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Two-stage stratified sampling is a complex design that involves nested sampling units and stratification. This complexity increases when the strata have too few sampled units for variance estimation, necessitating the use of collapsed strata, where multiple strata are combined to ensure an adequate sample size. When collapsing strata, two cases can be distinguished depending on whether a size variable associated with the variable of interest is available at the stratum level.•We present computer-implementable formulas for total, mean, and ratio estimators, along with their corresponding sampling variance estimators, for stratified two-stage simple random sampling without replacement, and we provide ready-to-use algorithms.•We introduce two methods for grouping strata: (1) a deterministic approach that uses stratum codes to define an ordinal variable, which orders the strata, and (2) a stochastic method that aims to minimize within-group inertia, which measures the heterogeneity within the newly formed groups of strata.•We emphasize that, unlike the correlation between a size variable and the variable of interest at the stratum level, the bias of the sampling variance estimator for the collapsed strata technique is not invariant to linear transformations. It follows that a high correlation does not ensure a low-bias estimator of the sampling variance.

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INTRODUCTION: Systemic Lupus Erythematosus (SLE) warrants an early diagnosis and prompt management. Delay in diagnosis can result in repeated flares, permanent damage, and even death. There is a large variability in the time taken to diagnose SLE across the world. We undertook this study to determine the time taken for diagnosis of SLE in India and to identify the factors associated. METHODS: Patients with SLE diagnosed within the previous 1 year as per Systemic Lupus Erythematosus International Collaborating Clinics criteria (SLICC) 2012 criteria were included in a cross-sectional multicentre questionnaire-based survey. Demographic profile, self-reported socioeconomic status as per Kuppuswamy classification of socioeconomic status (version 2022) (SES), and several healthcare related parameters including referral pattern were recorded. Median time taken for diagnosis was used to demarcate early or late diagnosis and associated factors were explored. RESULTS: We included 488 patients with SLE from 10 rheumatology centres. The median time to diagnosis was 6 months Interquartile Range (IQR 3,14.7) and within 3 months in about one third [150(30.7%)]. Very early diagnosis (<1 month) was established in 78(16.0%) patients. The mean SLE Disease Activity Index (SLEDAI) at diagnosis was 10.28+7.24. In univariate analysis, an older age, lower SES, non-southern state of residence and larger family size were significantly associated with late diagnosis. In the multivariate analysis, higher SES (AOR 0.95, 95% CI: 0.92-0.98), multiple organ system involvement at initial presentation (AOR1.75 95%CI: 1.08-2.84) and place of residence in south Indian states (AOR1.92 95%CI: 1.24-2.97) had lesser odds of being associated with late diagnosis. Distance from the closest medical centre/professional did not influence the time to diagnosis. Majority of patients had first consulted a medical graduate (42.5%) or postgraduate doctor (48.2%), and referral to rheumatologist was largely done by postgraduate (65%) doctors. More than half of our patients (61%) self-finance their treatment. CONCLUSION: Median time to diagnosis of SLE was 6 months, 1/3rd being diagnosed within 3 months and 78(16.0%) with 1 month of symptom onset. Delay in diagnosis was noted in those belonging to lower socioeconomic strata and those with single organ disease. Distance to the health care facility did not influence time to diagnosis.

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BACKGROUND: There is limited evidence to support treatment recommendations in patients with pulmonary arterial hypertension (PAH) and comorbidities. To investigate the impact of riociguat treatment in this patient population we analyzed pooled data from randomized controlled trials of riociguat. METHODS: This post hoc analysis included data from the PATENT-1, PATENT-2, PATENT PLUS, and REPLACE studies. Safety, efficacy (6-minute walk distance [6MWD], World Health Organization functional class [WHO-FC], and N-terminal pro-brain natriuretic peptide [NT-proBNP]), and COMPERA 2.0 risk status were assessed in patients with 0, 1-2, or 3-4 cardiometabolic comorbidities (obesity, systemic hypertension, diabetes mellitus, coronary artery disease) in the main phase of the studies. Safety was also assessed in the long-term extensions. RESULTS: The analysis included 686 patients (riociguat, n = 440; placebo, n = 132; phosphodiesterase type 5 inhibitors [PDE5i], n = 114), of whom 55%, 39%, and 6% had 0, 1-2, and 3-4 comorbidities, respectively. In the main phase, rates, and severity of adverse events (AEs) were similar in riociguat-treated patients across comorbidity subgroups. After 2 years, discontinuations of riociguat due to AEs were also similar across subgroups. Compared with placebo and PDE5i, riociguat improved 6MWD and NT-proBNP across comorbidity groups, and improved WHO-FC and COMPERA 2.0 risk status in patients with 0 or 1-2 comorbidities. CONCLUSIONS: Riociguat had an acceptable safety profile in PAH patients with cardiometabolic comorbidities. Efficacy and risk assessment results suggest that riociguat can be beneficial for patients with PAH irrespective of the presence of comorbidities.

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The hydrogeological conditions of the Qianbei coalfield are complex, and karst water in the roof rock frequently disrupts mining operations, leading to frequent water inrush incidents. Taking the representative Longfeng Coal Mine as a case study, research was conducted on the development pattern of the water-conducting fracture zone and the water inrush mechanisms beneath karst aquifers. On the basis of key stratum theory and calculations of the stratum stretching rate, the karst aquifer in the Changxing Formation was identified as the primary key stratum. It was deduced that the water-conducting fracture zone would develop into the karst aquifer, indicating a risk of roof water inrush at the working face. Numerical simulations were used to study the stress field, displacement field, and plastic zone distribution patterns in the overlying roof strata. Combined with similar simulation tests and digital speckle experiments, the spatiotemporal evolution characteristics of the water-conducting fracture zone were investigated. During the coal mining process, the water-conducting fracture zone will exhibit a "step-type" development characteristic, with the fracture morphology evolving from vertical to horizontal. Near the goaf boundary, the strain gradually decreases, and the instability of the primary key stratum significantly impacts the mining space below, leading to the closure of interlayer voids or the redistribution of water-conducting fissure patterns. Field measurements of the water-conducting fracture zone reveal that postmining roof fractures can be classified into tensile-shear, throughgoing, and discrete types, with decreasing water-conducting capacity in that order, the measured development height of the water-conducting fracture zone (51 m) aligns closely with the theoretical height (51.37 m) and the numerical simulation height (49.17 m). Finally, from the perspective of key stratum instability, the disaster mechanisms of dynamic water inrush and hydrostatic pressure water inrush beneath the karst aquifers in the northern Guizhou coalfield were revealed. The findings provide valuable insights for water prevention and control efforts in the Qianbei coalfield mining area.

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INTRODUCTION: Risk assessment can aid management of pulmonary arterial hypertension (PAH) and clinical decision-making. This analysis describes characteristics, treatment patterns and outcomes of patients with PAH, categorised by risk status at time of treatment escalation with selexipag in clinical settings. METHODS: Patients initiating selexipag in the ongoing multicentre, prospective EXPOSURE (EUPAS19085) study were grouped as low, intermediate-low, intermediate-high or high risk of 1-year mortality according to the ESC/ERS 4-strata method. RESULTS: As of November 2022, 77% (535/698) of patients initiating selexipag had data allowing for risk calculation; 14% (N = 76) were low, 31% (N = 168) intermediate-low, 34% (N = 182) intermediate-high and 20% (N = 109) high risk of 1-year mortality. Overall, patients were predominantly female (71%), with idiopathic/heritable PAH (56%) or PAH associated with connective tissue disease (CTD-PAH; 27%), median age of 60 years and prevalent (2 years) disease. From low to high risk, proportion of CTD-PAH and age increased (from 12%-40% and 46-68 years, respectively); time from diagnosis decreased and presence of cardiovascular risk factors increased. Most patients across risk groups (74-81%) initiated selexipag as part of triple oral combination therapy. Overall median (Q1, Q3) selexipag exposure duration was 10.1 (3.5, 24.1) months. Proportions of hospitalised patients increased with increasing risk group (16-42% from low to high, respectively); more hospitalisations were PAH-related for the high risk (71%) versus other risk groups (47-54%). Kaplan-Meier survival estimates were 98%, 98%, 93% and 80% at 1-year and 98%, 92%, 81% and 67% at 2-years, from low to high risk, respectively. CONCLUSIONS: In clinical settings, selexipag is initiated across all risk groups, predominantly as triple therapy. Only 45% of patients being at low/intermediate-low risk at selexipag initiation suggests an opportunity for more frequent patient monitoring and earlier treatment escalation, given that 4-strata risk assessment was prognostic for hospitalisations and survival in this contemporary PAH cohort. A graphical abstract is available with this article.

Pulmonary arterial hypertension (PAH) is a disease that gets worse over time. To make decisions about treatment, we need to know the stage of the disease. We can do this by measuring the patient's risk of death during the next few years. Selexipag is a medication for PAH. This analysis included patients living in Europe and Canada who started treatment with selexipag for their PAH disease. Our findings suggest that the monitoring of patients' health and the timing of starting selexipag can be improved. This analysis includes 698 patients taking part in the EXPOSURE study (EUPAS19085), which looks at the real-life treatment of patients with PAH. Overall, 71% of patients were female, the median age was 60 years, most had been diagnosed with PAH for around 2 years and were already taking two other medications for their PAH disease. At the beginning of selexipag treatment, 14% of patients were classified as low risk, 31% as intermediate-low risk, 34% as intermediate-high risk and 20% as high risk of mortality within the next year. More high-risk patients were hospitalised compared with the lower risk groups. After 1 year of treatment, more patients in the low (98%) and intermediate-low groups (98%) were alive than those in the intermediate-high (93%) and high risk groups (80%). The same was true after 2 years of treatment with selexipag (98%, 92%, 81% and 67%, respectively). This study confirms that assessing patients' risk levels can indicate how well they will do over time and shows that earlier treatment with selexipag should be considered to potentially prevent worsening of the disease.

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While tunnel boring machines (TBMs) tunneling in clayey strata, the adhered excavated soil on the cutterhead and cutting tools tends to form mudcake after compaction and consolidation. Mudcake can obstruct the cutterhead openings and rendering the cutting tools ineffective, leads to a substantial reduction in advance rate. Dispersants are recognized as an effective method for the disintegration of mudcakes. A novel set of equipment, comprising a mudcake compression device and a mudcake disintegration apparatus, is developed for assessing mudcake disintegration properties. The results showed that mudcakes underwent a tripartite disintegration process in water, including an initial stage, a rapid disintegration stage, and a stable stage. In the initial stage, the mudcakes absorbed water before disintegration, resulting in marginal changes in the weight of the disintegrated mudcakes. In the rapid disintegration stage, the weight of the disintegrated mudcakes increased quickly. During the stable stage, the weight of the disintegrated mudcakes remained relatively constant. The submersion of mudcakes in a dispersant solution substantially increased the rate of disintegration. Greater dispersant concentration corresponded to an increase in the disintegration rate. No weight gain was observed in mudcakes during the initial disintegration stage. When mudcakes disintegrated in a bentonite slurry, the weight of the disintegrated mudcakes initially decreased and then stabilized. The weight of the disintegrated mudcakes turned negative, indicating an increase in the weight of mudcakes. This suggested that bentonite significantly hindered mudcake disintegration.

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Due to the large mining area, the fully-mechanized top-caving mining with thick-hard roof is easy to form cantilever structure on the lateral roof of the working face, which on the one hand causes high stress level of adjacent roadway and serious deformation of roadway, on the other hand causes gas accumulation in corners, which brings severe challenges to safe and efficient mining of the mine. In this study, a mine facing such problems in Jincheng, China was taken as the research object. Based on the mechanical characteristics of coal and rock, the characteristics of overlying strata activity in the mining process of working face are mastered, and the dual effects of controlled transformation of lateral overlying strata structure on stress field and gas field were revealed. On this basis, roadway reinforcement and gas drainage schemes were put forward and applied. The results showed that the strength of the hard rock stratum was high in the triaxial stress environment, and it was not easily destroyed. However, once the strata exceed their strength threshold, they break down. In addition, the strength of coal is relatively low, and it is continuously deformed when the force exceeds its strength. The overlying strata structure after thick-hard roof fully-mechanized top-caving mining evolves in the following manner: "long cantilever length formed by the main roof being broken in the initial stage, voussoir beam formed by the upper hard roof being broken in the middle stage, and double cantilever beam formed by overlying strata compaction." The stress carried by upper hard rock stratum is transferred to coal pillars, which is the main reason for the high stress environment of multi-purpose roadway with large coal pillars. The controlled transformation of lateral overlying strata structure by pre-splitting and roof cutting can realize the "transfer-unloading" of coal pillar stress and the "plugging and driving" of corner gas. Based on the hydraulic fracturing reconstruction of lateral overburden structure, the grouting reinforcement scheme of roadway and dynamic gas drainage scheme were put forward. The results demonstrated that after roof cutting, the maximum deformation of the surrounding rock in the multi-purpose roadway was reduced by approximately 90 %, and the maximum concentration of corner gas was decreased by 15.28 %. This approach successfully achieved a collaborative control effect on roadway surrounding rock stability and gas emission well within the safety limits.

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The surrounding rock pressure of vertical shafts is one of the basic parameters of shaft lining design. Investigating its calculation methods and applicable scopes has great engineering significance. The paper classifies and compares the calculation methods, discusses the application scopes of various calculation methods, and proposes that the axisymmetric layered method is highly consistent with the field monitoring data for the calculation of surrounding rock pressure of vertical shafts in bedrock sections on the basis of practical engineering examples. On the basis of Terzaghi theory, the calculation formula of surrounding rock pressure of vertical shaft in inclined rock strata with single group joints is derived. The formula can reflect the influence of rock strata dip angle and joints.

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This article focuses on the health perceptions of people across social strata and nations using the combined dataset of the World Values Survey and the European Values Study (EVS/WVS). An intercategorical intersectional analysis model was developed to examine the social determinants underlying differences in health perceptions. Using logistic regression of the interactions between sex, age, level of educational attainment and income, we calculated the impact of these variables (main effects) and their interactions within the intersecting categories on health perceptions. The group with the best perception of their health includes men aged 16-49, with a high income and an upper-middle level of education. Comparative analysis has been carried out to identify differences in the influence of intersectional categories across countries. Of particular relevance is the number of Eastern European countries where the perception of people aged 50 and over with low income is very poor.

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This study presents a case of weakly consolidated strata developed in Dananhu No.7 coal mine. Using a combination of numerical simulation, field measurement comparison, and the critical hydraulic gradient criterion, we investigate the overburden failure and the risk possibility of water-sand mixture inrush during excavation. The following are the principal findings: (1) Weakly consolidated rocks have poor physical characteristics, particularly when they are mudded and disintegrated after encountering water, which may become a favorable source of water-sand inrush; (2) The water-conducting zone develops to a height of 160.5 m with a crack-mining ratio of 15.29 times, extending upward to Toutunhe Formation aquifer. The predictions are consistent with measurements in adjacent mines with similar geological conditions; (3) Cracks without larger subsidence are developed at the front edge of the mining direction, and some parallel stepped cracks behind the goaf could be easily observed. Ground subsidence along the goaf center finally displays a symmetrically wide-gentle U shape; (4) The critical hydraulic gradient of Toutunhe Formation aquifer, aquifer above 3# coal seam, and aquifer of 3#-7# coal seam in Xishanyao Formation is 1.314, 1.351, and 1.380, the actual value is 0.692, 2.089, and 7.418 accordingly. It is inferred water-sand mixture outburst will not occur in Toutunhe Formation aquifer, while the potential risk exists in the aquifers of Xishanyao Formation. Through drainage and depressurization projects, a water-sand mixture outburst accident does not occur during excavation. This study reveals the overburden failure characteristics and the initiation mechanism of water-sand inrush in weakly cemented strata, as well as the internal relationship between them, which provides new research ideas for safe operation in other mining areas with similar geological conditions. The research work has certain practical guiding significance.

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Progressive recombination loss is a common feature of sex chromosomes. Yet, the evolutionary drivers of this phenomenon remain a mystery. For decades, differences in trait optima between sexes (sexual antagonism) have been the favoured hypothesis, but convincing evidence is lacking. Recent years have seen a surge of alternative hypotheses to explain progressive extensions and maintenance of recombination suppression: neutral accumulation of sequence divergence, selection of nonrecombining fragments with fewer deleterious mutations than average, sheltering of recessive deleterious mutations by linkage to heterozygous alleles, early evolution of dosage compensation, and constraints on recombination restoration. Here, we explain these recent hypotheses and dissect their assumptions, mechanisms, and predictions. We also review empirical studies that have brought support to the various hypotheses.

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In the Vetrix clade of Salix, a genus of woody flowering plants, sex determination involves chromosome 15, but an XY system has changed to a ZW system. We studied the detailed genetic changes involved. We used genome sequencing, with chromosome conformation capture (Hi-C) and PacBio HiFi reads to assemble chromosome level gap-free X and Y of Salix arbutifolia, and distinguished the haplotypes in the 15X- and 15Y-linked regions, to study the evolutionary history of the sex-linked regions (SLRs). Our sequencing revealed heteromorphism of the X and Y haplotypes of the SLR, with the X-linked region being considerably larger than the corresponding Y region, mainly due to accumulated repetitive sequences and gene duplications. The phylogenies of single-copy orthogroups within the SLRs indicate that S. arbutifolia and Salix purpurea share an ancestral SLR within a repeat-rich region near the chromosome 15 centromere. During the change in heterogamety, the X-linked region changed to a W-linked one, while the Z was derived from the Y.

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BACKGROUND: Risk stratification is the cornerstone of the management of pulmonary arterial hypertension (PAH). Current European Society of Cardiology/European Respiratory Society guidelines recommend using the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) three-strata risk model at baseline and the COMPERA 2.0 four-strata model at follow-up. However, the guidelines did not take into consideration other available risk scores such as the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2. RESEARCH QUESTION: Is REVEAL Lite 2 better at discriminating risk than the COMPERA risk assessment models at baseline or follow-up evaluations? STUDY DESIGN AND METHODS: This study analyzed data from patients with PAH consecutively enrolled between June 2011 and February 2022 in the PAH registry at our expert Pulmonary Hypertension Center. Patients were stratified according to REVEAL Lite 2 and COMPERA three- and four-strata risk scores at baseline and follow-up to predict the composite outcome for lung transplantation or death. Receiver-operating characteristic curves in predicting the binary outcome at 3, 5, and 7 years were plotted. Areas under the curve of the scores were compared by using the χ2 test. The performance of the scores was determined according to the Harrel C statistic. RESULTS: A total of 296 patients were included for baseline and 196 for follow-up evaluation. The overall transplant-free survival in the patient population at 1, 3, 5, and 7 years was 93.6%, 81.3%, 75.1%, and 68.8%, respectively. At baseline, the C statistic of REVEAL Lite 2 was 0.74 (95% CI, 0.69-0.80), compared with 0.68 (95% CI, 0.63-0.74) for the COMPERA four-strata model and 0.63 (95% CI, 0.58-0.69) for the COMPERA three-strata model. All C statistic differences between REVEAL Lite 2 and the other models were statistically significant at baseline. INTERPRETATION: Our analysis showed that REVEAL Lite 2 was better at baseline at discriminating risk in this patient population. Future guidelines should consider including REVEAL Lite 2 in the management algorithm to help clinicians make informed decisions. Further analysis in larger cohorts could help validate these findings.

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The feeding posture of a group of François' langurs in Fusui County, Guangxi, was studied using instantaneous scan sampling from January to December 2016 to explore how the species adapts to karst limestone forests by collecting data on feeding posture, forest strata height, and substrate use. The results showed that leaves were the main food type of the François' langurs, with young leaves accounting for 64.97% ± 19.08% of the food composition, mature leaves accounting for 11.88% ± 12.09%, fruits accounting for 12.96% ± 12.89%, flowers accounting for 4.16% ± 4.06%, and other food types, including stems, petioles, and other unknown parts of the tree, accounting for a total of 6.03% ± 9.09%. The François' langurs had four main postures during feeding, of which sitting and bipedal standing feeding accounted for the largest proportions, at 85.99% ± 5.97% and 12.33% ± 6.08% of the total records, respectively. Quadrupedal standing and suspending were rarely observed and only appeared occasionally during feeding activities at the peak resting period, the two postures together accounting for 1.39% ± 1.59% of the total records. The feeding postures of the langurs had marked seasonal variation, as evidenced by the fact that seated feeding accounted for a significantly higher proportion of the total behavioral records in the rainy season than in the dry season, whereas feeding while standing bipedally was significantly more frequent during the dry season. Correlation analyses showed that feeding posture was correlated with food composition, showing a positive correlation between the proportion of bipedal standing feeding and mature leaf consumption. François' langurs preferred to forage in the lower and middle forest layers, with the lower forest layer accounting for 55.93% ± 16.50% of the total number of recordings and the middle forest layer accounting for 33.63% ± 18.33%. Langurs were less likely to forage on the ground (rocks), accounting for only 6.79% ± 4.78% of the records. The frequency of langurs feeding in the upper part of the forest layer was the lowest at 3.65% ± 2.73%. Additionally, in the dry season, langurs utilized the lower forest layer more but used the middle forest layer less than in the rainy season. This study demonstrates that the spatial distribution of foods in the limestone forest has an important effect on the feeding posture of François' langurs and their forest layer utilization.

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INTRODUCTION: Pulmonary arterial hypertension (PAH) is a rare, progressive disease associated with significant morbidity and mortality. The phase 3 STELLAR trial tested sotatercept plus background therapy (BGT) versus placebo plus BGT. BGT was comprised of mono-, double-, or triple-PAH targeted therapy. Building on STELLAR findings, we employed a population health model to assess the potential long-term clinical impact of sotatercept. METHODS: Based on the well-established ESC/ERS 4-strata risk assessment approach, we developed a six-state Markov-type model (low risk, intermediate-low risk, intermediate-high risk, high risk, lung/heart-lung transplant, and death) to compare the clinical outcomes of sotatercept plus BGT versus BGT alone over a lifetime horizon. State-transition probabilities were obtained from STELLAR. Risk stratum-adjusted mortality and lung/heart-lung transplant probabilities were based on COMPERA PAH registry data, and the post-transplant mortality probability was obtained from existing literature. Model outcomes were discounted at 3% annually. Sensitivity analyses were conducted to examine model robustness. RESULTS: In the base case, sotatercept plus BGT was associated with longer life expectancy from model baseline (16.5 vs 5.1 years) versus BGT alone, leading to 11.5 years gained per patient. Compared with BGT alone, sotatercept plus BGT was further associated with a gain in infused prostacyclin-free life years per patient, along with 683 PAH hospitalizations and 4 lung/heart-lung transplant avoided per 1000 patients. CONCLUSIONS: According to this model, adding sotatercept to BGT increased life expectancy by roughly threefold among patients with PAH while reducing utilization of infused prostacyclin, PAH hospitalizations, and lung/heart-lung transplants. Real-world data are needed to confirm these findings. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT04576988 (STELLAR).

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Within the principal stratification framework in causal inference, the majority of the literature has focused on binary compliance with an intervention and modelling means. Yet in some research areas, compliance is partial, and research questions-and hence analyses-are concerned with causal effects on (possibly high) quantiles rather than on shifts in average outcomes. Modelling partial compliance is challenging because it can suffer from lack of identifiability. We develop an approach to estimate quantile causal effects within a principal stratification framework, where principal strata are defined by the bivariate vector of (partial) compliance to the two levels of a binary intervention. We propose a conditional copula approach to impute the missing potential compliance and estimate the principal quantile treatment effect surface at high quantiles, allowing the copula association parameter to vary with the covariates. A bootstrap procedure is used to estimate the parameter to account for inflation due to imputation of missing compliance. Moreover, we describe precise assumptions on which the proposed approach is based, and investigate the finite sample behavior of our method by a simulation study. The proposed approach is used to study the 90th principal quantile treatment effect of executive stay-at-home orders on mitigating the risk of COVID-19 transmission in the United States.

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BACKGROUND: To date there remains much ambiguity in the literature regarding the immunological interplay between SARS-CoV-2 and HIV and the true risk posed to coinfected individuals. There has been little conclusive data regarding the use of CD4 cell count and HIV viral load stratification as predictors of COVID-19 severity in this cohort. METHODS: We performed a retrospective, observational cohort study on people living with HIV (PLWH) who contracted COVID-19 in central and eastern Europe. We enrolled 536 patients from 16 countries using an online survey. We evaluated patient demographics, HIV characteristics and COVID-19 presentation and outcomes. Statistical analysis was performed using SPSS 20.1. RESULTS: The majority of the study cohort were male (76.4%) and 152 (28.3%) had a significant medical comorbidity. Median CD4 cell count at COVID-19 diagnosis was 605 cells/µL [interquartile range (IQR) 409-824]. The majority of patients on antiretroviral therapy (ART) were virally suppressed (92%). In univariate analysis, CD4 cell count <350 cells/µL was associated with higher rates of hospitalization (p < 0.0001) and respiratory failure (p < 0.0001). Univariate and multivariate analyses found that an undetectable HIV VL was associated with a lower rate of hospitalization (p < 0.0001), respiratory failure (p < 0.0001), ICU admission or death (p < 0.0001), and with a higher chance of full recovery (p < 0.0001). CONCLUSION: We can conclude that detectable HIV viral load was an independent risk factor for severe COVID-19 illness and can be used as a prognostic indicator in this cohort.

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Carbon nanomaterial is widely used in structural health monitoring due to the advantage of sensitivity and good mechanical properties. This study presents a novel approach employing carbon nanocomposite materials (CNMs) to characterize deformation and damage evolution in physical modelling. As the primary measurement method, the CNM is used to investigate the deformation characteristics of a 200-400 m thick sandstone bed at a 1 km deep longwall mine. The sandstone unit is identified as an ultra-thick key stratum (UTKS), with its thicknesses varying across different mining panels of the UTKS. The results of CNM monitoring show that the UTKS remains stable even after a consecutive excavation of 900 m in width. This stability impedes the upward propagation of overlying strata failure, leading to minimal surface subsidence. The study demonstrates the huge potential of CNM in the mining area, which can be useful for investigating material damage in physical modelling studies. The findings suggest that the cumulative extraction width in individual mining areas of the mine should be controlled to avoid a sudden collapse of the UTKS, and that special attention should be paid to where the UTKS's thickness changes substantially. The substantial variation in UTKS thickness significantly impacts the pattern of overburden subsidence.

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BACKGROUND: Sequential triple combination therapy is recommended for pulmonary arterial hypertension (PAH) patients who are not at therapeutic goal on dual therapy, but long-term data on efficacy and safety is scarce. OBJECTIVE: To assess the long-term impact of sequential triple combination therapy in patients with PAH who are not at goal on dual combination therapy. STUDY DESIGN AND METHODS: We performed a retrospective observational study in a racially/ethnically diverse cohort of consecutive PAH patients on a stable dual therapy regimen who remained in intermediate- or high-risk category and were subsequently initiated on sequential triple combination therapy. We studied interval change in functional, echocardiographic, and hemodynamic parameters, REVEAL 2.0 risk category and ERS/ESC 2022 simplified four-strata risk category. Multivariate logistic regression analysis was performed to identify independent predictors of successful risk reduction (achievement or maintenance of REVEAL 2.0 low-risk category). Kaplan-Meier survival curves were created to assess the effect of risk reduction on survival. RESULTS: Out of 414 PAH patients seen in our program, 55 patients received add-on sequential triple combination regimen and had follow-up hemodynamic data. The mean age was 57 years, with 85% women. The most common etiology of PAH was idiopathic/heritable (41.8%). Most patients were WHO functional class III (76.4%), and 34.5% of patients were in high-risk category (REVEAL 2.0). On a median follow-up of 68 weeks, there was a significant improvement in WHO Functional Class (p < 0.001), six-minute walk distance (35 m) with 61.8% of patients achieving low-risk status by REVEAL 2.0, and a 28% of patients' improvement in pulmonary vascular resistance. Female gender was identified as a strong predictor of successful risk reduction, whereas Hispanic ethnicity estimated right atrial pressure on echocardiogram and pericardial effusion predicted lower probability of risk reduction. Patients who achieved or maintained low-risk status had significantly improved survival. CONCLUSION: Add-on sequential triple combination therapy significantly increased functional, echocardiographic, and hemodynamic parameters with improvement in risk category and survival.

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Congenital malformations pose significant challenges in the low socioeconomic strata of developing countries. This review critically examines the prevalence, patterns, and factors influencing congenital malformations in these settings. It explores the physical, psychological, and economic consequences for affected individuals and their families and the social stigma and discrimination they face. The review highlights the importance of equity and access to healthcare services, the role of environmental factors and nutritional deficiencies, and the ethical considerations and policy implications associated with congenital malformations. Existing interventions, challenges in implementation, and innovative approaches are discussed. Gaps in knowledge and areas for further research are identified. Addressing congenital malformations in low socioeconomic strata requires multidisciplinary collaboration, advocacy, and inclusive policies. By prioritizing preventive measures, early detection, and comprehensive care, the burden of congenital malformations can be reduced, improving the quality of life for affected individuals and their communities.