U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently c...U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or （and） sacral decompression. EQ-5d score was applied to evaluate the patients＇ quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years （range： 15-55 years） at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months （range： 9-47 months） and mean full weight-bearing time was 9.9 weeks （range： 8-14 weeks）. Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle （mean 27.87°, and range： 8°-90°） of the sacrum was smaller than that pre-operation （mean 35.67; range： 15-90） with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score （VAS） was reduced from preoperative 7.07 （range： 5-9） to postoperetive 1.93 （range： 1-3）. All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.展开更多
Urban development in arid and semi-arid regions is largely constrained by fragile physical environ- ments. The characteristics of an urban settlement are different from those in other regions of China. This paper anal...Urban development in arid and semi-arid regions is largely constrained by fragile physical environ- ments. The characteristics of an urban settlement are different from those in other regions of China. This paper analyses the coupling characteristics and spatio-temporal variations for oasis urban development and water-land resources at the northern slopes of the Tianshan Mountains by principal component analysis and a coupling degree model. The result shows that the degree and change in regional use of water and land resources are different among the studied cities/counties during their development. The built-up areas of these cities/counties have changed little with increasing populations and urbanization levels, which well reflects that the urban development in arid and semi-arid regions is limited by oasis areas. Per capita amount of water supplied, however, presented a trend of slowed growth with increasing levels of urbanization. Water consumption gradually increased with urban development and the improvement of people＇s living standards, accompanied by enhanced water use efficiency. The level of urbanization can be assessed through the coupling degree between oasis urban development and the use of water and land resources. A high coupling degree represents a high level of comprehensive urban devel- opment and use of water-land resources. Alternatively, a low coupling degree denotes a low level of urban devel- opment and water-land resource use.展开更多
BACKGROUND T1b gallbladder carcinoma(GBC)is defined as a tumor that invades the perimuscular connective tissue without extension beyond the serosa or into the liver.However,controversy still exists over whether patien...BACKGROUND T1b gallbladder carcinoma(GBC)is defined as a tumor that invades the perimuscular connective tissue without extension beyond the serosa or into the liver.However,controversy still exists over whether patients with T1b GBC should undergo cholecystectomy alone or radical GBC resection.AIM To explore the optimal surgical approach in patients with T1b gallbladder cancer of different pathological grades.METHODS Patients with T1bN0M0 GBC who underwent surgical treatment between 2000 and 2017 were included in the Surveillance,Epidemiology,and End Results database.The Kaplan-Meier method and log-rank test were used to analyze the overall survival(OS)and disease-specific survival(DSS)of patients with T1b GBC of different pathological grades.Cox regression analysis was used to identify independent predictors of mortality and explore the selection of surgical methods in patients with T1b GBC of different pathological grades and their relationship with prognosis.RESULTS Of the 528 patients diagnosed with T1bN0M0 GBC,346 underwent simple cholecystectomy(SC)(65.5%),131 underwent SC with lymph node resection(SC+LN)(24.8%),and 51 underwent radical cholecystectomy(RC)(9.7%).Without considering the pathological grade,both the OS(P<0.001)and DSS(P=0.003)of T1b GBC patients who underwent SC(10-year OS:27.8%,10-year DSS:55.1%)alone were significantly lower than those of patients who underwent SC+LN(10-year OS:35.5%,10-year DSS:66.3%)or RC(10-year OS:50.3%,10-year DSS:75.9%).Analysis of T1b GBC according to pathological classification revealed no significant difference in OS and DSS between different types of procedures in patients with grade Ⅰ T1b GBC.In patients with grade Ⅱ T1b GBC,obvious survival improvement was observed in the OS(P=0.002)and DSS(P=0.039)of those who underwent SC+LN(10-year OS:34.6%,10-year DSS:61.3%)or RC(10-year OS:50.5%,10-year DSS:78.8%)compared with those who received SC(10-year OS:28.1%,10-year DSS:58.3%).Among patients with grade Ⅲ or Ⅳ T1b GBC,SC+LN(10-year OS:48.5%,10-year DSS:72.2%),and RC(10-year OS:80%,10-year DSS:80%)benefited OS(P=0.005)and DSS(P=0.009)far more than SC(10-year OS:20.1%,10-year DSS:38.1%)alone.CONCLUSION Simple cholecystectomy may be an adequate treatment for grade Ⅰ T1b GBC,whereas more extensive surgery is optimal for grades Ⅱ-Ⅳ T1b GBC.展开更多
Objective:To translate the English version of Infertility Self-Efficacy Scale into Chinese and to validate the psychometric properties of the Chinese version of the Infertility Self-Efficacy Scale(CISE).Method(s):Part...Objective:To translate the English version of Infertility Self-Efficacy Scale into Chinese and to validate the psychometric properties of the Chinese version of the Infertility Self-Efficacy Scale(CISE).Method(s):Participants were recruited from the Gynecology Department of two city hospitals.Five main processes were involved in the formation of CISE[1]:scale translation based on expert consultation[2];pre-test questionnaire development with infertile women's feedback(N=20)[3];factor structure assessed by exploratory and confirmatory factor analysis(N=177)[4];assessment of reliability by internal consistency(N=177)and test-retest reliability(N=21);and[5]assessment of convergent validity with Self-rating Anxiety Scale,Self-rating Depression Scale,and Simplified Coping Style Questionnaire(N=177).Results:This study established a 16-item CISE.Factor analyses confirmed a onecomponent solution,which explained 54.59% of total variances and showed an acceptable model fit.Cronbach's a and test-retest correlation coefficients for the scale were 0.94 and 0.84,respectively.The CISE score was significantly correlated with anxiety(r=0.47),depression(r=0.60),positive coping style(r=0.37),and certain negative coping style items.Conclusion:This 16-item CISE is a reliable and valid measure to evaluate perceived selfefficacy among a sample of Chinese women who underwent infertility treatment.展开更多
Objective To compare the quality and quantity of total RNA from different source-original neurons applied in LMPC technique. Methods （ 1 ） Aglient 2100 bioanalyzer and RT-PCR were used to check the concentration and...Objective To compare the quality and quantity of total RNA from different source-original neurons applied in LMPC technique. Methods （ 1 ） Aglient 2100 bioanalyzer and RT-PCR were used to check the concentration and fragmentation of total RNA from unfixed, temporal fixed and fixed 12 h hypothalamus sections; （2）Different neurons of PVN and SON were collected by LMPC, CRH, TRH, AVP, OT mRNA level were measured by RT-PCR; （3）Labeled neurons by injecting CTB into stomach and non-labeled neurons in DMV collected by LMPC were checked for house keeping genes by RT-PCR. Results （ 1 ） Unfixed section had higher concentration and better quality of total RNA compared with fixed sections applied in LMPC ; relative short amplicons such as GAPDH, NSE, MCH and MCAR were successfully obtained from fixed and unfixed and long amplicon of GR can only be obtained from unfixed material; （2） In magnocellular PVN and SON the expressions of AVP and OT were more special than those in the parvocellular PVN. Oppositely, the expressions of CRH, TRH in the parvocellular were more special than the other two ; （3） The expressions of house keeping genes had no significant difference between labeled and non-labeled DMV neurons. Conclusion The quality and quantity of total RNA from unfixed brain tissues were better than fixed tissues applied in LMPC and the CTB tracer which may differentiate neurons had no significant effect on physiology of the neurons applied in LMPC. The results showed that the LMPC technique is suitable for the qualitative and quantitative study on individual neurons at mRNA level.展开更多
We utilized two structurally different long chains(linear and branched ultra-high molecular weight polyethylene)to reveal the dependence of flow-induced crystallization on long chain architecture,and prepared two bi-d...We utilized two structurally different long chains(linear and branched ultra-high molecular weight polyethylene)to reveal the dependence of flow-induced crystallization on long chain architecture,and prepared two bi-disperse systems of 98 wt%short chain and 2 wt%long chain.A flow field was applied to the bi-disperse polyethylene melt by a modified injection-molding machine,known as oscillation shear injection molding(OSIM).For the first time,the structural influence of long chains on flow-induced shish-kebab formation was systematically investigated.For the intermediate layer of OSIM samples,the branched long chains were better than the linear long chains at inducing shish-kebab formation,agreeing with the reported literatures,because the branches can maintain their oriented conformations longer.But unexpectedly,the reverse is the case for the core layer of OSIM samples,where the shear flow was much weaker than the intermediate layer.To understand the unexpected phenomenon,the lifetime of shishes induced by different long chains was compared.Result demonstrated that the linear-induced shishes possessed higher thermal stability than the branched-induced ones so that the linear-induced shishes could survive in the core layer of OSIM samples.Additionally,unlike other methods for flow-induced crystallization,OSIM could create samples for measuring mechanical properties,and thus offer the chance to reveal the relationship between structure and performance.The mechanical results demonstrated that both long chains remarkably enhanced the mechanical properties because of the significant promoting effect of long chains and intense flow fields on shish-kebab formation.However,the linear long chains induced more stable and flawless shishes with higher tensile strength and modulus(80.4 and 1613.5 Mpa,respectively)than the branched ones(74.4 and 1489.3 Mpa).Our research not only helps elucidate the mechanism of shish-kebab formation but also provides a better choice to reinforce polymers by adding long chains with suitable structure.展开更多
The exact mechanism by which knockout of Toll-like receptor 4(TLR4)attenuates the liver injury remains unclear.The present study aimed to examine the role of TLR4 in the pathogenesis of bile duct ligation(BDL)-induced...The exact mechanism by which knockout of Toll-like receptor 4(TLR4)attenuates the liver injury remains unclear.The present study aimed to examine the role of TLR4 in the pathogenesis of bile duct ligation(BDL)-induced liver cholestatic injury and the underlying mechanism.Wild type(WT)mice and TLR4 knockout(TLR4-KO)mice were used for the establishment of the BDL model.Metabolomics were applied to analyze the changes of small molecular metabolites in the serum and liver of the two groups.The serum biochemical indexes and the HE staining results of liver tissue showed that liver damage was significantly reduced in TLR4-KO mice after BDL when compared with that in WT mice.The metabolite analysis results showed that TLR4 KO could maintain the metabolisms of amino acids-and choline-related metabolites.After BDL,the amino acids-and choline-related metabolites,especially choline and 3-hydroxybutyrate,were significantly increased in WT mice(both in serum and liver),but these metabolites in the liver of TLR4-KO mice after BLD were not significant different from those before BLD.In conclusion,TLR4 KO could attenuate BDL-induced liver cholestatic injury through regulating amino acid and choline metabolic pathways.展开更多
Given the significant potential of multi-directional functionally graded materials(MFGMs)for customizable performance,it is crucial to develop versatile material models to enhance design optimization in engineering ap...Given the significant potential of multi-directional functionally graded materials(MFGMs)for customizable performance,it is crucial to develop versatile material models to enhance design optimization in engineering applications.This paper introduces a material model for an MFGM plate described by trigonometric functions,equipped with four parameters to control diverse material distributions effectively.The bending and vibration analysis of MFGM rectangular and cutout plates is carried out utilizing isogeometric analysis,which is based on a novel third-order shear deformation theory(TSDT)to account for transverse shear deformation.The present TSDT,founded on rigorous kinematics of displacements,is demonstrated to surpass other preceding theories.It is derived from an elasticity formulation,rather than relying on the hypothesis of displacements.The effectiveness of the proposed method is verified by comparing its numerical results with those of other methods reported in the relevant literature.Numerical results indicate that the structure,boundary conditions,and gradient parameters of the MFGM plate significantly influence its deflection,stress,and vibration frequency.As the periodic parameter exceeds four,the model complexity increases,causing result fluctuations.Additionally,MFGM cutout plates,when clamped on all sides,display almost identical first four vibration frequencies.展开更多
Objective: To study the clinical effect of terbutaline injection aerosol inhalation combined with conventional drug therapy for acute attack of bronchial asthma in children. Methods:Children with acute attack of bronc...Objective: To study the clinical effect of terbutaline injection aerosol inhalation combined with conventional drug therapy for acute attack of bronchial asthma in children. Methods:Children with acute attack of bronchial asthma who were treated in Wusheng Hospital of Traditional Chinese Medicine and Qiandongnan Prefecture People's Hospital between January 2014 and July 2017 were selected as the study cases for prospective study and randomly divided into the experimental group who received terbutaline + budesonide aerosol inhalation and the control group who received budesonide aerosol inhalation. The expression levels of immune cell transcription factors in peripheral blood as well as the contents of adhesion factors, chemokines, proteases and their inhibitory molecules in serum were determined before treatment and 3 days after treatment. Results: Foxp3 and T-bet expression in peripheral blood as well as TIMP1 and TIMP2 contents in serum of both groups after treatment were higher than those before treatment whereas RORγt and GATA-3 expression in peripheral blood as well as TARC, Eotaxin, ICAM-1, VCAM-1, L-selectin, ADAM8, NE and MMP9 contents in serum were lower than those before treatment, and Foxp3 and T-bet expression in peripheral blood as well as TIMP1 and TIMP2 contents in serum of experimental group after treatment were higher than those of control group whereas RORγt and GATA-3 expression in peripheral blood as well as TARC, Eotaxin, ICAM-1, VCAM-1, L-selectin, ADAM8, NE and MMP9 contents in serum were lower than those of control group. Conclusion: Terbutaline injection aerosol inhalation combined with conventional drug therapy can effectively regulate the immune response and inflammatory response and inhibit the airway remodeling mediated by protease in children with acute attack of bronchial asthma.展开更多
Achieving low friction and wear of poly(phenylene sulfide)(PPS) without using fillers or blending is a challenging task, but one of considerable practical importance. Here we describe how neat PPS with high tribologic...Achieving low friction and wear of poly(phenylene sulfide)(PPS) without using fillers or blending is a challenging task, but one of considerable practical importance. Here we describe how neat PPS with high tribological performance is achieved by manipulating processing parameters(pressure, flow and temperature). The key to achieving high tribological performance is comparatively high molecular chain orientation, realized in neat PPS, at high shear rates and low pressure. The friction coefficient and wear rate are as low as ~0.3 and~10^(-6) mm^(3)·N^(-1)·m^(-1), respectively, which break the record for neat PPS. These values are even better than those for PPS-based blends and comparable to PPS composites. Further studies show, for the first time, that wear rate decreases exponentially with increasing molecular chain orientation, prompting us to revise the classical Archard's law by including the effect of molecular chain orientation. These findings open the possibility of using neat PPS in highly demanding tribological applications.展开更多
The main active components of ginseng are ginsenosides,which play significant roles in treating cardiovascular diseases,cancer,and providing antioxidant effects.Ginsenosides are primarily synthesized through the mevalo...The main active components of ginseng are ginsenosides,which play significant roles in treating cardiovascular diseases,cancer,and providing antioxidant effects.Ginsenosides are primarily synthesized through the mevalo-nate pathway and the methylerythritol phosphate pathway.Many key enzyme genes involved in this biosynthetic process have been cloned and validated,yet the regulatory functions of transcription factors remain unclear.The C_(2)H_(2)-type zincfinger protein family,one of the largest families of transcription factors,is crucial in plant growth and development,response to biotic and abiotic stresses,and regulation of secondary metabolism.This study,based on the ginseng transcriptome database from Jilin,conducted a correlation analysis between the expression levels of PgZFPs genes in the Jilin ginseng C_(2)H_(2)-type zincfinger protein family and ginsenoside content,a gen-ome-wide association study of PgZFPs,and co-expression analysis of PgZFPs with validated key enzyme genes.Ultimately,five candidate genes involved in ginsenoside biosynthesis were identified.The involvement of PgZFP27 and PgZFP-59-02 genes from the PgZFPs family in the biosynthesis of ginsenosides was validated through in vitro methyl jasmonate(MeJA)induction experiments.This result provides new genetic resources for the biosynthesis of ginsenosides.展开更多
Objective:To assess the prognostic value of maximum standardized uptake value(SUVmax),metabolic tumor volume(MTV),and total lesion glycolysis(TLG)determined by 18F-fluorodeoxyglucose positron emission tomography-compu...Objective:To assess the prognostic value of maximum standardized uptake value(SUVmax),metabolic tumor volume(MTV),and total lesion glycolysis(TLG)determined by 18F-fluorodeoxyglucose positron emission tomography-computed tomography(18F-FDG PET/CT)imaging in Hodgkin’s lymphoma patients.Methods:A total of 148 Hodgkin’s lymphoma patients diagnosed with lymph node biopsy from October 2014 to October 2015 were retrospectively analyzed followed by categorizing into good(125 cases)and poor(23 cases)prognosis groups.The chi-squared test was used to analyze the clinicopathological characteristics of Hodgkin’s lymphoma patients with the semi-quantitative 18F-FDG PET/CT parameters;the Spearman method was used to analyze the correlation between the semi-quantitative parameters and clinicopathological features of Hodgkin’s lymphoma;receiver operating characteristic curve was used to analyze the predictive value of the semi-quantitative parameters for poor prognosis of Hodgkin’s lymphoma patients.Results:Mean SUVmax,MTV,and TLG of the 148 cases of Hodgkin’s lymphoma were 7.26±2.38,12.46±3.14 cm3,and 76.83±18.56 g,respectively.Significant variations in the Ann Arbor stage and clinical classification were observed with different levels of semi-quantitative parameters(P<0.05).The semi-quantitative parameters were not correlated with age and gender(P>0.05)but positively correlated with Ann Arbor stage and clinical classification(P<0.05).These parameters in the poor prognosis group were higher than those in the good prognosis group(P<0.05).The area under the curve(AUC)of SUVmax,MTV,and TLG in predicting the poor prognosis group was 0.881,0.875,and 0.838,with cut-off values of 7.264,12.898 cm3,and 74.580g,as well as specificity of 88.8%,84.0%,and 78.4%,and sensitivity of 87.0%,87.0%,and 78.3%,respectively;the AUC of the combined prediction was 0.986,with a specificity of 97.6%and sensitivity of 86.3%.Conclusion:The semi-quantitative 18F-FDG PET/CT parameters provide valuable insights for Hodgkin’s lymphoma prognosis assessment.展开更多
The antimicrobial susceptibility testing was performed with Kirby-Bauer disc diffusion and agar diffusion methods, and the crude β-lactamase was extracted by sonication with its isoelectric point （pI） determined wi...The antimicrobial susceptibility testing was performed with Kirby-Bauer disc diffusion and agar diffusion methods, and the crude β-lactamase was extracted by sonication with its isoelectric point （pI） determined with isoelectric focusing, and purified by two steps of chromatography. The genome DNA fragments of bacterial strains were amplified with PCR and subjected to sequencing. The kinetic parameters for β-lactamase were detected by spectrophoto metric method. It was found that the bacterial strains isolated from clinical specimens were resistant to penicillin, ceftazidine, cefotaxime and azitreonam, but sensitive to imipenem and cefoxitin, in which two resistant strains to ceftazidine were found to produce a single extended spectrum β-lactamase（ESBL） with pI value of 8.7. Results of cloning and sequencing of the β-lactamase encoding gene showed that this gene was similar to blactx-m-l with 6 point mutations including 3 silent mutations. The amino acid sequence derived from the nucleic acid data indicated that this enzyme was distinct from β-lactamse CTX-M-1 by 3 amino acids, i.e. Val-80→Ala, Asp-117→Asn and Ser-143→Ala（CTX-M-Ⅳ）. Molecular weight of this enzyjne was 29 kDa. Kinetic analysis of the partially purified β-lactamase confirmed that this enzyine was ＇able to hydrolyze cefotaxime and aztreonanl, but not to imipenem. In addition, the the β-lactamase was well inhibited by sulbactam（IC50 94 nM） and tazobactam（IC50 5 nM）. It is concluded that CTX-M-Ⅳ is a CTX-M-type extended spectrum β-lactamase.展开更多
Osteoporosis is a degenerative disease caused by an imbalance between osteoblast and osteoclast activity.Repairing osteo-porotic bone defects is challenging due to decreased osteogenesis,increased osteoclast activity,...Osteoporosis is a degenerative disease caused by an imbalance between osteoblast and osteoclast activity.Repairing osteo-porotic bone defects is challenging due to decreased osteogenesis,increased osteoclast activity,and impaired angiogenesis.To address this challenge,a novel scaffold,inspired by the structure of multilayer fishing nets,is developed through a com-bination of template-assisted electrospinning and advanced three-dimensional(3D)printing technologies.The 3D nanofiber scaffold exhibits a hierarchical porous architecture.This design maintains the high specific surface area and extracellular matrix(ECM)mimicry of the nanofiber membrane.Additionally,the sparsely distributed nanofibers within the mesh-like structure facilitate cell infiltration.This unique topological configuration,particularly the strontium-hydroxyapatite(Sr-HAp)-enriched polycaprolactone/silk fibroin nanofibers,plays a critical role in synergistically promoting angiogenesis,enhancing osteogenesis,and suppressing osteoclast differentiation.In an osteoporotic cranial bone defect model,the scaffold demonstrates an exceptional repair efficiency of nearly 100%within 8 weeks,marked by significant new bone formation throughout the implanted area.In conclusion,our approach,which leverages intricate biomimicry and strategic active ion release,emerges as a highly promising strategy for repairing osteoporotic bone defects.展开更多
Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multist...Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multistep,rapid,and thermodynamic nature,tracing and comprehending polymer crystallization pose a formidable challenge,particularly when it encounters practical processing scenarios that involve complex coupledfields(such as temperature,flow,and pressure).The advent of high-time and spatially resolved experiments paves the way for in situ investigations of polymer crystallization.In this review,we delve into the strides in studying polymer crystallization under the effects of coupled externalfields via state-of-the-art high-throughput experiments.We highlight the intricate setup of these high-throughput experimental devices,spanning from the laboratory and pilot levels to the industrial level.The individual and combined effects of externalfields on polymer crystallization are discussed.By breaking away from the conventional“black box”research approach,special interest is paid to the in situ crystalline behavior of polymers during realistic processing.Finally,we underscore the advancements in polymer crystallization via high-throughput experiments and outline its promising development.展开更多
Polymer-based positive temperature coefficient(PTC)composites show exceptional potential for smart thermal management owing to temperature-responsive resistivity.However,conventional PTC composites with high Curie tem...Polymer-based positive temperature coefficient(PTC)composites show exceptional potential for smart thermal management owing to temperature-responsive resistivity.However,conventional PTC composites with high Curie temperatures(Tc>50℃)are unsuitable for precision electronics requiring room-temperature operation.The development of low-Tc composites(Tc<50℃)faces challenges in balancing electrical resistivity,stability,and sensitivity.We present a ternary composite design where carbon black(CB)is selectively dispersed in myristyl alcohol(MA)phase,stabilized by an ethylene vinyl acetate(EVA)matrix.The reversible solid-liquid transition of MA dynamically modulates CB conductive networks,while the elasticity of EVA suppresses phase migration under elevated thermal conditions.The MA/EVA/CB composite achieves unprecedented performance:low Tc(35℃),ultralow initial resistivity(50Ωcm),high PTC intensity(7.0),and exceptional cycling stability(>95%resistivity retention after 100 thermal cycles),surpassing previous benchmarks.Even after real space-environment exposure for 14 days,it retains ultralow resistivity and high PTC intensity.DSC/FTIR analyses confirm molecular integrity,validating stability under extreme conditions.Microstructural studies reveal that MA phase melting/crystallization governs conductive network disruption/reconfiguration.A self-regulating heater fabricated from this composite stabilizes an aluminum block at near Tc(30.6±0.03℃)at 20 V and−10℃ environments without external controls.The low-Tc PTC composites demonstrate transformative potential in adaptive thermal management for aerospace electronics.展开更多
文摘U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or （and） sacral decompression. EQ-5d score was applied to evaluate the patients＇ quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years （range： 15-55 years） at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months （range： 9-47 months） and mean full weight-bearing time was 9.9 weeks （range： 8-14 weeks）. Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle （mean 27.87°, and range： 8°-90°） of the sacrum was smaller than that pre-operation （mean 35.67; range： 15-90） with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score （VAS） was reduced from preoperative 7.07 （range： 5-9） to postoperetive 1.93 （range： 1-3）. All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.
基金supported by the Dr.Western-funded Projects of Chinese Academy of Sciences(XBBS200805)the National Natural Science Foundation of China(40901092)
文摘Urban development in arid and semi-arid regions is largely constrained by fragile physical environ- ments. The characteristics of an urban settlement are different from those in other regions of China. This paper analyses the coupling characteristics and spatio-temporal variations for oasis urban development and water-land resources at the northern slopes of the Tianshan Mountains by principal component analysis and a coupling degree model. The result shows that the degree and change in regional use of water and land resources are different among the studied cities/counties during their development. The built-up areas of these cities/counties have changed little with increasing populations and urbanization levels, which well reflects that the urban development in arid and semi-arid regions is limited by oasis areas. Per capita amount of water supplied, however, presented a trend of slowed growth with increasing levels of urbanization. Water consumption gradually increased with urban development and the improvement of people＇s living standards, accompanied by enhanced water use efficiency. The level of urbanization can be assessed through the coupling degree between oasis urban development and the use of water and land resources. A high coupling degree represents a high level of comprehensive urban devel- opment and use of water-land resources. Alternatively, a low coupling degree denotes a low level of urban devel- opment and water-land resource use.
基金Supported by the National Natural Science Foundation of China,No.81773126,No.81560475,and No.82160486.
文摘BACKGROUND T1b gallbladder carcinoma(GBC)is defined as a tumor that invades the perimuscular connective tissue without extension beyond the serosa or into the liver.However,controversy still exists over whether patients with T1b GBC should undergo cholecystectomy alone or radical GBC resection.AIM To explore the optimal surgical approach in patients with T1b gallbladder cancer of different pathological grades.METHODS Patients with T1bN0M0 GBC who underwent surgical treatment between 2000 and 2017 were included in the Surveillance,Epidemiology,and End Results database.The Kaplan-Meier method and log-rank test were used to analyze the overall survival(OS)and disease-specific survival(DSS)of patients with T1b GBC of different pathological grades.Cox regression analysis was used to identify independent predictors of mortality and explore the selection of surgical methods in patients with T1b GBC of different pathological grades and their relationship with prognosis.RESULTS Of the 528 patients diagnosed with T1bN0M0 GBC,346 underwent simple cholecystectomy(SC)(65.5%),131 underwent SC with lymph node resection(SC+LN)(24.8%),and 51 underwent radical cholecystectomy(RC)(9.7%).Without considering the pathological grade,both the OS(P<0.001)and DSS(P=0.003)of T1b GBC patients who underwent SC(10-year OS:27.8%,10-year DSS:55.1%)alone were significantly lower than those of patients who underwent SC+LN(10-year OS:35.5%,10-year DSS:66.3%)or RC(10-year OS:50.3%,10-year DSS:75.9%).Analysis of T1b GBC according to pathological classification revealed no significant difference in OS and DSS between different types of procedures in patients with grade Ⅰ T1b GBC.In patients with grade Ⅱ T1b GBC,obvious survival improvement was observed in the OS(P=0.002)and DSS(P=0.039)of those who underwent SC+LN(10-year OS:34.6%,10-year DSS:61.3%)or RC(10-year OS:50.5%,10-year DSS:78.8%)compared with those who received SC(10-year OS:28.1%,10-year DSS:58.3%).Among patients with grade Ⅲ or Ⅳ T1b GBC,SC+LN(10-year OS:48.5%,10-year DSS:72.2%),and RC(10-year OS:80%,10-year DSS:80%)benefited OS(P=0.005)and DSS(P=0.009)far more than SC(10-year OS:20.1%,10-year DSS:38.1%)alone.CONCLUSION Simple cholecystectomy may be an adequate treatment for grade Ⅰ T1b GBC,whereas more extensive surgery is optimal for grades Ⅱ-Ⅳ T1b GBC.
基金China Hunan Provincial Science and Technology Department,the Hunan Provincial Natural Science Foundation(10JJ3074)Health Department of Hunan Province,High-level Medical Talents“225”Project of Hunan Province(Xiangwei[2013]13).
文摘Objective:To translate the English version of Infertility Self-Efficacy Scale into Chinese and to validate the psychometric properties of the Chinese version of the Infertility Self-Efficacy Scale(CISE).Method(s):Participants were recruited from the Gynecology Department of two city hospitals.Five main processes were involved in the formation of CISE[1]:scale translation based on expert consultation[2];pre-test questionnaire development with infertile women's feedback(N=20)[3];factor structure assessed by exploratory and confirmatory factor analysis(N=177)[4];assessment of reliability by internal consistency(N=177)and test-retest reliability(N=21);and[5]assessment of convergent validity with Self-rating Anxiety Scale,Self-rating Depression Scale,and Simplified Coping Style Questionnaire(N=177).Results:This study established a 16-item CISE.Factor analyses confirmed a onecomponent solution,which explained 54.59% of total variances and showed an acceptable model fit.Cronbach's a and test-retest correlation coefficients for the scale were 0.94 and 0.84,respectively.The CISE score was significantly correlated with anxiety(r=0.47),depression(r=0.60),positive coping style(r=0.37),and certain negative coping style items.Conclusion:This 16-item CISE is a reliable and valid measure to evaluate perceived selfefficacy among a sample of Chinese women who underwent infertility treatment.
文摘Objective To compare the quality and quantity of total RNA from different source-original neurons applied in LMPC technique. Methods （ 1 ） Aglient 2100 bioanalyzer and RT-PCR were used to check the concentration and fragmentation of total RNA from unfixed, temporal fixed and fixed 12 h hypothalamus sections; （2）Different neurons of PVN and SON were collected by LMPC, CRH, TRH, AVP, OT mRNA level were measured by RT-PCR; （3）Labeled neurons by injecting CTB into stomach and non-labeled neurons in DMV collected by LMPC were checked for house keeping genes by RT-PCR. Results （ 1 ） Unfixed section had higher concentration and better quality of total RNA compared with fixed sections applied in LMPC ; relative short amplicons such as GAPDH, NSE, MCH and MCAR were successfully obtained from fixed and unfixed and long amplicon of GR can only be obtained from unfixed material; （2） In magnocellular PVN and SON the expressions of AVP and OT were more special than those in the parvocellular PVN. Oppositely, the expressions of CRH, TRH in the parvocellular were more special than the other two ; （3） The expressions of house keeping genes had no significant difference between labeled and non-labeled DMV neurons. Conclusion The quality and quantity of total RNA from unfixed brain tissues were better than fixed tissues applied in LMPC and the CTB tracer which may differentiate neurons had no significant effect on physiology of the neurons applied in LMPC. The results showed that the LMPC technique is suitable for the qualitative and quantitative study on individual neurons at mRNA level.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51533004,51773135,and 21878194).We also thank Shanghai Synchrotron Radiation Facility(SSRF)for the kind help in X ray measurements.
文摘We utilized two structurally different long chains(linear and branched ultra-high molecular weight polyethylene)to reveal the dependence of flow-induced crystallization on long chain architecture,and prepared two bi-disperse systems of 98 wt%short chain and 2 wt%long chain.A flow field was applied to the bi-disperse polyethylene melt by a modified injection-molding machine,known as oscillation shear injection molding(OSIM).For the first time,the structural influence of long chains on flow-induced shish-kebab formation was systematically investigated.For the intermediate layer of OSIM samples,the branched long chains were better than the linear long chains at inducing shish-kebab formation,agreeing with the reported literatures,because the branches can maintain their oriented conformations longer.But unexpectedly,the reverse is the case for the core layer of OSIM samples,where the shear flow was much weaker than the intermediate layer.To understand the unexpected phenomenon,the lifetime of shishes induced by different long chains was compared.Result demonstrated that the linear-induced shishes possessed higher thermal stability than the branched-induced ones so that the linear-induced shishes could survive in the core layer of OSIM samples.Additionally,unlike other methods for flow-induced crystallization,OSIM could create samples for measuring mechanical properties,and thus offer the chance to reveal the relationship between structure and performance.The mechanical results demonstrated that both long chains remarkably enhanced the mechanical properties because of the significant promoting effect of long chains and intense flow fields on shish-kebab formation.However,the linear long chains induced more stable and flawless shishes with higher tensile strength and modulus(80.4 and 1613.5 Mpa,respectively)than the branched ones(74.4 and 1489.3 Mpa).Our research not only helps elucidate the mechanism of shish-kebab formation but also provides a better choice to reinforce polymers by adding long chains with suitable structure.
基金the National Natural Science Foundation of China(Nos.81960101,81860483).
文摘The exact mechanism by which knockout of Toll-like receptor 4(TLR4)attenuates the liver injury remains unclear.The present study aimed to examine the role of TLR4 in the pathogenesis of bile duct ligation(BDL)-induced liver cholestatic injury and the underlying mechanism.Wild type(WT)mice and TLR4 knockout(TLR4-KO)mice were used for the establishment of the BDL model.Metabolomics were applied to analyze the changes of small molecular metabolites in the serum and liver of the two groups.The serum biochemical indexes and the HE staining results of liver tissue showed that liver damage was significantly reduced in TLR4-KO mice after BDL when compared with that in WT mice.The metabolite analysis results showed that TLR4 KO could maintain the metabolisms of amino acids-and choline-related metabolites.After BDL,the amino acids-and choline-related metabolites,especially choline and 3-hydroxybutyrate,were significantly increased in WT mice(both in serum and liver),but these metabolites in the liver of TLR4-KO mice after BLD were not significant different from those before BLD.In conclusion,TLR4 KO could attenuate BDL-induced liver cholestatic injury through regulating amino acid and choline metabolic pathways.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030001)the National Key Research and Development Program of China(2021YFA0716304)+3 种基金the project supported by the Space Utilization System of China Manned Space Engineering(KJZ-YY-WCL03)the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(6142902210109)Independent Innovation Projects of the Hubei Longzhong Laboratory(2022ZZ-32)the National Natural Science Foundation of China(Nos.11902232,51972246,and 51521001).
文摘Given the significant potential of multi-directional functionally graded materials(MFGMs)for customizable performance,it is crucial to develop versatile material models to enhance design optimization in engineering applications.This paper introduces a material model for an MFGM plate described by trigonometric functions,equipped with four parameters to control diverse material distributions effectively.The bending and vibration analysis of MFGM rectangular and cutout plates is carried out utilizing isogeometric analysis,which is based on a novel third-order shear deformation theory(TSDT)to account for transverse shear deformation.The present TSDT,founded on rigorous kinematics of displacements,is demonstrated to surpass other preceding theories.It is derived from an elasticity formulation,rather than relying on the hypothesis of displacements.The effectiveness of the proposed method is verified by comparing its numerical results with those of other methods reported in the relevant literature.Numerical results indicate that the structure,boundary conditions,and gradient parameters of the MFGM plate significantly influence its deflection,stress,and vibration frequency.As the periodic parameter exceeds four,the model complexity increases,causing result fluctuations.Additionally,MFGM cutout plates,when clamped on all sides,display almost identical first four vibration frequencies.
文摘Objective: To study the clinical effect of terbutaline injection aerosol inhalation combined with conventional drug therapy for acute attack of bronchial asthma in children. Methods:Children with acute attack of bronchial asthma who were treated in Wusheng Hospital of Traditional Chinese Medicine and Qiandongnan Prefecture People's Hospital between January 2014 and July 2017 were selected as the study cases for prospective study and randomly divided into the experimental group who received terbutaline + budesonide aerosol inhalation and the control group who received budesonide aerosol inhalation. The expression levels of immune cell transcription factors in peripheral blood as well as the contents of adhesion factors, chemokines, proteases and their inhibitory molecules in serum were determined before treatment and 3 days after treatment. Results: Foxp3 and T-bet expression in peripheral blood as well as TIMP1 and TIMP2 contents in serum of both groups after treatment were higher than those before treatment whereas RORγt and GATA-3 expression in peripheral blood as well as TARC, Eotaxin, ICAM-1, VCAM-1, L-selectin, ADAM8, NE and MMP9 contents in serum were lower than those before treatment, and Foxp3 and T-bet expression in peripheral blood as well as TIMP1 and TIMP2 contents in serum of experimental group after treatment were higher than those of control group whereas RORγt and GATA-3 expression in peripheral blood as well as TARC, Eotaxin, ICAM-1, VCAM-1, L-selectin, ADAM8, NE and MMP9 contents in serum were lower than those of control group. Conclusion: Terbutaline injection aerosol inhalation combined with conventional drug therapy can effectively regulate the immune response and inflammatory response and inhibit the airway remodeling mediated by protease in children with acute attack of bronchial asthma.
基金financially supported by the National Natural Science Foundation of China (Nos. 21676217, 52003215, 21978240 and 52003219)Youth Project of Basic Research Program of Natural Science in Shaanxi Province (No. 2020JQ179)+1 种基金the Fundamental Research Funds for the Central Universities (Nos. 3102018AX004 and 3102017jc01001)the Open Testing Foundation of the Analytical & Testing Center of Northwestern Polytechnical University (No. 2020T020)。
文摘Achieving low friction and wear of poly(phenylene sulfide)(PPS) without using fillers or blending is a challenging task, but one of considerable practical importance. Here we describe how neat PPS with high tribological performance is achieved by manipulating processing parameters(pressure, flow and temperature). The key to achieving high tribological performance is comparatively high molecular chain orientation, realized in neat PPS, at high shear rates and low pressure. The friction coefficient and wear rate are as low as ~0.3 and~10^(-6) mm^(3)·N^(-1)·m^(-1), respectively, which break the record for neat PPS. These values are even better than those for PPS-based blends and comparable to PPS composites. Further studies show, for the first time, that wear rate decreases exponentially with increasing molecular chain orientation, prompting us to revise the classical Archard's law by including the effect of molecular chain orientation. These findings open the possibility of using neat PPS in highly demanding tribological applications.
基金This work was supported by the Department of Science and Technology of Jilin Province(20240101227JC,20210402043GH,20200801063GH,20190201264JC,20190103104JH,20180414077GH,and 20180101027JC)the Development and Reform Commission of Jilin Province(2016C064 and 2018C047-3).
文摘The main active components of ginseng are ginsenosides,which play significant roles in treating cardiovascular diseases,cancer,and providing antioxidant effects.Ginsenosides are primarily synthesized through the mevalo-nate pathway and the methylerythritol phosphate pathway.Many key enzyme genes involved in this biosynthetic process have been cloned and validated,yet the regulatory functions of transcription factors remain unclear.The C_(2)H_(2)-type zincfinger protein family,one of the largest families of transcription factors,is crucial in plant growth and development,response to biotic and abiotic stresses,and regulation of secondary metabolism.This study,based on the ginseng transcriptome database from Jilin,conducted a correlation analysis between the expression levels of PgZFPs genes in the Jilin ginseng C_(2)H_(2)-type zincfinger protein family and ginsenoside content,a gen-ome-wide association study of PgZFPs,and co-expression analysis of PgZFPs with validated key enzyme genes.Ultimately,five candidate genes involved in ginsenoside biosynthesis were identified.The involvement of PgZFP27 and PgZFP-59-02 genes from the PgZFPs family in the biosynthesis of ginsenosides was validated through in vitro methyl jasmonate(MeJA)induction experiments.This result provides new genetic resources for the biosynthesis of ginsenosides.
基金Social Science Foundation of Xinjiang Uygur Autonomous Region(Project No.:19BGL110)State Key Laboratory of Pathogenesis,Prevention,Treatment of Central Asian High Incidence Diseases Fund(SKL-HIDCA-2021-28).
文摘Objective:To assess the prognostic value of maximum standardized uptake value(SUVmax),metabolic tumor volume(MTV),and total lesion glycolysis(TLG)determined by 18F-fluorodeoxyglucose positron emission tomography-computed tomography(18F-FDG PET/CT)imaging in Hodgkin’s lymphoma patients.Methods:A total of 148 Hodgkin’s lymphoma patients diagnosed with lymph node biopsy from October 2014 to October 2015 were retrospectively analyzed followed by categorizing into good(125 cases)and poor(23 cases)prognosis groups.The chi-squared test was used to analyze the clinicopathological characteristics of Hodgkin’s lymphoma patients with the semi-quantitative 18F-FDG PET/CT parameters;the Spearman method was used to analyze the correlation between the semi-quantitative parameters and clinicopathological features of Hodgkin’s lymphoma;receiver operating characteristic curve was used to analyze the predictive value of the semi-quantitative parameters for poor prognosis of Hodgkin’s lymphoma patients.Results:Mean SUVmax,MTV,and TLG of the 148 cases of Hodgkin’s lymphoma were 7.26±2.38,12.46±3.14 cm3,and 76.83±18.56 g,respectively.Significant variations in the Ann Arbor stage and clinical classification were observed with different levels of semi-quantitative parameters(P<0.05).The semi-quantitative parameters were not correlated with age and gender(P>0.05)but positively correlated with Ann Arbor stage and clinical classification(P<0.05).These parameters in the poor prognosis group were higher than those in the good prognosis group(P<0.05).The area under the curve(AUC)of SUVmax,MTV,and TLG in predicting the poor prognosis group was 0.881,0.875,and 0.838,with cut-off values of 7.264,12.898 cm3,and 74.580g,as well as specificity of 88.8%,84.0%,and 78.4%,and sensitivity of 87.0%,87.0%,and 78.3%,respectively;the AUC of the combined prediction was 0.986,with a specificity of 97.6%and sensitivity of 86.3%.Conclusion:The semi-quantitative 18F-FDG PET/CT parameters provide valuable insights for Hodgkin’s lymphoma prognosis assessment.
文摘The antimicrobial susceptibility testing was performed with Kirby-Bauer disc diffusion and agar diffusion methods, and the crude β-lactamase was extracted by sonication with its isoelectric point （pI） determined with isoelectric focusing, and purified by two steps of chromatography. The genome DNA fragments of bacterial strains were amplified with PCR and subjected to sequencing. The kinetic parameters for β-lactamase were detected by spectrophoto metric method. It was found that the bacterial strains isolated from clinical specimens were resistant to penicillin, ceftazidine, cefotaxime and azitreonam, but sensitive to imipenem and cefoxitin, in which two resistant strains to ceftazidine were found to produce a single extended spectrum β-lactamase（ESBL） with pI value of 8.7. Results of cloning and sequencing of the β-lactamase encoding gene showed that this gene was similar to blactx-m-l with 6 point mutations including 3 silent mutations. The amino acid sequence derived from the nucleic acid data indicated that this enzyme was distinct from β-lactamse CTX-M-1 by 3 amino acids, i.e. Val-80→Ala, Asp-117→Asn and Ser-143→Ala（CTX-M-Ⅳ）. Molecular weight of this enzyjne was 29 kDa. Kinetic analysis of the partially purified β-lactamase confirmed that this enzyine was ＇able to hydrolyze cefotaxime and aztreonanl, but not to imipenem. In addition, the the β-lactamase was well inhibited by sulbactam（IC50 94 nM） and tazobactam（IC50 5 nM）. It is concluded that CTX-M-Ⅳ is a CTX-M-type extended spectrum β-lactamase.
基金supported by the Program of Excellent Doctoral(Postdoctoral)of Zhongnan Hospital of Wuhan University(Grant No.ZNYB2021005)the Fundamental Research Funds for the Central Universities(2042022kf1121)National Natural Science Foundation of China(Grant No.32101084).
文摘Osteoporosis is a degenerative disease caused by an imbalance between osteoblast and osteoclast activity.Repairing osteo-porotic bone defects is challenging due to decreased osteogenesis,increased osteoclast activity,and impaired angiogenesis.To address this challenge,a novel scaffold,inspired by the structure of multilayer fishing nets,is developed through a com-bination of template-assisted electrospinning and advanced three-dimensional(3D)printing technologies.The 3D nanofiber scaffold exhibits a hierarchical porous architecture.This design maintains the high specific surface area and extracellular matrix(ECM)mimicry of the nanofiber membrane.Additionally,the sparsely distributed nanofibers within the mesh-like structure facilitate cell infiltration.This unique topological configuration,particularly the strontium-hydroxyapatite(Sr-HAp)-enriched polycaprolactone/silk fibroin nanofibers,plays a critical role in synergistically promoting angiogenesis,enhancing osteogenesis,and suppressing osteoclast differentiation.In an osteoporotic cranial bone defect model,the scaffold demonstrates an exceptional repair efficiency of nearly 100%within 8 weeks,marked by significant new bone formation throughout the implanted area.In conclusion,our approach,which leverages intricate biomimicry and strategic active ion release,emerges as a highly promising strategy for repairing osteoporotic bone defects.
基金supported by the National Key Research and Development Program of China(2023YFB3712500)the National Natural Science Foundation of China(52273142,52033005,U23A20583)the Science and Technology Department of Sichuan Province(2024NSFTD0003).
文摘Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multistep,rapid,and thermodynamic nature,tracing and comprehending polymer crystallization pose a formidable challenge,particularly when it encounters practical processing scenarios that involve complex coupledfields(such as temperature,flow,and pressure).The advent of high-time and spatially resolved experiments paves the way for in situ investigations of polymer crystallization.In this review,we delve into the strides in studying polymer crystallization under the effects of coupled externalfields via state-of-the-art high-throughput experiments.We highlight the intricate setup of these high-throughput experimental devices,spanning from the laboratory and pilot levels to the industrial level.The individual and combined effects of externalfields on polymer crystallization are discussed.By breaking away from the conventional“black box”research approach,special interest is paid to the in situ crystalline behavior of polymers during realistic processing.Finally,we underscore the advancements in polymer crystallization via high-throughput experiments and outline its promising development.
基金supported by the National Natural Science Foundation of China(U24A2074,52403045)the Natural Science Foundation of Sichuan Province(24NSFSC0160)+1 种基金the Postdoctoral Fellowship Program of CPSF(GZC20241106)the Opening Project of Robotic Satellite Key Laboratory of Sichuan Province。
文摘Polymer-based positive temperature coefficient(PTC)composites show exceptional potential for smart thermal management owing to temperature-responsive resistivity.However,conventional PTC composites with high Curie temperatures(Tc>50℃)are unsuitable for precision electronics requiring room-temperature operation.The development of low-Tc composites(Tc<50℃)faces challenges in balancing electrical resistivity,stability,and sensitivity.We present a ternary composite design where carbon black(CB)is selectively dispersed in myristyl alcohol(MA)phase,stabilized by an ethylene vinyl acetate(EVA)matrix.The reversible solid-liquid transition of MA dynamically modulates CB conductive networks,while the elasticity of EVA suppresses phase migration under elevated thermal conditions.The MA/EVA/CB composite achieves unprecedented performance:low Tc(35℃),ultralow initial resistivity(50Ωcm),high PTC intensity(7.0),and exceptional cycling stability(>95%resistivity retention after 100 thermal cycles),surpassing previous benchmarks.Even after real space-environment exposure for 14 days,it retains ultralow resistivity and high PTC intensity.DSC/FTIR analyses confirm molecular integrity,validating stability under extreme conditions.Microstructural studies reveal that MA phase melting/crystallization governs conductive network disruption/reconfiguration.A self-regulating heater fabricated from this composite stabilizes an aluminum block at near Tc(30.6±0.03℃)at 20 V and−10℃ environments without external controls.The low-Tc PTC composites demonstrate transformative potential in adaptive thermal management for aerospace electronics.
