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INTRODUCTION: To evaluate the efficacy and safety of myopia control using a multifocal soft contact lens designed with high peripheral add power in schoolchildren. METHODS: This 1-year multi-center, prospective, randomized, double-blind, controlled study enrolled myopic schoolchildren aged 6-15 years with refractive errors between - 1.0 D and - 10.0 D. Each participant was randomly allocated to wear a daily disposable multifocal soft contact lens as the treatment in one eye and a single-vision soft contact lens as the control in the other eye. The primary endpoints were changes in the cycloplegic spherical equivalent (SE) and axial length at 1 year. RESULTS: Fifty-two of the 59 participants (88.1%) completed the study protocol. The mean change in SE was - 0.73 ± 0.40 D in the treatment group. and - 0.85 ± 0.51 D in the control group (mean difference: - 0.12 ± 0.34 D, p = 0.012). The mean change in axial length was 0.25 ± 0.14 mm in the treatment group, and 0.33 ± 0.17 mm in the control group (mean difference: 0.08 ± 0.10 mm, p < 0.001). The treatment was well tolerated, and no serious adverse events were observed. CONCLUSIONS: Treatment with multifocal soft contact lenses with high peripheral add power was effective in controlling the progression of myopia and axial length elongation in myopic schoolchildren.

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Understanding heat transfer across an interface is essential to a variety of applications, including thermal energy storage systems. Recent studies have shown that introducing a self-assembled monolayer (SAM) can decrease thermal resistance between solid and fluid. However, the effects of the molecular structure of SAM on interfacial thermal resistance (ITR) are still unclear. Using the gold-SAM/PEG system as a model, we performed nonequilibrium molecular dynamics simulations to calculate the ITR between the PEG and gold. We found that increasing the SAM angle value from 100° to 150° could decrease ITR from 140.85 × 10-9 to 113.79 × 10-9 m2 K/W owing to penetration of PEG into SAM chains, which promoted thermal transport across the interface. Moreover, a strong dependence of ITR on bond strength was also observed. When the SAM bond strength increased from 2 to 640 kcal⋅mol-1Å-2, ITR first decreased from 106.88 × 10-9 to 102.69 × 10-9 m2 K/W and then increased to 123.02 × 10-9 m2 K/W until reaching a steady state. The minimum ITR was obtained when the bond strength of SAM was close to that of PEG melt. The matching vibrational spectra facilitated the thermal transport between SAM chains and PEG. This work provides helpful information regarding the optimized design of SAM to enhance interfacial thermal transport.

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It is of great significance to understand the dynamics and risk level of pedestrians at the multi-exit inspection points, since they are the bottlenecks of pedestrian flow leaving public places, such as subway and railway stations. Microscopic simulations were carried out with a cellular automata model to investigate the effects of ticket-checking failure on pedestrian dynamics when passing through the multi-exit inspection points with parallel, convex and concave layouts. It was found that although ticket-checking failure could reduce the passing efficiency, it also lowers the competitive level between pedestrians and enhances passing safety in the range of medium and high pedestrian density. The competitive level decreases when increasing the probability of ticket-checking failure and the corresponding delay. The probability of ticket-checking failure and the corresponding delay have equivalent effects on passing efficiency and safety, and can be integrated as average delay. A fitted equation was proposed for the dependence of passing efficiency and safety on average delay. With the existence of ticket-checking failure in reality, the concave layout of the multi-exit inspection points gives rise to a much lower competitive level compared with the parallel and convex ones, which would enhance the safety of pedestrians at the exits.

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Experimental characterization of membrane proteins often requires solubilization. A recent approach is to use styrene-maleic acid (SMA) copolymers to isolate membrane proteins in nanometer-sized membrane disks, or so-called SMA lipid particles (SMALPs). The approach has the advantage of allowing direct extraction of proteins, keeping their native lipid environment. Despite the growing popularity of using SMALPs, the molecular mechanism behind the process remains poorly understood. Here, we unravel the molecular details of the nanodisk formation by using coarse-grained molecular dynamics simulations. We show how SMA copolymers bind to the lipid bilayer interface, driven by the hydrophobic effect. Due to the concerted action of multiple adsorbed copolymers, large membrane defects appear, including small, water-filled pores. The copolymers can stabilize the rim of these pores, leading to pore growth and membrane disruption. Although complete solubilization is not seen on the timescale of our simulations, self-assembly experiments show that small nanodisks are the thermodynamically preferred end state. Our findings shed light on the mechanism of SMALP formation and on their molecular structure. This can be an important step toward the design of optimized extraction tools for membrane protein research.

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Laser induced graphitization of polyacrylonitrile-based carbon fibers (CFs) was carried out in a self-designed furnace with a CO2 laser source. The microstructures combined with mechanical properties of the irradiated CFs were measured by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and single filament tensile test, respectively. The results exhibited that the hierarchical structures of CFs showed different responses to the CO2 laser. After laser graphitization, the surface and cross-section structure were characterized by Raman spectroscopy. As the power density increased, a profound increase of graphitization degree happened and obvious skin-core structures were observed. Furthermore, the results of XPS measurements indicated that the irradiated CFs showed more conjugated structures. For crystallite structure, the interlayer spacing of the (002) lattice decreased and the thickness of crystallite increased after graphitization. The size of the (002) lattice parallel to the fiber axis changed slightly. The surface morphology was also investigated by SEM, sheet structures and particles could be observed on the surface of CFs. This was attributed to fast energy addition of laser and the characteristics of the material. Further HRTEM investigation revealed that the sheet structure is multilayered graphene. The Young's modulus of irradiated fibers showed obvious improvements compared to that of as-received ones.

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As environmentally friendly and degradable material, Poly(lactic acid) (PLA) ultrafine fibers are promising candidates for the removal of oil from water. In this work, a self-established needleless melt-electrospinning process was used to produce PLA ultrafine fibers with diameters in the range of 800 nm⁻9 µm. In order to obtain ultrafine fibers, three types of hyperbranched polymers were respectively added into the melt for electrospinning. Effects of amount and molecular weight of the added hyperbranched polymers on average fiber diameter and its distribution, and contact angle were investigated. The prepared PLA ultrafine fibers exhibited superhydrophobicity with the contact angle as high as 156°, making it a potential candidate in marine oil spill recovery. The oil sorption capability of these fibers is as high as 159, 118, and 96 g/g for motor oil, crude oil, and diesel, respectively. Even after seven cycles of reuse, the fiber still maintained about 60% of its initial capacity of sorption. The kinetics of oil sorption in the film agrees very well with the pseudo-second-order kinetic model. This work is expected to promote the mass production and application of biodegradable PLA fibers in the treatment of marine oil spill pollution.

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As a stacked form of ultrathin polymer films, multilayer nanostructures are of great interest in various applications. Coarse-grained molecular dynamics simulations were carried out to understand the behaviors of interfacial diffusion and bonding of multilayer polymer films. We found two obvious stages for the interfacial diffusion of polymers in the multilayer film, and it is 3 times faster in the first stage than in the second one due to the evolution of molecular conformations. The polymers near the interfaces have an in-plane mobility much higher than the out-of-plane one. The strength of interfacial bonding has been characterized by the fast tensile stress-strain curve along the normal direction. It shows multiple yielding points for the multilayer polymer films, which is distinct from the tensile behavior of the bulk. The ultimate tensile stress (UTS) and corresponding separating strain, surprisingly, do not necessarily increase with diffusion time. Because of the dramatic molecular rotation and extension during the first stage of interfacial diffusion, the interlayer interpenetration is nonuniformly distributed in the plane of the interface. Such a nonuniform distribution may be one of the reasons for the decrease of the UTS and separating strain.

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Collembolans are common soil arthropods that may be exposed to insecticidal proteins produced in genetically engineered (GE) plants by ingestion of crop residues or root exudates. In the present study, a dietary exposure assay was validated and used to assess the lethal and sublethal effects of two Bacillus thuringiensis (Bt) insecticidal proteins, Cry1C and Cry2A, on Folsomia candida. Using the insecticidal compounds potassium arsenate (PA), protease inhibitor (E-64), and Galanthus nivalis agglutinin (GNA) mixed into Baker's yeast, we show that the assay used can detect adverse effects on F. candida. Survival and development were significantly reduced when F. candida was fed a diet containing PA, E-64, and GNA at 9, 75, and 100 µg/g diet, respectively, but not when fed a diet containing 300 µg/g Cry1C or 600 µg/g Cry2A. The activities of test antioxidant-, detoxification-, and digestion-related enzymes in F. candida were unaltered by a diet containing 300 µg/g Cry1C or 600 µg/g Cry2A, but were significantly increased by a diet containing 75 µg/g E-64. The results confirm that Cry1C and Cry2A are not toxic to F. candida at concentrations that are much higher than those encountered under field conditions.

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By consuming mulberry leaves covered with pollen from nearby genetically engineered, insect-resistant rice lines producing Cry proteins derived from Bacillus thuringiensis (Bt), larvae of the domestic silkworm, Bombyx mori (Linnaeus) (Lepidoptera: Bombyxidae), could be exposed to insecticidal proteins. Laboratory experiments were conducted to assess the potential effects of Cry1C- or Cry2A-producing transgenic rice (T1C-19, T2A-1) pollen on B. mori fitness. In a short-term assay, B. mori larvae were fed mulberry leaves covered with different densities of pollen from Bt rice lines or their corresponding near isoline (control) for the first 3 d and then were fed mulberry leaves without pollen. No effect was detected on any life table parameter, even at 1800 pollen grains/cm(2) leaf, which is much higher than the mean natural density of rice pollen on leaves of mulberry trees near paddy fields. In a long-term assay, the larvae were fed Bt and control pollen in the same way but for their entire larval stage (approximately 27 d). Bt pollen densities ≥ 150 grains/cm(2) leaf reduced 14-d larval weight, increased larval development time, and reduced adult eclosion rate. ELISA analyses showed that 72.6% of the Cry protein was still detected in the pollen grains excreted with the feces. The low exposure of silkworm larvae to Cry proteins when feeding Bt rice pollen may be the explanation for the relatively low toxicity detected in the current study. Although the results demonstrate that B. mori larvae are sensitive to Cry1C and Cry2A proteins, the exposure levels that harmed the larvae in the current study are far greater than natural exposure levels. We therefore conclude that consumption of Bt rice pollen will pose a low to negligible risk to B. mori.

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Brownian dynamics simulations are carried out to study the aggregation behavior of polymer-grafted nanoparticles (NPs) in good solvents by using the coarse-grained model derived from the all-atom force field, according to the hierarchical modeling strategy, and here PEG-grafted gold nanoparticles (GNPs) were taken as an example. Generally, grafting PEG to the surface of GNPs is to protect them from aggregation in the solution. However, our results reveal that PEG-grafted GNPs may also aggregate when concentration increases. Our simulations indicate that there exists a critical aggregating concentration (CAC), beyond which the PEG-grafted GNPs will aggregate. We further check the effects of grafting density and the length of grafted chains on the aggregation behavior of the grafted GNPs, and find that there exists an optimized length of grafted chain, at which the system has the maximal CAC. Furthermore, the aggregate size of self-assembled mesostructures formed by the grafted GNPs increases with the concentration. Interestingly, it is observed that the aggregation favors to form linear gold nanowires rather than compact gold nanoclusters, and the corresponding mechanism is also addressed. It is expected that this work would provide useful information for the fabrication of metal nanowires and the surface modification of metal nanoparticles.

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Owing to the important roles of chemical gates in biological systems, the biomimetic design of artificial switchable nanodevices has been attracting tremendous interest. Here, we design a cylindrical thermo-sensitive channel, in which nanofliudic transport properties can be controlled by manipulating environmental temperature. The switchable channel is formed by a polystyrene-b-poly(acrylic acid)-b-polystyrene (PS-PAA-PS)-like triblock copolymer brush whose conformation and phase behavior are dependent on temperature. With the increase of temperature, the designed channel exhibits "close→open→close" behavior, which can serve as a kind of excellent switchable nanodevice for nanofluidic controllable transportation.

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PURPOSE: To evaluate the accuracy of corneal surgically induced astigmatism (SIA) estimation when neglecting the posterior corneal surface measurement. METHODS: Fifty right eyes undergoing phacoemulsification were measured with a rotating Scheimpflug camera (Pentacam; Oculus Inc., Wetzlar, Germany) both before and after surgery. Clear corneal incisions with one suture were used in the phacoemulsification surgery. The keratometric corneal SIA (KSIA) was derived using the anterior corneal surface measurement and the keratometric index (1.3375) while neglecting the posterior corneal surface measurement. The Pentacam-derived total corneal SIA (PSIA) was derived by vergence tracing and polar value analysis [KP(135) and KP(180)] of the measurements on both corneal surfaces. RESULTS: The mean arithmetic estimation errors of the KSIA for the PSIA were 0.16 ± 0.32 (-0.52 to 1.14) D for the KP(135), and -0.02 ± 0.30 (-0.75 to 1.29) D for the KP(180). There was a significant difference between the KP(135) components of the KSIA and PSIA. Bivariate analysis revealed a statistically significant difference between the combined means of the KSIA and PSIA. Overall, 24% had either a KP(135) component of the KSIA that differed by > 0.50 D from that of the PSIA or a KP(180) component of the KSIA that differed by > 0.50 D from that of the PSIA. The blurring strength caused by neglecting the posterior corneal measurement was > 0.50 D in 24% of eyes. CONCLUSION: Neglecting the posterior corneal surface measurement may lead to significant deviation in the corneal SIA estimation after phacoemulsification in a proportion of eyes.

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BACKGROUND: To compare the effects of laser photocoagulation combined with subtenon injection of triamcinolone acetonide with photocoagulation alone, for diabetic cystoid macular edema. METHODS: This retrospective comparative study analyzed data for 34 eyes with cystoid macular edema treated with photocoagulation alone (n=17) or combined with triamcinolone (n=17). All patients were followed for 6 months after the procedure. Laser photocoagulation included focal photocoagulation focused on microaneurysms and light grid photocoagulation spread over the edematous retina. Subtenon injection of triamcinolone (20 mg/0.5 cc) was performed in the superior-temporal conjunctiva. RESULTS: In the photocoagulation only group, the pretreatment mean visual acuity (VA) measured by the logarithm of the minimum angle of resolution (LogMAR) was 1.06+/-0.49. The number of laser spots was 34+/-10. The 6 -month post- treatment mean LogMAR was 1.13+/-0.60. In the photocoagulation combined with triamcinolone group, the pretreatment mean LogMAR was 1.31+/-0.49. The number of laser spots was 42+/-14. The 6 -month post- treatment mean LogMAR was 1.26+/-0.49. In the photocoagulation only group, 7 eyes had stable vision (improved, stable or loss of <2 lines) and 8 eyes had vision loss (loss>or=2 lines). In the photocoagulation combined with triamcinolone group, 15 eyes had stable vision and 2 eyes had vision loss. Fewer eyes had vision loss in the photocoagulation combined with triamcinolone group. (chi-square test, p=0.024). CONCLUSIONS: This study, with a follow-up of 6 months, suggests that subtenon injection of triamcinolone combined with macular photocoagulation provides a better chance of stabilizing vision loss in patients with diabetic cystoid macular edema than photocoagulation alone.

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Brownian dynamics simulations were carried out to explore the self-assembly of amphiphilic copolymers composed of a linear hydrophilic head and a hydrophobic tail with different architectures. In order to investigate the effect of architecture of hydrophobic tail on self-assembling behavior, these architectures of linear, branched, starlike, and dendritic tails were selected for comparison, and the branching parameter of the tail was employed to characterize the tail architectures. The critical micelle concentration (cmc), dynamics of aggregation, aggregate distribution, gyration radius distribution, density profiles of micelle, shape anisotropy, and thermal stability were examined for the four typical types of copolymers. The calculated results reveal that the self-assembly of linear tail copolymer has the lowest cmc, and the consequently formed polymeric micelles have narrow dispersion and greater aggregate size, and the micelle is closer to spherical shape. It was found that the cmc is inversely proportional to the branching parameter. Linear tail aggregates in solution to form polymeric micelles with higher physical stability, compared to other architectures of tail. The size of polymeric micelle increases with the increase of the branching parameter of the tail, and it exhibits an exponential relationship with the branching parameter. In addition, the micelles formed from copolymers with a high branching parameter of the tail were found to have higher thermal stability. This work provides useful information on designing self-assembling systems for preparing polymeric micelles applied to drug delivery.

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Rod-coil diblock copolymers are a special kind of molecule containing a rigid rod and a flexible part. We present a systematic study on self-assembly of the rod-coil copolymers in nanoslits using a hybrid density functional theory. The self-assembly of the rod-coil molecule is driven by the bulk concentration, and there exists a critical bulk concentration beyond which the rod-coil molecule self-assembled into ordered lamellar structures in the slit, otherwise it is in a disordered state. By monitoring the effect of the interaction (epsilon(TT)(*)) of molecular tail on the self-assembly, we found that in the nanoslit of H=13sigma, it is at epsilon(TT)(*)=8 rather than epsilon(TT)(*)=10 or epsilon(TT)(*)=12 that the minimal critical bulk concentration occurs. It may be because the strong tail-tail interaction leads to aggregation of the copolymer molecules in bulk phase, and the resulting supramolecular structures are fairly difficult to enter the slit due to the depletion effect. At a fixed slit, the structural evolution of the self-assembled film with the bulk concentration is observed, including trilayer and five-layer lamellar structures, smectic-A, smectic-C, and a mixture of smectic-A and smectic-C liquid crystal phases and so on. We found that the critical bulk concentration, corresponding to the disordered-ordered phase transition, greatly depends on the separation between two walls, and it changes periodically with the increase of the slit width. In addition, it is also found that the molecular flexibility is one of key factors determining the self-assembled structure in the slit, and the critical bulk density increases with the molecular flexibility.

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With Cocos nucifera, Hyophorbe lagenicaulis, Washingtonia filifera, Roystonea regia and Areca catechu as test host plants, this paper studied the effects of their un-spread leaves on the development and fecundity of experimental population of Brontispa longissima. The results showed that the development duration of one generation B. longissima fed on different hosts varied significantly, with the longest (72.8 days) on W. filifera and the shortest (39.8 days) on H. lagenicaulis. The average pupa weight of B. longissima was bigger on H. lagenicaulis than on the other four host plants, and the female B. longissima had the highest fecundity (157.6 ova) on W. filifera while the lowest one (65.2 ova) on A. catechu. The longevity of B. longissima adults fed on H. lagenicaulis was 207.52 days, being significantly longer than that on the other host plants. The trend index of experimental population of B. longissima fed on the five host plants was 53.57, 54.98, 48.56, 20.46 and 11.54, respectively.

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Dendrimers are of interest in a number of applications and theoretical studies due to their interesting and complex architectures. We use a hybrid approach to investigate the microstructure of hard dendrimers and self-assembly of diblock dendrimers confined between two hard walls. In the hybrid approach, a single-chain Monte Carlo simulation is used to evaluate the ideal-gas contribution of the Helmholtz energy and a density functional theory is employed to calculate the excess Helmholtz energy. In our calculations, a coarse-grained model is used to represent the dendrimers of generations 1-4. The effects of generation and bulk packing fraction on the microscopic properties of the hard dendrimers are explored. With the increase of generations, the complexity of the dendritic architecture increases. Accordingly, the depletion effect becomes stronger with the generation at etabulk = 0.1. Furthermore, it is found that the more complex the molecular architecture and the higher the molecular stiffness, the smaller is the partitioning coefficient of confined dendrimers. In addition, we also investigate the effects of the width of the slit and the interaction (epsilon*AA) between hydrophilic segments on the self-assembly of diblock dendrimers in the slit. With the increase of epsilon*AA, we observe that the curves of average packing fraction of the dendrimers in the slit exist an abrupt jump, which corresponds to the first-order phase transition from a disordered state to a lamellar ordered structure. In the slit of H = 11sigma, it is at epsilon*AA = 8 rather than epsilon*AA = 10 or epsilon*AA = 12 that the minimum critical bulk packing fraction appears. This observation is distinctively different from the case of self-assembly of rod-like molecules in the slit, where the critical bulk concentration increases with the decrease of the head-head interaction linearly.

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BACKGROUND: To evaluate the surgical results of patients with persistent fetal vasculature (PFV), also known as persistent hyperplastic primary vitreous (PHPV). METHODS: From 1991 to 2001, a retrospective, noncomparative study of 7 eyes of 7 patients diagnosed with PFV was conducted. In each case, type of anterior and/or posterior PHPV findings, preoperative testing, surgical procedures, and visual outcomes were obtained from the records. Follow-up ranged from 12 to 43 months, with a mean of 15 months. RESULTS: Of the 7 eyes, one (14%) had strictly anterior PFV, 1 (14%) had strictly posterior PFV, and 5 (71%) had components of both anterior and posterior disease. Initial lens aspiration only was performed in 3 (43%) eyes. Initial vitrectomy only was performed in 1 eye (14%). Initial lensectomy and vitrectomy was performed in 3 (42.8%) eyes. The reoperation rate was 43% for membrane reproliferation, glaucoma, vitreous hemorrhage, and retinal detachment. Final best-corrected visual acuity ranged from light perception only to 20/70 on the Snellen chart. CONCLUSIONS: Functional vision is possible in selected patients. However, poor final visual outcome despite adequate anatomic success were noted in this study. The poor outcomes might have been due to patients delaying vitrectomy until retinal detachment developed or that the patients had poor compliance with postoperative ocular rehabilitation.

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