Towards characterizing the solution space of the 1-Dollo Phylogeny problem

Cancer cells may mutate multiple times, from a normal state to a mutated state and vice versa. Given our sequenced data, we can model the mutation process with a phylogenetic tree. One representative model is the k-Dollo parsimony, where all observed mutations mutate from a single normal cell and each character of a cell is gained at most once and lost at most k times. We examine the 1-Dollo Phylogeny problem, does a 1-Dollo phylogeny, a tree that follows the 1-Dollo parsimony model, exist for the observations. Current algorithms to solve the 1-Dollo Phylogeny problem only tell us whether or not a set of observations has a 1-Dollo phylogeny by outputting a single solution. We explore the structure of 1-Dollo phylogenies and use our idea of a skeleton to develop an algorithm that enumerates all 1-Dollo phylogenies for any set of observations. This algorithm runs much faster than the naive brute force enumeration algorithm for random input. The implementation is here: https://github.com/sxie12/skeleton_solver

Pulse Radar Imaging Method in an Anechoic Chamber Based on an Amplitude Modulation Design

The application of a pulse radar in anechoic chamber imaging is a new way to obtain the electromagnetic characteristics of targets. However, the limited size of an anechoic chamber causes the coupling between the transmitted signal and echo so the target image cannot be accurately achieved. To solve this problem, an imaging method using a pulse radar in an anechoic chamber based on an amplitude modulation design is proposed in this paper. Firstly, amplitude modulation is performed to solve the coupling of the transmitted signal and echo. In order to cancel the false targets in the target image after the amplitude modulation, different amplitude modulation sequences are designed. Secondly, echo processing based on the designed amplitude modulation is discussed to obtain the target image. Simulations and experiments are conducted and the results show that the proposed amplitude design and echo processing method can accurately obtain the target image in an anechoic chamber

Pulse Radar Imaging Method in an Anechoic Chamber Based on an Amplitude Modulation Design

The application of a pulse radar in anechoic chamber imaging is a new way to obtain the electromagnetic characteristics of targets. However, the limited size of an anechoic chamber causes the coupling between the transmitted signal and echo so the target image cannot be accurately achieved. To solve this problem, an imaging method using a pulse radar in an anechoic chamber based on an amplitude modulation design is proposed in this paper. Firstly, amplitude modulation is performed to solve the coupling of the transmitted signal and echo. In order to cancel the false targets in the target image after the amplitude modulation, different amplitude modulation sequences are designed. Secondly, echo processing based on the designed amplitude modulation is discussed to obtain the target image. Simulations and experiments are conducted and the results show that the proposed amplitude design and echo processing method can accurately obtain the target image in an anechoic chamber

Dry Permanent Magnetic Separator: Present Status and Future Prospects

Dry permanent magnetic separators have been widely used in the mineral and coal processing industries due to their simple operation and high separation efficiency. These tools not only discard some amount of bulk gangue from the raw ore, thereby reducing the volume of the grinding operation and cutting energy consumption, but also do not require water in the sorting process, thereby expanding their applicability to arid and cold areas. With the depletion of global iron ore resources, a dry, low-cost processing or pre-sorting prior to the wet separation has received the attention of industrial practitioners as a potential alternative. The performance of dry magnetic separators plays a critical role in dry processing This paper reviews the dry magnetic separators available in the literature and describes their operating principles, separation performance, and applications. A detailed comparison of different separators is also conducted to evaluate the differences in their sorting performance and mechanisms and to provide a reference for the optimization of dry magnetic separators

Effects of Obstructive Sleep Apnea on Cardiac Function and Clinical Outcomes in Chinese Patients with ST-Elevation Myocardial Infarction

Aim. The objective of this study was to investigate the influence of OSA on cardiac function in Chinese patients with ST-elevation myocardial infarction (STEMI) and determine the prognostic impact of OSA among these patients. Methods. In this retrospective study, 198 STEMI patients were enrolled. Doppler echocardiography was performed to detect the effect of OSA on cardiac function. Major adverse cardiac events (MACE) and cardiac mortality were analyzed to determine whether OSA was a clinical prognostic factor; its prognostic impact was then assessed adjusting for other covariates. Results. The echocardiographic results showed that the myocardium of STEMI patients with OSA appeared to be more hypertrophic and with a poorer cardiac function compared with non-OSA STEMI patients. A Kaplan-Meier survival analysis revealed significantly higher cumulative incidence of MACE and cardiac mortality in the OSA group compared with that in the non-OSA group during a mean follow-up of 24 months. Multivariate Cox regression analysis revealed that OSA was an independent risk factor for MACE and cardiac mortality. Conclusion. These results indicate that the OSA is a powerful predictor of decreased survival and exerts negative prognostic impact on cardiac function in STEMI patients

A robust Multi-Band Water Index (MBWI) for automated extraction of surface water from Landsat 8 OLI imagery

Surface water is vital resources for terrestrial life, while the rapid development of urbanization results in diverse changes in sizes, amounts, and quality of surface water. To accurately extract surface water from remote sensing imagery is very important for water environment conservations and water resource management. In this study, a new Multi-Band Water Index (MBWI) for Landsat 8 Operational Land Imager (OLI) images is proposed by maximizing the spectral difference between water and non-water surfaces using pure pixels. Based on the MBWI map, the K-means cluster method is applied to automatically extract surface water. The performance of MBWI is validated and compared with six widely used water indices in 29 sites of China. Results show that our proposed MBWI performs best with the highest accuracy in 26 out of the 29 test sites. Compared with other water indices, the MBWI results in lower mean water total errors by a range of 9.31%-25.99%, and higher mean overall accuracies and kappa coefficients by 0.87%-3.73% and 0.06-0.18, respectively. It is also demonstrated for MBWI in terms of robustly discriminating surface water from confused backgrounds that are usually sources of surface water extraction errors, e.g., mountainous shadows and dark built-up areas. In addition, the new index is validated to be able to mitigate the seasonal and daily influences resulting from the variations of the solar condition. MBWI holds the potential to be a useful surface water extraction technology for water resource studies and applications

High-performance liquid chromatographic analysis of as-synthesised N,N '-dimethylformamide-stabilised gold nanoclusters product

Reverse-phase high-performance liquid chromatographic (RP-HPLC) separation and analysis of polydisperse water-soluble gold nanoclusters (AuNCs) stabilised with N,N'-dimethylformamide (DMF) were investigated. Under optimal elution gradient conditions, the separation of DMF-AuNCs was monitored by absorption and fluorescence spectroscopy. The UV-vis spectral characteristics of the separated DMF-AuNCs have been captured and they do not possess distinct surface plasmon resonance bands, indicating that all DMF-AuNCs are small AuNCs. The photoluminescence emission spectra of the separated DMF-AuNCs are in the blue-light region. Moreover, cationic DMF-AuNCs are for the first time identified by ion chromatography. Our proposed RP-HPLC methodology has been successfully applied to separate AuNCs of various Au atoms as well as DMF-stabilised ligands. Finally, the composition of the separated DMF-AuNCs was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and electrospray ionisation mass spectrometry, proving that the as-synthesised DMF-AuNCs product consists of Au-10(+), Au-10, Au-11, Au-12, Au-13, and Au-14 NCs stabilised with various numbers of DMF ligands

Practice of the Qualification and Recognition for Orphan Drugs in the World and its Inspiration

We have analyzed the current status of recognization and qualification of orphan drugs in China and abroad, looking at the aspects of the authority institutions, identification and qualification process, and the number of orphan drugs identified and available in the market. By comparing and analyzing horizontally the differences in orphan drugs identification between representative developed countries vs. some developing countries, we discuss the inadequacy of orphan drugs supervision in China. We introduce the advanced experience from the developed countries and some developing countries to provide suggestions for the identification and management of orphan drugs, hoping to speed up the process of development and market availability of orphan drugs and to maximize patient's accessibility to treatment in China

Defect Chemistry of the Metal Cation Defects in the p- and n‑Doped SnO₂ Nanocrystalline Films

Cationic interstitial and substitutional defects, which serve as a key role in shaping the material’s performance, are considered as two kinds of important defect structures in the doped SnO₂. To give a clear characterization of such metal cation defects, temperature-dependent electrical conduction measurement by the high throughput screening platform of gas-sensing materials is carried out, for the first time, to perform the defect structure studies of the p-type (Li⁺, Cd²⁺, Al³⁺), isovalent (Ti⁴⁺), and n-type (Nb⁵⁺, W⁶⁺) doped SnO₂ nanocrystalline films in the oxygen-free atmosphere. The temperature-dependent measurements indicate that subtle induced impurities are capable of evidently modifying the electrical conduction mechanism of the SnO₂. In terms of the small-polaron hopping mechanism, an improved defect chemical model is proposed in which the properties of the metal cation defects are explicitly depicted. Values for the ionization energy (Δ<i>E_D</i>) of the metal cation defects and electron hopping energy (<i>E_H</i>) in the doped SnO₂ are extracted by fitting the experimental data to the defect model. These data that reflect the nature of the metal cation defects and their effects on the electronic structure of the SnO₂ are first introduced here, and the validity of these data are confirmed. What’s more, the Δ<i>E_D</i> calculated here is of critical importance for understanding the defect structure of the metal dopants in the SnO₂

Synchronously Deriving Electron Concentration and Mobility by Temperature- and Oxygen-Dependent Conductivity of Porous ZnO Nanocrystalline Film

A simple and effective way to get electron concentration and mobility accurately is significant for the electronic and photoelectric applications of porous ZnO nanocrystalline film. On the basis of the defect ionization and the electron scattering, we proposed here a new temperature-programmed-dependent conductivity-based synchronous derivation method (TPDCBSD) to evaluate electron concentration and mobility of porous ZnO nanocrystalline film independently. The obtained results were consistent with others. Compared with the commonly used Hall-effect measurements, the TPDCBSD method is much more simple, has lower noise, and is convenient to couple external fields. More importantly, the extracted electron concentration and electron mobility are relatively independent. Besides, a series of physical parameters related to the effects of temperature and oxygen partial pressure were obtained, and the coupling effect of temperature and oxygen was discussed in this work, which are inspiring for the applications of porous ZnO nanocrystalline film