快速识别假劣化肥

<正> 化肥质量的假劣,可用“看、烧、摸、试、测”等方法快速判断。现将几类主要化肥的假劣识别法介绍如下: 氮肥市场上出现的假冒尿素有两种情况:一是尿素与碳酸氢铵混装,即化肥袋内上面是尿素,下面是碳酸氢铵。其特点是上面流动性好,下面不流动甚至结块,且可闻到刺鼻的氨气味。出现这种情况的尿素,即可断     

滴灌和滴灌施肥对伏令夏橙果实产量和果汁品质的影响

在5年滴灌研究期间,对果实产量和果汁品质进行了测定。灌溉处理以不灌溉为对照。设每株2个、4个滴嘴,1个、2个喷嘴处理;施肥处理以干肥为对照。设通过灌溉系统(滴灌施肥)分别供给15％、30％N和K处理结果表明:灌溉增加了39—64％的果实产量,超过对照;果实产量随各灌溉处理所及面积的增大而增加;灌溉和局部滴灌施肥处理,降低了果汁的可溶性固形物(白利糖度)和酸浓度;局部滴灌施肥处理对果实产量影响不太。滴灌或低容量灌溉作为佛州柑桔最流行的灌溉方式正在得到承认,因为该系统仅灌溉根系的一部分。成本相当低,且具有节水省能的潜力。通过灌溉系统供给肥料的滴灌施肥是滴灌方式的潜在优越性之一。而树下喷嘴系统,还具有防冻的可能性。据报道,砂质土上的柑桔果实产量,随滴灌处理所及的地表面积的增大而增加。本研究始于1978年,旨在评定不同的处理面积和滴灌比率对植株的影响。此外将局部滴灌施肥处理与干肥处理作一比较。本文总结了5年来的叶分析、果实产量和果实品质的数据。     

砧木和修剪对元帅苹果植株第一个生长季干重分布的影响

将MM_(106)和M_9砧上的首红元帅苹果植株采取不修剪、冬剪(定植当年),和夏剪(定植后12周)等处理以研究修剪和砧木对植株第一个生长季节期间的根系和枝梢间的干重分布的影响。在定植后最初6周期间,冬剪促进了新梢干重增加,降低了新根干重。然而,到12周时新根干重和新梢干重间则几乎无差异。夏剪导致了新梢生长的显著     

Pharmacokinetics of amoxycillin and the rate of depletion of its residues in pigs

Six pigs were used in a two-period crossover study to investigate the pharmacokinetics of amoxycillin after single intravenous and oral doses of 20 mg/kg bodyweight. Twelve pigs were used to study the residues of the drug in muscle, kidney, liver and fat after they had received daily oral doses of 20 mg/kg amoxycillin for five days. The mean (sd) elimination half life (t1/2beta) and mean residence time of amoxycillin in plasma were 3.38 (0.30) and 3.54 (0.43) hours, respectively, after intravenous administration and 4.13 (0.50) and 4.47 (0.30) hours, respectively, after oral administration. After oral administration, the maximum plasma concentration (Cmax) was 7.37 (0.42) microg/ml and it was reached after 0.97 (0.29) hours. Six days after the last oral dose, the mean concentration of amoxycillin in the pigs' kidneys was 21.38 ng/g and in the liver it was 12.32 ng/g, but no amoxycillin could be detected in fat or muscle; the concentrations of amoxycillin in edible tissues were less than the European Union maximal residue limit of 50 microg/kg.     

Toxicity, dosage, and efficacy of vinorelbine (Navelbine) in dogs with spontaneous neoplasia

The purpose of this study was to evaluate short-term adverse effects and determine a safe dosage for vinorelbine (Navelbine)--a new semisynthetic vinca alkaloid--in dogs with malignant tumors. Nineteen dogs were treated with vinorelbine as a 5-minute IV infusion every 7 days at starting dosages ranging from 10 to 20 mg/m2. The median number of treatments per dog was 7 (range, 1-11). The maximum tolerated dosage varied between 15 and 18 mg/m2, and a starting dosage of 15 mg/m2 is recommended. Neutropenia was the dose-limiting toxicity. Although efficacy was a secondary endpoint of this dosage-finding study, 2 dogs with metastatic bronchoalveolar carcinoma experienced a partial response for an overall response rate of 12.5% in 16 dogs with gross measurable disease. Three dogs with microscopic disease were treated (incompletely excised bronchoalveolar carcinoma or lymph node metastatic disease). Two died of pulmonary metastatic disease 113 and 196 days posttreatment, and 1 is still alive after at least 730 days. The well-tolerated toxicity profile and clinical activity observed in dogs with bronchoalveolar carcinoma warrants further investigation.     

The tear film and ocular mucins

Abstract The trilaminar tear film, composed of the lipid, aqueous and mucin layers, has many functions including defending the ocular surface. The aqueous layer has several soluble antimicrobial factors that protect the ocular surface. Ocular mucins have recently been studied with regard to their role in the defense of the eye as well as in dry eye syndromes. To date, 15 mucin genes have been identified, and six of these mucin genes are localized to or secreted by ocular glands or epithelia. Understanding the production, secretion and function of ocular mucins will aid in the treatment of dry eye syndromes and ocular surface microbial infections.     

Preparing protein microarrays by soft-landing of mass-selected ions

Intact, multiply protonated proteins of particular mass and charge were selected from ionized protein mixtures and gently landed at different positions on a surface to form a microarray. An array of cytochrome c, lysozyme, insulin, and apomyoglobin was generated, and the deposited proteins showed electrospray ionization mass spectra that matched those of the authentic compounds. Deposited lysozyme and trypsin retained their biological activity. Multiply charged ions of protein kinase A catalytic subunit and hexokinase were also soft-landed into glycerol-based liquid surfaces. These soft-landed kinases phosphorylated LRRASLG oligopeptide and D-fructose, respectively.