The identification of human remains is a major challenge in forensic science, particularly in cases of advanced decomposition. Human teeth are among the most resilient tissues to environmental and post-mortem degradation, making them a valuable source of DNA for forensic identification. However, DNA preservation in teeth is influenced by multiple factors that can compromise the success of genetic analysis. Objective: This review analyzes the intrinsic and extrinsic factors affecting DNA preservation in human teeth, focusing on ante-mortem and post-mortem variables rather than the methodological aspects of DNA extraction and analysis. Methodology: A review of the literature was conducted, evaluating studies that assess the impact of biological factors (such as dental structure, pathology, and treatment) and environmental conditions (such as burial environment, temperature, and humidity) on DNA degradation in human teeth. Results: The findings indicate that DNA preservation is significantly influenced by the type of tooth, the presence of dental restorations or pathological conditions, and exposure to environmental factors. While some studies address these variables individually, forensic cases often involve complex interactions among multiple factors, making DNA recovery outcomes unpredictable. Conclusions: The degradation of DNA in human teeth results from a multifactorial process where intrinsic and extrinsic elements interact dynamically. A comprehensive understanding of these factors is essential for optimizing sampling strategies and improving DNA recovery success rates in forensic applications. Future research should aim to develop predictive models that account for these variables, enabling more effective case-specific approaches to forensic DNA analysis.

Irritable bowel syndrome (IBS) is a stress-related disease linked to psychosocial factors, though knowledge about its occupational psychosocial aspects is scarce. A cross-sectional study of the prevalence of IBS and its association with occupational psychosocial factors in Chilean workers was conducted. IBS prevalence, using the IBS-Rome IV criteria, in the working population was estimated using data from the National Health Survey of 2009. Data on occupational psychosocial aspects were drawn from the Chilean Survey of Employment, Health, and Work of 2009, and allocated to individual survey participants at the occupation-region level. Data on family and community stressors were available at the individual level. Prevalence ratios (PR) for IBS were computed using generalized linear mixed models to account for variability at the group level. The IBS prevalence in the overall working population (weighted n = 5 435 253) was 18.4%, but varied substantially by industry sector. Compared with 'professionals' (IBS prevalence = 7.3%), jobs with high prevalence of IBS included 'health and social work activities' [PR = 4.9; 95% confidence interval (CI) = 1.4-16.7], 'household employment' (PR = 4.8; 95% CI = 1.5-15.9), and 'manufacturing' (PR = 3.5; 95% CI = 1.0-11.8). With Karasek Job Demand Control scores assigned to occupations within regions, high job demand doubled the prevalence of IBS (PR = 2.0; 95% CI = 1.4-2.9), whereas high-skill discretion was associated with lower prevalence of IBS (PR = 0.6; 95% CI = 0.4-0.8). There was also evidence that these two factors were not independent; high-skill discretion appeared to buffer the effect of high job demand on IBS prevalence (P < 0.001). Occupational factors were associated with IBS prevalence, showing effects as important as those for non-occupational stresses such as civic insecurity or having health problems. High job skill discretion appeared to reduce the prevalence of IBS in the presence of high job demands. Given its high overall prevalence and poorly understood risk factors, further research on occupational psychosocial factors of IBS is warranted.

Objective To evaluate if extensive use of tear gas during the Chilean social uprising of 2019 was associated with a higher frequency of respiratory emergencies and bronchial diseases in a residential vulnerable population. Design Observational, longitudinal, repeated measures study. Settings Six healthcare centres (one emergency department and five urgent care centres) in the city of Concepción, Chile during 2018 and 2019. Participants This study was conducted on daily respiratory emergencies and diagnosis. Daily frequency of urgency and emergency visits are administrative data, publicly available and previously de-identified. Primary and secondary outcome measures Absolute and relative frequency of daily respiratory emergencies in infants and older adults. A secondary outcome was the relative frequency of bronchial diseases (International Classification of Diseases 10th Revision, ICD-10: J20–J21; J40–J46) in both age groups. We finally measured the rate ratio (RR) of bronchial diseases above the daily grand mean, since the number of visits with these diagnoses in several days was zero. Tear gas exposure was assessed as the uprising period. Models were adjusted by weather and air pollution information. Results Percentage of respiratory emergencies during the uprising rose by 1.34 percentage points (95% CI 1.26 to 1.43) in infants and 1.44 percentage points (95% CI 1.34 to 1.55) in older adults. In infants, the emergency department experienced a larger increment in respiratory emergencies (6.89 percentage points; 95% CI 1.58 to 2.28) than the urgent care centres (1.67 percentage points; 95% CI 1.46 to 1.90). The RR of bronchial diseases above the daily grand mean during the uprising period was 1.34 in infants (95% CI 1.15 to 1.56) and 1.50 in older adults (95% CI 1.28 to 1.75). Conclusions The massive use of tear gas increases the frequency and probability of respiratory emergencies and particularly bronchial diseases in the vulnerable population; we recommend revising public policy to restrict its use.

This protocol investigates the relationship between indoor air quality (IAQ) and respiratory health as well as academic performance in students. The effects of air purifiers in real-world educational settings on lung health and academic outcomes have not been extensively studied. Our objectives are to: (1) evaluate the effectiveness of low-cost air purifiers in improving IAQ; (2) assess their impact on children's lung function; and (3) examine their influence on academic performance. This prospective, pragmatic controlled trial involves students from two schools in central-southern Chile, with three classrooms at each school equipped with air purifiers over three weeks. IAQ is initially measured without purifiers, followed by two weeks of alternating between purifier models "A" and "B," with participants blinded to the brand of the devices. Measured outcomes include IAQ (PM 2.5, PM 10), lung function (peak flow measurements), and cognitive performance (memory, attention, language, and problem-solving). Confounding factors are controlled through guardian questionnaires and evaluations of outdoor air quality and weather conditions. Ethical approvals are obtained, and data collection is conducted during the winter of 2023.•A pragmatic controlled trial involving middle school students monitored and intervened during three weeks in selected classrooms to evaluate the impact of air purifiers.•Classrooms were equipped with air purifiers, and indoor air quality and thermal comfort was assessed both with and without the intervention, employing randomization and a blinding method for purifier brands in use.•Key outcomes on students were measured weekly, including environmental conditions, lung function, and academic performance.

Bone marrow involvement in B-cell non-Hodgkin lymphoma is an adverse prognostic factor; therefore, its detection is necessary at the time of diagnosis and during follow-up. This study evaluates the concordance between flow cytometry (FC) and bone marrow biopsy (BMB) in detecting bone marrow involvement in B-cell non-Hodgkin lymphomas as well as their prognostic relevance in a Chilean cohort. A total of 202 samples from 172 patients with diffuse large B-cell (DLBCL), follicular (FL), marginal-zone (MZL), and mantle cell (MCL) lymphoma were retrospectively analyzed; all patients underwent simultaneous BMB and FC. Bone marrow involvement was identified in 29% of samples via BMB and in 40% via FC, with an overall concordance of 89% (kappa: 0.75), which was lower in mantle cell lymphoma. Eleven percent of cases showed BMB-FC+ discordance, generally associated with low tumor burden. In survival analyses, the BMB+/FC+ group exhibited shorter overall and progression-free survival, and concordant involvement was associated with a higher risk of mortality and progression, particularly among patients with an intermediate or high IPI. Involvement detected exclusively by FC did not have a significant prognostic impact. These findings support the role of FC as a complementary or alternative diagnostic tool in settings with limited resources, improving sensitivity for detecting bone marrow involvement without compromising clinical relevance.