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Traditional Chinese medicine (TCM) is characterized by synergistic therapeutic effect involving multiple compounds and targets, which provide potential new therapy for the treatment of complex cancer conditions. However, the main contributors and the underlying mechanisms of synergistic TCM cancer therapies remain largely undetermined. Machine learning now provides a new approach to determine synergistic compound combinations from complex components of TCM. In this study, a prediction model based on extreme gradient boosting (XGBoost) algorithm was constructed by integrating gene expression data of different cancer cell lines, targets information of natural compounds and drug response data. Radix Paeoniae Rubra (RPR) was selected as a model herbal sample to evaluate the reliability of the constructed model. The optimal XGBoost prediction model achieved a good performance with Mean Square Error (MSE) of 0.66, Mean Absolute Error (MAE) of 0.61, and the Root Mean Squared Error (RMSE) of 0.81 on test dataset. The superior synergistic anti-tumor combinations of D15 (Paeonol + Ethyl gallate) and D13 (Paeoniflorin + Paeonol) were successfully predicted from RPR and experimentally validated on MCF-7 cells. Moreover, the combination of D13 could work as a main contributor to a synergistic anti-proliferative activity in the compatibility of RPR and Cortex Moutan (CM). Our XGBoost model could be a reliable tool for the efficient prediction of synergistic anti-tumor multi-compound combinations from TCM. [ABSTRACT FROM AUTHOR]

We report on the observation of quasi-trapezoid noise-like pulses (NLPs) in a fiber laser with a large anomalous dispersion regime based on nonlinear polarization rotation. Trapezoidal NLPs operate at 1568 nm with a fundamental repetition rate of 946.14 kHz. The pulse width can widen from 12.54 to 32.17 ns, and the pulse energy can be increased from 8.81 to 25.84 nJ by increasing the pump power from 77.4 to 244.4 mW. The maximum intracavity energy of a trapezoidal pulse can reach ~258.4 nJ. Furthermore, stable high-order harmonics are obtained by regulating the pump power and polarization state. In the harmonic mode-locking regime, the second- to the tenth-order harmonic trapezoidal pulses can be achieved in the fiber laser. [ABSTRACT FROM AUTHOR]

Multi-wavelength square pulses are generated in the dissipative soliton resonance (DSR) regime by a Yb-doped fiber laser (YDFL) with a long cavity configuration. The spectral filter effect provided by a passive fiber with low-stress birefringence facilitates the establishment of multi-wavelength operation. Through appropriate control of the cavity parameters, a multi-wavelength DSR pulse can be generated in single- and dual-waveband regions. When the multi-wavelength DSR works in the 1038 nm waveband, the pulse duration can broaden from 2 ns to 37.7 ns. The maximum intra-cavity pulse energy is 152.7 nJ. When the DSR works in the 1038 nm and 1080 nm wavebands, the pulse duration can be tuned from 2.3 ns to 10.5 ns with rising pump power. The emergence of the 1080 nm waveband is attributed to the stimulated Raman scattering (SRS) effect. Our work might help a deeper insight to be gained into DSR pulses in all-normal-dispersion YDFLs. [ABSTRACT FROM AUTHOR]

The aim of the present work was to develop a novel method integrating two-step aqueous two-phase extraction and temperature-controlled affinity precipitation for the separation and purification of horseradish peroxidase (HRP) from horseradish roots. First, a two-step aqueous two-phase extraction (ATPE) process was used as a primary separation process to remove sugars and pigments, and then a temperature-controlled affinity precipitation process based on a thermosensitive triblock copolymer (PEG113-b-PVBA49-b-PNIPAM105) was exploited as a further purification process to selectively isolate HRP from other impurity proteins. The optimum PEG4000 (0.20, w/w) − (NH4)2SO4 (0.18, w/w) aqueous two-phase system (ATPS) was obtained by studying the liquid–liquid equilibrium of PEG (400/1000/2000/4000) + (NH4)2SO4/K3C6H5O7/K2HPO4 ATPSs and the distribution behaviors of 9 kinds of model compounds in these PEG-salt ATPSs. The successful isolation of HRP from horseradish roots was achieved by the integrated method without having a negative effect on the structure of HRP, and the extraction efficiency and purification factor of HRP reached 84.26 ± 0.15% and 9.15 ± 0.10, respectively. The integrated method shows outstanding separation and purification performances and has good prospects for the industrial production of plant glycoprotein. [ABSTRACT FROM AUTHOR]

• Propose a NCUE index for monitoring grassland dynamic to reduce climate fluctuation. • NCUE is suitable for cold and dry climate characteristics of Tibetan Plateau, China. • Construct an Integrated Meteorological Factor (IMF) • Reveal the spatio-temporal characteristics of grassland change from 1982 to 2012. • NCUE can mitigate the impact of climate fluctuation and reflect grassland changes. Grassland degradation is one of the most pressing challenges in natural environment and anthropogenic society. However, there is yet no effective approach for monitoring the spatio-temporal pattern of large-scale grassland degradation. In particular, the research on grassland changes in the harsh natural environment such as the Qinghai-Tibet Plateau is still in its infancy due to complexity, and it is extremely difficult for humans to reach these remote areas. The annual changes in the grassland biomass might be the results of climate fluctuations or grassland degradation. To test the hypothesis, the impact of inter-annual climate fluctuations needs to be considered when monitoring the grassland degradation based on spatio-temporal change of grassland biomass. In this paper, we propose a Novel Climate Use Efficiency index (NCUE) by considering rainfall, temperature, sunlight time, wind speed, surface temperature, accumulated temperature, time lag effect, light, temperature and water suitability and their coordination climatic factors that mainly affect vegetation growth comprehensively, to monitor grassland change suitable for cold and dry climate characteristics of the Qinghai-Tibet Plateau, and to reduce the effect of inter-annual variability of grassland productivity caused by climate fluctuation. As a consequence, grassland degradation monitoring could be more accurate and objective than existing ecological indicators. Our experiments show that the slope of NCUE over 31 years from 1982 to 2012 is 0.0028, showing a recovery trend in grassland. Degradation and restoration of grassland exist at the same time, and their proportions are 20.49% and 23.89%, respectively. By comparing with in-situ measurements in 2013 and 2009, 68% consistency was achieved with our prediction, and the 70% consistency is achieved by comparing with the positive and negative change trend of accumulated NDVI during the growing season. Moreover, the comparative analysis of land use/cover changes (LUCC) from 1990 to 2010 shows 69% of consistency. The ratio of the area of grassland significantly degradation and recovered predicted by NCUE change trend is 1.41% and 1.43%, respectively. It occupies a very small area of the study area. Yet, that predicted by NDVI change trend is 42.17% and 31.90%, respectively, and about 70% of the area is detected as drastic changes. It shows that NDVI is sensitive to climate fluctuations, while NCUE reduces the impact of climate fluctuations, reflecting change of grassland being affected by human activities and long-term climate change. The novel NCUE has great potential and utility to minify the impact of climate fluctuation and reflect grassland changes over space and time quantitatively. Such ecological index provides a new understanding of spatial and temporal patterns of grassland degradation in the Three River Headwaters Region (TRHR) at the same time. [ABSTRACT FROM AUTHOR]