China's Chang'E-3 (CE-3) spacecraft touched down on the northern Mare Imbrium of the lunar nearside (340.49°E, 44.12°N), a region not directly sampled before. We report preliminary results with data from the CE-3 lander descent camera and from the Yutu rover's camera and penetrating radar. After the landing at a young 450-meter crater rim, the Yutu rover drove 114 meters on the ejecta blanket and photographed the rough surface and the excavated boulders. The boulder contains a substantial amount of crystals, which are most likely plagioclase and/or other mafic silicate mineral aggregates similar to terrestrial dolerite. The Lunar Penetrating Radar detection and integrated geological interpretation have identified more than nine subsurface layers, suggesting that this region has experienced complex geological processes since the Imbrian and is compositionally distinct from the Apollo and Luna landing sites.

This article explores the question of whether the norms based on native speakers of English should be kept in English teaching in an era when English has become World Englishes. This is an issue that has been keenly debated in recent years, not least in the pages of TESOL Quarterly. However, China English in such debates has been given lesser attention, and the voices of English learners and teachers in China have not been adequately reported. This article serves as such an attempt in the context of China having the largest English‐learning population in the world. The present study drew comprehensive data from 984 college students and their teachers at 4 universities in different parts of China. With three cross‐validated research methods (questionnaire survey, matched‐guise technique, and focused interview), this article argues that native speaker‐based norms and models are the most desirable in China's English classroom at the tertiary level, but they could be supplemented by the well‐codified and successfully promoted features of China English.

The D-alanine incorporation system allows Lactobacillus casei to modulate the chemical properties of lipoteichoic acid (LTA) and hence control its proposed functions, i.e., regulation of autolysin action, metal ion binding, and the electromechanical properties of the cell wall. The system requires the D-alanine-D-alanyl carrier protein ligase (Dcl) and the D-alanyl carrier protein (Dcp). Our results indicate that the genes for these proteins are encoded in the dlt operon and that this operon contains at least 2 other genes, dltB and dltD. The aim of this paper is to describe the genetic organization of the operon, the role of the D-alanyl carrier protein, and the function of the putative protein encoded by dltB in the intramembranal translocation of the activated D-alanine.

Therapeutic monoclonal antibodies (mAbs) are an important class of drugs for a wide spectrum of human diseases. Liquid chromatography (LC) coupled to mass spectrometry (MS) is one of the techniques in the forefront for comprehensive characterization of analytical attributes of mAbs. Among various protein chromatography modes, hydrophobic interaction chromatography (HIC) is a popular offline nondenaturing separation technique utilized to purify and analyze mAbs, typically with the use of non-MS-compatible mobile phases. Herein we demonstrate for the first time, the application of direct HIC-MS and HIC-tandem MS (MS/MS) with electron capture dissociation (ECD) for analyzing intact mAbs on quadrupole-time-of-flight (Q-TOF) and Fourier transform ion cyclotron resonance (FTICR) mass spectrometers, respectively. Our method allows for rapid determination of relative hydrophobicity, intact masses, and glycosylation profiles of mAbs as well as sequence and structural characterization of the complementarity-determining regions in an online configuration.

BackgroundBrain glucose hypometabolism is an invariant feature and has significant diagnostic value for Alzheimer's disease. Thiamine diphosphate (TDP) is a critical coenzyme for glucose metabolism and significantly reduced in brain and blood samples of patients with Alzheimer's disease (AD).AimsTo explore the diagnostic value of the measurement of blood thiamine metabolites for AD.MethodsBlood TDP, thiamine monophosphate, and thiamine levels were detected using high performance liquid chromatography (HPLC). The study included the exploration and validation phases. In the exploration phase, the samples of 338 control subjects and 43 AD patients were utilized to establish the models for AD diagnosis assayed by receiver operating characteristic (ROC) curve, including the variable γ that represents the best combination of thiamine metabolites and age to predict the possibility of AD. In the validation phase, the values of models were further tested for AD diagnosis using samples of 861 control subjects, 81 AD patients, 70 vascular dementia patients, and 13 frontotemporal dementia patients.ResultsTDP and the γ exhibited significant and consistent values for AD diagnosis in both exploration and validation phases. TDP had 0.843 and 0.837 of the areas under ROC curve (AUCs), 77.4% and 81.5% of sensitivities, and 78.1% and 77.2% of specificities respectively in the exploration and validation phases. The γ had 0.938 and 0.910 of AUCs, 81.4% and 80.2% of sensitivities, and 90.5% and 87.2% of specificities respectively in the exploration and validation phases. TDP and the γ can effectively distinguish AD from vascular dementia (64.3% for TDP, 67.1% for γ) and frontotemporal dementia (84.6% for TDP, 100.0% for γ).Interpretation.The measurement of blood thiamine metabolites by HPLC is an ideal diagnostic test for AD with inexpensive, easy to perform, noninvasive merits.

The pharmaceutical industry's interest in monoclonal antibodies (mAbs) and their derivatives has spurred rapid growth in the commercial clinical pipeline of these effective therapeutics. The complex micro-heterogeneity of mAbs requires in-depth structural characterization for critical quality attribute assessment and quality assurance. Currently, mass spectrometry (MS)-based methods are the gold standard in mAb analysis, primarily with a bottom-up approach in which immunoglobulins G (IgGs) and their variants are digested into peptides to facilitate the analysis. Comprehensive characterization of IgGs and the micro-variants remains challenging at the proteoform level. Here, we used both top-down and middle-down MS for in-depth characterization of a human IgG1 using ultra-high resolution Fourier transform MS. Our top-down MS analysis provided characteristic fingerprinting of the IgG1 proteoforms at unit mass resolution. Subsequently, the tandem MS analysis of intact IgG1 enabled the detailed sequence characterization of a representative IgG1 proteoform at the intact protein level. Moreover, we used the middle-down MS analysis to characterize the primary glycoforms and micro-variants. Micro-variants such as low-abundance glycoforms, C-terminal glycine clipping, and C-terminal proline amidation were characterized with bond cleavages higher than 44% at the subunit level. By combining top-down and middle-down analysis, 76% of bond cleavage (509/666 amino acid bond cleaved) of IgG1 was achieved. Taken together, we demonstrated the combination of top-down and middle-down MS as powerful tools in the comprehensive characterization of mAbs.

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An SIR epidemic model with free boundary is investigated.This model describes the transmission of diseases. The behavior of positive solutions to a reaction-diffusion system in a radially symmetric domain is investigated. The existence and uniqueness of the global solution are given by the contraction mapping theorem. Sufficient conditions for the disease vanishing or spreading are given. Our result shows that the disease will not spread to the whole area if the basic reproduction number R 0 < 1 or the initial infected radius h 0 is sufficiently small even that R 0 > 1. Moreover, we prove that the disease will spread to the whole area if R 0 > 1 and the initial infected radius h 0 is suitably large. IntroductionRecently epidemic model has been received a great attention in mathematical ecology. To describe the development of an infectious disease, compartmental models have been given to separate a population into various classes based on the stages of infection [2]. The classical SIR model is described by partitioning the population into susceptible, infectious and recovered individuals, denoted by S, I and R, respectively. Assume that the disease incubation period is negligible so that each susceptible individual becomes infectious and later recovers with a permanently or temporarily acquired immunity, then the SIR model is governed by the following system of differential equations:( 1.1) where the total population size has been normalized to one and the influx of the susceptible comes from a constant recruitment rate b. The death rate for the S, I and R class is, respectively, given by µ 1 , µ 2 and µ 3 . Biologically, it is natural to assume that µ 1 < min{µ 2 , µ 3 }. The standard incidence of disease is denoted by βSI, where β is the constant effective contact rate, which is the average number of contacts of the infectious per unit time. The recovery rate of the infectious is