bluuebunny/crossref_metadata_2025 huggingface dataset:
Posterior composite restorations: Theoretical and practical teaching of undergraduate students in Serbia and abroad
Authors: Miletic Vesna , Sakic Dusan , Supljeglav Igor
Published: October 2013

Introduction. Due to the educational process inertia based on textbook
literature, teaching of undergraduate students in dental schools is often
behind modern practice. From the aspect of minimally invasive dentistry,
composites are materials of choice for the reconstruction of most lesions in
posterior teeth. The objective of the study was to systematize data about
theoretical and practical teaching of undergraduate students regarding the
application of posterior resin composites in the world?s dental schools and
compare it with the data obtained from the School of Dental Medicine,
University of Belgrade. Material and Methods. MEDLINE database was searched
for articles based on keywords dental education and posterior composites.
Only articles published in the last five years and those which used the same
questionnaire were included in the study. Results. Data were analyzed for the
dental schools from the UK and Ireland, Spain, Japan, United States and
Canada. Increased theoretical and practical teaching of students regarding
posterior composites is noted in most schools. The dominant contraindication
for using resin composite is allergy to its ingredients. Rubber dam is the
most common method of providing aseptic conditions and dry field in the
world, whereas in our school it is used in negligible number of cases. In a
number of schools, metal matrices and wooden wedges are recommended for the
proximal cavity restoration. Glass-ionomer cement is commonly used as a
liner. Polishing and finishing of restorations is performed in the same
session in 90-100% of the schools except in Japan, where it is carried out
after 24 hours. Conclusion. Theoretical and practical teaching of posterior
composite restorations is increasing in the world?s dental centers. It is
necessary to harmonize teaching in our school with international trends in
the use of rubber dam, certain aspects of cavity design and protocols for the
treatment of deep caries lesions.
Effect of 10% urea solution on epithelialization of thermally wounded gingiva
Authors: Djordjevic Stevanka , Ivanovic Dragan , Ivanovic Tanja
Published: October 2013

Introduction. Urea is the final product of protein degradation secreted in
saliva. It has low molecular weight and neutral molecule that can freely
diffuse through bacterial wall, mature plaque and extracellular
polysaccharides exerting a buffering effect. In the presence of urease, urea
is broken down into one molecule of ammonia and two molecules of weak
carbonic acid, causing alkalization of the substrate and pH increase.
Hydrolysis of urea begins at pH 4-6. In mature plaque with low pH, urea
hydrolysis is a compensatory mechanism that opposes pH decrease trying to
keep an optimal acidbase balance. This mechanism explains the role of urea in
controlling plaque, caries and gingivitis. The aim of this study was to
investigate the effect of urea on the quality and speed of epithelialisation
of thermally wounded gingiva in rats. Material and Methods. The study
included 36 Wistar albino rats, 3-4 months old, divided in three groups (12
in each group). According to the protocol thermal wounding of gingiva was
performed in all animals. Wounded gingival epithelial tissue was treated
with: 10% urea solution (experimental group), 3% hydrogen peroxide and saline
(control groups). The extent and quality of epithelialisation was verified
histologically after 3, 5, 8, 11 and 14 days. Results. There was a strong
cellular infiltration and stromal edema with no significant morphological
differences between groups in the samples analyzed after 3 days. The
acceleration of epithelialisation in the experimental group observed in
samples obtained after 5 days was evidenced by rapid mitotic division of
epithelium and initial covering of defects in both directions. In samples
obtained after 8 days, in the experimental group, epithelial defect was
covered and in some areas cells were differentiated in vertical direction.
After 11 days horizontal coverage of defects as well as accelerated cell
differentiation in the vertical direction were noted. Restitutio ad integrum
in the experimental group and significant delay in wound healing in the
control groups was demonstrated in 14-day samples. Conclusion. Complete
epithelialisation of gingiva occurred significantly faster in the group
treated with 10% urea solution, than in the control groups treated with 3%
hydrogen peroxide solution and saline.
Analysis of Microsatellite Polymorphisms in South Indian Patients with Non Syndromic Cleft Lip and Palate
Authors: Xavier D.L. , Arif Y.A. , Murali R.V. , Kishore Kumar S , Vipin Kumar S , Tamang R , Thangaraj K , Bhaskar L.V.K.
Published: October 2013

Non syndromic cleft lip and/or palate (NSCLP) is a complex congenital anomaly with varying incidence among patients of different geographical origins. Multiple contributing factors are known to trigger the cleft formation. There are several genes involved in the aetiology of NSCLP and they are different in different populations. The genetic components of clefts that underlie the susceptibility to respond to the environment still remain unclear. In this study, five microsatellite polymorphisms from five candidate genes were employed to analyze the association between these genes and NSCLP in 83 patients and 90 controls. Genotyping was performed by separating and visualizing the fluorescently-labeled polymerase chain reaction (PCR) products. The association of the five microsatellite polymorphisms with NSCLP was tested by using the CLUMP v1.9 program that uses the Monte Carlo method. The genotypic distribution is in Hardy-Weinberg equilibrium in the control group for only the MSX1 and DLX3 genes. The RARA microsatellite was significantly associated with NSCLP. Our results suggest that the RARA gene is involved in pathogenesis of cleft lip and palate in South Indians.
A Homozygous Deletion of the DPY19L2 Gene is a Cause of Globozoospermia in Men From the Republic of Macedonia
Authors: Noveski P , Madjunkova S , Maleva I , Sotiroska V , Petanovski Z , Plaseska-Karanfilska D
Published: October 2013

Globozoospermia is a rare but severe teratozoospermia, characterized by ejaculates consisting completely of round-headed spermatozoa that lack an acrosome or, in partial globozoospermia, containing a variable proportion (20.0-90.0%) of acrosomeless spermatozoa. Men that are affected with total globozoospermia are infertile, and even the application of intracytoplasmic sperm injection (ICSI) has met with disappointingly low success rates.

In humans, several case reports of globozoospermia have demonstrated that two or more siblings were affected in each family, which suggested a genetic component to this disease. Currently, three genes are known to be associated with total globozoospermia in humans, SPATA16, PICK1 and DPY19L2 genes. Mutations in SPATA16 and PICK1 are rare causes of globozoospermia, found in only one patient each. Several studies have suggested that DPY19L2 mutations are the major cause of globozoospermia in patients from different ethnic origins and different geographic regions. The most common DPY19L2 mutation is the 200 kb deletion arising from a nonallelic homologous recombination (NAHR) between the flanking low copy repeats (LCRs). Here we describe the presence of a homozygous deletion of the DPY19L2 gene in two infertile Macedonian patients with 100.0% round headed spermatozoa, thus suggesting that this deletion represents a major cause of globozoospermia among Macedonian men.
New herpesvirus isolated from geese in Poland
Authors: Kozdruń Wojciech , Woźniakowski Grzegorz , Czekaj Hanna , Kozaczyński Wojciech , Samorek–Salamonowicz Elżbieta
Published: October 2013

Neoplastic changes characteristic of Marek’s disease (MD) in the geese flock were described. The investigations were performed on White Italian reproductive geese kept on a farm where MD was previously diagnosed in broilers. Neither antibodies against MD virus (MDV) were detected by AGID method, nor MDV antigen was found by RID. The histopathological examination revealed the presence of lymphoid infiltrations characteristic of MD in all examined tissues. No lesions typical for avian leukosis or reticuloendotheliosis were observed. PCR products characteristic of meq, and ICP4 and pp38 genes were not observed, but real-time PCR for gB gene of MDV were positive in DNA samples from visceral organs. The realtime PCR results may indicate the presence of a new MDV variant or a new herpesviral infection among geese.
Stability of antibiotics in milk samples during storage
Authors: Różańska Hanna , Osek Jacek
Published: October 2013

Raw, inhibitors free milk was spiked with penicillin G, ampicillin, cloxacillin, and ceftiofur at the levels 1 × MRL, 1.5 × MRL, and 2 × MRL, and oxytetracycline at the levels 100 ppb (MRL), 500 ppb and 700 ppb. The samples were stored at 4 ± 2 C and -18 ± 2 C and were tested every day and week, respectively. The analyses were performed using microbiological diffusion test Delvotest SP-NT and receptor assay CHARM ROSA MRL BL/TET for the detection of β-lactams and tetracyclines. In cooled samples antibiotics were detected up to 72 h. After this time, the samples were acidulated and not suitable for investigations. In frozen samples, depending on type and concentration of antibiotics, these substances were detected from one week (penicillin G - 4 ppb) to 35 weeks (ampicillin and ceftiofur).
Effects of dietary phytogenic product on the performance and immune response of pigs
Authors: Pomorska-Mól Małgorzata , Kwit Krzysztof , Czyżewska Ewelina , Markowska-Daniel Iwona
Published: October 2013

The aim of the study was to determine the effects of supplementation of sows’ and weaners’ diet with Stresomix, preparation containing extracts from Magnifera indica, Withania somnifera, Phyllanthus emblica, and Ocimum sanctum, on pig performance and immunity under field condition. The hypothesis was that anti-inflammatory, antistress, and immunomodulatory properties of the herbs would enhance production parameters and immune response, according to the manufacturer's claim. The study was performed on 16 sows and 160 piglets. The following parameters were recorded: concentration and proportion of white blood cells and their populations, concentration of serum immunoglobulins, specific humoral postvaccinal response after vaccination against swine influenza and swine erysipelas, and main production parameters. No significant differences among treatment groups were found with regard to concentrations of leukocyte subpopulations and immunoglobulins, as well as all investigated production parameters (P>0.05). In conclusion, the results of the study did not confirm that the investigated polyherbal product, administered at dose recommended by manufacturer, is able to significantly improve the performance and postvaccinal humoral response in clinically healthy pigs under field condition.
Action of Some Organomercury Compounds on Photosynthesis in Spinach Chloroplasts
Authors: Šeršeň František , Kráľová Katarína
Published: October 2013

The effects of five organomercury compounds (methylmercuric chloride, phenylmercuric acetate, phenylmercuric borate, phenylmercuric citrate and diphenylmercury) on photosynthetic electron transport (PET) in spinach chloroplasts were investigated. The IC50 values of organomercury compounds related to PET inhibition in spinach chloroplasts varied in the range from 468 mmol dm-3 to 942 mmol dm-3 and were approximately by one order higher than the corresponding value determined for HgCl2 applied also in DMSO solution (IC50 = 58 mmol dm-3). Due to extremely low aqueous solubility of diphenylmercury, the corresponding IC50 value could not be determined. Using EPR spectroscopy as probable sites of action of organomercury compounds in photosynthetic apparatus ferredoxin on the acceptor side of PS 1 and the quinone electron acceptors QA or QB on the reducing side of PS 2 were suggested.
Fractional Derivatives for Description of Sorption Kinetics in the Plant Sorbent - Metal Ions System
Authors: Tomczak Elwira , Kamiński Władysław , Szczerkowska Dominika
Published: October 2013

It was examined if buckwheat hull has a potential to be used to adsorb heavy metal ions Zn(II), Cd(II), Co(II), Cu(II), Ni(II) from water. The research involved experiments aimed at the determination of sorption kinetics taking into consideration changes of concentration in a solution and sorbent over time. According to the literature data, kinetics is described with the use of pseudo first-order equations. Application of fractional derivatives for the description of sorption kinetics enables the development of the generalised sorption kinetics equation. Result analysis with this concept requires making a computational procedure using gamma functions and infinite series. Kinetics description using fractional derivatives will be equations with two parameters ie fraction of derivative α and the kinetics constant K dependent on the analysed sorbent-adsorbate system.
Traffic and Tillage Effects on Soil Water Conservation and Winter Wheat Yield in the Loess Plateau, China
Authors: Chen Hao
Published: October 2013

In semi-humid Loess Plateau of northern China, water is the limiting factor for rain-fed crop yields. In this region, long-term traditional ploughing with straw removal has resulted in poor soil structure, water conservation and crop yield. Controlled traffic, combined with no-till and straw cover has been proposed to improve soil water conservation and crop yield. From 1999 to 2007, a field experiment on winter wheat was conducted in the dryland area of Loess Plateau of northern China, to investigate the effects of traffic and tillage on soil water conservation and crop yield. The field experiment was conducted using two controlled traffic treatments, no tillage with residue cover and no compaction (NTCN), shallow tillage with residue cover and no compaction (STCN) and one conventional tillage treatment (CK). Results showed that controlled traffic system reduced soil compaction in the top soil layer, increased soil water infiltration. The benefit on soil water infiltration translated into more soil conservation (16.1%) in 0-100 cm soil layer in fellow period, and achieved higher soil water availability at planting (16.5%), with less yearly variation. Consequently, controlled traffic system increased wheat yield by 12.6% and improved water use efficiency by 5.2%, both with less yearly variation, compared with conventional tillage. Within controlled traffic treatments, no tillage treatment NTCN showed better overall performance. In conclusion, controlled traffic combined with no-tillage and straw cover has higher performance on conserving water, improving yield and water use efficiency. It is a valuable system for soil and water conservation for the sustainable development of agriculture in dryland China.
The 2012 Morris Hansen Lecture: Thank You Morris, et al., For Westat, et al.
Authors: Prewitt Kenneth
Published: October 2013

This article, delivered as the 22nd Memorial Morris Hansen lecture, argues that the contract houses, typified by Westat, are uniquely situated in the cluster of institutions, practices, and principles that collectively constitute a bridge between scientific evidence on the one hand and public policy on the other. This cluster is defined in The Use of Science as Evidence in Public Policy as a policy enterprise that generates a form of social knowledge on which modern economies, policies, and societies depend (National Research Council 2012).

The policy enterprise in the U. S. largely took shape in the first half of the twentieth century, when sample surveys and inferential statistics matured into an information system that provided reliable and timely social knowledge relevant to the nation’s policy choices. In ways described shortly, Westat and other social science organizations that respond to “request for proposals” (RFP) from the government for social data and social analysis came to occupy a unique niche.

The larger question addressed is whether the policy enterprise as we know it is prepared for the tsunami beginning to encroach on its territory. Is it going to be swamped by a data tsunami that takes information from very different sources than the familiar census/survey methods?
First find of biogenic activity in the Palaeoproterozoic of the Singhbhum craton (E India)
Authors: Loon A.J. van , Mazumder R.
Published: October 2013

The Palaeoproterozoic succession of the Singhbhum craton in E. India was hitherto considered as almost entirely siliciclastic and partly volcanogenic. Here we describe, from the fine-grained, tidally influenced shale facies of the Palaeoproterozoic Chaibasa Formation (2.1-1.6 Ga), a fine, originally more or less horizontal, wavy to strongly undulating (later locally deformed) lamination. Investigation of these laminae shows that they must be ascribed to the accumulation of fine particles on microbial mats that covered a sandy substrate. The structures must therefore be considered as stromatolites, features that are accepted as proof of the presence of micro-organisms, in this case most probably cyanobacteria. The interpretation of biogenic activity is supported by microscopic analysis. It is the first description of traces left by biogenic activity that took place in the Palaeoproterozoic of the Singhbhum craton.
Recombinant human erythropoietin alters gene expression and stimulates proliferation of MCF-7 breast cancer cells
Authors: Trost Nina , Stepisnik Tina , Berne Sabina , Pucer Anja , Petan Toni , Komel Radovan , Debeljak Natasa
Published: October 2013

Background. Functional erythropoietin (EPO) signaling is not specific only to erythroid lineages and has been confirmed in several solid tumors, including breast. Three different isoforms of erythropoietin receptor (EPOR) have been reported, the soluble (EPOR-S) and truncated (EPOR-T) forms acting antagonistically to the functional EPOR. In this study, we investigated the effect of human recombinant erythropoietin (rHuEPO) on cell proliferation, early gene response and the expression of EPOR isoforms in the MCF-7 breast cancer cell line.

Materials and methods. The MCF-7 cells were cultured with or without rHuEPO for 72 h or 10 weeks and assessed for their growth characteristics, expression of early response genes and different EPOR isoforms. The expression profile of EPOR and EPOR-T was determined in a range of breast cancer cell lines and compared with their invasive properties.

Results. MCF-7 cell proliferation after rHuEPO treatment was dependent on the time of treatment and the concentration used. High rHuEPO concentrations (40 U/ml) stimulated cell proliferation independently of a preceding long-term exposure of MCF-7 cells to rHuEPO, while lower concentrations increased MCF-7 proliferation only after 10 weeks of treatment. Gene expression analysis showed activation of EGR1 and FOS, confirming the functionality of EPOR. rHuEPO treatment also slightly increased the expression of the functional EPOR isoform, which, however, persisted throughout the 10 weeks of treatment. The expression levels of EPOR-T were not influenced. There were no correlations between EPOR expression and the invasiveness of MCF-7, MDA-MB-231, Hs578T, Hs578Bst, SKBR3, T-47D and MCF-10A cell lines.

Conclusions. rHuEPO modulates MCF-7 cell proliferation in time- and concentration-dependent manner. We confirmed EGR1, FOS and EPOR as transcription targets of the EPO-EPOR signaling loop, but could not correlate the expression of different EPOR isoforms with the invasiveness of breast cancer cell lines.
Bernstein type operators having 1 and x j as fixed points
Authors: Finta Zoltán
Published: October 2013

For certain generalized Bernstein operators {L n} we show that there exist no i, j ∈ {1, 2, 3,…}, i < j, such that the functions e i(x) = x i and e j (x) = x j are preserved by L n for each n = 1, 2,… But there exist infinitely many e i such that e 0(x) = 1 and e j (x) = x j are its fixed points.
An inverse problem for Sturm-Liouville operators on the half-line having Bessel-type singularity in an interior point
Authors: Fedoseev Alexey
Published: October 2013

We study the inverse problem of recovering Sturm-Liouville operators on the half-line with a Bessel-type singularity inside the interval from the given Weyl function. The corresponding uniqueness theorem is proved, a constructive procedure for the solution of the inverse problem is provided, also necessary and sufficient conditions for the solvability of the inverse problem are obtained.
Classification of invariant AHS-structures on semisimple locally symmetric spaces
Authors: Gregorovič Jan
Published: October 2013

We discuss which semisimple locally symmetric spaces admit an AHS-structure invariant under local symmetries. We classify them for all types of AHS-structures and determine possible equivalence classes of such AHS-structures.
Application of high intensity THz pulses for gas high harmonic generation
Authors: Balogh Emeric , Fülöp József , Hebling János , Dombi Péter , Farkas Győző , Varjú Katalin
Published: October 2013

The main effects of an intense THz pulse on gas high harmonic generation are studied via trajectory analysis on the single atom level. Spectral and temporal modifications to the generated radiation are highlighted.
Resource Use of Wind Farms in the German North Sea—The Example of Alpha Ventus and Bard Offshore I
Authors: Wiesen Klaus , Teubler Jens , Rohn Holger
Published: October 2013

The German government aims to obtain at least 40 percent of its electricity from renewable sources by 2030. One of the central steps to reach this target is the construction of deep sea offshore wind farms. The paper presents a material intensity analysis of the offshore wind farms “Alpha Ventus” and “Bard Offshore I” under consideration of the grid connection. An additional onshore scenario is considered for comparison. The results show that offshore wind farms have higher resource consumption than onshore farms. In general, and in respect to the resource use of other energy systems, both can be tagged as resource efficient.
Imagerie de la caverne-miroir dans l'art du Mexique ancien
Authors: Magni Caterina
Published: October 2013

Résumé - Dans la pensée méso-américaine, la caverne occupe une place privilégiée. Dés l'époque préclassique, les artistes diffusent son image figurative et codifiée, peinte et sculptée. Variété technique et formelle qui ne modifie pas son contenu sémantique. Parfois, l'image de la caverne se double de celle du miroir. Pétales, volutes, cercles concentriques... viennent l'enrichir. Autant de motifs qui nous guident vers la figure du jaguar olmèque, du dieu K maya et de la divinité mexica, Tezcatlipoca.
Flow synthesis of a versatile fructosamine mimic and quenching studies of a fructose transport probe
Authors: Plutschack Matthew B , McQuade D Tyler , Valenti Giulio , Seeberger Peter H
Published: October 2013

We describe the synthesis of 1-amino-2,5-anhydro-D-mannose (“mannitolamine”), a key intermediate to the 7-nitro-1,2,3-benzadiazole conjugate (NBDM), using commercially available fluidic devices to increase the throughput. The approach is the first example of a flow-based Tiffeneau–Demjanov rearrangement. Performing this step in flow enables a ~64-fold throughput enhancement relative to batch. The flow process enables the synthesis to be accomplished three times faster than the comparable batch route. The high throughput enabled the production of larger quantities of the fluorescent fructose transport probe NBDM, enabling us to measure key photophysical properties that will facilitate future uptake studies.
Digital Citizenship and Distance Education
Authors: Farmer Lesley S. J.
Published: October 2013

This chapter describes the role of digital citizenship as it relates to school librarianship in online learning environments. It discusses the need for digital citizenship, its curriculum and standards, its place in school librarianship program preparation, distance education issues, learning resources, and implementation for the school community. Emerging issues are also noted.
Architecture Pattern for Context-Aware Smart Environments
Authors: Degeler Viktoriya , Lazovik Alexander
Published: October 2013

Recent years marked many smart environment solutions hitting the market and applying latest pervasive computing research advancements on an industrial scale. Context-aware smart environments are able to act accordingly to the immediate environment information in an intelligent, predefined, learned, or automatically inferred way, and are able to communicate to their users, thus increasing users’ comfort and awareness level. Since the beginning of the 2000s, many projects have been designing and implementing smart environment systems. When looking post-factum at the architectures of these systems, one can notice a lot of similarities among them. With the same basic structure, the biggest differences usually arise at the level of individual components, aimed to satisfy different end-level requirements. Taking many successful and undergoing projects as case-studies, this chapter looks for the common structure, the common patterns, and the “best practices” that can help future projects to reduce the efforts spent on the general system frame, and redirect those efforts to more specific requirements that are unique in every project. It introduces several architecture layers that inevitably exist in one form or another, discusses the possible layer components and the common information flows, and mentions the most notable problems, such as scalability and fault tolerance. Several case studies of successful or undergoing smart building projects show that the presented pattern can be easily mapped to their architectures.
News Recommendation for China Sina Weibo Microblog Service Based on User Social Behaviors
Authors: Yuchu Zuo , Fang You , Jianmin Wang , Zhengle Zhou
Published: October 2013

Sina weibo microblog is an increasingly popular social network service in China. In this work, the authors conducted a study of detecting news in Sina weibo microblog. They found the traditional definition for news can be generalized here. They first expanded the definition of news by conducting user surveys and quantitative analysis. The authors built a news recommendation system by modeling the users, classifying them into four different groups, and applying several heuristic rules, which derived from the generalized definition of news. By applying the new recommendation system, people got newsworthy information, while the funny and interesting tweets, which are popular in Sina weibo microblog, were put in the last ranking list. This study helps us achieve better understanding of heuristic rules about news. Some official organizations can also benefit from the work by supervising the most popular news around civilians.
From Content Engagement to Cognitive Engagement
Authors: Abdelaziz Hamdy A.
Published: October 2013

The objective of this paper was to develop an immersive Web-based learning model and measure its effectiveness on improving self-questioning and self-study skills among graduate students. The proposed model was guided theoretically by the flipped classroom as a new Web-based learning trend. It was also guided pedagogically by active and reflective learning principles that support transforming the teaching and learning practices from content engagement to cognitive engagement. The targeted immersive learning model encompasses four reciprocal phases: Pro-act, Act, Reflect, and Re-act (PARR). A control group post-test only experimental design was applied in this paper to examine the effect of this new learning model on both self-questioning and self-study skills. To validate the suggested model, a convenience sample of graduate students studying an advanced statistics course was selected from the Distance Teaching and Training Program at the Arabian Gulf University during the second semester of the 2012/2013 academic year. The dependent variables in this research were measured by self-questioning skills scale and self-study skills scale. After designing and applying this new immersive Web-based learning model (PARR), findings revealed that using the flipped classroom through this immersive Web-based learning model has a statistical and practical impact on developing self-questioning and self-study skills among graduate students. Each student in the experimental group was able to master self-questioning skills needed to apply quantitative research data analysis knowledge and methods. In addition, each student in the experimental group scored more than theoretical average of the self-study skills scale. The results of this paper may increase the probability and genralizability of using flipped classroom to deliver other statistical course at all educational levels. The contribution of this research is that it qualifies the Web-based instructional practices to shift from content acquisition act to knowledge expression and creation act. In addition, the paper will be of benefit to people looking for pedagogical applications of virtual and blended learning environments for developing multiple ways to express what learners know and be able to do.
Study of the Reverse Saturate Absorption in Copper Phthalocyanine Solution
Authors: Li Fang , He Zhi Cong
Published: October 2013

The nonlinear absorption (NLA) properties of copper phthalocyanine (CuPc) acetone solution were investigated by femtosecond open-aperture (OA) Z-scan technique. The reverse saturable absorption (RSA) was observed, and it was found that the RSA effect was origin from three-photon absorption. Moreover, the influences of concentration and excitation laser power on the NLA of CuPc solution are studied. Results show that the RSA effect increases with the increase of sample concentration and excitation laser power. It indicates that the CuPc could be a promising candidate for optical limiting material.
Study on Extraction Technology and Stability of Melanin from Banana Peel
Authors: Min Li Jing , Li Jing Fen
Published: October 2013

[Objectiv The aim is to study the extraction technology of melanin from banana peel, and discuss its stability. [Metho We used banana peel as raw material, the absorbance at 410 nm as the index, extracted melanin by base-acid method, and optimized the extraction technology by the single factor and orthogonal test. Then we discussed the melanins stability at different temperature, light source, pH value, metal ions, antioxidant and reducing agents.[Result The best extraction conditions of melanin is that, hydrochloric acid soak time 5 h, alkaline solution pH value 14, extracting time 20 min, extraction temperature 70 °C, absorbance value about 0.309 A. Melanin from banana peel is stable at high temperature, different light source irradiation, reducing agent coexist; but at room temperature, metal ions and oxidizing agent coexist, it is unstable. [Conclusio This study provided experimental basis for the optimization and development of melanin from banana peel.
The Thermal Stability of Bi-Pb-Sn-Cd Heat Transfer Fluid
Authors: Cheng Xiao Min , MA Jun , Ye Jian Yuan , Yang Xian Jie
Published: October 2013

The charge and discharge process of heat transfer fluid in the solar thermal power generation system was simulated. A thermal cycle test repeated between high temperature and low temperature was put on prepared Bi-Pb-Sn-Cd low-melting-point alloy. The thermal physical performance tests were put on the alloy samples which experimented with 200, 400 and 800 times thermal cycle test respectively. The test results show that the specific heat capacity of alloy sample declines slowly and the thermal conductivity increases slowly. The phase change temperature of alloy increases slightly and latent heat decreases slightly with the thermal cycle continuing.
Fabrication of Stable PVA/PVP Hydrogels
Authors: Sun Hong , Wu Tao , He Yong Qiang , Gong Qiao Juan , Gao Jian Ping , Liu Yu
Published: October 2013

PVA hydrogel has been used in the field of cartilage replacement in recent year. In order to improve the water-keeping ability of PVA gel and mechanical property, PVP was introduced into PVA and crosslinked by adding ammonium persulfate to form a composite gel. The crosslinkage of the gel was identified, and the effect of PVP and ammonium persulfate amount on the composite gel was studied. The crosslinkage, the degree of swelling and the compress stress of the composite gels have been tested. UV analysis was used to investigate the release of PVP from the composite gels. The dried composite gels were put into water to investigate the degree and velocity of the rehydration of different composite gels.
Study on the Antibacterial Performance of the Antibacterial Shutter Blades
Authors: Liu Ming Li , Li Chun Feng , Wang Yun Long , Lu Kai , Pang Jiu Yin , Luo Wei Jie , Liu Yan Long
Published: October 2013

This study used Ag-embedded nanoTiO2, xylan and water-soluble Chitosan as antibacterial agents, respectively prepared shutter blades through the treating solution of the different concentration and the different drug loading amount of the poplar veneer. Through a single factor experiment, this paper analyzes that the different antibacterial agent, concentration of antibacterial agent and the drug loading amount have an effect on the antibacterial properties of the shutter blades. The results show that the order of antibacterial performance of the shutter blades impregnated antibacterial agents is the Ag-embedded nanoTiO2, Chitosan, Xylan. Comprehensiv-ely thought the antibacterial properties and economic index, the optimal concentration of the Ag-embedded nanoTiO2 impregnation solution is 1%.
Inhibition of Recombinant Chicken Cystatin on Expression of Aflatoxin Biosynthesis Genes on Peanut
Authors: Zhang Hui Li , Zhang Li Nan , He Jian Wei , Jiang Kun , Lou Hong , Meng Xian Jun
Published: October 2013

Purposes: Cystatins, as a kind of reversible cysteine proteases and potential inhibitor, have been found widely distributed in organisms and have potential capability of inhibiting fungi. Aflatoxins, toxic and extremely carcinogenic natural secondary metabolites, result in worldwide contamination. Procedures and Methods: Recombinant Chicken Cystatin was conducted to surface of peanut followed by inoculation withA. flavusEstimation of growth scores and detection of Aflatoxin by HPLC and relative quantification expression level of biosynthetic genesnor-1,Ver-1,omtandaflRvia Real-time PCR were investigated indifferent days culture peanuts after incubating for 8d. Results: Scores were observed and aflatoxin B1 was detected since 4d in control and 5d in treatment. All of four expression levels of treatment groups were lower than control, beginning at 5d later one day than control group. Conclusions: Inhibition function of Cystatins was observed markedly, and it may bring promising contribution in the respective of peanut storage.
Preliminary Researches on Conditions to Extract Chlorophyll from Leaves of Wedelia Trilobata (L.) Hitchc
Authors: Li Tuan Na , Zhao Gan , Qiu Li Guo
Published: October 2013

Among the extractants used, the extraction effect by acetone was the best, and the one by mixed extractant B was the second. The extraction effect declined gradually according to the order below: acetone >mixed extractant B >alcohol >95% alcohol >ethyl acetate >80% acetone >90% acetone >mixed extractant A >aether. Otherwise, when extraction time was 10 min, the extraction effect by acetone was the best. When dosage was 5 mL, the extraction effect by acetone was the best. With 95% alcohol being used to prepare extractants with acetone, the extraction effect was the best when the volume ratio of acetone and 95% alcohol was 2:1. With alcohol solution of different concentration being used to prepare extractants with acetone, where acetone/alcohol solution volume ratio was 2:1, the extraction effect was the best when the concentration of alcohol solution was 75% (v/v).
Luminescence Properties of Eu2+ Doped Ba3La(PO4)3 Phosphor
Authors: Wang Ji You , Wang Jian Bo , Liu Hong Mei , Duan Ping
Published: October 2013

Eu2+-doped Ba3La (PO4)3phosphors were synthesized by solid-state reaction method. The X-ray diffraction (XRD) results showed that the obtained phosphors were cubic phase. The structure of Ba3La (PO4)3doped slight Eu2+does not changed. Ba3La1-x(PO4)3:xEu2+phosphor can be excited by UV-visible light, which emits intensely blue light with broadband peaked at about 466 nm. The relative PL intensity increases with Eu2+-concentration increasing until a maximum intensity is reached, at about x=0.015mol. According to the Dexters theory, it was found that the major mechanism for concentration quenching as a result of dipole-dipole (d-d) interaction.
Laser Cladding of Fluoridated Hydroxyapatite Coatings on Titanium Alloy for Bone Replacement Structures
Authors: Huang An Guo , Liu Yuan , Hu Shu Hui , Wang Qing Hua , Zhen Li Ling
Published: October 2013

Bone-like fluoridated hydroxyapatite (FHA) coatings were prepared on Ti-6Al-4V substrates (TC4) by using laser cladding. This bioceramic coating was fabricated by adding CaF2 micron-particles into the hydroxyapatite before presetted on the Ti alloy substrate and radiated by laser beam which aimed at obtaining lower solubility, fine thermostability and maintaining the comparable bioactivity and biocompatibility. Coatings, which were processed using a Nd:YAG laser cladding, presented FHA crystallization on the surface with a uniform morphology along the coating cross-section and no significant dilution of the titanium alloy was observed. Phase analysis by X-ray diffraction indicated the generation of fluoridated hydroxyapatite phase in the laser cladded coatings. The coatings showed the formation of a metallurgically sound and diffused substrate-coating interface, which significantly increased bonding strength between the coatings and subtrate. The bioactive coatings afforded favourable bone bioactivity by inducing the rapid precipitation of apatite on their surface when immersed in a simulated body fluid (SBF). The work demonstrated the potential of using laser cladding for fabricating fluoridated hydroxyapatite bioceramic coatings on Ti alloy.
Evaluation of Modified Poly by UV-Induced Graft Polymerization as a Novel Hydrophilic Films
Authors: Wang Bing Qiang
Published: October 2013

In order to improve the hydrophilic performances, the surface of poly films was modified through grafting polymerization of styrene (ST) initiated by ultraviolet (UV) in ethanol/water mixture solution. The effects of irradiation time, concentration of inhibitor (ferrous ammonium sulfate) on the grafting degree of ST will be investigated. The original and grafted poly films were characterized by scanning electron microscopy (SEM) and Static contact angle (CA), to characterize the chemical changes of the poly film surface. The results showed that the hydrophilic of poly films was improved significantly than that of the original film. The contact angle of PO-g-ST increased from 70° to 120.4° over a critical grafting degree of 26.35%, the hydrophilic of PP membranes improved dramatically.
Effect of Electron Beam Scanning on Ni60A Alloy Layer of H13 Steel Surface
Authors: Wei De Qiang , Zhao Zhen Lei , Wang Rong
Published: October 2013

Prepare Ni60A on the H13 steel matrix in thermal spraying. Then, the alloy layer is treated with electron beam in multichannel lapping. Microstructure, the direction of grain growth, the situation of crack initiation on surface modification are analyzed and researched by optical microscope,electron scanning microscope,energy disperse spectroscopy. Experimental results show that the alloy layer which is scan with an electron beam is fuse together with the steel matrix. The organizations of the strengthened layer are dendritic crystal and columnar crystal. Moreover, the grain refinement is well done. Some microcosmic or macroscopic crack appear in the scan regions.
The Corrosion Resistance Discrimination of TC11 Titanium Alloy Using Scanning Kelvin Probe
Authors: Ai Yun Long , Liu Li , He Wen
Published: October 2013

Surface potential of TC11 titanium alloy handled by beta phase (1150°C) solid solution for one hour and then taking water cooling, air cooling and furnace cooling as cold method were investigated using scanning Kelvin probe technique. The corrosion resistance difference of samples was analyzed through their surface potential. At the same time, corrosion experiments were adopted to verify it. The results show that the result of the samples corrosion resistance analyzed by scanning Kelvin probe technique is reliable and the method is feasible. Compared with water cooling sample, the corrosion resistance of furnace cooling and air cooling samples is worse and their surface potential present cathode and anode area obviously. The corrosion of furnace cooling sample is slight serious to that of air cooling sample in the early corrosion, but their corrosion resistances are almost equal. Passivation layer formed by alloy elements in the water cooling sample avails to prevent alloy from corrosion.
Study on the Graft Copolymerization of AN onto PP by Using Supercritical Carbon Dioxide
Authors: Wang Ya Zhen , Ma Di , Yue Cheng E , Jia Wei Nan , Li Yong
Published: October 2013

The research reported in this paper aimed at exploring the advantages of using supercritical carbon dioxide (scCO2) as an environmentally benign solvent and swelling agent for carrying out the grafting process of acrylonitrile (AN) onto polypropylene (PP) in the solid state by using benzoyl peroxide (BPO) as initiator in the reaction. In order to get a well graft ratio, the effects of various factors in this grafting reaction are investigated. Those factors included the reaction time, reaction temperature, monomer and initiator concentrations and the CO2 pressure. IR was used to characterize the constituent of the graft polymer. Then anti-aging of the PP-g-AN was studied by UV-vis. Results showed that the scCO2-assisted solid-state grafting process of AN onto PP did have some scientifically interesting and industrially relevant advantages over the melt process. Compare with virgin PP, the graft polymer have a better performance in anti-aging.
Numerical Simulation of Temperature Field and Microstructure in the Quenching Process of Steel Rail
Authors: Liu Yu Yan , Zhang Fang , Zhang Zhi Yang , Chen Lin
Published: October 2013

In this paper, the effect of rail head organization, cooling and quenching microstructure transformation time in different cooling speed are analyzed by the numerical simulation of the 60kg/m U75V, and study the change law of the rail temperature field and microstructure in the quenching process in the field.
Gamma-Ray Compton Spectroscopy for Determination of Electron Momentum Distributions in Iron
Authors: Hamouda Samir Ahmed
Published: October 2013

Compton profile measurement of iron polycrystalline sample has been performed with 662 keV γ-radiation from a caesium-137 source. The spectrometer calibration and data corrections for the high energy experiment are discussed. The data are compared with the augmented-plane-wave (APW) and linear combination of atomic orbitals (LCAO) band theoretical Compton profiles of iron. Both theoretical predictions show the band theories overestimate the momentum density at low momenta and underestimate it at intermediate momenta.
An Experimental Method of LY12 Duralumin Alloy Affected by the Ultrahigh Pressure
Authors: Zhang Yu Xian , Liu Bin Bin , Wang Hong
Published: October 2013

Design an experimental method which can test the strength change of materials under the ultrahigh pressure, and a set of experimental data about the LY12 duralumin alloys materials yield strength and tensile strength are gained under the different ultrahigh pressure environment. The analysis result shows the strength of LY12 duralumin alloys will enhance. Because of effect of ultrahigh pressure, both yield strength and tensile strength increment of materials will approximately increase linearly. Beyond this, the method that can effectively build ultrahigh pressure environment has guidance significance for a real project.
Influence of Acidic Impurities on Rheological Properties of Boron/Agglomerated Boron and HTPB Slurry
Authors: Hu Xiu Li , Zhou Wei Liang , Xiao Le Qin , Jian Xiao Xia
Published: October 2013

The rheological properties of HTPB mixed with boron (B) or agglomerated boron (TB) were investigated to explore the effect of the impurities of boron on the processing of propellant. The phase structure, morphology, and acidity of each sample were characterized by XRD, SEM and pH, respectively. The results show that rheological property of B/HTPB can be significantly improved by agglomerating boron with binder. Time has little effect on the viscosity of TB/HTPB while that of B/HTPB is a strong function of time. The viscosity of TB/HTPB decreases when the temperature increases from 303K to 343K, while that of B/HTPB decreases from 303K to 323K and then increases sharply after 323K. After agglomerating with binder, theTonsetof boron reduces from 1056K to 954K andTpdrops from 1076K to 998K. Compared with B2, the weight gain and oxidation degree of TB2 increases by 27% and 8.5%, respectively.
Biofilm Formation, Communication and Interactions of Mesophilic Leaching Bacteria during Pyrite Oxidation
Authors: Bellenberg Sören , Barthen Robert , Vera Mario , Guiliani Nicolas , Sand Wolfgang
Published: October 2013

A functional luxIR-type Quorum Sensing (QS) system is present in Acidithiobacillus ferrooxidans. However, cell-cell communication among various acidophilic chemolithoautotrophs growing on pyrite has not been studied in detail. These aspects are the scope of this study with emphasis on the effects exerted by the N-acyl-homoserine lactone (AHL) type signaling molecules which are produced by Acidithiobacillus ferrooxidans. Their effects on attachment and leaching efficiency by other leaching bacteria, such as Acidithiobacillus ferrivorans, Acidiferrobacter spp. SPIII/3 and Leptospirillum ferrooxidans in pure and mixed cultures growing on pyrite is shown.
Cyanobacteria and Photosynthetic Species as Part of the Microbial Community Structure of Biofilms in Copahue Geothermal Springs (Neuquén, Argentina)
Authors: Urbieta María Sofía , González Toril Elena , Aguilera Ángeles , Giaveno Maria Alejandra , Donati Edgardo , Donati Edgardo R.
Published: October 2013

Copahue is a geothermal field located in the Northwest corner of Neuquén province in Argentina. It is dominated by the still active Copahue volcano. In the area there are many acidic pools, hot springs and solfataras with different temperature and pH conditions that influence their microbial diversity. On the surrounding rocks and the borders of the pools, where water movements and thermal activity are less intense, many biofilms can be found. They have different aspects and structure, and they present less extreme temperature and pH conditions than the ponds and hot springs. Biofilms are a different ecological niche and they have different microbial community structure. In this study carried out by molecular ecology techniques, mainly 16S and 18S rRNA sequencing, we report a strong presence of cyanobacterias, cloroflexi and eukaryotes, not detected in previous biodiversity studies done on water samples. Almost no acidophilic bacteria were found, with the exception of members of genusThiomonas, also found in the acidic pools. Archaea were detected only in one of the biofilms and the structure of that community seems to be similar to those found in water samples, with many uncultured species mainly related to orderSulfolobales. The aim of this study is to assess microbial community diversity in the biofilms present in this acidic geothermal area, with particular emphasis on detection of cyanobacterias and eukaryotes with potential biotechnological applications like production of alternative energy sources, synthesis and accumulation of biomolecules with antiviral or antibiotic activities or potential ability to bioremediate contaminated areas.