Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Biol Chem ; : 107466, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38876302

RESUMO

Glycosaminoglycan (GAG) lyases are often strictly substrate specific, and it is especially difficult to simultaneously degrade GAGs with different types of glycosidic bonds. Herein, we found a new class of GAG lyases (GAGases) from different bacteria. These GAGases belong to polysaccharide lyase 35 family and share quite low homology with the identified GAG lyases. The most surprising thing is that GAGases can not only degrade three types of GAGs: HA, CS and HS, but even one of them can also degrade alginate. Further investigation of structural preferences revealed that GAGases selectively act on GAG domains composed of non/6-O-/N-sulfated hexosamines and d-glucoronic acids, as well as on alginate domains composed of d-mannuronic acids. Additionally, GAG lyases were once speculated to have evolved from alginate lyases, but no transitional enzymes have been found. The discovery of GAGases not only broadens the category of GAG lyases, provides new enzymatic tools for the structural and functional studies of GAGs with specific structures, but also provides candidates for the evolution of GAG lyases.

2.
Mol Biol Rep ; 51(1): 197, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38270746

RESUMO

Cancer metastasis is the leading cause of cancer-related death. Metastasis occurs at all stages of tumor development, with unexplored changes occurring at the primary site and distant colonization sites. The growing understanding of the metastatic process of tumor cells has contributed to the emergence of better treatment options and strategies. This review summarizes a range of features related to tumor cell metastasis and nanobased drug delivery systems for inhibiting tumor metastasis. The mechanisms of tumor metastasis in the ideal order of metastatic progression were summarized. We focus on the prominent role of nanocarriers in the treatment of tumor metastasis, summarizing the latest applications of nanocarriers in combination with drugs to target important components and processes of tumor metastasis and providing ideas for more effective nanodrug delivery systems.


Assuntos
Sistemas de Liberação de Medicamentos , Neoplasias , Humanos , Neoplasias/tratamento farmacológico
3.
J Biol Chem ; 298(12): 102609, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36265583

RESUMO

The high heterogeneity and mutation rate of cancer cells often lead to the failure of targeted therapy, and therefore, new targets for multitarget therapy of tumors are urgently needed. Aberrantly expressed glycosaminoglycans (GAGs) have been shown to be involved in tumorigenesis and are promising new targets. Recently, the GAG-binding domain rVAR2 of the Plasmodium falciparum VAR2CSA protein was identified as a probe targeting cancer-associated chondroitin sulfate A-like epitopes. In this study, we found that rVAR2 could also bind to heparin (Hep) and chondroitin sulfate E. Therefore, we used rVAR2 as a model to establish a method based on random mutagenesis of the GAG-binding protein and phage display to identify and optimize probes targeting tumor GAGs. We identified a new probe, VAR2HP, which selectively recognized Hep by interacting with unique epitopes consisting of a decasaccharide structure that contains at least three HexA2S(1-4)GlcNS6S disaccharides. Moreover, we found that these Hep-like epitopes were overexpressed in various cancer cells. Most importantly, our in vivo experiments showed that VAR2HP had good biocompatibility and preferentially localizes to tumors, which indicates that VAR2HP has great application potential in tumor diagnosis and targeted therapy. In conclusion, this study provides a strategy for the discovery of novel tumor-associated GAG epitopes and their specific probes.


Assuntos
Heparina , Neoplasias , Humanos , Heparina/metabolismo , Epitopos/química , Glicosaminoglicanos/metabolismo , Sulfatos de Condroitina/genética , Sulfatos de Condroitina/metabolismo , Neoplasias/genética
4.
Environ Res ; 237(Pt 1): 116987, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37633636

RESUMO

Efficiently addressing initial rainwater pollution is crucial for mitigating urban water pollution. However, the performance evaluation of initial rainwater pollution control project is rarely introduced. In this study, the architecture of effective comprehensive engineering measures for improving the water quality of initial rainwater in Anhui Province, China, was described. Three water quality indicators, ammonia nitrogen (NH3-N), chemical oxygen demand (COD), and total phosphorus (TP), were selected to explore the severity of urban pollution caused by initial rainwater under various rainfall scenarios. A single-factor evaluation method was used to contrast and assess the benefits of the initial rainfall interception project in terms of water quality enhancement. Results showed that initial rainfall pollution was gentler under light rainfall conditions but more prominent under moderate and heavy conditions. The percentages of NH3-N, COD, and TP in Lotus Pond that met the tertiary drinking water standard were 100%, 74.91%, and 100% with great improvement, and the average concentrations of NH3-N, COD, and TP in Fushan Road Drainage have decreased by 91.43%, 10.49%, and 57.33% respectively, after the construction of the interception project. These indicated that the nitrogen and phosphorus pollution were successfully controlled by the control techniques in both locations, but COD concentration has to be addressed with more specialized strategies. Overall, the water quality improvement project for initial rainwater pollution plays a great role in effectively governing initial rainwater pollution and improving river water quality, and provides an effective technical reference for urban water ecological environment management.

5.
Altern Ther Health Med ; 29(1): 52-57, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35951073

RESUMO

Context: In-stent restenosis (ISR) is a common clinical complication after carotid artery stenting (CAS) and a major risk for a stent's fatigue life. Duplex ultrasound (DUS) is widely used for the preliminary evaluation and follow-up of extracranial carotid artery disease, but DUS stenosis grading is mainly based on the original or nonsurgical carotid artery. That grading may not be applicable to carotid artery stenosis after CAS. Objective: The study intended to investigate the predictive value of quantitative analysis of results from the DUS examination in the evaluation of ISR following CAS. Design: The research team designed a control analysis of result samples. Setting: The study took place in the Ultrasound Department at the Affiliated Yantai Yuhuangding Hospital of Qingdao University in Yantai, Shandong, China. Participants: Participants were 103 patients who underwent carotid artery stenting (CAS) between March 2017 and April 2018 at the hospital. Outcome Measures: The study used Doppler DUS and digital subtraction angiography (DSA) of the carotid artery at 12 months postoperatively to analyze the consistency of DUS and DSA in the evaluation of ISR. Taking the results of the DSA examination as the standard, the research team analyzed the differences between those results and the indicators from the DUS examination for participants with different severities of stenosis. The research team plotted the receiver operating characteristic curve (ROC) and evaluated the diagnostic efficiency of DUS indicators in the determination of restenosis, including diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value. Results: The DSA examination showed that stenosis severity was 0%-30% for 51 participants, 31%-50% for 27 participants, 51%-80% for 16 participants, and >80% for 9 participants. The DUS showed that stenosis severity was 0%-30% for 35 participants, 31%-50% for 38 participants, 51%-80% for 22 participants, and >80% for 8 participants. The consistency was found to be Kappa (ĸ) = 0.74. Taking the DSA as the standard, the peak systolic velocity (PSV), end diastolic velocity (EDV), peak systolic velocity of the internal carotid artery/peak systolic velocity of the common carotid artery (PSVICA/PSVCCA) significantly increased in participants with a stenosis severity of 51-80% and >80%, compared with those with a stenosis severity of <50%, and the difference was statistically significant (P < .05). The ROC curve showed that the area under curve (AUC) of the PSV predicting restenosis at a >50% severity was significantly higher than those of the EDV and PSVICA/PSVCCA (P < .05). Where the optimal cut-off-off point for the PSV was 195 cm/s, the ROC curve showed that the AUC of the PSV predicting restenosis at an >80% severity was significantly higher than that of the EDV and PSVICA/PSVCCA (P < .05). Where the optimal cut-off point for the PSV was 280 cm/s, the PSV had significantly higher diagnostic accuracy, sensitivity, and positive predictive value than the EDV and PSVICA/PSVCCA in evaluating the restenosis at a severity of >50% and >80%. Conclusions: Doppler DUS can effectively evaluate restenosis after carotid artery stenting (CAS), where a PSV ≥195 cm/s and 280 cm/s can be used as the reference indicators for >50% and >80% restenosis.


Assuntos
Estenose das Carótidas , Humanos , Constrição Patológica , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Sensibilidade e Especificidade , Stents , Artéria Carótida Primitiva , Artérias Carótidas , Velocidade do Fluxo Sanguíneo , Estudos Retrospectivos
6.
Opt Express ; 29(5): 6434-6444, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33726164

RESUMO

Absorbers have high potential application values in the military field, such as electronic screening, radar cross-section reduction and invisible cloaking. However, most methods have the defects of narrow bandwidth, low absorptivity, complex three-dimensional structure and fixed polarizations. In this paper, we realize an ultra-broadband and full-polarization planar metamaterial absorber (PMA) with a three-layer composite structure, which exhibits multi-resonant and impedance matching properties by combining the ultra-light foams and indium tin oxide (ITO) films. The bottom two layers achieve a high-efficiency absorption rate at the low and medium spectrum, while the upper layer realizes a absorption property at a high frequency. Also, an equivalent circuit model is extracted to explain its operating mechanism. The experimental results show that our meta-absorber can achieve great absorber performance of better than 90% within 1-18 GHz for full-polarization incident waves, which is in great agreement with the numerical simulations. Moreover, our device is insensitive to oblique incidences and polarizations and possesses the physical characteristics of an ultralight, weighing 0.6 kg for a square meter, which is only 1/85.0-1/126.7 of the conventional absorbers under the same size. All these excellent performances determine that our research can be a good candidate for military stealth materials.

7.
Med Sci Monit ; 25: 1718-1728, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30838977

RESUMO

BACKGROUND In this study, we assessed the role of CD200 and CD200 receptor (CD200R) in regulating CD4+T cell subsets and assessed the therapeutic efficacy of thermal ablation for liver hepatocellular carcinoma (HCC) in rats. MATERIAL AND METHODS Seventy-eight male C57BL/6 rats were randomly divided into 7 groups: a control group, a model group, a CD200FC group, an anti-CD200R1 mAb group, a thermal ablation group, a thermal ablation+CD200 FC group, and a thermal ablation+anti-CD200R1 mAb group. The levels of CD200, CD200R1, Th1, Th17, and Treg in peripheral blood were detected by flow cytometry. Immunohistochemistry was used to detect CD200, CD200R1, IFN-γ, IL-17, Foxp3 protein expression in tumor tissues. RESULTS The levels of CD200, CD200R1, Th17, and Treg were significantly increased after CD200FC treatment (p<0.05). After treatment with anti-CD200R1 mAb, the levels of CD200, CD200R1, Th17, and Treg decreased and Th1 increased. Compared with the control group, the expression of CD200, CD200R1, IL-17, and Foxp3 in the model group increased significantly, and the expression of IFN-γ decreased significantly (p<0.05). The expression of CD200, CD200R1, IL-17, and Foxp3 was significantly reduced by adding anti-CD200R1 mAb, and the expression of IFN-γ was increased (p<0.05). After the thermal ablation treatment, the proteins continued to decrease and the expression of IFN-γ continued to increase. CONCLUSIONS The CD200/CD200R pathway participates in HCC tumor growth and the expression of CD4+T cell subsets in cancer tissues. Furthermore, thermal ablation treatment inhibited cancer recurrence.


Assuntos
Técnicas de Ablação/métodos , Carcinoma Hepatocelular/metabolismo , Animais , Antígenos CD/genética , Antígenos CD/fisiologia , Antígenos de Superfície/metabolismo , Linfócitos T CD4-Positivos/fisiologia , Carcinoma Hepatocelular/fisiopatologia , China , Citometria de Fluxo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/fisiopatologia , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Recidiva Local de Neoplasia , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/fisiologia , Subpopulações de Linfócitos T , Linfócitos T Reguladores/metabolismo , Células Th17/metabolismo
8.
Langmuir ; 34(44): 13192-13202, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30338684

RESUMO

Aiming to realize the wastewater treatment of various pollutants simultaneously, a dual-functional poly(ether amine)-polydopamine (PEA-PDA)-modified filter material was fabricated in this work for in situ separation of stable oil-in-water emulsion and adsorption of anionic azo dyes. PEA and PDA could be copolymerized via the Michael addition reaction on a polyurethane sponge substrate firmly. The as-prepared filter shows superhydrophilic and underwater superoleophobic wettability. After being squeezed in a glass tube, the material could separate different kinds of stabilized oil-in-water emulsions with high flux and efficiency. Besides, the PEA-PDA copolymer endows the material with the ability to adsorb large amounts of anionic azo dyes during the separation of emulsions with good adsorption capacity. Moreover, adsorbed dyes in the filter material could be easily desorbed in base aqueous solution and the whole process is conducted under gravity without external aid. This dual-functional material shows great potential for the application in industrial field because of its ability for the complex wastewater treatment.

9.
Soft Matter ; 14(14): 2649-2654, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29557475

RESUMO

The facile fabrication of a hydrogel-networks coated membrane for efficient oil-in-water emulsion separation was successfully achieved through the photo-initiated free radical polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). Due to the combination of the special wettability of the PAMPS hydrogel with the microscale multi-porous structure of the substrate, such a membrane is able to achieve the separation of sundry surfactants stabilized oil-in-water emulsions with high separation efficiency, large permeation flux and excellent stability. In particular, the PAMPS hydrogel coated membrane exhibits selective separation for cationic and nonionic types of surfactants stabilized emulsions via hydrogen bond interactions. The fabrication protocol is facile, cost-efficient and environmentally friendly, which can be scaled up to facilitate its practicability in sewage remediation.

10.
Angew Chem Int Ed Engl ; 57(20): 5740-5745, 2018 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-29578276

RESUMO

A thermoresponsive Poly(N-isopropylacrylamide) (PNIPAAm)-modified nylon membrane was fabricated via hydrothermal route. Combining rough structure, proper pore size, and thermoresponsive wettability, the membrane can separate at least 16 types of stabilized oil-in-water and water-in-oil emulsions at different temperatures. Below the LCST (ca. 25 °C), the material exhibits hydrophilicity and underwater superoleophobicity, which can be used for the separation of various kinds of oil-in-water emulsions. Above the LCST (ca. 45 °C), the membrane shows the opposite property with high hydrophobicity and superoleophilicity, and it can then separate stabilized water-in-oil emulsions. The material exhibits excellent recyclability and high separation efficiency for various kinds of emulsions and the hydrothermal method is facile and low-cost. The membrane shows good potential in real situations such as on-demand oil-spill cleanup, industrial wastewater treatment, remote operation of oil/water emulsion separation units, and fuel purification.

11.
Langmuir ; 33(30): 7380-7388, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28485972

RESUMO

The decontamination of various pollutants including oils, organic dyes, and surfactants from water is an unprecedented issue throughout the world. A facile filtration process for in situ multifunctional water purification by employing a low-cost and easy-made catechol-polyethylenimine (PEI) nanocomposite deposited membrane has been designed. In combination with the intrinsic hydrophilicity of amino-rich groups, the resultant membrane possesses superhydrophilicity and underwater superoleophobicity, which is simultaneously advantageous for capturing anionic pollutants due to the electrostatic interaction. Such membrane can be successfully used for sundry surfactant-stabilized oil-in-water emulsions separation and pH-controllable removal of water-soluble dyes and the remaining surfactants at the same time. The excellent characteristics, i.e., fabrication protocol that is easy to scale up, better alkaline resistance, selectively controllable removal ability of anionic dyes, and surfactants with unaltered adsorption performance over 30 consecutive adsorption-desorption-washing cycles, will facilitate its versatility and practicability in environmental remediation and wastewater purification.

12.
J Environ Sci (China) ; 52: 314-324, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28254053

RESUMO

T3-induced Xenopus metamorphosis is an ideal model for detecting thyroid hormone (TH) signaling disruption of chemicals. To optimize the T3-induced Xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for T3 induction. Xenopus laevis at stage 52 were exposed to series of concentrations of T3 (0.31-2.5nmol/L) for 6days. By comparing morphological changes induced by T3, we propose head area, mouth width, unilateral brain width/brain length, and hindlimb length/snout-vent length as quantitative parameters for characterizing T3-induced morphological changes, with body weight as a parameter for indicating integrated changes. By analyzing time-response curves, we found that following 4-day exposure, T3-induced grossly morphological changes displayed linear concentration-response curves, with moderate morphological changes resulting from 1.25nmol/L T3 exposure. When using grossly morphological endpoints to detect TH signaling disruption, we propose 4days as exposure duration of T3, with concentrations close to 1.25nmol/L as induction concentrations. However, it is appropriate to examine morphological and molecular changes of the intestine on day 2 due to their early response to T3. The quantitative endpoints and T3 induction concentrations and durations we determined would improve the sensitivity and the reproducibility of the T3-induced Xenopus metamorphosis assay.


Assuntos
Bioensaio/métodos , Complexo CD3/metabolismo , Hormônios Tireóideos/metabolismo , Animais , Disruptores Endócrinos/toxicidade , Transdução de Sinais/efeitos dos fármacos , Xenopus
13.
Sensors (Basel) ; 16(9)2016 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-27589742

RESUMO

For the deficiencies of traditional stress detection methods for steel strips in industrial production, this paper proposes a non-contact stress detection scheme based on the magnetoelastic effect. The theoretical model of the transmission-type stress detection is established, in which the output voltage and the tested stress obey a linear relation. Then, a stress detection device is built for the experiment, and Q235 steel under uniaxial tension is tested as an example. The result shows that the output voltage rises linearly with the increase of the tensile stress, consistent with the theoretical prediction. To ensure the accuracy of the stress detection method in actual application, the temperature compensation, magnetic shielding and some other key technologies are investigated to reduce the interference of the external factors, such as environment temperature and surrounding magnetic field. The present research develops the theoretical and experimental foundations for the magnetic stress detection system, which can be used for online non-contact monitoring of strip flatness-related stress (tension distribution or longitudinal residual stress) in the steel strip rolling process, the quality evaluation of strip flatness after rolling, the life and safety assessment of metal construction and other industrial production links.

14.
Artigo em Zh | MEDLINE | ID: mdl-24630006

RESUMO

OBJECTIVE: To investigate the impact of occupational stress on serum monoamine neurotransmitters in nurses. METHODS: A total of 131 nurses were included as study subjects by stratified cluster sampling. The occupational health information collection system (based on the Internet of things) was used to measure occupational stress. Serum levels of monoamine neurotransmitters were also measured. RESULTS: Epinephrine (E) was negatively correlated with superior support (P < 0.05) and colleague support (P < 0.05). Negative correlation was also found between dopamine (DA) and job prospect (P < 0.05). Level of 5-hydroxytryptamine was negatively correlated with promotion opportunities (P < 0.05). Norepinephrine (NE), E, and DA were all negatively correlated with work satisfaction (P < 0.05) and positively correlated with daily stress (P < 0.01). NE and E were negatively correlated with sufficient confidence (P < 0.05) and positively correlated with physical complaints (P < 0.01). There was a negative correlation between NE and psychological satisfaction (P < 0.05). CONCLUSION: Occupational stress in nurses is correlated with serum monoamine neurotransmitters, and it may affect serum levels of monoamine neurotransmitters to a certain extent.


Assuntos
Monoaminas Biogênicas/sangue , Neurotransmissores/sangue , Enfermeiras e Enfermeiros/psicologia , Estresse Psicológico , Adulto , Feminino , Humanos , Satisfação no Emprego , Pessoa de Meia-Idade , Inquéritos e Questionários
15.
Artigo em Zh | MEDLINE | ID: mdl-24630007

RESUMO

OBJECTIVE: To investigate the effect of occupational stress on the oxidation/antioxidant capacity in nurses. METHODS: A total of 131 nurses were included as study subjects. The occupational health information collection system (based on the Internet of things) was used for measurement of occupational stress. Levels of hydroxyl free radicals and antioxidant enzymes were determined. RESULTS: The serum level of superoxide dismutase (SOD) was the highest in nurses under the age of 30 and the lowest in those over 45 (P < 0.05). The serum levels of glutathione peroxidase (GSH-Px) and peroxidase (POD) were the highest in nurses of working age less than 5 years, followed by those of 5-15 years, and nurses with more than 25 years' working experience showed the lowest GSH-Px and POD levels (P < 0.05). Furthermore, nurses with a university (college) degree had a higher GSH-Px level and a lower POD level compared with those with junior and senior high school degrees (P < 0.05). Job prospects and job control were positive occupational stress factors for SOD. Job hazards were negative occupational stress factors for POD. Psychological satisfaction was negative occupational stress reaction for hydroxyl free radicals. Calmness was positive occupational stress reaction for SOD, and daily stress was a negative one. The positive occupational stress reactions for GSH-Px were psychological satisfaction and job satisfaction, and daily stress was negative reaction. CONCLUSION: Nurses with higher occupational stress have stronger oxidation and weaker antioxidant capacity, which intensifies oxidant-antioxidant imbalance and leads to oxidative stress damage.


Assuntos
Enfermeiras e Enfermeiros/psicologia , Estresse Psicológico/sangue , Adulto , Glutationa Peroxidase/sangue , Humanos , Malondialdeído/sangue , Pessoa de Meia-Idade , Estresse Oxidativo , Espécies Reativas de Oxigênio/sangue , Superóxido Dismutase/sangue , Inquéritos e Questionários
16.
Sci Rep ; 14(1): 14722, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926495

RESUMO

This study explores the hot deformation behavior of Al-Zn-Mg-Cu alloy through uniaxial hot compression (200 °C-450°C) using the Gleeble-1500. True stress-strain curves were corrected, and three models were established: the Arrhenius model, strain compensated (SC) Arrhenius model, and strain compensated recrystallization temperature (RT) segmentation-based (TS-SC) Arrhenius model. Comparative analysis revealed the limited predictive accuracy of the SC Arrhenius model, with a 25.12% average absolute relative error (AARE), while the TS-SC Arrhenius model exhibited a significantly improved to 9.901% AARE. Material parameter calculations displayed variations across the temperature range. The SC Arrhenius model, utilizing an average slope method for parameter computation, failed to consider temperature-induced disparities, limiting its predictive capability. Hot processing map, utilizing the Murty improved Dynamic Materials Model (DMM), indicated optimal conditions for stable forming of the Al-Zn-Mg-Cu alloy. Microstructural analysis revealed MgZn2 precipitation induced by hot deformation, with crystallographic defects enhancing nucleation rates and precipitate refinement.

17.
Int J Biol Macromol ; 266(Pt 2): 131283, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38561119

RESUMO

Glycosaminoglycan (GAG) lyases are important tools for investigating the structure of GAGs and preparing low-molecular-weight GAGs. The PL35 family, a recently established polysaccharide lyase family, should be further investigated. In this study, we discovered a new GAG lyase, CHa1, which belongs to the PL35 family. When expressed heterologously in Escherichia coli (BL21), CHa1 exhibited high expression levels and solubility. The optimal activity was observed in Tris-HCl buffer (pH 7.0) or sodium phosphate buffer (pH 8.0) at 30 °C. The specific activities towards HA, CSA, CSC, CSD, CSE, and HS were 3.81, 13.03, 36.47, 18.46, 6.46, and 0.50 U/mg protein, respectively. CHa1 digests substrate chains randomly that acting as an endolytic lyase and shows a significant preference for GlcA-containing structures, prefers larger oligosaccharides (≥UDP8) and can generate a series of oligosaccharides composed mainly of the A unit when digesting CSA. These oligosaccharides include ΔC-A, ΔC-A-A, ΔC-A-A-A, ΔC-A-A-A-A, and ΔC-A-A-A-A-A. The residues Tyr257 and His421 play crucial roles in the catalytic process, and Ser211, Asn212, Asn213, Trp214, Gln216, Lys360, Arg460 and Gln462 may participate in the binding process of CHa1. This study on CHa1 contributes to our understanding of the PL35 family and provides valuable tools for investigating the structure of GAGs.


Assuntos
Polissacarídeo-Liases , Polissacarídeo-Liases/química , Polissacarídeo-Liases/metabolismo , Polissacarídeo-Liases/genética , Especificidade por Substrato , Acetilgalactosamina/química , Acetilgalactosamina/metabolismo , Escherichia coli/genética , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/química , Sequência de Aminoácidos , Oligossacarídeos/química , Oligossacarídeos/metabolismo
18.
Methods Mol Biol ; 2619: 249-256, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662475

RESUMO

Heparin/heparan sulfate (HP/HS) is a class of acidic polysaccharides with many potential medical applications, especially HP, and its derivatives, low molecular weight heparins (LMWHs), have been widely used as anticoagulants to treat thrombosis for decades. However, the complex structure endows HP/HS a variety of biological functions and hinders the structural and functional studies of HP/HS. Heparinases derived from bacteria are useful tools for the structural studies of HP/HS as well as the preparation of LMWHs. The enzymatic method for the structural analysis of HP/HS chains is easy to operate, requires less samples, and is low cost. Here, we describe an enzymatic approach to investigate the primary sequences of the HP/HS oligosaccharides using a recently discovered exotype heparinase.


Assuntos
Heparina , Heparitina Sulfato , Heparina/química , Heparitina Sulfato/química , Heparina Liase , Anticoagulantes , Oligossacarídeos/química
19.
Biotechnol Genet Eng Rev ; : 1-8, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37018441

RESUMO

Hypertension diabetes mellitus is one of the serious complications of hypertension. In this study, ambulatory blood pressure monitoring (ABPM) and ultrasonic cardiogram (UCG) were used to investigate the cardiac changes and its influencing factors in hypertensive patients with type 2 diabetes mellitus. The ABPM, UCG, Hemoglobin A1c (HbA1c) and body mass index (BMI) of patients were examined. The comparison of HbA1c, BMI, gender, age, daytime and nighttime blood pressure, left ventricular mass index (LVMI), left ventricular hypertrophy (LVH), isovolumic relaxation time (IVRT) and E/A ratio were made between the two groups. The cardiac function of control group was better than that of group B, while that of group B was better than group A. The cardiac index level in group B was better than that in group A, but lower than that in control group. The LVMI in group A was clearly higher than group B and control group, and the incidence of LVH increased. In group A, the nocturnal systolic blood pressure was higher than control group and group B. Nocturnal diastolic blood pressure, daytime diastolic blood pressure and systolic blood pressure in groups A and B were higher than those the control group. The findings indicated that hypertension complicated with type 2 diabetes mellitus can cause degeneration of the heart, and complicated with type 2 diabetes mellitus can accelerate ventricular remodeling and functional deterioration. Hypertension with type 2 diabetes mellitus are more prone to left ventricular damage.

20.
Micromachines (Basel) ; 14(10)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37893411

RESUMO

The high level of stress and dimension deviation induced by glass molding are the main causes of the low yield rate of large, irregular glass components on vehicles. To solve this issue, a numerical model of large glass component molding was established in this study, which aimed to analyze the dominant factors of molding quality and achieve a synergistic balance between quality characteristics and energy consumption. The results show that molding temperature is the dominant factor affecting the energy consumption and residual stress, and the molding pressure is the main factor affecting the dimension deviation. Furthermore, the NSGA-II optimization algorithm was used to optimize the maximum residual stress, dimension deviation, and energy consumption with the numerical results. The combination of a heating rate of 1.95 °C/s, holding time of 158 s, molding temperature of 570 °C, molding pressure of 34 MPa, and cooling rate of 1.15 °C/s was determined to be the optimized scheme. The predictive error of the numerical result, based on the optimized scheme, was experimentally verified to be less than 20%. It proved the accuracy of the model in this study. These results can provide guidance for the subsequent precision molding of large, irregular glass components.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA