Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Front Oncol ; 14: 1349308, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590651

RESUMO

Pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC), stands as the fourth leading cause of cancer-related deaths in the United States, marked by challenging treatment and dismal prognoses. As immunotherapy emerges as a promising avenue for mitigating PDAC's malignant progression, a comprehensive understanding of the tumor's immunosuppressive characteristics becomes imperative. This paper systematically delves into the intricate immunosuppressive network within PDAC, spotlighting the significant crosstalk between immunosuppressive cells and factors in the hypoxic acidic pancreatic tumor microenvironment. By elucidating these mechanisms, we aim to provide insights into potential immunotherapy strategies and treatment targets, laying the groundwork for future studies on PDAC immunosuppression. Recognizing the profound impact of immunosuppression on PDAC invasion and metastasis, this discussion aims to catalyze the development of more effective and targeted immunotherapies for PDAC patients.

2.
ACS Appl Mater Interfaces ; 15(19): 23457-23469, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37148254

RESUMO

Currently, the photodetectors (PDs) assembled by vertically aligned nanostructured arrays have attracted intensive interest owing to their unique virtues of low light reflectivity and rapid charge transport. However, in terms of the inherent limitations caused by numerous interfaces often existed within the assembled arrays, the photogenerated carriers cannot be effectively separated, thus weakening the performance of target PDs. Aiming at resolving this critical point, a high-performance ultraviolet (UV) PD with a single-crystal integrated self-supporting 4H-SiC nanohole arrays is constructed, which are prepared via the anode oxidation approach. As a result, the PD delivers an excellent performance with a high switching ratio (∼250), remarkable detectivity (6 × 1010 Jones), fast response (0.5 s/0.88 s), and excellent stability under 375 nm light illumination with a bias voltage of 5 V. Moreover, it has a high responsivity (824 mA/W), superior to those of most reported ones based on 4H-SiC. The overall high performance of the PDs could be mainly attributed to the synergistic effect of the SiC nanohole arrays' geometry, a whole single-crystal integrated self-supporting film without interfaces, established reliable Schottky contact, and incorporated N dopants.

3.
Environ Technol ; : 1-16, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36763460

RESUMO

The in-situ reduction of zero-valent iron (ZVI) is an effective method for removing chlorinated aliphatic hydrocarbons (CAHs) from groundwater. The heterogeneity of environmental conditions is also crucial in affecting dechlorination efficiency. Until now, the effect of Sulfate (SO42-) on ZVI activity has been debated, and the related mechanism research on SO42- behaviour during the abiotic reduction process of chlorinated alkanes is still lacking. In this study, the impacts of SO42- concentrations (0, 2, 4, 8, 80 mM) on the degradation of 1,1,2-trichloroethane (1,1,2-TCA) by micron-size ZVI (mZVI) and nano-size ZVI (nZVI) were systematically investigated. For mZVI, Kobs increased by 0.6 (2 mM), 0.5 (4 mM), 1.1 (8 mM), and 1.6 times (80 mM). For nZVI, Kobs decreased by 32% (2 mM), 39% (4 mM), 45% (8 mM), and 9% (80 mM). The results showed that SO42- increased the rate of 1,1,2-TCA degradation by mZVI but weakened the reduction performance of nZVI; however, this inhibition was reduced when the concentration reached 80 mM. SO42- controlled the degradation of 1,1,2-TCA mainly through the formation of different iron-sulfate complexes on the ZVI surface: water-soluble bidentate iron-sulfate complexes formed on the mZVI surface promoted the corrosion of the oxide layer and accelerated the reduction of 1,1,2-TCA, monodentate complexes mainly formed on the nZVI surface inhibited the reduction of 1,1,2-TCA by blocking surface sites. These results demonstrate the proof of concept to assist land managers in the field application of ZVI technology for the remediation of CAHs contaminated sites with different background concentrations of SO42-.

4.
J Environ Manage ; 325(Pt B): 116407, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36302302

RESUMO

The proportion of activated persulfate (PS) oxidation technology in the remediation of domestic organic contaminated sites has increased every year, and the potential corrosion risk of site reuse caused by residual oxidants and by-products has also attracted the attention of researchers. In this work, the potential corrosion degree such as the mass reduction rate and surface crack width of standard iron flakes under different conditions, including with different PS dosages and release times, was monitored quantitatively over a long period, and the corresponding corrosion risk was quantitatively assessed. The results showed that when n (Na2S2O8):n (PAHs) increased from 5:1 to 100:1, the higher the oxidizer dosage, the more severe the corrosion weight loss and surface crack width, indicating that the oxidizer dosage was positively correlated with the potential corrosion risk. In addition, the corrosion crack width of the standard iron flake had a significant positive correlation with the reaction time and a significant negative correlation with the mass change. According to the changes in the standard iron flake, the corrosion process could be divided into three stages, in which the corrosion risk from high to low followed the order of oxidant corrosion stage > oxidant and salt corrosion stage > salt and microbial corrosion stage. Therefore, the dosage of chemicals should be controlled, the molar ratio of oxidizer to contaminant should not exceed 25:1, and a natural recovery period of at least one year should be left post remediation. During the reuse of the remediation sites in the future, the potential corrosion risks should also be calculated based on the dosage and time, to avoid redevelopment and use of the restoration site in the high corrosion risk stage.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Poluentes do Solo/análise , Corrosão , Oxirredução , Ferro , Oxidantes , Solo , Sulfatos
5.
Biosci Trends ; 15(1): 41-49, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33627573

RESUMO

There is little information concerning whether incorporating clinically significant portal hypertension (CSPH) into albumin-bilirubin (ALBI) grading could improve its predictive capacity. In this study, we investigated the predictive ability of ALBI grade plus CSPH (ALBI-P score) for patients with hepatocellular carcinoma (HCC) after liver resection. Data from 1,679 patients were retrospectively reviewed. The ALBI-P score was calculated from the ALBI grade and a point for CSPH (0 for absence of CSPH and 1 for presence of CSPH). Independent risk factors for recurrence-free survival (RFS) and overall survival (OS) were analyzed. Multivariate analysis suggested that the ALBI-P score was an independent risk factor for both postoperative recurrence (HR = 1.441, 95% CI = 1.328-1.563, P < 0.001) and mortality (HR = 1.332, 95% CI = 1.156-1.535, P < 0.001). Both the RFS and OS of patients with an ALBI-P score of 1 were significantly better than those of patients with ALBI-P scores of 2 and 3 (5-year RFS of 38.9%, 26.1%, and 14.7%, respectively, P < 0.001; 5-year OS of 52.7%, 42.6%, and 29.3%, P < 0.001). When the ALBI-P score and BCLC stage were combined, the ALBI-P-BCLC score showed the highest area under the receiver operating characteristic curve to predict both postoperative recurrence and mortality compared with BCLC stage alone, BCLC stage combined with ALBI grade, or platelet-albumin-bilirubin grade. These results suggested incorporating CSPH into the ALBI grade could strengthen its prognostic power. The ALBI-P score may serve as a surrogate marker to predict HCC patient outcomes after liver resection.


Assuntos
Bilirrubina/sangue , Carcinoma Hepatocelular/patologia , Hipertensão Portal/complicações , Neoplasias Hepáticas/patologia , Albumina Sérica/análise , Adulto , Idoso , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/cirurgia , Intervalo Livre de Doença , Feminino , Seguimentos , Hepatectomia , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
6.
Biosci Trends ; 14(4): 297-303, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32641640

RESUMO

Inflammation-based markers are considered prognostic indicators for patients with hepatocellular carcinoma (HCC) after liver resection. However, there is little information concerning whether they are useful for HCC patients with clinically significant portal hypertension (CSPH). In this study, 1452 patients were enrolled. Independent risk factors for recurrence-free survival (RFS) and overall survival (OS) were analyzed for patients with and without CSPH. For HCC patients without CSPH, multivariate analysis suggested that microvascular invasion (MVI), neutrophil-to-lymphocyte ratio (NLR) ≥ 3, platelet-to-lymphocyte ratio (PLR) ≥ 150, tumor size > 5 cm, and the presence of a satellite lesion were independently associated with RFS. MVI, NLR ≥ 3, PLR ≥ 150, and advanced Barcelona clinical liver cancer (BCLC) stage contributed to mortality. However, neither NLR nor PLR showed any prognostic power in HCC patients with CSPH. For HCC patients with CSPH, tumor size > 5 cm, MVI, satellite lesion, and albumin-bilirubin (ALBI) grade were independent risk factors for RFS, whereas tumor size > 5 cm, MVI, multiple tumors, ALBI grade and advanced BCLC stage showed prognostic power for OS. Our study confirmed CSPH influences the predictive ability of inflammation-based markers. This result reminds us to pay more attention to the influence of CSPH when we apply inflammation-based markers in patients with HCC after liver resection.


Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia , Hipertensão Portal/cirurgia , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Adulto , Plaquetas , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/mortalidade , Intervalo Livre de Doença , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Hipertensão Portal/sangue , Hipertensão Portal/imunologia , Hipertensão Portal/mortalidade , Inflamação/sangue , Inflamação/diagnóstico , Inflamação/imunologia , Estimativa de Kaplan-Meier , Fígado/imunologia , Fígado/patologia , Fígado/cirurgia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/mortalidade , Contagem de Linfócitos , Linfócitos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/imunologia , Neutrófilos , Contagem de Plaquetas , Prognóstico , Estudos Retrospectivos , Medição de Risco/métodos , Fatores de Risco
7.
ACS Appl Mater Interfaces ; 12(19): 21903-21911, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32319289

RESUMO

Improving the sensitivity of the piezoresistive behavior of semiconductor nanostructures is critically important because it is one of the keys to explore advanced pressure sensors with desired sensitivity. Herein, we reported a strategy for improving the piezoresistive behavior of SiC nanowire by coupling with the piezoelectric effect of ZnO nanolayers, which were grown by an atomic layer deposition approach. As a result, the detected current of the as-constructed ZnO/SiC heterojunction nanowires is 6 times more than SiC nanowires, suggesting its substantially improved sensitivity. Moreover, the measured ΔR/R0 value and gauge factor (GF) of the ZnO/SiC heterojunction nanowires could be up to 0.82 and 50.93, respectively, which was profoundly higher than those of the SiC counterpart and most of reported positive piezoresistive SiC sensors.

8.
Medicine (Baltimore) ; 98(37): e17158, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31517863

RESUMO

RATIONALE: Glucagonoma is a rare neuroendocrine tumor of the pancreas. Glucagonoma syndrome is often misdiagnosed as other skin lesions by clinicians due to a typical clinical sign of necrolytic migratory erythema (NME) with severe erythematous rash. PATIENT CONCERNS: A 48-year-old female patient was admitted to our department because she presented with unclear recurrent severe erythematous rash. The patient was diagnosed as skin disease. DIAGNOSES: Histopathologic examination revealed a pancreatic glucagonoma. Immnohistochemical staining of tumor tissue was positive for glucagon. INTERVENTIONS: The distal pancreatectomy plus splenectomy was performed in 2017. OUTCOMES: The skin lesions disappeared after surgery. She was followed up and showed no recurrence until now. LESSONS: Clinicians should consider the diagnosis of glucagonoma according to the typical initial symptoms. Early diagnosis is very important to provide a better prognosis. A multidisciplinary approach is effective in patients with unresectable metastatic tumors.


Assuntos
Exantema/complicações , Glucagonoma/complicações , Eritema Migratório Necrolítico/complicações , Neoplasias Pancreáticas/complicações , Diagnóstico Diferencial , Exantema/diagnóstico , Exantema/patologia , Exantema/cirurgia , Feminino , Glucagonoma/diagnóstico , Glucagonoma/patologia , Glucagonoma/cirurgia , Humanos , Pessoa de Meia-Idade , Eritema Migratório Necrolítico/diagnóstico , Eritema Migratório Necrolítico/patologia , Eritema Migratório Necrolítico/cirurgia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia
9.
Artigo em Inglês | MEDLINE | ID: mdl-31174699

RESUMO

Sepsis is a life-threatening condition that may develop to multiple organ failure and septic shock. Autophagy is considered to play an important role in the regulation of inflammation. The present study aims to investigate the protective role of mTORC1 inhibitor, rapamycin, on septic death using cecal ligation and puncture (CLP) mice model. Here, results showed that pretreatment with rapamycin reduced the pyroptosis of peritoneal macrophages stimulated by cecal contents and the release of inflammatory factors such as interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α); In septic mice, rapamycin treatment decreased the activation of inflammasome in lung, and alleviated the pathological injuries in lung, liver and spleen tissues during acute stage of sepsis. Treatment of rapamycin rescued animals from septic death significantly. Our results indicated that activation of autophagy is a potential strategy to regulate the excessive inflammation in acute stage of sepsis.


Assuntos
Autofagia/efeitos dos fármacos , Inflamassomos/efeitos dos fármacos , Sepse/tratamento farmacológico , Sirolimo/uso terapêutico , Animais , Ceco , Citocinas/imunologia , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Ligadura , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
10.
Cell Microbiol ; 21(4): e12984, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30463105

RESUMO

Bartonella effector proteins (named Beps) are substrates of VirB type IV secretion system for translocation into host cells evolved in Bartonella spp. Among these, BepE has been shown to protect cells from fragmentation effects triggered by other Beps and to promote in vivo dissemination of bacteria from the dermal site of inoculation to the bloodstream. Bacterial pathogens secreted effectors to modulate the interplay with host autophagy, either to combat autophagy to escape its bactericidal effect or to exploit autophagy to benefit intracellular replication. Here, we reported a distinct phenotype that selective autophagy in host cells is activated as a countermeasure, to attack BepE via conjugation with K63 polyubiquitin chain on BepE. We found that ectopic expression of Bartonella quintana BepE specifically induced punctate structures that colocalised with an autophagy marker (LC3-II) in host cells, in addition to filopodia and membrane ruffle formation. Two tandemly arranged Bartonella Intracellular Delivery (BID) domains in the BepE C-terminus, where ubiquitination of sister pairs of lysine residues was confirmed, were essential to activate host cell autophagy. Multiple polyubiquitin chain linkages of K27, K29, K33, and K63 were found to be conjugated at sites of K222 and K365 on BepE, of which K63 polyubiquitination on BepE K365 determined the selective autophagy (p62/SQSTM1 positive autophagy) independent of the PI3K pathway. Colocalisation of BepE with LAMP1 confirmed the maturation of BepE-induced autophagosomes in which BepE were targeted for degradation. Moreover, host cells employed selective autophagy to counter-attack BepE to rescue cells from BepE-induced endocytosis deficiency.


Assuntos
Bartonella quintana/metabolismo , Sistemas de Secreção Tipo IV/metabolismo , Autofagossomos/metabolismo , Autofagia/genética , Autofagia/fisiologia , Linhagem Celular , Células HeLa , Humanos , Imunoprecipitação , Microscopia de Fluorescência , Poliubiquitina/metabolismo , Espectrometria de Massas em Tandem
11.
Mol Med Rep ; 18(2): 1644-1650, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29901083

RESUMO

C-X-C chemokine receptor type 7 (CXCR7) is reported to be overexpressed in tumor endothelial cells (TECs), which are the primary target cells of antivascular chemotherapy. However, the role of CXCR7 in TECs is not fully understood. In the present study, CXCR7 expression was inhibited in TECs derived from hepatocellular carcinoma (HCC) using short hairpin (sh)RNA plasmids to investigate the role of CXCR7 in the regulation of migration and invasion of TECs as well as its underlying mechanisms. The data showed that the downregulation of CXCR7 significantly inhibited the migration and invasion of TECs. Further study showed that silencing CXCR7 resulted in decreased phosphorylated signal transducer and activator of transcription 3 (STAT3) at Tyr705 and its downstream target genes in TECs, including matrix metalloproteinase­2 (MMP2) and vascular endothelial growth factor (VEGF). However, restoring STAT3 phosphorylation abolished the CXCR7­shRNA­induced decrease in TECs migration and invasion, as well as the downregulation of MMP2 and VEGF in TECs. These findings indicate that CXCR7 may regulate the migration and invasion of TECs derived from HCC via the STAT3 signaling pathway and that CXCR7 could be a potential target for the antivascular therapy of HCC.


Assuntos
Células Endoteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Metaloproteinase 2 da Matriz/genética , Receptores CXCR/genética , Fator de Transcrição STAT3/genética , Fator A de Crescimento do Endotélio Vascular/genética , Linhagem Celular Tumoral , Movimento Celular , Células Endoteliais/patologia , Humanos , Fígado/metabolismo , Fígado/patologia , Metaloproteinase 2 da Matriz/metabolismo , Neovascularização Patológica/prevenção & controle , Fosforilação , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores CXCR/antagonistas & inibidores , Receptores CXCR/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Radiat Res ; 189(4): 409-417, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29420126

RESUMO

For dendritic cells (DCs) to initiate an immune response, their ability to migrate and to produce interleukin-12 (IL-12) is crucial. It has been previously shown that low-dose radiation (LDR) promoted IL-12 production by DCs, resulting in increased DC activity that contributed to LDR hormesis in the immune system. However, the molecular mechanism of LDR-induced IL-12 production, as well as the effect of LDR on DC migration capacity require further elucidation. Using the JAWSII immortalized mouse dendritic cell line, we showed that in vitro X-ray irradiation (0.2 Gy) of DCs significantly increased DC migration and IL-12 production, and upregulated CCR7. The neutralizing antibody against CCR7 has been shown to abolish LDR-enhanced DC migration, demonstrating that CCR7 mediates LDR-promoting DC migration. We identified nuclear factor kappaB (NF-κB) as the central signaling pathway that mediated LDR-enhanced expression of IL-12 and CCR7 based on findings that 0.2 Gy X-ray irradiation activated NF-κB, showing increased nuclear p65 translocation and NF-κB DNA-binding activity, while an NF-κB inhibitor blocked LDR-enhanced expression of IL-12 and CCR7, as well as DC migration. Finally, we demonstrated that 0.2 Gy X-ray irradiation promoted ATM phosphorylation and reactive oxygen species generation; however, only the ATM inhibitor abolished the LDR-induced NF-κB-mediated expression of IL-12 and CCR7. Altogether, our data show that exposure to LDR resulted in a hormetic effect on DCs regarding CCR7-mediated migration and IL-12 production by activating the ATM/NF-κB pathway.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Movimento Celular/efeitos da radiação , Células Dendríticas/efeitos da radiação , Interleucina-12/biossíntese , NF-kappa B/metabolismo , Transdução de Sinais/efeitos da radiação , Animais , Linhagem Celular , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Relação Dose-Resposta à Radiação , Camundongos , Receptores CCR7/metabolismo
13.
Int J Clin Exp Pathol ; 10(8): 8820-8828, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31966748

RESUMO

Tumor infiltrating lymphocytes in a certain tumor microenvironment are associated with the prognosis of cancer patients. The function of CD4+ and CD8+ T cells in the microenvironment of pancreatic cancer remains largely unknown. This study aimed to investigate the prognostic value of both CD4+ and CD8+ TIL subsets and their combined role in pancreatic cancer. In this study, pancreatic cancer tissues and corresponding adjacent normal tissues were collected from 90 patients. The expression levels of CD4 and CD8+ T cells in pancreatic cancer tissues were detected by immunohistochemistry method. The results showed that CD4+ iTIL expression was significantly correlated with tumor stage. CD8+ iTILs were significantly correlated with lymphatic vessel invasion and tumor stage; CD8+ sTILs not only showed correlation with lymphatic vessel invasion and tumor stage, but also had correlation with pathologic differentiation; the survival time of high CD4 expression group was longer compared to the low CD4 expression group. CD4+ T cells were capable of killing tumor cells and prolonging the survival time of patients either directly or indirectly. According to Cox regression analysis, it was indicated that pathological differentiation, lymphatic vessel invasion, tumor stage, CD4+ and CD8+ TILs were the principle risk factors of pancreatic cancer prognosis. Especially multivariate analysis showed that pathological differentiation and the combination of CD4+ and CD8+ TILs expression were independent predictors of pancreatic cancer survival. Expression levels of CD4+ and CD8+ TILs in pancreatic cancer may provide promising and useful markers for prognosis of pancreatic cancer.

14.
Int J Clin Exp Pathol ; 10(9): 9846-9852, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31966872

RESUMO

Pancreatic cancer is one of the most aggressive cancers. Interleukin-22 (IL-22) is a member of IL-10 cytokine family and primarily produced by Th17 cells which were differentiated from CD4 T cells. CD4 T cells play a central role in regulating the immune response and resisting cancer cells. However, the function of CD4 T cells and Interleukin-22 (IL-22) in the microenvironment of pancreatic cancer remains largely unknown. In the present study, we investigated expression of the IL-22 in tumor cells, CD4 expression in microenvironment of pancreatic cancer and assessed their effects on pathological characteristics and prognosis of pancreatic cancer. To analyze prognostic factors of pancreatic cancer, Kaplan-Meier survival and Cox proportional-hazards regression were applied. Expression of CD4 in pancreatic cancer was associated with pTNM stage (P=0.005). Expression of IL-22 in pancreatic cancer was related not only to pTNM stage (P=0.011) but also to lymph node involvement (P=0.016). Univariate analysis demonstrated that the main prognostic factors of pancreatic cancer are pathological differentiation, expression of low CD4, expression of high IL-22 and the combination of low CD4 expression and high IL-22 expression in pancreatic cancer tissues. Moreover, multivariate analysis clearly showed that pathological differentiation, and the combination of low CD4 expression and high IL-22 expression in pancreatic cancer tissues were independent prognostic factors for overall survival in pancreatic cancer. the present study indicated that CD4 and IL-22 might be used as independent prognostic markers and molecular targets for pancreatic cancer.

15.
Materials (Basel) ; 9(11)2016 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-28773996

RESUMO

Surface texturing-plasma nitriding duplex treatment was conducted on AISI 316 stainless steel to improve its tribological performance. Tribological behaviors of ground 316 substrates, plasma-nitrided 316 (PN-316), surface-textured 316 (ST-316), and duplex-treated 316 (DT-316) in air and under grease lubrication were investigated using a pin-on-disc rotary tribometer against counterparts of high carbon chromium bearing steel GCr15 and silicon nitride Si3N4 balls. The variations in friction coefficient, mass loss, and worn trace morphology of the tested samples were systemically investigated and analyzed. The results showed that a textured surface was formed on 316 after electrochemical processing in a 15 wt % NaCl solution. Grooves and dimples were found on the textured surface. As plasma nitriding was conducted on a 316 substrate and ST-316, continuous and uniform nitriding layers were successfully fabricated on the surfaces of the 316 substrate and ST-316. Both of the obtained nitriding layers presented thickness values of more than 30 µm. The nitriding layers were composed of iron nitrides and chromium nitride. The 316 substrate and ST-316 received improved surface hardness after plasma nitriding. When the tribological tests were carried out under dry sliding and grease lubrication conditions, the tested samples showed different tribological behaviors. As expected, the DT-316 samples revealed the most promising tribological properties, reflected by the lowest mass loss and worn morphologies. The DT-316 received the slightest damage, and its excellent tribological performance was attributed to the following aspects: firstly, the nitriding layer had high surface hardness; secondly, the surface texture was able to capture wear debris, store up grease, and then provide continuous lubrication.

16.
Se Pu ; 26(3): 310-3, 2008 May.
Artigo em Chinês | MEDLINE | ID: mdl-18724665

RESUMO

A novel method for the determination of monoethylglycinexylidide (MEGX) (lidocaine metabolin) in serum using solid phase extraction (SPE) and capillary gas chromatography-mass spectrometry (GC-MS) was established. The serum sample was extracted with a CN-SPE column. An HP-5MS capillary column (15 m x 0.25 mm x 0.1 microm) was used. The initial temperature of the column was set at 100 degrees C, held for 1 min, then raised to 200 degrees C at 40 degrees C/min, and held at 200 degrees C for 0.5 min. The sample size was 2 microL, and the split ratio was set at 1 : 1. The carrier gas was high purity helium with a flow rate of 1.0 mL/min. The monitoring ions for the determination were m/z 58 for MEGX and m/z 86 for procaine (internal standard). The calibration curve of MEGX had good linear relationship in the range of 1.562 - 25 ng/mL ( r = 0.998 1). The limit of detection was 0.5 ng/mL. The extraction recovery ranged from 80.1% to 85.7%. The method advanced the quantitative analysis of MEGX in serum by combining rapid and efficient SPE with specific and sensitive quantitation by GC-MS.


Assuntos
Análise Química do Sangue/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lidocaína/análogos & derivados , Extração em Fase Sólida/métodos , Animais , Calibragem , Lidocaína/sangue , Lidocaína/isolamento & purificação , Ratos , Reprodutibilidade dos Testes , Fatores de Tempo
17.
Hepatobiliary Pancreat Dis Int ; 7(1): 97-100, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18234647

RESUMO

BACKGROUND: Caroli's disease, a rare congenital hepatic disease, has a poor prognosis, especially in patients with diffuse dilatation of the bile ducts. But liver transplantation has been a curative option. The aim of this study was to investigate the feasibility and rationality of orthotopic liver transplantation as an indication for patients with diffuse Caroli's disease. METHODS: The data from 3 patients with diffuse Caroli's disease who had undergone orthotopic liver transplantation in our unit were analyzed retrospectively. RESULTS: On postoperative day 7, patient 1 had acute rejection which was relieved after pulse treatment with methylprednisolone. He was discharged from hospital on postoperative day 27 and has been in good health for 82 months. Patient 2 had no acute rejection or severe complications, but died of chronic graft dysfunction 34 months postoperatively. Patient 3 had acute rejection on postoperative days 10 and 35, complicated with pulmonary infection, pleural effusion and opportunistic infection. After successful treatment, she resumed work and has been followed up for 47 months. Her condition is good. CONCLUSION: Liver transplantation can offer an effective therapy for patients with diffuse Caroli's disease, and can provide satisfactory long-term results.


Assuntos
Doença de Caroli/cirurgia , Transplante de Fígado , Doença Aguda , Adolescente , Adulto , Anti-Inflamatórios/uso terapêutico , Criança , Doença Crônica , Evolução Fatal , Feminino , Rejeição de Enxerto/tratamento farmacológico , Humanos , Masculino , Metilprednisolona/uso terapêutico , Prognóstico
18.
Ai Zheng ; 26(5): 524-7, 2007 May.
Artigo em Chinês | MEDLINE | ID: mdl-17672945

RESUMO

BACKGROUND & OBJECTIVE: Intrahepatic biliary cystadenocarcinoma (IBC) is a rare intrahepatic malignant tumor which is scarcely reported, and there is relatively little experience in the diagnosis and treatment. This study was to analyze the clinicopathologic features, diagnosis, and treatment of IBC. METHODS: Clinical data of 11 patients with pathologically confirmed papillary IBC, treated between Mar. 1999 and Oct. 2006 with surgical operation in West China Hospital, were analyzed retrospectively. Of the 11 patients, 2 were men and 9 were women, with a median age of 54 (range 45-68). RESULTS: The chief complaints of the IBC patients were pain and distention in the epigastrium. Four cases were determined by immunohistochemistry, and showed cytokeratin 7 (CK7) expression. Four patients showed infiltration of carcinoma cells in the surrounding liver tissues; 3 of them received palliative hepatectomy and 1 received radical excision; they survived for 12-23 months. The rest 7 showed carcinoma cells confined to the cyst wall, and received radical excision; 3 of them survived for over 3 years; of the rest 4 patients, 1 received operation again 10 months later because of tumor recurrence and was still alive 14 months after the second operation, 1 suffered from intrahepatic multi-metastasis 12 months after operation and received expectant treatment, 1 suffered from ascites 15 month after operation and died without further treatment, 1 was lost during follow-up. CONCLUSIONS: IBC occurs mainly in elder women, and its malignant degree is lower than that of solid carcinoma. The prognosis of the patients with IBC confined to the cyst wall after complete tumor removal is better than that of the patients with IBC infiltrated into the liver.


Assuntos
Neoplasias dos Ductos Biliares/diagnóstico , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/cirurgia , Cistadenocarcinoma/diagnóstico , Cistadenocarcinoma/cirurgia , Idoso , Neoplasias dos Ductos Biliares/sangue , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/patologia , Antígeno CA-19-9/sangue , Cistadenocarcinoma/sangue , Cistadenocarcinoma/patologia , Feminino , Seguimentos , Hepatectomia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Prognóstico , Estudos Retrospectivos
19.
Zhonghua Gan Zang Bing Za Zhi ; 14(6): 445-8, 2006 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-16792870

RESUMO

OBJECTIVES: To study the effectiveness of the lidocaine test in evaluating the liver reserve of rats with experimental liver injury in different phases. METHODS: 40 healthy male Wistar rats were divided randomly into experimental and control groups. Rats of the experimental group received subcutaneous CCl4 in oil injection, and rats of the control group received saline injections. Monoethylglycinexylidide (MEGX) test, common hepatic function tests and histological examination of the livers were performed on all the rats. RESULTS: With the development of the severity in liver injury, the concentrations of the serum MEGX in lidocaine test decreased gradually, which were consistent with liver histological changes. However, the results from the common liver function tests were all abnormal in the experimental group and were not consistent with the liver histological changes. CONCLUSION: The results obtained from the MEGX test are more agreeable to liver histological changes than those from common liver function tests. The results from the MEGX test can represent liver histological changes concisely.


Assuntos
Cirrose Hepática Experimental/patologia , Cirrose Hepática Experimental/fisiopatologia , Fígado/fisiopatologia , Animais , Tetracloreto de Carbono , Intoxicação por Tetracloreto de Carbono , Lidocaína/análogos & derivados , Fígado/patologia , Cirrose Hepática Experimental/induzido quimicamente , Testes de Função Hepática , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar
20.
Fa Yi Xue Za Zhi ; 22(6): 401-3, 2006 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-17285856

RESUMO

OBJECTIVE: To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA CO II. METHODS: A 635 bp region for CO II of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura's two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft. RESULTS: It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for CO II. CONCLUSION: This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).


Assuntos
DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Medicina Legal/métodos , Muscidae/genética , Animais , Genética Populacional , Geografia , Muscidae/classificação , Filogenia , Reação em Cadeia da Polimerase/métodos , Especificidade da Espécie , Tempo (Meteorologia)
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA