The Influences of Key Factors on the Consequences Following the Natural Gas Leakage from Pipeline

AbstractThe effects of the environmental dispersion (i.e. atmospheric stability, wind speed, temperature, humidity and ground roughness) and source release factors (i.e. pipeline diameter, length, pressure and release opening area) on the suffocation distance, flammable vapor cloud distance, overpressure distance and thermal radiation distance after the natural gas released from pipeline were evaluated and analyzed. The results show that all the environmental dispersion factors except humidity have an effect on the flammable vapor cloud distance. The more stable atmospheric condition, lower wind speed and smaller ground roughness lead to the longer flammable vapor cloud distance. The atmosphere temperature has a very limited influence on the flammable vapor cloud distance. The higher ambient temperature and larger humidity result in the longer downwind thermal radiation distance, while the atmospheric stability, wind speed and ground roughness nearly does not. All the four source release factors significantly influence the flammable vapor cloud distance and thermal radiation distance, which is due to the different release amount, release rate and initial momentum

Digital Image Watermarking Algorithm Using the Intermediate Frequency

Digital image watermarking is one of the proposed solutions for copyright protection of multimedia data. This technique is better than Digital Signatures and other methods because it does not increase overhead. Watermarking adds the additional requirement of robustness. To improve the robustness of digital image watermarking method based on the image frequency, this paper adopts the intermediate frequency to embed the watermarking and proposes an digital image watermarking algorithm based on robust principal component analysis (RPCA) and discrete cosine transform (DCT). Firstly, the high frequency part and the low frequency part of the image are extracted by the RPCA algorithm. Because the high frequency part has complex statistical characteristics, this paper processes the high frequency part with "8×8" DCT method to obtain intermediate frequency coefficients and then the watermarking information is embedded into the obtained intermediate frequency coefficients. The experimental results show that the proposed algorithm leads to satisfactory robustness to the attacks of impulse noise and cropping

Cutting Force Predication Based on Integration of Symmetric Fuzzy Number and Finite Element Method

In the process of turning, pointing at the uncertain phenomenon of cutting which is caused by the disturbance of random factors, for determining the uncertain scope of cutting force, the integrated symmetric fuzzy number and the finite element method (FEM) are used in the prediction of cutting force. The method used symmetric fuzzy number to establish fuzzy function between cutting force and three factors and obtained the uncertain interval of cutting force by linear programming. At the same time, the change curve of cutting force with time was directly simulated by using thermal-mechanical coupling FEM; also the nonuniform stress field and temperature distribution of workpiece, tool, and chip under the action of thermal-mechanical coupling were simulated. The experimental result shows that the method is effective for the uncertain prediction of cutting force

Percutaneous nephrolithotripsy: C-arm CT with 3D virtual navigation in non-dilated renal collecting systems

PURPOSE:We aimed to evaluate the clinical superiority of using C-arm computed tomography (CT) to establish percutaneous nephrolithotripsy (PCNL) access for patients with non-dilated renal collecting systems.METHODS:From May 2014 to May 2015, 33 patients underwent C-arm CT-guided puncture to establish PCNL access after failed attempts of ultrasonography-guided nephrostomy. Technical success, procedure details, radiation exposure, complications, and stone-free rate were recorded.RESULTS:The technical success rate was 97% (32/33) with a mean puncture score of 4.5/5. Mean puncture, dilation, and fragmentation times were 17.9±6.0, 12.6±3.9, and 33.1±8.8 minutes, respectively. Mean radiation exposure was 4.8±2.1 mSv without serious complications. Stone-free rate was 93.8%.CONCLUSION:C-arm CT is a useful tool to establish PCNL access, particularly in cases of upper pole access or complicated anatomy

Disseminated varicella-zoster virus infection in an aplastic anemia- paroxysmal nocturnal hemoglobinuria syndrome patient: A case report

BackgroundVaricella-zoster virus (VZV) is a common and widespread human-restricted pathogen. It is famous for its dermatological manifestations, such as varicella and herpes zoster. Patients with aplastic anemia-paroxysmal nocturnal hemoglobinuria (AA-PNH) syndrome complicated with fatal disseminated varicella zoster virus infection are very rare and in danger.Patient concernsA 26-year-old man with a history of AA-PNH syndrome was receiving cyclosporine and corticosteroid treatment in the hematology department. During his hospitalization in our hospital, he developed fever, abdominal pain, and lower back pain, and his face, penis, trunk, and limbs developed itchy rash. Subsequently, the patient had to undergo cardiopulmonary resuscitation because of sudden cardiac arrest, and be transferred to ICU for treatment. It was presumed that the cause is unknown severe sepsis. The patient’s condition quickly progressed to multiple organ failure, accompanied by liver, respiratory, and circulatory failure, and signs of disseminated intravascular coagulation. Unfortunately, the patient died after 8 h of active treatment. Finally, we collected all the evidence and concluded that the patient died of AA-PNH syndrome combined with poxzoster virus.ConclusionAA-PNH syndrome patients treated with steroids and immunosuppressants are prone to various infections, considering that herpes virus infection with chickenpox and rash as the initial manifestations is characterized by rapid progress and often accompanied by serious complications. It is more difficult to distinguish it from AA-PNH syndrome with skin bleeding points. If it is not identified in time, it may delay the treatment opportunity, make the condition worse, and cause serious adverse prognosis. Therefore, clinicians need to pay attention to it

ISA-Net: Improved spatial attention network for PET-CT tumor segmentation

Achieving accurate and automated tumor segmentation plays an important role in both clinical practice and radiomics research. Segmentation in medicine is now often performed manually by experts, which is a laborious, expensive and error-prone task. Manual annotation relies heavily on the experience and knowledge of these experts. In addition, there is much intra- and interobserver variation. Therefore, it is of great significance to develop a method that can automatically segment tumor target regions. In this paper, we propose a deep learning segmentation method based on multimodal positron emission tomography-computed tomography (PET-CT), which combines the high sensitivity of PET and the precise anatomical information of CT. We design an improved spatial attention network(ISA-Net) to increase the accuracy of PET or CT in detecting tumors, which uses multi-scale convolution operation to extract feature information and can highlight the tumor region location information and suppress the non-tumor region location information. In addition, our network uses dual-channel inputs in the coding stage and fuses them in the decoding stage, which can take advantage of the differences and complementarities between PET and CT. We validated the proposed ISA-Net method on two clinical datasets, a soft tissue sarcoma(STS) and a head and neck tumor(HECKTOR) dataset, and compared with other attention methods for tumor segmentation. The DSC score of 0.8378 on STS dataset and 0.8076 on HECKTOR dataset show that ISA-Net method achieves better segmentation performance and has better generalization. Conclusions: The method proposed in this paper is based on multi-modal medical image tumor segmentation, which can effectively utilize the difference and complementarity of different modes. The method can also be applied to other multi-modal data or single-modal data by proper adjustment

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Injury by Inhibiting ROS-Activated ERK1/2 and p38MAPK Signaling Pathways in PC12 Cells

Hydrogen sulfide (H2S) has been proposed as a novel neuromodulator and neuroprotective agent. Cobalt chloride (CoCl2) is a well-known hypoxia mimetic agent. We have demonstrated that H2S protects against CoCl2-induced injuries in PC12 cells. However, whether the members of mitogen-activated protein kinases (MAPK), in particular, extracellular signal-regulated kinase1/2(ERK1/2) and p38MAPK are involved in the neuroprotection of H2S against chemical hypoxia-induced injuries of PC12 cells is not understood. We observed that CoCl2 induced expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α), decreased cystathionine-β synthase (CBS, a synthase of H2S) expression, and increased generation of reactive oxygen species (ROS), leading to injuries of the cells, evidenced by decrease in cell viability, dissipation of mitochondrial membrane potential (MMP) , caspase-3 activation and apoptosis, which were attenuated by pretreatment with NaHS (a donor of H2S) or N-acetyl-L cystein (NAC), a ROS scavenger. CoCl2 rapidly activated ERK1/2, p38MAPK and C-Jun N-terminal kinase (JNK). Inhibition of ERK1/2 or p38MAPK or JNK with kinase inhibitors (U0126 or SB203580 or SP600125, respectively) or genetic silencing of ERK1/2 or p38MAPK by RNAi (Si-ERK1/2 or Si-p38MAPK) significantly prevented CoCl2-induced injuries. Pretreatment with NaHS or NAC inhibited not only CoCl2-induced ROS production, but also phosphorylation of ERK1/2 and p38MAPK. Thus, we demonstrated that a concurrent activation of ERK1/2, p38MAPK and JNK participates in CoCl2-induced injuries and that H2S protects PC12 cells against chemical hypoxia-induced injuries by inhibition of ROS-activated ERK1/2 and p38MAPK pathways. Our results suggest that inhibitors of ERK1/2, p38MAPK and JNK or antioxidants may be useful for preventing and treating hypoxia-induced neuronal injury

Detecting Structure of Complex Network by Quantum Bosonic Dynamics

We introduce a non-interacting boson model to investigate topological structure of complex networks in the present paper. By exactly solving this model, we show that it provides a powerful analytical tool in uncovering the important properties of real-world networks. We find that the ground state degeneracy of this model is equal to the number of connected components in the network and the square of coefficients in the expansion of ground state gives the averaged time for a random walker spending at each node in the infinite time limit. Furthermore, the first excited state appears always on its largest connected component. To show usefulness of this approach in practice, we carry on also numerical simulations on some concrete complex networks. Our results are completely consistent with the previous conclusions derived by graph theory methods.Comment: 4 pages, 3 figure

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Cytotoxicity and Inflammation in HaCaT Cells through Inhibition of ROS/NF-κB/COX-2 Pathway

Hydrogen sulfide (H2S) has been shown to protect against oxidative stress injury and inflammation in various hypoxia-induced insult models. However, it remains unknown whether H2S protects human skin keratinocytes (HaCaT cells) against chemical hypoxia-induced damage. In the current study, HaCaT cells were treated with cobalt chloride (CoCl2), a well known hypoxia mimetic agent, to establish a chemical hypoxia-induced cell injury model. Our findings showed that pretreatment of HaCaT cells with NaHS (a donor of H2S) for 30 min before exposure to CoCl2 for 24 h significantly attenuated CoCl2-induced injuries and inflammatory responses, evidenced by increases in cell viability and GSH level and decreases in ROS generation and secretions of IL-1β, IL-6 and IL-8. In addition, pretreatment with NaHS markedly reduced CoCl2-induced COX-2 overexpression and PGE2 secretion as well as intranuclear NF-κB p65 subunit accumulation (the central step of NF-κB activation). Similar to the protective effect of H2S, both NS-398 (a selective COX-2 inhibitor) and PDTC (a selective NF-κB inhibitor) depressed not only CoCl2-induced cytotoxicity, but also the secretions of IL-1β, IL-6 and IL-8. Importantly, PDTC obviously attenuated overexpression of COX-2 induced by CoCl2. Notably, NAC, a ROS scavenger, conferred a similar protective effect of H2S against CoCl2-induced insults and inflammatory responses. Taken together, the findings of the present study have demonstrated for the first time that H2S protects HaCaT cells against CoCl2-induced injuries and inflammatory responses through inhibition of ROS-activated NF-κB/COX-2 pathway