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1.
J Environ Radioact ; 241: 106771, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34775288

RESUMO

Natural radium isotopes have been widely used to study groundwater discharge in different systems. Therefore, it is of great significance to understand the desorption behavior of radium isotopes on sediments to trace water-land exchange processes. However, there is very limited studies observing the desorption Ra isotopes to lake water of the brine lake. 224Ra desorption experiments with different salinities and particle sizes were carried out by collecting samples of brackish water from Qinghai Lake, brine from Dabuxun Lake and river sediments entering the lakes. The results show that the desorption activity of 224Ra from the river sediments to lake water of Qinghai Lake is 0.2 dpm/g when the salinity is 10.07‰. The maximum desorption activity of 224Ra from river sediments to lake water of Dabuxun Lake is 0.195 dpm/g at a salinity of 40.81‰. A salinity of 41.81‰ and particle size of 16.28 µm are the threshold points affecting the desorption behavior of Ra. When the salinity is less than 40.81‰, the desorption activity of Ra increases linearly with increasing salinity. When the salinity is greater than 40.81‰, the desorption activity of Ra decreases nonlinearly with increasing salinity and tends toward a stable low value. When the particle size is larger than 16.28 µm, the small particle size promotes desorption. The smaller the particle size is, the greater the desorption activity is. When the particle size is less than 16.28 µm, the small particle size inhibits desorption. The smaller the particle size is, the smaller the desorption activity. The co-precipitation of Ra2+ with supersaturated Ca2+, SO42- and other ions may be the main reason for the threshold point of salinity and particle size in Ra desorption process in salt lake system.

2.
Exp Ther Med ; 22(5): 1308, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34630662

RESUMO

Yiqi Huoxue (YQHX) is widely used in traditional Chinese medical practice due to its reported cardioprotective effects. The aim of the present study was to investigate the mechanism underlying these effects of YQHX via the regulation of the Sigma-1 receptor. The Sigma-1 receptor is a chaperone protein located on the mitochondrion-associated endoplasmic reticulum (ER) membrane. It serves an important role in heart function by regulating intracellular Ca2+ homeostasis and enhancing cellular bioenergetics. In the present study, male Sprague Dawley rats with myocardial infarction (MI)-induced heart failure were used. MI rats were administered different treatments, including normal saline, YQHX and fluvoxamine, an agonist of the Sigma-1 receptor. Following four weeks of treatment, YQHX was revealed to improve heart function and attenuate myocardial hypertrophy in MI rats. Additionally, YQHX increased the ATP content and improved the mitochondrial ultrastructure in the heart tissues of MI rats in comparison with acontrol. Treatment was revealed to attenuate the decreased expression of the Sigma-1 receptor and increase the expression of inositol triphosphate type 2 receptors (IP3R2) in MI rats. By exposing H9c2 cells to angiotensin II (Ang II), YQHX prevented cell hypertrophy and normalized the decreased ATP content. However, these positive effects were partially inhibited when the Sigma-1 receptor was knocked down via small interfering RNA transfection. The results of the present study suggested that the Sigma-1 receptor serves an important role in the cardioprotective efficacy of YQHX by increasing ATP content and attenuating cardiomyocyte hypertrophy.

3.
Artigo em Inglês | MEDLINE | ID: mdl-34659440

RESUMO

Acupuncture and moxibustion have definite clinical effects on treating ulcerative colitis (UC), but their mechanism is still unclear. To investigate the molecular mechanisms, we applied herb-partitioned moxibustion or electroacupuncture at the Tianshu (ST25) points on UC rats and used RNA sequencing to identify molecular consequences. Male Sprague Dawley (SD) rats were divided into 6 groups randomly: the normal control (NC) group, the control + herb-partitioned moxibustion (NCHM) group, the control + electroacupuncture (NCEA) group, the model (UC) group, the model + herb-partitioned moxibustion (UCHM) group, and the model + electroacupuncture (UCEA) group. Compared to the UC group, HE staining in the UCHM group and UCEA group indicated that colitis was relieved, the histopathological score and MPO were both significantly reduced, and the serum hs-CRP concentration was decreased significantly. The results of RNA-seq suggested that, compared to the NC group, 206 upregulated genes and 167 downregulated genes were identified in colon tissues from the UC group; compared to the UC group, the expression levels of some genes were both affected in the UCHM group and the UCEA group (684 differentially expressed genes were identified in the UCHM group, and 1182 differentially expressed genes were identified in the UCEA group). KEGG signal pathway analysis indicated that the differentially expressed genes in the UCHM group were associated with the JAK-STAT signaling pathway and cell adhesion molecule (CAM); the differentially expressed genes in the UCEA group were associated with the NF-κB signaling pathway, the toll-like receptor signaling pathways, the PI3K-Akt signaling pathway, the MAPK signaling pathway, and the Wnt signaling pathway. This is the first study to reveal the gene expression characteristics of the anti-inflammatory effect of UC rats from the perspective of acupuncture and moxibustion control, which provide a clue for further investigation into the molecular mechanisms of UC treatment by acupuncture and moxibustion.

4.
ACS Appl Mater Interfaces ; 13(41): 49146-49152, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34617726

RESUMO

The controllable manipulation of graphene to create three-dimensional (3D) structures is an intriguing approach for favorably tuning its properties and creating new types of 3D devices. However, due to extremely low bending stiffnesses, it is rather challenging to construct monolayer graphene into stable 3D structures. Here, we demonstrate the stable formation of monolayer graphene microtubes with accompanying pre-patterned strain layers. The diameter of graphene microtubes can be effectively tuned by changing the thickness of the strain layers. Benefiting from a high surface-to-volume ratio of the tubular geometry, the 3D geometry leads to a prominent Raman enhancement, which was further applied to molecular sensing. The R6G molecules on graphene microtubes can be detected even for a concentration as low as 10-11 M. We believe that this method can be a generalized way to realize the 3D tubular structure of other 2D materials.

5.
IEEE Trans Image Process ; 30: 8410-8425, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34596539

RESUMO

This paper strives to predict fine-grained fashion similarity. In this similarity paradigm, one should pay more attention to the similarity in terms of a specific design/attribute between fashion items. For example, whether the collar designs of the two clothes are similar. It has potential value in many fashion related applications, such as fashion copyright protection. To this end, we propose an Attribute-Specific Embedding Network (ASEN) to jointly learn multiple attribute-specific embeddings, thus measure the fine-grained similarity in the corresponding space. The proposed ASEN is comprised of a global branch and a local branch. The global branch takes the whole image as input to extract features from a global perspective, while the local branch takes as input the zoomed-in region-of-interest (RoI) w.r.t. the specified attribute thus able to extract more fine-grained features. As the global branch and the local branch extract the features from different perspectives, they are complementary to each other. Additionally, in each branch, two attention modules, i.e., Attribute-aware Spatial Attention and Attribute-aware Channel Attention, are integrated to make ASEN be able to locate the related regions and capture the essential patterns under the guidance of the specified attribute, thus make the learned attribute-specific embeddings better reflect the fine-grained similarity. Extensive experiments on three fashion-related datasets, i.e., FashionAI, DARN, and DeepFashion, show the effectiveness of ASEN for fine-grained fashion similarity prediction and its potential for fashion reranking. Code and data are available at https://github.com/maryeon/asenpp.

6.
Chem Commun (Camb) ; 57(75): 9626, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34558576

RESUMO

Correction for 'Dynamic visualization of mRNA splicing variants with a transactivating reporter' by Si Chen et al., Chem. Commun., 2021, DOI: 10.1039/d1cc02439f.

7.
J Biol Eng ; 15(1): 23, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479610

RESUMO

BACKGROUND: The physiologic regenerative capacity of cartilage is severely limited. Current studies on the repair of osteochondral defects (OCDs) have mainly focused on the regeneration of cartilage tissues. The antler cartilage is a unique regenerative cartilage that has the potential for cartilage repair. METHODS: Antler decellularized cartilage-derived matrix scaffolds (adCDMs) were prepared by combining freezing-thawing and enzymatic degradation. Their DNA, glycosaminoglycans (GAGs), and collagen content were then detected. Biosafety and biocompatibility were evaluated by pyrogen detection, hemolysis analysis, cytotoxicity evaluation, and subcutaneous implantation experiments. adCDMs were implanted into rabbit articular cartilage defects for 2 months to evaluate their therapeutic effects. RESULTS: AdCDMs were observed to be rich in collagen and GAGs and devoid of cells. AdCDMs were also determined to have good biosafety and biocompatibility. Both four- and eight-week treatments of OCDs showed a flat and smooth surface of the healing cartilage at the adCDMs filled site. The international cartilage repair society scores (ICRS) of adCDMs were significantly higher than those of controls (porcine dCDMs and normal saline) (p < 0.05). The repaired tissue in the adCDM group was fibrotic with high collagen, specifically, type II collagen. CONCLUSIONS: We concluded that adCDMs could achieve excellent cartilage regeneration repair in a rabbit knee OCDs model. Our study stresses the importance and benefits of adCDMs in bone formation and overall anatomical reconstitution, and it provides a novel source for developing cartilage-regenerating repair materials.

8.
Chem Commun (Camb) ; 57(75): 9594-9597, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34546238

RESUMO

Dynamic changes in intron sequences, with their loss and gain, are poorly detected due to the limited methods for the non-invasive monitoring of the pre-mRNA splicing process. Here, we describe the design of a two-step transcriptional activation (TSTA) reporter for the real-time imaging of the splicing process in living subjects. By taking advantage of the strong transactivating properties of the GAL4-VP16 fusion protein, which can target upstream activation sequence (UAS) elements to boost subsequent firefly luciferase reporter gene expression, we successfully and consistently detected the dynamic pre-mRNA splicing activity in response to exogenous splicing modulators in living cells and animals. Our findings provide a valuable tool for the high-throughput screening of splicing modulators, which could speed up the development of new drugs for the treatment of disordered splicing diseases.


Assuntos
RNA Mensageiro/genética , Transativadores/genética , Humanos , Splicing de RNA/genética , RNA Mensageiro/metabolismo , Transativadores/metabolismo
9.
J Nanobiotechnology ; 19(1): 255, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34425832

RESUMO

Although nanomedicine have greatly developed and human life span has been extended, we have witnessed the soared incidence of central nervous system (CNS) diseases including neurodegenerative diseases (Alzheimer's disease, Parkinson's disease), ischemic stroke, and brain tumors, which have severely damaged the quality of life and greatly increased the economic and social burdens. Moreover, partial small molecule drugs and almost all large molecule drugs (such as recombinant protein, therapeutic antibody, and nucleic acid) cannot cross the blood-brain barrier. Therefore, it is especially important to develop a drug delivery system that can effectively deliver therapeutic drugs to the central nervous system for the treatment of central nervous system diseases. Cell penetrating peptides (CPPs) provide a potential strategy for the transport of macromolecules through the blood-brain barrier. This study analyzed and summarized the progress of CPPs in CNS diseases from three aspects: CPPs, the conjugates of CPPs and drug, and CPPs modified nanoparticles to provide scientific basis for the application of CPPs for CNS diseases.

10.
Artigo em Inglês | MEDLINE | ID: mdl-34460404

RESUMO

Multiagent reinforcement learning methods, such as VDN, QMIX, and QTRAN, that adopt centralized training with decentralized execution (CTDE) framework have shown promising results in cooperation and competition. However, in some multiagent scenarios, the number of agents and the size of the action set actually vary over time. We call these unshaped scenarios, and the methods mentioned above fail in performing satisfyingly. In this article, we propose a new method, called Unshaped Networks for Multiagent Systems (UNMAS), which adapts to the number and size changes in multiagent systems. We propose the self-weighting mixing network to factorize the joint action-value. Its adaption to the change in agent number is attributed to the nonlinear mapping from each-agent Q value to the joint action-value with individual weights. Besides, in order to address the change in an action set, each agent constructs an individual action-value network that is composed of two streams to evaluate the constant environment-oriented subset and the varying unit-oriented subset. We evaluate UNMAS on various StarCraft II micromanagement scenarios and compare the results with several state-of-the-art MARL algorithms. The superiority of UNMAS is demonstrated by its highest winning rates especially on the most difficult scenario 3s5z_vs_3s6z. The agents learn to perform effectively cooperative behaviors, while other MARL algorithms fail. Animated demonstrations and source code are provided in https://sites.google.com/view/unmas.

11.
J Biol Chem ; 297(2): 100933, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34216622

RESUMO

Precursor messenger RNA (pre-mRNA) splicing is critical for cell growth and development, and errors in RNA splicing frequently cause cellular dysfunction, abnormal gene expression, and a variety of human diseases. However, there is currently a lack of reliable systems to noninvasively monitor the mRNA splicing efficiency in cells and animals. Here, we described the design of a genetically engineered ratiometric dual luciferase reporter to continuously quantify the changes in mRNA splice variants in vivo. This reporter system is encoded within a single polypeptide but on separate exons, thus generating two distinct luciferase signals derived from spliced and unspliced mRNAs. With this reporter, the two kinds of luciferase in the same individual can minimize the influence of indirect factors on splicing, and the ratio of these two luciferase intensities represents the dynamic splicing efficiency of pre-mRNA. Our study offers a convenient and robust tool for the screening and identification of small molecules or trans-acting factors that affect the efficiency of specific splicing reactions.


Assuntos
Luciferases , Precursores de RNA , Splicing de RNA , Processamento Alternativo , Éxons
12.
Med Ultrason ; 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34216452

RESUMO

AIMS: According to a novel in-utero classification termed "umbilical-portal-systemic venous shunt (UPSVS)" recently proposed for an abnormal umbilical, portal and ductal venous system, the portal-systemic shunt belongs to type III UPSVS. This study was designed to examine the ultrasonographic characteristics and outcome of type III UPSVS.Material and methods: All cases of Type III UPSVS diagnosed at our department from April 2016 to December 2020 were retrospectively studied. RESULTS: Seventeen patients with type III UPSVS including 12 type IIIa and 5 IIIb cases were identified. Sonography showed a shunt between the inferior left portal vein and the left hepatic vein in all type IIIa cases. Three cases of type IIIb had a combination of another shunt (2 with type I and one with type IIIa). Integrate intrahepatic portal vein system was not seen in those 2 cases of type IIIb combined with type I UPSVS, leading to termination of pregnancy (TOP). TOP occurred in 4 patients with type IIIa as requested by the parents. Two cases (type IIIa and type IIIb each) underwent surgical procedure for the closure of the shunt. Spontaneous complete closure in 4 type IIIa cases and partial closure in one type IIIb case occurred during a period of 3-16 months. CONCLUSIONS: The majority of patients had type IIIa UPSVS presenting a good outcome. The lack of integrate intrahepatic portal vein system was the main reason for TOP in patients with type IIIb UPSVS. These data suggest the UPSVS classification is a useful tool for a prognosis prediction of type III UPSVS.

13.
ACS Appl Mater Interfaces ; 13(27): 32136-32148, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34225448

RESUMO

Rapid development of electronic technology shortens the development time for new products and accelerates the obsolescence of consumer electronics, resulting in the explosive growth of electronic waste that is difficult to recycle and hazardous to the environment and human health. Transient electronics that can dissolve in water may potentially be adopted to tackle the issues of electronic waste; however, promising approaches to yield large-scale and high-performance transient consumer electronics have not yet been developed. Here, the joint effect of galvanic corrosion and redeposition has been utilized to develop bimetallic transient nanocomposites, which can be printed and water-sintered to yield high-performance transient PCB circuits with excellent electrical conductivity and mechanical robustness. The entire sintering process requires no external energy and strict environmental conditions. The achieved PCB circuits offer a conductivity of 307,664.4 S/m that is among the highest in comparison with other printed transient circuits. The supreme performance of the transient circuits eventually leads to the first dissolvable smartwatch that offers the same functions and similar performance as conventional smartwatches and dissolves in water within 40 h. The joint effect of galvanic corrosion and redeposition between two metals with distinct activities leads to novel nanocomposites and processing techniques of transient electronics. The resulting high-performance transient devices may reshape the appearance of consumer electronics and reform the electronics recycling industry by reducing recycling costs and minimizing environmental pollution and health hazard.

14.
Sci Total Environ ; 793: 148623, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328960

RESUMO

There are many sources of volatile organic compounds (VOCs) in indoor environments, leading to much higher total indoor VOC concentrations than outdoor counterparts. Given the potential health hazards associated with VOC exposure, it is necessary to estimate the indoor VOC emission strengths. In this study, the indoor and outdoor concentrations of 43 VOCs were concurrently measured in 8 urban residences, Beijing. The indoor/outdoor concentration ratio was used to screen out 36 species having significant indoor sources. A one-compartment steady-state model was developed to estimate the indoor emission strengths of these VOCs, in which ventilation and reaction with ozone were included as sink routes. The order of VOCs in terms of indoor emission strength was d-limonene (a median value of 1.05 g/h), α-pinene (82.50 mg/h), styrene (24.12 mg/h), ß-pinene (9.70 mg/h), formaldehyde (1.97 mg/h), n-dodecane (1.82 mg/h), n-pentadecane (1.66 mg/h), n-hexadecane (1.62 mg/h), n-undecane (1.20 mg/h), acetaldehyde (1.05 mg/h) and 1, 4-dichlorobenzene (0.80 mg/h). The sum of estimates of those VOCs accounted for >95% of total emission strength. Specific indoor sources of those VOCs in the tested homes were identified. Air exchange rate, indoor temperature and air humidity were found to pose significant impacts to the indoor emission strengths of VOCs.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Pequim , Monitoramento Ambiental , Formaldeído/análise , Compostos Orgânicos Voláteis/análise
15.
Am J Chin Med ; 49(5): 1093-1114, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34107859

RESUMO

Idiopathic pulmonary fibrosis (IPF), a tumor-like disease, is a serious and fatal pulmonary inflammatory condition usually characterized by irreversible destruction of the lung parenchyma, excessive matrix accumulation, and decline in lung function. IPF still remains a great burden to the universe. At the moment, the available therapeutic regimens utilized for IPF such as non-pharmacological therapies (lung transplantation) and pharmacological therapies (drugs, nintedanib, pirfenidone, etc.) are normally accompanied by significant limitations, such as adverse reactions, low bioavailability, poor selectivity, low-tissue distribution, in vivo instability, systemic toxicity, inconveniency and unsafe usage. There is a need for the exploration and discovery of new novel remedies by researchers and scientists globally. Recent numerous preliminary studies have laid significant emphasis and demonstrated the antifibrotic importance, good curative actions (little or no adverse reactions), and multiple target sites of the active components from traditional herbal medicine (THM) against IPF, which could serve as a modern, alternative and potential therapeutics or drug candidates in treating IPF. This paper extensively summarizes the pharmacological actions and signaling pathways or mechanisms of active components obtained from THM for treating IPF. Moreover, the sources and modernization, markets, relevant FDA and CFDA studies (the USA and China), preclinical analysis, and various compositions of THM currently under clinical trials are also highlighted. Additionally, this present analytical data would be instrumental towards further drug progression or advancement of active components from THM for the potential therapeutics of IPF in the future.


Assuntos
Medicina Herbária/métodos , Fibrose Pulmonar Idiopática/tratamento farmacológico , Medicina Tradicional/métodos , Fitoterapia/métodos , Humanos , Plantas Medicinais
16.
PeerJ ; 9: e11599, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178467

RESUMO

Background: Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs with unique characteristics. These RNA can regulate cancer cells' survival, proliferation, invasion, metastasis, and angiogenesis and are potential diagnostic and prognostic markers. We identified a seven-lncRNA signature related to the overall survival (OS) of patients with Ewing's sarcoma (EWS). Methods: We used an expression profile from the Gene Expression Omnibus (GEO) database as a training cohort to screen out the OS-associated lncRNAs in EWS and further established a seven-lncRNA signature using univariate Cox regression, the least absolute shrinkage, and selection operator (LASSO) regression analysis. The prognostic lncRNA signature was validated in an external dataset from the International Cancer Genome Consortium (ICGC) as a validation cohort. Results: We obtained 10 survival-related lncRNAs from the Kaplan-Meier and ROC curve analysis (log-rank test P < 0.05; AUC >0.6). Univariate Cox regression and LASSO regression analyses confirmed seven key lncRNAs and we established a lncRNA signature to predict an EWS prognosis. EWS patients in the training cohort were categorized into a low-risk group or a high-risk group based on their median risk score. The high-risk group's survival time was significantly shorter than the low-risk group's. This seven-lncRNA signature was further confirmed by the validation cohort. The area under the curve (AUC) for this lncRNA signature was up to 0.905 in the training group and 0.697 in the 3-year validation group. The nomogram's calibration curves demonstrated that EWS probability in the two cohorts was consistent between the nomogram prediction and actual observation. Conclusion: We screened a seven-lncRNA signature to predict the EWS patients' prognosis. Our findings provide a new reference for the current prognostic evaluation of EWS and new direction for the diagnosis and treatment of EWS.

17.
BMC Cancer ; 21(1): 600, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34034688

RESUMO

BACKGROUND: Malignant tumor is one of the most serious diseases endangering human health. Circular RNAs play an important role in the tumorigenesis and progression of various malignant tumors. Although various studies have investigated the biological function of circular RNA circSMARCA5 in malignant tumors, the prognostic value of circSMARCA5 in malignant tumor patients has not been systematically analyzed. METHODS: Relevant studies were obtained from the PubMed and Web of Science database. The quality of the enrolled studies was evaluated using the Newcastle-Ottawa Scale quality assessment system. Survival features and clinicopathological features were assessed using pooled hazard ratios and odds ratios with 95% confidence intervals, respectively. RESULTS: Overall, 7 relevant publications were enrolled in the meta-analysis. CircSMARCA5 expression was significantly correlated with better OS (HR = 0.51, 95%CI 0.41-0.65) or DFS/RFS/PFS (HR = 0.56, 95%CI 0.43-0.73) in malignant tumors. In the pooled analyses of clinicopathological characteristics, malignant tumors with higher circSMARCA5 were better differentiated (OR = 0.41, 95%CI 0.19-0.88). CircSMARCA5 expression was correlated with less advanced TNM stage (OR = 0.33, 95%CI 0.19-0.55). Moreover, malignant tumors with higher circSMARCA5 expression have less advanced lymph node metastasis (OR = 0.26, 95%CI 0.08-0.79). CONCLUSION: These results indicated that circSMARCA5 was a promising biomarker in malignant tumors, which may potentially facilitate clinical decisions in the future.


Assuntos
Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/mortalidade , RNA Circular/metabolismo , Biomarcadores Tumorais/análise , Carcinogênese/genética , Diferenciação Celular/genética , Humanos , Metástase Linfática/genética , Neoplasias/genética , Neoplasias/patologia , Neoplasias/terapia , Prognóstico , RNA Circular/análise
18.
Vet Microbiol ; 258: 109102, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33991786

RESUMO

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that causes serious economic losses in the pig industry. Phosphorylation is an important mechanism of protein modification. Recent studies have reported that the serine/threonine kinase (STK) gene contributes to the growth and virulence of SS2. However, the mechanism underlying the regulatory functions of STK in SS2 has not been thoroughly elucidated to date. In this study, phosphoproteomic analysis was performed to determine substrates of the STK protein. Twenty-two proteins with different cell functions were identified as potential substrates of STK. Phosphoglucosamine mutase (GlmM) was selected for further investigation among them. In vitro phosphorylation assay and immunoprecipitation assay indicated that GlmM was phosphorylated by STK at the Ser-101 site and the phosphorylation level of GlmM can be affected. We observed that compared to the wild-type strain ZY05719, the glmM-deficient strain (ΔglmM) and the glmM S101A point mutation strain (CΔglmM S101A) showed aberrant cell morphology and attenuated virulence, including enlarged cell volume, absent capsule, decreased resistance, lower survival caused by unusual peptidoglycan synthesis, and significantly attenuated pathogenicity in a mouse infection model. Additionally, compared to ZY05719 and CΔglmM, GlmM enzyme acivities and peptidoglycan concentrations of the stk-deficient strain (Δstk), CΔglmM S101A decreased significantly. These experiments revealed that STK phosphorylates GlmM at the Ser-101 site to impact GlmM enzyme activity and control cell wall peptidoglycan synthesis to affect SS2 pathogenicity.


Assuntos
Parede Celular/metabolismo , Fosfoglucomutase/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Streptococcus suis/metabolismo , Animais , Biologia Computacional , Feminino , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Fosfoglucomutase/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Distribuição Aleatória , Infecções Estreptocócicas/microbiologia , Streptococcus suis/classificação , Streptococcus suis/patogenicidade , Virulência
19.
Materials (Basel) ; 14(6)2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33804760

RESUMO

The interface bonding behavior between the steel tube and the concrete of concrete-filled steel tube (CFST) blended with circulating fluidized bed bottom ash (CFB-BA) was investigated in this study. A total of 8 groups of CFSTs stub columns were prepared with different dosage of CFB-BA, water-binder ratio (W/B), and interface bonding length. A series of push-out tests were carried out to acquire the data representing the interface bonding behavior. The results show that the dosage of CFB-BA has a direct effect on interface bonding behavior of CFST. CFB-BA can improve the interface bonding behavior of CFST. The highest ultimate bonding load and strength are achieved when the dosage of CFB-BA is 30%. When the dosage of CFB-BA increases to 50%, its interface bonding behavior decreases, but is still better than that of CFST without CFB-BA. W/B has a negative correlation with the interface bonding behavior of CFST. While the W/B increases, the interface bonding load and strength of CFST decreases. The increase of the interface bonding length can improve the interface bonding load, but cannot improve the interface bonding strength.

20.
Polymers (Basel) ; 13(8)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923827

RESUMO

The crystallization and II-I phase transition of functionalized polybutene-1 with hydroxyl groups were investigated by differential scanning calorimetry. The results show that the incorporated hydroxyl groups increase the nucleation density but decrease the growth rate in melt crystallization. Interestingly, for the generated tetragonal form II, the presence of polar hydroxyl groups can effectively accelerate the phase transition into the thermodynamically stable modification of trigonal form I, especially with stepwise annealing and high incorporation. Using stepwise annealing, II-I phase transition was enhanced by an additional nucleation step performed at a relatively low temperature, and the optimal nucleation temperature to obtain the maximum transition degree was ‒10 °C, which is independent from the content of hydroxyl groups. Furthermore, the accelerating effect of hydroxyl groups on the II-I transition kinetics can be increased by reducing the crystallization temperature when preparing form II crystallites. These results provide a potential molecular design approach for developing polybutene-1 materials.

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