The interplay of extracellular polymeric substances and oil/Corexit to affect the petroleum incorporation into sinking marine oil snow in four mesocosms

Large amounts of oil containing mucous-like marine snow formed in surface waters adjacent to the Deepwater Horizon spill that was implicated in oil delivery to the seafloor. However, whether chemical dispersants that were used increased or decreased the oil incorporation and sedimentation efficiency, and how exopolymeric substances (EPS) are involved in this process remains unresolved. To investigate the microbial responses to oil and dispersants in different oceanic settings, indicated by EPS production, petro- and non-petro carbon sedimentation, four mesocosm (M) experiments were conducted: 1) nearshore seawater with a natural microbial consortia (M2); 2) offshore seawater with f/20 nutrients (M3); 3) coastal seawater with f/20 nutrients (M4); 4) nearshore seawater with a natural microbial consortia for a longer duration (M5). Four treatments were conducted in M2, M3 and M4 whereas only three in M5: 1) a water accommodated fraction of oil (WAF), 2) a chemically-enhanced WAF prepared with Corexit (CEWAF, not in M5), 3) a 10-fold diluted CEWAF (DCEWAF); and 4) controls. Overall, oil and dispersants input, nutrient and microbial biomass addition enhanced EPS production. Dispersant addition tended to induce the production of EPS with higher protein/carbohydrate (P/C) ratios, irrespective of oceanic regions. EPS produced in M4 was generally more hydrophobic than that produced in M3. The P/C ratio of EPS in both the aggregate and the colloidal fraction was a key factor that regulated oil contribution to sinking aggregates, based on the close correlation with %petro-carbon in these fractions. In the short term (4-5 days), both the petro and non-petro carbon sedimentation efficiencies showed decreasing trends when oil/dispersants were present. In comparison, in the longer-term (16 days), petro-carbon sedimentation efficiency was less influenced by dispersants, possibly due to biological and physicochemical changes of the components of the oil-EPS-mineral phase system, which cooperatively controlled the sinking velocities of the aggregates.

[Association between weight control and recurrence of atrial fibrillation after catheter ablation in overweight and obese patients]

Objectives: This study explored the relationship between weight control and atrial fibrillation (AF) recurrence after catheter ablation in overweight and obese patients. Methods: We prospectively enrolled consecutive 333 overweight and obese patients aged 28 to 87 years old, who underwent catheter ablation for AF in Beijing Anzhen Hospital between October 2015 and February 2016. Data of patients' characteristics, laboratory examination and treatment were collected at baseline. Each patient was followed up at 3, 6 and 12 months after ablation to collect information on weight, AF recurrence, stroke, major bleeding, hospitalization for cardiovascular reasons and death, etc. Patients were divided into weight controlled group (ΔBMI<-1 kg/m(2)) and weight uncontrolled group (ΔBMI≥-1 kg/m(2)), according to the changes in the most recent exposure BMI before AF recurrence in patients with recurrence or the BMI at 12 months' follow-up in patients without recurrence and the BMI at baseline. Multivariate logistic regression was performed to adjust other known risk factors of AF recurrence and to explore the association between weight control and AF recurrence after catheter ablation. Results: There were 54 patients in weight controlled group and 279 patients in weight uncontrolled group. There were no significant differences in age, gender, education level, left atrial size and history of hypertension between the two groups (all P>0.05). The proportion of patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers was higher in the weight controlled group (50.0%(27/54) vs. 34.8%(97/279), P=0.034). However, there was no significant difference in the proportion of patients with obesity (33.3% (18/54) vs. 29.7% (83/279)), paroxysmal AF (59.3% (32/54) vs. 56.6% (158/279)) and AF duration less than 5 years (76.9% (40/52) vs. 65.4% (178/272)) between the weight controlled group and the uncontrolled group. During 1-year follow-up after ablation, the recurrence rate of AF was significantly lower in the weight controlled group than that in the weight uncontrolled group (14.8% (8/54) vs. 32.6%(91/279), P=0.009). Multivariable logistic regression analysis shows that weight control is independently associated with a lower postoperative AF recurrence rate (OR=0.40, 95%CI 0.18-0.90, P=0.026). Conclusion: Weight control is strongly associated with a lower AF recurrence rate after catheter ablation in overweight and obese patients.

InAs/GaAs quantum dot semiconductor saturable absorber for controllable dual-wavelength passively Q-switched fiber laser

We experimentally demonstrate the first use of 1550-nm InAs/GaAs quantum dot semiconductor saturable absorber mirror (QD-SESAM) in the dual-wavelength passively Q-switched (QS) erbium doped fiber (EDF) laser. The dual-wavelength QS lasing was obtained at a pump threshold of 180 mW with the average output power of 2.2 mW and the spacing between the two lasing wavelengths is 14 nm. A large absorption ranging from 1520 to 1590 nm has been realized when no substrate rotation was employed during the molecular beam epitaxy growth of the QD-SESAM indicating the potential to generate a 60 nm spacing of the dual-wavelength QS lasing peaks by changing the positions in the QD-SESAM and replacing EDF by co-doped fiber as gain medium. These results have provided a new opportunity towards achieving the stable and wide wavelength-tunable dual-modes fiber lasers.

[Application of direct antiviral drugs in special patients with HCV infection]

Patients with HCV infection can develop decompensated cirrhosis, hepatocellular carcinoma (HCC), even liver failure. As a result, efficient antiviral treatment is very essential to prevent HCV-related disease progression. Newly developed direct-acting antiviral agents (DAAs) have shown safety profile, favorable tolerability, and relatively short duration, which provide an opportunity to expand the number of patients who can be treated for HCV infection. There is a need for further clinical observation and summaries for DAAs in a real world. In the era of DAAs, special patients with HCV infection still get lots of attention from doctors. This review aims at the application of DAAs in patients with HCV infection, combined with chronic kidney diseases, hepatocellular carcinoma, HBV/HCV co-infection, HIV/HCV co-infection, post liver transplantation, pregnancy, children, lymphoma and retreatment.

Abstract P6-02-14: Not presented

This abstract was not presented at the conference.

Citation Format: Xing W, Li Q, Sun G, Cao R, Chen B, Jiang C, Ma L, Wang K. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-14.

Abstract P2-01-25: Not presented

This abstract was not presented at the conference.

Citation Format: Xing W, Li Q, Cao R, Sun G, Jiang C. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-01-25.

Fast distributed dynamic strain sensing using a modified gain-profile tracing technique

Gain-profile tracing (GPT) is a useful strategy of distributed sensing in BOTDA technique for achieving high spatial resolution, which has not been used for the dynamic strain measurement previously. In this paper, we propose a modified gain-profile tracing (MGPT) technique for fast dynamic strain measurement while maintaining the advantage of high spatial resolution. This technique is based on a modified pump pulse modulation scheme and the slope-assisted demodulation method. The time consumption using MGPT technique for a single pump pulse measurement of dynamic strain is less by 25% than the conventional GPT technique. The spatial resolution of our BOTDA system using MGPT technique is 50cm and maximal frequency of dynamic strain detection could be up to 53.5 Hz for 248m sensing length. In the experiments, we measure two vibration events spacing 50 cm with the frequency of 14.0 Hz and 17.0 Hz in a 248 m single-mode fiber. The proposed method is a potential real-time dynamic alternative for distributed structural health monitoring.

High-transmission polarization-dependent active plasmonic color filters

Plasmonic color filters, exhibiting great promise as an alternative for existing colorant-based filters, often only output one fixed color. Developing active color filters with controllable color output will lead to more compact color filter-based devices. In this paper, we present an approach to achieve active color filtering with a polarization-dependent plasmonic structural color filter, which comprises arrays of asymmetric cross-shaped nanoapertures in an ultrathin film of silver. A systematical study for aperture size, array period, and the thickness of silver film dependences of color filter properties is carried out, and strategies for polarization-dependent color filter designing are generated. A polarization-dependent and high tunability of color can be achieved by selecting the appropriate nanostructure parameters, which imply many potential applications.

New Optical Manipulation of Relativistic Vortex Cutter

A new relativistic vortex cutter driven by the Laguerre-Gaussian (LG) mode is carried out for the first time in three-dimensional particle-in-cell simulations. Studies show that the electric fields periodically concentrate and emanate within every laser wavelength for the reflected circularly polarized LG_{p}^{l} (p=0, l=1, σ_{z}=-1) laser, which works just like a vortex cutter, resulting in a relativistic ultrashort collimated electron cluster with a constant period in space. A single particle model is given and verifies that the cluster formation has a close relation with the parameters of orbital angular momentum (l) and spin angular momentum (σ_{z}). Such a relativistic vortex cutter potentially can be applied for the accelerator, generating high-flux particle and coherent radiation sources, and so on.

Effect of the acrosome reaction on the efficiency of sperm-mediated DNA transfer

Sperm-mediated gene transfer (SMGT) is based on the ability of spermatozoa to bind exoge- nous DNA and transfer it into oocytes by fertilization. However, SMGT is still undergoing opti- mization to improve its efficiency to produce transgenic animals. The acrosome reaction is neces- sary for spermatozoa to carry the exogenous DNA into oocytes. In this study, the effect of the acrosome reaction on the efficiency of spermatozoa carrying exogenous DNA was evalua- ted. The results showed that the efficiency of the acrosome reaction was significantly higher (p⟨0.05) after incubation with 50 μmol/L progesterone compared to incubation without proges- terone. It was significantly higher (p⟨0.05) in the 20, 40, and 60 min of progesterone treatment groups than in the 0 min treatment group. The spermatozoa were further incubated with cyanine dye Cy5 labeled DNA (Cy5-DNA) for 30 min at 37°C, and positive fluorescence signals were detected after the acrosome reaction was induced by progesterone at concentrations of 0 and 50 μmol/L for 40 min. The percentage of positive Cy5-DNA signals in spermatozoa was 96.61±2.06% and 97.51±2.03% following exposure to 0 and 50 μmol/L progesterone, respective- ly. The percentage of partial spermatozoa heads observed following combination with Cy5-DNA was 39.73±3.03% and 56.88±3.12% following exposure to 0 and 50 μmol/L progesterone, respec- tively. The ratio of positively stained spermatozoa combined with exogenous DNA showed no reduction after the acrosome reaction. These results suggest that the acrosome reaction might not be the key factor affecting the efficiency of SMGT.

Motion induced phase error reduction using a Hilbert transform

Object motion can introduce phase error and thus measurement error for phase-shifting profilometry. This paper proposes a generic motion error compensation method based on our finding that the dominant motion-introduced phase error doubles the frequency of the projected fringe frequency, and the Hilbert transform shifts the phase of a fringe pattern by π/2. We apply a Hilbert transform to phase-shifted fringe patterns to generate another set of fringe patterns, calculate one phase map using the original fringe patterns and another phase map using Hilbert transformed fringe patterns, and then use the average of these two phase maps for three-dimensional reconstruction. Both simulation and experiments demonstrated that the proposed method can substantially reduce motion-introduced measurement error.