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An increasing number of MOOCs use learning videos featuring an instructor and slides, but there are few specific guidelines for the design of instructor images for these videos. A pedagogical agent (PA) is a kind of virtual instructor image in a learning video, and its image design is mostly guided by anthropomorphism. Our research attempts to introduce zoomorphism, which is the opposite of traditional anthropomorphism, into the image design of PA. This study tested the effects of two different types of PA images (i.e. anthropomorphic and zoomorphic) as well as a control condition of no PA image on learning from a learning video in a sample of 94 s-grade children. The children were randomly assigned to watch one of three learning videos on pandas. The ANOVA and Kruskal–Wallis tests showed that children who watched the zoomorphic PA image video obtained significantly higher retention, transfer, learning interest, and experience than children who watched the other two types of videos. Children self-reported more enjoyment in the zoomorphic PA image condition than in the no PA condition. Furthermore, the results of multiple regression analysis showed that children's learning interest and experience positively predicted retention and transfer scores; boredom negatively predicted transfer scores. These findings highlight the positive effect of zoomorphism on PA image design, suggesting that zoomorphism holds great prospects in PA image development. [ABSTRACT FROM AUTHOR]

Experiments were conducted to investigate the influence of different factors on the adsorption of Zn 2+ and Cd 2+ ions from aqueous solution onto vermiculite. The ratio of the initial concentration of ions, C 0 , to the adsorbent concentration, W 0 , was shown to be the key factor determining the equilibrium ion adsorption density, q e . Subject to the magnitude of C 0 /W 0 , the value of q e could either attain its maximum level, q m (the maximum adsorption density), when the solid surface was fully saturated, or approach its critical limit, q c (the C 0 /W 0 ratio), when the ions in the bulk solution had been completely removed. The main mechanism for adsorption in the systems studied was ion-exchange. An increase in Zn 2+ or Cd 2+ ion adsorption from the single metal ion solution resulted in an increase in the concentrations of unadsorbed K + , Na + , Ca 2+ and Mg 2+ ions remaining in the bulk solution. Competition between adsorbing ions was observed in the mixed K + –Zn 2+ –Cd 2+ ion system. Although temperature had a positive effect upon the adsorption of Zn 2+ and Cd 2+ ions, its effect was statistically negligible over the range 15–45°C. The negative effect of decreasing pH values on the adsorption process was only significant below a pH value of 4.0, indicating that the adsorption of Zn 2+ and Cd 2+ ions would be significantly depressed when high amounts of H + ions are present in the system.

Aim: This study investigated the association between clinical data and T790M mutation in rebiopsy after EGFR tyrosine kinase inhibitors (EGFR-TKIs) failure, and explored the prognosis of T790M-positive patients. Methods: Patients with non-small-cell lung cancer undergoing rebiopsy after first-generation TKI failure were reviewed. Results & conclusion: Patients with brain metastases, negative TP53, initial 19del and longer initial PFS had higher positive rate of T790M. The median progression-free survival (PFS) of T790M-positive patients with cytology and tissue rebiopsy were longer than patients with liquid rebiopsy. The median PFS of T790M-positive patients rebiopsied by ordinary bronchoscope and endobronchial ultrasound-guided transbronchial lung biopsy with a guided sheath (EBUS-GS-TBLB) were longer than that of the patients rebiopsied by EBUS transbronchial needle aspiration (TBNA). [ABSTRACT FROM AUTHOR]

Gliomas are the most common type of primary brain tumor, yet the prognosis for glioma patients remains poor. Mutations in the promoter region of the telomerase reverse transcriptase gene (TERTp) are associated with diagnosis and poor prognosis in gliomas. Here, we developed a precise and rapid Sanger sequencing assay to screen or TERTp mutations. We established the Sanger sequencing approach for the detection of TERTp mutations based on human glioma cell lines U251 and assessed the analytical validation by determining the accuracy, sensitivity, precision, and specificity. In our study, we verified the accuracy of Sanger sequencing by the real-time polymerase chain reaction method. Our data showed that TERTp mutations were detected at an analytical sensitivity of 10% per mutant. The precision and specificity validation also showed the desired results. In total, 147 glioma patients were investigated for TERTp mutations, and of each patient, clinical data and molecular characteristics were analyzed. We found that anaplastic oligodendroglioma had the highest frequency of TERTp mutations (66.7%). No differences in TERTp mutation frequency were observed between frozen tissue specimens and formalin-fixed and paraffin-embedded tissue. TERTp mutations were associated with older patients (≥45 years), whereas isocitrate dehydrogenase (IDH) mutations were inclined to a younger age (<45 years), frontal location, and pathologic stage II-III patients. IDH mutations were significantly associated with O6-methylguanine-DNA methyltransferase (MGMT) methylation (P = 0.003) and lower Ki-67 protein expression (P = 0.011). Moreover, MGMT methylation was enriched in IDH-mutant/TERTp-mutant gliomas, and Ki-67 protein expression was the highest in the IDH-wild type/TERTp-mutant group. Taken together, the findings of this study indicate the establishment of a rapid, precise, and practical Sanger sequencing technique for TERTp mutations in gliomas that may show promising results in clinical applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] We determined the first structure of human α1M with heavy electron density of the chromophore. [•] We proposed a new structural model of the chromophore. [•] We first revealed that the two conserved surface regions of α1M are proposed as putative protein–protein interface sites. [ABSTRACT FROM AUTHOR]

Pathogenic bacteria produce a wide variety of virulence factors that are considered to be potential antibiotic targets. In this study, we report the crystal structure of a novel S. pneumoniae virulence factor, GHIP, which is a streptococcus-specific glycosyl hydrolase. This novel structure exhibits an α/β-barrel fold that slightly differs from other characterized hydrolases. The GHIP active site, located at the negatively charged groove in the barrel, is very similar to the active site in known peptidoglycan hydrolases. Functionally, GHIP exhibited weak enzymatic activity to hydrolyze the PNP-(GlcNAc)5 peptidoglycan by the general acid/base catalytic mechanism. Animal experiments demonstrated a marked attenuation of S. pneumoniae-mediated virulence in mice infected by ΔGHIP-deficient strains, suggesting that GHIP functions as a novel S. pneumoniae virulence factor. Furthermore, GHIP participates in allowing S. pneumoniae to colonize the nasopharynx and invade host epithelial cells. Taken together, these findings suggest that GHIP can potentially serve as an antibiotic target to effectively treat streptococcus-mediated infection. [ABSTRACT FROM AUTHOR]

Experiments were conducted to investigate the influence of different factors on the adsorption of Zn2+ and Cd2+ ions from aqueous solution onto vermiculite. The ratio of the initial concentration of ions, C0, to the adsorbent concentration, W0, was shown to be the key factor determining the equilibrium ion adsorption density, qe. Subject to the magnitude of C0/W0, the value of qe could either attain its maximum level, qm (the maximum adsorption density), when the solid surface was fully saturated, or approach its critical limit, qc (the C0/W0 ratio), when the ions in the bulk solution had been completely removed. The main mechanism for adsorption in the systems studied was ion-exchange. An increase in Zn2+ or Cd2+ ion adsorption from the single metal ion solution resulted in an increase in the concentrations of unadsorbed K+, Na+, Ca2+ and Mg2+ ions remaining in the bulk solution. Competition between adsorbing ions was observed in the mixed K+-Zn2+-Cd2+ ion system. Although temperature had a positive effect upon the adsorption of Zn2+ and Cd2+ ions, its effect was statistically negligible over the range 15-45°C. The negative effect of decreasing pH values on the adsorption process was only significant below a pH value of 4.0, indicating that the adsorption of Zn2+ and Cd2+ ions would be significantly depressed when high amounts of H+ ions are present in the system. [ABSTRACT FROM AUTHOR]

With the increasing incidence of papillary thyroid cancer (PTC), it is important to risk-stratify patients who may have a more aggressive tumor biology. The present study aimed to evaluate the risk factors for lymph node metastasis (LNM) in patients with PTC, which may provide a significant reference for clinical diagnosis and treatment. In total, 1,045 patients with PTC [313 with PT microcarcinoma (PTMC) and 732 with non-PTMC] between August 2016 and August 2019 were investigated. The B-type Raf kinase (BRAF) V600E mutation was tested in all samples. The clinical data (sex, age, tumor location, sample type and pathological features) were retrospectively analyzed. Logistic regression analysis was performed to evaluate independent risk factors for LNM. A total of 181/313 (57.8%) PTMC cases and 145/732 (19.8%) non-PTMC cases had a BRAF V600E mutation. In the PTMC cases, significant differences in sex and sample type were identified (BRAF V600E mutation vs. wild-type). In the non-PTMC cases, significant differences in sex and age were identified (BRAF V600E mutation vs. wild-type). Female sex and tumor diameter ≤1 cm were significant independent predictors of LNM in PTC. In PTMC, female sex was a significant independent predictor of LNM. A bilateral tumor was an independent protective factor for LNM in PTC, PTMC and non-PTMC. The BRAF V600E mutation rate of ultrasound-guided fine-needle aspiration cytology was higher compared with FFPE in PTMC (P=0.018). In contrast to previous studies, the results of the present study suggested that being female and having a tumor of diameter ≤1 cm were risk factors for LNM, and that the BRAF wild-type of PTMC may be more aggressive than other types. Notably, the position of the tumor in the bilateral thyroid was also an independent protective factor for LNM. Therefore, ultrasound-guided fine-needle aspiration should be recommended for gene analysis (BRAF V600E) in PTMC. In addition, clinicians should consider an individualized treatment according to gene mutations, sex, age, tumor size and the location of the tumor, in order to achieve an improved therapeutic efficacy. [ABSTRACT FROM AUTHOR]

With the development of urbanization in developing countries, some large cities have experienced rapid population growth and industrial expansion in a short period of time. In order to reasonably expand the scale of the city and guide the orderly outward movement of population and industries, it is urgent to improve the human settlement environment (THSE) in the surrounding areas of large cities. In the case of limited financial funds, different areas around the city need to be improved one by one according to the order of improvement grades. Since THSE is a comprehensive system involving multiple levels and indexes, it is difficult to assess it in a simple way. The previous assessment of THSE mainly focused on qualitative and semi-quantitative aspects, with poor accuracy. In this paper, the author takes JianYang County under the jurisdiction of Chengdu City in Southwest China as an example and uses the Fuzzy Analytic Hierarchy Process (FAHP) to quantitatively calculate the improvement grade of THSE in 55 townships of JianYang County. The author carried out an investigation for more than one year. According to the actual situation of JianYang County, five primary indexes and 22 secondary indexes were selected to establish a comprehensive evaluation index system. This index system contains 1210 statistical data points, and more than 30,000 data points were calculated and derived in this article. Finally, the author calculated the improvement grade of 55 townships by FAHP quantitatively and carried out a horizontal comparison of townships within the same grade to further determine the order of improvement of THSE. [ABSTRACT FROM AUTHOR]

Tuning the free energy difference between a molecular probe and the target has been regarded as a feasible way to realize selective mutant recognition. But due to limited extent of variation on the probing sequences, it remains a challenge to moderately leverage the thermodynamic kinetics simply by changing the base composition of probes. Herein we propose the modulation of discrimination capability for single nucleotide variations (SNVs) detection by insertion of bulge-loop into duplex DNA probes. Based on controllable tuning of free energy change (ΔG) before and after strand exchange with either mutated or wild-type DNAs, much higher specificity than conventional linear probes is obtained. As-proposed bulge-loop probes allows excellent discrimination of SNVs in high guanine and cytosine (GC) rich regions, and reaches a detection limit of 0.02% abundance with down to 2 femtomolar target gene. The probes also demonstrate excellent consistence with droplet digital PCR (ddPCR) in identifying low abundant L858R mutant in lung tissue samples that are not resolved by either a commercial PCR kit or Sanger sequencing. Our work not only provides insight into the rational design of strand exchange probes for point-of-care diagnosis but also advance the construction of customizable cascade reactions in dynamic DNA nanotechnology more broadly. • We propose for the first time the modulation of discrimination capability to detect SNV by insertion of bulge-loop into duplex DNA probes. • As-proposed bulge-loop probes reaches a detection limit of down to 0.02% mutant with minimal 2 femtomolar gene sample. • A limit of 0.1% for the detection of target mutant in human serum is achieved without isolation of DNA from serum or plasma. • Discrimination ability comparable to droplet digital PCR (ddPCR) was realized in identifying low-abundant L858R mutant in lung tissue samples. [ABSTRACT FROM AUTHOR]

Abstract BRAF V600E mutation is an important drive gene mutation and biomarker for tumor diagnosis, monitoring and target treatment. In order to meet the needs of identifying low abundance BRAF V600E mutation from real clinical specimens, a real time fluorescent biosensing strategy was developed by perfectly integrating dual padlock-gap-ligase chain reaction (DP-gLCR) with hyperbranched rolling circle amplification (HRCA). A pair of padlock probes was designed to induce DP-gLCR by using single-base gap coupling with matched deoxyribonucleotides substrates, which significantly increased the specificity of mutation discrimination. A large amount of circularized padlock probes were produced and triggered subsequent HRCA, generating numerous dendritic double-stranded DNA (dsDNA) products for highly sensitive real time fluorescent biosensing. The designed biosensing strategy could detect as low as 200 zM mutation target and distinguish as low as 0.01% genomic DNA with B-type Raf kinase (BRAF) V600E mutation in 40 ng wild-type genomic DNA, which was equal to almost one copy of mutant genomic DNA. Moreover, the proposed method was successfully applied in the detection of BRAF V600E mutation from real clinical samples, proving great potential for ultrasensitive biosensing of low abundance somatic mutation for early cancer diagnosis and treatment. [ABSTRACT FROM AUTHOR]

An LHRH -peptide conjugated ruthenium(II) complex exhibited excellent photophysical properties and antitumor effects, which has been explored as a tumor-targeted theranostic anticancer agent. [Display omitted] • LHRH peptide conjugated Ru1-LHRH exhibited about 8-fold higher cytotoxicity than the parent complex Ru1 against the targeted cells. • Ru1-LHRH could perform theranostic functions by simultaneously imaging and killing targeted tumor cells. • Ru1-LHRH induced apoptosis via the activation of the Caspase3/7 protein family. In the present study, an LHRH peptide-conjugated tumor targeting ruthenium(II) complex (Ru1-LHRH) was synthesized and characterized. Ru1-LHRH selectively targeted the mitochondria of LHRH receptor-overexpressing A2780 tumor cells. In particular, the cytotoxicity of Ru1-LHRH against A2780 cells was approximately 8 times higher than that of nontargeted L02 cells. In addition, this conjugate could perform theranostic functions by simultaneously imaging and killing targeted tumor cells. Further study demonstrated that Ru1-LHRH induced apoptosis by inducing ROS, which involves the activation of the Caspase3/7 protein family. Taken together, Ru1-LHRH exhibited both antitumor and imaging properties, indicating that Ru1-LHRH may be a viable drug candidate as a multifunctional tumor-targeted theranostic anticancer agent. [ABSTRACT FROM AUTHOR]

Toxin YafQ functions as a ribonuclease in the dinJ-yafQ toxin-antitoxin system of Escherichia coli. Antitoxin DinJ neutralizes YafQ-mediated toxicity by forming a stable protein complex. Here, crystal structures of the (DinJ)2-(YafQ)2 complex and the isolated YafQ toxin have been determined. The structure of the heterotetrameric complex (DinJ)2-(YafQ)2 revealed that the N-terminal region of DinJ folds into a ribbon-helix-helix motif and dimerizes for DNA recognition, and the C-terminal portion of each DinJ exclusively wraps around a YafQ molecule. Upon incorporation into the heterotetrameric complex, a conformational change of YafQ in close proximity to the catalytic site of the typical microbial ribonuclease fold was observed and validated. Mutagenesis experiments revealed that a DinJ mutant restored YafQ RNase activity in a tetramer complex in vitro but not in vivo. An electrophoretic mobility shift assay showed that one of the palindromic sequences present in the upstream intergenic region of DinJ served as a binding sequences for both the DinJ-YafQ complex and the antitoxin DinJ alone. Based on structure-guided and site-directed mutagenesis of DinJ-YafQ, we showed that two pairs of amino acids in DinJ were important for DNA binding; the R8A and K16A substitutions and the S31A and R35A substitutions in DinJ abolished the DNA binding ability of the DinJ-YafQ complex., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)

Pathogenic bacteria produce a wide variety of virulence factors that are considered to be potential antibiotic targets. In this study, we report the crystal structure of a novel S. pneumoniae virulence factor, GHIP, which is a streptococcus-specific glycosyl hydrolase. This novel structure exhibits an α/β-barrel fold that slightly differs from other characterized hydrolases. The GHIP active site, located at the negatively charged groove in the barrel, is very similar to the active site in known peptidoglycan hydrolases. Functionally, GHIP exhibited weak enzymatic activity to hydrolyze the PNP-(GlcNAc)5 peptidoglycan by the general acid/base catalytic mechanism. Animal experiments demonstrated a marked attenuation of S. pneumoniae-mediated virulence in mice infected by ΔGHIP-deficient strains, suggesting that GHIP functions as a novel S. pneumoniae virulence factor. Furthermore, GHIP participates in allowing S. pneumoniae to colonize the nasopharynx and invade host epithelial cells. Taken together, these findings suggest that GHIP can potentially serve as an antibiotic target to effectively treat streptococcus-mediated infection.

α(1)-Microglobulin (α(1)m) is one of the phylogenetically most widespread lipocalins and is distributed in various organs and tissues, including liver, heart, eye, kidney, brain, lung, pancreas and skeletal muscle. α(1)m has been found to exert multifarious functions, including interacting with IgA, albumin and prothrombin, binding strongly to haem and exhibiting reductase activity. Nevertheless, little structural information is available regarding these functions of α(1)m. Since determination of three-dimensional structure is a powerful means of functional characterization, X-ray crystallography was used to accomplish this task. Here, the expression, purification, crystallization and preliminary crystallographic analysis of human α(1)m are reported. The crystal belonged to space group P4(3), with unit-cell parameters a = b = 36.45, c = 112.68 Å, and diffracted to a resolution of 2.0 Å. The crystals are most likely to contain one molecule in the asymmetric unit, with a V(M) value of 1.63 Å(3) Da(-1).