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91.
Eviostachya hoegii Stockmans在中国五通组的首次发现   总被引:2,自引:0,他引:2  
首次描述了Eviostachya hoegii Stockmans的营养部分,通过大量标本的观察,修订了前人有关其生殖部分和解剖部分的描述,并对其生殖部分进行了复原.同意Emberger(1968)的观点,将其归于Eviostachyrales中.  相似文献   
92.
对北祁连山东段和鄂尔多斯西缘新材料的研究表明,甘肃景泰红水堡晚石炭世早期的杂羊齿属(Palaeoweichselia)与西欧的模式标本存在明显差异,遂另建-新属——Reticalethopteris gen.nov..新属与Neuralethopteris是脉延羊齿类植物中分别代表网状叶脉和羽状叶脉的一对姐妹属.  相似文献   
93.
滇西晚石炭世 Triticites 带的苔藓虫,产于施甸的10种,内含1新种,群体形状单一,生活于温暖、清洁、高能、面向外海的硬基底浅海区;产于腾冲的只有1种,是低能深水特提斯区分子.早二叠世苔藓虫12种,内含1新种,产耿马永德组 Polydiexodina 带之下,系特提斯区分子,据对其中的3层苔藓虫的硬体类型及标本数量分析,耿马含苔藓虫地层代表一个海侵过程.  相似文献   
94.
论晚二叠世的“克氏蛤”   总被引:6,自引:3,他引:3  
方宗杰 《古生物学报》1993,32(6):653-661
系统评述目前世界上出现的晚二叠世克氏蛤类标本,并描述采自贵州,云南藏东的有关化石1属3种。其中1新属1新种,右壳足丝凹口特征在克氏蛤类研究中具有重要意义。晚二叠世的Claraioides gen.nov.以足丝凹口内端明显向腹方或后腹方扩展膨大成足丝凹湾而不同于早三叠世的Claraia.后者似由前者演化而来,它们在二叠-三叠系界线附近发生替代,可能与古生代末的绝灭事件相关。  相似文献   
95.
文章通过贵州盘新塘原下二叠统下部紫松阶珊瑚化石的分析,将该地层划归上石炭统上部。描述上炭统威宁阶,过岩阶和紫松阶的四射珊瑚6属7种,其中5新种,通过对这些珊瑚的形态构造进行了剖析,略述了该地区在晚石炭世的环境特征。  相似文献   
96.
The rates of canopy apparent photosynthesis (PC) and canopy respiration (Rc) were studied during vegetation season in two erectophile and two planophile hybrids of maize (Zea mays L.) grown at two canopy densities [7.5 plants m-2 (HD) and 4.5 plants m-2 (LD)]. Large differences in PC, Rc, RC/PC, leaf area index (LAI), dry matter accumulation and grain yield were found among hybrids and plant densities. Variations in PC and RC were associated mainly with changes in LAI. There was also found change in PC per unit LAI with time. The average RC/PC was 28.9 % for all treatments throughout the vegetation season. PC and RC per unit dry matter were higher in LD than in HD and decreased throughout the measurement period. The HD stand had higher PC and yield in hybrids with erectophile foliage, whereas LD stand had higher PC after male tetrad and got higher yield in hybrids with planophile foliage. Only RC in hybrids of the two foliage types was higher under HD than under LD throughout the vegetation period.  相似文献   
97.
<正> 我们用国内的新鲜酵母为材料,从中分离纯化到一种多肽——酵母多肽,其分子量为14kD。在低血清培养体系中能促使人成纤维细胞(HFB)和人脐静脉内皮细胞(HUVEC)的DNA合成。当培养液中酵母多肽的浓度为1μg/mL时能引起最大的刺激作用。但此多肽对胎牛心脏内皮细胞(FBHEC)的DNA合成则无作用。  相似文献   
98.
Noctiluca scintillans is one of the most common harmful algal species and widely known due to its bioluminescence. In this study, the spatial distribution, seasonal variations, and long-term trends of N. scintillans blooms in China and the related drivers were analyzed and discussed. From 1933 to 2020, a total of 265 events of N. scintillans blooms were recorded in Chinese coastal waters, with a total duration of 1052 days. The first N. scintillans bloom occurred in Zhejiang in 1933, and only three events were recorded before 1980. From 1981 to 2020, N. scintillans caused harmful algal blooms (HABs) almost every year, both the average duration and the proportion of multiphase HABs showed an increasing trend. 1986–1992, 2002–2004, and 2009–2016 were the three peak periods with a frequency of no less than five events of N. scintillans blooms per year. In terms of spatial distribution, N. scintillans blooms spread from the Southeast China Sea to the Bohai Sea after 2000, Guangdong, Fujian, and Hebei were the three provinces with the highest numbers of recorded events of N. scintillans blooms. Moreover, 86.8% of the events of N. scintillans blooms occurred in spring (March, April, and May) and summer (June, July, and August). Among environmental factors, the dissolved inorganic phosphate, dissolved silicate and chemical oxygen demand were significantly correlated with the cell density of N. scintillans during N. scintillans blooms, and most of N. scintillans blooms were recorded in the temperature range of 18.0–25.0°C. Precipitation, hydrodynamics, water temperature, and food availability might be the main factors affecting the spatial–temporal distribution of N. scintillans blooms along the Chinese coast.  相似文献   
99.
四种主要大豆食叶害虫种群空间分布型及其应用研究   总被引:1,自引:0,他引:1  
通过分层随机与连片调查获得114个样本.利用微机分别对豆天蛾卵和豆天蛾.银纹夜蛾.棉铃虫.豆灰蝶及混合种群的幼虫.进行了4种频次分布型检验和6项聚集度指标的测定.结果表明.上述害虫在豆田内均属零集分布.中分析了聚集原因.提出了“Z”字型10样点,每样点以1/3m双行为单位的抽样方法.确立了在两种允许误差下的抽样数量.进行了序贯抽样分析。  相似文献   
100.

Background

The treatment of Helicobacter pylori (H. pylori) infection is a challenge for those who cannot use amoxicillin.

Objective

To evaluate the eradication rate and adverse effects of vonoprazan and tetracycline dual therapy as first-line and rescue treatment regimens used in special populations with penicillin allergy or failed in previous amoxicillin-containing therapies.

Design

Patients enrolled were those who were H. pylori-positive with selected conditions: (1) allergic to penicillin, either naïve to treatment or had failed before; or (2) failed in previous amoxicillin-containing therapies. All enrolled patients accepted 14-day vonoprazan and tetracycline dual therapy (VT dual therapy) as follows: vonoprazan (20 mg b.i.d.) and tetracycline (500 mg t.i.d. [body weight < 70 kg] or 500 mg q.i.d. [body weight ≥ 70 kg]). H. pylori status was evaluated by 13C-urease breath test 6 weeks after treatment. All adverse effects were recorded. Some patients underwent bacterial culture and antibiotic susceptibility testing.

Results

A total of 62 patients were enrolled; 18 of them received VT dual therapy as first-line treatment, 44 patients received VT dual therapy as rescue treatment. Overall, 58 of 62 patients achieved successful eradication (93.5%), while all involved (100%,18/18) succeeded in the first-line treatment group and 40 cases (90.9%, 40/44) succeeded in the rescue treatment group. Sixty-one (61/62, 98.4%) patients completed the whole course of treatment. Adverse events occurred in 6 patients (6/62, 9.7%), while one patient quit because of skin rash. All adverse effects were mild and relieved spontaneously after H. pylori treatment. Five patients achieved successful H. pylori culture, and all strains isolated were sensitive to tetracycline.

Conclusions

For the treatment of H. pylori infection in special populations with penicillin allergy or failed in previous amoxicillin-containing therapies, a 14-day vonoprazan and tetracycline dual therapy was effective and safe as first-line and rescue treatment in our study. Further study is warranted to verify its efficacy, especially for those who cannot use amoxicillin.  相似文献   
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