The Effect of Colloidal Nanoparticles on Phase Separation of Block and Heteroarm Star Copolymers Confined between Polymer Brushes.

The effect of colloidal nanoparticles on the phase changes of the amphiphilic AB linear diblock, A1A2B, and A2B heteroarm star copolymers confined between two polymer brush substrates was investigated by using a real-space self-consistent field theory. By changing the concentrations of nanoparticles and polymer brushes, the phase structure of the amphiphilic AB copolymer transforms from lamellar to core-shell hexagonal phase to cylinder phase. The pattern of A2B heteroarm star copolymer changes from core-shell hexagonal phases to lamellar phases and the layer decreases when increasing the density of the polymer brushes. The results showed that the phase behavior of the system is strongly influenced by the polymer brush architecture and the colloidal nanoparticle numbers. The colloidal nanoparticles and the soft confined surface of polymer brushes make amphiphilic AB copolymers easier to form ordered structures. The dispersion of the nanoparticles was also investigated in detail. The soft surfaces of polymer brushes and the conformation of the block copolymers work together to force the nanoparticles to disperse evenly. It will give helpful guidance for making some new functional materials by nano etching technology, nano photoresist, and nanoprinting.

Ultra-fast fabrication of Bi2Te3 based thermoelectric materials by flash-sintering at room temperature combining with spark plasma sintering.

Highly crystalline Bi2Te3 based compounds with small grain size were successfully synthesized by flash sintering (FS) method in 10 s at room temperature under suitable current density using Bi, Te and Se powders. The instantaneously generated local Joule heat at grain boundary is regarded as the main reason for the rapid completion of chemical reaction and crystallization. By combining FS synthesis method with spark plasma sintering (SPS), Bi2Te3 based bulk materials with high relative density were fabricated in 10 min. Suitably prolonging sintering temperature and holding time in SPS process can decrease carrier concentration and phonon thermal conductivity, while increasing carrier mobility. Hence, the sample prepared at 753 K for 3 min shows 20% higher ZT value than that of the sample prepared at 723 K for 3 min. Compared with common zone melting or powder metallurgy methods taking several hours by complex operation, this method is time-saving and low cost.

Phase Behaviors of ABA Star Polymer and Nanoparticles Confined in a Sphere with Soft Inner Surface.

The phase behaviors of an ABA star polymer and nanoparticles confined in a sphere with soft inner surface, which is grafted with homopolymer brushes have been studied by the self-consistent field theory (SCFT). The morphologies of mixture in the center slice of sphere were focused. Two cases are considered: one is that the nanoparticles interact with the B blocks and the other is that the nanoparticles preferentially wet the B blocks. Under the two conditions, through changing the block ratio of the ABA star polymer, the concentration and radius of the nanoparticles, the phase behaviors of the mixtures confined the soft sphere are studied systematically. With increasing the concentration of nanoparticles, the entropy and the steric repulsive interaction of nanoparticles, and the nanoparticle density distributions along the perpendicular line through the center of sphere are plotted. The phase diagram is also constructed to analyze the effects of the nanoparticle volume fraction and radius on morphologies of ABA star polymers, and to study the effect of confinement on the phase behaviors. The results in this work provide a useful reference for controlling the ordered structures in experiment, which is an effective way to fabricate the newly multifunctional materials.

The effects of solution-focused nursing on leukemia chemotherapy patients' moods, cancer-related fatigue, coping styles, self-efficacy, and quality of life.

OBJECTIVE: To explore the effects of solution-focused nursing on leukemia chemotherapy patients' moods, cancer-related fatigue, coping styles, self-efficacy, and quality of life. METHODS: A total of 103 patients who underwent leukemia chemotherapy in our hospital were analyzed retrospectively and were divided into two groups based on the intervention method. Group A underwent routine nursing intervention, and group B underwent solution-focused nursing. The Hamilton Anxiety Rating Scale (HAMA) scores, the Montgomery-Asberg Depression Rating Scale (MADRS) scores, the Trait Coping Style Questionnaire (TCSQ) scores, the cancer-related fatigue self-rating scores, the General Self-Efficacy Scale (GSES) scores, and the Spitzer Quality of Life Index scores were compared between the two groups. RESULTS: Compared with group A, group B had lower HAMA scores, lower MADRS scores, lower cognitive, behavioral, perception, and emotional scores, and higher self-efficacy scores (P<0.05). Group B had higher activity scores, and better psychological statuses, support from family and friends, health perception, and outlook on life than group A after the intervention (P<0.05). CONCLUSION: Solution-focused nursing can alleviate leukemia chemotherapy patients' negative emotions and cancer-related fatigue, improve their coping styles, and increase their self-efficacy and quality of life.

Phase transition of a symmetric diblock copolymer induced by nanorods with different surface chemistry.

We investigate the phase transition of a symmetric diblock copolymer induced by nanorods with different surface chemistry. The results demonstrate that the system occurs the phase transition from a disordered structure to ordered parallel lamellae and then to the tilted layered structure as the number of rods increases. The dynamic evolution of the domain size and the order parameter of the microstructure are also examined. Furthermore, the influence of rod property, rod-phase interaction, rod-rod interaction, rod length, and polymerization degree on the behavior of the polymer system is also investigated systematically. Moreover, longer amphiphilic nanorods tend to make the polymer system form the hexagonal structure. It transforms into a perpendicular lamellar structure as the polymerization degree increases. Our simulations provide an efficient method for determining how to obtain the ordered structure on the nanometer scales and design the functional materials with optical, electronic, and magnetic properties.

Effect of high-fat diet on liver and placenta fatty infiltration in early onset preeclampsia-like mouse model.

BACKGROUND: Preeclampsia, especially early onset of preeclampsia (PE), is a common and serious disorder with high maternal and perinatal morbidity and mortality. Dietary factor is one of the most important factors which may affect the occurrence and development of the disease. The aim of this study is to investigate the effects of dietary factors on pathological changes of liver and placenta in preeclampsia-like mouse model by establishing the model at multiple stages of gestation. METHODS: Wild-type (WT) mice were injected subcutaneously with nitric oxide synthase (NOS) inhibitor L-arginine methyl ester (L-NAME, 50 mg×kg(-1)×d(-1)) to establish PE-like model (L-NAME group) at early-, mid-, and late-pregnant periods respectively; simultaneously, the control mice were injected with normal saline (NS group). All the groups were divided into subgroups, standard chow group (SC), and high-fat diet group (HF). ApoE(-/-) pregnant mice served as a control group. Systolic blood pressure (SBP), urine protein, and histopathologic changes of placenta and liver in all groups were observed and statistically analyzed. RESULTS: In WT and apoE(-/-) L-NAME subgroups, blood pressure and urine protein were significantly higher than those in all the gestational age matched NS groups (P < 0.05). Compared to other groups, remarkable liver fatty infiltration and lipid storage in placenta were found in early- and mid-L-NAME subgroups in apoE(-/-) mice (P < 0.05), especially in the early- and mid-HF+L-NAME subgroups in apoE(-/-) mice (P < 0.05). More lipid storage droplets both in liver and placenta were found in ApoE(-/-) mice than that of WT groups (P < 0.05). Morphology histopathologic examination of placentas showed varying degrees of fibrinoid necrosis and villous interstitial edema in early- and mid-L-NAME both in HF and SC of apoE(-/-) and WT subgroups compared to NS controls (P < 0.05). But there was no significant difference between HF and SC subgroups (P > 0.05), and no difference between apoE(-/-) and WT groups (P > 0.05). CONCLUSIONS: Preeclampsia-like conditions could be induced by L-NAME in mice at different gestational stages. Both WT and apoE(-/-) genotype mice with preeclampsia-like symptoms in early and mid stages of pregnancy presented lipid deposition in the placenta and hepatic fatty infiltration. To alter the environmental condition by feeding high-fat diet was harmful to the mother and the fetus. High-fat diet aggravated the impact of liver fatty infiltration at early and mid gestational stages especially in the apoE(-/-) mouse model. These results further revealed the association between early-onset preeclampsia and the dysoxidation of fatty acids.

Inhibition of nitric oxide synthase lowers fatty acid oxidation in preeclampsia-like mice at early gestational stage.

BACKGROUND: Preeclampsia is one of hypertensive disorders in pregnancy. It is associated with abnormal lipid metabolism, including fatty acid oxidation metabolism. Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) plays an indispensable role in the oxidation of fatty acids. It has been reported that nitric oxide (NO) is one of the regulatory factors of the fatty acid oxidation pathway. The aim of this research was to investigate whether the nitric oxide synthase (NOS) inhibitor L-NAME may cause down-regulation of LCHAD in the pathogenesis of preeclampsia. METHODS: Pregnant wild-type (WT) mice were treated with L-NAME or normal saline (NS) during gestation days 7 - 18 (early group), days 11 - 18 (mid group) and days 16 - 18 (late group), and apoE-/- mice served as a control. Systolic blood pressure (SBP), urine protein, feto-placental outcome, plasma lipid levels and NO concentrations were measured, and the expression of mRNA and protein for LCHAD in placental tissue were determined by real-time polymerase chain reaction (RT-PCR) and Western blotting, respectively. RESULTS: In WT and apoE-/- mice, SBP and urinary protein increased following L-NAME injection. Fetal and placental weights and NO concentrations were reduced and total cholesterol, triglycerides and free fatty acid levels were increased in early and mid L-NAME groups in WT and apoE-/- mice, compared with the NS group. There was no significant difference between the late L-NAME group and NS group. RT-PCR and Western blotting analysis showed that the mRNA and protein levels of LCHAD expression were significantly down-regulated in the early and mid L-NAME groups but not in the late L-NAME group in the WT and apoE-/- mice compared with the corresponding NS groups. CONCLUSIONS: Inhibition of NO in early and mid gestation in mice may cause hyperlipidemia and suppression of fatty acid oxidation, whereas preeclampsia-like conditions in late gestation may be a maternal vascular response to inhibition of NO.

[Correlation between severe preeclampsia and abnormal expression of long-chain fatty acid oxidative enzyme].

OBJECTIVE: To explore the correlation between severe preeclampsia and abnormal expression of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD). METHODS: Serum-free trophoblast cells cultured in vitro were divided into 4 groups under the stimulations of normal pregnancy serum (NP group), early onset severe preeclampsia serum (E-PE group), late onset severe preeclampsia serum (L-PE group) and HELLP (hemolysis, elevated liver enzymes & low platelets) syndrome serum (HELLP group) respectively. The expressions of mRNA and protein of LCHAD in trophoblast cells were detected by real-time polymerase chain reaction (PCR) and Western blot. RESULT: (1) Expression of LCHAD mRNA: the relative expressions of mRNA of LCHAD in NP, E-PE, L-PE and HELLP groups were 1.00 ± 0.00, 3.08 ± 0.22, 1.62 ± 0.23 and 3.36 ± 0.18 respectively. The relative expressions of LCHAD mRNA were significantly reduced in the E-PE, L-PE and HELLP groups versus the NP group (P < 0.05). Compared with the L-PE group, the gene expressions of LCHAD significantly decreased in the E-PE and HELLP groups (P < 0.05) while no significant difference was found between the E-PE and HELLP groups (P > 0.05). (2) Expression of LCHAD protein: the relative expressions of LCHAD protein were 4.94 ± 0.02, 2.93 ± 0.13, 4.14 ± 0.06 and 2.80 ± 0.09 in the NP, E-PE, L-PE and HELLP groups respectively. The protein expressions of LCHAD were remarkably reduced in the E-PE, L-PE and HELLP groups versus the NP group (P < 0.05). The expressions of LCHAD protein remarkably decreased in the E-PE and HELLP groups versus the L-PE group (P < 0.05) while no significant difference was found between the E-PE and HELLP groups (P > 0.05). CONCLUSION: Long chain fatty acid oxidation is involved in the pathogenesis and development of preeclampsia. The expressions of LCHAD gene and protein are remarkably affected by early onset severe preeclampsia and HELLP syndrome. The interacting mechanism and influence between fatty acid oxidation and the development of preeclampsia are worth further exploring.

Domain patterns in a diblock copolymer-diblock copolymer mixture with oscillatory particles.

We investigate the orientational order transition of striped patterns in microphase structures of diblock copolymer-diblock copolymer mixtures in the presence of periodic oscillatory particles. Under certain conditions, although the macrophase separation of a system is almost isotropic, microphase separation of one diblock copolymer takes place and becomes anisotropic gradually. By changing the oscillatory frequency and amplitude, the orientational order transition of a striped microphase structure from the state parallel to the oscillatory direction to the state perpendicular to the oscillatory direction is observed. We also find that the order transition occurs when we change the initial composition ratio. Furthermore, we examine the domain size and the orientational order parameter of microstructure in the process of orientational order transition. The results may provide guidance for experimentalists. This model system can also give a simple way to realize orientational order transition of soft materials by changing the oscillatory field.

[Interaction of fatty acid oxidation with oxidative stress in preeclampsia-like mouse model at multiple stages of gestation].

OBJECTIVE: To investigate the interactions of fatty acid oxidation with oxidative stress on the preeclampsia (PE)-like development by establishing murine models at multiple stages of gestation. METHODS: Wild-type (WT) mice were injected subcutaneously with nitric oxide synthase (NOS) inhibitor L-arginine methyl ester (L-NAME, 50 mg×kg(-1)×d(-1)) to establish PE-like model (L-NAME group) at early, middle and late pregnant periods respectively. Normal saline (NS group) was injected simultaneously as a control. All groups were divided into subgroups, standard chow group (SC) and high-fat diet group (HF). From Day 1 of pregnancy, all groups were fed simultaneously. ApoE(-/-) pregnant mice were selected as a control group. Identification of mice model and the expressions of mRNA and protein of LCHAD, p47phox, p38MAPK and COX-2 were confirmed by RT-PCR (reverse transcription-polymerase chain reaction) and Western blot respectively. Data were analyzed statistically. RESULTS: The expressions of mRNA and protein of LCHAD significantly decreased in early and middle L-NAME groups in both apoE(-/-) and WT mice (P < 0.05). The expressions of mRNA and protein of LCHAD in the HF groups were lower than the SC groups. The changes were marked in the early HF + L-NAME subgroup in apoE(-/-) mice (P < 0.05). As compared with other groups, the placental expressions of mRNA and protein of p47phox and COX-2 markedly increased in the early and middle L-NAME subgroups in apoE(-/-) mice (P < 0.05), especially in early and middle HF + L-NAME subgroups in apoE(-/-) mice (P < 0.05). ApoE(-/-) mice had a higher expression than that of WT groups (P < 0.05). The expressions of mRNA and protein of p38MAPK showed no differences among all groups. Correlation analysis showed a negative correlation between gene and protein expressions of LCHAD and p47phox, COX-2 (P < 0.05). There was significantly positively correlated between the expression of p47phox, COX-2 and protein (P < 0.05). CONCLUSIONS: The PE-like symptoms have fatty acid oxidation dysfunctions. There is a lower expression of LCHAD. The earlier its onset, the more obvious dysfunctions. In early and middle L-NAME groups, oxidative stress and inflammatory injury occur in both apoE(-/-) and WT mice. A high-fat diet may aggravate the level of oxidative stress especially in PE-like apoE(-/-) murine model.

[Dietary effect on plasma lipid changes and pregnant outcomes in early-onset pre-eclampsia-like murine model].

OBJECTIVE: To investigate the effects of dietary factors on the pre-eclampsia-like mouse model development at multiple stages of gestation. METHODS: Pre-eclampsia-like model was established in C57 wild-type (WT) and apoE(-/-) pregnant mice at early, middle and late gestational stages by injecting nitric oxide synthase (NOS) inhibitor L-arginine methyl ester (L-NAME) subcutaneously. Control groups received normal saline (NS) simultaneously. Each group was subdivided into standard chow subgroup (SC, n = 6) and high-fat diet subgroup (HF, n = 6). Blood pressure, urinary protein and plasma lipid were measured and fetal outcomes compared. Data were analyzed statistically. RESULTS: In early and middle L-NAME subgroups, the plasma concentrations of cholesterol (TC), triglyceride (TG) and free fatty acid (FFA) all increased. And the early L-NAME subgroup in apoE(-/-) mice was the most remarkable (P < 0.05). In apoE(-/-) groups (both L-NAME and NS groups), the plasma concentrations of total TC and TG were higher than those of WT groups (P < 0.05). But there was no significant difference in FFA between them. The plasma lipid levels of apoE(-/-) HF + L-NAME group were the highest among all the groups (P < 0.05). Fetal and placental weights significantly decreased in early and middle L-NAME groups in both apoE(-/-) and WT mice (P < 0.05). But no significant difference was found between late L-NAME subgroup and NS groups (P > 0.05). Compared with WT groups, the weights were lower in apoE(-/-) mice. The fetal and placental weights in HF groups were lower than SC groups and the changes in early HF + L-NAME subgroup in apoE(-/-) mice were the most remarkable (P < 0.05). A lower live fetal rate and a higher absorbed fetal rate were found in early L-NAME groups than those of the NS groups (P < 0.05). CONCLUSION: Pre-eclampsia occurring at an early stage is more likely to have abnormal plasma lipid levels and adverse feto-placental outcomes. High-fat dietary may aggravate the impact of L-NAME pre-eclampsia on pregnancy outcomes at an early gestational stage especially in ApoE(-/-) mice.

Effects of preeclampsia-like symptoms at early gestational stage on feto-placental outcomes in a mouse model.

BACKGROUND: Early and late-onset preeclampsia is thought to be different disease entities. This study aimed to determine the effects of early-onset preeclampsia-like symptoms on feto-placental outcomes and the adverse impacts of various factors on placental and fetal growth and development at different gestational stages in a mouse model. METHODS: Pregnant C57BL/6J mice were divided into control and preeclampsia (PE) groups, and injected subcutaneously with the nitric oxide synthase inhibitor L-arginine methyl ester (L-NAME) 50 mgxkg(-1)d(-1). The PE group was divided into early-, mid- and late-PE groups with L-NAME injections starting on days 7, 11 and 16 of pregnancy, respectively. Corresponding control groups were injected with saline at the same time points. Blood pressure was measured until days 14 and 18, when the fetuses and placentas were removed under anesthesia. Blood pressure, urinary protein, and fetal and placental conditions were analyzed. RESULTS: Blood pressure and urinary protein increased following L-NAME injection. The fetal survival rate and fetal weight were reduced and the fetal absorption rate was increased in the early-PE group on days 14 and 18 of pregnancy, compared with the control group. There were no significant differences in these parameters between the late-PE group and the respective control group. Placental weights in the early- and mid-PE groups were significantly reduced at days 14 and 18 of pregnancy compared with the control groups, but there was no significant difference in placental weight between the late-PE group and the respective control group. Morphologic examination of placentas from the early- and mid-PE groups showed varying degrees of fibrinoid necrosis and villous interstitial edema, but no significant pathologic changes were found in the placentas from the late-PE or control groups. CONCLUSION: Preeclampsia-like symptoms occurring during the early stage of pregnancy are more likely to affect placental and fetal development, whereas late onset preeclampsia-like symptoms have a direct impact on the mothers.