bluuebunny/crossref_metadata_2025 huggingface dataset:
MECHANICAL OXIDATION OF MULTI-WALLED CARBON NANOTUBES AS A REPLACEMENT OF ACID OXIDATION METHOD
Authors: PANDEY PRIYANKA , MOHANTY SMITA , NAYAK SANJAY K.
Published: July 2014

In the present study, a candid approach using mechanical oxidation, for modification of multi-walled carbon nanotubes (CNTs) has been utilized, and its advantages over conventional acid oxidation methods have been established. Higher concentration of acidic groups was found in case of mechanically oxidized CNTs (i.e., McCNT) as compared to acid oxidized CNT (i.e., ACNT). Raman spectrum exhibited greater degree of transformation of sp2 carbon into sp3 carbon. X-ray diffraction (XRD) analysis revealed maintained crystalline organization in McCNT. The major finding of the study was that, the mechanical oxidation method can be used easily to replace the conventional acid treatment method. This is because in the mechanical oxidation crystalline organization of CNTs can be maintained, relatively higher number of acid groups can be incorporated, no loss to the mass of CNTs is allowed etc.
A SIMULATION STUDY ON THE PROCESS OF NICKEL FILLING INTO CARBON NANOTUBES
Authors: LIU BAI , LIU LIRUI , ZHAO ZHENYU
Published: July 2014

Carbon Nanotubes (CNTs) filled with metals can be used in capacitors, sensors, rechargeable batteries and so on. In this study, the process of Nickel filling into single wall CNTs was studied by molecular dynamics (MD) simulation. Three models consisting of Nickel atoms and CNTs were established. These models were cooled from 1500 K to 100 K to analyze the factors that influence the filling height, such as temperature, the force between Carbon and Nickel atoms, as well as CNTs diameter. The results showed that filling height increased as the temperature and the force between Carbon–Nickel atoms rised. Filling height reduced with the increasing diameter of CNTs.
Endogenous flow-induced superoxide stimulates Na/H exchange activity via PKC in thick ascending limbs
Authors: Hong Nancy J. , Garvin Jeffrey L.
Published: July 2014

Luminal flow stimulates Na reabsorption along the nephron and activates protein kinase C (PKC) which enhances endogenous superoxide (O2−) production by thick ascending limbs (TALs). Exogenously-added O2− augments TAL Na reabsorption, a process also dependent on PKC. Luminal Na/H exchange (NHE) mediates NaHCO3 reabsorption. However, whether flow-stimulated, endogenously-produced O2− enhances luminal NHE activity and the signaling pathway involved are unclear. We hypothesized that flow-induced production of endogenous O2− stimulates luminal NHE activity via PKC in TALs. Intracellular pH recovery was measured as an indicator of NHE activity in isolated, perfused rat TALs. Increasing luminal flow from 5 to 20 nl/min enhanced total NHE activity from 0.104 ± 0.031 to 0.167 ± 0.036 pH U/min, 81%. The O2− scavenger tempol decreased total NHE activity by 0.066 ± 0.011 pH U/min at 20 nl/min but had no significant effect at 5 nl/min. With the NHE inhibitor EIPA in the bath to block basolateral NHE, tempol reduced flow-enhanced luminal NHE activity by 0.029 ± 0.010 pH U/min, 30%. When experiments were repeated with staurosporine, a nonselective PKC inhibitor, tempol had no effect. Because PKC could mediate both induction of O2− by flow and the effect of O2− on luminal NHE activity, we used hypoxanthine/xanthine oxidase to elevate O2−. Hypoxanthine/xanthine oxidase increased luminal NHE activity by 0.099 ± 0.020 pH U/min, 137%. Staurosporine and the PKCα/β1-specific inhibitor Gö6976 blunted this effect. We conclude that flow-induced O2− stimulates luminal NHE activity in TALs via PKCα/β1. This accounts for part of flow-stimulated bicarbonate reabsorption by TALs.
Modification of persistent responses in medial prefrontal cortex during learning in trace eyeblink conditioning
Authors: Siegel Jennifer J.
Published: July 2014

Persistent spiking in response to a discrete stimulus is considered to reflect the active maintenance of a memory for that stimulus until a behavioral response is made. This response pattern has been reported in learning paradigms that impose a temporal gap between stimulus presentation and behavioral response, including trace eyeblink conditioning. However, it is unknown whether persistent responses are acquired as a function of learning or simply represent an already existing category of response type. This fundamental question was addressed by recording single-unit activity in the medial prefrontal cortex (mPFC) of rabbits during the initial learning phase of trace eyeblink conditioning. Persistent responses to the tone conditioned stimulus were observed in the mPFC during the very first training sessions. Further analysis revealed that most cells with persistent responses showed this pattern during the very first training trial, before animals had experienced paired training. However, persistent cells showed reliable decreases in response magnitude over the first training session, which were not observed on the second day of training or for sessions in which learning criterion was met. This modification of response magnitude was specific to persistent responses and was not observed for cells showing phasic tone-evoked responses. The data suggest that persistent responses to discrete stimuli do not require learning but that the ongoing robustness of such responses over the course of training is modified as a result of experience. Putative mechanisms for this modification are discussed, including changes in cellular or network properties, neuromodulatory tone, and/or the synaptic efficacy of tone-associated inputs.
Multiple Sclerosis: Current Knowledge and Future Outlook
Authors: Kamm Christian P. , Uitdehaag Bernard M. , Polman Chris H.
Published: July 2014

Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by demyelination and axonal loss. The etiology of MS is unknown; however, environmental and genetic factors play a key role in the development of MS. Diagnostic criteria have been adapted to facilitate earlier diagnosis with increased sensitivity and specificity. Our understanding of the pathophysiology of MS has deepened considerably in recent years, resulting in different therapies to modify the disease course. Furthermore, several drugs have lately shown efficacy in phase III studies and their approval is expected in the near future. As treatment options expand, a future challenge will be to find the optimal treatment for the individual patient. Summary: This mini-review gives an overview of the current knowledge of MS with emphasis on the latest diagnostic criteria and both current and upcoming treatment options. Key Messages: Treatment of MS changes rapidly as the knowledge and therapeutic options in MS expand. Clinical Impact: Diagnosis of MS is based on McDonald criteria. MS therapy can be divided into relapse, disease-modifying and symptomatic treatment. Relapses are commonly treated with intravenous methylprednisolone. First-line therapy consists of either interferon-β, glatiramer acetate or teriflunomide. In general, agents used as escalation therapies (natalizumab, fingolimod and mitoxantrone) are more potent than the agents used for first-line therapy; however, these have potentially serious side effects and should be used with care.
Prevalence of Lactose Intolerance in Chile: A Double-Blind Placebo Study
Authors: Latorre Gonzalo , Besa Pablo , Parodi Carmen G. , Ferrer Verónica , Azocar Lorena , Quirola Marife , Villarroel Luis , Miquel Juan F. , Agosin Eduardo , Chianale José
Published: July 2014

Background and Study Aims: Lactase non-persistence (LNP), or primary hypolactasia, is a genetic condition that mediates lactose malabsorption and can cause lactose intolerance. Here we report the prevalence of lactose intolerance in a double-blind placebo study. Methods: The LCT C>T-13910 variant was genotyped by RT-PCR in 121 volunteers and lactose malabsorption was assessed using the hydrogen breath test (HBT) after consuming 25 g of lactose. Lactose intolerance was assessed by scoring symptoms (SS) using a standardized questionnaire following challenge with a lactose solution or saccharose placebo. Results: The LNP genotype was observed in 57% of the volunteers, among whom 87% were HBT(+). In the HBT(+) group the median SS was 9 and in the HBT(-) group the median SS was 3 (p < 0.001). No difference was observed in the SS when both groups were challenged with the placebo. The most common symptoms included audible bowel sounds, abdominal pain and meteorism. In the ROC curve analysis, an SS ≥6 demonstrated 72% sensitivity and 81% specificity for predicting a positive HBT. To estimate prevalence, lactose intolerance was defined as the presence of an SS ≥6 points after subtracting the placebo effect and 34% of the study population met this definition. Conclusions: The LNP genotype was present in more than half of subjects evaluated and the observed prevalence of lactose intolerance was 34%.
iPS Cell–Derived Cardiogenicity is Hindered by Sustained Integration of Reprogramming Transgenes
Authors: Martinez-Fernandez Almudena , Nelson Timothy J. , Reyes Santiago , Alekseev Alexey E. , Secreto Frank , Perez-Terzic Carmen , Beraldi Rosanna , Sung Hoon-Ki , Nagy Andras , Terzic Andre
Published: July 2014

Background—

Nuclear reprogramming inculcates pluripotent capacity by which de novo tissue differentiation is enabled. Yet, introduction of ectopic reprogramming factors may desynchronize natural developmental schedules. This study aims to evaluate the effect of imposed transgene load on the cardiogenic competency of induced pluripotent stem (iPS) cells.

Methods and Results—

Targeted inclusion and exclusion of reprogramming transgenes (
c-MYC
,
KLF4
,
OCT4
, and
SOX2
) was achieved using a drug-inducible and removable cassette according to the piggyBac transposon/transposase system. Pulsed transgene overexpression, before iPS cell differentiation, hindered cardiogenic outcomes. Delayed in counterparts with maintained integrated transgenes, transgene removal enabled proficient differentiation of iPS cells into functional cardiac tissue. Transgene-free iPS cells generated reproducible beating activity with robust expression of cardiac α-actinin, connexin 43, myosin light chain 2a, α/β-myosin heavy chain, and troponin I. Although operational excitation–contraction coupling was demonstrable in the presence or absence of transgenes, factor-free derivatives exhibited an expedited maturing phenotype with canonical responsiveness to adrenergic stimulation.

Conclusions—

A disproportionate stemness load, caused by integrated transgenes, affects the cardiogenic competency of iPS cells. Offload of transgenes in engineered iPS cells ensures integrity of cardiac developmental programs, underscoring the value of nonintegrative nuclear reprogramming for derivation of competent cardiogenic regenerative biologics.
Constraining Transient Climate Sensitivity Using Coupled Climate Model Simulations of Volcanic Eruptions
Authors: Merlis Timothy M. , Held Isaac M. , Stenchikov Georgiy L. , Zeng Fanrong , Horowitz Larry W.
Published: July 2014

Coupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR; defined with the 1% yr−1 CO2-increase scenario) can be estimated from shorter-time-scale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes but is 5%–15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10 yr) time scales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure.

The response of the GMST to volcanic eruptions is similar in GFDL CM2.1 and GFDL Climate Model, version 3 (CM3), even though the latter has a higher TCR associated with a multidecadal time scale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.
All-Food-Seq (AFS): a quantifiable screen for species in biological samples by deep DNA sequencing
Authors: Ripp Fabian , Krombholz Christopher Felix , Liu Yongchao , Weber Mathias , Schäfer Anne , Schmidt Bertil , Köppel Rene , Hankeln Thomas
Published: July 2014

Background

DNA-based methods like PCR efficiently identify and quantify the taxon composition of complex biological materials, but are limited to detecting species targeted by the choice of the primer assay. We show here how untargeted deep sequencing of foodstuff total genomic DNA, followed by bioinformatic analysis of sequence reads, facilitates highly accurate identification of species from all kingdoms of life, at the same time enabling quantitative measurement of the main ingredients and detection of unanticipated food components.

Results

Sequence data simulation and real-case Illumina sequencing of DNA from reference sausages composed of mammalian (pig, cow, horse, sheep) and avian (chicken, turkey) species are able to quantify material correctly at the 1% discrimination level via a read counting approach. An additional metagenomic step facilitates identification of traces from animal, plant and microbial DNA including unexpected species, which is prospectively important for the detection of allergens and pathogens.

Conclusions

Our data suggest that deep sequencing of total genomic DNA from samples of heterogeneous taxon composition promises to be a valuable screening tool for reference species identification and quantification in biosurveillance applications like food testing, potentially alleviating some of the problems in taxon representation and quantification associated with targeted PCR-based approaches.
Altered regional homogeneity in experimentally induced low back pain: a resting-state fMRI study
Authors: Zhang Shan-shan , Wu Wen , Liu Zi-ping , Huang Guo-zhi , Guo Shi-gui , Yang Jian-ming
Published: July 2014

Background

Functional imaging studies have indicated that patients with low back pain can have significant reductions in cerebral cortex grey matter. However, the mechanisms governing the nociceptive pathways in the human brain are unclear. The aim of this study was to use functional magnetic resonance imaging (fMRI) and regional homogeneity (ReHo) to investigate changes in resting-state brain activity in subjects that experienced experimentally induced low back pain.

Methods

Healthy subjects (n = 15) underwent fMRI (3.0 T) at baseline and during painful stimulation (intramuscular injection of 3% hypertonic saline).

Results

Compared to the scans conducted at baseline, scans conducted during experimentally induced low back pain showed increased ReHo on the right side in the medial prefrontal cortex, precuneus, insula, parahippocampal gyrus and cerebellum (posterior lobe), but decreased ReHo in the primary somatosensory cortex, anterior cingulate cortex and parahippocampal gyrus on the left side. The right inferior parietal lobule also showed a decreased ReHo (P < 0.05, cluster threshold ≥10).

Conclusions

These findings suggest that abnormally spontaneous resting-state activity in some brain regions may be associated with pain processing. These changes in neural activity may contribute to the recognition, execution, memory and emotional processing of acute low back pain.
Laboratory determination of the complex conductivity tensor of unconventional anisotropic shales
Authors: Woodruff William F. , Revil André , Torres-Verdín Carlos
Published: July 2014

We developed a four-electrode acquisition system to measure the complex conductivity tensor of tight and anisotropic shale cores using an accurate impedance meter. The complex conductivity tensor was obtained by inverting complex electrical potential data (amplitude and phase) acquired over a distributed array of electrodes. Inversion of the acquired data was performed with a Markov chain Monte Carlo (McMC) sampler that can explicitly take into account the nonuniqueness of the inverse problem. This approach was validated with direct measurements of impedance tensor eigenvalues with a single-component measurement technique. Consistent results were obtained using these two methods validating those obtained through the McMC sampling strategy. Both the in-phase and quadrature conductivities were anisotropic with the same anisotropic ratio in agreement with a recently developed petrophysical model based on volume averaging. The type of anisotropy of the Bakken and Haynesville core samples was found to be transverse isotropic, with the anisotropic ratio on the order of 10. In-phase conductivity was found to be independent of frequency up to 100 Hz, while the magnitude of the quadrature conductivity increased with frequency in the range from 0.1 to 45 kHz. Both components were sensitive to water saturation. Surface conductivity could be reliably predicted from the quadrature conductivity in agreement with the model prediction. The relationship between surface and quadrature conductivities was independent on saturation and anisotropy.
The Altered Mononuclear Cell-Derived Cytokine Response to Glucose Ingestion Is Not Regulated by Excess Adiposity in Polycystic Ovary Syndrome
Authors: González Frank , Sia Chang Ling , Shepard Marguerite K. , Rote Neal S. , Minium Judi
Published: July 2014

Context:

Excess adipose tissue is a source of inflammation. Polycystic ovary syndrome (PCOS) is a proinflammatory state and is often associated with excess abdominal adiposity (AA) alone and/or frank obesity.

Objective:

To determine the effect of glucose ingestion on cytokine release from mononuclear cells (MNC) in women with PCOS with and without excess AA and/or obesity.

Design:

A cross-sectional study.

Setting:

Academic medical center.

Patients:

Twenty-three women with PCOS (seven normal weight with normal AA, eight normal weight with excess AA, eight obese) and 24 ovulatory controls (eight normal weight with normal AA, eight normal weight with excess AA, eight obese).

Intervention:

Three-hour 75-g oral glucose tolerance test (OGTT).

Main Outcome Measures:

Body composition was measured by dual energy x-ray absorptiometry. Insulin sensitivity was derived from the OGTT (ISOGTT). TNFα, IL-6, and IL-1β release was measured in supernatants of cultured MNC isolated from blood samples drawn while fasting and 2 hours after glucose ingestion.

Results:

Insulin sensitivity was lower in obese subjects regardless of PCOS status and in normal-weight women with PCOS compared with normal-weight controls regardless of body composition status. In response to glucose ingestion, MNC-derived TNFα, IL-6, and IL-1β release decreased in both normal-weight control groups but failed to suppress in either normal-weight PCOS group and in obese women regardless of PCOS status. For the combined groups, the cytokine responses were negatively correlated with insulin sensitivity and positively correlated with abdominal fat and androgens.

Conclusions:

Women with PCOS fail to suppress MNC-derived cytokine release in response to glucose ingestion, and this response is independent of excess adiposity. Nevertheless, a similar response is also a feature of obesity per se. Circulating MNC and excess adipose tissue are separate and distinct sources of inflammation in this population.
The Future of Reading? Memories and Thoughts toward a Genealogical Approach
Authors: Gumbrecht Hans Ulrich
Published: July 2014

Hans Ulrich Gumbrecht’s “The Future of Reading? Memories and Thoughts Toward a Genealogical Approach” asks a fundamental question: How does the younger generation of students and readers approach a text, and in which ways does their constant reading via one online device or another, as a ubiquitous electronic background activity, change their experience of interacting with the printed word? Gumbrecht bases his observations on two seminars that he taught in Santiago de Chile in 2013, in which Stanford undergraduates were reading fiction and nonfiction texts in both English and Spanish. While he notes that today’s younger readers possess breathtaking agility in identifying the key subject matters and problems of a text, he found their way of interacting with a text “endlessly puzzling.” Against a backdrop of the various methods and theories of reading from the past decades (e.g., deconstructive, cultural, hermeneutic), Gumbrecht asks what it means to have “everything always at hand” via various electronic forms of communication. If, for example, classic texts are those that have maintained their freshness and immediacy against the erosion of time, how is the electronic revolution, which makes the cultures and literatures of any time accessible to us, changing the “reading culture” of the younger generations? The questions and the argument developed in this essay go back to my contribution, on October 17, 2011, to the lecture series “How I Think about Literature,” in the Division of Literatures, Cultures, and Languages, at Stanford University.
Assessment of Hedley’s Sequential Extraction Method for Phosphorus Forms in Biosolids Using P K-edge X-ray Absorption Near-edge Structure Spectroscopy
Authors: Takamoto Akira , Hashimoto Yohey
Published: July 2014

We determined P species in biosolids and their residues after applying Hedley’s sequential extractions using P K-edge X-ray absorption near-edge structure (XANES) spectroscopy. HCl extraction successfully removed P associated with Ca minerals from the biosolids. The majority of P associated with Fe minerals (FeP) was extracted by the NaOH fluid. However, recalcitrant FeP phases remained persistent even after the final extraction process, suggesting that NaOH-extracted P fractions may be underestimated in biosolids with abundant Fe. The XANES technique is essential to identify secondary P phases in biosolids, which could not be detected by an XRD technique.
A rare case: Vena cava inferior agenesis with aberrant hepatic vein in an asymptomatic patient
Authors: Karasu S. , Demir R. O. , Apaydin M. , Erdogan N. K. , Oyar O. , Kalayci T. O.
Published: July 2014

Inferior vena cava agenesis is a rare anomaly in an asymptomatic patient. A 58-year-old female patient with complete absence of the inferior vena cava and aberrant right hepatic vein is presented with radiologic findings. To our best knowledge, such a combination of venous anomalies has not previously been documented in the literature and this is the first case in the literature due to the coincidence of total inferior vena cava agenesis with aberrant hepatic vein.
Long-term results after radiofrequency ablation in 1998
Authors: Brunner A. , Noppeney J. , Noppeney T.
Published: July 2014

Introduction: In 1998, radiofrequency ablation (VNUS Closure Plus™) was authorised in Germany and Europe for the treatment of superficial reflux. We participated in a clinical registry set up by the manufacturing company in 1998. The aim of this retrospective paper was to analyse the long-term results after radiofrequency ablation.

Materials, methods and patients: In 1998, we operated on twelve patients (8 women, 4 men). In accordance with the concept of standard vein stripping surgery, all endovenous ablations were combined with crossectomy or ligature of the saphenopopliteal junction. Each vein was thermally ablated over its entire length and no tumescent anaesthesia was performed. The mean age of the twelve patients was 44.9 years. On ten occasions, the entire length of the great saphenous vein was treated, on one occasion the great saphenous vein at the level of the lower leg and on one occasion the entire length of the small saphenous vein. The mean duration of surgery was 80 minutes.

Results: The follow-up period was 3 to 168 months, with a mean duration of 80 months. Six patients were followed up for longer than 120 months. In eight cases, the follow-up examination was performed using duplex ultrasound, in two cases using clinical examination and non-invasive testing, in one case using clinical examination and in one case via a telephone interview.

The most frequent perioperative complication, occurring in six cases, was hypaesthesia at the medial malleolus or lower leg. There was one case of perioperative thrombophlebitis of a lateral branch in the lower leg and one case of a third-degree thigh burn with subsequent infection of the great saphenous vein canal. No deep vein thrombosis or pulmonary embolism occurred in any of the operated patients.

Of the eleven great saphenous veins treated, one recanalised after 14 months, the others had closed or were no longer detectable on ultrasound. The small saphenous vein treated was also no longer detectable.

In one patient, a major recurrence at the saphenofemoral junction with recurrent lateral branches in the thigh and lower leg were determined 168 months after surgery. No recurrent varicosis was determined in the other patients.
Genital lymphoedema as an early symptom of a signet-ring cell carcinoma
Authors: Uhlemann H. , Hirsch T.
Published: July 2014

Ein 51-jähriger Mann stellt sich wegen eines rasch progredienten Bein- und Genitallymphödems vor. Die komplexe physikalische Entstauung bleibt ohne Erfolg. Nach ergebnisloser Bildgebung wird in der endoskopischen Exploration ein metastasierendes Siegelring-Karzinom der Kardia als Ursache nachgewiesen.
El enfoque del buen vivir como una visión colectiva
Authors: Ávila Larrea Javier Alejandro
Published: July 2014

El problema presente en la actual sociedad es la excesiva valoración que se le otorga a su dimensión económica y su bienestar se mide en base a tal aspecto; por lo cual hemos visto la necesidad de proponer un bienestar colectivo que sea medido a través de la integración de distintas dimensiones y rescatando lo específico de cada territorio. En cuanto al aspecto metodológico, la elección de un “diseño flexible” nos ha permitido la elección del territorio específico de investigación (Nabón), en el cual se realizaron análisis estadísticos que responden a un enfoque mixto de variables subjetivas como objetivas.
Quando la Generazione Erasmus incontra la Generazione Precaria. La mobilità transnazionale dei giovani italiani e spagnoli
Authors: Raffini Luca
Published: July 2014

Uno dei più importanti risultati del processo di integrazione europea è la costruzione di uno spazio transnazionale in cui i cittadini europei possono muoversi liberamente. La mobilità favorisce dinamiche di europeizzazione dal basso –o di europeizzazione orizzontale–, e lo sviluppo di pratiche cross-nazionali e amplia le risorse individuali e relazionali a disposizione dei giovani per progettare i propri percorsi professionali e di vita. La Generazione Erasmus definisce giovani socializzati a un humus culturale transnazionale e fortemente identificati con l’Europa. Nell’attuale contesto di crisi economica, a sperimentare la mobilità sono sempre più i giovani altamente qualificati dei paesi dell’Europa del sud, quale strategia individuale cui ricorrere per trovare risposta ai problemi connessi alla precarietà, alla disoccupazione, alla sotto-qualificazione degli impieghi. Il risultato è che la mobilità può assumere il volto di un obbligo, più che di una scelta e, più che dinamiche di europeizzazione orizzontale, può favorire una “fuga dei cervelli” dai paesi del sud ai paesi del centro e del nord Europa. L’articolo, focalizzandosi sui giovani italiani e spagnoli, si chiede cosa succede quando la Generazione Erasmus incontra la Generazione Precaria, analizzando cause ed effetti della mobilità, sul piano micro e macro sociale e sul piano politico.
Drug-resistant Tuberculosis
Authors: Taylor Jessica M. , Davidson Rebecca M. , Strong Michael
Published: July 2014

Tuberculosis (TB) continues to be a serious global health problem, resulting in >1.4 million deaths each year. Of increasing concern is the evolution of antibiotic-resistant strains of the bacterium that causes TB. Using this real-world scenario, we created a 90-minute activity for high school or undergraduate students to use online bioinformatics tools to detect single-nucleotide polymorphisms (SNPs) between a wild-type and a variant Mycobacterium tuberculosis gene that could confer resistance to a commonly used TB antibiotic, rifampin. Students write a scientific explanation, providing evidence and reasoning, to support their claim of antibiotic resistance or susceptibility. The entire lesson can be found online at http://www.stronglab.org/taylor.
CRITICAL CARE ECHO ROUNDS: Haemodynamic instability
Authors: Roshdy Ashraf , Francisco Nadia , Rendon Alejandro , Gillon Stuart , Walker David
Published: July 2014

The use of echocardiography, whilst well established in cardiology, is a relatively new concept in critical care medicine. However, in recent years echocardiography's potential as both a diagnostic tool and a form of advanced monitoring in the critically ill patient has been increasingly recognised. In this series of Critical Care Echo Rounds, we explore the role of echocardiography in critical illness, beginning here with haemodynamic instability. We discuss the pathophysiology of the shock state, the techniques available to manage haemodynamic compromise, and the unique role which echocardiography plays in this complex process.

Case:

A 69-year-old female presents to the emergency department with a fever, confusion and pain on urinating. Her blood pressure on arrival was 70/40, with heart rate of 117 bpm Despite 3 l of i.v. fluid she remained hypotensive. A central venous catheter was inserted and noradrenaline infusion commenced, and she was admitted to the intensive care unit for management of her shock state. At 6 h post admission, she was on high dose of noradrenaline (0.7 μg/kg per min) but blood pressure remained problematic. An echocardiogram was requested to better determine her haemodynamic state.
Difficulties of genetic counselling in rare, mainly neurogenetic disorders
Authors: Horváth Emese , Nagy Nikoletta , Széll Márta
Published: July 2014

Introduction: In recent decades methods used for the investigation of the genetic background of rare diseases showed a great improvement. Aim: The aim of the authors was to demonstrate difficulties of genetic counselling and investigations in case of five rare, mainly neurogenetic diseases. Method: During pre-test genetic counselling, the disease suspected from the clinical symptoms and the available genetic tests were considered. During post-test genetic counselling, the results of the genetic tests were discussed. Results: In three of the five cases genetic tests identified the disease-causing genetic abnormalities, while in two cases the causative abnormalities were not identified. Conclusions: Despite a great improvement of the available genetic methods, the causative genetic abnormalities cannot be identified in some cases. The genetic counsellor has a key role in the assessment and interpretation of the results and in helping the family planning. Orv. Hetil., 2014, 155(31), 1221–1227.
Is there any progress in the blood glucose lowering therapy of type 2 diabetes?
Authors: Winkler Gábor
Published: July 2014

Principles of glycemic treatment of type 2 diabetes are well outlined for a long time, however, emphasis of therapeutic strategies and treatment guidelines are continuously changing partially due to the continuous expansion of the available antihyperglycemic drugs. This article overviews the modifications of the drug selection arising from the broadening of the pathogenetic knowledge and recent therapeutic guidelines. It presents the role of the patient-centered approach in the therapeutic choice, highlights occasional contradictions between recent international and national guidelines and financing rules in Hungary. While consideration of the different antidiabetics by the same criteria and the choice of the most appropriate drug characterize international practice, prescription of certain compounds is often restricted by financial rules in Hungary. Orv. Hetil., 2014, 155(31), 1215–1220.
Transmission electron microscopy analysis of secondary phases in Cu2ZnSnS4 thin film solar cells
Authors: Li Wei , Liu Ziheng , Chen Jian , Liu Fangyang , Hao Xiaojing
Published: July 2014

Secondary phases are likely to occur in the Cu2ZnSnS4 (CZTS) films since the CZTS is thermodynamically stable in only a narrow region of the phase diagram. The CZTS solar cell performance can be influenced by the existence and precipitated position of secondary phases. Therefore, locally investigate the distribution of secondary phases is important to further improve CZTS solar cell efficiency. In this study, two different kinds of transmission electron microscopy imaging techniques, bright field scanning TEM image (BF-STEM) and High-angle annular dark-field (HAADF) image, are applied to analyze the distribution of secondary phases. Due to the atomic number differences between CZTS and secondary phases, secondary phases are evident in the HAADF images. Therefore, HAADF image is a more powerful and convenient method to analyze the secondary phases than the BF-STEM image.
Radiolarian biodiversity dynamics through the Triassic and Jurassic: implications for proximate causes of the end-Triassic mass extinction
Authors: Kocsis Ádám T. , Kiessling Wolfgang , Pálfy József
Published: July 2014

Within a ∼60-Myr interval in the Late Triassic to Early Jurassic, a major mass extinction took place at the end of Triassic, and several biotic and environmental events of lesser magnitude have been recognized. Climate warming, ocean acidification, and a biocalcification crisis figure prominently in scenarios for the end-Triassic event and have been also suggested for the early Toarcian. Radiolarians, as the most abundant silica-secreting marine microfossils of the time, provide a control group against marine calcareous taxa in testing selectivity and responses to changing environmental parameters. We analyzed the origination and extinction rates of radiolarians, using data from the Paleobiology Database and employing sampling standardization, the recently developed gap-filler equations and an improved stratigraphic resolution at the substage level. The major end-Triassic event is well-supported by a late Rhaetian peak in extinction rates. Because calcifying and siliceous organisms appear similarly affected, we consider global warming a more likely proximate trigger of the extinctions than ocean acidification. The previously reported smaller events of radiolarian turnover fail to register above background levels in our analyses. The apparent early Norian extinction peak is not significant compared to the long-term trajectory, and is probably a sampling artifact. The Toarcian Oceanic Anoxic Event, previously also thought to have caused a significant radiolarian turnover, did not significantly affect the group. Radiolarian diversity history appears unique and complexly forced, as its trajectory parallels major calcareous fossil groups at some events and deviates at others.
Forest stand structure, productivity, and age mediate climatic effects on aspen decline
Authors: Bell David M. , Bradford John B. , Lauenroth William K.
Published: July 2014

Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand‐scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing‐season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.
Demography linked to climate change projections in an ecoregional case study: integrating forecasts and field data
Authors: Mclaughlin B. C. , Morozumi C. N. , MacKenzie J. , Cole A. , Gennet S.
Published: July 2014

Anticipating species movement under climate change is a fundamental concern in 21st century conservation. For blue oak (Quercus douglasii), an endemic, flagship species in California, we modeled potential responses to future climate, then tested the fit of those projections to empirical field data from natural populations. Specifically, we tested how well species forecasts captured observed recruitment and adult tree mortality, and whether recruitment was structured spatially as a function of fine‐scale micro‐topographic and hydrologic environments. In this ecoregional case study, observed demographic patterns were broadly consistent with theoretical expectations. Adult survivorship was three times lower in areas forecasted to be least suitable as a result of climate change than in areas projected to become suitable. This novel field validation exercise documents patterns of adult tree mortality consistent with model predictions of an emergent shift in distribution. Seedlings and saplings showed evidence of spatial structuring into local refugia in areas projected to contract, suggesting that climate change may reshape how blue oak associates with California landscapes and highlighting the potential importance of micro‐environmental diversity in enhancing species resilience to warming.
Modelling uncertainty of flood quantile estimations at ungauged sites by Bayesian networks
Authors: Santillán D. , Mediero L. , Garrote L.
Published: July 2014

Prediction at ungauged sites is essential for water resources planning and management. Ungauged sites have no observations about the magnitude of floods, but some site and basin characteristics are known. Regression models relate physiographic and climatic basin characteristics to flood quantiles, which can be estimated from observed data at gauged sites. However, some of these models assume linear relationships between variables and prediction intervals are estimated by the variance of the residuals in the estimated model. Furthermore, the effect of the uncertainties in the explanatory variables on the dependent variable cannot be assessed. This paper presents a methodology to propagate the uncertainties that arise in the process of predicting flood quantiles at ungauged basins by a regression model. In addition, Bayesian networks (BNs) were explored as a feasible tool for predicting flood quantiles at ungauged sites. Bayesian networks benefit from taking into account uncertainties thanks to their probabilistic nature. They are able to capture non-linear relationships between variables and they give a probability distribution of discharge as a result. The proposed BN model can be applied to supply the estimation uncertainty in national flood discharge mappings. The methodology was applied to a case study in the Tagus basin in Spain.
Diagnostic value of combined magnetic resonance imaging examination of brachial plexus and electrophysiological studies in multifocal motor neuropathy
Authors: Basta Ivana , Nikolic Ana , Apostolski Slobodan , Lavrnic Slobodan , Stosic-Opincal Tatjana , Banjalic Sandra , Knezevic-Apostolski Sladjana , Ilic Tihomir , Marjanovic Ivan , Milicev Milena , Lavrnic Dragana
Published: July 2014

Background/Aim. Multifocal motor neuropathy (MMN) is an immune-mediated
disorder characterized by slowly progressive asymetrical weakness of limbs
without sensory loss. The objective of this study was to investigate the
involvement of brachial plexus using combined cervical magnetic stimulation
and magnetic resonance imaging (MRI) of plexus brachialis in patients with
MMN. We payed special attention to the nerve roots forming nerves inervating
weak muscles, but without detectable conduction block (CB) using conventional
nerve conduction studies. Methods. Nine patients with proven MMN were
included in the study. In all of them MRI of the cervical spine and brachial
plexus was performed using a Siemens Avanto 1.5 T unit, applying T1 and turbo
spinecho T1 sequence, axial turbo spin-echo T2 sequence and a coronal
fat-saturated turbo spin-echo T2 sequence. Results. In all the patients
severe asymmetric distal weakness of muscles inervated by radial, ulnar,
median and peroneal nerves was observed and the most striking presentation
was bilateral wrist and finger drop. Three of them had additional proximal
weakness of muscles inervated by axillar and femoral nerves. The majority of
the patients had slightly increased cerebrospinal fluid (CSF) protein
content. Six of the patients had positive serum polyclonal IgM anti-GM1
antibodies. Electromyoneurography (EMG) showed neurogenic changes, the most
severe in distal muscles inervated by radial nerves. All the patients had
persistent partial CBs outside the usual sites of nerve compression in
radial, ulnar, median and peroneal nerves. In three of the patients cervical
magnetic stimulation suggested proximal CBs between cervical root emergence
and Erb?s point (prolonged motor root conduction time). In all the patients
T2-weighted MRI revealed increased signal intensity in at least one cervical
root, truncus or fasciculus of brachial plexus. Conclusion. We found clinical
correlation between muscle weakness, prolonged motor root conduction time and
MRI abnormalities of the brachial plexus, which was of the greatest
importance in the nerves without CB inervating weak muscles.
Dr. Stefan Nedok (1828-1878), Medical Corps Major, the First Head of the Internal Department of the Belgrade Military Hospital, the Head of Medical Services of the Division and Corps in wars with Turkey (1876 and 1877-78)
Authors: Nedok Aleksandar
Published: July 2014

nema
Evaluating Methods for Intersectoral Comparison of Quality of Care
Authors: Ohlmeier C. , Linder R. , Enders D. , Mikolajczyk R. , Haverkamp W. , HorenkampSonntag D. , Garbe E.
Published: July 2014

Objectives: To compare the quality of care regarding the use of elective percutaneous coronary interventions (PCIs) in the inpatient and outpatient setting and to evaluate different methods of confounder control in this context.

Methods: Based on data of three statutory health insurances including more than nine million insurance members, a retrospective cohort study between 2005 and 2009 was conducted. The occurrence of myocardial infarction, stroke, further coronary intervention and death was ascertained following the first PCI in the study period, which was preceded by a one-year period without a PCI. A Cox proportional hazard model was used to assess the influence of the setting of the elective PCI on the risk for complications after the PCI for each outcome separately. Age, sex, the number of diseases of the Elixhauser comorbidity measure, past acute coronary syndrome, coronary artery disease, dyslipidemia, past stroke, past coronary artery bypass surgery and the year of the PCI were included as covariables. The analyses were repeated in a propensity score matched cohort as well as in inverse probability of treatment weighted analyses.

Results: The cohort comprised 4,269 patients with an outpatient PCI and 26,044 patients with an inpatient PCI. The majority of the analyses revealed no statistically significant effect of the setting of the PCI on the risk of myocardial infarction, stroke and further coronary interventions, whereas a reduced mortality risk was observed for out-patient PCIs. Similar results were obtained in the propensity score analyses.

Conclusions: The analysis revealed that the adjusted risk for complications following an elective PCI is similar between the inpatient and the outpatient setting. For mortality the risk differed but this might be explained by residual or unmeasured confounding. The different methods applied in this study revealed mostly similar results. Since our study only covered one aspect of quality of care in the field of PCI and did not consider drug treatment in hospital or in the outpatient setting, further studies are needed which include these aspects.
Fringe structures and tunable bandgap width of 2D boron nitride nanosheets
Authors: Feng Peter , Sajjad Muhammad , Li Eric Yiming , Zhang Hongxin , Chu Jin , Aldalbahi Ali , Morell Gerardo
Published: July 2014

We report studies of the surface fringe structures and tunable bandgap width of atomic-thin boron nitride nanosheets (BNNSs). BNNSs are synthesized by using digitally controlled pulse deposition techniques. The nanoscale morphologies of BNNSs are characterized by using scanning electron microscope (SEM), and transmission electron microscopy (TEM). In general, the BNNSs appear microscopically flat in the case of low temperature synthesis, whereas at high temperature conditions, it yields various curved structures. Experimental data reveal the evolutions of fringe structures. Functionalization of the BNNSs is completed with hydrogen plasma beam source in order to efficiently control bandgap width. The characterizations are based on Raman scattering spectroscopy, X-ray diffraction (XRD), and FTIR transmittance spectra. Red shifts of spectral lines are clearly visible after the functionalization, indicating the bandgap width of the BNNSs has been changed. However, simple treatments with hydrogen gas do not affect the bandgap width of the BNNSs.
Technology and Products Supporting E-learning by Knowledge Management - A Review
Authors: Wang Ying
Published: July 2014

Abstract—Knowledge management is supported by many strategies such as business intelligence, collaboration, document management and e-learning. With the development of modern information technology and the increases of demand for building and maintaining dynamic capabilities, E-learning has played more and more important role of all the technologies in the supporting knowledge management. A successful e-learning system is supported by many critical success factors and technology has become the key factor among these factors. Consequently, the review of basic technologies and corresponding products that support e-learning will be in favor of further study on e-learning. From perspective of knowledge management, this paper makes a review about the relationship between e-learning and knowledge management and advanced technologies and corresponding products that support the design and operation of e-learning system. At the end of this paper, we analyze the main trends of the development direction of e-learning technology.