LC Content Research Articles

Changing the land use from degraded pasture into integrated farming systems enhance soil carbon stocks in the Cerrado biome

Integrated agricultural production systems can increase soil organic carbon stocks over time and contribute to the mitigation of climate change. The present study aimed to evaluate soil carbon stocks, accumulation rates (TOC), total nitrogen (TN), and the quality of soil organic matter (SOM) after the transition of a low-productivity pasture into agrosilvopastoral systems in the Cerrado biome. We evaluated an 11-year-old experiment, and the treatments studied were: Eucalyptus + buffel grass; Eucalyptus + cowpea; Eucalyptus + pigeon pea; eucalyptus + buffel grass + cowpea; Eucalyptus + buffel grass + pigeon pea; Eucalyptus in monoculture (with a 20 × 3 m tree arrangement and no cultivation between rows but with a history of forage and grain crop production); and a low-productivity pasture as additional treatment and reference to the soil condition previously the land-use change. In this study, TOC and TN stocks and accumulation, labile (LC) and non-labile carbon (NLC), and SOM humic fractions were evaluated at 0-10, 10-20, 20-40, and 0-40 cm depth layers. Integrated farming systems have increased TOC and TN, NLC, carbon contents and stocks in SOM chemical fractions in all depths and TOC and TN accumulation of 5.22 Mg ha-1 year-1 and 0.23 Mg ha-1 year-1, respectively, at the 0-40 cm depth layer. The integration of Eucalyptus with legumes or buffel grass increased the LC content in the surface layer of the soil. The transition from low-productivity pasture into integrated farming systems can promote the recovery of SOM and soil quality. Hence, our results suggest that agrosilvopastoral systems can be used as sustainable farming systems in the Cerrado biome.

Polymer-Dispersed Liquid Crystal Films on Flexible Substrates with Excellent Bending Resistance and Spacing Stability

Polymer-dispersed liquid crystals (PDLCs) are very attractive due to their electrically switchable properties. However, current PDLC films still have problems such as high driving voltages, low contrast ratio (CR), and poor bending resistance and spacing stability. To solve these problems, a PDLC film with a system of coexisting polymer spacer columns and polymer network was proposed. First, based on the adhesive systems of IBMA and UV6301, the effects of IBMA concentration and LC content on the morphology of the polymer network and the electro-optical properties of PDLC were investigated, respectively. Then, the effects of the process conditions of mask polymerization such as temperature, time, and UV light intensity on the morphology and electro-optical properties of the polymer spacer columns were systematically investigated. It was found that PDLC films with the coexistence system exhibit both excellent electro-optical properties and outstanding bending resistance and spacing stability. Thus, it provides new practical possibilities for the preparation of high-performance PDLC films used in flexible devices.

E7 nematic liquid crystal encapsulated in a polymeric photonic crystal

This study presents the synthesis and characterization of nano encapsulated liquid crystals in the polymer (nano-ELCP) obtained by the soap-free emulsion polymerization of the system styrene (ST) and acrylic acid (AA) in the presence of the liquid crystal E7 (LC). The obtained emulsion and the photonic crystal film (PC) were characterized by optical microscopy, SEM, DLS, UV–Vis, DSC, TEM, GPC, TGA, and fluorescence spectroscopy to highlight the encapsulation of E7 in the polymer particles and their properties. The DLS and SEM analyses confirmed a narrow polymer particle size distribution and the possibility to form highly arranged PCs, which contain the dispersed LC. The DSC, TEM, and TGA analyses sustain the encapsulation of E7 with an LC content of 11.87 % and 25.19 % (weight %) for ST-AA-E7-1 and ST-AA-E7-2, respectively. An increase in the fluorescence response was demonstrated for the polymer encapsulated LC which can be attributed to PCs that augments the intensity of the nematic crystal fluorescence response, in the absence of external stimuli.

Impacts of a Nano-Laponite Ceramic on Surface Performance, Apatite Mineralization, Cell Response, and Osseointegration of a Polyimide-Based Biocomposite.

IntroductionPolyimide (PI) exhibits good biocompatibility and high mechanical strength, but biological inertness that does not stimulate bone regeneration, while laponite possesses excellent bioactivity.MethodsIn this study, to improve the bioactivity of PI, nano–laponite ceramic (LC)–PI composites (LPCs) were fabricated by melt processing as implantable materials for bone repair.ResultsThe compressive strength, hydrophilicity, and surface roughness of LPCs with 40 w% LC content (LPC40s) were higher than LPC20s, and LPC20s higher than pure PI. In addition, no apatite mineralization occurred on PI, while apatite mineralized on LPCs in simulated body fluid. Compared with LPC20, more apatite deposited on LPC40, indicating good bioactivity. Moreover, the adhesion, proliferation, and alkaline phosphatase activity of rat bone mesenchymal stem cells on LPCs significantly increased with LC content increasing in vitro. Furthermore, the evaluations of animal experiments (micro-CT, histology, and pushout load) revealed that compared with LPC20 and PI, LPC40 significantly enhanced osteogenesis and osseointegration in vivo.DiscussionIncorporation of LC into PI obviously improved not only surface physicochemical properties but also biological properties of LPCs. LPC40 with high LC content displayed good biocompatibility and bioactivity, which markedly promoted osteogenesis and osseointegration. Therefore, with its superior biocompatibility and bioactivity, LPC40 could be an alternative candidate as an implant for orthopedic applications.

Linkages between soil organic carbon fractions and carbon-hydrolyzing enzyme activities across riparian zones in the Three Gorges of China

The effect of flooding on soil enzyme activities and soil organic carbon (SOC) dynamics remains a widely debated topic. Here, we investigated spatial variations in C-hydrolyzing enzyme activities, soil C contents in different fractions [i.e. labile and recalcitrant carbon (LC and RC)] from 6 sites with four different elevations at two soil depths (0–10 cm and 10–30 cm) in riparian zones of the Three Gorges Reservoir, China. At region scales, the SOC, RC contents, and RC/SOC (RIC) generally showed decreasing tendency from the upstream to the downstream. The C-hydrolyzing enzyme activities were higher in the midstream compared to other sites, which did not correspond well with the changing trend of SOC content, but matched with the spatial variation in LC content. At ecosystem scales, the RC and RIC declined with decreased elevations, but the LC showed opposite trend. Whereas, the four C-hydrolyzing enzyme activities and the specific enzyme activities were corresponded well with the changing trend of LC content. Soil C contents and enzyme activities were generally higher in top soil than deep soil across sites and elevation zones. These results reveal that the LC is the tightest factor in regulating C-hydrolyzing enzyme activities, whereas the soil C quality (i.e. RIC) and flooding collectively drive C-hydrolyzing enzyme activities possibly by affecting decomposition rates of SOC in the riparian zones.

Soil labile and recalcitrant carbon and nitrogen dynamics in relation to functional vegetation groups along precipitation gradients in secondary grasslands of South China.

Soil labile and recalcitrant carbon (C) and nitrogen (N) are strongly controlled by plant inputs and climatic conditions. However, the interrelation of labile and recalcitrant pools with changes in plant functional groups (i.e., C3 and C4) along precipitation gradients is not fully understood. Here, we investigated the soil organic C and N (SOC and SON), labile C and N (LC and LN), recalcitrant C and N (RC and RN), and their isotopes (δ13C, and δ15N) in relation to C3 and C4 plant inputs from 20 sites across a 600-km precipitation gradient in secondary grasslands of South China. The SOC content decreased first slightly and then increased along precipitation gradients, largely due to the increase in C4 plant C inputs in the lower precipitation regions. In contrast, the SON content increased with increasing N inputs from C3 plant at higher precipitation regions. The LC and LN contents increased with increasing precipitation, whereas RC and RN did not change with precipitation. The LC and LN were correlated with plant C and N contents, as well as the mean annual precipitation, respectively. Increases in LC and LN stocks were tightly related to enhanced plant C and N inputs influenced by precipitation, suggesting stronger sensitivity of labile pools to both plant functional groups inputs and precipitation compared to the recalcitrant pool. Moreover, the δ13C values in RC declined with precipitation, while the δ15N values of both labile and recalcitrant N increased with increasing precipitation, further revealing that soil labile and recalcitrant C and N pools closely related to the shift in the C3 and C4 plant along precipitation gradients. Overall, our findings indicated that soil labile and recalcitrant fractions should be considered in context of precipitation under which plant inputs takes place in predicting soil C and N dynamics.

A switchable optical diffuser based on a polymer/nematic liquid crystal composite film with transient polymer balls-networks microstructure

ABSTRACTWith the increasing development of multifunction liquid crystal displays (LCDs), multifunction optical diffusers have attracted more attention. In this work, switchable optical diffusers based on the transient polymer balls-networks in polymer/nematic liquid crystal composite films have been prepared and investigated, and the effects of thiol content, curing time, LC content and photo-initiator content on the polymer microstructures and optical properties of optical diffusers are systematically studied. An optical diffuser with the transient polymer balls-networks microstructure has achieved the high transmission (96.42%), high haze (90.49%), excellent optical diffusing ability and wide viewing angle of 150° (from −75° to 75°) on its off state. By the application of electric field of 40.0 voltage, the viewing angle of the optical diffuser turns to be narrower (from −60° to 60°), which gives great applications in tunable viewing angle devices and other electric optical devices.

One-pot in-situ preparation of a lignin-based carbon/ZnO nanocomposite with excellent photocatalytic performance

This work demonstrated a facile one-pot in-situ method to prepare lignin-based carbon/ZnO (LC/ZnO) nanocomposites by using lignin that was extracted from paper pulping waste liquor as the carbon source. The morphological, physical and optical properties of the prepared LC/ZnO nanocomposites was characterized with Scanning electron microscope (SEM), Transmission electron microscopy (TEM), Thermal-gravimetric analysis (TGA), Raman, X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses. The resulting LC/ZnO is composed of highly dispersed ZnO nanoparticles embedded on a lignin-based carbon nanosheet. The typical D and G bonds of carbon materials obviously appeared. The TGA shows that the LC contents could be controlled. The BET surface area of the LC/ZnO was much larger than the BET surface area of the pure ZnO. The prepared LC/ZnO nanocomposites exhibited excellent photocatalytic performance for the degradation of organic dyes. LC/ZnO that contained ∼6.38% lignin-based carbon exhibited an excellent photo-degradation efficiency of methyl orange as high as 98.9% under sunlight irradiation for 30 min, superior to the performance of pure ZnO and other reported ZnO/GRs. The improved photocatalytic performance was attributed to a homogeneous structure and stronger absorption ability for organic dyes. The mechanism exploration experiment showed that h+ was the main active specie. Meanwhile, the photocatalytic electron transfer mechanism was also investigated. In addition, this work demonstrates a green and valuable pathway for the high-value-added utilization of lignin.

Study on the electro-optical properties of polyimide-based polymer-dispersed liquid crystal films

The reflectivity control device, initially developed for attitude control, is utilised to control the solar sail orbit by switching the states between absorption and specular reflection. Actually, the major parts of the device are the polymer-dispersed liquid crystal (PDLC) films. Here, PDLC films based on polyimide (PI) as polymer matrix and a low molecular weight LC can be prepared by the thermally induced phase separation (TIPS) method. The influences of cooling rate and the content of LC on the size and uniformity of LC droplets dispersed in a polymer matrix by a TIPS process were investigated. It was found that a fast cooling rate gave smaller droplet sizes and hence a more uniform distribution as compared to the ones produced under a slow cooling rate. If the LC content was increased, the droplet size would be increased. Furthermore, the effect of LC droplet size on the electro-optical properties of the PI-based PDLC films was discussed, such as transmittance, threshold voltage, driving voltage and contrast ratio (CR).

Phosphorus-containing flame retardant modified layered double hydroxides and their applications on polylactide film with good transparency

Polylactide (PLA)/layered double hydroxide (LDH) films with good flame retardant property and transparency were synthesized by solution exfoliation and film casting method. The organic–inorganic interfacial interaction between PLA and NiAl-LDH was carefully modified by 2-carboxylethyl-phenyl-phosphinic acid (CEPPA) to well solve the dispersion problem of NiAl-LDH nanolayers and get enhanced flame retardancy of PLA composites. The results showed the NiAl-LDH/CEPPA (LC) nanolayers had exfoliated structures and were homogenously dispersed in PLA matrixes. All the PLA/LDH films had good transparency even LC content was up to 10wt%. The PLA/LDH films absorbed the ultraviolet light, which alleviates the embrittlement of PLA films in the using procedure. The flame retardant effect characterized by microscale combustion calorimeter was observed when LC contents increased. The total heat release value of the sample with 10wt% LC decreased to 9.7kJ/g from 12.0kJ/g of virgin PLA.

Influence of the multi-functional epoxy monomers structure on the electro-optical properties and morphology of polymer-dispersed liquid crystal films

Polymer dispersed liquid crystal (PDLC) films were prepared by polymerization-induced phase separation method with nematic LC content as low as 40 wt%, and the electro-optical properties were carefully investigated. To accomplish this, the structure of multi-functional curable epoxy monomers with different composition feed ratios and the weight percentages of the two groups were examined in this study. The combined effects of heat-curable monomers’ structure on the conspicuous morphology of polymer network of PDLC films formed small holes and suitably distributed coin-like networks in both groups A and B, respectively. The detailed characteristics and morphology of polymer network of PDLC films were analyzed by employing liquid crystal device parameter tester, UV-Vis-NIR spectrophotometer and scanning electron microscope. Meanwhile, the enhanced curing temperature effects on the alkyl chain length, short flexible chain length, and rigid chain segment containing epoxy monomers structure on the increasing morphology of polymer network as well as electro-optical properties of PDLC films were also studied. It was found that the LC domain size of the polymer network could be regulated by adjusting the structure and composition ratio of curable epoxy monomers, and then the electro-optics of the PDLC films could be optimized, which is beneficial for decreasing the total LC content in PDLC devices.

Enhanced mechanical properties and blood compatibility of PDMS/liquid crystal cross-linked membrane materials

A novel polydimethylsiloxane/liquid crystal cross-linked membrane (PDMS/LC) was prepared by using PDMS containing vinyl groups and LCs containing unsaturated linkages as matrix materials. Mechanical properties, liquid crystalline performance and blood compatibility of the PDMS/LC cross-linked membrane containing different LC contents and LC groups were investigated, respectively. The results showed that mechanical properties of the membrane increased more significantly than those of pure PDMS membranes. The PDMS/LC cross-linked membrane also possessed better membrane-forming ability, lower hemolysis rate, less platelets adhesion and more favorable anti-coagulant properties. Additionally, mechanical properties and blood compatibility of the membrane can be enhanced simultaneously and obviously due to the introduction of the cholesteric liquid crystals and the application of the preferred cross-linked reaction without byproducts.

Preparation and electro‐optical properties of polymer dispersed liquid crystal films with relatively low liquid crystal content

In this paper, polymer dispersed liquid crystals (PDLC) films with LC content as low as 40 wt% were prepared, and the electro‐optical properties were carefully investigated. To accomplish this, different (meth)acrylate copolymerizaiton monomers have been used. The electro‐optical properties and morphologies of the PDLC films were strongly influenced by the chemical structure of copolymerization monomers (hydroxypropyl methacrylate (HPMA), glycidyl methacrylate, hydroxypropyl acrylate) and their feed ratio. Lower driven voltage and higher contrast ratio were achieved when the PDLC films showed a morphology with suitably LC domain size. At high HPMA content, a thin polymer film was formed on the surface of PDLC samples, which is beneficial to decrease the total LC content in PDLC devices. Copyright © 2013 John Wiley & Sons, Ltd.

Preparation, characterization and cytocompatibility of polyurethane/cellulose based liquid crystal composite membranes

Two types of polyurethane/liquid crystal (PU/LC) composite membranes with different LC contents, namely polyurethane/octyl hydroxypropyl cellulose ester (PU/OPC) and polyurethane/propyl hydroxypropyl cellulose ester (PU/PPC), were prepared and studied. The effects of surface properties on cell compatibility of the membranes were elucidated. PPC tended to assemble to independent phases in the composite membranes, while OPC formed uniformly distributed LC domains. As the introduction of LC, phase separation occurred, and the crystallization of PU was disrupted. The surface of PU/LC composite membranes showed fingerprint texture and two-phase morphology. Hydrophilicity of the two types of composite membranes exhibited a reversal tendency with the increase of LC contents. Cells seeded on the composite membranes presented favorable growth when the content of LC was over 30%, especially on PU/OPC complex. The surface morphology, phase separation between LC and PU as well as the type of LC showed significant effects on the cell behaviors.

A Comparison of Lycopene, Anthocyanins, and Proanthocyanidins Consumption between College Students and their Respective Older Generations Living in the Same Household

Carotenoid (lycopene LC) and flavonoids (anthocyanins AN and proanthocyanidins PA) are effective antioxidants found in daily diets. 94 pairs of college students (CS) and their respective older generations (OG) living in the same household were recruited with their self‐reported three‐day dietary records to determine intakes of LC, AN, and PA. USDA National Nutrient Database for LC (2011) and for PA (2004) were employed to determine LC and PA contents. AN content was determined by Wu et al. (J. Agric Food Chem V.64, 2006). The variables, such as subjects’ BMIs and three day total energy intakes were used to determine the statistical correlations between the intakes of these three compounds and the variables. The results showed that CS consumed more LC and AN (LC: CS vs OG 4179.25 mcg ± S.E. 748.39 vs 2928.56 mcg ± S.E. 475.57 respectively, p=0.14) (AN: CS vs OG 92.95 mg ± S.E. 20.10 vs 57.69 mg ± S.E. 12.72 respectively, p=0.11) and CS consumed slightly lower PA than OG (CS vs OG 333.82 mg ± S.E 49.38 and 371.46 mg ± S.E 92.61 respectively, p=0.55) and no significant differences were found. Whereas there were no significant correlations were found between variables and these compounds, except there was a significant positive correlation found between LC consumption and three day total energy intakes in the CS (p=0.01) but not found significance in the OG (p=0.08). The adequate intakes of these compounds are important for their health.Grant Funding Source: Self‐support

Effects of the chain length of crosslinking agents on the electro-optical properties of polymer-dispersed liquid crystal films

Polymer-dispersed liquid crystal (PDLC) films were prepared by photochemical polymerisation from an ultraviolet-curable monomer/crosslinking agent/initiator/liquid crystal (LC) mixture. The influences of the chain length of crosslinking agents on the PDLC system have been studied. The microstructures of the PDLC films were strongly influenced by the chain length of the crosslinker, which in turn influences the electro-optic properties of PDLC films. It is proved that adjusting the chain length of the crosslinking agents and the LC content can produce PDLC films that have good electro-optic properties with a lower LC content.

Influence of LC Content on the Phase Structures of Side-Chain Liquid Crystalline Block Copolymers with Bent-Core Mesogens

We report the phase structures of a series of poly(styrene-block-{3′-[4-(4-n-dodecyloxybenzoyloxy)benzoyloxy]-4-(12-methacryloyloxydodecyloxy)benzoyloxybiphenyl}) (PS-b-PMAC) side-chain liquid crystalline block copolymers (SC LCBCP). The SC liquid crystalline polymer was formed by side attaching a bent-core mesogen to the polymer backbone using a 12-carbon spacer. The phase structure of the high and low fPMAC samples were investigated using differential scanning calorimetry, small-angle and wide-angle X-ray scattering, and transmission electron microscopy techniques. The PS coil block and PMAC LC block phase separate into a lamellar morphology in all of the samples investigated (volume fraction of PMAC fPMAC ∼ 0.31−0.65). However, both the LC phase and the orientation of the hierarchical structure under mechanical shear showed strong dependence on the LC content. Samples having a high fPMAC (0.5−0.65) showed a SmC2 LC phase (Smectic C denotes the LC molecules are tilted with respect to the layer normal, and 2 represents a bilayered structure), similar to that observed in PMAC homopolymers. Upon mechanical shear, these smectic layers oriented parallel to the shear plane and the BCP lamellae oriented perpendicular to the shear plane with the layer normal parallel to the vorticity direction. In samples having a lower fPMAC, the BCP lamellae laid parallel to the shear plane and the LC phase structure in these samples was columnar rectangular. A detailed structural and morphological study will be reported.

Haematological Profile Of <i>Parachanna (Channa)</i> Obscura Gunther 1861, <i>Malapterurus electricus</i> Gmelin 1789 And <i>Malapterurus minriya</i> Sagua 1987

Reference values for some haematological indices of Parachanna obscura, Malapterurus electricus and Malapterurus minjiriya were determined. The mean ± SD values for erythrocyte count (Ec), leucocyte count (Lc), haematocrit (Hct), haemoglobin concentration (Hbc), erythrocyte sedimentation rate (ESR), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), and plasma protein content (g/dl) determined for P. obscura were 2.00 ± 0.71 x 10 12 /litre, 40.10 ± 1.32 x 10 9 /litre, 26.40 ± 3.89 %, 11.48 ± 1.55 g/dl, 13.12 ± 1.26 mm/h, 131.70 ± 108.20 fl, 57.28 ± 43.25 pg, 43.48 ± 6.97 g/dl, 62.90 ± 9.70 g/dl respectively. Ec, Lc, Hct, Hbc, ESR, MCV, MCH, MCHC and plasma protein content determined for M. electricus were 1.96 ± 0.17 x 10 12 /litre, 31.87 ± 2.30 x 10 9 /litre, 32.03 ± 1.94 %, 7.08 ± 0.22 g/dl, 2.56 ± 0.53 mm/h, 158.59 ± 5.16 fl, 35.24 ± 1.79 pg, 0.225 ± 0.018 g/dl and 52.89 ± 7.23 g/dl, respectively. Ec, Lc, Hct, Hbc, ESR, MCV, MCH, MCHC and plasma protein content determined for M. minjiriya were 2.09 ± 0.21 x 10 12 /litre, 38.48 ± 3.10 x 10 9 /litre, 34.04 ± 2.15 %, 8.28 ± 0.25 g/dl, 2.71 ± 0.58 mm/h, 168.15 ± 8.01 fl, 36.43 ± 2.17 pg, 0.255 ± 0.027 g/dl and 50.85 ± 9.86 g/dl, respectively.

LC dependent electro-optical properties of holographic polymer dispersed liquid crystals

Holographic polymer dispersed liquid crystals (HPDLC) have been fabricated from four different types of LC at a specific resin composition to optimize the electro-optical performance of the film. Among them, ZLI-3417-100 gave the lowest driving voltage (<2.5V/μm) and fastest response time (<10ms) which was interpreted in terms of high dielectric anisotropy (Δɛ) and low viscosity of the LC. However, diffraction efficiency of the film was a bit low due to the relatively small refractive anisotropy (Δn) of the LC giving rise to a small mismatch of refractive index with resin. With regard to the LC content, 40% LC gave the greatest diffraction efficiency, whereas saturation time decreased with increasing content of LC, which emphasizes the viscosity reducing effect of LC.

登熟温度が米のアミロペクチン単位鎖長分布と超長鎖（ＬＣ）含量に及ぼす影響

アミロペクチン単位鎖長分布と超長鎖(LC)含量に及ぼす登熟温度の影響をHanashiroらの蛍光標識ゲル濾過HPLC法で調べた．北海道米の主要品種である「きらら397」のアミロペクチンLC含量は，低温(21/17°C)2.58%，中温(25/21°C)1.30%，高温(29/25°C)0.48%で登熟温度が低いほど多かった(Table 1)．アミロペクチン単位鎖の短鎖(A+B1)と長鎖(B2+B3)の重量比およびモル比(A+B1)/(B2+B3)は登熟温度が低いほど大きかった(Table 2)．これらの結果は，近年育成された北海道米5品種と4系統およびミルキークイーンを供試して確証された．登熟温度は22/16，26/20，30/24，34/28°C(昼/夜)で行った．アミロペクチンLC含量の平均登熟温度1°C当たりの変動量は，19-23°Cの範囲では0.542%，23-27°Cでは0.152%，27-31°Cでは0.037%で，低温ほど大きかった(Fig. 4)．見かけのアミロース含有率は登熟温度と負の相関があることが知られているが，アミロペクチンLC含量も同様に低温で増加することが明らかとなった．低アミロース品種はうるち品種に比べて見かけのアミロース含量に占めるアミロペクチンLC含量の割合が高かった(Fig. 6)．見かけのアミロース含量とアミロペクチンLC含量は品種よりも登熟温度の影響が大きかった(Table 4)．以上のことから，今後の良食味米の選抜において，アミロペクチンLC含量が低く，異なる登熟温度条件でも澱粉の構造が安定している品種の育成が目標である．これはアミロペクチンLCの生合成に関与する酵素の遺伝子分析によって達成できるかもしれない．