bluuebunny/crossref_metadata_2025 huggingface dataset:
Inquiry‐based examination of chemical disruption of bacterial biofilms
Authors: Redelman Carly V. , Hawkins Misty A. W. , Drumwright Franklin R. , Ransdell Beverly , Marrs Kathleen , Anderson Gregory G.
Published: February 2012

Inquiry‐based instruction in the sciences has been demonstrated as a successful educational strategy to use for both high school and college science classrooms. As participants in the NSF Graduate STEM Fellows in K‐12 Education (GK‐12) Program, we were tasked with creating novel inquiry‐based activities for high school classrooms. As a way to introduce microbiology, molecular biology, ecology, and human health to students, we created a laboratory activity involving formation of biofilms composed of environmental bacteria from pond water and investigation into the resistance of these biofilms to antimicrobial agents. Two high schools participated in this study in different ways. Pike High School biology and advanced environmental science classrooms obtained pond water samples and grew biofilms from the bacteria in the pond water on plastic plates. They also observed killing of these biofilms by common household antimicrobial agents. As a senior capstone project, students at Arsenal Technical High School built on these research findings by isolating two different bacterial strains from the pond water and demonstrating the stimulatory effect of ethanol on biofilms formed by isolated bacterial strains. These activities were successful at introducing complex biological topics to high school students in a unique and exciting way. The students scored significantly higher on postactivity surveys compared with preactivity surveys that measured microbiology knowledge and experimental design knowledge. Furthermore, these projects seemed to elicit an excitement for science in the students who participated.
Evaluation of oxidative stress markers and vascular risk factors in patients with diabetic peripheral neuropathy
Authors: El Boghdady Noha Ahmed , Badr Gamal Ali
Published: February 2012

Diabetic peripheral neuropathy (DPN) is one of the most common diabetic chronic complications. The pathogenesis of DPN is complex and involves an intertwined array of mechanisms. The purposes of this study were to evaluate the association of oxidative stress and vascular risk factors with the prevalence of DPN and to determine the role of these biochemical parameters in the prognosis of DPN. One hundred patients with type 2 diabetes mellitus and 40 clinically healthy individuals were evaluated. The patients were divided into two groups. Group 1 included 40 diabetic patients without peripheral neuropathy, and group 2 consisted of 60 patients with DPN. Erythrocytes glutathione (GSH) level, plasma malondialdehyde (MDA), nitrite/nitrate (NOx) and homocysteine (Hcy) levels as well as serum ceruloplasmin (Cp), total antioxidants (TAO), endothelin‐1 (ET‐1) levels and γ‐glutamyl transferase (GGT) activity were estimated. A significant decrease of erythrocyte GSH was observed in groups 1 and 2 relative to the controls. An increase in glycosylated haemoglobin (HbA1c), MDA, NOx, GGT, Cp, TAO, Hcy and ET‐1 was noted in patients with DPN. In conclusion, oxidative stress biomarkers and vascular risk factors could be important in the pathogenesis of DPN. The measurement of serum GGT and Hcy in addition to HbA1c and disease duration could facilitate the early detection of neuropathy in diabetic patients. Copyright © 2012 John Wiley & Sons, Ltd.
Atrial Fibrillation and Acid Reflux Disease
Authors: Velagapudi Poonam , Turagam Mohit K , Leal Miguel A , Kocheril Abraham G
Published: February 2012

To date, the precise mechanism of atrial fibrillation (AF) as a possible cause of reflux disease remains uncertain, although some possibilities can be postulated. Inflammation and vagal stimulation may have a key role linking these 2 common diseases. There is some evidence in the form of case reports and limited observational studies reporting that reflux disease, and more specifically esophagitis, can cause paroxysmal AF, and various mechanisms have been proposed. Some studies have demonstrated that acid suppressive therapy by proton pump inhibitors (PPIs) may help ameliorate symptoms associated with AF and also facilitate conversion to normal sinus rhythm in a subset of patients. Further prospective studies are needed to determine if a true causal mechanism exists between the two and assess whether the mechanism is dependent on a specific subtype of AF. In addition, the response of AF‐related symptoms to PPI therapy and the potential for PPI therapy to reduce the development of AF merits further investigation. Clin. Cardiol. 2011 DOI: 10.1002/clc.21969

The authors have no funding, financial relationships, or conflicts of interest to disclose.
MR imaging of human pancreatic cancer xenograft labeled with superparamagnetic iron oxide in nude mice
Authors: Wu Chao Ying , Pu Yu , Liu Gang , Shao Yang , Ma Qing Song , Zhang Xiao Ming
Published: February 2012

The aim of this work was to investigate the MRI findings on tumor xenografts induced in nude mice by the inoculation of human pancreatic cancer cells labeled with superparamagnetic iron oxide (SPIO), and to monitor the kinetics of SPIO distribution in tumor xenografts. The labeled cancer cells were subcutaneously inoculated into 11 nude mice to induce tumor xenograft. The unlabeled cancer cells served as a control inoculated into nine nude mice. MR imaging was performed with a 1.5 T MR scanner for the tumor xenograft at the first, second and third week after the inoculation. We found that the tumor xenograft was induced in 100% nude mice on MR imaging for both groups in the first week after the inoculation. In the SPIO group, the tumors showed homogeneous hypointensity on T1‐ and T2‐weighted and FIESTA images 1 week after inoculation. Two and 3 weeks after inoculation, the center of the tumors was still hypointense on all the above sequences. The tumor periphery was isointense on T1‐weighted, and hyperintense on T2‐weighted and FIESTA images. The tumors in control group were homogeneously hypointense or isointense on T1‐weighted, and hyperintense on T2‐weighted and FIESTA images in the first, second and third week after the inoculation. The size and signal‐to‐noise ratio of the tumor center in the SPIO group had decreased subsequent to the inoculation in all T1‐ and T2‐weighted images and FIESTA. Our results showed the human pancreatic cancer cells labeled with SPIO can induce tumor xenograft in nude mice and MRI can monitor the kinetics of SPIO distribution in tumor xenografts. Copyright © 2012 John Wiley & Sons, Ltd.
Postinjury administration of 17β‐estradiol induces protection in the gray and white matter with associated functional recovery after cervical spinal cord injury in male rats
Authors: Siriphorn Akkradate , Dunham Kelly A. , Chompoopong Supin , Floyd Candace L.
Published: February 2012

The majority of spinal cord injuries (SCIs) in the clinic occur at the lower cervical levels, resulting in both white and gray matter disruption. In contrast, most experimental models of SCI in rodents induce damage in the thoracic cord, resulting primarily in white matter disruption. To address this disparity, experimental cervical SCI models have been developed. Thus, we used a recently characterized model of cervical hemicontusion SCI in adult male rats to assess the potential therapeutic effect of post‐SCI administration of 17β‐estradiol. Rats received a hemicontusion at the level of the fifth cervical vertebra (C5) followed by administration of 17β‐estradiol via a slow release pellet (0.5 or 5.0 mg/pellet) beginning at 30 minutes post‐SCI. Behavioral evaluation of skilled and unskilled forelimb function and locomotor function were conducted for 7 weeks after SCI. Upon conclusion of the behavioral assessments, spinal cords were collected and histochemistry and stereology were conducted to evaluate the effect of treatment on the lesion characteristics. We found that post‐SCI administration of 17β‐estradiol decreased neuronal loss in the ventral horn, decreased reactive astrogliosis, decreased the immune response, and increased white mater sparing at the lesion epicenter. Additionally, post‐SCI administration of 17β‐estradiol improved skilled forelimb function and locomotor function. Taken together, these data suggest that post‐SCI administration of 17β‐estradiol protected both the gray and white matter in cervical SCI. Moreover, this treatment improved function on skilled motor tasks that involve both gray and white matter components, suggesting that this is likely a highly clinically relevant protective strategy. J. Comp. Neurol. 520:2630–2646, 2012. © 2012 Wiley Periodicals, Inc.
The origin of the Drosophila subretinal pigment layer
Authors: Tomlinson Andrew
Published: February 2012

Optical insulation plays a critical role in the fine visual acuity of the Drosophila compound eye. Screening pigments expressed by a number of cell types contribute to this phenomenon. They provide optical insulation that prevents extraneous light rays from inappropriately activating the photoreceptors. This optical insulation can be divided into two categories; the insulation of the individual ommatidia, and the insulation of the compound eye as a whole. The whole‐eye insulation is provided by two sources. The sides of the eye are optically insulated by the pigment rim, a band of pigment cells that circumscribes the eye. The base of the eye is insulated by the subretinal pigment layer; a thick layer of pigment that lies directly underneath the retina. How this subretinal pigment layer is generated has not been clearly described. Here, experiments that manipulate pigment expression during eye development suggest that the subretinal pigment layer is directly derived from pigment cells in the overlying retina. J. Comp. Neurol. 520:2676–2682, 2012. © 2012 Wiley Periodicals, Inc.
Glial responses after chorda tympani nerve injury
Authors: Bartel Dianna L.
Published: February 2012

The chorda tympani (CT) nerve innervates lingual taste buds and is susceptible to damage during dental and inner ear procedures. Interruption of the CT results in a disappearance of taste buds, which can be accompanied by taste disturbances. Because the CT usually regenerates to reinnervate taste buds successfully within a few weeks, a persistence of taste disturbances may indicate alterations in central nervous function. Peripheral injury to other sensory nerves leads to glial responses at central terminals, which actively contribute to abnormal sensations arising from nerve damage. Therefore, the current study examined microglial and astrocytic responses in the first central gustatory relay, the nucleus of the solitary tract (nTS), after transection of the CT. Damage to the CT resulted in significant microglial responses in terms of morphological reactivity and an increased density of microglial cells from 2 to 20 days after injury. This increased microglial population resulted primarily from microglial proliferation from 1.5 to 3 days, which was supplemented by microglial migration within subdivisions of the nTS between days 2 and 3. Unlike other nerve injuries, CT injury did not result in recruitment of bone marrow‐derived precursors. Astrocytes also reacted in the nTS with increased levels of glial fibrillary acidic protein (GFAP) by 3 days, although none showed evidence of cell division. GFAP levels remained increased at 30 days, by which time microglial responses had resolved. These results show that nerve damage to the CT results in central glial responses, which may participate in long‐lasting taste alterations following CT lesion. J. Comp. Neurol. 520:2712–2729, 2012. © 2012 Wiley Periodicals, Inc.
Intercage Electron Transfer Driven by Electric Field in Robin–Day‐Type Molecules
Authors: Wang Yin‐Feng , Li Ying , Zhou Zhong‐Jun , Li Zhi‐Ru , Wu Di , Huang Jiangen , Gu Feng Long
Published: February 2012

A new class of isomers, namely, intercage electron‐transfer isomers, is reported for fluorinated double‐cage molecular anion e−@C20F18(NH)2C20F18 with C20F18 cages: 1 with the excess electron inside the left cage, 2 with the excess electron inside both cages, and 3 with the excess electron inside the right cage. Interestingly, the C20F18 cages may be considered as two redox sites existing in a rare nonmetal mixed‐valent (0 and −1) molecular anion. The three isomers with two redox sites may be the founding members of a new class of mixed‐valent compounds, namely, nonmetal Robin–Day Class II with localized redox centers for 1 and 3, and Class III with delocalized redox centers for 2. Two intercage electron‐transfers pathways involving transfer of one or half an excess electron from one cage to the other are found: 1) Manipulating the external electric field (−0.001 a.u. for 1→3 and −0.0005 a.u. for 1→2) and 2) Exciting the transition from ground to first excited state and subsequent radiationless transition from the excited state to another ground state for 1 and 3. For the exhibited microscopic electron‐transfer process 1→3, 2 may be the transition state, and the electron‐transfer barrier of 6.021 kcal mol−1 is close to the electric field work of 8.04 kcal mol−1.
Cytotoxic functions and susceptibility to apoptosis of human CD56bright NK cells differentiated in vitro from CD34+ hematopoietic progenitors
Authors: Zamai Loris , Del Zotto Genny , Buccella Flavia , Galeotti Laura , Canonico Barbara , Luchetti Francesca , Papa Stefano
Published: February 2012

Cytotoxic functions and susceptibility to apoptosis are crucial aspects of NK cells suitable to counter cancer after infusion in oncologic patients. To test the feasibility and the usefulness of infusing in vitro generated NK cells, these two features were investigated in NK cells developed in vitro from CD34+ hematopoietic progenitors. Purified CD34+ cells were cultured for 15–30 days with FLT‐3 ligand (FLT3‐L) and IL‐15 with or without IL‐21. To induce terminal differentiation, NK cells were cultured for further 15 days with IL‐15, IL‐21, or their combination. A CD56dim/CD16+ NK subset, expressing high level of perforin, granzymes, and LFA‐1, appeared early in cultures with FLT3‐L, IL‐15, and IL‐21, but it quickly died, indicating its predisposition to apoptosis. On the contrary, CD56bright NK cells generated after 30 days of culture with FLT3‐L plus IL‐15 did not show a considerable apoptosis, nevertheless only a subset of these cells expressed granzyme‐B, perforin, LFA‐1, and CD94‐CD159a heterodimer, indicating a functional immaturity. Interestingly, further 15 days of culture with IL‐21 plus IL‐15 did not induce the generation of CD56dim cells from the CD56bright subset and actually inhibited IL‐15‐induced maturation/activation of this latter subset. In fact, IL‐15 alone upregulated granzyme‐B, TRAIL, Fas ligand, CD94‐CD159a, LFA‐1, CD16, KIRs, and TRAIL‐R2 on CD56bright NK cells. Our results suggest that during differentiation CD56bright NK cells, similarly to mature activated NK cells, become highly cytotoxic and are relatively resistant to apoptosis induced by TNF family members. © 2012 International Society for Advancement of Cytometry.
Association of serum 25‐hydroxyvitamin D with type 2 diabetes and markers of insulin resistance in a general older population in Finland
Authors: Hurskainen Anne‐Riina , Virtanen Jyrki K. , Tuomainen Tomi‐Pekka , Nurmi Tarja , Voutilainen Sari
Published: February 2012

Background

Vitamin D insufficiency and type 2 diabetes are both common in Finland, and low vitamin D status has been suggested as a risk factor for type 2 diabetes. Our aim was to study the associations between serum 25‐hydroxyvitamin D [25(OH)D], a marker of vitamin D status, and glucose homeostasis and type 2 diabetes in a general population sample in Eastern Finland.

Methods

Cross‐sectional analysis in the Kuopio Ischaemic Heart Disease Risk Factor Study. A total of 850 men and 906 women, aged 53–73 years, were analysed. Relative risk (RR) of prevalent diabetes was estimated as odds ratios by logistic regression. Associations between serum 25(OH)D and markers of impaired glucose metabolism in tertiles of serum 25(OH)D concentration were assessed by linear regression.

Results

The mean serum 25(OH)D concentration was 43.4 nmol/L (SD 17.6, range 8.5–122.8 nmol/L) in the study population. Serum 25(OH)D concentration <50 nmol/L were observed in 65.5% of the participants. Serum 25(OH)D was inversely associated with fasting serum insulin, fasting blood glucose and oral glucose tolerance test (OGTT) 2‐h glucose levels after adjustment for age, gender and examination year. Association with the OGTT 2‐h glucose remained statistically significant after multivariate adjustments. The RR (95% confidence interval) for type 2 diabetes in tertiles of serum 25(OH)D were 1, 1.26 (0.86, 1.85) and 1.44 (0.96, 2.15) after multivariate adjustments (p for trend = 0.08).

Conclusions

Our results suggest that low serum 25(OH)D is associated with impaired glucose and insulin metabolism. Copyright © 2012 John Wiley & Sons, Ltd.
New Yttrium and Europium(+3) Alkoxides Bearing Thiophene Units: Syntheses, Crystal Structure Determinations and Physico‐Chemical Properties
Authors: Veith Michael , Belot Céline , Huch Volker
Published: February 2012

The synthesis, structural characterization, electrochemistry and luminescence properties of a series of new yttrium and europium(+3) alkoxides bearing thiophene moieties are presented. The yttrium compounds were obtained by the reaction between Y[N(SiMe3)2]3 and the tertiary alcohols HO–C(C16H13S) (2), HO–C(C17H15S) (3), HO–C(C14H11S2) (4) and HO–C(C16H13S) (5) in thf or in a mixture of toluene and pyridine. The X‐ray crystal diffraction measurements show a five‐coordinated yttrium atom in distorted trigonal‐bipyramidal geometry. The metal centres are surrounded by threemethoxido ligands in equatorial positions and two tetrahydrofuran [for {Y[OC(C16H13S)]3(thf)2}·toluene (8), {Y[OC(C17H15S)]3(thf)2}·toluene (10) and {Y[OC(C14H11S2)]3(thf)2}·1/2 toluene (12)] or two pyridine [for {Y[OC(C16H13S)]3(py)2}·toluene (9) and {Y[OC(C17H15S)]3(py)2}·toluene (11)] molecules in axial positions. The compounds Y[OC(C14H11S2)]3(py)2 (13) and Y[OC(C16H13S)]3(py)2 (14) were identified by NMR spectroscopy. In addition, a novel europium(+3) alkoxide {Eu[OC(C4H3S)3]3(thf)3}·thf (15) was synthesized by the reaction between Eu[N(SiMe3)2]3 and the tertiary alcohol HO–C(C4H3S)3 (1) in thf. The molecular structure of this compound reveals an approximately octahedral coordination sphere around the europium(+3) metal centre with three methoxido ligands and three facially arranged tetrahydrofuran molecules. The cyclic voltammograms of the yttrium alkoxides indicate that the electrochemical properties are essentially dominated by the organic ligands. The electrochemical properties of {Eu[OC(C4H3S)3]3(thf)3}·thf (15) are dominated by the oxidation of the thienyl moieties and in addition a reduction wave due to the reduction of Eu3+ to Eu2+ is visible. In comparison to the carbinols, the oxidation peak potentials of the thienyl units for the yttrium and europium(3+) alkoxides are marginally shifted towards higher values. The emission spectra of the carbinols and their derived yttrium compounds display broad bands attributed to the π*→π transitions of the aromatic ligands. Luminescence studies performed on compound 15 reveal the typical f–f transitions of the Eu3+ ions and suggest that an energy transfer from the ligand to the metal atom operates.
Structural Diversity and Magnetic Properties of the Manganese(II)/Carbazol‐9‐ylacetate/N,N′‐Donor Reaction System
Authors: Ma Yun‐Sheng , Tang Xiao‐Yan , Xue Feng‐Feng , Chen Bin , Dai Yao‐Liang , Yuan Rong‐Xin , Roy Soumyajit
Published: February 2012

Four manganese‐based carbazol‐9‐ylacetato complexes [Mn2(cabo)4(2,2′‐bpy)2] (1), [Mn2(cabo)2(2,2′‐bpy)4](ClO4)2 (2), [Mn(cabo)2(CH3OH)2]n (3), and [Mn(cabo)2(4,4′‐bpy)2]n (4) (cabo– = carbazol‐9‐ylacetate, 2,2′‐bpy = 2,2′‐bipyridine, 4,4′‐bpy = 4,4′‐bipyridine) have been synthesized and characterized. The crystal structure of 1 consists of a symmetrical dimeric MnII carboxylato paddle‐wheel unit, whereas dinuclear 2 consists of a dimeric unit with two MnII ions bridged by two carboxylato ligands. Compounds 3 and 4 present comparable 1D structures with MnII ions bridged by carboxylato ligands. Magnetic‐property studies show that antiferromagnetic exchange interactions propagate among the MnII ions in 1, 2, and 3.
Glycolipids improve lutein bioavailability and accumulation in eyes in mice
Authors: Gorusupudi Aruna , Vallikannan Baskaran
Published: February 2012

Intestinal carotenoid absorption is greatly affected by dietary factors. In this study, it was hypothesized that lipids with varying functional groups may influence differentially lutein bioavailability. Hence, the influence of glyco‐, phospho‐, neutral, crude (mixture of lipids) lipids, or mixed micelles (control) on the percent lutein micellarization in vitro and its postprandial plasma, liver, and eye response in mice were investigated. Results show that the percent micellarization of lutein with crude lipids and glycolipids were higher (91.4 and 45.7%) than control, while no significant difference was found between phospho‐ and neutral lipids. The mean plasma response of lutein was higher for crude‐ (6 times), glyco‐ (3 times), phospho‐ (2.7 times), and neutral (2 times) lipid than control (12.4 ± 1.18 nmol/mL 8 h−1) group. Lutein levels (pmol/g) in liver were higher in crude (7.4 ± 1) and phospho‐ (3.6 ± 0.8) lipid groups while in eyes it was higher in glyco‐ (54.0) and neutral (21.2) lipid groups than control. The influential effect of glyco‐ and phospholipids may be due to smaller micellar size (glyco‐upto 3.43 µm, phospho‐ upto 5.78 µm) than the neutral lipids (upto 66 µm). Ingestion of lutein with glycolipid or phospholipids may improve lutein bioavailability.

Practical applications: The findings of the present study will be useful in nutritional and biomedical applications for feeding lutein with specific lipid combinations to achieve enhanced lutein absorption. Specifically, feeding diet/emulsion with lutein and glyco‐ and phospholipid combination may reduce the risk of macular degeneration, owing to the influential effect of these lipids on intestinal absorption of lutein.
A novel conversion of sesamolin to sesaminol by acidic cation exchange resin
Authors: Huang Jinian , Song Guohui , Zhang Lixia , Sun Qiang , Lu Xin
Published: February 2012

Sesame (Sesamum indicum L.) seed and its oil contain abundant lignans, including sesamin, sesamolin, sesamol, sesaminol, and their glycosides. In the present study, a novel reaction pathway, using an anhydrous solvent system, cation exchange resin catalyst, and HPLC for detection, was employed for the conversion of sesamolin into sesaminol. Under optimal conditions of 5 mL toluene, 90°C, initial sesamolin concentration of 6 mM, and catalyst dosage of 16.66 g/mmol of sesamolin, a 75.0% yield of sesaminol was achieved. The reaction mechanism was inferred to be that of a Friedel–Crafts reaction, with the catalyst showing remarkable catalytic activity and producing only slightly decreased yield after reuse in five subsequent batches. Owing to excellent reusability, low cost, and ready availability, this catalyst provides a very satisfactory option for converting sesamolin to sesaminol.

Practical applications: Sesaminol is a potential natural antioxidant for use as a food additive and in medicinal applications, but it is a naturally occurring trace compound, and could be transformed from sesamolin under proper, specific conditions. The cation exchange resin 732 provides a satisfactory option for catalyzing the conversion of sesamolin into sesaminol. This suggests encouraging prospects for practical or industrial applications utilizing its notable catalytic performance, reusability, low cost, and easy availability.
Suzuki–Miyaura Cross‐Coupling Reactions in a Solkane365/227/Ethanol Blend at Ambient Temperature
Authors: Xu Xiu‐Hua , Azuma Ayaka , Kusuda Akihiro , Tokunaga Etsuko , Shibata Norio
Published: February 2012

An environmentally benign solvent system, Solkane365/227/ethanol blend, was developed for Suzuki–Miyaura cross‐coupling reactions of aryl boronic acids and aryl halides. The reaction is quite general and gives excellent yields for various aryl, heteroaryl, and fluoroaryl boronic acids or halides. Interestingly, this system also allows the synthesis of polyaryls.
Effect of carrier frequency offset and symbol timing offset on the performance of FMT over time‐frequency selective channels
Authors: Zheng Jing , Wang Zulin
Published: February 2012

This paper presents the effects of carrier frequency offset (CFO) and symbol timing offset (STO) in filtered multitone (FMT) systems over time and frequency selective multipath fading channels. The analysis is based on an FMT system using a square‐root raised cosine pulse. The performance of FMT systems in the presence of CFO and STO over different fading channels are derived and compared with that of orthogonal frequency division multiplexing systems. The offsets degrade the performance of the FMT systems because they cause filter mismatch. The CFO changes the amplitude frequency characteristic of the receiver filter, while the STO changes the phase frequency characteristic of the receiver filter. The simulations are conducted over different fading channels. To achieve signal‐to‐interference ratio above 20 dB, over a flat static channel, the frequency offset relative to symbol duration must be less than 5% in the orthogonal frequency division multiplexing system, while the upper limit is 8% in the FMT system. The simulation results also show that the FMT system is less sensitive to CFO in time frequency selective channels. The signal‐to‐interference ratio expressions help predict the bit‐error‐rate performance of FMT with single tap subchannel equalization. The analysis also helps synchronization algorithm design after analyzing the synchronization offset effect in FMT systems under certain channel conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Spatial heterogeneity in hyper‐arid vegetation of the South Western Desert, Egypt
Authors: Sheded Mohamed Gabr , Radwan Usama Ahmed , Taher Mostafa Ahmed , Springuel Irina
Published: February 2012

A vegetation survey of 124 stands in the South Western Desert of Egypt identified 79 species of angiosperms belonging to 25 families. 54 species (68.3%) are annuals (including one hydrophyte) and 25 species (31.7%) are perennials. Grasses (Poaceae or Gramineae) contributed 21.5% of the total flora, considered the most dominant family in the South Western Desert. Two herbaceous species were recorded for the first time in this region: Eragrostis lepida and Enarthrocarpus pterocarpus. Eleven vegetation clusters were obtained and categorized into five distinct groups according to soil composition and chemical characteristics. The large number of weeds appears in the extreme arid desert due to the recent extensive and intensive anthropogenic effects. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Geoarchaeology of Mudbricks in Architecture: A Methodological Study fromÇatalhöyük,Turkey
Authors: Love Serena
Published: February 2012

This article provides a methodology for extracting social information through an analysis of mudbrick compositions, using a case study fromÇatalhöyük,Turkey. Particle size analysis, loss on ignition, and magnetic susceptibility were used to examine variability in mudbrick recipe. The analysis revealed that neither magnetic susceptibility nor calcium carbonate were significantly altered through tempering. The results suggest that the greatest degree of compositional variability was a result of the manufacture process and not raw materials used in production. Mudbricks are products of deliberate human actions, similar to any other artifact assemblage, but have been long overlooked. Examining the technology involved with mudbrick manufacture highlights aspects ofNeolithic social life through shared resources, production choices, and organization of labor. The analysis of mudbrick compositions considers how raw materials were used within and between groups of houses, represented in 1000 years of uninterrupted occupation atÇatalhöyük.
Regulation of CCL20 expression in astrocytes by IL‐6 and IL‐17
Authors: Meares Gordon P. , Ma Xiangyu , Qin Hongwei , Benveniste Etty N.
Published: February 2012

Astrocytes have an important role in the regulation of inflammation within the central nervous system (CNS). In neuroinflammatory conditions such as multiple sclerosis, numerous cytokines and chemokines are elevated including IL‐6, IL‐17, and CCL20. IL‐17 enhances IL‐6 signaling and subsequent IL‐6 expression in astrocytes. CCL20 is a CC motif chemokine that functions as a chemoattractant to facilitate the recruitment of CCR6‐expressing cells, including Th17 cells. In this study, we examined the role of IL‐6 and IL‐17 on CCL20 production in primary murine astrocytes. IL‐6 in combination with the IL‐6 soluble receptor (sIL‐6R) stimulated CCL20 expression in part through STAT3 activation, whereas IL‐17 alone had no effect. However, the combination of IL‐6, sIL‐6R, and IL‐17 led to a robust increase in CCL20 production. IL‐17 increased the activation‐associated phosphorylation of NF‐κB, and inhibition of the NF‐κB pathway significantly inhibited the enhancement of CCL20 expression by IL‐17. In addition, chromatin immunoprecipitation revealed that stimulation of primary astrocytes with IL‐6 plus the sIL‐6R induced STAT3 binding to the CCL20 promoter. Combined stimulation with IL‐6, sIL‐6R, and IL‐17 increased the recruitment of phosphorylated NF‐κB to the CCL20 promoter, increased binding of coactivators such as p300 and CBP, and enhanced H3 and H4 histone acetylation, consistent with a transcriptionally active gene. The astrocyte‐produced CCL20 increased T cell migration as determined by transwell migration assay. Collectively, these results suggest that astrocytes, in response to IL‐6, sIL‐6R, and IL‐17, may shift chemokine production to that favoring T cell recruitment to the CNS. © 2012 Wiley Periodicals, Inc.
(σ3,λ5)‐phosphoranes versus (σ3,λ3)‐thiaphosphiranes: Quantum chemical investigation of products of phosphaalkene sulfurization
Authors: Turcheniuk K. V. , Rozhenko A. B.
Published: February 2012

By sulfurization of phosphaalkenes (a) either (σ3,λ5)‐phosphoranes (b) or (σ3,λ3)‐thiaphosphiranes (c) are formed. In this study, Density Functional Theory (DFT) and coupled cluster (CCSD(T)) calculations have been carried out for model and experimental structures of (σ3,λ5)‐phosphoranes and (σ3,λ3)‐thiaphosphiranes to elucidate the factors influencing relative stabilities of b and c. According to the results of quantum chemical calculations, sterically bulky substituents make the phosphorane form more favored. Conversely, electronic effects of the most substituents provide higher stability for thiaphosphirane isomers. The only exception has been found in the cases where the substituent at the phosphorus atom possesses π‐donor and σ‐acceptor properties (e.g., in the case of amino group) and the substituents at carbon atom exhibit σ‐donor/π‐acceptor effects (e.g., silyl groups). The stability of the cyclic form c decreases further, if the substituents at the carbon atom are amino groups. In this case, a quite unusual structure has been theoretically predicted, which is considerably different from those of the hitherto known phosphoranes. It indicates a pyramidal configuration at the phosphorus atom and can be conventionally presented as a donor–acceptor adduct of diaminocarbene with thioxophosphine. © 2012 Wiley Periodicals, Inc.
Platinum Complexes of 4‐Hydoxy‐1,5‐naphthyridines as Emitting Dyes
Authors: Chien Ching‐Ting , Shiu Jin‐Ruei , Chang Chih‐Ping , Hon Yung‐Son , Huang Duo‐Fong , Chou Po‐Ting , Liu Ching‐Yang , Chow Tahsin J.
Published: February 2012

4‐Hydoxy‐1,5‐naphthyridines (HNt) are derivatives of 8‐hydroxyquinolines, yet possess a wider HOMO and LUMO band gap than the latter. The cyclometalated complex of platinum(II) with Nt exists in a square planner geometry, and has a high tendency to aggregate in condensed media. Such a phenomenon was verified by examining its photo‐luminescence spectra in different concentrations. In a dilute solution, it exhibits a yellow phosphorescence centered at 530∼555 nm, yet red‐shifted to ∼660 nm in a concentrated solution or in the solid state. This series of compounds can be used as emitting dyes in light‐emitting diodes (LED). The LED devices with a configuration ITO/NPB/dye (6%) in CBP/BCP/AlQ3 or TPBI/LiF/Al displayed a yellow to red color, where NPB, CBP, BCP, AlQ3 and TPBI denote 4,4′‐bis[N‐(1‐naphthyl),N‐phenylamino]biphenyl, 4,4′‐bis(carbazol‐9‐yl)biphenyl, 2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline, tris(8‐hydoxyquinolinato)aluminium, and 2,2′,2″‐(1,3,5‐benzenetriyl)tris(1‐phenyl‐1H‐benzimidazole), respectively. The maximal light intensity exceeds 2.6 × 104 cd/m2 with an external quantum efficiency up to 5.8%.
Photodegradation of four fluoroquinolone compounds by titanium dioxide under simulated solar light irradiation
Authors: Li Weihong , Guo Changsheng , Su Bin , Xu Jian
Published: February 2012

BACKGROUND; In this study, simultaneous photocatalytic degradation of four fluoroquinolone (FQ) compounds (i.e. ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin) was investigated in TiO2 suspensions under simulated solar light irradiation. Effects of experimental variables including pH, TiO2 dosage, initial substrate concentration and hydrogen peroxide (H2O2) on the degradation processes were also investigated.

RESULTS: The antibiotics degradation was pH‐influenced. The photocatalytic reaction followed the pseudo‐first‐order model, with reaction rate constants (k) 0.026, 0.027, 0.022 and 0.026 min−1 for ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin, respectively. Complete elimination of four FQs was achieved in a reaction system composed of 0.5 g L−1 of TiO2 and 82.5 mg L−1 of H2O2 at pH 6 after 90 min irradiation. Mineralization of FQs during TiO2 photocatalysis was slower than the FQs conversion, and the antibacterial activity of the four FQs was completely removed by TiO2 under simulated solar light irradiation.

CONCLUSION: The four FQs can be simultaneously degraded and mineralized with commercially available TiO2 under simulated solar light irradiation. Microbiological analysis showed that the antibacterial activity of the four FQs was completely removed. These results are helpful for antibiotics removal in the environment, and for exploring new technology for wastewater treatment. Copyright © 2012 Society of Chemical Industry
Electrolysis of progesterone with conductive‐diamond electrodes
Authors: Martín de Vidales María José , Sáez Cristina , Cañizares Pablo , Rodrigo Manuel Andrés
Published: February 2012

BACKGROUND: Progesterone is considered an endocrine disruptor chemical. It can be found in industrial discharges, municipal wastewaters, and, in some instances, even in treated effluents at the level of ng dm−3.

RESULTS: Conductive diamond electrolysis can be used to remove progesterone from aqueous solutions. Increases in current density lead to less efficient processes, indicating mass transfer control of the process rate. Occurrence of chlorides in the electrolytic media favors the depletion of progesterone compared with sulphates, although it does not affect the mineralization rate. Independently of the solubilizing agent used, the process behaves similarly during a first stage of the electrolysis (at the four ranges of pollutant concentration studied). However, in a second stage, the rate changes abruptly due to reduced action of hydroxyl radicals in methanol media.

CONCLUSIONS: Progesterone can be removed efficiently by conductive diamond electrolysis from aqueous solutions within the range of initial concentrations 10−2 to 102 mg dm−3. The process efficiency increases with the current density. Removal rate does not depend on the nature of the electrolyte, but this parameter affects the intermediates formed during the experiment. When pure methanol is used as solubilizing agent, only direct electro‐oxidation takes place. Copyright © 2012 Society of Chemical Industry
Transcranial magnetic stimulation reduces nociceptive threshold in rats
Authors: Ambriz‐Tututi Mónica , Sánchez‐González Violeta , Drucker‐Colín René
Published: February 2012

Transcranial magnetic stimulation (TMS) is a procedure that uses magnetic fields to stimulate or inhibit nerve cells in the brain noninvasively. TMS induces an electromagnetic current in the underlying cortical neurons. Varying frequencies and intensities of TMS increase or decrease excitability in the cortical area directly targeted. It has been suggested that TMS has potential in the treatment of some neurological disorders such as Parkinson's disease, stroke, and depression. Initial case reports and open label trials reported by several groups support the use of TMS in pain treatment. In the present study, we evaluated the effect of TMS on the nociceptive threshold in the rat. The parameters used were a frequency of 60 Hz and an intensity of 2 and 6 mT for 2 hr twice per day. After 5 days of TMS treatment, rats were evaluated for mechanical, chemical, and cold stimulation. We observed a significant reduction in the nociceptive threshold in TMS‐treated rats but not in sham‐treated rats in all behavioral tests evaluated. When TMS treatment was stopped, a slow recovery to normal mechanic threshold was observed. Interestingly, i.c.v. MK‐801 or CNQX administration reverted the TMS‐induced pronociception. The results suggest that high‐frequency TMS can alter the nociceptive threshold and produce allodynia in the rats; results suggest the involvement of NMDA and AMPA/KA receptors on TMS‐induced allodynia in the rat. © 2012 Wiley Periodicals, Inc.
Application of denaturing gradient gel electrophoresis to microbial diversity analysis in Chinese Douchi
Authors: Chen Tingtao , Jiang Shuying , Xiong Shunqiang , Wang Mengjuan , Zhu Daochen , Wei Hua
Published: February 2012

BACKGROUND: Douchi is a traditional Chinese soybean food which has been consumed for thousands years as an important protein source and flavouring ingredient. Studies have rarely been carried out to investigate its microbial composition and these are urgently required for the commercial labels and safety considerations.

RESULTS: Microbial counts were statistically significant different among Douchi samples. Although the maximum diversity indexes of bacterial, bacillus and fungal polymerase chain reaction–denaturing gradient gel electrophoresis (PCR‐DGGE) patterns were only 79%, 70% and 64%, some microorganisms, e.g. Bacillus subtilis, Bacillus amyloliquefaciens, Pseudomonas sp., Saccharomyces cerevisiae and Pichia farinose, were found to share dominant positions in most Douchi samples. In addition, some pathogens, e.g. Staphylococcus saprophyticus, Pantoea sp., Staphylococcus sciuri, Enterobacter sp. and Staphylococcus sp., were also identified.

CONCLUSION: The PCR‐DGGE technique was used for the first time as an effective method to assess the microbial communities in different Chinese Douchi samples. This information may be useful in improving the product quality, reformatting production methods, extending shelf life and scaling up the fermentation process. Copyright © 2012 Society of Chemical Industry
Quinoa starch granules: a candidate for stabilising food‐grade Pickering emulsions
Authors: Rayner Marilyn , Timgren Anna , Sjöö Malin , Dejmek Petr
Published: February 2012

BACKGROUND: Particle‐stabilised emulsions, so‐called Pickering emulsions, are known to possess many beneficial properties, including being extremely stable. Starch granules isolated from quinoa have been used as emulsion stabilising particles. The granules were intact, 1–3 µm in diameter and modified with octenyl succinic anhydride to increase their hydrophobicity. Starch granules, as opposed to most other particles used to generate Pickering emulsions, are edible, abundant and derived from natural sources.

RESULTS: Emulsions produced by high shear homogenisation had droplet sizes of 9–70 µm depending on the starch‐to‐oil ratio. Droplet size decreased with increasing starch‐to‐oil ratio, but was unaffected by the oil phase volume over a range of 5–33% oil (v/v). Although the drops were large and subject to creaming, their size remained unchanged over a period of 7 days. By adjusting the starch‐to‐oil ratio drops could be made to be buoyancy neutral to prevent creaming. Rheological characterisation indicated a gel structure with an elastic modulus in the range 200–2000 Pa depending on droplet size.

CONCLUSION: This work has demonstrated the successful use of starch granules to stabilise emulsions which may find applications beyond that of food, for example in cosmetics and pharmaceutical formulations. Copyright © 2012 Society of Chemical Industry
Screening of the antioxidant properties and polyphenol composition of aromatised green tea infusions
Authors: Pȩkal Anna , Dróżdż Paulina , Biesaga Magdalena , Pyrzynska Krystyna
Published: February 2012

BACKGROUND: Aromatised green teas are widely sold and popular owing to their fragrance. In this study the antioxidant activity of six commercial green tea infusions was assessed by three complementary assays.

RESULTS: In order to evaluate the tea infusions as antioxidant sources, their phenolic content (Folin‐Ciocalteu assay), cupric ion‐reducing antioxidant capacity (CUPRAC) and 2,2‐diphenyl‐1‐picryhydrazyl (DPPH) radical‐scavenging ability were determined. Their content of polyphenols was also determined by high‐performance liquid chromatography/mass spectrometry (HPLC/MS) in negative electrospray ionisation mode. Some teas with citrus aroma, besides having a relatively high content of catechins, also contain other phenolic compounds such as naringin and hesperidin. The three assays used to evaluate the antioxidant capacity of the tea infusions gave different rank orders. Therefore an antioxidant index was calculated for better correlation of the results, and its highest value was obtained for Clear Green Mint tea infusion.

CONCLUSION: The studied teas, besides having a relatively high content of catechins, also contain naringin and hesperidin, which are not present in ‘pure’ green tea. It is important to run multiple assays to get a better estimate of the antioxidant capacity of a given sample. Copyright © 2012 Society of Chemical Industry
Automated analysis of lidocaine and its metabolite in plasma by in‐tube solid‐phase microextraction coupled with LC‐UV for pharmacokinetic study
Authors: Caris Juciene Aparecida , Silva Bruno José Gonçalves , Moisés Elaine Christine Dantas , Lanchote Vera Lúcia , Queiroz Maria Eugênia Costa
Published: February 2012

A sensitive, selective, and reproducible in‐tube solid‐phase microextraction and liquid chromatographic (in‐tube SPME/LC‐UV) method for determination of lidocaine and its metabolite monoethylglycinexylidide (MEGX) in human plasma has been developed, validated, and further applied to pharmacokinetic study in pregnant women with gestational diabetes mellitus (GDM) subjected to epidural anesthesia. Important factors in the optimization of in‐tube SPME performance are discussed, including the draw/eject sample volume, draw/eject cycle number, draw/eject flow rate, sample pH, and influence of plasma proteins. The limits of quantification of the in‐tube SPME/LC method were 50 ng/mL for both metabolite and lidocaine. The interday and intraday precision had coefficients of variation lower than 8%, and accuracy ranged from 95 to 117%. The response of the in‐tube SPME/LC method for analytes was linear over a dynamic range from 50 to 5000 ng/mL, with correlation coefficients higher than 0.9976. The developed in‐tube SPME/LC method was successfully used to analyze lidocaine and its metabolite in plasma samples from pregnant women with GDM subjected to epidural anesthesia for pharmacokinetic study.
PROJECTED CHANGES IN SOIL ORGANIC CARBON STOCKS UPON ADOPTION OF RECOMMENDED SOIL AND WATER CONSERVATION PRACTICES IN THE UPPER TANA RIVER CATCHMENT, KENYA
Authors: Batjes N. H.
Published: February 2012

Large areas in the Upper Tana river catchment, Kenya, have been over‐exploited, resulting in soil erosion, nutrient depletion and loss of soil organic matter (SOM). This study focuses on sections of the catchment earmarked as being most promising for implementing Green Water Credits, an incentive mechanism to help farmers invest in land and soil management activities that affect all fresh water resources at source. Such management practices can also help restore SOM levels towards their natural level. Opportunities to increase soil organic carbon (SOC) stocks, for two broadly defined land use types (croplands and plantation crops, with moderate input levels), are calculated using a simple empirical model, using three scenarios for the proportion of suitable land that may be treated with these practices (low = 40 per cent, medium = 60 per cent, high = 80 per cent). For the medium scenario, corresponding to implementation on ~348 000 ha in the basin, the eco‐technologically possible SOC gains are estimated at 4·8 to 9·3 × 106 tonnes (Mg) CO2 over the next 20 years. Assuming a conservative price of US$10 per tonne CO2‐equivalent on the carbon offset market, this would correspond to ~US$48–93 million over a 20‐year period of sustained green water management. This would imply a projected (potential) payment of some US$7–13 ha−1 to farmers annually; this sum would be in addition to incentives that are being put in place for implementing green water management practices and also in addition to the benefits that farmers would realize from the impact on production of these practices themselves. Copyright © 2012 John Wiley & Sons, Ltd.
Femtosecond pulse written fiber gratings: a new avenue to integrated fiber technology
Authors: Thomas J. , Voigtländer C. , Becker R.G. , Richter D. , Tünnermann A. , Nolte S.
Published: February 2012

The use of ultrashort laser pulses for fiber grating inscription has many advantages in comparison to continuous wave and long pulse lasers. The most important one is that it allows inscription in nonphotosensitive fiber materials. In this paper the principal inscription techniques and the physical properties of femtosecond (fs) pulse written in‐fiber gratings are reviewed. The role of focusing and order walk‐off on the inscribed structures is emphasized. A fs pulse written fiber Bragg grating (FBG) also has a unique coupling behavior, due to a refractive index change that is independent from the fiber geometry. Selected applications of such gratings for sensing and fiber lasers are discussed.
Tribological performance of poly(sodium 4‐styrenesulphonate) as additive in water–glycol hydraulic fluid
Authors: Wang Junming , Wang Jianhua , Li Chunsheng , Zhao Gaiqing , Wang Xiaobo
Published: February 2012

The tribological behaviour of poly(sodium 4‐styrenesulphonate) (PSS) as additive in the base fluid of water–glycol hydraulic fluid was evaluated with four‐ball machine and Optimol SRV‐IV (Optimol Instruments, Munich, Germany) oscillating friction and wear tester, and its viscosity‐enhancing performance was also investigated. The results show that PSS exhibits excellent friction‐reducing and anti‐wear properties in the base fluid and can significantly improve the latter's welding load and viscosity. The worn surfaces were characterised by scanning electron microscope and X‐ray photoelectron spectroscopy. The analytical results of typical elements on the worn surfaces demonstrate that PSS molecules adsorb on the rubbing surface and form a stable chemically absorbed film through the interactions between the sulphonate anions and surface metallic atoms during the sliding process, which contributed to improve the tribological properties of the base fluid. Copyright © 2012 John Wiley & Sons, Ltd.