基于ROC图的油菜生长期光谱敏感波段的研究     

段少新  姜珊  王访  邹锐标  廖桂平 《湖南农业大学学报(自然科学版)》2017,43(6)

测定了直播和移栽油菜的苗期、抽薹期、花期、盛花期和角果期的冠层光谱,构建了比值光谱植被指数(RSI)和归一化光谱植被指数(NDSI)。为了获得区分直播和移栽的最佳RSI和NDSI,利用降采样法和精细采样法相结合的受试者工作特征(ROC)图寻找油菜生长期光谱的敏感波长,直播和移栽油菜各时期RSI和NDSI的最敏感波长分别为:苗期(458 nm,511 nm)和(433 nm,517 nm);抽薹期(997 nm,501 nm)和(990 nm,510 nm);花期(1 235 nm,1 180 nm)和(1 235 nm,1 180 nm);盛花期(478 nm,396 nm)和(484 nm,416 nm);角果期(1 073 nm,1 037 nm)和(1 092 nm,1 024 nm)。用敏感波长下的2种植被指数为特征,以最近邻法为分类器的定性识别模型,结果花期的区分效果最好,最大约登指数分别为0.941 7和0.945 0。  相似文献   

寸三莲染色体核型和Giemsa C—带带型     

杨瑞芳  郭清泉 《湖南农业大学学报(自然科学版)》1998,24(3):191-193

采用Ｆ－ＢＳＧ制片法对寸三莲染色体组型及ＧｉｅｍｓａＣ－带带型进行了研究。结果表明：其染色体数目为２ｎ＝１６,核型公式为２ｎ＝１６＝２ｓｔ＋４ｓｍ＋８ｍ＋２ｍ（ＳＡＴ）,第６对梁色体有随体,染色体长度比为３．３,Ｎ．Ｆ．值为３０,属２Ｂ核类型,染色体相对长度组成为２ｎ＝１６＝４Ｌ＋２Ｍ２＋４Ｍ１＋６Ｓ,Ｇｉｅｍｓａ Ｃ－带带型主要为着丝点带。  相似文献   

草坪种子品种快速鉴定技术研究 III几种冷季型草坪草品种间相关性及差异性评定     

唐红 《草业科学》2003,(7)

通过软件分析,对几种冷季型草坪草种品种真实性鉴定的实验结果进行了定性定量评定,充分表明了品种间的相关性及差异性,经过聚类分析测得各品种间遗传关系的远近程度,并证明分析结果与植物分类学及室内种植结果基本一致,确定了此技术作为草坪草种品种鉴定手段的可靠性。  相似文献   

促进香椿休眠芽萌发和抑制新梢生长的研究     

王金增  马淑玲  许中旗  裴东 《河北林果研究》1995,(3)

通过环割及芽体涂抽枝宝、发枝素等措施，研究了促进矮化香椿园幼树休眠芽萌发和成枝的作用，证明以芽体涂发枝素的综合效果最好。用喷施或土施的方法研究了ＰＰ３３３对香椿播种苗和幼树生长的影响。喷施以２５０～５００ｍｇ／Ｌ为宜，土施可达５００ｍｇ／株。  相似文献   

Inhibitory effect of high-dose Xuezhikang on inflammatory response induced by percutaneous coronary intervention in patients with unstable angina     

LIU Zun-qi  CUI Lian-qun  WANG Yong  KONG Qing-zan  LIU Ji-dong  LI Feng  GAI Yu-sheng  ZHAO Chuan-yan 《园艺学报》2007,23(9):1703-1705

AIM: To study the inhibitory effect of high-dose Xuezhikang,administered before percutaneous coronary intervention (PCI) on inflammatory response induced by PCI in patients with unstable angina (UA).METHODS: All patients with UA in class Ⅲ and ⅡB according to Braunwald classification were considered for inclusion in the present study.Finally,196 patients received Xuezhikang treatment 72 h before coronary angiography and successfully performed PCI with elevated C-reactive protein (CRP) level (>3 mg/L) were randomised to 2 groups: 1.2 g/d of Xuezhikang as group A,or 2.4 g/d of Xuezhikang as group B.The levels of CRP were measured at baseline,after 3 days of therapy (before procedure) and 48 hours after PCI.The patients were followed-up for 6 months for major adverse coronary events and left ventricular ejection fraction.RESULTS: There was no significant difference in the mean CRP level among the two randomized groups (P>0.05),however,after three days of pharmacological treatment,there was significantly reduced CRP content in group A ［(5.44±1.57） mg/L vs （4.04±1.54） mg/L,P<0.05］ and in group B ［(5.42±1.36） mg/L vs （3.60±1.14） mg/L,P<0.05］ compared with admission.Measurements performed 48 hours after the procedure revealed a marked CRP level increase in group A (up to 9.22 mg/L±5.03 mg/L) and an obvious increase in groups B (up to 4.97 mg/L±1.75 mg/L,P<0.05) compared with pre-procedure.The serum level of CRP in B group was distinctly lower than that in A group before (P<0.05) and after the procedure (P<0.05),respectively.Major adverse coronary events during the 6-month clinical follow-up occurred less in group A than that in group B ［21/104 (20.2%) vs 9/92 (9.8%); patients,P<0.05］.Follow-up echocardiography revealed lower left ventricular ejection fraction in group A than that in group B (55.41%±10.93% vs 59.30%±9.99%,P<0.05).CONCLUSION: High-dose Xuezhikang therapy,administered before PCI,has better inhibition effect than low-dose on inflammatory response induced by PCI in patients with UA.Attenuation of inflammatory response may be crucial for the reduction of coronary events following invasive coronary interventions.  相似文献   

Thoracic duct ligation and pericardectomy for treatment of idiopathic chylothorax     

Fossum TW  Mertens MM  Miller MW  Peacock JT  Saunders A  Gordon S  Pahl G  Makarski LA  Bahr A  Hobson PH 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2004,18(3):307-310

Chylothorax is a devastating disease, and the success rates from either medical or surgical management are less than satisfactory. In some animals with chylothorax, a thickening of the pericardium occurs that is associated with chronic irritation induced by chyle. We hypothesized that pericardial thickening would lead to increased right-sided venous pressures and that abnormal venous pressures would act to impede the drainage of chyle via lymphaticovenous communications after thoracic duct (TD) ligation. We also hypothesized that serosanguineous effusions that occurred after TD ligation could effectively be treated or prevented by pericardectomy in affected animals. TD ligation plus pericardectomy was performed in 17 animals, and pericardectomy alone was performed in an additional 3 animals that presented during a 5.5-year period to the Texas A&M University (College Station, TX). Nineteen animals presented for an evaluation of idiopathic chylothorax (9 dogs and 10 cats), and 1 dog presented for serosanguineous pleural fluid after TD ligation that had been performed elsewhere. Echocardiography was normal in all animals, except for a subjectively thickened pericardium in 7 cats and 6 dogs. Clinical signs of pleural fluid accumulation resolved in 10 of 10 dogs and in 8 of 10 cats after surgery. The overall success rate for the surgical treatment of chylothorax (ie, the resolution of pleural fluid accumulation) in this study was 90% (100% in dogs and 80% in cats). These data suggest that TD ligation in conjunction with pericardectomy has a favorable outcome in animals with idiopathic chylothorax.  相似文献   

Transcatheter closure of congenital ventricular septal defects in 3 dogs with a detachable coil   总被引：3，自引：0，他引：3  

Fujii Y  Fukuda T  Machida N  Yamane T  Wakao Y 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2004,18(6):911-914

The purpose of this study was to evaluate the feasibility, safety, and efficacy of transcatheter closure in dogs with a congenital perimembranous ventricular septal defect (VSD) by using a detachable coil. No dogs showed any symptoms, and results of chest X-rays and ECGs were normal. The diameters of VSD ranged from 2 to 4 mm on echocardiogram. The defect was 2-2.5 mm from the aortic valve. A detachable coil (size 5 mm with 5 loops) designed for patent ductus arteriosus was delivered via the transarterial route. The device was successfully employed in all dogs. A minimal residual shunt was observed in all dogs even though Qp/Qs decreased. Hemolysis and a rate-dependent right-bundle branch block were observed in 1 dog, but there was no clinical significance. No major complication was noted. Pathologic examination after 1 year revealed that the coils were covered with tissue without significant damage to the His-Purkinje conduction system. In conclusion, transcatheter closure of a small perimembranous VSD with a detachable coil can be achieved without major complications or significant pathologic damage at the lesion site.  相似文献   

Congenital portosystemic shunts in toy and miniature poodles     

Hunt GB  Tisdall PL  Webb A  MacPherson GC  Brain P  Malik R 《Australian veterinary journal》2000,78(8):530-532

Three male Poodles (two Toy, one Miniature) were presented to their veterinarians for evaluation of urolithiasis and varying degrees of hepatic encephalopathy. All three dogs were diagnosed as having intrahepatic shunts and referred for surgical correction. In each case, shunts arose from the right branch of the portal vein and were amenable to perivascular dissection caudal to where the vessel entered the hepatic parenchyma and to placement of perivascular cellophane bands to achieve shunt attenuation. During the same period, a female Miniature Poodle also presented for treatment of a congenital portosystemic shunt discovered during evaluation for generalised motor seizures. This animal had an extrahepatic portoazygous shunt that was completely ligated. Congenital portosystemic shunts have not previously been identified in Toy and Miniature Poodles at the University Veterinary Centre, Sydney and the anatomical types of shunt seen in this breed have not previously been reported in a consecutive series of cases. The three male dogs are noteworthy for a number of reasons: all had intrahepatic shunts, despite being small breed dogs; all three presented in a similar fashion, and all had shunts of an anatomical type amenable to placement of cellophane bands. One male dog died within 12 hours of surgery, the remaining three dogs survived and their liver function was normal at follow-up between 2 and 3 months after surgery. Use of cellophane bands for successful attenuation of intrahepatic shunts has not been previously reported.  相似文献   

R-factor Pseudo-circular Extension Method     

GONG Qu  GONG Jian  CAO Chang xiu 《保鲜与加工》2000,(5):112-115

The extension methods of finite length signals for sub band coding associated with wavelet transformation are investigated.Considering the weakness of the existing extension methods,an extension method is presented which is named r factor pseudo circular extension method.It turns out theoretically that the input signal can be reconstructed exactly from the truncated section of the analyzed signals by our method and the method is better than other existing extension methods,as shown in many examples.A new valid way is provided for wavelet transform application in data compression.  相似文献   

Accelerated ageing of wheat grains: Part II-influence on thermal characteristics of wheat starch and FTIR spectroscopy of gluten     

《Journal of Cereal Science》2017

Wheat quality characteristics are influenced by different factors such as moisture content, storage time and temperature. In this study accelerated ageing of wheat grains was carried out by increasing moisture content (16, 18 and 20%) and keeping the samples in different temperatures (30, 40 and 50 °C) for different periods (2, 5 and 8 days). After milling, the thermal properties of starch and structure of gluten were investigated using Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR); respectively. The experimental set up was designed using response surface methodology and the three distinct factors were combined by central composite design. Results showed that increasing moisture content caused a decrease in onset, peak and end set temperatures of gelatinization while increasing storage time and temperature increased these parameters. By progressing storage time the band intensity of thiol groups decreased while that of disulfide groups of gluten increased indicating an improvement in gluten quality. Increasing moisture content from 16 to 20% and higher storage temperature (50 °C) decreased intensity of disulfide bands.  相似文献