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1.
Int J Gen Med ; 17: 1533-1543, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38680194

RESUMO

Purpose: The association between serum uric acid (SUA) and atrial fibrillation (AF) has been widely focused on and studied in recent years. However, the exact association between SUA and AF is unclear, and the effect of gender on the association between SUA levels and AF has been controversial. This study aimed to investigate the association between SUA levels and non-valvular AF (NVAF) and the potential effect of gender on it. Patients and Methods: A total of 866 NVAF patients (463 males, age 69.44 ± 8.07 years) and 646 sex-matched control patients in sinus rhythm, with no history of arrhythmia were included in this study. t-test, ANOVA, and chi-square test were used for baseline data analysis. The receiver operating characteristic curve, logistic regression and Pearson correlation analysis were used for correlation analysis. Results: Compared to controls, NVAF patients exhibited higher SUA (P<0.001). After adjusting for confounders of NVAF, SUA remained significantly associated with NVAF, regardless of gender (OR= 1.31, 95% CI 1.18-1.43, P<0.001). SUA demonstrated higher predictability and sensitivity in predicting the occurrence of female NVAF compared to male (area under the curve was 0.68 (95% CI 0.64-0.72, P<0.001), sensitivity 87.3%), with the optimal cut-off point identified as 5.72 mg/dL. Furthermore, SUA levels correlated with APOA1, Scr and NT-proBNP in NVAF patients. SUA levels varied significantly among NVAF subtypes. Conclusion: High SUA levels were independently associated with NVAF, regardless of gender. SUA exhibited higher predictability and sensitivity in predicting the occurrence of NVAF in females compared to males. High SUA levels may affect other NVAF-related factors and participate in the pathophysiological process of NVAF.

2.
Sci Rep ; 14(1): 5807, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461163

RESUMO

To improve the efficiency of frozen soil excavation, the new shaft tunneling machine was developed. The new shaft tunneling machine exerts pressure on the frozen soil through the cutter under the joint action of its own gravity, the drum rotational force and the inertia force, and the frozen soil is damaged. By unique way of breaking frozen soil to improve the efficiency of frozen soil excavation, the drum rotation speed is one of the factors affecting the performance of frozen soil excavation. This article applies SolidWorks software to establish the model of cutter breaking frozen soil, takes advantage of Hyper Mesh finite element software coupled with LS-DYNA solver to acquire the regular pattern of change in the force change, frozen soil stress-strain and specific energy of cutter crushing frozen soil, etc., which analyzes the destruction of frozen soil when the drum of the new shaft tunneling machine is rotating at the speed of 25-40 rpm. Combine with field test to investigate the mechanism of cutter breaking frozen soil under the optimal drum rotation speed. The investigation results demonstrate that: when frozen soil's self-bearing capacity is lower than the force of cutter, it breaks up and detaches from the soil body, and frozen soil undergoes tensile, compressive and shear damages. For this research, it is instructive for practical engineering.

3.
Biotechnol J ; 19(3): e2300706, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38479984

RESUMO

4-cyanobenzoic acid serves as a crucial intermediate for the synthesis of various high-value organic compounds. The enzymatic hydrolysis of terephthalonitrile to produce 4-cyanobenzoic acid using nitrilase offers the advantages of a simple reaction pathway, environmental friendliness, and easy product separation. In order to efficiently develop nitrilases that meet industrial production requirements, the virtual screening method used in the study is established and mature. From a total of 371 amino acids in the nitrilase AfNIT, which exhibits activity in terephthalonitrile hydrolysis, three candidate sites (F168, S192, and T201) were identified, and a "small and accurate" mutant library was constructed. The triple mutant F168V/T201N/S192F was screened from this small mutant library with a specific activity of 227.3 U mg-1 , which was 3.8 times higher than that of the wild-type AfNIT. Using the whole-cell biocatalyst containing the mutant F168V/T201N/S192F, terephthalonitrile was successfully hydrolyzed at a concentration of 150 g L-1 to produce 4-cyanobenzoic acid with a final yield of 170.3 g L-1 and a conversion rate of 98.7%. The obtained nitrilase mutant F168V/T201N/S192F in this study can be effectively applied in the biomanufacturing of 4-cyanobenzoic acid using terephthalonitrile as a substrate. Furthermore, the results also demonstrate the significant improvement in predictive accuracy achieved through the latest AI-assisted computer simulation methods. This approach represents a promising and feasible new technological pathway for assisting enzyme engineering research, laying a theoretical foundation for other related studies.


Assuntos
Aminoidrolases , Benzoatos , Simulação por Computador , Aminoidrolases/genética , Aminoidrolases/química
4.
BMC Infect Dis ; 23(1): 786, 2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-37951894

RESUMO

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a common complication in patients with cirrhosis. The diagnosis of SBP is still mostly based on ascites cultures and absolute ascites polymorphonuclear (PMN) cell count, which restricts the widely application in clinical settings. This study aimed to identify reliable and easy-to-use biomarkers for both diagnosis and prognosis of cirrhotic patients with SBP. METHODS: We conducted a retrospective study including 413 cirrhotic patients from March 2013 to July 2022 in the First Affiliated Hospital of Guangxi Medical University. Patients' clinical characteristics and laboratory indices were collected and analyzed. Two machine learning methods (Xgboost and LASSO algorithms) and a logistic regression analysis were adopted to screen and validate the indices associated with the risk of SBP. A predictive model was constructed and validated using the estimated area under curve (AUC). The indices related to the survival of cirrhotic patients were also analyzed. RESULTS: A total of 413 cirrhotic patients were enrolled in the study, of whom 329 were decompensated and 84 were compensated. 52 patients complicated and patients with SBP had a poorer Child-Pugh score (P < 0.05). Patients with SBP had a greater proportion of malignancies than those without SBP(P < 0.05). The majority of laboratory test indicators differed significantly between patients with and without SBP (P < 0.05). Albumin, neutrophil-to-lymphocyte ratio (NLR), and ferritin-to-neutrophil ratio (FNR) were found to be independently associated with SBP in decompensated cirrhotic patients using LASSO algorithms, and logistic regression analysis. The model established by the three indices showed a high predictive value with an AUC of 0.808. Furthermore, increased neutrophils, ALP, and C-reactive protein-to-albumin ratio (CAR) were associated with the shorter survival time of patients with decompensated cirrhosis, and the combination of these indices showed a greater predictive value for cirrhotic patients. CONCLUSIONS: The present study identified FNR as a novel index in the diagnosis of SBP in decompensated patients with cirrhosis. A model based on neutrophils, ALP and CAR showed high performance in predicting the prognosis of patients with decompensated cirrhosis.


Assuntos
Infecções Bacterianas , Peritonite , Humanos , Prognóstico , Ascite/complicações , Estudos Retrospectivos , Infecções Bacterianas/complicações , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , China , Peritonite/microbiologia , Cirrose Hepática/diagnóstico , Proteína C-Reativa
5.
Polymers (Basel) ; 15(21)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37960000

RESUMO

Some photosensitive resins have poor mechanical properties after 3D printing. To overcome these limitations, a polyurethane acrylate oligomer (PUA) microsphere was prepared using the Pickering emulsion template method and ultraviolet (UV) curing technology in this paper. The prepared PUA microspheres were added to PUA-1,6-hexanediol diacrylate (HDDA) photosensitive resin system for digital light processing (DLP) 3D printing technology. The preparation process of PUA microspheres was discussed based on micromorphology, and it was found that the oil-water ratio of the Pickering emulsion and the emulsification speed had a certain effect on the microsphere size. As the oil-water ratio and the emulsification speed increased, the microsphere particle size decreased to a certain extent. Adding a suitable proportion of PUA microspheres to the photosensitive resin can improve the mechanical properties and thermal stability. When the modified photosensitive resin microsphere content was 0.5%, the tensile strength, elongation at break, bending strength, and initial thermal decomposition temperature were increased by 79.14%, 47.26%, 26.69%, and 10.65%, respectively, compared with the unmodified photosensitive resin. This study provides a new way to improve the mechanical properties of photosensitive resin 3D printing. The resin materials studied in this work have potential application value in the fields of ceramic 3D printing and dental temporary replacement materials.

7.
Int J Mol Sci ; 24(4)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36835464

RESUMO

In recent years, porous titanium (Ti) scaffolds with BaTiO3 coatings have been designed to promote bone regeneration. However, the phase transitions of BaTiO3 have been understudied, and their coatings have yielded low effective piezoelectric coefficients (EPCs < 1 pm/V). In addition, piezoelectric nanomaterials bring many advantages in eliciting cell-specific responses. However, no study has attempted to design a nanostructured BaTiO3 coating with high EPCs. Herein, nanoparticulate tetragonal phase BaTiO3 coatings with cube-like nanoparticles but different effective piezoelectric coefficients were fabricated via anodization combining two hydrothermal processes. The effects of nanostructure-mediated piezoelectricity on the spreading, proliferation, and osteogenic differentiation of human jaw bone marrow mesenchymal stem cells (hJBMSCs) were explored. We found that the nanostructured tetragonal BaTiO3 coatings exhibited good biocompatibility and an EPC-dependent inhibitory effect on hJBMSC proliferation. The nanostructured tetragonal BaTiO3 coatings of relatively smaller EPCs (<10 pm/V) exhibited hJBMSC elongation and reorientation, broad lamellipodia extension, strong intercellular connection and osteogenic differentiation enhancement. Overall, the improved hJBMSC characteristics make the nanostructured tetragonal BaTiO3 coatings promising for application on implant surfaces to promote osseointegration.


Assuntos
Células-Tronco Mesenquimais , Nanoestruturas , Humanos , Osteogênese , Titânio/química , Diferenciação Celular , Nanoestruturas/química
8.
RSC Adv ; 12(54): 35452-35460, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36540246

RESUMO

A novel catalyst, consisting of hollow silica-coated porous carbon with embedded iron oxide particles (FeO x @C/SiO2), was synthesized by the extended Stöber method. Iron ions were incorporated in a resorcinol-formaldehyde resin in the presence of citric acid to form a template, which was then coated with a silica layer. The iron oxide-embedded porous carbon and hollow silica were simultaneously formed during calcination under N2 atmosphere. Through this process, silica endowed the iron oxide with low crystallinity and small size, resulting in a higher catalytic activity in the heterogeneous Fenton system for the decolorization of a methylene blue (MB) solution within 25 min. Moreover, the sample maintained 78.71% of its catalytic activity after three cycles.

9.
Med Sci Monit ; 28: e938511, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36424830

RESUMO

BACKGROUND D-dimer level can reflect the hypercoagulable state of atrial fibrillation (AF) and predict thromboembolic events. However, no effective indicator associated with D-dimer of AF patients has been found to prevent thromboembolic events in AF. This retrospective study from a single center aimed to investigate the correlation between serum albumin and D-dimer levels in 909 patients with non-valvular AF (NVAF) and 653 subjects in sinus rhythm. MATERIAL AND METHODS A total of 909 NVAF patients and 653 sex- and age-matched sinus rhythm participants were used to compare serum albumin and D-dimer levels. Serum albumin was determined by colorimetry, and D-dimer level was determined by latex-enhanced photoimmunoassay. We analyzed the correlation of serum albumin and D-dimer with NVAF by correlation analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve. RESULTS Albumin (P<0.001) and D-dimer (P<0.001) were significantly associated with NVAF. Among NVAF patients, D-dimer level was negatively correlated with albumin levels (P<0.001), and albumin level was an independent risk factor of abnormal D-dimer level (>0.5 ug/mL), which was also an effective predictor of abnormal D-dimer level (the area under the ROC curve was 0.77, P<0.001), and the optimal cutoff value was 36.95 g/L. CONCLUSIONS Serum albumin and D-dimer levels were significantly associated with NVAF. In NVAF patients, D-dimer level was inversely correlated with albumin levels, and albumin level was an independent risk factor and effective predictor of abnormal D-dimer level. Close examination and supplementation of serum albumin can prevent thromboembolic events, but further clinical research and confirmation are needed.


Assuntos
Fibrilação Atrial , Tromboembolia , Humanos , Fibrilação Atrial/complicações , Estudos Retrospectivos , Albumina Sérica , Biomarcadores , Tromboembolia/etiologia
10.
Front Pharmacol ; 13: 780991, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814212

RESUMO

Aims: Carbapenem-resistant K. pneumoniae (CRKP) is the most common carbapenem-resistant Enterobacteriaceae with high mortality. Ceftazidime-avibactam (CAZ-AVI) has exhibited excellent in vitro activity in vivo against CRKP. However, the efficacy of CAZ-AVI in KPC-producing CRKP-infected patients with different kidney statuses varies, such as renal insufficiency, normal renal function, and augmented renal clearance (ARC). We explored the use of therapeutic drug monitoring (TDM) to evaluate the concentration and efficacy of CAZ-AVI in CRKP-infected patients with different kidney statuses. Methods: Serum concentrations for CAZ and AVI were determined by the high-performance liquid chromatography method. Bacterial identification, routine susceptibility testing, renal function index, and others were performed in standard protocols in the hospital's clinical laboratories. Results: In the two patients with ARC, in case 1, CAZ-AVI 2.5g q6h was used with good efficacy, and the concentrations were up to the pharmacokinetics/pharmacodynamics targets. In Case 2, 2.5 g q8h was used with invalid effectiveness, and AVI Cmin was only 0.797 mg/l, which is lower than the PK/PD target. Case 3 was renal insufficiency using CAZ-AVI 1.25 q8h, and case 4 was normal renal function using 2.5 g q8h. Their concentrations were both up to the PK/PD targets. Conclusion: TDM results demonstrated that CAZ-AVI steady-state plasma concentration varies among patients with different kidney statuses, providing evidence for the utility of TDM of CAZ-AVI in individualized drug dose adjustment. ARC patients may need more CAZ-AVI daily doses than the standard dose.

11.
RSC Adv ; 12(21): 13209-13219, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35520114

RESUMO

Porcine decellularized small intestine submucosa (SIS) is a collagen membrane, which offers great potential as an organic substrate template in mineralization processes due to its good biodegradability and biocompatibility. However, a long period of mineralization and low efficiency are apparent, and the mechanism of collagen fiber mineralization has often been neglected in the previous literature. Thus, in this paper, we present a novel model of biomimetic collagen mineralization which uses dopamine (DA) molecules with the activating and retouching function of SIS collagen membranes and regulating collagen mineralization to construct the structure of mineralized collagen hard tissues. The crystal biomimetic mineralization growth of calcium phosphate on membranes is studied in different solid-liquid interfaces with a double ion self-assembled diffusion system under the simulated physiological microenvironment. In the system, pDA@SIS membranes are used to control the concentration of Ca2+ and PO4 3- ionic diffusion to generate supersaturation reaction conditions in 1-14 days. The system can successfully obtain polycrystals with low crystallinity on the pDA-collagen complex template surface of collagen fibers and along the collagen fibers. It initiates a generalized bionic mineralization pathway which can reduce the nucleation interfacial energy to promote rapid hydroxyapatite (HAP) nucleation and crystallization and accelerate the rate of collagen fiber mineralization. The pDA@SIS mineralized collagen membrane shows good biocompatibility with 100% cellular activity in the CCK-8 test, which significantly improved the adhesion proliferation of MC3T3-E1 cells. The pDA-SIS collagen complex, as a new type of mineralization template, may propose a new collagen mineralization strategy to produce a mineralized pDA@SIS scaffold bone-like material for tissue engineering or can potentially be applied in bone repair and regeneration.

12.
Materials (Basel) ; 15(8)2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35454481

RESUMO

The orientation, distribution, and contact point density of BF (basalt fiber) in the concrete matrix play significant roles in the mechanical properties of BF concrete, but represent a weak point in current research. It is meaningful to study the morphological characteristics of BF in concrete. In this study, the transparent model test and joint blocking method were innovatively adopted to investigate the correlation of dosage with the BF morphological parameters and concrete mechanical properties. A focus on a BF dosage of 0-7.5 kg/m3 and the contribution index of fibers Cf was defined. Furthermore, NMR and CT techniques were used to observe the changes in the microstructure of BF concrete. The experimental results show that the BF contribution index Cf reaches the largest value when the BF content is around 3 kg/m3, approximately 2.7; in this case, the mechanical properties of BF concrete were also optimal, and the Cf was only 2.34 when the BF content was 7.5 kg/m3. NMR and CT test results show that there is a strong correlation between the BF morphological parameters and the distribution of pore structure in the concrete matrix. The overlapping contact of BF clusters led to the penetration of pores, which led the macro-pore proportion to increase dramatically. The increase in the macro-pore proportion is the main reason for the deterioration in concrete performance. In addition, these macro-pores may have adverse effects on the chloride ion permeability of BF concrete.

13.
Oxid Med Cell Longev ; 2022: 1733834, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35035656

RESUMO

Calycosin (CAL) is the main active component present in Astragalus and reportedly possesses diverse pharmacological properties. However, the cardioprotective effect and underlying mechanism of CAL against doxorubicin- (DOX-) induced cardiotoxicity need to be comprehensively examined. Herein, we aimed to investigate whether the cardioprotective effects of CAL are related to its antipyroptotic effect. A cardiatoxicity model was established by stimulating H9c2 cells and C57BL/6J mice using DOX. In vitro, CAL increased H9c2 cell viability and decreased DOX-induced pyroptosis via NLRP3, caspase-1, and gasdermin D signaling pathways in a dose-dependent manner. In vivo, CAL-DOX cotreatment effectively suppressed DOX-induced cytotoxicity as well as inflammatory and cardiomyocyte pyroptosis via the same molecular mechanism. Next, we used nigericin (Nig) and NLRP3 forced overexpression to determine whether CAL imparts antipyroptotic effects by inhibiting the NLRP3 inflammasome in vitro. Furthermore, CAL suppressed DOX-induced mitochondrial oxidative stress injury in H9c2 cells by decreasing the generation of reactive oxygen species and increasing mitochondrial membrane potential and adenosine triphosphate. Likewise, CAL attenuated the DOX-induced increase in malondialdehyde content and decreased superoxide dismutase and glutathione peroxidase activities in H9c2 cells. In vivo, CAL afforded a protective effect against DOX-induced cardiac injury by improving myocardial function, inhibiting brain natriuretic peptide, and improving the changes of the histological morphology of DOX-treated mice. Collectively, our findings confirmed that CAL alleviates DOX-induced cardiotoxicity and pyroptosis by inhibiting NLRP3 inflammasome activation in vivo and in vitro.


Assuntos
Cardiotoxicidade/tratamento farmacológico , Doxorrubicina/efeitos adversos , Medicamentos de Ervas Chinesas/uso terapêutico , Inflamassomos/efeitos dos fármacos , Isoflavonas/uso terapêutico , Proteína 3 que Contém Domínio de Pirina da Família NLR/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Humanos , Isoflavonas/farmacologia , Masculino , Camundongos , Piroptose
14.
J Nanosci Nanotechnol ; 21(1): 354-361, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33213635

RESUMO

The preparation of high-density tailings is a prerequisite for cemented paste backfill technology, and the flocculated fine tailings of sealed water leads to challenges in the slurry thickening of tailings. Shearing conditions can compact the micro floc structure to improve the underflow concentration. The nm-µm scales of pore characteristics and connectivity are essential for the dewatering process. The computed tomography (CT) results show that the underflow concentration increases from 62.3 wt% to 68.6 wt% after undergoing rake shearing at 2 rpm, and the porosity decreases from 42.7% to 35.54%. The shearing conditions reduces the spheres and sticks by 43.14% and 43.3%, respectively, from the pore network model (PNM). The seepage flow states were affected by the changes in the pore structure. The maximum surface velocity and the maximum internal pressure decrease after undergoing shearing. Shearing conditions can break the micro floc structures, and the fine particles can fill in the micron-scale pores by gravity and shearing conditions, resulting in the forced drainage of water into the pores. Shearing conditions can break the thickening floc network structures; natural fine particles can fill the micron-scale pores by gravity and shearing conditions. The upward seepage of sealed water along the µm-scale pore channel causes a higher bed concentration. However, the sealed water in the nm-scale pores cannot flow upward due to water cohesion and particle adhesion resistance.

15.
Curr Med Sci ; 40(4): 625-635, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32767264

RESUMO

Nurses' work-related fatigue has been recognized as a threat to nurse health and patient safety. The aim of this study was to assess the prevalence of fatigue among first-line nurses combating with COVID-19 in Wuhan, China, and to analyze its influencing factors on fatigue. A multi-center, descriptive, cross-sectional design with a convenience sample was used. The statistical population consisted of the first-line nurses in 7 tertiary general hospitals from March 3, 2020 to March 10, 2020 in Wuhan of China. A total of 2667 samples from 2768 contacted participants completed the investgation, with a response rate of 96.35%. Social-demographic questionnaire, work-related questionnaire, Fatigue Scale-14, Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, and Chinese Perceived Stress Scale were used to conduct online survey. The descriptive statistic of nurses' social-demographic characteristics was conducted, and the related variables of work, anxiety, depression, perceived stress and fatigue were analyzed by t-tests, nonparametric test and Pearson's correlation analysis. The significant factors which resulted in nurses' fatigue were further analyzed by multiple linear regression analysis. The median score for the first-line nurses' fatigue in Wuhan was 4 (2, 8). The median score of physical and mental fatigue of them was 3 (1, 6) and 1 (0, 3) respectively. According to the scoring criteria, 35.06% nurses (n=935) of all participants were in the fatigue status, their median score of fatigue was 10 (8, 11), and the median score of physical and mental fatigue of them was 7 (5, 8) and 3 (2, 4) respectively. Multiple linear regression analysis revealed the participants in the risk groups of anxiety, depression and perceived stress had higher scores on physical and mental fatigue and the statistically significant positive correlation was observed between the variables and nurses' fatigue, the frequency of exercise and nurses' fatigue had a statistically significant negative correlation, and average daily working hours had a significantly positive correlation with nurses' fatigue, and the frequency of weekly night shift had a low positive correlation with nurses' fatigue (P<0.01). There was a moderate level of fatigue among the first-line nurses fighting against COVID-19 pandemic in Wuhan, China. Government and health authorities need to formulate and take effective intervention strategies according to the relevant risk factors, and undertake preventive measures aimed at reducing health hazards due to increased work-related fatigue among first-line nurses, and to enhance their health status and provide a safe occupational environment worldwide. Promoting both medical and nursing safety while combating with the pandemic currently is warranted.


Assuntos
Betacoronavirus , Infecções por Coronavirus/enfermagem , Fadiga/etiologia , Enfermeiras e Enfermeiros , Doenças Profissionais/etiologia , Estresse Ocupacional/etiologia , Pandemias , Pneumonia Viral/enfermagem , Adulto , COVID-19 , China/epidemiologia , Infecções por Coronavirus/epidemiologia , Estudos Transversais , Fadiga/epidemiologia , Fadiga/psicologia , Feminino , Humanos , Modelos Lineares , Masculino , Fadiga Mental/epidemiologia , Fadiga Mental/etiologia , Fadiga Mental/psicologia , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros/psicologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/psicologia , Estresse Ocupacional/epidemiologia , Estresse Ocupacional/psicologia , Pneumonia Viral/epidemiologia , Prevalência , Fatores de Risco , SARS-CoV-2 , Inquéritos e Questionários , Centros de Atenção Terciária , Carga de Trabalho/psicologia , Adulto Jovem
16.
J Biomater Sci Polym Ed ; 31(12): 1552-1565, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32403996

RESUMO

The biodegradable material poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffold has good biodegradability, but poor biocompatibility limits its application in the biological field. And it can effectively improve its biological activity by compounding with the bone conduction activity material of Barium titanate (BT). The PHBV and piezoelectric material BT were prepared into porous composite scaffolds with porosity of 45-50%. The mechanical properties and electrical properties of BT/PHBV scaffolds were systematically studied. The results showed that the piezoelectric coefficient d33 was 0.2-1.5 pC/N. Moreover, the compressive strength and elastic modulus were 1.0-2.0 MPa and 100-200 MPa, respectively. The results of degradation and mineralization showed that BT/PHBV scaffolds had good degradation and mineralization performance which was indicated that the materials had good biological activity.


Assuntos
Poliésteres , Alicerces Teciduais , Bário , Materiais Biocompatíveis , Porosidade , Engenharia Tecidual
17.
Artigo em Inglês | MEDLINE | ID: mdl-34804348

RESUMO

At NASA Goddard Space Flight Center, we have been developing spaceborne lidar instruments for space sciences. We have successfully flown several missions in the past based on mature diode pumped solid-state laser transmitters. In recent years, we have been developing advanced laser technologies for applications such as laser spectroscopy, laser communications, and interferometry. In this article, we will discuss recent experimental progress on these systems and instrument prototypes for ongoing development.

18.
Math Biosci Eng ; 16(5): 5851-5861, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31499741

RESUMO

Aiming at the problems of low efficiency and poor accuracy of traditional CAPTCHA recognition methods, we have proposed a more efficient way based on deep convolutional neural network (CNN). The Dense Convolutional Network (DenseNet) has shown excellent classification performance which adopts cross-layer connection. Not only it effectively alleviates the vanishing-gradient problem, but also dramatically reduce the number of parameters. However, it also has caused great memory consumption. So we improve and construct a new DenseNet for CAPTCHA recognition (DFCR). Firstly, we reduce the number of convolutional blocks and build corresponding classifiers for different types of CAPTCHA images. Secondly, we input the CAPTCHA images of TFrecords format into the DFCR for model training. Finally, we test the Chinese or English CAPTCHAs experimentally with different numbers of characters. Experiments show that the new network not only keeps the primary performance advantages of the DenseNets but also effectively reduces the memory consumption. Furthermore, the recognition accuracy of CAPTCHA with the background noise and character adhesion is above 99.9%.

19.
Med Sci Monit ; 24: 3720-3725, 2018 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-29860264

RESUMO

BACKGROUND The transient receptor potential melastatin 8 (TRPM8) was found to be expressed abnormally in a variety of tumors and is associated with unfavorable prognosis in human cancers. However, its clinical significance in pancreatic cancer (PC) is mostly unknown. MATERIAL AND METHODS qRT-PCR was performed to measure the expression of TRPM8 in 110 pairs of PC tissues and the adjacent non-cancerous tissues. The association of TRPM8 expression with the clinical characters of PC patients was analyzed using the chi-square test. Furthermore, the prognostic value of TRPM8 was determined with Kaplan-Meier survival curve and Cox regression analysis. RESULTS We found that the expression level of TRPM8 was significantly elevated in PC tissues compared to the non-cancerous controls (P<0.001). In addition, a close relationship was observed between elevated TRPM8 expression with large tumor size (P=0.001), advanced TNM (P=0.013), and distant metastasis (P=0.034). Survival analysis suggested that patients with high TRPM8 expression has worse OS (P=0.001) and DFS (P<0.001) than those with low TRPM8 expression. Moreover, TRPM8 was confirmed as a valuable prognostic biomarker for OS (HR=1.913; 95% CI: 1.020-3.589; P=0.043) or DFS (HR=2.374; 95% CI: 1.269-4.443; P=0.007) of PC patients. CONCLUSIONS This study shows that TRPM8 expression is significantly up-regulated in PC and it might be a useful prognostic factor for patients with PC.


Assuntos
Neoplasias Pancreáticas/metabolismo , Canais de Cátion TRPM/biossíntese , Adulto , Idoso , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidade , Prognóstico , Análise de Sobrevida , Canais de Cátion TRPM/genética , Transcriptoma
20.
Sheng Li Xue Bao ; 69(5): 703-714, 2017 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-29063118

RESUMO

DREAM (downstream regulatory element antagonist modulator), Calsenilin and KChIP3 (potassium channel interacting protein 3) belong to the neuronal calcium sensor (NCS) superfamily, which transduces the intracellular calcium signaling into a variety of activities. They are encoded by the same gene locus, but have distinct subcellular locations. DREAM was first found to interact with DRE (downstream regulatory element) site in the vicinity of the promoter of prodynorphin gene to suppress gene transcription. Calcium can disassemble this interaction by binding reversibly to DREAM protein on its four EF-hand motifs. Apart from having calcium dependent DRE site binding, DREAM can also interact with other transcription factors, such as cAMP responsive element binding protein (CREB), CREB-binding protein (CBP) and cAMP responsive element modulator (CREM), by this concerted actions, DREAM extends the gene pool under its control. DREAM is predominantly expressed in central nervous system with its highest level in cerebellum, and accumulating evidence demonstrated that DREAM might play important roles in pain sensitivity. Novel findings have shown that DREAM is also involved in learning and memory processes, Alzheimer's disease and stroke. This mini-review provides a brief introduction of its discovery history and protein structure properties, focusing on the mechanism of DREAM nuclear translocation and gene transcription regulation functions.


Assuntos
Regulação da Expressão Gênica , Proteínas Interatuantes com Canais de Kv/fisiologia , Proteínas Repressoras/fisiologia , Animais , Sinalização do Cálcio/fisiologia , Humanos , Proteínas Interatuantes com Canais de Kv/genética , Limiar da Dor , Proteínas Repressoras/genética
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