DUDA-Net: a double U-shaped dilated attention network for automatic infection area segmentation in COVID-19 lung CT images.

PURPOSE: The global health crisis caused by coronavirus disease 2019 (COVID-19) is a common threat facing all humankind. In the process of diagnosing COVID-19 and treating patients, automatic COVID-19 lesion segmentation from computed tomography images helps doctors and patients intuitively understand lung infection. To effectively quantify lung infections, a convolutional neural network for automatic lung infection segmentation based on deep learning is proposed. METHOD: This new type of COVID-19 lesion segmentation network is based on a U-Net backbone. First, a coarse segmentation network is constructed to extract the lung areas. Second, in the encoding and decoding process of the fine segmentation network, a new soft attention mechanism, namely the dilated convolutional attention (DCA) mechanism, is introduced to enable the network to focus on better quantitative information to strengthen the network's segmentation ability in the subtle areas of the lesions. RESULTS: The experimental results show that the average Dice similarity coefficient (DSC), sensitivity (SEN), specificity (SPE) and area under the curve of DUDA-Net are 87.06%, 90.85%, 99.59% and 0.965, respectively. In addition, the introduction of a cascade U-shaped network scheme and DCA mechanism can improve the DSC by 24.46% and 14.33%, respectively. CONCLUSION: The proposed DUDA-Net approach can automatically segment COVID-19 lesions with excellent performance, which indicates that the proposed method is of great clinical significance. In addition, the introduction of a coarse segmentation network and DCA mechanism can improve the COVID-19 segmentation performance.

Acute toxicological effects of zinc oxide nanoparticles in mice after intratracheal instillation.

BACKGROUND: Zinc oxide nanoparticles (ZnO NPs) are increasingly being used in industry. OBJECTIVE: To evaluate the acute toxicology of ZnO NPs in Mice. METHODS: ZnO NPs were intratracheally instilled into mice at different dose (200, 400, 800 µg/kg), which was 1, 2, or 4 times of accumulative intake in one week according to the threshold limit value. Acute toxicity was assessed by animal mortality, organ/body weight ratios, hematology, blood biochemistry, and histopathology as well as by the determination of cells, proteins, and lactate dehydrogenase activity in bronchoalveolar lavage fluid. RESULTS: Exposure to ZnO NPs also resulted in bodyweight loss and a higher level of total cell number, total protein, and hydroxyproline content in BALF. Nitric oxide and malondialdehyde levels in the lung homogenates were also increased. In addition, inflammatory and hyperplastic changes in the lungs were observed. CONCLUSION: Threshold limit value (5 mg/m3) may unfit for ZnO NPs.

[ARTHROSCOPIC SINGLE BUNDLE POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING HAMSTRING TENDONS THROUGH POSTERIOR TRANS-SEPTUM PORTAL APPROACH WITH PRESERVATION OF REMNANT POSTERIOR CRUCIATE LIGAMENT FIBERS].

OBJECTIVE: To introduce the arthroscopic single bundle posterior cruciate ligament (PCL) reconstruction using hamstring tendons through posterior trans-septum portal approach with preservation of the remnant PCL fibers, and to evaluate the clinical results. METHODS: Between June 2010 and April 2014, 57 patients with PCL rupture were treated with arthroscopic single bundle PCL reconstruction using hamstring tendons through posterior trans-septum portal approach with preservation of the remnant PCL fibers. There were 41 males and 16 females, aged 19-42 years (mean, 27.7 years). All the patients had history of injury. The results of posterior drawer test were positive, including 9 cases of grade II and 48 cases of grade III. The disease duration ranged from 2 weeks to 25 months (mean, 13 months). The Lysholm score and the range of motion of knee joint were used to evaluate the knee function. RESULTS: The operation performed smoothly, and no complications of blood vessel and nerve injuries and infection occurred. Primary healing was obtained in all incisions; no early complication occurred after operation. The patients were followed up 16.6 months on average (range, 12-20 months). At last follow-up, the knee range of motion returned to normal in all cases (120-130° in flexion). MRI at last follow-up showed good continuity of the PCL graft and complete healing of the remnant PCL tissues between the femoral and tibial attachments. The Lysholm score was significantly improved when compared with preoperative score (t= -27.429, P = 0.000). CONCLUSION: Arthroscopic single bundle PCL reconstruction using hamstring tendons through posterior trans-septum portal approach with preservation of the remnant PCL fibers has the advantages of firm fixation, simple operation, and good knee function recovery.

Renal impairment caused by chronic occupational chromate exposure.

PURPOSE: To determine the nephritic toxicity of chromate after chronic occupational exposure. METHODS: The environmental contamination was assessed by measuring the chromium (Cr) in 8-h airborne sampler. The integrated level of Cr was determined by Cr concentrations in the whole blood (WB-Cr) and the urine (U-Cr). The renal glomerular and tubule impairment was evaluated by determination of cystatin C (Cys-C) in the serum and microalbumin (mALB), urinary beta(2)-microglobulin (ß(2)M), N-acetyl-beta-D-glucosaminidase (NAG) activity in the urine. RESULTS: The mean occupational exposure time to Cr was 12.86 years with average daily air level of 27.13 µg/m(3) comparing to 0.11 µg/m(3) of the background level. The WB-Cr and U-Cr were 23.49 µg/L and 17.41 µg/g creatinine (Cre), respectively in the chromate-exposed workers comparing to 3.32 µg/L and 1.52 µg/g Cre in the controls. The serum Cys-C and urinary mALB were significantly increased in the chromate-exposed workers. Exposure to Cr seems to induce an enhanced level of urinary NAG activity and ß(2)M concentration. The increased serum Cys-C concentration was positively correlated with the level of serum Cre. The U-Cr was positively correlated to the concentrations of urinary mALB, ß(2)M, and the activity of NAG. CONCLUSIONS: Chronic occupational exposure to chromate causes comprehensive renal impairment though more severity could occur in the tubule than in the glomerular.

Large-scale graphene transistors with enhanced performance and reliability based on interface engineering by phenylsilane self-assembled monolayers.

In this letter, we report the dielectric/graphene interface physics and engineering of large-scale, chemical vapor deposited (CVD) graphene transistors by self-assembling a molecular-scale organosilane monolayer onto the dielectric surface. We show that phenyl-alkyl-terminated self-assembled monolayers (SAM) at the dielectric/graphene interface consistently improve the graphene device performance and reliability. The extrinsic field-effect mobility of large-scale CVD graphene transistors on the phenyl-SAM engineered dielectric is currently up to 2500 cm(2)/(V s) at room temperature, considerably higher than the counterparts without the SAM. In addition, significant reduction on the bias stress instability and hysteresis is achieved by the SAM-based interface engineering. Further analysis reveals that charge injection from graphene to the dielectric/graphene interface dominates the observed hysteresis behavior. For both graphene transistors with and without SAMs, the bias stress stability, that is, Dirac point shift under bias stress, is well described by the stretched exponential model with its fitting parameters clearly indicating different interface properties.

[Study on DNA strand breaks in workers exposed to soluble chromate].

OBJECTIVE: To explore the biological effective markers, we investigated DNA strand breaks in peripheral lymphocytes from occupational population with broad ranges of soluble chromate exposure. METHODS: We conducted a cross-sectional study in the chromate exposed workers employed at a chromate factory in a district of Jinan, Shandong Province. The studied population contained 114 workers from different processes of the chromate plants, in addition, 30 farmers in the countryside about one hundred kilometers away from the factory, without exposure to chromate were matched with the exposed subjects by age, gender and smoking status being identified as a control group. Personal information on age, chromate exposure, medical history (including acute infection and medicine usage), smoking habit and alcohol consumption was obtained by questionnaire. DNA strand breaks in lymphocytes were detected by single-cell gel electrophoresis assay (comet assay) and the DNA damaged degree was evaluated by the score weighted by comet type. The air concentration of chromate was determined by individual sampling for 8 hours per day as shift work and chromium was assayed by atomic absorption spectrometry. The chromium content in the erythrocytes from peripheral blood was determined by graphite furnace atomic absorption spectrometry. The data were analyzed by SPSS10.0 software for statistical significance. RESULTS: (1) The results showed that the score for DNA strand breaks in lymphocytes were 54.52 +/- 23.51 in the exposed group, which was significantly higher than those in the control group (24.70 +/- 11.84) (P < 0.01). (2) The degree of DNA strand breaks in lymphocytes was increased in a dose-dependent manner ranging from 0 microg/m(3) to 106.00 microg/m(3). (3) Correlation analysis showed that there was a significant positive correlation between airborne chromate concentration and the degree of DNA strand break in lymphocytes (P < 0.01). (4) By multiple regression analysis, it was found that the airborne concentrations, chromium contents in red blood cells and smoking habits were factors which might affect the degree of DNA breaks. CONCLUSION: Our findings suggest that DNA strand break in lymphocytes should be an effective biomarker for occupational chromate-exposed population and be applied in biological monitoring and health risk assessment for occupational chromate-exposed population.

Characterizing Transmission and Control of the SARS Epidemic: Novel Stochastic Spatio-Temporal Models.

Severe Acute Respiratory Syndrome (SARS), the first epidemic of the 21st century, has an outbreak history of more than 2 years till today and caused tremendous damage to the human society. Accordingly, many studies on modeling the SARS epidemic have been reported, whereas deficiencies were still lying in those models because of their separate space/time methodology. In this paper, we propose novel comprehensive stochastic spatio-temporal models from both of the macro aspect and individual aspect for characterizing transmission and control of the SARS disease. Based on a new SARS spread process in consideration of "suspicious" population, we firstly establish the stochastic temporal models from two different aspects: the macro model is described with birth-death process and the individual Markov model is described with probability transition matrix (PTM). And then, we amalgamate the deterministic/stochastic population-flow model with the stochastic temporal models together to set up the comprehensive stochastic spatio-temporal models. Simulations on computer have evaluated the effect of various realistic parameters and control policies, and also have testified the accuracy and efficacy of the new models. Additionally, particular studies on the cases of Tsinghua University and Beijing City are presented. The comprehensive stochastic spatio-temporal models have considerably reduced the complexity plus errors as compared with previous works and will be able to characterize other various epidemics, e.g. Avian Flu.

Design proposal of imaging activities of cultured neural network on a silicon substrate with neural-electronic-optical integrated microsystem.

Multielectrode Arrays have currently been widely used as Neural-Network research tools. In this paper, we propose a novel mixed integrated sensor array microsystem combining cultured biological neurons, silicon integrated circuits and optical components together on a single silicon substrate. Using the light emitting property of GaAs-LED dependent on current passing from the recorded action potentials signals by a Multielectrode-Array in situ, we are able to characterize the neural activities of the cultured neural networks directly with a visible image displayed by a monitoring CCD Camera. Researchers may use various ready image process tools for experimental data analysis to directly observe results.