Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Cell Biochem ; 124(1): 89-102, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36306470

RESUMO

Testes control the development of male reproductive system. The testicular interstitial Leydig cells (Leydig cells) synthesize testosterone for promoting spermatogenesis and secondary sexual characteristics. Type A platelet-derived growth factor (PDGF-AA) is one of the most important growth factors in regulating Leydig cell growth and function. Knockout of PDGF-AA or its congenital receptor PDGFR-α leads to poor testicular development caused by reducing Leydig cell numbers, supporting PDGF-AA/PDGFR-α signaling regulates Leydig cell development. Primary cilium is a cellular antenna that functions as an integrative platform to transduce extracellular signaling for proper development and differentiation. Several receptors including PDGFR-α are observed on primary cilia for initiating signaling cascades in distinct cell types. Here we showed that PDGF-AA/PDGFR-α signaling promoted Leydig cells growth, migration, and invasion via primary cilia. Upon PDGF-AA treatment, AKT and ERK signaling were activated to regulate these cellular events. Interestingly, active AKT and ERK were detected around the base of primary cilia. Depletion of ciliary genes (IFT88 and CEP164) alleviated PDGF-AA-activated AKT and ERK, thus reducing Leydig cell growth, migration, and invasion. Thus, our study not only reveals the function of PDGF-AA/PDGFR-α signaling in maintaining testicular physiology but also uncovers the role of primary cilium and downstream signaling in regulating Leydig cell development.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular , Células Intersticiais do Testículo , Fator de Crescimento Derivado de Plaquetas , Proteínas Proto-Oncogênicas c-akt , Humanos , Masculino , Cílios/metabolismo , Células Intersticiais do Testículo/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo
2.
BMC Cancer ; 22(1): 307, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35317758

RESUMO

BACKGROUND: The tumorigenesis of infused umbilical cord mesenchymal stem cells (UC-MSCs) is being preclinically evaluated. METHODS: We observed tumor formation in NOD SCID mice after a single subcutaneous injection of hUC-MSCs and the effect of these cells on tumor growth in tumor-bearing mice. Three generations (P5, P7, and P10) of hUC-MSCs (1 × 107) from two donors (hUC-MSC1 and hUC-MSC2) were inoculated subcutaneously into NOD SCID mice. Subcutaneous transplantation models were established in NOD SCID mice with human cervical cancer HeLa cells (solid tumor) and human B cell lymphoma Raji cells (hematological tumor). Then, the animals were euthanized, gross dissection was performed, and tissues were collected. Various organs were observed microscopically to identify pathological changes and tumor metastasis. RESULTS: In the tumorigenesis experiment, no general anatomical abnormalities were observed. In the tumor promotion experiment, some animals in the HeLa groups experienced tumor rupture, and one animal died in each of the low- and medium-dose hUC-MSC groups. The results may have occurred due to the longer feeding time, and the tumor may have caused spontaneous infection and death. Pathological examination revealed no metastasis to distant organs in any group. In the Raji tumor model, some animals in each group experienced tumor rupture, and one animal in the medium-dose hUC-MSC group died, perhaps due to increased tumor malignancy. Thus, hUC-MSCs neither promoted nor inhibited tumor growth. No cancer cell metastasis was observed in the heart, liver, spleen, lungs, kidneys or other important organs, except that pulmonary venule metastasis was observed in 1 animal in the model group. CONCLUSIONS: Injected hUC-MSCs were not tumorigenic and did not significantly promote or inhibit solid or hematological tumor growth or metastasis in NOD SCID mice.


Assuntos
Carcinogênese/patologia , Células-Tronco Mesenquimais/fisiologia , Cordão Umbilical/citologia , Animais , Feminino , Células HeLa , Humanos , Linfoma de Células B/patologia , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Modelos Animais , Metástase Neoplásica , Células Tumorais Cultivadas
3.
Endocr J ; 69(8): 971-982, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-35321989

RESUMO

Diabetic retinopathy (DR) is a progressive microvascular complication of diabetes mellitus and is characterised by excessive inflammation and oxidative stress. Urolithin A (UA), a major metabolite of ellagic acid, exerts anti-inflammatory and antioxidant functions in various human diseases. This study, for the first time, uncovered the role of UA in DR pathogenesis. Streptozotocin-induced diabetic rats were used to determine the effects of UA on blood glucose levels, retinal structures, inflammation, and oxidative stress. High glucose (HG)-induced human retinal endothelial cells (HRECs) were used to elucidate the anti-inflammatory and antioxidant mechanisms of UA in DR in vitro. The in vivo experiments demonstrated that UA injection reduced blood glucose levels, decreased albumin and vascular endothelial growth factor concentrations, and ameliorated the injured retinal structures caused by DR. UA administration also inhibited inflammation and oxidative damage in the retinal tissues of diabetic rats. Similar anti-inflammatory and antioxidant effects of UA were observed in HRECs induced by HG. Furthermore, we found that UA elevated the levels of nuclear Nrf2 and HO-1 both in vivo and in vitro. Nrf2 silencing reversed the inhibitory effects of UA on inflammation and oxidative stress during DR progression. Together, our findings indicate that UA can ameliorate DR by repressing inflammation and oxidative stress via the Nrf2/HO-1 pathway, which suggests that UA could be an effective drug for clinical DR treatment.


Assuntos
Cumarínicos , Diabetes Mellitus Experimental , Retinopatia Diabética , Animais , Humanos , Ratos , Antioxidantes , Glicemia , Cumarínicos/farmacologia , Células Endoteliais , Heme Oxigenase-1/metabolismo , Inflamação , Proteínas de Membrana/metabolismo , Fator 2 Relacionado a NF-E2 , Estresse Oxidativo , Fator A de Crescimento do Endotélio Vascular
4.
Biochem Biophys Res Commun ; 535: 39-46, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33340764

RESUMO

BACKGROUND: Age-related macular degeneration (AMD) may lead to irreversibly vision loss among aging populations. In this work, in an in vitro AMD cell model, we examined the expression and function of long non-coding RNA, Prader-Willi Region Non-Protein Coding RNA 2 (PWRN2) in injured human retinal pigment epithelial cells. METHOD: ARPE-19 cell line was maintained in vitro and treated with multi-module stressful conditions, including hydrogen peroxide (H2O2) tert-butylhydroperoxide (t-BuOOH) and ultraviolet B (UVB). Multi-module-stressor-induced cell death was monitored by a viability assay, and PWRN2 expression by qRT-PCR. PWRN2 was either downregulated or upregulated in ARPE-19 cells. The effects of PWRN2 downregulation or upregulation on t-BuOOH-induced cell death, cellular apoptosis and mitochondrial injuries were then quantitatively evaluated. RESULTS: Multi-module stressful conditions induced cell death and PWRN2 upregulation in ARPE-19 cells in vitro. We created ARPE-19 subpopulations with either downregulated or upregulated PWRN2 expressions. Quantitative assays demonstrated that, PWRN2 downregulation effectively alleviated t-BuOOH-induced cell death, apoptosis and various-type of mitochondrial injuries. On the other hand, PWRN2 upregulation worsened t-BuOOH-induced cellular damages in ARPE-19 cells. CONCLUSION: We demonstrated that downregulating PWRN2 protected multi-module-stressor-induced cell death, apoptosis and mitochondrial injuries in human retinal pigment epithelial cells, suggesting PWRN2 may be an active factor in human AMD.


Assuntos
Degeneração Macular/genética , Modelos Biológicos , RNA Longo não Codificante/metabolismo , Morte Celular , Linhagem Celular , Sobrevivência Celular/genética , Regulação para Baixo/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Degeneração Macular/patologia , Mitocôndrias/metabolismo , RNA Longo não Codificante/genética , Epitélio Pigmentado da Retina/patologia , Regulação para Cima/genética , terc-Butil Hidroperóxido
5.
Cells Tissues Organs ; 210(2): 118-134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34182545

RESUMO

Based on the characteristics of modern weapon injury, a repetitive model of traumatic systemic inflammatory response syndrome (SIRS) and an evaluation system were established. The models were treated with GFP-labeled tree shrew umbilical cord mesenchymal stem cells (UCMSCs). Forty out of 50 tree shrews were used to make a unilateral femoral comminuted fracture. Lipopolysaccharide was injected intravenously to create a traumatic SIRS model. The other 10 shrews were used as normal controls. After the model was established for 10 days, 20 tree shrews were injected intravenously with GFP-labeled UCMSCs, and 18 tree shrews were not injected as the model control group. The distribution of GFP-labeled cells in vivo was measured at 2 and 10 days after injection. Twenty days after treatment, the model group, the normal control group, and the treatment group were taken to observe the pathological changes in each tissue, and blood samples were taken for the changes in liver, renal, and heart function. Distribution of GFP-positive cells was observed in all tissues at 2 and 10 days after injection. After treatment, the HE staining results of the treatment group were close to those of the normal group, and the model group had a certain degree of lesions. The results of liver, renal, and heart function tests in the treatment group were returned to normal, and the results in the model group were abnormally increased. UCMSCs have a certain effect on the treatment of traumatic SIRS and provide a new technical solution for modern weapon trauma treatment.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Humanos , Rim , Síndrome de Resposta Inflamatória Sistêmica/terapia , Cordão Umbilical
6.
Int J Med Sci ; 17(15): 2292-2298, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922194

RESUMO

Background: Sesamin is a major bioactive compound in sesame seeds and has various biological properties, including anti-inflammatory and anticancer activities. Here, we explored whether sesamin activates p53, which is widely inhibited in cervical cancer cells, thereby inducing p53-mediated apoptosis. Methods: Human HeLa and SiHa cervical cancer cells and normal Hs68 dermal cells were used as cell models. Cell proliferation, cell cycle distribution, and apoptosis were evaluated by the CCK-8 assay and flow cytometry using PI/Annexin V staining, respectively. Protein expression and phosphorylation were determined using western blotting. The involvement of p53 in the apoptotic cascade was assessed by a specific inhibitor. Results: Sesamin (75 and 150 µM) clearly inhibited SiHa and HeLa cell proliferation in a dose-dependent fashion, but did not affect the proliferation of Hs68 cells. Meanwhile, sesamin increased the sub-G1 phase ratio and apoptosis, up to approximately 38.5% and 37.8%, respectively. Furthermore, sesamin induced p53 phosphorylation at serine-46 and serine-15 and upregulated the levels of PUMA, Bax, and PTEN, while inhibiting AKT phosphorylation at serine-473. Inhibition of p53 by pifithrin-α significantly reduced the levels of PUMA, Bax, and PTEN but restored AKT phosphorylation in SiHa cells exposed to sesamin. Pifithrin-α also reduced apoptosis and restored the proliferation of HeLa and SiHa cells exposed to sesamin. Conclusions: These findings indicate that sesamin inhibits cervical cancer cell proliferation, and its mechanism may be attributed to the induction of p53/PTEN-mediated apoptosis. This suggests that sesamin might be useful as an adjuvant in promoting anti-cervical cancer treatments.


Assuntos
Apoptose/efeitos dos fármacos , Dioxóis/farmacologia , Lignanas/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Dioxóis/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células HeLa , Humanos , Lignanas/uso terapêutico , PTEN Fosfo-Hidrolase/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Neoplasias do Colo do Útero/patologia
7.
IUBMB Life ; 71(10): 1611-1618, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31317640

RESUMO

High-glucose-induced retinal tissue impairment is the major pathological phenotype of diabetic retinopathy. In an in vitro diabetic apoptosis cell model, we evaluated the function of long noncoding RNA, insulin growth factor 2 antisense (IGF2-AS) in high-glucose-injured human retinal pigment epithelial cells. A human retinal pigment epithelial cell line, ARPE-19 was incubated with high-glucose in vitro to induce apoptosis. SiRNA-mediated IGF2-AS downregulation was conducted in ARPE-19 cells to evaluate its effect on high-glucose induced apoptosis, assessed by a TUNEL assay. qRT-PCR and western blot assays were applied to examine the functional effect of IGF2-AS on IGF2/AKT/Casp-9 expressions in glucose-injured ARPE-19 cells. ART was further knocked down, specifically in IGF2-AS-downregualted ARPE-19 cells, to investigate its functional involvement in IGF2-AS-inhibition-mediated apoptotic protection in glucose-injured ARPE-19 cells. High-glucose induced apoptosis in ARPE-19 cells, and upregulated IGF-2AS in a dose-dependent manner. SiRNA-mediated IGF2-AS downregulation ameliorated apoptosis, upregulated IGF2/AKT and decreased Casp-9, in high-glucose-treated ARPE-19 cells. AKT knockdown was shown to dramatically reverse the preventive effect of IGF2-AS-downregulation on high-glucose-induced apoptosis in ARPE-19 cells. Moreover, it was demonstrated that AKT knockdown directly upregulated Casp-9 in IGF2-AS-downregulated and high-glucose-treated ARPE-19 cells. We demonstrated that inhibiting IGF2-AS, possibly also through activation of AKT signaling pathway, has a protective function in high-glucose-induced apoptosis in human retinal pigment epithelial cells in diabetic retinopathy.


Assuntos
Apoptose/genética , Retinopatia Diabética/genética , Proteínas/genética , Epitélio Pigmentado da Retina/metabolismo , Caspase 9/genética , Retinopatia Diabética/patologia , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Glucose/metabolismo , Humanos , Fator de Crescimento Insulin-Like II/genética , Neurônios/metabolismo , Neurônios/patologia , Proteínas/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Epitélio Pigmentado da Retina/patologia , Transdução de Sinais/genética
8.
Medicine (Baltimore) ; 103(30): e39001, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058858

RESUMO

Diabetic retinopathy (DR) is a common and highly blinding disease. Many clinical studies have shown a causal relationship between Rheumatoid arthritis (RA) and DR, but the results are contradictory. In addition, some clinical results and pathological inferences have certain paradoxes, and the influence of RA on the pathogenesis and development of DR Is unclear. Our research assessed the causal association between RA and the development of DR using a 2-sample Mendelian randomization method. Single nucleotide polymorphisms (SNPs) relevant to the study were extracted and filtered from genome-wide association study (GWAS) data. A DR GWAS with a sample size of 190,594 and an RA GWAS with a sample size of 58,284 were obtained. Inverse variance weighted (IVW) method was used to analyze the results, and Mendelian randomization (MR)-Egger regression method and weighted median method were used to evaluate the robustness. Sensitivity analysis was performed using pleiotropy test, heterogeneity test, leave-one-out test to ensure that the results were unbiased. Confounding factors were eliminated to ensure robustness. A total of 83 related SNPs were screened. IVW method showed a positive correlation between RA and the increased relative risk of diabetic retinopathy (OR = 1.06, 95%CI: 1.04-1.23). The same trend was shown by MR-Egger regression method and weighted median method. Sensitivity analysis showed that there was no heterogeneity in SNPs, and the results were less likely to be affected by potential bias. After removing SNPs linked to confounders, the MR results remained significant and stable in direction. There is a positive causal association between rheumatoid arthritis and diabetic retinopathy. It is important to strengthen retina-related screening and prevention in diabetic patients with RA to reduce the risk of DR In RA patients.


Assuntos
Artrite Reumatoide , Retinopatia Diabética , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Polimorfismo de Nucleotídeo Único , Humanos , Artrite Reumatoide/genética , Artrite Reumatoide/complicações , Artrite Reumatoide/epidemiologia , Retinopatia Diabética/genética , Retinopatia Diabética/epidemiologia , Predisposição Genética para Doença , Fatores de Risco
9.
Mol Med Rep ; 29(5)2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38551159

RESUMO

Recurrent miscarriage is used to refer to more than three pregnancy failures before 20 weeks of gestation. Defective trophoblast cell growth and invasion are frequently observed in recurrent miscarriage. Several microRNAs (miRs), including miR­155­5p, are aberrantly upregulated in recurrent miscarriage; however, the underlying molecular mechanisms remain unclear. The centrosome orchestrates microtubule networks and coordinates cell cycle progression. In addition, it is a base for primary cilia, which are antenna­like organelles that coordinate signaling during development and growth. Thus, deficiencies in centrosomal functions can lead to several disease, such as breast cancer and microcephaly. In the present study, the signaling cascades were analyzed by western blotting, and the centrosome and primary cilia were observed and analyzed by immunofluorescence staining. The results showed that overexpression of miR­155­5p induced centrosome amplification and blocked primary cilia formation in trophoblast cells. Notably, centrosome amplification inhibited trophoblast cell growth by upregulating apoptotic cleaved­caspase 3 and cleaved­poly (ADP­ribose) polymerase in miR­155­5p­overexpressing trophoblast cells. In addition, overexpression of miR­155­5p inhibited primary cilia formation, thereby inhibiting epithelial­mesenchymal transition and trophoblast cell invasion. All phenotypes could be rescued when cells were co­transfected with the miR­155­5p inhibitor, thus supporting the role of miR­155­5p in centrosomal functions. It was also found that miR­155­5p activated autophagy, whereas disruption of autophagy via the depletion of autophagy­related 16­like 1 alleviated miR­155­5p­induced apoptosis and restored trophoblast cell invasion. In conclusion, the present study indicated a novel role of miR­55­5p in mediating centrosomal function in recurrent miscarriage.


Assuntos
Aborto Habitual , MicroRNAs , Gravidez , Feminino , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Trofoblastos/metabolismo , Proliferação de Células/genética , Centrossomo/metabolismo , Movimento Celular/genética , Aborto Habitual/metabolismo
10.
Heliyon ; 9(4): e15182, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37077684

RESUMO

Maritime Autonomous Surface Ships (MASS) have received increasing attention from industrial practitioners, researchers, and policymakers because of industry 4.0 and the digitization of the maritime industry. Crucial questions related to security, safety of personnel and vessels, and socio-economic domains have been addressed to a certain extent. In recent years, China has arisen as one of the leading maritime players worldwide, and unmanned vessels could remarkably influence the Chinese maritime industry. However, there is still a lack of systematic studies aiming to develop a deep understanding of potential advantages and challenges associated with the deployment of unmanned vessels in China. Therefore, using a mixed-method research design, this study attempts to obtain valuable insights based on the viewpoints of the key Chinese stakeholders concerning unmanned vessels, including the benefits, the restrictions, the obstacles to large-scale implementation, the risks, and how to mitigate possible implementation barriers. The main advantage of deploying unmanned ships was found to be the reduction in the ship crew size or complete elimination of the ship crew, which would reduce the operating costs and eliminate human errors on board the ships. Nevertheless, along with important advantages, a number of challenges associated with the development and deployment of unmanned ships were identified, including technological challenges, regulatory challenges, safety and security challenges, and technology investment challenges. All these challenges have to be adequately addressed by the relevant stakeholders to ensure the successful deployment of unmanned ships around the globe in the following years.

11.
Materials (Basel) ; 15(9)2022 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-35591702

RESUMO

The fabricated Al-Zn-Mg-Cu alloy build has low mechanical properties due to the dissolution of strengthening precipitates back into the matrix during friction stir additive manufacturing (FSAM). Post-fabricated aging was considered an effective approach to improve the mechanical performance of the build. In this study, various post-fabricated aging treatments were applied in the underwater FSAM of Al-7.5 Zn-1.85 Mg-1.3 Cu-0.135 Zr alloy. The effect of the post-fabricated aging on the microstructure, microhardness, and local tensile properties of the build was investigated. The results indicated that over-aging occurred in the low hardness zone (LHZ) of the build after artificial aging at 120 °C for 24 h as the high density of grain boundaries, subgrain boundaries, dislocations, and Al3Zr particles facilitated the precipitation. Low-temperature aging treatment can effectively avoid the over-aging problem. After aging at 100 °C for 48 h, the average microhardness value of the build reached 178 HV; the yield strength of the LHZ and high hardness zone (HHZ) was 453 MPa and 463 MPa, respectively; and the ultimate tensile strength of the LHZ and HHZ increased to 504 MPa and 523 MPa, respectively.

12.
Materials (Basel) ; 15(11)2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35683101

RESUMO

Friction stir additive manufacturing (FSAM) can be potentially used for fabricating high-performance components owing to its advantages of solid-state processing. However, the inhomogeneous microstructures and mechanical properties of the build attributed to the complex process involving restirring and reheating deserve attention. This study is based on the previous research of the underwater FSAMed 7A04 aluminum alloy and adopts a quasi in situ experimental method, i.e., after each pass of the underwater FSAM, samples were taken from the build for microstructural observation to investigate the restirring and reheating effects on microstructural evolution during the underwater FSAM. Fine-grain microstructures were formed in the stir zone during the single-pass underwater FSAM. After restirring, the grain size at the bottom of the overlapping region decreased from 1.97 to 0.87 µm, the recrystallization degree reduced from 74.0% to 29.8%, and the initial random texture transformed into a strong shear texture composed of the C {110}<11¯0>. After reheating, static recrystallization occurred in the regions close to the new additive zones, increasing the grain size and recrystallization degree. This study not only revealed the microstructural evolution during the underwater FSAM but also provided a guideline for further optimization of the mechanical properties of the Al−Zn−Mg−Cu alloy build.

13.
Materials (Basel) ; 15(2)2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35057339

RESUMO

In the present study, the fatigue life and fatigue fracture characteristics of annealed 7005 aluminum alloy plates subjected to different pre-tensile deformations were investigated. The results obtained upon increasing the pre-tensile deformation of the alloy plate to 20% revealed that the second-phase particles did not show any obvious changes, and that the thickness of the thin strip grain slightly decreased. The dislocation distribution in the alloy matrix varied significantly among the grains or within each grain as the dislocation density gradually increased with increasing pre-tensile deformation. Moreover, the fatigue performance of the annealed 7005 aluminum alloy plate was significantly improved by the pre-tensile deformation, and the alloy plate subjected to 20% pre-tensile deformation exhibited an optimal fatigue life of ~1.06 × 106 cycles, which was 5.7 times and 5.3 times that of the undeformed and 3% pre-stretched alloy plates, respectively. Two fatigue life plateaus were observed in the pre-tensile deformation ranges of 3-5% and 8-12%, which corresponded to heterogeneous dislocation distribution among various grains and within each grain, respectively. Moreover, two large leaps in the plot of the fatigue-life-pre-tensile-deformation curve were observed, corresponding to the pre-tensile deformation ranges of 5-8% and 16-20%, respectively.

14.
Materials (Basel) ; 15(14)2022 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-35888437

RESUMO

In the present study, the PLC characteristic parameters and DSA mechanism of Al-(2.86~9.41) Mg alloy sheets were investigated during tensile testing at room temperature with a tensile rate of 1 × 10-3 s-1. On the basis of the solution Mg concentrations in the α-Al matrix, the initial vacancy concentration, the second-phase particle configuration and the recrystallized grain configuration are almost the same by quenching treatment. The results show that the type of room-temperature tensile stress-strain curves of quenched Al-(2.86~9.41) Mg alloy sheets varied according to the Mg content. The type of stress-strain curve of the Al-2.86 Mg alloy sheet was B + C, while the type of stress-strain curve of the Al-(4.23~9.41) Mg alloy sheets was C. When the quenched Al-(2.86~9.41) Mg alloy sheets were stretched at room temperature, the strain cycle of the rectangular waves corresponding to the high stress flow ΔεTmax and stress drop amplitude Δσ on the zigzag stress-strain curve of alloy sheets increased with increasing the Mg content. Moreover, the strain cycle of ΔεTmax and Δσ on the stress-strain curve of alloy sheets increased gradually with increasing tensile deformation. The yield stress of quenched Al-(2.86~9.41) Mg alloy sheets increased gradually with increasing the Mg content. Moreover, the critical strain corresponding to yield stress εσ and the critical strain corresponding to the occurrence of the PLC shearing band εc of alloy sheets both increased with increasing the Mg content. However, the difference in flow strain value Δεc-σ between εc and εσ of alloy sheets decreased gradually with increasing the Mg content.

15.
Materials (Basel) ; 15(17)2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36079333

RESUMO

In this study, the strength, elongation, and fatigue properties of 7005 aluminum alloy plates with different configurations of precipitates were investigated by means of tensile tests, fatigue tests, and microstructural observation. We found that the number and size of GP zones in an alloy plate matrix increased and the distribution was more uniform after the aging time was extended from 1 h to 4 h at 120 °C, which led to a rise in both strength and elongation of alloy plates with the extending aging time. The fatigue life of the alloy plates shortened slightly at first, then significantly prolonged, and then shortened again with the aging time extending from 1 h to 192 h and a fatigue stress level of 185 MPa and stress ratio (R) = 0. After aging at 120 °C for 96 h, the precipitates in the alloy plate matrix were almost all metastable η'-phase particles, which had the optimal aging strengthening effect on the alloy matrix, and the degree of mismatch between the α-Al matrix and second-phase particles was the smallest; the fatigue crack initiation and propagation resistances were the largest, leading to the best fatigue performance of alloy plates, and the fatigue life of the aluminum plate was the longest, up to 1.272 × 106 cycles. When the aging time at 120 °C was extended to 192 h, there were a small number of equilibrium η phases in the aluminum plates that were completely incoherent with the matrix and destroyed the continuity of the aluminum matrix, easily causing stress concentration. As a result, the fatigue life of alloy plates was shortened to 9.422 × 105 cycles.

16.
Artigo em Inglês | MEDLINE | ID: mdl-35069757

RESUMO

BACKGROUND: Diabetic kidney disease (DKD) is the most important cause of the end-stage renal disease (ESRD) and the main cause of renal replacement therapy. Excessive inflammatory response and renal fibrosis are the keys to the development of this disease, and the conventional Western medical treatment is difficult to achieve and obtain long-term stable clinical results in all patients with DKD. Many studies have shown that Chinese medicine as a complementary and alternative medicine may be another therapeutic option to mitigate the progression of DKD to ESRD. In recent years, many doctors have used the Bushen Huoxue therapy to assist Western medicine in the treatment of the disease and have achieved certain clinical effects. However, most of the current studies are small sample studies, and there is no evidence-based confirmation. OBJECTIVE: To systematically evaluate the efficacy and safety of the Bushen Huoxue therapy combined with conventional Western medicine in the treatment of DKD. METHODS: A comprehensive search of literature databases such as CNKI, Wanfang, Pubmed, and Cochrane Library was conducted. The screening condition was that the control group was treated with conventional Western medicine and the experimental group was treated with Bushen Huoxue therapy's RCT on top of the control group, and the RCTs were published from January 2011 to October 2021. The Cochrane risk bias assessment tool was used for literature quality evaluation, and RevMan 5.3 software was used for statistical analysis. RESULTS: A total of 23 RCTs were finally included, with a total of 2,105 patients. Meta-analysis results show that the experimental group can effectively improve the clinical efficacy (RR = 1.28, 95% CI (1.22, 1.34), P < 0.01), significantly reduce Crea (SMD = -0.45, 95% CI (-0.57, -0.33), P < 0.01), 24 h UTP (SMD = -0.57, 95% CI (-0.69, -0.45), P < 0.01), BUN (SMD = -0.36, 95%CI (-0.48, -0.24), P < 0.01), UAER (SMD = -1.58, 95% CI (-1.78, -1.37), P < 0.01), and blood sugar, and have certain medication safety (RR = 0.00, 95% CI (-0.03, 0.03), P=0.87). CONCLUSIONS: Chinese medicine based on the Bushen Huoxue therapy has a good clinical effect in the treatment of diabetic kidney disease and has certain safety. However, due to the limitation of the quality and quantity of the included literature, the above conclusion still needs more rational experiments to further verify.

17.
Taiwan J Obstet Gynecol ; 61(6): 1077-1081, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36427979

RESUMO

OBJECTIVE: We present a female neonate with de novo trisomy 9p24.3-q21.2 presented with a neurological anomaly. CASE REPORT: Her birth length was 41 cm (<3rd percentile), birth body weight was 1600 g (<5th percentile), and head circumference was 29.5 cm (<5th percentile). She had low-set ears, deep and wide-set eyes with downslanting palpebral fissures, and a full nasal bridge with a globular nose. In addition, a rocker bottom foot was noted after further evaluation. Congenital heart anomalies, including patent ductus arteriosus (0.43 cm), large atrial septal defect, and malalignment ventricular septal defect (0.64 cm) were also confirmed. Brain magnetic resonance imaging showed partial agenesis of the cerebellum and corpus callosum. Furthermore, severe bilateral communicating hydrocephalus was found. CTG-banded chromosome analysis revealed 47, XX, +mar. CONCLUSION: DNA analysis may be mandatory for small gene segments. In trisomy 9p, we proposed further delineation of the critical region correlating to neurological malformations.


Assuntos
Anormalidades Múltiplas , Síndrome de Dandy-Walker , Hidrocefalia , Humanos , Recém-Nascido , Feminino , Síndrome de Dandy-Walker/genética , Trissomia/genética , Anormalidades Múltiplas/genética , Hidrocefalia/genética
18.
Cardiovasc Intervent Radiol ; 45(4): 488-501, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34282489

RESUMO

PURPOSE: To evaluate the effectiveness and safety of prophylactic intraoperative uterine artery embolization (UAE) performed immediately after fetal delivery during planned cesarean section or cesarean hysterectomy in patients with placenta accreta spectrum disorder or placenta previa. METHODS: A systematic search was conducted on Ovid MEDLINE and Embase, PubMed, Web of Science, and Cochrane databases. Studies were selected using the Population/Intervention/Comparison/Outcomes (PICO) strategy. The intraoperative blood loss and the rate of emergent peripartum hysterectomy (EPH) were the primary outcomes, whereas the length of hospital stay and volume of blood transfused were the secondary outcomes. A random-effects model was employed to pool each effect size. The cumulative values of the primary outcomes were calculated using the generic inverse variance method. RESULTS: Eleven retrospective cohort studies and five case series were included, recruiting 421 women who underwent prophylactic intraoperative UAE (UAE group) and 374 women who did not (control group). Compared with the control group, the UAE group had significantly reduced intraoperative blood loss (p = 0.020) during cesarean section or cesarean hysterectomy. Furthermore, the EPH rate was also significantly decreased (p = 0.020; cumulative rate: 19.65%), but not the length of hospital stay (p = 0.850) and volume of pRBC transfused (p = 0.140), after cesarean section in the UAE group. The incidence of major complications was low (3.33%), despite two patients with uterine necrosis. CONCLUSION: The currently available data provides encouraging evidence that prophylactic intraoperative UAE may contribute to hemorrhage control and fertility preservation in women with abnormal placentation. REGISTRATION: PROSPERO registration code: CRD42021230581. https://clinicaltrials.gov/ct2/show/CRD42021230581 LEVEL OF EVIDENCE: Level 2a, systematic review of retrospective cohort studies.


Assuntos
Placenta Acreta , Placenta Prévia , Hemorragia Pós-Parto , Embolização da Artéria Uterina , Cesárea/métodos , Feminino , Humanos , Histerectomia , Placenta Acreta/cirurgia , Placenta Prévia/cirurgia , Placentação , Hemorragia Pós-Parto/prevenção & controle , Gravidez , Estudos Retrospectivos , Embolização da Artéria Uterina/métodos
19.
Materials (Basel) ; 14(4)2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33561943

RESUMO

Mg-containing high-silicon aluminum alloy is a heat-treatable aluminum alloy that is now widely used in the aerospace and automotive industries because of its high specific strength, high wear resistance and corrosion resistance, low thermal expansion coefficient, and low cost. More attention has been paid to optimizing the microstructure to increase the performance of this type of aluminum alloy. In the present work, the solidification processes of Mg-free and Mg-containing (0.33-1.32%) Al-8Si alloys were analyzed by the experimental results combined with the thermodynamic calculation. The results showed that α-Al, Si, and Al5FeSi were in the Mg-free Al-8Si alloy ingots, while the Al5FeSi phases in alloys with Mg additions were transformed into π phases (Al8Mg3FeSi6) by the reaction L+Al5FeSi→α-Al+Si+Al8Mg3FeSi6. There was a binary eutectic reaction of L→α-Al+Al5FeSi when the Mg content exceeded 0.51% and the Fe content was higher than 0.17%. With the increase of Mg content, the volume of Mg2Si was gradually increased while the divorced eutectic phenomenon of the quaternary eutectic structure (α-Al+Si+Mg2Si+Al8Mg3FeSi6) was weakened and the eutectic structure was significantly refined.

20.
Artigo em Inglês | MEDLINE | ID: mdl-34122595

RESUMO

This study aimed to examine the components of the volatile oil derived from the integration processing technology of origin (IPTO) of Moslae Herba (MH) and their effects on the treatment of rats with Lung-Yin deficiency. IPTO was compared with the traditional cutting processing technology (TCPT) to provide a feasible basis. The chemical constituents of the volatile oil were identified by gas chromatography-mass spectrometry (GC-MS). The Lung-Yin deficiency model was established by subjecting the animals to smoke and administering them with thyroid tablet suspension. The rats were randomly divided into six groups: control, model, Tween-80, positive, IPTO, and TCPT. After 30 days of intragastric administration, the macroscopic signs of rats and pathological morphology of the lung tissues were observed by the hematoxylin and eosin (H & E) staining method. The positive expression of the tumor necrosis factor (TNF-α) was observed by an immunohistochemical method. The levels of cholesterol (CHO), albumin (ALB), total protein (TP), blood urea nitrogen (BUN), interleukin-1 (IL-1), interleukin-1beta (IL-1ß), cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP) were detected in the serum of rats. A total of 42 and 37 components were identified from the volatile oils of IPTO and TCPT, respectively. Among them, the contents of carvacrol and thymol were higher in IPTO. The volatile oil of MH derived from IPTO and TCPT could improve the general signs and autonomous activities of the rats with Lung-Yin deficiency; increase the contents of cGMP, TP, and ALB; and decrease the anal temperature of the rats, the contents of IL-1ß, CHO, and BUN in serum, the ratio of cAMP to cGMP, and the average optical density of TNF-α in their lung tissues. The findings indicated that IPTO was more efficient than TCPT. Its therapeutic effect might be associated with the change in TNF-α expression; the increase in cGMP, TP, and ALB contents; and the decrease in IL-1ß, CHO, and BUN levels, laying the foundation for the clinical development and application of MH.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA