Dynamic Simulation of Deposition Processes of Spacecraft Molecular Contamination

Accurate simulation and calculation of the deposition of outgassing molecule can shorten the cycle and reduce the cost of vacuum tests on satellites. It also provides a reference for contamination protection design by systems engineers. In this study, the molecular outgassing, transport and deposition processes were simulated by diffusion theory, the angle coefficient method, and the first-order desorption equation, respectively. The simulation results were consistent with the test data trends, but deviated from the test values. Given the effect of initial molecular outgassing rate, diffusion coefficient and residence time on the deposition mass, it was surmised that considering the molecular species and the weight mass rate would improve the calculation result. These considerations indeed improved the numerical simulations of high-vacuum contamination

Clinical efficacy of vitrectomy combined with inverted internal limiting membrane flap technique for macular hole retinal detachment of high myopia

AIM: To evaluate the effectiveness of pars plana vitrectomy(PPV)combined with inverted internal limiting membrane(ILM)flap technique for macular hole retinal detachment(MHRD)of high myopia. METHODS: This was a retrospective case series. Totally 27 patients(27 eyes)who were diagnosised with MHRD of high myopia and underwent vitrectomy combined with inverted ILM flap covering technique were eIlrolled in this study. The diopter was ≥-6.00D and axial length was ≥26mm. The mean age was 53.69±7.23 years. And there 9 males and 18 females. The logarithm of the minimum angle of resolution(LogMAR)best-corrected visual acuity(BCVA)was 1.41±0.28. All patients were performed PPV with inverted ILM flap, resected the vitreous gel and cortex completely. Bright blue G stained the ILM around the fovea. The ILM was peeled off around the MH, and some portion of the ILM flap was left attached to the edge of the MH. Covering the MH with the ILM flap.Then, C3F8 gas or silicone oil was injected into the vitreous cavity. The mean follow-up was more than 6mo and BCVA, MH closure, retinal reattachment, complications were retrospectively observed. RESULTS: After surgery, visual acuity improved in 21 eyes(78%), unchanged in 4 eyes(15%), decreased in 2 eyes(7%). The mean LogMAR BCVA was 0.84±0.40, the difference was significant(t=7.32, PCONCLUSION: PPV combined with inverted internal limiting membrane flap is an effective and safe management for the MHRD of high myopia

Intravitreous injection of Lucentis combined with argon laser photocoagulation for treatment of retinal macroaneurysm

AIM: To evaluate the clinical efficacy of intravitreous injection of Lucentis combined with argon laser photocoagulation on retinal macroaneurysm.<p>METHODS: A retrospective observation about intravitreous injection of Lucentis combined with argon laser photocoagulation was performed on 9 patients(9 eyes)with retinal macroaneurysms with macular edema between January 2011 and July 2013. Through the collection of clinical data in patients best-corrected visual acuity, change of the retinal macroaneurysm, optical coherence tomography and fluoresce in fundus angiography before therapy and 1 mouth,3 mouths after therapy, comparative analysis the changes in best-corrected visual acuity and central macular retinal thickness(CMT)between before and after treatment.<p>RESULTS: Followed for more than 3 months, all patients' best-corrected visual acuity were improved obviously, the difference was significant(<i>P</i><0.05); The patients' macular edema was obviously absorbed and the average CMT was significantly lower, the difference was significant(<i>P</i><0.05). In fundus fluorescein angiography, the neoplasia body was atrophied inordinately after 3 months of treatment.<p>CONCLUSION:Intravitreous injection of Lucentis combined with argon laser photocoagulation is effective and security to improving visual acuity of retinal macroaneurysms with macular edema

A visible, targeted high-efficiency gene delivery and transfection strategy

<p>Abstract</p> <p>Background</p> <p>To enhance myocardial angiogenic gene expression, a novel gene delivery strategy was tested. Direct intramyocardial injection of an angiogenic gene with microbubbles and insonation were applied in a dog animal model. Dogs received one of the four different treatments in conjunction with either the enhanced green fluorescence protein (EGFP) gene or the hepatocyte growth factor (HGF) gene: gene with microbubbles (MB) and ultrasound (US); gene with US; gene with MB; or the gene alone.</p> <p>Results</p> <p>Distribution of MB and the gene in the myocardium was visualized during the experiment. Compared with the EGFP gene group, an average 14.7-fold enhancement in gene expression was achieved in the EGFP+MB/US group (P < 0.01). Compared with the HGF gene group, an average 10.7-fold enhancement in gene expression was achieved in the HGF+MB/US group (P < 0.01). In addition, capillary density increased from 20.8 ± 3.4/mm2 in the HGF gene group to 146.7 ± 31.4/mm2 in HGF+MB/US group (P < 0.01).</p> <p>Conclusions</p> <p>Thus, direct intramyocardial injection of an angiogenic gene in conjunction with microbubbles plus insonation synergistically enhances angiogenesis. This method offers an observable gene delivery procedure with enhanced expression efficiency of the delivered gene.</p

Orthokeratology lens and conventional frame glasses for ocular parameters of myopia adolescent

AIM: To explore the effects of overnight orthokeratology lens and conventional frame glasses on the myopic diopter, uncorrected visual acuity and ocular parameters of myopia adolescent. METHODS: Totally 102 cases of(204 eyes)of adolescent myopia patients were randomly divided into observation group and control group with 51 cases(102 eyes)in each group during April 2014 to April 2017. Control group was only given conventional frame glasses, and observation group was given overnight orthokeratology lens. The myopic diopter and uncorrected visual acuity(UCVA)before wearing glasses and at 1wk, 1, 3, 6mo and 1a of wearing glasses, and the ocular parameters before wearing glasses and at 1a after wearing glasses were observed in the two groups, and the occurrence of complications was compared between the two groups. RESULTS: After 1wk to 1a of wearing glasses, the myopic diopter in observation group was gradually decreased(PP>0.05), but there was statistically significant difference between-groups at different time points(PPPP>0.05), and the axial length in control group was significantly longer than that before wearing glasses and that in observation group(PP>0.05).CONCLUSION: Overnight orthokeratology lens for adolescent myopia can effectively correct the myopic diopter, and improve the uncorrected visual acuity. It is less harmful to the eyes and less complications, and it is safe and reliable in clinical application

Ocular complications of HIV infection

In recent years,with the widespread application of highly effective antiretroviral therapy(HAART), the incidence of human immunodeficiency virus(HIV)and acquired immunodeficiency syndrome(AIDS)related eye complications was significantly reduced. The absolute number of patients infected with HIV and AIDS increased year by year, and the survival rate increased and the survival time prolonged. The clinical manifestations of associated ocular complications in these patients are variable, affecting almost all ocular structures. At present, there is a lack of large-scale and long-term systematic observation of eye lesions in HIV-infected and AIDS patients in China. Misdiagnosis and missed diagnosis occur in many hospitals and even in some of the top-three hospitals. This not only delays the treatment of patients, but also easily cause iatrogenic transmission. Therefore, ophthalmologists and even other medical workers should enhance their knowledge of HIV/AIDS. This paper reviews the common complications of non-infection, opportunistic infection, and immune reconstitution inflammatory response syndrome(IRIS)in the HIV/AIDS patients, and discusses the manifestations and research progress of posterior ocular complications of HIV/AIDS

Using combination of lifting wavelet and multiclass SVM based on global optimization class strategy for fault pattern identification

This paper presents a new method based on lifting wavelet for obtaining a fast multiclass SVM classification based on global optimization class strategy for fault diagnosis of roller bearing. Decision making was performed in two stages: feature extraction by computing the lifting wavelet coefficients and classification using the multiclass SVM classifiers trained on the extracted features. Experiments demonstrate that in comparison to discrete wavelet transform the lifting wavelet feature extraction can speed up the identification phase as well as achieve higher accuracy of multiclass SVM that is based on global optimization class strategy. Experimental results also reveal that the proposed multiclass SVM of global optimization is better than strategy of one against one and DAGSVM

Protective effects of ciliary neurotrophic factor on the retinal ganglion cells by injure of hydrogen peroxide

AIM: To explore the effect of ciliary neurotrophic factor (CNTF) on retinal ganglion cell (RGC)-5 induced by hydrogen peroxide (H2O2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H2O2 from 50 to 150 µmol/L at four time points (0.5, 1, 1.5 and 2h) to select the concentration and time point for H2O2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells (BMSCs) for co-culture with RGC-5. RESULTS: Compared to the control group, H2O2 led to RGC-5 death closely associated with concentrations and action time of H2O2 and we chose 125 µmol/L and 2h to establish the H2O2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION: Both the two administration routes of CNTF have effects on RGC-5 cells induced by H2O2. If their own advantages were combined, there may be a better administration route