall announcement. This study attempts to elucidate the determinants of information-seeking intention in the context of food safety in food recalls by using an augmented risk information-seeking model. A survey of 631 Chinese residents was used to explore the proposed framework. The results show that current knowledge, risk perception, perceived channel beliefs, and perceived information-gathering capacity (PIGC) are all significant predictors of information need and information-seeking intention. It was also confirmed that risk perception has a positive correlation with seeking need. These findings are important for policymakers, recalling manufacturers, and retailers to develop strategies for better risk communication in food recall announcements.
An Assessment of the Relationships between Extreme Weather Events, Vulnerability, and the Impacts on Human Wellbeing in Latin America
Authors: Nagy Gustavo J. , Filho Walter Leal , Azeiteiro Ulisses M. , Heimfarth Johanna , Verocai José E. , Li Chunlan
Published: August 2018

Climate change and variability are known to have an influence on human wellbeing in a variety of ways. In Latin America, such forces are especially conspicuous, particularly in respect of extreme climatological, hydrological, and weather events (EWEs) and climate-sensitive disasters (CSDs). Consistent with the need to study further such connections, this paper presents an analysis of some of the vulnerabilities of environmental health issues and climate-related impacts that are focusing on EWEs and CSDs in Latin American countries. The research includes an analysis of the (i) human and socio-economic development; (ii) geographical and socio-economic determinants of vulnerability and adaptability of environmental health issues (exposure, sensitivity, and adaptive capacity); (iii) occurrence of CSDs from 1988 to 2017 and their direct impacts on human wellbeing (Total death and Affected people); (iv) an online survey on the perceptions of the effects of EWEs on human wellbeing in a sample of countries in the region; and (v) discussion of possible solutions. The socio-economic and development indices, and the International Disaster Database (EM-DAT) and Climate-Risk Index (CRI) disaster statistics suggest that the impacts of CSDs are primarily related to socio-economic determinants of human wellbeing and health inequalities. Also, >80% respondents to the survey say that the leading causes of climate-related human impacts are the lack of (i) public awareness; (ii) investment and (iii) preparedness. The paper concludes by adding some suggestions that show how countries in Latin America may better cope with the impacts of Climate-sensitive Disasters.
Functional Expression of TRP Ion Channels in Endometrial Stromal Cells of Endometriosis Patients
Authors: Persoons Eleonora , Hennes Aurélie , De Clercq Katrien , Van Bree Rita , Vriens Goede , O Dorien F. , Peterse Daniëlle , Vanhie Arne , Meuleman Christel , Voets Thomas , Tomassetti Carla , Vriens Joris
Published: August 2018

Endometriosis is a common gynecological disease that is characterized by the presence of functional endometrial-like lesions in the abdominal cavity. Aside from epithelial cells, these lesions consist of stromal cells that have the capacity to migrate, adhere, proliferate, and induce neuro- and lymphangiogenesis, which allows them to survive at ectopic locations. However, the exact underlying mechanisms that regulate these changes are yet to be elucidated. The common ground of these processes, however, is the second messenger, calcium. In this regard, members of the superfamily of transient receptor potential (TRP) ion channels, which are known to be calcium-permeable and expressed in the endometrium, have emerged as key regulators. Here, we assessed the molecular and functional expression of TRP channels in stromal cells isolated from the eutopic endometrium of endometriosis patients and controls. Using RT-qPCR, high mRNA levels of TRPV2, TRPV4, TRPM4, TRPM7, TRPC1, TRPC3, TRPC4, and TRPC6 were observed in the whole endometrium throughout the menstrual cycle. Additionally, and in line with previous reports of control patients, TRPV2, TRPV4, TRPC1/4, and TRPC6 were present in human endometrial stromal cells (hESC) from endometriosis patients both at the molecular and functional level. Moreover, proliferation and migration assays illustrated that these parameters were not affected in stromal cells from endometriosis patients. Furthermore, comparison between eutopic and ectopic endometrial samples revealed that the RNA expression pattern of TRP channels did not differ significantly. Collectively, although a functional expression of specific ion channels in hESCs was found, their expression did not correlate with endometriosis.
Involvement of Connexin Hemichannels in the Inflammatory Response of Chronic Diseases
Authors: Sáez Juan C. , Green Colin
Published: August 2018

Over the last decade it has become evident that under normal conditions connexin hemichannels are either not expressed (e.g., skeletal muscle) or are expressed in very low numbers with low open probability in various mammalian tissues (e.g., liver and central nervous system (CNS)).[...]
Unraveling the Molecular Mechanism of Immunosenescence in Drosophila
Authors: Min Kyung-Jin , Tatar Marc
Published: August 2018

A common feature of the aging process is a decline in immune system performance. Extensive research has sought to elucidate how changes in adaptive immunity contribute to aging and to provide evidence showing that changes in innate immunity have an important role in the overall decline of net immune function. Drosophila is an emerging model used to address questions related to immunosenescence via research that integrates its capacity for genetic dissection of aging with groundbreaking molecular biology related to innate immunity. Herein, we review information on the immunosenescence of Drosophila and suggest its possible mechanisms that involve changes in insulin/IGF(insulin-like growth factor)-1 signaling, hormones such as juvenile hormone and 20-hydroxyecdysone, and feedback system degeneration. Lastly, the emerging role of microbiota on the regulation of immunity and aging in Drosophila is discussed.
Inside the Endometrial Cell Signaling Subway: Mind the Gap(s)
Authors: Makieva Sofia , Giacomini Elisa , Ottolina Jessica , Sanchez Ana Maria , Papaleo Enrico , Viganò Paola
Published: August 2018

Endometrial cells perceive and respond to their microenvironment forming the basis of endometrial homeostasis. Errors in endometrial cell signaling are responsible for a wide spectrum of endometrial pathologies ranging from infertility to cancer. Intensive research over the years has been decoding the sophisticated molecular means by which endometrial cells communicate to each other and with the embryo. The objective of this review is to provide the scientific community with the first overview of key endometrial cell signaling pathways operating throughout the menstrual cycle. On this basis, a comprehensive and critical assessment of the literature was performed to provide the tools for the authorship of this narrative review summarizing the pivotal components and signaling cascades operating during seven endometrial cell fate “routes”: proliferation, decidualization, implantation, migration, breakdown, regeneration, and angiogenesis. Albeit schematically presented as separate transit routes in a subway network and narrated in a distinct fashion, the majority of the time these routes overlap or occur simultaneously within endometrial cells. This review facilitates identification of novel trajectories of research in endometrial cellular communication and signaling. The meticulous study of endometrial signaling pathways potentiates both the discovery of novel therapeutic targets to tackle disease and vanguard fertility approaches.
Interpolation Filter Design Based on All-Phase DST and Its Application to Image Demosaicking
Authors: Zhou Xiao , Wang Chengyou , Zhang Zhi , Fu Qiming
Published: August 2018

Based on a deep understanding of all-phase digital filter (APDF) design and all-phase biorthogonal transform (APBT), this paper will further study the windowed all-phase digital filter (WAPDF) and windowed all-phase biorthogonal transform (WAPBT), discuss the principle of the WAPBT, and provide a unified construction method of the all-phase transform (APT). Based on a type of orthogonal transform, i.e., discrete sine transform (DST), an interpolation filter called an all-phase DST (APDST) filter is constructed and used for image demosaicking; it is compared with bilinear interpolation and all-phase inverse discrete cosine transform (APIDCT) interpolation filters, to test its performance in image interpolation and provide analysis and discussion. The experimental results show that APIDCT and APDST filters with a size of 7 × 7 are similar in interpolation performance, but better than the bilinear interpolation method. In addition to its use in image interpolation demosaicking, the low-pass filter designed in this paper can also be widely used in image interpolation, image denoising, image resizing, and other fields of image processing.
Phenotypic Plasticity Promotes Overwintering Survival in A Globally Invasive Crop Pest, Drosophila suzukii
Authors: Stockton Dara , Wallingford Anna , Loeb Gregory
Published: August 2018

Spotted wing drosophila, Drosophila suzukii Matsumura, is a major pest of small fruit worldwide in temperate and subtropical growing regions. In Northern climates, D. suzukii likely overwinters locally under leaf litter and snow pack, but our understanding of the factors affecting thermal susceptibility is limited. While previous investigations of thermal susceptibility in this species have employed conventional static acclimation protocols, we aimed to determine whether gradual cooling, or dynamic acclimation, may extend the limits of known thermal tolerance by more closely approximating naturally occurring shifts in temperature. First, we assessed survival among adult and pupal D. suzukii using static acclimation. Then, we re-assessed survival using a novel dynamic acclimation method. We found that while static acclimation was sufficient to induce cold tolerance, dynamic acclimation significantly improved survival at temperatures as low as −7.5 °C. Following static acclimation, the lower lethal limit of adult D. suzukii was −1.1 °C in winter morphotype (WM) adults compared to 1.7 °C in non-acclimated summer morphotype (SM) adults. Dynamic acclimation reduced the lower limit to −5 °C in SM flies. At the end of our study 50% of WM flies survived 72 h at −7.5 °C. Below 0 °C pupal survival declined significantly regardless of acclimation procedure. However, pupal acclimation improved survival outcomes significantly compared to non-acclimated pupae, suggesting that while juvenile diapause is unlikely, cold hardening likely benefits those flies which may develop into the overwintering WM population. These data suggest that the degree of cold hardening is proportional to the thermal environment, a finding previously unrecognized in this species. Given the economic impact of this pest, these data may have important implications for offseason population monitoring and management. We discuss how phenotypic plasticity may drive geographical range expansion, and the impact of climate change on the spread of this species.
Risks of Pneumonia in COPD Patients with New-Onset Atrial Fibrillation
Authors: Wang Ya-Hui , Lai Chih-Cheng , Wang Cheng-Yi , Wang Hao-Chien , Yu Chong-Jen , Chen Likwang ,   On Behalf of the Taiwan Clinical Trial Consortium for Respiratory Diseases
Published: August 2018

The association between Atrial Fibrillation (AF) and pneumonia remains unclear. This study aims to assess the impact of AF on high pneumonia risk group—chronic obstructive pulmonary disease (COPD)—In order to find the association between AF and the risk of pneumonia. The COPD cohort was extracted from National Health Research Institute of Taiwan. The AF cohort comprised all COPD patients with new-onset AF (International Classification of Diseases (ICD)-9 code 427.31) after COPD diagnosis. We further sampled non-AF cohort and performed 1:1 propensity score matched analysis to improve the balance of baseline characteristics between AF and non-AF cohort. The outcomes were pneumonia and pneumonia requiring mechanical ventilation (MV). From 2000–2011, a total of 6228 patients with COPD and AF, and matched 84,106 control subjects were enrolled. After propensity score matching, we identified 6219 patients, each with AF, and matched controls without AF. After propensity score matching, the AF cohorts had higher risk of mortality (adjusted hazard ratio (aHR), 1.24; 95% confidence interval (CI), 1.15–1.34), pneumonia (aHR, 1.17; 95% CI, 1.07–1.27), and pneumonia requiring MV (aHR, 1.33; 95% CI, 1.18–1.50) in comparison with the matched non-AF cohort. After adjusting for mortality from causes other than outcomes of interest as a competing risk, AF remains significantly associated with pneumonia and pneumonia requiring MV. The risks of pneumonia were higher in this population with AF than in those without AF, and the risk was still significant after the adjustment for the competing risk of all-cause mortality.
Tailoring the Interface of Biomaterials to Design Effective Scaffolds
Authors: Parisi Ludovica , Toffoli Andrea , Ghiacci Giulia , Macaluso Guido M.
Published: August 2018

Tissue engineering (TE) is a multidisciplinary science, which including principles from material science, biology and medicine aims to develop biological substitutes to restore damaged tissues and organs. A major challenge in TE is the choice of suitable biomaterial to fabricate a scaffold that mimics native extracellular matrix guiding resident stem cells to regenerate the functional tissue. Ideally, the biomaterial should be tailored in order that the final scaffold would be (i) biodegradable to be gradually replaced by regenerating new tissue, (ii) mechanically similar to the tissue to regenerate, (iii) porous to allow cell growth as nutrient, oxygen and waste transport and (iv) bioactive to promote cell adhesion and differentiation. With this perspective, this review discusses the options and challenges facing biomaterial selection when a scaffold has to be designed. We highlight the possibilities in the final mold the materials should assume and the most effective techniques for its fabrication depending on the target tissue, including the alternatives to ameliorate its bioactivity. Furthermore, particular attention has been given to the influence that all these aspects have on resident cells considering the frontiers of materiobiology. In addition, a focus on chitosan as a versatile biomaterial for TE scaffold fabrication has been done, highlighting its latest advances in the literature on bone, skin, cartilage and cornea TE.
Intra- and Inter-Repeatability of Profile Deviations of an AlSi10Mg Tooling Component Manufactured by Laser Powder Bed Fusion
Authors: Zongo Floriane , Tahan Antoine , Aidibe Ali , Brailovski Vladimir
Published: August 2018

Laser powder bed fusion (LPBF) is one of the most potent additive manufacturing (AM) processes. Metallic LPBF is gaining popularity, but one of the obstacles facing its larger industrial use is the limited knowledge of its dimensional and geometrical performances. This paper presents a metrological investigation of the geometrical and dimensional deviations of a selected LPBF-manufactured component, according to the ASME Y14.5-2009 standard. This approach allows for an estimation of both the process capability, as per ISO 22514-4 standard, and the correlations between the part location in the manufacturing chamber and the profile deviations. Forty-nine parts, which are representative of a typical aerospace tooling component (30 mm in diameter and 27.2 mm in height) were manufactured from AlSi10Mg powder using an EOSINT M280 printer and subjected to a stress relief annealing at 300 °C for two hours. This manufacturing procedure was repeated three times. A complete statistical analysis was carried out and the results of the investigation show that LPBF performances for all geometrical variations of 147 identical parts fall within a range of 230 µm at a 99.73% level.
Coupled and Decoupled Force/Motion Controllers for an Underwater Vehicle-Manipulator System
Authors: Barbalata Corina , Dunnigan Matthew W. , Petillot Yvan
Published: August 2018

Autonomous interaction with the underwater environment has increased the interest of scientists in the study of control structures for lightweight underwater vehicle-manipulator systems. This paper presents an essential comparison between two different strategies of designing control laws for a lightweight underwater vehicle-manipulator system. The first strategy aims to separately control the vehicle and the manipulator and hereafter is referred to as the decoupled approach. The second method, the coupled approach, proposes to control the system at the operational space level, treating the lightweight underwater vehicle-manipulator system as a single system. Both strategies use a parallel position/force control structure with sliding mode controllers and incorporate the mathematical model of the system. It is demonstrated that both methods are able to handle this highly non-linear system and compensate for the coupling effects between the vehicle and the manipulator. The results demonstrate the validity of the two different control strategies when the goal is located at various positions, as well as the reliable behaviour of the system when different environment stiffnesses are considered.
A Simulation Study for the Design of Membrane Restrictor in an Opposed-Pad Hydrostatic Bearing to Achieve High Static Stiffness
Authors: Lai Ta-Hua , Lin Shih-Chieh
Published: August 2018

The effects of a membrane restrictor’s design parameters on the performance of a hydrostatic opposed-pad bearing are presented in this article. Compared to the single-pad bearing, the opposed-pad bearing can perform much better in terms of static stiffness over a wider load range. It is also found that, for small bearing eccentricity, the optimal design restriction ratio of 0.25 still results in high bearing stiffness even if the dimensionless stiffness of membrane is not the optimal value of 1.33. Furthermore, decreasing the ratio of the upper effective area to the lower effective area generally increases the applicable working range of the bearing. Additionally, for high loading demands, the chance for further improvement of bearing performance by employing different design parameter for each pad is examined. Finally, a design procedure for designing the membrane restrictor for an opposed-pad bearing to achieve high static stiffness is given.
Nanoporous 3D-Printed Scaffolds for Local Doxorubicin Delivery in Bone Metastases Secondary to Prostate Cancer
Authors: Ahangar Pouyan , Akoury Elie , Ramirez Garcia Luna Ana Sofia , Nour Antone , Weber Michael H. , Rosenzweig Derek H.
Published: August 2018

The spine is the most common site of bone metastasis, often originating from prostate, lung, and breast cancers. High systemic doses of chemotherapeutics such as doxorubicin (DOX), cisplatin, or paclitaxel often have severe side effects. Surgical removal of spine metastases also leaves large defects which cannot spontaneously heal and require bone grafting. To circumvent these issues, we designed an approach for local chemotherapeutic delivery within 3D-printed scaffolds which could also potentially serve as a bone substitute. Direct treatment of prostate cancer cell line LAPC4 and patient derived spine metastases cells with 0.01 µM DOX significantly reduced metabolic activity, proliferation, migration, and spheroid growth. We then assessed uptake and release of DOX in a series of porous 3D-printed scaffolds on LAPC4 cells as well as patient-derived spine metastases cells. Over seven days, 60–75% of DOX loaded onto scaffolds could be released, which significantly reduced metabolic activity and proliferation of both LAPC4 and patient derived cells, while unloaded scaffolds had no effect. Porous 3D-printed scaffolds may provide a novel and inexpensive approach to locally deliver chemotherapeutics in a patient-specific manner at tumor resection sites. With a composite design to enhance strength and promote sustained drug release, the scaffolds could reduce systemic negative effects, enhance bone repair, and improve patient outcomes.
Porous AlGaN-Based Ultraviolet Distributed Bragg Reflectors
Authors: Griffin Peter , Zhu Tongtong , Oliver Rachel
Published: August 2018

Utilising dislocation-related vertical etching channels in gallium nitride, we have previously demonstrated a simple electrochemical etching (ECE) process that can create layered porous GaN structures to form distributed Bragg reflectors for visible light at wafer scale. Here, we apply the same ECE process to realise AlGaN-based ultraviolet distributed Bragg reflectors (DBRs). These are of interest because they could provide a pathway to non-absorbing UV reflectors to enhance the performance of UV LEDs, which currently have extremely low efficiency. We have demonstrated porous AlGaN-based UV DBRs with a peak reflectance of 89% at 324 nm. The uniformity of these devices is currently low, as the as-grown material has a high density of V-pits and these alter the etching process. However, our results indicate that if the material growth is optimised, the ECE process will be useful for the fabrication of UV reflectors.
The Impact of Surface Treatment and Degree of Vacuum on the Interface and Mechanical Properties of Stainless Steel Clad Plate
Authors: Feng Ying-ying , Yu Huan , Luo Zong-an , Xie Guang-ming , Misra R.
Published: August 2018

In this study, the impact of different surface treatment and degree of vacuum on the interface and mechanical properties of 304/Q345 stainless steel clad plate was investigated. The study indicated that more continuous or aggregated Al2O3 and Si-Mn composite oxides were formed at the interface after brush grinding. However, less inclusions such as Al2O3, MnS and Ca-Mg-Al-Si composite oxides were formed at the interface after pickling treatment. For the vacuum degrees of 10−2 Pa, 1 Pa and 105 Pa, the oxidation reaction became more intense with the decrease in vacuum degree. The interface inclusions were gradually changed from Al2O3 and Si-Mn complex oxides to oxide scale and MnCr2O4 spinel oxide. The interfacial bonding strength of stainless steel clad plate was improved with the increase in degree of vacuum. The bonding strength was 55 MPa at vacuum of 105 Pa, but it was 484 MPa at vacuum of 10−2 Pa, which is far greater than that of the national standard, and an excellent performance was obtained.
A New Prediction Method for the Ultimate Tensile Strength of Steel Alloys with Small Punch Test
Authors: Calaf Chica Jose , Bravo Díez Pedro Miguel , Preciado Calzada Mónica
Published: August 2018

The load–deflection curve acquired from the Small Punch Test (SPT) is used to obtain the mechanical properties of materials using different correlation methods. The scattering level of these regressions tends to be high when a wide set of materials is analyzed. In this study, a correlation method based on a specific slope of the SPT curve was proposed to reduce scattering. Assuming the Ramberg–Osgood hardening law, the dependence of the SPT curve slope on the yield strength and the hardening coefficient is demonstrated by numerical simulations (FEM). Considering that the ultimate tensile strength could be obtained from the hardening coefficient, a response surface of the ultimate tensile strength with the yield strength and SPT curve slope, along with its equation, is presented for steel alloys. A summary of steel mechanical properties, based on the Boiler and Pressure Vessel Code (BPVC) and limited to yield strengths lower than 1300 MPa, is shown to select a set of experimental tests (tensile tests and SPTs) for which the range is completely covered. This experimental analysis validates the previous FEM analyses and the validity of the proposed correlation method, which shows more accurate correlations compared to the current methods.
Outstanding Photoluminescence in Pr3+-Doped Perovskite Ceramics
Authors: Zhang Jiameng , Hao Yanan , Bi Meihua , Dong Guoyan , Liu Xiaoming , Bi Ke
Published: August 2018

Ba (Zr0.2Ti0.8) O3-50% (Ba0.7Ca0.3) TiO3 (BZT-0.5BCT) ceramics with different doping contents of Pr3+ were prepared by the conventional solid-state reaction. The phase structure and crystallinity of the fabricated ceramics were investigated by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Photoluminescence (PL) emission spectra were measured to analyze the PL characteristics. The strong intensities of a green band at 489 nm and a red band at 610 nm were observed. The maximum emission intensity of the PL spectrum was achieved in the BZT-0.5BCT ceramic with 0.2% mol of Pr3+ ions. Furthermore, the PL spectra of BZT-0.5BCT ceramics were found to be sensitive to polarization of the ferroelectric ceramics. Compared with the unpoled ceramics, the green emission increased about 42% and a new emission peak at 430 nm appeared for the poled ceramics. With excellent intrinsic ferroelectricity and an enhanced PL property, such material has potential to realize multifunctionality in a wide application range.
Authigenic Clay Minerals from Interface Reactions of Concrete-Clay Engineered Barriers: A New Perspective on Mg-Clays Formation in Alkaline Environments
Authors: Cuevas Jaime , Ruiz Ana Isabel , Fernández Raúl , González-Santamaría Daniel , Angulo María , Ortega Almudena , Torres Elena , Turrero María Jesús
Published: August 2018

Artificial and singular geochemical environments are created around the engineered barrier systems (EBS) designed to isolate high level nuclear wastes in deep geological repositories. A concrete-bentonite interface takes place within the EBS and it builds a significant chemical gradient (pH), approximately from pH 8 (bentonite) to pH 12 (low alkali concrete), in a few millimetre thickness. This disequilibrium triggers dissolution and precipitation reactions and form a thin altered region. In this area, poorly ordered authigenic clay minerals, mainly hydrated magnesium silicates, are formed adjacent to hydrated calcium silicates and calcite precipitates adhered to the interface with concrete. This paper presents the development of this authigenic mineral layer comparing 6–18 months to 13 years interfaces. Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (SEM-EDX) morphological and chemical characterization with the aid of ternary plots, X-ray diffraction (XRD) and infrared (IR) data show the young to old interface evolution from single brucite layers to stevensite-saponite silicates composition. Geochemical calculations indicate that this layer acts as a pH~11 buffer useful to minimize bentonite alteration and to favour the retention of amphoteric metal ions.
Hydrothermal Metasomatism and Gold Mineralization of Porphyritic Granite in the Dongping Deposit, North Hebei, China: Evidence from Zircon Dating
Authors: Wei Hao , Xu Jiuhua , Zhang Guorui , Cheng Xihui , Chu Haixia , Bian Chunjing , Zhang Zeyang
Published: August 2018

A porphyritic granite intrusion was recently discovered in the Zhuanzhilian section of the Dongping gold deposit. There is as many as one tonnage of Au in the fractured shear zone within the porphyritic granite intrusion, but no relevant reports concerning the origin and age of the intrusion has been published as yet. In this paper, zircon U-Pb dating is used to study the geochronology of porphyritic granite, in order to find out the evidence of age and the relationship with gold mineralization. There are two groups of zircon 207Pb/235U-206Pb/238U concordant ages of porphyritic granites: The concordant age of 373.0 ± 3.5 Ma, with the weighted mean age of 373.0 ± 6.4 Ma; and the concordant age of 142.02 ± 1.2 Ma with the weighted mean age of 142.06 ± 0.84 Ma. We believe that the first group might represent the age of residual zircon of alkaline complex, while the second group might be related with main gold mineralization. The obtained results of the petrography and electron probe analysis indicate that the porphyritic quartz and porphyritic granite, as well as gold mineralization, might be products of a late replacement of tectonic-hydrothermal fluid, which was rich in Si, Na and K originally and later yielded gold-forming fluids.
Study on the Quality Evaluation of Compound Danshen Preparations Based on the xCELLigence Real-Time Cell-Based Assay and Pharmacodynamic Authentication
Authors: Yan Guojun , Zhu Zhitao , Jin Liliang , Chen Jun , Xie Hui , Miozzi Jackelyn , Lei Feifei , Wei Xuchao , Pan Jinhuo
Published: August 2018

Objective: To perform a preliminary study on the quality evaluation of compound Danshen preparations based on the xCELLigence Real-Time Cell-based Assay (RTCA) system and make a pharmacodynamics verification. Methods: The compound Danshen was discussed as a methodological example, and the bioactivity of the compound Danshen preparations were evaluated by real-time cell electronic analysis technology. Meanwhile, an in vivo experiment on an acute blood stasis rat model was performed in order to verify this novel evaluation through the curative effect of dissipating blood stasis. Results: We determined the cell index (CI) and IC50 of the compound Danshen preparations and produced time/dose-dependent cell response profiles (TCRPs). The quality of the three kinds of compound Danshen preparations was evaluated through the RTCA data. The trend of CI and TCRPs reflected the effect of drugs on the cell (promoting or inhibiting), and it was verified that the results correlated with the biological activity of the drugs using a pharmacodynamics experiment. Conclusion: The RTCA system can be used to evaluate the quality of compound Danshen Preparations, and it can provide a new idea and new method for quantitatively characterizing the biological activity of traditional Chinese medicines (TCMs).
Correction: Koch, W., et al. Black Tea Samples Origin Discrimination Using Analytical Investigations of Secondary Metabolites, Antiradical Scavenging Activity and Chemometric Approach. Molecules 2018, 23, 513
Authors: Koch Wojciech , Kukula-Koch Wirginia , Komsta Łukasz
Published: August 2018

The authors wish to make the following corrections to their paper [...]
Linear Triquinane Sesquiterpenoids: Their Isolation, Structures, Biological Activities, and Chemical Synthesis
Authors: Qiu Yi , Lan Wen-Jian , Li Hou-Jin , Chen Liu-Ping
Published: August 2018

Linear triquinane sesquiterpenoids represent an important class of natural products. Most of these compounds were isolated from fungi, sponges, and soft corals, and many of them displayed a wide range of biological activities. On account of their structural diversity and complexity, linear triquinane sesquiterpenoids present new challenges for chemical structure identification and total synthesis. 118 linear triquinane sesquiterpenoids were classified into 8 types, named types I–VIII, based on the carbon skeleton and the position of carbon substituents. Their isolation, structure elucidations, biological activities, and chemical synthesis were reviewed. This paper cited 102 articles from 1947 to 2018.