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  • Kring Clemmensen posted an update 1 month ago

    A mutant library of the key amino acid residue site E387 in γ-glutamyltranspeptidase was constructed to screen the mutant enzymes with significantly improved thermal stability (E387Q). The reaction temperature of the mutant enzyme (E387Q) was 10℃ higher than that of the parent enzyme. Ultrasound-assisted synthesis of L-theanine by γ-glutamyltranspeptidase was investigated. The effects of ultrasonic power, reaction pH and substrate concentration on the enzymatic synthesis of L-theanine were studied by the response surface method. The results showed that the optimal process conditions are ultrasonic power of 100 W, reaction pH of 9, substrate L-glutamine concentration of 120 mmol/L, reaction temperature of 45℃, and L-theanine yield of 89.1%. The yield of L-theanine is 2.61 times higher than that obtained without ultrasound. Ultrasound can significantly promote the synthesis of L-theanine by γ-glutamyltranspeptidase. PURPOSE Practical considerations dictated a change in the craniospinal irradiation (CSI) technique. We report our experience in developing and refining CSI planning and treatment parameters, using a 3-isocenter image-guided intensity-modulated radiation therapy (IG-IMRT) technique. METHODS AND MATERIALS Two institutional values guided development multidisciplinary decision-making and coordinated considerations throughout simulation, planning, and delivery. Patient immobilization and simulation parameters were selected based on treatment delivery system limitations. Commissioning fluence verification maps were acquired to verify dose in regions of overlapping fields. Robustness analysis was performed to assess impact of potential setup errors measured through IGRT verification. Treatment considerations included order of isocenter imaging and treatment and respective IGRT frequency, modality, and image registration thresholds. check details RESULTS Overall film measurements were within 3% of planned dose, confirmed by phantom composite measurements showing all points were within 97% of planned dose. Setup sensitivity analysis suggested a 3-mm setup tolerance was sufficient to ensure confidence in the delivered plan. As the most critical organs at risk were in the superior isocenter, the daily isocenter treatment order was confirmed as superior, middle, and inferior. Daily cone beam computed tomography guidance was chosen for all isocenters (3° rotational threshold). Except for the superior/inferior direction of the middle and inferior isocenters, which were adjusted to 3 mm based on sensitivity analysis, a 1-mm translational threshold was used. CONCLUSIONS An IG-IMRT CSI technique has been developed and implemented in our institution through a multidisciplinary approach. This process highlights the collaborative, iterative approach used to successfully integrate a new treatment technique in an image-guidance era. OBJECTIVE The oncologic efficacy of minimally invasive thymectomy for thymoma is not well characterized. We compared short-term outcomes and overall survival between open and minimally invasive (video-assisted thoracoscopic and robotic) approaches using the National Cancer Data Base. METHODS Perioperative outcomes and survival of patients who underwent open versus minimally invasive thymectomy for clinical stage I to III thymoma from 2010 to 2014 in the National Cancer Data Base were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis. Predictors of minimally invasive use were evaluated using multivariable logistic regression. Outcomes of surgical approach were evaluated using an intent-to-treat analysis. RESULTS Of the 1223 thymectomies that were evaluated, 317 (26%) were performed minimally invasively (141 video-assisted thoracoscopic and 176 robotic). The minimally invasive group had a shorter median length of stay when compared with the open group (3 [2-4] days vs 4 [3-6] days, P  less then  .001). In a propensity score-matched analysis of 185 open and 185 minimally invasive (video-assisted thoracoscopic + robotic) thymectomy, the minimally invasive group continued to have a shorter median length of stay (3 vs 4 days, P  less then  .01) but did not have significant differences in margin positivity (P = .84), 30-day readmission (P = .28), 30-day mortality (P = .60), and 5-year survival (89.4% vs 81.6%, P = .20) when compared with the open group. CONCLUSIONS In this national analysis, minimally invasive thymectomy was associated with shorter length of stay and was not associated with increased margin positivity, perioperative mortality, 30-day readmission rate, or reduced overall survival when compared with open thymectomy. The field of public health is replete with mathematical models and numerical targets. In the case of disease eliminations, modelled projections and targets play a key role in evidencing elimination futures and in shaping actions in relation to these. Drawing on ideas within science and technology studies, we take hepatitis C elimination as a case for reflecting on how to think with mathematical models and numerical targets as ‘performative actors’ in evidence-making. We focus specifically on the emergence of ‘treatment-as-prevention’ as a means to trace the social and material effects that models and targets make, including beyond science. We also focus on how enumerations are made locally in their methods and events of production. We trace the work that models and targets do in relation to three analytical themes governing; affecting; and enacting. This allows us to situate models and targets as technologies of governance in the constitution of health, which affect and are affected by their material relations, including in relation to matters-of-concern which extend beyond calculus. By emphasising models and targets as enactments, we draw attention to how these devices give life to new enumerated entities, which detach from their calculative origins and take flight in new ways. We make this analysis for two reasons first, as a call to bring the social and enumeration sciences closer together to speculate on how we might think with models and targets differently and more carefully; and second, to encourage an approach to science which treats evidencing-making interventions, such as models and targets, as performative and political. V.