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1.
N-acetyl-d-glucosamine (GlcNAc) is a monosaccharide that polymerizes linearly through (1,4)-β-linkages. GlcNAc is the monomeric unit of the polymer chitin. GlcNAc is a basic component of hyaluronic acid and keratin sulfate found on the cell surface. The aim of this study was to examine amino acid metabolism after oral GlcNAc administration in dogs. Results showed that plasma levels of ectoine were significantly higher after oral administration of GlcNAc than prior to administration (p < 0.001). To our knowledge, there have been no reports of increased ectoine concentrations in the plasma. The mechanism by which GlcNAc administration leads to increased ectoine plasma concentration remains unclear; future studies are required to clarify this mechanism.  相似文献   

2.
We examined the effects of oral glucosamine hydrochloride (GlcN), N-acetyl-D-glucosamine (GlcNAc) and d-glucose (Glc) administration on plasma total free amino acid (PFAA) concentrations in dogs. The PFAA concentrations increased in the control group and the GlcNAc group at one hour after feeding, and each amino acid concentration increased. On the other hand, in the GlcN group and the Glc group PFAA concentrations decreased at one hour after feeding. A significant decrease in amino acid concentration was observed for glutamate, glycine and alanine. Our results suggest the existence of differences in PFAA dynamics after oral administration of GlcN and GlcNAc in dogs.  相似文献   

3.
为探究磷铝互作对茶树生长的影响,设置了3个铝浓度以及5个磷浓度进行磷铝交互处理,分析茶树根系生长、有机酸分泌以及磷铝元素吸收的变化。结果表明,低磷(0.01 mmol∙L-1)或高铝(1 mmol∙L-1)均能显著促进茶树新根生长,且低磷高铝共同处理下茶树新根根尖数、根长、平均直径及干物质增加量均达到最大值;高铝能够使高磷(0.5 mmol∙L-1)条件下受阻的新根恢复生长;除高磷处理外,提高环境中的磷铝浓度能够显著促进另一元素在茶树根部的积累。一定范围内磷能够显著促进铝在嫩叶中的积累;但磷充足时(>0.05 mmol∙L-1)铝却会抑制磷在嫩叶中的积累。在磷充足时,提高铝浓度均能促进草酸、苹果酸、柠檬酸的分泌;提高磷浓度能促进柠檬酸的分泌,低磷能促进草酸和苹果酸的分泌,且低磷高铝协同促进苹果酸的分泌。双因素方差分析结果表明,磷、铝浓度及其交互作用对茶树新根的根长、根尖数、磷铝吸收及有机酸分泌均有极显著影响(P<0.01),可见磷铝互作能够显著影响茶树根系生长及有机酸分泌。  相似文献   

4.
The absorption, distribution and elimination of carnosic acid, the main antioxidant found in rosemary was studied, in vivo, in rats. Therefore, carnosic acid was administrated in a single dose, intravenously (20.5 ± 4.2 mg/kg) and orally (64.3 ± 5.8 mg/kg), to four and nine rats, respectively. Blood samples were collected at different time points, and plasma concentrations of carnosic acid were determined using LC-MS. Furthermore, total collection of urine and feces was done during 4 h and 24 h for the intravenous and oral administrations, respectively. After euthanizing the rats, intestinal content, liver and muscle tissue were sampled to determine carnosic acid concentrations. The bioavailability of carnosic acid, after 360 min, was 40.1%. Traces of carnosic acid were found in the rats intestinal content, liver and muscle tissue of abdomen and legs. The recovery of carnosic acid in the feces, 24 h after oral administration, was 15.6 ± 8.2%. Carnosic acid is absorbed into the bloodstream after oral administration in rats and is therefore bioavailable. It was found that carnosic acid in vivo is present in its free form and that its main elimination route is the fecal route.  相似文献   

5.
Deamidated wheat gliadins were prepared using hydrochloric acid (HCl) and citric acid (HDWG and CADWG), respectively. Their secondary structure, protein molecular interaction, thermal properties and nutritional changes were compared by Fourier transform infrared spectroscopy (FTIR), Raman spectrum, atomic force microscopy (AFM), differential scanning calorimetry (DSC), and amino acid analysis, respectively. Secondary structures and molecular vibration model showed slight difference between HDWG and CADWG, but significant difference between control gliadin and deamidated wheat gliadins. HDWG and CADWG had different shapes on the mica surface that the former showed some extent of linear aggregates and fibrils while the latter mainly exhibited globular aggregates. This result was further supported by thermal characteristics that CADWG had higher denaturation temperature than control gliadin and HDWG. Citric acid deamidation could increase the Lysine content and better maintain the total essential amino acids of in vitro digests of gliadin compared with HCl.  相似文献   

6.
【目的】探明秸秆还田和氮肥管理对麦/油后直播杂交稻氮素积累、转运、氮肥利用效率及籽粒产量的影响。【方法】选用优质三系杂交稻宜香优2115,采用二因素裂区设计,麦、油茬田同步开展试验,处理完全一致。主区为麦/油秸秆全量翻埋还田(M1)和秸秆不还田(对照,M0),副区设4个氮肥管理,即不施氮对照(N0)、m基肥m分蘖肥m促花肥m保花肥比例分别为1∶0∶0∶0(N1)、3∶3∶2∶2(N2)、2∶2∶3∶3(N3),测定了直播杂交稻主要生育时期各器官的氮素积累量及籽粒产量。【结果】结果表明,两种轮作方式下,氮肥管理对直播杂交稻主要生育时期的氮素积累、齐穗后茎鞘、叶片的氮素转运及稻株氮素利用效率均存在显著或极显著的调控效应。秸秆还田显著提高麦/油茬杂交稻中后期的氮素积累量、茎鞘和叶片的氮素转运量以及氮肥利用效率,其中,氮肥农学利用率、氮肥偏生产力和氮肥表观利用率较秸秆不还田分别提高了34.96%/28.76%、2.52%/2.61%和31.91%/22.30%。同时,油菜秸秆还田下直播杂交稻各生育时期氮素积累和产量较麦秆还田表现更好,籽粒产量提高481 kg/hm2(5.22%)。M1N2处理、M0N3处理下,直播杂交稻各阶段的氮素积累速率明显加大,促进结实期茎鞘和叶片的氮素向穗部转运,成熟期稻株氮素积累量优势明显且有较高的氮素利用效率(麦/油茬稻氮肥农学利用率、偏生产力和表观利用率分别达17.87 kg∙kg-1/17.85 kg∙kg-1、67.27 kg∙kg-1/71.28 kg∙kg-1、74.93%/75.05%),最终实现高产。【结论】在麦/油-稻轮作下秸秆全量还田,配合N2氮肥管理,可有效提高直播杂交稻氮素吸收、利用效率,增加籽粒产量,尤以油菜秸杆还田的效果更好。  相似文献   

7.
This study was conducted to develop near-infrared reflectance spectroscopy (NIRS) equations to predict the amino acid and nitrogen content of milled rice powder. The samples were scanned by NIRS and analyzed for amino acid composition and total nitrogen by HCl hydrolysis–HPLC methodology and Kjeldahl method, respectively. The NIRS equations of 15 different amino acids, except for cystine, methionine and histidine, showed high coefficients of determination (RSQ=84.8–97.5%) and low standard errors in calibration (SEC) with 3 g samples for NIRS scanning, while the calibration models of cystine and histidine could explain less variation (RSQ with 77.7 and 65.0%). Calibration for methionine was not suitable to estimate methionine because of its very low RSQ (10.2%). The equations for total amino acids and nitrogen also showed high RSQ and lower SEC, respectively. Furthermore, calibration equations developed with only about 500 mg samples showed similar accuracy and reliability to those with the full cup by using the same calibration set. The equations developed for relative contents of total amino acids did not show good, effective calibration and cross-validation. Only eight different amino acids can be predicted using the equations because their RSQs of calibration were higher than 50.6% (50.6–73.9%). The others cannot be estimated with confidence by their relative contents due to lower RSQ in calibration. Moreover, their relative contents can be calculated from their absolute contents estimated by NIRS calibration.  相似文献   

8.
In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2%) produced contractions in the abdominal musculature (writhes). The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the beginning of the first writhe was significantly (p < 0.05) increased and the number of writhes was significantly (p < 0.05) decreased by curcumin (20 and 40 mg kg(-1) body weight). The same results were obtained after subcutaneous injection of morphine (1 mg kg(-1) b.wt.). Naloxone at the dose of 1 mg kg(-1) body weight had no effect on pain intensity. Curcumin significantly (p < 0.05) enhanced the effect of morphine on the visceral pain responses, however did not reverse the effect of naloxone. Present data suggest that in the acetic acid-induced visceral nociception of rats, curcumin may produce an antinociceptive effect and the endogenous analgesic opioid system is involved in the curcumin-induced antinociception.  相似文献   

9.
喷施“双酸肥”对水稻作用效果的初步研究   总被引:2,自引:0,他引:2  
 在田间和盆栽试验中分别于水稻孕穗期、抽穗期和秧苗三叶期用富含核苷酸和氨基酸的双酸肥(DAF)喷施水稻,结果表明:DAF对水稻叶片叶绿素的形成和光合作用、呼吸酶活性和ATP形成、氮素的吸收与同化、DNA和RNA的合成、根系吸收能力、孕穗期茎鞘贮存性碳水化合物的积累及抽穗后向穗部的转移均有明显的促进作用,最终导致水稻产量的增加和谷粒蛋白质含量的提高。  相似文献   

10.
邻苯二甲酰亚胺(PI)和灭菌丹总量作为灭菌丹残留限量标准,造成茶叶中灭菌丹检测的假阳性误判,成为阻碍我国茶叶出口主要因素之一。本文优化了QuEChERS前处理条件,建立了气相色谱串联质谱法检测茶叶中PI残留的方法。样品经乙腈提取,多壁碳纳米管、十八烷基硅烷和苯磺基强阳离子交换剂组成的混合分散吸附剂净化。在10、20、50、100βμg∙kg-1添加水平下,回收率为73%~104%,相对标准偏差低于20%。方法定量限为10.0βμg∙kg-1。该方法简便、可靠、准确,灵敏度高,适用于茶叶中PI残留检测。  相似文献   

11.
Proso millet belongs to the oldest cereals that human is using. Eight varieties of proso millet were cultivated in Ceske Budejovice from1998 to 2000 and Cerveny Dvur from 1999 to 2000. The crude protein content was determined according to Kjehladl method and amino acid content was determined chromatographically after acid and oxidative acid hydrolysis. Although the protein content of proso (11.6% of dry matter) was similar to wheat, the grain of proso was significant richer in essential amino acids (leucine, isoleucine, methionine) then wheat. Hence, the protein quality of proso (Essential Amino Acid Index) was higher (51%) compared to wheat. The proso grain contained about 3.3 g kg−1 of the limiting amino acid-lysine. Significant differences in protein and its quality were found among the evaluated proso varieties. The varieties Toldanskoe and Lipetskoe were the most different from the others in protein and amino acid content and Amino Acid Score of individual acids. They had the lowest content and quality of protein. The seed coat of these varieties was red. The amino acid and protein content was significantly influenced by weather during the year. Dry conditions caused an increase of protein but its quality was decreased.  相似文献   

12.
Peritrophic matrix/membrane (PM) critically prevents the midgut of insects from external invasion by microbes. The proteins in the peritrophic membrane are its major structural components. Additionally, they determine the formation and function of this membrane. However, the role of PM proteins in immune regulation is unclear. Herein, we isolated a novel PM protein (MdPM-17) from Musca domestica larvae. Further, the function of MdPM-17 in regulating host innate immunity was identified. Results showed that the cDNA of MdPM-17 full is 635 bp in length. Moreover, it consists of a 477-bp open reading frame encoding 158 amino acid residues. These amino acid residues are composed of two Chitin-binding type-2 domain (ChtBD2) and 19 amino acids as a signal peptide. Moreover, tissue distribution analysis indicates that MdPM-17 was enriched expressed in midgut, and moderate levels in the fat body, foregut, and malpighian tubule. Notably, MdPM-17 recombinant protein showed high chitin-binding capacity, thus belongs to the Class III PM protein group. MdPM-17 protein silencing via RNA interference resulted in the expression of antimicrobial peptide (defensin, cecropins, and diptericin) genes, and this occurred after oral inoculation with exogenous microbes Escherichia coli (Enterobacteriales:Enterobacteriaceae), Staphylococcus aureus (Bacillales:Staphylococcaceae), and Candida albicans (Endomycetales:Saccharomycetaceae)). Therefore, all the antimicrobial peptide (AMP) gene expression levels are high in MdPM-17-depleted larvae during microbial infection compared to controls. Consequently, these findings indicate that MdPM-17 protein is associated with the antibacterial response from the housefly.  相似文献   

13.
Production of Xylose from Sorghum Straw Using Hydrochloric Acid   总被引:1,自引:0,他引:1  
Xylose is a hemicellulosic sugar mainly used for its bioconversion to xylitol. Sorghum straw is a raw material for xylose production that has been studied scarcely. The objective of this work was to study the xylose production by hydrolysis of sorghum straw with hydrochloric acid at 122 °C. Several concentrations of HCl (2–6%) and reaction time (0–300 min) were evaluated. Kinetic parameters of mathematical models for predicting the concentration of xylose, glucose, acetic acid and furfural in the hydrolysates were found. Optimal conditions for hydrolysis were 6% HCl at 122 °C for 70 min, which yielded a solution with 16·2 g xylose/L, 3·8 g glucose/L, 2·0 g furfural/L and 1·9 g acetic acid/L.  相似文献   

14.
This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS) in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD) at 250 nm (excitation) and 435 nm (emission) using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1–500 μg/mL, and the lower limit of detection (LLOD) was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (PSS-NP) in rat plasma after a single intravenous (PSS only) and oral administration (PSS and PSS-NP). Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.  相似文献   

15.
蓝光对水稻幼苗呼吸代谢的影响   总被引:14,自引:0,他引:14  
 就蓝光对水稻幼苗呼吸代谢的影响进行了研究。蓝光下生长幼苗叶片呼吸速率较白光幼苗提高了50%。蓝光处理提高了幼苗丙酮酸激酶和苹果酸脱氢酶的活性。丙二酸和正磷酸钠对蓝光幼苗叶片呼吸速率的抑制率分别为76%和24%;而对相应的白光幼苗的抑制率分别为70%和32%。这些结果说明蓝光主要是通过EMP-TCA途径而加强呼吸。蓝光处理提高了幼苗叶片ATP含量。  相似文献   

16.
Veterinarians working under remote field conditions are routinely presented with variety of surgical interventions in equines like castrations, management of wound, traumatic and congenital hernias and musculoskeletal disorders thus necessitating the use of general anaesthesia for management of these conditions. The present study was carried out to evaluate and recommend the suitable short term anaesthetic technique for Spiti ponies under field conditions. Seven clinically healthy male Spiti ponies presented for castration were evaluated for short term Total Intravenous Anaesthesia (TIVA) using detomidine (0.02 mg kg(-1)), butorphanol (0.01 mg kg(-1)), 5% guaifenesin (20 mg kg(-1)) and ketamine (2.0 mg kg(-1)). The studies conducted were open label trials and all the animals received same treatment. After proper tetanus prophylaxis and preanesthetic fasting, detomidine was administered intravenously. Subsequently at head down position the animals received butorphanol intravenously. Thereafter, guaifenesin was administered intravenously. As soon as the signs of ataxia developed, the induction of surgical anaesthesia was achieved by intravenous administration of ketamine hydrochloride. The onset of sedation was observed in 2.43 +/- 0.53 min following detomidine administration and the animals were ataxic in 1.43 +/- 0.43 min after butorphanol and guaifenesin administration when ketamine was injected. The ponies were in surgical plane of anaesthesia within 2.28 +/- 0.42 min following ketamine administration. During recovery the limb/head movement and sternal recumbency were attained in 18.71 +/- 1.98 and 26.14 +/- 1.62 min, respectively whereas standing ataxia and normal gait were seen at 29.42 +/- 3.21 and 71.14 +/- 4.74 min, respectively. There was excellent to good muscle relaxation. The surgical anaesthesia remained for 22.57 +/- 1.48 min. The recovery was smooth. Moderate to good suppression of palpebral and corneal reflexes were observed immediately after induction and during anaesthesia. The analgesia was excellent. A highly significant (p < 0.01) to significant (p < 0.05) decrease in respiration rate was observed after induction, during anaesthesia and after recovery. The mean SpO2 value in equines of this group was 76.50 +/- 4.14 and 83.33 +/- 4.18% after induction and during anaesthesia, respectively. Some of the blood biochemical parameters like plasma alanine amino transferase (ALT), total proteins and glucose showed significant increase without clinical consequence. It was concluded that detomidine (0.02 mg kg(-1)), butorphanol (0.01 mg kg(-1)), guaifenesin 5% (20 mg kg(-1)) and ketamine (2.0 mg kg(-1)) combination can safely be used for short term total intravenous anaesthesia in equines under field conditions where the monitoring facilities are meager.  相似文献   

17.
取健康家兔10只,随机分为2组,单剂量静注和灌服脂质体儿茶素(Catechin Liposome)25mg/kg。用高效液相色谱法测定血浆中儿茶素原药质量浓度。房室模型分析表明:健康家兔静注儿茶素脂质体的药时数据符合无吸收二室开放模型,主要药物动力学参数为:t1/2α0.18±0.01βh,t1/2β1.52±0.08βh,Vd4.48±0.24L,ClB2.05±0.07L/h,AUC29.20±1.00βmg/(L.h),K101.64±0.19h–1,K211.08±0.06h–1,K121.61±0.19h–1。健康家兔灌服脂质体儿茶素的药时数据符合一级吸收一室开放模型,主要药物动力学参数为:t1/2ka 0.27±0.03βh,t1/2ke 1.72±0.04βh,tmax0.87±0.05βh,Cmax6.53±0.62βmg/L,AUC 25.90±1.34βmg/(L.h),F 88.60±5.73%。脂质体儿茶素在健康家兔体内的药动学特征是:吸收迅速,达峰时间较短,消除慢,半衰期延长,表现分布容积大,口服生物利用度高。结果表明:儿茶素经脂质体包封后,药物动力学及组织分布均发生了明显改变。  相似文献   

18.
常温下荔枝贮藏保鲜的研究   总被引:7,自引:0,他引:7  
测定了不同保贮条件下荔枝褐变相关生理指标:多酚氧化酶(PPO)、过氧化物酶(POD)、透性和呼吸强度的变化,同时,也测定了保贮期相应的营养成分:可溶性固形物、维生素C、类胡萝卜素、水溶性蛋白、游离氨基酸、糖等的变化。结果表明:乙烯吸收剂+SSC(1%NaCl+2%Na2So3+5%柠檬酸的溶液)浸果贮藏,糯米糍品种荔枝在常温条件下,可延长贮藏7-1d,保持色香味不变。  相似文献   

19.
铝胁迫下大豆根系分泌物对根际土壤的影响   总被引:1,自引:2,他引:1  
以2个大豆品种(浙春2号和浙春3号)为材料,设置了4个铝浓度,分别在铝处理7d和14d时,测定大豆根系分泌物中的氨基酸、有机酸及可溶性糖,同时对大豆根际土壤的pH值、土壤酶和土壤呼吸速率进行分析。实验结果显示,虽然根系分泌物对根际土壤具有一定的酸化作用,但是随着铝浓度的升高,根系分泌物有使根际土壤酸碱度趋向平衡的效应。低铝浓度下,大豆根系分泌较多的可溶性糖和氨基酸,促使根际土壤酶活性的增强和土壤呼吸速率的提高,同时还可分泌较多的柠檬酸,与大豆的耐铝性相关。高铝浓度抑制主要根系分泌物的分泌,降低土壤酶活性和土壤呼吸速率;但高铝胁迫增加可溶性糖分泌量。实验结果表明,浙春2号大豆比浙春3号大豆耐铝;随着铝处理时间的延长,铝毒害作用明显。  相似文献   

20.
Amino acid chromatograms of freeze-dried potato powder have shown an unknown peak before the aspartic acid peak. The unknown amino acid derivative has been identified as methionine sulfoxide which is produced during acid hydrolysis of potato powder; it is not a naturally occurring component of potato protein. The presence of methionine sulfoxide after acid hydrolysis should be considered when reporting amino acid data.  相似文献   

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