Deep transfer learning artificial intelligence accurately stages COVID-19 lung disease severity on portable chest radiographs

This study employed deep-learning convolutional neural networks to stage lung disease severity of Coronavirus Disease 2019 (COVID-19) infection on portable chest x-ray (CXR) with radiologist score of disease severity as ground truth. This study consisted of 131 portable CXR from 84 COVID-19 patients (51M 55.1±14.9yo; 29F 60.1±14.3yo; 4 missing information). Three expert chest radiologists scored the left and right lung separately based on the degree of opacity (0-3) and geographic extent (0-4). Deep-learning convolutional neural network (CNN) was used to predict lung disease severity scores. Data were split into 80% training and 20% testing datasets. Correlation analysis between AI-predicted versus radiologist scores were analyzed. Comparison was made with traditional and transfer learning. The average opacity score was 2.52 (range: 0-6) with a standard deviation of 0.25 (9.9%) across three readers. The average geographic extent score was 3.42 (range: 0-8) with a standard deviation of 0.57 (16.7%) across three readers. The inter-rater agreement yielded a Fleiss' Kappa of 0.45 for opacity score and 0.71 for extent score. AI-predicted scores strongly correlated with radiologist scores, with the top model yielding a correlation coefficient (R2) of 0.90 (range: 0.73-0.90 for traditional learning and 0.83-0.90 for transfer learning) and a mean absolute error of 8.5% (ranges: 17.2-21.0% and 8.5%-15.5, respectively). Transfer learning generally performed better. In conclusion, deep-learning CNN accurately stages disease severity on portable chest x-ray of COVID-19 lung infection. This approach may prove useful to stage lung disease severity, prognosticate, and predict treatment response and survival, thereby informing risk management and resource allocation.

Predicting COVID-19 Pneumonia Severity on Chest X-ray With Deep Learning

Introduction

The need to streamline patient management for coronavirus disease-19 (COVID-19) has become more pressing than ever. Chest X-rays (CXRs) provide a non-invasive (potentially bedside) tool to monitor the progression of the disease. In this study, we present a severity score prediction model for COVID-19 pneumonia for frontal chest X-ray images. Such a tool can gauge the severity of COVID-19 lung infections (and pneumonia in general) that can be used for escalation or de-escalation of care as well as monitoring treatment efficacy, especially in the ICU.

Methods

Images from a public COVID-19 database were scored retrospectively by three blinded experts in terms of the extent of lung involvement as well as the degree of opacity. A neural network model that was pre-trained on large (non-COVID-19) chest X-ray datasets is used to construct features for COVID-19 images which are predictive for our task.

Results

This study finds that training a regression model on a subset of the outputs from this pre-trained chest X-ray model predicts our geographic extent score (range 0-8) with 1.14 mean absolute error (MAE) and our lung opacity score (range 0-6) with 0.78 MAE.

Conclusions

These results indicate that our model’s ability to gauge the severity of COVID-19 lung infections could be used for escalation or de-escalation of care as well as monitoring treatment efficacy, especially in the ICU. To enable follow up work, we make our code, labels, and data available online.

Resveratrol protects myocardial apoptosis induced by ischemia-reperfusion in rats with acute myocardial infarction via blocking P13K/Akt/e-NOS pathway

OBJECTIVE

To elucidate the protective role of resveratrol (RSV) in myocardial apoptosis induced by ischemia-reperfusion injury in rats with acute myocardial infarction (AMI), and to explore its underlying mechanism.

MATERIALS AND METHODS

The AMI rat model was successfully established by ligation of the left anterior descending coronary artery. Rat cardiomyocytes were isolated and cultured. Cells were divided into four groups, including: control group (no specific treatment), AMI group (acute ischemia-reperfusion treatment), AMI+RSV group (RSV pretreatment for 24 h before acute ischemia-reperfusion) and AMI+ RSV+LY group (RSV pretreatment combined with 40 μmol/L phosphatidylinositide 3-kinases (PI3K) pathway inhibitor LY294002 for 24 h before acute ischemia-reperfusion). Morphology of apoptotic cardiomyocytes in each group was observed by Hoechst staining. The proliferation, apoptosis and cell cycle progression of cardiomyocytes were determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, terminal dexynucleotidyl transferase(TdT)-mediated dUTP nick end labeling (TUNEL) assay and flow cytometry, respectively. Finally, the protein levels of genes relative to PI3K/Akt/eNOS pathway were detected by Western blot.

RESULTS

Hoechst staining showed a large number of necrotic cells, cell retraction, enhanced refractive index and enlarged cell gap in AMI group. A small number of necrotic cells were found in AMI+RSV group, which was significantly fewer than that of AMI group. Meanwhile, remaining cells presented normal morphology. However, a great number of necrotic cells were observed in AMI+RSV+LY group, which was obviously more than that of AMI+RSV group. Compared with control group, cells in AMI group showed significantly decreased proliferative rate, increased early phase, late phase and total one of apoptosis. In AMI group, the ratio of G0/G1 phase was remarkably increased, whereas those of S and G2/M phases were decreased. Moreover, the expression levels of phosphorylated Akt (p-Akt) and phosphorylated e-NOS (p-eNOS) were significantly downregulated in AMI group. In AMI+RSV group, cell apoptosis, cell cycle progression and levels of p-Akt and p-eNOS showed the opposite trends as those of AMI group. However, LY294002 pretreatment reversed the protective role of RSV in cellular behaviors of cardiomyocytes.

CONCLUSIONS

RSV protects cardiomyocyte apoptosis from ischemia-reperfusion injury through regulating phosphorylation levels of proteins relative to PI3K/Akt/e-NOS pathway.

Genotyping and characterization of Toxoplasma gondii strain isolated from pigs in Hubei province, central China

Toxoplasma gondii, a ubiquitous pathogen that infects nearly all warm-blooded animals and humans, can cause severe complications to the infected people and animals as well as serious economic losses and social problems. Here, one local strain (TgPIG-WH1) was isolated from an aborted pig fetus, and the genotype of this strain was identified as ToxoDB #3 by the PCR RFLP typing method using 10 molecular markers (SAG1, SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico). A comparison of the virulence of this isolate with other strains in both mice and piglets showed that TgPIG-WH1 was less virulent than type 1 strain RH and type 2 strain ME49 in mice, and caused similar symptoms to those of ME49 such as fever in piglets. Additionally, in piglet infection with both strains, the TgPIG-WH1 caused a higher IgG response and more severe pathological damages than ME49. Furthermore, TgPIG-WH1 caused one death in the 5 infected piglets, whereas ME49 did not, suggesting the higher virulence of TgPIG-WH1 than ME49 during piglet infection. Experimental infections indicate that the virulence of TgPIG-WH1 relative to ME49 is weaker in mice, but higher in pigs. This is probably the first report regarding a ToxoDB #3 strain from pigs in Hubei, China. These data will facilitate the understanding of genetic diversity of Toxoplasma strains in China as well as the prevention and control of porcine toxoplasmosis in the local region.

Greatly enhanced performance of AlGaN-based deep ultraviolet light emitting diodes by introducing a polarization modulated electron blocking layer

Carrier transport in AlGaN-based deep ultraviolet (DUV) light emitting diodes (LEDs) with the wavelength of 273 nm has been investigated by introducing polarization modulated electron blocking layer (EBL) that adopts an Al composition and thickness graded multiple quantum barriers (MQB) structure. The experimental result shows that the maximum light output power and external quantum efficiency for the proposed structure at the current of 250 mA are 9.6 mW and 1.03% respectively, severally increasing by 405% and 249% compared to traditional one, meanwhile, the efficiency droop at 250 mA is also dramatically reduced from 42.2% to 16.6%. Further simulation analysis indicates that this graded MQB-EBL enhances the potential barrier height for electrons and meanwhile reduces that for holes, hence effectively suppresses the electron leakage, and at the same time significantly improves the hole injection efficiency. As a result, the whole performance of the LED with the proposed MQB-EBL is dramatically improved.

The relationship of platelet to lymphocyte ratio and neutrophil to monocyte ratio to radiographic grades of knee osteoarthritis

OBJECTIVE

Accumulating data show that platelet to lymphocyte ratio (PLR) and neutrophil to monocyte ratio (NMR) undergo changes during inflammation in various diseases; however, the clinical features remain unclear in knee osteoarthritis (OA) patients. The purpose of our study was to evaluate PLR and NMR in knee OA patients, and assess their relationship to knee OA's radiographic grades.

METHODS

A retrospective study on 132 adult knee OA patients and 162 healthy controls (HC) was performed. All clinical characteristics of the knee OA patients were obtained from their medical records. PLR and NMR were compared between knee OA patients and HC by non-parametric tests. Correlations of PLR and NMR with Kellgren-Lawrence (KL) classification (KL grade 2, KL grade 3, and KL grade 4) were also analyzed through a Spearman correlation test. Ordinal polytomous logistic regression was used to determine independent factors influencing radiographic grades of knee OA patients.

RESULTS

PLR was increased significantly in knee OA patients, while a statistical difference in NMR was not observed. However, PLR was not relevant to KL grades, while NMR was negatively correlated with these (r = -0.330, P < 0.01) and was independently associated with KL grades of knee OA.

CONCLUSION

PLR could reflect the inflammation response of knee OA. NMR emerged as an independent factor and could be used as a potential marker indicating the severity of knee OA.

Difference in the frequency of pouchitis between ulcerative colitis and familial adenomatous polyposis: is the explanation in peripouch fat?

AIM

Patients with ulcerative colitis (UC) have an unexplained higher incidence of pouchitis and a greater amount of peripouch fat compared with patients with familial adenomatous polyposis (FAP). The aims of this study were to compare the peripouch fat areas between patients with UC and patients with FAP, and to explore relationship between peripouch fat and pouchitis or chronic antibiotic-refractory pouchitis (CARP).

METHOD

Patients with an abdominal CT image from our prospectively maintained Pouch Database were included. Abdominal fat and peripouch fat were measured on CT images at different levels or planes. Comparisons of peripouch fat and CARP were performed before and after propensity score matching.

RESULTS

A total of 277 patients with UC and 40 patients with FAP were included. Compared with patients with FAP, patients with UC were found to have a higher incidence of pouchitis (58.5% vs 15.0%, P < 0.001) and CARP (24.5% vs 2.5%, P = 0.002) and a higher total peripouch fat area (P = 0.030) and mesenteric peripouch fat area (P = 0.022) at Level-3. Univariate and multivariate analyses showed that diagnosis (UC vs FAP) and peripouch fat areas at Level-3 and Level-5 were independent risk factors for CARP. With propensity score matching, 38 pairs of patients with UC and FAP were matched successfully. After matching, patients with UC were found to have higher total peripouch fat area and higher mesenteric peripouch fat area at Level-3, and a higher incidence of pouchitis (57.9% vs 13.2%, P < 0.001) and CARP (23.7% vs 2.6%, P = 0.007).

CONCLUSION

Our study demonstrates that patients with UC have more peripouch fat than those with FAP, which may explain the difference in the frequency of pouchitis and CARP between these groups of patients.

[Diagnostic value of serum alpha-fetoprotein, alpha-fetoprotein variant and abnormal prothrombin in primary hepatocellular carcinoma]

Objective: To explore the diagnostic value of single or combined detection of serum tumor markers alpha-fetoprotein (AFP), α-fetoprotein (AFP)-L3 and abnormal clotting (PIVKA-II) in the primary hepatic carcinoma. Methods: Serum AFP, AFP-L3 and PIVKA-II of 56 cases with primary hepatic carcinoma, 46 cases with cirrhosis, 45 cases with other liver disease and 41 healthy persons (control group) were examined by chemiluminescence method, and the differences in the levels of AFP, AFP-L3 and PIVKA-II in each group were compared. Results: Serum level of AFP, AFP-L3 and PIVKA-II in patients with primary liver cancer was significantly higher than that of the cirrhosis, other liver disease and control groups, and the difference was statistically significant (P < 0.05). The receiver operating characteristic curve analysis showed that the areas under the curve for the diagnosis of primary hepatic carcinoma by AFP, AFP-L3 and PIVKA-II were 0.887, 0.846 and 0.885, respectively. The combined use of the three tumor markers for the diagnosis of primary hepatic carcinoma increased the area under the curve to 0.899. Among the single detection, AFP had the highest sensitivity of 91.07% and PIVKA-II had the highest specificity at 88.63%. In the combined detection, AFP/PIVKA-II combination had the highest sensitivity of 94.64 %, while the AFP + AFP-L3 + PIVKA-II combination had the highest specificity at 98.48%. Conclusion: Combined detection of AFP, AFP-L3 and PIVKA-II could improve the diagnostic specificity and the sensitivity of primary hepatic carcinoma; thereby make up the deficiency of single detection and improve the early diagnosis rate.

Operating behavior of micro-LEDs on a GaN substrate at ultrahigh injection current densities

Near-ultraviolet micro-LEDs with different diameters were fabricated on GaN substrates. The electroluminescence and the light output power-current density and current density-voltage relationships were measured. A saturated current density of 358 kA/cm² was achieved with a 20 µm LED. The ideality factor curves showed steps and peaks when the injection current density was increased from 20 to 150 kA/cm² and an abnormal efficiency increase. The transport and recombination processes of micro-LEDs at high injection current densities were simulated, and the many-body effect and phase space filling in the integrated quantum drift-diffusion model were considered. Serious current crowding was observed above 100 kA/cm², even for the 20 µm LED.

A cluster of CYP6 gene family associated with the major quantitative trait locus is responsible for the pyrethroid resistance in Culex pipiens pallen

The emergence and rapid spread of insecticide resistance in several mosquito species has become a significant obstacle in management of mosquito-borne diseases, including deltamethrin resistance in Culex pipiens pallens. Previous study identified a major deltamethrin resistance quantitative trait locus (DR-6) that alone explained 62% of the genetic variance. In this study, the marker L4B1.102 and L4B1.175 associated with the DR-6 were characterized. We searched for potential candidate genes in the flank region of two markers in the genome sequence and showed that a cluster of CYP6 cytochrome P450 genes (CYP6BB4, CYP6BB3, CYP6CC2, CYP6P14, CYP6BZ2, CYP6AA9, CYP6AA8, CYP6AA7) was in the vicinity of DR-6. Significant differences in the expression of these P450s in the larval and adult stages were identified in the resistant strains compared with the susceptible strain. For CYP6AA9 and CYP6BB4, the correlation analysis showed a highly positive correlation between relative gene expression quantification and the resistance level in different strains. Knockdown of CYP6BB4 increased the sensitivity of mosquitoes to deltamethrin. We identified that the deltamethrin resistance was in a cluster of CYP6 genes in C. pipiens pallens, and CYP6BB4 may play a significant role in the development of deltamethrin resistance.

Tracking Ultrafast Photocurrents in the Weyl Semimetal TaAs Using THz Emission Spectroscopy

We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.

[Severe acute pancreatitis with iatrogenic duodenal fistula: cause and minimal invasive treatment]

Objective: To investigate the causes and treatment of severe acute pancreatitis (SAP) with iatrogenic duodenal fistula. Methods: The clinical data of the SAP patients with duodenal fistula treated in the Severe Acute Pancreatitis Center of Sir Run Run Shaw Hospital from May 2015 to May 2018 was analyzed retrospectively. Results: A total of 11 patients were enrolled, among which 5 cases of duodenal fistula were caused by iatrogenic injury, including 2 cases of puncture injury, 2 cases of nutritional tube injury and 1 case of drainage tube injury. For patients with poor infection control after conservative treatment, laparoscopic assisted debridement through the right retroperitoneal approach was performed. Treatment of two patients failed for liver failure and the remaining patients were cured. Conclusions: Iatrogenic injury is one of the causes of duodenal fistula in patients with severe pancreatitis. Laparoscopic assisted debridement through the right retroperitoneal approach is an effective treatment for duodenal fistula.

[Acquired blood coagulation factor Ⅴ deficiency in a patient with severe burn]

In March 2017, a severely burned male patient aged 36 years with hypovolemic shock was admitted to our hospital. The patient received large quantities of antibiotics and blood products and repeated skin graft after admission, and then he suffered wound errhysis and throat congestion. The patient was healthy before without family history of bleeding or thrombosis disease. Laboratory tests showed that prothrombin time and activated partial coagulation time were remarkably prolonged, blood coagulation factor Ⅴ activity was extremely low, and the result of qualitative test of coagulation factor inhibitor was positive. Acquired blood coagulation factor Ⅴ deficiency was diagnosed. After application of dexamethasone (5 mg, twice per day) and infusion of fresh frozen plasma, blood coagulation indicators of patients recovered in 4 days, the result of qualitative test of coagulation factor inhibitor was negative, and bleeding symptoms were improved.

The sapphire substrate pretreatment effects on high-temperature annealed AlN templates in deep ultraviolet light emitting diodes

Evolution of crystalline quality of AlN via high-temperature (HT) annealing induced by different sapphire pretreatments is investigated.

Realization of low dislocation density AlN on a small-coalescence-area nano-patterned sapphire substrate

Growth behaviors of AlN on hexagonal configuration hole-type and truncated-cone-pillar-type nano-patterned sapphire substrates (NPSSs) have been investigated.

Crystal quality evolution of AlN films via high-temperature annealing under ambient N2 conditions

The crystal quality evolution of AlN films via high-temperature (HT) annealing under nitrogen is investigated.

[Evaluation of neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in children of obstructive sleep apnea hypopnea syndrome]

Objective:To evaluate neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in children of obstructive sleep apnea hypopnea syndrome (OSAHS). Method:122 cases of OSAHS patients were selected, and divided into 3 groups： mild OSAHS group (41 cases), moderate OSAHS group (41 cases), and severe OSAHS group （40 cases）, according to the stage apnea hypoventilation index (AHI) and the lowest oxygen saturation (LSaO₂). In addition, 40 cases healthy children were selected as control group. The differences NLR and PLR between 4 groups were compared. Result:The NLR in the severe OSAHS group (1.57±0.58) was significantly higher than that in the normal control group (0.98±0.22), mild OSAHS group (1.24±0.47), and moderate OSAHS group (1.36±0.46), P<0.05. However, there was no significant difference in PLR between the normal control group and other OSAHS groups (P> 0.05). A positive correlation between AHI and NLR (r=0.385,P=0.000), and a negative correlation between AHI and minimal oxygen saturation were observed (r=-0.686,P=0.000). Conclusion:NLR might be used as a marker to evaluate the severity of inflammatory status in OSAHS patients, but PLR could no.