Cohesive framework for non-line-of-sight imaging based on Dirac notation.

The non-line-of-sight (NLOS) imaging field encompasses both experimental and computational frameworks that focus on imaging elements that are out of the direct line-of-sight, for example, imaging elements that are around a corner. Current NLOS imaging methods offer a compromise between accuracy and reconstruction time as experimental setups have become more reliable, faster, and more accurate. However, all these imaging methods implement different assumptions and light transport models that are only valid under particular circumstances. This paper lays down the foundation for a cohesive theoretical framework which provides insights about the limitations and virtues of existing approaches in a rigorous mathematical manner. In particular, we adopt Dirac notation and concepts borrowed from quantum mechanics to define a set of simple equations that enable: i) the derivation of other NLOS imaging methods from such single equation (we provide examples of the three most used frameworks in NLOS imaging: back-propagation, phasor fields, and f-k migration); ii) the demonstration that the Rayleigh-Sommerfeld diffraction operator is the propagation operator for wave-based imaging methods; and iii) the demonstration that back-propagation and wave-based imaging formulations are equivalent since, as we show, propagation operators are unitary. We expect that our proposed framework will deepen our understanding of the NLOS field and expand its utility in practical cases by providing a cohesive intuition on how to image complex NLOS scenes independently of the underlying reconstruction method.

Microplastics and plastisphere at surface waters in the Southwestern Caribbean sea.

Pollution generated by plastic waste has brought an environmental problem characterized by the omnipresence of smaller pieces of this material known as microplastics (MP). This issue was addresses by collecting samples with 250 µm pore size nets in two marine-coastal sectors of Southwestern Caribbean Sea during two contrasting seasons. Higher concentrations were found in rainy season than in dry season, reaching respectively 1.72 MP/m3 and 0.22 MP/m3. Within each sector, there were differences caused firstly by localities of higher concentrations of semi-closed water bodies localities during rainy season (Ciénaga Grande de Santa Marta and La Caimanera marsh), and secondly by lower concentrations of localities with less influenced of flow rates during dry season (Salamanca and Isla Fuerte). Moreover, the lowest concentration in dry season corresponding to La Caimanera marsh reflects how the community environmental management might decrease MP pollution. In both sectors and seasons, the particles of 0.3 mm (0.3-1.4 mm) size class dominated over those of 1.4 mm (1.4-5.0 mm) (reaching each respectively 1.33 MP/m3 and 0.39 MP/m3), with a dominance of fibers, except in the rainy season in Magdalena, where they were films. Using the FTIR technique, polypropylene was identified as the most abundant polymer in both sectors. The composition of the assemblage of microorganisms attached to microplastics presented higher richness and differed from that of free-living planktonic microbes. The most abundant members of the plastisphere were proteobacteria whose major representation was the pathogenic genus Vibrio, while the cyanobacteria dominated in seawater samples.

Structure-aware parametric representations for time-resolved light transport.

Time-resolved illumination provides rich spatiotemporal information for applications such as accurate depth sensing or hidden geometry reconstruction, becoming a useful asset for prototyping and as input for data-driven approaches. However, time-resolved illumination measurements are high-dimensional and have a low signal-to-noise ratio, hampering their applicability in real scenarios. We propose a novel method to compactly represent time-resolved illumination using mixtures of exponentially modified Gaussians that are robust to noise and preserve structural information. Our method yields representations two orders of magnitude smaller than discretized data, providing consistent results in such applications as hidden-scene reconstruction and depth estimation, and quantitative improvements over previous approaches.

Compression and denoising of time-resolved light transport.

Exploiting temporal information of light propagation captured at ultra-fast frame rates has enabled applications such as reconstruction of complex hidden geometry and vision through scattering media. However, these applications require high-dimensional and high-resolution transport data, which introduces significant performance and storage constraints. Additionally, due to different sources of noise in both captured and synthesized data, the signal becomes significantly degraded over time, compromising the quality of the results. In this work, we tackle these issues by proposing a method that extracts meaningful sets of features to accurately represent time-resolved light transport data. Our method reduces the size of time-resolved transport data up to a factor of 32, while significantly mitigating variance in both temporal and spatial dimensions.

Examining database persistence of ISO/EN 13606 standardized electronic health record extracts: relational vs. NoSQL approaches.

BACKGROUND: The objective of this research is to compare the relational and non-relational (NoSQL) database systems approaches in order to store, recover, query and persist standardized medical information in the form of ISO/EN 13606 normalized Electronic Health Record XML extracts, both in isolation and concurrently. NoSQL database systems have recently attracted much attention, but few studies in the literature address their direct comparison with relational databases when applied to build the persistence layer of a standardized medical information system. METHODS: One relational and two NoSQL databases (one document-based and one native XML database) of three different sizes have been created in order to evaluate and compare the response times (algorithmic complexity) of six different complexity growing queries, which have been performed on them. Similar appropriate results available in the literature have also been considered. RESULTS: Relational and non-relational NoSQL database systems show almost linear algorithmic complexity query execution. However, they show very different linear slopes, the former being much steeper than the two latter. Document-based NoSQL databases perform better in concurrency than in isolation, and also better than relational databases in concurrency. CONCLUSION: Non-relational NoSQL databases seem to be more appropriate than standard relational SQL databases when database size is extremely high (secondary use, research applications). Document-based NoSQL databases perform in general better than native XML NoSQL databases. EHR extracts visualization and edition are also document-based tasks more appropriate to NoSQL database systems. However, the appropriate database solution much depends on each particular situation and specific problem.

Compliance with antibiotic prophylaxis in spinal fusion surgery and surgical wound infection.

BACKGROUND: Surgical wound infection is an important complication of spinal surgery. Antibiotic prophylaxis has served to decrease its rates significantly, with the ensuing reduction in hospital stay, costs, and morbidity and mortality. To date, a large assessment of the degree of compliance with antibiotic prophylaxis in spinal fusion surgery has not been undertaken in Spain with large prospective studies. We sought to assess the degree of compliance with our antibiotic prophylaxis protocol among patients who underwent spinal fusion surgery and its effect on surgical wound infection. MATERIAL AND METHODS: A prospective cohort study was carried out. Six hundred and forty patients with at least 1-year clinical followup who underwent spinal fusion surgery were included. Percentage of administration and degree of compliance with protocol was studied. Both overall and the different aspects of prophylaxis received by patients to those stipulated in the protocol in force at our hospital were compared. Percentages of compliance were assessed and the effect of prophylaxis compliance on the incidence of infection was estimated using the Relative Risk. RESULTS: The study covered 640 patients. Overall compliance with the protocol was 71.5% (95% CI = 67.9- 75.1). The most frequent cause of non-compliance with the protocol was the duration of recommended antibiotic prophylaxis (77.8%). Incidence of surgical wound infection was 4.1% (95% CI: 2.5-5.5). No relationship was found between surgical wound infection and antibiotic prophylaxis non-compliance (RR 0.92, 95% CI = 0.38-2.22). CONCLUSIONS: Compliance and administration of antibiotic prophylaxis were high. Surgical wound infection rate was similar to those found in the literature although there is always room for improvement.

Heart failure in primary care: co-morbidity and utilization of health care resources.

BACKGROUND: In order to ensure proper management of primary care (PC) services, the efficiency of the health professionals tasked with such services must be known. Patients with heart failure (HF) are characterized by advanced age, high co-morbidity and high resource utilization. OBJECTIVE: To ascertain PC resource utilization by HF patients and variability in the management of such patients by GPs. METHODS: Descriptive, cross-sectional study targeting a population attended by 129 GPs over the course of 1 year. All patients with diagnosis of HF in their clinical histories were included, classified using the Adjusted Clinical Group system and then grouped into six resource utilization bands (RUBs). Resource utilization and Efficiency Index were both calculated. RESULTS: One hundred per cent of patients with HF were ranked in RUBs 3, 4 and 5. The highest GP visit rate was 20 and the lowest in excess of 10 visits per year. Prescription drug costs for these patients ranged from €885 to €1422 per patient per year. Health professional efficiency varied notably, even after adjustment for co-morbidity (Efficiency Index Variation Ratio of 28.27 for visits and 404.29 for prescription drug cost). CONCLUSIONS: Patients with HF register a high utilization of resources, and there is great variability in the management of such patients by health professionals, which cannot be accounted for by the degree of case complexity.

Comorbidity in patients with chronic obstructive pulmonary disease in family practice: a cross sectional study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is frequent and often coexists with other diseases. The aim of this study was to quantify the prevalence of COPD and related chronic comorbidity among patients aged over 40 years visiting family practices in an area of Madrid. METHODS: An observational, descriptive, cross-sectional study was conducted in a health area of the Madrid Autonomous Region (Comunidad Autónoma de Madrid). The practice population totalled 198,670 persons attended by 129 Family Physicians (FPs), and the study population was made up of persons over the age of 40 years drawn from this practice population. Patients were deemed to have COPD if this diagnosis appeared on their clinical histories. Prevalence of COPD; prevalence of a further 25 chronic diseases in patients with COPD; and standardised prevalence ratios, were calculated. RESULTS: Prevalence of COPD in family medicine was 3.2% (95% CI 3.0-3.3) overall, 5.3% among men and 1.4% among women; 90% of patients presented with comorbidity, with a mean of 4 ± 2.04 chronic diseases per patient, with the most prevalent related diseases being arterial hypertension (52%), disorders of lipid metabolism (34%), obesity (25%), diabetes (20%) and arrhythmia (15%). After controlling for age and sex, the observed prevalence of the following ten chronic diseases was higher than expected: heart failure; chronic liver disease; asthma; generalised artherosclerosis; osteoporosis; ischaemic heart disease; thyroid disease; anxiety/depression; arrhythmia; and obesity. CONCLUSIONS: Patients with COPD, who are frequent in family practice, have a complex profile and pose a clinical and organisational challenge to FPs.

Assessing the Predictive Factors for Bleeding in Esophageal Variceal Disease: A Systematic Review.

Esophageal varices, dilated submucosal distal esophageal veins, are a common source of upper gastrointestinal bleeding in patients with portal hypertension. This review aims to comprehensively assess predictive factors for both the first occurrence and subsequent risk of esophageal variceal bleeding. A systematic search was conducted in PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online) and Cochrane databases. A total of 33 studies were selected using rigorous inclusion and exclusion criteria. The risk of bias was assessed using the Newcastle-Ottawa Scale. Several predictive factors were identified for esophageal variceal bleeding, including the Child-Pugh score, Fibrosis Index, specific endoscopic findings, ultrasound parameters, portal vein diameter, presence and size of collaterals, CT scan findings, ascites, platelet counts, coagulation parameters, albumin levels, Von Willebrand Factor, bilirubin levels, diabetes mellitus, and the use of b-blocking agents in primary prophylaxis. The findings of this systematic review shed light on multiple potential predictive factors for esophageal variceal bleeding. Endoscopic findings were found to be reliable predictors. Additionally, ultrasound parameters showed associations with bleeding risk. This systematic review identifies multiple potential predictive factors for esophageal variceal bleeding in patients with portal hypertension. While certain factors exhibit strong predictive capabilities, further research is needed to refine and validate these findings, considering potential limitations and biases. This study serves as a critical resource for bridging knowledge gaps in this field.

Use of Generic Antiretroviral Drugs and Single-Tablet Regimen De-Simplification for the Treatment of HIV Infection in Spain.

The present study sought to describe the use of generic drugs and single-tablet regimen (STR) de-simplification for the treatment of human immunodeficiency virus (HIV) infection among 41 hospitals from the cohort of the Spanish HIV/AIDS Research Network (CoRIS). In June 2018, we collected information on when generic antiretroviral drugs (ARVs) were introduced in the different hospitals, how the decisions to use them were made, and how the information was provided to the patients. Most of the nine available generic ARVs in Spain by June 2018 had been introduced in at least 85% of the participating hospitals, except for zidovudine (AZT)/lamivudine (3TC) and AZT. The time difference between the effective marketing date of each generic ARV and its first dispensing date in the hospitals was much shorter for the more recently approved generic ARV since the year 2017. However, only up to 20% of the hospitals de-simplified efavirenz (EFV)/tenofovir disoproxil (TDF)/emtricitabine (FTC), dolutegravir (DTG)/abacavir (ABC)/3TC, and rilpivirine (RPV)/TDF/FTC (to generic EFV+TDF/FTC, DTG+generic ABC/3TC, and RPV+generic TDF/FTC, respectively), whereas the generic STR EFV/TDF/FTC was introduced in 87.8% of the centers. The median times between the date of effective marketing of generic TDF/FTC and the date of de-simplification of EFV/TDF/FTC and RPV/TDF/FTC were 723 [interquartile range (IQR): 369-1,119] and 234 (IQR: 142-264) days, respectively; this time was 155 (IQR: 28-287) days for de-simplification of DTG/ABC/3TC. In conclusion, despite the widespread use of generic ARVs, STRs de-simplification was only undertaken in <20% of the hospitals. There was wide variability in the timing of the introduction of each generic ARV after they were available in the market.

Predator control of marine communities increases with temperature across 115 degrees of latitude.

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115° of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.

Heart failure in the family practice: a study of the prevalence and co-morbidity.

BACKGROUND: Heart failure (HF) is a health problem that particularly affects the elderly population. Its onset is associated with other chronic diseases, a circumstance that makes it a challenge for health care services. The aim of this study is to quantify the prevalence of HF in family medicine offices and describe the chronic co-morbidity associated with it. METHODS: A cross-sectional, observational descriptive study set in a health area of the Community of Madrid, Spain. The study was carried out in a population of 198,670 individuals over 14 years of age, attended to by 129 specialists in family medicine. The patient was considered to have HF when this diagnosis (ICPC code K77) appeared in his or her electronic medical record. The prevalence of HF was quantified and its association with another 25 chronic diseases was analysed. RESULTS: The prevalence of HF was 6.9‰, 7.9‰ among women and 5.9‰ among men. Patients with HF had a high rate of chronic co-morbidity, with an average of 5.2 + 2.1 chronic diseases. Only 3% of the patients present with isolated HF and >60% have four or more additional chronic problems. Hypertension, cardiac arrhythmias, hyperlipidaemia, obesity and diabetes mellitus are the chronic diseases most frequently detected in HF patients. CONCLUSION: Patients with HF frequently visit the offices of family physicians, presenting with a high rate of cardiac and non-cardiac co-morbidity that proves to be a challenge on the clinical level and in terms of the organization of health care services.

How patients with COVID-19 managed the disease at home during the first wave in Spain: a cross-sectional study.

OBJECTIVE: Most patients with mild COVID-19 had to stay at home trying to implement an optimal quarantine. The aim of this study was to describe the COVID-19 cases during the first wave of the pandemic in Spain, how they managed the disease at home, focusing on differences by age, as well as differences in knowledge, attitudes and preventive practices, compared with the uninfected population. DESIGN: An online survey was used to conduct a cross-sectional study of individuals who were 14 years or older living in Spain during the COVID-19 lockdown. The main variable was a COVID-19 case. Logistic regression models for COVID-19 cases were obtained using a backward stepwise procedure to assess the association between social variables, disease knowledge, attitudes, prevention practices and emotional impact. RESULTS: 3398 people completed the survey. Participants' mean age was 49.6 (SD=14.3). COVID-19 was significantly more prevalent among married people (5.3%) and those currently doing an on-site work (8.7%). Most of the COVID-19 cases stayed at home (84.0%) during the episode. There were significant age-based differences with regard to self-isolation conditions at home during the disease. COVID-19 cases showed better attitudes, practices and knowledge about disease symptoms and transmission than the uninfected population. COVID-19 cases also felt more depressed (adjusted OR: 3.46, 95% CI 1.45 to 8.26) and had better preventive behaviour than the uninfected population, such as always wearing a mask outside the home (adjusted OR 1.58, 95% CI 1.06 to 2.30). CONCLUSION: COVID-19 cases found it difficult to comply with recommended home self-isolation conditions, with differences by age group. COVID-19 had an important impact on care dependency in non-hospitalised patients, who were mostly dependent on their families for care. It is necessary to reinforce social and health services and to be ready to meet the care needs of populations during the different waves or in future epidemics.

Late presentation for HIV impairs immunological but not virological response to antiretroviral treatment.

OBJECTIVES: The aim of this study was to examine the impact of late presentation (CD4+ cell count <350 cells/µl or an AIDS-defining event) on effectiveness and safety of initial antiretroviral therapy (ART) and to evaluate whether treatment response depends on first-line ART regimen in late presenters. DESIGN: ART-naive adults from the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) starting triple ART between 2010 and 2018. METHODS: We used multivariable models to assess differences in viral suppression (viral load <50 copies/ml), immunological response (change in CD4+ cell count, CD4% (>29%) and CD4/CD8 normalization (>0.4 and >1) multiple T-cell marker recovery (MTMR): CD4+ cell count more than 500 cells/µl and CD4% >29% and CD4/CD8 >1), and treatment discontinuation due to adverse events (TDAE) at 48 weeks from ART initiation. RESULTS: Out of 8002 participants, 48.7% were late presenters. Of them, 45.8% initiated ART with a NNRTI- (mostly TDF/FTC/EFV), 33.9% with a protease inhibitor (mostly TDF/FTC+boosted DRV) and 20.3% with an INI-based regimen (mostly ABC/3TC/DTG). At 48 weeks, late presenters had similar viral suppression, but worse immunological response, than non-late presenters with no difference on TDAE. Late presenters initiating with NNRTI-based regimens were more likely to achieve viral suppression than those starting with INI-based, due to the higher chance of achieving viral suppression observed with TDF/FTC/RPV compared to ABC/3TC/DTG. Initial treatment with NNRTI or protease inhibitor based showed similar immunological response than the INI-based regimens, which showed lower rates of TDAE than NNRTI- and protease inhibitor based regimens. CONCLUSION: Despite safety and effectiveness of initial ART in terms of viral suppression, late presenters may not experience complete immunological response. In late presenters, effectiveness and safety depends on both the class and the specific first-line ART regimen.

Seamless integration of ISO/IEEE11073 personal health devices and ISO/EN13606 electronic health records into an end-to-end interoperable solution.

The new paradigm of personal health demands open standards and middleware components that permit transparent integration and end-to-end interoperability from new personal health devices to healthcare information system. The use of standards seems to be the internationally accepted way to face this challenge. In this article, the implementation of an end-to-end standard-based personal health solution is presented. It integrates the ISO/IEEE11073 standard for the interoperability of personal health devices in the patient environment and the ISO/EN13606 standard for the interoperable exchange of electronic healthcare records and proposes a new approach for the end-to-end ISO/IEEE11073-ISO/EN13606 communication. The design strictly fulfills all the technical requirements of the most recent versions of both standards. An entire prototype has been designed, developed, and tested as a proof-of-concept of a personal health solution.

Defining a Standardized Information Model for Multi-Source Representation of Breast Cancer Data.

This work aims to define a standardized information model for representation of multiple data sources in breast cancer. A set of data elements has been identified using ICHOM Breast Cancer as the minimum data set and adapting it to the needs of Hospital Universitario 12 de Octubre. With this, an information model has been defined according to ISO 13606 and SNOMED CT standards.

[Epidemiological study in patients with nasal polyposis]. / Estudio epidemiológico en pacientes con poliposis nasal.

OBJECTIVE: To investigate the epidemiologic data in 165 patients suffering nasal polyposis. MATERIAL AND METHOD: We collected different variables that included age, gender, asthma, ASA sensitive, allergic rhinitis, smoker, drinker, familiar history. We studied the main symptoms (nasal blockage, rhinorrhea, anosmia, and headache) as well as otological and dermatological involvement. RESULTS: Nasal polyposis affects men (63%) more frequently, with a mean age of 46.5 years. Asthma was found in 36.6 % of patients with nasal polyposis. The most frequent symptom was nasal blockage (88 %) followed by anosmia (78 %). Ears were affected in 42 % of patients and 20 % of first-degree relatives also suffer the same condition. CONCLUSIONS: Nasal polyposis affects both genders in middle age and may have an associated genetic factor in some patients. We must rule out asthma in all these patients.

Executing Complexity-Increasing Queries in Relational (MySQL) and NoSQL (MongoDB and EXist) Size-Growing ISO/EN 13606 Standardized EHR Databases.

This research shows a protocol to assess the computational complexity of querying relational and non-relational (NoSQL (not only Structured Query Language)) standardized electronic health record (EHR) medical information database systems (DBMS). It uses a set of three doubling-sized databases, i.e. databases storing 5000, 10,000 and 20,000 realistic standardized EHR extracts, in three different database management systems (DBMS): relational MySQL object-relational mapping (ORM), document-based NoSQL MongoDB, and native extensible markup language (XML) NoSQL eXist. The average response times to six complexity-increasing queries were computed, and the results showed a linear behavior in the NoSQL cases. In the NoSQL field, MongoDB presents a much flatter linear slope than eXist. NoSQL systems may also be more appropriate to maintain standardized medical information systems due to the special nature of the updating policies of medical information, which should not affect the consistency and efficiency of the data stored in NoSQL databases. One limitation of this protocol is the lack of direct results of improved relational systems such as archetype relational mapping (ARM) with the same data. However, the interpolation of doubling-size database results to those presented in the literature and other published results suggests that NoSQL systems might be more appropriate in many specific scenarios and problems to be solved. For example, NoSQL may be appropriate for document-based tasks such as EHR extracts used in clinical practice, or edition and visualization, or situations where the aim is not only to query medical information, but also to restore the EHR in exactly its original form.

Proof-of-concept design and development of an EN13606-based electronic health care record service.

OBJECTIVE: The authors present an Electronic Healthcare Record (EHR) server, designed and developed as a proof of concept of the revised prEN13606:2005 European standard concerning EHR communications. METHODS: The development of the server includes five modules: the libraries for the management of the standard reference model, for the demographic package and for the data types; the permanent storage module, built on a relational database; two communication interfaces through which the clients can send information or make queries; the XML (eXtensible Markup Language) process module; and the tools for the validation of the extracts managed, implemented on a defined XML-Schema. RESULTS: The server was subjected to four phases of trials, the first three with ad hoc test data and processes to ensure that each of the modules complied with its specifications and that the interaction between them provided the expected functionalities. The fourth used real extracts generated by other research groups for the additional purpose of testing the validity of the standard in real-world scenarios. CONCLUSION: The acceptable performance of the server has made it possible to include it as a middleware service in a platform for the out-of-hospital follow-up and monitoring of patients with chronic heart disease which, at the present time, supports pilot projects and clinical trials for the evaluation of eHealth services.

Service for the Pseudonymization of Electronic Healthcare Records Based on ISO/EN 13606 for the Secondary Use of Information.

The availability of electronic health data favors scientific advance through the creation of repositories for secondary use. Data anonymization is a mandatory step to comply with current legislation. A service for the pseudonymization of electronic healthcare record (EHR) extracts aimed at facilitating the exchange of clinical information for secondary use in compliance with legislation on data protection is presented. According to ISO/TS 25237, pseudonymization is a particular type of anonymization. This tool performs the anonymizations by maintaining three quasi-identifiers (gender, date of birth, and place of residence) with a degree of specification selected by the user. The developed system is based on the ISO/EN 13606 norm using its characteristics specifically favorable for anonymization. The service is made up of two independent modules: the demographic server and the pseudonymizing module. The demographic server supports the permanent storage of the demographic entities and the management of the identifiers. The pseudonymizing module anonymizes the ISO/EN 13606 extracts. The pseudonymizing process consists of four phases: the storage of the demographic information included in the extract, the substitution of the identifiers, the elimination of the demographic information of the extract, and the elimination of key data in free-text fields. The described pseudonymizing system was used in three telemedicine research projects with satisfactory results. A problem was detected with the type of data in a demographic data field and a proposal for modification was prepared for the group in charge of the drawing up and revision of the ISO/EN 13606 norm.