bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrobiology in Brazil: early history and perspectives
Authors: Rodrigues Fabio , Galante Douglas , Paulino-Lima Ivan G. , Duarte Rubens T.D. , Friaça Amancio C.S. , Lage Claudia , Janot-Pacheco Eduardo , Teixeira Ramachrisna , Horvath Jorge E.
Published: July 2012

This review reports the Brazilian history in astrobiology, as well as the first delineation of a vision of the future development of the field in the country, exploring its abundant biodiversity, highly capable human resources and state-of-the-art facilities, reflecting the last few years of stable governmental investments in science, technology and education, all conditions providing good perspectives on continued and steadily growing funding for astrobiology-related research. Brazil is growing steadily and fast in terms of its worldwide economic power, an effect being reflected in different areas of the Brazilian society, including industry, technology, education, social care and scientific production. In the field of astrobiology, the country has had some important landmarks, more intensely after the First Brazilian Workshop on Astrobiology in 2006. The history of astrobiology in Brazil, however, is not so recent and had its first occurrence in 1958. Since then, researchers carried out many individual initiatives across the country in astrobiology-related fields, resulting in an ever growing and expressive scientific production. The number of publications, including articles and theses, has particularly increased in the last decade, but still counting with the effort of researchers working individually. That scenario started to change in 2009, when a formal group of Brazilian researchers working with astrobiology was organized, aiming at congregating the scientific community interested in the subject and to promote the necessary interactions to achieve a multidisciplinary work, receiving facilities and funding from the University de Sao Paulo and other funding agencies.
A comparative density functional study of the high-pressure phases of solid ZnX, CdX, and HgX (X = S, Se, and Te): Trends and relativistic effects
Authors: Biering S. , Schwerdtfeger P.
Published: July 2012

The pressure dependence of bulk properties for the group 12 chalcogenides MX (M = Zn, Cd, Hg; X = S, Se, Te) from density functional theory are presented. Energy-volume and corresponding enthalpy-pressure relationships are determined to obtain the transition paths and properties of various high-pressure phases. The influence of relativistic effects is discussed with the aim to explain the unique behavior of the mercury chalcogenides as compared to the lighter zinc and cadmium homologs at high pressures. The neglect of relativistic effects leads to a more CdX like behavior of the mercury chalcogenides, and the pronounced change in coordination of the cinnabar phase at high pressures is due to relativistic effects.
Electromigration induced failure on lead-free micro bumps in three-dimensional integrated circuits packaging
Authors: Ouyang Fan-Yi , Hsu Hao , Su Yu-Ping , Chang Tao-Chih
Published: July 2012

We report electromigration induced failure on lead-free micro bumps in three-dimensional integrated circuits samples with chip on chip configuration. Compared to flip chip solder joints, micro bumps of chip-on-chip samples exhibit better electromigration resistance and are able to withstand a higher current density. No exhibited electromigration-induced failure was observed when current density was below 2 × 104 A/cm2. A threshold current density to trigger electromigration in chip-on-chip samples was found to be 3.43 × 104 A/cm2. When current density was higher than 7.5 × 104 A/cm2 at an ambient temperature of 150 °C, no void propagation through whole bump opening was found; instead, electromigration induced voids were observed at the cathode side of Al trace.
Light amplification in zero-index metamaterial with gain inserts
Authors: Zhu Weiren , Rukhlenko Ivan D. , Premaratne Malin
Published: July 2012

The concept of light amplification in a system of zero-index metamaterial with gain inserts is studied. We demonstrate that the radiation from a point source embedded in the system can be effectively amplified and the net gain is independent of the positions of gain inserts and the source. We further investigate how the net gain grows with the imaginary part of the inserts’ permittivities and find that it saturates when the imaginary part is sufficiently large. It is also shown that the efficiency of amplification is significantly reduced when lossy inserts are introduced into the system.
CdS buffer-layer free highly efficient ZnO-CdSe photoelectrochemical cells
Authors: Mane Rajaram S. , Shinde Dipak V. , Joon Yoon Seog , Ambade Swapnil B. , Kee Lee Joong , Han Sung-Hwan
Published: July 2012

Highly reproducible, wet-chemically processed, CdS buffer-layer free ZnO-CdSe photoelectrochemical cells with 3.38% power conversion efficiency have been fabricated. An enhanced current density is observed due to increase in number of injected photoelectrons with CdSe nanoparticles loading time. Impedance spectroscopy results suggest that interfacial resistance is strongly dependant on CdSe nanoparticles loading time.
Direct generation of optical vortex pulses
Authors: Zhao Yongguang , Wang Zhengping , Yu Haohai , Zhuang Shidong , Zhang Huaijin , Xu Xiaodong , Xu Jun , Xu Xinguang , Wang Jiyang
Published: July 2012

We demonstrate the direct generation of optical vortex pulses with stable energy and changeable orbital angular momentum. Single Laguerre-Gaussian (LG0,l) laser modes were directly generated using a laser diode with output intensity profile of doughnut distribution. With passive Q-switching, vortex pulses with stable energy were obtained. Moreover, the topological charge was changeable by variation of the pump power. By a mode-converter and second harmonic generation, the LG0,2l mode was identified. It can be proposed that this pulsed laser should have promising applications in various fields based on its compact structure, stable and high pulse energy, and changeable orbital angular momentum.
Chromatin-interaction compartment switch at developmentally regulated chromosomal domains reveals an unusual principle of chromatin folding
Authors: Takebayashi Shin-ichiro , Dileep Vishnu , Ryba Tyrone , Dennis Jonathan H. , Gilbert David M.
Published: July 2012

Several 400- to 800-kb murine chromosome domains switch from early to late replication during loss of pluripotency, accompanied by a stable form of gene silencing that is resistant to reprogramming. We found that, whereas enhanced nuclease accessibility correlated with early replication genome-wide, domains that switch replication timing during differentiation were exceptionally inaccessible even when early-replicating. Nonetheless, two domains studied in detail exhibited substantial changes in transcriptional activity and higher-order chromatin unfolding confined to the region of replication timing change. Chromosome conformation capture (4C) data revealed that in the unfolded state in embryonic stem cells, these domains interacted preferentially with the early-replicating chromatin compartment, rarely interacting even with flanking late-replicating domains, whereas after differentiation, these same domains preferentially associated with late-replicating chromatin, including flanking domains. In both configurations they retained local boundaries of self-interaction, supporting the replication domain model of replication-timing regulation. Our results reveal a principle of developmentally regulated, large-scale chromosome folding involving a subnuclear compartment switch of inaccessible chromatin. This unusual level of regulation may underlie resistance to reprogramming in replication-timing switch regions.
Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology
Authors: Schreiber Eric C. , Chang Sha X.
Published: July 2012

Purpose:

Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x‐ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design.

Methods:

Monte Carlo calculations were performed using EGSnrc‐based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200μm at 18.6 cm source‐to‐axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations.

Results:

Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50μm. Dose vs depth was weakly dependent on filtration material. The peak‐to‐valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm.

Conclusions:

Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak‐to‐valley ratio for small animal MRT studies.
Into the wardrobe of Narnia: beyond HIV infection a world of cardiovascular risk
Authors: Colotto Marco , Renzi Alessandra , Durante Cosimo
Published: July 2012

A 38-years-old HIV-hepatitis C virus (HCV) coinfected woman presented to us for dyslipidemia. Clinical, familial and laboratory data were consistent with the diagnosis of familial heterozygous hypercholesterolaemia. History, clinical examination and laboratory findings also supported suspected acromegaly. A pituitary MRI showed a sellar macroadenoma that was removed by transphenoidal surgery without complications. MRI carried out 6 months after surgery showed almost complete removal of the adenoma. This case report describes an uncommon association of diseases, very different for aetiology—genetic for FH, infectious for HIV and HCV, caused by excessive hormone secretion for acromegaly-clinical features and therapy, but all sharing a significant impact on cardiovascular risk as a common feature.
Adult-Onset Fluoxetine Treatment Does Not Improve Behavioral Impairments and May Have Adverse Effects on the Ts65Dn Mouse Model of Down Syndrome
Authors: Heinen Markus , Hettich Moritz M. , Ryan Devon P. , Schnell Susanne , Paesler Katharina , Ehninger Dan
Published: July 2012

Down syndrome is caused by triplication of chromosome 21 and is associated with neurocognitive phenotypes ranging from severe intellectual disability to various patterns of more selective neuropsychological deficits, including memory impairments. In the Ts65Dn mouse model of Down syndrome, excessive GABAergic neurotransmission results in local over-inhibition of hippocampal circuits, which dampens hippocampal synaptic plasticity and contributes to cognitive impairments. Treatments with several GABAAreceptor antagonists result in increased plasticity and improved memory deficits in Ts65Dn mice. These GABAAreceptor antagonists are, however, not suitable for clinical applications. The selective serotonin reuptake inhibitor fluoxetine, in contrast, is a widely prescribed antidepressant that can also enhance plasticity in the adult rodent brain by lowering GABAergic inhibition. For these reasons, we wondered if an adult-onset 4-week oral fluoxetine treatment restores spatial learning and memory impairments in Ts65Dn mice. Fluoxetine did not measurably improve behavioral impairments of Ts65Dn mice. On the contrary, we observed seizures and mortality in fluoxetine-treated Ts65Dn mice, raising the possibility of a drug × genotype interaction with respect to these adverse treatment outcomes. Future studies should re-address this in larger animal cohorts and determine if fluoxetine treatment is associated with adverse treatment effects in individuals with Down syndrome.
Taxifolin Suppresses UV-Induced Skin Carcinogenesis by Targeting EGFR and PI3K
Authors: Oi Naomi , Chen Hanyong , Ok Kim Myoung , Lubet Ronald A. , Bode Ann M. , Dong Zigang
Published: July 2012

Skin cancer is one of the most commonly diagnosed cancers in the United States. Taxifolin reportedly exerts multiple biologic effects, but the molecular mechanisms and direct target(s) of taxifolin in skin cancer chemoprevention are still unknown. In silico computer screening and kinase profiling results suggest that the EGF receptor (EGFR), phosphoinositide 3-kinase (PI3K), and Src are potential targets for taxifolin. Pull-down assay results showed that EGFR, PI3K, and Src directly interacted with taxifolin in vitro, whereas taxifolin bound to EGFR and PI3K, but not to Src in cells. ATP competition and in vitro kinase assay data revealed that taxifolin interacted with EGFR and PI3K at the ATP-binding pocket and inhibited their kinase activities. Western blot analysis showed that taxifolin suppressed UVB-induced phosphorylation of EGFR and Akt, and subsequently suppressed their signaling pathways in JB6 P+ mouse skin epidermal cells. Expression levels and promoter activity of COX-2 and prostaglandin E2 (PGE2) generation induced by UVB were also attenuated by taxifolin. The effect of taxifolin on UVB-induced signaling pathways and PGE2 generation was reduced in EGFR knockout murine embryonic fibroblasts (MEF) compared with EGFR wild-type MEFs. Taxifolin also inhibited EGF-induced cell transformation. Importantly, topical treatment of taxifolin to the dorsal skin significantly suppressed tumor incidence, volume, and multiplicity in a solar UV (SUV)-induced skin carcinogenesis mouse model. Further analysis showed that the taxifolin-treated group had a substantial reduction in SUV-induced phosphorylation of EGFR and Akt in mouse skin. These results suggest that taxifolin exerts chemopreventive activity against UV-induced skin carcinogenesis by targeting EGFR and PI3K. Cancer Prev Res; 5(9); 1103–14. ©2012 AACR.
The Effect of Superior Semicircular Canal Dehiscence on Intracochlear Sound Pressures
Authors: Pisano Dominic V. , Niesten Marlien E.F. , Merchant Saumil N. , Nakajima Hideko Heidi
Published: July 2012

Semicircular canal dehiscence (SCD) is a pathological opening in the bony wall of the inner ear that can result in conductive hearing loss. The hearing loss is variable across patients, and the precise mechanism and source of variability are not fully understood. Simultaneous measurements of basal intracochlear sound pressures in scala vestibuli (SV) and scala tympani (ST) enable quantification of the differential pressure across the cochlear partition, the stimulus that excites the cochlear partition. We used intracochlear sound pressure measurements in cadaveric preparations to study the effects of SCD size. Sound-induced pressures in SV and ST, as well as stapes velocity and ear canal pressure were measured simultaneously for various sizes of SCD followed by SCD patching. Our results showed that at low frequencies (<600 Hz), SCD decreased the pressure in both SV and ST, as well as differential pressure, and these effects became more pronounced as dehiscence size was increased. Near 100 Hz, SV decreased by about 10 dB for a 0.5-mm dehiscence and by 20 dB for a 2-mm dehiscence, while ST decreased by about 8 dB for a 0.5-mm dehiscence and by 18 dB for a 2-mm dehiscence. Differential pressure decreased by about 10 dB for a 0.5-mm dehiscence and by about 20 dB for a 2-mm dehiscence at 100 Hz. In some ears, for frequencies above 1 kHz, the smallest pinpoint dehiscence had bigger effects on the differential pressure (10-dB decrease) than larger dehiscences (less than 10-dB decrease), suggesting larger hearing losses in this frequency range. These effects due to SCD were reversible by patching the dehiscence. We also showed that under certain circumstances such as SCD, stapes velocity is not related to how the ear can transduce sound across the cochlear partition because it is not directly related to the differential pressure, emphasizing that certain pathologies cannot be fully assessed by measurements such as stapes velocity.
Synergistic Effect of Pasireotide and Teriflunomide in Carcinoids in vitro
Authors: Somnay Yash , Chen Herbert , Kunnimalaiyaan Muthusamy
Published: July 2012

Background/Aim: Somatostatin (SST) analogs are mainstay for controlling tumor proliferation and hormone secretion in carcinoid patients. Recent data suggest that extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation may potentiate the anti-tumor effects of SST analogs in carcinoids. Additionally, ERK1/2 phosphorylating agents have been shown to suppress biomarker expression in carcinoids. Thus, Raf-1/MEK/ERK1/2 pathway activating drugs may be synergistic with SST analogs such as pasireotide (SOM230), which may be more effective than others in its class given its elevated receptor affinity and broader binding spectrum. Here, we investigate the effects of SOM230 in combination with teriflunomide (TFN), a Raf-1 activator, in a human carcinoid cell line. Methods: Human pancreatic carcinoid cells (BON) were incubated in TFN, SOM230 or a combination. Cell proliferation was measured using a rapid colorimetric assay. Western analysis was performed to analyze expression levels of achaete-scute complex-like 1 (ASCL1), chromogranin A (CgA), phosphorylated and total ERK1/2, and markers for apoptosis. Results: Combination treatment with SOM230 and TFN reduced cell growth beyond the additive effect of either drug alone. Combination indices (CI) fell below 1, thus quantifiably verifying synergy between both drugs as per the Chou-Talalay CI scale. Combined treatment also reduced ASCL1 and CgA expression beyond the additive effect of either drug alone. Furthermore, it increased levels of phosphorylated ERK1/2, cleaved poly(ADP)-ribose polymerase and caspase-3, and reduced levels of anti-apoptotic biomarkers. Elevated phosphorylated ERK1/2 expression following combination therapy may underlie the synergistic interaction between the two drugs. Conclusion: Since efficacy is achieved at lower doses, combination therapy may palliate symptoms at low toxicity levels. Because each drug has already been evaluated in clinical trials, combinatorial drug trials are warranted.
Jugular Veins in Transient Global Amnesia
Authors: Baracchini Claudio , Tonello Simone , Farina Filippo , Viaro Federica , Atzori Matteo , Ballotta Enzo , Manara Renzo
Published: July 2012

Background and Purpose—

Transient global amnesia (TGA) has been associated with an increased prevalence of internal jugular valve insufficiency and many patients report Valsalva-associated maneuvers before TGA onset. These findings have led to the assumption of hemodynamic alterations in intracranial veins inducing focal hippocampal ischemia. We investigated this hypothesis in patients with TGA and control subjects.

Methods—

Seventy-five patients with TGA and 75 age- and sex-matched healthy subjects were enrolled into a cross-sectional study. Extracranial and transcranial high-resolution venous echo-color-Doppler sonography was performed blindly in all patients and control subjects. Blood flow direction and velocities were recorded at the internal jugular veins, basal veins of Rosenthal, and vein of Galen, both at rest and during Valsalva-associated maneuvers.

Results—

Mean age of patients with TGA was 60.3±8.0 years (median, 60 years; range, 44–78 years); 44 (59%) were female (female/male ratio: 1.42). Internal jugular valve insufficiency (left, right, or bilateral) was found to be more frequent in patients with TGA than in control subjects: 53 (70.7%) versus 22 (29.3%;
P
<0.05). Blood flow velocities in the deep cerebral veins of patients with TGA did not differ from control subjects both at rest and during Valsalva-associated maneuvers. Intracranial venous reflux was neither observed in patients with TGA nor in control subjects despite unilateral or bilateral internal jugular valve insufficiency during prolonged and maximal Valsalva-associated maneuvers.

Conclusions—

This study, although confirming the association between TGA and internal jugular valve insufficiency, challenges the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of TGA.
Airline Alliances, Antitrust Immunity, and Market Foreclosure
Authors: Bilotkach Volodymyr , Hüschelrath Kai
Published: July 2012

We examine the issue of market foreclosure by airline partnerships with antitrust immunity. Overlapping data on frequency of service and passenger volumes on nonstop transatlantic routes with information on the dynamics of airline partnerships, we find evidence consistent with the airlines operating under antitrust immunity refusing to accept connecting passengers from the outside carriers at respective hub airports. Following the antitrust immunity, airlines outside the partnership reduce their traffic to the partner airlines' hub airports by 4.1% to 11.5%. We suggest regulators should take possible market foreclosure effects into account when assessing the competitive effects of antitrust immunity for airline alliances.
Quercetin-induced inhibition and synergistic activity with cisplatin – a chemotherapeutic strategy for nasopharyngeal carcinoma cells
Authors: Daker Maelinda , Ahmad Munirah , Khoo Alan SB
Published: July 2012

Background

Nasopharyngeal carcinoma (NPC) is a unique tumour of epithelial origin with a distinct geographical distribution, genetic predisposition and environmental as well as dietary influence as aetiological factors. Standard NPC treatment regimes, such as radiotherapy and concurrent chemotherapy with cytotoxic drugs, can produce undesirable complications often associated with significant toxicity. Here, we report the effects of a widely distributed flavonoid, quercetin, on cell proliferation, apoptosis and cell cycle arrest. The effects of combining quercetin and cisplatin on human NPC cells were explored.

Methods

Cell proliferation was monitored by the dynamic, impedance-based cell analyzer (xCELLigence system) and the MTS assay. Ki67 proliferation antigen and fatty acid synthase (FASN) level was examined by Western blotting. Flow cytometry was also carried out to study the effects of quercetin on cell cycle and apoptosis status.

Results

At 100 μM, quercetin inhibited cell proliferation and decreased expression of FASN and Ki67 antigen. Cell cycle analysis revealed a substantial increase in the proportion of cells in the G2/M phase. We also demonstrated the enhanced cytotoxic effects of quercetin treatment in concomitant with the chemotherapeutic drug, cisplatin, in cultured NPC cells. The combination index (CI) value of quercetin-cisplatin combination was < 1, indicating synergism.

Conclusions

Our study showed that quercetin exhibited synergistic effects with cisplatin against NPC cells. Dose-reduction index (DRI) values > 1 implied the possibility of reducing the cisplatin dosage required to treat NPC, with the addition of quercetin. In turn, this could reduce the risk of cisplatin-associated toxicity. The potential of combining quercetin with cisplatin as a chemotherapeutic strategy for treatment of NPC should be explored further.
Elective minimally invasive coronary artery bypass: Shunt or tournique occlusion? Assessment of a protective role of perioperative left anterior descending shunting on myocardial damage. A prospective randomized study
Authors: Sorm Zdenek , Vojacek Jan , Cermakova Eva , Pudil Radek , Stock Ulrich A , Harrer Jan
Published: July 2012

Background

To determine impact of intraluminal-left anterior descending shunt to prevent myocardial damage in minimally invasive coronary artery bypass.

Methods

38 patients were randomly assigned to external tournique occlusion (n = 19) or intraluminal-left anterior descending shunt group (n = 19). Blood samples for cardiac troponin T were collected at 30 minutes prior to, 6 and 24 hours after surgery.

Results

One patient in external tournique occlusion and two patients in intraluminal-left anterior descending shunt group were excluded from futher analysis due to preoperative cardiac troponin T level above the 99th-percentile. Postoperatively, each six patients in external tournique occlusion (33.3%) and intraluminal-left anterior descending shunt (35.3%) group were above the 99th-percentile. Two patients from each group (external tournique occlusion group 11.1% vs. intraluminal-left anterior descending shunt group 11.8%) had peak values above 10-% coeficient of variation cutoff (p = 1). There were no significant differences in between both groups at all studied timepoints.

Conclusion

There was no protective effect of intraluminal shunting on myocardial damage compared to short-term tournique occlusion. It is upon the surgeon's discretion which method may preferrably be used to achieve a bloodless field in grafting of the non-occluded left anterior descending in minimally invasive coronary artery bypass.
Enhancing saltiness in emulsion based foods
Authors: Lad Mita , Hewson Louise , Wolf Bettina
Published: July 2012

Background

The concept of enhancing saltiness perception in emulsions and a liquid food formulated with the emulsions (ambient vegetable soup) through increasing salt concentration in the continuous phase while retaining the fat content of the (aqueous continuous) product was evaluated. This was accomplished by increasing the droplet phase volume using duplex emulsion technology. Viscosity and droplet size distribution was measured. Saltiness evaluation was based on simple paired comparison testing (2-Alternate Forced Choice tests, BS ISO 5495:2007).

Results

Single and duplex emulsions and emulsion-based products had comparable mean oil droplet diameters (25 to 30 μm); however, viscosity of the duplex emulsion systems was considerably higher. Sensory assessment of saltiness of emulsion pairs (2AFC) indicated duplex technology enhanced saltiness perception compared to a single emulsion product at the same salt content (6.3 g/100 g) in both simple emulsions and the formulated food product (P = 0.0596 and 0.0004 respectively) although assessors noted the increased viscosity of the duplex systems. The formulated food product also contained pea starch particles which may have aided product mixing with saliva and thus accelerated tastant transport to the taste buds. Lowering salt content in the duplex systems (to levels of aqueous phase salt concentration similar to the level in the single systems) resulted in duplex systems being perceived as less salty than the single system. It appears that the higher viscosity of the duplex systems could not be “overruled” by enhanced mixing through increased droplet phase volume at lowered salt content.

Conclusions

The results showed that salt reduction may be possible despite the added technology of duplex systems increasing the overall measured viscosity of the product. The changes in viscosity behavior impact mouthfeel, which may be exploitable in addition to the contribution towards salt reduction. With a view to applying this technology to real processed foods, it needs to be tested for the product in question but it should be considered as part of a salt reduction tool box.
Fluoroscopically guided nose tube drainage of mediastinal abscesses in post-operative gastro-oesophageal anastomotic leakage
Authors: Xu Q Y , Yin G W , Chen S X , Jiang F , Bai X J , Wu J D
Published: July 2012

Objective

The aim of this study was to retrospectively evaluate the technical success rates and clinical effectiveness of fluoroscopically guided nose tube drainage of mediastinal abscesses and a nasojejunum feeding tube in post-operative gastro-oesophageal anastomotic leakage (GEAL).

Methods

From January 2006 to June 2011, 18 cases of post-operative GEAL with mediastinal abscesses after oesophagectomy with intrathoracic oesophagogastric anastomotic procedures for oesophageal and cardiac carcinoma were treated by insertion of a nose drainage tube and nasojejunum feeding tube under fluoroscopic guidance. We evaluated the feasibility of two-tube insertion to facilitate leakage site closure and complete resolution of the abscess, and the patients’ nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube.

Results

The two tubes were placed successfully under fluoroscopic guidance in 18 patients (100%). The procedure time for two-tube insertion ranged from 20 to 40 min (mean 30 min). 17 patients (94%) achieved leakage site closure after two-tube insertion and had a good tolerance of two tubes in the nasal cavity. The serum albumin level was significant, increased from pre-enteral feeding (2.49±0.42 g dl−1) to the post-enteral feeding (3.58±0.47 g dl−1) via the feeding tube (p<0.001). The duration of follow-up ranged from 1 to 49 months (mean 19 months).

Conclusion

The insertion of nose tube drainage and a nasojejunum feeding tube under fluoroscopic guidance is safe, and it provides effective relief from mediastinal abscesses in GEAL after oesophagectomy. Moreover, our findings indicate that two-tube insertion may be used as a selective procedure to treat mediastinal abscesses in post-operative GEAL.

Advances in knowledge

Directive drainage of mediastinal abscesses in post-operative GEAL may be an effective treatment.
Patrocínio e Mecenato: ferramentas de enorme potencial para as empresas
Authors: Reis Ana Carla Fonseca , Santos Rubens da Costa
Published: July 2012

O Marketing apoiado em atividade de patrocínio e mecenato surge como uma nova tendência da mídia. Este artigo busca compreender as especificidades e similitudes dessas novas "ferramentas"', além de discutir os maiores desafios a elas associados.
Serviço pós-venda: a dimensão esquecida do Marketing
Authors: Abreu Claudia Buhamra
Published: July 2012

Tradicionalmente, o marketing tem negligenciado os serviços pós-venda. Sua preocupação sempre foi com as atividades que antecedem a venda de um produto, e com a venda propriamente dita. Hoje, essa visão está mudando. Ganha destaque o marketing de relacionamento, centrado nos serviços que podem ser oferecidos ao consumidor depois de efetuada a compra. Mas o conceito e a importância do serviço pós-venda ainda não foram devidamente internalizados pela maioria das organizações brasileiras. Ainda está longe o entendimento entre vendedores e compradores, depois de consumada a venda. E os relatórios anuais do Procon confirmam essa realidade.
O papel das organizações não-governamentais na cooperação internacional em saúde pública
Authors: Torronteguy Marco Aurélio Antas , Dallari Sueli Gandolfi
Published: July 2012

O presente artigo pergunta pela possibilidade de as ONGs atuarem na cooperação internacional sanitária e pelo modo como essa atuação é regulada. Primeiramente se apresenta a cooperação internacional e sua relação com a saúde pública. Então são referidos dados sobre a cooperação bilateral sanitária brasileira, nos quais se pode verificar o reconhecimento formal das ONGs como parceiras dos Estados. Isso permite refletir sobre o papel das ONGs na cooperação e se percebe que, embora o direito internacional legitime a atuação das ONGs, ele regula essa atuação de modo incipiente. Isso sugere importantes aspectos a serem aperfeiçoados na relação jurídica que as ONGs travam com Estados no campo da saúde pública.
Professores das primeiras séries do ensino fundamental e relações estabelecidas com o conhecimento
Authors: Penna Marieta Gouvêa de Oliveira
Published: July 2012

Este artigo apresenta análise realizada sobre as relações estabelecidas pelo professor com o conhecimento no exercício da docência, nas séries iniciais do ensino fundamental em escolas públicas. Foi possível verificar que as professoras entrevistadas estabelecem relação utilitária e superficial, seja com o conhecimento científico, seja com o conhecimento das disciplinas escolares, em decorrência de aprendizado ocorrido nos momentos de formação inicial ou de formação continuada e referido à sua aplicabilidade prática, bem como daquilo que o exercício docente proporciona e exige dos professores em sua lida cotidiana. Além disso, destaca-se a valorização de conhecimento adquirido com a experiência.
Trajetória de crescimento da economia brasileira e mudança estrutural de 1971 a 2008: uma interpretação a partir do framework space
Authors: Lamonica Marcos Tostes , Feijó Carmem Aparecida , Punzo Lionello F.
Published: July 2012

O objetivo do texto é analisar a trajetória de crescimento da economia brasileira dos anos de 1970 até 2008, considerando as flutuações do investimento e da produtividade como determinantes do comportamento dessa trajetória. Assim, identificamos e qualificamos diferentes fases ou caminhos de crescimento compondo a trajetória de longo prazo. O comportamento oscilatório dessa trajetória tem sido atribuído a conjecturas de várias naturezas; aqui enfatizaremos as mudanças nas políticas econômicas e seus efeitos sobre a estrutura produtiva via mudança estrutural induzida que repercute na dinâmica observada. Apoiados na visão kaldoriana e neo-schumpeteriana introduziremos o Framework Space como instrumento de análise da dinâmica da trajetória de crescimento econômico do Brasil.
Diferença entre span verbal e visual nos gêneros: estudo piloto
Authors: Sagrilo Mariana Cristina Pedrassa , Ferreira Tais de Lima
Published: July 2012

OBJETIVO: avaliar a memória de trabalho analisando a capacidade de retenção de estímulos auditivos (span verbal) e visuais (span visual) e estabelecer a relação com o gênero (masculino e feminino). MÉTODO: participaram deste estudo 20 crianças entre seis anos e cinco meses e sete anos, sendo 10 sujeitos do sexo masculino e 10 sujeitos do sexo feminino. Todos os sujeitos foram submetidos às provas de avaliação do span verbal e visual em ordem direta e inversa. RESULTADOS: apenas na prova de palavras dissílabas com fonologia semelhante e semântica diferente do span verbal, houve variância significante entre os gêneros. As crianças do sexo feminino apresentaram melhor desempenho em relação ao outro gênero, bem como maior capacidade de retenção de palavras dissílabas com fonologia e semântica diferentes. No span visual (ordem direta e inversa) as crianças do sexo masculino obtiveram melhor desempenho, apesar de não ter diferenças significantes. Em relação à idade não houve diferença de retenção de estímulos. CONCLUSÃO: as crianças do sexo feminino, neste estudo, apresentaram tendência à melhor desempenho do span verbal e as crianças do sexo masculino tendência a melhor desempenho no span visual. No entanto, o estudo é limitado devido ao reduzido número de participantes na amostra.
Tradução e adaptação cultural do Charing Cross Venous Ulcer Questionnaire - Brasil
Authors: Couto Renata Cardoso , Leal Flávia de Jesus , Pitta Guilherme Benjamin Brandão , Bezerra Rita de Cássia B. , Segundo Walmir S. S. , Porto Tatiana de Mendonça
Published: July 2012

CONTEXTO: A tradução e a adaptação cultural são etapas que permitirão que um instrumento criado em determinado idioma e cultura possa ser usado em outro contexto cultural. O Charing Cross Venous Ulcer Questionnaire (CCVUQ) é um questionário de qualidade de vida em portadores de úlceras venosas que para ser utilizado no Brasil é necessária a execução do processo de adaptação transcultural. OBJETIVO: Traduzir e adaptar culturalmente para a população brasileira o CCVUQ. MÉTODOS: O processo consistiu em duas traduções e duas retrotraduções realizadas por tradutores independentes, da avaliação das versões, seguida da elaboração de versão consensual e de pré-teste comentado. RESULTADOS: No processo de tradução, algumas palavras foram modificadas no seu aspecto literal. A análise posterior dos resultados do pré-teste apontou necessidades de modificações de alguns termos para melhor compreensão do respondente. O tempo médio de aplicação do questionário foi de 5 minutos e 23 segundos. CONCLUSÃO: A versão na língua portuguesa do Charing Cross Venous Ulcer Questionnaire foi traduzida e adaptada para uso na população brasileira.
Tratamento da síndrome de roubo de fístula arteriovenosa pela técnica de revascularização distal e ligadura arterial: relato de três casos
Authors: Polimanti Afonso César , Galego Sidnei José , Fürst Rafael Vilhena de Carvalho , Moraes Gabriela da Silveira , Barbosa Rafael Camacho da Silva , Silveira Sônia Regina , Kawhage Maria do Carmo Silva Neves , Correa João Antônio
Published: July 2012

Fístulas arteriovenosas para hemodiálise podem apresentar complicações a longo prazo. Entre as complicações mais raras, há a isquemia distal por síndrome de roubo. Os autores relataram a experiência de três casos de pacientes portadores de fístulas braquiocefálicas, em funcionamento por longo prazo e que evoluíram com isquemia crítica do membro, sem resposta com tratamento clínico. Com o intuito de tratar esta afecção e preservar o acesso vascular, optou-se pela realização da revascularização distal interposta por ligadura arterial. Devido à raridade dos casos, relatou-se a experiência e apresentou-se uma revisão de literatura.
Influence of sulphate source on Portland cement hydration
Authors: Tang Fulvio J. , Gartner Ellis M.
Published: July 2012

Synopsis

Cements were synthesized by blending a Type I low alkali Portland cement clinker with sulphate salts. A quantitative X-ray diffraction method was developed to measure the rate at which the C3A and C4AFphases in these cements were consumed in pastes hydrated at 23°C. The initial high rate of aluminate phase consumption was influenced significantly by the rate of solubility of the sulphate source, and especially the rate at which it released CaSO4 into solution. Interground gypsum was far more effective than interblended gypsum in controlling aluminate hydration. Better control of the initial aluminate hydration generally led to higher 28-day paste strengths.
The viscometric examination of cement pastes with interrupted helical impellers
Authors: Gill S. M. , Banfill P. F. G.
Published: July 2012

Synopsis

The use of an interrupted helical impeller is known to prevent the occurrence of sedimentation during viscometric examination of cement pastes up to a water/cement ratio of 1·0. This feature is used to advantage in the study of time-dependent structural changes. Tests on high alumina cement pastes show that turbulence is likely to occur at Reynolds numbers exceeding 13 which leads to errors in the quantitative determination of yield stress and plastic viscosity. Guidance on the selection of an impeller for a particular cement paste is given so that flow is non-turbulent and quantitative analysis of the flow curves is justified.
A study of the effects of saccharide retarders on Portland cement hydration using trimethylsilylation
Authors: Dunster A. M. , Parsonage J. R.
Published: July 2012

Synopsis

A structural and mechanistic study using trimethylsilylation to investigate the effects of saccharide retarders and starch on the formation of C-S-H gel showed that sucrose delayed hydration and setting. At a low concentration (1 m mol/li), however, an acceleration of initial set was observed. The onset of silicate anion condensation, calcium hydroxide precipitation, and final set occurred almost simultaneously once the poisoning effect of sucrose had been overcome. The superiority of cellobiose over sucrose as a retarder was attributed to its better calcium solubilizing ability, and the poor performance of starch was due to the low solubility of its alkaline degradation products. Although the kinetics of hydration are altered, the silicate anion distribution of C-S-H at a given degree of hydration is unaffected.
The role of microsilica in the alkali-aggregate reaction
Authors: Wei Xiaoling , Glasser F. P.
Published: July 2012

Mortars containing as reactive aggregates Pyrex, cristobalite and Thames valley sand have been modified by inclusion of microsilica. Their expansivity is correlated with pore fluid analyses, mercury intrusion porosimetry and microstructure, determined by electron microscopy. Afler 180 days, the chemistry of the pore fluid becomes very similar in all mortars made with reactive aggregates. Much transport of silica away from the aggregate occurs and is believed to exert a levelling effect on pore fiuid alkali contents. Microsilica curbs expansion over the first six months, but it is concluded that considerahle potential for further expansion exists. The presence of microsilica as well as a reactive aggregate decreases the effective water/reactive solid (cement + pozzolan) ratio, with the result that the mortars undergo self-dessication and cease to expand. In real situations, where water uptake may occur, dessication is unlikely to occur; differences in the availahility of water constitutes an important distinction between laboratory simulations and ‘real-life’ materials.
Polymerization of acrylamide in the presence of calcium sulphate hemihydrate: compressive strength and microstructure of the composite
Authors: Stav E. , Bentur A. , Kohn D. H.
Published: July 2012

In continuation of our study on the concurrent polymerization of acrylamide with the hydration of calcium sulphate hemihydrate to calcium sulphate dihydrate, the influence of the polymer on the compressive strength, porosity and on the microstructure of the composite products has been studied.
Carbonation, moisture and empty pores
Authors: Parrott L. J.
Published: July 2012

Carbonation was measured on cement pastes preconditioned and maintained at selected relative humidities. Specimens with a range of water/cement ratios were tested, and the effect of replacing Portland cement with pulverized fuel ash or ground granulated blastfurnace slag was investigated. Carbonation was characterized using a variety of techniques in parallel. The various techniques provided descriptions of carbonation that were generally, but not always, self-consistent. Carbonation under normal environmental conditions of carbon dioxide concentration and relative humidity was largely controlled by gas diffusion through the empty pores in the exposed surface layer. The relative carbonation performance for mixes with different pore structures was strongly dependent upon moisture conditions during carbonation; the more porous mixes carbonated rapidly at the higher relative humidities where reinforcing steel in carbonated concrete would be likely to corrode.
The reaction between cement and natural waters containing dissolved carbon dioxide
Authors: Cowie J. , Glasser F. P.
Published: July 2012

Water regimes are known to vary markedly in their aggressivity towards cement. It has long been appreciated that the damaging regimes are associated with the presence of dissolved CO2, Historial efforts to correlate cement performance with groundwater compositions are reviewed, especially in respect of CO2 behaviour, as functions of its ‘aggressive’ and ‘non-aggressive’ speciations. The basic physical chemistry of the relevant aqueous solutions is explored, leading to new definitions of aggressivity and a computer-based iterative method of solving the necessary equations. Interpretation of the results is complicated by the formation of passivating layers of CaCO3 and SiO2 (gel) at the cement-water interface. These factors are explored and ‘coverage mapping’ is developed as a guide to their likely protective value. The model is related to dynamic situations; for example, the process of crack reheating which can occur spontaneously in concrete.
Superplasticizers for Ciment Fondu. Part 1: Effects on rheological properties of fresh paste and mortar
Authors: Banfill P. F. G. , Gill S. M.
Published: July 2012

As part of a systematic investigation of their use with Ciment Fondu, the rheology of pastes containing three superplasticizers is reported. The effects were not as dramatic as those observed with Portland cements, and at low concentrations the yield values and plastic viscosities were higher than in pastes without admixture. However, at 0·6% and 1% (dry weight of cement) a sulphonated phenol formaldehyde resin reduced these parameters for long enough to be of practical use. A naphthalene-type resin was effective over a shorter time, but pastes containing a melamine-type resin stiffened too rapidly to be useful. The stiffening was generally less rapid at 5°C than at 20°C, and is attributed to the precipitation of alumina gel in the paste.
Total and external chemical shrinkage of low w/c ratio cement pastes
Authors: Justnes H. , Van Gemert A. , Verboven F. , Sellevold E. J.
Published: July 2012

Practical use of high performance concrete (w/c ≤ 0·40) has shown that it is sensitive to cracking at early ages. Based on a belief that early volume contraction due to chemical shrinkage is a driving force for cracking, experiments to determine total chemical shrinkage and external chemical shrinkage have been carried out on cement pastes in the w/c range 0·30-0·50 over a 48 h period, using two types of cements. Measurements of true external chemical shrinkage are very difficult to carry out because of the disturbance of bleeding. To avoid this, the samples were placed in very thin walled, elastic rubber containers and rotated continuously under water. The results show that the total chemical shrinkage was largely independent of w/c for the first 48 h, but occurred with a faster rate at lower w/c during the first 12 h. The external chemical shrinkage was equal to the total chemical shrinkage until it ‘flattened out’, demonstrating that a semi-rigid skeleton was established which led to empty contracting pores during further hydration (i.e. shrinkage). The ‘flattening out level’ (vol %) increased with decreasing w/c. Furthermore, the transition from fluid paste to semi-rigid skeleton was more gradual at lower water-to-cement ratios. It is proposed that both these effects of external chemical shrinkage indicate that high performance concrete is more sensitive to cracking at early ages under conditions of some degree of external restraint.
Peristaltic flow of a Jeffrey fluid in a rectangular duct having compliant walls
Authors: Nadeem S. , Riaz Arshad , Ellahi R.
Published: July 2012

In this article, the theoretical and mathematical study of peristaltic
transport of a Jeffrey fluid in a rectangular duct with compliant walls is
discussed. The constitutive equations are simplified under the implementation
of low Reynolds number and long wavelength approximations. The analytical
solution of the resulting equations is evaluated by Eigen function expansion
method. The graphical aspects of all the parameters of interest are also
analyzed. The graphs of velocity for two and three dimensional flow are
plotted. The trapping bolus phenomenon is also discussed though streamlines.
In-process measuring procedure for sub-100 nm structures
Authors: Zimmermann M. , Tausendfreund A. , Patzelt S. , Goch G. , Kieß S. , Shaikh M. Z. , Gregoire M. , Simon S.
Published: July 2012

Fast and nondestructive laser light scattering measurements characterize the quality of surfaces with sub-100 nm structures during the production process. The aim is to detect defective surface structures. The measurement procedure is based on a primary comparison of measured speckle patterns with a multitude of numerically calculated speckle patterns caused by defect-free and defective surface structures. The comparison shows characteristic light scattering effects, which have to be detected by the in-process measurement setup. An efficient rigorous algorithm, implemented on a graphics processing unit, calculates the scattered light intensity distributions within reasonable computing times. The measurements are performed with an angle resolved light scattering measurement setup. The measuring procedure is applied to zinc oxide nanograss surfaces.