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With development of recommendation systems, they are faced with more and more challenges. In order to relieve problems existing in commodity selection by users of different preferences from different regions, personalized recommendation based on location information has emerged. Nowadays most recommendation systems based on location information neglect the fact that users’ preference will change with time. To solve the above problem, geographic location and time factor of users are effectively combined in this paper, and a personalized recommendation algorithm TLPR combining time and location information is proposed. This algorithm determines the users’ geographic location according to postcode information of the users, uses pyramid quadtree model to distribute users into nodes at each layer in the pyramid, utilizes collaborative filtering algorithm for local recommendation in each node, introduces a time function to regulate time-dependent change of user interests when calculating user similarity at each node and finally realizes a comprehensive recommendation by distributing a weight for recommendation result at each layer in the pyramid quadtree. A comparative experience is carried out for recommendation performance of this algorithm on MovieLens dataset, and experimental results indicate that this algorithm is of better recommendation effect

Raptors are getting more attention from researchers because of their excellent flight abilities. And the excellent wing morphing ability is critical for raptors to achieve high maneuvering flight, which can be a good bionic inspiration for unmanned aerial vehicles (UAV) design. However, morphing wing motions of Falco peregrinus with multi postures cannot be consulted since such a motion database was nonexistent. This study aimed to provide data reference for future research in wing morphing kinetics. We used the computed tomography (CT) approach to obtain nine critical postures of the Falco peregrinus wing skeleton, followed with motion analysis of each joint and bone. Based on the obtained motion database, a six-bar kinematic model was proposed to regenerate wing motions with a high fidelity.

Exploiting the solid-state drawing (SSD) process toward polymer materials for medical implant devices is of significance to simultaneously improve the mechanical property and biocompatibility. Herein, for the first time, the bionic implants with a microvalley surface of oriented long chain branching PLA (b-PLA) was fabricated by a feasible SSD process. The as-obtained b-PLAs could not only show a high tensile strength (278.1 MPa) and modulus (4.32 GPa) but also bear a superior protein adsorption as high as 622 ng/cm2. Such exceptional mechanical properties and biocompatibility could be ascribed to the SSD process-induced highly orientation degree and the morphology of parallel grooves within ridges structures, resulting in the greatly enhanced crystallinity and surface hydrophobicity as well as a biocompatible vascular endothelial microstructure for cell to adhesion and growth and thus an improved proliferation, differentiation, and activity of osteoblasts with spindle-shaped and spread morphology on surface of the b-PLAs. These findings may pave the way for designing the novel biomaterials for vascular stent or tissue engineering devices by the SSD process.

Achieving better anatomic restoration and decreasing the associated complications are necessary for material repair of pelvic floor dysfunction (PFD). This study was aimed to investigate host response to tissue-engineered repair material (TERM) in rat models by comparing different materials and study the changes in biomechanical properties over time. TERM was constructed by seeding adipose-derived stem cells (ADSCs) on electrospun poly(L-lactide)-trimethylene carbonate-glycolide (PLTG) terpolymers. The TERM, PLTG, porcine small intestine submucosa mesh (SIS), and polypropylene (PP) (n = 6 / group per time point) were implanted in rats for 7, 30, 60, and 90 days. Hematoxylin-eosin and Masson’s trichrome staining were used to assess the host response, and mechanical testing was used to evaluate the changes in biomechanical properties. In vivo imaging showed that the ADSCs were confined to the abdominal wall and did not migrate to other organs or tissues. The TERM was encapsulated by a thicker layer of connective tissue and was associated with less reduced inflammatory scores compared with PLTG and PP over time. The vascularization of the TERM was greater than that with PP and PLTG over time (p

For metal-insulator-metal (MIM) capacitors applicated in the fields of RF, DRAM, and analog/mixed-signal integrated circuits, a high capacitance density is imperative with the downscaling of the device feature size. In this work, the microwave annealing technique is investigated to enhance the dielectric characteristics of Al2O3/ZrO2/Al2O3 based MIM capacitors. The results show that the permittivity of ZrO2 is increased to 41.9 (~ 40% enhanced) with a microwave annealing at 1400 W for 5 min. The substrate temperature is lower than 400 °C, which is compatible with the back end of line process. The leakage current densities are 1.23 × 10−8 and 1.36 × 10−8 A/cm2 for as-deposited sample and 1400 W sample, respectively, indicating that the leakage property is not deteriorated. The conduction mechanism is confirmed as field-assisted tunneling.

A series of poly(1,3-trimethylene carbonate-b-(L-lactide-ran-glycolide)) (PTLG) with the three-armed PDLA and PLLA stereoblock copolymer (sc-PLA) acting as the nucleating agent was prepared via the solution-casting method. The effects of the incorporation of various amounts of sc-PLA crystallites on the crystallization behavior and mechanical properties of the PTLG matrix were characterized via DSC, WAXD, POM, and mechanical measurements. The results exhibited that the sc-PLA crystallites obviously enhanced the crystallization rate of the PLLA segments in the PTLG matrix. The results from the investigation of non-isothermal crystallization behavior showed that the crystallization process was significantly accelerated with the sc-PLA crystallites, and with an increase in the content of sc-PLA crystallites, the crystallization temperature shifted to 123.5 °C compared to that of the pure PTLG matrix. The results from the isothermal crystallization behavior study showed that the relative degree of crystallinity (Xt) gave a typical S-shape curve and the half-time of crystallization (t0.5) decreased with an increase in the amount of added sc-PLA crystallites. The crystallization accelerating effects mainly depended on the preeminent nucleation ability of the sc-PLA crystallites, which was proven by POM measurement. The mechanical measurement results showed that with the introduction of sc-PLA crystallites, the tensile strength of the blends was remarkably improved from 21.1 to 85.8 MPa. Furthermore, the biocompatibility of PTLG/sc-PLA was evaluated using the CCK-8 assay and live/dead staining. The results indicated that PTLG/sc-PLA presented very low cytotoxicity. Therefore, the low crystallization rate of the PLLA segments in the PTLG matrix can be largely improved by using sc-PLA crystallites as nucleating agents, and PTLG/sc-PLA blends possess good cytocompatibility and are expected to be used as bioresorbable vascular stents in the bio-medical field.

On-chip supercapacitors have attracted considerable attention because of their high power density, long cycling life, and compatibility with integrated circuits. One critical drawback that restrict...

The development of green material possessing with great mechanical properties and biocompatibility has become a primary goal for high-performance biological material applications. Herein, the oriented shish-kebab crystals of stereocomplex poly(lactic acid) (SC-PLA) are first reported to be successfully fabricated through a feasible solid-state drawing (SSD) process to simultaneously enhance the mechanical performance and biocompatibility. The resultant biomaterial exhibits a tensile strength of 373 MPa and elongation about 9%, with elastic modulus about 8.1 GPa. Such an outstanding toughening effect is due to an amalgamation of enhanced crystallinity of epitaxial secondary growth lamellae and orientation degree of the fibrous backbone of the SC-PLA samples, both gradually increasing with the draw ratio of SSD increasing. Uniquely distinguished from the typical biomedical polymer with the smooth surface structure, the as-obtained SC-PLA samples possess a surface morphology of parallel microgrooves within ridge structures, attributing to the highly oriented fibrous backbone structure complemented with regularly arranged epitaxial lamellas. This unique trait well represents the human vascular endothelial microstructure that is desirable for cell adhesion-growth to extend its proliferation, differentiation, and activity on the surface of SC-PLA.

The complications related to the use of mesh implants for pelvic floor disorders are increasing and have attracted the focus of international scrutiny. This study aimed to investigate the host response to the biodegradable tissue engineered repair material (TERM) in a rat abdominal defect model and to study the changes in mechanical properties over time. The adipose-derived stem cells (ADSCs) were seeded on electrospun poly(L-lactide)-trimethylene carbonate-gycolide (PLLA-TMC-GA, PLTG) terpolymers to construct the TERM. In vivo imaging showed that the ADSCs was confined to the abdominal wall and did not migrate to other organs or tissues. The TERM was encapsulated by a thicker layer of connective tissue and was associated with less reduced inflammatory scores compared with PLTG and polypropylene (PP) over time. The vascularization of TERM was greater than that of PP and PLTG over time, and was greater than that of porcine small intestine submucosa graft (SIS) in 90 days. The ultimate tensile strain and Young's modulus of this TERM increased greatly over time. Our results show that this TERM may be an alternative material for pelvic floor disorders with better biocompatibility and biomechanics.

Metal-assisted chemical etching (MACE) is a facile process to produce mesoporous silicon compared with conventional stain etching and electrochemical etching. However, less work focuses on the MACE...

We collected multi‐locus data to test whether hybridization has occurred between a critically endangered waterbird, the Chinese Crested Tern Thalasseus bernsteini, and the Greater Crested Tern Thalasseus bergii. Phylogenetic analysis shows these two tern species are sister species, having diverged

Compared to pure poly(L-lactic acid) (PLLA), PLLA/nano-sized β-tricalcium phosphate (PLLA/nβ-TCP) composites show both superior interfacial compatibility and osteoinductive, and consequently hold great potential for bone defect repair applications. However, their dismal osteointegration limits their further development in bone regeneration, adding the need for tailored modification. In this study, a bioinspired modification approach was proposed to construct gelatinhydroxyapatite (GEL/HAP) coating onto PLLA/nβ-TCP composites by combining chemical grafting with in situ reaction methods. The incorporation of the biomimetic GEL/HAP coating substantially improved MC3T3-E1 cell adhesion, proliferation and osteogenic differentiation, as demonstrated by morphological observation. Cell Counting Kit-8 (CCK-8) assay, alkaline phosphate activity test (ALP), and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Furthermore, GEL/HAP-PLLA/nβ-TCP composites and their control counterparts (i.e., bare PLLA/nβ-TCP) were synchronously implanted into femoral condylar defects of an identical rabbit. Characterizations including microcomputed tomography (micro-CT), histological analysis and the push-out test revealed that the biomimetic coating not only improved osteointegration but also significantly promoted bone regeneration. Overall, for the first time, bioinspired surface modification of the PLLA/nβ-TCP composite with GEL/HAP coating was demonstrated to be an efficient strategy for enhancing the osteointegration and osteogenesis functions of bone implants.

A PLTGA (poly l-lactide, trimethylene carbonate, glycolide) terpolymer possesses great potential for orthopedic applications due to its excellent biocompatibility and controllable biodegradability. However, the unfavorable surface conditions of bare PLTGA such as its poor hydrophilicity and smooth morphology impede its clinical applications, highlighting the need for tailored surface modifications to improve its cytological behavior and osteogenic capacity. We herein develop a facile and effective strategy to deposit a gelatin/hydroxyapatite (GEL/HAP) hybrid coating onto the surface of PLTGA that involves consecutive chemical grafting and in situ reaction steps. Following the surface modification treatment, the resultant PLTGA scaffold with the GEL/HAP coating exhibited drastically improved hydrophilicity (79.1°vs. 48.2° in water contact angle) and increased surface roughness (18.4 vs. 267.9 nm, more than 14-fold, in root-mean-square roughness), respectively. In addition, preosteoblast (MC3T3-E1) cells were seeded onto the bare/modified PLTGA scaffold to evaluate biological performance, including cell adhesion, proliferation, mineralization and osteogenic differentiation. Based on these results, the GEL/HAP hybrid coating can endow the PLTGA terpolymer substrate with enhanced cell adhesion, proliferation and osteogenic functionality. Overall, post-treatment of PLTGA with the GEL/HAP hybrid coating may be a promising methodology in bone regeneration applications.

Producing carbon/transition metal oxide composites is a promising strategy for improving the stability of high energy alkali-ion batteries. However, fracture of the thin carbon layer by enormous volume change of the oxide and sluggish ion transport in the composite lead to premature cell failure. In this study, we show that anodes consisting of an active ZnO nanosheet sandwiched between two layers of porous thick carbon coating can cycle over 1650 times without obvious capacity decay. The outer thick carbon coating with mechanical robustness suppresses the expansion of the inner oxides without cracks, resulting in a stable SEI layer. Its porous structure and conductive nature also facilitate Li+/electron transportation into the inner oxides. The battery containing composite nanosheets shows a fast and high capacity of 330 mA h g−1 at 5000 mA g−1. We notice that a critical thickness ratio of ZnO to the carbon layer may exist, and the carbon layer is prone to fracture in the case of large thickness ratio. The results have important applications in designing carbon/metal oxide composites for high performance anodes of Li-ion batteries.

The Chinese Crested Tern, Thalasseus bernsteini, is one of the most endangered seabird species in the world, with only small breeding populations of around 100 individuals. To profile the genetic properties of this population, we screened 200 short tandem repeat sequences from a de novo assembled genome of the Great Crested Tern, T. bergii, which is the sister species of T. bernsteini. We designed a panel of 12 novel microsatellites, and genotyped nine and 23 individuals of T. bernsteini and T. bergii, respectively. The results showed that T. bernsteini genetic diversity was lower than that of T. bergii, and no inbreeding was detected. There was no sign of recent bottleneck events in the two species, but T. bernsteini showed signals of a post-bottleneck population expansion. Gene flow analysis indicated introgression between the two species, but the magnitude from T. bernsteini to T. bergii was higher than the opposite. This could be explained by Hubb’s principle, which states that there is a propensity of rarer species to reproduce with abundant congeners. Overall, our efforts provide useful genetic tools for conservation genetic studies of T. bernsteini and potentially other crested terns which face several natural and anthropogenic threats. The findings of this study further highlight that introgression may be a neglected factor in species conservation that needs to be seriously considered for conservation management. Availability of data and materials The dataset of all microsatellite are available from the corresponding author upon request.

Synthetic non-absorbable meshes are widely used to augment surgical repair of pelvic organ prolapse (POP) and stress urinary incontinence (SUI), but these meshes are associated with serious complications. This study compares the attachment and extracellular matrix (ECM) production of adipose-derived stem cells (ADSCs) on different biodegradable nanomaterials to develop tissue engineered repair materials. Rat ADSCs were isolated and cultured on electrospun poly-L-lactic acid (PLA) and electrospun poly(L-lactide)-trimethylene carbonate-gycolide (PLTG) terpolymers for 1 and 2 weeks. Samples were tested for cell proliferation (cell counting kit-8), microstructure, and morphology (scanning electron microscopy), production of ECM components (immunostaining for collagen I, collagen III, and elastin) and biomechanical properties (uniaxial tensile methods). The ADSCs showed good attachment and proliferation on both PLA and PLTG scaffolds. The production of collagen I and collagen III on both scaffolds was greater at 14 days than at 7 days and was greater on PLTG scaffolds than on PLA scaffolds, but these differences were not significant. The addition of ADSCs onto scaffolds led to a significant increase in the biomechanical properties of both PLA and PLTG scaffolds compared with unseeded scaffolds. These data support the use of both PLA and PLTG as tissue-engineered repair materials for POP or SUI.

This work aims to evaluate the potential of a bioresorbable composite as material for bone regeneration. Surface-modified calcium carbonate whiskers (CCWs) were prepared by grafting of ethylene glycol (EG) using 1,6-hexamethylene diisocyanate as coupling agent, followed by ring-opening polymerization of l-lactide initiated by the hydroxyl group of EG. The resulting PLLA-EG-g-CCW was used as filler to reinforce a bioresorbable terpolymer, poly(l-lactide-co-trimethylene carbonate-co-glycolide) (PLTG). The mechanical properties and thermal stability of the PLTG/PLLA-EG-g-CCW composites were greatly improved. Compared with neat PLTG, a 39.3% increase in tensile strength and 26.7% increase in elongation at break were obtained for the composite with 2 wt% PLLA-EG-g-CCW filler. This was assigned to the reinforcement effect of evenly dispersed PLLA-EG-g-CCW in the polymeric matrix. In fact, entanglement of PLLA grafts at the surface of PLLA-EG-g-CCW with PLTG chains results in a homogeneous distribution of the filler in the matrix. Thus, the composites are simultaneously strengthened and toughened. The cytocompatibility of the materials was evaluated from cell morphology and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay using L929 mouse fibroblast cell line. The results indicate that the composite presents very low cytotoxicity. Copyright © 2017 John Wiley & Sons, Ltd.

Three arm poly(propylene oxide) block poly( d -lactide) block poly( l -lactide) (PPO-PDLA-PLLA) stereoblock copolymers melted at various melting temperature and recrystallized. The role of crystallization memory effect of stereocomplex structures was demonstrated utilizing in situ FTIR and WAXD. There is a critical temperature (Tcr) for detachment of stereocomplex structures of melt samples. When the melting temperature (Tmelt) is lower than Tcr, crystallization temperature (Tc) of samples decreases with Tmelt increasing. If the Tmelt is higher than Tcr, the samples’ Tc is as a constant temperature. We attribute the decrease in Tc to crystallization memory effect and correlate it with the detachment of stereocomplex structures in melt. When Tm

On-chip supercapacitors have attracted considerable attention because of their high power density, long cycling life, and compatibility with integrated circuits. One critical drawback that restricts their practical application is the low energy density. In this work, low-resistivity mesoporous silicon with a high aspect ratio is prepared by Pt film-assisted chemical etching and utilized as the scaffold of the supercapacitors. Subsequently, low-resistivity (0.0015 Ω·cm) and ultrathin In

A star-shaped poly(D-lactide)-block-poly(L-lactide) (PDLA-PLLA) stereoblock copolymer was introduced into a poly(L-lactide) (PLLA) matrix. The impacts of the PDLA-PLLA copolymer on PLLA melt crystallization, mechanical properties and rheological properties were investigated. The research results indicated that the PDLA-PLLA copolymer could significantly accelerate the crystallization rate of PLLA. The non-isothermal crystallization results showed that the crystallization temperature shifted to a higher temperature with the increase in the addition of the PDLA-PLLA copolymer. The crystallization temperature increased to about 25 °C with the addition of 10 wt% PDLA-PLLA copolymer. The isothermal crystallization results showed that the half-time of crystallization (t0.5) decreased from 10 min to 2.5 min at 120 °C as the PDLA-PLLA copolymer fraction increased from 0 to 10 wt%. Nucleation efficiency (NE) was used to describe the nucleation efficiency of the PDLA-PLLA copolymer. The highest NE of 65% was obtained for PLLA samples with a PDLA-PLLA copolymer content of 10 wt%. As polarized optical microscopy revealed, this accelerating effect resulted from the good nucleation ability of the PDLA-PLLA copolymer. Moreover, dynamic mechanical analysis results indicated that the addition of the PDLA-PLLA copolymer enhanced the storage modulus of PLLA in the glass state. Rheological properties of nucleated PLLA showed the existence of a network structure of a stereocomplex crystallite (sc-crystallite) above 5 wt% addition of the PDLA-PLLA copolymer.

Social attraction techniques have been demonstrated effective in restoring seabird breeding colonies, especially colonies of terns (Subfamily: Sterninae). The Chinese crested tern (Thalasseus bernsteini) is a critically endangered seabird with a global population of about 100 breeding adults and a breeding range restricted to the East China Sea and the Yellow Sea. In order to restore a breeding colony of Chinese crested terns in an archipelago where a former colony had been abandoned, social attraction (decoys and audio playback systems) was deployed on a small, uninhabited island with no history of seabird nesting. The objective was to establish a breeding colony of greater crested terns (T. bergii), a closely-related common species, in the hope that Chinese crested terns would follow. Thousands of greater crested terns and at least 19 Chinese crested terns colonized the island during the first breeding season after deployment of social attraction. After three years of successful breeding, the colony was abruptly abandoned early in the fourth breeding season because of invasive king rat snakes (Elaphe carinata), which consumed all tern eggs. Following removal of all snakes from the colony, terns resumed nesting the subsequent year. Recovery of this critically endangered seabird depends on repeating this process at multiple islands. Careful planning, in conjunction with habitat management, close colony monitoring, and deployment of social attraction, can establish a conservation network of suitable, secure colony sites where most breeding adults can reproduce successfully. This approach can be used to restore a variety of declining seabird species along the Chinese coastline.

The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail. The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video. A shape reconstruction method is proposed to describe wing contours and tail contours during perching. The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner. The wing planform, chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry. A three-jointed arm model is proposed to associate with the 3D wing geometry, while a one-joint arm model is proposed to describe the kinematics of tail. Therefore, a 3D bird model is established. The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model. A quasi-steady aerodynamic model is applied in the aerodynamic predictions, a four-step Adams–Bashforth method is used to calculate the ordinary differential equations, thus a BFGS based optimization method is established to predict the perching motions.

Birds have impressive flying abilities in part because of the remarkable structural aspects of their feathers. It is also interesting that a feather has the ability to reconstitute its structural integrity in a convenient and effective way. To reveal this mechanism, separating and recovering processes of neighboring barbs were observed after stretching a barb of an Aquila chrysaetos. Thereafter, a three-dimensional model of barbs was proposed herein. A connecting force in range of 0.47 N/mm to 1.26 N/mm between distal barbules and proximal barbules was quantified by an experimental approach that combined an in situ stretching device and a strain sensor.

Compared to pure poly(L-lactic acid) (PLLA), PLLA/nano-sized β-tricalcium phosphate (PLLA/nβ-TCP) composites show both superior interfacial compatibility and osteoinductive, and consequently hold great potential for bone defect repair applications. However, their dismal osteointegration limits their further development in bone regeneration, adding the need for tailored modification. In this study, a bioinspired modification approach was proposed to construct gelatinhydroxyapatite (GEL/HAP) coating onto PLLA/nβ-TCP composites by combining chemical grafting with in situ reaction methods. The incorporation of the biomimetic GEL/HAP coating substantially improved MC3T3-E1 cell adhesion, proliferation and osteogenic differentiation, as demonstrated by morphological observation. Cell Counting Kit-8 (CCK-8) assay, alkaline phosphate activity test (ALP), and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Furthermore, GEL/HAP-PLLA/nβ-TCP composites and their control counterparts (i.e., bare PLLA/nβ-TCP) were synchronously implanted into femoral condylar defects of an identical rabbit. Characterizations including microcomputed tomography (micro-CT), histological analysis and the push-out test revealed that the biomimetic coating not only improved osteointegration but also significantly promoted bone regeneration. Overall, for the first time, bioinspired surface modification of the PLLA/nβ-TCP composite with GEL/HAP coating was demonstrated to be an efficient strategy for enhancing the osteointegration and osteogenesis functions of bone implants.

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Effect of Poly(l-lactide)/Poly(d-lactide) (PLLA/PDLA) block length ratio on the crystallization behavior of star-shaped poly(propylene oxide) block poly(d-lactide) block poly (l-lactide) (PPO–PDLA–PLLA) stereoblock copolymers with molecular weights (Mn) ranging from 6.2 × 104 to 1.4 × 105 g mol−1 was investigated. Crystallization behaviors were studied utilizing differential scanning calorimetry (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). Only stereocomplex crystallites formed in isothermal crystallization at 140 to 156°C for all samples. On one hand, the overall crystallization rate decreased as PLLA/PDLA block length ratio increased. As PLLA/PDLA block length ratio increased from 7:7 to 28:7, the value of half time of crystallization (t1/2) delayed form 2.85 to 5.31 min at 140°C. On the other hand, according to the Lauritzen–Hoffman theory, the fold-surface energy (σe) was calculated. σe decreased from 77.7 to 73.3 erg/cm2 with an increase in PLLA/PDLA block length ratio. Correspondingly increase in nucleation density was observed by the polarized optical microscope. Results indicated that the PLLA/PDLA block length ratio had a significant impact on the crystallization behavior of PPO–PDLA–PLLA copolymers. POLYM. ENG. SCI., 2015. © 2015 Society of Plastics Engineers

A series of terpolymers with various compositions were synthesized by ring-opening polymerization of l -lactide (LLA), trimethylene carbonate (TMC) and glycolide (GA), using stannous (II) octoate as initiator. The microstructure–property relationship of the terpolymers was investigated with the aim of evaluating their potential as cardiovascular stent material. The chain microstructure of the PLLA–TMC–GA terpolymers was examined by means of both 1H and 13C nuclear magnetic resonance (NMR) analysis, in comparison with corresponding PLLA–TMC copolymers. The results show that the incorporation of GA moiety instead of TMC moiety leads to shorter average LLA block length. Differential scanning calorimetry (DSC) results show a close relationship between the crystallization behavior and the microstructural sequence. The crystallinity of PLLA-based copolymers mainly depends on the average LLA block length. The mechanical and thermal degradation properties are also affected by both the composition and the chain microstructure, which is of major importance for the development of bioresorbable cardiovascular stent.

Application of degradable organic electronics based on biomaterials, such as polylactic-co-glycolic acid and polylactide (PLA), is severely limited by their low thermal stability. Here, a highly thermally stable organic transistor is demonstrated by applying a three-arm stereocomplex PLA (tascPLA) as dielectric and substrate materials. The resulting flexible transistors are stable up to 200 °C, while devices based on traditional PLA are damaged at 100 °C. Furthermore, charge- trapping effect induced by polar groups of the dielectric is also utilized to significantly enhance the temperature sensitivity of the electronic devices. Skin-like temperature sensor array is successfully demonstrated based on such transistors, which also exhibited good biocompatibility in cytotoxicity measurement. By presenting combined advantages of transparency, flexibility, thermal stability, temperature sensitivity, degradability, and biocompatibility, these organic transistors thus possess a broad applicability such as environment friendly electronics, implantable medical devices, and artificial skin.

Purpose. To evaluate the effectiveness and safety of three biodegradable terpolymers prepared from L-lactide, trimethylene carbonate, and glycolide (PTLGA) as an aid for trabeculectomy compared with the Ologen (OLO).Methods. Trabeculectomy was carried out on rabbits with implantation made from OLO or three PTLGA terpolymers. Intraocular pressure (IOP) was recorded 1, 2, 3, and 6 months postoperatively and bleb evaluations were performed using ultrasound biomicroscopy (UBM) 3 months after surgery, optical coherence tomography (OCT) every month, and transmission electron microscopy (TEM) six months after surgery followed by histological examination 1, 2, 3, and 6 months postoperatively.Result. IOP was significantly reduced in all groups after surgery. There were no significant differences in the IOL between groups at any time after implantation. There was no significant difference between the groups examined by OCT, UBM, and TEM. Exposure of the implant was observed in one eye from the OLO group and one eye in the P1. Subconjunctiva hyperblastosis was observed in one eye from group P3 and two eyes from the OLO group.Conclusions. Subconjunctival implantation of filtering devices made from PTLGA may present a safe and effective additional surgical tool for the treatment of filtering surgery. Fewer complications were observed in the group with P2 implants compared to other groups.