Tag: statistics

Nature. 2026 Apr;652(8109):328-334. doi: 10.1038/s41586-026-10339-4. Epub 2026 Apr 8.

ABSTRACT

The outcomes of modern particle physics experiments, such as proton-proton collisions at the Large Hadron Collider at CERN (European Organization for Nuclear Research), depend crucially on the precise description of the scattering processes in terms of the fundamental forces. Among all the known forces that contribute, the limited understanding of the strong nuclear force is a key source of inaccuracy. At the fundamental level, the strong force is described by quantum chromodynamics, the theory of quarks and gluons. Their coupling, α_s, becomes weaker at high energies (asymptotic freedom), enabling power series expansions in α_s, but the confinement of quarks in hadronic bound states usually requires additional model assumptions. Consequently, determinations of α_s from experiment mostly remain with large systematic theory errors^1,2. Here we report the model-free determination of α_s with unprecedented precision from low-energy experimental input combined with large-scale numerical simulations of the first-principles formulation of quantum chromodynamics on a space-time lattice. The uncertainty, about half that of all other results combined³, originates predominantly from the statistical Monte Carlo evaluation and has a clear probabilistic interpretation. The result for α_s describes both low-energy hadronic physics with the help of lattice quantum chromodynamics and high-energy scattering using the perturbative expansion. By removing a source of theoretical uncertainty, our estimate of α_s could enable markedly improved analyses of many high-energy experiments⁴. This will contribute to the likelihood that small effects of yet unknown physics are uncovered, as well as enable stringent precision tests of the Standard Model.

PMID:41951966 | DOI:10.1038/s41586-026-10339-4

Nat Genet. 2026 Apr 8. doi: 10.1038/s41588-026-02554-6. Online ahead of print.

ABSTRACT

Genetic variants in RNU4-2, which is transcribed into the U4 small nuclear RNA component of the major spliceosome, were recently shown to cause ReNU syndrome, a prevalent dominant neurodevelopmental disorder (NDD). These variants almost exclusively arise de novo and cluster within 18 nucleotides of RNU4-2. Here we describe a new recessive NDD associated with homozygous and compound heterozygous variants in RNU4-2. We identify 38 individuals with biallelic variants outside the 18-nucleotide ReNU syndrome region that cluster within other functionally important elements of U4: Stem II, the k-turn and the Sm protein binding site. We characterize the clinical phenotype in 31 individuals, demonstrating that the recessive disorder is clinically distinct from ReNU syndrome and is associated with distinctive white matter abnormalities, including enlarged perivascular spaces. Finally, we find reduced RNU4-2 transcript levels in individuals with the recessive disorder, suggesting a loss-of-function disease mechanism that is distinct from the mechanism underlying ReNU syndrome. Together, these findings expand the genotypic and phenotypic spectrum of RNU4-2-associated NDDs.

PMID:41951959 | DOI:10.1038/s41588-026-02554-6

Aesthetic Plast Surg. 2026 Apr 8. doi: 10.1007/s00266-026-05811-5. Online ahead of print.

ABSTRACT

BACKGROUND: The inframammary fold (IMF) plays a central role in breast augmentation surgery, yet its long-term positional stability following implant placement remains insufficiently characterized. Accurate prediction of IMF location is essential for aesthetic outcomes, particularly when selecting surgical approaches or implant types.

METHODS: A retrospective observational study was conducted on 156 breasts (78 patients) who underwent augmentation between 2018 and 2022, with a minimum follow-up of 12 months. Pre- and postoperative measurements were obtained using 3D imaging in arm-adducted position. Variables included SN-Ni, Ni-Ni, Ni-IMF, SN-Nimid, Ni-IMFmid, and SN-IMFmid. Patients were stratified by implant shape (anatomic vs. round), placement plane (submuscular, subfascial, dual plane II), and incision type. Statistical analyses were performed to evaluate IMF displacement and associated factors.

RESULTS: The IMF was displaced by more than 10 mm from the planned position in 53.8% of cases. Anatomic implants demonstrated slightly less fold displacement than round implants (3 ± 14.7 mm vs. 8.1 ± 14 mm), although this was not statistically significant. Submuscular placement significantly increased lower pole expansion and IMF descent compared to subfascial placement (p < 0.05). There was no significant difference in fold stability based on incision type, including inframammary incisions where reinforcement sutures were used.

CONCLUSIONS: Caudal displacement of the IMF is common following breast augmentation. Submuscular placement contributes significantly to this effect. Anatomic implants may offer improved fold stability. Preoperative planning using the implant radius from the sternal midline is reliable. IMF reinforcement appears non-essential but warrants further study.

LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

PMID:41951896 | DOI:10.1007/s00266-026-05811-5

EJNMMI Phys. 2026 Apr 9;13(1):32. doi: 10.1186/s40658-026-00844-w.

ABSTRACT

BACKGROUND: The digital cadmium-zinc-telluride (CZT)-based SPECT system offers good energy resolution. However, the impacts of dual-energy window scatter correction on image quality under narrower primary energy windows remain to be determined. This study aimed to assess the impacts of SC (with scatter correction) and NOSC (without scatter correction) on image quality under different primary energy windows.

METHODS: We used a standard NEMA/IEC 2007 phantom containing six hollow spheres of various sizes to simulate the human body at four target-to-background ratios (T/B ratio, the ratio of the average radioactive activity concentration in the target region to that in the background region, 32:1, 16:1, 8:1, and 4:1, respectively), by filling with ^99mTcO₄^–. For clinical validation, we recruited 20 patients and analyzed their whole-body bone scan images. Phantom and patient images were acquired with the Discovery NM/CT 670 CZT with list mode. Image quality of phantom was measured by calculating indicators from the NEMA NU 2-2018 standard, including percent background variability and percent contrast. Image quality of patients was measured by calculating coefficient of variation (COV), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR). Visual quality was evaluated by two experts.

RESULTS: Higher percent background variability and COV values were present when SC was applied regardless of which energy window, acquisition time, or T/B ratio used, and statistically significant differences were observed between all SC and NOSC groups for both phantoms and patients. For phantoms, percent contrast values of most SC groups were higher than those of NOSC groups. For patients, CNRs and SNRs of SC groups were higher than those of NOSC groups (all P < 0.05). Visually, SC had higher visual scores than NOSC for both phantoms and patients.

CONCLUSIONS: SC significantly improves image contrast while minimizing concomitant image noise to a great extent and provides good visual image quality across different primary energy windows overall.

PMID:41951861 | DOI:10.1186/s40658-026-00844-w

Support Care Cancer. 2026 Apr 9;34(5):414. doi: 10.1007/s00520-026-10625-x.

ABSTRACT

PURPOSE: Hodgkin lymphoma survivors (HLSs) are at risk of developing late effects (LEs), and their knowledge is crucial for prevention and treatment. We explored HLSs’ knowledge and experience with LEs, their needs for information about LEs, lifestyle and rehabilitation, their needs for long-term follow-up, and factors associated with these needs.

METHODS: HLSs, treated from 1997 to 2006, aged < 49 years at diagnosis, were invited to this Norwegian cross-sectional questionnaire-based study performed in 2018/19. Medical records provided information on histology, stage, and treatment. Descriptive statistics and logistic regression analyses were employed.

RESULTS: In total, 304 responded (59% response rate), median age at diagnosis was 29 years (range 8-49), median age at survey was 46 (21-70), and 48% were females. Ninety percent had classical HL, 62% stage I-IIA disease, 94% received chemotherapy, and 77% radiotherapy. Thirty-two percent had experienced 1-2 LEs, and 40% ≥ 3 LEs. Information about lifestyle and/or rehabilitation was requested by 64%, and 58% wanted follow-up for LEs. In the multivariable analysis, lower education (OR 2.3, 95% CI 1.3-4.0), chronic fatigue (CF) (OR 2.3, 1.3-4.3), and physical inactivity (OR 2.1, 1.2-3.7) were associated with need for information on lifestyle and/or rehabilitation. CF (OR 2.4, 1.3-4.2) and received radiotherapy (OR 2.8, 1.5-5.3) were associated with the need for follow-up.

CONCLUSION: A high proportion of HLSs report LEs, and about 60% report a need for information and follow-up. Our findings contribute to the ongoing discussion on how to best organize cancer survivorship care. CF is associated with both information needs and follow-up, indicating that these survivors could benefit from a structured follow-up programme.

PMID:41951854 | DOI:10.1007/s00520-026-10625-x

Bone Marrow Transplant. 2026 Apr 8. doi: 10.1038/s41409-026-02827-y. Online ahead of print.

ABSTRACT

The selection of the best available donor is crucial for patients’ outcome after allogeneic stem cell transplantation (allo-SCT). In the absence of fully Human leucocyte antigen (HLA) -matched donors, mismatched unrelated donor (9/10-MUD) or haploidentical donor (haplo) can be considered. No consensus has been reached on the best alternative and large real-world data are warranted to support decisional processes. We compared the outcome of 1413 patients with myeloid malignancies undergoing allo-SCT from 9/10-MUD with anti-thymocyte-globulin (ATG) (n = 1134) or haplo with post-transplant cyclophosphamide (PT-Cy, n = 279) between 2009 and 2020 in 48 German centres. Donor type with related graft versus host disease (GvHD) prophylaxis showed in multivariable analysis no significant impact on acute GvHD development, both grade II-IV (HR 0.90, 95% CI 0.69-1.19, p = 0.469) and severe (HR 1.22, 95% CI 0.82-1.81, p = 0.319), nor on moderate to severe chronic GvHD (HR 0.78, 95% CI 0.59-1.03, p = 0.077). Moreover, no influence from donor type was observed on GVHD-relapse-free survival (HR 1.12, 95% CI 0.92-1.36, p = 0.227), progression-free survival (HR 1.2, 95% CI 0.95-1.51, p = 0.121), non-relapse mortality (HR 1.1, 95% CI 0.81-1.51, p = 0.542) and overall survival (HR 1.16, 95% CI 0.91-1.48, p = 0.235). Our real-world data demonstrate that haplo allo-SCT with PT-Cy is not inferior to 9/10-MUD allo-SCT with ATG.

PMID:41951842 | DOI:10.1038/s41409-026-02827-y

NPJ Digit Med. 2026 Apr 8. doi: 10.1038/s41746-026-02606-5. Online ahead of print.

ABSTRACT

While thousands of AI prediction models are published annually, few are adopted into routine practice, partly because improved statistical performance does not necessarily translate into meaningful impact on clinical decision-making. We conducted a prospective randomized multi-reader multi-case study to evaluate how a machine learning-based prognostic tool influences clinician performance in colorectal liver metastases (CRLM). In a prospective, randomized multi-reader multi-case trial (NCT07027605; Registration Date: January 1, 2025), 12 surgical oncologists assessed 166 retrospective CRLM cases with and without tool assistance in a crossed design with a 5-week washout. The primary endpoint was the difference in AUC for predicting 3-year mortality. Between January and July 2025, 12 readers completed 3984 assessments. Model assistance significantly improved the AUC for 3-year mortality prediction (mean difference 0.091; 95% CI 0.001-0.181; P = 0.048) and consistently improved accuracy across secondary prognostic endpoints. It also reduced decision time (2.53 vs. 3.04 minutes) and increased reader confidence. Benefits were greatest for junior to mid-level surgical oncologists. This exploratory study demonstrates that a machine learning prognostic tool can significantly improve accuracy, efficiency, and confidence in CRLM evaluation.

PMID:41951838 | DOI:10.1038/s41746-026-02606-5

Sci Rep. 2026 Apr 8. doi: 10.1038/s41598-026-47594-4. Online ahead of print.

ABSTRACT

The primary objective of this research is to explore changes in brain activity among astigmatism patients, employing functional near-infrared spectroscopy (fNIRS). A prospective cross-sectional study comprising 57 participants (99 eyes) was conducted and segmented into three distinct sections. In PART I, 24 participants (48 eyes) with astigmatism (Group A) and 18 participants (36 eyes) without astigmatism (Group B) were assessed using fNIRS to investigate the variations across different brain regions and channels. PART II involved 15 participants with monocular astigmatism (15 eyes), who received complete spherical optical correction, followed by fNIRS assessments after visual stimulation using E-Prime software. The study examined the activation levels of the occipital visual cortex and the functional connectivity strength of the brain, comparing these metrics pre- and post-cylindrical correction.

PART III: Following the correction of the initial refractive error in Group A, + 2.00 diopter cylinder (DC) lenses were employed to induce astigmatism at various axes. These axes were categorized into three groups: oblique astigmatism group, with-the-rule astigmatism (WTR), and against-the-rule astigmatism (ATR). fNIRS was conducted during task performance to assess the strength and activation level of brain functional connectivity across different astigmatism axes of the same diopter.

PART I: The functional connectivity strength of HbO₂-based occipital cortex was stronger in group B than in group A (P < 0.001).

PART II: Significant differences in the β values of the left and right visual cortex were detected in cases of monocular astigmatism before and after astigmatism correction. (P = 0.002 and P = 0.004). The functional connectivity strength in the post-cylindrical correction condition exceeded that in the pre-cylindrical correction condition; nevertheless, this variation did not attain statistical significance (P > 0.05).

PART III: The functional connectivity strength and activation level of the HbO₂-based occipital visual cortex exhibited significant variations across different astigmatism axes (P < 0.001 and P = 0.045). Specifically, the functional connectivity strength in the oblique astigmatism group was greater than that observed in both the WTR and ATR groups. Conversely, the degree of brain activation in the oblique astigmatism group was lower compared to the ATR group (P = 0.042). These observations imply that astigmatism may decrease both the activation of the occipital visual cortex and the strength of brain functional connectivity. The functional activities of the occipital cortex can be enhanced to a certain degree following optical correction of astigmatism. The strength of functional connectivity and the degree of activation in the occipital visual cortex vary with different axes of astigmatism.Trial Registration This study was registered in the China Clinical Trials Registry (registration number: ChiCTR2300070613, date of registration: 2023-04-18), and the study followed the ethical principles required by the Declaration of Helsinki, and the subjects were informed and signed the informed consent form, and it has been reviewed and approved by the Medical Ethics Committee of the Affiliated Hospital of North Sichuan Medical College (Approval No. 2022ER541-1).

PMID:41951802 | DOI:10.1038/s41598-026-47594-4

J Perinatol. 2026 Apr 8. doi: 10.1038/s41372-026-02648-3. Online ahead of print.

ABSTRACT

We sought to characterize bedside nurses’ perceptions of providing intensive care to patients with trisomy 18 (T18) in a level IV neonatal intensive care unit (NICU). NICU nurses were anonymously surveyed with an electronic, mixed-methods survey. Items included quantitative questions about whether T18 is “incompatible with life,” whether interventions should be offered, open-ended free-text questions, and demographic items. Survey results were analyzed with descriptive statistics and thematic analysis. There were 145 responses (response rate 46%). Most (53%) agreed that T18 was “incompatible with life”, and 59% felt that this diagnosis should impact interventions offered. Two major themes emerged from 114 free-text responses, including “perceptions of prognosis” and “ethical considerations.” Though most nurses believe that T18 is “incompatible with life” and interventions should be restricted, a substantial minority endorse other perspectives. A range of ethical considerations shape nurses’ diverse views, suggesting that they are morally rooted and may contribute to ethical distress.

PMID:41951800 | DOI:10.1038/s41372-026-02648-3

Sci Rep. 2026 Apr 8. doi: 10.1038/s41598-026-47790-2. Online ahead of print.

ABSTRACT

Adolescent depression is a public development crisis that needs to be paid attention to and addressed under the rapid development of the Internet. It is of great significance to investigate the associations among adolescent depression, family relationship and physical activity (PA) for promoting adolescent mental health. A total of 3990 valid questionnaires were obtained through self-reports from adolescents. Data were collected using measurement tools for adolescent depression, parental marital conflict (PMC), and PA, followed by statistical analysis. Adolescent depression and PMC was significantly positive correlation (β = 0.315, p < 0.001) and PA is significantly negatively correlated (β = – 0.093, p < 0.001). After introducing moderating variables, PMC is still a significant positive correlation and adolescent depression (β = 0.303, p < 0.001). The study provides preliminary support for the association between PMC and adolescent depression, as well as the potential moderating roles of gender and PA in this association. These findings generate hypotheses for future research on the roles of PA and family relationships in adolescent depression, rather than providing direct evidence for prevention or intervention strategies.

PMID:41951798 | DOI:10.1038/s41598-026-47790-2