Resurvey After 20 Years:Updating the Distribution,Population,and Potential Threats of the Chinting Alpine Toad

Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.

Interaction between adolescent sleep rhythms and gender in an obese population

BACKGROUND The obesity rate of adolescents is gradually increasing,which seriously affects their mental health,and sleep plays an important role in adolescent obesity.AIM To investigate the relationship between sleep rhythm and obesity among adolescents and further explores the interactive effect of sleep rhythm and gender on adolescent obesity,providing a theoretical basis for developing interventions for adolescent obesity.METHODS Research data source Tianjin Mental Health Promotion Program for Students.From April to June 2022,this study selected 14201 students from 13 middle schools in a certain district of Tianjin as the research subject using the convenient cluster sampling method.Among these students,13374 accepted and completed the survey,with an effective rate of 94.2%.The demographic data and basic information of adolescents,such as height and weight,were collected through a general situation questionnaire.The sleep rhythm of adolescents was evaluated using the reduced version of the morningness-eveningness questionnaire.RESULTS A total of 13374 participants(6629 females,accounting for 49.56%;the average age is 15.21±1.433 years)were analyzed.Among them,the survey showed that 2942 adolescent were obesity,accounting for 22%and 2104 adolescent were overweight,accounting for 15.7%.Among them,1692 male adolescents are obese,with an obesity rate of 25.1%,higher than 18.9%of female adolescents.There is a statistically significant difference between the three groups(χ2=231.522,P<0.000).The obesity group has the smallest age(14.94±1.442 years),and there is a statistical difference in age among the three groups(F=69.996,P<0.000).Obesity rates are higher among individuals who are not-only-child,have residential experience within six months,have family economic poverty,and have evening-type sleep(P<0.05).Logistic regression analysis shows a correlation between sleep rhythm and adolescent obesity.Evening-type sleep rhythm can increase the risk of obesity in male adolescents[1.250(1.067-1.468)],but the effect on female obesity is not remarkable.Further logistic regression analysis in the overall population demonstrates that the interaction between evening-type sleep rhythm and the male gender poses a risk of adolescent obesity[1.122(1.043-1.208)].CONCLUSION Among adolescents,the incidence of obesity in males is higher than in females.Evening-type sleep rhythm plays an important role in male obesity but has no significant effect on female obesity.Progressive analysis suggests an interactive effect of sleep rhythm and gender on adolescent obesity,and the combination of evening-type sleep and the male gender promotes the development of adolescent obesity.In formulating precautions against adolescent obesity,obesity in male adolescents with evening-type sleep should be a critical concern.

Development and Validation of a Postoperative Prognostic Nomogram to Predict Recurrence in Patients with Persistent Atrial Fibrillation:A Retrospective Cohort Study

Background:Patients with persistent atrial fibrillation(PsAF)have a high risk of recurrence after catheter radiofre-quency ablation.Nevertheless,no effective prognostic tools have been developed to identify these high-risk patients to date.This study sought to develop and validate a simple linear predictive model for predicting postoperative recurrence in patients with PsAF.Methods:From June 2013 to June 2021,patients with PsAF admitted to our hospital were enrolled in this single-center,retrospective,observational study.The characteristics substantially associated with recurrence in patients with PsAF were screened through univariate and multivariate logistic regression analysis.The receiver operating charac-teristic curve was used to assess the predictive significance of the nomogram model after nomogram development.Furthermore,to assess the clinical value of the nomogram,we performed calibration curve and decision curve analyses.Results:A total of 209 patients were included in the study,42(20.10%)of whom were monitored up to 1 year for recurrent AF.The duration of AF episodes,left atrial diameter,BMI,CKMB,and alcohol consumption were found to be independent risk factors(P<0.05)and were integrated into the nomogram model development.The area under the curve was 0.895,the sensitivity was 93.3%,and the specificity was 71.4%,thus indicating the model’s excellent predic-tive ability.The C-index of the predictive nomogram model was 0.906.Calibration curve and decision curve analyses further revealed that the model had robust prediction and strong discrimination ability.Conclusion:This simple,practical,and innovative nomogram can help clinicians in evaluation of the risk of PsAF recurrence after catheter ablation,thus facilitating preoperative evaluation,postoperative monitoring and ultimately the construction of more personalized therapeutic protocols.

States of graphene oxide and surface functional groups amid adsorption of dyes and heavy metal ions

Water pollution regarding dyes and heavy metal ions is crucial facing the world.How to effectively separate these contaminants from water has been a key issue.Graphene oxide(GO)promises the greenwater world as a long-lasting spotlight adsorbent material and therefore,harnessing GO has been the research hotspot for over a decade.The state of GO as well as its surface functional groups plays an important role in adsorption.And the way of preparation and structural modification matters to the performance of GO.In this review,the significance of the state of existence of stock GO and surface functional groups is explored in terms of preparation,structural modification,and adsorption.Besides,various adsorbates for GO adsorption are also involved,the discussion of which is rarely established elsewhere.

Review of Simultaneous Localization and Mapping Technology in the Agricultural Environment

Simultaneous localization and mapping(SLAM)is one of the most attractive research hotspots in the field of robotics,and it is also a prerequisite for the autonomous navigation of robots.It can significantly improve the autonomous navigation ability of mobile robots and their adaptability to different application environments and contribute to the realization of real-time obstacle avoidance and dynamic path planning.Moreover,the application of SLAM technology has expanded from industrial production,intelligent transportation,special operations and other fields to agricultural environments,such as autonomous navigation,independent weeding,three-dimen-sional(3D)mapping,and independent harvesting.This paper mainly introduces the principle,sys-tem framework,latest development and application of SLAM technology,especially in agricultural environments.Firstly,the system framework and theory of the SLAM algorithm are introduced,and the SLAM algorithm is described in detail according to different sensor types.Then,the devel-opment and application of SLAM in the agricultural environment are summarized from two aspects:environment map construction,and localization and navigation of agricultural robots.Finally,the challenges and future research directions of SLAM in the agricultural environment are discussed.

Exploring the Mechanism of CircRNA-vgll3 in Osteogenically Differentiated Human Bone Marrow Mesenchymal Stem Cells

Objective:To explore the mechanism of circRNA-vgll3 in osteogenic differentiation of human bone marrow mesenchymal stem cells.Methods:BMSCs cells were transfected with circRNA-vgll3,and divided into circRNA-vgll3 high-level group,circRNA-vgll3 low-level group,and negative control group(circRNA-vgll3 not transfected)according to the amount of transfection.The proliferation and apoptosis of BMSCs osteoblasts in each group were analyzed,and the alkaline phosphatase(ALP)activity,type I collagen gray value,bone morphogenetic protein 2(BMP-2),Runx2 protein,and mRNA expression levels were detected.Results:The circRNA-vgll3 low-level group had a significant inhibitory effect on the proliferation of BMSCs osteoblasts,and the apoptosis rate of the circRNA-vgll3 low-level group was significantly higher than that of the circRNA-vgll3 high-level group(P<0.05);ALP activity,type I collagen gray value,BMP-2,Runx2 protein,and mRNA expression levels in the high-level circRNA-vgll3 group were significantly higher than those in the low-level circRNA-vgll3 group,and the difference was statistically significant(P<0.05).Conclusion:Overexpression of circRNA-vgll3 can promote the osteogenic differentiation ability of BMSCs,while low expression of circRNA-vgll3 can inhibit the osteogenic differentiation ability of BMSCs.The main mechanism of action is that circRNA-vgll3 can affect osteogenic differentiation by regulating the Runx2 protein.

Latest Progress of the Chinese Meteorological Satellite Program and Core Data Processing Technologies

In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.

Structure and synthesis of graphene oxide

Graphene oxide(GO)is one typical two-dimension structured and oxygenated planar molecular material.Researchers across multiple disciplines have paid enormous attention to it due to the unique physiochemical properties.However,models used to describe the structure of GO are still in dispute and ongoing to update.And currently,synthesis methods for mass production are seemingly abundant but in fact,dominated by a few core methodologies.To update with the state-of-art opinions and progresses,herein we present a mini critical review regarding the synthesis of GO as well as its models and simulations of structure.Also,we discuss the perspectives.

FY-3E:The First Operational Meteorological Satellite Mission in an Early Morning Orbit

Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.

宫腔镜应用于绝经后子宫内膜病变的临床诊断价值

目的探讨宫腔镜应用于绝经后子宫内膜病变诊断的临床价值。方法选取2016年4月-2018年4月该院100例绝经后子宫内膜病变患者,根据随机数字法,将其分为对照组(诊断性刮宫)和观察组(宫腔镜),每组各50例,比较两组患者子宫腔病变检出率,以及诊断各种子宫内膜病变的敏感度、特异度、阳性预测值和阴性预测值。结果观察组子宫内膜病变检出率明显高于对照组(P <0.05);观察组患者子宫内膜息肉、子宫黏膜下肌瘤检出率明显高于对照组(P <0.05);观察组患者子宫内膜息肉、子宫黏膜下肌瘤、子宫内膜增生和子宫内膜癌等病变诊断的敏感度、特异度、阳性预测值和阴性预测值均高于对照组。结论宫腔镜能够有效、准确地诊断绝经后子宫内膜病变,其简单、快速、损伤小,值得临床推广。

快速康复外科护理在慢性硬膜下血肿围手术期的应用

目的探讨快速康复外科护理应用于慢性硬膜外血肿围手术期对患者术后恢复影响。方法选取本院2018年1月-2018年11月收治的87例慢性硬膜外血肿患者,根据随机数字表法分组,分为实验组和对照组;对照组采用神经外科硬膜外常规护理,实验组除常规外采用快速康复外科护理;收集统计患者首次下床时间、住院日、术后并发症和住院满意度资料。结果快速康复外科护理能够有效缩短患者首次下床时间,缩短患者住院日,减少并发症的发生,提高患者满意度。结论快速康复外科护理提高慢性硬膜外血肿患者治疗效果,有利于促进患者的术后快速康复,值得临床推广。

Simulation of Synergism Effect Using Temperature Switching Irradiation on Bipolar Comparator

The synergism effect of total ionizing dose（TID） on a single event transient（SET） in a bipolar comparator is investigated. Experimental results show that the shapes of the SET are considerably influenced by the TID accumulated in low dose rates. The variation tendency of SET shapes can be accurately simulated by temperature switching irradiation. The mechanism of this synergism effect is also analyzed in brief via the operating schematic of a comparator. After the accumulation of 100 krad（Si）, the lower tendency of negative SET can be attributed to the degeneration of . The change tendency of a positive SET, either lower or higher, is dependent on the load condition that limits the output range of the comparator.

Forkhead box protein A2 and T helper type 2-mediated pulmonary inflammation

The transcription factor forkhead box protein A2(FOXA2, also known as hepatocyte nuclear factor 3β or transcription factor 3β), has been found to play pivotal roles in multiple phases of mammalian life, from the early development to the organofaction, and subsequently in homeostasis and metabolism in the adult. In the embryonic development period, FOXA2 is require d for the formation of the primitive node and notochord, and its absence results in embryonic lethality. Moreover, FOXA2 plays an important role not only in lung development, but also in T helper type 2(Th2)-mediated pulmonary inflammation and goblet cell hyperplasia. In this article, the role of FOXA2 in lung development and Th2-mediated pulmonary inflammation, as well as in goblet cell hyperplasia, is reviewed. FOXA2 deletion in airway epithelium results into Th2-mediated pulmonary inflammation and goblet cell hyperplasia in developing lung. Leukotriene pathway and signal transducers and activators of transcription 6 pathway may mediate this inflammation through recruitment and activation of denditric cell during lung developments. FOXA2 is a potential treatment target for lung diseases with Th2 inflammation and goblet cell hyperplasia, such as asthma and chronic obstructive pulmonary disease.

Spatiotemporal Variations of Microwave Land Surface Emissivity(MLSE)over China Derived from Four-Year Recalibrated Fengyun 3B MWRI Data

Microwave Land Surface Emissivity(MLSE)over China under both clear and cloudy sky conditions was retrieved using measurements of recalibrated microwave brightness temperatures(Tbs)from Fengyun-3B Microwave Radiation Imager(FY-3B MWRI),combined with cloud properties derived from Himawari-8 Advanced Himawari Imager(AHI)observations.The contributions from cloud particles and atmospheric gases to the upwelling Tbs at the top of atmosphere were calculated and removed in radiative transfer.The MLSEs at horizontal polarizations at 10.65,18.7,and 36.5 GHz during 7 July 2015 to 30 June 2019 over China showed high values in the southeast vegetated area and low values in the northwest barren,or sparsely vegetated,area.The maximum values were found in the belt area of the Qinling-Taihang Mountains and the eastern edge of the Qinghai-Tibet Plateau,which is highly consistent with MLSEs derived from AMSR-E.It demonstrates that the measurements of FY-3B MWRI Tbs,including its calibration and validation,are reliable,and the retrieval algorithm developed in this study works well.Seasonal variations of MLSE in China are mainly driven by the combined effects of vegetation,rainfall,and snow cover.In tropical and southern forest regions,the seasonal variation of MLSE is small due to the enhancement from vegetation and the suppression from rainfall.In the boreal area,snow causes a significant decrease of MLSE at 36.5 GHz in winter.Meanwhile,the MLSE at lower frequencies experiences less suppression.In the desert region in Xinjiang,increases of MLSEs at all frequencies are observed with increasing snow cover.

Bone morphogenetic protein-4 and transforming growth factor-beta1 mechanisms in acute valvular response to supra-physiologic hemodynamic stresses

AIM:To explore ex vivo the role of bone morphogenetic protein-4(BMP-4) and transforming growth factorbeta1(TGF-β1) in acute valvular response to fluid shear stress(FSS) abnormalities.METHODS:Porcine valve leaflets were subjected ex vivo to physiologic FSS,supra-physiologic FSS magnitude at normal frequency and supra-physiologic FSS frequency at normal magnitude for 48 h in a double-sided cone-and-plate bioreactor filled with standard culture medium. The role of BMP-4 and TGF-β1 in the valvular response was investigated by promoting or inhibiting the downstream action of those cytokines via culture medium supplementation with BMP-4 or the BMP antagonist noggin,and TGF-β1 or the TGF-β1 inhibitor SB-431542,respectively. Fresh porcine leaflets were used as controls. Each experimental group consisted of six leaflet samples. Immunostaining and immunoblotting were performed to assess endothelial activation in terms of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expressions,paracrine signaling in terms of BMP-4 and TGF-β1 expressions and extracellular matrix(ECM) remodeling in terms of cathepsin L,cathepsin S,metalloproteinases(MMP)-2 and MMP-9 expressions. Immunostained images were quantified by normalizing the intensities of positively stained regions by the number of cells in each image while immunoblots were quantified by densitometry. R E S U LT S :Regardless of the culture medium,physiologic FSS maintained valvular homeostasis. Tissue exposure to supra-physiologic FSS magnitude in standard medium stimulated paracrine signaling(TGF-β1:467% ± 22% vs 100% ± 6% in freshcontrols,BMP-4:258% ± 22% vs 100% ± 4% in fresh controls; P < 0.05) and ECM degradation(MMP-2:941% ± 90% vs 100% ± 19% in fresh controls,MMP-9:1219% ± 190% vs 100% ± 16% in fresh controls,cathepsin L:1187% ± 175% vs 100% ± 12% in fresh controls,cathepsin S:603% ± 88% vs 100% ± 13% in fresh controls; P < 0.05),while BMP-4 supplementation also promoted fibrosa activation and TGF-β1 inhibition reduced MMP-9 expression to the native tissue level(MMP-9:308% ± 153% with TGF-β1 inhibition vs 100% ± 16% in fresh control; P > 0.05). Supra-physiologic FSS frequency had no effect on endothelial activation and paracrine signaling regardless of the culture medium but TGF-β1 silencing attenuated FSS-induced ECM degradation via MMP-9 downregulation(MMP-9:302% ± 182% vs 100% ± 42% in fresh controls; P > 0.05).CONCLUSION:Valvular tissue is sensitive to FSS abnormalities. The TGF-β1 inhibitor SB-431542 is a potential candidate molecule for attenuating the effects of FSS abnormalities on valvular remodeling.

Room-temperature operating extended short wavelength infrared photodetector based on interband transition of InAsSb/GaSb quantum well

Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As（0.91）Sb（0.09） embedded in the Ga Sb barrier is calculated to be 0.53 e V（2.35μm）,which makes the absorption range of In As Sb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum.The fabricated photodetector exhibits a narrow response range from 2.0μm to 2.3μm with a peak around 2.1μm at 300 K.The peak responsivity is 0.4 A/W under-500-m Vapplied bias voltage,corresponding to a peak quantum efficiency of 23.8%in the case without any anti-reflection coating.At 300 K,the photodetector exhibits a dark current density of 6.05×10^-3A/cm^2 under-400-m V applied bias voltage and 3.25×10^-5A/cm^2 under zero,separately.The peak detectivity is 6.91×10^10cm·Hz^1/2/W under zero bias voltage at 300 K.

Effect of Mirena placement on reproductive hormone levels at different time intervals after artificial abortion

BACKGROUND Improper methods of contraception greatly increase the risk of abortion,cervical or endometrial lesions,and the number of recurrent artificial abortions.These complications result in the deterioration of a patient’s outcome.Further,the proportion of artificial abortions is highest among unmarried females.Placement of an intrauterine device,such as the Mirena,after an artificial abortion may decrease the likelihood of an endometrial injury caused by recurrent abortions while significantly improving its contraceptive effects.AIM To discuss the effect of Mirena placement on reproductive hormone levels at different time points after an artificial abortion.METHODS Women(n=119)undergoing an artificial abortion operation were divided into the study(n=56)and control(n=63)groups.In the study group,the Mirena was inserted immediately after the artificial abortion,whereas in the control group,it was inserted 4–7 d after the onset of the first menstrual cycle after abortion.All participants were followed-up for 6 mo to observe the continuation and expulsion rates and adverse reactions and to measure the levels of serum estradiol(E2),follicle stimulating hormone(FSH),and luteinizing hormone(LH).RESULTS The continuation rates were 94.64%and 93.65%in the study group and the control group,respectively.The expulsion rates were 1.79%and 3.17%in the study group and the control group,respectively.There was no statistically significant difference between the two groups(P>0.05).There were also no statistically significant differences in the proportion of patients with bacterial vaginitis,trichomonas vaginitis,or cervicitis between the groups(P>0.05).Six months after Mirena placement,E2 Levels were 45.50±7.13 pg/mL and 42.91±8.10 pg/mL,FSH 13.60±3.24 mIU/mL and 14.54±3.11 mIU/mL,and LH 15.11±2.08 mIU/mL and 14.60±3.55 mIU/mL in the study and control groups,respectively.There were no significant differences in hormone levels between the two groups(P>0.05).There were also no statistically significant differences in the proportions of abnormal menstruation,prolonged menstruation,or pain during intercourse between the study and control groups after Mirena placement(P>0.05).There were no statistically significant differences in uterine volume,sexual desire,sexual activity,or the sexual satisfaction score between the study and control groups before and after Mirena placement(P>0.05).CONCLUSION Placement of a Mirena intrauterine device immediately after an artificial abortion does not increase the risk of adverse reactions and can help prevent endometrial injury caused by recurrent abortions.

A method to extend wavelength into middle-wavelength infrared based on InAsSb/(Al)GaSb interband transition quantum well infrared photodetector

We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified In As Sb quantum well, Ga Sb is replaced with Al Sb/Al Ga Sb, the valence band of the barrier material is lowered, the first restricted energy level is higher than the valence band of the barrier material, the energy band structure forms type-II structure. The photocurrent spectrum manifest that the fabricated photodetector exhibits a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.

Tunable oxygen defect density and location for enhancement of energy storage

Defect engineering is in the limelight for the fabrication of electrochemical energy storage devices.However,determining the influence of the defect density and location on the electrochemical behavior remains challenging.Herein,self-organized TiO_(2)nanotube arrays(TNTAs)are synthesized by anodization,and their oxygen defect location and density are tuned by a controllable post-annealing process.TNTAs annealed at 600℃ in N2 exhibit the highest capacity(289.2 m Ah g^(-1)at 0.8 C)for lithium-ion storage,while those annealed at 900℃ in N2 show a specific capacitance of 35.6 m F cm^(-2)and stability above96%after 10,000 cycles for supercapacitor.Ex situ electron paramagnetic resonance spectra show that the surface-exposed oxygen defects increase,but the bulk embedded oxygen defects decrease with increasing annealing temperature.Density functional theory simulations reveal that a higher density of bulk oxygen defects corresponds to higher localized electrons states,which upshift the Fermi level and facilitate the lithium intercalation kinetic process.Meanwhile,differential charge density calculation indicates that the increase of surface oxygen defects in the anatase(101)plane leads to higher density excess electrons,which act as negative charge centers to enhance the surface potential for ion adsorption.This oxygen-deficient location and density tunable strategy introduce new opportunities for high-energy and high-power-density energy storage systems.

NITROXIDE-MEDIATED FREE RADICAL SYNTHESIS OF MESOGEN-JACKETED LIQUID CRYSTAL POLYMERS

The first TEMPO-mediated 'living' free radical polymerization of liquid crystalline monomer, 2, 5-bis[(4-methoxyphenyl)oxycarbonyl]styrene (MPCS), was carried out at 130 degrees C with BPO as an initiator. The molecular weight of the polymer can be varied from rather low values to high values while maintaining narrow polydispersity. It was observed that the polymerization of MPCS proceeded much faster than that of styrene. A tentative explanation for this fast polymerization was suggested.