Peking University

Development and benchmark validation of PubChat for PubMed-grounded multilingual biomedical literature retrieval

The rapid growth of biomedical literature has rendered traditional systematic reviews unsustainable. Although large language models (LLMs) offer automation potential, citation fabrication and unreliable evidence discrimination remain critical barriers. Here, using PubChat as a Pu...

Iterated Agent for Symbolic Regression

Abstract Symbolic regression (SR), the automated discovery of mathematical expressions from data, is a cornerstone of scientific inquiry. However, it is often hindered by the combinatorial explosion of the search space and a tendency to overfit. Popular methods, rooted in genetic...

Diagnosing year-round ozone-relevant VOC reactivity under meteorological constraints in urban Beijing

Abstract Static volatile organic compound (VOC) rankings can identify abundant or reactive compounds, but their ozone relevance depends on the meteorological and photochemical state during ozone production. Here we combine yearlong hourly observations of speciated VOCs in urban B...

SciRep: A Ranking-Aware Representation Model for Scientific Text

Existing scientific text representation methods based on contrastive learning typically adopt a binary classification paradigm of positive and negative samples, which struggles to capture the complex, hierarchical semantic similarity relationships inherent in scientific texts. To...

Exploring baryon semileptonic decays through polarization and entanglement

Abstract The unitarity of the Cabibbo–Kobayashi–Maskawa (CKM) matrix is a cornerstone of the standard model (SM). Precise tests of this unitarity require independent determinations of its elements, such as | V us |, which governs the transition between strange and up quarks. Curr...

52‐week ivarmacitinib in moderate‐to‐severe atopic dermatitis: A phase 3 trial

BACKGROUND: Ivarmacitinib, an oral JAK1 inhibitor, improved efficacy outcomes versus placebo at Week 16 in a phase 3 trial in patients with moderate-to-severe atopic dermatitis (AD). OBJECTIVES: To describe efficacy and safety outcomes through Week 52. METHODS: In this multicentr...

Mixed‐Dimensional 1D/2D Ternary CMOS for High‐Performance Integrated Circuits

ABSTRACT Ternary logic offers a path to higher information density and lower power consumption beyond the limits of binary CMOS, yet its progress has been limited by the absence of high‐performance ternary transistors and scalable circuit technologies. Here we report a mixed‐dime...

Increased maximum carbon release offsets half of the growth trend in annual land carbon sink

The terrestrial carbon sink has strengthened in recent decades through enhanced maximum CO2 uptake (MCU) and a longer carbon uptake period (CUP), whereas maximum CO2 release (MCR) remains less quantified. Using atmospheric inversion estimates and 16 terrestrial biosphere models,...

Association of socioeconomic status transition with arthritis: a life-course study

Childhood socioeconomic status (SES) and adulthood SES have independent effects on health outcomes. However, the varied effects of SES transition throughout the life course on arthritis remain underrecognized. This study aimed to investigate the association of SES transition with...

Cyclic steepest descent is R-superlinearly convergent for almost every initialization on two-spectrum quadratics

We completely classify cyclic steepest descent (CSD) on strictly convex quadratics whose Hessian has exactly two distinct eigenvalues. At the beginning of each cycle CSD recomputes an exact steepest-descent stepsize and reuses it for m updates. For every m >= 2, write A = aP + bQ...

Impact of combined medial and lateral bone marrow lesions on clinical outcomes after medial unicompartmental knee arthroplasty

Aims Although the influence of medial bone marrow lesions (BMLs) on outcomes after medial unicompartmental knee arthroplasty (UKA) has been studied, the impact of concomitant lateral compartmental BMLs remains unclear. This study aims to determine whether the lateral BMLs, in add...

Cyclic steepest descent is R-superlinearly convergent for almost every initialization on two-spectrum quadratics

We completely classify cyclic steepest descent (CSD) on strictly convex quadratics whose Hessian has exactly two distinct eigenvalues. At the beginning of each cycle CSD recomputes an exact steepest-descent stepsize and reuses it for m updates. For every m >= 2, write A = aP + bQ...

Development and validation of an interpretable machine learning model for predicting ICU prognosis in critically ill patients with invasive pulmonary aspergillosis: a multicenter study

Invasive pulmonary aspergillosis (IPA) is associated with elevated mortality among intensive care unit (ICU) patients. Early prognostic risk stratification is of great importance; however, validated clinical tools remain limited. This study aimed to develop and validate an interp...

Fröberg's Conjecture for Quintics and Septics in Four Variables

Let k be a field of characteristic zero and let S = k[x_1,x_2,x_3,x_4]. We prove Fröberg's predicted Hilbert series for ideals generated by r general forms of equal degree d for every r ≥ 1 in each of the two cases d = 5 and d = 7. Relative to the classical cases r ≤ 5 and the eq...

A counterexample to R-superlinear convergence of cyclic steepest descent

Cyclic steepest descent recomputes an exact steepest-descent stepsize once per cycle and reuses it for m updates. Dai's ICM 2022 survey states that this method is likely to converge R-superlinearly on n-dimensional convex quadratics when m is at least (n+1)/2. We show that the co...

Hyperplane graph models for cotangent cohomology and quadratic obstructions of matroids

Let M be a finite matroid and let T^i(M) denote the cotangent cohomology of its Stanley--Reisner ring over a field. The paper gives a uniform hyperplane-graph model for every multigraded component of T^2(M) and derives a characteristic-independent fine Hilbert series. It proves t...

Compatibility Restores Spin Alignment for Three Qubits

We study a spectral majorization problem for lifted quantum marginals. For every three-qubit state, every single-qubit replacement state, arbitrary nonnegative weights on all eight supports, and compatible marginals arising from one global state, we prove that the weighted margin...

Clinical value of the endoscopic scratch sign in diagnosing Helicobacter pylori infection status

Accurate assessment of Helicobacter pylori ( H. pylori ) infection status is essential for clinical decision-making. This study aimed to evaluate the clinical utility of the endoscopic scratch sign which refers to linear reddish streaks observed along the greater curvature of the...

Health literacy mediation in online medical consultations: Advancing inclusion and expanding access to digital healthcare

This paper explores health literacy mediation in Chinese online medical consultations (OMCs). Adopting a social practice view of (health) literacy, the study examines naturally occurring instances of health literacy mediation in which caregivers act as “mediators” by initiating a...

Fröberg's Conjecture for Quintics and Septics in Four Variables

Let k be a field of characteristic zero and let S = k[x_1,x_2,x_3,x_4]. We prove Fröberg's predicted Hilbert series for ideals generated by r general forms of equal degree d for every r ≥ 1 in each of the two cases d = 5 and d = 7. Relative to the classical cases r ≤ 5 and the eq...