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Selective Conversion of Polyolefin Waste to Branched Alkanes via Methane‐Free Tandem Hydrocracking–Isomerization
Full text linkIn recent years, catalytic hydrocracking has emerged as a promising waste‐to‐feedstock solution for processing plastic waste. Although ruthenium nanoparticle catalysts exhibit high activity in converting polyolefins into small alkanes, they also tend to produce undesirable methane (CH4) via terminal C─C bond hydrogenolysis. Herein, we report a Ru‐supported sulfated zirconia (RuSZ1) catalyst for the efficient isomerization and hydrocracking of polyolefins without generating CH4. Various high‐Mw polyethylene and polypropylene samples (up to 1 000 000 g/mol) were fully converted into branched alkanes (C4‐C20). Control experiments using RuSZ1 revealed negligible scission activity for alkanes with fewer than seven carbons, suggesting that isomerization precedes hydrocracking. Hydrogenolysis to form C1 and C2 products is likely inhibited by saturation of sulfate species at the Ru sites, and these products were not observed under any reaction conditions. Full conversion of polyolefins under solvent‐free conditions was achieved, with up to 93% yield of C3‐C12 alkanes
The ethics of Wegovy in pediatric mental health
Full text linkSemaglutide (Wegovy), a glucagon-like peptide-1 receptor agonist (GLP-1 RA), has attracted global attention for its appetite-suppressing and weight-loss effects. Approved by the U.S. FDA in 2022 for adolescents aged 12 and older, it has since been authorized in several other countries. Despite this, its use among youth remains limited, with ongoing concerns about its long-term safety, efficacy, and suitability during periods of growth and development. Advocates see Wegovy as an important tool for addressing pediatric obesity and its psychological burdens, while critics caution against widespread use in such a vulnerable population. This paper examines an underexplored ethical dimension of Wegovy's use in children: its impact on mental health. We argue that Wegovy may offer mental health benefits for children—such as reducing weight stigma, improving self-esteem, and avoiding invasive interventions such as bariatric surgery. However, these potential benefits are constrained by barriers to access, supply shortages, risks of misuse, and the possibility of reinforcing stigma and class-based discrimination. In light of these considerations, we argue that while Wegovy offers promising health benefits for children, its long-term effects on growth, development, and mental health remain uncertain, warranting further study before definitive policy decisions are made. If future evidence confirms its value, it is our view that access should be equitable and accompanied by reforms to reduce stigma, regulate prescribing, and prevent misuse. Until then, clinicians should prescribe cautiously, ensuring clear medical need and implementing safeguards against risks such as weight regain, treatment interruption, and bias in care
Self-defeating and self-fulfilling reactivity
Full text linkTheory-deduced predictions might change agents’ beliefs, and thus also agents’ behavior. Since agents react to their beliefs by modifying their behavior to obtain their goals, they might react to a belief inspired by a theory-deduced prediction by modifying their behavior to obtain their goals, and this may have implications for the theory and its predictive success. In this paper, I first theorize this phenomenon. I disqualify past formulations of so-called reflexive predictions and advocate my account of self-defeating and self-fulfilling reactivity. I then examine the implications of three kinds of self-defeating reactivity, weak, strong, and vicious, for predicting. I conclude that self-defeating reactivity makes it impossible to predict, at least in some cases. Finally, I rethink whether self-defeating and self-fulfilling reactivity is exclusive to the human/social sciences or to states of affairs where human beings/social actors are involved. Here, I conclude that while reactivity is not exclusive to the human/social sciences, it is exclusive to cases where agents are involved. Thus, it is exclusive to cases where human beings/social actors are involved only de facto
L²-Betti numbers and kernels of maps to ℤ
Full text linkThe main focus of this thesis is the connection between the L²-Betti numbers of RFRS groups and the existence of epimorphisms to ℤ with kernels having certain desirable properties. In particular, we show that if G is a RFRS group of type FPn(ℚ) for some n ⩾ 0, then G has a finite-index subgroup H ⩽ G admitting an epimorphism H → ℤ with kernel of type FPn(ℚ) if and only if bᵢ⁽²⁾(G) = 0 for all i ⩽ n. A consequence is that the fundamental group of any closed hyperbolic manifold with cubulated fundamental group virtually algebraically fibres with kernel of type FP(ℚ). We also prove that if G is a RFRS group of type FP(ℚ) and with cd_ℚ(G) = n, then G admits a virtual map to ℤ with kernel of rational cohomological dimension n - 1 if and only if bn⁽²⁾(G) = 0. In particular, we show that a finitely generated RFRS group of cohomological dimension two is virtually free-by-cyclic if and only if its second L²-Betti number vanishes (we stress that the free kernel of the free-by-cyclic group is finitely generated if and only if the first L²-Betti number vanishes as well). We obtain more general results in the wider class of residually poly-ℤ groups. We also prove analogues of the results in this and the previous paragraph over fields of positive characteristic, where the L²-Betti numbers must be replaced with suitable positive characteristic analogues. Finally, and in a slightly different direction, we show that any group algebra of a torsion-free 3-manifold group embeds into a division ring, and as a consequence show that group algebras of torsion-free 3-manifold groups satisfy Kaplansky's Zero Divisor Conjecture
Tradeoffs between brain and digestive tissues across elevations in Typhlomys daloushanensis: evidence for sexual dimorphism
Full text linkTo cope with highly stochastic and/or heterogeneous environmental conditions, animals must balance energy resource allocation across physiological processes. The digestive tract and brain exhibit structural variations under strong developmental and selective pressures that vary across environmental gradients both between and within species. Here, we measured body mass, body length, digestive tract segments lengths (stomach, cecum, small intestine, large intestine), brain weight, and relative brain size (scale mass index, SMI residuals) for 67 Chinese pygmy dormice Typhlomys daloushanensis (29 females and 38 males), an ancient, small, arboreal rodent species with echolocation abilities, captured at 37 sites between 414 and 1757 m a.s.l. From standardized major axis (SMA) regressions, we found no significant relationship between body size (SMI) and elevation. Notably, neither digestive tract segment lengths and their residuals nor brain weight (absolute and residual) correlated significantly with elevation in either sex, and slopes did not differ between males and females, providing no support for the digestive tract theory (DTT) or the cognitive buffer hypothesis (CBH). However, brain–digestive tract relationships exhibited sex‐specific differences, partially supporting the expensive tissue hypothesis (ETH), suggesting that energy allocation to high‐cost organs is sex‐dependent. Males maintained relatively heavier brain weight under comparable digestive tract lengths, likely to meet cognitive demands associated with mate competition, territorial defense, and exploratory behavior, whereas females tended to prioritize digestive tract investment to meet the energetic demands of gestation and lactation. Thus, classical predictions of body size–environment relationships may be overridden by sex‐specific physiological tradeoffs in specialized species, providing new insights into how small mammals may adapt to rapid environmental change
Impact of real-time continuous glucose monitoring on glycaemic control in adults with type 2 diabetes: systematic review and meta-analysis
Full text linkObjective: To evaluate the effectiveness of real-time continuous glucose monitoring compared with self-monitoring of blood glucose in adults with type 2 diabetes, focusing on glycaemic control, cardiometabolic outcomes, and patient-centred measures. Methods: Randomised controlled trials published in English with study intervention period ≥12 weeks, which compared real-time continuous glucose monitoring with self-monitoring of blood glucose in adults with type 2 diabetes were included in this systematic review. Analyses were conducted using Review Manager version 9.6. Risk of bias was evaluated using the Cochrane risk-of-bias tool. The Grading of Recommendations Assessment, Development and Evaluations approach was used to assess certainty of evidence. Data Sources: The search was conducted across PubMed, CINAHL, Web of Science, the Cochrane Library databases and ClinicalTrials.gov from inception to July 2025. Results: This systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eleven studies which compared real-time continuous glucose monitoring (n=437) with self-monitoring of blood glucose (n=352) were included. Real-time continuous glucose monitoring use was associated with a significant reduction in HbA1c (mean difference=−0.20%), improved time-in-range (mean difference=7.41%), reduced time-above-range (mean difference=6.93%) and reduced time-below-range (mean difference=0.26%). Glucose variability was significantly lower (mean difference=-1.06%) and users demonstrated greater improvements in readiness for diabetes self-management (standardised mean difference=0.69). No significant differences were observed in cardiometabolic or psychosocial outcomes. Conclusion: Real-time continuous glucose monitoring improves glycaemic control and self-management capacity compared with self-monitoring of blood glucose in adults with type 2 diabetes. These findings support the integration of real-time continuous glucose monitoring into routine clinical care, particularly for individuals requiring intensive glucose monitoring and tailored self-care support. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42025625444
The Relationship Between Thyroid Function or Subclinical Hypothyroidism in Early Pregnancy and Risk of Low Birth Weight and Small for Gestational Age of the Offspring: A Multicentre Prospective Cohort Study
Full text linkObjective: To examine how maternal thyroid-stimulating hormone (TSH), free thyroxine (FT4) and thyroid peroxidase antibody (TPOAb) status in early pregnancy relate to low birth weight (LBW) or small for gestational age (SGA) outcomes. Methods: This prospective cohort analysis utilized data from 125,365 singleton pregnancies in the China Birth Cohort Study (2018-2022), with participants enrolled at 6-13+6weeks gestation from 9 tertiary hospitals. The potential associations among maternal thyroid functional indices, spectrum of thyroid dysfunction, and adverse neonatal outcomes (LBW/SGA) were statistically evaluated employing generalized linear mixed modeling techniques. Besides, to verify the consistency of these findings, we conducted comprehensive subgroup analyses across multiple demographic and clinical strata. Results: Among the final 86,015 eligible participants, LBW and SGA occurred in 3.18% (n=2,731) and 3.56% (n=3,060), respectively. After adjusting for maternal and neonatal characteristics, analyses revealed significant negative associations between circulating maternal thyroid hormone levels and offspring birth weight measurements (per 1 mIU/L increase in TSH: β = -5.62, 95% CI: -7.29 to -3.95, P < 0.001; per 1 pmol/L increase in FT4: β = -1.43, 95% CI: -2.21 to -0.65, P < 0.001). First-trimester subclinical hypothyroidism (SCH) was associated with increased risks of both LBW (aOR = 1.29, 95% CI: 1.04-1.59; P = 0.021) and SGA (aOR = 1.18, 95% CI:1.01-1.38; P = 0.037). Women in the highest TSH quintile had 20% higher LBW risk (aOR = 1.20, 95% CI: 1.02-1.41; P = 0.028) and 16% higher SGA risk compared to the lowest quintile (aOR = 1.16, 95% CI: 1.03-1.30; P = 0.012). The associations of TSH and FT4 with LBW and SGA were consistent across all subgroups. Conclusions: Elevated maternal TSH, elevated FT4 (even within high-normal ranges), and SCH in early pregnancy serve as significant risk indicators for LBW and SGA
Detecting Dementia Using Lexical Analysis: Terry Pratchett's Discworld Tells a More Personal Story
Full text linkBackground/Objectives: Dementia, characterised by cognitive decline, significantly impacts language abilities. While the risk of dementia increases with age, it often manifests years before clinical diagnosis. Identifying early warning signs is crucial for timely intervention. Previous research has demonstrated that changes in language, such as reduced vocabulary diversity and simpler sentence structures, may be observed in individuals with dementia. This study investigates the potential of linguistic analysis to detect early signs of cognitive decline by examining the writing of Sir Terry Pratchett, a renowned author diagnosed with Posterior Cortical Atrophy (PCA), typically a form of dementia caused by Alzheimer's disease. Methods: This study analysed 33 Discworld novels by Terry Pratchett, comparing linguistic features before and after a potential turning point identified through analysis of adjective type-token ratios (TTR). Results: A significant decrease in lexical diversity (TTR) was observed for nouns and adjectives in later works. Total wordcount increased, while lexical diversity decreased, suggesting a shift towards simpler language. This shift coincided with a decrease in adjective TTR below a defined threshold, occurring approximately ten years before Pratchett's formal diagnosis. Conclusions: These findings suggest that subtle changes in linguistic patterns, such as decreased lexical diversity, may precede clinical diagnosis of dementia by a considerable margin. This research highlights the potential of linguistic analysis as a valuable tool for early detection of cognitive decline. Further research is needed to validate these findings in larger cohorts and explore the specific linguistic markers associated with different types of dementia
Application of Transthoracic and Endobronchial Elastography-A Systematic Review
Full text linkIntroduction: Ultrasound elastography is increasingly used across medical imaging, yet its role in thoracic disease remains poorly defined. While both transthoracic ultrasonography (TUS) and endobronchial ultrasound (EBUS) offer real-time assessment of pleural and pulmonary structures, the diagnostic and clinical value of elastography in this context remains uncertain. Materials and Method: A systematic search of MEDLINE, EMBASE, and the Cochrane Library was conducted according to PRISMA guidelines (April 2023; updated January 2025). Original studies evaluating transthoracic or endobronchial elastography for pleural or pulmonary conditions were included. Data extraction and quality assessment were performed independently by three reviewers, with QUADAS-2 used to evaluate risk of bias. Results: Thirty studies met inclusion criteria. Twenty-eight evaluated TUS elastography and two examined EBUS. Shear wave elastography was most frequently applied, particularly for differentiating malignant from benign pleural effusion or subpleural lesions. Surface wave elastography demonstrated consistently higher stiffness values in patients with interstitial lung disease compared with healthy controls, correlating with radiological and functional disease severity. Elastography-guided pleural biopsy improved diagnostic yield compared with conventional ultrasound-guided biopsy. Overall, substantial methodological variation existed among scanning techniques, elastography modalities, reporting methods, and diagnostic thresholds, limiting cross-study comparison. Conclusions: Ultrasound elastography shows promise for evaluating pleural effusion and pulmonary lesions, procedural guidance, and interstitial lung disease possibly improving diagnostic possibilities with bedside evaluation and reducing patient exposure to radiation. However, methodological variation and limited high-quality evidence preclude clinical implementation. Standardized acquisition protocols and multicentre validation studies are necessary to define its diagnostic utility in thoracic imaging