CT-based radiomics nomogram for the preoperative prediction of microsatellite instability and clinical outcomes in colorectal cancer: a multicentre study

AIM

To develop and validate a computed tomography (CT)-based radiomics nomogram for preoperative prediction of microsatellite instability (MSI) status and clinical outcomes in colorectal cancer (CRC) patients.

MATERIALS AND METHODS

This retrospective study enrolled 497 CRC patients from three centres. Least absolute shrinkage and selection operator regression was utilised for feature selection and constructing the radiomics signature. Univariate and multivariate logistic regression analyses were employed to identify significant clinical variables. The radiomics nomogram was constructed by integrating the radiomics signature and the identified clinical variables. The performance of the nomogram was evaluated through receiver operating characteristic curves, calibration curves, and decision curve analysis. Kaplan-Meier analysis was performed to investigate the prognostic value of the nomogram.

RESULTS

The radiomics signature comprised 10 radiomics features associated with MSI status. The nomogram, integrating the radiomics signature and independent predictors (age, location, and thickness), demonstrated favourable calibration and discrimination, achieving areas under the receiver operating characteristic (ROC) curves (AUCs) of 0.89 (95% confidence interval [CI]: 0.83-0.95), 0.87 (95% CI: 0.79-0.95), 0.88 (95% CI: 0.81-0.96), and 0.86 (95% CI: 0.78-0.93) in the training cohort, internal validation cohort, and two external validation cohorts, respectively. The nomogram exhibited superior performance compared to the clinical model (p<0.05). Additionally, survival analysis demonstrated that the nomogram successfully stratified stage II CRC patients based on prognosis (hazard ratio [HR]: 0.357, p=0.022).

CONCLUSION

The radiomics nomogram demonstrated promising performance in predicting MSI status and stratifying the prognosis of patients with CRC.

A Multicenter Study on Deep Learning for Glioblastoma Auto-Segmentation with Prior Knowledge in Multimodal Imaging

PURPOSE/OBJECTIVE(S)

A precise radiotherapy plan is required to ensure accurate delineation of gross tumor volumes (GTV) and clinical target volumes (CTV1 and CTV2) of glioblastomas (GBMs). However, traditional manual delineation is labor intensive and highly dependent on oncologists' experience. To construct and evaluate a deep learning-based automatic delineation method using prior knowledge in multimodal medical imaging to automate precise GTV, CTV1 and CTV2 contouring in GBM patients.

MATERIALS/METHODS

We retrospectively collected the CT and MRI scans of 55 eligible patients with histologically proven high-grade glioma (HGG) from an institute, these scans were performed with non-enhanced CT (CT), contrast-enhanced T1-weighted (T1C) and T2-FLAIR (T2F) sequences. We proposed a two-stage automatic segmentation framework (PKMI-Net) for GTV, CTV1 and CTV2 based on deep learning using prior knowledge in multimodal medical imaging, and its segmentation performance was evaluated with dice similarity coefficient (DSC), 95% Harsdorff distance (HD95), average surface distance (ASD) and relative volume difference (RVD). To further investigate the generalizability of our method, we designed and conducted two evaluation strategies (Mix and Cross) on four multicenter datasets (including 55 patients, 37 patients, 21 patients and 35 patients).

RESULTS

The evaluation results with an 11-patient test set from the single institute were summarized in Table 1, the proposed method demonstrated the best accuracy in segmenting, respectively, GTV, CTV1 and CTV, achieving a DSC of 0.94, 0.95 and 0.92; HD95 of 2.07 mm, 1.18 mm and 3.80 mm; ASD of 0.69 mm, 0.39 mm and 1.13 mm and RVE of 5.50%, 3.97% and 9.68%. In the multicenter evaluation, the segmentation performance of our method implemented with the Cross strategy was comparable to that with the Mix strategy, demonstrating that our method had high and stable generalizability across multicenter datasets in automatically segmenting GTV, CTV1 and CTV2.

CONCLUSION

Our proposed method achieved promising results in automatically segmenting gliomas across various datasets, which could improve the quality and efficiency of glioblastoma radiotherapy.

[The clinical practice and consideration for donor liver expansion]

Liver transplantation is the most effective method to address end-stage liver disease. However, there is a huge imbalance between organ supply and demand in China. Recently,effective expansion of the donor liver has become a hot research direction in academia. Authors' group comprehensively integrates domestic and foreign evidence-based medical evidence, the latest academic outcomes and clinical experience. Based on the innovative viewshed of crossfusion between biomedical engineering and medicine, author group systematically elaborate in the main strategies for expanding the liver donor pool, including the multichannel expansion of marginal donor liver,multidimensional innovation of technologies in transplant surgery and diversified exploration of alternative resources of organs. The author group aims to promote the construction of a large cohort,the integration of big data,and the output of high quality research,achieving innovative theory and clinical translation in organ transplantation,thus promoting the higher quality development of liver transplantation in China.

[Comparison of incubation periods of infections of Omicron variants BA.2 and BF.7 in Beijing]

Objective: To understand the incubation periods of infections of Omicron variants BA.2 and BF.7 in two COVID-19 epidemics and related factors in Beijing and provide basic parameters for the establishment of 2019-nCoV dynamic transmission model. Methods: The COVID-19 cases with specific exposure time and onset time in the Omicron variant BA.2 infection epidemic in April 2022 and in the Omicron variant BF.7 infection epidemic in October 2022 in Beijing were included in the analysis. The rank-sum test was conducted to estimate the differences in the incubation period between two types of infections. The incubation period distribution of the Omicron variant infection was fitted by using Weibull, Gamma and lognormal distributions. Multivariate analysis of variance was conducted to assess the effects of age, sex, variant type and vaccination status on the incubation periods. Results: A total of 64 cases of variant BA.2 infection and 58 cases of variant BF.7 infection were included. The M(Q1,Q3) of the incubation period was 3.00 (3.00, 4.00) days for BA.2 infection and 3.00 (2.00, 3.25) days for BF.7 infection. The lognormal distribution was the best fit. Multivariate analysis of variance showed that there were some differences in the incubation periods between two types of infections of Omicron variants, and the incubation period of variant BF.7 infection was shorter than that of variant BA.2 infection. Conclusion: Omicron variant BF.7 infection had shorter incubation period compared with Omicron variant BA.2 infection.

3,5-diCQA suppresses colorectal cancer cell growth through ROS/AMPK/mTOR mediated mitochondrial dysfunction and ferroptosis

3,5-diCQA has been shown to have anti-tumor effect by decreasing cancer cell growth. However, the molecular mechanism by which 3,5-diCQA impacts colorectal cancer (CRC) cells is unknown. This study discovered that 3,5-diCQA had a suppressive effect on CRC cells, mainly in the inhibition of proliferation, migration, and the enhancement of apoptosis in HCT116 and SW480 cells. Additionally, 3,5-diCQA was found to cause cell cycle arrest in CRC cells. Meanwhile, we found that 3,5-diCQA activates the AMPK pathway through the generation of ROS, mediates mitochondrial damage, and reduces mitochondrial aerobic glycolysis and oxidative phosphorylation levels. 3,5-diCQA promoted oxidative damage and ferroptosis in CRC cells. Hence, we added ROS inhibitor NAC and found that the NAC reversed the effects of 3,5-diCQA on proliferation, apoptosis, ROS generation, and ferroptosis in CRC cells. Moreover, 3,5-diCQA was also shown to suppress the development of CRC tumor in a tumor-forming model of nude mice. In conclusion, we found that 3,5-diCQA enhances the oxidative damage and ferroptosis while reducing proliferation and migration of CRC cells, depending on mitochondrial dysfunction caused by the ROS/AMPK/mTOR pathway.

Long-term outcomes to neoadjuvant pembrolizumab based on pathological response for patients with resectable stage III/IV cutaneous melanoma

BACKGROUND

While neoadjuvant immunotherapy for melanoma has shown promising results, the data have been limited by a relatively short follow-up time, with most studies reporting 2-year outcomes. The goal of this study was to determine long-term outcomes for stage III/IV melanoma patients treated with neoadjuvant and adjuvant programmed cell death receptor 1 (PD-1) inhibition.

PATIENTS AND METHODS

This is a follow-up study of a previously published phase Ib clinical trial of 30 patients with resectable stage III/IV cutaneous melanoma who received one dose of 200 mg IV neoadjuvant pembrolizumab 3 weeks before surgical resection, followed by 1 year of adjuvant pembrolizumab. The primary outcomes were 5-year overall survival (OS), 5-year recurrence-free survival (RFS), and recurrence patterns.

RESULTS

We report updated results at 5 years of follow-up with a median follow-up of 61.9 months. No deaths occurred in patients with a major pathological response (MPR, <10% viable tumor) or complete pathological response (pCR, no viable tumor) (n = 8), compared to a 5-year OS of 72.8% for the remainder of the cohort (P = 0.12). Two of eight patients with a pCR or MPR had a recurrence. Of the patients with >10% viable tumor remaining, 8 of 22 patients (36%) had a recurrence. Additionally, the median time to recurrence was 3.9 years for patients with ≤10% viable tumor and 0.6 years for patients with >10% viable tumor (P = 0.044).

CONCLUSIONS

The 5-year results from this trial represent the longest follow-up of a single-agent neoadjuvant PD-1 trial to date. Response to neoadjuvant therapy continues to be an important prognosticator with regard to OS and RFS. Additionally, recurrences in patients with pCR occur later and are salvageable, with a 5-year OS of 100%. These results demonstrate the long-term efficacy of single-agent neoadjuvant/adjuvant PD-1 blockade in patients with a pCR and the importance of long-term follow-up for these patients.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02434354.

[Sinogram interpolation combined with unsupervised image-to-image translation network for CT metal artifact correction]

OBJECTIVE

To propose a framework that combines sinogram interpolation with unsupervised image-to-image translation (UNIT) network to correct metal artifacts in CT images.

METHODS

The initially corrected CT image and the prior image without artifacts, which were considered as different elements in two different domains, were input into the image transformation network to obtain the corrected image. Verification experiments were carried out to assess the effectiveness of the proposed method using the simulation data, and PSNR and SSIM were calculated for quantitative evaluation of the performance of the method.

RESULTS

The experiment using the simulation data showed that the proposed method achieved better results for improving image quality as compared with other methods, and the corrected images preserved more details and structures. Compared with ADN algorithm, the proposed algorithm improved the PSNR and SSIM by 2.4449 and 0.0023 when the metal was small, by 5.9942 and 8.8388 for images with large metals, and by 8.8388 and 0.0130 when both small and large metals were present, respectively.

CONCLUSION

The proposed method for metal artifact correction can effectively remove metal artifacts, improve image quality, and preserve more details and structures on CT images.

First Measurement of the Michel Parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} Decay at Belle

We report the first measurement of the Michel parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decay with a new method proposed just recently. The measurement is based on the reconstruction of the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} events with subsequent muon decay in flight in the Belle central drift chamber. The analyzed data sample of 988  fb^{-1} collected by the Belle detector corresponds to approximately 912×10^{6} τ^{+}τ^{-} pairs. We measure ξ^{'}=0.22±0.94(stat)±0.42(syst), which is in agreement with the standard model prediction of ξ^{'}=1. Statistical uncertainty dominates in this study, being a limiting factor, while systematic uncertainty is well under control. Our analysis proved the practicability of this promising method and its prospects for further precise measurement in future experiments.

Acute Respiratory Infection Incidence and Outpatient Antibiotic Prescription Patterns in People With or Without Human Immunodeficiency Virus Infection: A Virtual Cohort Study

Background

Inappropriate antibiotic use in acute respiratory infections (ARIs) is a major public health concern; however, data for people with human immunodeficiency virus (PWH) are limited.

Methods

The HIV Virtual Cohort Study is a retrospective cohort of adult Department of Defense beneficiaries. Male PWH cases (n = 2413) were matched 1:2 to controls without HIV (n = 4826) by age, gender, race/ethnicity, and beneficiary status. Acute respiratory infection encounters between 2016 and 2020 and corresponding antibiotic prescriptions were characterized as always, sometimes, or never appropriate based on International Classification of Diseases, Tenth Revision coding. Incidence of ARI encounters and antibiotic appropriateness were compared between PWH and controls. Subgroup analyses were assessed by CD4 count and viral load suppression on antiretroviral therapy.

Results

Mean rates of ARI encounters were similar for PWH (1066 per 1000 person-years) and controls (1010 per 1000 person-years); however, the rate was double among PWH without viral load (VL) suppression (2018 per 1000 person-years). Antibiotics were prescribed in 26% of encounters among PWH compared to 34% for controls (P ≤ .01); antibiotic use was "never" appropriate in 38% of encounters with PWH and 36% in controls. Compared to controls, PWH received more sulfonamides (5.5% vs 2.7%; P = .001), and variation existed among HIV subgroups in the prescription of sulfonamides, fluoroquinolones, and β-lactams.

Discussion

Acute respiratory infection encounters were similar for PWH and those without HIV; however, PWH with lower CD4 counts and/or nonsuppressed VL had more frequent ARI visits. Inappropriate antibiotic use for ARIs was high in both populations, and focused interventions to improve antibiotic appropriateness for prescribers caring for PWH should be pursued.

Significance of Hypofractionated Radiotherapy in Postoperative Irradiation for Breast Cancer: An Asian Multi-institutional Prospective Study

AIMS

There is a need for the adequate distribution of healthcare resources in Southeast Asia. Many countries in the region have more patients with advanced breast cancer who are eligible for postmastectomy radiotherapy (PMRT). Therefore, it is critical that hypofractionated PMRT is effective in most of these patients. This study investigated the significance of postoperative hypofractionated radiotherapy in patients with breast cancer, including advanced breast cancer, in these countries.

MATERIALS AND METHODS

Eighteen facilities in 10 Asian countries participated in this prospective, interventional, single-arm study. The study included two independent regimens: hypofractionated whole-breast irradiation (WBI) for patients who had undergone breast-conserving surgery and hypofractionated PMRT for patients who had undergone total mastectomy at a dose of 43.2 Gy in 16 fractions. In the hypofractionated WBI group, patients with high-grade factors received additional 8.1 Gy boost irradiation sessions for the tumour bed in three fractions.

RESULTS

Between February 2013 and October 2019, 227 and 222 patients were enrolled in the hypofractionated WBI and hypofractionated PMRT groups, respectively. The median follow-up periods in the hypofractionated WBI and hypofractionated PMRT groups were 61 and 60 months, respectively. The 5-year locoregional control rates were 98.9% (95% confidence interval 97.4-100.0) and 96.3% (95% confidence interval 93.2-99.4) in the hypofractionated WBI and hypofractionated PMRT groups, respectively. Regarding adverse events, grade 3 acute dermatitis was observed in 2.2% and 4.9% of patients in the hypofractionated WBI and hypofractionated PMRT groups, respectively. However, no other adverse events were observed.

CONCLUSION

Although further follow-up is required, hypofractionated radiotherapy regimens for postoperative patients with breast cancer in East and Southeast Asian countries are effective and safe. In particular, the proven efficacy of hypofractionated PMRT indicates that more patients with advanced breast cancer can receive appropriate care in these countries. Hypofractionated WBI and hypofractionated PMRT are reasonable approaches that can contain cancer care costs in these countries. Long-term observation is required to validate our findings.

[Effect of different abutment materials on the expression of genes and proteins related to hemidesmosome adhesion in human gingival epithelial cells]

Objective: To investigate the effects of polyetheretherketone, zirconium dioxide, and titanium abutment materials on the expression of genes and proteins related to hemidesmosome adhesion in human gingival epithelial cells, in order to screen out abutment materials that are easier for epithelial adhesion. Methods: Forty-eight specimens were prepared in each of the three materials, polyetheretherketone, zirconium oxide, and pure titanium specimens. The surface morphology of each group of specimens was observed by scanning electron microscopy, the surface roughness was measured by the white light interferometer, and the contact angle was measured by optical contact angle measuring instrument. The early adhesion status of human gingival epithelial cells on the surface of each group of specimens was observed by scanning electron microscopy, and the proliferation ability of human gingival epithelial cells on the surface of each group of specimens was assessed by using a cell counting kit, and the expression levels of genes and proteins related to the adhesion of human gingival epithelial cells on the surface of each group of specimens were detected by real-time fluorescence quantitative PCR and Western blotting, respectively. Results: The surface morphology of the three groups of specimens was flat and smooth. The mean roughness (Ra value) of the polyetheretherketone, zirconia, and pure titanium groups were (95.63±2.06), (37.93±3.56), and (134.2±4.62) nm (F=368.16, P<0.001), respectively, and the mean maximum height (Rz value) was (2.42±0.22), (0.87±0.10) and (3.77±0.28) nm (F=91.95, P<0.001), with statistical significance (P<0.05). The contact angles were 81.23°±0.91°, 82.08°±2.10°, and 80.47°±1.85°, respectively, with no statistically significant overall difference (F=0.45, P=0.658). Human gingival epithelial cells showed irregular shapes such as flattened and extended polygons and polygons on the surface of the three groups of specimens, exhibiting a typical paving stone pattern. The differences in cell proliferation among the three groups at 1 and 3 d of culture were not statistically significant (P>0.05). Cell proliferation in the polyetheretherketone group was significantly greater those those in the zirconia and pure titanium groups at 5 and 7 d of culture (P<0.05). The mRNA expression levels and protein expression levels of laminin α3, integrin β4, and collagen ⅩⅦ in the polyetheretheretherketone group at 3 and 7 d of incubation were significantly greater than those in the zirconium oxide and pure titanium groups at the same time points (P<0.05). Conclusions: Polyetheretherketone is more conducive to the adhesion of hemidesmosome in human gingival epithelial cells than zirconium dioxide and pure titanium abutment materials.

Search for the Lepton Flavor Violating Decays B^{+}→K^{+}τ^{±}ℓ^{∓} (ℓ=e, μ) at Belle

We present a search for the lepton flavor violating decays B^{+}→K^{+}τ^{±}ℓ^{∓}, with ℓ=(e,μ), using the full data sample of 772×10^{6}  BB[over ¯] pairs recorded by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. We find no evidence for B^{±}→K^{±}τℓ decays and set upper limits on their branching fractions at the 90% confidence level in the (1-3)×10^{-5} range. The obtained limits are the world's best results.

Plasma position measurements by O-mode and X-mode reflectometry systems in tokamak plasmas

Plasma Position Reflectometry (PPR) is planned to provide plasma position and shape information for plasma operation in future fusion reactors. Its primary function is to calibrate the drift of the magnetic signals due to the integral nature of magnetic measurement. Here, we attempt to measure plasma position using ordinary mode (O-mode) and extraordinary mode (X-mode) reflectometry systems on two tokamaks. A new physical model based on the phase shift is proposed to deduce the relative movement of the cut-off layer without density inversion. We demonstrate the plasma position measurements by absolute measurement from density profile inversion and relative measurement from phase shift. The combination of X-mode and O-mode reflectometers can minimize the limitations of single polarization reflectometry and further increase the accuracy of plasma position measurement. These results could provide an important technical basis for the further development of a real-time control system based on PPR.

A fifty-locus phylogenetic analysis provides deep insights into the phylogeny of Tricholoma (Tricholomataceae, Agaricales)

As an ectomycorrhizal fungal genus that contains matsutake and other edible mushrooms, Tricholoma has great economic and ecological significance. However, the phylogenetic relationships within the genus remain unsettled. To clarify the infrageneric relationships of Tricholoma, including the identification of monophyletic subgenera and sections, three phylogenetic analyses were conducted employing single-locus (ITS), five-locus (ITS/ RPB2/EF-1α/MCM7/mtSSU) and 50-locus (45 single-copy orthologous genes plus the aforementioned ones) DNA nucleotide sequences. Our data indicated that ITS sequences could serve the species delimitation of Tricholoma in most cases and monophyletic groups recognition in some cases, and the five-locus dataset could resolve a section-level phylogeny of this genus, while the 50-locus dataset could clarify the delimitation of subgenera and settle the relationships among sections within this genus. A fifty-locus dataset was firstly employed to construct a robust phylogeny of Tricholoma. Based on this, a new infrageneric arrangement for the genus Tricholoma, with four subgenera, of which two are in accordance with the previous subgenera Pardinicutis and Sericeicutis, and eleven sections, is suggested. Subgenus Pardinicutis, occupying the basal position, only harbors sect. Pardinicutis, while the subg. Sericeicutis comprises sects. Lasciva and Sericella located at the sub-basal position with good support. Subgenus Terrea is newly erected here and consists of sect. Terrea, sect. Atrosquamosa and two as yet unnamed phylogenetic lineages. Besides an unnamed section-level lineage, subg. Tricholoma consists of sects. Genuina, Muscaria, Rigida, Tricholoma, Fucata and Matsutake, of which the two latter are newly proposed. The previously defined subg. Contextocutis is clustered within subg. Tricholoma and is a synonym of the latter. Tricholoma colossus, T. acerbum and their allies, which used to be allocated in sect. Megatricholoma (or genus Megatricholoma), are relocated to sect. Genuina since they form a strongly supported monophyletic group and share rusty or black spots on lamellae with other species in this section. Taxonomic descriptions of the new infrageneric taxa and a key to subgenera and sections of the genus Tricholoma are presented. Citation: Ding XX, Xu X, Cui YY, et al. 2023. A fifty-locus phylogenetic analysis provides deep insights into the phylogeny of Tricholoma (Tricholomataceae, Agaricales). Persoonia 50: 1-26. https://doi.org/10.3767/persoonia.2023.50.01.

Latent class analysis of structured histopathology in prognosticating surgical outcomes of chronic rhinosinusitis with nasal polyps in Singapore

BACKGROUND

Structured histopathology profiling is recommended when reporting chronic rhinosinusitis with nasal polyp (CRSwNP) tissue. The objective of this study is to identify features in structured histopathology that predict outcome after functional endoscopic sinus surgery (FESS) in a cohort of CRSwNP patients from Singapore.

METHODS

Latent class analysis was performed on structured histopathology reports of 126 CRSwNP patients who had undergone FESS. Outcome measures were polyp recurrence, need for systemic corticosteroids, revision surgery or biologics, and disease control at 2 years post-FESS.

RESULTS

Three classes were identified. Class 1 was characterised by mild, predominantly lymphoplasmacytic inflammation. Class 2 comprised of 100 eosinophils/HPF, hyperplastic seromucinous glands, mucosal ulceration and mucin containing eosinophil aggregates and Charcot-Leyden crystals. Classes 2 and 3 were significantly associated with uncontrolled disease at 2 years post-FESS. Class 3 was additionally associated with the need for systemic corticosteroids.

CONCLUSIONS

Eosinophil count, degree of inflammation, predominant inflammatory type, hyperplastic seromucinous glands, mucosal ulceration and mucin containing eosinophil aggregates and Charcot-Leyden crystals predicted need for systemic corticosteroids and uncontrolled disease at 2 years post-FESS. The presence of &gt;100 eosinophils/HPF should be reported, as this subset of tissue eosinophilia was associated with less favourable outcomes after FESS.

[Meta analysis of the prevalence and influencing factors of WMSDs among dentists in China]

Objective: To explore the relevant factors of work-related musculoskeletal disorders (WMSDs) among dentists through Meta analysis, providing a basis for the prevention and control of WMSDs among dentists. Methods: In April 2022, cross-sectional research literatures on the prevalence correlation of WMSDs among Chinese dentists were searched in databases such as China National Knowledge Infrastructure, Wanfang, VIP, PubMed, Web of Science, and Em Base database. The search was conducted from the establishment of the database until April 2022, literatures were selected using keywords such as musculoskeletal disorders and dentists. To extract gender, age, length of service, disease classification and other related influencing factors as indicator, and prevalence was selected as the outcome indicator. After evaluating the quality of the literatures, RevMan 5.3 software was used to calculate the combined RD (95%CI) values of the included literatures. Results: A total of 15 articles were included, with a total sample size of 3646 people. Meta analysis results showed that the prevalence of WMSDs among dentists in China was 80%, and the top three parts of the incidence rates were 65% of the waist, 58% of the neck, and 50% of the back. Gender, age, length of service, region and disease classification all increased the risk of WMSDs, and the combined effect size were 75%, 78%, 71%, 77% and 82% respectively (P<0.05) . Conclusion: The occurrence of WMSDs among dentists in China is related to multiple factors such as gender, age, length of service and disease classification. The above risk factors should be taken into account in the workplace and preventive measures should be actively implemented to prolong the working life of dentists.

Mass Measurement of Upper fp-Shell N=Z-2 and N=Z-1 Nuclei and the Importance of Three-Nucleon Force along the N=Z Line

Using a novel method of isochronous mass spectrometry, the masses of ^{62}Ge, ^{64}As, ^{66}Se, and ^{70}Kr are measured for the first time, and the masses of ^{58}Zn, ^{61}Ga, ^{63}Ge, ^{65}As, ^{67}Se, ^{71}Kr, and ^{75}Sr are redetermined with improved accuracy. The new masses allow us to derive residual proton-neutron interactions (δV_{pn}) in the N=Z nuclei, which are found to decrease (increase) with increasing mass A for even-even (odd-odd) nuclei beyond Z=28. This bifurcation of δV_{pn} cannot be reproduced by the available mass models, nor is it consistent with expectations of a pseudo-SU(4) symmetry restoration in the fp shell. We performed ab initio calculations with a chiral three-nucleon force (3NF) included, which indicate the enhancement of the T=1 pn pairing over the T=0 pn pairing in this mass region, leading to the opposite evolving trends of δV_{pn} in even-even and odd-odd nuclei.

Multiple Mechanisms in Proton-Induced Nucleon Removal at ∼100 MeV/Nucleon

We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient ^{14}O nucleus with large Fermi-surface asymmetry S_{n}-S_{p}=18.6  MeV at ∼100  MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the ^{13}N and ^{13}O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively. These multiple reaction mechanisms should be considered in analyses of inclusive one-nucleon removal cross sections measured at intermediate energies for quantitative investigation of single-particle strengths and correlations in atomic nuclei.

First Observation of Λπ^{+} and Λπ^{-} Signals near the K[over ¯]N(I=1) Mass Threshold in Λ_{c}^{+}→Λπ^{+}π^{+}π^{-} Decay

Using the data sample of 980  fb^{-1} collected with the Belle detector operating at the KEKB asymmetric-energy e^{+}e^{-} collider, we present the results of an investigation of the Λπ^{+} and Λπ^{-} invariant mass distributions looking for substructure in the decay Λ_{c}^{+}→Λπ^{+}π^{+}π^{-}. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ^{+} (Λπ^{-}) combination a mass of 1434.3±0.6(stat)±0.9(syst)  MeV/c^{2} [1438.5±0.9(stat)±2.5(syst)  MeV/c^{2}], an intrinsic width of 11.5±2.8(stat)±5.3(syst)  MeV/c^{2} [33.0±7.5(stat)±23.6(syst)  MeV/c^{2}] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K[over ¯]N threshold, we also investigate the possibility of a K[over ¯]N cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.

Cyclic di-AMP Rescues Porphyromonas gingivalis-Aggravated Atherosclerosis

Growing evidence demonstrates the relationship between periodontitis and atherosclerotic cardiovascular diseases. The periodontal pathogen Porphyromonas gingivalis (Pg) has been shown to contribute to the progression of atherosclerosis. Cyclic diadenylate monophosphate (c-di-AMP) has been widely studied as an immune adjuvant for tumor immunotherapy, given its ability to activate the stimulator of interferon genes (STING) and regulate trained immunity. This study sought to elucidate the role of c-di-AMP in Pg-associated atherosclerosis. Periodontitis and atherosclerosis mouse models were established by ligature application around maxillary second molars and feeding ApoE knockout mice with a high-fat diet. We found that periodontitis and atherosclerosis were more severe in mice exposed to Pg than mice that underwent ligature placement only, while prophylactic treatment with c-di-AMP activated trained immunity and elicited significant alleviation of alveolar bone resorption, as well as reduced blood lipid levels and atherosclerotic plaque accumulation. After 3 mo of intervention, c-di-AMP limited the elevation of cytokines interleukin (IL)-6, IL-1β, tumor necrosis factor α, and interferon β; extracellular matrix remodeling enzymes MMP-2 and MMP-9; and adhesion molecules ICAM-1 and VCAM-1 gene expression. The mechanism underlying Pg-aggravated atherosclerosis may be attributed to changes in microbiota composition in oral and aortic plaques and excess inflammatory response, whereas c-di-AMP could prevent the effects of Pg infection due to its potential ability to activate trained immunity and regulate microecological balance. Our findings suggest a positive role of c-di-AMP in alleviating Pg-aggravated atherosclerosis by regulating the immune response and influencing the local microenvironment.

Octahedral Distortion and Displacement-Type Ferroelectricity with Switchable Photovoltaic Effect in a 3d^{3}-Electron Perovskite System

Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5  μC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.

PGRMC1 promotes triple-negative breast cancer cell growth via suppressing ferroptosis

OBJECTIVE

Triple-negative breast cancer (TNBC) is the most malignant form of breast cancer with increasing incidence and mortality worldwide. The progesterone receptor membrane component-1 (PGRMC1) is a well-identified hormone receptor with unknown functions in TNBC. The current study aims to explore the involvement of PGRMC1 in regulation of glutathione metabolism and ferroptosis during development of TNBC, providing new therapy options for TNBC patients.

METHODS

Bioinformatic analysis, cell proliferation assay, western blot assay and other biochemistry methods were performed in TNBC cells.

RESULTS

Our results revealed that the expression of PGRMC1 is higher in TNBC than the other subtypes of breast cancer. Interestingly, as an iron binding protein, increased PGRMC1 expression in TNBC cells leads to resistance to ferroptosis inducer. On the contrary, silenced PGRMC1 expression enhanced sensitivity of MDA-MB231 cells to Erastin. Mechanistically, overexpression of PGRMC1 decreased the intracellular free iron concentration, which was reduced by AG205 treatment.

CONCLUSIONS

PGRMC1 increases the possibility of TNBC development through binding to intracellular iron and suppressing ferroptosis, providing the molecular basis of combined treatment for TNBC.

Diagnostic Performance of High-Resolution Vessel Wall MR Imaging Combined with TOF-MRA in the Follow-up of Intracranial Vertebrobasilar Dissecting Aneurysms after Reconstructive Endovascular Treatment

BACKGROUND AND PURPOSE

Few studies have reported the utility of high-resolution vessel wall MR imaging in the follow-up of endovascularly treated vertebrobasilar dissecting aneurysms. This study aimed to evaluate the diagnostic performance of high-resolution vessel wall MR imaging combined with TOF-MRA in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.

MATERIALS AND METHODS

Patients with intracranial vertebrobasilar dissecting aneurysms with reconstructive endovascular treatment and followed up with TOF-MRA, high-resolution vessel wall MR imaging, and DSA were included. With DSA as the criterion standard, the diagnostic performance of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA in the evaluation of aneurysm occlusion status and parent artery patency was assessed. Visualization of the stented artery on TOF-MRA and high-resolution vessel wall MR imaging was rated on a 5-point scale.

RESULTS

Twenty-seven patients with 29 aneurysms were included. The sensitivity, specificity, positive predictive value, and negative predictive value of TOF-MRA, high-resolution vessel wall MR imaging, and high-resolution vessel wall MR imaging combined with TOF-MRA for diagnosing aneurysm remnants were 80.0%, 100.0%, 100.0%, and 82.4%; 53.3%, 100.0%, 100.0%, and 66.7%; and 93.3%, 100.0%, 100.0%, and 93.3%, respectively. For the visualization of the stented artery, the mean score of high-resolution vessel wall MR imaging was significantly higher than that of TOF-MRA (4.88 [SD, 0.32] versus 2.53 [SD, 1.25], P < .001). In the evaluation of parent artery patency (normal or pathologic), whereas TOF-MRA had a sensitivity, specificity, positive predictive value, and negative predictive value of 100.0%, 8.0%, 14.8%, and 100.0%, respectively, high-resolution vessel wall MR imaging was completely consistent with the DSA.

CONCLUSIONS

High-resolution vessel wall MR imaging combined with TOF-MRA at 3T showed good diagnostic performance in the follow-up of intracranial vertebrobasilar dissecting aneurysms after reconstructive endovascular treatment.