[Mechanism of scavenger receptor-A in high glucose-induced inflammatory injury of mesangial cells]

Objective: To investigate the effect of high glucose on scavenger receptor-A (SR-A) in human glomerular mesangial cells (HMC) and explore the mechanism of inflammatory injury mediated by SR-A in HMC cultured in high-glucose medium. Methods: According to the concentration of D-glucose in culture medium, HMC were divided into normal glucose group (5.5 mmol/L) and high glucose group (30 mmol/L), with mannitol group as hypertonic control. High glucose group was transfected with SR-A small interfering RNA (siSR-A) and the transfection control (siNC) group were set up. Western blotting technology was used to detect the levels of SR-A, NOD-like receptor family pyrin domain-containing 3 (NLRP3), interleukin-1β (IL-1β) protein. Immunofluorescent staining was applied to measure the SR-A in HMC. The mRNA of NLRP3, Caspase-1, IL-1β, FN, ColⅣ, α-SMA and GRP78 were detected by real-time quantitative PCR. The relative activity of Caspase-1 was detected by enzyme method and the concentration of IL-1β in culture medium was detected by enzyme linked immunosorbent assay. Flow cytometry was used to measure the cell cycles of HMC. One-way ANOVA and SNK-q test were used for statistical analysis. Results: The protein level of SR-A in high glucose group was higher than that in normal glucose group and mannitol group (1.23±0.21 vs. 0.68±0.10, 1.23±0.21 vs. 0.78±0.13, all P<0.05). In addition, mean fluorescence intensity of SR-A, protein levels of NLRP3 and IL-1β, mRNA of NLRP3, Caspase-1 and IL-1β, relative activity of Caspase-1 as well as the concentration of IL-1β in high glucose group were all significantly higher than those in normal glucose group and mannitol group (all P<0.05).After transfection induced silencing, SR-A protein in high glucose siNC group was higher than that in high glucose siSR-A group and normal glucose siNC group (1.23±0.10 vs. 0.20±0.01, 1.23±0.10 vs. 0.87±0.01, all P<0.01). In high glucose siNC group, the NLRP3, IL-1β proteins, the NLRP3, Caspase-1 and IL-1β mRNA, all of the mRNA levels of FN, ColⅣ, α-SMA, GRP78 and the proportion of DNA synthesis phase were all higher than those in high glucose siSR-A group and normal glucose siNC group (all P<0.05). Conclusion: High glucose can promote abnormal cell proliferation, increase mesangial matrix production and enhance oxidative stress response through upregulating SR-A expression, and ultimately aggravate cellular inflammatory damage in HMC, which may be associated with NLRP3-Caspase-1-IL-1β pathway regulated by SR-A expression.

Physics-informed machine learning: case studies for weather and climate modelling

Machine learning (ML) provides novel and powerful ways of accurately and efficiently recognizing complex patterns, emulating nonlinear dynamics, and predicting the spatio-temporal evolution of weather and climate processes. Off-the-shelf ML models, however, do not necessarily obey the fundamental governing laws of physical systems, nor do they generalize well to scenarios on which they have not been trained. We survey systematic approaches to incorporating physics and domain knowledge into ML models and distill these approaches into broad categories. Through 10 case studies, we show how these approaches have been used successfully for emulating, downscaling, and forecasting weather and climate processes. The accomplishments of these studies include greater physical consistency, reduced training time, improved data efficiency, and better generalization. Finally, we synthesize the lessons learned and identify scientific, diagnostic, computational, and resource challenges for developing truly robust and reliable physics-informed ML models for weather and climate processes. This article is part of the theme issue 'Machine learning for weather and climate modelling'.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Observation of a Near-Threshold Structure in the K^{+} Recoil-Mass Spectra in e^{+}e^{-}→K^{+}(D_{s}^{-}D^{*0}+D_{s}^{*-}D^{0})

We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7  fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrt[s]=4.681  GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1)  MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0)  MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3  σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.

Model-Independent Determination of the Spin of the Ω^{-} and Its Polarization Alignment in ψ(3686)→Ω^{-}Ω[over ¯]^{+}

We present an analysis of the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} (Ω^{-}→K^{-}Λ, Ω[over ¯]^{+}→K^{+}Λ[over ¯], Λ→pπ^{-}, Λ[over ¯]→p[over ¯]π^{+}) based on a dataset of 448×10^{6}  ψ(3686) decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω^{-}Ω[over ¯]^{+} and the decay parameters of the subsequent decay Ω^{-}→K^{-}Λ (Ω[over ¯]^{+}→K^{+}Λ[over ¯]) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω^{-} is determined to be 3/2 for the first time since its discovery more than 50 years ago.

[Effects of Astragaloside Ⅳ on exosome secretion and its microRNA-126 expression in human endothelial progenitor cells]

Objective: To investigate the effects of Astragaloside Ⅳ on the secretion of exosomes in human endothelial progenitor cells (EPCs) and the expression of microRNA (miRNA)-126 in exosomes. Methods: The umbilical cord blood from one healthy full-term newborn from the Department of Obstetrics and Gynecology of the First Affiliated Hospital of Hunan University of Traditional Chinese Medicine in 2019 was harvested for isolating mononuclear cells by density gradient centrifugation and cultured for 7 days. Morphological observation was performed during this period. Cells of the third passage were collected for identification by CD31 immunomagnetic bead sorting and double fluorescence staining. According to the random number table, the identified EPCs were divided into Astragaloside Ⅳ group and phosphate buffer solution (PBS) group. The cells in Astragaloside Ⅳ group were cultured with Astragaloside Ⅳ in final mass concentration of 100 mg/L for 24 hours, and the cells in PBS group were cultured with the same volume of PBS for 24 hours. After culture, the exosomes from the cell culture supernatant of the two groups were collected, and the expressions of characteristic markers of exosomes CD9, CD63, and CD81 were detected by Western blotting, the morphology of EPC exosomes (EPC-Exos) was observed under transmission electron microscope, and the particle size of EPC-Exos was detected by nanoparticle tracking analysis technique. The concentration of EPC-Exos was determined by dioctyl butyric acid method (the sample number was 3), and the expressions of miRNA-126-3p and miRNA-126-5p related to angiogenesis in EPC-Exos were determined by reverse transcription polymerase chain reaction (the sample number was 3). Data were statistically analyzed with independent sample t test. Results: (1) On the 4th day of culture, the cells began to adhere to the wall, and the multi-forms such as circle, fusiform, and strip appeared at the same time. On the 7th day of culture, the edge of the cells was clear and arranged like a paving stone, the central cells were round, and the surrounding cells were fusiform. (2) CD31 immunomagnetic beads sorting method identification showed that the membrane was stained with green fluorescence and the nucleus was stained with blue fluorescence. Double fluorescence staining method showed that the cells were orange-yellow. The cells were identified as EPCs. (3) After 24 hours of culture, the expressions of CD9, CD63, and CD81 in EPC-Exos were all positive, confirming that EPC-Exos were extracted successfully in this experiment. (4) After 24 hours of culture, the EPC-Exos of the two groups showed round membrane vesicles, and there was no significant difference in morphology. (5) After 24 hours of culture, the particle size of 98.7% EPC-Exos in Astragaloside Ⅳ group was 84.7 to 143.1 nm, and that of 98.0% EPC-Exos in PBS group was 88.7 to 123.5 nm. (6) After 24 hours of culture, the mass concentration of EPC-Exos in Astragaloside Ⅳ group was (310±5) μg/mL, which was significantly higher than (257±5) μg/mL in PBS group, t=13.369, P<0.01. (7) After 24 hours of culture, there were more miRNA-126-3p (t=16.062, P<0.01) and miRNA-126-5p (t=3.252, P<0.05) in EPC-Exos of Astragaloside Ⅳ group than in PBS group. Conclusions: Astragaloside Ⅳ can improve the function of human EPC secretory exosomes, and the secreted exosomes are loaded with miRNA-126.

[Application of rigid curved laryngoscope in the examination of hypopharynx and the treatment of early hypopharyngeal cancer]

Objective: To evaluate the efficacy of curved suspension laryngoscope assistant transoral surgery (CLATOS) in the examination of hypopharynx, and diagnosis and surgery of early hypopharyngeal carcinoma. Methods: Thirty-four patients who underwent detailed examination for lower part of hypopharynx and surgery for early hypopharyngeal carcinoma with CLATOS technique in the Second Affiliated Hospital of Harbin Medical University from January 2019 to January 2020 were analyzed retrospectively. The age ranged from 42 to 74 years old including 28 males and 6 females. Among them, 25 patients complaining of foreign body sensation in the pharynx for more than half a year with a poor exposure of the lower pharynx in the examination with flexible laryngoscope in the outpatient department were admitted to the hospital for the further examination with rigid curved laryngoscopy and 9 patients with stage T1-2 hypopharyngeal squamous cell carcinoma were operated with CLATOS technique. Preoperative, intraoperative and postoperative data were analized. Results: One case of squamous cell carcinoma in esophageal entrance (T1N0M0) and one case of carcinoma in pyriform sinus (T1N0M0) with cervical esophageal carcinoma (T1N0M0) were found in the 25 patients with foreign body sensation in the pharynx. En bloc resection of cancer was obtained in 9 patients with stage T1-2 hypopharyngeal carcinomas and 2 of them underwent tracheotomy. One patient with T1 retrocricoid carcinoma was found to have a carcinoma in situ at the lower part of posterior hypopharyngeal wall in the examination during follow-up, which was resected simultaneously. Postoperatively this patient developed a stenosis in the esophageal entrance, which was dilated twice until swallowing normally. Two patients of T2N0M0 and one of T2N1M0 underwent bilateral neck lymph node dissection just after the removal of primary tumors. During follow-up, none of the 9 patients showed tumor recurrence and complications such as dysphonia and dyspnea. Conclusion: CLATOS technique can provide a promising way in the examination of hypopharynx and the detection of early lesions of hypopharynx and esophageal entrance, and this technique has also the advantages such as full visual angle and easy operation for the resection of early hypopharyngeal carcinoma. The quality of life of patients can be improved while the tumor is removed en bloc with this technique.

Observation of the Doubly Cabibbo-Suppressed Decay D^{+}→K^{+}π^{+}π^{-}π^{0} and Evidence for D^{+}→K^{+}ω

Using 2.93  fb^{-1} of e^{+}e^{-} collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the doubly Cabibbo-suppressed decay D^{+}→K^{+}π^{+}π^{-}π^{0} is reported. After removing decays that contain narrow intermediate resonances, including D^{+}→K^{+}η, D^{+}→K^{+}ω, and D^{+}→K^{+}ϕ, the branching fraction of the decay D^{+}→K^{+}π^{+}π^{-}π^{0} is measured to be (1.13±0.08_{stat}±0.03_{syst})×10^{-3}. The ratio of branching fractions of D^{+}→K^{+}π^{+}π^{-}π^{0} over D^{+}→K^{-}π^{+}π^{+}π^{0} is found to be (1.81±0.15)%, which corresponds to (6.28±0.52)tan^{4}θ_{C}, where θ_{C} is the Cabibbo mixing angle. This ratio is significantly larger than the corresponding ratios for other doubly Cabibbo-suppressed decays. The asymmetry of the branching fractions of charge-conjugated decays D^{±}→K^{±}π^{±}π^{∓}π^{0} is also determined, and no evidence for CP violation is found. In addition, the first evidence for the D^{+}→K^{+}ω decay, with a statistical significance of 3.3σ, is presented and the branching fraction is measured to be B(D^{+}→K^{+}ω)=(5.7_{-2.1}^{+2.5}_{stat}±0.2_{syst})×10^{-5}.