Contributions of capsular releases to femoral exposure in total hip arthroplasty via the direct anterior approach.

BACKGROUND: In total hip arthroplasty via the direct anterior approach, appropriate exposure is critical to allow preparation of the femur. The objective of this study was to explore the optimal soft tissue releases needed to allow broaching of the femur through a combination of experimental tests and computer simulations. METHODS: Fourteen full-body cadaveric specimens were included in this study. Total hip arthroplasty was performed via the direct anterior approach with the femur at 20° adduction and 20°extension. Soft tissue releases were performed sequentially, namely, the transverse iliofemoral ligament, descending iliofemoral ligament, ischio-femoral ligament, conjoint tendon, and obturator externus. After each release, the femur mobility was assessed by applying a 6 Nm external rotation torque and a 120 N distraction force. Subsequently, using specimen-specific models and models of the broach and handle, the broach passage after each release was simulated, and the release that allowed broach passage was analyzed. FINDINGS: The average external rotation after releasing the transverse and descending iliofemoral ligaments increased by 14.1° ± 6.1° and 13.8° ± 5.3°. With subsequent soft tissue releases, the rotational mobility increased incrementally, though the impact decreased. Impingement between the broach passage and the pelvis was mainly at the anterior superior iliac spine and the anterior inferior iliac spine. The volume of impingement decreased from 4.8 ± 4.5 cm3 after resection of the femoral head to 1.8 ± 1.6 cm3 and 1.2 ± 1.9 cm3 after release of the transverse and descending iliofemoral ligament, respectively. INTERPRETATION: With sequential soft-tissue releases, the femur mobility increased incrementally. However, the number of releases needed for each femur varied extensively between specimens. Most (10/14) femurs became accessible after the release of the ilio-femoral or ischio-femoral ligament.

Wearing a Surgical Vest With a Sterile Surgical Helmet System Decreases Contamination of the Surgical Field.

BACKGROUND: Sterile surgical helmet systems are frequently utilized in total knee arthroplasty procedures to protect the surgeon while maintaining a comfortable working environment. However, common helmet systems pressurize the space between the surgical gown and the surgeon's skin. In gowns with a back seam, this may allow contaminated skin particles to escape into the surgical field. By measuring bacterial colony-forming units (CFUs), this study sought to determine if occlusion of the open back seam reduced the risk of potential contamination. METHODS: First, qualitative analysis depicting airflow variations between gown configurations was performed using the Schlieren Spherical Mirror imaging system. Each gown configuration consisted of a sterile surgical helmet and one of 3 gown configurations: a standard gown with rear-tied closure, a standard gown with a surgical vest, and a zippered Toga-style gown. Next, a surgeon then performed simulated surgical activities for 60 minutes within a 1.4 m3 isolation chamber with work surfaces and controllable filtered air exchanges. During each procedure, contaminated particles were collected on sets of agar settle plates positioned directly behind the surgeon. Upon completion, the agar plates were incubated in a biolab, and the number of bacterial and fungal CFUs was counted. The experimental procedure was repeated 12 times for each gown configuration, with sterilization of the chamber between runs. Contamination rates were expressed as CFUs/m2/h. RESULTS: The mean contamination rate measured with the standard gown was 331.7 ± 52.0 CFU/m2/h. After the addition of a surgical vest, this rate decreased by 45% to 182.2 ± 30.8 CFU/m2/h (P = .02). Similarly, with the Toga-style gown, contamination rates dropped by 49% to 170.5 ± 41.9 CFU/m2/h (P = .01). CONCLUSIONS: When used in conjunction with surgical helmet systems, conventional surgical gowns do not prevent potential contamination of the surgical field. We recommend that staff within the surgical field cover the back seam of standard gowns with a vest or don a zippered Toga-style gown.

Development and Validation of the Bilingual Catalan/Spanish Cross-Cultural Adaptation of the Consensus Auditory-Perceptual Evaluation of Voice.

PURPOSE: This study aimed to develop a valid and reliable bilingual version of the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) for the auditory-perceptual evaluation of voice in Catalan and Spanish speakers. METHOD: The development of this CAPE-V adaptation included Delphi methodology with 20 voice and speech experts reaching consensus on the optimal adapted terminology of the perceptual vocal attributes, considering also input from the original instrument authors. The adaptation and validation of vocal tasks followed a sequential validation procedure, with input from phoneticians and speech-language pathologists. Following pilot testing with a large sample of speech-language pathology students, a refined adapted version was empirically tested for validity and reliability. Concurrent validity was assessed by comparing the adapted CAPE-V with the reference Grade, Roughness, Breathiness, Asthenia, Strain scale. Construct validity was assessed through convergent and discriminant validity analysis. Intrarater and interrater reliability were assessed via intraclass correlation coefficient calculations. User experience was evaluated through a questionnaire. Scale properties were validated using a confusion matrix, and cutoff values were calculated to achieve the optimal balance between sensitivity and specificity. RESULTS: Through a formalized consensus process, optimal Catalan/Spanish terminology was determined for the perceptual attributes of voice present in the CAPE-V. An adapted protocol of tasks was obtained that preserves the objectives of the original instrument and the relevance of the phonetic criteria in the target languages. The results demonstrated concurrent validity, construct validity, and intrarater reliability. Interrater reliability was found to depend on the extent to which evaluators shared their internal standards. The raters identified CAPE-V as an effective and preferred instrument. CONCLUSION: An adapted, validated version of the CAPE-V is made available to clinical professionals for the evaluation of voice in Catalan and Spanish speakers.

Pelvic tilt affects superolateral coverage, but not superomedial coverage of the femoral head following periacetabular osteotomy.

BACKGROUND: Pelvic tilt is an important sagittal parameter that varies greatly among individuals. The objective of this study was to quantify the effect of pelvic tilt on femoral head coverage and range of motion in a dysplastic population following periacetabular osteotomy. METHODS: Twenty-three dysplastic hips from 19 patients (17 female, 2 male) were included in this study. Three-dimensional models were reconstructed using pre-operative CT images, and patient-specific neutral pelvic tilt was obtained on an anteroposterior X-ray. Following a simulated periacetabular osteotomy, the pelvic tilt was changed from -15° to +15°, and the effects on femoral head coverage and hip range of motion was quantified using a customized MATLAB program. FINDINGS: Pelvic tilt did not significantly affect total femoral head coverage (P > 0.2). However, a 15° anterior tilt from neutral resulted in a 17.72 ± 9.45% increase in anterolateral coverage and a 23.96 ± 7.48% decrease in posterolateral coverage (P < 0.0001), as well as an 18.2 ± 8.4° loss of internal rotation at 90° of hip flexion. Contrarily, posterior pelvic tilt led to a 26.79 ± 9.04% reduction in anterolateral coverage (P < 0.0001) and an 18.02 ± 9.57% increase in posterolateral coverage (P < 0.0001), and the maximum internal rotation increased 11.8 ± 3.7°. INTERPRETATION: While pelvic tilt did not affect total femoral head coverage, it had a significant impact on the distribution of coverage within the superolateral region of the femoral head. Anterior pelvic tilt led to increased anterolateral coverage, but also had a negative impact on hip range of motion. An optimal surgical plan should achieve adequate coverage while not significantly limiting the patient's mobility.

Variations in Trochlear Morphology of Contemporary and Legacy Total Knee Arthroplasty Prostheses: A Review of 22 Designs.

BACKGROUND: The morphology of the trochlear compartment of total knee arthroplasty (TKA) prostheses is a major determinant of postoperative patello-femoral kinematics, particularly with unresurfaced patellae. The objective of this study was to quantify and compare the trochlear morphology of a large series of contemporary and legacy TKA designs. METHODS: The 3-dimensional surface models of 22 femoral components (13 contemporary and 9 legacy) were created using high-resolution laser scanning. The trochlear profile of each component was analyzed from proximal to distal in 15° increments around the trochlear axis. In each profile, the following variables were measured: sulcus angle, medio-lateral deviation of the sulcus, the height and width of the facets, and the trochlear groove orientation. RESULTS: In the contemporary group, the sulcus angle decreased progressively along the trochlear arc to varying degrees, except for 2 symmetrical designs, whereas the sulcus angle of the legacy designs showed considerable variability. The height of the medial facet was very strongly correlated with that of the lateral facet in the contemporary group (R2 = 0.89), whereas the correlation was weak for the legacy designs (R2 = 0.36). Moreover, the trochlear sulcus deviated laterally from distal to proximal in 10 contemporary designs and 7 legacy designs, resulting in a trochlear groove orientation of 4.2 to 11.1° and 4.3 to 10.5°, respectively. In the remaining 5 designs (3 contemporary and 2 legacy), the sulcus was vertical. CONCLUSIONS: There is more consistency in trochlear morphology of contemporary TKA designs compared to that of legacy designs, yet there are still large variations between different designs.

Limitations and solutions of low cost virtual reality mirror therapy for post-stroke patients.

Mirror therapy is applied to reduce phantom pain and as a rehabilitation technique in post-stroke patients. Using Virtual Reality and head-mounted displays this therapy can be performed in virtual scenarios. However, for its efficient use in clinical settings, some hardware limitations need to be solved. A new system to perform mirror therapy in virtual scenarios for post-stroke patients is proposed. The system requires the patient a standalone virtual reality headset with hand-tracking features and for the rehabilitator an external computer or tablet device. The system provides functionalities for the rehabilitator to prepare and follow-up rehabilitation sessions and a virtual scenario for the patient to perform rehabilitation. The system has been tested on a real scenario with the support of three experienced rehabilitators and considering ten post-stroke patients in individual sessions focused on upper limb motor rehabilitation. The development team observed all the sessions and took note of detected errors regarding technological aspects. Solutions to solve detected problems will be proposed and evaluated in terms of feasibility, performance cost, additional system cost, number of solved issues, new limitations, or advantages for the patient. Three types of errors were detected and solved. The first error is related to the position of the hands relative to the head-mounted display. To solve it the exercise area can be limited to avoid objectives that require turning the head too far. The second error is related to the interaction between the hands and the virtual objects. It can be solved making the main hand non-interactive. The last type of error is due to patient limitations and can be mitigated by having a virtual hand play out an example motion to bring the patient's attention back to the exercise. Other solutions have been evaluated positively and can be used in addition or instead of the selected ones. For mirror therapy based on virtual reality to be efficient in post-stroke rehabilitation the current head-mounted display-based solutions need to be complemented with specific strategies that avoid or mitigate the limitations of the technology and the patient. Solutions that help with the most common issues have been proposed.

The Influence of Computerized Tomography Imaging on Treatment of Periprosthetic Proximal Femur Fractures.

Introduction Periprosthetic femur fractures (PPFF) are increasing in incidence and management of such injuries requires a specialized skill set combined with detailed knowledge of component design. To assist with planning, computed tomography (CT) can be used pre-operatively to give a surgeon more information. No study to date has shown the utility of obtaining preoperative CT. The goal of this study is to show that CT is a useful diagnostic adjunct and report any differences in how subspecialties such as orthopedic traumatologists and arthroplasty surgeons use it. Methods Seventeen PPFF cases met our inclusion criteria. They were shown to six faculty, three trauma and three arthroplasty surgeons. They viewed the plain radiographs and then CTs. After each they filled out the same questionnaire that included their assessment of diagnosis and proposed treatment plan both before and after access to CT imaging. Fleiss and Cohen kappa were used to compare inter- and intra-observer reliability. Results The interobserver kappa values (k) in diagnosis were 0.348 pre- and 0.371 post-CT, while trauma and arthroplasty were 0.328 to 0.260 and 0.821 to 0.881 respectively. The interobserver reliability in treatment was 0.336 pre- and 0.254 post-CT, while trauma and arthroplasty were 0.323 to 0.288 and 0.688 to 0.519. For intraobserver the average k for diagnosis and treatment were 0.818 and 0.671. Broken down by subspecialty they were 0.874 and 0.831 and 0.762 and 0.510 for trauma and arthroplasty. There were 11 diagnostic and 24 treatment changes. Conclusion CT provides diagnostic changes 10% and treatment changes 24% of the time. However, it does not lead to greater agreement among the surgeons on either. Arthroplasty uses CT more to guide both their treatment and the diagnosis, and they agree more than trauma surgeons. Most of the treatment changes come from adding or removing a plate, and the most common diagnostic change was shared by A to B1 and B2 to B3. This suggests fracture extension and bone stock are better evaluated by CT.

The Stability of Fixation of Vancouver B2 Periprosthetic Femoral Fractures: Effect of Implantation Technique.

BACKGROUND: Due to increasing volume of total hip arthroplasties, periprosthetic femoral fractures have become a common complication with increased revision burden and perioperative morbidity. The objective of this study was to evaluate the fixation stability of Vancouver B2 fractures treated with 2 techniques. METHODS: A common B2 fracture was created by reviewing 30 type B2 cases. The fracture was then reproduced in 7 pairs of cadaveric femora. The specimens were divided into 2 groups. In Group I ("reduce-first"), the fragments were reduced first, followed by implantation of a tapered fluted stem. In Group II ("ream-first"), the stem was implanted in the distal femur first, followed by fragment reduction and fixation. Each specimen was loaded in a multiaxial testing frame with 70% of peak load during walking. A motion capture system was used to track the motion of the stem and fragments. RESULTS: The average stem diameter in Group II was 16.1 ± 0.4 mm, versus 15.4 ± 0.5 mm in Group I. The fixation stability was not significantly different in the 2 groups. After the testing, the average stem subsidence was 0.36 ± 0.31 mm and 0.19 ± 0.14 mm (P = .17) and the average rotation was 1.67 ± 1.30° and 0.91 ± 1.11° (P = .16) in Groups I and II, respectively. Compared to the stem, there was less motion of the fragments and there was no difference between the 2 groups (P > .05). CONCLUSIONS: When tapered fluted stems were used in combination with cerclage cables for treatment of Vancouver type B2 periprosthetic femoral fractures, both the "reduce-first" and "ream-first" techniques showed adequate stem and fracture stability.

Infarto omental como causa inusual de dolor abdominal: un reporte de caso / Omental infarction as an unusual cause of abdominal pain: a case report

Resumen El infarto omental es una causa infrecuente de abdomen agudo y de etiología no muy conocida, su presentación clínica inespecífica puede simular otras patologías más comunes, lo que hace su diagnóstico un reto clínico. Se presenta el caso de una mujer de 33 años que asiste a urgencias con clínica de dolor abdominal agudo, atípico, con hallazgos ecográficos sugestivos de apendicitis aguda, sin embargo, por la clínica inusual se realizó tomografía axial computarizada (TAC) de abdomen, con reporte sugestivo de diverticulitis. Ante la no concordancia clínica ni imagenológica, la paciente fue llevada a laparoscopia diagnóstica, como hallazgo intraoperatorio se evidenció isquemia del epiplón como único hallazgo, por lo cual se realizó omentectomía parcial. Siendo este un caso de importancia clínica debido a que el infarto omental debe considerarse entre los diagnósticos diferenciales de dolor abdominal agudo, en especial cuando la presentación es atípica y se han excluido las patologías más frecuentes. MÉD.UIS.2022;35(1): 43-8.

Abstract Omental infarction is an uncommon cause of acute abdomen and its etiology is not well known. Its nonspecific clinical presentation can simulate bibr more common pathologies which makes its diagnosis a clinical challenge. We present the case of a 33-year-old woman who attends the emergency room with symptoms of acute, atypical abdominal pain, ultrasound findings were suggestive of acute appendicitis, however, due to unusual symptoms, a computerized axial tomography (CT) of the abdomen was performed, with a suggestive report of diverticulitis. Given the clinical and imagenologycal findings mismatch, the patient underwent to diagnostic laparoscopy where omentum ischemia was evidenced as the only finding, partial omentectomy was performed. This is a case of clinical importance because the omental infarction should be considered among the differential diagnoses of acute abdominal pain, especially when the presentation is atypical and the most frequent pathologies have been excluded. MÉD.UIS.2022;35(1): 43-8.

The Length of Diaphyseal Contact of Tapered Fluted Stems is Highly Dependent on Canal Morphology.

BACKGROUND: Diaphyseal fixation remains the mainstay of revision THA. The stability of diaphyseal fixation can be quantified by the extent of contact between the stem and the endosteal cortex. This is highly affected by the morphology of the proximal femur. The purpose of this study was to examine factors affecting diaphyseal contact in the revision THA and to identify preoperative predictors of adequate fixation. METHODS: Three-dimensional femur models were created from CT scans of 33 Dorr B and C femora. The proximal 120 mm of the femur was omitted to mimic proximal bone deficiency. A tapered fluted stem (3 degrees, 150 mm) model was virtually implanted after reaming of the medullary canal. The contact length between stem and endosteal cortex was measured, in addition to other variables. The relationship between variables was evaluated using Spearman's correlation, and logistic regression analysis was used to identify predictors of the contact length (P < .05). RESULTS: The contact length varied widely between specimens (66.5 ± 16.6 mm, range: 21-98 mm). Contact increased with the depth of the isthmus below the lesser trochanter (range: 55-155 mm; r2 = 0.473, P = .005) and the distance between the isthmus and the distal edge of the damage zone (range: -9 to 96 mm; r2 = 0.508, P = .002). Stepwise regression identified the reaming length, distance between fracture and the isthmus, and isthmus diameter as independent predictors of contact length (r = 0.643). CONCLUSIONS: Contact is limited in specimens where the isthmus is more proximally located. In these cases, supplementary fixation using plating and/or longer, curved prosthesis may be considered.

Resampled Efficient Frontier Integration for MOEAs.

Mean-variance portfolio optimization is subject to estimation errors for asset returns and covariances. The search for robust solutions has been traditionally tackled using resampling strategies that offer alternatives to reference sets of returns or risk aversion parameters, which are subsequently combined. The issue with the standard method of averaging the composition of the portfolios for the same risk aversion is that, under real-world conditions, the approach might result in unfeasible solutions. In case the efficient frontiers for the different scenarios are identified using multiobjective evolutionary algorithms, it is often the case that the approach to averaging the portfolio composition cannot be used, due to differences in the number of portfolios or their spacing along the Pareto front. In this study, we introduce three alternatives to solving this problem, making resampling with standard multiobjective evolutionary algorithms under real-world constraints possible. The robustness of these approaches is experimentally tested on 15 years of market data.

Contemporary Robotic Systems in Total Knee Arthroplasty: A Review of Accuracy and Outcomes.

The success of total knee arthroplasty (TKA) depends on restoration of the stability and biomechanical efficiency of the native knee. The emergence of robotic surgical technologies has greatly increased the precision and reproducibility. We discuss contemporary robotic TKA systems by reviewing the features of the individual platforms, their accuracy, and the clinical outcomes. While early results suggest significant gains in patient outcomes, long-term evidence is still awaited from multicenter prospective clinical trials. Moreover, advances in this technology are needed to address knee laxity while individualizing the functional performance of each patient's new joint.

High-Copy Yeast Library Construction and High-Copy Rescue Genetic Screen in Saccharomyces cerevisiae.

High-copy rescue genetic screening is a powerful strategy for the identification of suppression genetic interactions in the model eukaryotic organism Saccharomyces cerevisiae (budding yeast). The strain carrying the mutant allele of interest is transformed with a genomic library cloned in a high-copy plasmid. Each clone carries a genomic fragment insertion of around 10 kb, typically containing one to three complete genes under their own promoters. The high-copy vector favors the accumulation of high levels of the corresponding protein, aimed at suppressing the mutant phenotype. Typically, high-copy genetic screens select for viable clones under conditions restrictive or lethal for the query mutant strain. Here, we describe in detail the procedure to generate a high-copy genomic library and a protocol for rescue genetic screening and identification of the suppressor clones.

Trafficking of Stretch-Regulated TRPV2 and TRPV4 Channels Inferred Through Interactomics.

Transient receptor potential cation channels are emerging as important physiological and therapeutic targets. Within the vanilloid subfamily, transient receptor potential vanilloid 2 (TRPV2) and 4 (TRPV4) are osmo- and mechanosensors becoming critical determinants in cell structure and activity. However, knowledge is scarce regarding how TRPV2 and TRPV4 are trafficked to the plasma membrane or specific organelles to undergo quality controls through processes such as biosynthesis, anterograde/retrograde trafficking, and recycling. This review lists and reviews a subset of protein-protein interactions from the TRPV2 and TRPV4 interactomes, which is related to trafficking processes such as lipid metabolism, phosphoinositide signaling, vesicle-mediated transport, and synaptic-related exocytosis. Identifying the protein and lipid players involved in trafficking will improve the knowledge on how these stretch-related channels reach specific cellular compartments.

Synthetic and real data sets for benchmarking non-cryptographic hash functions.

The overall assessment of non-cryptographic functions is very complex and there is not a widely used benchmark. These data have been collected and created as a benchmark for testing non-cryptographic hash functions. It is made up of eight dataset which comes from two different groups, real and synthetic data sources. The objective when selecting and generating the data has been redundancy and structures present in real-world scenarios. These data have been used for benchmarking non-cryptographic hash functions in [1] and [2].

Data-Driven Interaction Review of an Ed-Tech Application.

Smile and Learn is an Ed-Tech company that runs a smart library with more that100 applications, games and interactive stories, aimed at children aged two to 10 and their families.The platform gathers thousands of data points from the interaction with the system to subsequentlyoffer reports and recommendations. Given the complexity of navigating all the content, the libraryimplements a recommender system. The purpose of this paper is to evaluate two aspects of such systemfocused on children: the influence of the order of recommendations on user exploratory behavior, andthe impact of the choice of the recommendation algorithm on engagement. The assessment, based ondata collected between 15 October 2018 and 1 December 2018, required the analysis of the number ofclicks performed on the recommendations depending on their ordering, and an A/B/C testing wheretwo standard recommendation algorithmswere comparedwith a randomrecommendation that servedas baseline. The results suggest a direct connection between the order of the recommendation and theinterest raised, and the superiority of recommendations based on popularity against other alternatives.

Assessing the effectiveness of integrating ergonomics and sustainability: a case study of a Mexican maquiladora.

In 2015, the United Nations defined sustainable industrialization as one of 17 sustainable development goals. In this article, an analysis is performed to assess the opportunities for ergonomics to contribute toward sustainability in the manufacturing industry. To that effect, a case study was carried out in a maquiladora of electronic components in the northwestern region of Mexico. The investigation was developed in four stages: (a) diagnosis; (b) planning; (c) implementations; (d) verification of results. Barriers found during each stage are presented. Finally, a discussion of the obtained results is provided, and areas of opportunity for programs or actions to prevent health risks are identified.

Incremental Market Behavior Classification in Presence of Recurring Concepts.

In recent years, the problem of concept drift has gained importance in the financial domain. The succession of manias, panics and crashes have stressed the non-stationary nature and the likelihood of drastic structural or concept changes in the markets. Traditional systems are unable or slow to adapt to these changes. Ensemble-based systems are widely known for their good results predicting both cyclic and non-stationary data such as stock prices. In this work, we propose RCARF (Recurring Concepts Adaptive Random Forests), an ensemble tree-based online classifier that handles recurring concepts explicitly. The algorithm extends the capabilities of a version of Random Forest for evolving data streams, adding on top a mechanism to store and handle a shared collection of inactive trees, called concept history, which holds memories of the way market operators reacted in similar circumstances. This works in conjunction with a decision strategy that reacts to drift by replacing active trees with the best available alternative: either a previously stored tree from the concept history or a newly trained background tree. Both mechanisms are designed to provide fast reaction times and are thus applicable to high-frequency data. The experimental validation of the algorithm is based on the prediction of price movement directions one second ahead in the SPDR (Standard & Poor's Depositary Receipts) S&P 500 Exchange-Traded Fund. RCARF is benchmarked against other popular methods from the incremental online machine learning literature and is able to achieve competitive results.

Variability of arterial and peripheral venous blood gases parameters in subjects with stable obstructive pulmonary disease / Variabilidad de los parámetros de la gasometría arterial y venosa periférica en sujetos con enfermedad pulmonar obstructiva crónica en condición estable

Background: Peripheral venous blood gases may be useful in subjects with exacerbation of chronic obstructive pulmonary disease to evaluate their gas exchange. Objective: To describe the variability of parameters of arterial and peripheral venous blood gases in subjects with stable obstructive pulmonary disease. Methods: Cross-sectional design, consecutive subjects were studied in a blinded manner, while arterial and peripheral venous blood was obtained for analysis. Variability was established with Bland-Altman statistical method and its magnitude with the intraclass correlation coefficient (95 % confidence interval). Results: Three hundred blood samples from 150 patients were studied, 89 (59.3%) women, age 66 ± 10 years old, body mass index 28.44 ± 4.81 Kg/m2. Mean difference (bias) [intraclass correlation coeficient] pH 0.012 (-0.009, 0.032) [0.927], Carbon dioxide pressure -6.5 (-14.1, 1.1) [ 0.643], serum bicarbonate -1.3 (-3.3, 0.7) [0.929], base excess -1 (-4, 2.1) [0.904], hemoglobin -0.1 (-1.9, 1.8) [0.947]. Conclusions: The variability of pH, serum bicarbonate, and hemoglobin are similar in both blood samples. These arterial or peripheral venous blood gas parameters could be used interchangeably.

Introducción: la gasometría venosa periférica puede ser de utilidad en sujetos con exacerbación de la enfermedad pulmonar obstructiva crónica para evaluar su intercambio gaseoso. Objetivo: describir la variabilidad de los parámetros de la gasometría arterial y venosa periférica en sujetos con enfermedad pulmonar obstructiva crónica en condición estable. Métodos: diseño transversal, se estudiaron sujetos consecutivos de forma cegada, al mismo tiempo se obtuvo sangre arterial y venosa periférica para su análisis. La variabilidad se determinó con el método estadístico de Bland-Altman y su magnitud con el coeficiente de correlación intraclase (intervalo de confianza al 95%). Resultados: se estudiaron 300 muestras sanguíneas de 150 pacientes, 89 mujeres (59.3%), edad del grupo 66 ± 10 años, el índice de masa corporal 28.44 ± 4.81 Kg/m2. La diferencia media (sesgo) [coeficiente de correlación intraclase] para el pH: 0.012 (-0.009, 0.032) [0.927], presión de bióxido de carbono: -6.5 (-14.1, 1.1) [ 0.643], bicarbonato sérico: -1.3 (-3.3, 0.7) [0.929], y exceso de base: -1 (-4, 2.1) [0.904], hemoglobina: -0.1 (-1.9, 1.8) [0.947]. Conclusiones: la variabilidad del pH, el bicarbonato sérico y la hemoglobina son similares en ambas muestras sanguíneas. Estos parámetros de la gasometría arterial o venosa periférica podrían ser utilizados en forma intercambiable.

Internet Use and Psychological Well-Being at Advanced Age: Evidence from the English Longitudinal Study of Aging.

This work explores the connection between psychological well-being and Internet use in older adults. The study is based on a sample of 2314 participants in the English Longitudinal Study of Aging. The subjects, aged 50 years and older, were interviewed every two years over the 2006-2007 to 2014-2015 period. The connection between the use of Internet/Email and the main dimensions of psychological well-being (evaluative, hedonic and eudaimonic) was analyzed by means of three generalized estimating equation models that were fitted on 2-year lagged repeated measurements. The outcome variables, the scores on three well-being scales, were explained in terms of Internet/Email use, controlling for covariates that included health and socioeconomic indicators. The results support the existence of a direct relationship between Internet/Email use and psychological well-being. The connection between the main predictor and the score of the participants on the scale used to measure the eudaimonic aspect was positive and statistically significant at conventional levels (p-value: 0.015). However, the relevance of digital literacy on the evaluative and the hedonic components could not be confirmed (p-values for evaluative and hedonic dimensions were 0.078 and 0.192, respectively).