Bis-ortho-metalation/silylation of unprotected o-phthalic acids. Straightforward access to new silylated N-hydroxyphthalimide (NHPI) analogs

The one pot, in situ ortho-metalation/silylation of unprotected o-phthalic acids using lithium tetramethylpiperidide (LiTMP) and chlorotrimethylsilane is described. This method gives a straightforward access to silylated phthalic anhydrides. These can be easily converted into the corresponding silylated N-hydroxyphthalimide (NHPI) analogs, which are promising new aerobic oxidation catalysts.     

含有手性和发光官能团侧基的聚1-苯基-1-辛炔的合成与性能研究

设计并合成了一系列含手性和发光生色团侧基的聚（1-苯基-1-辛炔）衍生物{-[（C6H13）C=C（C6H4-p-CO2-R）]n-,R=[（1S）-endo]-（-）-冰片基（P3）,（1R,2S,5R）-（-）-薄荷基（P4）,-C6H4-p-（1R,2S,5R）-（-）-薄荷基（P5）,2-萘基（P6）,4-联苯基（P7）}.用WCl6-Ph4Sn作催化剂,成功地制备了这些具有中等产率和高分子量（Mw高达64000）的聚合物.聚合物的结构和性能通过NMR,TGA,UV,CD,PL和EL等分析方法进行了表征.所有聚合物都表现出良好的热稳定性,在N2保护条件下,其失重5%的温度在300～416℃之间.所有聚合物的带隙约为3.0eV.聚合物P4和P5表现出与聚合物链段螺旋性相对应的CD吸收.在UV辐照下,P3～P7的THF溶液均发射强烈蓝光,其最大发射波长位于485nm左右,量子效率均高于20%.聚合物薄膜发射与其溶液发射在相同的光谱区域,并表现出轻微的聚集诱导猝灭.制备了ITO/聚合物：PVK/BCP/Alq3/LiF/Al多层聚合物EL器件,其最大发射波长为487nm.随着侧基的改变,器件的最大亮度和外量子效率也随之发生变化,其中P6表现出最高的外量子效率（0.16%）.EL器件均具有良好的光谱稳定性,其EL最大发射峰几乎不随外加电压的变化而改变.     

The complexation of rhodium(III) with acyclic diaminedithioether (DADTE) ligands

(103)Rhodium(III) complexes derived from seven acyclic tetradentate N(2)S(2) ligands (one diaminedithiol and six diaminedithioether ligands) have been synthesized and characterized. Structural variations in the ligand include the length of carbon backbone between the coordinating atoms (222; 232; 323; 333), the presence or absence of gem-dimethyl groups α to sulfur, and the nature of the organic moiety on the sulfurs (hydrogen, p-methoxybenzyl and methyl). For each ligand, the formation of cis and/or trans dichloro isomeric complexes was assessed. Two complexes have been further characterized by single crystal X-ray diffraction. Preparation of the (103)Rhodium(III) complexes was conducted and overall radiochemical yields, in vitro stability and log D(7.4) values were measured. From these studies, the ligand with the 232 chain length, gem-dimethyl groups and the methyl thioether (L4) emerged as a preferred ligand for formation of rhodium complexes with trans geometry and highest radiochemical yields.     

Mechanism and origin of exciton spin relaxation in CdSe nanorods

The dynamics of exciton spin relaxation in CdSe nanorods of various sizes and shapes are measured by an ultrafast transient polarization grating technique. The measurement of the third-order transient grating (3-TG) signal utilizing linear cross-polarized pump pulses enables us to monitor the history of spin relaxation among the bright exciton states with a total angular momentum of F = +/-1. From the measured exciton spin relaxation dynamics, it is found that the effective mechanism of exciton spin relaxation is sensitive to the size of the nanorod. Most of the measured cross-polarized 3-TG signals show single-exponential spin relaxation dynamics, while biexponential spin relaxation dynamics are observed in the nanorod of the largest diameter. This analysis suggests that a direct exciton spin flip process between the bright exciton states with F = +/-1 is the dominant spin relaxation mechanism in small nanocrystals, and an indirect spin flip via the dark states with F = +/-2 contributes as the size of the nanocrystal increases. This idea is examined by simulations of 3-TG signals with a kinetic model for exciton spin relaxation considering the states in the exciton fine structure. Also, it is revealed that the rate of exciton spin relaxation has a strong correlation with the diameter, d, of the nanorod, scaled by the power law of 1/d4, rather than other shape parameters such as length, volume, or aspect ratio.     

Current and Emerging Concepts in Muscle Tension Dysphonia: A 30-Month Review

The modern theory of hoarseness is that there are multifactorial etiologies contributing to the voice problem. The hypothesis of this study is that muscle tension dysphonia is multifactorial with various contributing etiologies. METHODS: This project is a retrospective chart review of all patients seen in the Voice Speech and Language Service and Swallowing Center at our institution with a diagnosis of muscle tension (functional hypertensive) dysphonia over a 30-month period. A literature search and review is also performed regarding current and emerging concepts of muscle tension dysphonia. RESULTS: One hundred fifty subjects were identified (60% female, 40% male, with a mean age of 42.3 years). Significant factors in patient history believed to contribute to abnormal voice production were gastroesophageal reflux in 49%, high stress levels in 18%, excessive amounts of voice use in 63%, and excessive loudness demands on voice use in 23%. Otolaryngologic evaluation was performed in 82% of patients, in whom lesions, significant vocal fold edema, or paralysis/paresis was identified in 52.3%. Speech pathology assessment revealed poor breath support, inappropriately low pitch, and visible cervical neck tension in the majority of patients. Inappropriate intensity was observed in 23.3% of patients. This set of multiple contributing factors is discussed in the context of current and emerging understanding of muscle tension dysphonia. CONCLUSIONS: Results confirm multifactorial etiologies contributing to hoarseness in the patients identified with muscle tension dysphonia. An interdisciplinary approach to treating all contributing factors portends the best prognosis.     

Comparative Bioinformatics Analyses and Profiling of Lysosome-Related Organelle Proteomes

Complete and accurate profiling of cellular organelle proteomes, while challenging, is important for the understanding of detailed cellular processes at the organelle level. Mass spectrometry technologies coupled with bioinformatics analysis provide an effective approach for protein identification and functional interpretation of organelle proteomes. In this study, we have compiled human organelle reference datasets from large-scale proteomic studies and protein databases for 7 lysosome-related organelles (LROs), as well as the endoplasmic reticulum and mitochondria, for comparative organelle proteome analysis. Heterogeneous sources of human organelle proteins and rodent homologs are mapped to human UniProtKB protein entries based on ID and/or peptide mappings, followed by functional annotation and categorization using the iProXpress proteomic expression analysis system. Cataloging organelle proteomes allows close examination of both shared and unique proteins among various LROs and reveals their functional relevance. The proteomic comparisons show that LROs are a closely related family of organelles. The shared proteins indicate the dynamic and hybrid nature of LROs, while the unique transmembrane proteins may represent additional candidate marker proteins for LROs. This comparative analysis, therefore, provides a basis for hypothesis formulation and experimental validation of organelle proteins and their functional roles.     

Inkjet-like printing of single-cells

Cell sorting and separation techniques are essential tools for cell biology research and for many diagnostic and therapeutic applications. For many of these applications, it is imperative that heterogeneous populations of cells are segregated according to their cell type and that individual cells can be isolated and analysed. We present a novel technique to isolate single cells encapsulated in a picolitre sized droplet that are then deposited by inkjet-like printing at defined locations for downstream genomic analysis. The single-cell-manipulator (SCM) developed for this purpose consists of a dispenser chip to print cells contained in a free flying droplet, a computer vision system to detect single-cells inside the dispenser chip prior to printing, and appropriate automation equipment to print single-cells onto defined locations on a substrate. This technique is spatially dynamic, enabling cell printing on a wide range of commonly used substrates such as microscope slides, membranes and microtiter plates. Demonstration experiments performed using the SCM resulted in a printing efficiency of 87% for polystyrene microbeads of 10 μm size. When the SCM was applied to a cervical cancer cell line (HeLa), a printing efficiency of 87% was observed and a post-SCM cell viability rate of 75% was achieved.     

Broadband cavity-enhanced absorption spectroscopy for real time, in situ spectral analysis of microfluidic droplets

Broadband cavity-enhanced absorption spectroscopy has been used to record, in real time, the absorption spectrum of microlitre volume aqueous phase droplets within a microfluidic chip assembly. Using supercontinuum radiation and broadband coated external mirrors, the full visible spectrum (430 nm < λ < 700 nm) of each passing droplet is acquired in situ at high repetition rates (273 Hz/3.66 ms acquisition time) and high sensitivity (α(min) < 10(-2) cm(-1)). The possibilities for further improvements in sensitivity and acquisition rate using custom designed chips are discussed.     

Balance between fluorescence enhancement and association affinity in fluorescent heteroditopic indicators for imaging zinc ion in living cells

A fluorescent heteroditopic indicator for the zinc(II) ion possesses two different zinc(II) binding sites. The sequential coordination of zinc(II) at the two sites can be transmitted into distinct fluorescence changes. In the heteroditopic ligand system that our group developed, the formations of mono- and dizinc(II) complexes along an increasing gradient of zinc(II) concentration lead to fluorescence enhancement and an emission bathochromic shift, respectively. The extents of these two changes determine the sensitivity and, ultimately, the effectiveness of the heteroditopic indicator in quantifying zinc(II) ion over a large concentration range. In this work, a strategy to increase the degree of fluorescence enhancement upon the formation of the monozinc(II) complex of a heteroditopic ligand under simulated physiological conditions is demonstrated. Fluorination of the pyridyl groups in the pentadentate N,N,N'-tris(pyridylmethyl)ethyleneamino group reduces the apparent pK(a) value of the high-affinity site, which increases the degree of fluorescence enhancement as the monozinc(II) complex is forming. However, fluorination impairs the coordination strength of the high-affinity zinc(II) binding site, which in the triply fluorinated ligand reduces the binding strength to the level of the low-affinity 2,2'-bipyridyl. The potential of the reported ligands in imaging zinc(II) ion in living cells was evaluated. The subcellular localization properties of two ligands in five organelles were characterized. Both benefits and deficiencies of these ligands were revealed, which provides directions for the near future in this line of research.