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Temporal and spatial variations of low-molecular-weight organic acids in Dianchi Lake, China 被引量:4
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作者 Min Xia Fengchang Wu Runyu Zhang Liying Wang XinqingLi Rongsheng Huang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第8期1249-1256,共8页
Low-molecular-weight organic acids (LMWOAs) in eutrophic lake water of Dianchi, Southwestern China Plateau were investigated diurnally and vertically using ion chromatography. Two profiles (P1 and P2) were studied... Low-molecular-weight organic acids (LMWOAs) in eutrophic lake water of Dianchi, Southwestern China Plateau were investigated diurnally and vertically using ion chromatography. Two profiles (P1 and P2) were studied due to the difference of hydrochemical features. Lactic, formic, pyruvic and oxalic acid were detected as major components at P1 and P2 which were on average 7.98 and 6.53 ~tmol/L, respectively, corresponding to their proportions of 2.68% and 2.48% relative to DOC. Pyruvic acid was regarded as the uppermost species at P1 and P2, reaching up to 3.82 and 3.35 μmol/L and accounting for 47.9% and 51.3%, respectively, in individual TOA. Although humus were of biogenetic production at both sites, the significant negative correlation between diurnal variations of TOAs, fluorescence intensity (FI) of protein-like components and humic-like components at P1 indicated LMWOAs were greatly originated from bacterioplankton excretion and degradation. However, correlations between diurnal variations of humic-like FI and physicochemical parameters demonstrated algal origination of LMWOAs at P2. Although content of humus was high, TOA at P2 was 1.45 ~tmol/L lower than that at P1, due to the co-influence of more intense photo-oxidation and aggregation at P2. Therefore, TOAs exhibited quite opposite diurnal variation trends of increasing-decreasing and decreasing-increasing at P1 and P2, respectively. Except for impact of solar radiation, bacterial decomposition and assimilation rendered shifts of maximal LMWOAs along water column at P1. Covering with massive algae, UV rays penetrated shallower depth that LMWOAs assembled in surface layer water before 18:00 at P2 and represented decreasing profiles. 展开更多
关键词 Dianchi Lake humus algae solar radiation low-molecular-weight organic acids
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Composition and Content of High-Molecular-Weight Glutenin Subunits and Their Effects on Wheat Quality 被引量:1
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作者 SONG Jian-min, LIU Ai-feng, WU Xiang-yun, LIU Jian-jun, ZHAO Zhen-dong and LIU Guang-tian(China Agricultural University, Beijing 100094 , P.R.China Shandong Academy of Agricultural Sciences , Jinan 250100 ,P.R. China ) 《Agricultural Sciences in China》 CAS CSCD 2002年第10期1094-1099,共6页
Sedimentation values, flour glutenin macropolymer (GMP) contents, composition and contents of high-molecular-weight (HMW) glutenin subunits (GS) of 233 flour samples were determined. Our data indicated that subunit 1 ... Sedimentation values, flour glutenin macropolymer (GMP) contents, composition and contents of high-molecular-weight (HMW) glutenin subunits (GS) of 233 flour samples were determined. Our data indicated that subunit 1 occurred more frequently at Glu-A1 , subunit pair 7 + 8 at Glu-B1 and 2 + 12 at Glu-D1. The significant relationships between Glu-1 quality score and total HMW glutenin content, sedimentation value and GMP content suggested that the composition of HMW-GS affects wheat quality strongly. Moreover, the total content of HMW-GS was correlated with certain quality parameters more significantly. Relationship between subunit 5 + 10 content and breadmaking quality was better than others, but 2 + 12, 7 + 8, 7 + 9 and 4 + 12 also correlated with certain quality parameters significantly. The contents of total HMW-glutenin, x-type subunits and y-type subunits related with sedimentation value, flour GMP content, and Glu-1 quality score more strongly than that of individual subunit or subunit pair. The flour GMP content, with excellent correlation to sedimentation value, total contents of HMW glutenin, x- and y-type subunits and many other quality parameters, could be an ideal indicator of breadmaking quality at earlier generations for breeding purpose for its simple procedure and small scale. 展开更多
关键词 WHEAT High-molecular-weight glutenin subunit Sedimentation value Glutenin macropoly-mer
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Attenuation of corneal neovascularization by topical low-molecular-weight heparin-taurocholate 7 without bleeding complication 被引量:1
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作者 Jae Yong Kim Soo Yeon Kim +4 位作者 Mi Hyun Cheon Eun-Soon Kim In Seok Song Myoung Joon Kim Hungwon Tchah 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第9期1255-1259,共5页
AIM:To investigate the antiangiogenic effects and safety of topically administered low-molecular-weight heparintaurocholate 7(LHT7) on corneal neovascularization(CoNV).METHODS:Twenty-four Sprague-Dawley rats wer... AIM:To investigate the antiangiogenic effects and safety of topically administered low-molecular-weight heparintaurocholate 7(LHT7) on corneal neovascularization(CoNV).METHODS:Twenty-four Sprague-Dawley rats were randomly distributed into four groups of six rats each.The central corneas were cauterized using a silver/potassium nitrate solution.From 2d after cauterization,12.5 mg/mL(low LHT7 group) or 25 mg/mL(high LHT7group) LHT7 was topically administered three times daily;12.5 mg/mL bevacizumab was topically administered as positive control(bevacizumab) group,with normal saline(NS) administered as negative control(NS group).The corneas were digitally photographed to calculate the CoNV percentage from the neovascularized corneal area at 1 and 2wk.RESULTS:The 4 study groups did not have different CoNV percentages at 1wk after injury(P〉0.05).However,the low LHT,high LHT,and bevacizumab groups had significantly lower CoNV percentages than the NS group at 2wk(all P〈0.05).No significant differences in CoNV percentage were found among the low LHT,high LHT,and bevacizumab groups(all P〉0.05).All groups except the NS group had lower CoNV percentages at 2wk postinjury than the levels observed at 1wk(all P〈0.05).CONCLUSION:Topically-administered LHT7 inhibited CoNV without complication after chemical cauterization in the rat. 展开更多
关键词 BEVACIZUMAB chemical cauterization corneal neovascularization low-molecular-weight heparin-taurocholate 7
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High-Molecular-Weight Glutenin Subunit Composition of Chinese Wheat Germplasm 被引量:1
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作者 ZHANG Ling-li LI Xiu-quan +3 位作者 YANG Xin-ming LI Hong-jie WANG Hui LI Li-hui 《Agricultural Sciences in China》 CAS CSCD 2007年第8期899-907,共9页
The objective of the present study was to characterize the high molecular glutenin subunits (HMW-GS) composition and the presence of 1B/1R translocation in newly developed wheat (Triticum aestivum L.) germplasm, w... The objective of the present study was to characterize the high molecular glutenin subunits (HMW-GS) composition and the presence of 1B/1R translocation in newly developed wheat (Triticum aestivum L.) germplasm, which have one or more traits that are useful in wheat improvement. Sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE) and acid polyacrylamide-gel electrophoresis (A-PAGE) were used to detect HMW-GS composition and the presence of 1B/1R wheat-rye (Secale cereale L.) chromosome translocation in the wheat germplasm. Bread-making quality scores of these lines were determined. A high level of variations in HMW-GS encoded by Glu-1 locus was observed. Sixteen major HMW-GS, with 30 combinations, were detected. The percentage of cultivars with more than two desirable subunits was 38.7%. Thirteen cultivars had bread-making quality scores of 10 in combination with one or two desirable agronomical traits, such as high-yield potential, dwarfing stem, resistance to diseases, and/or tolerance to abiotic stress. Sixty-eight (36.6%) cultivars possessed 1B/1R translocation. The newly developed germplasm with HMW-GS for good quality can be promising resources for improving bread-making quality of wheat. 展开更多
关键词 bread wheat high-molecular-weight glutenin subunits (HMW-GS) 1B/1R translocation
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Inhibitory effects and mechanisms of high molecular-weight phlorotannins from Sargassum thunbergii on ADP-induced platelet aggregation
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作者 魏玉西 王长云 +2 位作者 李敬 郭奇 齐宏涛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第3期558-563,共6页
We evaluated the effects of high molecular-weight phlorotannins from Sargassum thunbergii(STP) on ADP-induced platelet aggregation and arachidonic acid(AA) metabolism in New Zealand white rabbits and Wistar rats.The i... We evaluated the effects of high molecular-weight phlorotannins from Sargassum thunbergii(STP) on ADP-induced platelet aggregation and arachidonic acid(AA) metabolism in New Zealand white rabbits and Wistar rats.The inhibition of STP on platelet aggregation was investigated using a turbidimetric method,and the levels of the terminal products of AA metabolism were measured using the corresponding kits for maleic dialdehyde(MDA),thromboxane B2(TXB2) and 6-keto-prostaglandin F1α(6-keto-PGF1α) by colorimetry and radioimmunoassay,as appropriate.We found that STP could inhibit ADP-induced platelet aggregation,and the inhibitory ratio was 91.50% at the STP concentration of 4.0 mg/mL.Furthermore,STP markedly affected AA metabolism by decreasing the synthesis of MDA(P<0.01) and increasing the synthesis of 6-keto-PGF1α,thus changing the plasma TXB2/6-keto-PGF1α balance when the platelets were activated(P<0.01).Therefore,STP altered AA metabolism and these findings partly revealed the molecular mechanism by which STP inhibits ADP-induced platelet aggregation. 展开更多
关键词 high molecular-weight phlorotannins Sargassum thunbergii Kuntze platelet aggregation arachidonic acid metabolism
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Combined effect of Traditional Chinese Medicine decoction and low-molecular-weight heparin calcium on the postoperative deep venous thrombosis in patients with lower limb fracture 被引量:2
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作者 张惠煊 马翰斐 袁杰 《World Journal of Integrated Traditional and Western Medicine》 2015年第1期9-13,共5页
OBJECTIVE: To investigate the combined effect of Traditional Chinese Medicine(TCM) decoction and low-molecular-weight heparin calcium on deep vein thrombosis(DVT) induced by surgery in patients with lower limb fractur... OBJECTIVE: To investigate the combined effect of Traditional Chinese Medicine(TCM) decoction and low-molecular-weight heparin calcium on deep vein thrombosis(DVT) induced by surgery in patients with lower limb fracture.METHODS: Totally 86 hospitalized patients with DVT after surgery of lower limb fracture between September 2012 and January 2015 were recruited and randomly divided into control group and observation group, 43 cases in each group. The patients in the control group were treated with subcutaneous injection of low-molecular-weight heparin calcium, and those in the observation group were additionally given Danshen Injection and TCM decoction. The differences between two groups in occurrence rate, medication time, therapeutic effects,recurrence rate of thrombosis, activated partial thromboplastin time(APTT), and prothrombin time(PT) were compared.RESULTS: The occurrence rate of DVT in observation group(4.65%, 2/43) was lower than that in control group(27.91%,12/43)(P<0.05). The medication time of observation group was(6.15±2.94) d, shorter than(9.76±3.12) d in the control group(P<0.05). In observation group, 2 cases of DVT were cured(2/2); in the control group, 9 cases presented therapeutic effects and the total effective rate was 75.00%(9/12). The improvement of APTT and PT in the observation group was better than that in the control group(P<0.05).CONCLUSION: Integrative TCM decoction plus low-molecularweight heparin calcium is superior to applicaton of low-molecularweight heparin calcium alone in reducing and treating DVT in the postoperative patients with lower limb fracture. 展开更多
关键词 Surgery of lower limb fracture Deep vein thrombosis Traditional Chinese Medicine LOW-molecular-weight
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Utilizing Water Treatment Residuals for Phosphorus Removal:Batch Trials,Column Trials and Effects of Three Low-Molecular-Weight Organic Acids
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作者 任新 崔崇威 +1 位作者 赵雪松 许铁夫 《Journal of Donghua University(English Edition)》 EI CAS 2014年第3期304-311,共8页
Phosphorus( P) has been recognized as a major limited nutrient responsible for the eutrophication of surface waters. Water treatment residuals( WTRs) are safe by-products of water treatment plants and are cost-efficie... Phosphorus( P) has been recognized as a major limited nutrient responsible for the eutrophication of surface waters. Water treatment residuals( WTRs) are safe by-products of water treatment plants and are cost-efficient adsorbents. In this study, batch experiments and column experiments based on WTRs were employed to study the characteristics of P adsorption and the effects of lowmolecular-weight organic acids( LMWOAs)( citric acid, oxalic acid,and tartaric acid) on P adsorption. Different models of adsorption were used to describe equilibrium and kinetic data. The adsorption data were fitted well by a pseudo-second order kinetic model. The adsorption process was determined to be controlled by three steps of diffusion mechanisms through the intra-particle model.The adsorption equilibrium was well described by the Langmuir,Freundlich,Redlich-Peterson,and Sips isotherm models. Batch and continuous flow experiments indicated that the LMWOAs exhibited inhibitory action,and as pH increased,the inhibitory action became weaker for all the three acids. The effect of LMWOAs concentration was not significant on inhibition. The effects of LMWOAs were closely related to reaction time. 展开更多
关键词 adsorption capability PHOSPHORUS water treatment residuals low-molecular-weight organic acids(LMWOAs)
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The Safety and Feasibility of Low-Molecular-Weight He-parin Prophylaxis in Major Abdominal Surgery Combined with Neuraxial Anesthesia
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作者 Bogdan Protyniak Michael C. Meadows +1 位作者 H. Rae Pak Ronald S. Chamberlain 《Surgical Science》 2012年第4期177-184,共8页
Background: Global guidelines for venous thromboembolism (VTE) prophylaxis of patients undergoing major surgery are well established. However, their applicability and safety in patients receiving neuraxial anesthesia ... Background: Global guidelines for venous thromboembolism (VTE) prophylaxis of patients undergoing major surgery are well established. However, their applicability and safety in patients receiving neuraxial anesthesia is unproven. We sought to evaluate the safety and feasibility of chemical VTE prophylaxis in a prospective group of patients undergoing major foregut procedures under a combination of epidural and general anesthesia. Methods: A prospective database of all patients undergoing major foregut surgery from 2004-2009 was maintained and analyzed. Epidural catheters were placed pre-operatively and used for post-operative analgesia for three days in all patients. Factors evaluated included age, ethnicity, sex, length of stay, duration of epidural placement, complications of epidural placement and post-operative management, and VTE events. A uniform protocol was followed regarding the timing of low-molecular-weight heparin (LMWH) administration with epidural catheter insertion/removal. Results: A total of 237 patients formed the study group. The mean age was 57 years (range, 19 - 88) among 121 (51.1%) women and 65 years (range, 20 - 95) among 116 (48.9%) men. One hundred and sixty-six patients were Caucasian (70%), 37 Black (15.6%), 15 Hispanic (6.3%), 12 Asian/Pacific (5.1%), and 7 other (3%). All epidural catheters were removed on the third post-operative day. There were a total of five VTE (2.1%) events postoperatively. No peri-operative or post-operative epidural catheter associated complications occurred. Conclusions: Concomitant epidural catheterization and LMWH anticoagulation is safe and feasible in major abdominal surgery patients, including those undergoing major hepatic resection. Guidelines for VTE prophylaxis and LMWH administration in the setting of neuraxial anesthesia are well established and applicable to this unique patient population. 展开更多
关键词 Abdominal Surgery EPIDURAL Anesthesia LOW-molecular-weight HEPARIN Complications VENOUS THROMBOEMBOLISM
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Impact of Pharmaceutical Care on Self-Administration of Outpatient Low-Molecular-Weight Heparin Therapy
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作者 Seraina Mengiardi Dimitrios A. Tsakiris +4 位作者 Viviane Molnar Urs Kohlhaas-Styk Michael Mittag Stephan Kraehenbuehl Kurt E. Hersberger 《Pharmacology & Pharmacy》 2014年第4期372-385,共14页
Outpatient subcutaneous (s.c.) therapies are becoming more and more common in the treatment of different diseases. The effectiveness of community-pharmacy-based interventions in preventing problems that arise during s... Outpatient subcutaneous (s.c.) therapies are becoming more and more common in the treatment of different diseases. The effectiveness of community-pharmacy-based interventions in preventing problems that arise during s.c. self-injections of low-molecular-weight heparins (LMWH) is unknown. Our objective was to provide a standard operating procedure (SOP) for community pharmacists and to compare pharmaceutical vs. standard care in both clinical and daily life settings. We hypothesized that: pharmaceutical care results in improved adherence, safety, and satisfaction, and in fewer complications;the interventions used are feasible in daily life;and the results achieved in clinical and daily life settings are comparable. In the clinical setting (randomized controlled trial), patients were recruited sequentially in hospital wards;in the daily life setting (quasi-experimental design with a comparison group), recruitment took place in community pharmacies by pharmacists and trained master students during their internship. Interventions were offered according to patient needs. Data were collected by means of a monitored self-injection at home and structured questionnaire-based telephone interviews at the beginning and the end of the LMWH treatment. The main outcome measures were: scores to assess patient’s skills;syringe count to assess adherence;and frequency, effectiveness, and patient’s assessment of received interventions. The results show a median age of the 139 patients of 54 years. Interventions resulted in improved application quality (p p = 0.03). Oral instructions were pivotal for improving patients’ application quality. We found no significant score differences between the intervention groups in the clinical and daily life settings. Patients’ baseline skills were high, with the lowest score being 0.86 (score range ?2.00 to +2.00). Adherence rate was high (95.8%). In conclusion, our SOP for pharmacist interventions was of good quality, adequate, appreciated, and feasible in daily life. Patients are capable of managing s.c. injection therapies if adequate assistance is provided. 展开更多
关键词 LOW-molecular-weight Heparin OUTPATIENTS SUBCUTANEOUS INJECTIONS Self Administration Pharmaceutical Care Community Pharmacy Switzerland
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Evaluation of a Dose-Monitoring Method for Prophylactic Anticoagulant Therapy with Low-Molecular-Weight Heparin
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作者 Shintaro Makino Motoi Sugimura +3 位作者 Takashi Yorifuji Taro Koshiishi Toshitaka Tanaka Satoru Takeda 《International Journal of Clinical Medicine》 2011年第4期429-434,共6页
Objective: In the present study, we report on the results of our investigation of optimum dose monitoring using coagulation and fibrinolytic system indicators during obstetric prophylactic anticoagulant therapy with e... Objective: In the present study, we report on the results of our investigation of optimum dose monitoring using coagulation and fibrinolytic system indicators during obstetric prophylactic anticoagulant therapy with enoxaparin. Study Design: Of 103 cases of cesarean section performed at our hospital, 37 cases were selected for this study after obtain ing their consent for blood collection. Variables of the coagulation and fibrinolytic systems [anti-factor Xa activity, endogenous thrombin potential (ETP), prothrombin time (PT) or international normalized ratio (INR), activated partial thromboplastin time (APTT) and D-dimer levels] were determined. Results: In the 5-day administration group, the anti-factor Xa activitywas 0.0 U/ml on the postoperative day 1, increased to 0.05 U/ml ± 0.04 U/ml on the postoperative day 3, and mildly increased to 0.06 U/ml ± 0.05 U/ml on the postoperative day 5. On the other hand, the anti-factor Xa activity in the 3-day administration group was 0.0 U/ml on the postoperative day 1 (before enoxaparin administration), increased to 0.06 U/ml ± 0.05 U/ml on the postoperative day 3, and significantly decreased to 0.02 U/ml ± 0.03 U/ml on the postoperative day 5 (p = 0.003);thus, the pattern of change was significantly different from that in the 5-day administration group (p = 0.004). Enoxaparin administration did not result in any significant fluctuation of the ETP, and no significant difference was observed between the 5-day and 3-day administration groups. Conclusion: Enoxaparin administration was associated with increase of the anti-factor Xa activity, and prolonged administration led to more sustained increase of the activity. 展开更多
关键词 CESAREAN Section PROPHYLACTIC ANTICOAGULANT Therapy LOW-molecular-weight HEPARIN Anti-factor Xa Activity Endogenous THROMBIN Potentialintroduction
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Hot-Drawing of Ultrahigh-Molecular-Weight Polyethylene Gel Films
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作者 戚嵘嵘 朱清仁 +2 位作者 周持兴 刘萌戈 周贵恩 《Journal of Shanghai University(English Edition)》 CAS 2004年第1期101-108,共8页
The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the firs... The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the first stage of the drawing process, the lamellae in the gel films rotate and/or slip with the b-axis preferentially perpendicular to the drawing direction. With increased drawing, the c-axis of the lamellae become parallel to the stretching direction while unfolding of the chain begins, and the chains of the amorphous phase also orient along the drawing direction in the strain-chain domain. When the draw ratio is large enough, the lamellar structure is transformed into a fibrillar structure in a two-dimensional fashion. 展开更多
关键词 ultrahigh-molecular weight polyethylenes (UHMWPE) gel film hot-drawing morphological changes.
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脑安颗粒联合低分子肝素治疗急性脑干梗死的临床评价
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作者 洪亮 周明洁 +3 位作者 杨言府 宋杰 孙平 裴林 《中国药物应用与监测》 2026年第1期127-130,共4页
目的 探讨脑安颗粒联合低分子肝素治疗急性脑干梗死的疗效。方法 选取六安市中医院2021年1月至2024年12月收治的急性脑干梗死患者80例,以随机数字表法将其分成对照组和观察组(各40例)。对照组和观察组患者均给予控制血压、维持水电解质... 目的 探讨脑安颗粒联合低分子肝素治疗急性脑干梗死的疗效。方法 选取六安市中医院2021年1月至2024年12月收治的急性脑干梗死患者80例,以随机数字表法将其分成对照组和观察组(各40例)。对照组和观察组患者均给予控制血压、维持水电解质平衡、营养支持等基础治疗。对照组为常规基础治疗+低分子肝素治疗,观察组为常规基础治疗+低分子肝素+脑安颗粒治疗。对照组和观察组患者均连续治疗14 d。比较对照组和观察组患者治疗前后的中医证候积分、神经功能及神经因子水平、临床疗效、不良反应发生情况。结果 治疗后,观察组患者的主症、次症及证候总积分[分别为(6.36±1.49)、(2.25±0.53)、(8.60±1.45)分]均低于对照组[分别为(9.57±1.84)、(3.64±0.78)、(13.22±2.17)分],差异有统计意义(t=8.575、9.322、11.196,均P<0.05);观察组患者的美国国立卫生院卒中量表评分、S100B蛋白水平[分别为(5.40±1.19)分、(4.56±0.91)ng/L]均低于对照组[分别为(7.12±1.51)分、(6.02±1.05)ng/L],神经生长因子水平[(44.33±5.68)ng/L]高于对照组[(39.06±5.12)ng/L],差异有统计意义(t=5.658、6.646、4.359,均P<0.05);观察组患者的临床总有效率为92.50%(37/40),高于对照组的75.00%(30/40),差异有统计意义(χ^(2)=4.501,P<0.05);对照组和观察组不良反应发生率比较,差异无统计意义(χ^(2)=0.556,P>0.05)。结论 脑安颗粒联合低分子肝素治疗急性脑干梗死患者具有确切疗效,可改善其中医证候积分和神经功能,且安全性高。 展开更多
关键词 急性脑干梗死 脑安颗粒 低分子肝素 神经功能 疗效
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不同蛋白酶酶解对小麦面筋蛋白酶解效果及结构的影响
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作者 刘向军 张雨婷 +3 位作者 王学东 吴艳 李库 胥怀 《食品工业科技》 北大核心 2026年第1期54-62,共9页
本文旨在研究木瓜蛋白酶、碱性蛋白酶、中性蛋白酶、碱性蛋白酶+TG酶组合和木瓜蛋白酶+碱性蛋白酶组合酶解对面筋蛋白的酶解效果及对其结构的影响。研究以水解度、三氯乙酸氮溶指数(TCA-NSI)和分子量分布等为指标,判断酶解效果。利用傅... 本文旨在研究木瓜蛋白酶、碱性蛋白酶、中性蛋白酶、碱性蛋白酶+TG酶组合和木瓜蛋白酶+碱性蛋白酶组合酶解对面筋蛋白的酶解效果及对其结构的影响。研究以水解度、三氯乙酸氮溶指数(TCA-NSI)和分子量分布等为指标,判断酶解效果。利用傅里叶红外光谱、内源荧光光谱、紫外光谱等方法,测定了表面疏水性、游离巯基和蛋白质微观结构,系统表征了酶解产物的结构变化。结果表明,酶解处理显著提高了小麦面筋蛋白的水解度;表面疏水性和游离巯基含量的增加表明蛋白质三级结构发生显著改变;二级结构分析显示,小麦面筋蛋白中,β-折叠结构减少,无规则卷曲增加;对比酶解前后分子量分布结果表明,木瓜蛋白酶+碱性蛋白酶组合能够更有效地水解小麦醇溶蛋白;此外,微观结构变化也表明酶解处理显著改变了蛋白质分子的构象。因此,本研究为小麦面筋蛋白酶解后结构变化的研究提供了理论支持,并为开发高溶解度、高功能性的面筋蛋白产品提供了科学依据。 展开更多
关键词 小麦面筋蛋白 酶法改性 水解度 分子量分布 结构
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不同品种大米米粥的食用品质分析比较
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作者 殷泽 王雪纯 +4 位作者 王世鑫 张津睿 韦菲菲 翟爱华 王颖 《食品工业科技》 北大核心 2026年第2期337-346,共10页
为筛选适宜煮粥的粥米品种,选用7种不同品种大米,分析大米的理化特性,从大米提取淀粉,分析直链淀粉、淀粉分子量分布及糊化特性,并测定米粥的蒸煮特性、质构特性及食用品质,以期获得大米淀粉相关特性与米粥品质的相关性。结果表明,7种... 为筛选适宜煮粥的粥米品种,选用7种不同品种大米,分析大米的理化特性,从大米提取淀粉,分析直链淀粉、淀粉分子量分布及糊化特性,并测定米粥的蒸煮特性、质构特性及食用品质,以期获得大米淀粉相关特性与米粥品质的相关性。结果表明,7种不同品种间蛋白质及直链淀粉含量方面均存在显著差异(P<0.05),‘绥粳101’和‘龙粳31’的蛋白质含量为7.90%和7.84%,直链淀粉含量分别为19.76%和19.96%,均处于米粥品质的理想范围内,避免了过高或过低的含量导致米粥的粘度和硬度失衡。大米淀粉分子量分布存在差异(P<0.05),其中‘绥粳101’的分子量分布最窄,使米粥结构更均匀。糊化特性分析表明,‘绥粳101’的崩解值最低为930 mPa·s,蒸煮过程中米粥结构不易被破坏。在米粥品质方面,‘绥粳101’和‘龙粳31’具有较高的感官评分,质构特性中‘绥粳101’的米粥弹性最高为2.71 mm,‘龙粳31’的米汤内聚性最低为0.68。相关性分析显示,感官评价与蛋白质含量呈极显著正相关(P<0.01),崩解值与米粥质构特性呈显著负相关(P<0.05)。综上,淀粉分子量分布和糊化特性可作为测定米粥品质的指标,‘绥粳101’和‘龙粳31’是适合煮粥且具有开发潜力的品种,并为大米品种的选育提供了理论依据。 展开更多
关键词 大米粥 食用品质 淀粉 分子量 质构特性
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乳液静电纺丝法制备聚己内酯/低分子量褐藻多糖纳米纤维及生物相容性评价
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作者 汪影 王雅文 +2 位作者 徐颖婕 王元非 吴桐 《中国组织工程研究》 北大核心 2026年第2期433-442,共10页
背景:目前人工血管的远期通畅率仍是一个亟需解决的问题,提高小口径人工血管的抗凝血性能对于其远期通畅至关重要。目的:探讨壳芯结构聚己内酯/低分子量褐藻多糖纳米纤维的抗凝血活性以及对人脐静脉内皮细胞活性的影响。方法:采用乳液... 背景:目前人工血管的远期通畅率仍是一个亟需解决的问题,提高小口径人工血管的抗凝血性能对于其远期通畅至关重要。目的:探讨壳芯结构聚己内酯/低分子量褐藻多糖纳米纤维的抗凝血活性以及对人脐静脉内皮细胞活性的影响。方法:采用乳液静电纺丝方法制备聚己内酯纳米纤维膜与壳层为聚己内酯、芯层为低分子量褐藻多糖的聚己内酯/低分子量褐藻多糖纳米纤维膜(其中低分子量褐藻多糖与聚己内酯的质量比分别为10%,25%,40%,55%),通过扫描电子显微镜、荧光显微镜、红外光谱表征纤维的形态与结构,拉伸实验检测纤维膜的机械强度,1,9-二甲基亚甲蓝染料检测纳米纤维中低分子量褐藻多糖的负载率与缓释率,通过溶血实验、动态凝血实验、血浆再钙化实验与血小板黏附实验验证纤维膜的抗凝血性能。将5种纤维膜分别与人脐静脉内皮细胞共培养,通过CCK-8检测细胞增殖,荧光显微镜观察细胞形态。结果与结论:①扫描电镜下可见聚己内酯/低分子量褐藻多糖纳米纤维膜表面光滑,纤维直径粗细均匀,无明显串珠结构,随着纤维膜中低分子量褐藻多糖含量的增加,纤维膜的直径增加、最大拉伸应力降低,但仍符合小口径人工血管的力学性能要求;荧光图像和红外光谱图证实低分子量褐藻多糖成功载入聚己内酯纳米纤维膜中,各组纤维膜负载的低分子量褐藻多糖在12 h内存在突释,48 h后以相对低的速度进行释放。②与聚己内酯纳米纤维膜相比,聚己内酯/低分子量褐藻多糖纳米纤维膜具有更好的抗凝活性,其中低分子量褐藻多糖与聚己内酯质量比为25%组抗凝效果最好。5种纤维膜均支持人脐静脉内皮细胞的生长增殖且不影响细胞形态,无明显的细胞毒性。③结果表明,聚己内酯/低分子量褐藻多糖纳米纤维膜具有良好的抗凝血功能、血液相容性与细胞相容性。 展开更多
关键词 乳液静电纺丝 壳芯结构 低分子量褐藻多糖 聚己内酯 抗凝血 工程化血管材料
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湖泊水体溶解有机质行为及生态环境效应研究进展与展望
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作者 徐华成 李昂 《湖泊科学》 北大核心 2026年第1期29-46,共18页
溶解有机质(DOM)是一类结构组成多样、理化性质复杂、分子量分布范围广的混合物质,主要包含腐殖酸、富里酸、蛋白质、脂类等多种有机组分以及羧基、羟基、酚基、醛基等活性基团。DOM在湖泊生态系统中广泛存在,可参与多种生物地球化学过... 溶解有机质(DOM)是一类结构组成多样、理化性质复杂、分子量分布范围广的混合物质,主要包含腐殖酸、富里酸、蛋白质、脂类等多种有机组分以及羧基、羟基、酚基、醛基等活性基团。DOM在湖泊生态系统中广泛存在,可参与多种生物地球化学过程,影响生源要素及污染物的迁移转化和归趋行为,并在生态系统碳源汇转换中发挥着重要作用。湖泊水体DOM具有多种环境行为,如DOM可吸附至水体颗粒表面,调控DOM在溶解/悬浮相中的分配特征;环境条件下湖泊DOM会经历光及微生物降解过程,改变DOM在湖泊水体中的浓度和结构组成;湖泊DOM中的多官能团极易与金属离子发生络合,还可因电子跃迁产生活性氧物种。此外,湖泊DOM还具有显著的生态环境效应。例如,DOM可负载在胶体颗粒表面,影响胶体颗粒稳定性及水体透明度;DOM与重金属络合会改变重金属离子生物有效性,进而影响湖泊生态系统健康;湖泊DOM可通过活性氧物种媒介作用促进有机污染物降解,也可通过光屏蔽作用抑制污染物的降解。需要指出的是,湖泊DOM行为及生态环境效应与其分子量、活性基团及分子结构组成息息相关。本文系统综述了湖泊DOM行为及生态环境效应及其与DOM分子结构组成的关联性,以期为湖泊污染过程及机理研究、湖泊修复及调控、湖泊管理及规划等提供理论指导和技术支持。 展开更多
关键词 湖泊 溶解有机质 环境行为 生态环境效应 分子量分布 结构组成表征
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高剂量低分子量肝素对股骨干骨折愈合的影响
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作者 石腾博 倘艳锋 +7 位作者 张孟瑜 王幸飞 李晨阳 师锦玉 郭超韡 李彦州 贺自克 王上增 《中国组织工程研究》 北大核心 2026年第12期2957-2964,共8页
背景:股骨干骨折患者常伴随深静脉血栓风险,低分子量肝素是预防深静脉血栓的常用药物。然而,低分子量肝素对骨折愈合的影响尚存争议,部分研究表明其可能抑制成骨细胞分化,延缓骨折愈合。目的:探讨高剂量低分子量肝素对股骨干骨折愈合的... 背景:股骨干骨折患者常伴随深静脉血栓风险,低分子量肝素是预防深静脉血栓的常用药物。然而,低分子量肝素对骨折愈合的影响尚存争议,部分研究表明其可能抑制成骨细胞分化,延缓骨折愈合。目的:探讨高剂量低分子量肝素对股骨干骨折愈合的影响。方法:分析2023年1-12月期间100例股骨干骨折患者的资料,男51例,女49例,年龄(56.26±15.46)岁,根据入院后12 h内双下肢彩超筛查深静脉血栓存在情况分为无血栓组和血栓形成组,每组50例。无血栓组应用低分子量肝素腹部皮下注射预防血栓,每次100 U/kg,1次/d,连续应用2周;血栓形成组应用低分子量肝素腹部皮下注射抗凝治疗血栓,每次100 U/kg,1次/12 h,连续应用2周。记录两组患者的患肢肿胀评分、RUST骨折愈合评分、骨折愈合时间和HSS肢体功能评分。结果与结论:共93例患者完成随访,其中血栓形成组48例,无血栓组45例。两组患者术前一般资料比较差异均无显著性意义(P> 0.05)。血栓形成组在术后3 d、术后1周的肢体肿胀评分均显著高于无血栓组(P <0.05);血栓形成组的骨折愈合时间显著长于无血栓组(P <0.05);血栓形成组术后3个月的RUST骨折愈合评分和HSS肢体功能评分均显著低于无血栓组(P <0.05),术后6,9个月时两组患者RUST骨折愈合评分和HSS肢体功能评分无显著差异(P> 0.05)。结果表明,高剂量低分子量肝素应用早期可延迟骨折愈合时间,增加潜在出血风险,但对于股骨干骨折最终愈合无明显影响。 展开更多
关键词 低分子量肝素 股骨干骨折 深静脉血栓 骨折愈合 炎症 抗凝 肢体肿胀 成骨细胞
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Cp_(2)TiCl_(2)/Z-N催化混合端烯烃共聚合石油减阻剂的结构及其性能
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作者 付广钦 柴琳琳 +3 位作者 陈德军 殷德刚 曾城 赵梦奇 《精细石油化工》 2026年第1期1-4,共4页
采用第四代Ziegler-Natta催化剂体系,以二氯二茂钛(Cp_(2)Ti Cl_(2))为主催化剂,以三乙基铝[(C_(2)H_(5))_(3)Al]为助催化剂,以C_(12)为主的C_(5)~C_(14)混合烯烃为单体,采用本体聚合法合成了具有超高相对分子质量的石油减阻剂(α-烯烃... 采用第四代Ziegler-Natta催化剂体系,以二氯二茂钛(Cp_(2)Ti Cl_(2))为主催化剂,以三乙基铝[(C_(2)H_(5))_(3)Al]为助催化剂,以C_(12)为主的C_(5)~C_(14)混合烯烃为单体,采用本体聚合法合成了具有超高相对分子质量的石油减阻剂(α-烯烃类聚合物)。采用正交实验法确定的最佳条件为:(Et)_(3)Al用量为0.15 mL;Z-N催化剂用量为0.020 g;Cp_(2)TiCl_(2)催化剂用量为0.030 g;在5℃下聚合180 min。在此条件下,聚合物的M_(w)为4716253,M_(n)为1218235,多分散系数(M_(w)/M_(n))为3.871,减阻率为33.87%。 展开更多
关键词 二氯二茂钛 石油减阻剂 减阻性能 相对分子质量及其分布
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