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1.
Sensors (Basel) ; 24(3)2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38339631

RESUMEN

As a key component of the rolling mill, the four-row cylindrical roller bearing (FCRB) operates under complex working conditions of high speed, high temperature, and heavy load. Due to the lack of an effective temperature test scheme for rolling mill bearings, a too high temperature can easily lead to bearing failure or damage under unsteady conditions. To reveal the internal temperature distribution law of four-row roller bearings of rolling mills and solve the common problem of difficult temperature monitoring of rolling mill bearings, in this paper, a four-row cylindrical roller bearing of 1140 mm cold rolling six-high mill is taken as the research object, and the temperature field calculation model for four-row cylindrical roller bearings is established. Firstly, the mechanical analysis model of FCRB is established on the basis of single row bearing by slice method. Secondly, the mechanical calculation model of FCRB is established by the Newton-Raphson method (NRM) and the finite element method (FEM). Thirdly, based on the mechanical calculation model, the finite element method is used to establish the temperature field model of FCRB under uniform load distribution and non-uniform load distribution. Finally, the temperature test experiment is carried out with the FCRB in the rolling mill fault diagnosis test bench. The results show that the error between the FCRB temperature calculation model and the experimental results is less than 10%. It can be seen that the uneven temperature distribution of FCRB is mainly caused by the uneven load distribution. The temperature distribution along the axial direction of the bearing is related to the load distribution of each column, while the circumferential temperature distribution is related to the azimuth angle.

2.
J Environ Sci (China) ; 138: 650-659, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38135428

RESUMEN

Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zero-valent iron (Fe0) for the removal of oxidative contaminants from wastewater. This study thus proposed an approach to fabricate micron-sized sulfidated zero-valent iron-aluminum particles (S-Al0@Fe0) with high reactivity, electron selectivity and capacity using recycled waste aluminum scraps. S-Al0@Fe0 with a three-layer structure contained zero-valent aluminum (Al0) core, Fe0 middle layer and iron sulfide (FeS) shell. The rates of chromate (Cr(VI)) removal by S-Al0@Fe0 at pH 5.0‒9.0 were 1.6‒5.9 times greater than that by sulfidated zero-valent iron (S-Fe0). The Cr(VI) removal capacity of S-Al0@Fe0 was 8.2-, 11.3- and 46.9-fold greater than those of S-Fe0, zero-valent iron-aluminum (Al0-Fe0) and Fe0, respectively. The chemical cost of S-Al0@Fe0 for the equivalent Cr(VI) removal was 78.5% lower than that of S-Fe0. Negligible release of soluble aluminum during the Cr(VI) removal was observed. The significant enhancement in the reactivity and capacity of S-Al0@Fe0 was partially ascribed to the higher reactivity and electron density of the Al0 core than Fe0. More importantly, S-Al0@Fe0 served as an electric cell to harness the persistent and selective electron transfer from the Al0-Fe0 core to Cr(VI) at the surface via coupling Fe0-Fe2+-Fe3+ redox cycles, resulting in a higher electron utilization efficiency. Therefore, S-Al0@Fe0 fabricated using recycled waste aluminum scraps can be a cost-effective and environmentally-friendly alternative to S-Fe0 for the enhanced removal of oxidative contaminants in industrial wastewater.


Asunto(s)
Cromatos , Contaminantes Químicos del Agua , Hierro/química , Aguas Residuales , Aluminio , Contaminantes Químicos del Agua/química , Cromo/química
3.
BMC Anesthesiol ; 23(1): 141, 2023 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-37106341

RESUMEN

BACKGROUND: Children with OSAS are prone to various airway complications during tracheal extubation after tonsillectomy and adenoidectomy due to oropharyngeal secretions and oozing blood. However, few studies have examined the effect of position on airway complications after tracheal extubation in children with OSAS. The aim of this study was to investigate the appropriate position for extubation in children with OASA. METHODS: A total of 459 children aged 3-14 years with OSAS who underwent tonsillectomy and adenoidectomy were recruited for this study. All children were treated with the same surgical approach and standard anesthesia methods of induction of anesthesia, tracheal intubation and maintenance of anesthesia. At the end of surgery, the children were delivered to the post anesthesia care unit and randomly divided into three groups: Group A: Head-high 0° in lateral position; Group B: Head-high 15° in lateral position; Group C: Head-high 30° in lateral position. The main outcomes of this study were the pulse oxygen saturation (SpO2) and the Sedation-Agitation Scale (SAS) scores of the children after extubation, the outflow of oral-nasal secretions and the respiratory complications. Secondary outcomes were blood pressure, heart rate, end-respiratory carbon dioxide, respiratory rate, and post-operative awakening time of the children in three groups. RESULTS: Data from a total of 423 children were statistically analyzed, 141 in Group A, 142 in Group B, and 140 in Group C. The main results showed a significant decrease in choking response after extubation in Group B (46.5%) and Group C (40.7%) compared to Group A (60.3%) (P < 0.05). The SAS score for postoperative agitation was higher in Group A (4.6 [Formula: see text] 0.9) than in Group B (4.4 [Formula: see text] 0.7) and Group C (4.3 [Formula: see text] 0.6) (P < 0.05). Also the SpO2 after extubation was higher in Group B (97.2%) and Group C (97.1%) than in Group A (95.8%) (P < 0.05). In contrast, there was no difference in the occurrence of respiratory complication and postoperative agitation in children between Group B and Group C (all P > 0.05). In addition, there was no difference in the amount of oral-nasal secretions among the children in the three groups (all P > 0.05). CONCLUSION: The head-high 15° lateral position and head-high 30° lateral position can reduce the incidence of airway complications and agitation and provide safe and comfortable extubation conditions for children during the peri-extubation period after tonsillectomy and adenoidectomy, which has certain clinical guidance value. TRIAL REGISTRATION: Registration Number: NO.ChiCTR2200055835(20,01,2022) https://www.chictr.org.cn.


Asunto(s)
Apnea Obstructiva del Sueño , Tonsilectomía , Niño , Humanos , Extubación Traqueal/métodos , Anestesia General , Tonsilectomía/efectos adversos , Adenoidectomía/efectos adversos , Apnea Obstructiva del Sueño/cirugía
4.
BMC Anesthesiol ; 23(1): 304, 2023 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-37684574

RESUMEN

OBJECTIVE: To observe and evaluate the effectiveness and safety of Esketamine or Sufentanil combined with Dexmedetomidine for sedation and analgesia in lung tumor percutaneous radiofrequency ablation (PRFA) to provide a clinical basis for the optimization of sedation and analgesia in lung tumor PRFA protocols outside the operating room. METHODS: In this trial, 44 patients aged 37 to 84 undergoing lung tumor PRFA were enrolled and assigned to Group E (n = 22, Esketamine 0.2 mg/kg) or Group S (n = 22,Sufentanil 0.1 µg/kg ). Dexmedetomidine was infused intravenously as a sedative in both groups. The modified observer's assessment of alertness and sedation scale (MOAAS), physical movement pain scale, intraoperative vital signs, anesthesia recovery time, radiologist and patient satisfaction rates, incidence of respiratory depression, and incidence of postoperative nausea and vomiting were recorded. RESULTS: Although there was no significant difference in the physical movement pain scale, blood oxygen saturation or incidence of perioperative adverse events between the two groups during ablation, the MOAAS, mean arterial pressure (MAP) and heart rate (HR) were higher in Group E than in Group S. The anesthesia recovery time was shorter in Group E than in Group S, and radiologist satisfaction was better in Group E than in Group S, but there was no significant difference between the two groups in terms of patient satisfaction. CONCLUSION: Esketamine or Sufentanil combined with Dexmedetomidine is safe for lung tumor PRFA. However, in elderly patients with multiple underlying diseases, low-dose Esketamine combined with Dexmedetomidine has fewer hemodynamic effects on patients, milder respiratory depression, shorter recovery time, and better radiologist satisfaction because of its better controllability of sedation depth. TRIAL REGISTRATION: Chinese Clinical Trial Registry (Registration number#ChiCTR ChiCTR21000500 21); Date of Registration: 16/08/2021.


Asunto(s)
Analgesia , Anestesia , Dexmedetomidina , Neoplasias Pulmonares , Anciano , Humanos , Sufentanilo , Neoplasias Pulmonares/cirugía , Dolor
5.
Sensors (Basel) ; 23(13)2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37447885

RESUMEN

Rolling is the main process in steel production. There are some problems in the rolling process, such as insufficient ability of abnormal detection and evaluation, low accuracy of process monitoring, and fault diagnosis. To improve the accuracy of quality-related fault diagnosis, this paper proposes a quality-related process monitoring and diagnosis method for hot-rolled strip based on weighted statistical feature KPLS. Firstly, the process-monitoring and diagnosis model of strip thickness and quality based on the KPLS method is introduced. Then, considering that the KPLS diagnosis method ignores the contribution of process variables to quality, it is easy to misjudge the root cause of quality in the diagnosis process. Based on the rolling mechanism model, the influence weight of strip thickness is constructed. By weighing the statistical data features, a quality diagnosis framework of series structure data fusion is constructed. Finally, the method is applied to the 1580 mm hot-rolling process for industrial verification. The verification results show that the proposed method has higher diagnostic accuracy than PLS, KPLS, and other methods. The results show that the diagnostic model based on weighted statistical feature KPLS has a diagnostic accuracy of more than 96% for strip thickness and quality-related faults.


Asunto(s)
Industrias , Acero
6.
J Environ Sci (China) ; 125: 630-640, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36375945

RESUMEN

Biogenic hydrogen sulfide is an odorous, toxic and corrosive gas released from sewage in sewers. To control sulfide generation and emission, nitrate is extensively applied in sewer systems for decades. However, the unexpected sulfide rebound after nitrate addition is being questioned in recent studies. Possible reasons for the sulfide rebounds have been studied, but the mechanism is still unclear, so the countermeasure is not yet proposed. In this study, a lab-scale sewer system was developed for investigating the unexpected sulfide rebounds via the traditional strategy of nitrate addition during 195-days of operation. It was observed that the sulfide pollution was even severe in a sewer receiving nitrate addition. The mechanism for the sulfide rebound can be differentiated into short-term and long-term effects based on the dominant contribution. The accumulation of intermediate elemental sulfur in biofilm resulted in a rapid sulfide rebound via the high-rate sulfur reduction after the depletion of nitrate in a short period. The presence of nitrate in sewer promoted the microorganism proliferation in biofilm, increased the biofilm thickness, re-shaped the microbial community and enhanced biological denitrification and sulfur production, which further weakened the effect of nitrate on sulfide control during the long-term operation. An optimized biofilm-initiated sewer process model demonstrated that neither the intermittent nitrate addition nor the continuous nitrate addition was a sustainable strategy for the sulfide control. To minimize the negative impact from sulfide rebounds, a (bi)monthly routine maintenance (e.g., hydraulic flushing with nitrate spike) to remove the proliferative microorganism in biofilm is necessary.


Asunto(s)
Sulfuro de Hidrógeno , Nitratos , Aguas del Alcantarillado , Sulfuros , Azufre , Óxidos de Nitrógeno
7.
Sensors (Basel) ; 22(10)2022 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-35632213

RESUMEN

The roll-bearing-bearing housing (RBBH) system is one of the most common kernel structures used to determine strip mill stability and product surface quality in modern metallurgical machinery. To better understand dynamic characteristics of the RBBH system, this paper provides a nonlinear dynamic model and designs an engineering test platform on the RBBH system in the whole rolling process. First, a nonlinear dynamic model of the RBBH system supported by four-row rolling bearings under high speed and heavy load is established. Then, the method of combining Riccati transfer matrix and Newmark-ß numerical integration is employed to solve nonlinear dynamic equations. After that, the engineering test platform is designed and assembled to capture and analyze the vibration signals of weathering steel (SPA-H) with finished thicknesses of 1.6 and 3.2 mm. Finally, the dynamic characteristics of the RBBH system are studied with the method of the dynamic model and vibration data fusion. The results show that the SPA-H with a finished thickness of 1.6 mm is rolled, the RBBH system fluctuates violently in both horizontal and vertical directions, and numerical results are highly consistent with experimental results in acceleration response, velocity response, and displacement response. In addition, the dynamic performance parameters of the four-row rolling bearing will also fluctuate greatly. Finally, there is significant interest to gain the benefits for the RBBH system design and mill stable rolling purposes.

8.
Sensors (Basel) ; 21(16)2021 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-34450936

RESUMEN

Rolling mill multi-row bearings are subjected to axial loads, which cause damage of rolling elements and cages, so the axial vibration signal contains rich fault character information. The vertical shock caused by the failure is weakened because multiple rows of bearings are subjected to radial forces together. Considering the special characters of rolling mill bearing vibration signals, a fault diagnosis method combining Adaptive Multivariate Variational Mode Decomposition (AMVMD) and Multi-channel One-dimensional Convolution Neural Network (MC1DCNN) is proposed to improve the diagnosis accuracy. Additionally, Deep Convolutional Generative Adversarial Network (DCGAN) is embedded in models to solve the problem of fault data scarcity. DCGAN is used to generate AMVMD reconstruction data to supplement the unbalanced dataset, and the MC1DCNN model is trained by the dataset to diagnose the real data. The proposed method is compared with a variety of diagnostic models, and the experimental results show that the method can effectively improve the diagnosis accuracy of rolling mill multi-row bearing under unbalanced dataset conditions. It is an important guide to the current problem of insufficient data and low diagnosis accuracy faced in the fault diagnosis of multi-row bearings such as rolling mills.

9.
Crit Rev Biotechnol ; 38(7): 1089-1105, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29631429

RESUMEN

Consolidated bioprocessing (CBP) by micro-organisms is desired for efficient conversion of lignocellulosic biomass to bioethanol fuels. Potential candidates have been discovered, including cellulolytic bacteria and filamentous fungi. Genetic and metabolic manipulation of these organisms further promotes their fermentation capacities and the ethanol tolerance. In addition, Saccharomyces cerevisiae and several other yeasts were genetically modified to express recombinant cellulases in media or display them on the cell surface for CBP of cellulose. To compensate the insufficient capacity of a single strain, various microbial consortia have also been developed. In this article, we reviewed the recent advances in CBP microbes and focused on the efforts in strain improvement employing genetic engineering.


Asunto(s)
Biocombustibles , Celulosa/metabolismo , Etanol/metabolismo , Fermentación , Ingeniería Genética , Celulasa , Proteínas Fúngicas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
10.
Environ Sci Technol ; 52(8): 4754-4762, 2018 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-29547691

RESUMEN

The conventional flue gas treatment technologies require high capital investments and chemical costs, which limit their application in industrial sectors. This study developed a sulfur-cycling technology to integrate sulfide production by biological sulfur reduction and simultaneous catalytic desulfurization and denitrification with H2S (H2S-SCDD) for flue gas treatment and sulfur recovery. In a packed bed reactor, high-rate sulfide production (1.63 ± 0.16 kg S/m3-d) from biological sulfur reduction was achieved using organics in wastewater as electron donors at pH around 5.8. 93% of sulfide in wastewater was stripped out as H2Sg, which can be a low-cost reducing agent in the H2S-SCDD process. Over 90% of both SO2 and NO were removed by the H2S-SCDD process under the test conditions, resulting in the formation of sulfur. 88% of the input S (H2Sg and SO2) were recovered as octasulfur with high purity. Besides partial recycling to produce biogenic sulfide, excessive sulfur can be obtained as a sellable product. The integrated sulfur-cycling technology is a chemical-saving and even profitable solution to the flue gas treatment in industrial sectors with wastewater available.


Asunto(s)
Sustancias Reductoras , Azufre , Catálisis , Desnitrificación , Aguas Residuales
11.
Toxicol Mech Methods ; 28(1): 38-44, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28707553

RESUMEN

The neurotoxicity of ziram is largely unknown. In this study, we investigated the direct inhibitions of ziram on rat neurosteroid synthetic and metabolizing enzymes, 5α-reductase 1 (SRD5A1), 3α-hydroxysteroid dehydrogenase (AKR1C14), and retinol dehydrogenase 2 (RDH2). Rat SRD5A1, AKR1C14, and RDH2 were cloned and transiently expressed in COS1 cells, and the effects of ziram on these enzymes were measured. Ziram inhibited rat SRD5A1 and AKR1C14 with IC50 values of 1.556 ± 0.078 and 1.017 ± 0.072 µM, respectively, when 1000 nM steroid substrates were used. Ziram weakly inhibited RDH2 at 100 µM, when androstanediol (1000 nM) was used. Ziram competitively inhibited SRD5A1 and non-competitively inhibited AKR1C14 when steroid substrates were used. Docking study showed that ziram bound to NADPH-binding pocket of AKR1C14. In conclusion, our results demonstrated that ziram inhibited SRD5A1 and AKR1C14 activities, thus possibly interfering with neurosteroid production in rats.


Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Fungicidas Industriales/toxicidad , Proteínas de la Membrana/antagonistas & inhibidores , Neurotransmisores/biosíntesis , Ziram/toxicidad , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/química , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Oxidorreductasas de Alcohol/antagonistas & inhibidores , Oxidorreductasas de Alcohol/química , Oxidorreductasas de Alcohol/genética , Oxidorreductasas de Alcohol/metabolismo , Aldehído Reductasa/química , Aldehído Reductasa/genética , Aldehído Reductasa/metabolismo , Animales , Sitios de Unión , Unión Competitiva , Células COS , Chlorocebus aethiops , Fungicidas Industriales/química , Fungicidas Industriales/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Simulación del Acoplamiento Molecular , Unión Proteica , Conformación Proteica , Medición de Riesgo , Relación Estructura-Actividad , Transfección , Ziram/química , Ziram/metabolismo
12.
Tumour Biol ; 39(6): 1010428317704821, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28653900

RESUMEN

Prostate cancer is the most commonly diagnosed malignancy and is the second leading deadly reason among male cancer. WDFY2, which is found to be a cancer-specific fusion gene with CDKN2D in ovarian cancer, is a new gene with unknown function in carcinogenesis. In this study, we investigated the role of WDFY2 in prostate cancer development. We examined WDFY2 expression in human prostate tissue specimens and prostate cancer cell lines BPH-1, LNCaP, PC3, and DU-145. Overexpression of WDFY2 was performed to evaluate the role of WDFY2 in cell proliferation, migration, and colony formation of prostate cancer cells. We analyzed the clinical impact and prognosis of WDFY2 expression on the progress of prostate cancer through data from online datasets. Our results showed that WDFY2 had lower expression level in prostate tumors than in normal tissues. Overexpression of WDFY2 in prostate cancer cells DU145 and PC-3 led to the suppression of cancer cell migration and colony formation. Furthermore, we found that WDFY2 exerted its role by suppressing the activity of Akt pathway other than the epithelial-mesenchymal transition progression. In conclusion, we have uncovered WDFY2 as a tumor suppressor gene and a new potential biomarker for cancer progression. Our results showed that WDFY2 inhibited cancer cell colony formation and migration via suppressing Akt pathway, making it a potential new therapeutic target in prostate cancer.


Asunto(s)
Proliferación Celular/genética , Transición Epitelial-Mesenquimal/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias de la Próstata/genética , Anciano , Carcinogénesis/genética , Línea Celular Tumoral , Movimiento Celular/genética , Inhibidor p19 de las Quinasas Dependientes de la Ciclina/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Péptidos y Proteínas de Señalización Intracelular/biosíntesis , Masculino , Persona de Mediana Edad , Pronóstico , Neoplasias de la Próstata/patología , Transducción de Señal
13.
Molecules ; 22(8)2017 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-28809813

RESUMEN

Water-miscible alkylimidazolium ionic liquids (ILs) are "green" co-solvents for laccase catalysis, but generally inhibit enzyme activity. Here, we present novel insights into inhibition mechanisms by a combination of enzyme kinetics analysis and molecular simulation. Alkylimidazolium cations competitively bound to the TI Cu active pocket in the laccase through hydrophobic interactions. Cations with shorter alkyl chains (C2~C6) entered the channel inside the pocket, exhibiting a high compatibility with laccase (competitive inhibition constant Kic = 3.36~3.83 mM). Under the same conditions, [Omim]Cl (Kic = 2.15 mM) and [Dmim]Cl (Kic = 0.18 mM) with longer alkyl chains bound with Leu296 or Leu297 near the pocket edge and Leu429 around TI Cu, which resulted in stronger inhibition. Complexation with alkylimidazolium cations shifted the pH optima of laccase to the right by 0.5 unit, and might, thereby, lead to invalidation of the Hofmeister series of anions. EtSO4- showed higher biocompatibility than did Ac- or Cl-, probably due to its binding near the TI Cu and its hindering the entry of alkylimidazolium cations. In addition, all tested ILs accelerated the scavenging of 2, 2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, which, however, did not play a determining role in the inhibition of laccase.


Asunto(s)
Proteínas Fúngicas/antagonistas & inhibidores , Imidazoles/química , Líquidos Iónicos/química , Lacasa/antagonistas & inhibidores , Sitios de Unión , Catálisis , Proteínas Fúngicas/química , Tecnología Química Verde , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Lacasa/química , Leucina/química , Simulación del Acoplamiento Molecular , Unión Proteica , Conformación Proteica , Solventes , Sordariales/enzimología
14.
J Environ Sci (China) ; 58: 146-154, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28774603

RESUMEN

The formation of disinfection by-products (DBPs) from the degradation of N,N-diethyl-3-methyl benzoyl amide (DEET) and ibuprofen (IBP) by the ultraviolet irradiation (UV)/chlorine process and subsequent post-chlorination was investigated and compared with the UV/H2O2 process. The pseudo first-order rate constants of the degradation of DEET and IBP by the UV/chlorine process were 2 and 3.1 times higher than those by the UV/H2O2 process, respectively, under the tested conditions. This was due to the significant contributions of both reactive chlorine species (RCS) and hydroxyl radicals (HO) in the UV/chlorine process. Trichloromethane, 1,1,1-trichloro-2-propanone and dichloroacetic acid were the major known DBPs formed after 90% of both DEET and IBP that were degraded by the UV/chlorine process. Their yields increased by over 50% after subsequent 1-day post-chlorination. The detected DBPs after the degradation of DEET and IBP comprised 13.5% and 19.8% of total organic chlorine (TOCl), respectively, and the proportions increased to 19.8% and 33.9% after subsequent chlorination, respectively. In comparison to the UV/H2O2 process accompanied with post-chlorination, the formation of DBPs and TOCl in the UV/chlorine process together with post-chlorination was 5%-63% higher, likely due to the generation of more DBP precursors from the attack of RCS, in addition to HO.


Asunto(s)
DEET/química , Desinfectantes/análisis , Ibuprofeno/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Desinfectantes/química , Desinfección , Halogenación , Peróxido de Hidrógeno , Radical Hidroxilo , Rayos Ultravioleta , Contaminantes Químicos del Agua/química
15.
Molecules ; 20(11): 19907-13, 2015 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26556325

RESUMEN

The biosynthetic utilization of laccase/mediator system is problematic because the use of organic cosolvent causes significant inhibition of laccase activity. This work explored how the organic cosolvent impacts on the laccase catalytic capacity towards 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in aqueous solution. Effects of acetone on the kinetic constants of laccase were determined and the results showed Km and Vmax varied exponentially with increasing acetone content. Acetone as well as some other cosolvents could transform ABTS radicals into its reductive form. The content of acetone in media significantly affected the radical scavenging rates. Up to 95% of the oxidized ABTS was successfully recovered in 80% (v/v) acetone in 60 min. This allows ABTS recycles at least six times with 70%-75% of active radicals recovered after each cycle. This solvent-based recovery strategy may help improve the economic feasibility of laccase/ABTS system in biosynthesis.


Asunto(s)
Acetona/química , Benzotiazoles/química , Depuradores de Radicales Libres/química , Lacasa/química , Oxidación-Reducción , Ácidos Sulfónicos/química , Catálisis , Cinética , Solventes/química
16.
Zhonghua Yi Xue Za Zhi ; 95(6): 444-8, 2015 Feb 10.
Artículo en Zh | MEDLINE | ID: mdl-25916782

RESUMEN

OBJECTIVE: To explore the effects of intra-PAG injection of ZIP on sensory and affective components of pain. METHODS: For determining the role of ZIP on pain-induced aversion, the effects of intra-PAG injection of ZIP on formalin-induced conditioned place avoidance (F-CPA) was investigated. To determine the role of ZIP on pain perception, formalin-induced inflammatory pain model was established and the effects of intra-PAG injection of ZIP on formalin-induced nociceptive behaviors was investigated. RESULTS: In the NS-treated rats, the time in the pain-paired compartment during the test session was significantly shorter than that during the preconditioning session 2 and 24 hours after administration of the drug at both 1 and 7 day post-training (Group NS-1 d-2 h: (465.1 ± 40.6) vs (133.8 ± 29.4) s (P < 0.001); Group NS-7 d-2 h: (432.3 ± 43.7) vs (150.5 ± 26.6) s (P < 0.01); Group NS-1 d-24 h: (500.5 ± 20.6) vs (107.0 ± 15.7) s (P < 0.001); Group NS-7 d-24 h: (450.8 ± 27.4) vs (129.4 ± 21.1) s (P < 0.001)). On the contrary, in the ZIP-treated rats, no significant differences were observed in the time in the pain-paired compartment between the post-conditioning and pre-conditioning sessions at the same time-points. CPA scores also showed the attenuation of F-CPA by intra-PAG injection of ZIP in comparison to the saline-injected rats (P < 0.05). Compared with the intra-PAG saline-injected group, intra-PAG microinjection of ZIP did not affect the formalin-induced nociceptive behaviors (P > 0.05). CONCLUSION: The study suggests that PAG contributes to pain-related aversion in rats, and the mechanism of pain emotion encoding in PAG may attribute to the activation of targets of ZIP.


Asunto(s)
Dolor , Sustancia Gris Periacueductal , Animales , Formaldehído , Dimensión del Dolor , Péptidos , Ratas
18.
Zhonghua Yi Xue Za Zhi ; 94(9): 646-50, 2014 Mar 11.
Artículo en Zh | MEDLINE | ID: mdl-24842200

RESUMEN

OBJECTIVE: To investigated the effect of a hyperoncotic CPB-prime with hydroxyethyl starch (HES) 6% (130/0.4) on extravascular lung water (EVLW) and post-pump cardiac and pulmonary functions. METHODS: This study plan approved by the hospital ethics committee review. In 40 randomized patients undergoing elective coronary artery bypass graft surgery (CABG), a colloid prime (COP:42.5 mmHg, HES-group, n = 20) and a crystalloid prime (Ringer's lactate, crystalloid group, n = 20) of equal volume were compared with respect to the effects on cardiopulmonary function. Cardiac index (CI), mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), systemic vascular resistance index (SVRI), pulmonary artery pressure (PAP), pulmonary vascular resistance index (PVRI), alveolo-arterial oxygen difference (AaDO2), pulmonary shunt fraction (Qs/QT), extravascular lung water (EVLW), COP, fluid balance and body weight were evaluated peri-operatively. RESULTS: Pre-operative demographic and clinical data, CPB-time, crossclamp time and the number of anastomoses were comparable for both groups. During CPB, COP was reduced by 22% in the HES-group [(16.7 ± 3.9) vs (21.5 ± 2.2) mmHg, P < 0.05] while it was reduced by more than 50% of the pre-CPB value [10.7 ± 2.0 vs (22.7 ± 1.9) mmHg, P < 0.05] in the crystalloid group (P < 0.05 HES-group vs. crystalloid group). Post-CPB EVLW was unchanged in the HES-group but it was elevated by 21% in the crystalloid group (P < 0.05 HES-group vs crystalloid group), CI was higher in the HES-group [(3.3 ± 0.3) vs (2.7 ± 0.7) L/min, P < 0.05]. Fluid balance was less in the HES-group (715 ± 544 vs 1 951 ± 487, P < 0.05). Post-operative weight gain could be prevented in the HES-group but not in the crystalloid group (1.4 ± 1.1 vs -0.3 ± 1.3, P < 0.05). No significant differences were seen for MAP, PAP, PCWP, SVRI, PVRI, AaDO2 and (Qs/QT) between the two groups at any time. CONCLUSIONS: Hyperoncotic CPB-prime using HES 6% improves CI and prevents EVLW accumulation in the early post-pump period, while pulmonary function is unchanged.


Asunto(s)
Puente Cardiopulmonar/métodos , Agua Pulmonar Extravascular , Puente de Arteria Coronaria , Humanos , Soluciones Hipertónicas/administración & dosificación , Presión Osmótica , Periodo Posoperatorio , Presión Esfenoidal Pulmonar , Equilibrio Hidroelectrolítico
19.
J Vasc Access ; : 11297298241233713, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38390724

RESUMEN

BACKGROUND: The dynamic needle tip positioning technique represents an advanced version of the short-axis out-of-plane ultrasound-guided approach employed for radial artery catheterization. The study aimed to explore the most effective insertion site capable of expeditiously and accurately executing the procedure in a clinical setting. METHODS: A prospective randomized controlled study encompassed 246 elective surgery patients necessitating invasive arterial monitoring. Participants were randomly assigned to three distinct groups: Site 1 (targeting the radial styloid process), Site 2 (midway between Sites 1 and 3), and Site 3 (distal one-third of the forearm). The dynamic needle tip positioning technique was implemented across all groups. Crucial parameters, such as first-attempt success rate, time to success, overall success rate, total catheterization time, number of attempts, and complications, were meticulously documented and compared. RESULTS: The Site 2 cohort presented a significantly heightened first-attempt success rate compared to Site 1 (97.5% vs 80%, p = 0.003) and Site 3 (97.5% vs 81.25%, p = 0.006). Moreover, Site 2 displayed a reduced time to success in contrast to Site 1 (31.5 vs 38, p = 0.003) and Site 3 (31.5 vs 40, p = 0.006). Total catheterization time was significantly shorter in Site 2 compared to Site 1 (32 vs 42.5, p < 0.001) and Site 3 (32 vs 43.5, p < 0.001). Site 2 necessitated fewer attempts than Site 1 (p = 0.02) and Site 3 (p = 0.03). Male gender and puncture at Site 2 were associated with expedited time to success. Adverse events manifested more frequently in the Site 3 group compared to the Site 1 group (15% vs 3.75%, p = 0.03) and the Site 2 group (15% vs 2.5%, p = 0.01). CONCLUSIONS: The optimal insertion site for ultrasound-guided radial artery catheterization utilizing the dynamic needle tip positioning technique in adult patients is situated midway between the radial styloid process and the distal one-third of the forearm.

20.
Neurotherapeutics ; : e00359, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38664193

RESUMEN

Postoperative cognitive dysfunction (POCD) is a common postoperative complication in elderly patients, and neuroinflammation is a key hallmark. Recent studies suggest that the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome-mediated astrocytes pyroptosis is involved in the regulation of neuroinflammation in many neurocognitive diseases, while its role in POCD remains obscure. Carnosine is a natural endogenous dipeptide with anti-inflammatory and neuroprotective effects. To explore the effect of carnosine on POCD and its mechanism, we established a POCD model by exploratory laparotomy in 24-month-old male Sprague-Dawley rats. We found that the administrated of carnosine notably attenuated surgery-induced NLRP3 inflammasome activation and pyroptosis in astrocytes, central inflammation, and neuronal damage in the hippocampus of aged rats. In addition, carnosine dramatically ameliorated the learning and memory deficits of surgery-induced aged rats. Then in the in vitro experiments, we stimulated primary astrocytes with lipopolysaccharide (LPS) after carnosine pretreatment. The results also showed that the application of carnosine alleviated the activation of the NLRP3 inflammasome, pyroptosis, and inflammatory response in astrocytes stimulated by LPS. Taken together, these findings suggest that carnosine improves POCD in aged rats via inhibiting NLRP3-mediated astrocytes pyroptosis and neuroinflammation.

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