Efficacy of 1.2L polyethylene glycol plus ascorbic acid for bowel preparations

BACKGROUND A low-volume polyethylene glycol(PEG) solution that combines ascorbic acid with PEG-based electrolyte solution(PEG-ASC) is gaining mainstream acceptance for bowel preparation due to reduced volume and improved taste.Although several reports showed that bowel preparation with PEG-ASC volume lower than 2.0 L with laxative agents could be an alternative to traditional preparation regimen, the cleansing protocols have not been fully investigated.AIM To evaluate the cleansing efficacy of 1.2 L PEG-ASC solution comparing with 2.0 L PEG electrolyte(PEG-ELS) for bowel preparations.METHODS A randomized, single-blinded, open-label, single-center, non-inferiority study was conducted. In total, 312 Japanese adult patients(aged > 18 years) who underwent colonoscopy were enrolled. Patients were randomly allocated to bowel lavage with either 1.2 L of PEG-ASC solution with at least 0.6 L of an additional clear fluid(1.2 L PEG-ASC group) or 2.0 L of PEG-ELS(PEG-ELS group). Then, 48 mg of sennoside was administered at bedtime on the day before colonoscopy, and the designated drug solution was administered at the hospital on the day of colonoscopy. Bowel cleansing was evaluated using the Boston Bowel Preparation Scale(BBPS). The volume of fluid intake and required time for bowel preparation were evaluated. Furthermore, compliance, patient tolerance,and overall acceptability were evaluated using a patient questionnaire, which was assessed using a visual analog scale.RESULTS In total, 291 patients(1.2 L PEG-ASC group, 148; PEG-ELS group, 143) completed the study. There was no significant difference in successful cleansing, defined as a BBPS score ≥ 2 in each segment, between the two groups(1.2 L PEG-ASC group, 91.9%; PEG-ELS group, 90.2%; 95%CI:-0.03-0.09). The required time for bowel preparation was significantly shorter(164.95 min ± 68.95 min vs 202.16 min± 68.69 min, P < 0.001) and the total fluid intake volume was significantly lower(2.23 L ± 0.55 L vs 2.47 L ± 0.56 L, P < 0.001) in the 1.2 L PEG-ASC group than in the PEG-ELS group. Palatability, acceptability of the volume of solution, and overall acceptability evaluated using a patient questionnaire, which was assessed by the visual analog scale, were significantly better in the 1.2 L PEG-ASC group than in the PEG-ELS group(7.70 cm ± 2.57 cm vs 5.80 cm ± 3.24 cm, P < 0.001). No severe adverse event was observed in each group.CONCLUSION The 1.2 L PEG-ASC solution was non-inferior to the 2.0 L PEG-ELS solution in terms of cleansing efficacy and had better acceptability among Japanese patients.

Pediatric bowel preparation: Sodium picosulfate, magnesium oxide, citric acid vs polyethylene glycol, a randomized trial

BACKGROUND Bowel preparation in children can be challenging.AIM To describe the efficacy, safety, and tolerability of sodium picosulfate, magnesium oxide, and citric acid(SPMC) bowel preparation in children.METHODS Phase 3, randomized, assessor-blinded, multicenter study of low-volume, divided dose SPMC enrolled children 9-16 years undergoing elective colonoscopy. Participants 9-12 years were randomized 1:1:1 to SPMC ? dose × 2, SPMC 1 dose × 2, or polyethylene glycol(PEG). Participants 13-16 years were randomized 1:1 to SPMC 1 dose × 2 or PEG. PEG-based bowel preparations were administered per local protocol. Primary efficacy endpoint for quality of bowel preparation was responders(rating of ‘excellent' or ‘good') by modified Aronchick Scale. Secondary efficacy endpoint was participant's tolerability and satisfaction from a 7-item questionnaire. Safety assessments included adverse events(AEs) and laboratory evaluations.RESULTS 78 participants were randomized, 48 were 9-12 years, 30 were 13-16 years. For the primary efficacy endpoint in 9-12 years, 50.0%, 87.5%, and 81.3% were responders for SPMC ? dose × 2, SPMC 1 dose × 2, and PEG groups, respectively. Responder rates for 13-16 years were 81.3% for SPMC 1 dose × 2 and 85.7% for PEG. Overall, 43.8% of participants receiving SPMC 1 dose × 2 reported it was ‘very easy' or ‘easy' to drink, compared with 20.0% receiving PEG. Treatment-emergent AEs were reported by 45.5% of participants receiving SPMC 1 dose × 2 and 63.0% receiving PEG.CONCLUSION SPMC was an efficacious and safe for bowel preparation in children 9-16 years, with comparable efficacy to PEG. Tolerability for SPMC was higher compared to PEG.

Improved Cellulose by Ionic Liquid Mixture with Solid Acid Catalysis and Its Application in Polyethylene Glycol Liquefaction

Ionic liquid (IL), [BMIM]Cl-water was applied in cellulose pretreatment process and the pretreated cellulose was used in subsequent polyethylene glycol liquefaction process as a new application method. Cellulose recovery rate and molecular weight value of pretreated cellulose were investigated to understand the influence of IL-water mixtures by adding the different amount of catalysis on cellulose crystalline structure. Gel permeation chromatograph, X-ray diffraction, Fourier transform infrared spectrometer and thermo gravimetric/differential thermal analysis were used to clarify the changes of pretreated cellulose. The results showed that the pretreated cellulose was improved in crystalline structure, molecular weight distribution and thermal stability. The liquefied residues from untreated cellulose and pretreated cellulose were considered as a significant index to determine the effect of IL-water mixture on cellulose. It suggested that the lower molecular weight of cellulose was obtained, the crystalline structure was disrupted and less order was formed. The liquefied residues result suggested that the lower residues at the latter stages of the reaction from the pretreated cellulose were observed.

One step graft copolymerization of acrylic acid and sodium styrene sulfonate onto high-density polyethylene film by preirradiation method

High-density polyethylene (HDPE) films were irradiated by 60Co gamma ray with a dose of 100 kGy in air and then immersed in aqueous solution of acrylic acid (AA) and sodium styrene sulfonate (SSS) at different temperature. The effects of grafting conditions such as temperature, reaction time, Mohr’s salt concentration, and total concentration of monomer on grafting yield were studied. Both grafting yield of AA and SSS onto HDPE respectively increases with total concentration of monomers. The highest grafting yield was observed at 3 mol/L monomers where the grafted PE swelled to the largest extent in the monomers mixture. The grafting yield increases with reaction time and then levels off. At higher temperature, the grafting yield decreases with Mohr’s salt concentration, but increases at low temperature when Mohr’s salt concentration is 0.083%. Which can be interpreted that in the presence of Fe2+ diperoxides and hydroperoxides may decompose at low temperature to form radical which can initiate the grafting. The physical and chemical properties of grafting films were also investigated.

MESOPOROUS ACID SOLID AS A CARRIER FOR METALLOCENE CATALYST IN ETHYLENE POLYMERIZATION AND A CATALYST IN CATALYTIC DEGRADATION OF POLYETHYLENE

The possibility of mesoporous acid solid as a carder for metallocene catalyst in ethylene polymerization and catalyst for polyethylene （PE） catalytic degradation was investigated. Here, HMCM-41 and AIMCM-41, and mesoporous silicoaluminophosphate molecular sieves （SAPO1 and SAPO2） were synthesized and used as acid solid. Much more gases were produced during catalytic degradation in PE/acid solid mixtures via in situ polymerization than those via physical mixing. The particle size distribution results exhibited that the particle size of SAPO1 in the PE/SAPOI mixture via in situ polymerization was about 1/14 times of that of the original SAPO1 or SAPO1-supported metallocene catalyst. This work shows a novel technology for chemical recycling of polyolefin.

Synthesis and Characterization of a Novel Functional Biodegradable Copolymer-Poly(lactic acid-4-hydroxyproline-polyethylene glycol)

A series of poly（lactic acid-4-hydroxyproline-polyethylene glycol） （PLA-Hpr-PEG） copolymers were synthesized by direct melt copolymerization of D,L-lactic acid and 4-hydroxyproline with different feed amount of polyethylene glycol （PEG） 0.1%, 0.5%, 1% and 5%, respectively. The properties of these copolymers were characterized by using IR spectroscopy, proton nuclear magnetic resonance （1H-NMR） spectroscopy, gel permeation chromatography （GPC）, X-ray diffraction and differential scaning calorimetry （DSC）. PLA-Hpr-PEG are amorphous copolymers. Copolymers showed increasing water uptake capacity with increasing PEG percentage in the feed, which result in an increasing degradable rate in phosphate buffer solution （pH 7.4） at 37℃.

Ascorbic acid and low-volume polyethylene glycol for bowel preparation prior to colonoscopy:A meta-analysis

AIM: To evaluate the benefits of low-volume polyethylene glycol(PEG) with ascorbic acid compared to fulldose PEG for colonoscopy preparation. METHODS: MEDLINE, Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, CINAHL, Pub Med, and recent abstracts from major conferences were searched(January 2012). Only randomized-controlled trials on adult subjects comparing lowvolume PEG(2 L) with ascorbic acid vs full-dose PEG(3 or 4 L) were included. Meta-analysis for the efficacy of low-volume PEG with ascorbic acid and full-dose PEG were analyzed by calculating pooled estimates of number of satisfactory bowel preparations as well as adverse patient events(abdominal pain, nausea, vomiting). Separate analyses were performed for each main outcome by using OR with fixed and random effects models. Heterogeneity was assessed by calculating the I2 measure of inconsistency. Rev Man 5.1 was utilized for statistical analysis.RESULTS: The initial search identified 242 articles and trials. Nine studies(n = 2911) met the inclusion criteria and were analyzed for this meta-analysis with mean age range from 53.0 to 59.6 years. All studies were randomized controlled trials on adult patients comparing large-volume PEG solutions(3 or 4 L) with low-volume PEG solutions and ascorbic acid. No statistically significant difference was noted between lowvolume PEG with ascorbic acid and full-dose PEG for number of satisfactory bowel preparations(OR 1.07, 95%CI: 0.86-1.33, P = 0.56). No statistically significant difference was noted between low-volume PEG with ascorbic acid and full-dose PEG for abdominal pain(OR 1.09, 95%CI: 0.81-1.48, P = 0.56), nausea(OR 0.70, 95%CI: 0.49-1.00, P = 0.05), or vomiting(OR 0.99, 95%CI: 0.78-1.26, P = 0.95). No publication bias was noted.CONCLUSION: Low-volume PEG with the addition of ascorbic acid demonstrates no statistically significant difference to full-dose PEG for satisfactory bowel preparation and side-effects.

Characteristic of hyaluronic acid derivative films cross-linked by polyethylene glycol of low water content

Objective:To test the characteristics of hyaluronic acid(HA)derivative cross-linked by polyethylene glycol films of low water content.Methods:The cross-linked HA film with 200μm thickness was got at atmospheric pressure at 25℃for 5 d.After dried,cross-linked films of 10 mm×10 mm were weighed and immersed in phosphate buffered saline (PBS pH 7.45)at 37℃for 24 h.Then the solution fraction and water content were estimated.Meanwhile,cross-linked HA derivative films were immersed in phosphate buffered saline(PBS:pH 7.45)at 37℃for determined time and then implanted subcutaneously in the back of white rats to test in vitro or in vivo degradation characteristic.Results and Conclusion:HA hydrogel cross-linked by polyethylene glycol with water content is as low as 60% and this kind of HA derivative has a slow degradation rate.

Reduced Sensitivity of Campomanesia adamantium(Cambess.)O.Berg Seeds to Desiccation:Effects of Polyethylene Glycol and Abscisic Acid

The Campomanesia adamantium is a threatened species from Brazil Savannah which seeds are desiccation-sensitive and do not withstand storage. This study aimed to reduce the sensitivity of Campomanesia adamantium seeds to desiccation using polyethylene glycol (PEG) and abscisic acid (ABA). Initially, seeds were subjected to PEG (0, -1.48, and -2.04 MPa) with or without ABA (100 μM) during 120 h, followed fast drying (silica gel) or slow drying (laboratory environment), at 20%, 15%, and 10% moisture content. In the second experiment, the seeds were PEG treated (-1.48 MPa) which provided the best results in the first experiment;the seeds were then subjected to different incubation times in PEG (30, 60, 90, or 120 h) and ABA (0, 10ˉ3, 10ˉ4, and 10ˉ5 μM), following the seeds were fast dried at 15% moisture content. The slow drying should be avoided, even in seeds previously subjected to osmotic conditioning with or without ABA. Seeds submitted to PEG treatment (-1.48 MPa/120h) without ABA and PEG (-1.48 MPa) with 10ˉ3 or 10ˉ4 μM of ABA (90 h), followed by fast drying at 15% moisture content showed reduction of desiccation sensitivity and high germination and vigor when compared to the other treatments.

Recycling and depolymerization of waste polyethylene terephthalate bottles by alcohol alkali hydrolysis

In this work,a novel alcohol alkali hydrolysis method was explored for the preparation of terephthalic acid(TPA)from waste polyethylene terephthalate(PET).First,a series of single factor experiments on the depolymerization rate of waste PET bottles and the yield of TPA were conducted to determine the optimized experimental conditions,in terms of reaction time,reaction temperature,dosage of ethylene glycol and sodium bicarbonate,amount of distilled water and stirring rate.Then IR spectra and elemental analysis were carried out for the characterization of obtained product.Under optimal experimental conditions,over 98%PET can be depolymerized into the target product(TPA)and the purity and yield of TPA are over 97%and 94%,respectively.Both the experimental and analytical results support a feasible process for the preparation of TPA from waste PET.It is expected that this alcohol alkali hydrolysis method can promise an effective way for the sustainable recycling of waste PET.

PHOTOINDUCED GRAFTING OF ACRYLIC AND ALLYL MONOMERS ON POLYETHYLENE SURFACE

Photoinduced grafting of acrylic and allyl monomers on polyethylene surface was generally studied by using benzophenone (BP) as a photoinitiator. The grafting process was carried out either in vapor-phase or in solution of the monomers. In the vapor-phase reaction with a filter used to cut off the short wavelength UV light, allyl amine is the most reactive of the four monomers used and acrylic amide is comparatively more reactive than acrylic acid and allyl alcohol. Acetone, as a solvent and carrier for initiator and monomers, however, shows its reactivity to participate the reaction. The solution grafting with a filter is much faster than the corresponding vapor-phase reaction, and a fully covered surface by the grafted polymer can be achieved in this way.

薰衣草精油缓释固体分散体的制备及其体外释药性能研究

目的:优化薰衣草精油(LEO)缓释固体分散体的制备工艺,并探讨体外释药模型。方法:以芳樟醇及乙酸芳樟酯为指标,建立气相-色谱质谱联用(GC-MS)技术测定溶出度的方法;选用硬脂酸、聚乙二醇6000(PEG 6000)和单硬脂酸甘油酯为辅料,优化辅料配比,采用熔融法制备LEO缓释固体分散体,考察其体外释药性能。结果:LEO缓释固体分散体的最佳处方配比为硬脂酸∶PEG 6000∶单硬脂酸甘油酯:LEO=3∶5∶1∶1,该条件下所制备的固体分散体在体外能够持续释药12 h,体外释药符合一级动力学模型。结论:所优选的处方配比工艺稳定可靠,所得缓释固体分散体能显著改善药物溶出,缓释效果令人满意。

聚氨酯绷带用PEG-CL-LA共聚物的制备及其性能的研究

以辛酸亚锡为催化剂,聚乙二醇(PEG)为起始剂,ε-己内酯(CL)和乳酸(LA)为原料,在170℃和高真空的条件下直接缩聚合成了不同数量CL单元与LA单元的二元醇共聚物(PLCA)。PLCA与过量的4,4’-二苯基甲烷二异氰酸酯(MDI-100)及少量叔胺类催化剂混合,在70℃反应,得到异氰酸酯封端的共聚物混合胶体(PLCA-PU),并涂覆在聚酯多孔编织带上制备出聚氨酯绷带。保持PEG的量,改变CL和LA的比例和异氰酸酯的量,得到一系列的PLCA和PLCA-PU。对它们的结构进行了分析,并对聚氨酯绷带的固化时间、径向压缩力值进行了测试。研究结果表明:成功制备了PLCA和PLCA-PU;当R=5、n(PEG)∶n(CL)∶n(LA)=1∶6∶7时,PLCA-PU制备的绷带的固化时间为383 s,压缩力值最高能达到19.4 N;选用合适的物料配比可以满足绷带尽快固化、具有合适刚性强度的要求。

PEI@PLA气凝胶制备及其染料吸附性能研究

研究聚乳酸接枝聚乙烯亚胺气凝胶(PEI@PLA气凝胶)用于处理染料废水的效果。采用冷冻干燥法制备出具有定向通道形态的PEI@PLA气凝胶,对其外观形貌、化学组成、表面润湿性和压缩性能进行了测试,探讨了PEI@PLA气凝胶在不同温度、pH值和NaCl含量条件下与含染料废水的反应,评估了PEI@PLA气凝胶对染料的吸附效果。结果表明:PEI@PLA气凝胶具有超强的亲水性和在60%恒定应变下优异的压缩性能;PEI@PLA气凝胶对于废水中染料的吸附量随着PEI含量的增加而不断增加,气凝胶中PEI含量为210 mg,其对橙黄G(OYG)和刚果红(CR)染料的吸附能力高达(408.4±14.4)mg/g和(637.5±22.7)mg/g;吸附动力学表明,伪二阶动力学模型更适合分析PEI@PLA-150气凝胶对CR的吸附,同时,CR在气凝胶上的吸附平衡行为更符合朗格缪尔等温线模型。认为:PEI@PLA气凝胶作为染料废水吸附材料展现出优异的吸附性能。

抗坏血酸联合复方聚乙二醇电解质散在患者肠道准备中的临床应用

目的对比抗坏血酸联合2L聚乙二醇电解质散与分剂量3L聚乙二醇电解质散在患者肠道准备中的应用效果及安全性。方法选取2023年11月至2024年5月安徽理工大学第一附属医院(淮南市第一人民医院)接受结肠镜检查的200例门诊患者作为研究对象,采用随机数字表法将患者分为对照组和实验组,每组100例。其中,对照组患者服用3L聚乙二醇电解质散,实验组患者服用2L聚乙二醇电解质散和4 g抗坏血酸。比较两组肠道清洁效果、病变检出率、首次排便时间、进镜时间、退镜时间、排便次数、不良反应发生率、依从性、满意度及重复检查意愿的相关数据。结果两组波士顿肠道准备评分量表总评分及右半结肠、横结肠、左半结肠评分,差异均无统计学意义(P>0.05)。实验组的病变检出率高于对照组,差异有统计学意义(P<0.05)。两组首次排便时间、进镜时间、退镜时间,差异无统计学意义(P>0.05)。对照组排便次数比实验组多,差异有统计学意义(P<0.05)。实验组患者满意度、依从性、重复检查意愿高于对照组,差异有统计学意义(P<0.05),实验组不良反应发生率低于对照组,差异有统计学意义(P<0.05)。结论抗坏血酸联合2 L聚乙二醇电解质散对肠道清洁的效果不亚于3 L聚乙二醇电解质散,同时提高了病变检出率,减少了患者服用液体的总量及不良反应发生率,改善了患者的依从性、满意度及重复检查意愿,是一种很有前景的肠道清洁药物。

基于废弃PET的环氧超支化聚酯扩链剂应用性能

以废弃聚对苯二甲酸乙二酯(PET)的降解产物为核心,制备了环氧超支化聚酯扩链剂(EHBP),探究了该扩链剂对聚对苯二甲酸-己二酸丁二酯/聚乳酸/碳酸钙(PBAT/PLA/CaCO_(3))三元复合材料微观结构、热性能、力学性能的影响。结果表明,以PET降解产物制备的EHBP对复合材料有明显的增容作用。扩链剂中的高活性环氧基团能够与PBAT和PLA上的端羧基、端羟基发生开环加成反应,形成扩链大分子以增强PBAT和PLA之间的界面相互作用。当EHBP添加量达到0.6份时,可以明显观察到两相间变得模糊、孔洞减少。缺口冲击强度由6.48 kJ/m^(2)增加到43.02 kJ/m^(2),拉伸强度由10.15 MPa增加到24.59 MPa,断裂伸长率由11.8%增加到56.72%。

富里酸对聚乙烯微塑料污染土壤水分入渗过程的影响

为研究富里酸对聚乙烯污染土壤水分入渗过程的影响,本研究通过土柱一维垂直入渗试验,分别在含有质量比为0.1%、1%和3%荧光染色聚乙烯污染的土壤中添加0.3%的富里酸进行探究。结果表明:与空白土壤相比,0.1%、1%聚乙烯均减少土壤表面孔状结构和粗糙度,抑制土壤水分入渗速率,减小土壤饱和导水率,3%聚乙烯增加土壤表面孔状结构和粗糙度,降低入渗速率和饱和导水率;施加0.3%富里酸后,0.1%、1%和3%聚乙烯污染土壤表面孔状结构增多,粗糙度增大,水分入渗速率降低,饱和导水率随聚乙烯含量增大而增大,但较不施加富里酸前的饱和导水率分别下降48.75%、32.01%和3.64%;添加0.3%富里酸,可使聚乙烯微塑料在土壤中垂直向下的迁移速度分别提高33.33%、37.50%和38.33%。研究表明,富里酸增加了聚乙烯污染土壤的孔状结构和粗糙度,降低了聚乙烯污染土壤的水分入渗速率和饱和导水率,同时提高了聚乙烯在土壤中垂直向下的迁移速度。

EAA及致孔剂PEG400改性PVDF膜的结构及其渗透性能

为了调控聚偏氟乙烯(PVDF)膜的孔状结构和性能,以乙烯丙烯酸(EAA)为添加剂、PEG400为致孔剂,通过浸入沉淀相转换法制备了PVDF/EAA复合膜。采用SEM、FTIR表征了其结构和成分;对复合膜的渗透性能和抗污染性能进行了测试,考察了不同EAA、PEG400质量分数对复合膜结构和性能的影响。结果表明,与未加EAA的PVDF膜(E-0)相比,PVDF/EAA复合膜表现出更高的渗透性能、分离性能和抗污染性能。EAA可以改善复合膜表面的亲水性,PEG400可以提高铸膜液和凝固浴之间的亲和性,加快成膜速率,从而在膜表面形成更多的孔洞。当EAA质量分数为3%,PEG400的质量分数为4%时,PVDF/EAA复合膜(E-3)的纯水渗透通量和牛血清白蛋白截留率分别为271.57L/(m^(2)·h)和64.83%,比E-0分别提高了486.42%和116.10%;通量恢复率和总污染率分别为75.97%和46.51%,比E-0分别提升了19.37%和降低了26.92%。当EAA的质量分数为3%,PEG400的质量分数为3%时,PVDF/EAA复合膜(P-3)的孔隙率为53.33%,平均孔径为4.55 nm,比未加PEG400的PVDF/EAA复合膜(P-0)的孔隙率和平均孔径分别提高了33.33%和88.02%。

两亲性聚乙二醇-聚氨基酸胶束用于药物载体的研究进展

两亲性嵌段共聚物自组装形成的壳核结构胶束是一种很有前景的药物载体,亲水壳聚乙二醇可以延长其在血液中的循环时间,疏水壳聚氨基酸通过疏水相互作用负载疏水药物并通过侧链官能团共价修饰药物。聚氨基酸及其衍生物,尤其是聚天冬氨酸、聚谷氨酸、聚赖氨酸,由于其具有易于生物降解、生物相容性好和侧链官能团可得到有效利用等优点,广泛应用于胶束形成材料。本文综述了两亲性聚氨基酸、胶束的结构,合成及其作为药物载体的应用。

Conversion of polyethylene to gasoline:Influence of porosity and acidity of zeolites

Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but remains to be a challenging task. Zeolites are cheap and stable, but they are usually not efficient for plastic conversion at a low temperature. Herein a series of microporous and mesoporous zeolites were used to study the influence of porosity and acidity of zeolite on catalytic activity for plastics conversion. It was observed that H-Beta zeolite was an efficient catalyst for cracking high-density polyethylene to gasoline at 240℃, and the products were almost C_(4)–C_(12) alkanes. The effect of porosity and acidity on catalytic performance of zeolites was evaluated, which clearly visualized the good performance of H-Beta due to high surface area, large channel system, large amount accessible acidic sites. This study provides very useful information for designing zeolites for efficient conversion of plastics.