In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: In Crohn's disease (CD), rapid response to anti-tumor necrosis factor therapy improves short- and medium-term outcomes, but the relationship between early remission (ER) and long-term remission is unclear.", 'This exploratory analysis of PRECiSE 3 (NCT00160524) assessed whether ER after initiation of certolizumab pegol predicted long-term remission.', 'Patients enrolled in PRECiSE 3 had completed PRECiSE 1 or 2, two randomized placebo-controlled studies for moderate to severe CD, and received open-label certolizumab pegol 400\u2009mg every 4 weeks for a total treatment duration of ≤7.5 years. Time to loss of remission between patients with and without ER (Harvey-Bradshaw Index ≤4 at or before Week 6 of PRECiSE 1 or 2) was compared by log-rank test of Kaplan-Meier estimates.', 'At baseline, patients with (n\u2009=\u2009242) and without (n\u2009=\u2009148) ER had mean (standard deviation [SD]) durations of CD of 6.8 (6.6) and 7.4 (7.8) years, mean (SD) CD Activity Index scores of 280.3 (53.4) and 311.1 (55.5), with 45.5% and 41.9% of patients having ileocolonic CD, and median C-reactive protein concentrations of 8.0 and 5.0\u2009mg/L, respectively. Median certolizumab pegol plasma concentrations during the first 6 weeks of therapy were similar in both groups. Mean time to loss of remission was significantly longer in patients with versus without ER (2.77 vs. 1.14 years, p\u2009<\u20090.0001).\Question: Does early remission status predict long-term outcomes in patients with Crohn 's disease treated with certolizumab pegol?
[EX A]: In certolizumab pegol-treated patients with CD, ER appears to be an important predictor of long-term clinical remission. Prospective trials are needed to determine whether ER improves other long-term outcomes.

[EX Q]: Context: Nonviral vectors based on polyethylenimine (PEI) usually contain an excess of PEI that is not complexed to DNA. Since unbound PEI contributes to cellular and systemic toxicity, purification of polyplexes from unbound PEI is desirable.', 'Size exclusion chromatography (SEC) was used to purify PEI polyplexes of free PEI. Transfection properties of purified polyplexes and the effect of free PEI on gene delivery were studied in vitro and in vivo after systemic application into mice.', 'SEC did not change the size and zeta-potential of polyplexes. Independent of the amount of PEI used for complex formation, purified PEI polyplexes had the same final PEI nitrogen/DNA phosphate ratio of 2.5. Notably, purified PEI polyplexes demonstrated low cellular and systemic toxicity. High transfection efficiency was achieved with purified polyplexes at high DNA concentrations (8-15 microg/ml). At low DNA concentrations (2-4 microg/ml) gene transfer with purified particles was less efficient than with polyplexes containing free PEI both in vitro and in vivo. Mechanistic studies showed that free PEI partly blocked cellular association of DNA complexes but was essential for the following intracellular gene delivery. Adding free PEI to cells treated with purified particles with a delay of up to 4 h resulted in significantly enhanced transfection efficiency compared with non-purified particles or purified particles without free PEI.\Question: Does purification of polyethylenimine polyplexes highlight the role of free polycations in gene transfer?
[EX A]: This study presents an efficient method to remove free PEI from PEI polyplexes by SEC. Our results from transfection experiments demonstrate that free PEI substantially contributes to efficient gene expression but also mediates toxic effects in a dose-dependent manner. Purified polyplexes without free PEI have to be applied at increased concentrations to achieve high transfection levels, but exhibit a greatly improved toxicity profile.

[EX Q]: Context: Microbial leakage and colonization between implants and their abutments may cause inflammatory reactions in the peri-implant tissues. This study evaluated microbial leakage at the implant-abutment interface with a new in vitro model.', 'Bacterial leakage was tested during dynamic loading in a 2-axis chewing simulator. The authors theorized that dynamic loading would decrease the stability of the implant-abutment connections and thereby lead to bacterial penetration along the gap. Five different implant systems with 8 standard implant-abutment combinations for single molar crowns were tested. The internal aspects of the implants were inoculated with a bacterial suspension and connected to the superstructure with the recommended torque. The specimens were immersed in a nutrient solution and loaded with 1,200,000 cycles of 120 N in the chewing simulator.', 'Statistically significant differences (P < or = .05) between implant systems with respect to number of chewing cycles until bacterial penetration were found.\Question: Do in vitro evaluation of bacterial leakage along the implant-abutment interface of different implant systems?
[EX A]:
The degree of penetration in a specific implant system presumably is a multifactorial condition dependent on the precision of fit between the implant and the abutment, the degree of micromovement between the components, and the torque forces used to connect them.