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During the transition from embryonic to adult life, the sites of hematopoiesis undergo dynamic shifts across various tissues. In adults, while bone marrow becomes the primary site for definitive hematopoiesis, the establishment of the bone marrow niche for accommodating hematopoietic stem cells (HSCs) remains incompletely understood. Here, we reveal that perinatal bone marrow mesenchymal stem cells (BMSCs) exhibit highly activated insulin-like growth factor 1 receptor (IGF1R) signaling compared to adult BMSCs. Deletion of Igf1r in perinatal BMSCs hinders the transition of HSCs from the fetal liver to the bone marrow in perinatal mice and disrupts hematopoiesis in adult individuals. Conversely, the deletion of Igf1r in adult BMSCs, adipocytes, osteoblasts, or endothelial cells does not affect HSCs in the bone marrow. Mechanistically, IGF1R signaling activates the transcription factor nuclear factor of activated T cells c1 (NFATc1) in perinatal BMSCs, which upregulates CXCL12 and other niche factors for HSC retention. Overall, IGF1R signaling in perinatal BMSCs regulates the development of the bone marrow niche for hematopoiesis.
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Recent genomic analyses have provided new insights into the process of interspecific introgression and its consequences on species evolution. Most recent studies, however, focused on hybridization between recently radiated species, with few examining the genomic outcomes of ancient hybridization across deeply diverged species. Using whole genome data of moustache toads (Leptobrachium), we identified signals of three hybridization events among nine species that diverged at the Eocene. An ancient introgression from L. leishanense to the ancestral branch (C1) of L. liui introduced adaptive variants. The highly introgressed regions include genes with important functions in odorant detection and immune responses. These genes are preserved in all three descendent populations of L. liui_C1, and these regions likely have been positively selected over a long filtering process. A recent introgression occurred from L. huashen to L. tengchongense, with the introgressed regions being mostly neutral. Furthermore, one F1 hybrid individual was detected between sympatric L. ailaonicum and L. promustache. The signals of introgression largely disappeared after removing the hybrid individual, indicating an occasional hybridization but minimal introgression. Further examination of highly divergent but low introgressed genomic regions revealed both pre-mating isolation and genetic incompatibility as potential mechanisms of resisting introgression and maintaining species boundaries. Additionally, no large X-effect was found in these introgression events. Hybridization between deeply diverged amphibian species may be common, but detectable introgressions are likely less so, with recent introgression being mostly neutral and the rare ancient one potentially adaptive. Our findings complement recent genomic work, and together they provide a better understanding of the genomic characteristics of interspecific introgression and its significance in species adaptation and evolution.
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Bone marrow-derived mesenchymal stem cells (BMSCs) support bone formation and constitute the stromal niche in regulating hematopoietic stem cells (HSCs). Stromal niche dysfunction affects HSC engraftment during transplantation; however, the underlying mechanisms remain elusive. In the present study, we found that all-trans retinoic acid (ATRA) and inflammation stress upregulated retinoic acid-inducible gene I (RIG-I) in BMSCs. Excess RIG-I expression damaged the clonogenicity, bone-forming ability of BMSCs and particularly their stromal niche function that supports HSC expansion in vitro and engraftment in vivo. Mechanistically, RIG-I elevation promoted the degradation of NRF2, a checkpoint for antioxidant cellular response, by altering the RIG-I-Trim25-Keap1-NRF2 complex, leading to reactive oxygen species (ROS) accumulation and BMSC damage. Genetic inhibition of RIG-I sustained NRF2 protein levels and reduced ROS levels in ATRA-treated BMSCs, thus preserving their clonogenicity, bone-forming ability, and stromal niche function in supporting HSC engraftment in mice. More importantly, RIG-I inhibition recovered the ATRA-treated stromal niche function to enhance HSC engraftment and emergency myelopoiesis for innate immunity against the bacterium Listeria monocytogenes during transplantation. Overall, we identified a noncanonical role of RIG-I in the regulation of the stromal niche for HSC transplantation.
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Transplante de Medula Óssea , Proteína DEAD-box 58/metabolismo , Fator 2 Relacionado a NF-E2 , Animais , Células-Tronco Hematopoéticas/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Nicho de Células-Tronco/fisiologiaRESUMO
Hematopoietic stem cells (HSCs) have reduced capacities to properly maintain and replenish the hematopoietic system during myelosuppressive injury or aging. Expanding and rejuvenating HSCs for therapeutic purposes has been a long-sought goal with limited progress. Here, we show that the enzyme Sphk2 (sphingosine kinase 2), which generates the lipid metabolite sphingosine-1-phosphate, is highly expressed in HSCs. The deletion of Sphk2 markedly promotes self-renewal and increases the regenerative potential of HSCs. More importantly, Sphk2 deletion globally preserves the young HSC gene expression pattern, improves the function, and sustains the multilineage potential of HSCs during aging. Mechanistically, Sphk2 interacts with prolyl hydroxylase 2 and the Von Hippel-Lindau protein to facilitate HIF1α ubiquitination in the nucleus independent of the Sphk2 catalytic activity. Deletion of Sphk2 increases hypoxic responses by stabilizing the HIF1α protein to upregulate PDK3, a glycolysis checkpoint protein for HSC quiescence, which subsequently enhances the function of HSCs by improving their metabolic fitness; specifically, it enhances anaerobic glycolysis but suppresses mitochondrial oxidative phosphorylation and generation of reactive oxygen species. Overall, targeting Sphk2 to enhance the metabolic fitness of HSCs is a promising strategy to expand and rejuvenate functional HSCs.
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Células-Tronco Hematopoéticas , Esfingosina , Glicólise/genética , Células-Tronco Hematopoéticas/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool) , Prolil Hidroxilases/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Stereoselective inhibition aided by "tailor-made" polymeric additives is an efficient approach to obtain enantiopure compounds through conglomerate crystallization. The chemical and configurational match between the side groups of polymers and the molecules of undesired enantiomer is considered to be a necessary condition for successful stereoseparation. Whereas in this contribution, we present an effective resolution of chiral pharmaceuticals by using cellulose acetates as the additives, which stereoselectively reside on the specific crystal faces of one enantiomer and inhibit its crystal nucleation and growth through helical pattern and supramolecular interaction complementarity. An investigation of nimodipine serves as a case study to highlight the novelty of this strategy wherein R-crystals exhibiting an impressive enantiomeric excess value of 97 % can be attained by employing a mere 0.01â wt % cellulose acetate. Guaifenesin and phenyl lactic acid are also well-resolved by utilizing this methodology. Our work not only brings about a brand-new design strategy for "tailor-made" additives, but will also promote the further exploration of the endless potential for utilizing natural biomolecules in chiral recognition and resolution.
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BACKGROUND: This study aimed to establish a placental long non-coding RNA (lncRNA)-mRNA expression network for early-onset preeclampsia (early-onset PE). METHODS: The RNA sequencing data of the GSE14821 dataset were acquired. Several crucial lncRNAs and mRNAs were exerted based on the differential expression analysis of lncRNA and mRNA. By analyzing the differentially expressed lncRNA and mRNA, we constructed a regulatory network to explore the mechanism of the lncRNA in early onset preeclampsia. RESULTS: A total of 4436 differentially expressed lncRNAs (DElncRNAs) were identified in early-onset PE placenta samples compared with control placenta samples. Pearson correlation analysis revealed significant correlations between 3659 DElncRNAs and 372 DEmRNAs. KEGG analysis showed that the DEmRNAs were enriched in cytokine-cytokine receptor and hypoxia-inducible factor (HIF)-1 pathways. Several well-known early-onset PE-related mRNAs, such as vascular endothelial growth factor A (VEGFA) and VEGF receptor 1 (FLT1), were involved in the two pathways. Weighted gene co-expression network analysis and cis-regulatory analysis further suggested the involvement of the two pathways and potential DElncRNA-DEmRNA interactions in early-onset PE. Moreover, the upregulation of representative DElncRNAs, such as RP11-211G3.3 and RP11-65J21.3, and DEmRNAs, such as VEGFA and FLT1, were validated in clinical placenta samples from patients with early-onset PE by quantitative reverse transcription PCR. Importantly, overexpression of RP11-65J21.3 significantly promoted the proliferation of HTR-8 trophoblast cells at 72 h after transfection. CONCLUSIONS: In conclusion, we identified placental DElncRNAs of early-onset PE and established a DElncRNA-DEmRNA network that was closely related to the cytokine-cytokine receptor and HIF-1 pathways. Our results provide potential diagnostic markers and therapeutic targets for early-onset PE management.
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Redes Reguladoras de Genes , Placenta , Pré-Eclâmpsia , RNA Longo não Codificante , RNA Mensageiro , Humanos , Feminino , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/metabolismo , Gravidez , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , RNA Mensageiro/genética , Placenta/metabolismo , Adulto , Perfilação da Expressão Gênica , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Estudos de Casos e ControlesRESUMO
BACKGROUND: To investigate the value of semi-quantitative and quantitative parameters (PI-RADS score, T2WI score, ADC, Ktrans, and Kep) based on multiparametric MRI (mpMRI) or biparametric MRI (bpMRI) combined with prostate specific antigen density (PSAD) in detecting clinically significant prostate cancer (csPCa). METHODS: A total of 561 patients (276 with csPCa; 285 with non-csPCa) with biopsy-confirmed prostate diseases who underwent preoperative mpMRI were included. Prostate volume was measured for calculation of PSAD. Prostate index lesions were scored on a five-point scale on T2WI images (T2WI score) and mpMRI images (PI-RADS score) according to the PI-RADS v2.1 scoring standard. DWI and DCE-MRI images were processed to measure the quantitative parameters of the index lesion, including ADC, Kep, and Ktrans values. The predictors of csPCa were screened by logistics regression analysis. Predictive models of bpMRI and mpMRI were established. ROC curves were used to evaluate the efficacy of parameters and the model in diagnosing csPCa. RESULTS: The independent diagnostic accuracy of PSA density, PI-RADS score, T2WI score, ADCrec, Ktrans, and Kep for csPCa were 80.2%, 89.5%, 88.3%, 84.6%, 58.5% and 61.6%, respectively. The diagnostic accuracy of bpMRI T2WI score and ADC value combined with PSAD was higher than that of PI-RADS score. The combination of mpMRI PIRADS score, ADC value with PSAD had the highest diagnostic accuracy. CONCLUSIONS: PI-RADS score according to the PI-RADS v2.1 scoring standard was the most accurate independent diagnostic index. The predictive value of bpMRI model for csPCa was slightly lower than that of mpMRI model, but higher than that of PI-RADS score.
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Imageamento por Ressonância Magnética Multiparamétrica , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/patologia , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Antígeno Prostático Específico , Análise MultivariadaRESUMO
Background: Lung adenocarcinoma (LUAD) is a major pathological subtype of non-small cell lung cancer and occurs more commonly in females than other lung cancer subtypes. Studying female-specific oncogenes in LUAD may provide personalized medicine approaches for females with LUAD. Objective: We aimed to identify the possible female-specific oncogenes of LUAD and understand their potential impact on treatment strategies for specific cancer subgroups. Methods: The gene expression profiles of LUAD were downloaded from The Cancer Genome Atlas (TCGA) database and the GSE72094 dataset. TCGA database is currently the largest database of cancer genetic information. Female-specific differentially expressed genes (DEGs) were identified by R programming software. Functional annotation of DEGs was conducted based on KEGG pathway enrichment analysis. Univariate and multivariate Cox proportion analyses were applied to construct a prognostic risk score model with the DEGs. KaplanâMeier and ROC curves were plotted to validate the predictive effect of the prognostic DEGs signature. Gene set enrichment analysis (GSEA) was applied to identify the potential pathways in the high-risk groups in female LUAD. Finally, the immunohistochemical staining (IHC) was conducted to verify the expression of CABLES1 in human LUAD samples. Results: We constructed a prognostic signature that includes 12 female-specific DEGs (P < .05). Among them, ABHD6, CABLES1, CXCL5, DNAJB4, EFNB2, HLX, MEOX2, MTMR10, PPFIBP1, and RERG were down-regulated in LUAD, while MFSD6L and SOX9 were up-regulated in LUAD (P < .0001). The Kaplan-Meier, and receiver operator characteristic (ROC) curves revealed efficient and stable prediction of the prognostic signature in the female LUAD patients. It was showed the risk score model has a good predictive effect on the prognosis of female LUAD patients but is not effective for male patients (P < .0001). The ROC curve showed that the areas under the curve (AUC) of first-, third- and fifth-year survival were 0.70, 0.69, and 0.79, respectively, which indicated good sensitivity and specificity of the 12-gene risk score algorithm in predicting the prognosis of female LUAD. GSEA revealed that the high-risk group was significantly enriched in the EMT, E2F targets, Myc targets, G2/M checkpoint, glycolysis, hypoxia, and mTORC1 signaling pathways (P < .05). Immunohistochemical staining showed lower CABLES1 expression was associated with higher pTNM stage in female LUAD but not in male LUAD (P < .05). Conclusion: Our study constructed and verified a prognostic signature based on 12 female-specific DEGs of LUAD, which could improve the understanding of sex-related risk factors involved in LUAD carcinogenesis and progression, and may provide personalized treatment strategies for female LUAD patients.
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OBJECTIVE: This article describes an interdisciplinary treatment that helped a patient with displaced upper anterior teeth. A gingivectomy, root canal therapies, digital smile design, digital wax-up, and guided tooth preparations were applied. CLINICAL CONSIDERATIONS: A patient with pathologically migrated teeth asked for treatment without orthodontic involvement due to a primary failed orthodontic treatment history. A smile photo was taken and superimposed with the dentition in a CAD software to accomplish a digital smile design. The jaw movements were recorded with two different methods, a mechanical articulator and an intraoral scanner with Patient-Specific-Motion function. The occlusal contacts during protrusive and lateral movements were compared and the digital wax-up was designed according to the later occlusal data. An aesthetic crown lengthening and pre-op root canal treatment were carried out in advance accordingly. After guided tooth preparation with a silicone index, the final fixed restorations were manufactured and cemented. A 2-year follow-up showed that our prosthesis functions well. CONCLUSIONS: This clinical report revealed that an intraoral scanner with Patient-Specific-Motion function can effectively record individual dynamic occlusal patterns and these data can be integrated into the CAD/CAM process to enhance the fulfillment of clinical requirements. CLINICAL SIGNIFICANCE: This clinical procedure with a 2-year follow-up demonstrated that a prosthodontic-based interdisciplinary treatment of pathologically migrated teeth using dynamic occlusal recording with an intraoral scanner could achieve satisfactory esthetics in a relatively short treatment period. The Patient Specific Motion module may be used to record a personalized functional movement and the data can be integrated into the design process of the final restorations.
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Migração de Dente , Humanos , Migração de Dente/terapia , Feminino , Tratamento do Canal Radicular/métodos , Gengivectomia/métodos , Registro da Relação Maxilomandibular , Aumento da Coroa Clínica/métodos , Desenho Assistido por Computador , Maxila , Estética Dentária , Incisivo , Sorriso , Equipe de Assistência ao Paciente , Oclusão Dentária , AdultoRESUMO
Geographical features and palaeoclimatic fluctuations are two classical evolutionary forces that shape genetic diversification within species. Fine-grained analysis of the mechanisms involved through population demographic processes, however, remains limited. Taking advantage of two recently published reference genomes, we resequenced the genomes and examined the evolutionary history of the moustache toads, a group endemic to East Asia where complex topography and fluctuating palaeoclimate are known to have had profound impacts on organisms. Moustache toads probably originated in southeast Yunnan, China, and diversified towards the northwestern of Yunnan, as well as central and eastern China. Further exploration based on three widespread species (Leptobrachium ailaonicum, L. boringii and L. liui) using demographic modelling and species distribution models revealed that mountains and river valleys in East Asia not only functioned as geographical barriers, but also provided dispersal corridors and facilitated continuous migration or post-glacial secondary contact among moustache toad populations. Furthermore, periodic oscillation of effective population sizes accompanying fluctuations of historical temperature and population contraction at the Last Glacial Maximum support the widespread impact of climatic changes of the Pleistocene on species diversification in East Asia. This impact was moderate for populations of L. ailaonicum and L. boringii in the southwestern mountains but severe for populations of L. liui in the eastern lowland regions of continental East Asia, which is supported by different degrees of change of their effective population sizes. Our findings reveal mechanisms underlying genetic diversification among moustache toads, and highlight the power of genomic data and demographic modelling for examining complex historical population-level processes and for understanding how geographical and palaeoclimatic factors interactively shape current intraspecific diversity.
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Anuros , Evolução Biológica , Animais , Filogenia , China , Ásia Oriental , Geografia , Anuros/genéticaRESUMO
Recently developed image-free sensing techniques have achieved remarkable performance in various vision tasks. However, existing image-free methods still cannot simultaneously obtain the category, location, and size information of all objects. In this Letter, we report a novel image-free single-pixel object detection (SPOD) technique. SPOD enables efficient and robust multi-object detection directly from a small number of measurements, eliminating the requirement for complicated image reconstruction. Different from the conventional full-size pattern sampling method, the reported small-size optimized pattern sampling method achieves higher image-free sensing accuracy with fewer pattern parameters (â¼1 order of magnitude). Moreover, instead of simply stacking CNN layers, we design the SPOD network based on the transformer architecture. It can better model global features and reinforce the network's attention to the targets in the scene, thus improving the object detection performance. We demonstrate the effectiveness of SPOD on the Voc dataset, which achieves a detection accuracy of 82.41% mAP at a sampling rate of 5% with a refresh rate of 63 f.p.s.
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Diffusion-based translocation along DNA or RNA molecules is essential for genome regulatory proteins to execute their biological functions. The reduced dimensionality of the searching process makes the proteins bind specific target sites at a "faster-than-diffusion-controlled rate". We herein report a photoresponsive slider-track diffusion system capable of self-assembly rate acceleration, which consists of (-)-camphorsulfonic acid, 4-(4'-n-octoxylphenylazo)benzenesulfonic acid, and isotactic poly(2-vinylpyridine). The protonated pyridine rings act as the footholds for anionic azo sliders to diffusively bind and slide along polycationic tracks via electrostatic interactions. Ultraviolet light triggers the trans to cis isomerization and aggregation of azo sliders, which can be monitored by multiple spectroscopic methods without labeling. The presence of vinyl polymer track increases the aggregation rate of cis azobenzene up to â¼20 times, depending on the stereoregularity of the polymer chain, the acid/base ratio and the addition of salt. This system has a feature of simplicity, monitorability, controllability, and could find applications in designing molecular machines with desired functionalities.
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Compostos Azo , DNA , Compostos Azo/química , DNA/química , Polímeros/química , Piridinas , RNA , Raios UltravioletaRESUMO
BACKGROUND: Posttraumatic stress disorder (PTSD) is common among children and adolescents who have experienced traumatic events. Exposure therapy (ET) has been shown to be effective in treating PTSD in adults. However, its efficacy remains uncertain in children and adolescents. AIMS: To evaluate the efficacy and acceptability of ET in children and adolescents with PTSD. METHOD: We searched PubMed, EMBASE, Cochrane, Web of Science, PsycINFO, CINAHL, ProQuest, LILACS, and international trial registries for randomized controlled trials (RCTs) assessed ET in children and adolescents (aged ≤18 years) with PTSD up to August 31, 2020. The primary outcomes were efficacy (the endpoint score from PTSD symptom severity rating scales) and acceptability (all-cause discontinuation), secondary outcomes included efficacy at follow-up (score from PTSD scales at the longest point of follow-up), depressive symptoms (end-point score on depressive symptom severity rating scales) and quality of life/social functioning (end-point score on quality of life/social functioning rating scales). This study was registered with PROSPERO (CRD42020150859). RESULT: A total of 6 RCTs (278 patients) were included. The results showed that ET was statistically more efficacious than control groups (standardized mean differences [SMD]: - 0.47, 95% confidence interval [CI]: - 0.91 to - 0.03). In subgroup analysis, exposure therapy was more efficacious for patients with single type of trauma (SMD: - 1.04, 95%CI: - 1.43 to - 0.65). Patients with an average age of 14 years and older, ET was more effective than the control groups (SMD: - 1.04, 95%CI: - 1.43 to - 0.65), and the intervention using prolonged exposure therapy (PE) (SMD: - 1.04, 95%CI: - 1.43 to - 0.65) was superior than control groups. Results for secondary outcomes of efficacy at follow-up (SMD: - 0.64, 95%CI: - 1.17 to - 0.10) and depressive symptoms (SMD: - 0.58, 95%CI: - 0.93 to - 0.22) were similar to the previous findings for efficacy outcome. No statistically significant effects for acceptability and quality of life/social functioning were found. CONCLUSION: ET showed superiority in efficacy at post-treatment/follow-up and depressive symptoms improvement in children and adolescents with PTSD. Patients with single type of trauma may benefit more from ET. And ET is more effective in patients 14 years or older. Moreover, PE could be a better choice.
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Terapia Implosiva , Transtornos de Estresse Pós-Traumáticos , Adolescente , Adulto , Criança , Humanos , Qualidade de Vida , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/terapia , Listas de EsperaRESUMO
Milk proteins have received much awareness due to their bioactivity. However, their encapsulation functions have not attracted enough attention. Milk proteins as encapsulation walls can increase the bioavailability of bioactive compounds. As the benefits of bioactive compounds are critically determined by bioavailability, the effect of interactions between milk proteins and active substances is a critical topic. In the present review, we summarize the effects of milk proteins as encapsulation walls on the bioavailability of active substances with a special focus. The methods and mechanisms of interactions between milk proteins and active substances are also discussed. The evidence collected in the present review suggests that when active substances are encapsulated by milk proteins, the bioavailability of active substances can be significantly affected. This review also provides valuable guidelines for the use of milk protein-based microcarriers.
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Proteínas do Leite , Estudantes , Animais , Disponibilidade Biológica , HumanosRESUMO
Chiral recognition is of importance not only in living systems but also in estimating the optical purity of enantiomeric drugs and fabricating advanced materials. Herein we report a novel self-reporting activated ester-amine reaction that can provide multi-channel visual detection of organic amines. It relies on the reaction extent dependent cis-transoid to cis-cisoid helical transition of the polyphenylacetylene backbone and the thus triggered fluorescence. Owing to the high selectivity, this visual process can recognize structurally diverse achiral amines and quantitatively check the impurity content. It also shows an outstanding enantioselectivity towards various chiral amines and can be applied to determine enantiomeric composition. The multiple responses in absorption, circular dichroism, photoluminescence, and circularly polarized luminescence make the helical transition of the polymer backbone a potential detection mode for high-throughput screening of chiral chemicals.
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Aminas , Ésteres , Aminas/química , Dicroísmo Circular , Luminescência , EstereoisomerismoRESUMO
Two-dimensional (2D) chiral materials have been attracting immense attentions owing to their unique properties. Herein, we successfully developed a unique assembly strategy of amphiphilic homopolymers to construct stable free-standing 2D chiral nanosheets in solution. The amphiphilic poly(phenylacetylene) (PPA) homopolymers bearing the hydrophobic and hydrophilic dendritic side chains adopt a DNA-like double-helical conformation. The regular hexagonal nanosheets were formed in THF/EtOH through nucleation and epitaxial growth. The sizes of the nanosheets can be modulated from nanometers to submillimeters upon varying the ratio of binary solvents, while the thickness is linearly correlated with the molecular weights. The 2D architecture can significantly enhance the CPL of polymers with a high dissymmetry factor ≈0.1. Driven by a discrimination of helical conformation, the PPAs can self-sort into homochiral 2D nanosheets, as directly visualized by using fluorescent microscopy.
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Acetileno , Luminescência , Acetileno/química , Polímeros/químicaRESUMO
Polyhedral carbon nano-onions (CNOs) compared with traditional quasi-spherical CNOs are more stable and have less defects, which will greatly broaden their potential applications. However, there still lacks of a suitable synthetic method. Here, we developed a simple molecular fusion route and templet growth method by which polyhedral CNOs can be successfully synthesized. Characterization of the polyhedral CNOs by transmission electron microscopy, x-ray diffraction and Raman spectroscopy indicates that they have an ultra-high degree of graphitization and a large cavity diameter of about 10 nm, which results in their low density of 1.42 g cm-3. In addition, the deeper reaction mechanism of polyhedral CNOs growth was also elucidated. It was found that the channel structure and the absorption of the templet play the crucial role during the formation of polyhedral CNOs.
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The Keggin polyoxometalates (POM) H3PW12O40 (PW) electrostatically complexed with poly(styrene-block-2-vinyl pyridine) (PS-b-P2VP) in DMF, and ordered microphase separation occurred through solvent evaporation. The phase behaviors of PS-b-P2VP/PW in bulk were systematically investigated by using SAXS and TEM to discover the effect of POM content and molecular weight of the block copolymers. Computational simulation was also performed to reveal the same phase transition sequence as the experimental results. As the POM content increases, the PS-b-P2VP/PW complex with a low molecular weight changed from lamellar phase (LAM) to hexagonal cylindrical phase (HEX), and finally transited into spherical phase (SPH). Unexpectedly, PS-b-P2VP/PW complexes with a high molecular weight were inclined to form a kinetic-trapped intermediate phase (inverted HEX). The mechanism of formation of inverted phases was proposed based on simulation that asymmetric swelling in the concentrated DMF solution would result in the ultimate kinetic-trapped nanostructure in the bulk.
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BACKGROUND: Polymerized whey protein-sodium tripolyphosphate can be induced to gel in an acidic environment provided during fermentation. The variety of thickening agent has an influence on texture that is an essential aspect of yogurt quality affecting consumer preference. Similar to polysaccharide stabilizers, the cold gelation properties of whey proteins can improve the body texture of yogurt products. Polymerized whey protein-sodium tripolyphosphate could be a favorable and interesting thickening agent for making set yogurt. RESULTS: The effects of whey protein isolate (WPI), heat-treated whey protein-sodium tripolyphosphate (WPI-STPP), heat-treated WPI and pectin on the storage properties and microstructure of yogurt were investigated. All samples were analyzed for syneresis, pH, titratable acidity, viscosity, texture profile and microstructure during storage. The results showed that incorporating heat-treated WPI-STPP had a significant impact on syneresis (32.22 ± 0.60), viscosity (10 956.67 ± 962.1) and hardness (209.24 ± 12.48) (p < 0.05) with uniform body texture. CONCLUSION: Yogurt fermented with modified WPI-STPP had higher levels of protein and better hardness compared with yogurt using pectin. The microstructure was observed to be a uniform and denser, complicated network. Heat-treated WPI-STPP may be useful for improving yogurt texture. © 2016 Society of Chemical Industry.
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Aditivos Alimentares/química , Polifosfatos/química , Proteínas do Soro do Leite/química , Iogurte/análise , Comportamento do Consumidor , Manipulação de Alimentos , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , ViscosidadeRESUMO
The impact of climates on the radial growth of muti-species remains insufficiently understood in the climate-sensitive southeastern Tibetan Plateau, and this hampers an effective assessment of forest growth under the background of global warming. Here, we studied the growth-climate relationships of three major species (Abies georgei, Larix potaninii, and Picea likiangensis) on the Baima Snow Mountain (BSM) by using dendrochronology methods. We constructed basal area increment (BAI) residual chronologies based on the dated ring-width measurements and correlated the chronologies with four climate factors. We also calculated the contributions of each climate factor to species growth. We found that photothermal conditions played a more important role than moisture in modulating radial growth, and P. likiangensi presented the strongest sensitivity to climate change among the three species. The growing season (June and July) temperature positively affected the radial growth of three species. Winter (previous December and current January) SD negatively impacted the tree growth of A. georgei and P. likiangensis. Significant correlations between growth and precipitation were detected only in A. georgei (January and May). Warming since the beginning of the 1950s promoted the growth of A. georgei and P. likiangensis, while the same effect on L. potaninii growth was found in the recent 50 years.