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1.
Opt Lett ; 48(10): 2519-2522, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37186697

RESUMEN

Cryogenic ultra-stable lasers have extremely low thermal noise limits and frequency drifts, but they are more seriously affected by vibration noise from cryostats. Main material candidates for cryogenic ultra-stable cavities include silicon and sapphire. Although sapphire has many excellent properties at low temperature, the development of sapphire-based cavities is less advanced than that of silicon-based. Using a homemade cryogenic sapphire cavity, we develop an ultra-stable laser source with a frequency instability of 2(1) × 10-16. This is the best frequency instability level among similar systems using cryogenic sapphire cavities reported so far. Low vibration performance of the cryostat is demonstrated with a two-stage vibration isolation, and the vibration suppression is optimized by tuning the mixing ratio of the gas-liquid-helium. With this technique, the linear power spectral densities of vibrations at certain frequencies higher than tens of hertz are suppressed by two orders of magnitude in all directions.

2.
Anesth Analg ; 136(1): 60-69, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36301724

RESUMEN

BACKGROUND: The effect of anesthesia regimens on postoperative delirium after on-pump cardiac valve surgery is yet undetermined. This study aimed to evaluate the effect of volatile anesthesia compared with propofol-based total intravenous anesthesia (TIVA) on the occurrence of delirium after on-pump cardiac valve surgery. METHODS: This randomized clinical trial was conducted at a university academic hospital in China, from February 2019 to January 2021. Patients scheduled for on-pump cardiac valve surgery or combined valve with coronary artery bypass grafting (CABG) surgeries were randomly assigned to receive anesthesia maintenance with either a volatile anesthetic (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was the incidence of delirium during the first 7 days after surgery, assessed using the confusion assessment method for the intensive care unit (ICU). The secondary outcomes included duration of delirium, subtypes of delirium, 30-day mortality, pain score, major morbidity (including cerebral infarction, respiratory failure, and pneumonia), duration of mechanical ventilation, and lengths of ICU and hospital stay. The statistical analysis of the primary outcome variable was by Pearson's χ 2 test. RESULTS: Among the 684 patients analyzed (mean age, 53.8 years; 381 [55.7%] women), 676 were assessed for the primary outcome. Postoperative delirium occurred in 63 of 337 (18.7%) patients receiving volatile anesthesia versus 76 of 339 (22.4%) patients receiving propofol-based TIVA (relative risk, 0.80; 95% confidence interval [CI], 0.55-1.16; P = .231). There were no significant differences between the groups in any of the secondary outcomes. CONCLUSIONS: Among patients undergoing on-pump cardiac valve surgery, anesthesia maintenance with a volatile agent did not result in significantly fewer occurrences of postoperative delirium than propofol-based TIVA.


Asunto(s)
Anestésicos por Inhalación , Procedimientos Quirúrgicos Cardíacos , Delirio del Despertar , Propofol , Humanos , Adulto , Femenino , Persona de Mediana Edad , Masculino , Propofol/efectos adversos , Delirio del Despertar/etiología , Anestesia Intravenosa/efectos adversos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Válvulas Cardíacas , Anestésicos Intravenosos/efectos adversos
3.
BMC Musculoskelet Disord ; 24(1): 715, 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37684622

RESUMEN

OBJECTIVES: The relationship between abdominal adipose tissue and osteoporosis is poorly understood. The purpose of this study was to examine the associations of abdominal adipose tissue with bone mineral density (BMD) among a nationally representative sample of US middle-aged adults. MATERIAL AND METHODS: This study included 1498 participants from the National Health and Nutrition Examination Survey 2013-2014 and 2017-2018. Dual-energy x-ray absorptiometry was used to measure BMD at the lumbar spine and femoral neck, as well as to assess abdominal adipose mass by categorizing total adipose tissue (TAT) into visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Linear regression was used to assess the relationship between abdominal adipose tissue and BMD, and logistic regression and generalized additive model were used to assess the associations of abdominal adipose tissue with the development of low BMD. RESULTS: In our study, men accounted for 51.3%, and the mean age and body mass index for men and women were 49.3 and 49.6 years, and 23.9 and 28.3 kg/m2, respectively. In the univariate model, we found that abdominal adipose mass was positively associated with BMD at femoral neck and spine in both genders. In the multivariate model, among men, a negative correlation was observed between TAT and SAT and BMD at the femoral neck. Additionally, higher masses of TAT, SAT, and VAT were found to significantly increase the risk of low BMD at both the femoral neck and lumbar spine. In contrast, there was no significant association between abdominal adipose mass and BMD in middle-aged women, regardless of menopausal status. CONCLUSIONS: Our finding suggested that abdominal adipose tissue, regardless of its location (SAT or VAT), may have a negative impact on BMD in middle-aged men independently of body weight, but this relationship was not observed in women. Further research is needed to confirm these findings and investigate potential mechanisms underlying these associations.


Asunto(s)
Densidad Ósea , Enfermedades Óseas Metabólicas , Adulto , Persona de Mediana Edad , Femenino , Humanos , Masculino , Encuestas Nutricionales , Obesidad , Adiposidad , Vértebras Lumbares/diagnóstico por imagen
4.
J Cardiothorac Vasc Anesth ; 36(10): 3758-3765, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35863984

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate the effect of volatile anesthesia and propofol-based total intravenous anesthesia (TIVA) on postoperative pulmonary complications (PPCs) among patients undergoing cardiac surgery. DESIGN: Parallel-group, randomized controlled trial. SETTING: Single-center tertiary care hospital. PARTICIPANTS: Five hundred twenty-four patients undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: The patients were assigned randomly (1:1) to receive anesthesia maintenance with a volatile anesthetic (sevoflurane or desflurane) or propofol-based TIVA. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite of postoperative pulmonary complications within the first 7 postoperative days. The PPCs occurred in 118 of 262 patients (45.0%) in the volatile anesthesia group compared with 105 of 262 patients (40.1%) in the propofol-based intravenous anesthesia group (relative risk: 1.17 [95% CI 0.96-1.42], p = 0.123). There were no significant differences in the severity of PPCs within 7 days postoperatively, the occurrence and severity grade of PPCs within 30 days, the incidence of hypoxia, and 30-day mortality. CONCLUSIONS: In adult patients undergoing cardiac surgery with cardiopulmonary bypass, general anesthesia with a volatile anesthetic compared with propofol-based TIVA had not reduced pulmonary complications within the first 7 days after surgery.


Asunto(s)
Anestésicos por Inhalación , Procedimientos Quirúrgicos Cardíacos , Propofol , Adulto , Anestesia General , Anestesia Intravenosa/efectos adversos , Anestésicos por Inhalación/efectos adversos , Anestésicos Intravenosos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Propofol/efectos adversos
5.
Pak J Pharm Sci ; 35(1): 49-52, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35221272

RESUMEN

Ovarine cancer is a common woman malignancy in the world. Majority of the ovarian cancers are originated in the epithelial region which are lack of symptomps and this type of cancer is often get localized, when the tumour has spread outside the pelvis. Based on this context, the present study evaluated the effects of both aqueous and ethanolic extracts of Ipomoea staphylina leaves on ovarian cancer cell line. The SKOV-3 ovarian cancer cell line was used for evaluation of the effects of both extracts. Both extracts showed IC50 effects on ovarian cancer cell lines as sensitivity index (SI) for both extracts were recorded to above 1.iFurther, ethanol extract was more effective in the moderation of gene expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in comparison to aqueous extract. Further, morphological changes of SKOV-3 cells after treatment with both extracts also confirmed the results. The study, therefore, concludes that the ethanolic extract of Ipomoea staphylina leaves is more effective against ovarian cancer cell line.


Asunto(s)
Antineoplásicos Fitogénicos , Ipomoea/química , Neoplasias Ováricas/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/farmacología , Supervivencia Celular/efectos de los fármacos , Femenino , Humanos , Extractos Vegetales/química , Hojas de la Planta/química
6.
Opt Express ; 29(19): 30567-30578, 2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34614779

RESUMEN

State-of-the-art laser frequency stability has been pushed to the 10-17 level. The laser reference cavity is typically nested in a multi-layer thermal enclosure to increase vacuum thermal time constant and thermally controlled at the zero-thermal-expansion temperature to reduce the external temperature fluctuation effect. It is rather time consuming to accurately determine the zero-thermal-expansion temperature for a large thermal time constant system. Here we develop a fast method for measuring the zero-thermal-expansion temperature of the cavity by relying on just one single temperature scan. We first develop a theoretical model to predict the performance of the laser locked to the reference cavity, and then construct an evaluation system for verification of the model. The zero-thermal-expansion temperature of a 30-cm cavity is measured to be 4.3±0.5 °C. The fast and high precision method for determining the zero-thermal-expansion temperature will be valuable in improving long-term frequency stabilities of cavity stabilized lasers.

7.
J Cardiothorac Vasc Anesth ; 35(8): 2438-2446, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33183935

RESUMEN

OBJECTIVES: Sternal incisions can generate persistent and intense post-sternotomy pain. Propofol has been shown to improve postoperative analgesia, but the preventive effect on persistent pain after cardiac surgery is unknown. The hypothesis of the present study was that intraoperative propofol-based anesthesia compared with volatile anesthesia could reduce the risk of chronic pain after cardiac surgery. DESIGN: A single-center, two-arm, patient-and-evaluator-blinded, randomized controlled trial. SETTING: A single major urban teaching and university hospital. PATIENTS: Five-hundred adult patients undergoing cardiac surgery via sternotomy randomly were assigned. With six withdrawals from the study and five from surgery, 244 in the total intravenous anesthesia group and 245 in the volatile group were included in the modified intention-to-treat analysis. INTERVENTIONS: Patients randomly were assigned to receive either propofol-based total intravenous anesthesia or volatile anesthesia during surgery. MEASUREMENTS AND MAIN RESULTS: The primary outcomes were the incidence of pain at three, six, and 12 months after surgery defined as pain score >0 on the numeric rating scale. The secondary outcomes included acute pain, opioid use during the first 72 hours after surgery, and quality of life. The use of propofol did not significantly affect chronic pain at three months (55.4% v 52.9%, difference 2.5%, 95% confidence interval [CI] -6.6 to 11.6; p = 0.656), six months (35.5% v 37.5%, difference -2.0%, 95% CI -10.9 to 6.9; p = 0.657), or 12 months (18.2% v 20.7%, difference -2.5%, 95% CI -9.8 to 4.8; p = 0.495) compared with volatile anesthetics. Furthermore, there were no differences in acute pain score; morphine-equivalent consumption during the first 72 hours; and quality of life at three, six, and 12 months after surgery. CONCLUSIONS: Intraoperative administration of propofol did not reduce persistent pain after cardiac surgery compared with volatile anesthetics.


Asunto(s)
Dolor Agudo , Anestésicos por Inhalación , Procedimientos Quirúrgicos Cardíacos , Propofol , Adulto , Anestésicos por Inhalación/efectos adversos , Anestésicos Intravenosos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Humanos , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/etiología , Calidad de Vida
8.
Sensors (Basel) ; 21(14)2021 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-34300435

RESUMEN

Cryogenic ultrastable laser cavities push laser stability to new levels due to their lower thermal noise limitation. Vibrational noise is one of the major obstacles to achieve a thermal-noise-limited cryogenic ultrastable laser system. Here, we carefully analyze the vibrational noise contribution to the laser frequency. We measure the vibrational noise from the top of the pulse-tube cryocooler down to the experiment space. Major differences emerge between room and cryogenic temperature operation. We cooled a homemade 6 cm sapphire optical resonator down to 3.4 K. Locking a 1064 nm laser to the resonator, we measure a frequency stability of 1.3×10-15. The vibration sensitivities change at different excitation frequencies. The vibrational noise analysis of the laser system paves the way for in situ accurate evaluation of vibrational noise for cryogenic systems. This may help in cryostat design and cryogenic precision measurements.

9.
J Cell Mol Med ; 23(2): 1174-1182, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30450674

RESUMEN

The incidence rate of head and neck squamous cell carcinoma (HNSCC) has steadily increased over the past decade. However, treatment options for metastatic HNSCC are often limited and the 5-year survival rate has remained static. Therefore, the development and assessment of more efficient but less toxic therapeutic strategies is an unmet need for treatment of more extensive HNSCC. Here, we report that CYT997, a novel microtubule-disrupting agent, exerts strong activity in inhibiting HNSCC cell invasion and metastasis. The loss of invasion capacity by CYT997 was accompanied by an associated increase in cell adhesion and the reversal of epithelial-mesenchymal transition (EMT). Increased expression of E-cadherin protein and decreased expression of Vimentin protein became evident in HNSCC cells following CYT997 exposure, which were consistently observed in HNSCC xenografts from the mice receiving CYT997. Moreover, the capacity of invasive HNSCC cells to form pulmonary metastases was significantly blocked with CYT997 treatment, indicating that the diminishment of EMT traits contributes to CYT997-suppressed metastasis. Intriguingly, CYT997 impaired intracellular ATP levels in HNSCC cells, at least in part, through its inhibitory effect on the mitochondrial protein IF1. The addition of ATP attenuated CYT997-induced suppression of cell invasion, coupled with down-regulation of E-Cadherin and up-regulation of Vimentin. These findings support a critical role of ATP levels in cell invasion and metastasis under the influence of CYT997. Collectively, our data unveil the mechanism involved in mediating CYT997 action, and provide preclinical rationale for possible clinical application of CYT997 as a novel therapeutic strategy against aggressive HNSCC.


Asunto(s)
Adenosina Trifosfato/metabolismo , Movimiento Celular/efectos de los fármacos , Neoplasias de Cabeza y Cuello/metabolismo , Metástasis de la Neoplasia/tratamiento farmacológico , Piridinas/farmacología , Pirimidinas/farmacología , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Animales , Cadherinas/metabolismo , Línea Celular Tumoral , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias de Cabeza y Cuello/patología , Humanos , Ratones , Ratones Endogámicos NOD , Invasividad Neoplásica/patología , Metástasis de la Neoplasia/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Factores de Transcripción/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Vimentina/metabolismo
10.
Phys Chem Chem Phys ; 20(25): 17487-17496, 2018 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-29911703

RESUMEN

In order to probe into the effect of the promoter on the selectivity and activity towards C2H4 formation in the selective hydrogenation of C2H2 over cost-effective Cu-based bimetallic catalysts, different metal promoter M-modified Cu catalysts including Ni, Ag, Au, Pt, Pd and Rh have been employed to fully investigate the selective hydrogenation of C2H2 using density functional theory calculations together with microkinetic modeling. The results show that the adsorption ability of C2H2 is far stronger than that of C2H4 on different Cu-based catalysts, which favors the activation and hydrogenation of C2H2. The type of promoter obviously affects the preferable pathway of C2H2 selective hydrogenation, and ultimately alters the selectivity of the products; only on PdCu(211) and AgCu(211) surfaces, the C2H4 desorption pathway is the most favorable for gaseous C2H4 formation, suggesting that the promoter Pd or Ag has good selectivity towards C2H4 formation. The catalytic activity towards C2H4 formation follows the order PdCu(211) > PtCu(211) > NiCu(211) > RhCu(211) > AgCu(211) > AuCu(211) > Cu(211), indicating that the promoter can obviously increase the catalytic activity towards C2H4 formation compared to the Cu catalyst alone. Thus, the promoter Pd-modified Cu catalysts exhibit the highest catalytic activity and selectivity for C2H2 hydrogenation to C2H4. This work provides a method to evaluate and obtain the type of promoter with the best activity and selectivity in the selective hydrogenation of C2H2.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38421572

RESUMEN

Palladium (Pd) and zinc oxide (ZnO) (Pd/ZnO NPs) bimettalic nanocomposites still lag much too far behind other nanoparticles investigated for various biological uses in the area of cancer treatments. Chemically created nanoparticles agglomerate under physiological conditions, impeding their use in biomedical applications. In this study, a straightforward and environmentally friendly method for creating bimetallic nanoparticles (NPs) by combining palladium (Pd) and zinc oxide (ZnO) using Crocus sativus extract (CS-Pd/ZnO NCs) was reported; the bio-synthesize bimetallic palladium/zinc oxide nanocomposites and their antioxidant and anti-cancer properties were assessed. The developed Pd/ZnO NPs were characterized using different approaches, including UV-vis, DLS, FTIR, EDX, and SEM analyses. The present investigation shows how nanocomposites are made, their distinctive properties, antioxidant activity, anticancer mechanisms, and their potential therapeutic applications. DPPH and ABTS tests were used to investigate antioxidant activity. Further, the effects of CS-Pd/ZnO NCs on HeLa cells were assessed using the cell viability, ROS generation, MMP levels, and induced apoptosis. Apoptosis induction was measured using an Annexin V-fluorescein isothicyanate assay. Cell DNA was stained with propidium iodide to evaluate the impact upon this cell cycle. Time-dependent cell death was carried on by CS-Pd/ZnO NCs. The maximum inhibitory effect was 59 ± 3.2 when dosages of 4.5 µg/mL or higher were delivered after 24 h of treatment. Additionally, the CS-Pd/ZnO NCs caused HeLa cells to undergo apoptosis. Apoptotic HeLa cells were present in 35.64% of the treated cells at 4.5 µg/mL, and the cell cycle arrest at G0/G1 phase occurred concurrently. According to these findings, the CS-Pd/ZnO NCs may be a promising candidate for the creation of brand-new cervical cancer treatment.

12.
Reprod Sci ; 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38653857

RESUMEN

Studies have highlighted the significant role of focal adhesion signaling in cancer. Nevertheless, its specific involvement in the pathogenesis of endometrial cancer and its clinical significance remains uncertain. We analyzed TCGA-UCEC and GSE119041 datasets with corresponding clinical data to investigate focal adhesion-related gene expression and their clinical significance. A signature, "FA-riskScore," was developed using LASSO regression in the TCGA cohort and validated in the GSE dataset. The FA-riskScore was compared with four existing models in terms of their prediction performance. We employed univariate and multivariate Cox regression analyses towards FA-riskScore to assess its independent prognostic value. A prognostic evaluation nomogram based on our model and clinical indexes was established subsequently. Biological and immune differences between high- and low-risk groups were explored through functional enrichment, PPI network analysis, mutation mining, TME evaluation, and single-cell analysis. Sensitivity tests on commonly targeted drugs were performed on both groups, and Connectivity MAP identified potentially effective molecules for high-risk patients. qRT-PCR validated the expressions of FA-riskScore genes. FA-riskScore, based on FN1, RELN, PARVG, and PTEN, indicated a poorer prognosis for high-risk patients. Compared with published models, FA-riskScore achieved better and more stable performance. High-risk groups exhibited a more challenging TME and suppressive immune status. qRT-PCR showed differential expression in FN1, RELN, and PTEN. Connectivity MAP analysis suggested that BU-239, potassium-canrenoate, and tubocurarine are effective for high-risk patients. This study introduces a novel prognostic model for endometrial cancer and offers insights into focal adhesion's role in cancer pathogenesis.

13.
J Colloid Interface Sci ; 659: 191-202, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38176229

RESUMEN

Electrolysis for producing hydrogen powered by renewable electricity can be dramatically expanded by adapting different electrolytes (brine, seawater or pure water), which means the anode materials must stand up to complex electrolyte conditions. Here, a novel catalyst/support hybrid of binary Ru3.5Ir1Ox supported by barium strontium sulfate (BaSrSO4) was synthesized (RuIrOx/BSS) by exchanging the anion ligands of support. The as-synthesized RuIrOx/BSS exhibits compelling oxygen evolution (OER) and chlorine evolution (CER) performances, which affords to 10 mA cm-2 with only overpotential of 244 mV and 38 mV, respectively. The performed X-ray adsorption spectra clearly indicate the presence of an interface charge transfer effect, which results in the assignment of more electrons to the d orbitals of the Ru and Ir sites. The theoretical calculations demonstrated that the electronic structures of the catalytic active sites were modulated to give a lower overpotential, confirming the intrinsically high OER and CER catalytic activity.

14.
Blood ; 117(17): 4542-51, 2011 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-21300981

RESUMEN

We describe the application of a novel, bispecific antibody platform termed dual affinity retargeting (DART) to eradicate B-cell lymphoma through coengagement of the B cell-specific antigen CD19 and the TCR/CD3 complex on effector T cells. Comparison with a single-chain, bispecific antibody bearing identical CD19 and CD3 antibody Fv sequences revealed DART molecules to be more potent in directing B-cell lysis. The enhanced activity with the CD19xCD3 DART molecules was observed on all CD19-expressing target B cells evaluated using resting and prestimulated human PBMCs or purified effector T-cell populations. Characterization of a CD19xTCR bispecific DART molecule revealed equivalent potency with the CD19xCD3 DART molecule, demonstrating flexibility of the DART structure to support T-cell/B-cell associations for redirected T cell-killing applications. The enhanced level of killing mediated by DART molecules was not accompanied by any increase in nonspecific T-cell activation or lysis of CD19(-) cells. Cell-association studies indicated that the DART architecture is well suited for maintaining cell-to-cell contact, apparently contributing to the high level of target cell killing. Finally, the ability of the CD19xTCR DART to inhibit B-cell lymphoma in NOD/SCID mice when coadministered with human PBMCs supports further evaluation of DART molecules for the treatment of B-cell malignancies.


Asunto(s)
Anticuerpos Biespecíficos/inmunología , Anticuerpos Biespecíficos/farmacología , Linfocitos B/inmunología , Linfoma de Células B , Linfocitos T/inmunología , Animales , Antígenos CD19/inmunología , Antígenos CD19/metabolismo , Linfocitos B/citología , Complejo CD3/inmunología , Complejo CD3/metabolismo , Comunicación Celular/inmunología , Línea Celular Tumoral , Femenino , Humanos , Linfocinas/inmunología , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/inmunología , Linfoma de Células B/patología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Sialoglicoproteínas/inmunología , Linfocitos T/citología , Ensayos Antitumor por Modelo de Xenoinjerto
15.
J Mol Model ; 29(4): 101, 2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36928363

RESUMEN

CONTEXT: Viscosity and viscosity index are the crucial properties of lubricant base stocks. Molecular dynamics simulation and quantum calculation were used to simulate the five isomers of C26H54 to study the intrinsic relationship between viscosity, viscosity index, and the molecular structure of isoalkanes. The results showed that the intermolecular interaction energy and the volume of rigid-like groups were the intrinsic factors that affected the viscosity and which could describe the viscosity quantitatively. The molecule conformation was studied by calculating the rotational energy barrier of the dihedral angle in the isoalkane molecule, and combined with molecular dynamics, the effect of temperature on the molecular conformation at 313 K and 373 K was further investigated. The α, ß, and γ carbon atoms adjacent to the tertiary carbon in the isoalkane molecule were difficult to rotate due to steric hindrance and could be regarded as rigid-like groups at 313 K. The tertiary carbon and the three adjacent carbon atoms formed a regular tetrahedral rigid-like group at 373 K. The changes in the intermolecular interaction energy and the volume of the rigid-like group with temperatures could better describe the viscosity index and reveal the fundamental reasons that affect the viscosity and the viscosity index. The molecular-level understanding of the relationship between the molecular structure and properties of isoalkanes provided theoretical support and scientific guidance for designing isoalkane molecules with specific properties. METHODS: Molecular dynamics simulation and quantum calculation were performed using Material Studio 8.0 software. The Amorphous Cell module was used to create an amorphous cell. The Foricite module was used for molecular dynamics simulation; the forcefield was assigned as COMPASS II. Nose-Hoover thermostat and Berendsen barostat were applied to maintain the temperature and pressure, respectively. To describe the non-bond interactions, the Ewald method was applied to calculate the van der Waals and electrostatic interactions. The Conformers module was used to study the conformation and the Dmol3 module was used to calculate the conformational energy with fine quality; the functional of GGA-PW91 and the basis set of DNP were used to calculate the energy.

16.
Chem Sci ; 14(46): 13453-13462, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38033882

RESUMEN

Nickel-iron (oxy)hydroxides (NiFeOxHy) have been validated to speed up sluggish kinetics of the oxygen evolution reaction (OER) but still lack satisfactory substrates to support them. Here, non-stoichiometric blue titanium oxide (B-TiOx) was directly derived from Ti metal by alkaline anodization and used as a substrate for electrodeposition of amorphous NiFeOxHy (NiFe/B-TiOx). The performed X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations evidenced that there is a charge transfer between B-TiOx and NiFeOxHy, which gives rise to an elevated valence at the Ni sites (average oxidation state ∼ 2.37). The synthesized NiFe/B-TiOx delivers a current density of 10 mA cm-2 and 100 mA cm-2 at an overpotential of 227 mV and 268 mV, respectively, which are better than that of pure Ti and stainless steel. It also shows outstanding activity and stability under industrial conditions of 6 M KOH. The post-OER characterization studies revealed that the surface morphology and valence states have no significant change after 24 h of operation at 500 mA cm-2, and also can effectively inhibit the leaching of Fe. We illustrate that surface modification of Ti which has high corrosion resistance and mechanical strength, to generate strong interactions with NiFeOxHy is a simple and effective strategy to improve the OER activity and stability of non-precious metal electrodes.

17.
Artículo en Inglés | MEDLINE | ID: mdl-35497912

RESUMEN

The deficiency of traditional calcium preparation will gradually be replaced by the new type of calcium preparation. Rosa roxburghii fruit (R. roxburghii) is popular for its rich nutrients and functional ingredients. The fermentation broth of R. roxburghii, involving amino acids, flavonoids, triterpenes, polysaccharides, and other compounds, is favorable for calcium chelation. Thus, this study fabricated calcium-incorporated R. roxburghii (FECa) and further illustrated its efficacy on bone mineral density (BMD) in rats. The calcium holding capacity of FECa was identified and confirmed using AAS. Ion complexation of FECa was characterized using 1H-NMR, UV, SEM and EDS, and FTIR. The calcium contents of femurs were increased by 36%, and the bone trabeculae of femurs were significantly increased. Net calcium balance was enhanced to further improve BMD by oral administration of FECa. The above results indicate that FECa can be a potential and efficient calcium supplementation agent.

18.
Perioper Med (Lond) ; 10(1): 16, 2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-33971968

RESUMEN

BACKGROUND: The safety of perioperative intravenous hydroxyethyl starch (HES) products, specifically HES 130/0.4, continues to be the source of much debate. The aim of this meta-analysis was to update the existing evidence and gain further insight into the clinical effects of HES 130/0.4 on postoperative outcomes for volume replacement therapy in surgical patients. METHODS: MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to March 2020 for relevant randomized controlled trials (RCTs) on perioperative use of HES 130/0.4 in adult surgical patients. The primary outcome was postoperative mortality and secondary outcomes were the incidence of acute kidney injury (AKI) and requirement for renal replacement therapy (RRT). The analysis was performed using the random-effects method and the risk ratio (RR) with a 95% confidence interval (CI). We performed the risk-of-bias assessment of eligible studies and assessed the overall quality of evidence for each outcome. RESULTS: Twenty-five RCTs with 4111 participants were finally included. There were no statistical differences between HES 130/0.4 and other fluids in mortality at 30 days (RR 1.28, 95% CI 0.88 to 1.86, p = 0.20), the incidence of AKI (RR 1.23, 95% CI 0.99 to 1.53, p = 0.07), or requirement for RRT (RR 0.75, 95% CI 0.37 to 1.53, p = 0.43). Overall, there was a moderate certainty of evidence for all the outcomes. There was no subgroup difference related to the type of surgery (p = 0.17) in the incidence of AKI. As for the type of comparator fluids, however, there was a trend that was not statistically significant (p = 0.06) towards the increased incidence of AKI in the HES 130/0.4 group (RR 1.22, 95% CI 0.97 to 1.54) compared with the crystalloid group (RR 1.21, 95% CI 0.27 to 3.91). Subgroup analyses according to the type of surgery demonstrated consistent findings. CONCLUSIONS: This systematic review and meta-analysis suggests that the use of HES 130/0.4 for volume replacement therapy compared with other fluids resulted in no significant difference in postoperative mortality or kidney dysfunction among surgical patients. Given the absent evidence of confirmed benefit and the potential trend of increased kidney injury, we cannot recommend the routine clinical use of HES 130/0.4 for volume replacement therapy in surgical patients from the perspective of benefit/risk profile. However, the results need to be interpreted with caution due to the limited sample size, and further well-powered RCTs are warranted. TRIAL REGISTRATION: PROSPERO registry reference: CRD42020173058.

19.
Artículo en Inglés | MEDLINE | ID: mdl-34567215

RESUMEN

Psoraleae Fructus (PF) is a botanical medicine widely used in Asian countries, of which salt products have higher safety and efficacy. However, the biological mechanism of the detoxification of salt-processing Psoraleae Fructus (SPF) has not yet been revealed. In this study, UPLC-MS/MS technology was used to explore the metabolic differences between SPF and PF in normal rats and reveal the mechanism of salt processing. The histopathological results of rat liver and kidney showed that the degree of liver and kidney injure in the SPF group was less than that in the PF group. The results of metabolomics showed that the detoxification mechanism of PF by salt processing might be related to glycerophospholipid metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, arginine and proline metabolism, phenylalanine metabolism, and linoleic acid metabolism. PF-induced inflammation could be reduced by regulating the expression of metabolites to achieve the purpose of salt processing and detoxification. It included reducing the production of metabolites such as 1-acyl-sn-glycero-3-phosphocholine, sn-glycero-3-phosphocholine, tyrosine, arginine, linoleic acid, arachidonic acid, and phenylacetylglycine/hippuric acid ratio and upregulating the expression of metabolites such as creatine.

20.
Toxicol Rep ; 8: 657-667, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33868952

RESUMEN

Oxidative stress is considered to be one of main pathophysiological mechanisms in myocardial ischemia/reperfusion (I/R) injury. Lycium barbarum polysaccharides (LBP), the main ingredient of Lycium barbarum, have potential antioxidant activity. We aimed to investigate the effects of LBP on myocardial I/R injury and explore the underlying mechanisms. Myocardial I/R group was treated with or without LBP to evaluate oxidative stress markers and the role of Nrf2 signal pathway. Our results showed that I/R increased infarct size and the activities of creatine kinase (CK) and lactate dehydrogenase (LDH) when compared with control group. Meanwhile, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were enhanced and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were decreased. These changes were associated with a significant increase in myocardial apoptosis, ultimately leading to cardiac dysfunction. LBP reduced infarct size (38.4 ± 2 % versus 19.4 ± 1.8 %, p < 0.05), CK and LDH activities and myocardial apoptotic index. Meanwhile, LBP suppressed the production of ROS and restored redox status. Additionally, LBP increased protein level of nuclear Nrf2 in vivo (2.1 ± 0.3 versus 3.8 ± 0.4, p < 0.05) and in vitro (1.9 ± 0.2 versus 3.8 ± 0.1, p < 0.05) and subsequently upregulated heme oxygenase 1 and NADPH dehydrogenase quinone 1 compared to I/R group. Interestingly, Nrf2 siRNA abolished the protective effects of LBP. LBP suppressed oxidative stress damage and attenuated cardiac dysfunction induced by I/R via activation of the Nrf2 antioxidant signal pathway.

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