bluuebunny/crossref_metadata_2025 huggingface dataset:
All-oxide Photovoltaics
Authors: Rühle Sven , Zaban Arie
Published: July 2014

Recently a new field in photovoltaics (PV) is emerging, focusing on solar cells that are entirely based on metal oxide semiconductors. The all-oxide PV approach is very attractive due to the chemical stability, non-toxicity and abundance of many metal oxides that potentially allow manufacturing under ambient conditions. Metal oxides (MOs) are today widely used as components in PV cells such as transparent conducting front electrodes or electron transport layers, while only very few MOs have been used as light absorbers. In this chapter we review recent developments of all-oxide PV systems, which until today are mostly based on Cu2O as a light absorber. Furthermore, new PV systems based on Bi2O3, Fe2O3 or ferroelectric BiFeO3 are discussed, which have recently attracted considerable attention. The performance of all-oxide PV cells is discussed in terms of general photovoltaic principles and directions for progress are proposed pointing towards the development of novel metal oxide semiconductors using combinatorial methods.
Active Layer Limitations and Non-geminate Recombination in Polymer–Fullerene Bulk Heterojunction Solar Cells
Authors: Clarke Tracey M. , Zhang Guanran , Mozer Attila J.
Published: July 2014

A possible route to 15% power conversion efficiency from donor–acceptor bulk heterojunction solar cells is to optimize the energy levels of the donor and acceptor materials for maximum light harvesting while maintaining a high open circuit voltage. In order to attain this high efficiency, the ability to coat thick active layers is required. Thick active layers are necessary to achieve high external quantum efficiencies (90%) for all photon energies larger than the optical bandgap, while maintaining a high fill factor (FF>0.7). However, as demonstrated—based on an extensive literature review of more than 30 high performing copolymer donor–acceptor heterojunctions—achieving a high fill factor using relatively thick (> 300 nm) active layers is very challenging. Reduced bimolecular recombination as a fundamentally important characteristic of high fill factor bulk heterojunction solar cells with large active layer thicknesses is discussed using transient charge extraction measurements. Twelve different models aimed at explaining this reduced bimolecular recombination in bulk heterojunction solar cells are discussed and compared.
Singlet Fission and 1,3-Diphenylisobenzofuran as a Model Chromophore
Authors: Johnson Justin C. , Michl Josef
Published: July 2014

A brief description is provided of a phenomemon known as singlet fission (SF), in which a singlet excited chromophore and a ground state chromophore share energy to produce two triplet excited chromophores. In principle, the process permits the absorption of a single photon to produce two electrons and two holes, leading to a theoretical solar cell efficiency close to 1/2, significantly above the 1/3 Shockley–Queisser limit. The prerequisites for efficient singlet fission are considered, both in terms of the properties of individual chromophores and in terms of their mutual coupling. The design rules for efficient chromophores derived from first principles led to the formulation of a model system, 1,3-diphenylisobenzofuran. This chromophore is used to illustrate the singlet fission process and the complications that can arise.
Intermediate Band Solar Cells
Authors: Okada Yoshitaka , Sogabe Tomah , Shoji Yasushi
Published: July 2014

In order to surpass the thermodynamic Shockley–Queisser limit of energy conversion efficiency of single-junction solar cells, advanced concepts using multi-junction tandem structure and quantum nanostructure are currently under active research. Recent developments and future research opportunities in high-efficiency intermediate band photovoltaics technology based on high-density quantum dot arrays are reviewed.
Spectral Conversion for Thin Film Solar Cells and Luminescent Solar Concentrators
Authors: van Sark Wilfried , de Wild Jessica , Krumer Zachar , de Mello Donegá Celso , Schropp Ruud
Published: July 2014

Full spectrum absorption combined with effective generation and collection of charge carriers is a prerequisite for attaining high efficiency solar cells. Two examples of spectral conversion are treated in this chapter, i.e., up-conversion and down-shifting. Up-conversion is applied to thin film silicon solar cells and efficiency improvements using lanthanides as up-converter material under monochromatic as well as broadband light are presented. Down-shifting is demonstrated in luminescent solar concentrators, and material issues hampering efficiency improvements are discussed, in particular re-absorption of light emitted by luminescent species. A new class of semiconductor hetero-nanocrystals is shown to be an excellent candidate for surpassing the 10% luminescent solar concentrator efficiency barrier.
Grid Parity and its Implications for Energy Policy and Regulation
Authors: Watt Muriel , MacGill Iain
Published: July 2014

The transformational possibilities of photovoltaics (PV) were recognized very early in its development but it has taken more than 50 years to begin to fully realize this potential. Recent years have seen extraordinary uptake and price reductions driven by ongoing technology progress yet also, critically, PV specific deployment policies in some key markets. Underlying these policies was the goal of ‘grid parity’ where PV can compete against grid supply without explicit policy support. In a growing number of countries this goal has arrived for some residential and even commercial energy users. The widespread availability of affordable PV, producing electricity at prices cheaper than retail electricity tariffs is creating a new category of ‘prosumer’ (an electricity consumer who is also an energy producer) whose growing options and engagement in their energy services seems set to transform the energy sector. However PV's success has highlighted some of the limitations of the ‘grid parity’ concept, and the growing importance of broader electricity market policy and regulatory arrangements. In particular, highly variable and somewhat unpredictable PV is not functionally equivalent to the very reliable grid supply present in many electricity industries. However, current retail electricity tariff arrangements, against which PV is increasingly competing, often do not appropriately reflect the true underlying cost drivers of grid supply. Of course, the key environmental benefits of PV are also generally not reflected in these electricity tariffs. Particular challenges now arising include managing the threat that PV poses to incumbent market participants and current business models. This chapter follows the growth of PV markets, the policy support strategies employed to stimulate deployment to date, and the new impacts and implications of low-cost PV for electricity systems the world over.
A halogenophilic pathway in the reactions of transition metal carbonyl anions with [(η6-iodobenzene)Cr(CO)3]
Authors: Sazonov Petr K. , Ivushkin Vasiliy A. , Khrustalev Victor N. , Kolotyrkina Natal'ya G. , Beletskaya Irina P.
Published: July 2014

Formal nucleophilic substitution in [(η6-iodobenzene)Cr(CO)3] begins with the attack of the carbonylmetallate at iodine to form the aryl carbanion and [IM(CO)nL], which then give all of the variety of products observed.
Efficient planar heterojunction mixed-halide perovskite solar cells deposited via spray-deposition
Authors: Barrows Alexander T. , Pearson Andrew J. , Kwak Chan Kyu , Dunbar Alan D. F. , Buckley Alastair R. , Lidzey David G.
Published: July 2014

Perovskite solar cells prepared via spray-deposition of the active layer have been realized, advancing this promising technology towards roll-to-roll compatible processing methods.
Surface functional groups and defects on carbon nanotubes affect adsorption–desorption hysteresis of metal cations and oxoanions in water
Authors: Li Jie , Chen Changlun , Zhang Shouwei , Wang Xiangke
Published: July 2014

This study probed the effects of functional groups, specific surface area and defects on metal ion adsorption and desorption.
Relative contractile motion of the rings in a switchable palindromic [3]rotaxane in aqueous solution driven by radical-pairing interactions
Authors: Witus Leah S. , Hartlieb Karel J. , Wang Yuping , Prokofjevs Aleksandrs , Frasconi Marco , Barnes Jonathan C. , Dale Edward J. , Fahrenbach Albert C. , Stoddart J. Fraser
Published: July 2014

This communication describes a mechanically interlocked molecule (MIM), capable of switchable and reversible linear molecular motion.
Shadow ribbon: a detailed study of complex chemical plants with a simple integrated approach
Authors: Monitto R. , Tuccitto N.
Published: July 2014

A multisensory device, named shadow ribbon, to acquire shadow data in order to study pollution dispersion in complex chemical plants.
Hydrogen-activation mechanism of [Fe] hydrogenase revealed by multi-scale modeling
Authors: Finkelmann Arndt Robert , Senn Hans Martin , Reiher Markus
Published: July 2014

A complete atomistic model of [Fe] hydrogenase reveals important details of its mechanism.
Polyaniline nanofiber/vanadium pentoxide sprayed layer-by-layer electrodes for energy storage
Authors: Shao Lin , Jeon Ju-Won , Lutkenhaus Jodie L.
Published: July 2014

Spray-assisted layer-by-layer assembly allows for the rapid assembly of porous battery electrodes containing functional cathode materials.
Self-assembling doxorubicin-prodrug nanoparticles as siRNA drug delivery system for cancer treatment: in vitro and in vivo
Authors: Liu Hongmei , Qiao Chenmeng , Yang Jun , Weng Jie , Zhang Xin
Published: July 2014

The DOX-prodrug NPs can complex siRNA in pH 3 citrate buffer and have slight negative charges on the surface of NPs in pH 7.4 PBS.
Temperature- and pH-tunable plasmonic properties and SERS efficiency of the silver nanoparticles within the dual stimuli-responsive microgels
Authors: Liu Xiaoyun , Wang Xiuqin , Zha Liusheng , Lin Danli , Yang Jianmao , Zhou Jianfeng , Zhang Li
Published: July 2014

Plasmonic property and SERS efficiency of the silver nanoparticles embedded within the microgels with an interpenetrating polymer network structure can be reversibly tuned by temperature and pH value.
Effect of thermal annealing on active layer morphology and performance for small molecule bulk heterojunction organic solar cells
Authors: Yi Zuo , Ni Wang , Zhang Qian , Li Miaomiao , Kan Bin , Wan Xiangjian , Chen Yongsheng
Published: July 2014

Bulk heterojunction solar cells based on a novel small molecule (DRDTSBDTT) were systematically investigated to understand the impact of thermal annealing on Voc, Jsc and FF.
Low complexity PARAFAC‐based channel estimation for non‐regenerative MIMO relay systems
Authors: Du Jianhe , Yuan Chaowei , Zhang Jinbo
Published: July 2014

In this study, the authors present a novel channel estimation scheme for a two‐hop non‐regenerative multiple‐input multiple‐output relay system. The proposed scheme has two stages. In the first stage, the source node transmits channel training sequence to the relay node. The relay node amplifies the received signal and forwards it to the destination node. During the second stage, the relay node amplifies the pre‐received signal with another amplification matrix, and forwards it to the destination node. Based on the proposed scheme, by using parallel factor (PARAFAC) analysis, they further propose a low complexity channel estimation algorithm, where full knowledge of all channel matrices involved in the communication can be estimated at the destination node. Compared with existing algorithms, the proposed algorithm yields smaller channel estimation error with lower complexity. Numerical examples are shown to demonstrate the effectiveness of the low complexity PARAFAC‐based channel estimation algorithm.
Room‐temperature ferromagnetism of single‐crystalline MoS2 nanowires
Authors: Sun Bai , Li Qi Ling , Chen Peng
Published: July 2014

Single‐crystalline molybdenum disulphide (MoS2) nanowires are prepared by a hydrothermal method. The single‐crystalline MoS2 nanowires display substantial ferromagnetism at room temperature. The S vacancies and Mo‐edges are possible mechanisms responsible for the observed ferromagnetism at room temperature.
Dust acoustic solitary and shock excitations in a Thomas-Fermi magnetoplasma
Authors: Rahim Z. , Ali S. , Qamar A.
Published: July 2014

The linear and nonlinear properties of dust-acoustic waves are investigated in a collisionless Thomas-Fermi magnetoplasma, whose constituents are electrons, ions, and negatively charged dust particles. At dust time scale, the electron and ion number densities follow the Thomas-Fermi distribution, whereas the dust component is described by the classical fluid equations. A linear dispersion relation is analyzed to show that the wave frequencies associated with the upper and lower modes are enhanced with the variation of dust concentration. The effect of the latter is seen more strongly on the upper mode as compared to the lower mode. For nonlinear analysis, we obtain magnetized Korteweg-de Vries (KdV) and Zakharov-Kuznetsov (ZK) equations involving the dust-acoustic solitary waves in the framework of reductive perturbation technique. Furthermore, the shock wave excitations are also studied by allowing dissipation effects in the model, leading to the Korteweg-de Vries-Burgers (KdVB) and ZKB equations. The analysis reveals that the dust-acoustic solitary and shock excitations in a Thomas-Fermi plasma are strongly influenced by the plasma parameters, e.g., dust concentration, dust temperature, obliqueness, magnetic field strength, and dust fluid viscosity. The present results should be important for understanding the solitary and shock excitations in the environments of white dwarfs or supernova, where dust particles can exist.
The formation and electronic properties of hydrogenated bilayer silicene from first-principles
Authors: Rui Wang , Shaofeng Wang , Xiaozhi Wu
Published: July 2014

Density-functional calculations of the formation and electronic properties of bilayer silicene and hydrogenated bilayer silicene are present. The structure optimization and phonon calculations are carried out to demonstrate that bilayer silicene has stable structure with AB stacking and preserves the linear energy dispersions near the K and K′ points in the hexagonal Brillouin zone, and our results agree well with the previous calculations. Based on the symmetry of bilayer silicene, we study the stability of four hydrogenated bilayer silicene by the phonon-mode analysis. The configurations of semihydrogenated one-layer and semihydrogenated double-layer are confirmed as dynamically stable with no imaginary phonon frequencies. The case of semihydrogenated one-layer shows ferromagnetic ground state due to the unpaired 3p electrons, while that of semihydrogenated double-layer is predicted to be a indirect band gap semiconductor with nonmagnetic ground state.
Damping in free layers of tunnel magneto-resistance readers
Authors: Lu Lei , Wang Zihui , Mead Griffin , Kaiser Christian , Leng Qunwen , Wu Mingzhong
Published: July 2014

Damping properties in the free layers of tunnel magneto-resistance (TMR) readers were reported. The study used a free layer sample consisting of the same stacking structure as in TMR readers, involved comprehensive ferromagnetic resonance (FMR) measurements, and included numerical analysis of the FMR data. The results indicate that the free layer shows a Gilbert damping constant of 8.1 × 10−3. When the free layer is magnetized with a field which is not normal to the film plane, two-magnon scattering also occurs, although its contribution to the relaxation is at least 2.5 times smaller than the Gilbert contribution.
Target feeding for improved smallholder beef production in the Mekong region: lessons from Cambodia and Lao PDR
Authors: Bush R. D. , Page B. , Macdonald T. , Young J. R. , Nampanya S. , Suon S. , Khounsy S. , Henry L. A. , Thomson P. C. , Windsor P. A.
Published: July 2014

Increased demand for red meat throughout the Greater Mekong Subregion (GMS) presents smallholder cattle and buffalo farmers with an opportunity to supply better quality animals to expanding regional markets. Cattle were target-fed in Cambodia with introduced forages to achieve gains of 0.19 kg/day over a 104-day period and this practice was compared with traditional cut-and-carry feeding practices where animals lost on average 0.04 kg/day. Target-fed animals were predicted to gain, on average, 25.9 kg more weight than animals fed in a traditional manner (P = 0.057), and to improve their estimated value by more than US$60. These outcomes were similar to outcomes in Lao PDR, where cattle and buffalo in fattening stalls gained 0.32 and 0.22 kg/day, respectively, over a 4-month period, and 0.04 and 0.09 kg/day when free-grazing. Greater weight gains are possible if farmers feed forages at the recommended 15% of bodyweight on a fresh-weight basis per day. Lack of knowledge of animal weights by farmers and traders was addressed by the creation of an accurate weight tape to provide a cheap and easy tool to monitor animal production and health, and to assist in negotiating a fair sale value. However, increased knowledge of appropriate forage plot size and feeding requirements of animals to be target-fed is required for farmers to change from being livestock keepers to livestock producers. To increase supply for the growing demand for red meat, an ongoing, multi-disciplinary extension program should be a priority for livestock improvement programs in the GMS.
Animal welfare: towards transdisciplinarity – the European experience
Authors: Veissier Isabelle , Miele Mara
Published: July 2014

The premises of animal welfare science can be found in the debate about the moral status of animals in philosophy, the introduction of the concept of stress in physiology, and the description of the behaviour of animals by ethologists. In the 1970s animal welfare became an object of study for applied research with the aim of improving the life of domesticated animals. It was first studied within disciplines, e.g. applied ethologists compared the behaviour of domesticated animals to that of their wild counterparts and identified behavioural needs. Then it became clear that stress is more a psychological concept than a physiological one. The links between stress and behavioural needs and preferences were also established. Similarly the links between animal welfare and health were investigated by looking at malaise behaviour and at stress-immunity relations. More recently, frameworks developed in human psychology were applied to animals to identify the emotions they can experience. This typically requires that researchers from one discipline engage with other disciplines for a cross fertilisation of concepts and frameworks. Animal welfare scientists now use many indicators, covering a wide range of possible disorders from abnormal behaviour, diseases, production failure, and poor emotional states. Animal scientists started to work with social scientists to relate their own perception of animal welfare and that of society at large. This interdisciplinary approach is illustrated by the Welfare Quality project where an overall assessment of animal welfare was built according to scientific evidence of what matters to animals as seen by animal scientists and of what society value as good care to these animals. We feel that animal welfare requires breaking frontiers between disciplines to create a holistic approach. We discuss whether we need to move from an interdisciplinary to a transdisciplinary approach, across and beyond disciplines, whereby not only scientists but also stakeholders and society at large can contribute to the definition of this particular research object: animal welfare.
The Efficacy of Contingency Management for Adolescent Cannabis Use Disorder: A Controlled Study
Authors: Kaminer Yifrah , Burleson Joseph A. , Burke Rebecca , Litt Mark D.
Published: July 2014

Background

This study was performed to investigate the efficacy of a voucher-based reinforcement therapy (VBRT) rewarding drug-free urine for adolescents with cannabis use disorder.

Methods

A controlled 10-week study where 59 adolescents aged 14–18 years were assigned by cohorts into groups of either an integrated cognitive-behavioral therapy (CBT) and VBRT or CBT with attendance-based reward program. Substance use was monitored by twice-weekly urinalysis. Other measures were collected at pre- and posttreatment and at 3-month follow-up.

Results

There was no significant difference in the linear change between conditions for cannabis use either from Sessions 1 to 10 or between end-of-treatment to 3-month follow-up. Also, self-efficacy and coping response did not show improvement during treatment.

Conclusions

In this study, the addition of contingency management (CM) to CBT in youth was not found to be more efficacious than similar compensation rewarding attendance only. Continued examination of the efficacy of CM and its interaction with the associated mechanisms of behavior change of CBT in youth is necessary. Examination of the effect of the magnitude of the reward as well as considering the emotional and cognitive developmental differences from adults is warranted.
Short-term induction of assimilation and accommodation
Authors: Leipold Bernhard , Bermeitinger Christina , Greve Werner , Meyer Birgit , Arnold Manuel , Pielniok Marianna
Published: July 2014

The dual-process model of developmental regulation distinguishes two processes of self-regulation (assimilation = tenacious goal pursuit, and accommodation = flexible goal adjustment) that depend on differing conditions, but both contribute to successful development. Four experiments were conducted to investigate whether assimilation and accommodation can be induced or at least shifted by sensorimotor and cognitive manipulations. Experiment 1 investigated the relation between body manipulation and self-regulation. It was shown that assimilation could be triggered when participants were asked to hold on to golf balls as compared to being asked to drop them. Experiment 2 showed that a semantic priming of “let go” or “hold on” via instructions influenced the processes of self-regulation. Experiment 3 and Experiment 4 investigated the role of cognitive sets (divergent thinking) and motivational processes (thinking about one's action resources) in enhancing accommodation or assimilation. As expected, accommodation was triggered by an intervention activating divergent thought, and participants were more assimilative when they thought about their action resources. In sum, the results indicate that assimilation and accommodation can be induced experimentally; they were systematically dependent on physical, cognitive, and motivational states. The implications of the findings were discussed in the light of the dual-process model.
Whither Sudan?
Authors: Ali Hayder Ibrahim
Published: July 2014

This article deals with the political transformation of Sudan since the colonial period. It also depicts the instability of the governing process since independence by showing how the traditional social and political organization of society has played a major role in shaping its future. It shows how the ruling Islamic regime, while reinforcing the tribal factor in political and constitutional matters, has at the same time exacerbated the problem of ethnicity and religious differences in a multiethnic society. Beneath the whole political spectrum the article offers a detailed description of the economic conundrum of this country as well as its failure in building a ‘nation-state’. It concludes in pointing out how in the current conflicting situation the future of Sudan is being jeopardized.
Some Western concepts through Arab eyes: toward a new Arab epistemology
Authors: Hafez Ziad
Published: July 2014

This article is a call to re-examine current Arab epistemology in behavioural sciences in order to develop an Arab grown set of tools and concepts that will contribute to the civilization renewal as promoted by the Arab Renaissance Project. In particular, some thoughts relating to debates about ‘freedom’, ‘state’, and ‘democracy’ are provided.
Political Islam in Saudi Arabia: recent trends and future prospects
Authors: al-Saif Tawfiq
Published: July 2014

This article focuses on the Muslim Brotherhood and political Salafism, two influential currents of political Islam that formed a two-pronged political movement prevailing in Saudi Arabia over the past two decades. It examines how they have both influenced, in separate and distinct ways, the development of political Islam in that country. What began initially as a religious movement, striving to assert a national character, has subsequently over time separated itself from the political regime and the official religious establishment in a process that witnesses profound social change in Saudi society. It suffers from an inherent paradox linked to the context in which it developed; an organic relationship with the state in the 1980s, on the one hand, and a struggle against it in the 1990s, on the other. It enshrines the contradictory constraints with which it grapples with respect to government reluctance to modernize the society, on the one level, and popular, progressive aspirations linked to individual civil rights, on the another. In the opinion of the author, this religious movement has failed to comprehend and cope with the social change that has been taking place in Saudi society since 1994. The movement has suffered from an inability to set political priorities, and its ageing leadership has prevented it from keeping abreast with change and developments occurring within the society at large. With its uncompromising stance against women’s rights, and most particularly their right to work, as one example, it has got bogged down on many issues – in blatant opposition to popular demand – and failed to take into account the transformation under way in the society. This paper argues that the outlook for Saudi political Islam, within the two groups under study in this article – the Muslim Brotherhood and Salafist Islam – is bleak and does not augur well for its promising future. It is likely to be the same for other Arab countries.
The survival decrease in gastric cancer is associated with the methylation of B-cell CLL/lymphoma 6 member B promoter
Authors: Deng Jingyu , Liang Han , Dong Qiuping , Hou Yachao , Xie Xingming , Yu Jun , Fan Daiming , Hao Xishan
Published: July 2014

The methylation of B-cell CLL/lymphoma 6 member B (BCL6B) DNA promoter was detected in several malignancies. Here, we quantitatively detect the methylated status of CpG sites of BCL6B DNA promoter of 459 patients with gastric cancer (GC) by using bisulfite gene sequencing. We show that patients with three or more methylated CpG sites in the BCL6B promoter were significantly associated with poor survival. Furthermore, by using the Akaike information criterion value calculation, we show that the methylated count of BCL6B promoter was identified to be the optimal prognostic predictor of GC patients.
Unravelling the genetic basis for competence development of auxotrophic Bacillus licheniformis 9945A strains
Authors: Jakobs Mareike , Hoffmann Kerstin , Grabke Anja , Neuber Stefania , Liesegang Heiko , Volland Sonja , Meinhardt Friedhelm
Published: July 2014

Bacterial natural genetic competence – well studied inBacillus subtilis– enables cells to take up and integrate extracellularly supplied DNA into their own genome. However, little is known about competence development and its regulation in other members of the genus, although DNA uptake machineries are routinely encoded. AuxotrophicBacillus licheniformis9945A derivatives, obtained from repeated rounds of random mutagenesis, were long known to develop natural competence. Inspection of the colony morphology and extracellular enzyme secretion of two of these derivatives, M28 and M18, suggested that regulator genes are collaterally hit. M28 emerged as a 14 bp deletion mutant concomitantly displaying a shift in the reading frame ofdegSthat encodes the sensor histidine kinase, which is part of the molecular switch that directs cells to genetic competence, the synthesis of extracellular enzymes or biofilm formation, while for M18, sequencing of the suspected gene revealed a 375 bp deletion inabrB, encoding the major transition state regulator. With respect to colony morphology, enzyme secretion and competence development, both of the mutations, when newly generated on the wild-typeB. licheniformis9945A genetic background, resulted in phenotypes resembling M28 and M18, respectively. All of the known naturally competentB. licheniformisrepresentatives, hitherto thoroughly investigated in this regard, carry mutations in regulator genes, and hence genetic competence observed in domesticated strains supposedly results from deregulation.
Role of the yakA gene in morphogenesis and stress response in Penicillium marneffei
Authors: Suwunnakorn Sumanun , Cooper Chester R. , Kummasook Aksarakorn , Vanittanakom Nongnuch
Published: July 2014

Penicillium marneffeiis a thermally dimorphic fungus and a highly significant pathogen of immunocompromised individuals living in or having travelled in south-east Asia. At 25 °C,P. marneffeigrows filamentously. Under the appropriate conditions, these filaments (hyphae) produce conidiophores bearing chains of conidia. Yet, when incubated at 37 °C, or upon infecting host tissue,P. marneffeigrows as a yeast that divides by binary fission. Previously, anAgrobacterium-mediated transformation system was used to randomly mutagenizeP. marneffei, resulting in the isolation of a mutant defective in normal patterns of morphogenesis and conidiogenesis. The interrupted gene was identified asyakA. In the current study, we demonstrate that theyakAmutant produced fewer conidia at 25 °C than the wild-type and a complemented strain. In addition, disruption of theyakAgene resulted in early conidial germination and perturbation of cell wall integrity. TheyakAmutant exhibited abnormal chitin distribution while growing at 25 °C, but not at 37 °C. Interestingly, at both temperatures, theyakAmutant possessed increased chitin content, which was accompanied by amplified transcription of two chitin synthase genes,chsBandchsG. Moreover, the expression ofyakAwas induced during post-exponential-phase growth as well as by heat shock. Thus,yakAis required for normal patterns of development, cell wall integrity, chitin deposition, appropriatechsexpression and heat stress response inP. marneffei.
Mycobacterium tuberculosis adhesins: potential biomarkers as anti-tuberculosis therapeutic and diagnostic targets
Authors: Govender Viveshree S. , Ramsugit Saiyur , Pillay Manormoney
Published: July 2014

Adhesion to host cells is a precursor to host colonization and evasion of the host immune response. Conversely, it triggers the induction of the immune response, a process vital to the host’s defence against infection. Adhesins are microbial cell surface molecules or structures that mediate the attachment of the microbe to host cells and thus the host–pathogen interaction. They also play a crucial role in bacterial aggregation and biofilm formation. In this review, we discuss the role of adhesins in the pathogenesis of the aetiological agent of tuberculosis,Mycobacterium tuberculosis. We also provide insight into the structure and characteristics of some of the characterized and putativeM. tuberculosisadhesins. Finally, we examine the potential of adhesins as targets for the development of tuberculosis control strategies.
The short-term storage characteristics of cut kimchi cabbages treated with Ca2+
Authors: Kim Sang-Seop , Seong Gi-Un , Hwang Hee-Young , Jeong Moon-Cheol , Chung Shin-Kyo
Published: July 2014

To enhance the commercialization of fresh cut kimchi cabbage, the short-term storage effect of cut kimchi cabbage treated with Ca2+ was studied. Cut kimchi cabbages (3×3 cm) were treated with 2% calcium chloride (Ca), ascorbic acid (As), citric acid (Ct), and calcium chloride and citric acid (Ca/Ct), were put inside LDPE bags, and stored at 5℃ for 6 weeks. The weights reduced about 0.13~0.72%, and the ratio was the lowest in the Ca/Ct treatment. The reduction ratios of soluble soilds were 18.85~35.00%, and were the lowest in the Ca/Ct treatment. The titratable acidity decreased in all the treatments. The L values decreased, but a and b values of Hunter colorimeter increased in all the treatments. The preference for Ca/Ct treatment was the highest among all the treatments in the sensory evaluation. The marketing shelf-life of cut kimchi cabbage can be prolonged by the combination treatment of Ca2+ and citric acid.
Rapid detection of the hepatitis a virus from fresh lettuce using immunomagnetic separation and quantum dots assay
Authors: Lee Hee-Min , Kwon Joseph , Choi Jong-Soon , Won Yong-Gwan , Kim Eun-Sun , Chung Jae-Keun , Kim Min-Ji , Kim Duwoon
Published: July 2014

Hepatitis A virus (HAV) infection leads to acute liver failure and death through the intake of contaminated food. The polymerase chain reaction (PCR) has been used to detect HAV in food samples. HAV detection takes a long time, however, due to the virus concentration step required before PCR assay. In this study, a rapid method of detecting the HAVs present in lettuce using immunomagnetic separation combined with quantum dots (IMS-QDs) assay was developed. The detection limit of IMS-QDs for HAV was 10 TCID50/mL, similar to the result that was obtained using RT-PCR combined with PEG or IMS. The application of IMS-QDs assay completed the viral detection within one hour, but this was not possible using PEG combined with RT-PCR. In conclusion, IMS-QDs assay is a rapid and efficient method for detecting HAV at a low concentration in agricultural products.
Processing and quality characteristics of salad dressing using jujube puree
Authors: Namgung Ran , Park Sang-Ah , An So-Jeong , Lee Young-Hyeon , Kim Han-Soo , Lee Young-Guen , Seong Jong-Hwan , Chung Hun-Sik
Published: July 2014

This study was conducted to develop a salad dressing using jujube (Zizyphus jujuba Miller) puree and to evaluate the processing and quality characteristics of the salad dressing containing various amounts (0, 10, 20, 30, 40, and 50%) of jujube puree. Jujube puree was prepared by crushing peeled, deseeded and steamed fruit flesh. The dressing ingredients (jujube flesh puree, soy sauce, vinegar, oligosaccharide, olive oil, and water) were mixed, homogenized, and packaged in glass bottles. The quality characteristics (color property, total titratable acidity, soluble solids, viscosity, phenolic compound content, antioxidant activity, and sensory acceptability) of the dressing were analyzed. The lightness (L*) and redness (a*) of the dressing tended to increase as the amount of the jujube puree increased whereas the hue angle (h°) decreased. The total titratable acidity, soluble solids, viscosity, phenolic compound content, and antioxidant activity of the dressing increased with the addition of more jujube puree. The sensory acceptability (color, smell, taste, texture, and overall acceptability) were significantly higher in the dressing added with 30% added jujube puree than in the other samples. The results show that jujube flesh puree (approximately 30%) can be utilized as an additive for preparing a dressing with simultaneously high antioxidant activity and acceptability.
Quality and antioxidant charactistics of Elaeagnus multiflora wine through the thermal processing of juice
Authors: Cho Kye-Man , Joo Ok-Soo
Published: July 2014

In this study, the characteristics of alcohol fermentation using Elaeagnus multiflora juice were studied under static fermentation condition in an effort to develop new types of functional wine. After 9 days of fermentation at 25℃, the pH, soluble solids, reducing sugar, viable cell numbers, and alcohol contents were shown to be 3.32～3.33, 7.8～9.0°, 29.84～31.05 g/L, 7.26～8.73 cfu/mL, and 11.0%, respectively. The heat treated juice exhibited significantly higher antioxidant activity than untreated juice while the soluble phenolic and flavonoid contents became higher. Also, the fermented wine after the heat treated at 120℃ for 30 min contained free sugar such as fructose (0.42 g/L) and glucose (0.09 g/L), major organic acids such as lactic acid (7.32 g/L), malic acid (2.59 g/L), succinic acid (2.16 g/L), and oxalic acid (3.08 g/L), and major flavanols and phenolic acids such as catechin (99.45 mg/L), epicatechin (264.55 mg/L), epigallocatechin (82.19 mg/L), gallic acid (6.44 mg/L), and salicylic acid (60.53 mg/L). In addition, DPPH radical and ABTS radical scavenging activities and FRAP assay results were 70.47%,, 65.93%, and 1.254, respectively. These results suggest that it is possible to produced a new type of wine using Elaeagnus multiflora fruits.
Quality characteristics and antioxidant activity of tofu made from lipoxygenase-free genotypes
Authors: Kim In-Sung , Lee Soo-Jung , Lee Hye-Jin , Oh Soo-Jeong , Chung Jong-Il , Sung Nak-Ju
Published: July 2014

The quality characteristics and antioxidant activity of three kinds of tofu made from lipoxygenase (LOX)-free genotypes soybeans were compared to the Taekwang (LOX-present) tofu as the control. The mineral contents of Jinyang tofu were significantly higher than those of the control. The hardness and gumminess of tofu made from LOX-free genotypes were significantly higher than those of the control. Gaechuck#2 tofu showed higher sensory evaluation results than the other kinds of tofu in terms of taste, flavor and overall acceptability. The total isoflavone contents were higher in the LOX-free genotypes than in the control. The total phenol content was similar for the Gaechuck#1, #2 and Taekwang tofu. The flavonoid content was higher in Gaechuck#1 and #2 tofu than in the control. The antioxidant activities were the highest in Gaechuck#1 tofu, followed by the Gaechuck#2. During the 15-day storage at 4℃, the turbidity of the immersing water tended to increase, but Gaechuck#1 and #2 tofu were significantly lower than in the control after 15-day storage. Therefore it is suggested that Gaechuck#2 tofu could be the suitable genotype for tofu products because it is the most effective in terms of overall acceptability, antioxidant activity, and storage stability.
Changes in antioxidant activities and flavor patterns of Coffea arabica beans during roasting
Authors: Suh Yeon-Soo , Lee Seung-Heon , Shang Yafang , Yoon Jung-Ro , Lee Won-Jong
Published: July 2014

Brazil (Monte Alegro) and Ethiopia (Sidamo) coffee beans were roasted at three different roasting levels(light, medium, and dark), and were analyzed for color, total phenolic compound, caffeine, and chlorogenic acid contents. The total phenolic and caffeine contents remained unchanged during roasting. The chlorogenic acid levels of the Brazil and Ethiopia samples decreased with roasting. The antioxidant activities were measured using DPPH and ABTS. The radical scavenging activities of the light-roasted and dark-roasted coffee beans were similar. The flavor patterns of roasted coffee beans were analyzed using an electronic nose system based on gas chromatography. The data revealed that the flavor patterns of the roasted coffee beans could be separated via discriminant function analysis (DFA) method. The taste of the roasted coffee beans was analyzed using an electronic tongue system. The sourness and sweetness were decreased with roasting.
Antioxidant activity and quality characteristics on the maturation period of the soy sauce with Gastrodia elata and oak mushroom (Lentinus edodes)
Authors: Kwon Hyuk-Jin , Kim Hwa-Sun , Choi Yoon-Hee , Choi Ji-Ho , Choi Hae-Sun , Song Jin , Park Shin-Young
Published: July 2014

This study was performed to investigate the changes in antioxidant activity and quality characteristics of soy sauce with Gastrodia elata (GK) and oak mushroom (MK) in maturation period to develop a new Kanjang product with improved functional and sensory characteristics. The pH was decreased, and the total acidity was higher in GK at 25-day maturation period. Although the total sugar content increased at 15 days with GK, it was reduced after 20 days. The reducing sugar, however, showed no notable differences after 20 days. The protease activities of GK was rapidly increased after 20 days. The total polyphenol and flavonoid contents tended to be similar and dramatically increased after 15 days. On the other hand, the DPPH radical scavenging activity of MK was higher than that of GK. These results showed that the 20-day maturation period of GK greatly enhanced its antioxidant activity and quality characteristics. It is thus expected to be used as functional materials.
Effect of the container and temperature on the quality of buckwheat (Fagopyrum esculentum) Soksungjang during storage
Authors: Lee Sun Young , Baik Soo Hwa , Choi Hye Sun
Published: July 2014

This study was performed to provide fundamental information regarding the quality change of buckwheat Soksungjang (BWS) during its storage. BWS was divided into three different containers (pot, plastic, and glass) and was stored at three different temperatures (5, 15, and 25℃), and the changes in pH, acidity, amino-type nitrogen, total bacterial count, and chromaticity were examined during the storage period. The pH (0 day, pH 4.37) and acidity (0 day, 2.93% acidity) of the samples, except at the 15 and 25℃ pots, did not show any significant change during storage, but 98 days after storage, the pH values of the 15 and 25℃ pots were pH 5.6 and 7.4, and their acidity values were 1.85 and 0.71%, respectively. At 98 days, the amino-type nitrogen of the 25℃ plastic sample had slightly increased to 0.75±0.01%, and that of the 25℃ pot had drastically risen to 0.92±0.01%. It was also shown that little change in the total bacterial count was found during the experiment period in every sample. The chromaticity results confirmed that the L (lightness), a (redness), and b (yellowness) values of the 25℃ pot sample showed relatively large changes during storage compared to the other samples. These results suggest that the desirable storage temperature of BWS is in the range of 5-15℃, and that a glass container is the most suitable container for BWS as it can reduce the quality alteration during storage.
Antioxidative activities of various solvent extracts from haw (Crataegus pinnatifida Bunge)
Authors: Duan Yishan , Kim Min-A , Seong Jong-Hwan , Chung Hun-Sik , Kim Han-Soo
Published: July 2014

The objective of this study was to investigate the antioxidative acitivities of various solvent extracts from haw (Crataegus pinnatifida Bunge) pulpy. The Freeze-dried pulpy of haw was extracted with five solvents (70% methanol, 70% ethanol, chloroform:methanol (CM, 2:1, v/v), n-butanol, and ethyl acetate or EA), and the DPPH, reducing power, ferric-reducing antioxidant power (FRAP), ABTS, NO, hydroxyl radical scavenging activity were then measured. The DPPH radical scavenging activity of the 70% methanol and 70% ethanol extracts were 92.89% and 91.17% in the 0.8 mg/mL concentrations, respectively, which were higher than those of the other extracts. The reducing power and FRAP decreased in the following order: 70% methanol, 70% ethanol, n-butanol, EA, and CM extracts. The ABTS radical scavenging activity was high in the 70% methanol and 70% ethanol extracts and low in the n-butanol extract. The NO radical scavenging activity was high in the 70% methanol and 70% ethanol extracts but low in the CM extracts. On the other hand, the hydroxyl radical scavenging activity was high in the n-butanol and 70% methanol extracts but low in the EA extract. These results suggest that the 70% methanol and 70% ethanol extracts from haw will be useful as natural antioxidant and biohealth foods.
Antioxidant activity and inhibition activity against α-amylase and α-glucosidase of Smilax China L.
Authors: Lee Soo-Yeon , Kim Jeung-Hoan , Park Jung-Mi , Lee In-Chul , Lee Jin-Young
Published: July 2014

This study was carried out to analyze the effects of water and 70% ethanol extract on the antioxidative and antidiabetic activities of Smilax china L., a vine shrub belonging to the lily family. The activities of the extracts were measured based on the total phenolic and flavonoid contents and through on the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activities, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), TBARs content and ACE inhibition activity, and α-glucosidase, and α-amylase inhibition activity. The resulting total phenolic and flavonoid contents of the 70% ethanol extract from S. china L. were greater than those of the water extract from S. china L. With regard to the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activity, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), and TBARs content, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. Also, with regard to the ACE inhibition effect and α-glucosidase and α-amylase inhibition, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. All these findings show that the 70% ethanol extract from S. china L. has greater antioxidative and antidiabetic effects and can be used as a preventive agent for oxidation and diabetes.
Improving the efficacy of Lespedeza cuneata ethanol extract on ultraviolet-induced photoaging
Authors: Jung Hee Kyoung , Choi Mi Ok , Kim Bae Jin , Jo Seung Kyeung , Jeong Yoo Seok
Published: July 2014

This study evaluated the improving efficacy of Lespedeza cuneata ethanol extract on skin photoaging induced by ultraviolet (UV) irradiation. The total polyphenol and flavonoid contents of the extract were respectively 134.98±1.70 and 16.20±0.05 mg/g, respectively. The superoxide anion radical scavenging activity and electron-donating ability of the extract were shown to be dependent on concentration, and the antioxidant ability was shown to be more effective in superoxide anion radical scavenging activity than in electron-donating ability under the same concentration conditions. In the in vivo test conducted using hairless mouse with skin photoaging induced by UVB irradiation, the skin erythema of the groups treated with the extract (AS) reduced to 28% of the control, and the skin moisture content increased to 131%.. The extract treatment of the UV-damaged skin improved the morphological and histopathological state of the skin. Furthermore, the SOD, GST and CAT activities in the skin tissue of the AS group increased, and the XO activity and TBARS generation decreased. With regard to the genes related to the photoaging skin, the expression of PAK, p38, c-Fos, c-Jun, TNF-α and MMP-3 in the skin of the AS group were found to have decreased. It was therefore concluded that Lespedeza cuneata ethanol extract can reduce wrinkle formation in the skin due to the regulation of the gene expression caused by the exposure to UVB light.
(Z)-2,3-Dichloro-1,4-bis(4-chlorophenyl)but-2-ene-1,4-dione
Authors: Tittal Ram K. , Kumar Satish , Ram R. N.
Published: July 2014

The title compound, C16H8Cl4O2, crystallizes with two independent molecules in the asymmetric unit. Both molecules have aZconformation around the central double bond and they show significantly different C—C—C—O torsion angles between the aromatic ring and the carbonyl group [30.1 (7) and 3.9 (7)° in one molecule and 23.5 (7) and 9.3 (8)° in the other]. The crystal packing shows short halogen Cl...O [3.003 (5) and 3.246 (4) Å] and Cl...Cl [3.452 (2) Å] contacts and aromatic C—H...Cl and C—H...O interactions link the molecules, resulting in chains propogating along [100]. The crystal structure also features π–π stacking interactions between aromatic units of the two independent molecules, with a centroid–centroid distance of 3.9264 (6) Å.