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2.
目的:研究不同氮素形态配施对浙贝母产量和品质的影响,为浙贝母氮肥的科学施用及重庆地区的迁地引种提供依据。方法:采用盆栽试验法,研究了2种氮素形态的5种浓度水平即硝态氮(NO_3~--N)-铵态氮(NH_4~+-N)为15∶0(N1),12∶3(N2),7. 5∶7. 5(N3),3∶12(N4),0∶15(N5)处理下,引种栽培的浙贝母生长及生理生化、土壤因子、生物碱含量及产量的变化。结果:与不施氮(CK)处理组相比,不同氮素营养配施对浙贝母生长和品质均有显著提高,相互间存在差异。其中,随着铵态氮浓度的增加:①在硝态氮-铵态氮比为3∶12时,株高、超氧化物歧化酶(SOD)活性达到最大,较CK组分别增加了9. 27%,206. 62%;②在硝态氮-铵态氮比为0∶15时,叶长,叶宽,茎粗,叶绿素a,叶绿素b,叶绿素总量,速效磷含量,有机质含量、总生物碱含量/产量达到最大,分别高于CK处理组14. 02%,16. 44%,13. 68%,40. 75%,45. 31%,41. 72%,77. 70%,14. 70%,24. 61%/47. 39%;随着硝态氮浓度的增加;③在硝态氮-铵态氮比为7. 5∶7. 5时,叶形指数、可溶性蛋白含量、贝母辛含量/产量、贝母素乙产量、鳞茎干重均达到最大,分别高于CK处理组2. 54%,5. 92%,21. 76%/54. 55%,60. 61%,26. 93%;④在硝态氮-铵态氮比为12∶3时,类胡萝卜素含量、色素含量、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、贝母素甲含量/产量、贝母素乙含量、贝母素(甲+乙)含量/产量、贝母素(甲+乙)+贝母辛含量/产量、鳞茎湿重均达到最大,分别高于CK处理组45. 39%,45. 31%,271. 38%,67. 45%,39. 82%/64. 87%,36. 01%,38. 90%/63. 80%,37. 03%/61. 57%,20. 29%。结论:较高比例的铵态氮利于浙贝母的生长;而较高比例的硝态氮利于浙贝母鳞茎的生长以及代谢产物生物碱的积累。氮素配比施用(硝态氮-铵态氮比为12:3)较单一形态氮素更有利于提高浙贝母的产量和品质。  相似文献   
3.
目的氮素是中药材有效成分积累的重要影响元素,为探讨不同氮源对丹参Salviamiltiorrhiza和藏丹参Salvia castanea毛状根生长和活性成分积累的影响。方法分别采用硝酸铵、水解乳蛋白、蛋白胨、牛肉浸膏、酪蛋白和酵母提取物6种氮源处理对丹参和藏丹参毛状根的影响,分析毛状根生长及活性成分积累的变化。结果硝酸铵最有利于2种丹参毛状根的生长。水解乳蛋白能够显著促进丹酚酸类成分的积累,与硝酸铵对照相比,丹参迷迭香酸和丹酚酸B含量分别提高了2.94倍和3.27倍,藏丹参二者含量分别提高了13.74倍和2.01倍。酵母提取物对2种丹参毛状根二氢丹参酮Ι和隐丹参酮积累的促进效果最为显著,水解乳蛋白能显著促进丹参根中丹参酮IIA的积累,牛肉浸膏则对藏丹参中丹参酮IIA积累的促进作用最为显著。结论硝酸铵是2种丹参毛状根生长的最佳氮源,水解乳蛋白是丹酚酸积累的最佳氮源,不同氮源对4种丹参酮的影响不一致,丹参和藏丹参对不同氮源的响应也不一致。该研究不仅对丹参毛状根规模化培养及活性成分工业化生产具有一定指导意义,也对藏丹参资源的开发利用提供了借鉴作用。  相似文献   
4.
Abstract

Wharton’s Jelly (WJ) tissue is a promising biomaterial, for tissue engineering applications. However, its preservation over a long period in order to be readily available needs further optimization. A possible solution could be the vitrification and storage of WJ tissue at low temperatures. The aim of this study is to evaluate the effect of low temperature in the WJ tissue, which was stored at ?196?°C, either with the vitrification or conventional cryopreservation methods. WJ tissues were isolated from human umbilical cords, cryopreserved with the above methods and remained for 1?year at ?196?°C. Histological analysis of tissue’s extracellular matrix (ECM), isolation, and characterization of mesenchymal stromal cells (MSCs) were performed. Histological analysis revealed the presence of ECM components such as collagen, sulfated glycosaminoglycans (sGAGs), and the presence of cell nuclei only in vitrified samples. Furthermore, MSCs were isolated and expanded successfully from vitrified WJ tissues, whereas a few viable cells were obtained from conventionally cryopreserved tissues that were not further expanded. In conclusion, this study indicated the proper preservation of vitrified WJ tissues after 1?year of storage, which eventually could be used in tissue engineering and regenerative medicine approaches.  相似文献   
5.
Lymphomatoid papulosis (LyP) is a paraneoplastic primary cutaneous CD30+ lymphoproliferative disorder (LPD) that has been associated with malignant lymphomas, most commonly mycosis fungoides (MF). We observed 10 patients with MF who developed severe inflammation after using nitrogen-mustard (NM) gel from 1 to 8 months and who developed LyP. We hypothesized that NM gel produced local inflammation, which induced CD30 expression in malignant T cells in situ leading to the appearance of LyP papules. The high frequency of induction of LyP lesions in patients with severe inflammation while on treatment with NM gel suggests an association between inflammatory stimuli and development of LyP. Our observation provides insight into the pathogenesis of CD30+ LPD.  相似文献   
6.
Introduction: Multicomponent reactions are paramount in drug discovery for their ability to achieve high levels of diversity within the chemical space, generating complex structures from simple building blocks. Among them, the isocyanide-based Ugi-Joulliè reaction is particularly suited for the rapid synthesis of peptidomimetics and nitrogen-containing compounds.

Areas covered: The latest achievements in drug discovery and synthetic chemistry regarding the application of the Ugi-Joulliè reaction in the field of natural compounds, peptidomimetics and small molecules, are reported in this article. All relevant literature was disclosed applying most common web-based literature searching tools, namely Web of Science, PubMed, SciFinder and Google Scholar.

Expert opinion: The Ugi-Joulliè reaction represents an extremely versatile and simple synthetic methodology, useful for designing efficiently new molecular frameworks. Particularly relevant to drug discovery is the Ugi-Joulliè-based synthesis of conformationally constrained peptidomimetics and antibacterial depsipeptides. On the other hand, the many syntheses of new, nitrogen-containing heterocycles are not always followed by biological evaluation, losing opportunities for the disclosure of unprecedented lead compounds.  相似文献   

7.
Rational design and sustainable preparation of high-performance carbonaceous electrode materials are important to the practical application of supercapacitors. In this work, a cost-effective synthesis strategy for nitrogen and oxygen co-doped porous carbon (NOC) from petroleum sludge waste was developed. The hierarchical porous structure and ultra-high surface area (2514.7 m2 g−1) of NOC electrode materials could provide an efficient transport path and capacitance active site for electrolyte ions. The uniform co-doping of N and O heteroatoms brought enhanced wettability, electrical conductivity and probably additional pseudo-capacitance. The as-obtained NOC electrodes exhibited a high specific capacitance (441.2 F g−1 at 0.5 A g−1), outstanding rate capability, and cycling performance with inconspicuous capacitance loss after 10,000 cycles. Further, the assembled all-solid-state MnO2/NOC asymmetrical supercapacitor device (ASC) could deliver an excellent capacitance of 119.3 F g−1 at 0.2 A g−1 under a wide potential operation window of 0–1.8 V with flexible mechanical stability. This ASC device yielded a superior energy density of 53.7 W h kg−1 at a power density of 180 W kg−1 and a reasonable cycling life. Overall, this sustainable, low-cost and waste-derived porous carbon electrode material might be widely used in the field of energy storage, now and into the foreseeable future.  相似文献   
8.
目的探索大气二氧化氮(NO_2)对苏州市居民肺癌发病、死亡影响的程度和特点,确定滞后时间,评估健康效应。方法收集2006—2014年苏州市居民肺癌发病、死亡资料,大气污染物和气象数据,采用时间序列的广义相加模型,在控制长期趋势、星期几效应和气象因素的影响后,定量分析单污染物模型和双污染物模型中,大气NO_2对肺癌发病死亡人数的影响。结果单污染物模型中,滞后3天的NO_2(lag3)对肺癌日发病数的效应有统计学意义(P=0.03)。随着NO_2浓度每升高10μg/m~3,肺癌全人群和女性人群日发病数分别增加1.001%(95%CI:0.075,1.926)和2.541%(95%CI:0.744,4.338)。双污染物模型结果显示,NO_2对肺癌发病影响需要和PM2.5相互作用才发挥效应,不受SO_2和PM10的影响。结论苏州市肺癌,特别是女性肺癌发病人数随着大气NO_2浓度的增加而呈上升趋势;其影响存在滞后性,需要PM2.5的联合作用才能发挥效应。  相似文献   
9.
Pancreatic ductal adenocarcinoma is highly lethal and surgical resection is the only potential curative treatment for the disease. In this study, hyaluronic acid derived nanoparticles with physico-chemically entrapped indocyanine green, termed NanoICG, were utilized for intraoperative near infrared fluorescence detection of pancreatic cancer. NanoICG was not cytotoxic to healthy pancreatic epithelial cells and did not induce chemotaxis or phagocytosis, it accumulated significantly within the pancreas in an orthotopic pancreatic ductal adenocarcinoma model, and demonstrated contrast-enhancement for pancreatic lesions relative to non-diseased portions of the pancreas. Fluorescence microscopy showed higher fluorescence intensity in pancreatic lesions and splenic metastases due to NanoICG compared to ICG alone. The in vivo safety profile of NanoICG, including, biochemical, hematological, and pathological analysis of NanoICG-treated healthy mice, indicates negligible toxicity. These results suggest that NanoICG is a promising contrast agent for intraoperative detection of pancreatic tumors.  相似文献   
10.
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