Excitons in mesoscopically reconstructed moiré heterostructures

Moiré effects in vertical stacks of two-dimensional crystals give rise to new quantum materials with rich transport and optical phenomena that originate from modulations of atomic registries within moiré supercells. Due to finite elasticity, however, the superlattices can transform from moiré-type to periodically reconstructed patterns. Here we expand the notion of such nanoscale lattice reconstruction to the mesoscopic scale of laterally extended samples and demonstrate rich consequences in optical studies of excitons in MoSe₂-WSe₂ heterostructures with parallel and antiparallel alignments. Our results provide a unified perspective on moiré excitons in near-commensurate semiconductor heterostructures with small twist angles by identifying domains with exciton properties of distinct effective dimensionality, and establish mesoscopic reconstruction as a compelling feature of real samples and devices with inherent finite size effects and disorder. Generalized to stacks of other two-dimensional materials, this notion of mesoscale domain formation with emergent topological defects and percolation networks will instructively expand the understanding of fundamental electronic, optical and magnetic properties of van der Waals heterostructures.

Machine-learning models for prediction of sepsis patients mortality

OBJECTIVES

Sepsis is an infection-caused syndrome, that leads to life-threatening organ damage. We aim to develop machine learning models with large-scale data to predict sepsis patients' mortality.

DESIGN

we extracted sepsis patients from two databases, Medical Information Mart for Intensive Care IV (MIMIC-IV) as a train set and Philips eICU Collaborative Research Database as a test set.

SETTING

ICUs in multicenter hospitals in the USA during 2012-2019.

PATIENTS OR PARTICIPANTS

A total of 21,680 sepsis-3 patients are included in the study, in which, 3771 patients were dead and 17,909 survived during hospitalization, respectively.

INTERVENTIONS

No interventions.

MAIN VARIABLES OF INTEREST

Basic information, examination items during hospitalization and some medication and treatment information are incorporated into analyzed. Seven different models were built with a Support vector machine, Decision Tree Classifier, Random Forest, Gradients Boosting, Multiple Layer Perception, Xgboost, light Gradients Boosting to predict dead or live during hospitalization.

RESULTS

Algorithms with an AUC value in the test set of the top three: light GBM, GBM, Xgboost. Considering the performance of the training set and the test set, the light GBM model performs best, and then the parameters of the model were adjusted, after that the AUC value was 0.99 in the train set, 0.96 in the test set, respectively.

CONCLUSIONS

Models built with light GBM algorithm from real-world sepsis patients from electronic health records accurately predict whether sepsis patients are dead and can be incorporated into clinical decision tools to enhance the prognosis of the patient and prevent adverse outcomes.

Prediction of clinicopathological features, multi-omics events and prognosis based on digital pathology and deep learning in HR+/HER2- breast cancer

Background

Breast cancer has the highest incidence and mortality rates among women worldwide. Hormone receptor (HR)⁺/human epidermal growth factor receptor 2 (HER2)^- breast cancer is the most common molecular subtype, accounting for 50-79% of breast cancers. Deep learning has been widely used in cancer image analysis, especially for predicting targets related to precise treatment and patient prognosis. However, studies focusing on therapeutic target and prognosis predicting in HR⁺/HER2^- breast cancer are lacking.

Methods

This study retrospectively collected hematoxylin and eosin (H&E)-stained slides of HR⁺/HER2^- breast cancer patients between January 2013 and December 2014 at Fudan University Shanghai Cancer Center (FUSCC) and scanned to generate whole-slide images (WSIs). Then, we built a deep-learning-based workflow to train and validate model to predict clinicopathological features, multi-omics molecular features and prognosis; the area under the curve (AUC) of the receiver operating characteristic (ROC) and the concordance index (C-index) of the test set were used to assess model effectiveness.

Results

A total of 421 HR⁺/HER2^- breast cancer patients were included in our study. Regarding clinicopathological features, grade III could be predicted with an AUC of 0.90 [95% confidence interval (CI): 0.84-0.97]. Regarding somatic mutations, TP53 and GATA3 mutation could be predicted with AUCs of 0.68 (95% CI: 0.56-0.81) and 0.68 (95% CI: 0.47-0.89), respectively. Regarding gene set enrichment analysis (GSEA) pathways, the G2-M checkpoint pathway was predicted with an AUC of 0.79 (95% CI: 0.69-0.90). Regarding markers of immunotherapy response, intratumoral tumor-infiltrating lymphocytes (iTILs), stromal tumor-infiltrating lymphocytes (sTILs), CD8A, and PDCD1 were predicted with AUCs of 0.78 (95% CI: 0.55-1.00), 0.76 (95% CI: 0.65-0.87), 0.71 (95% CI: 0.60-0.82), and 0.74 (95% CI: 0.63-0.85), respectively. In addition, we found that the integration of clinical prognostic variables and deep features of images can improve the stratification of patient prognosis.

Conclusions

Using a deep-learning-based workflow, we developed models to predict the clinicopathological features, multi-omics features and prognosis of patients with HR⁺/HER2^- breast cancer using pathological WSIs. This work may contribute to efficient patient stratification to promote the personalized management of HR⁺/HER2^- breast cancer.

Fluoride resistance capacity in mammalian cells involves global gene expression changes associate with ferroptosis

OBJECTIVE

The purpose of this study was to understand mouse osteoblast ferroptosis under high fluoride environment by stimulating fluoride levels to corresponding levels. In order to define the underlying mechanism of fluoride resistance in mammals and provide a theoretical basis for fluorosis treatment, high-throughput sequencing was applied to map the genetic changes of fluoride-resistant mouse osteoblasts and analyze the role of ferroptosis-related genes.

METHODS

Cell Counting Kit-8, Reactive Oxygen Species Assay Kit and C11 BODIPY 581/591 were used to monitor proliferation and ferroptosis of mouse osteoblasts MC3T3-E1 under high fluoride environment. Fluoride-tolerant MC3T3-E1 cells were developed by gradient fluoride exposure. The differentially expressed genes of fluorine-resistant MC3T3-E1 cells were identified by high-throughput sequencing.

RESULTS

MC3T3-E1 cells cultured in medium containing 20, 30, 60, 90 ppm F^- exhibited decreased viability and increased reactive oxygen species and lipid peroxidation levels in correlation with F^- concentrations. High-throughput RNA sequencing identified 2702 differentially expressed genes (DEGs) showed more than 2-fold difference in 30 ppm FR MC3T3-E1 cells, of which 17 DEGs were associated with ferroptosis.

CONCLUSION

High fluoride environment affected the content of lipid peroxides in the body and increased the level of ferroptosis, further, ferroptosis-related genes played specific roles in the fluoride resistance of mouse osteoblasts.

Lattice Reconstruction in MoSe2-WSe2 Heterobilayers Synthesized by Chemical Vapor Deposition

Vertical van der Waals heterostructures of semiconducting transition metal dichalcogenides realize moiré systems with rich correlated electron phases and moiré exciton phenomena. For material combinations with small lattice mismatch and twist angles as in MoSe₂-WSe₂, however, lattice reconstruction eliminates the canonical moiré pattern and instead gives rise to arrays of periodically reconstructed nanoscale domains and mesoscopically extended areas of one atomic registry. Here, we elucidate the role of atomic reconstruction in MoSe₂-WSe₂ heterostructures synthesized by chemical vapor deposition. With complementary imaging down to the atomic scale, simulations, and optical spectroscopy methods, we identify the coexistence of moiré-type cores and extended moiré-free regions in heterostacks with parallel and antiparallel alignment. Our work highlights the potential of chemical vapor deposition for applications requiring laterally extended heterosystems of one atomic registry or exciton-confining heterostack arrays.

"But not the music": psychopathic traits and difficulties recognising and resonating with the emotion in music

Recognising and responding appropriately to emotions is critical to adaptive psychological functioning. Psychopathic traits (e.g. callous, manipulative, impulsive, antisocial) are related to differences in recognition and response when emotion is conveyed through facial expressions and language. Use of emotional music stimuli represents a promising approach to improve our understanding of the specific emotion processing difficulties underlying psychopathic traits because it decouples recognition of emotion from cues directly conveyed by other people (e.g. facial signals). In Experiment 1, participants listened to clips of emotional music and identified the emotional content (Sample 1, N = 196) or reported on their feelings elicited by the music (Sample 2, N = 197). Participants accurately recognised (t(195) = 32.78, p < .001, d = 4.69) and reported feelings consistent with (t(196) = 7.84, p < .001, d = 1.12) the emotion conveyed in the music. However, psychopathic traits were associated with reduced emotion recognition accuracy (F(1, 191) = 19.39, p < .001) and reduced likelihood of feeling the emotion (F(1, 193) = 35.45, p < .001), particularly for fearful music. In Experiment 2, we replicated findings for broad difficulties with emotion recognition (Sample 3, N = 179) and emotional resonance (Sample 4, N = 199) associated with psychopathic traits. Results offer new insight into emotion recognition and response difficulties that are associated with psychopathic traits.

Feature-correlation-aware history-preserving-sparse-coding framework for automatic vertebra recognition

Automatic vertebra recognition from magnetic resonance imaging (MRI) is of significance in disease diagnosis and surgical treatment of spinal patients. Although modern methods have achieved remarkable progress, vertebra recognition still faces two challenges in practice: (1) Vertebral appearance challenge: The vertebral repetitive nature causes similar appearance among different vertebrae, while pathological variation causes different appearance among the same vertebrae; (2) Field of view (FOV) challenge: The FOVs of the input MRI images are unpredictable, which exacerbates the appearance challenge because there may be no specific-appearing vertebrae to assist recognition. In this paper, we propose a Feature-cOrrelation-aware history-pReserving-sparse-Coding framEwork (FORCE) to extract highly discriminative features and alleviate these challenges. FORCE is a recognition framework with two elaborated modules: (1) A feature similarity regularization (FSR) module to constrain the features of the vertebrae with the same label (but potentially with different appearances) to be closer in the latent feature space in an Eigenmap-based regularization manner. (2) A cumulative sparse representation (CSR) module to achieve feed-forward sparse coding while preventing historical features from being erased, which leverages both the intrinsic advantages of sparse codes and the historical features for obtaining more discriminative sparse codes encoding each vertebra. These two modules are embedded into the vertebra recognition framework in a plug-and-play manner to improve feature discrimination. FORCE is trained and evaluated on a challenging dataset containing 600 MRI images. The evaluation results show that FORCE achieves high performance in vertebra recognition and outperforms other state-of-the-art methods.

[Differences in clinicopathological features, gene mutations, and prognosis between primary gastric and intestinal gastrointestinal stromal tumors in 1061 patients]

Objective: To analyze the clinicopathological features and gene mutations of primary gastrointestinal stromal tumors (GISTs) of the stomach and intestine and the prognosis of intermediate- and high-risk GISTs. Methods: This was a retrospective cohort study. Data of patients with GISTs admitted to Tianjin Medical University Cancer Institute and Hospital from January 2011 to December 2019 were collected retrospectively. Patients with primary gastric or intestinal disease who had undergone endoscopic or surgical resection of the primary lesion and were confirmed pathologically as GIST were included. Patients treated with targeted therapy preoperatively were excluded. The above criteria were met by 1061 patients with primary GISTs, 794 of whom had gastric GISTs and 267 intestinal GISTs. Genetic testing had been performed in 360 of these patients since implementation of Sanger sequencing in our hospital in October 2014. Gene mutations in KIT exons 9, 11, 13, and 17 and PDGFRA exons 12 and 18 were detected by Sanger sequencing. The factors investigated in this study included: (1) clinicopathological data, such as sex, age, primary tumor location, maximum tumor diameter, histological type, mitotic index (/5 mm²), and risk classification; (2) gene mutation; (3) follow-up, survival, and postoperative treatment; and (4) prognostic factors of progression-free survival (PFS) and overall survival (OS) for intermediate- and high-risk GIST. Results: (1) Clinicopathological features: The median ages of patients with primary gastric and intestinal GIST were 61 (8-85) years and 60 (26-80) years, respectively; The median maximum tumor diameters were 4.0 (0.3-32.0) cm and 6.0 (0.3-35.0) cm, respectively; The median mitotic indexes were 3 (0-113)/5 mm² and 3 (0-50)/5 mm², respectively; The median Ki-67 proliferation indexes were 5% (1%-80%) and 5% (1%-50%), respectively. The rates of positivity for CD117, DOG-1, and CD34 were 99.7% (792/794), 99.9% (731/732), 95.6% (753/788), and 100.0% (267/267), 100.0% (238/238), 61.5% (163/265), respectively. There were higher proportions of male patients (χ²=6.390, P=0.011), tumors of maximum diameter > 5.0 cm (χ²=33.593, P<0.001), high-risk (χ²=94.957, P<0.001), and CD34-negativity (χ²=203.138, P<0.001) among patients with intestinal GISTs than among those with gastric GISTs. (2) Gene mutations: Gene mutations were investigated in 286/360 patients (79.4%) with primary gastric GISTs and 74/360 (20.6%) with primary intestinal GISTs. Among the 286 patients with gastric primary GISTs, 79.4% (227/286), 8.4% (24/286), and 12.2% (35/286), had KIT mutations, PDGFRA mutations, and wild-type, respectively. Among the 74 patients with primary intestinal GISTs, 85.1% (63/74) had KIT mutations and 14.9% (11/74) were wild-type. The PDGFRA mutation rate was lower in patients with intestinal GISTs than in those with gastric GISTs[ 0% vs. 8.4%(24/286), χ²=6.770, P=0.034], whereas KIT exon 9 mutations occurred more often in those with intestinal GISTs [22.2% (14/63) vs. 1.8% (4/227), P<0.001]. There were no significant differences between gastric and intestinal GISTs in the rates of KIT exon 11 mutation type and KIT exon 11 deletion mutation type (both P>0.05). (3) Follow-up, survival, and postoperative treatment: After excluding 228 patients with synchronous and metachronous other malignant tumors, the remaining 833 patients were followed up for 6-124 (median 53) months with a follow-up rate of 88.6% (738/833). None of the patients with very low or low-risk gastric (n=239) or intestinal GISTs (n=56) had received targeted therapy postoperatively. Among 179 patients with moderate-risk GISTs, postoperative targeted therapy had been administered to 88/155 with gastric and 11/24 with intestinal GISTs. Among 264 patients with high-risk GISTs, postoperative targeted therapy had been administered to 106/153 with gastric and 62/111 with intestinal GISTs. The 3-, 5-, and 10-year PFS of patients with gastric or intestinal GISTs were 96.5%, 93.8%, and 87.6% and 85.7%, 80.1% and 63.3%, respectively (P<0.001). The 3-, 5-, and 10-year OS were 99.2%, 98.8%, 97.5% and 94.8%, 92.1%, 85.0%, respectively (P<0.001). (4) Analysis of predictors of intermediate- and high-risk GISTs: The 5-year PFS of patients with gastric and intestinal GISTs were 89.5% and 73.2%, respectively (P<0.001); The 5-year OS were 97.9% and 89.3%, respectively (P<0.001). Multivariate analysis showed that high risk (HR=2.918, 95%CI: 1.076-7.911, P=0.035) and Ki-67 proliferation index > 5% (HR=2.778, 95%CI: 1.389-5.558, P=0.004) were independent risk factors for PFS in patients with intermediate- and high-risk GISTs (both P<0.05). Intestinal GISTs (HR=3.485, 95%CI: 1.407-8.634, P=0.007) and high risk (HR=3.753,95%CI:1.079-13.056, P=0.038) were independent risk factors for OS in patients with intermediate- and high-risk GISTs (both P<0.05). Postoperative targeted therapy was independent protective factor for PFS and OS (HR=0.103, 95%CI: 0.049-0.213, P<0.001; HR=0.210, 95%CI:0.078-0.564,P=0.002). Conclusions: Primary intestinal GIST behaves more aggressively than gastric GISTs and more frequently progress after surgery. Moreover, CD34 negativity and KIT exon 9 mutations occur more frequently in patients with intestinal GISTs than in those with gastric GISTs.

Detection of haemodynamic obstruction in hypertrophic cardiomyopathy using the sub-aortic complex: a cardiac MRI and Doppler study

AIM

To investigate the "sub-aortic complex (SAC)", a new cardiac magnetic resonance imaging (CMRI)-derived parameter, for the evaluation of left ventricular (LV) outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM), compared with conventional CMRI parameters and Doppler echocardiography.

MATERIALS AND METHODS

A total of 157 consecutive patients with HCM were recruited retrospectively. The patients were divided into two groups, 87 with LVOT obstruction and 70 without obstruction. The SAC was defined as a specific anatomical SAC affecting the LVOT, which were measured on the LV three-chamber steady-state free precession (SSFP) cine image at the end-systolic phase. The relations between the existence and severity of obstruction and SAC index (SACi) were evaluated using Pearson's correlation coefficient, receiver operating characteristic (ROC) curves, and logistic regression.

RESULTS

The SACs were significantly different between the obstructive and non-obstructive groups. The ROC curves indicated that the SACi was able to discriminate obstructive and non-obstructive patients with the best predictive accuracy (AUC = 0.949, p<0.001). The SACi was an independent predictor of LVOT obstruction and there was a significant negative correlation between resting LVOT pressure gradient and SACi (r=0.72 p<0.001). In the subgroup of patients with or without severe basal septal hypertrophy, the SACi was still able to predict LVOT obstruction with excellent diagnostic accuracy (AUC = 0.944 and 0.948, p<0.001, respectively).

CONCLUSION

The SAC is a reliable and straightforward CMRI marker for assessing LVOT obstruction. It is more effective than CMRI two-dimensional flow in diagnosing the severity of obstruction in patients with HCM.

[Establishment and evaluation of a method for extracting exogenous short DNA fragments of Schistosoma japonicum from urine samples]

OBJECTIVE

To establish the method for extracting exogenous short DNA fragments of Schistosoma japonicum from urine samples, and to evaluate the efficiency of this method for extraction from urine samples treated with various methods.

METHODS

The S. japonicum SjG28 gene fragment was selected as a target sequence, and the 81 bp short DNA fragment was amplified on the target sequence using PCR assay. Following characterization using sequencing, the short DNA fragment was added into the urine samples as an exogenous short DNA fragment. Primers and probes were designed with SjG28 as a target gene, to establish the real-time fluorescent quantitative PCR (qPCR) assay. The sensitivity of this qPCR assay was evaluated with exogenous short DNA fragments that were diluted at a 1:10 dilution ratio as the DNA template, and the specificity of the qPCR assay was evaluated with the genomic DNA of S. mansoni, S. haematobium, Babesia, Ancyiostoma duodenaie, Cionorchis sinensis, and Paragonimus westermani as DNA templates. Exogenous short DNA fragments were added into artificial and healthy volunteers' urine samples, followed by pH adjustment, centrifugation and concentration, and the efficiency of extracting exogenous short DNA fragments from urine samples was compared with the QIAmp Viral RNA Mini Kit (Qiagen kit) and BIOG cfDNA easy kit (BIOG kit).

RESULTS

An 81 bp small DNA fragment of S. japonicum was successfully prepared, and the lowest detection limit of the established qPCR assay was 100 copies/μL of the 81 bp small DNA fragment of S. japonicum. If the genomic DNA of S. japonicum, S. mansoni, S. haematobium, Babesia, A. duodenaie, C. sinensis, and P. westermani served as DNA templates, the qPCR assay only detected fluorescent signals with S. japonicum genomic DNA as the DNA template. If the pH values of artificial urine samples were adjusted to 5, 6, 7 and 8, the recovery rates were (49.12 ± 2.09)%, (84.52 ± 4.96)%, (89.38 ± 3.32)% and (87.82 ± 3.90)% for extracting the exogenous short DNA fragment of S. japonicum with the Qiagen kit, and were (2.30 ± 0.07)%, (8.11% ± 0.26)%, (13.35 ± 0.61)% and (20.82 ± 0.68)% with the BIOG kit, respectively (t = 38.702, 26.955, 39.042 and 29.571; all P values < 0.01). If the Qiagen kit was used for extracting the exogenous short DNA fragment from artificial urine samples, the lowest recovery rate was seen from urine samples with a pH value of 5 (all P values < 0.05), and there were no significant differences in the recovery rate from urine samples with pH values of 6, 7 and 8 (all P values > 0.05). Following centrifugation of artificial [(64.30 ± 1.00)% vs. (58.87 ± 0.26)%; t = 12.033, P < 0.05] and healthy volunteers' urine samples [(31 165 ± 1 017) copies/μL vs. (28 471 ± 818) copies/μL; t = 23.164, P < 0.05]. In addition, concentration of artificial urine samples with the 10 kDa Centrifugal Filter and concentration of healthy volunteers' urine samples with the 100 kDa Centrifugal Filter were both effective to increase the recovery of the Qiagen kit for extracting the exogenous short DNA fragment of S. japonicum (both P values < 0.01).

CONCLUSIONS

A method for extracting exogenous short DNA fragments of S. japonicum from urine samples has been successfully established, and the Qiagen kit has a high extraction efficiency. Adjustment of urine pH to 6 to 8 and concentration of healthy volunteers' urine samples with the 100 kDa Centrifugal Filter are both effective to increase the efficiency of extracting exogenous short DNA fragments of S. japonicum.

[Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction]

OBJECTIVE

To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.

METHODS

A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe²⁺, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.

RESULTS

The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe²⁺ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).

CONCLUSION

SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Molecular cloning and expression analysis of Myxovirus resistance gene in Yangzhou goose (Anser cygnoides domesticus)

1. Myxovirus resistance (Mx) is a protein produced by the interferon-induced natural immune response with broad spectrum antiviral function. However, the role and expression characteristics of the Mx gene in immune defence against viral infection in goose have not yet been reported.2. This study found a 2576 bp genomic sequence and a 2112 bp mRNA sequence for Mx, encoding 703 amino acids. Multiple sequence alignments of the amino acid sequences showed that the Yangzhou goose Mx (goMx) had 86.99% similarity to the mallard duck (Anas platyrhynchos).3. Tissue-specific expression profiling revealed that the expression of goMx was highest in the lung and spleen. Both poly (I:C) and GPV were found to elevate the expression of goMx. The upregulated expression of goMx was associated with interferon pathway-related genes IRF7, JAK1, STAT1, and STAT2. Furthermore, overexpression of goMx significantly activated the transcription of poly (I:C) induced TNF-α, IL-1β, IL-6, and IL-18.4. The findings of this study suggest that the goMx modulation of the antiviral response is mediated by the interferon pathway.

Association between transferred embryos and multiple pregnancy/live birth rate in frozen embryo transfer cycles: A retrospective study

Background

Physicians need an appropriate embryo transfer strategy to address the challenge of reducing multiple birth rates, while maintaining the couples' live birth rate during assisted reproductive technology.

Methods

We included 10,060 frozen embryo transfer cycles from January 2015 to March 2020 in reproductive medical center of Ruijin hospital, Shanghai, China. Patients were grouped according to the number and grade of cleavage-stage embryo or blastocysts transferred. Live birth rate and multiple live birth rate were compared among groups of women of different ages. Multivariable logistic regression models were used to estimate the risk of multiple live birth using different combinations of transferred embryos.

Results

The transfer of double good-quality embryos was an independent predictor for multiple birth in women aged <30 years and those aged 36-39 years [<30 years: aOR =1.54 (95% CI: 1.14-2.06, P < 0.01); 36-39 years: aOR =1.84 (95% CI: 1.0-3.4, P < 0.01)]. Further, for women aged <36 years, the transfer of good-quality + poor-quality blastocysts was an independent predictor for multiple birth rate [<30 years: aOR=2.46 (95% CI: 1.45-4.18, P < 0.01); 31-35 years: aOR =4.45 (95% CI: 1.97-10.06, P < 0.01)].

Conclusions

Single-good-quality blastocyst transfer is recommended for women of all ages. When good-quality cleavage embryos are available, the choice of single or double embryo transfer with good- or average-quality embryo should depend on the age of women. Double embryo transfer with the highest possible grade of embryos is recommended for women aged ≥40 years.

The serum follicle stimulating hormone-to-luteinizing hormone ratios can predict assisted reproductive technology outcomes in women undergoing gonadotropin releasing hormone antagonist protocol

BACKGROUND

The basal follicle stimulating hormone (FSH)/luteinizing hormone (LH) ratio is a useful predictor of ovarian response. In this study, we investigated whether the FSH/LH ratios during the entire controlled ovarian stimulation (COS) can be used as effective predictors of outcomes in women undergoing in vitro fertilization (IVF) treatment using the gonadotropin releasing hormone antagonist (GnRH-ant) protocol.

METHODS

A total of 1,681 women undergoing their first GnRH-ant protocol were enrolled in this retrospective cohort study. A Poisson regression model was used to analyze the association between the FSH/LH ratios during COS and embryological outcomes. Receiver operating characteristic analysis was performed to determine the optimal cutoff values for poor responders (≤ 5 oocytes) or poor reproductive potential (≤ 3 available embryos). A nomogram model was constructed to provide a tool for predicting the cycle outcomes of individual IVF treatments.

RESULTS

The FSH/LH ratios (at the basal day, stimulation day 6 (SD6) and trigger day) were significantly correlated with the embryological outcomes. The basal FSH/LH ratio was the most reliable predictor of poor responders with a cutoff value of 1.875 (area under the curve (AUC) = 72.3%, P < 0.05), or of poor reproductive potential with a cutoff value of 2.515 (AUC = 66.3%, P < 0.05). The SD6 FSH/LH ratio predicted poor reproductive potential with a cutoff value of 4.14 (AUC = 63.8%, P < 0.05). The trigger day FSH/LH ratio predicted poor responders with a cutoff value of 9.665 (AUC = 63.1%, P < 0.05). The basal FSH/LH ratio, combined with the SD6 and trigger day FSH/LH ratios, slightly increased these AUC values and improved the prediction sensitivity. The nomogram provides a reliable model with which to assess the risk of poor response or poor reproductive potential directly based on the combined indicators.

CONCLUSIONS

FSH/LH ratios are useful predictors of poor ovarian response or reproductive potential throughout the entire COS with the GnRH antagonist protocol. Our findings also provide insights into the potential for LH supplementation and regimen adjustment during COS to achieve improved outcomes.

PCCT: Progressive Class-Center Triplet Loss for Imbalanced Medical Image Classification

Imbalanced training data in medical image diagnosis is a significant challenge for diagnosing rare diseases. For this purpose, we propose a novel two-stage Progressive Class-Center Triplet (PCCT) framework to overcome the class imbalance issue. In the first stage, PCCT designs a class-balanced triplet loss to coarsely separate distributions of different classes. Triplets are sampled equally for each class at each training iteration, which alleviates the imbalanced data issue and lays solid foundation for the successive stage. In the second stage, PCCT further designs a class-center involved triplet strategy to enable a more compact distribution for each class. The positive and negative samples in each triplet are replaced by their corresponding class centers, which prompts compact class representations and benefits training stability. The idea of class-center involved loss can be extended to the pair-wise ranking loss and the quadruplet loss, which demonstrates the generalization of the proposed framework. Extensive experiments support that the PCCT framework works effectively for medical image classification with imbalanced training images. On four challenging class-imbalanced datasets (two skin datasets Skin7 and Skin 198, one chest X-ray dataset ChestXray-COVID, and one eye dataset Kaggle EyePACs), the proposed approach respectively obtains the mean F1 score 86.20, 65.20, 91.32, and 87.18 over all classes and 81.40, 63.87, 82.62, and 79.09 for rare classes, achieving state-of-the-art performance and outperforming the widely used methods for the class imbalance issue.

Artificial Intelligence-Assisted Evaluation of the Spatial Relationship between Brain Arteriovenous Malformations and the Corticospinal Tract to Predict Postsurgical Motor Defects

BACKGROUND AND PURPOSE

Preoperative evaluation of brain AVMs is crucial for the selection of surgical candidates. Our goal was to use artificial intelligence to predict postsurgical motor defects in patients with brain AVMs involving motor-related areas.

MATERIALS AND METHODS

Eighty-three patients who underwent microsurgical resection of brain AVMs involving motor-related areas were retrospectively reviewed. Four artificial intelligence-based indicators were calculated with artificial intelligence on TOF-MRA and DTI, including FN5mm/50mm (the proportion of fiber numbers within 5-50mm from the lesion border), FN10mm/50mm (the same but within 10-50mm), FP5mm/50mm (the proportion of fiber voxel points within 5-50mm from the lesion border), and FP10mm/50mm (the same but within 10-50mm). The association between the variables and long-term postsurgical motor defects was analyzed using univariate and multivariate analyses. Least absolute shrinkage and selection operator regression with the Pearson correlation coefficient was used to select the optimal features to develop the machine learning model to predict postsurgical motor defects. The area under the curve was calculated to evaluate the predictive performance.

RESULTS

In patients with and without postsurgical motor defects, the mean FN5mm/50mm, FN10mm/50mm, FP5mm/50mm, and FP10mm/50mm were 0.24 (SD, 0.24) and 0.03 (SD, 0.06), 0.37 (SD, 0.27) and 0.06 (SD, 0.08), 0.06 (SD, 0.10) and 0.01 (SD, 0.02), and 0.10 (SD, 0.12) and 0.02 (SD, 0.05), respectively. Univariate and multivariate logistic analyses identified FN10mm/50mm as an independent risk factor for long-term postsurgical motor defects (P = .002). FN10mm/50mm achieved a mean area under the curve of 0.86 (SD, 0.08). The mean area under the curve of the machine learning model consisting of FN10mm/50mm, diffuseness, and the Spetzler-Martin score was 0.88 (SD, 0.07).

CONCLUSIONS

The artificial intelligence-based indicator, FN10mm/50mm, can reflect the lesion-fiber spatial relationship and act as a dominant predictor for postsurgical motor defects in patients with brain AVMs involving motor-related areas.

Dehydrocostus Lactone Reduced Malignancy of HepG2 Human Hepatocellular Carcinoma Cells via Down-Regulation of the PI3K/AKT Signaling Pathway

We studied the effect of dehydrocostus lactone (DHL) on the biological characteristics of HepG2 human hepatocellular carcinoma cells. The inhibition of cell viability by different concentrations of DHL (10, 20, 40, 80, and 160 μmol/liter) was measured using MTT test. As the determined half-maximum inhibitory concentration (IC₅₀) was 20.33 μmol/liter, DHL in a concentration of 20 μmol/liter was used in further experiments. Cell proliferation, migration, invasion ability, and apoptosis were assessed by Ki-67 immunofluorescence, Transwell assay, and TUNEL analysis. The level of p-AKT protein was determined by Western blotting. DHL significantly inhibited the viability, proliferation, migration, and invasion of HepG2 cells in comparison with the control group, and induced cells apoptosis. DHL down-regulated the expression of p-AKT protein in the HepG2 cells in comparison with the control group. PI3K/AKT signaling pathway activator 740Y-P could block the above-mentioned effects of DHL. Thus, DHL inhibits the malignancy of HepG2 human hepatocellular carcinoma cells via down-regulation of PI3K/AKT signaling pathway.

[Analysis of the whole genome traceability and transmission path simulation experiment of the local cluster COVID-19 epidemic]

Objective: To trace and characterize the whole genome of SARS-CoV-2 of confirmed cases in the outbreak of COVID-19 on July 31, 2021 in Henan Province. Method: Genome-wide sequencing and comparative analysis were performed on positive nucleic acid samples of SARS-CoV-2 from 167 local cases related to the epidemic on July 31, 2021, to analyze the consistency and evolution of the whole genome sequence of virus. Results: Through high-throughput sequencing, a total of 106 cases of SARS-CoV-2 whole genome sequences were obtained. The results of genome analysis showed that the whole genome sequences of 106 cases belonged to the VOC/Delta variant strain (B.1.617.2 clade), and the whole genome sequences of 106 cases were shared with the genomes of 3 imported cases from Myanmar admitted to a hospital in Zhengzhou. On the basis of 45 nucleotide sites, 1-5 nucleotide variation sites were added, and the genome sequence was highly homologous. Conclusion: Combined with the comprehensive analysis of viral genomics, transmission path simulation experiments and epidemiology, it is determined that the local new epidemic in Henan Province is caused by imported cases in the nosocomial area, and the spillover has caused localized infection in the community. At the same time, it spills over to some provincial cities and results in localized clustered epidemics.

Venc Design and Velocity Estimation for Phase Contrast MRI

In phase-contrast magnetic resonance imaging (PC-MRI), spin velocity contributes to the phase measured at each voxel. Therefore, estimating velocity from potentially wrapped phase measurements is the task of solving a system of noisy congruence equations. We propose Phase Recovery from Multiple Wrapped Measurements (PRoM) as a fast, approximate maximum likelihood estimator of velocity from multi-coil data with possible amplitude attenuation due to dephasing. The estimator can recover the fullest possible extent of unambiguous velocities, which can greatly exceed twice the highest venc. The estimator uses all pairwise phase differences and the inherent correlations among them to minimize the estimation error. Correlations are directly estimated from multi-coil data without requiring knowledge of coil sensitivity maps, dephasing factors, or the actual per-voxel signal-to-noise ratio. Derivation of the estimator yields explicit probabilities of unwrapping errors and the probability distribution for the velocity estimate; this, in turn, allows for optimized design of the phase-encoded acquisition. These probabilities are also incorporated into spatial post-processing to further mitigate wrapping errors. Simulation, phantom, and in vivo results for three-point PC-MRI acquisitions validate the benefits of reduced estimation error, increased recovered velocity range, optimized acquisition, and fast computation. A phantom study at 1.5T demonstrates 48.5% decrease in root mean squared error using PRoM with post-processing versus a conventional "dual-venc" technique. Simulation and 3T in vivo results likewise demonstrate the proposed benefits.

Ultrasonographic pathological grading of prostate cancer using automatic region-based Gleason grading network

The Gleason scoring system is a reliable method for quantifying the aggressiveness of prostate cancer, which provides an important reference value for clinical assessment on therapeutic strategies. However, to the best of our knowledge, no study has been done on the pathological grading of prostate cancer from single ultrasound images. In this work, a novel Automatic Region-based Gleason Grading (ARGG) network for prostate cancer based on deep learning is proposed. ARGG consists of two stages: (1) a region labeling object detection (RLOD) network is designed to label the prostate cancer lesion region; (2) a Gleason grading network (GNet) is proposed for pathological grading of prostate ultrasound images. In RLOD, a new feature fusion structure Skip-connected Feature Pyramid Network (CFPN) is proposed as an auxiliary branch for extracting features and enhancing the fusion of high-level features and low-level features, which helps to detect the small lesion and extract the image detail information. In GNet, we designed a synchronized pulse enhancement module (SPEM) based on pulse-coupled neural networks for enhancing the results of RLOD detection and used as training samples, and then fed the enhanced results and the original ones into the channel attention classification network (CACN), which introduces an attention mechanism to benefit the prediction of cancer grading. Experimental performance on the dataset of prostate ultrasound images collected from hospitals shows that the proposed Gleason grading model outperforms the manual diagnosis by physicians with a precision of 0.830. In addition, we have evaluated the lesions detection performance of RLOD, which achieves a mean Dice metric of 0.815.

Alias-Free Arrays

Nonuniform array geometries provide freedom for increased aperture and reduced mutual coupling. A necessary and sufficient condition is given for an array of isotropic sensor elements to be unambiguous for any specified set of directions of arrival. The set of unambiguous spatial frequencies is shown to be a parallelepiped, admitting simple geometrical interpretation. Results are used in design of linear, planar, and 3D arrays.

[Predictive models and prophylactic strategies for anastomotic leakage in colorectal surgery]

Anastomotic leakage (AL) has always been a persistent issue for colorectal surgeons. It is still difficult to reduce the incidence of AL despite the advances in technology and equipment. With the development of evidence-based medicine, increasing high-risk factors for AL have been identified. How to efficiently and systematically combine and quantify these isolated risk factors to provide a scientific early warning of AL in clinical practices and help surgeons in choosing the optimal prophylactic strategies, is of great significance for reducing the incidence of AL. There are generally two types of AL prediction models in colorectal surgery, including prognostic models (for preoperative and intraoperative AL prediction) and diagnostic models (for early warning and improving the early diagnosis rate of AL). Prophylactic strategies for AL include stabilizing the underlying diseases, improving anemia and hypoalbuminemia, choosing an appropriate operative time window, and emphasizing and improving anastomotic techniques (including choosing an appropriate size of stapler). However, a prophylactic ostomy is still the most common method for surgeons. However, how to reduce the morbidity of complications following prophylactic ostomy and how to avoid the conversion of the prophylactic stoma to permanent stoma need further study.

Prevalence of USP and hlyA Genes and Association with Drug Resistance in Uropathogenic Escherichia coli Isolated from Patients in a Tertiary Hospital from Southeast China

E. coli was cultured from the urine of patients from the tertiary hospital located in Southeast China from 2017 to 2019. The species were identified, drug sensitivity test was performed, and the presence of the virulence genes USP and hlyA was determined. A total of 483 strains of E. coli were isolated, including 132 from patients with urinary tract infection (UTI). The resistance to ciprofloxacin was more common in non-UTI patients, while resistance to gentamycin was significantly higher in the UTI group. In the UTI group, the proportions of isolated bacteria with the virulence USP (40.15%) and hlyA (8.33%) genes were significantly higher than in the non-UTI group (19.60 and 2.56%, respectively). The rate of resistance of E. coli toward levofloxacin in the USP⁺ group was significantly (p<0.05) higher than in the USP- group. Thus, we revealed the differences in the rate of drug resistance and prevalence of USP and hlyA between the UTI and non-UTI groups. Furthermore, the presence of the USP gene was found to be associated with greater resistance to levofloxacin.

Isolated hand weakness due to brain lesion

When hand weakness is linked to a brain lesion, there is risk of misdiagnosis. A case of hand weakness related to stroke is presented. The electromyography report indicated a segmental lesion of the median nerve at the wrist. Thus, the patient was initially diagnosed with carpal tunnel syndrome, and was referred to the orthopedic department for release surgery. Because the symptom was immediate and did not include hand numbness, the orthopedic surgeon ruled out the previous diagnosis and ordered a head CT scan, which revealed stroke. Aspirin and other medications were given. Percutaneous carotid balloon angioplasty with stent implantation and percutaneous vertebral artery balloon angioplasty were performed. The weakness of the left hand was greatly improved. So far, only a few cases suggest that hand weakness may be linked to stroke. Therefore, physicians should pay attention to physical examination.

Phase 2 randomized controlled trial of intravenous or intraperitoneal paclitaxel plus mFOLFOX6 vs. mFOLFOX6 as first-line treatment of advanced gastric cancer

Objective

We conducted a phase 2 trial to compare the safety and efficacy of intravenous paclitaxel or intraperitoneal paclitaxel plus mFOLFOX6 vs. mFOLFOX6 in untreated advanced gastric cancer.

Methods

Participants with untreated advanced gastric cancer were randomly assigned (1:1:1) to: intravenous paclitaxel 135 mg/m² or intraperitoneal paclitaxel 80 mg/m² plus mFOLFOX6 omitting bolus fluorouracil; or mFOLFOX6 (oxaliplatin 85 mg/m², leucovorin 400 mg/m², fluorouracil 400 mg/m² bolus, fluorouracil 2,400 mg/m² 46-h continuous infusion). Treatment was every 14 days for up to 9 cycles followed by S-1 maintenance. The primary outcome was progression-free survival.

Results

Of 90 enrolled participants, 30 in the intravenous paclitaxel group, 29 in the intraperitoneal paclitaxel group, and 30 in the mFOLFOX6 group were included in the analyses. The median progression-free survival was 6.52, 5.83, and 4.55 months, respectively, for the intravenous paclitaxel group, intraperitoneal paclitaxel group, and mFOLFOX6 group. The hazard ratios were 0.56 (95% CI: 0.33–0.94; p = 0.026) and 0.56 (95% CI: 0.33–0.96; p = 0.037), respectively, for the intravenous paclitaxel group and the intraperitoneal paclitaxel group vs. the mFOLFOX6 group. The most common grade 3/4 adverse events for the intravenous paclitaxel group, intraperitoneal paclitaxel group, and mFOLFOX6 group, respectively, were neutropenia (30.0%, 34.5%, 33.3%), diarrhea (13.3%, 20.7%, 13.3%), and leukopenia (10.0%, 13.8%, 10.0%). No treatment-related death occurred.

Conclusion

The findings of this phase 2 trial suggest that adding intravenous paclitaxel or intraperitoneal paclitaxel to mFOLFOX6 for untreated advanced gastric cancer improved progression-free survival with manageable adverse events.

Intravenous Patient-Controlled Analgesia Versus Oral Opioid to Maintain Analgesia for Severe Cancer Pain: A Randomized Phase II Trial

BACKGROUND

Optimal analgesic maintenance for severe cancer pain is unknown. This study evaluated the efficacy and safety of intravenous patient-controlled analgesia (IPCA) with continuous infusion plus rescue dose or bolus-only dose versus conventional oral extended-release morphine as a background dose with normal-release morphine as a rescue dose to maintain analgesia in patients with severe cancer pain after successful opioid titration.

METHODS

Patients with persistent severe cancer pain (≥7 at rest on the 11-point numeric rating scale [NRS]) were randomly assigned to 1 of 3 treatment arms: (A1) IPCA hydromorphone with bolus-only dose where dosage was 10% to 20% of the total equianalgesic over the previous 24 hours (TEOP24H) administered as needed, (A2) IPCA hydromorphone with continuous infusion where dose per hour was the TEOP24H divided by 24 and bolus dosage for breakthrough pain was 10% to 20% of the TEOP24H, and (B) oral extended-release morphine based on TEOP24H/2 × 75% (because of incomplete cross-tolerance) every 12 hours plus normal-release morphine based on TEOP24H × 10% to 20% for breakthrough pain. After randomization, patients underwent IPCA hydromorphone titration for 24 hours to achieve pain control before beginning their assigned treatment. The primary endpoint was NRS over days 1 to 3.

RESULTS

A total of 95 patients from 9 oncology study sites underwent randomization: 30 into arm A1, 32 into arm A2, and 33 into arm B. Arm B produced a significantly higher NRS over days 1 to 3 compared with arm A1 or A2 (P<.001). Daily NRS from day 1 to day 6 and patient satisfaction scores on day 3 and day 6 were worse in arm B. Median equivalent-morphine consumption increase was significantly lower in A1 (P=.024) among the 3 arms. No severe adverse event occurred in any arm.

CONCLUSIONS

Compared with oral morphine maintenance, IPCA hydromorphone for analgesia maintenance improves control of severe cancer pain after successful titration. Furthermore, IPCA hydromorphone without continuous infusion may consume less opioid.

Histological functions of parathyroid hormone on bone formation and bone blood vessels

BACKGROUND

The intermittent administration of parathyroid hormone (PTH) has been prescribed to osteoporotic patients due to its bone anabolic effects. In addition to its actions on bone cells, PTH appears to affect bone-specific blood vessels. These blood vessels are derived from bone marrow sinusoids, which express EphB4, a hallmark of veinous vascular endothelial cells. Given the presence of osteo-vascular interactions, it is important to elucidate the effects of PTH on bone cells and blood vessels in murine models.

HIGHLIGHTS

PTH stimulates preosteoblastic proliferation and osteoblastic bone formation. The former appears to be directly affected by PTH, whereas the latter requires osteoclast-mediated coupling. The administration of PTH through high-frequency dosage schemes accelerates bone turnover featuring remodeling-based bone formation, whereas low-frequency schemes cause mainly remodeling-based and partly modeling-based bone formation. Normally, many blood vessels lack alpha smooth muscle actin (αSMA)-immunoreactive vascular muscle cells surrounding basement membranes, indicating them being capillaries. However, PTH administration increases the number of blood vessels surrounded by αSMA-positive cells. These αSMA-positive cells spread out of blood vessels and express alkaline phosphatase and c-kit, suggesting their potential to differentiate into osteogenic and vascular endothelial/perivascular cells. Unlike bone cells, αSMA-positive cells did not appear in the periphery of blood vessels in the kidney and liver, and the thickness of the tunica media did not change regardless of PTH administration.

CONCLUSION

Based on the results of the study and presence of osseous-vascular interactions, PTH appears to influence not only osteoblastic cells, but also blood vessels in bone.

POF (paclitaxel/oxaliplatin/5-fluorouracil/leucovorin) vs. SOX/CAPOX/FOLFOX as a postoperative adjuvant chemotherapy for curatively resected stage III gastric cancer: Study protocol for a randomized controlled trial, FNF-014 trial

Background

Postoperative chemotherapy is a standard treatment for stage II and III gastric cancer in Asia. With regard to single-agent or doublet, the need for improvement has consistently been pointed out because of the relatively poor outcome for patients with stage III gastric cancer. Triplet has shown significant survival benefits in the perioperative setting. We conducted a randomized, multicenter, phase III study to compare triplet to doublet regimens for patients with stage III gastric cancer.

Methods

This is currently enrolling patients (n = 230) with pathologic stage III gastric cancer after D2 lymph node dissection and achieved R0 resection. Patients are randomized 1:1 and stratified by tumor stage (IIIA, IIIB, or IIIC, AJCC 8th) into POF or SOX/CAPOX/FOLFOX. S-1 and oxaliplatin (SOX): oxaliplatin 130 mg/m² on day 1, oral S-1 80–120 mg/m² divided by two on days 1–14 every 21 days for 8 cycles. Capecitabine and oxaliplatin (CAPOX): oxaliplatin 130 mg/m² on day 1, oral capecitabine 1000 mg/m² twice daily on days 1–14 every 21 days for 8 cycles. Folinic acid (or leucovorin), 5-fluorouracil and oxaliplatin (FOLFOX): oxaliplatin 85 mg/m², levo-leucovorin 200 mg/m², and 5-fluorouracil (5-FU) 400 mg/m² bolus on day 1, then 5-FU 2400 mg/m² continuous infusion over 46 h, every 14 days for 12 cycles. Three doublets were chosen by the clinicians. Paclitaxel, oxaliplatin, 5-fluorouracil, and leucovorin (POF): paclitaxel 135 mg/m², followed by FOLFOX omitted 5-FU bolus, every 14 days for 12 cycles. The primary end point is 3-year disease-free survival (3-year-DFS). Secondary end points are overall survival (OS) and safety (any adverse event).

Discussion

The results of this study will help establish postoperative clinical evidence for patients with locally advanced gastric adenocarcinoma or gastroesophageal junction adenocarcinoma.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT0378826].

Skin Cancer Classification With Deep Learning: A Systematic Review

Skin cancer is one of the most dangerous diseases in the world. Correctly classifying skin lesions at an early stage could aid clinical decision-making by providing an accurate disease diagnosis, potentially increasing the chances of cure before cancer spreads. However, achieving automatic skin cancer classification is difficult because the majority of skin disease images used for training are imbalanced and in short supply; meanwhile, the model’s cross-domain adaptability and robustness are also critical challenges. Recently, many deep learning-based methods have been widely used in skin cancer classification to solve the above issues and achieve satisfactory results. Nonetheless, reviews that include the abovementioned frontier problems in skin cancer classification are still scarce. Therefore, in this article, we provide a comprehensive overview of the latest deep learning-based algorithms for skin cancer classification. We begin with an overview of three types of dermatological images, followed by a list of publicly available datasets relating to skin cancers. After that, we review the successful applications of typical convolutional neural networks for skin cancer classification. As a highlight of this paper, we next summarize several frontier problems, including data imbalance, data limitation, domain adaptation, model robustness, and model efficiency, followed by corresponding solutions in the skin cancer classification task. Finally, by summarizing different deep learning-based methods to solve the frontier challenges in skin cancer classification, we can conclude that the general development direction of these approaches is structured, lightweight, and multimodal. Besides, for readers’ convenience, we have summarized our findings in figures and tables. Considering the growing popularity of deep learning, there are still many issues to overcome as well as chances to pursue in the future.

[Clinicopathological features of polymorphous low-grade neuroepithelial tumor of the young]

Objective: To investigate the clinicopathological features and differential diagnosis of polymorphous low-grade neuroepithelial tumor of the young (PLNTY). Methods: Five cases of PLNTY diagnosed at the First Affiliated Hospital and Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China from 2019 to 2021 were collected. All cases were evaluated using clinical and imaging data, histology, immunohistochemical staining and molecular genetics. The relevant literature was reviewed. Results: There were two male and three female patients, aged 10 to 39 years, with an average age of 25 years. Clinically, the tumors were in the temporal lobe (3 cases), the lateral ventricle (1 case) and the left head of caudate nucleus (1 case). The clinical manifestations included epilepsy in 3 cases, right visual disturbance in 1 case, and post-trauma incidental finding in 1 case. Microscopically, the lesions were characterized with infiltrative growth, cellular pleomorphism (oligodendroglioma-like cells were always present, with low-grade, pleomorphic nuclei) and variable calcifications. Immunohistochemically, the tumor cells were positive for GFAP and Olig2. They also showed intense and diffuse expression of CD34 while CD34 expressing ramified neural elements were present in regional cortex. Ki-67 proliferation index was less than 3%. Molecular genetics showed the BRAF V600E mutation in 2 cases, the PAK5-Q337R missense mutation in 1 case, the FGFR2-CTNNA3 fusion in 1 case, and the FGFR2-INA and FGFR2-PPRC1 concomitant fusion in 1 case. No postoperative chemoradiotherapy was given. Follow-up intervals ranged from 3 to 29 months while no recurrence or metastasis was identified. Conclusions: PLNTY is uncommon. A definite diagnosis of PLNTY relies on histopathological examination and molecular genetics. It is important to distinguish PLNTY from high grade gliomas and avoid overtreatment. The recently reported the PAK5-Q337R missense mutation and the FGFR2-PPRC1 gene fusion in PLNTY may help diagnose and understand the pathogenesis of PLNTY.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.