On-chip phase-shift induced control of supercontinuum generation in a dual-core Si3N4 waveguide.

We investigate on-chip spectral control of supercontinuum generation, taking advantage of the additional spatial degree of freedom in strongly-coupled dual-core waveguides. Using numerical integration of the multi-mode generalized nonlinear Schrödinger equation, we show that, with proper waveguide cross-section design, selective excitation of supermodes can vary the dispersion to its extremes, i.e., all-normal or anomalous dispersion can be selected via phase shifting in a Mach-Zehnder input circuit. The resulting control allows to provide vastly different supercontinuum spectra with the same waveguide circuit.

Survival of cervical cancer patients at Moi teaching and Referral Hospital, Eldoret in western Kenya.

BACKGROUND: Cervical cancer is a major health burden and the second most common cancer after breast cancer among women in Kenya. Worldwide cervical cancer constitutes 3.1% of all cancer cases. Mortality rates are greatest among the low-income countries because of lack of awareness, screening and early-detection programs and adequate treatment facilities. The main aim was to estimate survival and determine survival predictors of women with cervical cancer and limited resources in western Kenya. METHODS: Retrospective charts review of women diagnosed with cervical cancer and follow-up for two years from the date of the histologic diagnosis. The outcome of interest was death or survival at two years. Kaplan Meier estimates of survival, log-rank test and Cox proportional hazards regression were used in the survival analysis. RESULTS: One hundred and sixty-two (162) participants were included in the review. The median duration was 0.8 (interquartile range (IQR) 0.3, 1.6) years. The mean age at diagnosis was 50.6 years (SD12.5). The mean parity was 5.9 (SD 2.6). Fifty percent (50%) did not have health insurance. Twenty six percent (26%) used hormonal contraceptives, 25.9% were HIV positive and 70% of them were on anti-retroviral treatment. The participants were followed up for 152.6 person years. Of the 162 women in the study, 70 (43.2%) died giving an overall incidence rate (IR) of 45.9 deaths per 100 person years of follow up. The hazard ratios were better for the patients who survived (0.44 vs 0.88, p-value < 0.001), those who had medical insurance (0.70 vs 0.48, p-value = 0.007) and those with early stage at diagnosis (0.88 vs 0.39, p-value < 0.001). Participants who were diagnosed at late stage of the disease according to the International Federation of Gynecology and Obstetrics staging for cervical cancer (FIGO stage 2B-4B) had more than eight times increased hazard of death compared to those who were diagnosed at early stage (1-2A): Hazard Ratio: 8.01 (95% CI 3.65, 17.57). Similarly, those who underwent surgical management had 84% reduced hazard of mortality compared to those who were referred for other modes of care: HR: 0.16 (95% CI: 0.07, 0.38). CONCLUSION: Majority of the participants were diagnosed late after presenting with symptoms. The 1 and 2-year survival probability after diagnosis of cervical cancer was 57% AND 45% respectively. It is imperative that women present early since surgery gives better prognosis or better still screening of all women prioritized.

Systematic review of international clinical guidelines for the promotion of physical activity for the primary prevention of cardiovascular diseases.

BACKGROUND: Cardiovascular diseases are the world's leading cause of morbidity and mortality. An active lifestyle is one of the cornerstones in the primary prevention of cardiovascular disease. An initial step in guiding primary prevention programs is to refer to clinical guidelines. We aimed to systematically review clinical practice guidelines on primary prevention of cardiovascular disease and their recommendations regarding physical activity. METHODS: We systematically searched Trip Medical Database, PubMed and Guidelines International Network from January 2012 up to December 2020 using the following search strings: 'cardiovascular disease', 'prevention', combined with specific cardiovascular disease risk factors. The identified records were screened for relevance and content. We methodologically assessed the selected guidelines using the AGREE II tool. Recommendations were summarized using a consensus-developed extraction form. RESULTS: After screening, 27 clinical practice guidelines were included, all of which were developed in Western countries and showed consistent rigor of development. Guidelines were consistent about the benefit of regular, moderate-intensity, aerobic physical activity. However, recommendations on strategies to achieve and sustain behavior change varied. Multicomponent interventions, comprising education, counseling and self-management support, are recommended to be delivered by various providers in primary health care or community settings. Guidelines advise to embed patient-centered care and behavioral change techniques in prevention programs. CONCLUSIONS: Current clinical practice guidelines recommend similar PA lifestyle advice and propose various delivery models to be considered in the design of such interventions. Guidelines identify a gap in evidence on the implementation of these recommendations into practice.

Reflective aperiodic multilayer filters for metrology at XUV sources.

We present a general method for designing XUV aperiodic multilayer mirrors that can mimic a given target spectrum, specifically, the spectral transmission of an XUV optical system. The method is based on minimizing a merit function and using fidelity parameters that quantify the matching of the multilayer reflectivity spectrum with that of the target spectrum. To assess the feasibility of fabricating such a system, we show how to reduce the layer-to-layer thickness variations throughout the aperiodic layer stack. We demonstrate the design method using an example of an EUV optical system composed of 12 identical Mo/Si multilayer mirrors having a reflectivity peak at 13.5 nm. We found that the target spectrum can be mimicked with high fidelity either with a single reflection at an aperiodic multilayer mirror combined with standard absorbing filters or, if required, with two subsequent reflections at a mimic mirror. These examples demonstrate the applicability for metrology at XUV sources, including spectrally proper source imaging. Because our approach is of general applicability, the process can be used to mimic any other narrowband, single-peaked target spectrum in the XUV region.

Which positive view of general practice do medical students and trainees have? A systematic literature review.

Background: Despite several studies focusing on the negative aspects of general medicine, the speciality seems attractive for students. Researchers from the European General Practice Research Network created a group to study job satisfaction in general practice. The aim of this eight-country European study was to determine which positive view students have about general practice.Method: Systematic review of the literature from Pubmed, Embase and Cochrane databases. Articles published between 01/01/2000 and 12/31/2018 were searched and analysed by two researchers working blind. The data on satisfaction factors were extracted from the full text article used as verbatims. Then the data were coded with a thematic analysis.Results: 24 articles out of 414 were selected. Satisfaction factors were classified: teaching of general practice, workplace and organisational freedom, quality of life, variety in practice, workload balance and income. The analysis highlighted intellectual stimulation and the relationship built with patients and other professionals.Conclusion: Literature on the appeal of general practice for students revealed many factors of job satisfaction in general practice. It is possible to create a global view of a satisfied GP on the students' opinion. Courses and clerkships in general practice with positive role models are determining factors in career choice.

Which positive factors give general practitioners job satisfaction and make general practice a rewarding career? A European multicentric qualitative research by the European general practice research network.

BACKGROUND: General Practice (GP) seems to be perceived as less attractive throughout Europe. Most of the policies on the subject focused on negative factors. An EGPRN research team from eight participating countries was created in order to clarify the positive factors involved in appeals and retention in GP throughout Europe. The objective was to explore the positive factors supporting the satisfaction of General Practitioners (GPs) in clinical practice throughout Europe. METHOD: Qualitative study, employing face-to-face interviews and focus groups using a phenomenological approach. The setting was primary care in eight European countries: France, Belgium, Germany, Slovenia, Bulgaria, Finland, Poland and Israel. A thematic qualitative analysis was performed following the process described by Braun and Clarke. Codebooks were generated in each country. After translation and back translation of these codebooks, the team clarified and compared the codes and constructed one international codebook used for further coding. RESULTS: A purposive sample of 183 GPs, providing primary care to patients in their daily clinical practice, was interviewed across eight countries. The international codebook included 31 interpretative codes and six themes. Five positive themes were common among all the countries involved across Europe: the GP as a person, special skills needed in practice, doctor-patient relationship, freedom in the practice and supportive factors for work-life balance. One theme was not found in Poland or Slovenia: teaching and learning. CONCLUSION: This study identified positive factors which give GPs job satisfaction in their clinical practice. This description focused on the human needs of a GP. They need to have freedom to choose their working environment and to organize their practice to suit themselves. In addition, they need to have access to professional education so they can develop specific skills for General Practice, and also strengthen doctor-patient relationships. Stakeholders should consider these factors when seeking to increase the GP workforce.

Temporal model for quasi-phase matching in high-order harmonic generation.

We present a model for quasi-phase matching (QPM) in high-order harmonic generation (HHG). Using a one-dimensional description, we analyze the time-dependent, ultrafast wave-vector balance to calculate the on-axis harmonic output versus time, from which we obtain the output pulse energy. Considering, as an example, periodically patterned argon gas, as may be provided with a grid in a cluster jet, we calculate the harmonic output during different time intervals within the drive laser pulse duration. We find that identifying a suitable single spatial period is not straightforward due to the complex and ultrafast plasma dynamics that underlies HHG at increased intensities. The maximum on-axis harmonic pulse energy is obtained when choosing the QPM period to phase match HHG at the leading edge of the drive laser pulse.

Narrowband and tunable anomalous transmission filters for spectral monitoring in the extreme ultraviolet wavelength region.

We present the first experimental demonstration of a novel type of narrowband and wavelength-tunable multilayer transmission filter for the extreme ultraviolet (EUV) region. The operating principle of the filter is based on spatially overlapping the nodes of a standing wave field with the absorbing layers within the multilayer structure. For a wavelength with a matching node pattern, this increases the transmission as compared to neighboring wavelengths where anti-nodes overlap with the absorbing layers. Using Ni/Si multilayers where Ni provides strong absorption, we demonstrate the proper working of such anomalous transmission filter. The demonstration is carried out at the example of 13.5 nm wavelength and at normal incidence, providing a 0.27 nm-wide transmission peak. We also demonstrate wavelength tunability by operating the same Ni/Si filter at different wavelengths by varying the angle of incidence. As the multilayer filter is directly deposited on the active area of an EUV-sensitive photodiode, this provides an extremely compact device for easy spectral monitoring in the EUV. The transmission spectrum of the filter is modeled and found to be in good agreement with the experimental data. The agreement proves that such filters and compact monitoring devices can be straightforwardly designed and fabricated, as desired, also for other EUV wavelengths, bandwidths and angles of incidence, thereby showing a high potential for applications.

Which positive factors determine the GP satisfaction in clinical practice? A systematic literature review.

BACKGROUND: Looking at what makes General Practitioners (GPs) happy in their profession, may be important in increasing the GP workforce in the future. The European General Practice Research Network (EGPRN) created a research team (eight national groups) in order to clarify the factors involved in GP job satisfaction throughout Europe. The first step of this study was a literature review to explore how the satisfaction of GPs had been studied before. The research question was "Which factors are related to GP satisfaction in Clinical Practice?" METHODS: Systematic literature review according to the PRISMA statement. The databases searched were Pubmed, Embase and Cochrane. All articles were identified, screened and included by two separate research teams, according to inclusion or exclusion criteria. Then, a qualitative appraisal was undertaken. Next, a thematic analysis process was undertaken to capture any issue relevant to the research question. RESULTS: The number of records screened was 458. One hundred four were eligible. Finally, 17 articles were included. The data revealed 13 subthemes, which were grouped into three major themes for GP satisfaction. First there were general profession-related themes, applicable to many professions. A second group of issues related specifically to a GP setting. Finally, a third group was related to professional life and personal issues. CONCLUSIONS: A number of factors leading to GP job satisfaction, exist in literature They should be used by policy makers within Europe to increase the GP workforce. The research team needs to undertake qualitative studies to confirm or enhance those results.

Spectral control of high-harmonic generation via drive laser pulse shaping in a wide-diameter capillary.

We experimentally investigate spectral control of high-harmonic generation in a wide-diameter (508 µm) capillary that allows using significantly lower gas pressures coupled with elevated drive laser energies to achieve higher harmonic energies. Using phase shaping to change the linear chirp of the drive laser pulses, we observe wavelength tuning of the high-harmonic output to both larger and smaller values. Comparing tuning via the gas pressure with the amount of blue shift in the transmitted drive laser spectrum, we conclude that both adiabatic and non-adiabatic effects cause pulse-shaping induced tuning of high harmonics. We obtain a fractional wavelength tuning, Δλ/λ, in the range from -0.007 to + 0.01, which is comparable to what is achieved with standard capillaries of smaller diameter and higher pressures.

Single-shot fluctuations in waveguided high-harmonic generation.

For exploring the application potential of coherent soft x-ray (SXR) and extreme ultraviolet radiation (XUV) provided by high-harmonic generation, it is important to characterize the central output parameters. Of specific importance are pulse-to-pulse (shot-to-shot) fluctuations of the high-harmonic output energy, fluctuations of the direction of the emission (pointing instabilities), and fluctuations of the beam divergence and shape that reduce the spatial coherence. We present the first single-shot measurements of waveguided high-harmonic generation in a waveguided (capillary-based) geometry. Using a capillary waveguide filled with Argon gas as the nonlinear medium, we provide the first characterization of shot-to-shot fluctuations of the pulse energy, of the divergence and of the beam pointing. We record the strength of these fluctuations vs. two basic input parameters, which are the drive laser pulse energy and the gas pressure in the capillary waveguide. In correlation measurements between single-shot drive laser beam profiles and single-shot high-harmonic beam profiles we prove the absence of drive laser beam-pointing-induced fluctuations in the high-harmonic output. We attribute the main source of high-harmonic fluctuations to ionization-induced nonlinear mode mixing during propagation of the drive laser pulse inside the capillary waveguide.

Fabrication and characterization of free-standing, high-line-density transmission gratings for the vacuum UV to soft X-ray range.

We present state-of-the-art high resolution transmission gratings, applicable for spectroscopy in the vacuum ultraviolet (VUV) and the soft X-ray (SRX) wavelength range, fabricated with a novel process using ultraviolet based nano imprint lithography (UV-NIL). Free-standing, high-line-density gratings with up to 10,000 lines per mm and various space-to-period ratios were fabricated. An optical characterization of the gratings was carried out in the range from 17 to 34 nm wavelength using high-harmonic generation in a capillary waveguide filled with Ne, and around 13.5 nm wavelength (from 10 to 17 nm) using a Xenon discharge plasma.

Clinical data integration model. Core interoperability ontology for research using primary care data.

INTRODUCTION: This article is part of the Focus Theme of METHODS of Information in Medicine on "Managing Interoperability and Complexity in Health Systems". BACKGROUND: Primary care data is the single richest source of routine health care data. However its use, both in research and clinical work, often requires data from multiple clinical sites, clinical trials databases and registries. Data integration and interoperability are therefore of utmost importance. OBJECTIVES: TRANSFoRm's general approach relies on a unified interoperability framework, described in a previous paper. We developed a core ontology for an interoperability framework based on data mediation. This article presents how such an ontology, the Clinical Data Integration Model (CDIM), can be designed to support, in conjunction with appropriate terminologies, biomedical data federation within TRANSFoRm, an EU FP7 project that aims to develop the digital infrastructure for a learning healthcare system in European Primary Care. METHODS: TRANSFoRm utilizes a unified structural / terminological interoperability framework, based on the local-as-view mediation paradigm. Such an approach mandates the global information model to describe the domain of interest independently of the data sources to be explored. Following a requirement analysis process, no ontology focusing on primary care research was identified and, thus we designed a realist ontology based on Basic Formal Ontology to support our framework in collaboration with various terminologies used in primary care. RESULTS: The resulting ontology has 549 classes and 82 object properties and is used to support data integration for TRANSFoRm's use cases. Concepts identified by researchers were successfully expressed in queries using CDIM and pertinent terminologies. As an example, we illustrate how, in TRANSFoRm, the Query Formulation Workbench can capture eligibility criteria in a computable representation, which is based on CDIM. CONCLUSION: A unified mediation approach to semantic interoperability provides a flexible and extensible framework for all types of interaction between health record systems and research systems. CDIM, as core ontology of such an approach, enables simplicity and consistency of design across the heterogeneous software landscape and can support the specific needs of EHR-driven phenotyping research using primary care data.

Extended theory of soft x-ray reflection for realistic lamellar multilayer gratings.

An extended set of coupled wave equations were derived to describe non-idealized lamellar multilayer grating structures with properties as obtained with state-of-the-art fabrication techniques. These generalized equations can include all relevant effects describing the influence of passivation and contamination layers, non-rectangular lamel profiles and sidewall scalloping. The calculations showed that passivation and contamination plays an important role in that it may significantly reduce peak reflectivity. However, we also derived a condition for layer thicknesses having negligible effects. Slightly positive tapered lamel profiles are shown to further reduce the bandwidth as compared to a rectangular lamel profile, whereas negative tapers significantly increased the bandwidth. The influence of intriguing effects, such as the sidewall scalloping caused by Bosch Deep Reactive Ion Etching, are also modeled. We identified the signature of such scalloping as additional side peaks in the reflectivity spectrum and present parameters with which these can be effectively suppressed.

Analytic theory of soft x-ray diffraction by Lamellar Multilayer Gratings.

An analytic theory describing soft x-ray diffraction by Lamellar Multilayer Gratings (LMG) has been developed. The theory is derived from a coupled waves approach for LMGs operating in the single-order regime, where an incident plane wave can only excite a single diffraction order. The results from calculations based on these very simple analytic expressions are demonstrated to be in excellent agreement with those obtained using the rigorous coupled-waves approach. The conditions for maximum reflectivity and diffraction efficiency are deduced and discussed. A brief investigation into p-polarized radiation diffraction is also performed.

Facilitating robot-assisted training in MS patients with arm paresis: a procedure to individually determine gravity compensation.

Gravity compensation (GC) of the arm is used to facilitate arm movements in conventional therapy as well as in robot-assisted rehabilitation of neurologically impaired persons. Positive effects of GC on Range of Motion (ROM) have been demonstrated in stroke. In Multiple Sclerosis (MS), research regarding this topic is lacking. Since an active participation of the patient is required for effective training, full support of the arm might not be advisable. The present study reports on the development of a procedure to measure actively the individual need for GC and to estimate the influence of GC on ROM during reaching, lifting and transporting in severely affected Persons with MS (PwMS). Ten PwMS were tested with the procedure for determination of GC. Maximal reaching movements were performed in a 3D space in three conditions: No support (NS), with GC by the HapticMaster (GC-HM) and with GC by the HapticMaster combined with a sling suspension system (GC-HMS). For the total sample, significant correlations were found between the amount of GC and clinical tests for upper limb function. In four subjects with severe arm dysfunction it was found that mean ROM is larger in the GC-HMS condition compared to the GC-HM condition, and in the GC-HM condition compared to the NS condition, suggesting positive effects of GC on active ROM in PwMS. Therefore, GC could have a positive effect on arm rehabilitation by enabling the PwMS to actively reach a larger ROM during training.

High-resolution, high-reflectivity operation of lamellar multilayer amplitude gratings: identification of the single-order regime.

High resolution while maintaining high peak reflectivities can be achieved for Lamellar Multilayer Amplitude Gratings (LMAG) in the soft-x-ray (SXR) region. Using the coupled waves approach (CWA), it is derived that for small lamellar widths only the zeroth diffraction order needs to be considered for LMAG performance calculations, referred to as the single-order regime. In this regime, LMAG performance can be calculated by assuming a conventional multilayer mirror with decreased density, which significantly simplifies the calculations. Novel analytic criteria for the design of LMAGs are derived from the CWA and it is shown, for the first time, that the resolution of an LMAG operating in the single-order regime is not limited by absorption as in conventional multilayer mirrors. It is also shown that the peak reflectivity of an LMAG can then still be as high as that of a conventional multilayer mirror (MM). The performance of LMAGs operating in the single-order regime are thus only limited by technological factors.

Collecting information on the quality of prescribing in primary care using semi-automatic data extraction from GPs' electronic medical records.

OBJECTIVES: To evaluate a semi-automatic data extraction from the electronic medical record (EMR) of general practitioners (GPs) through a comparison with a paper sheets data collection simultaneously used in a primary care research project on the quality of prescribing for osteoarthritis in the elderly. SUBJECTS: One hundred and fifty-two GPs using five different EMR-software systems participated with the semi-automatic data extraction from the EMR and 233 GPs collected data with paper registration sheets. METHODS: The proportion of patients with respectively a drug prescription, paracetamol, a non-steroidal anti-inflammatory drug (NSAID) and ibuprofen were compared between the semi-automatic extraction and the paper data collection and among the EMR-software systems. RESULTS: Using the semi-automatic data extraction, a significantly lower proportion of patients on drugs was obtained compared to the paper data collection (adjusted OR: 0.31; 95% CI 0.25-0.39). However, the proportion of patients on a specific type of drug was comparable. Within the results from the semi-automatic extraction, the results were heterogeneous among the different EMR-software systems. CONCLUSIONS: The semi-automatic data extraction with multiple EMR-software systems proposed in this study seems suitable for quality of prescribing assessment in primary care. However, it may be less reliable when only a single EMR-software is used.

Assessment of a three-year experience with a Belgian Primary Care data Network.

The paper describes the experiences with a Belgian Primary Care data Network from 1999 till 2002. Three cycles of data collection have been performed. The network involves about 300 general practitioners (GPs) and up to 8 different software packages. This network is semi-anonymous, semi-automatic and mixed (paper and electronic with various software's). For the coming next years, efforts should be focused on solving some frequently occurring problems with the data collection through the EPR, such as a considerable number of data lacking and the fact that GPs do not always use the problem oriented structure of the EPR (Electronic Patient Record). Afterwards, more promising usage could be considered and developed such as repeated data collection using a same GPs' sample, long-term recording studies, usage of larger GPs' samples, etc.