Five- and six-coordinate ruthenium(II) porphyrin tetiaryphosphine complexes,and their reactions with dioxygen via inner- and outer-sphere mechanisms

The 5-coordinate ruthenium(II) octaethylporphyrin complex Ru(OEP)(PPh₃) has been prepared by reduction of Ru(OEP)(PPh₃)Br using zinc amalgam. Both the Ru(OEP)(PPh₃)₃ complexes (n = 1,2) undergo reaction in toluene with O₂ to generate OPPh₃, RuO₂, and the parent porphyrin H₂(OEP); trace water and the μ-oxo dimer [Ru(OEP)(OH)]₂O are implicated in the oxidation reaction, which is considered to be initiated by coordination of O₂ to Ru(OEP)(PPh₃). In contrast, a catalytic O₂-oxidation of excess PPh₃ to the oxide probably goes via an initial outer-sphere reaction with Ru(OEP)(PPh₃)₂, that generates superoxides and Ru(III), both detectable by ESR; the superoxide is believed to be stabilized via portion addition as HO₂· that subsequently disproportionates to O₂ and H₂O₂. PPh₃ is oxidized by the peroxide, and during a reduction step that regenerates the Ru(II) catalyst from Ru(III).     

THE ANTARCTIC PSYCHROPHILE,CHLAMYDOMONAS RAUDENSIS ETTL (UWO241) (CHLOROPHYCEAE,CHLOROPHYTA), EXHIBITS A LIMITED CAPACITY TO PHOTOACCLIMATE TO RED LIGHT1

The psychrophilic Antarctic alga, Chlamydomonas raudensis Ettl (UWO241), grows under an extreme environment of low temperature and low irradiance of a limited spectral quality (blue‐green). We investigated the ability of C. raudensis to acclimate to long‐term imbalances in excitation caused by light quality through adjustments in photosystem stoichiometry. Log‐phase cultures of C. raudensis and C. reinhardtii grown under white light were shifted to either blue or red light for 12 h. Previously, we reported that C. raudensis lacks the ability to redistribute light energy via the short‐term mechanism of state transitions. However, similar to the model of mesophilic alga, C. reinhardtii, the psychrophile retained the capacity for long‐term adjustment in energy distribution between PSI and PSII by modulating the levels of PSI reaction center polypeptides, PsaA/PsaB, with minimal changes in the content of the PSII polypeptide, D1, in response to changes in light quality. The functional consequences of the modulation in PSI/PSII stoichiometry in the psychrophile were distinct from those observed in C. reinhardtii. Exposure of C. raudensis to red light caused 1) an inhibition of growth and photosynthetic rates, 2) an increased reduction state of the intersystem plastoquinone pool with concomitant increases in nonphotochemical quenching, 3) an uncoupling of the major light‐harvesting complex from the PSII core, and 4) differential thylakoid protein phosphorylation profiles compared with C. reinhardtii. We conclude that the characteristic low levels of PSI relative to PSII set the limit in the capacity of C. raudensis to photoacclimate to an environment enriched in red light.     

叶绿素合成缺陷型小球藻突变株的选育及其蛋白产能和品质评价

本研究旨在利用常压室温等离子体(atmospheric pressure room temperature plasma, ARTP)诱变技术构建叶绿素合成缺陷型凯式小球藻突变株,筛选出极低叶绿素、适用于发酵生产蛋白质的新藻种。首先经优化诱变处理时间后建立了野生型兼养细胞的致死率曲线,在高于95%致死率条件下处理对数早期兼养细胞,基于可视化藻落颜色变化初筛获得4株突变株。随后在摇瓶中异养培养突变株,系统评价了蛋白生产性能,发现在含有30 g/L葡萄糖和5 g/L NaNO₃的Basal培养基中,突变株P. ks4表现最优,蛋白含量及产率分别为39.25%干重及1.15g/(L·d),氨基酸评分达101.34,叶绿素a含量下降98.78%且不含叶绿素b,含有叶黄素0.62 mg/g而使藻体呈金黄色。本研究为微藻替代蛋白的发酵生产提供了高性能、高品质的新种质P. ks 4。     

Chiral ionic liquids: synthesis and applications

Over the last ten years, interest and publications involving ionic liquids have expanded exponentially. Thus far, they have predominantly been used in organic synthesis and separations. However, their use is rapidly expanding into other areas of science and technology. Research involving chiral ionic liquids has been much more limited and only recently has come to the forefront. In this work, we review the synthesis of chiral ionic liquids and their use. Today, this is an area of research that is poised for rapid development and expansion.     

手术室工作流程现状分析

目的 通过具体的手术室流程分析，探索医院手术室流程科学合理的管理方法。方法 运用现场调研法对手术室的流程进行考察分析，并应用流程图的方法显化现有手术室的流程，对现有流程采用德尔菲法和FTA的方法进行分析。结果 得到手术室工作流程的问题报告。结论 手术室的流程问题主要有：等待浪费，沟通失效，操作行为不当，管理技术不当，设施布局不合理。     

Challenges and prospects for biomarker research: A current perspective from the developing world

Majority of deaths due to communicable and non-communicable diseases occur in the low and middle-income nations (LMNs), mainly due to the lack of early diagnoses and timely treatments. In such a scenario, biomarkers serve as an indispensible resource that can be used as indicators of biological processes, specific disease conditions or response to therapeutic interventions. Evaluation, diagnosis and management of diseases in developing world by following/extrapolating the findings obtained on the basis of the research work involving only the populations from the developed countries, could often be highly misleading due to existence of diverse patterns of diseases in developing countries compared to the developed world. Biomarker candidates identified from high-throughput integrated omics technologies have promising potential; however, their actual clinical applications are found to be limited, primarily due to the challenges of disease heterogeneity and pre-analytical variability associated with the biomarker discovery pipeline. Additionally, in the developing world, economic crunches, lack of awareness and education, paucity of biorepositories, enormous diversities in socio-epidemiological background, ethnicity, lifestyle, diet, exposure to various environmental risk factors and infectious agents, and ethical and social issues also cumulatively hinder biomarker discovery ventures. Establishment of standard operating procedures, comprehensive data repositories and exchange of scientific findings are crucial for reducing the variability and fragmentation of data. This review highlights the challenges associated with the discovery, validation and translational phases of biomarker research in LMNs with some of their amenable solutions and future prospects. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge.     

Determination of trace carvedilol by solid substrate–room temperature phosphorimetry,based on its activating effect on hypochlorite‐oxidizing amaranth using sodium dodecyl benzene sulphonate as sensitizer

This work proposes a simple and sensitive solid substrate–room temperature phosphorimetry (SS–RTP) for the selective determination of carvedilol (CV). The method is based on the sensitizing effect of sodium dodecyl benzene sulphonate (SDBS) on CV to activate the oxidation between NaClO and amaranth, resulting in the intense quenching of room temperature phosphorescence (RTP) of the system. Compared with non‐SDBS system, the reduction of phosphorescence intensity (ΔI_p) with SDBS is 16.5 times higher and is directly proportional to the content of CV, covering a wide range 0.080–16.00 fg/spot. The regression equation of the working curve can be expressed as ΔI_p = 0.7780 + 7.057 m_CV (fg/spot) (correlation coefficient (r) = 0.9976, n = 8), with a detection limit (LD) of 0.020 fg/spot (corresponding concentration is 5.1 × 10⁻¹⁴ g/mL, sample volume is 0.40 μL/spot). This sensitive method has also been applied to determine trace CV in human plasma and the results agreed with synchronous fluorimetry (SF). The activation energy (E) and rate constant (k) of this activating reaction were 69.04 kJ/mol and 3.580 × 10⁻⁴ s⁻¹, respectively. The reaction mechanism is also discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

New steroidal 17β-carboxy derivatives present anti-5α-reductase activity and anti-proliferative effects in a human androgen-responsive prostate cancer cell line

The androgens testosterone (T) and dihydrotestosterone (DHT), besides playing an important role in prostate development and growth, are also responsible for the development and progression of benign prostate hyperplasia (BPH) and prostate cancer. Therefore, the actions of these hormones can be antagonized by preventing the irreversible conversion of T into DHT by inhibiting 5α-reductase (5α-R). This has been a useful therapeutic approach for the referred diseases and can be achieved by using 5α-reductase inhibitors (RIs). Steroidal RIs, finasteride and dutasteride, are used in clinic for BPH treatment and were also proposed for chemoprevention of prostate cancer. Nevertheless, due to the increase in bone and muscle loss, impotency and occurrence of high-grade prostate tumours, it is important to seek for other potent and specific molecules with lower side effects. In the present work, we designed and synthesized steroids with the 3-keto-Δ⁴ moiety in the A-ring, as in the 5α-R substrate T, and with carboxamide, carboxyester or carboxylic acid functions at the C-17β position. The inhibitory 5α-R activity, in human prostate microsomes, as well as the anti-proliferative effects of the most potent compounds, in a human androgen-responsive prostate cancer cell line (LNCaP cells), were investigated. Our results showed that steroids 3, 4 and 5 are good RIs, which suggest that C-17β lipophylic amides favour 5α-R inhibition. Moreover, these steroids induce a decrease in cell viability of stimulated LNCaP cells, in a 5α-R dependent-manner, similarly to finasteride.     

耐碱性木聚糖酶

造纸工业是我国国民经济中具有可持续发展特点的重要产业,也是我国重要的工业污染源之一.近年来,世界范围内的造纸工业都受到资源、环境和效益等多方面的约束,都力求寻找能够达到节能减耗、保护生态环境、提高生产效率和经济效益及产品质量的先进生产技术.木聚糖酶及其潜在的工业应用前景引起人们关注,低(无)纤维素酶活性的木聚糖酶尤其有着诱人的应用前景,它可以应用于生物制浆、纸浆漂白、废纸二次纤维回收、废纸脱墨处理、纸浆纤维改性剂和纺织工业等,特别是其在纸浆漂白工艺中的巨大应用潜力,已成为各界同行的研究热点.应用于生物漂白过程中的木聚糖酶必须满足没有或者只有少量纤维素酶伴随产生,具有良好的耐碱性及耐高温性,在纸浆中具有稳定的酶活性等条件.自然界中微生物产生的木聚糖降解酶系比较复杂,许多会伴随纤维素酶的产生,这些酶的性质相近,不易分离纯化.此外,除了一些生长在极端环境中的微生物如嗜热菌、嗜碱菌等分泌的木聚糖酶能够满足生物漂白的要求之外,大多数来源于真菌、细菌或放线菌的木聚糖酶都需要在应用过程中调节反应条件.以上这些限制条件严重阻碍了木聚糖酶规模化生产及应用工艺的建立.     

常压室温等离子体技术在微生物诱变中的应用进展

微生物是人类赖以生存的重要资源,为提高微生物的生产效率或者赋予其新的生物学功能,需要通过理化方法进行诱变或通过分子生物学技术对其进行定点突变。在目前的理化诱变方法中,常压室温等离子（atmospheric and room temperature plasma,ARTP）诱变技术具有操作简单、条件温和、安全性高、诱变快速等优点,成为倍受青睐的新方法。基于此,综述了ARTP诱变技术的原理及其在微生物诱变育种方面的应用,以期为选育性能优越的微生物菌种的诱变育种相关研究提供借鉴。