Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene g...Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.展开更多
Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripher...Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.展开更多
Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Walle...Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.展开更多
With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysi...With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.展开更多
This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification wa...This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification was revealed combining thermogravimetric(TG)analysis,Fourier transform infrared spectroscopy,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state 13C nuclear magnetic resonance spectroscopy.Furthermore,crucible coking experiments were also conducted using industrial coal mixture and treated PET with the optimum G(PET300)or raw PET to evaluate the applicability of PET waste in coal-blending coking.According to characterization results of coke reactivity(CR),coke strength after reaction(CSR)indices,TG-related curves,pore volumes,and Raman spectra of the resultant cokes,LTPT could greatly increase the G of PET,and the optimum temperature was 300℃.Specifically,compared with the coke obtained from the blend with PET,the CR of the coke produced from the blend with PET300 decreased by 4.9%,whereas the CSR of the increased by 7.4%,suggesting that LTPT could increase the proportion of PET used for coal-blending coking.The improvement in G is attributed to the changes in C-O/C=O ratio,aliphatic H and aromaticity caused by LTPT.展开更多
BACKGROUND Excipients may improve the palatability of polyethylene glycol(PEG),the firstline treatment for childhood functional constipation(FC),leading to good compliance and improved treatment outcomes.AIM To compar...BACKGROUND Excipients may improve the palatability of polyethylene glycol(PEG),the firstline treatment for childhood functional constipation(FC),leading to good compliance and improved treatment outcomes.AIM To compare the developed PEG-based formula(PEG-Chula)to the commercial formula for treating childhood FC.METHODS In this randomized controlled trial,we enrolled children aged<18 years with FC diagnosed by the Rome Ⅳ criteria to receive PEG-Chula[four flavors:(1)Strawberry;(2)Lychee;(3)Apple;and(4)Lychee-rose]or Forlax(orange-grapefruit flavor)for eight weeks.The primary outcomes included changes in stool frequency and consistency measured by the Bristol Stool scale.The secondary outcomes were constipation-related symptom improvement,adverse events,and palatability measured by the facial hedonic scale.RESULTS Fifty-two children diagnosed with FC[median age:4.21(2.33,7.88)years;35(67.31%)females]were enrolled.After the 8-week treatment,the mean weekly stool frequency increased in both groups,the mean change was 4.02(95%CI:3.09-4.95)in PEG-Chula and 3.78(95%CI:2.79-4.78)in commercial PEG compared to baseline(P<0.001).The extent of stool consistency improvement did not differ significantly.The most preferred PEG-Chula flavor was rated more palatable than the commercial PEG.Treatment compliance correlated with medication palatability(r=0.34,P=0.013).No significant differences in adverse events were found.CONCLUSION Both PEG-based formulas are effective and safe for managing pediatric FC.展开更多
Incorporating a low density of ester units into the backbone of polyethylene materials enhances their sustainability and recyclability while maintaining the main material properties of polyethylenes.Here we report a n...Incorporating a low density of ester units into the backbone of polyethylene materials enhances their sustainability and recyclability while maintaining the main material properties of polyethylenes.Here we report a new way to access degradable polyethylene materials with a low content of in-chain ester units via mechanochemical backbone editing.Initially,ester groups are incorporated as side groups through catalytic copolymerization of ethylene with a cyclobutene-fused lactone monomer(CBL),yielding polyethylene materials with high molecular weights and adjustable thermomechanical properties.Subsequent solid-state ball-milling treatment selectively introduces side-chain ester groups into the main chain of the polyethylene materials via force-induced cycloreversion of the cyclobutane units.Under acidic conditions,hydrolysis of the resultant polyethylene materials with in-chain ester units facilitates further degradation into oligomers.展开更多
In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative ro...In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative rotary shear system(RSS)to address these deficiencies through controlled mandrel rotation and cooling rates.We successfully prepared self-reinforced HDPE pipes with a three-layer structure combining spherical and shish-kebab crystals.Rotational processing aligned the molecular chains in the ring direction and formed shish-kebab crystals.As a result,the annular tensile strength of the rotationally processed three-layer shish-kebab structure(TSK)pipe increased from 26.7 MPa to 76.3 MPa,an enhancement of 185.8%.Notably,while maintaining excellent tensile strength(73.4 MPa),the elongation at break of the spherulite shishkebab spherulite(SKS)tubes was improved to 50.1%,as compared to 33.8%in the case of shish-kebab spherulite shish-kebab(KSK)tubes.This improvement can be attributed to the changes in the micro-morphology and polymer structure within the SKS tubes,specifically due to the formation of small-sized shish-kebab crystals and the low degrees of interlocking.In addition,2D-SAXS analysis revealed that KSK tubes have higher tensile strength due to smaller crystal sizes and larger shish dimensions,forming dense interlocking structures.In contrast,the SKS and TSK tubes had thicker amorphous regions and smaller shish sizes,resulting in reduced interlocking and mechanical performance.展开更多
It has been widely recognized that the mixing process has significant impacts on the performance of low-density polyethylene(LDPE)reactors due to the rapid radical polymerization occurred in the reactors,but how the m...It has been widely recognized that the mixing process has significant impacts on the performance of low-density polyethylene(LDPE)reactors due to the rapid radical polymerization occurred in the reactors,but how the macro-and micro-mixing affect the reactor performance was still controversial in publications.In this work,a cold-flow LDPE autoclave with multi-feedings was scaled down(1/2)from an industrial reactor and built to systematically investigate the macro-and micro-mixing characteristics of fluid by experiments.Furthermore,the effects of macro-and micro-mixing on the polymerization were comprehensively analyzed.The results showed that according to the delay time t_(d) and macro-mixing times tM calculated from residence time distribution(RTD)curves,the macro-mixing states are significantly different at various axial positions(h/H),especially at lower agitation Reynolds number Re.But with the increase of Re,since the circulation flow in the reactor is strengthened,the t_(d) for each feed gradually decreases to 0,and the t_(M) at different axial positions tend to be identical.For micro-mixing,the qualities of micro-mixing at different axial positions are similar,and the average micro-mixing time t_(m) in the reactor decreases exponentially with the increase of Re.Moreover,a fitting model was established.Through the comparison of the characteristic times of macro-mixing(t_(d),t_(M)),micro-mixing(t_(m))and elementary reactions within the industrial range of Re,it can be concluded that the properties of LDPE products are dominated by the macro-mixing behavior,and the consumption of initiators is affected by both the macro-and micro-mixing behaviors.This conclusion is of great significance for the design,optimization and operation of LDPE reactors.展开更多
To enhance the hydrophilicity and antistatic properties of the polyethylene terephthalate(PET)fabric,the lawsone dye was employed in dyeing the PET fabric.It was dissolved in ethanol/deionized water mixture and deioni...To enhance the hydrophilicity and antistatic properties of the polyethylene terephthalate(PET)fabric,the lawsone dye was employed in dyeing the PET fabric.It was dissolved in ethanol/deionized water mixture and deionized water separately,forming different lawsone dye solutions(LDSs).The study investigated how the compounds in the LDS improve the surface properties and color durability of the PET fabric,resulting in increased dye uptake.An infrared dyeing machine was utilized to expedite the reactions between the lawsone dye and the PET fabric.Additionally,the chemical composition of the dyed PET fabric was verified using techniques such as Fourier transform infrared(FTIR)spectroscopy,X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and ultraviolet-visible(UV-Vis)spectrophotometry.The K/S value was measured to assess color durability.After dyeing,the PET fabric exhibited high hydrophilicity which improved the hygroscopicity of the PET fabric and thus the conductivity of the PET fabric surface increased,thereby providing an antistatic effect.展开更多
BACKGROUND In the field of clinical intestinal preparation,compound polyethylene glycol electrolyte solution(SF-PEG)is a commonly used intestinal cleaner.However,practice has shown that using only a single polyethylen...BACKGROUND In the field of clinical intestinal preparation,compound polyethylene glycol electrolyte solution(SF-PEG)is a commonly used intestinal cleaner.However,practice has shown that using only a single polyethylene glycol formulation often fails to achieve the desired intestinal preparation effect.Linalotide has a unique mechanism of action,which can effectively enhance the secretion of small intestinal fluid and promote intestinal peristalsis.The combination of linaclotide and SF-PEG may provide a better solution for intestinal preparation and improve the quality of intestinal cleaning.Therefore,exploring the application value and clinical efficacy of linaclotide capsules combined with SF-PEG in intestinal preparation is of great clinical significance.AIM To explore the effects of the combination of linaclotide capsules and SF-PEG,including its efficacy in intestinal preparation and patient tolerance.METHODS To investigate the differences in the effectiveness of different bowel preparation plans in colonoscopy,this article conducted a comprehensive and detailed retrospective analysis of the medical records of patients who underwent colonoscopy from January 2023 to December 2023.In this study,116 patients were accurately divided into three groups based on the different intestinal preparation drugs used before colonoscopy.Among them,group A consisted of 29 patients who underwent intestinal preparation using 3 liters of SF-PEG combined with linaclotide;group B consists of 50 patients who underwent intestinal preparation using 3 liters of SF-PEG;group C consisted of 37 patients who underwent intestinal preparation using a combination of 2-liter SF-PEC and linaclotide.Subsequently,this article evaluated the quality of intestinal preparation in these three groups of patients,using the Boston bowel preparation scale(BBPS)as a quantitative indicator,while comparing multiple indicators such as intestinal preparation completion rate and detection of positive lesions,providing a strong basis for optimizing clinical intestinal preparation plans.RESULTS No statistically significant differences were found in BBPS scores(7.75±1.23,7.69±1.14,and 7.66±1.31;P=0.240),bowel preparation completion rates(96.55%,90.00%,and 97.30%;P=0.293),adenoma detection rates(20.69%,38.00%,and 32.43%;P=0.281),polyp detection rates(34.48%,50.00%,37.84%;P=0.326),insertion time(6.03±4.34,6.12±3.60,and 5.33±2.42;P=0.584),and patient satisfaction rates(89.66%,84.00%,and 97.30%;P=0.398)among the three groups.However,statistically significant differences were observed in withdrawal time(7.45±2.91,9.02±3.54,and 6.86±2.66;P=0.027)and adverse reaction rates(6.90%,20.00%,and 2.70%;P=0.029)among the three groups.Multiple comparisons showed that group C had significantly lower withdrawal time and adverse reaction rates than group B(P=0.013,P=0.016).CONCLUSION Linaclotide capsules show a trend in improving bowel preparation quality and reducing the dosage of SF-PEG.展开更多
Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)...Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.展开更多
Flexible polymer-based foam sensors have significant potential for application in wearable electronics and motion monitoring.However,these prospects are hindered by the complex and unenvironmentally friendly manufactu...Flexible polymer-based foam sensors have significant potential for application in wearable electronics and motion monitoring.However,these prospects are hindered by the complex and unenvironmentally friendly manufacturing processes.In this study,we employed melt blending and supercritical carbon dioxide foaming to fabricate an ethylene-vinyl acetate copolymer(EVA)/low-density polyethylene(LDPE)/carbon nanotube(CNT)piezoresistive foam sensor.The cross-linking agent bis(tert-butyldioxyisopropyl)benzene and the conductive filler CNT were incorporated into the EVA/LDPE composite,successfully achieving a chemically cross-linked and physically entangled composite structure that significantly enhanced the storage modulus and complex viscosity.Additionally,the compressive strength of EVA/LDPE/CNT foam with 10 parts per hundred rubber(phr)CNT reached 1.37 MPa at 50%compression,marking a 340%increase compared to the 0.31 MPa of the CNT-free sample.Furthermore,the EVA/LDPE/CNT composite foams,which incorporated 10 phr CNT,were prepared under specific foaming conditions,resulting in an ultra-low density of 0.11 g/cm^(3) and a higher sensitivity,with a gauge factor of–2.3.The piezoresistive foam sensors developed in this work could accurately detect human motion,thereby expanding their applications in the field of piezoresistive foam sensors and providing an effective strategy for the advancement of high-performance piezoresistive foam sensors.展开更多
Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving t...Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.展开更多
The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substi...The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substitut-ing commercial plastics for a biodegradable renewable polymer for many applications,low-density polyethylene(LDPE)was mixed with varying concentrations of algal biomass(AB).Algae are considered a clean,renewable energy source because they don’t harm the environment and can be used to create bioplastics.Algal biomass grown in a high rate algal pond(HRAP)used for wastewater treatment used at 12.5-50 weight percent.Mechan-ical,thermal,and morphological characteristics of the LDPE/AB mixes were studied.Improved compatibility and uniformity between the LDPE matrix and algal biomass phase were evident in the morphology of LDPE/AB blends.Tensile strength(TS)and elastic modulus(EM)of the prepared LDPE/AB blends significantly decreased to 4.63 and 255 MPa,respectively.Nevertheless,by increasing the concentration of AB up to 25%and 37.5%,the mechanical properties enhanced and raised to(TS=6.75 MPa,EM=426 MPa)and(TS=7 MPa,EM=494 MPa),respectively.Using 25%and 37.5%of AB significantly enhanced the miscibility and interaction between algal bio-mass and LDPE polymer.However,increasing the percentage of AB led to a reduction in the thermal stability of the LDPE/AB.In contrast,compatibilized blends demonstrated better thermal stability compared to un-compa-tibilized blends.These findings indicate that it is possible to develop a blend with improved structural,thermal,and mechanical properties by partially replacing LDPE with biodegradable algal biomass.展开更多
The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the ...The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the hot pressing adhesive method. Then, the uniaxial tensile tests were conducted to investigate the mechanical properties of AA5052/polyethylene/ AA5052 sandwich sheets, and the stretching tests were carried out to investigate the influences of polymer core thickness on the limit dome height of the sandwich sheet. The forming limit curves for three kinds of sandwich sheets were obtained. The experimental results show that the forming limit of the AA5052/polyethylene/AA5052 sandwich sheet is higher than that of the monolithic AA5052 sheet, and it increases with increasing the thickness of polyethylene core.展开更多
Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin w...Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.展开更多
The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved ...The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays（EDAX）,and morphologies of catalyst particles and polymer products were examined by scanning electron microscope（SEM）.Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance.展开更多
High density polyethylene （HDPE）/polyethylene-block-poly（ethylene glycol） （PE-b-PEG） blend porous membranes were prepared via thermally induced phase separation （TIPS） process using diphenyl ether （DPE） as d...High density polyethylene （HDPE）/polyethylene-block-poly（ethylene glycol） （PE-b-PEG） blend porous membranes were prepared via thermally induced phase separation （TIPS） process using diphenyl ether （DPE） as diluent. The phase diagrams of HDPE/PE-b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry （DSC）. By varying the content of PE-b-PEG, the effects of PE-b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy （SEM） and wide angle X-ray diffraction （WAXD）. The chemical compositions of whole membranes and surface layers were characterized by elementary analysis, Fourier transform infrared spectroscopy-attenuated total reflection （FTIR-ATR） and X-ray photoelectron spectroscopy （XPS）. Water contact angle, static protein adsorption and water flux experiments were used to evaluate the hydrophilicity, antifouling and water permeation properties of the membranes. It was found that the addition of PE-b-PEG increased the pore size of the obtained blend membranes. In the investigated range of PE-b-PEG content, the PEG blocks could not aggregate into obviously separated domains in membrane matrix. More importantly, PE-b-PEG could not only be retained stably in the membrane matrix during membrane formation, but also enrich at the membrane surface layer. Such stability and surface enrichment of PE-b-PEG endowed the blend membranes with improved hydrophilicity, protein absorption resistance and water permeation properties, which would be substantially beneficial to HDPE membranes for water treatment application.展开更多
Polyethylene (PE) films with additives consisting mainly of oleic acid and ferrous ions were subjected to accelerated degradation at simulated composting temperatures.Based on Fourier transform infrared spectroscopy a...Polyethylene (PE) films with additives consisting mainly of oleic acid and ferrous ions were subjected to accelerated degradation at simulated composting temperatures.Based on Fourier transform infrared spectroscopy and measurements of mechanical properties and viscosity average molecular weight,the degradation of the films was characterized and the degradation mechanism was discussed.The films containing additives with ferrous ions represent considerable decreases in molecular weight,and the carbonyl groups and hydroperoxides in the aging films show different trends of increase with the aging time.These results indicate that the ferrous ion plays an important role in the degradation of PE films and accelerates the degradation of PE.展开更多
基金supported by the Department of Defense AFIRMⅢW81XWH-20-2-0029 grant subcontractLone Star Paralysis gift,UT POC19-1774-13 grant+1 种基金Neuraptive Therapeutics Inc.26-7724-56 grantNational Institutes of Health R01-NS128086(all to GDB)。
文摘Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.
基金supported by grants from the Lone Star Paralysis Foundation,NIH R01NS081063Department of Defense award W81XWH-19-2-0054 to GDB+2 种基金supported by University of Wyoming Startup funds,Department of Defense grant W81XWH-17-1-0402the University of Wyoming Sensory Biology COBRE under National Institutes of Health(NIH)award number 5P20GM121310-02the National Institute of General Medical Sciences of the NIH under award number P20GM103432 to JSB。
文摘Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.
基金supported by DOD AFIRMⅢW81XWH-20-2-0029 subcontract,UT POC19-1774-13Neuraptive Therapeutics Inc.26-7724-56+1 种基金NIH R01-NS128086 grantsLone Star Paralysis gift(to GDB)。
文摘Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.
文摘With the aim to effectively depolymerize polyethylene terephthalate(PET)under mild reaction conditions,PET methanolysis and dimethyl terephthalate(DMT)hydrolysis are integrated in a catalyst system.Firstly,methanolysis of PET to DMT is achieved over Cu-Mg-Al oxide catalyst.Next,terephthalic acid(TPA)is prepared by DMT hydrolysis.It is found that hydrolysis of DMT to TPA can be promoted by introducing trace amount of water in this catalyst system.CuO-MgO-4.5Al_2O_(3)catalyst demonstrates the excellent catalytic performance for the depolymerization of PET with high conversion rate and TPA yield(100%and 99.5%,respectively)after reaction at 160℃for 6 h,which provides a new idea for the depolymerization of PET.
基金supported by the National Natural Science Foundation of China(22308006,22278001)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification was revealed combining thermogravimetric(TG)analysis,Fourier transform infrared spectroscopy,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state 13C nuclear magnetic resonance spectroscopy.Furthermore,crucible coking experiments were also conducted using industrial coal mixture and treated PET with the optimum G(PET300)or raw PET to evaluate the applicability of PET waste in coal-blending coking.According to characterization results of coke reactivity(CR),coke strength after reaction(CSR)indices,TG-related curves,pore volumes,and Raman spectra of the resultant cokes,LTPT could greatly increase the G of PET,and the optimum temperature was 300℃.Specifically,compared with the coke obtained from the blend with PET,the CR of the coke produced from the blend with PET300 decreased by 4.9%,whereas the CSR of the increased by 7.4%,suggesting that LTPT could increase the proportion of PET used for coal-blending coking.The improvement in G is attributed to the changes in C-O/C=O ratio,aliphatic H and aromaticity caused by LTPT.
基金Supported by the 90th Anniversary of Chulalongkorn University Fund(Ratchadapiseksomphot Endowment Fund)Ratchadapiseksompotch Funds,Graduate Affairs,Faculty of Medicine,Chulalongkorn University,Bangkok,Thailand,No.GA68/028.
文摘BACKGROUND Excipients may improve the palatability of polyethylene glycol(PEG),the firstline treatment for childhood functional constipation(FC),leading to good compliance and improved treatment outcomes.AIM To compare the developed PEG-based formula(PEG-Chula)to the commercial formula for treating childhood FC.METHODS In this randomized controlled trial,we enrolled children aged<18 years with FC diagnosed by the Rome Ⅳ criteria to receive PEG-Chula[four flavors:(1)Strawberry;(2)Lychee;(3)Apple;and(4)Lychee-rose]or Forlax(orange-grapefruit flavor)for eight weeks.The primary outcomes included changes in stool frequency and consistency measured by the Bristol Stool scale.The secondary outcomes were constipation-related symptom improvement,adverse events,and palatability measured by the facial hedonic scale.RESULTS Fifty-two children diagnosed with FC[median age:4.21(2.33,7.88)years;35(67.31%)females]were enrolled.After the 8-week treatment,the mean weekly stool frequency increased in both groups,the mean change was 4.02(95%CI:3.09-4.95)in PEG-Chula and 3.78(95%CI:2.79-4.78)in commercial PEG compared to baseline(P<0.001).The extent of stool consistency improvement did not differ significantly.The most preferred PEG-Chula flavor was rated more palatable than the commercial PEG.Treatment compliance correlated with medication palatability(r=0.34,P=0.013).No significant differences in adverse events were found.CONCLUSION Both PEG-based formulas are effective and safe for managing pediatric FC.
基金financially supported by the National Natural Science Foundation of China(No.52473097)the Fundamental Research Funds for the Central Universities(No.24X010301678)Shanghai Jiao Tong University 2030 Initiative(No.WH510363002/002)。
文摘Incorporating a low density of ester units into the backbone of polyethylene materials enhances their sustainability and recyclability while maintaining the main material properties of polyethylenes.Here we report a new way to access degradable polyethylene materials with a low content of in-chain ester units via mechanochemical backbone editing.Initially,ester groups are incorporated as side groups through catalytic copolymerization of ethylene with a cyclobutene-fused lactone monomer(CBL),yielding polyethylene materials with high molecular weights and adjustable thermomechanical properties.Subsequent solid-state ball-milling treatment selectively introduces side-chain ester groups into the main chain of the polyethylene materials via force-induced cycloreversion of the cyclobutane units.Under acidic conditions,hydrolysis of the resultant polyethylene materials with in-chain ester units facilitates further degradation into oligomers.
基金supported by the National Natural Science Foundation of China(Nos.52373045 and 52033005).
文摘In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative rotary shear system(RSS)to address these deficiencies through controlled mandrel rotation and cooling rates.We successfully prepared self-reinforced HDPE pipes with a three-layer structure combining spherical and shish-kebab crystals.Rotational processing aligned the molecular chains in the ring direction and formed shish-kebab crystals.As a result,the annular tensile strength of the rotationally processed three-layer shish-kebab structure(TSK)pipe increased from 26.7 MPa to 76.3 MPa,an enhancement of 185.8%.Notably,while maintaining excellent tensile strength(73.4 MPa),the elongation at break of the spherulite shishkebab spherulite(SKS)tubes was improved to 50.1%,as compared to 33.8%in the case of shish-kebab spherulite shish-kebab(KSK)tubes.This improvement can be attributed to the changes in the micro-morphology and polymer structure within the SKS tubes,specifically due to the formation of small-sized shish-kebab crystals and the low degrees of interlocking.In addition,2D-SAXS analysis revealed that KSK tubes have higher tensile strength due to smaller crystal sizes and larger shish dimensions,forming dense interlocking structures.In contrast,the SKS and TSK tubes had thicker amorphous regions and smaller shish sizes,resulting in reduced interlocking and mechanical performance.
基金the support and encouragement of the Key Projects of the Ministry of Industry and Information Technology of China(TC220A04W-3,188)。
文摘It has been widely recognized that the mixing process has significant impacts on the performance of low-density polyethylene(LDPE)reactors due to the rapid radical polymerization occurred in the reactors,but how the macro-and micro-mixing affect the reactor performance was still controversial in publications.In this work,a cold-flow LDPE autoclave with multi-feedings was scaled down(1/2)from an industrial reactor and built to systematically investigate the macro-and micro-mixing characteristics of fluid by experiments.Furthermore,the effects of macro-and micro-mixing on the polymerization were comprehensively analyzed.The results showed that according to the delay time t_(d) and macro-mixing times tM calculated from residence time distribution(RTD)curves,the macro-mixing states are significantly different at various axial positions(h/H),especially at lower agitation Reynolds number Re.But with the increase of Re,since the circulation flow in the reactor is strengthened,the t_(d) for each feed gradually decreases to 0,and the t_(M) at different axial positions tend to be identical.For micro-mixing,the qualities of micro-mixing at different axial positions are similar,and the average micro-mixing time t_(m) in the reactor decreases exponentially with the increase of Re.Moreover,a fitting model was established.Through the comparison of the characteristic times of macro-mixing(t_(d),t_(M)),micro-mixing(t_(m))and elementary reactions within the industrial range of Re,it can be concluded that the properties of LDPE products are dominated by the macro-mixing behavior,and the consumption of initiators is affected by both the macro-and micro-mixing behaviors.This conclusion is of great significance for the design,optimization and operation of LDPE reactors.
文摘To enhance the hydrophilicity and antistatic properties of the polyethylene terephthalate(PET)fabric,the lawsone dye was employed in dyeing the PET fabric.It was dissolved in ethanol/deionized water mixture and deionized water separately,forming different lawsone dye solutions(LDSs).The study investigated how the compounds in the LDS improve the surface properties and color durability of the PET fabric,resulting in increased dye uptake.An infrared dyeing machine was utilized to expedite the reactions between the lawsone dye and the PET fabric.Additionally,the chemical composition of the dyed PET fabric was verified using techniques such as Fourier transform infrared(FTIR)spectroscopy,X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and ultraviolet-visible(UV-Vis)spectrophotometry.The K/S value was measured to assess color durability.After dyeing,the PET fabric exhibited high hydrophilicity which improved the hygroscopicity of the PET fabric and thus the conductivity of the PET fabric surface increased,thereby providing an antistatic effect.
基金Supported by the Science and Technology Program of Rui’an,No.MS2023030.
文摘BACKGROUND In the field of clinical intestinal preparation,compound polyethylene glycol electrolyte solution(SF-PEG)is a commonly used intestinal cleaner.However,practice has shown that using only a single polyethylene glycol formulation often fails to achieve the desired intestinal preparation effect.Linalotide has a unique mechanism of action,which can effectively enhance the secretion of small intestinal fluid and promote intestinal peristalsis.The combination of linaclotide and SF-PEG may provide a better solution for intestinal preparation and improve the quality of intestinal cleaning.Therefore,exploring the application value and clinical efficacy of linaclotide capsules combined with SF-PEG in intestinal preparation is of great clinical significance.AIM To explore the effects of the combination of linaclotide capsules and SF-PEG,including its efficacy in intestinal preparation and patient tolerance.METHODS To investigate the differences in the effectiveness of different bowel preparation plans in colonoscopy,this article conducted a comprehensive and detailed retrospective analysis of the medical records of patients who underwent colonoscopy from January 2023 to December 2023.In this study,116 patients were accurately divided into three groups based on the different intestinal preparation drugs used before colonoscopy.Among them,group A consisted of 29 patients who underwent intestinal preparation using 3 liters of SF-PEG combined with linaclotide;group B consists of 50 patients who underwent intestinal preparation using 3 liters of SF-PEG;group C consisted of 37 patients who underwent intestinal preparation using a combination of 2-liter SF-PEC and linaclotide.Subsequently,this article evaluated the quality of intestinal preparation in these three groups of patients,using the Boston bowel preparation scale(BBPS)as a quantitative indicator,while comparing multiple indicators such as intestinal preparation completion rate and detection of positive lesions,providing a strong basis for optimizing clinical intestinal preparation plans.RESULTS No statistically significant differences were found in BBPS scores(7.75±1.23,7.69±1.14,and 7.66±1.31;P=0.240),bowel preparation completion rates(96.55%,90.00%,and 97.30%;P=0.293),adenoma detection rates(20.69%,38.00%,and 32.43%;P=0.281),polyp detection rates(34.48%,50.00%,37.84%;P=0.326),insertion time(6.03±4.34,6.12±3.60,and 5.33±2.42;P=0.584),and patient satisfaction rates(89.66%,84.00%,and 97.30%;P=0.398)among the three groups.However,statistically significant differences were observed in withdrawal time(7.45±2.91,9.02±3.54,and 6.86±2.66;P=0.027)and adverse reaction rates(6.90%,20.00%,and 2.70%;P=0.029)among the three groups.Multiple comparisons showed that group C had significantly lower withdrawal time and adverse reaction rates than group B(P=0.013,P=0.016).CONCLUSION Linaclotide capsules show a trend in improving bowel preparation quality and reducing the dosage of SF-PEG.
基金financially supported by the Fundamental Research Program of the Russian Academy of Sciences for the Semenov Research Center of Chemical Physics,Russian Academy of Sciences。
文摘Single-step ethylene polymerization over a binary catalyst,including zirconocene precatalysts of various designs,has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene(UHMWPE)and low-molecular-weight HDPE(LMWPE)directly in synthesis.Zirconocenes rac-(CH_(3))_(2)Silnd_(2)ZrCl_(2)(Zr-1)and rac-(C_(6)H_(10))CplndZrCl_(2)(Zr-2)activated with methylaluminoxane(MAO)were used as the components of the binary catalyst.It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30℃leads to the production of UHMWPE with Mw=1000 kg-mol^(-1)and LMWPE with Mw=18 kg·mol^(-1),respectively.Reactor polymer compositions(RPC)with LMWPE fraction contents ranging from 9 wt%to 42 wt%were obtained when a molar fraction of Zr-2 in the binary catalyst(Zr-1+Zr-2)/MAO va ried in the range from 0.3 to 0.85.A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution(MWD)and includes UHMWPE(Mw=1000 kg·mol^(-1))and LMWPE(Mw=18 kg·mol^(-1))fractions.The degree of crystallinity of the polymer products was determined using the DSC method.The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition.UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.
基金supported by the National Natural Science Foundation of China(No.52473026)。
文摘Flexible polymer-based foam sensors have significant potential for application in wearable electronics and motion monitoring.However,these prospects are hindered by the complex and unenvironmentally friendly manufacturing processes.In this study,we employed melt blending and supercritical carbon dioxide foaming to fabricate an ethylene-vinyl acetate copolymer(EVA)/low-density polyethylene(LDPE)/carbon nanotube(CNT)piezoresistive foam sensor.The cross-linking agent bis(tert-butyldioxyisopropyl)benzene and the conductive filler CNT were incorporated into the EVA/LDPE composite,successfully achieving a chemically cross-linked and physically entangled composite structure that significantly enhanced the storage modulus and complex viscosity.Additionally,the compressive strength of EVA/LDPE/CNT foam with 10 parts per hundred rubber(phr)CNT reached 1.37 MPa at 50%compression,marking a 340%increase compared to the 0.31 MPa of the CNT-free sample.Furthermore,the EVA/LDPE/CNT composite foams,which incorporated 10 phr CNT,were prepared under specific foaming conditions,resulting in an ultra-low density of 0.11 g/cm^(3) and a higher sensitivity,with a gauge factor of–2.3.The piezoresistive foam sensors developed in this work could accurately detect human motion,thereby expanding their applications in the field of piezoresistive foam sensors and providing an effective strategy for the advancement of high-performance piezoresistive foam sensors.
基金supported by the National Natural Science Foundation of China(No.U23B6011)the Jilin Provincial Science and Technology Department Program(No.20230101347JC)。
文摘Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.
文摘The accumulation of non-biodegradable plastic debris in the environment raises serious concerns about potential long-term effects on the environment,the economy,and waste management.To assess the feasibility of substitut-ing commercial plastics for a biodegradable renewable polymer for many applications,low-density polyethylene(LDPE)was mixed with varying concentrations of algal biomass(AB).Algae are considered a clean,renewable energy source because they don’t harm the environment and can be used to create bioplastics.Algal biomass grown in a high rate algal pond(HRAP)used for wastewater treatment used at 12.5-50 weight percent.Mechan-ical,thermal,and morphological characteristics of the LDPE/AB mixes were studied.Improved compatibility and uniformity between the LDPE matrix and algal biomass phase were evident in the morphology of LDPE/AB blends.Tensile strength(TS)and elastic modulus(EM)of the prepared LDPE/AB blends significantly decreased to 4.63 and 255 MPa,respectively.Nevertheless,by increasing the concentration of AB up to 25%and 37.5%,the mechanical properties enhanced and raised to(TS=6.75 MPa,EM=426 MPa)and(TS=7 MPa,EM=494 MPa),respectively.Using 25%and 37.5%of AB significantly enhanced the miscibility and interaction between algal bio-mass and LDPE polymer.However,increasing the percentage of AB led to a reduction in the thermal stability of the LDPE/AB.In contrast,compatibilized blends demonstrated better thermal stability compared to un-compa-tibilized blends.These findings indicate that it is possible to develop a blend with improved structural,thermal,and mechanical properties by partially replacing LDPE with biodegradable algal biomass.
基金Project(HIT.NSRIF.2009033) supported by the Scientific Research Foundation of Harbin Institute of Technology,China
文摘The formability of AA5052/polyethylene/AA5052 sandwich sheets was experimentally studied. Three kinds of AA5052/polyethylene/AA5052 sandwich specimens with different thicknesses of core materials were prepared by the hot pressing adhesive method. Then, the uniaxial tensile tests were conducted to investigate the mechanical properties of AA5052/polyethylene/ AA5052 sandwich sheets, and the stretching tests were carried out to investigate the influences of polymer core thickness on the limit dome height of the sandwich sheet. The forming limit curves for three kinds of sandwich sheets were obtained. The experimental results show that the forming limit of the AA5052/polyethylene/AA5052 sandwich sheet is higher than that of the monolithic AA5052 sheet, and it increases with increasing the thickness of polyethylene core.
文摘Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.
文摘The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays（EDAX）,and morphologies of catalyst particles and polymer products were examined by scanning electron microscope（SEM）.Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance.
基金supported by the 863 program(No.2006AA03Z233)973 program(No.2009CB623402) of China
文摘High density polyethylene （HDPE）/polyethylene-block-poly（ethylene glycol） （PE-b-PEG） blend porous membranes were prepared via thermally induced phase separation （TIPS） process using diphenyl ether （DPE） as diluent. The phase diagrams of HDPE/PE-b-PEG/DPE systems were determined by optical microscopy and differential scanning calorimetry （DSC）. By varying the content of PE-b-PEG, the effects of PE-b-PEG copolymer on morphology and crystalline structure of membranes were studied by scanning electron microscopy （SEM） and wide angle X-ray diffraction （WAXD）. The chemical compositions of whole membranes and surface layers were characterized by elementary analysis, Fourier transform infrared spectroscopy-attenuated total reflection （FTIR-ATR） and X-ray photoelectron spectroscopy （XPS）. Water contact angle, static protein adsorption and water flux experiments were used to evaluate the hydrophilicity, antifouling and water permeation properties of the membranes. It was found that the addition of PE-b-PEG increased the pore size of the obtained blend membranes. In the investigated range of PE-b-PEG content, the PEG blocks could not aggregate into obviously separated domains in membrane matrix. More importantly, PE-b-PEG could not only be retained stably in the membrane matrix during membrane formation, but also enrich at the membrane surface layer. Such stability and surface enrichment of PE-b-PEG endowed the blend membranes with improved hydrophilicity, protein absorption resistance and water permeation properties, which would be substantially beneficial to HDPE membranes for water treatment application.
文摘Polyethylene (PE) films with additives consisting mainly of oleic acid and ferrous ions were subjected to accelerated degradation at simulated composting temperatures.Based on Fourier transform infrared spectroscopy and measurements of mechanical properties and viscosity average molecular weight,the degradation of the films was characterized and the degradation mechanism was discussed.The films containing additives with ferrous ions represent considerable decreases in molecular weight,and the carbonyl groups and hydroperoxides in the aging films show different trends of increase with the aging time.These results indicate that the ferrous ion plays an important role in the degradation of PE films and accelerates the degradation of PE.
