LLukas22/scidocs huggingface dataset:
Synthesis of amphiphilic graphene nanoplatelets.

Graphene, a flat monolayer of carbon atoms tightly packed into a two-dimensional honeycomb lattice, has attracted a great deal of attention in recent years for potential applications in many technological fields, such as nanoelectronics, nanocomposites, and hydrogen supercapacitors. One possible route to harnessing these properties would be to incorporate graphene sheets into composite materials. The manufacturing of such composites requires not only that the graphene sheets are produced on a sufficient scale, but also that they are incorporated, and homogeneously distributed, into various matrices. Graphite, which consists of a stack of flat graphene sheets, is available in large quantities from natural sources. It is likely the most readily available and least expensive source for the production of bulk graphene sheets. Graphite oxide (GO) is a layered material produced by the oxidation of graphite. In contrast to pristine graphite, the graphene-derived sheets in GO are heavily oxygenated and bear hydroxyl and epoxide functional groups on their basal planes, in addition to carbonyl and carboxyl groups located at the sheet edges. Unfortunately, owing to their hydrophilic nature, graphene oxide sheets can only be dispersed in aqueous media that are incompatible with most organic solvents and polymers. In addition, GO is electrically insulating, which limits its usefulness for the synthesis of composites. However, it has been demonstrated that the electrical conductivity of GO can be significantly increased and very thin graphene-like sheets can be obtained through the chemical reduction of exfoliated GO. Just like carbon nanotubes, a key challenge in the synthesis and processing of bulk-quantity graphene sheets is aggregation. Graphene sheets, due to their high specific surface area, tend to form irreversible agglomerates or even restack to form graphite through van der Waals interactions. As with carbon nanotubes, full utilization of graphene sheets in polymer nanocomposite applications will inevitably depend on their ability to achieve complete dispersion in the polymer matrix of choice.
Haemodynamic interactions of a new calcium sensitizing drug levosimendan and captopril

Objective: Levosimendan in a new inodilator drug that sensitises troponin C in heart muscle cells to calcium, thus improving contractility. In previous studies, a single 2 mg intravenous dose of levosimendan increased cardiac output (CO) in healthy volunteers by about 40% and decreased pulmonary capillary wedge pressure in heart failure patients by 40–50%. The aim of the present, double-blind study was to evaluate the safety of concomitant use of levosimendan and an ACE-inhibiting drug. Methods: The haemodynamic effects of levosimendan, given with or without captopril, were evaluated by using 2-dimensional echocardiography, repeated blood pressure measurements and by ambulatory ECG recordings. Twenty-four male patients with stable NYHA II-III heart failure (EF<40%) after a previous myocardial infarct were given, in randomised order, a single IV infusion of levosimendan or placebo. The infusions were repeated after 2 weeks treatment with upto 50 mg b.i.d. of captopril. Twelve patients received levosimendan 1 mg and twelve received 2 mg. Results: Mean CO was increased from 6.0 to 6.81·min−1 in patients receiving 1 mg levosimendan compared to placebo, but only from 6.3 to 6.51·min−1 in patients receiving 2 mg. The increase in CO was statistically significant when all levosimendan patients were compared to placebo. Heart rate did not change after either dose. Mean stroke volume increased significantly after 1 mg but not after 2 mg of levosimendan. The addition of captopril did not change the effects of levosimendan. No additional decrease in systolic or diastolic blood pressure was observed when levosimendan and captopril were given concomitantly. Conclusion: It seems that concomitant treatment with captopril does not change the haemodynamic effects of levosimendan. No adverse haemodynamic interactions were seen.
Availability of pediatric services and equipment in emergency departments: United States, 2006.

OBJECTIVES
This report presents data on the availability of pediatric services, expertise, and supplies for treating pediatric emergencies in U.S. hospitals.


METHODS
Data in this report are from the Emergency Pediatric Services and Equipment Supplement (EPSES), a self-administered questionnaire added to the 2006 National Hospital Ambulatory Medical Care Survey (NHAMCS). NHAMCS samples nonfederal short-stay and general hospitals in the United States. Sample data were weighted to produce annual estimates of pediatric services, expertise, and equipment availability in hospital emergency departments (EDs).


RESULTS
In 2006, only 7.2 percent of hospital EDs had all recommended pediatric emergency supplies, and 45.6 percent had at least 85.0 percent of recommended supplies. EDs in children's hospitals and hospitals with pediatric intensive care units (PICUs) were more likely to meet guidelines for pediatric emergency department services, expertise, and supplies. About 74.0 percent of these facilities had at least 85.0 percent of recommended supplies, compared with 42.4 percent of other facilities. Among children's hospitals and hospitals with PICUs, 66.0 percent had 24 hours a day, 7 days a week access to a board-certified pediatric emergency medicine attending physician; such access was uncommon in other types of hospitals. In general, little change was noted in the availability of emergency pediatric supplies between 2002-2003, when the initial EPSES was conducted, and 2006.
Tradeoffs in Neural Variational Inference Thesis

Humans understand the world on an operational and causal level, allowing us to make accurate predictions about the consequences of our actions, and enabling us to plan. What would it take to endow artificial intelligence with similar capabilities? An important component is the ability to learn from observations, that is, to translate data into a model that has a higher level representation. Such representation abstracts away irrelevant variation but preserves important characteristics of the observation, thus enabling data-efficient learning for recognition, classification, and causal modeling. In machine learning, the field of unsupervised learning addresses the challenge of learning models from observations. One recent advancement in this field has been the development of Variational Auto-Encoders (VAE) ([31], [54]). Since its inception, there have been several suggested improvements. While these works compare their results to the original VAE work, a thorough comparison between these improvements is lacking. In this work, we present a thorough comparison between several selected improvements. We compare the variational log likelihood between these models on three datasets of varying complexity: MSRC-12 ([19]), MNIST ([37]), and celebA ([39]). While variational lower bounds are often presented, most work often neglects to discuss model complexity and the associated training times and convergence rates. We compare the modeling times for these various approaches to provide practical guidelines regarding the trade-offs between the variational lower bound achieved and the run time required for training. Finally, we contribute an extensive code repository implementing these state of the art machine learning techniques on the datasets mentioned. These are developed using the Chainer ([66]) framework. These implemented models are also available for use on other datasets.
Substitution Matrices of Residue Triplets Derived from Protein Blocks

In protein sequence alignment, residue similarity is usually evaluated by substitution matrix, which scores all possible exchanges of one amino acid with another. Several matrices are widely used in sequence alignment, including PAM matrices derived from homologous sequence and BLOSUM matrices derived from aligned segments of BLOCKS. However, most matrices have not addressed the high-order residue-residue interactions that are vital to the bio-properties of protein. With consideration for the inherent correlation in residue triplet, we present a new scoring scheme for sequence alignment. Protein sequence is treated as overlapping and successive 3-residue segments. Two edge residues of a triplet are clustered into hydrophobic or polar categories, respectively. Protein sequence is then rewritten into triplet sequence with 2 x 20 x 2 = 80 alphabets. Using a traditional approach, we construct a new scoring scheme named TLESUM(hp) (TripLEt SUbstitution Matrices with hydrophobic and polar information) for pairwise substitution of triplets, which characterizes the similarity of residue triplets. The applications of this matrix led to marked improvements in multiple sequence alignment and in searching structurally alike residue segments. The reason for the occurrence of the "twilight zone," i.e., structure explosion of low identity sequences, is also discussed.
An Ontology-based Adaptive Personalized E-learning System, Assisted by Software Agents on Cloud Storage

E-Learning and online education have made great strides in the recent past. It has moved from a knowledge transfer model to a highly intellect, swift and interactive proposition capable of advanced decision-making abilities. Two challenges have been observed during the exploration of recent developments in e-learning. Firstly, to incorporate e-learning systems effectively in the evolving semantic web environment and secondly, to realize adaptive personalization according to the learner's changing behaviour. An ontology-driven system has proposed to implement the Felder-Silverman learning style model in addition to the learning contents, to validate its integration with the semantic web environment. Software agents are employed to monitor the learner's actual learning style and modify them accordingly. The learner's learning style and their modifications are made within the proposed e-learning system. Cloud storage is used as the primary back-end in order to maintain the ontology, databases and other required server resources. To verify the system, comparisons are made between the information presented and adaptive learning styles of the learner along with actions of agents according to learners' behaviour. Finally, various conclusions are drawn by exploring the learner’s behavior in an adaptive environment for the proposed e-learning system. Keywords—e-learning, ontology, semantic web, cloud storage, software agents, adaptive.
An e-health intervention designed to increase workday energy expenditure by reducing prolonged occupational sitting habits.

BACKGROUND
Desk-based employees face multiple workplace health hazards such as insufficient physical activity and prolonged sitting.


OBJECTIVE
The objective of this study was to increase workday energy expenditure by interrupting prolonged occupational sitting time and introducing short-bursts of physical activity to employees' daily work habits.


METHODS
Over a 13-week period participants (n=17) in the intervention group were regularly exposed to a passive prompt delivered through their desktop computer that required them to stand up and engage in a short-burst of physical activity, while the control group (n=17) was not exposed to this intervention. Instead, the control group continued with their normal work routine. All participants completed a pre- and post- intervention survey to estimate workplace daily energy expenditure (calories).


RESULTS
There was a significant 2 (Group) × 2 (Test) interaction, F (1, 32)=9.26, p < 0.05. The intervention group increased the calories expended during the workday from pre-test (M=866.29 ± 151.40) to post-test (M=1054.10 ± 393.24), whereas the control group decreased calories expended during the workday from pre-test (M=982.55 ± 315.66) to post-test (M=892.21 ± 255.36).


CONCLUSIONS
An e-health intervention using a passive prompt was an effective mechanism for increasing employee work-related energy expenditure. Engaging employees in regular short-bursts of physical activity during the workday resulted in reduced sitting time, which may have long-term effects on the improvement of employee health.
Cognitive load in hypertext reading: A review

A process model of hypertext reading was used to generate predictions about the effects of hypertext features on cognitive processing during text navigation and comprehension. We evaluated the predictions of the model with respect to the extant literature, focusing on studies in which versions of hypertexts were compared. Consistent with our predictions, the increased demands of decisionmaking and visual processing in hypertext impaired reading performance. Individual differences in readers, such as working memory capacity and prior knowledge, mediated the impact of hypertext features. For example, readers with low working memory and low prior knowledge were usually disadvantaged in hypertext. Some benefits were observed for learners with low prior knowledge, however, if the hypertext structure was hierarchical and consistent with that of the knowledge domain. We also surveyed the effectiveness of structural features designed to reduce cognitive load, including graphical overviews, restricted access to links, and visible link types. Complex graphical overviews did not reliably enable learning and navigation, whereas navigational support from restricted access and visible link types were helpful. We identified gaps in the empirical literature and suggested future studies to investigate cognitive processes in hypertext reading. 2005 Elsevier Ltd. All rights reserved.
Decline in male sexual desire, function, and satisfaction during and after antiviral therapy for chronic hepatitis C.

BACKGROUND & AIMS
The recommended therapy for chronic hepatitis C, pegylated interferon and ribavirin for 24 or 48 weeks, has many known adverse side effects. The aim of this study was to evaluate the impact of antiviral therapy on male sexual health.


METHODS
As part of the Study of Viral Resistance to Antiviral Therapy of Chronic Hepatitis C (Virahep-C), 260 men treated with pegylated interferon alfa-2a and ribavirin completed self-administered questionnaires concerning sexual desire, sexual function, including erectile and ejaculatory function, and sexual satisfaction before, during, and after treatment.


RESULTS
Before therapy, 37% of men reported at least some degree of impairment in sexual desire and 44% reported dissatisfaction with their sexual life, while 26% reported impairment in erectile and 22% in ejaculatory function. During therapy, significant declines were observed in all components of sexual health compared with pretreatment. At the end of therapy (24 or 48 weeks), an estimated 38%-48% of men reported that overall sexual function was worse than before treatment. African American patients reported less impairment in sexual desire and satisfaction than Caucasian American patients during therapy. By 24 weeks after treatment, sexual desire and satisfaction improved and were comparable to baseline levels. However, among men who received 48 weeks of therapy, the estimated percentage of men reporting posttreatment erectile or ejaculatory problems remained higher than baseline, although persistent erectile impairment was limited to Caucasian American patients.


CONCLUSIONS
Sexual impairment is common among men with chronic hepatitis C undergoing therapy with pegylated interferon and ribavirin and should be considered as a potential side effect of antiviral therapy.
Metabolic and electrophysiological validation of functional MRI.

OBJECTIVES
Although functional MRI is widely used for preoperative planning and intraoperative neuronavigation, its accuracy to depict the site of neuronal activity is not exactly known. Experience with methods that may validate fMRI data and the results obtained when coregistering fMRI with different preoperative and intraoperative mapping modalities including metabolically based (18)F-fluorodeoxyglucose PET, electrophysiologcally based transcranial magnetic stimulation (TMS), and direct electrical cortical stimulation (DECS) are described.


METHODS
Fifty patients were included. PET was performed in 30, TMS in 10, and DECS in 41 patients. After coregistration using a frameless stereotactic system, results were grouped into overlapping (<1 cm distance), neighbouring (<2 cm), or contradictory (>2 cm).


RESULTS
Comparing fMRI with PET, 18 overlapping, seven neighbouring, and one contradictory result were obtained. In four patients no comparison was possible (because of motion artefacts, low signal to noise ratio, and unusual high tumour metabolism in PET). The comparison of TMS and fMRI showed seven overlapping and three neighbouring results. In three patients no DECS results could be obtained. Of the remaining 38 patients, fMRI hand motor tasks were compared with DECS results of the upper limb muscles in 36 patients, and fMRI foot motor tasks were compared with DECS results of the lower limb on 13 occasions. Of those 49 studies, overlapping results were obtained in 31 patients, and neighbouring in 14. On four occasions fMRI did not show functional information (because of motion artefacts and low signal to noise).


CONCLUSIONS
All validation techniques have intrinsic limitations that restrict their spatial resolution. However, of 50 investigated patients, there was only one in whom results contradictory to fMRI were obtained. Although it is not thought that fMRI can replace the intraoperatively updated functional information (DECS), it is concluded that fMRI is an important adjunct in the preoperative assessment of patients with tumours in the vicinity of the central region.
Statin use and survival from lung cancer: a population-based cohort study.

BACKGROUND
Preclinical evidence from lung cancer cell lines and animal models suggest that statins could have anticancer properties. We investigated whether statin users had reduced risk of cancer-specific mortality in a population-based cohort of lung cancer patients.


METHODS
Newly diagnosed lung cancer patients, from 1998 to 2009, were identified from English cancer registry data and linked to the UK Clinical Practice Research Datalink, providing prescription records, and to Office of National Statistics mortality data up to 2012. Cox regression models were used to calculate HRs for cancer-specific mortality and 95% confidence intervals (CI) by statin use before and after diagnosis, and to adjust these HRs for potential confounders.


RESULTS
In 3,638 lung cancer patients, there was some evidence that statin use after diagnosis was associated with reduced lung cancer-specific mortality (adjusted HR, 0.89; 95% CI, 0.78-1.02; P = 0.09). Associations were more marked after 12 prescriptions (adjusted HR, 0.81; 95% CI, 0.67-0.98; P = 0.03) and when lipophilic statins were investigated (adjusted HR, 0.81; 95% CI, 0.70-0.94; P = 0.01), but were attenuated in some sensitivity analyses. Furthermore, in 11,051 lung cancer patients, statin use before diagnosis was associated with reduced lung cancer-specific mortality (adjusted HR, 0.88; 95% CI, 0.83-0.93; P < 0.001).


CONCLUSIONS
There was some evidence that lung cancer patients who used statins, and particularly simvastatin, had reduced rates of cancer-specific mortality.


IMPACT
These findings should first be confirmed in observational studies, but provide some support for conducting randomized controlled trials of simvastatin as adjuvant cancer therapy in lung cancer patients.
Missed opportunities to offer HIV tests to high-risk groups during general practitioners’ STI-related consultations: an observational study

OBJECTIVES
Prior research has shown that Dutch general practitioners (GPs) do not always offer HIV testing and the number of undiagnosed HIV patients remains high. We aimed to further investigate the frequency and reasons for (not) testing for HIV and the contribution of GPs to the diagnosis of HIV infections in the Netherlands.


DESIGN
Observational study.


SETTING
(1) Dutch primary care network of 42-45 sentinel practices where report forms during sexually transmitted infection (STI)-related consultations were routinely collected, 2008-2013. (2) Dutch observational cohort with medical data of HIV-positive patients in HIV care, 2008-2013.


OUTCOME MEASURES
The proportion of STI-related consultations in patients from high-risk groups tested for HIV, with additional information requested from GPs on HIV testing preconsultation or postconsultation for whom HIV testing was indicated, but not performed. Next, information was collected on the profile of HIV-positive patients entering specialised HIV care following diagnosis by GPs.


RESULTS
Initially, an HIV test was reported (360/907) in 40% of STI-related consultations in high-risk groups. Additionally, in 26% of consultations an HIV test had been performed in previous or follow-up consultations or at different STI-care facilities. The main reasons for not testing were perceived insignificant risk; 'too' recent risk according to GPs or the reluctance of patients. The initiative of the patient was a strong determinant for HIV testing. GPs diagnosed about one third of all newly found cases of HIV. Compared with STI clinics, HIV-positive patients diagnosed in general practice were more likely to be older, female, heterosexual male or sub-Saharan African.


CONCLUSIONS
In one-third of the STI-related consultations of persons from high-risk groups, no HIV test was performed in primary care, which is lower than previously reported. Risk-based testing has intrinsic limitations and implementation of new additional strategies in primary care is warranted.
Evaluation of the effect of intrinsic material properties and ambient conditions on the dimensional stability of white mineral trioxide aggregate and Portland cement.

INTRODUCTION
A number of factors affect the dimensional stability of a material. These factors include curing conditions, material solubility, leaching, and time. The aim of this study was to evaluate the restrained dimensional change in the vertical direction as a function of the ambient conditions, fluid uptake, solubility, and leaching of white mineral trioxide aggregate (MTA) and Portland cement stored in Hank's balanced salt solution (HBSS) over a period of 28 days.


METHODS
The dimensional change in the vertical direction over a 28-day period was determined using a linear variable differential transducer (LVDT) on laterally restrained test samples. The fluid uptake and solubility of both MTA and Portland cement was also evaluated. The leaching in water and HBSS was assessed using inductively coupled plasma.


RESULTS
MTA was more soluble than Portland cement. Both materials absorbed water and physiological solution, with Portland cement displaying a lower uptake than MTA. Both cements exhibited a net expansion when in contact with a physiological solution and released high levels of calcium. MTA leached bismuth. Both calcium and bismuth ion release was higher in HBSS than in water. Phosphorus ions in HBSS were depleted when in contact with both MTA and Portland cement.


CONCLUSIONS
The MTA was very susceptible to ambient conditions. The addition of bismuth oxide to MTA reduced the leaching of calcium hydroxide, increased the material solubility, and caused deterioration in material dimensional stability. Further research is necessary to establish the material porosity and its effect on the dimensional stability.