MOMENTUM: Microbial Optimization via Metabolic Network Minimization

We report a high-throughput metabolic engineering platform enabling the rapid optimization of microbial production strains. The platform, which bridges a gap between current in vivo and in vitro bio-production approaches, relies on dynamic minimization of the active metabolic network and is implemented in the context of standardized 2-stage bio-processes. Dynamic metabolic network minimization is accomplished using combinations of CRISPR interference and controlled proteolysis to reduce the activity of multiple enzymes in essential central metabolism. This approach not only results in a design space with greatly reduced complexity, but also in increased metabolic fluxes and production rates as well as in strains which are robust to environmental conditions. Robustness leads to predictable scalability from high-throughput µL-scale screens, to fully instrumented L-scale bioreactors. Predictive high-throughput approaches are critical for metabolic engineering programs to truly take advantage of the rapidly increasing throughput and decreasing costs of synthetic biology. We have not only demonstrated proof of principle for this approach in two common industrial microbes: E. coli and S. cerevisiae, but also have validated this approach with the rapid optimization of E. coli strains producing two important industrial chemicals: alanine and mevalonic acid, at commercially meaningful rates, titers (147 g/L and 97 g/L, respectively), and yields.1 References: Ye, Z., Burg, J.M., Poplyk, M.R., Moreb, E.A., Trahan, A.D., Rodrigiuez, D.L., Sheikh, W., Kelly, G.M., Luo, M.L., Beisel C.L., and Lynch, M.D. (2017) MOMENTuM: Microbial Optimization via MEtabolic NeTwork Minimization., Nature Biotechnology in review

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Mathematical Programming Model on Joint and Recovery of Paper Scrap

The joint and recovery of paper scrap was an optimal matching issue. The automatic restoration technology for the broken document was designed according to different cutting ways of the paper shredder. As the fragment data was an one-side print file, a nonlinear programming model with no constraint conditions was established for the straight-cutting broken paper scrap from a given print file of the same page, and the nonlinear programming model with restraint programming model was established for the broken scrap with straight cut and cross cut. For the paper scrap data from a one-page print file in English printed on both sides, the joint was accomplished by the ant colony algorithm

Spray combustion characteristics of a gas-liquid pintle injector with variable swirl intensities

The present paper experimentally verified and computationally explained an improved design concept of the spray combustion of a gas-liquid pintle injector with variable swirl intensities. By pintle injector, we mean a promising injector for the throttleable engines with variable thrust capacities, which features the moveable pintle continuously controlling the mass flow rates of fuel and oxidizer where the radial and axial flows encounter to form a spray cone and spray atomization. First, the cold flow test was conducted to study the swirl effects on the spray angle, followed by the combustion test to study the total pressure and the specific impulse under different swirl intensities. The results show that the swirl enhances the combustion performance by increasing the total pressure and specific impulse. Second, the swirl-assisted spray was numerically simulated based on a validated volume-of-fluid method to explain the experimental findings. The diameter distribution and spatial distribution of dispersed droplets were analyzed by the Sauter mean diameter (SMD) and the Voronoi tessellation, respectively. The results show that the swirl significantly promotes the breakup of liquid jet or film, producing smaller SMDs and a more uniform spatial distribution of dispersed droplets. The consolidated correlation between the non-reacting spray characteristics and the combustion performance suggests that the proposed methodology can be used to fast prescreen pintle injector designs

In Vitro Nanobody Library Construction by Using Gene Designated-Region Pan-Editing Technology

Camelid single-domain antibody fragments (nanobodies) are an emerging force in therapeutic biopharmaceuticals and clinical diagnostic reagents in recent years. Nearly all nanobodies available to date have been obtained by animal immunization, a bottleneck restricting the large-scale application of nanobodies. In this study, we developed three kinds of gene designated-region pan-editing (GDP) technologies to introduce multiple mutations in complementarity-determining regions (CDRs) of nanobodies in vitro. Including the integration of G-quadruplex fragments in CDRs, which induces the spontaneous multiple mutations in CDRs; however, these mutant sequences are highly similar, resulting in a lack of sequences diversity in the CDRs. We also used CDR-targeting traditional gRNA-guided base-editors, which effectively diversify the CDRs. And most importantly, we developed the self-assembling gRNAs, which are generated by reprogrammed tracrRNA hijacking of endogenous mRNAs as crRNAs. Using base-editors guided by self-assembling gRNAs, we can realize the iteratively diversify the CDRs. And we believe the last GDP technology is highly promising in immunization-free nanobody library construction, and the full development of this novel nanobody discovery platform can realize the synthetic evolution of nanobodies in vitro

Higher-order topological states in thermal diffusion

Unlike conventional topological materials that carry topological states at their boundaries, higher-order topological materials are able to support topological states at boundaries of boundaries, such as corners and hinges. While band topology has been recently extended into thermal diffusion for thermal metamaterials, its realization is limited to a one-dimensional (1D) thermal lattice, lacking access to the higher-order topology. In this work, we report on the experimental realization of a higher-order thermal topological insulator in a generalized two-dimensional (2D) diffusion lattice. The topological corner states for thermal diffusion are observed in the bandgap of diffusion rate of the bulk, as a consequence of the anti-Hermitian nature of the diffusion Hamiltonian. The topological protection of these thermal corner states is demonstrated with the stability of their diffusion profile in the presence of amorphous deformation. Our work constitutes the first realization of higher-order topology in a purely diffusive systems, and opens the door for future thermal management with topological protection beyond 1D geometries.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThis work was sponsored by the Singapore Ministry of Education (No. MOE2018-T2-2-189 (S) and MOE2019-T2-2-085), A*STAR SERC AME program „Nanoantenna Spatial Light Modulator for Next - Generation Display Technologies (NSLM)‟ under the grant No. A18A7b0058, A*STAR AME IRG Grant No. A20E5c0095, the National Research Foundation Singapore Competitive Research Program under the grant No. NRF-CRP22-2019-0006 and NRF-CRP23-2019-0007. The work at Southeast University was sponsored by National Key R & D Program of China (Grant No. 2022YFA1404903) and the National Natural Science Foundation of China (Grant No. 62288101)

Targeting adaptor protein SLP76 of RAGE as a therapeutic approach for lethal sepsis

RAGE signalling is implicated in sepsis. Here the authors use T7 phage display to identify SLP76 as a binding partner for the cytosolic tail of RAGE and provide a reagent that can block this interaction and protect mice from sepsis in a caecal ligation and puncture model