Achieving high tensile ductility is crucial in structural materials, as it supports reliable load-bearing performance and good formability. Steels, the most widely used structural metals, show a wide range of elongation to failure, from a few percent to a few tens of percent. Recently, heterostructured materials (HMs) have been reported to exhibit superior tensile properties that surpass those of their homogeneous counterparts. Classical HMs with heterogeneity in the length scale less than a few hundred nanometres attribute their enhanced mechanical performance mainly to the hetero-deformation induced (HDI) hardening. However, the underlying mechanisms for HMs with mesoscale heterogeneities, i.e., in the length scale of a few hundred micrometers, are overlooked. Recent advances in additive manufacturing (AM) have provided opportunities to fabricate HMs over the mesoscale range with structural complexity. In this work, we employ the AM method to fabricate a type of mesoscale HM: bi-metallic heterostructured steels (HSs), consisting of 316L and PH17-4 stainless steels with distinct tensile strength and ductility. By tuning the ratios and fractions of 316L/PH17-4, we achieved 27.3%, 11.5%, and 1.8% improvements in the tensile ductility, ultimate tensile strength, and yield strength over 316L, respectively. Such enhanced tensile properties are mainly attributed to (i) confined-necking co-deformation, where the necking of PH17-4 is confined and delayed by 316L, offering more work hardening to the whole sample, (ii) switching between necking-induced and shear-induced failure modes, and (iii) the HDI hardening effect. This study paves the way for understanding and designing bi-metallic HSs with improved tensile properties using AM methods.

Body mass index (BMI) has been associated with length of stay and post-operative complications; however, minimally invasive surgery has been proposed to mitigate this. Using real-world data of patients undergoing minimally invasive surgery for uterine cancer, we investigated the association between BMI and length of stay. Among patients discharged the same day, we explored post-operative complications associated with BMI. This was a National Surgical Quality Improvement Program retrospective cohort study including patients who underwent minimally invasive surgery for uterine cancer from 2013 to 2022. We performed a multi-variable Poisson regression to assess the association between BMI and length of stay, adjusting for a priori selected patient-level factors. In patients discharged the same day after surgery, we performed multi-variable linear regression to assess associations between BMI and the following post-operative complications: wound disruption, blood transfusion, surgical site infections, urinary tract infection, pneumonia, sepsis, deep vein thrombosis, pulmonary embolism, renal insufficiency, myocardial infarction, stroke/cerebrovascular accident, and re-admission, return to the operating room, and death within 30 days. A total of 33,307 patients were included. Their median BMI was 34.2 kg/m2 (interquartile range [IQR] 12.88) and median length of stay was 1 day (IQR 1). Length of stay increased by approximately 0.5 hours per 5 kg/m2 (per BMI obesity class categorization). In total, 9186 patients (27.6%) were discharged the same day after their minimally invasive surgery for uterine cancer, and in this cohort, no association between BMI and any post-operative complications were found. In patients undergoing minimally invasive surgery for uterine cancer, BMI was not associated with a clinically significant increase in length of stay, and in those discharged the same day, BMI was not associated with post-operative complications. Minimally invasive surgery for uterine cancer should be considered standard of care regardless of patient BMI, and same-day discharge for patients with elevated BMI is safe.

Statins, used for cardiovascular disease (CVD) prevention, may offer hepatoprotective benefits. However, adherence to treatment indications and the associations between statin use, metabolic dysfunction-associated steatotic liver disease (MASLD), and elevated liver stiffness in the general population remain poorly understood. This prospective, population-based study included adults aged ≥40 years between 2011 and 2020. We evaluated statin indications for CVD risk using prevailing European Society of Cardiology/European Atherosclerosis Society clinical practice guidelines based on SCORE2 and SCORE2-Older Persons algorithms. We used multivariable regression to examine associations between statins, MASLD, and elevated liver stiffness, adjusting for demographic, socioeconomic and metabolic covariables. We performed dose-response analyses using WHO defined daily dosages. Of 6,405 eligible individuals, 6,055 participants were included in the analysis (median age 64 years; 56% female); MASLD was present in 32%, elevated liver stiffness in 4.8%, and statin use in 21%. Participants with MASLD had higher predicted 10-year CVD risk compared to participants without MASLD (p <0.001), yet were less likely to use statins: 33% of individuals with MASLD and an indication for statin treatment remained untreated, compared to 19% of those without MASLD (p <0.001). Statin use was associated with lower prevalence of MASLD (adjusted odds ratio 0.76; 95% CI 0.63-0.92) and elevated liver stiffness (adjusted odds ratio 0.65; 95% CI 0.46-0.92) relative to untreated individuals with a statin treatment indication. The highest statin WHO defined daily dosage category was associated with lower prevalence of MASLD (p = 0.033) and elevated liver stiffness (p = 0.035). Individuals with MASLD are less likely to use statins despite a contemporary guideline-based indication. Statin use is independently associated with lower prevalence of both MASLD and elevated liver stiffness. These findings underscore the need to improve CVD risk management in this population with the potential added benefit of mitigating MASLD. In this large prospective, population-based study, statins were underutilized in metabolic dysfunction-associated steatotic liver disease (MASLD) compared to non-MASLD individuals, even though they had the highest cardiovascular risk and met guideline-based treatment criteria. Our findings further demonstrate that individuals who used statins had a lower likelihood of MASLD and elevated liver stiffness compared with statin-eligible individuals who were not treated. Taken together, these results highlight a missed opportunity: optimizing statin use in people with MASLD could strengthen cardiovascular disease prevention while also offering potential benefits for liver health.

The use of spinal cord stimulation (SCS) for managing severe refractory chronic pain has expanded considerably due to positive statistical evidence regarding its use; however, the statistical robustness of the underlying randomized controlled trials (RCTs) requires further scrutiny. One such tool that can be used for this purpose is the fragility index, which quantifies how many individual outcome events must be altered for an outcome to lose statistical significance. Thus the index can be used quantitatively to assess the stability and robustness of an RCT's conclusions, with higher values indicating increased trial stability. This study assesses the fragility of pain outcomes across RCTs investigating SCS for chronic pain to better understand the quality and robustness of evidence. A systematic search was conducted for RCTs assessing SCS for any chronic pain indication. The primary outcome was an evaluation of the trial-specific fragility index for the prespecified pain primary outcomes of RCTs. Secondary outcomes included an evaluation of fragility for (1) specified indications for SCS therapy, (2) reported pain outcomes appearing in three or more RCTs, (3) the presence/absence of a conflict of interest, and (4) comparisons of SCS to conservative management or different SCS waveform modalities. A total of 30 RCTs were included. The median (interquartile range [IQR]) fragility index across the primary outcome of all trials was 5.45 (3.00 to 11.45). There was no statistical difference between the (1) types of outcomes (dichotomous vs. continuous; P = 0.710), (2) primary versus secondary pain outcomes ( P = 0.771), or (3) presence versus absence of trial conflict of interest ( P = 0.753). Indications with a median (IQR) fragility score greater than three included persistent spinal pain syndrome type 2 with a score of 8.00 (2.80 to 12.60), painful diabetic neuropathy with a score of 6.00 (3.00 to 11.80), complex regional pain syndrome with a score of 7.20 (4.62 to 81.50), mixed etiologies with a score of 9.00 (3.00 to 38.00), and other etiologies with a score of 3.00 (1.00 to 8.55). This study suggests that the majority of RCTs investigating primary pain outcomes after SCS therapy are robust with relatively high fragility scores. Reporting the fragility of outcomes in trials can provide a more comprehensive assessment of trial robustness and can further aid clinicians in interpreting trial results and making informed treatment decisions.