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SummaryIn the present meta-analysis based on real-world data, the use of dipeptidyl peptidase-4 inhibitors (DPP-4i), glucagon-like peptide-1 receptor agonists (GLP-1ra), or sodium-glucose cotransporter-2 inhibitors (SGLT2i) was not associated with the risk of fracture.IntroductionCumulative evidence from randomized control trials (RCTs) with limited fracture events showed that the use of DPP-4i, GLP-1ra, or SGLT2i may not affect the risk of fracture. However, additional insights from large population-based studies with routinely collected data on fracture events and an adequate amount of fracture events are necessary to draw firm conclusions. To refine and complement the results from RCTs, a systematic review and meta-analysis of observational studies were performed to investigate the association between the use of DPP-4i, GLP-1ra, or SGLT2i and the risk of fracture in real-world settings.MethodsThe PubMed and Web of Science databases were searched to identify relevant observational studies. A random-effect model was used to estimate the summary relative risks (RRs).ResultsThe use of DPP-4i (RR 0.83, 95% CI [confidence interval] 0.60, 1.14; n = 11), GLP-1ra (RR 0.65, 95% CI 0.24, 1.74; n = 4), or SGLT2i (RR 1.02, 95% CI 0.91, 1.16; n = 4) was not associated with the risk of fracture. In general, there was a consistent lack of association between the use of DPP-4i or GLP-1ra and the risk of fracture across nearly all subgroups, except for a significantly reduced risk of hip fracture with the use of GLP-1ra (RR 0.21, 95% CI 0.04, 0.98).ConclusionsCumulative real-world evidence does not support an association between the use of DPP-4i, GLP-1ra, or SGLT2i and the risk of fracture. Our findings, together with the cumulative evidence from RCTs, should reassure policy makers and medical practitioners that the use of these medications is unlikely to increase the risk of fracture among type 2 diabetes mellitus patients in general. Further studies need to investigate the long-term impact of these drugs on the fracture risk, particularly in high-risk populations.

SummaryIn the present meta-analysis, reductions in the risk of hip fracture with milk consumption were only observed among American adults, but not among Scandinavian adults, possibly because milk products are more commonly fortified with vitamin D in the former population than in Scandinavian countries. The reduction in the risk of hip fracture was also observed with yogurt consumption, which is often associated with healthy lifestyles and dietary patterns that contribute to improved bone health.IntroductionAlthough dairy products contain bone-beneficial nutrients, the association between dairy consumption and the risk of hip fracture remains equivocal. Fueling this uncertainty, the elevated risk of hip fracture in association with milk consumption was observed in a cohort of Swedish women. A systematic review and meta-analysis of prospective cohort studies was performed to critically evaluate the association, or lack thereof, between dairy consumption (milk, yogurt, and cheese) and the risk of hip fracture.MethodsA random effects model was used to generate the summary relative risks (RRs) with their 95% confidence intervals (CIs) for the associations of interest.ResultsIn the meta-analysis of the highest versus lowest category of consumption, higher consumption of yogurt (RR 0.78, 95% CI 0.68, 0.90), but not milk (RR 0.86, 95% CI 0.73, 1.02) or cheese (RR 0.85, 95% CI 0.66, 1.08), was associated with a lower risk of hip fracture. For milk, the reduced risk of fracture with higher milk consumption was observed in the USA (RR 0.75, 95% CI 0.65, 0.87), but not in Scandinavian countries (RR 1.00, 95% CI 0.85, 1.17). These findings were further supported by the fact that American studies (RR 0.93, 95% CI 0.88, 0.98; per 1 glass/day), but not Scandinavian studies (RR 1.01, 95% CI 0.95, 1.07; per 1 glass/day), demonstrated a linear association between milk consumption and the risk of hip fracture.ConclusionsThe cumulative evidence from prospective cohort studies reassuringly suggests that the risk of hip fracture may not be elevated among people who consume milk, yogurt, and cheese, and that a greater consumption of milk or yogurt may even be associated with a lower risk of hip fracture depending on the factors that may differ across the population of interest.

Individuals with diabetes mellitus (DM) have an increased risk of fracture. Glycemic control is crucial to the management of DM, but there are concerns pertaining to hypoglycemia development in the course of glycemic control target achievement. The extent to which glycemic control may affect the risk of fracture remains less defined. Hypoglycemia-induced falls have been suggested to contribute to an elevated risk of fracture in DM patients. In this meta-analysis of observational studies, we aimed to investigate the relative contribution of glycemic control, as measured by glycated hemoglobin (HbA1c), and hypoglycemia to the risk of fracture in DM. The PubMed and Web of Science databases were searched for relevant studies. A random-effects model was used to generate summary relative risks (RRs) and 95% confidence intervals (CIs). Both increased HbA1c levels (RR per 1% increase 1.08, 95% CI 1.03, 1.14; nstudies = 10) and hypoglycemia (RR 1.52, 95% CI 1.23, 1.88; nstudies = 8) were associated with an increased risk of fracture. The association between HbA1c levels and the risk of fracture was somewhat nonlinear, with a noticeably increased risk observed at an HbA1c level ≥ 8%. The positive associations of HbA1c levels and hypoglycemia with the risk of fracture did not reach statistical significance in the studies that adjusted for insulin use, hypoglycemia, or falls for the former and in those that adjusted for falls for the latter. In summary, both increased HbA1c levels and hypoglycemia may increase the risk of fracture in patients with DM. The positive association between HbA1c levels and the risk of fracture appears to be, in part, explained by hypoglycemia-induced falls, possibly due to insulin use. The avoidance of hypoglycemia in the course of achieving good glycemic control through the careful selection of glucose-lowering medications may contribute to fracture prevention by reducing the risk of falls related to treatment-induced hypoglycemia.

We explore the interplay of electron-electron correlations and spin-orbit coupling in the model Fermi liquidSr2RuO4using laser-based angle-resolved photoemission spectroscopy. Our precise measurement of the Fermi surface confirms the importance of spin-orbit coupling in this material and reveals that its effective value is enhanced by a factor of about 2, due to electronic correlations. The self-energies for theβandγsheets are found to display significant angular dependence. By taking into account the multi-orbital composition of quasiparticle states, we determine self-energies associated with each orbital component directly from the experimental data. This analysis demonstrates that the perceived angular dependence does not imply momentum-dependent many-body effects but arises from a substantial orbital mixing induced by spin-orbit coupling. A comparison to single-site dynamical mean-field theory further supports the notion of dominantly local orbital self-energies and provides strong evidence for an electronic origin of the observed nonlinear frequency dependence of the self-energies, leading to “kinks” in the quasiparticle dispersion ofSr2RuO4.

Topological Kondo insulators have been proposed as a new class of topological insulators in which non-trivial surface states reside in the bulk Kondo band gap at low temperature due to strong spin–orbit coupling. In contrast to other three-dimensional topological insulators, a topological Kondo insulator is truly bulk insulating. Furthermore, strong electron correlations are present in the system, which may interact with the novel topological phase. By applying spin- and angle-resolved photoemission spectroscopy, here we show that the surface states of SmB 6 are spin polarized. The spin is locked to the crystal momentum, fulfilling time reversal and crystal symmetries. Our results provide strong evidence that SmB 6 can host topological surface states in a bulk insulating gap stemming from the Kondo effect, which can serve as an ideal platform for investigating of the interplay between novel topological quantum states with emergent effects and competing orders induced by strongly correlated electrons. The study and application of the conductive surface states of topological insulators are often restricted by the presence of bulk conduction states. Here, Xu et al. present evidence for such topological surface states with true bulk insulation in the strongly correlated Kondo insulator SmB 6 .

A Weyl semimetal possesses spin-polarized band-crossings, called Weyl nodes, connected by topological surface arcs. The low-energy excitations near the crossing points behave the same as massless Weyl fermions, leading to exotic properties like chiral anomaly. To have the transport properties dominated by Weyl fermions, Weyl nodes need to locate nearly at the chemical potential and enclosed by pairs of individual Fermi surfaces with non-zero Fermi Chern numbers. Combining angle-resolved photoemission spectroscopy and first-principles calculation, here we show that TaP is a Weyl semimetal with only a single type of Weyl fermions, topologically distinguished from TaAs where two types of Weyl fermions contribute to the low-energy physical properties. The simple Weyl fermions in TaP are not only of fundamental interests but also of great potential for future applications. Fermi arcs on the Ta-terminated surface are observed, which appear in a different pattern from that on the As-termination in TaAs and NbAs. Weyl semimetals exhibit exotic properties owing to the presence of Weyl fermions. Here, Xu et al . show that tantalum phosphide is an ideal platform for studying the transport properties of these particles because its low-energy properties are dominated by a single type of Weyl fermion.

Machine learning is widely used for predicting the compressive strength of concrete. However, the machine learning modeling process relies on expert experience. Automated machine learning (AutoML) aims to automatically select optimal data preprocessing methods, feature preprocessing methods, machine learning algorithms, and hyperparameters according to the datasets used, to obtain high-precision prediction models. However, the effectiveness of modeling concrete compressive strength using AutoML has not been verified. This study attempts to fill the above research gap. We construct a database comprising four different types of concrete datasets and compare one AutoML algorithm (Auto-Sklearn) against five ML algorithms. The results show that Auto-Sklearn can automatically build an accurate concrete compressive strength prediction model without relying on expert experience. In addition, Auto-Sklearn achieves the highest accuracy for all four datasets, with an average R2 of 0.953; the average R2 values of the ML models with tuned hyperparameters range from 0.909 to 0.943. This study verifies for the first time the feasibility of AutoML for concrete compressive strength prediction, to allow concrete engineers to easily build accurate concrete compressive strength prediction models without relying on a large amount of ML modeling experience.

The transition from a polaronic to a metallic state as the carrier density increases in strontium titanate overlaps with the onset and peak of the bulk superconducting behaviour. Surfaces and interfaces offer new possibilities for tailoring the many-body interactions that dominate the electrical and thermal properties of transition metal oxides 1 , 2 , 3 , 4 . Here, we use the prototypical two-dimensional electron liquid (2DEL) at the SrTiO 3 (001) surface 5 , 6 , 7 to reveal a remarkably complex evolution of electron–phonon coupling with the tunable carrier density of this system. At low density, where superconductivity is found in the analogous 2DEL at the LaAlO 3 /SrTiO 3 interface 8 , 9 , 10 , 11 , 12 , 13 , our angle-resolved photoemission data show replica bands separated by 100 meV from the main bands. This is a hallmark of a coherent polaronic liquid and implies long-range coupling to a single longitudinal optical phonon branch. In the overdoped regime the preferential coupling to this branch decreases and the 2DEL undergoes a crossover to a more conventional metallic state with weaker short-range electron–phonon interaction. These results place constraints on the theoretical description of superconductivity and allow a unified understanding of the transport properties in SrTiO 3 -based 2DELs.

Charge ordered kagome lattices have been demonstrated to be intriguing platforms for studying the intertwining of topology, correlation, and magnetism. The recently discovered charge ordered kagome material ScV 6 Sn 6 does not feature a magnetic groundstate or excitations, thus it is often regarded as a conventional paramagnet. Here, using advanced muon-spin rotation spectroscopy, we uncover an unexpected hidden magnetism of the charge order. We observe an enhancement of the internal field width sensed by the muon ensemble, which takes place within the charge ordered state. More importantly, the muon spin relaxation rate below the charge ordering temperature is substantially enhanced by applying an external magnetic field. Taken together with the hidden magnetism found in A V 3 Sb 5 ( A = K, Rb, Cs) and FeGe kagome systems, our results suggest ubiqitous time-reversal symmetry-breaking in charge ordered kagome lattices. Recently, time-reversal symmetry-breaking charge order was demonstrated in the AV 3 Sb 5 (A = K, Rb, Cs) family of kagome superconductors. Here the authors extend this observation to the recently discovered kagome material ScV 6 Sn 6 and discuss differences and similarities to other charge-ordered kagome lattices.