四种暖季型禾草对水分胁迫的生理响应

为筛选出西南地区适宜种植的暖季型禾草种类,以毛花雀稗（Paspalum dilatatum Poir）、小毛花雀稗（Paspalum urville S.）、柳枝稷（Panicum. virgatum L.）和非洲狗尾草（Setaria anceps）为材料,采用盆栽控水方法,研究干旱胁迫对植物叶片相对含水量、光合参数、游离脯氨酸含量和丙二醛含量等生理生化指标的影响。结果表明,随干旱时间的延长,几种暖季型禾草都表现出相对含水量下降、光合速率和蒸腾速率下降、气孔导度下降、游离脯氨酸含量上升、丙二醛含量上升等特征,但几种暖季型禾草的反应及复水后各指标的恢复能力各不相同。通过上述6项指标综合评价后初步认为,几种暖季型禾草的抗旱性顺序为柳枝稷＞小毛花雀稗＞非洲狗尾草＞毛花雀稗。     

p53: a frequent target for genetic abnormalities in lung cancer

Allele loss is a hallmark of chromosome regions harboring recessive oncogenes. Lung cancer frequently demonstrates loss of heterozygosity on 17p. Recent evidence suggests that the p53 gene located on 17p13 has many features of such an antioncogene. The p53 gene was frequently mutated or inactivated in all types of human lung cancer. The genetic abnormalities of p53 include gross changes such as homozygous deletions and abnormally sized messenger RNAs along with a variety of point or small mutations, which map to the p53 open reading frame and change amino acid sequence in a region highly conserved between mouse and man. In addition, very low or absent expression of p53 messenger RNA in lung cancer cell lines compared to normal lung was seen. These findings, coupled with the previous demonstration of 17p allele loss in lung cancer, strongly implicate p53 as an anti-oncogene whose disruption is involved in the pathogenesis of human lung cancer.     

Elimination of Lipid Hydrolysis in Aqueous Suspensions of Oat Flour

Aqueous suspensions of oat flour were studied to investigate the possibilities of eliminating the development of rancidity due to lipid hydrolysis. The hydrolysis was efficiently eliminated by immersing dry-milled flour in slightly alkaline water. Only a slight in pH was needed (pH 8-9) at the beginning of the soaking to prevent almost completely the hydrolysis of triglycerides, which under similar conditions, but in water without pH adjustment, led to free fatty acid content of up to 36% of the total lipids. In the alkaline suspensions the selective loss of linoleic acid from polar lipids, observed in a water slurry, was also very efficiently reduced. The hydrolysis of triglycerides was also diminished at acidic pH values (below pH 6) increasingly with reducing pH, although the same efficiency of inhibition as at alkaline pH was not reached. It was concluded that wet processes can be used for the preparation of non-deteriorated oat products by including simple pH adjustments in the process.     

Toward direct measurement of atmospheric nucleation

Atmospheric aerosol formation is known to occur almost all over the world, and the importance of these particles to climate and air quality has been recognized. Although almost all of the processes driving aerosol formation take place below a particle diameter of 3 nanometers, observations cover only larger particles. We introduce an instrumental setup to measure atmospheric concentrations of both neutral and charged nanometer-sized clusters. By applying the instruments in the field, we come to three important conclusions: (i) A pool of numerous neutral clusters in the sub-3 nanometer size range is continuously present; (ii) the processes initiating atmospheric aerosol formation start from particle sizes of approximately 1.5 nanometers; and (iii) neutral nucleation dominates over the ion-induced mechanism, at least in boreal forest conditions.     

Clinical findings,bronchoalveolar lavage fluid cytology and matrix metalloproteinase-2 and -9 in canine pulmonary eosinophilia

We characterized clinical and clinicopathological features, and the involvement of gelatinolytic matrix metalloproteinases (MMP-2 and -9) in canine pulmonary eosinophilia (PE). Study material consisted of 20 PE dogs and 16 healthy beagles. All dogs underwent a similar clinical examination and bronchoalveolar lavage (BAL). Analysis for cell count and differential cell count of BAL fluid (BALF), arterial blood gas analysis before and after BAL, and thoracic radiographs before BAL and after treatment were obtained. Twelve dogs were re-evaluated and six relavaged. MMP-2 and MMP-9 in BALF were analysed by zymography, Western immunoblotting and immunocytochemistry.In the PE dogs, BALF, cell count, number and percentage of eosinophils, and numbers of macrophages, lymphocytes, neutrophils, mast cells and epithelial cells were all significantly elevated. Blood eosinophilia was detected in half of the PE dogs. Three PE dogs had mild hypoxaemia. The BAL procedure had an equal effect on PE and healthy dogs' arterial blood gas values. Bronchointerstitial densities were seen in PE dogs' radiographs. Treatment of PE decreased BALF cell count, eosinophil count and percentage and diminished radiographic changes. Gelatinolytic activity was higher in PE dogs' BALF. BALF macrophages and epithelial cells were the principal sources of the MMP-9.     

Endoscopically guided nasojejunal tube placement in dogs for short‐term postduodenal feeding

Objective – To evaluate a method for endoscopically guided nasojejunal tube placement allowing short‐term postduodenal feeding and chyme withdrawal in dogs. Design – Pilot study. Setting – University teaching hospital. Animals – Three healthy Beagle dogs with jejunal nipple valve fistulas. Interventions – After the dogs were anesthetized, an 8 Fr, 250‐cm polyvinyl chloride catheter was advanced through a gastroscope into the jejunum. Correct jejunal placement was established using endoscopic visualization and confirmed by fluoroscopy and radiography. The proximal end of the tube was pulled out through 1 nostril and sutured to the skin of the forehead. Thereafter, jejunal feeding was administered for 4 days. Follow‐up examinations included daily confirmation of the tube's position using radiography, physical examination, and blood analyses. Withdrawal of jejunal chyme was performed after jejunal and oral feeding. Measurements and Main Results – Fluoroscopic examination confirmed that endoscopic visualization alone allowed correct jejunal placement. During a 4‐day postduodenal feeding period, repeated radiographic examination revealed stable positioning of the tubes within the jejunum with minor cranial displacement. The tubes were functional throughout the study without causing identifiable problems. Repeated physical examinations and blood analysis showed no abnormalities. We were able to administer the daily caloric requirements as a liquid diet. Jejunal chyme was successfully withdrawn via the tube. Conclusions – Endoscopically guided nasojejunal tube placement was shown to be a minimally invasive, well‐tolerated method for short‐term jejunal feeding in healthy dogs. This technique is a viable option for dogs requiring jejunal feeding but not laparotomy. The feasibility of chyme sampling is another unique application of the procedure.     

山刺玫化学成分及药理作用研究概况

山刺玫，又名野玫瑰，是蔷薇科之蔷薇属的一种落叶小灌木山刺玫的成熟果实，有健运脾气、调理月经、消食、敛肺止咳等功效，通过文献查阅，对山刺玫化学成分及药理作用的研究进行综述，为其进一步开发应用提供支持。     

饲用燕麦品种在晋北农牧交错区的生产性能和营养价值研究

在干旱半干旱地区，以17个饲用燕麦品种作为研究对象，连续3年观测其株高、干草产量、营养性状等指标，利用近红外光谱技术对干物质、酸性洗涤纤维、中性洗涤纤维和可溶性糖4个营养性状指标进行测定分析，并采用灰色关联度分析方法进行综合评价。结果表明：①青引2号的生育天数仅86 d，而林纳、锋利和定燕2号的生育天数均为105 d。②至乳熟期，参试品种中定燕2号的平均株高最高，而白燕19号、魁北克、KONA和早熟1号4个品种在乳熟期的平均株高均在90 cm以下，与其他参试品种间差异显著（P<0.05）。③至乳熟期，甜燕二号品种的干草产量迅速增加，平均产量较高，与早熟1号、白燕19号、林纳、定燕2号、青引2号和甜燕麦品种间差异显著（P<0.05），且这6个品种的平均干草产量均在7 000 kg·hm-2以下。④各品种的营养成分分析结果显示，在3个不同生育时期，参试品种的干物质含量均在90%以上（除林纳乳熟期外）；各品种的中性洗涤纤维和酸性洗涤纤维含量不同时期差异明显；可溶性糖含量在开花期各品种间存在较明显差异。⑤17个参试品种中，以定燕2号品种的主穗长最长，KONA品种的穗铃数最多，穗粒数以魁北克品种的数量最多，穗粒重以白燕19号品种最高，千粒重以甜燕麦品种最高。综合分析结果表明，甜燕二号、定燕2号、林纳、魁北克、甜燕麦5个品种的综合生产力最优，适宜在本地区优先推广利用。