Measurement of the Absolute Branching Fraction of D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}

Using a dataset of 6.32  fb^{-1} of e^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction of the leptonic decay D_{s}^{+}→τ^{+}ν_{τ} via τ^{+}→e^{+}ν_{e}ν[over ¯]_{τ}, and find B_{D_{s}^{+}→τ^{+}ν_{τ}}=(5.27±0.10±0.12)×10^{-2}, where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with f_{D_{s}^{+}} from lattice quantum chromodynamics calculations or the |V_{cs}| from the CKMfitter group, we extract |V_{cs}|=0.978±0.009±0.012 and f_{D_{s}^{+}}=(251.1±2.4±3.0)  MeV, respectively. Combining our result with the world averages of B_{D_{s}^{+}→τ^{+}ν_{τ}} and B_{D_{s}^{+}→μ^{+}ν_{μ}}, we obtain the ratio of the branching fractions B_{D_{s}^{+}→τ^{+}ν_{τ}}/B_{D_{s}^{+}→μ^{+}ν_{μ}}=9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.

Optimal placement of fixation system for scaffold-based mandibular reconstruction

A current challenge in bone tissue engineering is to create favourable biomechanical conditions conducive to tissue regeneration for a scaffold implanted in a segmental defect. This is particularly the case immediately following surgical implantation when a firm mechanical union between the scaffold and host bone is yet to be established via osseointegration. For mandibular reconstruction of a large segmental defect, the position of the fixation system is shown here to have a profound effect on the mechanical stimulus (for tissue regeneration within the scaffold), structural strength, and structural stiffness of the tissue scaffold-host bone construct under physiological load. This research combines computer tomography (CT)-based finite element (FE) modelling with multiobjective optimisation to determine the optimal height and angle to place a titanium fixation plate on a reconstructed mandible so as to enhance tissue ingrowth, structural strength and structural stiffness of the scaffold-host bone construct. To this end, the respective design criteria for fixation plate placement are to: (i) maximise the volume of the tissue scaffold experiencing levels of mechanical stimulus sufficient to initiate bone apposition, (ii) minimise peak stress in the scaffold so that it remains intact with a diminished risk of failure and, (iii) minimise scaffold ridge displacement so that the reconstructed jawbone resists deformation under physiological load. First, a CT-based FE model of a reconstructed human mandible implanted with a bioceramic tissue scaffold is developed to visualise and quantify changes in the biomechanical responses as the fixation plate's height and/or angle are varied. The volume of the scaffold experiencing appositional mechanical stimulus is observed to increase with the height of the fixation plate. Also, as the principal load-transfer mechanism to the scaffold is via the fixation system, there is a significant ingress of appositional stimulus from the buccal side towards the centre of the scaffold, notably in the region bounded by the screws. Next, surrogate modelling is implemented to generate bivariate cubic polynomial functions of the three biomechanical responses with respect to the two design variables (height and angle). Finally, as the three design objectives are found to be competing, bi- and tri-objective particle swarm optimisation algorithms are invoked to determine the most optimal Pareto solution, which represents the best possible trade-off between the competing design objectives. It is recommended that consideration be given to placing the fixation system along the upper boundary of the mandible with a small clockwise rotation about its posterior end. The methodology developed here forms a useful decision aid for optimal surgical planning.

What is an appropriate caesarean delivery rate for China: a multicentre survey

Objective

To assess the current status of caesarean delivery (CD) in China, propose reference CD rates for China overall, and by regions, investigate the main indications for CDs and identify possible areas for safe reduction.

Design

A multicentre cross‐sectional study.

Setting

A total of 94 hospitals across 23 provinces in China.

Population

A total of 73 977 randomly selected deliveries.

Methods

We used a modified Robson classification to characterise CDs in subgroups and by regions, and the World Health Organization (WHO) C‐Model to calculate reference CD rates.

Main outcome measures

CD rates in China.

Results

In 2015–2016, the overall CD rate in China was 38.9% (95% CI 38.6–39.3%). Considering the obstetric characteristics of the population, the multivariable model‐based reference CD rate was estimated at 28.5% (95% CI 28.3–28.8%). Accordingly, an absolute reduction of 10.4% (or 26.7% relative reduction) may be considered. The CD rate varied substantially by region. Previous CD was the most common indication in all regions, accounting for 38.2% of all CDs, followed by maternal request (9.8%), labour dystocia (8.3%), fetal distress (7.7%) and malpresentation (7.6%). Overall, 12.7% of women had prelabour CDs, contributing to 32.8% of the total CDs.

Conclusions

Nearly 39% of births were delivered by caesarean in China but a reduction of this rate by a quarter may be considered attainable. Repeat CD contributed more than one‐third of the total CDs. Given the large variation in maternal characteristics, region‐specific or even hospital‐specific reference CD rates are needed for precision management of CD.

Tweetable abstract

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

Linked article This article is commented on by M Varner, p. 148 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471-0528.16953.

Observation of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e}

Using 2.93  fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, the observation of the D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} semileptonic decay is presented. The statistical significance of the decay D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is greater than 10σ. The branching fraction of D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is measured to be (1.09±0.13_{-0.16}^{+0.09}±0.12)×10^{-3}. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of K_{1}(1270)^{-}→K^{-}π^{+}π^{-}. The fraction of longitudinal polarization in D^{0}→K_{1}(1270)^{-}e^{+}ν_{e} is determined for the first time to be 0.50±0.19_{stat}±0.08_{syst}.

First Measurement of the Absolute Branching Fraction of Λ→pμ^{-}ν[over ¯]_{μ}

The absolute branching fraction of Λ→pμ^{-}ν[over ¯]_{μ} is reported for the first time based on an e^{+}e^{-} annihilation sample of 10×10^{9}  J/ψ events collected with the BESIII detector at sqrt[s]=3.097  GeV. The branching fraction is determined to be B(Λ→pμ^{-}ν[over ¯]_{μ})=[1.48±0.21(stat)±0.08(syst)]×10^{-4}, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of B(Λ→pe^{-}ν[over ¯]_{e}), we obtain the ratio {[Γ(Λ→pμ^{-}ν[over ¯]_{μ})]/[Γ(Λ→pe^{-}ν[over ¯]_{e})]} to be 0.178±0.028, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions of Λ→pμ^{-}ν[over ¯]_{μ} and Λ[over ¯]→p[over ¯]μ^{+}ν_{μ} is also determined, and no evidence for CP violation is found.

Direct Measurement of the Branching Fractions B(ψ(3686)→J/ψX) and B(ψ(3770)→J/ψX), and Observation of the State R(3760) in e^{+}e^{-}→J/ψX

We report a measurement of the observed cross sections of e^{+}e^{-}→J/ψX based on 3.21  fb^{-1} of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(ψ(3686)→J/ψX)=(64.4±0.6±1.6)% and B(ψ(3770)→J/ψX)=(0.5±0.2±0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays ψ(3686)→J/ψX and ψ(3770)→J/ψX. Instead, it can be better described with one more BW amplitude of the decay R(3760)→J/ψX. Under this assumption, we extracted the R(3760) mass M_{R(3760)}=3766.2±3.8±0.4  MeV/c^{2} , total width Γ_{R(3760)}^{tot}=22.2±5.9±1.4  MeV, and product of leptonic width and decay branching fraction Γ_{R(3760)}^{ee}B[R(3760)→J/ψX]=(79.4±85.5±11.7)  eV. The significance of the R(3760) is 5.3σ. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.

A machine learning-based multiscale model to predict bone formation in scaffolds

Computational modeling methods combined with non-invasive imaging technologies have exhibited great potential and unique opportunities to model new bone formation in scaffold tissue engineering, offering an effective alternate and viable complement to laborious and time-consuming in vivo studies. However, existing numerical approaches are still highly demanding computationally in such multiscale problems. To tackle this challenge, we propose a machine learning (ML)-based approach to predict bone ingrowth outcomes in bulk tissue scaffolds. The proposed in silico procedure is developed by correlating with a dedicated longitudinal (12-month) animal study on scaffold treatment of a major segmental defect in sheep tibia. Comparison of the ML-based time-dependent prediction of bone ingrowth with the conventional multilevel finite element (FE2) model demonstrates satisfactory accuracy and efficiency. The ML-based modeling approach provides an effective means for predicting in vivo bone tissue regeneration in a subject-specific scaffolding system.

[Exendin-4 promotes autophagy to relieve lipid deposition in a NAFLD cell model by activating AKT/mTOR signaling pathway]

OBJECTIVE

To investigate the effect of exendin-4 on lipid deposition in hepatocytes and explore its possible mechanism for treatment of nonalcoholic fatty liver disease (NAFLD).

METHODS

Human normal hepatocyte line LO2 and hepatoma cell line HepG2 were treated with palmitic acid (PA) to mimic hepatocyte steatosis or with combined treatments with PA+exendin-4 or PA+exendin-4+3BDO. Lipid deposition and proliferation of the two cell lines following treatment with PA or PA+exendin-4 were detected using Oil Red O staining and CCK8 assay, and the expression of p-mTOR, m-TOR, p-AKT, AKT and autophagy-related proteins LC3-Ⅰ/Ⅱ and p62 were detected with Western blotting; the expression of GLP-1R was detected with both Western blotting and immunofluorescence assay. The expression of LC3-Ⅰ/Ⅱ and p62 in the cells following treatment with PA+exendin-4 and PA+exendin-4+3BDO was detected with Western blotting.

RESULTS

Lipid deposition in the two cell lines increased significantly after PA treatment, but was alleviated by co-treatment with exendin-4. PA treatment significantly inhibited the proliferation of the two cell lines (P < 0.01), and this inhibitory effect was obviously attenuated by exendin-4 (P < 0.05). Immunofluorescence assay showed that both LO2 and HepG2 cells expressed GLP-1R. The expression of p-mTOR was significantly lower and that of p-AKT was higher in cells treated with PA+exendin-4 than in PA-treated cells. Exendin-4 also down-regulated the autophagy-associated protein p62 and up-regulated the expression of LC3-Ⅱ in PA-treated cells, and this effect was obviously reversed by 3BDO.

CONCLUSION

Exendin-4 may activate the AKT-mTOR signal pathway to promote autophagy via its direct action on GLP-1R. Exendin-4 can also alleviate lipid deposition and promote proliferation of PA-treated hepatocytes, suggesting its important role in PA-induced lipid deposition in hepatocytes.

Anti-cancer effects of baicalein on cervical carcinoma cells through down-regulation of the ERK/p38/MAPK pathway

The objective of this study was to investigate the effects of baicalein on apoptosis of HeLa human cervical cancer (CC) cells and to elucidate the underlying mechanism. HeLa cells were treated with 20, 50, 100, or 200 μmol/L baicalein for 24, 36, and 48 hours, and CCK-8 assays were used to detect cell viability, and flow cytometry was performed to assess apoptosis rate. Reverse-transcription quantitative PCR was used to measure ERK1/2, p38, and JNK mRNA levels in HeLa cells, and western blotting was performed to measure ERK1/2, p38, and JNK protein levels. The CCK-8 assay showed that the OD value of HeLa cells gradually decreased with increasing baicalein concentrations (P < 0.01) and treatment time (P < 0.01). These results indicated a negative time- and dose-dependent effect of baicalein on HeLa cells. Baicalein treatment of HeLa cells significantly increased apoptosis rate (P < 0.01). In HeLa cells treated with 50 or 200 μmol/L baicalein for 24 h, expression levels of ERK1/2 and p38 mRNA were significantly reduced, whereas that of JNK mRNA was increased (P < 0.01). The levels of phosphorylated ERK1/2 and p38 were significantly reduced, and the level of JNK protein was increased (P < 0.01). Taken together, baicalein appeared to exert anti-cancer effects on HeLa cells through induction of apoptosis and regulation of the ERK/p38/mitogen-activated protein kinase pathway.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

MicroRNA-198 inhibits metastasis of thyroid cancer by targeting H3F3A

OBJECTIVE

This study was designed to investigate the role of microRNA-198 in thyroid cancer (TCa) progression.

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to examine microRNA-198 and H3F3A levels in tumor tissue specimens and paracancerous ones collected from 50 patients with TCa, and the interplay between microRNA-198 or H3F3A and some clinical indicators or prognosis of TCa patients was analyzed as well. MicroRNA-198 and H3F3A overexpression models were constructed using lentivirus in TCa cell lines TPC-1 and BHP2-7, and the impacts of microRNA-198 on TCa cell functions were evaluated by using cell counting kit-8 (CCK-8), plate clone formation, and transwell assays. Finally, recovery investigations were conducted to explore the underlying mechanisms as well as the interaction between microRNA-198 and H3F3A.

RESULTS

QRT-PCR indicated that in tumor tissues of TCa patients, microRNA-198 showed a remarkably lower expression than in adjacent normal tissue samples. Compared with patients with high expression of microRNA-198, those with microRNA-198 low expression had more advanced tumor stage, larger tumor size, higher lymph node metastasis rate, and lower overall survival rate. Meanwhile, the results of research on H3F3A were just opposite to the above observations on microRNA-198. In in vitro cell experiments, overexpression of microRNA-198 significantly weakened the proliferation and migration ability of thyroid tumor cells. Besides, Luciferase reporter gene experiment revealed that H3F3A was a specific target gene for microRNA-198. Moreover, qRT-PCR indicated that H3F3A and microRNA-198 were negatively correlated in thyroid carcinoma tissues. In addition, compared with NC group, overexpression of H3F3A markedly enhanced the migration and proliferative capacity of TCa cells. Lastly, recovery experiment revealed a mutual regulation between microRNA-198 and H3F3A, the two of which may together participate in the malignant progression of TCa.

CONCLUSIONS

MicroRNA-198 is remarkably reduced in TCa and inhibits malignant progression of TCa by regulating H3F3A. Meanwhile, microRNA-198 is remarkably associated with pathological stage, tumor size, lymph node metastasis, and poor prognosis of TCa.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

POS0234 SECUKINUMAB RETENTION AND SAFETY IN PATIENTS WITH ACTIVE PSORIATIC ARTHRITIS OR ANKYLOSING SPONDYLITIS: 2 YEAR INTERIM RESULTS OF THE OBSERVATIONAL SERENA STUDY

Background:

SERENA is an ongoing, prospective, non-interventional study evaluating retention, effectiveness, safety/tolerability and quality of life in more than 2900 patients (pts) with moderate to severe plaque psoriasis, active psoriatic arthritis (PsA) or active ankylosing spondylitis (AS) treated with secukinumab (SEC) at 438 sites across Europe for a period of up to 5 years1.

Objectives:

We present interim results reporting SEC treatment retention and safety data through 2 years in the PsA and AS pts enrolled in the study.

Methods:

This interim analysis presents data from 534 PsA and 470 AS pts who were enrolled (target population fulfilling all eligibility criteria) in the study and were followed up for at least 2 years. Pts (aged ≥18 years) with active PsA or AS should have received at least 16 weeks SEC treatment before enrolment in the study1. Retention rate was defined as the percentage of pts who have not discontinued SEC treatment. A treatment break was defined as interruption of therapy for at least 3 months after last injection.

Results:

The mean treatment duration prior to enrolment in the study was 1.0 year and 0.91 year for PsA and AS, respectively. The retention rates for SEC after 1 year since enrolment and since initiation of treatment were: PsA, 85.2% [n=519, CI: 82.01–88.32] and 96.8% [n=528, CI: 95.18–98.38]; AS, 85.8% [n=452, CI: 82.52–89.17] and 94.2% [n=464, CI: 91.94–96.42], respectively. After 2 years since enrolment and since initiation of treatment, the retention rates were: PsA, 74.9% [n=498, CI: 70.99–78.81] and 87.0% [n=515, CI: 83.99–89.99]; AS, 78.9% [n=437, CI: 75.01–82.88] and 84.8% [n=454, CI: 81.39–88.21], respectively. Survival probabilities for individual indications are presented in Figure 1. At baseline, the majority of PsA (79.5%; n/N=423/532) pts were receiving SEC 300 mg, while 97.0% (n/N=456/470) of AS pts were receiving SEC 150 mg. The majority of pts continued their initial SEC dose; “no dose change” in SEC treatment was reported after 1 and 2 years in the study (Year 1: PsA, 93.4% [n=499] and AS, 92.6% [n=435]; Year 2: PsA, 89.7% [n=479] and AS, 87.9% [n=413]). SEC treatment break was recorded for 31 PsA pts [median (min, max) treatment break duration in days: 125.0 (61, 461)] and for 42 AS [118.0 (61, 813)] pts mainly due to adverse events reported in 58.1% (n=18) and 45.2% (n=19) of pts, respectively. The retreatment started with monthly dosing in most of the cases: PsA, 80.6% (n/N=25/31) and AS, 76.2% (n/N=32/42). No new or unexpected safety signals were reported (Table 1).

Table 1.

Safety profile of treatment-emergent adverse events within the study period

AE summary, n (%)PsA N=575AS N=499Year 1Year 2Year 1Year 2Subject with any AE239 (41.6)289 (50.3)203 (40.7)247 (49.5)Subject with any serious AE29 (5.0)45 (7.8)29 (5.8)44 (8.8)Subject with AE leading to discontinuation55 (9.6)84 (14.6)47 (9.4)62 (12.4)Death0 (0.0)0 (0.0)0 (0.0)1 (0.2)AEs of special interest, n (IR per 100 subject-years)Serious infections and infestations5 (0.96)9 (0.95)8 (1.78)11 (1.33)Candida infections1 (0.19)2 (0.21)2 (0.44)2 (0.24)Malignancy5 (0.96)7 (0.74)N/R3 (0.36)Major adverse cardiovascular eventsN/R1 (0.11)2 (0.44)3 (0.36)Inflammatory bowel diseaseN/RN/R1 (0.22)1 (0.12)

N, total number of patients in the safety set; n, number of patients with event; AE, adverse events; IR, incidence rate; N/R, not reported.

Conclusion:

Secukinumab retention rates in a real world setting after more than 2 years since initiation of treatment and after 2 years since enrolment in the study indicate high persistence rates. Safety data collected prospectively for up to 2 years confirm the favorable safety profile of secukinumab.

References:

[1]Kiltz, U et al. Adv Ther 2020; 37:2865–83.

Disclosure of Interests:

Uta Kiltz Consultant of: AbbVie, Biocad, Biogen, Chugai, Eli Lilly, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche and UCB, Grant/research support from: AbbVie, Biocad, Biogen, Chugai, Eli Lilly, Grünenthal, Hexal, Janssen, MSD, Novartis, Pfizer, Roche and UCB, Petros Sfikakis Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Celgene, Eli-Lilly, Janssen, Novartis and Pfizer, Grant/research support from: AbbVie, Amgen, Boehringer Ingelheim, Celgene, Eli-Lilly, Janssen, Novartis and Pfizer, Nicola Gullick Speakers bureau: AbbVie, Celgene, Eli Lilly, Izana, Janssen, Novartis, UCB., Consultant of: AbbVie, Celgene, Eli Lilly, Izana, Janssen, Novartis, UCB., Grant/research support from: AbbVie, Celgene, Eli Lilly, Izana, Janssen, Novartis, UCB., Athina Theodoridou Consultant of: UCB, Amgen, Novartis, Jan Brandt-Juergens Speakers bureau: AbbVie, Pfizer, Roche, Sanofi-Aventis, Novartis, Lilly, MSD, UCB, BMS, Janssen, and Medac, Consultant of: AbbVie, Pfizer, Roche, Sanofi-Aventis, Novartis, Lilly, MSD, UCB, BMS, Janssen, and Medac, Eric Lespessailles Speakers bureau: Amgen, Expanscience, Lilly and MSD, Consultant of: Amgen, Expanscience, Lilly and MSD, Grant/research support from: Abbvie, Amgen, Lilly, MSD and UCB, Rasho Rashkov Speakers bureau: AbbVie, Amgen, Pfizer, Novartis, MSD, UCB, Roche and Janssen, Consultant of: AbbVie, Amgen, Pfizer, Novartis, MSD, UCB, Roche and Janssen, Jenny Fang Employee of: Novartis, Effie Pournara Shareholder of: Novartis, Employee of: Novartis, Barbara Schulz Employee of: Novartis, Piotr Jagiello Employee of: Novartis, Karl Gaffney Speakers bureau: AbbVie, Celgene, Lilly, Pfizer, Gilead, MSD, Novartis and UCB, Consultant of: AbbVie, Celgene, Lilly, Pfizer, Gilead, MSD, Novartis and UCB, Grant/research support from: AbbVie, Celgene, Lilly, Pfizer, Gilead, MSD, Novartis and UCB.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.