bluuebunny/crossref_metadata_2025 huggingface dataset:
A displacement‐based adaptive pushover method considering modal sign reversal for RC frame structures
Authors: Shafiee Navid , Tehranizadeh Mohsen
Published: August 2015

Nonlinear static procedures are favored tools for practical applications in the structural engineering profession. However, some limitations are associated with them, including their deficiencies to properly reflect higher modal effects and inertial seismic forces fluctuations in their responses. Some different adaptive pushover methods intended to improve these limitations have been proposed in the literature, but each one has come out with a special deficiency. In this study, based on the concepts of the displacement‐based adaptive pushover, a new dual‐run procedure method called Improved DAP (IDAP) has been developed, aiming to improve higher modal and sign reversal consideration of pushover methods. The seismic scope of this study has been focused on near‐fault regions. Four concrete SMRF with different heights have been employed for the evaluations. The results of the proposed method in terms of capacity curves, interstory and shear profiles are compared with those of the IDA method. Results indicate that the ability of the new method in reproducing seismic story forces and capacity curves, as well as interstory drifts, has been improved in comparison with its primitive counterpart. Copyright © 2015 John Wiley & Sons, Ltd.
Do All Candle-Flame-Shaped Flares Have the Same Temperature Distribution?
Authors: Gou Tingyu , Liu Rui , Wang Yuming
Published: August 2015

We performed a differential emission measure (DEM) analysis of candle-flame-shaped flares observed with the Atmospheric Imaging Assembly onboard the Solar Dynamic Observatory. The DEM profile of flaring plasmas generally exhibits a double peak distribution in temperature, with a cold component around

$\log T\approx6.2$

log
T
≈
6.2

and a hot component around

$\log T\approx7.0$

log
T
≈
7.0

. Attributing the cold component mainly to the coronal background, we propose a mean temperature weighted by the hot DEM component as a better representation of flaring plasma than the conventionally defined mean temperature, which is weighted by the whole DEM profile. Based on this corrected mean temperature, the majority of the flares studied, including a confined flare with a double candle-flame shape sharing the same cusp-shaped structure, resemble the famous Tsuneta flare in temperature distribution, i.e., the cusp-shaped structure has systematically higher temperatures than the rounded flare arcade underneath. However, the M7.7 flare on 19 July 2012 poses a very intriguing violation of this paradigm: the temperature decreases with altitude from the tip of the cusp toward the top of the arcade; the hottest region is slightly above the X-ray loop-top source that is co-spatial with the emission-measure-enhanced region at the top of the arcade. This signifies that a different heating mechanism from the slow-mode shocks attached to the reconnection site operates in the cusp region during the flare decay phase.
Osteochondral Defects of the Upper Extremity Treated with Particulated Juvenile Cartilage Transfer
Authors: Dunn John C. , Kusnezov Nicholas , Orr Justin , Mitchell Justin S.
Published: August 2015

We present the novel use of particulated juvenile cartilage transfer in the upper extremity. Our patient is an active duty solider with an osteochondral defect (OCD) of the capitellum that he sustained after an improvised explosive devise injury to his left elbow.
Multicentre prospective clinical application of the T14 paediatric outcome tool
Authors: Hopkins C , Almeyda R , Alreefy H , Ismail-Koch H , Lim J , Possamai V , Powell S , Sharma R , Hore I
Published: August 2015

Objective:

This study aimed to measure changes in disease-specific quality of life in children following tonsillectomy or adenotonsillectomy.

Methods:

A multicentre prospective cohort study was performed involving seven ENT departments in England. A total of 276 children entered the study over a 2-month period: 107 underwent tonsillectomy and 128 adenotonsillectomy. Forty-one children referred with throat problems initially managed by watchful waiting were also recruited. The follow-up period was 12 months. Outcome measures were the T14, parental impressions of their child's quality of life and the number of days absent from school.

Results:

One-year follow-up data were obtained from 150 patients (52 per cent). The mean baseline T14 score in the non-surgical group was significantly lower (T14 = 23) than in the tonsillectomy group (T14 = 31) or the adenotonsillectomy group (T14 = 35; p < 0.001). There was a significant improvement in the T14 scores of responders in all groups at follow up. The effect size was 1.3 standard deviations (SD) for the non-surgical group, 2.1 SD for the tonsillectomy group and 1.9 SD for the adenotonsillectomy group. Between-group differences did not reach statistical significance. A third of children in the non-surgical group underwent surgery during the follow-up period.

Conclusion:

Children who underwent surgical intervention achieved a significant improvement in disease-specific quality of life. Less severely affected children were managed conservatively and also improved over 12 months, but 1 in 3 crossed over to surgical intervention.
Shaping Vulnerable Bodies at the Thin Boundary between Environment and Organism: Skin, DNA Repair, and a Genealogy of DNA Care Strategies
Authors: von Schwerin Alexander
Published: August 2015

Argument

This paper brings together the history of risk and the history of DNA repair, a biological phenomenon that emerged as a research field in between molecular biology, genetics, and radiation research in the 1960s. The case of xeroderma pigmentosum (XP), an inherited hypersensitivity to UV light and, hence, a disposition to skin cancer will be the starting point to argue that, in the 1970s and 1980s, DNA repair became entangled in the creation of new models of the human body at risk – what is here conceptually referred to as the vulnerability aspect of body history – and new attempts at cancer prevention and enhancement of the body associated with the new flourishing research areas of antimutagenesis and anticarcinogenesis. The aim will be to demonstrate that DNA repair created special attempts at disease prevention: molecular enhancement, seeking to identify means to increase the self-repair abilities of the body at the molecular level. Prevention in this sense meant enhancing the body's ability to cope with the environmental hazards of an already toxic world. This strategy has recently been adopted by the beauty industry, which introduced DNA care as a new target for skin care research and anti-aging formulas.
The epidemiology and genetics of binge eating disorder (BED)
Authors: Davis Caroline
Published: August 2015

This narrative review provides an overview of the epidemiology of binge eating disorder (BED), highlighting the medical history of this disorder and its entry as an independent condition in the Feeding and Eating Disorders section of the recently publishedDiagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Estimates of prevalence are provided, as well as recognition that the female to male ratio is lower in BED than in other eating disorders. Evidence is also provided of the most common comorbidities of BED, including mood and anxiety disorders and a range of addiction disorders. In addition, discussion of the viewpoint that BED itself may be an addiction — at least in severe cases — is presented. Although the genetic study of BED is still in its infancy, current research is reviewed with a focus on certain neurotransmitter genes that regulate brain reward mechanisms. To date, a focal point of this research has been on the dopamine and the μ-opioid receptor genes. Preliminary evidence suggests that a predisposing risk factor for BED may be a heightened sensitivity to reward, which could manifest as a strong dopamine signal in the brain’s striatal region. Caution is encouraged, however, in the interpretation of current findings, since samples are relatively small in much of the research. To date, no genome-wide association studies have focused exclusively on BED.
Ornithine Transcarbamylase ArgK Plays a Dual role for the Self-defense of Phaseolotoxin Producing Pseudomonas syringae pv. phaseolicola
Authors: chen Li , li Pin , deng Zixin , zhao Changming
Published: August 2015

Pseudomonas syringae is a phytopathogenic bacterium widely spread on terrestrial plants. Sulfodiaminophosphinyl tripeptide Phaseolotoxins (PHTs), produced by P. syringae pv. phaseolicola and P. syringae pv. actinidiae, represent a kind of antimetabolic phytotoxins. PHTs inhibit host cell Ornithine transcarbamylase (OTCase) activity and induce Arginine auxotrophic phenotype. The biosynthesis of PHT is temperature dependent, being optically produced at around 18 °C, while blocked above 28 °C. PHT resistant OTCase ArgK acts as a functional replacement of housekeeping OTCase ArgF, which is the acting target of PHT, to confer PHT producers with self-resistance. It was postulated that argK might be regulated directly by a PHT biosynthetic precursor and indirectly by temperature with an unknown manner. Neither transcriptional regulator nor thermal regulation related protein encoding gene was detected from PHT biosynthetic gene cluster. The tripeptide, Cit-Ala-hArg, was identified to be a by-product of PHT biosynthetic pathway in this report. Formation of Cit-Ala-hArg was catalyzed by ArgK with tripeptide Orn-Ala-hArg and carbamyl phosphate as substrates. It showed that ArgK not only provided alternative Arginine source as reported previously, but also controlled the production of PHTs by converting PHT biosynthetic precursors to nontoxic Cit-Ala-hArg reservoir for producers’ self-defense.
Nationwide variation in the effects of temperature on infectious gastroenteritis incidence in Japan
Authors: Onozuka Daisuke , Hagihara Akihito
Published: August 2015

Although several studies have investigated the effects of temperature on the incidence of infectious gastrointestinal disease in a single city or region, few have investigated variations in this association using nationwide data. We obtained weekly data, gathered between 2000 and 2012, pertaining to infectious gastroenteritis cases and weather variability in all 47 Japanese prefectures. A two-stage analysis was used to assess the nonlinear and delayed relationship between temperature and morbidity. In the first stage, a Poisson regression allowing for overdispersion in a distributed lag nonlinear model was used to estimate the prefecture-specific effects of temperature on morbidity. In the second stage, a multivariate meta-analysis was applied to pool estimates at the national level. The pooled overall relative risk (RR) was highest in the 59.9th percentile of temperature (RR, 1.08; 95% CI: 1.01, 1.15). Meta-analysis results also indicated that the estimated pooled RR at lower temperatures (25th percentile) began immediately but did not persist, whereas an identical estimate at a higher temperature (75th percentile) was delayed but persisted for several weeks. Our results suggest that public health strategies aimed at controlling temperature-related infectious gastroenteritis may be more effective when tailored according to region-specific weather conditions.
Evaluation of genetic susceptibility of common variants in CACNA1D with schizophrenia in Han Chinese
Authors: Guan Fanglin , Li Lu , Qiao Chuchu , Chen Gang , Yan Tinglin , Li Tao , Zhang Tianxiao , Liu Xinshe
Published: August 2015

The heritability of schizophrenia (SCZ) has been estimated to be as high as 80%, suggesting that genetic factors may play an important role in the etiology of SCZ. Cav1.2 encoded by CACNA1C and Cav1.3 encoded by CACNA1D are dominant calcium channel-forming subunits of L-type Voltage-dependent Ca2+ channels, expressed in many types of neurons. The CACNA1C has been consistently found to be a risk gene for SCZ, but it is unknown for CACNA1D. To investigate the association of CACNA1D with SCZ, we designed a two-stage case-control study, including a testing set with 1117 cases and 1815 controls and a validation set with 1430 cases and 4295 controls in Han Chinese. A total of selected 97 tag single nucleotide polymorphisms (SNPs) in CACNA1D were genotyped and single-SNP association, imputation analysis and gender-specific association analyses were performed in the two independent datasets. None was found to associate with SCZ. Further genotype and haplotype association analyses indicated a similar pattern in the two-stage study. Our findings suggested CACNA1D might not be a risk gene for SCZ in Han Chinese population, which add to the current state of knowledge regarding the susceptibility of CACNA1D to SCZ.
Systems biology approach to studying proliferation-dependent prognostic subnetworks in breast cancer
Authors: Song Qianqian , Wang Hongyan , Bao Jiguang , Pullikuth Ashok K. , Li King C. , Miller Lance D. , Zhou Xiaobo
Published: August 2015

Tumor proliferative capacity is a major biological correlate of breast tumor metastatic potential. In this paper, we developed a systems approach to investigate associations among gene expression patterns, representative protein-protein interactions and the potential for clinical metastases, to uncover novel survival-related subnetwork signatures as a function of tumor proliferative potential. Based on the statistical associations between gene expression patterns and patient outcomes, we identified three groups of survival prognostic subnetwork signatures (SPNs) corresponding to three proliferation levels. We discovered 8 SPNs in the high proliferation group, 8 SPNs in the intermediate proliferation group and 6 SPNs in the low proliferation group. We observed little overlap of SPNs between the three proliferation groups. The enrichment analysis revealed that most SPNs were enriched in distinct signaling pathways and biological processes. The SPNs were validated on other cohorts of patients and delivered high accuracy in the classification of metastatic vs non-metastatic breast tumors. Our findings indicate that certain biological networks underlying breast cancer metastasis differ in a proliferation-dependent manner. These networks, in combination, may form the basis of highly accurate prognostic classification models and may have clinical utility in guiding therapeutic options for patients.
Systematic analyses reveal uniqueness and origin of the CFEM domain in fungi
Authors: Zhang Zhen-Na , Wu Qin-Yi , Zhang Gui-Zhi , Zhu Yue-Yan , Murphy Robert W. , Liu Zhen , Zou Cheng-Gang
Published: August 2015

CFEM domain commonly occurs in fungal extracellular membrane proteins. To provide insights for understanding putative functions of CFEM, we investigate the evolutionary dynamics of CFEM domains by systematic comparative genomic analyses among diverse animals, plants and more than 100 fungal species, which are representative across the entire group of fungi. We here show that CFEM domain is unique to fungi. Experiments using tissue culture demonstrate that the CFEM-containing ESTs in some plants originate from endophytic fungi. We also find that CFEM domain does not occur in all fungi. Its single origin dates to the most recent common ancestors of Ascomycota and Basidiomycota, instead of multiple origins. Although the length and architecture of CFEM domains are relatively conserved, the domain-number varies significantly among different fungal species. In general, pathogenic fungi have a larger number of domains compared to other species. Domain-expansion across fungal genomes appears to be driven by domain duplication and gene duplication via recombination. These findings generate a clear evolutionary trajectory of CFEM domains and provide novel insights into the functional exchange of CFEM-containing proteins from cell-surface components to mediators in host-pathogen interactions.
Feeding regulates sex pheromone attraction and courtship in Drosophila females
Authors: Lebreton Sébastien , Trona Federica , Borrero-Echeverry Felipe , Bilz Florian , Grabe Veit , Becher Paul G. , Carlsson Mikael A. , Nässel Dick R. , Hansson Bill S. , Sachse Silke , Witzgall Peter
Published: August 2015

In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females.
Scanning Transmission Electron Microscopy
Authors: Lupini A. R. , Rashkeev S. N. , Varela M. , Borisevich A. Y. , Oxley M. P. , van Benthem K. , Peng Y. , de Jonge N. , Veith G. M. , Pennycook T. J. , Zhou W. , Ishikawa R. , Chisholm M. F. , Pantelides S. T. , Pennycook S. J.
Published: August 2015

The scanning transmission electron microscope (STEM) is one of the most useful tools in many areas of atomic-scale materials science and nanocharacterization. A STEM has the ability to generate local maps of the chemical composition and electronic structure at atomic resolution, even in complex or unknown samples. Here we describe the important components of a state-of-the-art aberration-corrected STEM and review the application of STEM imaging to a variety of published nanocharacterisation examples in catalysis and solid state materials problems.
Scanning Tunnelling Microscopy of Surfaces and Nanostructures
Authors: Castell Martin R.
Published: August 2015

Over the last three decades the scanning tunnelling microscope (STM) has been one of the key instruments in the study of the atomic and electronic structure of surfaces. This chapter discusses the most important aspects of the technique. It starts with a brief overview of the invention of the STM and its subsequent evolution, followed by sections on the basic STM operating principles and how the tunnelling interaction between the fine scanning tip and the surface can lead to atomic-resolution images of crystal surfaces of metals and semiconductors. The next section describes examples of STM imaging of surface nanostructures such as Ge nanocrystals on a Si surface, SrTiO3 and MoS2 nanostructures, as well as fullerene clusters. This is followed by a discussion of atomic-scale lithography with the STM, including illustrations of the wave-like nature of quantum mechanical interactions seen in quantum corrals. The STM is not only sensitive to atomic-scale topography, but also to the local electronic surface states. This is described via the imaging of dopant atoms and TiO2 surfaces, and the theme is further developed in the section on tunnelling spectroscopy where the density of electronic states in a window of a few eV either side of the Fermi energy can be measured. The next section covers some common imaging artefacts that arise when the scanning tip is not perfect, and this is followed by a brief conclusion and outlook
An instantly usable paper-based screen-printed solid-state KCl/Ag/AgCl reference electrode with long-term stability
Authors: Shitanda Isao , Komoda Masato , Hoshi Yoshinao , Itagaki Masayuki
Published: August 2015

An instantly usable screen-printed paper-based Ag/AgCl electrode was fabricated for use as a cost-effective disposable reference electrode.
Facet-dependent acidic and catalytic properties of sulfated titania solid superacids
Authors: Hu Yichen , Guo Bin , Fu Yingyi , Ren Yuanhang , Tang Gangfeng , Chen Xueying , Yue Bin , He Heyong
Published: August 2015

Sulfated titania solid superacids with different dominant facets were prepared and dominant {001} facets facilitated the enhancement of acidic properties.
Tuning the properties of the UiO-66 metal organic framework by Ce substitution
Authors: Nouar Farid , Breeze Matthew I. , Campo Betiana C. , Vimont Alexandre , Clet Guillaume , Daturi Marco , Devic Thomas , Walton Richard I. , Serre Christian
Published: August 2015

Replacement of Zr by Ce in a metal organic framework gives defects and redox activity for use in heterogeneous catalysis.
Cu-based carbene involved in a radical process: a new crossover reaction to construct γ-peroxy esters and 1,4-dicarbonyl compounds
Authors: Jiang Jiewen , Liu Jiajun , Yang Ling , Shao Ying , Cheng Jiang , Bao Xiaoguang , Wan Xiaobing
Published: August 2015

Herein, a novel crossover reaction of Cu-based carbene, olefin, and tert-butyl hydroperoxide (TBHP) was well developed, leading to γ-peroxy esters and 1,4-dicarbonyl compounds.
A turn-on fluorescent probe for tumor hypoxia imaging in living cells
Authors: Cai Qi , Yu Tao , Zhu Weiping , Xu Yufang , Qian Xuhong
Published: August 2015

A turn-on fluorescent probe was designed and synthesized for tumor hypoxia imaging, which could show excellent reducing ability under chemical or bio-reductase conditions and good performance in hypoxia imaging for HeLa cells at different oxygen concentrations.
Fe2O3 icositetrahedra: evolution and their comparative photocatalytic activities
Authors: Li Pengwei , Ji Jianlong , Deng Xiao , Li Anli , Hu Jie , Li Gang , Zhang Wendong
Published: August 2015

Fe2O3 icositetrahedra, controllable synthesis and their comparative photocatalytic activities.
Transferable force fields for adsorption of small gases in zeolites
Authors: Martin-Calvo A. , Gutiérrez-Sevillano J. J. , Parra J. B. , Ania C. O. , Calero S.
Published: August 2015

We provide transferable force fields for oxygen, nitrogen, and carbon monoxide that are able to reproduce experimental adsorption in both pure silica and alumino-substituted zeolites at cryogenic and high temperatures.
A generalized method for the inversion of cohesive energy curves from isotropic and anisotropic lattice expansions
Authors: Schmidt Kevin M. , Vasquez Victor R.
Published: August 2015

Cohesive energy inversions are generalized to handle a broad range of lattice geometries, including systems with internal rigid bodies.
Air-processed polymer tandem solar cells with power conversion efficiency exceeding 10%
Authors: Li Ning , Brabec Christoph J.
Published: August 2015

Polymer tandem solar cells fabricated by doctor-blading in air achieve a high PCE exceeding 10% along with an unprecedentedly high FF of >76%.
Metal diselenide nanoparticles as highly active and stable electrocatalysts for the hydrogen evolution reaction
Authors: Liang Jia , Yang Yingchao , Zhang Jing , Wu Jingjie , Dong Pei , Yuan Jiangtan , Zhang Gengmin , Lou Jun
Published: August 2015

In this communication, metal diselenide nanoparticles (NiSe2, CoSe2, and PdSe2) are synthesized successfully by the hydrothermal method.
Multilayered silicene: the bottom-up approach for a weakly relaxed Si(111) with Dirac surface states
Authors: Fu Huixia , Chen Lan , Chen Jian , Qiu Jinglan , Ding Zijing , Zhang Jin , Wu Kehui , Li Hui , Meng Sheng
Published: August 2015

Combining first principles investigations and scanning tunneling microscopy, we identify that the presumable van der Waals packed multilayered silicene sheets spontaneously transform into a diamond-structure bulk Si film due to strong interlayer couplings.
Controlled morphology and EDTA-induced pure green upconversion luminescence of Er3+/Ho3+-Yb3+ co-doped NaCe(MoO4)2 phosphor
Authors: Yang Xingxing , Fu Zuoling , Liu Guofeng , Zhang Chunpeng , Wei Yanling , Wu Zhijian , Sheng Tianqi
Published: August 2015

An innovative route to increase the green UC emission and simultaneously suppress red UC emission in Er3+/Ho3+-Yb3+ co-doped NaCe(MoO4)2.
Shape memory effect on the formation of oxazoline and triazine rings of BCC/DGEBA copolymer
Authors: Ariraman Mathivathanan , Sasikumar Ramachandran , Alagar Muthukaruppan
Published: August 2015

The development of shape memory polymer by the copolymerization of 1,3-bis(4-cyanatophenyl) cyclohexane cyanate ester and DGEBA through the formation of oxazoline and triazine ring without using any external flexibilizer/plasticizer.
Ribbon-like and spontaneously folded structures of tungsten oxide nanofibers fabricated via electrospinning
Authors: Stanishevsky Andrei , Wetuski Joshua , Walock Michael , Stanishevskaya Inessa , Yockell-Lelièvre Hélène , Košťáková Eva , Lukáš David
Published: August 2015

Electrospinning of sub-100 nm thick WO3 ribbon-like nanofibers and their periodically folded patterns is reported for the first time.
The initial adsorption process of benzene in double-walled carbon nanotubes studied by in situ solid-state NMR
Authors: Shen Wanling , Li Xin , Zhang Hongbo
Published: August 2015

Adsorption kinetics of benzene in double-walled carbon nanotubes at the very earliest stages were directly monitored for the first time by using in situ solid-state 13C NMR.
Hierarchical metal nanomesh/microgrid structures for high performance transparent electrodes
Authors: Gao Tongchuan , Huang Po-Shun , Lee Jung-Kun , Leu Paul W.
Published: August 2015

We report a comprehensive study on the optical and electronic properties of hierarchical metal nanomesh (NM)/microgrid (MG) structures to evaluate their performance as transparent conductors (TCs).
Hemin–G-quadruplex-crosslinked poly-N-isopropylacrylamide hydrogel: a catalytic matrix for the deposition of conductive polyaniline
Authors: Lu Chun-Hua , Guo Weiwei , Qi Xiu-Juan , Neubauer Avner , Paltiel Yossi , Willner Itamar
Published: August 2015

Conducting polyaniline is deposited into a G-quadruplex-crosslinked pNIPAM copolymer undergoing switchable stimuli-responsive solution/hydrogel/solid transitions.
Practical and economic lithiations of functionalized arenes and heteroarenes using Cy2NLi in the presence of Mg, Zn or La halides in a continuous flow
Authors: Becker Matthias R. , Ganiek Maximilian A. , Knochel Paul
Published: August 2015

The economic amide base lithium dicyclohexylamide (Cy2NLi) undergoes fast (40 s) and convenient (0 °C)in situtrapping flow metalations of a broad range of functionalized aromatics in the presence of various metal salts.
Nanoparticle stability in biologically relevant media: influence of polymer architecture
Authors: Aguilar-Castillo Bethsy Adriana , Santos Jose Luis , Luo Hanying , Aguirre-Chagala Yanet E. , Palacios-Hernández Teresa , Herrera-Alonso Margarita
Published: August 2015

We contrast the behavior of nanoparticles formed by the self-assembly of polymers based on poly(ethylene glycol) (PEG) and poly(d,l-lactide), with linear, linear-dendritic and bottle-brush architectures in biologically relevant media.
A method for the estimation of 6-oxygenated metabolites of progesterone in urine
Authors: James F , Fotherby K
Published: August 2015

1. A method is described for the estimation of the 6-oxygenated metabolites of progesterone in urine. After hydrolysis the extract of urine is chromatographed on alumina to obtain a fraction containing mainly the 6-oxygenated metabolites. This fraction is oxidized to convert the metabolites into pregnane-3,6,20-triones, which are estimated as the dinitrophenylhydrazones. 2. The reliability criteria of the method are presented. Normal subjects excrete 0.1-0.6mg./day, and at the end of pregnancy values of 3.3-11.6mg./day are obtained.
Interconversions and production of volatile fatty acids in the sheep rumen
Authors: Bergman EN , Reid RS , Murray MG , Brockway JM , Whitelaw FG
Published: August 2015

1. Sheep fed at a constant rate were infused intraruminally with [1-(14)C]-acetate, -propionate or -butyrate during 5hr. periods. 2. Volatile fatty acids were estimated in the rumen contents and steady-state conditions were obtained. 3. Of the butyric acid carbon 60% was in equilibrium with 20% of the acetic acid carbon, and 2-3g.atoms of carbon were interconverted/day. 4. Little interconversion took place between propionic acid, acetic acid or butyric acid. 5. The net production rates for acetic acid, propionic acid and butyric acid were 3.7, 1.0 and 0.7moles/day respectively. 6. The production of volatile fatty acids accounted for 80% of the animal's energy expenditure.
Kinetic behaviour of calf-intestinal alkaline phosphatase with 4-methylumbelliferyl phosphate
Authors: Fernley HN , Walker PG
Published: August 2015

1. The effects of varying pH, ionic strength and temperature on the parameters K(m) and V(max.) for a purified alkaline phosphatase from calf intestinal mucosa with a new fluorogenic substrate, 4-methylumbelliferyl phosphate monoester disodium salt, and an ammediol-hydrochloric acid buffer system were determined. 2. It was found that, under varying conditions, a relationship exists between K(m) and V(max.) such that V(max.)=beta/(1+alpha/K(m)), where alpha and beta are constants, temperature- and ionic strength-dependent, but pH-independent. It is shown that this relationship accounts satisfactorily for the well-known effect of varying substrate concentration on optimum pH and velocity. 3. The various results are interpreted in terms of a pH-dependent conformational equilibrium between two forms of the enzyme, E(1) and E(2). Only E(1) combines with substrate, and only E(2) reacts to give inorganic phosphate. 4. To account for the pH-variation of K(m) and V(max.) in terms of this theory, it is postulated that the conformational change is associated with a change in pK of two basic groups in the enzyme.
The glycolipids from the non-capsulated strain of Pneumococcus I-192R, A.T.C.C. 12213
Authors: Brundish DE , Shaw N , Baddiley J
Published: August 2015

1. The total lipid was extracted from the non-capsulated strain of Pneumococcus I-192R, A.T.C.C. 12213, with chloroform-methanol mixtures. Two glycolipids were isolated by chromatography on silicic acid and DEAE-cellulose (acetate form). 2. The major glycolipid was obtained pure in a yield of 640mg./34g. dry wt. of cells and represents about 34% of the total lipid. It contained galactose, glucose, glycerol and fatty acid ester residues in the proportions 1:1:1:2, and yielded on saponification a crystalline non-reducing glycoside. 3. The structure of the glycoside was shown to be O-alpha-d-galactopyranosyl-(1-->2)-O-alpha-d-glucopyranosyl-(1-->1)-d-glycerol. The fatty acids obtained on saponification were identified by gas-liquid partition chromatography of their methyl esters. 4. The minor glycolipid was obtained as a 1:1 (w/w) mixture with the major component, but after saponification the two glycosides were separated by paper chromatography. Evidence was obtained for the structure of the glycoside derived from the minor glycolipid as 1-O-alpha-d-glucosylglycerol. 5. A general method is described for determining the stereochemistry of the glycerol moiety in 1-linked glycerol glycosides.
The formation of pyridine haemochromogen
Authors: Gallagher WA , Elliott WB
Published: August 2015

1. Titration of haem with pyridine in alkaline media of low ionic strength yields a true pyridine haemochromogen, compound III, at very low concentrations of pyridine. 2. Graphical analysis of this titration gives the first spectrophotometric evidence for a dimeric haem. 3. Compound III is unstable and tends to aggregate to a second compound, compound II, whose formation is enhanced under those conditions favourable to hydrophobic bonding. 4. At higher concentrations of pyridine, compound II is dispersed to yield the classical pyridine haemochromogen, compound I, whose spectral properties are essentially those of pyridine haemochromogen in a non-aqueous medium.
Histidine metabolism in experimental protein malnutrition in rats
Authors: Rao DR , Deodhar AD , Hariharan K
Published: August 2015

1. The activities of the enzymes histidase, urocanase and histidine-pyruvate transaminase were studied in rats under conditions of protein malnutrition. Urocanase and histidase activities in liver were markedly lowered in experimental protein malnutrition, but the activity of histidine-pyruvate transaminase was unaffected. There is a metabolic control in vivo of the enzymes involved in the catabolism of histidine. 2. Significant changes in the urinary excretion of histidine, composition of liver and serum were apparent in the protein-malnourished rat. 3. The changes in the activities of the enzymes and other parameters were of a reversible nature and dependent on the nature of the dietary protein. 4. The significance of these findings is discussed in relation to abnormal histidine metabolism in kwashiorkor.
The interaction of folic acid derivatives in the methylation of homocysteine
Authors: Guest JR , Woods DD
Published: August 2015

1. The cobalamin-independent synthesis of methionine from serine and homocysteine by ultrasonic extracts of E. coli with tetrahydropteroyltriglutamate as cofactor was inhibited competitively by tetrahydropteroylmonoglutamate and derivatives which were readily converted into this compound. 2. The potency of these inhibitors was directly related to their ability to function as cofactors or substrates in the alternative, cobalamin- dependent mechanism for homocysteine methylation. 3. The cobalamin-dependent and -independent mechanisms of homocysteine methylation were both inhibited by reduced derivatives of aminopterin in a similar manner. 4. It was tentatively concluded that the inhibition was due to a competitive interaction between the folates for N(5)N(10)-methylenetetrahydrofolate reductase.
The disulphide bonds of human and rabbit γ-globulins
Authors: Cecil R , Stevenson GT
Published: August 2015

1. The reaction of the disulphide bonds of the predominant species of human and rabbit gamma-globulins (the 7s gamma-globulins) with sulphite was studied in the presence and absence of denaturing agents and heavy-metal reagents. 2. The total number of bonds reacting/mol. of mol.wt. 160000 was approx. 18 for human and 20 for rabbit gamma-globulin. 3. Six S.S bonds/mol. of human and 6.5 S.S bonds/mol. of rabbit gamma-globulin reacted with sulphite alone at pH6. These appeared to include all the interchain S.S bonds. 4. The number of free SH groups was less than 0.2/mol. of human and less than 0.3/mol. of rabbit gamma-globulin.
The biosynthesis of rubber: Incorporation of isopentenyl pyrophosphate into purified rubber particles by a soluble latex-serum enzyme
Authors: McMullen AI , McSweeney GP
Published: August 2015

1. The rubber particles in Hevea brasiliensis latex have been partially purified by; washing' with buffer solution, and separated into active fractions of different particle size. 2. The enzyme responsible for incorporating isopentenyl pyrophosphate into rubber is distributed between the surface of the rubber particles and the aqueous serum phase of the latex. The enzyme at the surface can be removed or inactivated if the rubber particles are washed sufficiently with buffer solution. Enzyme in the serum phase can be concentrated by fractional precipitation with ammonium sulphate. 3. To incorporate isopentenyl pyrophosphate into rubber in vitro, active rubber particles are required as well as enzyme and soluble cofactors. The activity of the rubber particles per unit surface area increases with diminishing particle size.
Gluconeogenesis in mouse-liver slices
Authors: Krebs H A , Notton B M , Hems R
Published: August 2015

1. The rate of gluconeogenesis from amino acids and other known precursors in slices of mouse liver after depletion of liver glycogen by means of phlorrhizin was high with l-lactate, pyruvate, glycerol, d-glyceraldehyde, dihydroxyacetone, d-fructose, sorbitol, xylitol, alpha-glycerophosphate, alanine, proline, threonine, serine and propionate. 2. The rate was unexpectedly low or even negligible with glutamate, aspartate, other glucogenic amino acids and the intermediates of the tricarboxylic acid cycle. 3. Glutamine and asparagine gave higher rates than the corresponding amino acids but still much lower rates than kidney cortex. 4. Livers of male mice gave much lower rates than livers of female mice. Kidney cortex showed no sex difference. 5. Livers of mice fed on a low-carbohydrate diet gave the same rates as livers of mice fed on a normal diet under the test conditions, i.e. 3hr. after an injection of phlorrhizin. 6. Much carbohydrate was formed from endogenous precursors and this was accompanied by release of ammonia and urea. 7. Gluconeogenesis in well-fed mice not treated with phlorrhizin was low. 8. Maximum rates were observed 3hr. after phlorrhizin treatment. 9. Prolonged phlorrhizin treatment did not prevent extensive deposition of liver glycogen, after an initial depletion. 10. Gluconeogenesis in livers of mice fed on a high-fat diet was relatively low. 11. Livers of alloxan-diabetic mice had a high carbohydrate content after phlorrhizin treatment, and gluconeogenesis from endogenous sources was about twice as high as in normal animals. Added substrates had about the same effect in normal and diabetic livers.
Some effects of sugars and sugar phosphates on carbon dioxide fixation by isolated chloroplasts
Authors: Bucke C , Walker DA , Baldry CW
Published: August 2015

1. Carbon dioxide fixation by isolated pea chloroplasts was stimulated by the addition of intermediates of the Calvin photosynthesis cycle and by some related compounds. 2. Ribose 5-phosphate and fructose 1,6-diphosphate consistently produced the largest effects; free sugars such as erythrose and sedoheptulose and acids such as glycollate and glyoxylate were largely ineffective or even inhibitory. 3. Small effects were produced by fructose and ribose but not by their isomers, glucose and xylose. 4. Maximal rates in the presence of ribose 5-phosphate varied between 10 and 50mumoles of carbon dioxide fixed/mg. of chlorophyll/hr.
The deoxyribonucleic acid of Micrococcus radiodurans
Authors: Schein AH
Published: August 2015

The DNA of Micrococcus radiodurans was prepared by three methods. Although the recovery of DNA varied considerably, the percentage molar base ratios of the DNA from the three preparations were essentially the same: guanine, 33+/-2; adenine, 18+/-1; cytosine, 33+/-2; thymine, 17+/-1. Base compositions calculated from T(m) values and from density in caesium chloride gradients also yielded guanine+cytosine contents of 66 and 68% of total bases respectively. No unusual bases were observed. The S(20,w) values were characteristic of high-molecular-weight DNA. Electron microscopy showed the purified DNA in long strands; occasionally these were coiled.
The properties and reactions of haemoglobin FI and their bearing on the dissociation equilibrium of haemoglobin
Authors: Huehns ER , Shooter EM
Published: August 2015

1. Hb-F(I), with the previously proposed structure alpha(A) (2)gamma(F)gamma(AcF), would be an exception to the general hypothesis that haemoglobins are in mobile equilibrium with their sub-units at all pH values. However, studies presented in this paper suggest that this is not so. 2. Gel-filtration and sedimentation analyses show that Hb-F(I) dissociates at acid pH and gives only the usual types of hybrids in recombination experiments. When self-hybridized, Hb-F(I) is the main haemoglobin species re-formed, although small but increasing amounts of Hb-F(II) appear on prolonged exposure to acid. 3. Exchange experiments with isotopically labelled Hb-F(II) and unlabelled Hb-F(I) show no exchange of sub-units at neutral pH or after brief exposure to acid pH. Under equilibrium conditions at acid pH non-alpha(A)-chains do not exchange, although alpha(A)-chains equilibrate completely between the two species. 4. These results indicate that Hb-F(I) does not contain gamma(F)-chains and its possible structure is discussed on this basis. Since the dissociation properties of Hb-F(I) are not markedly different from those of Hb-A or Hb-F(II) it is concluded that Hb-F(I), like other haemoglobins, is an equilibrium system.
The lipid composition of rat brain myelin and subcellular fractions during development
Authors: Cuzner M. Louise , Davison A. N.
Published: August 2015

1. The lipids of whole brain and subcellular fractions of the rat were analysed during development. 2. The deposition of cholesterol occurred in two phases, one related to increasing wet weight of the brain and the second to myelination. Cerebroside accumulation was related only to myelination. 3. The composition of myelin isolated from 12-day-old rat brain was different in some respects from that of the adult. In the former there was an increase of phospholipid in relation to cholesterol and a marked deficiency in cerebroside. 4. It is suggested that early myelin is extruded glial plasma membrane, which only later becomes mature myelin.
The utilization of some halogenated aromatic acids by Nocardia. Effects on the growth and enzyme induction
Authors: Smith A. , Tranter E. Karen , Cain R B
Published: August 2015

1. Halogen analogues of benzoate and p-nitrobenzoate did not support growth of Nocardia erythropolis. 2. These analogues, when present together with the parent compounds, inhibited growth of the organism. 3. The halogen analogues similarly inhibited oxidation of benzoate or p-nitrobenzoate by competent cells. 4. Fluoroacetate and 2-fluoro-4-nitrobenzoate caused comparable inhibition of growth on p-nitrobenzoate and both led to some citrate accumulation. 5. The induction of the p-nitrobenzoate-oxidation system was strongly inhibited by all the 2-halogeno-4-nitrobenzoates although the 2-fluoro and 2-chloro derivatives also acted as inducers. 6. Halogen analogues of benzoate also induced the benzoate-oxidation system.
Studies on lipogenesis in vivo. Lipogenesis during extended periods of re-feeding after starvation
Authors: Jansen G. R. , Zanetti M. E. , Hutchison C. F.
Published: August 2015

1. Lipogenesis was studied in mice re-fed for up to 21 days after starvation. At appropriate times [U−14]glucose was given by stomach tube and incorporation of 14C into various lipid fractions measured. 2. In mice starved for 48hr. and then re-fed for 4 days with a diet containing 1% of corn oil, incorporation of 14C from [U−14C]glucose into liver fatty acids and cholesterol was respectively threefold and eightfold higher than in controls fed ad libitum. The percentages by weight of fatty acids and cholesterol in the liver also increased and reached peaks after 7 days. Both the radioactivity and weights of the fractions returned to control values after 10–14 days' re-feeding. These changes could be diminished by re-feeding the mice with a diet containing 20% of corn oil. Incorporation of 14C from [U−14C]glucose into extrahepatic fatty acids (excluding those of the epididymal fat pads) was not elevated during re-feeding with a diet containing either 1% or 20% of corn oil. However, incorporation of 14C from [U−14C]glucose into the fatty acids of the epididymal fat pads was increased in mice re-fed with either diet, as compared with non-starved controls. 3. Lipogenesis was also studied in mice alternately fed and starved. Mice given a diet containing 1% of corn oil for 6hr./day for 4 weeks lost weight initially and never attained the weight or carcass fat content of controls fed ad libitum. Incorporation of 14C from dietary [U−14C]-glucose into the fatty acids of the epididymal fat pads was elevated threefold in the mice allowed limited access to food, although the incorporation into the remainder of the extrahepatic fatty acids was not different from that found for controls. Mice given a diet containing 20% of corn oil for 6hr./day adapted to the limited feeding regimen quicker and in 4 weeks did attain the weight and carcass fat content of controls. Incorporation of 14C from [U−14C]glucose into the fatty acids of the epididymal fat pads and the remainder of the extrahepatic fatty acids was respectively fivefold and threefold higher than in controls fed ad libitum. 4. The elevation in liver lipogenesis during re-feeding was greatest on a diet containing 1% of corn oil, whereas in extrahepatic tissues the increase in lipogenesis was greater when the mice were re-fed or were allowed limited access to a diet containing 20% of corn oil. These results suggest that the causes of the increased rate of incorporation of 14C from [U−14C]glucose into fatty acids during re-feeding may be different in liver from that in extrahepatic tissues.
The biosynthesis of β-amyrin. Mechanism of squalene cyclization
Authors: Rees H H , Britton G. , Goodwin T W
Published: August 2015

1. β-Amyrin synthesized by pea seedlings in the presence of (3RS)-[2−14C,(4R)-4−3H1]mevalonic acid (for nomenclature see Cahn, Ingold & Prelog, 1956) was subjected to a series of degradations to locate the positions within the molecule of the incorporated tritium. 2. The location of five of the six labelled hydrogen atoms at C-3, C-9, C-18 and C-19 (two) confirms that the mechanism of cyclization of squalene expected from the biogenetic isoprene rule is functioning in vivo.
Clearing-factor lipase in adipose tissue. Studies with puromycin and actinomycin
Authors: Wing D. R. , Robinson D S
Published: August 2015

1. When adipose tissue from starved rats is incubated in a medium containing glucose, insulin, heparin and actinomycin (5μg./ml.) the total clearing-factor lipase activity of the system increases at least tenfold over a period of 9hr. In the absence of actinomycin, enzyme activity also increases, but to a lesser extent and for only about 3hr. Some enzyme activity appears in the incubation medium in both the presence and the absence of actinomycin. 2. When the glucose and insulin of the incubation medium are replaced by pyruvate and heparin is omitted, an increase in the total clearing-factor lipase activity in the presence of actinomycin still occurs, but only after a lag of several hours. When only heparin is omitted from the medium, the rise in enzyme activity begins immediately, but there is a shoulder in the time-course curve after a few hours. In the absence of heparin, little enzyme activity appears in the incubation medium. 3. The increases in enzyme activity in the presence of actinomycin are prevented if puromycin (0·5mg./ml.) is present in the incubation medium. 4. Catecholamines and corticotrophin inhibit the increase in enzyme activity caused by actinomycin. 5. The clearing-factor lipase activity of adipose tissue from fed animals declines with a half-life of between 1 and 1·5hr. when the tissue is incubated in the presence of puromycin. The clearing-factor lipase activity of adipose tissue from starved animals is stable under similar circumstances, as is the raised activity found after such tissue has been incubated in the presence of actinomycin. 6. Clearing-factor lipase extracted from adipose tissue of fed animals is less stable in solution than that extracted from the tissue of starved animals after this has been incubated in the presence of actinomycin.
The kinetics of the reversible inhibition of heart lactate dehydrogenase through the formation of the enzyme–oxidized nicotinamide–adenine dinucleotide–pyruvate compound
Authors: Gutfreund H. , Cantwell R. , McMurray C. H. , Criddle R. S. , Hathaway G.
Published: August 2015

The inhibition of lactate dehydrogenase at high pyruvate concentration was studied in three ways. First, a rapid decrease in the rate of the enzyme reaction was observed; secondly, the rate of formation of a pyruvate–NAD+ compound was followed by the change in E325; thirdly, the rate of quenching of the protein fluorescence was measured. The data obtained at pH6·0 at different temperatures and ionic strengths as functions of pyruvate, NAD+ and enzyme concentrations show that the extent of inhibition can be correlated with the reversible formation of a compound between pyruvate and enzyme-bound NAD+. It is suggested that the detailed kinetic analysis of the formation of this abortive ternary compound will give pertinent information about properties of the enzyme–NAD+ compound involved in the normal catalytic process.