Artificial self‐assembly systems typically exhibit limited capability in creating nature‐inspired complex materials with advanced functionalities. Here, an effective co‐assembly strategy is ...demonstrated for the facile creation of complex photonic structures with intriguing light reflections. Two different lipophilic and amphiphilic bottlebrush block copolymers (BCPs) are placed within shrinking droplets to enable a cooperative working mechanism of microphase segregation and organized spontaneous emulsification, respectively. Layer assemblies of the lipophilic BCP and uniform water nanodroplets stabilized by the bottlebrush surfactant are both generated, and co‐assembled into a bridged lamellar structure with the alternating arrangement of layers and closely packed nanodroplet arrays. Janus microspheres with diverse dual optical characteristics are successfully fabricated, and reflected wavelengths of light are highly tunable simply by changing the formulation or molecular weight of BCP.
A new complex photonic structure, bridged lamellae, with intriguing color reflections is successfully fabricated through well‐controlled co‐assembly of lipophilic and amphiphilic bottlebrush block copolymers within shrinking droplets. Self‐assembled Janus microspheres with precisely tunable dual light reflections are facilely obtained through the manipulation of the co‐assembly at a molecular level.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Photonic materials with angular‐independent structural color are highly desirable because they offer the broad viewing angles required for application as colorants in paints, cosmetics, textiles, or ...displays. However, they are challenging to fabricate as they require isotropic nanoscale architectures with only short‐range correlation. Here, porous microparticles with such a structure are produced in a single, scalable step from an amphiphilic bottlebrush block copolymer. This is achieved by exploiting a novel “controlled micellization” self‐assembly mechanism within an emulsified toluene‐in‐water droplet. By restricting water permeation through the droplet interface, the size of the pores can be precisely addressed, resulting in structurally colored pigments. Furthermore, the reflected color can be tuned to reflect across the full visible spectrum using only a single polymer (Mn = 290 kDa) by altering the initial emulsification conditions. Such “photonic pigments” have several key advantages over their crystalline analogues, as they provide isotropic structural coloration that suppresses iridescence and improves color purity without the need for either refractive index matching or the inclusion of a broadband absorber.
Photonic microparticles are produced in a single, scalable step from an amphiphilic, low‐molecular‐weight bottlebrush block copolymer. By controlling the formation, swelling, and subsequent self‐assembly of giant reverse micelles within an emulsified toluene‐in‐water droplet, a highly porous structure with short‐range correlation is produced. This isotropic inverse photonic architecture allows for a full spectrum of angular‐independent, structurally colored pigments.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background
Anastomotic leakage (AL) is a serious complication in laparoscopic rectal cancer surgery, and risk factors for AL are not well defined. Herein, we conducted a systematic review to quantify ...the clinicopathologic factors predictive for AL in patients who underwent laparoscopic anterior resection (LAR) for rectal cancer.
Methods
A systematic search of electronic databases (PubMed, Embase, Cochrane CENTRAL, Scopus Database, and Wanfang Database) for studies published until August 2014 was performed. Cohort, case–control studies, and randomized controlled trials that examined clinical risk factors for AL were included.
Results
Fourteen studies (seven prospective and seven retrospective studies) involving 4580 patients met final inclusion criteria. From the pooled analyses, five demographic factors were found to be significantly associated with the development of AL, including male gender (OR 2.04, 95 % CI 1.50–2.77), BMI ≥25 kg/m
2
(OR 1.46, 95 % CI 1.00–2.14), ASA score >2 (OR 1.74, 95 % CI 1.04–2.93,
P
= 0.04), tumor size >5 cm (OR 1.63, 95 % CI 1.01–2.64,
P
= 0.05), and preoperative chemotherapy (OR 1.67, 95 % CI 1.10–2.55,
P
= 0.02). Four operative factors were significantly associated with increased risk of AL, including longer operative time (95 % CI 1.71–5.77,
P
= 0.0002), number of stapler firings ≥3 (OR 0.17, 95 % CI 0.07–0.41,
P
< 0.001), intra-operative transfusions/blood loss >100 mL (OR 3.79, 95 % CI 2.48–5.49,
P
< 0.001), and anastomosis level within 5 cm from the anal verge (OR 9.63, 95 % CI 3.05–30.43,
P
= 0.0001), while pelvic drain (OR 0.43, 95 % CI 0.19–0.94,
P
= 0.04) was significantly associated with a lower AL rate.
Conclusion
Our analysis identified several clinicopathologic factors associated with AL in patients who underwent LAR. The knowledge of these risk factors may influence treatment- and procedure-related decisions and possibly reduce the leakage rate.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper surveys the extant research in the field of ocean container transport. A wide range of issues is discussed including strategic planning, tactical planning and operations management issues, ...which are categorized into six research areas. The relationships between these research areas are discussed and the relevant literature is reviewed. Representative models are selected or modified to provide a flavour of their functions and application context, and used to explain current shipping practices. Future research opportunities bearing in mind the emerging phenomena in the field are discussed. The main purpose is to raise awareness and encourage more research into and application of operations management techniques and tools in container transport chains.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Photonic balls can be facilely obtained through interfacial self‐assembly of amphiphilic bottlebrush block polymers (BBCPs) within a water‐in‐oil‐in‐water (w/o/w) multiple emulsion system, and ...polystyrene (PS) has been employed as the skeleton of the balls showing no responsive properties. Here, the design and synthesis of core‐shell BBCPs are demonstrated with a poly(tert‐butyl acrylate)‐block‐polystyrene (PtBA‐b‐PS) block copolymer as the hydrophobic side chains and poly(ethylene glycol) as the hydrophilic block. Interfacial self‐assembly of the core‐shell BBCPs within shrinking droplets produces porous microspheres with full‐spectrum structural colors through an organized spontaneous emulsification process. The PtBA core wrapped by PS in the skeleton of the balls can be converted into polyacrylic acid (PAA) forming an ionic channel responsive to pH variations. Consequently, the hydrolyzed photonic balls show different colors under different pH conditions dependent on varying degrees of ionization and hydration of the PAA channel. Reflected colors can be verified using an optical spectrometer, providing an effective strategy for precise pH indication.
Photonic porous balls with ionic channels are obtained simply through the interfacial self‐assembly of core‐shell bottlebrush block copolymers within an ordered water‐in‐oil‐in‐water multiple emulsion system. These photonic balls show different color reflections when placed in aqueous environments with varied pH, providing photonic indicators for pH dectection.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Reduction of the 17,18‐double bond in the D‐ring during chlorophyll biosynthesis is catalyzed by the rare, naturally occurring photoenzyme protochlorophyllide oxidoreductase (POR). A conserved ...tyrosine residue has been suggested to donate a proton to C18 of the substrate in the past decades. Taylor and colleagues scrutinized the model with a powerful tool that utilized a modified genetic code to introduce fluorinated tyrosine analogues into POR. The presented results show that the suggested catalytically critical tyrosine is unlikely to participate in the reaction chemistry but is required for substrate binding, and instead, a cysteine residue preceding the lid helix is proposed to have the role of proton donor.
Reduction of the 17,18‐double bond in the D‐ring during chlorophyll biosynthesis is catalyzed by the rare, naturally occurring photoenzyme protochlorophyllide oxidoreductase. Previously, a conserved tyrosine residue had been suggested to donate a proton to C18 of the substrate. Aoife Taylor and colleagues show that the suggested tyrosine is unlikely to participate in the reaction chemistry but is required for substrate binding, and instead, a cysteine residue preceding the lid helix is proposed to be the proton donor.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial ...soil information is urgently needed. This drives the worldwide development of digital soil mapping. In recent years, significant progresses have been made in different aspects of digital soil mapping. The main purpose of this paper is to provide a review for the major progresses of digital soil mapping in the last decade. First, we briefly described the rise of digital soil mapping and outlined important milestones and their influence, and main paradigms in digital soil mapping. Then, we reviewed the progresses in legacy soil data, environmental covariates, soil sampling, predictive models and the applications of digital soil mapping products. Finally, we summarized the main trends and future prospect as revealed by studies up to now. We concluded that although the digital soil mapping is now moving towards mature to meet various demands of soil information, challenges including new theories, methodologies and applications of digital soil mapping, especially for highly heterogeneous and human-affected environments, still exist and need to be addressed in the future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
► Model cargo routing and empty container repositioning at operational level. ► Develop an integer programming model for the joint routing and repositioning problem. ► Propose two solution methods to ...solve the optimisation problem. ► Illustrate the relative merits of two solution methods using case studies.
This paper considers the problem of joint cargo routing and empty container repositioning at the operational level for a shipping network with multiple service routes, multiple deployed vessels and multiple regular voyages. The objective is to minimize the total relevant costs in the planning horizon including: container lifting on/off costs at ports, customer demand backlog costs, the demurrage (or waiting) costs at the transhipment ports for temporarily storing laden containers, the empty container inventory costs at ports, and the empty container transportation costs. The laden container routing from the original port to the destination port is limited with at most three service routes. Two solution methods are proposed to solve the optimization problem. The first is a two-stage shortest-path based integer programming method, which combines a cargo routing algorithm with an integer programming of the dynamic system. The second is a two-stage heuristic-rules based integer programming method, which combines an integer programming of the static system with a heuristic implementation algorithm in dynamic system. The two solution methods are applied to two case studies with 30 different scenarios and compared with a practical policy. The results show that two solution methods perform substantially better than the practical policy. The shortest-path based method is preferable for relatively small-scale problems as it yields slightly better solution than the heuristic-rules based method. However, the heuristic-rules based method has advantages in its applicability to large-scale realistic systems while producing good performance, to which the shortest-path based method may be computationally inapplicable. Moreover, the heuristic-rules based method can also be applied to stochastic situations because its second stage is rule-based and dynamical.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
► We model vessel scheduling problem in liner shipping under port uncertainty. ► We minimize fuel consumption and emission subject to shipping service levels. ► The objective function is convex and ...differentiable under certain conditions. ► The shortest leg should be planned relatively longer time. ► Fuel consumption can be reduced by sacrificing service levels.
We consider the problem of designing an optimal vessel schedule in the liner shipping route to minimize the total expected fuel consumption (and emissions) considering uncertain port times and frequency requirements on the liner schedule. The general optimal scheduling problem is formulated and tackled by simulation-based stochastic approximation methods. For special cases subject to the constraint of 100% service level, we prove the convexity and continuous differentiability of the objective function. Structural properties of the optimal schedule under certain conditions are obtained with useful managerial insights regarding the impact of port uncertainties. Case studies are given to illustrate the results.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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