bluuebunny/crossref_metadata_2025_split huggingface dataset:
Export production and its regulating factors in the West Antarctica Peninsula region of the Southern Ocean
Authors: Huang Kuan , Ducklow Hugh , Vernet Maria , Cassar Nicolas , Bender Michael L. 
Published: March 2012

In connection with the Palmer LTER program, mixed layer water samples were collected during the cruise of the L.M. Gould in Jan., 2008 at 49 stations on a 20 × 100 km grid in the West Antarctica Peninsula (WAP) region of the Southern Ocean. In this study, [O2]/[Ar] ratios and the triple isotope composition of dissolved O2 were measured, and were used to estimate net community O2 production (NCP) and gross primary O2production (GPP), respectively. These estimates are further converted to carbon export production, primary production and the f‐ratio. Our measurements give NCP ranging from −3 to 76 mmol O2 m−2 day−1 (−25 to 650 mg C m−2 day−1), and GPP from 40 to 220 mmol O2 m−2 day−1 (180 to 1010 mg C m−2 day−1). The O2 NCP/GPP ratios range from −0.04 to 0.43, corresponding to f‐ratios of −0.08 to 0.83. NCP and the NCP/GPP ratio are highest in the northern coastal areas, and decrease to lower values toward the southern coastal area and the open ocean. The inshore‐offshore gradient appears to be regulated primarily by iron availability, as supported by the positive correlation between NCP and Fv/Fm ratios (r2 = 0.22, p < 0.05). Mixed layer depth (MLD) is inversely correlated with NCP (r2 = 0.21, p < 0.002) and NCP/GPP (r2 = 0.21, p < 0.02), and highest NCP occurred in the fresh water lenses probably formed from melted coastal glaciers. These results suggest that export production and the f‐ratio increase where water stratification is intensified by input of fresh meltwater, and that mixed layer stratification is the major factor regulating NCP in the inner‐shelf and coastal regions. Along‐shelf variability of phytoplankton community composition is highly correlated with NCP, i.e., NCP increases when the diatom‐dominated community in the south transitions to the cryptophyte‐dominated one in the north. A high correlation is also observed between NCP and the logarithm of the surface chlorophyll concentration (r2 = 0.72, p < 0.0001) , which makes it possible to estimate carbon export as a function of Chl a concentration in this region.
CARM1/PRMT4 is necessary for the glycogen gene expression programme in skeletal muscle cells
Authors: Wang Shu-Ching Mary , Dowhan Dennis H. , Eriksson Natalie A. , Muscat George E. O. 
Published: March 2012

CARM1 (co-activator-associated arginine methyltransferase 1)/PRMT4 (protein arginine methyltransferase 4), functions as a co-activator for transcription factors that are regulators of muscle fibre type and oxidative metabolism, including PGC (peroxisome-proliferator-activated receptor γ co-activator)-1α and MEF2 (myocyte enhancer factor 2). We observed significantly higher Prmt4 mRNA expression in comparison with Prmt1–Prmt6 mRNA expression in mouse muscle (in vitro and in vivo). Transfection of Prmt4 siRNA (small interfering RNA) into mouse skeletal muscle C2C12 cells attenuated PRMT4 mRNA and protein expression. We subsequently performed additional qPCR (quantitative PCR) analysis (in the context of metabolism) to examine the effect of Prmt4 siRNA expression on &gt;200 critical genes that control (and are involved in) lipid, glucose and energy homoeostasis, and circadian rhythm. This analysis revealed a strikingly specific metabolic expression footprint, and revealed that PRMT4 is necessary for the expression of genes involved in glycogen metabolism in skeletal muscle cells. Prmt4 siRNA expression selectively suppressed the mRNAs encoding Gys1 (glycogen synthase 1), Pgam2 (muscle phosphoglycerate mutase 2) and Pygm (muscle glycogen phosphorylase). Significantly, PGAM, PYGM and GYS1 deficiency in humans causes glycogen storage diseases type X, type V/McArdle's disease and type 0 respectively. Attenuation of PRMT4 was also associated with decreased expression of the mRNAs encoding AMPK (AMP-activated protein kinase) α2/γ3 (Prkaa2 and Prkag3) and p38 MAPK (mitogen-activated protein kinase), previously implicated in Wolff–Parkinson–White syndrome and Pompe Disease (glycogen storage disease type II). Furthermore, stable transfection of two PRMT4-site-specific (methyltransferase deficient) mutants (CARM1/PRMT4 VLD and CARM1E267Q) significantly repressed the expression of Gys1, Pgam2 and AMPKγ3. Finally, in concordance, we observed increased and decreased glycogen levels in PRMT4 (native)- and VLD (methylation deficient mutant)-transfected skeletal muscle cells respectively. This demonstrated that PRMT4 expression and the associated methyltransferase activity is necessary for the gene expression programme involved in glycogen metabolism and human glycogen storage diseases.
Ultrafast large-amplitude relocation of electronic charge in ionic crystals
Authors: Zamponi Flavio , Rothhardt Philip , Stingl Johannes , Woerner Michael , Elsaesser Thomas 
Published: March 2012

The interplay of vibrational motion and electronic charge relocation in an ionic hydrogen-bonded crystal is mapped by X-ray powder diffraction with a 100 fs time resolution. Photoexcitation of the prototype material KH
2
PO
4
induces coherent low-frequency motions of the PO
4
tetrahedra in the electronically excited state of the crystal while the average atomic positions remain unchanged. Time-dependent maps of electron density derived from the diffraction data demonstrate an oscillatory relocation of electronic charge with a spatial amplitude two orders of magnitude larger than the underlying vibrational lattice motions. Coherent longitudinal optical and tranverse optical phonon motions that dephase on a time scale of several picoseconds, drive the charge relocation, similar to a soft (transverse optical) mode driven phase transition between the ferro- and paraelectric phase of KH
2
PO
4
.
The influence of the solid thermal conductivity on active magnetic regenerators
Authors: Nielsen K K , Engelbrecht K 
Published: March 2012

Abstract
The influence of the thermal conductivity of the regenerator solid on the performance of a flat plate active magnetic regenerator (AMR) is investigated using an established numerical AMR model. The cooling power at different (fixed) temperature spans is used as a measure of the performance for a range of thermal conductivities, operating frequencies, a long and short regenerator, and finally a regenerator with a low and a high number of transfer units (NTU). In this way the performance is mapped out and the impact of the thermal conductivity of the solid is probed.
Modelling shows that under certain operating conditions, the AMR cycle is sensitive to the solid conductivity. It is found that as the operating frequency is increased it is not only sufficient to have a high NTU regenerator but the regenerator performance will also benefit from increased thermal conductivity in the solid. It is also found that a longer regenerator is generally better performing than a shorter one under the otherwise exact same conditions. This suggests that the thermal conductivity of candidate magnetocaloric materials should be considered when selecting them for use in a device.
Numerical simulation on a nanosecond-pulse surface dielectric barrier discharge actuator in near space
Authors: Che Xueke , Shao Tao , Nie Wansheng , Yan Ping 
Published: March 2012

Abstract
Lift-enhancement–drag-reduction technology is strongly required by near-space vehicles with low Reynolds number. It is known that a flow control method by a surface dielectric barrier discharge (SDBD) plasma can play an important role in this field. In order to obtain the discharge characteristics and evaluate the flow control effect of a SDBD actuator, the nanosecond-pulse discharge and induced flow field by the SDBD plasma are simulated at various altitudes using discharge-aerodynamics models. The results show that the ignition voltage decreases with altitude and it is very easy to discharge in near space. Compared with a SDBD at ground level, the plasma is produced on both sides of the exposed electrode and distributes more uniformly in near space. Although the body force generated by the SDBD actuator is less effective in inducing a jet with nanosecond-pulse excitation than that with alternating voltage excitation, the induced jet by body force is with longer extent, thicker profile and higher velocity in near space than at ground level. The plasma bulk heating should be taken into account for nanosecond-pulse excitation. The Joule heating of electrons is the main source of plasma bulk heating which acts as a micro-explosion and mainly induces pressure perturbation. The discharge at ground level is like a ‘point explosion’, but a ‘region explosion’ in near space, which indicates a diffuse distribution of energy, should be responsible for the fact that the effect of bulk heating is reduced in near space.
Modelling of an RF plasma shower
Authors: Atanasova M , Carbone E A D , Mihailova D , Benova E , Degrez G , van der Mullen J J A M 
Published: March 2012

Abstract
A capacitive radiofrequency (RF) discharge at atmospheric pressure is studied by means of a time-dependent, two-dimensional fluid model. The plasma is created in a stationary argon gas flow guided through two perforated electrodes, hence resembling a shower. The inner electrode, the electrode facing the flow entrance, is powered with a frequency of 13.56 MHz, and the outer electrode is grounded. The model solves the mass balance equations for the relevant active species and the electron energy balance equation in conjunction with the Poisson equation for the field sustaining the plasma. The mass balance equations of the active species are calculated using the drift–diffusion–convection approach, thus taking the bulk velocity into account. The velocity field is calculated with the Navier–Stokes module of the Plasimo toolkit. The plasma dynamics is studied in three connected regions; the space between the electrodes, the regions before the powered electrode and the extended region behind the grounded electrode. The effect of the shower holes and the recirculation gas flow on the plasma is examined.
Towards a deeper understanding of the formation of friction-induced hillocks on monocrystalline silicon
Authors: Yu Bingjun , Li Xiaoying , Dong Hanshan , Chen Yunfei , Qian Linmao , Zhou Zhongrong 
Published: March 2012

Abstract
Friction-induced hillocks can be produced on monocrystalline silicon by scratching under given conditions. Results show that the height of these hillocks increases with the applied normal load or number of scratching cycles, but decreases with the sliding velocity. Transmission electron microscope (TEM) and energy dispersive x-ray (EDX) analysis show that the hillock contains a thin superficial oxidation layer and a thick disturbed (amorphous and deformed) layer in the subsurface. Although the formation of the silicon hillock is the combined results of mechanical interaction and tribochemical reaction, the mechanical interaction plays a more dominant role. Further analysis indicates that the formation of hillock is mostly induced by the amorphization of crystal silicon during scratching. Low sliding speed is found to facilitate the formation of a thick amorphization layer under the same loading condition. Since the friction-induced hillock is the initial surface damage on the nanoscale, the results will shed new light on understanding and controlling the nanowear process of silicon in micro/nanoelectromechanical systems.
Characterization of an Isoflavonoid-Specific Prenyltransferase from Lupinus albus
Authors: Shen Guoan , Huhman David , Lei Zhentian , Snyder John , Sumner Lloyd W. , Dixon Richard A. 
Published: March 2012

Abstract
Prenylated flavonoids and isoflavonoids possess antimicrobial activity against fungal pathogens of plants. However, only a few plant flavonoid and isoflavonoid prenyltransferase genes have been identified to date. In this study, an isoflavonoid prenyltransferase gene, designated as LaPT1, was identified from white lupin (Lupinus albus). The deduced protein sequence of LaPT1 shared high homologies with known flavonoid and isoflavonoid prenyltransferases. The LaPT1 gene was mainly expressed in roots, a major site for constitutive accumulation of prenylated isoflavones in white lupin. LaPT1 is predicted to be a membrane-bound protein with nine transmembrane regions and conserved functional domains similar to other flavonoid and isoflavonoid prenyltransferases; it has a predicted chloroplast transit peptide and is plastid localized. A microsomal fraction containing recombinant LaPT1 prenylated the isoflavone genistein at the B-ring 3′ position to produce isowighteone. The enzyme is also active with 2′-hydroxygenistein but has no activity with other flavonoid substrates. The apparent K m of recombinant LaPT1 for the dimethylallyl diphosphate prenyl donor is in a similar range to that of other flavonoid prenyltransferases, but the apparent catalytic efficiency with genistein is considerably higher. Removal of the transit peptide increased the apparent overall activity but also increased the K m. Medicago truncatula hairy roots expressing LaPT1 accumulated isowighteone, a compound that is not naturally produced in this species, indicating a strategy for metabolic engineering of novel antimicrobial compounds in legumes.
Review article: intestinal lymphoid nodular hyperplasia in children – the relationship to food hypersensitivity
Authors: Mansueto P. , Iacono G. , Seidita A. , D'Alcamo A. , Sprini D. , Carroccio A. 
Published: March 2012

SummaryBackgroundLymphoid aggregates are normally found throughout the small and large intestine. Known as lymphoid nodular hyperplasia (LNH), these aggregates are observed especially in young children and are not associated with clinical symptoms being considered ‘physiological’. In children presenting with gastrointestinal symptoms the number and size of the lymphoid follicles are increased. Patients suffering from gastrointestinal symptoms (i.e. recurrent abdominal pain) should systematically undergo gastroduodenoscopy and colonoscopy. With these indications LNH, especially of the upper but also of the lower gastrointestinal tract has been diagnosed, and in some children it may reflect a food hypersensitivity (FH) condition.AimTo review the literature about the relationship between LNH and FH, particularly focusing on the diagnostic work‐up for LNH related to FH.MethodsWe reviewed literature using Pubmed and Medline, with the search terms ‘lymphoid nodular hyperplasia’, ‘food hypersensitivity’, ‘food allergy’ and ‘food intolerance’. We overall examined 10 studies in detail, selecting articles about the prevalence of LNH in FH patients and of FH in LNH patients.ResultsCollected data showed a median of 49% (range 32–67%) LNH in FH patients and a median of 66% (range 42–90%) FH in LNH patients. Literature review pointed out that the most important symptom connected with LNH and/or FH was recurrent abdominal pain, followed by diarrhoea and growth retardation. Both LNH and FH are associated with an increase in lamina propria γ/δ+ T cells, but the mechanisms by which enhanced local immune responses causing gastrointestinal symptoms still remain obscure.ConclusionsWhen assessing FH, we rely on clinical evaluation, including elimination diet and challenge tests, and endoscopic and immunohistochemical findings. Considering the possible co‐existence of duodenal and ileo‐colonic LNH, upper endoscopy can be recommended in children with suspected FH, especially in those presenting with additional upper abdominal symptoms (i.e. vomiting). Likewise, lower endoscopy might be additionally performed in patients with suspected FH and LNH of the duodenal bulb, also presenting with lower abdominal symptoms (i.e. recurrent abdominal pain).
Randomised clinical trial: the effect of baclofen in patients with gastro‐oesophageal reflux ‐ a randomised prospective study
Authors: Cossentino M. J. , Mann K. , Armbruster S. P. , Lake J. M. , Maydonovitch C. , Wong R. K. H. 
Published: March 2012

SummaryBackgroundBaclofen, a GABAB agonist, has been shown to reduce transient lower oesophageal sphincter relaxations (TLESRs), a major cause of gastro‐oesophageal reflux disease (GERD).AimTo examine the effect and tolerability of baclofen in GERD patients over a 2‐week period.MethodsForty‐three GERD patients with abnormal 24‐h pH tests were prospectively randomised to receive baclofen or placebo in a double‐blind fashion for 2 weeks. Oesophageal manometry, 24‐h pH monitoring, and a standard questionnaire was administered, before and after treatment.ResultsThirty‐four patients completed the study. In the baclofen group there were significant decreases in 24‐h pH score (P = 0.020), percent of upright reflux episodes (P = 0.016), percent total time pH <4 (P = 0.003), number of reflux episodes (P = 0.018), number of reflux episodes longer than 5 min (P = 0.016), number of postprandial reflux episodes (P = 0.045), and percentage of time pH <4 (P = 0.003). No significant changes in reflux parameters were noted in the placebo group. Patients receiving baclofen had significantly less belching (P = 0.038), regurgitation (P = 0.036) and overall symptom score (P = 0.004) whereas placebo patients had less heartburn (P = 0.001), chest pain (P = 0.002), regurgitation (P = 0.017) and overall symptom score (P = 0.000). However, there were no significant differences in changes of reflux parameters or symptoms when comparing the two groups. Drowsiness did not limit baclofen use.ConclusionsBaclofen was associated with a significant decrease in percent upright reflux by 24‐h pH monitoring and a significant improvement in belching, regurgitation and overall symptom score. Baclofen may be more effective in patients with predominantly upright reflux and belching.
Hypoxia induces apoptosis and autophagic cell death in human periodontal ligament cells through HIF‐1α pathway
Authors: Song Z.‐C. , Zhou W. , Shu R. , Ni J. 
Published: March 2012

AbstractObjectivesOxygen deficiency caused by occlusal trauma and smoking can be present in patients with periodontitis. However, biochemical events important in periodontal tissues during hypoxia remain unclear. The aim of this study was to investigate effects of hypoxia on apoptosis and autophagy of human periodontal ligament cells (PDLCs) in vitro.Materials and methodsHuman PDLCs were obtained and cultured in vitro. Cell viability, apoptosis, autophagy and gene and protein expression were measured in presence and absence of cobalt chloride (CoCl2).ResultsCoCl2 induced cytotoxicity of human PDLCs in a concentration‐dependent manner dependent on macromolecular synthesis, and resulted in apoptosis and mitochondrial dysfunction. CoCl2 also induced redistribution of autophagy marker LC3, increased ratio of LC3‐IIto LC3‐Iand function of lysosomes. Furthermore, CoCl2 promoted expression of HIF‐1α following upregulation of expressions of Bnip3. Significant increases in expression of IL‐1β and MMP‐8 were also observed. All these results were reversed by pre‐treatment with antioxidant N‐acetylcysteine.ConclusionsOur data showed that CoCl2 could induce cytotoxicity through mitochondria‐ apoptotic and autophagic pathways involved in HIF‐1α. CoCl2‐treated PDLCs may serve as an in vitro model for studies of molecular mechanisms in periodontitis.
Caspase‐mediated programmed cell death pathways as potential therapeutic targets in cancer
Authors: Wen X. , Lin Z.‐Q. , Liu B. , Wei Y.‐Q. 
Published: March 2012

AbstractThe caspase family is well characterized as playing a crucial role in modulation of programmed cell death (PCD), which is a genetically regulated, evolutionarily conserved process with numerous links to many human diseases, most notably cancer. In this review, we focus on summarizing the intricate relationships between some members of the caspase family and their key apoptotic mediators, involving tumour necrosis factor receptors, the Bcl‐2 family, cytochrome c, Apaf‐1 and IAPs in cancer initiation and progression. We elucidate new emerging types of cross‐talk between several caspases and autophagy‐related genes (Atgs) in cancer. Moreover, we focus on presenting several PCD‐modulating agents that may target caspases‐3, ‐8 and ‐9, and their substrates PARP‐1 and Beclin‐1, which may help us harness caspase‐modulated PCD pathways for future drug discovery.
Thermal sensitivity does not determine acclimation capacity for a tropical reef fish
Authors: Donelson Jennifer M. , Munday Philip L. 
Published: March 2012

Summary1. Short‐term measures of metabolic responses to warmer environments are expected to indicate the sensitivity of species to regional warming. However, given time, species may be able to acclimate to increasing temperature. Thus, it is useful to determine if short‐term responses provide a good predictor for long‐term acclimation ability.2. The tropical reef fish Acanthochromis polyacanthus was used to test whether the ability for developmental thermal acclimation of two populations was indicated by their short‐term metabolic response to temperature.3. While both populations exhibited similar short‐term responses of resting metabolic rate (RMR) to temperature, fish from the higher‐latitude population were able to fully acclimate RMR, while the lower‐latitude population could only partially compensate RMR at the warmest temperature. These differences in acclimation ability are most likely due to genetic differences between the populations rather than differences in thermal regimes.4. This research indicates that acclimation ability may vary greatly between populations and that understanding such variation will be critical for predicting the impacts of warming environmental temperatures. Moreover, the thermal metabolic reaction norm does not appear to be a good predictor of long‐term acclimation ability.