bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of catheter ablation of ventricular tachycardia in patients with prior myocardial infarctions
Authors: Fukunaga Masato , Goya Masahiko , Hiroshima Kenichi , Hayashi Kentaro , Ohe Masatsugu , Makihara Yu , Nagashima Michio , An Yoshimori , Shirai Shinichi , Ando Kenji , Yokoi Hiroyoshi , Iwabuchi Masashi
Published: May 2016

Background

Catheter ablation can reduce episodes of ventricular tachycardia (VT) after myocardial infarction (MI). However, the optimal endpoint of the ablation procedure remains unclear.

Methods

Fifty‐one consecutive patients who received catheter ablation for VT after MI were included. The procedures targeted the isthmus of all the induced, sustained VTs. When the patients with induced VTs were hemodynamically stable, radiofrequency energy was delivered at the mid‐diastolic potential recording site during VT. When the patients with VTs were hemodynamically unstable, the critical channel was identified at the delayed potential recording site, showing a good pace map, with a long stimulus‐QRS interval. We delivered radiofrequency energy along the identified isthmus and across the exit of the circuit.

Results

At the end of the procedure, all VTs became non‐inducible in 30 patients (59%) and some VTs were inducible in 21 patients (41%). During a mean of 40±29 months of follow‐up, no VT or ventricular fibrillation recurred in 24 patients (80%) in the non‐inducible group and in 12 patients (57%) in the inducible group, respectively (P=0.03). The identification of the channel during VT mapping tended to associate with no recurrence, although the difference was not statistically significant (P=0.2). Fourteen patients (27%) died during the follow‐up period, mostly due to non‐cardiac causes.

Conclusions

The catheter ablation targeting the isthmus of prior‐MIVT and non‐inducibility at the end of the procedure can provide a satisfactory follow‐up result.
Gene expression profiling of single circulating tumor cells in ovarian cancer – Establishment of a multi‐marker gene panel
Authors: Blassl Christina , Kuhlmann Jan Dominik , Webers Alessandra , Wimberger Pauline , Fehm Tanja , Neubauer Hans
Published: May 2016

The presence of circulating tumor cells (CTCs) in the blood of ovarian cancer patients was shown to correlate with decreased overall survival, whereby CTCs with epithelial–mesenchymal‐transition (EMT) or stem‐like traits are supposed to be involved in metastatic progression and recurrence. Thus, investigating the transcriptional profiles of CTCs might help to identify therapy resistant tumor cells and to overcome treatment failure. For this purpose, we established a multi‐marker panel for the molecular characterization of single CTCs, detecting epithelial (EpCAM, Muc‐1, CK5/7), EMT (N‐cadherin, Vimentin, Snai1/2, CD117, CD146, CD49f) and stem cell (CD44, ALDH1A1, Nanog, SOX2, Notch1/4, Oct4, Lin28) associated transcripts.

First primer specificity and PCR‐performance of the multiplex‐RT‐PCRs were successfully validated on genomic DNA and cDNA isolated from OvCar3 cells. The assay sensitivity of the epithelial panel was evaluated by adding defined numbers of tumor cells into the blood of healthy donors and performing a subsequent immunomagnetic tumor cell enrichment (AdnaTest OvarianCancerSelect), resulting in a 100% concordance for the epithelial markers EpCAM and Muc‐1 to the AdnaTest OvarianCancerDetect. Additionally, by processing blood from ovarian cancer patients, high assay sensitivity could be verified. In blood of healthy donors no signals for epithelial markers were detected, for EMT and stem cell markers, however, signals were obtained mainly originating from leukocytes which calls for single cell analysis.

To that aim by using the ovarian cancer cell line OvCar3, we successfully established a workflow enabling the characterization of single CTCs. It consists of a density gradient‐dependent enrichment for nucleated cells, a depletion of CD45‐positive cells of hematopoietic origin followed by immunofluorescent labeling of CTCs by EpCAM and Muc‐1. Single CTCs are then isolated by micromanipulation and processed for panel gene expression profiling. Finally, fifteen single CTCs from three ovarian cancer patients were analyzed and found to be positive for stem cell (CD44, ALDH1A1, Nanog, Oct4) and EMT markers (N‐cadherin, Vimentin, Snai2, CD117, CD146). Albeit, inter‐cellular and intra/inter‐patient heterogeneity and co‐expression of epithelial, mesenchymal and stem cell transcripts on the same CTC was observed.

We have established a robust workflow to perform sensitive single cell panel gene expression analysis without the need of pre‐amplification steps. Our data point towards a heterogeneous expression of stem cell and EMT associated transcripts in ovarian cancer CTCs.
Traumatic Amputation of Finger From an Alligator Snapping Turtle Bite
Authors: Johnson Robert D. , Nielsen Cynthia L.
Published: May 2016

Legend states that the alligator snapping turtle ( Macrochelys temminckii) should be handled with extreme caution as it has jaw strength powerful enough to bite a wooden broomstick in half. Tales of bite injuries from what is the largest freshwater turtle in North America exist anecdotally, yet there are few descriptions of medical encounters for such. The risk of infection from reptilian bites to the hand in an aquatic environment warrants thorough antibiotic treatment in conjunction with hand surgery consultation. We present the first case report of a near total amputation of an index finger in an adolescent boy who had been bitten by a wild “gator snapper.”
Body Positioning of Buried Avalanche Victims
Authors: Kornhall Daniel K. , Logan Spencer , Dolven Thomas
Published: May 2016

Objective

The immediate medical management of buried avalanche victims will to some extent be dictated by the victim’s body positioning in the snow. Medical personnel are trained to assess and manage victims in a supine body position. Furthermore, avalanche first responders are trained to handle extricated avalanche victims carefully out of concerns for causing hemodynamic instability or for aggravating spinal injury. Thus, locating and extricating avalanche victims in positions other than supine has the potential to complicate immediate medical management. To our knowledge, the current medical literature does not detail the body positioning of buried victims.

Methods

In order to ascertain the most common body positioning of buried avalanche victims we reviewed the avalanche incident database of the Colorado Avalanche Information Center (CAIC). This comprehensive database strives to track over 160 fields of information for each avalanche victim, including the body and head positioning of buried victims.

Results

Head positioning was recorded for 159 buried victims. We found that 65% of buried avalanche victims were found with their heads in a downhill position, 23% with their heads uphill and 11% with their heads in the same level as the rest of their bodies. Body positioning was recorded in 253 victims. 45% of victims were found lying prone, 24% supine, 16% were sitting or standing and 15% were found lying on their sides. We identified 135 victims where both head and body position was registered. 40% of victims were found prone with their heads in a downhill position

Conclusions

The majority of victims will be extricated with their heads in a downhill position. Moreover, almost half of victims will be found prone. We believe this will have significant impact on the immediate medical management. We believe current training in avalanche medical rescue should emphasize managing victims in non-supine positions. Finally, our findings may represent another benefit of modern extrication techniques.
A multifactorial regression analysis of the features of community-acquired rotavirus requiring hospitalization in Spain as represented in the Minimum Basic Data Set
Authors: REDONDO-GONZÁLEZ O. , TENÍAS-BURILLO J. M.
Published: May 2016

Over 10% of acute rotavirus gastroenteritis (ARGE) requires hospitalization because of complications. The aggravating factors have been widely analysed, but in an isolated way. We aimed to explore the interrelationship between the clinical and epidemiological factors that characterize rotavirus hospitalizations in Spain using information from the Minimum Basic Data Set (MBDS). Using ICD-9-CM codes, we classified acute gastroenteritis (AGE) cases by principal diagnosis fields and then categorized their comorbidities, complications, and epidemiological features by secondary fields. A multivariable, logistic, step-wise regression model was then constructed. We identified 1657 ARGE cases from 17 415 cases of AGE. Rotavirus hospitalizations were associated with place of residence, age, and season (P < 0·0001), as well as with dehydration [odds ratio (OR) 12·44, 95% confidence interval (CI) 1·52–40·38], intravenous rehydration (OR 1·74, 95% CI 1·29–2·35), metabolic acidosis (OR 1·51, 95% CI 1·24–1·83), respiratory tract infections (RTIs) (OR 1·60, 95% CI 1·09–1·98), and concomitant AGE (OR 1·52, 95% CI 1·03–2·25). Dehydration was four times more likely in patients aged <5 years (OR 4·36, 95% CI 1·20–12·96) and was associated with acidosis when ARGE and RTI were present simultaneously (P < 0·0001). Specific co-infecting viruses may play a role in acute respiratory symptoms and aggravation of gastrointestinal manifestations of rotaviruses, thus leading to complications requiring hospitalization.
Unusual coastal flood impacts in Salmon Valley, McMurdo Sound, Antarctica
Authors: Dayton Paul K. , Hammerstrom Kamille , Jarrell Shannon C. , Kim Stacy , Nordhausen Walter , Osborne D.J. , Thrush Simon F.
Published: May 2016

Large floods bringing significant sediments into the coastal oceans have not been observed in Antarctica. We report evidence of a large flood event depositing over 50 cm of sediment onto the nearshore benthic habitat at Salmon Bay, Antarctica, between 1990 and 2010. Besides direct observations of the sedimentation, the evidence involves a debris flow covering old tyre tracks from the early 1960s, as well as evidence of a considerable amount of sediment transported onto the Salmon Creek delta. We believe that the flood was sourced from the Salmon Glacier and possibly the smaller Blackwelder Glacier. Such floods will be more common in the future and it is important to better understand their ecological impacts with good monitoring programmes.
Brugada syndrome in the paediatric population: a comprehensive approach to clinical manifestations, diagnosis, and management
Authors: Gonzalez Corcia M. Cecilia , de Asmundis Carlo , Chierchia Gian-Battista , Brugada Pedro
Published: May 2016

Brugada syndrome is an inherited arrhythmogenic disorder, characterised by coved-type ST-segment elevation in the right precordial leads, and is associated with increased risk of sudden death. It is genetically and clinically heterogeneous, presenting typically in the fourth or fifth decade of life. The prevalence of Brugada syndrome in the paediatric population is low compared with the adult population. Interestingly, over the last several years, there has been growing evidence in the literature of onset of the disease during childhood. Most of the paediatric cases reported in the literature consist of asymptomatic Brugada syndrome; however, some patients manifest the disease at different regions of the cardiac conduction system at a young age. Early expression of the disease can be affected by multiple factors, including genetic substrate, hormonal changes, and still unknown environmental exposures. The initial manifestation of Brugada syndrome in children can include sinus node dysfunction and atrial arrhythmias. Brugada syndrome can also manifest as ventricular arrhythmias leading to sudden death at an early age. In symptomatic children, performance of the ajmaline test by an experienced team can be safely used as a diagnostic tool to unmask latent Brugada syndrome. Defining indications for an implantable cardioverter defibrillator in children with the diagnosis of Brugada syndrome remains challenging. Given the rarity of the syndrome in children, most paediatric cardiologists will only rarely see a young patient with Brugada syndrome and there is still no universal consensus regarding the optimal management approach. Care should be individualised according to the specific clinical presentation, taking into account the family history, genetic data, and the family’s specific preferences.
Under-diagnosis of mood disorders in Canada
Authors: Pelletier L. , O'Donnell S. , Dykxhoorn J. , McRae L. , Patten S. B.
Published: May 2016

Aims.

Under-diagnosis of mood disorders occurs worldwide. In this study, we characterized and compared Canadians with symptoms compatible with a mood disorder by diagnosis status; and described the associated health impacts, use of health services and perceived need for care.

Methods.

Respondents to the 2012 Canadian Community Health Survey – Mental Health, a nationally representative sample of Canadians age ≥15 years were assessed for symptoms compatible with mood disorders based on a Canadian adaptation of the World Health Organization Composite International Diagnostic Interview (n= 23 504). Descriptive and multivariate regression analyses were performed.

Results.

In 2012, an estimated 5.4% (1.5 million) Canadians aged 15 years and older reported symptoms compatible with a mood disorder, of which only half reported having been professionally diagnosed. The undiagnosed individuals were more likely to be younger (mean age: 36.2v. 41.8), to be single (49.5v. 32.7%), to have less than a post-secondary graduation (49.8v. 41.1%) and to have no physical co-morbidities (56.4v. 35.7%), and less likely to be part of the two lower income quintiles (49.6v. 62.7%) compared with those with a previous diagnosis. Upon controlling for all socio-demographic and health characteristics, the associations with age and marital status disappeared. While those with a previous diagnosis reported significantly greater health impacts and were more likely to have consulted a health professional for their emotional and mental health problems in the previous 12 months compared with those undiagnosed (79.4v. 31.0%), about a third of both groups reported that their health care needs were only partially met or not met at all.

Conclusions.

Mood disorders are prevalent and can profoundly impact the life of those affected, however, their diagnosis remains suboptimal and health care use falls short of apparent needs. Improvements in mental health literacy, help-seeking behaviours and diagnosis are needed. In light of the heterogeneity of mood disorders in terms of symptoms severity, impacts and prognosis, interventions must be tailored accordingly.
Safety Culture, Resilient Behavior, and Stress in Air Traffic Management
Authors: Schwarz Michaela , Kallus K. Wolfgang , Gaisbachgrabner Kerstin
Published: May 2016

Abstract. In today’s rapidly changing air traffic management (ATM) environment, safety culture and organizational resilience are seen as key enablers for effective safety management. Under normal conditions a positive safety culture is known to be reflected in proactive behavior and to serve as indirect indicator of organizational resilience. But how are safety culture development and resilient behavior affected by psychological stress? This study aims at relating safety culture to resilient behavior and psychological stress of 282 air traffic controllers, air traffic safety electronics personnel, and meteorologists. Results demonstrate that safety culture across different occupational groups is difficult to assess, but that facets of safety culture can be meaningfully related to resilient behavior. Structural equation modeling indicates that psychological stress has a positive effect on resilient behavior and a negative effect on safety culture development. Findings are discussed in the safety management context of the ATM system including air traffic control, engineering, and meteorological services. Finally, conclusions are drawn with a view on providing an initial position for future studies.
eEF1A1 binds and enriches protoporphyrin IX in cancer cells in 5-aminolevulinic acid based photodynamic therapy
Authors: Fan Zhichao , Cui Xiaojun , Wei Dan , Liu Wei , Li Buhong , He Hao , Ye Huamao , Zhu Naishuo , Wei Xunbin
Published: May 2016

Photodynamic therapy (PDT) with protoporphyrin IX (PpIX), which is endogenously derived from 5-aminolevulinic acid (5-ALA) or its derivatives, is a promising modality for the treatment of both pre-malignant and malignant lesions. However, the mechanisms of how ALA-induced PpIX selectively accumulated in the tumors are not fully elucidated. Here we discovered that eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) interacted with PpIX (with an affinity constant of 2.96 × 106 M−1). Microscopy imaging showed that ALA-induced PpIX was co-localized with eEF1A1 in cancer cells. eEF1A1 was found to enrich ALA-induced PpIX in cells by competitively blocking the downstream bioavailability of PpIX. Taken together, our study discovered eEF1A1 as a novel photosensitizer binding protein, which may play an essential role in the enrichment of ALA-induced PpIX in cancer cells during PDT. These suggested eEF1A1 as a molecular marker to predict the selectivity and efficiency of 5-ALA based PDT in cancer therapy.
A new structure of two-dimensional allotropes of group V elements
Authors: Li Ping , Luo Weidong
Published: May 2016

The elemental two-dimensional (2D) materials such as graphene, silicene, germanene, and black phosphorus have attracted considerable attention due to their fascinating physical properties. Structurally they possess the honeycomb or distorted honeycomb lattices, which are composed of six-atom rings. Here we find a new structure of 2D allotropes of group V elements composed of eight-atom rings, which we name as the octagonal tiling (OT) structure. First-principles calculations indicate that these allotropes are dynamically stable and are also thermally stable at temperatures up to 600 K. These allotropes are semiconductors with band gaps ranging from 0.3 to 2.0 eV, thus they are potentially useful in near- and mid-infrared optoelectronic devices. OT-Bi is also a 2D topological insulator (TI) with a band gap of 0.33 eV, which is the largest among the reported elemental 2D TIs, and this gap can be increased further by applying compressive strains.
Communicative signals support abstract rule learning by 7-month-old infants
Authors: Ferguson Brock , Lew-Williams Casey
Published: May 2016

The mechanisms underlying the discovery of abstract rules like those found in natural language may be evolutionarily tuned to speech, according to previous research. When infants hear speech sounds, they can learn rules that govern their combination, but when they hear non-speech sounds such as sine-wave tones, they fail to do so. Here we show that infants’ rule learning is not tied to speechper se, but is instead enhanced more broadly by communicative signals. In two experiments, infants succeeded in learning and generalizing rules from tones that were introduced as if they could be used to communicate. In two control experiments, infants failed to learn the very same rules when familiarized to tones outside of a communicative exchange. These results reveal that infants’ attention to social agents and communication catalyzes a fundamental achievement of human learning.
3H-1,2-dithiole-3-thione protects retinal pigment epithelium cells against Ultra-violet radiation via activation of Akt-mTORC1-dependent Nrf2-HO-1 signaling
Authors: Li Ke-ran , Yang Su-qing , Gong Yi-qing , Yang Hong , Li Xiu-miao , Zhao Yu-xia , Yao Jin , Jiang Qin , Cao Cong
Published: May 2016

Excessive UV radiation and reactive oxygen species (ROS) cause retinal pigment epithelium (RPE) cell injuries. Nrf2 regulates transcriptional activation of many anti-oxidant genes. Here, we tested the potential role of 3H-1,2-dithiole-3-thione (D3T) against UV or ROS damages in cultured RPE cells (both primary cells and ARPE-19 line). We showed that D3T significantly inhibited UV-/H2O2-induced RPE cell death and apoptosis. UV-stimulated ROS production was dramatically inhibited by D3T pretreatment. D3T induced Nrf2 phosphorylation in cultured RPE cells, causing Nrf2 disassociation with KEAP1 and its subsequent nuclear accumulation. This led to expression of antioxidant response elements (ARE)-dependent gene heme oxygenase-1 (HO-1). Nrf2-HO-1 activation was required for D3T-mediated cytoprotective effect. Nrf2 shRNA knockdown or S40T dominant negative mutation as well as the HO-1 inhibitor Zinc protoporphyrin (ZnPP) largely inhibited D3T’s RPE cytoprotective effects against UV radiation. Yet, exogenous overexpression Nrf2 enhanced D3T’s activity in RPE cells. Further studies showed that D3T activated Akt/mTORC1 in cultured RPE cells. Akt-mTORC1 inhibitors, or Akt1 knockdown by shRNA, not only inhibited D3T-induced Nrf2-HO-1 activation, but also abolished the RPE cytoprotective effects. In vivo, D3T intravitreal injection protected from light-induced retinal dysfunctions in mice. Thus, D3T protects RPE cells from UV-induced damages via activation of Akt-mTORC1-Nrf2-HO-1 signaling axis.
How maize monoculture and increasing winter rainfall have brought the hibernating European hamster to the verge of extinction
Authors: Tissier Mathilde L. , Handrich Yves , Robin Jean-Patrice , Weitten Mathieu , Pevet Paul , Kourkgy Charlotte , Habold Caroline
Published: May 2016

Over the last decades, climate change and agricultural intensification have been identified as two major phenomena negatively affecting biodiversity. However, little is known about their effects on the life-history traits of hibernating species living in agro-ecosystems. The European hamster (Cricetus cricetus), once a common rodent on agricultural land, is now on the verge of extinction in France. Despite the implemented measures for its protection, populations are still in sharp decline but the reasons for it remain unclear. To investigate how environmental change has affected this hibernating rodent, we used a data set based on 1468 recordings of hamster body mass at emergence from hibernation from 1937 to 2014. We reveal the adverse effects of increasing winter rainfall and maize monoculture intensification on the body mass of wild hamsters. Given the links that exist between body mass, reproductive success and population dynamics in mammals, these results are of particular importance to understand the decline of this species. In view of the rates of maize monoculture intensification and the predicted increase in winter rainfall, it is of the utmost importance to improve land management in Western Europe to avoid the extinction of this species.
Directional Selection from Host Plants Is a Major Force Driving Host Specificity in Magnaporthe Species
Authors: Zhong Zhenhui , Norvienyeku Justice , Chen Meilian , Bao Jiandong , Lin Lianyu , Chen Liqiong , Lin Yahong , Wu Xiaoxian , Cai Zena , Zhang Qi , Lin Xiaoye , Hong Yonghe , Huang Jun , Xu Linghong , Zhang Honghong , Chen Long , Tang Wei , Zheng Huakun , Chen Xiaofeng , Wang Yanli , Lian Bi , Zhang Liangsheng , Tang Haibao , Lu Guodong , Ebbole Daniel J. , Wang Baohua , Wang Zonghua
Published: May 2016

One major threat to global food security that requires immediate attention, is the increasing incidence of host shift and host expansion in growing number of pathogenic fungi and emergence of new pathogens. The threat is more alarming because, yield quality and quantity improvement efforts are encouraging the cultivation of uniform plants with low genetic diversity that are increasingly susceptible to emerging pathogens. However, the influence of host genome differentiation on pathogen genome differentiation and its contribution to emergence and adaptability is still obscure. Here, we compared genome sequence of 6 isolates of Magnaporthe species obtained from three different host plants. We demonstrated the evolutionary relationship between Magnaporthe species and the influence of host differentiation on pathogens. Phylogenetic analysis showed that evolution of pathogen directly corresponds with host divergence, suggesting that host-pathogen interaction has led to co-evolution. Furthermore, we identified an asymmetric selection pressure on Magnaporthe species. Oryza sativa-infecting isolates showed higher directional selection from host and subsequently tends to lower the genetic diversity in its genome. We concluded that, frequent gene loss or gain, new transposon acquisition and sequence divergence are host adaptability mechanisms for Magnaporthe species and this coevolution processes is greatly driven by directional selection from host plants.
Trafficking of Endogenous Immunoglobulins by Endothelial Cells at the Blood-Brain Barrier
Authors: Villaseñor Roberto , Ozmen Laurence , Messaddeq Nadia , Grüninger Fiona , Loetscher Hansruedi , Keller Annika , Betsholtz Christer , Freskgård Per-Ola , Collin Ludovic
Published: May 2016

The Blood-Brain Barrier (BBB) restricts access of large molecules to the brain. The low endocytic activity of brain endothelial cells (BECs) is believed to limit delivery of immunoglobulins (IgG) to the brain parenchyma. Here, we report that endogenous mouse IgG are localized within intracellular vesicles at steady state in BECs in vivo. Using high-resolution quantitative microscopy, we found a fraction of endocytosed IgG in lysosomes. We observed that loss of pericytes (key components of the BBB) in pdgf-bret/ret mice affects the intracellular distribution of endogenous mouse IgG in BECs. In these mice, endogenous IgG was not detected within lysosomes but instead accumulate at the basement membrane and brain parenchyma. Such IgG accumulation could be due to reduced lysosomal clearance and increased sorting to the abluminal membrane of BECs. Our results suggest that, in addition to low uptake from circulation, IgG lysosomal degradation may be a downstream mechanism by which BECs further restrict IgG access to the brain.
The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis
Authors: Sun Shaolong , Huang Yang , Sun Runcang , Tu Maobing
Published: May 2016

The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis.
Switching the regioselectivity in the copper-catalyzed synthesis of iodoimidazo[1,2-a]pyridines
Authors: Samanta Sadhanendu , Jana Sourav , Mondal Susmita , Monir Kamarul , Chandra Swapan K. , Hajra Alakananda
Published: May 2016

A unique copper-catalyzed binucleophilic switching of 2-aminopyridine has been developed for the regioselective synthesis of 2- and 3-iodoimidazo[1,2-a]pyridines using alkenes/alkynes as coupling partners in the presence of molecular iodine under aerobic reaction conditions.
Composition controlled nickel cobalt sulfide core–shell structures as high capacity and good rate-capability electrodes for hybrid supercapacitors
Authors: Zhang Lei , Zhang Haitao , Jin Long , Zhang Binbin , Liu Fangyan , Su Hai , Chun Fengjun , Li Qinghan , Peng Jinfang , Yang Weiqing
Published: May 2016

Tuning element content is an effective approach for achieving excellent rate-capability and cycling stability in polynary metal sulfides for hybrid supercapacitors.
Thermoelectric properties of half-Heusler ZrNiPb by using first principles calculations
Authors: Guo San-Dong
Published: May 2016

We investigate the electronic structures and thermoelectric properties of a recently synthesized half-Heusler ZrNiPb compound by using a generalized gradient approximation (GGA) and GGA plus spin–orbit coupling (GGA + SOC).
Visible light amination/Smiles cascade: access to phthalazine derivatives
Authors: Brachet Etienne , Marzo Leyre , Selkti Mohamed , König Burkhard , Belmont Philippe
Published: May 2016

We report the synthesis of various phthalazines via a new cascade reaction, initiated by visible light photocatalysis, involving a radical hydroamination reaction followed by a radical Smiles rearrangement.
Kinetics versus thermodynamics in the proline catalyzed aldol reaction
Authors: Orlandi M. , Ceotto M. , Benaglia M.
Published: May 2016

The reversibility of the reaction was proved and a new rate law was obtained; the use of a Multiple Transition State Approach (MTSA), that includes both kinetics and thermodynamics in the description of the process, successfully rationalizes the chemical and stereochemical outcomes of this paradigmatic reaction for the first time.
PCB‐integrated thin film thermocouples for transient temperature measurement
Authors: Wang WenLian , Zhang Hui , Du XiaoJun , Sun YouYi
Published: May 2016

A thin film thermocouple (TFTC) on printed circuit board (PCB) substrate is investigated for measuring transient high temperature. The thermal conductivity of PCB is smaller than that of ceramic, which indicates less influence of substrate on heat conduction of TFTC. Therefore, PCB is suitable to make fast response sensors although it cannot withstand continuous high temperature as ceramic. On the other hand, the TFTC is fabricated on the PCB with measurement circuit together, which integrates a miniature measurement unit. A k‐type TFTC was fabricated by magnetron sputtering while the film naturally connected with tracks of PCB, which achieves an integration of the sensor with measurement circuit. Experimental result indicates that the response time of TFTC is less than 2 ms.
Cross‐range scaling technique for ISAR images with affine projection matrix
Authors: Su Fu‐Lin , Yang Hong‐Xin
Published: May 2016

For better using of the inverse synthetic aperture radar (ISAR) images, it is more desirable to estimate the rotational velocity (RV) for image cross‐range scaling. To solve this problem, an algorithm based on affine projection matrix is proposed. This method consists of two parts. The first part is to transform the two sequenced sub‐aperture images by affine matrix. The aim is to eliminate the negative effects caused by ‘scaled–stretched’ transformation between the two images. In the second part, the processed images are mapped into polar coordinates system. In polar coordinates, the rotational motion in ISAR image is converted into the translation in the angle dimension. The correlation coefficient is used to search the right RV which provides the maximum correlation between the two processed images. Finally, experimental results based on simulated and real ISAR data are used to prove the effectiveness and practicability of the proposed method.
Constrained linear regularised state estimator for observability analysis in power systems
Authors: Schmidt Fabiano , Dardengo Victor Pellanda , de Almeida Madson Cortes
Published: May 2016

This study proposes a novel observability analysis approach for power systems state estimation. To support this approach, the study also proposes a constrained linear regularised state estimator in which equality constraints are explicitly represented, thus resulting in a well‐conditioned mathematical model where numerical problems are not prone to occur. A proper mode to specify values for the required pseudo‐measurements is also proposed. Except for some pathological cases, the coefficient matrix needs to be built and factorised just once. The implementation of the proposed approach is trivial, since the matrix to be factorised is symmetric and positive semi‐definite, requiring only classical and well‐established methods for sparse storage and factorisation. Additionally, pivoting strategies are not required. Tests based on small systems are used to present the proposed approach in a didactic way. Additional case studies based on IEEE‐14 buses and IEEE‐300 buses systems are used to highlight the robustness and usefulness of the proposed approach.
Modelling, analysis and control design of a two‐stage photovoltaic generation system
Authors: Cai Hongda , Xiang Ji , Wei Wei
Published: May 2016

Photovoltaic (PV) generation systems with two‐stage topology are recently emerged due to its flexibility of installation. However, most studies on dynamic stability of the PV generation system are based either on the first DC/DC stage or the second DC/AC stage in previous literature. A system‐level modelling and stability has not been reported significantly, which is a crucial issue for the design of the PV system controllers. In this study, an integrated small‐signal model for a two‐stage PV generation system is derived to investigate the system stability and sensitivity. The proposed model takes into account the dynamics of the DC‐link capacitor that was generally regarded as an ideal constant voltage source in previous researches. A v2 feedback based DC‐link voltage control scheme is presented to address the non‐linear relationship between capacitor energy and its voltage and thus a high performance DC‐link voltage regulation is achieved. Hardware‐in‐loop tests using real time digital simulator are presented to validate the feasibility of the proposed method.
Ambiguity function and accuracy of the hyperbolic chirp: comparison with the linear chirp
Authors: Balleri Alessio , Farina Alfonso
Published: May 2016

In this study, the authors derive the ambiguity function (AF) of a narrowband and a wideband hyperbolic chirp. They calculate the second derivatives of the squared amplitude of the narrowband complex AF and use them to calculate the Fisher information matrix (FIM) of the estimators of the target range and velocity. The FIM is then used to calculate the Cramér–Rao lower bounds (CRLBs) of the variance of the estimators and to carry out an analysis of estimation performance and a comparison with the case of a linear chirp with a rectangular and a Gaussian amplitude modulation. The analysis and the calculations of the CRLB are also extended to a train of hyperbolic chirps. Results corroborate that at narrowband the hyperbolic chirp is less Doppler tolerant than the linear chirp and show that the hyperbolic chirp provides a comparable measurement accuracy to the linear chirp. Results at wideband corroborate the superior Doppler tolerance of the hyperbolic chirp with respect to that of the linear chirp.
Michaelis-Menten dynamics in protein subnetworks
Authors: Rubin Katy J. , Sollich Peter
Published: May 2016

To understand the behaviour of complex systems, it is often necessary to use models that describe the dynamics of subnetworks. It has previously been established using projection methods that such subnetwork dynamics generically involves memory of the past and that the memory functions can be calculated explicitly for biochemical reaction networks made up of unary and binary reactions. However, many established network models involve also Michaelis-Menten kinetics, to describe, e.g., enzymatic reactions. We show that the projection approach to subnetwork dynamics can be extended to such networks, thus significantly broadening its range of applicability. To derive the extension, we construct a larger network that represents enzymes and enzyme complexes explicitly, obtain the projected equations, and finally take the limit of fast enzyme reactions that gives back Michaelis-Menten kinetics. The crucial point is that this limit can be taken in closed form. The outcome is a simple procedure that allows one to obtain a description of subnetwork dynamics, including memory functions, starting directly from any given network of unary, binary, and Michaelis-Menten reactions. Numerical tests show that this closed form enzyme elimination gives a much more accurate description of the subnetwork dynamics than the simpler method that represents enzymes explicitly and is also more efficient computationally.
Detailed flowfield and surface properties for high Knudsen number planar jet impingement at an inclined flat plate
Authors: Cai Chunpei , He Xin
Published: May 2016

This paper presents two sets of analytical exact solutions for collisionless gas flows from a planar exit, impinging at an inclined flat plate. These analytical results are obtained by using gaskinetic theories. The first set of solutions are for a diffuse reflective plate surface, and the other set of solutions are for a specular reflective plate surface. A virtual nozzle exit is adopted to aid analyzing the specular reflective plate scenario. New formulas for plate surface properties, including velocity slips, pressure, shear stress, and heat flux distributions, are provided. For both problems, the flowfield exact solutions are investigated as well. Numerical simulations with the direct simulation Monte Carlo method are performed to validate these new analytical results, and good agreement is obtained for flows with high Knudsen numbers. The results consider effects from many factors, such as the plate inclination angle, geometry ratios, and exit gas and plate properties (such as exit gas bulk density, gas speed ratio, and exit gas and plate temperatures). Compared with past work, these new solutions are more comprehensive and practical. The results also illustrate that if the plate is quite close to the nozzle exit, it is improper to adopt the traditional treatments of a point source and a simple cosine function.
One-dimensional nonlinear instability study of a slightly viscoelastic, perfectly conducting liquid jet under a radial electric field
Authors: Li Fang , Yin Xie-Yuan , Yin Xie-Zhen
Published: May 2016

A one-dimensional electrified viscoelastic model is built to study the nonlinear behavior of a slightly viscoelastic, perfectly conducting liquid jet under a radial electric field. The equations are solved numerically using an implicit finite difference scheme together with a boundary element method. The electrified viscoelastic jet is found to evolve into a beads-on-string structure in the presence of the radial electric field. Although the radial electric field greatly enhances the linear instability of the jet, its influence on the decay of the filament thickness is limited during the nonlinear evolution of the jet. On the other hand, the radial electric field induces axial non-uniformity of the first normal stress difference within the filament. The first normal stress difference in the center region of the filament may be greatly decreased by the radial electric field. The regions with/without satellite droplets are illuminated on the χ (the electrical Bond number)-k (the dimensionless wave number) plane. Satellite droplets may be formed for larger wave numbers at larger radial electric fields.
Penetrative phototactic bioconvection in a two-dimensional non-scattering suspension
Authors: Panda M. K. , Singh R.
Published: May 2016

Phototaxis is a directed swimming response dependent upon the light intensity sensed by microorganisms. Positive (negative) phototaxis denotes the motion directed towards (away from) the source of light. In this paper, we simulate numerically penetrative phototactic bioconvection in a non-scattering suspension of phototactic algae in the non-linear regime. The suspension is confined by a stress-free top boundary, and rigid bottom and lateral boundaries. The algae receive light from the source directly above it and thus they swim vertically upward by neglecting the effects of scattering. We use the phototaxis model proposed by Vincent and Hill [“Bioconvection in a suspension of phototactic algae,” J. Fluid Mech. 327, 343 (1996)] to investigate the onset of bioconvection in two dimensions using the stream function-vorticity formulation. The critical conditions from the onset of bioconvection are used to study the effects of different governing parameters on the structure and stability of the obtained solutions. The resulting bioconvective patterns differ qualitatively from those found by Ghorai and Hill [“Penetrative phototactic bioconvection,” Phys. Fluids 17, 074101 (2005)] at some particular swimming velocity of microorganisms due to rigid lateral walls. A significant stabilizing effect on suspension has been also observed due to lateral rigid walls for some governing parameters.
Characterization of the near-field and convectional transport behavior of micro and nanoparticles in nanoscale plasmonic optical lattices
Authors: Yang Tsang-Po , Yossifon Gilad , Yang Ya-Tang
Published: May 2016

Here, we report the characterization of the transport of micro- and nanospheres in a simple two-dimensional square nanoscale plasmonic optical lattice. The optical potential was created by exciting plasmon resonance by way of illuminating an array of gold nanodiscs with a loosely focused Gaussian beam. This optical potential produced both in-lattice particle transport behavior, which was due to near-field optical gradient forces, and high-velocity (∼μm/s) out-of-lattice particle transport. As a comparison, the natural convection velocity field from a delocalized temperature profile produced by the photothermal heating of the nanoplasmonic array was computed in numerical simulations. This work elucidates the role of photothermal effects on micro- and nanoparticle transport in plasmonic optical lattices.
The phenology and seed production of Cucumis melo as an invasive weed in northern Iran
Authors: Sohrabi Sima , Gherekhloo Javid , Kamkar Behnam , Ghanbari Ali , Mohassel Mohammad Hassan Rashed
Published: May 2016

Accurately representing plant development is essential for applying phenology knowledgement to investigate the effects of climate on weed management. Development in wild melon (Cucumis melo L.) is driven by temperature; thus, it could be simulated by thermal-time (TT) accumulation using limited accumulation when a lower optimum temperature (Topt) is exceeded. Experiments were conducted to investigate wild melon phenology (development rate) and seed production in soybean (Glycine max L.) at seven different sowing dates (April to August) in a completely randomised design (CRD) at Research Farm of Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2012. Results indicated that a slight shift in developmental rates occurs among plantings dates, except for those plants sown in August. The estimated TT for April–August planting dates were ~411 Celcius degree days, 448 Celcius degree days, 733 Celcius degree days, 672 Celcius degree days, 604 Celcius degree days, 558 Celcius degree days and 251 Celcius degree days respectively. Depending on planting date, weed emergence occurred at 5–20 days after planting. During the 79, 75, 92, 81, 71, 67 and 61 days of wild-melon growth, the mean number of fruits per plant and seeds per fruit were significantly different at each sowing date. Wild melon could produce a lot of fruits and seeds (up to 5000) within a growth cycle (average in 75 days) and also weed management is needed during the May and June because of the highest seed production of wild melons that emerged during May. The results attained here suggest that temperature alone could not reflect the effect of environment on C. melo development at each given growth stage. Thus, other environmental factors, such as daylength, maybe needed to better estimate weed development. Future research may use multiplicative models to clarify this claim. These results highlighted the value of testing a model over a wide range of environments.
Socio-ecological aspects of sustaining Ramsar wetlands in three biodiverse developing countries
Authors: Lynch A. Jasmyn J. , Kalumanga Elikana , Ospina Guillermo A.
Published: May 2016

Integrating conservation and ecologically sustainable development of wetlands is a major challenge, especially in developing countries. While many developing countries harbour significant biodiversity and socio-cultural resources, they have substantial development pressures. We explore the similarities in issues around wetland conservation and sustainability in three developing countries using case studies of internationally significant wetlands in Tanzania, Colombia and Papua New Guinea. We examine key aspects of their socio-ecological values, stakeholder and governance issues, conservation and management issues, and management responses. Key challenges across these regions include inadequate knowledge and data, population and development impacts, poor regulatory and planning processes, socio-economic inequities and conflict. All three areas lack adequate inventory, survey and monitoring, and there are significant risks to some wetland values. Mechanisms such as the Ramsar Convention provide a framework to assist in addressing global wetland loss, but implementation at these sites needs to be supported by effective, integrative approaches involving natural resource regulation, conservation and the development needs of local communities. Increased commitment and resourcing, along with comprehensive stakeholder engagement, are needed to develop and implement locally tailored plans to effectively manage these sites and their values, while also addressing the range of stakeholder needs and perspectives.
What's in a name? Concordance is better than adherence for promoting partnership and self-management of chronic disease
Authors: Randall Sue , Neubeck Lis
Published: May 2016

The choice of language health professionals use to discuss self-management of chronic disease is important and influences patients’ self-management. The words compliance, adherence and concordance are used to discuss patients’ agreement with prescribed treatment plans, but have different tone and meanings. Models of care linked to the words compliance and adherence are underpinned by interactions between patients and healthcare providers that merely reinforce instructions about treatments. The ‘patient-professional partnership’ is introduced as a model by Bodenheimer et al. (2002, p. 2469) whereby true partnership working should be an opportunity to pool the expertise of both parties to arrive at mutually agreed goals in concordance. The impact these words might have on partnership working is important in defining the patient–health professional relationship, and for the patients’ healthcare outcomes and the potential effect on healthcare utilisation.
First-principles study of the structural, electronic, and magnetic properties of double perovskite Sr2FeReO6 containing various imperfections*
Authors: Zhang Yan , Duan Li , Ji Vincent , Xu Ke-Wei
Published: May 2016

The structural, electronic, and magnetic properties of double perovskite Sr2FeReO6 containing eight different imperfections of FeRe or ReFe antisites, Fe1–Re1 or Fe1–Re4 interchanges, VFe, VRe, VO or VSr vacancies have been studied by using the first-principles projector augmented wave (PAW) within generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction (GGA+U). No obvious structural changes are observed for the imperfect Sr2FeReO6 containing FeRe or ReFe antisites, Fe1–Re1 or Fe1–Re4 interchanges, or VSr vacancy defects. However, the six (eight) nearest oxygen neighbors of the vacancy move away from (close to) VFe or VRe (VO) vacancies. The half-metallic (HM) character is maintained for the imperfect Sr2FeReO6 containing FeRe or ReFe antisites, Fe1–Re4 interchange, VFe, VO or VSr vacancies, while it vanishes when the Fe1–Re1 interchange or VRe vacancy is presented. So the Fe1–Re1 interchange and the VRe vacancy defects should be avoided to preserve the HM character of Sr2FeReO6 and thus usage in spintronic devices. In the FeRe or ReFe antisites, Fe1–Re1 or Fe1–Re4 interchanges cases, the spin moments of the Fe (Re) cations situated on Re (Fe) antisites are in an antiferromagnetic coupling with those of the Fe (Re) cations on the regular sites. In the VFe, VRe, VO, or VSr vacancies cases, a ferromagnetic coupling is obtained within each cation sublattice, while the two cation sublattices are coupled antiferromagnetically. The total magnetic moments μ
tot (μ
B/f.u.) of the imperfect Sr2FeReO6 containing eight different defects decrease in the sequence of VSr vacancy (3.50), VRe vacancy (3.43), FeRe antisite (2.74), VO vacancy (2.64), VFe vacancy (2.51), ReFe antisite (2.29), Fe1–Re4 interchange (1.96), Fe1–Re1 interchange (1.87), and the mechanisms of the saturation magnetization reduction have been analyzed.