Optofluidic wavelength division multiplexing for single-virus detection

Optical waveguides simultaneously transport light at different colors, forming the basis of fiber-optic telecommunication networks that shuttle data in dozens of spectrally separated channels. Here, we reimagine this wavelength division multiplexing (WDM) paradigm in a novel context––the differentiated detection and identification of single influenza viruses on a chip. We use a single multimode interference (MMI) waveguide to create wavelength-dependent spot patterns across the entire visible spectrum and enable multiplexed single biomolecule detection on an optofluidic chip. Each target is identified by its time-dependent fluorescence signal without the need for spectral demultiplexing upon detection. We demonstrate detection of individual fluorescently labeled virus particles of three influenza A subtypes in two implementations: labeling of each virus using three different colors and two-color combinatorial labeling. By extending combinatorial multiplexing to three or more colors, MMI-based WDM provides the multiplexing power required for differentiated clinical tests and the growing field of personalized medicine.The ability to overlay multiple electromagnetic waves in the same physical space by virtue of linear superposition is arguably at the root of modern communication as we know it. Originally implemented in the radiofrequency regime, this wavelength division multiplexing (WDM) principle was transferred to optical wavelengths in the visible and near-infrared range, which can be carried by a single, low-loss silica fiber (1). Available in both coarse and dense varieties, terabits of data are now shuttled between a source and their destination using anywhere from 4 to over 100 wavelengths (2, 3). Here, we transfer the WDM principle from data communications into a different realm, that of chip-based biomedical analysis, where much can be gained by superimposing multiple colors in an optical waveguide, albeit for different reasons.First, one of the key requirements for diagnostic test panels, aside from high sensitivity and specificity, is the ability to multiplex, i.e., detect and identify multiple biomarkers simultaneously. A standard influenza test, for example, simultaneously screens for eight pathogen types, enabling differential diagnosis of diseases with similar early symptoms (www.questdiagnostics.com/testcenter/testguide.action?dc=TS_RespVirusPanel). Current gold-standard techniques for nucleic acid and protein detection such as PCR and ELISA use fluorescent organic dyes as a means of signal reporting (4). Optical detection, by fluorescence or “label-free,” is extremely sensitive, allowing for single-molecule and even single-dye detection under appropriate conditions (5–11). The availability of over a dozen dyes across the visible spectrum opens the door to implementing the desired multiplexing capability with multiple dyes, i.e., spectral channels (12–14). Secondly, diagnostic tests are rapidly transitioning toward integrated laboratory-on-chip platforms on which small volumes of biological or chemical samples can be rapidly analyzed. The WDM principle of routing all spectral channels through the same physical space is, therefore, ideal for increasing compactness of an analytic device. Finally, chip-scale integration has recently been advanced by the advent of optofluidic devices in which both fluidic and optical components are miniaturized in the same system (15–17).Here, we implement WDM on an optofluidic platform for on-chip analysis of single influenza viruses. In place of silica fiber as the physical carrier, we create a single waveguide structure that combines multiple spectral channels for fluorescence excitation of biological targets. Instead of temporally modulating each channel to transport information, we use this waveguide to produce wavelength-dependent spatial patterns in an intersecting fluidic channel. The spatial encoding of spectral information then allows for direct identification of multiple labeled targets with extremely high sensitivity and fidelity. The technique is demonstrated in two implementations for direct counting and identification of individual virus particles from three different influenza A subtypes––H1N1, H2N2, and H3N2––at clinically relevant concentrations.     

多模式神经电生理监测在脊柱手术中的应用

目的:用多模式的神经电生理检测包括体感诱发电位(SEP)、运动诱发电位(MEP)、肌电图(EMG),以及肌松剂四联刺激肌肉收缩试验(TOF)对脊柱手术监测进行研究,探究检查的方法和对报警的判断.方法:用多模式神经电生理监测方法对120例不同类型脊柱手术进行监测.结果:术中报警67例(63.3％),其中SEP报警46.7％,MEP报警19.1％,EMG报警35.0％.术后均无严重的并发症,并且及时发现了1例术后的血肿压迫并及时予以将其清除.结论:多模式神经电生理监测能最大程度地有效降低脊柱手术的风险.     

An Experimental Investigation on the Cutting Quality of Three Different Rock Specimens Using High Power Multimode Fiber Laser

The laser cutting of rock has been popular recently because of its advantages over traditional rock cutting methods. Several types of research were performed to replace traditional rock cutting techniques with laser cutting. The purpose of this experiment is to observe cutting quality for intrusive igneous rocks using a high-power multimode fiber laser. The cutting quality, in terms of kerf width and penetration depth, resulted from different scanning speeds and was studied and compared. The specimens used in this study were gabbro, granite, and diorite, which are widely applied in the construction industry because of their high compressive strength and beautiful textures. Energy-dispersive X-ray Spectroscopy (EDX) analyses were conducted to observe the chemical content of three different areas, the melting area, the burnt area, and a non-processed area, for each rock specimen. The study of the compositional changes in each area will also go over the cutting quality of each rock specimen at different scanning speeds. According to the experimental results, the kerf widths of the specimens gradually decrease as the scanning speeds increase. The penetration depths into the specimens sharply decrease as scanning speeds increase. From a study of their compositional changes, it is found that the cutting quality for each rock depends on their silica content. This study summarizes that the cutting quality for a rock specimen greatly depends on the scanning speed of the laser cutting.     

多模态数据融合的可视化技术在咬合重建中的应用

目的　通过多模态医学数据融合,实现数字化升高咬合垂直距离并进行咬合重建,应用于临床诊断及修复。方法　利用软件手段,将口内扫描（IOS）、口外面部扫描（EOS）、锥形束计算机断层扫描（CBCT）、动态咬合运动轨迹进行多模态医学数据融合,创建可视化、可操作的四维虚拟牙科患者,对虚拟患者咬合及颞下颌关节进行系统性评估,在兼顾前牙美学及后牙修复空间的基础上,进行数字化升高咬合垂直距离,建立新的颌位并对接计算机辅助设计和计算机辅助制造（CAD/CAM）设备,实现咬合重建的固定修复。结果　通过多模态医学数据融合及CAD/CAM设备的对接,得到了可视化、可操控的四维虚拟牙科患者,使咬合重建的固定修复技术更加便捷与安全。结论　多模态数据融合创建四维虚拟患者创新地实现了同一患者各种数据在同时间、同空间的结合,方便、直观地展示了患者口颌系统解剖结构及功能状态,能够为临床医生提供有效的诊断与修复手段。     

基于CT和MRI的多模式影像学检查在多中心性肝细胞癌术前精准诊断中的应用价值

目的：探索CT联合MRI在多中心性肝细胞肝癌术前精准诊断中的应用价值。方法：回顾性分析2014年5月至2018年4月在丽水市中心医院就诊的经临床诊断为肝细胞肝癌患者42例,所有患者均接受外科手术治疗,并在术前1个月内行CT和（或）MRI扫描检查证实为多结节性病变,且所有结节均在术后经病理诊断是否为肝细胞肝癌,比较单独CT检查、单独MRI检查以及两者联合检查对肝脏结节的诊断效果。结果：纳入的42例患者,男31例,女11例,年龄（56.0±10.4）岁。经病理诊断共检出110个病灶,其中肝癌病灶76个。单独CT和单独MRI分别检出89个（占80.90%）和106个（占96.36%）病灶,其中肝癌病灶分别为64个（占84.21%）和75个（占98.68%）。联合检查共检出108个病灶（占98.18%）,肝癌病灶76个全部检出。联合检查的肝癌检出率高于单独CT和单独MRI（P＜0.001）,且不同的检查方法对病灶的检出灵敏度、特异度、准确性、阳性预测值和阴性预测值均与病灶直径相关,直径越大,各项指标均越高。当病灶直径大于2 cm时,CT增强和MRI增强检查诊断肝癌病灶的准确度与病理检查一致。结论：CT和MRI联合检查对肝癌病灶和小病灶的检出率和准确度均优于单独检查,对于多中心性肝癌术前的精准诊断具有较高的临床应用价值。     

帕瑞昔布钠对骨科患者术后舒芬太尼静脉镇痛效果的影响

目的观察帕瑞昔布钠对骨科患者术后舒芬太尼静脉镇痛效果的影响。方法全麻下行骨科手术的患者90例,ASAⅠ或Ⅱ级,随机平均分为3组:对照组(C组)、帕瑞昔布钠20 mg组(P1组)、帕瑞昔布钠40 mg组(P2组),采用咪唑安定—依托咪酯—舒芬太尼—罗库溴铵全麻诱导,七氟醚—舒芬太尼—顺式阿曲库铵维持。手术结束后采用舒芬太尼2μg/kg行患者静脉自控镇痛(PCIA)。分别于术后1(T1)、4(T2)、8(T3)、12(T4)、24(T5)、48 h(T6)时,采用视觉模拟评分(VAS)评分评价患者疼痛程度;记录上述各时间点患者自控镇痛(PCA)总次数、总有效次数;上述各时间点舒芬太尼用量;并记录术后48 h内恶心、呕吐、皮肤瘙痒、呼吸抑制和循环抑制的发生情况。结果与C组相比,P1组T2、T3时VAS评分降低,P2组T2～T6时VAS评分降低(P<0.05),P1组T2、T3时患者PCA总次数、总有效次数减少,P2组T2～T6时PCA总次数、总有效次数减少(P<0.05),P1组T2、T3时舒芬太尼用量减少,P2组T2～T6舒芬太尼用量减少(P<0.05)。与P1组比较,P2组T2-T6时VAS评分降低(P<0.05),T2～T6时患者PCA总次数、总有效次数减少(P<0.05),T2～T6舒芬太尼用量减少(P<0.05)。P2组较C组和P1组恶心、呕吐发生例数减少(P<0.05)。结论切皮前静脉给予帕瑞昔布钠40 mg能明显减少术后舒芬太尼的用量,术后镇痛效果满意。     

多模式神经电生理监测在脊柱手术中的应用

目的：用多模式的神经电生理检测包括体感诱发电位（SEP）、运动诱发电位（MEP）、肌电图（EMG）,以及肌松剂四联刺激肌肉收缩试验（TOF）对脊柱手术监测进行研究,探究检查的方法和对报警的判断。方法：用多模式神经电生理监测方法对120例不同类型脊柱手术进行监测。结果：术中报警67例（63．3％）,其中SEP报警46．7％,MEP报警19．1％,EMG报警35．0％。术后均无严重的并发症,并且及时发现了1例术后的血肿压迫并及时予以将其清除。结论：多模式神经电生理监测能最大程度地有效降低脊柱手术的风险。     

Multimode intravascular RF coil for MRI-guided interventions

Purpose:

To demonstrate the feasibility of using a single intravascular radiofrequency (RF) probe connected to the external magnetic resonance imaging (MRI) system via a single coaxial cable to perform active tip tracking and catheter visualization and high signal‐to‐noise ratio (SNR) intravascular imaging.

Materials and Methods:

A multimode intravascular RF coil was constructed on a 6F balloon catheter and interfaced to a 1.5T MRI scanner via a decoupling circuit. Bench measurements of coil impedances were followed by imaging experiments in saline and phantoms.

Results:

The multimode coil behaves as an inductively coupled transmit coil. The forward‐looking capability of 6 mm was measured. A greater than 3‐fold increase in SNR compared to conventional imaging using optimized external coil was demonstrated. Simultaneous active tip tracking and catheter visualization was demonstrated.

Conclusion:

It is feasible to perform 1) active tip tracking, 2) catheter visualization, and 3) high SNR imaging using a single multimode intravascular RF coil that is connected to the external system via a single coaxial cable. J. Magn. Reson. Imaging 2011;33:995–1002. © 2011 Wiley‐Liss, Inc.     

基于局部特征的多模态过程监控方法

多模态过程中各个模态均有不同的特征,因此模态数据的局部特征比全局特征更能有效、合理地表征实际化工过程。为利用多模态数据的局部特征,提出了基于数据局部特征的多模型方法（LFMM）用于多模态过程的监控。首先,离线阶段考虑到数据间的时序信息以及数据特征,利用不同时间窗内数据的变异系数（CV）完成多模态数据集的聚类;然后,考虑到不同模态的数据在空间分布上具有不同的疏密性特征,建模阶段利用局部离群因子（LOF）算法计算数据在其模态数据集中的局部密度,监控时将在线数据的局部密度作为统计特征,并构造全局概率指标用于多模态过程监控;最后,通过田纳西伊斯曼（TE）过程验证了本文方法的有效性。