Antibody-drug conjugates (ADCs) represent a promising class of therapeutics for the targeted delivery of highly potent cytotoxic drugs to tumor cells to improve bioactivity while minimizing side effects. ADCs are composed of both small and large molecules and therefore have complex molecular structures. In vivo biotransformations may further increase the complexity of ADCs, representing a unique challenge for bioanalytical assays. Quadrupole-time-of-flight mass spectrometry (Q-TOF MS) with electrospray ionization has been widely used for characterization of intact ADCs. However, interpretation of ADC biotransformations with small mass changes, for the intact molecule, remains a limitation due to the insufficient mass resolution and accuracy of Q-TOF MS. Here, we have investigated in vivo biotransformations of multiple site-specific THIOMAB antibody-drug conjugates (TDCs), in the intact form, using a high-resolution, accurate-mass (HR/AM) MS approach. Compared with conventional Q-TOF MS, HR/AM Orbitrap MS enabled more comprehensive identification of ADC biotransformations. It was particularly beneficial for characterizing ADC modifications with small mass changes such as partial drug loss and hydrolysis. This strategy has significantly enhanced our capability to elucidate ADC biotransformations and help understand ADC efficacy and safety in vivo.
Unmanned aerial vehicle (UAV) hyperspectral remote sensing technologies have unique advantages in high-precision quantitative analysis of non-contact water surface source concentration. Improving the accuracy of non-point source detection is a difficult engineering problem. To facilitate water surface remote sensing, imaging, and spectral analysis activities, a UAV-based hyperspectral imaging remote sensing system was designed. Its prototype was built, and laboratory calibration and a joint air–ground water quality monitoring activity were performed. The hyperspectral imaging remote sensing system of UAV comprised a light and small UAV platform, spectral scanning hyperspectral imager, and data acquisition and control unit. The spectral principle of the hyperspectral imager is based on the new high-performance acousto-optic tunable (AOTF) technology. During laboratory calibration, the spectral calibration of the imaging spectrometer and image preprocessing in data acquisition were completed. In the UAV air–ground joint experiment, combined with the typical water bodies of the Yangtze River mainstream, the Three Gorges demonstration area, and the Poyang Lake demonstration area, the hyperspectral data cubes of the corresponding water areas were obtained, and geometric registration was completed. Thus, a large field-of-view mosaic and water radiation calibration were realized. A chlorophyl-a (Chl-a) sensor was used to test the actual water control points, and 11 traditional Chl-a sensitive spectrum selection algorithms were analyzed and compared. A random forest algorithm was used to establish a prediction model of water surface spectral reflectance and water quality parameter concentration. Compared with the back propagation neural network, partial least squares, and PSO-LSSVM algorithms, the accuracy of the RF algorithm in predicting Chl-a was significantly improved. The determination coefficient of the training samples was 0.84; root mean square error, 3.19 μg/L; and mean absolute percentage error, 5.46%. The established Chl-a inversion model was applied to UAV hyperspectral remote sensing images. The predicted Chl-a distribution agreed with the field observation results, indicating that the UAV-borne hyperspectral remote sensing water quality monitoring system based on AOTF is a promising remote sensing imaging spectral analysis tool for water.
Within the context of Chinese culture and the theoretical framework of neo-tribes, this study explores the mobilities of road travelers on the Sichuan-Tibet Highway in China and explains their social interactions and group relations by using mobile ethnography and multi-sited ethnography. It finds that social interactions during road travels are "easily meet, easily part." However, between travelers and within travel groups, kindness and affective interactions are ubiquitous. The Chinese cultural concept "yuanfen," which means serendipity in relationships, explains the logic of interaction. A road traveling neo-tribe is also formed. The findings of this study enhance understanding of alternative travelers' social interactions and tourism experiences.neo-tribes, road travel, Sichuan-Tibet highway, social interactions, yuanfen
| INTRODUCTIONSocial interaction is a principal means by which people build social relationships, develop a sense of belonging, and enjoy positive psychological experiences in their daily lives (Bernstein, Zawadzki, Juth,
In this work, the electrochemical oxidation of L-cysteine (CySH) was investigated on a composite film modified electrode with Au nanoparticles dispersed in the fluorocarbon polymer (Nafion). The excellent electrocatalytic effect on CySH oxidation was attributed to the role of Au nanoparticles. The voltammetric studies revealed two anodic peaks for the oxidation of CySH in the pH range of 2.0-8.0. The electrode was used to detect cysteine at pH 2.0 and pH 7.0. At pH 2.0, a determination range of 3.0-50.0 mol/L was obtained with the detection sensitivity of 22.7 A/(mmol L 1 ), while at pH 7.0, a determination range of 2.0-80.0 mol/L was obtained with the detection sensitivity of 4.08 A/(mmol L 1 ). The detection limits were estimated to be as low as 1.0 mol/L at both pH 7.0 and pH 2.0. Additionally, at pH 7.0, the interferences of ascorbic acid and uric acid were reduced for the detection of cysteine. These made the Au/Nafion/GC electrode a promising candidate for efficient electrochemical sensors for the detection of CySH.
BackgroundThe oviparity-viviparity transition is a major evolutionary event, likely altering the reproductive process of the organisms involved. Residual yolk, a portion of yolk remaining unutilized at hatching or birth as parental investment in care, has been investigated in many oviparous amniotes but remained largely unknown in viviparous species. Here, we used data from 20 (12 oviparous and 8 viviparous) species of snakes to see if the oviparity-viviparity transition alters the partitioning of yolk in embryonic snakes. We used ANCOVA to test whether offspring size, mass and components at hatching or birth differed between the sexes in each species. We used both ordinary least squares and phylogenetic generalized least squares regressions to test whether relationships between selected pairs of offspring components were significant. We used phylogenetic ANOVA to test whether offspring components differed between oviparous and viviparous species and, more specifically, the hypothesis that viviparous snakes invest more in the yolk as parental investment in embryogenesis to produce more well developed offspring that are larger in linear size.ResultsIn none of the 20 species was sex a significant source of variation in any offspring component examined. Newborn viviparous snakes on average contained proportionally more water and, after accounting for body dry mass, had larger carcasses but smaller residual yolks than did newly hatched oviparous snakes. The rates at which carcass dry mass (CDM) and fat body dry mass (FDM) increased with residual yolk dry mass (YDM) did not differ between newborn oviparous and viviparous snakes. Neither CDM nor FDM differed between newborn oviparous and viviparous snakes after accounting for YDM.ConclusionsOur results are not consistent with the hypothesis that the partitioning of yolk between embryonic and post-embryonic stages differs between snakes that differ in parity mode, but instead show that the partitioning of yolk in embryonic snakes is species-specific or phylogenetically related. We conclude that the oviparity-viviparity transition does not alter yolk partitioning in embryonic snakes.Electronic supplementary materialThe online version of this article (10.1186/s12862-017-1083-z) contains supplementary material, which is available to authorized users.
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