BACKGROUND & AIMS: :The use of bacteriophages (phages) for antibacterial therapy is under increasing consideration to treat antimicrobial-resistant infections. Phages have evolved multiple mechanisms to target their bacterial hosts, such as high-affinity, environmentally hardy receptor-binding proteins. However, traditional phage therapy suffers from multiple challenges stemming from the use of an exponentially replicating, evolving entity whose biology is not fully characterized (e.g., potential gene transduction). To address this problem, we conjugate the phages to gold nanorods, creating a reagent that can be destroyed upon use (termed "phanorods"). Chimeric phages were engineered to attach specifically to several Gram-negative organisms, including the human pathogens Escherichia coli, Pseudomonas aeruginosa, and Vibrio cholerae, and the plant pathogen Xanthomonas campestris The bioconjugated phanorods could selectively target and kill specific bacterial cells using photothermal ablation. Following excitation by near-infrared light, gold nanorods release energy through nonradiative decay pathways, locally generating heat that efficiently kills targeted bacterial cells. Specificity was highlighted in the context of a P. aeruginosa biofilm, in which phanorod irradiation killed bacterial cells while causing minimal damage to epithelial cells. Local temperature and viscosity measurements revealed highly localized and selective ablation of the bacteria. Irradiation of the phanorods also destroyed the phages, preventing replication and reducing potential risks of traditional phage therapy while enabling control over dosing. The phanorod strategy integrates the highly evolved targeting strategies of phages with the photothermal properties of gold nanorods, creating a well-controlled platform for systematic killing of bacterial cells.

背景与目标： : 越来越多地考虑使用噬菌体 (噬菌体) 进行抗菌治疗，以治疗抗菌素耐药性感染。噬菌体已经进化出多种机制来靶向其细菌宿主，例如高亲和力，对环境有害的受体结合蛋白。然而，传统的噬菌体疗法遭受多种挑战，这些挑战源于使用指数复制，进化的实体，其生物学尚未完全表征 (例如，潜在的基因转导)。为了解决这个问题，我们将噬菌体与金纳米棒偶联，从而产生一种可以在使用后被破坏的试剂 (称为 “phanorods”)。嵌合噬菌体被设计成特异性附着于几种革兰氏阴性生物，包括人类病原体大肠杆菌，铜绿假单胞菌和霍乱弧菌，以及植物病原体黄单胞菌。生物缀合的phananods可以使用光热消融选择性地靶向并杀死特定的细菌细胞。在近红外光激发后，金纳米棒通过非辐射衰变途径释放能量，局部产生热量，有效杀死目标细菌细胞。在铜绿假单胞菌生物膜的背景下强调了特异性，其中包囊辐射杀死了细菌细胞，同时对上皮细胞造成了最小的损害。局部温度和粘度测量显示细菌高度局部化和选择性消融。辐射的phanorods也破坏了噬菌体，阻止了复制并降低了传统噬菌体疗法的潜在风险，同时可以控制剂量。phanorod策略将高度发展的噬菌体靶向策略与金纳米棒的光热特性相结合，从而为系统杀死细菌细胞创造了一个控制良好的平台。

BACKGROUND & AIMS: :The purpose of the present theoretical study was to examine the spatial resolution of electroencephalography (EEG) by means of the accuracy of the inverse cortical EEG solution. The study focused on effect of the amount of measurement noise and the number of electrodes on the spatial resolution with different resistivity ratios for the scalp, skull and brain. The results show that if the relative skull resistivity is lower than earlier believed, the spatial resolution of different electrode systems is less sensitive to the measurement noise. Furthermore, there is then also greater advantage to be obtained with high-resolution EEG at realistic noise levels.

背景与目标： : 本理论研究的目的是通过逆皮质脑电图解决方案的准确性来检查脑电图 (EEG) 的空间分辨率。研究的重点是测量噪声的量和电极的数量对头皮，头骨和大脑的电阻率比不同的空间分辨率的影响。结果表明，如果相对颅骨电阻率低于先前认为的水平，则不同电极系统的空间分辨率对测量噪声的敏感性较低。此外，在现实的噪声水平下，高分辨率EEG还可以获得更大的优势。

BACKGROUND & AIMS: Background:This work proposed a joint L1 and total variation (TV) regularized reconstruction method for X-ray fluorescence tomography (XFT), and investigated the performance of this method in quantitative imaging of gold nanoparticles (GNPs). Methods:We developed a dual-modality XFT/CT imaging system which consisted of a benchtop X-ray source, a translation/rotation stage, a silicon drift detector for X-ray fluorescence (XRF) detection, and a flat panel detector for transmission X-ray detection. A pencil-beam collimator was 3D printed with steel and employed in sample excitation. The sensitivity of the XFT imaging system was determined by imaging water phantoms with multiple inserts containing GNP solutions of various concentrations (0.02-0.16 wt.%). A joint L1 and total variation (TV) regularized algorithm was developed for XFT reconstruction, where the L1 regularization was used to reduce image artifacts and the TV regularization was used to preserve the shape of targets. Nonlinear conjugate gradient (NCG) descent algorithm with backtracking line search was adopted to solve the reconstruction problem. We compared the L1 + TV regularization method with filtered back projection (FBP), maximum likelihood expectation maximization (ML-EM), L1 regularization, and TV regularization methods. Contrast-to-noise ratio (CNR), Dice similarity coefficient (DSC) and localization error (LE) metrics were used to compare the performance of different methods. The CT and XFT imaging doses were also measured using EBT2 radiochromic films. Results:The 3D printed pencil-beam collimator shaped an excitation beam with a 2 mm full width at half maximum at the imaging isocenter. Based on the phantom imaging experiments, the joint L1 and TV regularization method performed better than FBP, ML-EM, L1 regularization and TV regularization methods, with higher localization accuracy (offset <0.6 mm), CNR and DSC values. Compared with CT, XFT with L1 + TV regularized reconstruction demonstrated higher sensitivity in GNP imaging, and could detect GNP at a concentration of 0.02 wt.% or lower. Moreover, there existed a significant linear correlation (R2>0.99) between the reconstructed and true GNP concentration. The estimated XFT imaging dose is about 41.22 cGy under current setting. Conclusions:The joint L1 + TV regularized reconstruction algorithm performed better in noise suppression and shape preservation. Using the L1 + TV regularized reconstruction, the XFT system is able to localize GNP targets with submillimeter accuracy and quantify GNP distribution at a concentration of 0.02 wt.% or lower.

背景与目标：

BACKGROUND & AIMS: :Gold nanoparticles (Au NPs), silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) are widely used in cosmetic products such as preservatives, colorants and sunscreens. This study investigated the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest with Escherichia coli PQ37. The maximum exposure concentrations for each nanoparticle were 3.23 mg l(-1) for Au NPs, 32.3 mg l(-1) for Ag NPs and 100 mg l(-1) for ZnO NPs and TiO2 NPs. Additionally, in order to compare the genotoxicity of nanoparticles and corresponding dissolved ions, the ions were assessed in the same way as nanoparticles. The genotoxicity of the titanium ion was not assessed because of the extremely low solubility of TiO2 NPs. Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn, in a range of tested concentrations, exerted no effects in the SOS chromotest, evidenced by maximum IF (IFmax) values of below 1.5 for all chemicals. Owing to the results, nanosized Au NPs, Ag NPs, ZnO NPs, TiO2 NPs and ions of Au, Ag and Zn are classified as non-genotoxic on the basis of the SOS chromotest used in this study. To the best of our knowledge, this is the first study to evaluate the genotoxicity of Au NPs, Ag NPs, ZnO NPs and TiO2 NPs using the SOS chromotest.

背景与目标： 金纳米粒子 (Au NPs) 、银纳米粒子 (Ag NPs) 、氧化锌纳米粒子 (ZnO NPs) 和二氧化钛纳米粒子 (TiO2 NPs) 广泛用于化妆品，如防腐剂、着色剂和防晒霜。本研究使用大肠杆菌pq37的SOS色测法研究了Au NPs，Ag NPs，ZnO NPs和TiO2 NPs的遗传毒性。对于Au NPs，每种纳米颗粒的最大暴露浓度为3.23  mg  l(-1)，对于Ag NPs为32.3  mg  l(-1)，对于ZnO NPs和TiO2 NPs为100  mg  l(-1)。此外，为了比较纳米颗粒和相应溶解离子的遗传毒性，以与纳米颗粒相同的方式评估离子。由于TiO2 NPs的溶解度极低，因此未评估钛离子的遗传毒性。在测试浓度范围内的Au NPs、Ag NPs、ZnO NPs、tio2nps和Au、Ag和Zn的离子在SOS色度测试中没有影响，所有化学品的最大IF (IFmax) 值低于1.5证明。根据结果，根据本研究中使用的SOS色度，将纳米级的Au NPs，Ag NPs，ZnO NPs，TiO2 NPs以及Au，Ag和Zn的离子分类为非遗传毒性。据我们所知，这是第一项使用SOS色度测试评估Au NPs，Ag NPs，ZnO NPs和TiO2 NPs的遗传毒性的研究。

BACKGROUND & AIMS: :The objective of this study was to synthesize and characterize a thermally responsive polymer-metal nanocomposite system comprised of a solid gold nanoparticle core and thermally responsive interpenetrating polymer network (IPN) shell, which was surface functionalized or PEGylated with a covalently bound linear poly(ethylene glycol) chain layer. Gold nanoparticles (50 nm diameter) were prepared using standard gold chloride and citrate reduction method. These particles were then encapsulated inside of a polyacrylamide (PAAm)/poly(acrylic acid) (PAA) IPN shell via an in situ inverse emulsion polymerization. The surface of the nanocomposite system was then PEGylated via covalent grafting of a linear methoxy-PEG-N-hydroxysuccinimide (M.W. 3400) to the primary amine groups of the PAAm network. Scanning and transmission electron microscopy were used to confirm the successful synthesis and encapsulation of gold nanoparticles within the IPN shell. Dynamic light scattering was used to examine the temperature swelling response of the IPN particles. Zeta-potential analysis was used to confirm the successful PEGylation of the final nanocomposite system.

背景与目标： : 本研究的目的是合成和表征热响应聚合物-金属纳米复合材料体系，该体系由固体金纳米颗粒核和热响应互穿聚合物网络 (IPN) 壳组成，该体系被共价结合的线性聚乙二醇链层表面官能化或聚乙二醇化。使用标准氯化金和柠檬酸盐还原法制备了直径为50 nm的金纳米颗粒。然后通过原位反相乳液聚合将这些颗粒封装在聚丙烯酰胺 (PAAm)/聚 (丙烯酸) (PAA) IPN壳内。然后通过将线性甲氧基-PEG-N-羟基琥珀酰亚胺 (M.W. 3400) 共价接枝到PAAm网络的伯胺基团，使纳米复合体系的表面聚乙二醇化。扫描和透射电子显微镜用于确认金纳米颗粒在IPN壳中的成功合成和封装。动态光散射用于检查IPN颗粒的温度溶胀响应。Zeta电位分析用于确认最终纳米复合材料系统的成功peg化。

BACKGROUND & AIMS: BACKGROUND:One of the critical problems in cancer management is local recurrence of disease. Between 20% and 30% of patients who undergo tumor resection surgery require reoperation due to incomplete excision. Currently, there are no validated methods for intraoperative tumor margin detection. In the present work, we demonstrate the potential use of gold nanoparticles (GNPs) as a novel contrast agent for photothermal molecular imaging of cancer. METHODS:Phantoms containing different concentrations of GNPs were irradiated with continuous-wave laser and measured with a thermal imaging camera which detected the temperature field of the irradiated phantoms. RESULTS:The results clearly demonstrate the ability to distinguish between cancerous cells specifically targeted with GNPs and normal cells. This technique, which allows highly sensitive discrimination between adjacent low GNP concentrations, will allow tumor margin detection while the temperature increases by only a few degrees Celsius (for GNPs in relevant biological concentrations). CONCLUSION:We expect this real-time intraoperative imaging technique to assist surgeons in determining clear tumor margins and to maximize the extent of tumor resection while sparing normal background tissue.

背景与目标：

BACKGROUND & AIMS: :Societies' increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of "no battery without binder" and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.

背景与目标： : 社会对储能的需求不断增长，因此有必要探索传统锂离子电池以外的新概念。一个有前途的候选者是锂硫技术，它有可能将电池的能量密度提高3-5倍。然而，到目前为止，锂硫系统的许多问题尚未得到令人满意的解决。在这里，我们报告了一种新的方法，该方法直接使用自立的还原氧化石墨烯基气凝胶作为电极，即无需进一步处理，也无需添加粘合剂或导电剂。因此，我们可以破坏 “没有粘合剂就没有电池” 的常见范例，并可以为具有高实用能量密度的锂硫电池铺平道路。气凝胶是通过一锅法合成的，并且由包含在多孔少层还原氧化石墨烯基质内的2/3多个硫组成。通过将石墨烯基气凝胶阴极与电解质和锂金属阳极相结合，我们证明了锂硫电池具有高面积容量 (75次循环后大于3 mah mah/cm2)，在200次循环中具有出色的容量保持率和良好的硫利用率。基于这种性能，我们估计该概念单元的能量密度可以大大超过用于运输应用的能源部 (DEO) 2020目标。

BACKGROUND & AIMS: PURPOSE:To compare estimates of change in percent body fat (Delta%BF) between DXA and BIA8 in abdominally obese women. METHODS:Six-month longitudinal study of 106 women (baseline: age 48.2 +/- 7.6 yr; BMI 30.4 +/- 2.9 kg.m; %BFDXA 45.8 +/- 3.6%) participating in an exercise-oriented behavior-change program (walking and bicycling). Fatness was measured by DXA and Tanita BC-418 (BIA8). Agreement between methods was assessed, and regression analysis was used to find predictors of the deviation between methods for estimating changes in fat mass percentage. RESULTS:The methods differed significantly, both at baseline and follow-up (-5.0 and -4.4%BF, respectively; both P < 0.001). The mean Delta%BF was -1.1 +/- 2.5%BFDXA and -0.5 +/- 2.2%BFBIA8 (mean difference between methods 0.6 +/- 1.8%BF; P < 0.001; 95% limits of agreement -3.0 to 4.2%BF), with a range of -14.8 to 3.3%BFDXA and -9.4 to 3.5%BFBIA8. Approximately 49% of the variation in the difference between methods was explained by variations in age (beta = -0.05; P = 0.006), DeltaBMI (beta = 0.98; P < 0.001), and Delta%BFDXA (beta = -0.71; P < 0.001), indicating that the larger the change, the greater the discrepancy between methods. CONCLUSION:The difference between methods regarding Delta%BF was statistically significant, but it was of small magnitude. However, with increasing Delta%BF, increasing discrepancies were observed, implying that the BIA equipment may have limited validity for detecting larger fat losses. Both clinicians and researchers may benefit from awareness of this potential limitation.

背景与目标：

BACKGROUND & AIMS: :In this research work, SnO2, NiO and SnO2/NiO nanocomposites were synthesized at low temperature by modified sol-gel method using ultrasonication. Prepared samples were investigated for their properties employing various characterization techniques. X-ray diffraction (XRD) patterns confirmed the purity and phase of the samples as no secondary phase was detected. The average crystallite size of the nanocomposites was found to decrease from 19.24 to 4.53 nm with the increase in NiO concentration. It was confirmed from SEM micrographs that the material has mesoporous morphology. This mesoporous morphology resulted in the increase of the surface to mass ratio of the material, which in turn increases the specific capacitance of the material. The UV-Visible spectra showed the variation in the band gap of SnO2/NiO at different weight ratio ranging from 3.49 to 3.25 eV on increasing NiO concentration in the samples. These composites with different mass ratio of SnO2 and NiO were also characterized by FT-IR spectroscopy that showed shifting of the peaks centered at 545 cm-1 in the spectra for NiO/SnO2 nanocomposite. The analysis of the electrochemical performance of the material was done with the help of cyclic voltammetry and Galvanostatic charge-discharge. The specific capacitance of the synthesized samples with different concentration of SnO2 and NiO was analyzed at different scan rates of 5 to 100 mV/s. Interestingly, 7:1 mass ratio of NiO and SnO2 (SN7) nanocomposite exhibited a maximum specific capacitance of ~ 464 F/g at a scan rate of 5 mV/s and good capacitance retention of 87.24% after 1,000 cycles. These excellent electrochemical properties suggest that the SnO2/NiO nanocomposite can be used for high energy density supercapacitor electrode material.

背景与目标： : 在这项研究工作中，通过改进的溶胶-凝胶法在低温下使用超声合成了SnO2，NiO和SnO2/NiO纳米复合材料。使用各种表征技术研究了制备的样品的性能。X射线衍射 (XRD) 图谱证实了样品的纯度和相，因为未检测到第二相。发现随着NiO浓度的增加，纳米复合材料的平均微晶尺寸从19.24 nm减小到4.53 nm。从SEM显微照片证实该材料具有介孔形态。这种介孔形态导致材料的表面质量比增加，进而增加材料的比电容。紫外可见光谱显示了在样品中增加NiO浓度时，在3.49至3.25 eV范围内的不同重量比下SnO2/NiO的带隙变化。这些具有不同质量比的SnO2和NiO的复合材料也通过ft-ir光谱进行表征，该光谱显示了NiO/SnO2纳米复合材料光谱中以545厘米-1为中心的峰的移动。借助循环伏安法和恒电流充放电对材料的电化学性能进行了分析。在5至100 mV/s的不同扫描速率下分析了具有不同浓度的SnO2和NiO的合成样品的比电容。有趣的是，NiO和SnO2 (SN7) 纳米复合材料的7:1质量比在5 mV/s的扫描速率下显示出〜   464 F/g的最大比电容，并且在1,000次循环后87.24% 保持良好的电容。这些优异的电化学性能表明，SnO2/NiO纳米复合材料可用于高能量密度的超级电容器电极材料。

BACKGROUND & AIMS: :Radiofrequency energy is used for thermal-assisted chondroplasty to treat grade II and III chondromalacia with the lowest possible energy setting that achieves the desired result. The purpose of this in vitro study was to determine the temperature changes associated with the use of radiofrequency energy delivered at different settings to bovine articular cartilage using a bipolar electrode. Cartilage samples were placed in a temperature-controlled (37 degrees C) saline bath for the delivery of radiofrequency energy. A fluoroptic thermometry probe was positioned to record the temperatures at the electrode-tissue interface. The electrode was activated for 2 seconds at settings of V2-120, V2-60, V2-40, and V2-20 in two modes: ablation and desiccation. Additionally, the cartilage samples were visually inspected to determine changes in appearance. The highest average temperatures were as follows: ablation mode, 78.5 degrees C (V2-120), 62.6 degrees C (V2-60), 58.1 degrees C (V2-40), and 54.1 degrees C (V2-20); desiccation mode, 71.8 degrees C (V2-120), 61.4 degrees C (V2-60), 57.7 degrees C (V2-40), and 53.3 degrees C (V2-20). There were statistically significant increases in temperatures associated with each of the respective settings. There were no substantial visual changes produced by the V2-20 settings, while the other settings produced a gradation of effects. These data provide information to help guide the use of a bipolar radiofrequency electrode and electrosurgical system for thermal-assisted chondroplasty.

背景与目标： : 射频能量用于热辅助软骨成形术，以尽可能低的能量设置治疗II级和III级软骨软化症，以达到预期的效果。这项体外研究的目的是确定与使用双极电极在不同环境下传递到牛关节软骨的射频能量相关的温度变化。将软骨样品置于温度控制的 (37 ℃) 盐水浴中，以输送射频能量。放置荧光测温探头以记录电极-组织界面的温度。在V2-120、V2-60、V2-40和V2-20的设置下，以两种模式激活电极2秒: 消融和干燥。此外，对软骨样品进行目视检查以确定外观变化。最高平均温度如下: 消融模式，78.5 ℃ (V2-120)，62.6 ℃ (V2-60)，58.1 ℃ (V2-40) 和54.1 ℃ (V2-20); 干燥模式，71.8 ℃ (V2-120)，61.4 ℃ (V2-60)，57.7 ℃ (V2-40)，和53.3 ℃ (V2-20)。与每种设置相关的温度均具有统计学上的显着升高。V2-20设置没有产生实质性的视觉变化，而其他设置产生了效果的渐变。这些数据提供了有助于指导使用双极射频电极和电外科系统进行热辅助软骨成形术的信息。

BACKGROUND & AIMS: :Exosomes are nanovesicles formed in the endosomal pathway with an important role in paracrine and autocrine cell communication. Exosomes secreted by cancer cells, malicious exosomes, have important roles in tumor microenvironment maturation and cancer progression. The knowledge of the role of exosomes in tumorigenesis prompted a new era in cancer diagnostics and therapy, taking advantage of the use of circulating exosomes as tumor biomarkers due to their stability in body fluids and targeting malignant exosomes' release and/or uptake to inhibit or delay tumor development. In recent years, nanotechnology has paved the way for the development of a plethora of new diagnostic and therapeutic platforms, fostering theranostics. The unique physical and chemical properties of gold nanoparticles (AuNPs) make them suitable vehicles to pursuit this goal. AuNPs' properties such as ease of synthesis with the desired shape and size, high surface:volume ratio, and the possibility of engineering their surface as desired, potentiate AuNPs' role in nanotheranostics, allowing the use of the same formulation for exosome detection and restraining the effect of malicious exosomes in cancer progression.

背景与目标： 外泌体是在内体途径中形成的纳米囊泡，在旁分泌和自分泌细胞通讯中起重要作用。癌细胞分泌的外泌体，即恶意外泌体，在肿瘤微环境成熟和癌症进展中起重要作用。关于外泌体在肿瘤发生中的作用的知识促使癌症诊断和治疗进入了一个新时代，利用循环外泌体作为肿瘤生物标志物的优势，因为它们在体液中具有稳定性，并靶向恶性外泌体的释放和/或摄取抑制或延迟肿瘤发展。近年来，纳米技术为开发大量新的诊断和治疗平台铺平了道路，从而促进了治疗。金纳米粒子 (AuNPs) 独特的物理和化学性质使它们成为追求这一目标的合适载体。Aunp的特性，例如易于合成所需的形状和尺寸，高表面: 体积比以及根据需要对其表面进行工程设计的可能性，增强了aunp在纳米生物学中的作用，从而允许将相同的配方用于外泌体检测并抑制恶意外泌体在癌症进展中的作用。

BACKGROUND & AIMS: :A modified non-cross-linking gold-nanoparticles (Au-NPs) aggregation strategy has been developed for the label free colorimetric detection of DNAs/RNAs based on self-assembling target species in the presence of thiolated probes. Two complementary thiol- modified probes, each of which specifically binds at one half of the target introduced SH groups at both ends of dsDNA. Continuous disulfide bond formation at 3' and 5' terminals of targets leads to the self-assembly of dsDNAs into the sulfur- rich and flexible products with different lengths. These products have a high affinity for the surface of Au-NPs and efficiently protect the surface from salt induced aggregation. To evaluate the assay efficacy, a small part of the citrus tristeza virus (CTV) genome was targeted, leading to a detection limit of about 5 × 10-9 mol.L-1 over a linear ranged from 20 × 10-9 to 10 × 10-7 mol.L-1. This approach also exhibits good reproducibility and recovery levels in the presence of plant total RNA or human plasma total circulating RNA extracts. Self-assembled targets can be then sensitively distinguished from non-assembled or mismatched targets after gel electrophoresis. The disulfide reaction method and integrating self-assembled DNAs/RNAs targets with bare AuNPs as a sensitive indicator provide us a powerful and simple visual detection tool for a wide range of applications.

背景与目标： : 已开发出一种改进的非交联金纳米颗粒 (Au-NPs) 聚集策略，用于在存在硫醇化探针的情况下基于自组装目标物种的dna/rna的无标记比色检测。两个互补的巯基修饰的探针，每个探针在dsDNA两端的目标引入的SH基团的一半处特异性结合。在靶标的3' 和5' 末端连续形成二硫键，导致dsdna自组装成具有不同长度的富硫和柔性产物。这些产品对Au-NPs的表面具有很高的亲和力，并有效地保护表面免受盐诱导的聚集。为了评估检测效果，一小部分柑橘tristeza病毒 (CTV) 基因组被靶向，导致检测限约为5  ×   10-9  mol。L-1线性范围为20  ×   10-9至10  ×   10-7  mol。L-1。在存在植物总RNA或人血浆总循环RNA提取物的情况下，该方法还表现出良好的重现性和回收率。然后，可以在凝胶电泳后敏感地将自组装的靶标与非组装或不匹配的靶标区分开。二硫键反应方法和将自组装的dna/rna靶标与裸AuNPs作为敏感指标的集成为我们提供了一种强大而简单的视觉检测工具，可用于广泛的应用。

BACKGROUND & AIMS: OBJECTIVES:To evaluate the performance of cast gold bonded restorations in clinical practice. MATERIALS AND METHODS:The records of all patients treated with cast gold bonded restorations between 1997 and 2004 of The Dental Hospital of Newcastle upon Tyne were reviewed. The following data were recorded: sex of patient, location of teeth (anterior or posterior), position of teeth (upper or lower) and type of cement (glass ionomer, zinc phosphate or resin cement). The survival time was calculated for each restoration; and the reason for failure (either debond or change of treatment plan) identified for each case. The restorations were stratified according to the age of the patient into 10-year age bands and survival analysis was used to identify variables associated with increased risk of failure. RESULTS:Restorations luted with resin cement showed the highest rate of survival after 7 years of follow-up. The alternative lutes had significantly worse survival (p<0.05). Restorations on anterior teeth had poorer survival than on posterior teeth but there were no differences between those placed in the mandible and the maxilla. CONCLUSIONS:Within the limitations of this study resin cements are most appropriate for this type of restoration with 80% survival at 7 years. Restorations placed on posterior teeth survived better.

背景与目标：

BACKGROUND & AIMS: :In the present study, the electrocatalytic oxidation of reduced β nicotinamide adenine dinucleotide (NADH) was investigated using a pencil graphite electrode modified with quercetin (PGE/QH(2)). The PGE/QH(2) was prepared through two steps: (i) the pre-treatment of PGE at 1.40 V vs. Ag|AgCl|KCl((sat.)) in pH 7.0 phosphate buffer containing 0.1 M KCl for 60s and (ii) adsorption of QH(2) on the PGE via immersion of PGE into a 1.0mM QH(2) solution (in ethanol) for 60s. Cyclic voltammetric studies show that the peak potential of NADH oxidation shifts from +500 mV at bare PGE to +300 mV at PGE/QH(2). The electrocatalytic currents obtained from amperometric measurements at +300 mV vs. Ag|AgCl|KCl((sat.)) and in phosphate buffer solution at pH 7.0 containing 0.1M KCl were linearly related to the concentration of NADH. Linear calibration plots are obtained in the concentration range from 0.5 μM to 100 μM. The limit of detection was found to be 0.15 μM.

背景与目标： : 在本研究中，使用槲皮素 (PGE/QH(2)) 修饰的铅笔石墨电极研究了还原的 β 烟酰胺腺嘌呤二核苷酸 (NADH) 的电催化氧化。通过两个步骤制备PGE/QH(2): (i) 在含有0.1 M KCl的pH 7.0磷酸盐缓冲液中1.40 V对Ag | AgCl | KCl((sat。)) 预处理60s，以及 (ii) 通过将PGE浸入1.0毫米QH(2) 在PGE上吸附QH(2)) 溶液 (在乙醇中) 60s。循环伏安研究表明，NADH氧化的峰电位从裸露PGE处的 + 500 mV转变为PGE/QH(2) 处的 + 300 mV。从在 + 300 mV对Ag | AgCl | KCl((sat。)) 和在含有0.1M KCl的pH 7.0的磷酸盐缓冲溶液中的安培测量获得的电催化电流与NADH的浓度线性相关。在从0.5微米到100微米的浓度范围内获得线性校准图。发现检出限为0.15微米。

BACKGROUND & AIMS: :Discrepancies of one pH unit and more have been observed after a few days, between continuous on-line in situ pH measurements and instant off-line pH measurements during anaerobic digestion of an agroindustrial wastewater. Concomitantly, the electrical resistance across the porous diaphragm of the on-line electrode increased, and a black clogging developed on its diaphragm. Measurements of the relative liquid junction potential in KCl or Na(2)S solutions excluded that high concentrations of ions such as, K(+), Na(+), Cl(-), HS(-), or S(2-) were the major cause of the drifts in pH values. It has been possible to limit the rapid increase of the liquid junction potential and the black clogging formation on the porous diaphragm either by acidification and/or by overpressurization of the electrode-filling liquid. Continuous on-line in situ pH values consistent with instant off-line pH values over long periods of time have been obtained with a newly designed pH sensor in which a special jellied electrode filling replaced the porous diaphragm.

背景与目标： : 几天后，在农业工业废水的厌氧消化过程中，连续在线原位pH测量与即时离线pH测量之间观察到一个pH单位或更多pH单位的差异。同时，在线电极的多孔隔膜上的电阻增加，并且隔膜上出现了黑色堵塞。KCl或Na(2)S溶液中相对液体结电位的测量排除了高浓度的离子，如，K(+)，Na(+)，Cl(-)，HS(-)，or S(2-) 是ph值漂移的主要原因。通过酸化和/或电极填充液体的过压，可以限制液体结电位的快速增加和多孔隔膜上的黑色堵塞形成。使用新设计的pH传感器，可以获得连续的在线原位ph值，与长时间的离线ph值一致，其中使用特殊的凝胶状电极填充代替了多孔隔膜。