The Tailored Material Removal Distribution on Polyimide Membrane Can Be Obtained by Introducing Additional Electrodes.

Reactive ion etching (RIE) is a promising material removal method for processing membrane diffractive optical elements and fabrication of meter-scale aperture optical substrates because of its high-efficiency parallel processing and low surface damage. However, the non-uniformity of the etching rate in the existing RIE technology will obviously reduce the machining accuracy of diffractive elements, deteriorate the diffraction efficiency and weaken the surface convergence rate of optical substrates. In the etching process of the polyimide (PI) membrane, additional electrodes were introduced for the first time to achieve the modulation of the plasma sheath properties on the same spatial surface, thus changing the etch rate distribution. Using the additional electrode, a periodic profile structure similar to the additional electrode was successfully processed on the surface of a 200-mm diameter PI membrane substrate by a single etching iteration. By combining etching experiments with plasma discharge simulations, it is demonstrated that additional electrodes can affect the material removal distribution, and the reasons for this are analyzed and discussed. This work demonstrates the feasibility of etching rate distribution modulation based on additional electrodes, and lays a foundation for realizing tailored material removal distribution and improving etching uniformity in the future.

Numerical Study on Entropy Generation of the Multi-Stage Centrifugal Pump.

The energy loss of the multi-stage centrifugal pump was investigated by numerical analysis using the entropy generation method with the RNG k-ε turbulence model. Entropy generation due to time-averaged motion and velocity fluctuation was mainly considered. It was found that the entropy generation of guide vanes and impellers account for 71.2% and 23.3% of the total entropy generation under the designed flow condition. The guide vanes are the main hydraulic loss domains and their entropy generation is about 9 W/K, followed by impellers. There are vortices at the tongue of the guide vane inlet as well as flow separations in the impellers, which lead to entropy generation. The fluid impacts the outer surface of the guide vanes, resulting in the increase in entropy generation. There are refluxes near the guide vane tongues which also increase the entropy generation of this part. The entropy generation distribution of the guide vanes and impellers was investigated, which found that the positive guide vane has more entropy generation compared with the reverse guide. The entropy generation of the blade suction surface is higher compared with the pressure surface. This study indicated that the entropy generation method has distinct advantages in the assessment of hydraulic loss.

Disease prediction based on multi-type data fusion from Chinese electronic health record.

Disease prediction by using a variety of healthcare data to assist doctors in disease diagnosis is becoming a more and more important research topic recently. This paper proposes a disease prediction model that fuses multiple types of encoded representations of Chinese electronic health records (EHRs). The model framework utilizes a multi-head self-attention mechanism, which combines textual and numerical features to enhance text representations. The BiLSTM-CRF and TextCNN models are used, respectively, to extract entities and then obtain the embedding representations of them. The representations of text and entities in it are combined together for formulating representations of EHRs. The experimental results on EHRs data collected from a Three Grade Class B Hospital General in Gansu Province, China, show that our model achieved an F1 score of 91.92%, which outperforms the previous baseline methods.

[Transhepatic arterial chemoembolization with gemcitabine and carboplatin for the treatment of stage III hepatocellular carcinoma].

OBJECTIVE: To evaluate the efficiency and safety of transhepatic arterial chemoembolization (TACE) with gemcitabine and carboplatin for the treatment of stage III hepatocellular carcinoma (HCC). METHODS: Sixty-one HCC patients were treated by TACE. During TACE, At first, intra-arterial infusion of carboplatin 300 mg/m2, then gemcitabine 1000 mg/m2 with 5-30 ml of ultra-lipoidal iodide oil emulsion was used for arterial embolization. The toxicity and hepatic damage were observed according to WHO anticancer drug toxicity criteria and Child-Pugh classification criteria, respectively. The survival time was also observed during follow-up. RESULTS: The blood toxicity was bone marrow suppression presented as grade I leucopenia in 39.3%, grade II in 29.5%, grade III-IV in 18.0%. Grade II-III nausea and vomiting developed in 96.8% of the patients. Hepatic function damage became aggravated in 16 patients from A to B class, in 2 from A to C class, and in 6 from B to C class according to Child-Pugh classification criteria. The median survival time was 20 months with a range of 5 to 3 5 months. CONCLUSION: Transhepatic arterial chemoembolization using carboplatin and mixture of gemcitabine with ultra-lipoidal iodide oil emulsion is safe and effective in the management of stage III hepatocellular carcinoma. This regimen can also improve their quality of life.

Association between vascular endothelial growth factor and metastasis after transcatheter arterial chemoembolization in patients with hepatocellular carcinoma.

BACKGROUND: Hypoxia up-regulates vascular endothelial growth factor (VEGF) and stimulates the growth of hepatocellular carcinoma (HCC) cells. This study was designed to investigate the association between changes in plasma VEGF levels after transcatheter arterial chemoembolization (TACE) and HCC progression, especially in relation to metastasis. METHODS: Plasma VEGF levels were measured by quantitative sandwich enzyme-linked immunosorbent assay (ELISA R&D system). Plasma VEGF levels were measured before, 3 days and 4 weeks after TACE in 30 patients with HCC. The development of metastasis was evaluated at the end of the third month after TACE. RESULTS: The plasma VEGF levels of the 30 patients with HCC were 154.47+/-90.17 pg/ml. The total plasma VEGF levels after TACE increased compared with their basal levels (P<0.05), and the plasma VEGF levels had a tendency to increase in patients with heterogeneous uptake of iodizdoil and portal vein thrombosis. Follow-up for six months showed metastatic foci in 20 patients (74%) with increased plasma VEGF, but none of the patients with decreased plasma VEGF developed metastasis. CONCLUSION: Increased plasma VEGF expression is associated with the development of metastasis in HCC after TACE.

[Relation between vascular endothelial growth factor and reoccurence-metastasis after transcatheter arterial chemoembolization in hepatocellar carcinoma].

OBJECTIVE: To investigate the relation between changes in serum vascular endothelial growth factor (VEGF) level after transcatheter arterial chemoembolization (TACE) and hepatocellular carcinoma (HCC) progression, especially in relation to metastasis. METHODS: Serum VEGF expression level, measured by quatitative sandwich enzyme-linked immunosorbent assay (ELISA, R&D system), was measured before, 3 days and 4 weeks after TACE in 30 patients with HCC. The development of metastasis was evaluated at the end of the third month after TACE. RESULTS: 1. The serum VEGF level in 30 patients was 154.47 +/- 90.17 pg/ml, 2. Post-TACE total serum VEGF level increased as compared with their basal level in 30 patients (P < 0.05) and serum VEGF level had a tendency to increase in patients with heterogeneous uptake of iodized oil and portal vein thrombosis. During the follow-up of 1 - 2 years, metastatic foci were found in 74% (20) patients with SVEGF increase, while none of the patients showing SVEGF decrease developed metastasis. CONCLUSION: Serum VEGF expression increase is associated with the development of metastasis in hepatocellular carcinoma after TACE.

[Acute respiratory tract obstruction during thyroid operation: analysis of 10 cases].

OBJECTIVE: To explore the causes and management of acute respiratory tract obstruction in patients undergoing thyroid operation. METHODS: A retrospective review was conducted in 10 such cases that we encountered in our 11 years' experience with thyroid operation. RESULTS: Respiratory tract obstructions occurred in 10(0.31%) of 3,186 cases during thyroid operation. The causes for the obstructions included tracheomalacia in 2 cases, hematoma compression in 5 cases, trachea convulsion in 2 cases and phlegm obstruction in 1 case. Tracheotomy or intratracheal intubation was performed in 6 cases and hematoma removal in 4 cases, with the occurrence of death in 1 case. CONCLUSION: Hematoma compression and tracheomalacia etc. are among the most common causes of acute respiratory tract obstruction during thyroid operation, the occasion of which demands immediate implementation of tracheotomy or intratracheal intubation.