Soil phosphorus fractions and adsorption as affected by organic and inorganic sources

The effect of organic and inorganic sources of phosphorus (P) on soil P fractions and P adsorption was studied in a field without plant growth on a Kandiudalf in western Kenya. A high-quality organic source, Tithonia diversifolia (Hemsley) A. Gray leaves, and a low-quality source, maize (Zea mays L.) stover, were applied alone or in combination with triple superphosphate (TSP). The P rate was kept constant at 15 kg P ha^-1. Soil extractable P (resin, bicarbonate and sodium hydroxide), microbial biomass P and C and P adsorption isotherms were determined during 16 weeks after application of treatments. Application of tithonia either alone or with TSP increased resin P, bicarbonate P, microbial P, and sodium hydroxide inorganic P. Tithonia alone reduced P adsorption at 2–16 weeks. Maize stover had no effect on any of the P fractions or P adsorption. At 8 weeks, the application of tithonia reduced microbial C-to-P ratio (20) as compared to maize stover, TSP and the control (31–34). The reduction in P adsorption by tithonia was accompanied by increases in all measured P fractions, the sum of P in those fractions (resin, bicarbonate and sodium hydroxide) being larger than the P added. The reduction in P adsorption apparently resulted from competition for adsorption sites, probably by organic anions produced during decomposition of the high quality tithonia. Integration of inorganic P (TSP) with organic materials had little added benefit compared to sole application of TSP, except that combination of tithonia with TSP increased microbial biomass. The results indicate that a high quality organic input can be comparable to or more effective than inorganic P in increasing P availability in the soil.     

Sensitivity optimized HCN and HCNCH experiments for 13C/15N labeled oligonucleotides

Triple resonance HCN and HCNCH experiments used in studies of ¹³C/¹⁵N labeled oligonucleotides include extended evolution periods (typically up to 100 ms) to allow coherence transfer through a complex heteronuclear spin network. Unfortunately, most of the magnetization is lost during the evolution due to fast spin–spin relaxation dominated by one-bond ¹H–¹³C dipolar interaction. As demonstrated recently, the sensitivity of the experiments can be dramatically improved by keeping the spin system in a state of proton–carbon multiple-quantum coherence, which is not affected by the strong dipolar coupling. However, the multiple-quantum coherence is very sensitive to homonuclear as well as long-range heteronuclear interactions. Unwanted magnetization transfer due to these interactions can reduce the sensitivity back to the level of a single-quantum experiment and, for some spin moieties, even eliminate the signal completely. In the present paper we show that a modified HCN scheme that refocuses the interfering coherences improves sensitivity routinely by a factor of 1.5 to 4 over a nonselective experiment. In addition, novel multiple-quantum 2D and 3D HCNCH experiments with substantially enhanced sensitivity are presented.     

三链核酸稳定性和生物学功能的研究进展

近10年来三链核酸的研究发展迅猛,已经成为分子生物学和基因工程的一个前沿领域.综述了最近在三链核酸稳定性和生物学功能方面的研究进展.较为详细地讨论了影响三链稳定性的各种内源和外源因素如：寡聚脱氧核苷酸(ODN)的长短 、序列、碱基修饰、骨架结构以及温度、酸度、离子强度 、配基等,同时对三链核酸的生物学功能进行了初步的总结,这些功能包括：控制基因转录,保护靶序列防止酶切,充当分子剪刀进行特定位点切割等.     

Influences of milk components on biofilm formation of Cronobacter spp. (Enterobacter sakazakii)

Aim:  To determine the critical component(s) of skim milk for biofilm formation of Cronobacter species.
Methods and Results:  Biofilm forming ability of 72 Cronobacter strains in skim milk preparation was assayed by crystal violet staining. The results revealed that whey protein and casein are more important determinants of skim milk for biofilm formation than lactose, although there was a wide variation in biofilm forming ability. Biofilm structure and capsular material of six strains exhibiting different biofilm forming ability was investigated via electron microscopes. Scanning electron microscopy showed visually that while the strong biofilm formers (E27B, FSM 30 and 2·82) resulted in almost complete coagulation of skim milk, the weak biofilm formers (55, FSM 290 and 2·84) caused less coagulation. No capsule was clearly delineated in transmission electron micrographs of either strong or weak biofilm formers.
Conclusion:  These results indicate that, for biofilm formation of Cronobacter species in skim milk, nitrogen source is probably a more important determinant than carbohydrate, and that strong biofilm formers are responsible for substantial coagulation of skim milk.
Significance and Impact of the Study:  This study provides information for better understanding of the underlying mechanisms by which Cronobacter species form biofilm in infant formula milk.     

Rodlet cells in epidermal explant cultures of Lepomis Macrochirus

Sunfish rodlet cells were examined in vitro using a novel tissue explant system. Outgrowth of epidermal cell layers from explanted fish scales enabled both live cell videomicroscopy and immunocytochemical analysis of rodlet cells within the cell layer. Cells stained with fluorescent phallotoxin and antibody to tubulin showed that F‐actin is a component of the fibrous capsule that envelopes the cell and a microtubule network extends from the basal to apical ends of the cell interior. The fibrous capsule is also enriched for phosphotyrosine suggesting a potential signal‐transducing capability is present in this structure. Videomicroscopy analysis of live explant cultures demonstrated that rodlet cells are immobile and that interior structures are highly dynamic. Rodlet sacs can undergo extension and retraction, while intracellular particles can move rapidly within these cells. Fish scale tissue explants provide a useful system for analyzing the molecular composition and dynamic behavior of rodlet cells.     

Highly selective screening of the bioactive compounds in Huoxue capsule using immobilized β2-adrenoceptor affinity chromatography

A highly selective assay was developed for screening compounds that bind to the porcine recombinant β₂-adrenoceptor (β₂-AR) with affinity chromatography coupled to quadrupole time-of-flight mass spectrometry (Q-TOF–MS). The methodology involved selective screening with immobilized β₂-AR, a highly accurate identification via Q-TOF–MS, and a functional evaluation of the screened compounds with a sensitive myograph system. Ferulic acid, hydroxysafflor yellow A (HSYA), and naringin were confirmed to be the bioactive compounds in Huoxue capsule that specifically bound to the β₂-AR. These compounds produced a concentration-dependent relaxation of arteries that were contracted by treatment with phenylephrine, and the relaxation caused by these compounds was attenuated in the presence of ICI 118551, a type of β₂-AR antagonist. Our data indicate that the use of an immobilized receptor is potentially an alternative method for the rapid screening of bioactive compounds in a complex matrix because of its high specificity. β₂-AR affinity chromatography was valuable in focusing attention on the further investigation of ferulic acid, HSYA, and naringin as β₂-AR agonists.     

Luminescence enhancement of the catalytic 19 kDa protein (KAZ) of Oplophorus luciferase by three amino acid substitutions

To characterize the luminescence properties of nanoKAZ, a 16 amino acid substituted mutant of the catalytic 19 kDa protein (KAZ) of Oplophorus luciferase, the effects of each mutated amino acid were investigated by site-specific mutagenesis. All 16 single substituted KAZ mutants were expressed in Escherichia coli cells and their secretory expressions in CHO-K1 cells were also examined using the signal peptide sequence of Gaussia luciferase. Luminescence activity of KAZ was significantly enhanced by single amino acid substitutions at V44I, A54I, or Y138I. Further, the triple mutant KAZ-V44I/A54I/Y138I, named eKAZ, was prepared and these substitutions synergistically enhanced luminescence activity, showing 66-fold higher activity than wild-KAZ and also 7-fold higher activity than nanoKAZ using coelenterazine as a substrate. Substrate specificity of eKAZ for C2- and/or C6-modified coelenterazine analogues was different from that of nanoKAZ, indicating that three amino acid substitutions may be responsible for the substrate recognition of coelenterazine to increase luminescence activity. In contrast, these substitutions did not stimulate protein secretion from CHO-K1 cells, suggesting that the folded-protein structure of KAZ might be different from that of nanoKAZ.     

康力欣胶囊联合FOLFOX4方案对中晚期胃癌患者免疫功能、生活质量和血清肿瘤标志物的影响

目的:观察康力欣胶囊联合奥沙利铂、亚叶酸钙、5-氟尿嘧啶(FOLFOX4)方案对中晚期胃癌患者免疫功能、生活质量和血清肿瘤标志物的影响。方法:前瞻性选取2018年7月~2021年1月期间来我院接受治疗的胃癌患者80例,根据抽签分为对照组和观察组两组,各为40例。对照组接受FOLFOX4方案治疗,观察组接受康力欣胶囊联合FOLFOX4方案治疗,以3周为1个疗程,治疗2个疗程。观察两组治疗2个疗程后的疗效、生活质量以及治疗期间不良反应状况,对比两组治疗前、治疗2个疗程后的肿瘤标志物和免疫功能指标变化情况。结果:观察组治疗2个疗程后的总有效率高于对照组(P<0.05)。治疗2个疗程后,观察组的肿瘤相关物质群(TSGF)、糖类抗原-199(CA-199)、癌胚抗原(CEA)低于对照组(P<0.05)。治疗2个疗程后,观察组的CD3;、CD4;、自然杀伤细胞(NK)、CD4;/CD8;高于对照组,CD8;低于对照组(P<0.05)。治疗2个疗程后,观察组的生活质量总改善率、卡氏评分(KPS)评分高于对照组(P<0.05)。两组不良反应发生率组间对比无统计学差异(P>0.05)。结论:中晚期胃癌患者采用康力欣胶囊联合FOLFOX4方案治疗,在阻止疾病进展、改善生活质量、提高免疫功能方面均效果确切,优于单纯化疗效果。     

Splash seed dispersal by raindrops

Splash seed dispersal by raindrops was investigated for plants in southern Japan. Nine families, 10 genera and 19 species were confirmed as raindrop-dispersed plants. The 10 genera were Gentiana, Gratiola, Chrysosplenium, Mazus, Mitella, Ophiorrhiza, Sagina, Sedum, Trigonotis and Veronica. The method of splash rain dispersal in these species was clarified. Raindrop-dispersed species were all small herbaceous plants with a vertical pedicel and an apically opening fresh capsule when the seeds mature. Open capsules were cup-shaped or boat-shaped and can accommodate raindrops easily. The raindrops splashed the seeds from the capsule. In general, the seeds weighed very little, but they were heavier than powder or dust seeds dispersed by wind. A strong negative correlation was found between seed weight and the number of seeds per capsule. In the case of Trigonotis brevipes (Maxim.) Maxim., raindrops were received into the cup-shaped calyx-tube and dispersed the fruitlets. Some species, such as Gentiana thunbergii (G. Don) Griseb., Gentiana zollingeri Fawcett and Ophiorrhiza japonica Blume, had hydroscopic movement capsules that opened widely only when wet. Raindrop-dispersed plants were found in various habitats. For example, some plants grew together on rocks along the mountain torrents where splash water could easily be caught. The results of the laboratory and field experiments indicated that the dispersal distance of seeds by raindrops was 1m or less. For small herbaceous plants, splash dispersal by rain might be an effective and advantageous method of seed dispersal because dispersal is not affected by plant height.     

葛兰心宁软胶囊联合替格瑞洛片对冠心病心绞痛患者心功能和血管内皮功能的影响

摘要 目的：观察葛兰心宁软胶囊联合替格瑞洛片治疗冠心病心绞痛的疗效及对心功能和血管内皮功能的影响。方法：选择我院心内科收治的150例冠心病心绞痛患者,按门诊号单双数分为对照组和研究组,各为75例。对照组给予替格瑞洛片治疗,研究组给予葛兰心宁软胶囊联合替格瑞洛片治疗,对比两组疗效、血管内皮功能、心功能、心绞痛发作次数和持续时间以及不良反应发生率。结果：治疗1个月后,研究组的临床总有效率85.33%（64/75）高于对照组的69.33%（52/75）,差异有统计学意义（P<0.05）。治疗1个月后,研究组左心室射血分数（LVEF）、心输出量（CO）、每搏输出量（SV）高于对照组（P<0.05）。治疗1个月后,与对照组比较,研究组的心绞痛发作次数更少,持续时间更短（P<0.05）。治疗1个月后,研究组一氧化氮（NO）、血流介导的舒张功能（FMD）高于对照组,内皮素-1（ET-1）、胞间黏附分子-1（ICAM-1）、血管紧张素Ⅱ（Ang Ⅱ）低于对照组（P<0.05）。两组不良反应发生率组间对比无明显差异（P>0.05）。结论：冠心病心绞痛患者经葛兰心宁软胶囊联合替格瑞洛片治疗后,疗效明确,可缓解患者临床症状,促进心功能和血管内皮功能恢复。