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1.
Sci Adv ; 10(29): eadp1439, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39018413

ABSTRACT

Spatiotemporally controllable droplet manipulation is vital across numerous applications, particularly in miniature droplet robots known for their exceptional deformability. Despite notable advancements, current droplet control methods are predominantly limited to two-dimensional (2D) deformation and motion of an individual droplet, with minimal exploration of 3D manipulation and collective droplet behaviors. Here, we introduce a bimodal actuation strategy, merging magnetic and optical fields, for remote and programmable 3D guidance of individual ferrofluidic droplets and droplet collectives. The magnetic field induces a magnetic dipole force, prompting the formation of droplet collectives. Simultaneously, the optical field triggers isothermal changes in interfacial tension through Marangoni flows, enhancing buoyancy and facilitating 3D movements of individual and collective droplets. Moreover, these droplets can function autonomously as soft robots, capable of transporting objects. Alternatively, when combined with a hydrogel shell, they assemble into jellyfish-like robots, driven by sunlight. These findings present an efficient strategy for droplet manipulation, broadening the capabilities of droplet-based robotics.

2.
Nanoscale ; 16(13): 6522-6530, 2024 Mar 28.
Article in English | MEDLINE | ID: mdl-38477150

ABSTRACT

Extensive studies have been carried out on silver nanowires (AgNWs) in view of their impressive conductivity and highly flexible one-dimensional structure. They are seen as a promising choice for producing deformable transparent conductors. Nonetheless, the widespread adoption of AgNW-based transparent conductors is hindered by critical challenges represented by the significant contact resistance at the nanowire junctions and inadequate interfacial adhesion between the nanowires and the substrate. This study presents a novel solution to tackle the aforementioned challenges by capitalizing on liquid metal microcapsules (LMMs). Upon exposure to acid vapor, the encapsulated LMMs rupture, releasing the fluid LM which then forms a metallic overlay and hybridizes with the underlying Ag network. As a result, a transparent conductive film with greatly enhanced electrical and mechanical properties was obtained. The transparent conductor displays negligible resistance variation even after undergoing chemical stability, adhesion, and bending tests, and ultrasonic treatment. This indicates its outstanding adhesion strength to the substrate and mechanical flexibility. The exceptional electrical properties and robust mechanical stability of the transparent conductor position it as an ideal choice for direct integration into flexible touch panels and wearable strain sensors, as evidenced in this study. By resolving the critical challenges in this field, the proposed strategy establishes a compelling roadmap to navigate the development of high-performance AgNW-based transparent conductors, setting a solid foundation for further advancement in the field of deformable electronics.

3.
Adv Mater ; 36(14): e2311627, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38174767

ABSTRACT

Sodium-oxygen battery has attracted tremendous interest due to its extraordinary theoretical specific energy (1605 Wh kg-1 NaO2) and appealing element abundance. However, definite mechanistic factors governing efficient oxygen diffusion and consumption inside electrolyte-flooded air cathodes remain elusive thus precluding a true gas diffusion electrode capable of high discharge current (i.e., several mA cm-2) and superior output power. Herein, 3D-printing technology is adopted to create gas channels with tailored channel size and structure to demystify the diffusion-limited oxygen delivery process. It is revealed that as the clogging discharging products increase, large channel size, and interconnected channel structure are essential to guaranteeing fast O2 diffusion. Moreover, to further encourage O2 diffusion, a bio-inspired breathable cathode with progressively branching channels that balances between O2 passage and reaction is 3D printed. This elaborated 3D electrode allows a sodium-oxygen cell to deliver an impressive discharging current density of up to 4 mA cm-2 and an output power of 8.4 mW cm-2, giving rise to an outstanding capacity of 18.4 mAh cm-2. The unraveled mystery of oxygen delivery enabled by 3D printing points to a valuable roadmap for the rational design of metal-air batteries toward practical applications.

4.
Commun Biol ; 5(1): 1120, 2022 10 22.
Article in English | MEDLINE | ID: mdl-36273041

ABSTRACT

Riboswitches normally regulate gene expression through structural changes in response to the specific binding of cellular metabolites or metal ions. Taking add adenine riboswitch as an example, we explore the influences of metal ions (especially for K+ and Mg2+ ions) on the structure and dynamics of riboswitch aptamer (with and without ligand) by using molecular dynamic (MD) simulations. Our results show that a two-state transition marked by the structural deformation at the connection of J12 and P1 (CJ12-P1) is not only related to the binding of cognate ligands, but also strongly coupled with the change of metal ion environments. Moreover, the deformation of the structure at CJ12-P1 can be transmitted to P1 directly connected to the expression platform in multiple ways, which will affect the structure and stability of P1 to varying degrees, and finally change the regulation state of this riboswitch.


Subject(s)
Aptamers, Nucleotide , Riboswitch , Ligands , Adenine , Nucleic Acid Conformation , Aptamers, Nucleotide/chemistry , Ions
5.
iScience ; 25(10): 105215, 2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36262315

ABSTRACT

A cluster is a special matter level above a single atom and between macroscopic and microscopic matter, and it is an important bridge to understanding the relationship between the structure and function of matter. Here, we perform a comprehensive theoretical study of 2D planar Aun (n = 1-12) clusters doped with both magnesium and germanium. Two interesting results are found, namely the rapid 3D "roll-up" structural growth of the GeMgAun (n = 1-12) cluster ground state isomers, and the relative "alienation" of the different sizes of the Aun (n = 1-12) cluster framework towards the Ge atom, and the relative "affinity" towards the Mg atom. This study will not only enrich the data on gold-based clusters but will also provide a simple and clear theoretical guide for the 3D structuring of planar clusters, i.e. the doping of different classes of "affinition" and "alienatation" atoms.

6.
J Chem Phys ; 157(11): 114303, 2022 Sep 21.
Article in English | MEDLINE | ID: mdl-36137789

ABSTRACT

Structure, stability, charge transfer, chemical bonding, and spectroscopic properties of Ga atom-doped neutral Mgn (n = 2-12) clusters have been systematically investigated by CALYPSO and density functional theory. All cluster structures are based on "tetrahedral" and "yurt-like" growth except for GaMg2. The ground state isomer of GaMg8 with high symmetry structure is predicted to be the best-fit candidate for the "magic" cluster because of its excellent stability. Natural bond orbital calculations reveal that Ga and Mg atoms play the role of electron acceptor and donor in all ground state isomers, while the orbitals in both Ga and Mg are sp-hybridized. Most importantly, chemical bonding studies based on atom-in-molecular theory have shown that the lowest-energy state of GaMg4 is so special, in that it has not only the critical size for the appearance of Mg-Mg covalent bonds, but also the only cluster that has both Ga-Mg covalent and non-covalent bonds. Finally, theoretical calculations of IR and Raman spectra of all ground state isomers indicate that the spectra of these clusters are observable in the low-frequency band, and thus they can be identified by spectroscopic experiments. Furthermore, the bond heterogeneity of the Ga-Mg in the GaMg4 ground state isomer has also been specifically investigated, including the fixed GaMg4 structure with Mg atoms added in different directions, as well as ab initio molecular dynamics sampling at different temperatures.

7.
Front Chem ; 10: 870985, 2022.
Article in English | MEDLINE | ID: mdl-35425762

ABSTRACT

Using CALYPSO crystal search software, the structural growth mechanism, relative stability, charge transfer, chemical bonding and optical properties of AuMgn (n = 2-12) nanoclusters were extensively investigated based on DFT. The shape development uncovers two interesting properties of AuMgn nanoclusters contrasted with other doped Mg-based clusters, in particular, the planar design of AuMg3 and the highly symmetrical cage-like of AuMg9. The relative stability study shows that AuMg10 has the robust local stability, followed by AuMg9. In all nanoclusters, the charge is transferred from the Mg atoms to the Au atoms. Chemical bonding properties were confirmed by ELF analysis that Mg-Mg formed covalent bonds in nanoclusters larger than AuMg3. Static polarizability and hyperpolarizability calculations strongly suggest that AuMg9 nanocluster possesses interesting nonlinear optical properties. Boltzmann distribution weighted average IR and Raman spectroscopy studies at room temperature verify that these nanoclusters are identifiable by spectroscopic experiments. Finally, the average bond distance and average nearest neighbor distance were fully investigated.

8.
Angew Chem Int Ed Engl ; 60(50): 26218-26225, 2021 Dec 06.
Article in English | MEDLINE | ID: mdl-34549498

ABSTRACT

We propose an in situ template method to directionally induce the construction of germanium phosphide nanobar (GeP-nb) corals with an adjustable aspect ratio. The GeP nanobars grown onto conductive matrix with high aspect ratio expose more quickest electron-ion transportation facets for fast reaction dynamics. The customized GeP-nb electrode delivers a self-healable homeostatic behavior by reversibly stabilizing GeP crystalline structure through multi-phase reactions to maintain structural integrity and cycling stability (850 mAh g-1 at 1 A g-1 after 500 cycles). As a result, the GeP-nb presents the highest Li+ diffusion coefficient (6.21×10-11  cm2 s-1 ) among all the Ge-based anode materials studied so far, rendering an excellent rate performance (620 mAh g-1 at 5 A g-1 ) as a lithium-ion battery (LIB) anode.

9.
ACS Appl Mater Interfaces ; 13(29): 34410-34418, 2021 Jul 28.
Article in English | MEDLINE | ID: mdl-34275271

ABSTRACT

Exploiting novel nanomaterials with fast and durable sodium/potassium ion storage capability is key to alleviate the application limitations of lithium-ion batteries. Herein, a novel energy storage material based on cobalt metaphosphate nanosheet arrays self-supported on carbon cloths [Co(PO3)2 NSs/CC] is fabricated by a two-step strategy. This rationally designed strategy avoids the preparation of the complex {Co[O2P(OtBu)2]2}n precursor, which significantly simplifies the synthesis process. The active CC acts not only as an electrically conductive substrate as usual but also as a functional basis to suppress PH3-involved reaction and to promote HPO3-involved reaction during the phosphating process, contributing to the formation of Co(PO3)2. The mutual cross-linked porous Co(PO3)2 nanosheets vertically grow on the surface of activated CC, ensuring sufficient electrolyte infiltration and fast electron transport among the electrodes. Sodium ion storage analysis for the Co(PO3)2 NSs/CC electrode reveals a multi-step reaction mechanism with high reversibility, as reflected by the high reversible capacity (667 mA h g-1 at 50 mA g-1) and excellent cyclability (with almost no capacity decay over 500 cycles). This novel electrode is also well capable of storing potassium ions, exhibiting high reversible capacity, which outperforms most reported anodes for potassium-ion batteries. The development of this novel high-performance nanomaterial would advance the performance of sodium/potassium-ion batteries toward practical applications.

10.
J Phys Chem B ; 125(11): 2821-2832, 2021 03 25.
Article in English | MEDLINE | ID: mdl-33689339

ABSTRACT

Internal friction is a valuable concept to describe the kinetics of proteins. As is well known, internal friction can be modulated by solvent features (such as viscosity). How can internal friction be affected by environmental temperature? The answer to this question is not evident. In the present work, we approach this problem with simulations on two model peptides. The thermodynamics and relaxation kinetics are characterized through long molecular dynamics simulations, with the viscosity modulated by varying the mass of solvent molecules. Based on the extrapolation to zero viscosity together with scaling of the relaxation time scales, we discover that internal friction is almost invariant at various temperatures. Controlled simulations further support the idea that internal friction is independent of environmental temperature. Comparisons between the two model peptides help us to understand the diverse phenomena in experiments.


Subject(s)
Peptides , Friction , Kinetics , Temperature , Viscosity
11.
Interact Cardiovasc Thorac Surg ; 33(1): 27-33, 2021 06 28.
Article in English | MEDLINE | ID: mdl-33729469

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of patients undergoing off-pump robotic coronary artery bypass grafting (CABG) with either interrupted nitinol U-Clips in totally endoscopic coronary artery bypass (TECAB) or standard running suture anastomosis in robotically assisted direct coronary artery bypass (RADCAB) over a decade. METHODS: From January 2007 to December 2017, 280 patients underwent robotic off-pump CABG using the da Vinci S/Si Surgical System in our centre. TECAB with interrupted nitinol U-Clips anastomosis was performed in the left internal mammary artery (LIMA) to LAD grafting in 126 patients and RADCAB (n = 154) of the LIMA to LAD was completed with standard running suture. After discharge, patients were contacted through telephone interview and were invited to attend the outpatient clinic every 6 months or 1 year. The graft patency was assessed by coronary angiography or computed tomography angiography. RESULTS: All cases were completed without conversion to median sternotomy or cardiopulmonary bypass. A total of 275 single internal mammary artery (IMA) grafts (271 LIMAs, 4 right internal mammary arteries) and 5 bilateral IMA grafts were used as single graft or composite grafts. All the patients were discharged without in-hospital mortality or adverse outcomes. The average follow-up was 89.7 ± 30.4 months (range, 14-143 months). The cumulative survival rates (P = 0.53), the cumulative IMA patency rates (P = 0.83), and the rates of freedom from major adverse cerebrovascular and cardiovascular events (P = 0.41) between TECAB and RADCAB all showed no significant difference in the follow-up. CONCLUSIONS: Robotic off-pump CABG using IMA grafts is safe and can provide reliable long-term outcomes. Compared with the standard hand-sewn running suture technique in RADCAB, interrupted suture with the nitinol U-Clips in TECAB showed similar long-term clinical results and graft patency in LIMA to LAD bypass grafting.


Subject(s)
Robotic Surgical Procedures , Coronary Artery Bypass , Humans , Surgical Instruments , Sutures , Treatment Outcome
12.
J Cardiovasc Surg (Torino) ; 62(2): 162-168, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33302613

ABSTRACT

BACKGROUND: To assess the safety and effectiveness, clinical experience with totally robotic mitral valve replacement (TE-MVR) for treating valvular heart disease was summarized and analyzed, and patients' recovery conditions were followed-up. METHODS: The clinical data of 47 patients who received TE-MVR in our hospital between October 2008 and December 2015 were retrospectively analyzed. Among the patients, there are 26 men and 21 women. The mean age was 47.53±10.80 years. We followed up the transesophageal echocardiography (TTE) data of post-discharge patients and analyzed the operation results to determine the surgical effects of TE-MVR. The surgeries were mainly performed with the da Vinci Si robotic surgical system. RESULTS: Thirty-five mechanical valves and twelve bioprosthetic valves were implanted. The cardiopulmonary bypass and aortic cross-clamping times were 122.02±25.45 min and 85.68±20.70 min, respectively. There was no operative mortality. The perioperative complication could only be found in one case, which was pleural effusion. All the TTE results were satisfying before discharge. No paravalvular leakage or prosthetic valve dysfunction was detected. All 47 patients were discharged successfully. During the long-term follow-up (28-110 months), 42 patients were followed-up (89.4%). Most of their heart function was NYHA class I and II. The postoperative TTE showed that the left atrial diameter and left ventricle diameter were decreased (P<0.01). CONCLUSIONS: TE-MVR is reliable and effective, and the postoperative follow-up results revealed good heart function. Patients will obtain benefits from TE-MVR, such as small trauma and rapid recovery. Thus, it is a good minimally-invasive surgery of choice.


Subject(s)
Heart Valve Prosthesis Implantation/methods , Mitral Valve Insufficiency/surgery , Robotic Surgical Procedures , Adult , Aged , Cardiopulmonary Bypass , Echocardiography, Transesophageal , Female , Follow-Up Studies , Humans , Male , Middle Aged , Mitral Valve Insufficiency/diagnostic imaging , Retrospective Studies
13.
Neurochem Res ; 45(9): 1986-1996, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32378074

ABSTRACT

Numerous studies have shown that the inhaled general anesthetic sevoflurane imposes toxicity on the central nervous system during the developmental period but the underlying mechanisms remain unclear. Neuropeptide Y (NPY) was reported to have important neuroprotective effects, which can attenuate neuronal loss under pathological conditions. However, the effects of NPY on sevoflurane-induced hippocampal neuronal apoptosis have not been investigated. In this study, postnatal day 7 (PND7) Sprague-Dawley rats and primary cultured cells separated from hippocampi were exposed to sevoflurane (2.4% for 4 h) and the NPY expression levels after treatment were analyzed. Furthermore, neuronal apoptosis assay was conducted via immunofluorescence staining of cleaved caspase-3 and flow cytometry after exogenous NPY administration to PND7 rats as well as cultured hippocampal neurons to elucidate the role of NPY in sevoflurane-induced neurotoxicity. Our results showed the level of NPY gradually decreased within 24 h after sevoflurane exposure in both the hippocampus of PND7 rats and cultured hippocampal neurons, but not in cultured astrocytes. In the exogenous NPY pretreatment study, the proportion of cleaved caspase-3 positive cells in the CA1 region of the hippocampus was increased significantly at 24 h after sevoflurane treatment, while NPY pretreatment could reduce it. Similarly, NPY could also reverse the apoptogenic effect of sevoflurane on cultured neurons. Herein, our results showed that sevoflurane caused a significant decrease in NPY expression, whereas exogenous NPY supplementation could reduce sevoflurane-induced hippocampal neuronal apoptosis both in vivo and in vitro.


Subject(s)
Anesthetics, Inhalation/pharmacology , Apoptosis/drug effects , Hippocampus/drug effects , Neuropeptide Y/metabolism , Sevoflurane/pharmacology , Animals , Animals, Newborn , Astrocytes/drug effects , Down-Regulation/drug effects , Hippocampus/metabolism , Male , Neurons/drug effects , Rats, Sprague-Dawley
14.
Nanoscale Res Lett ; 14(1): 317, 2019 Sep 18.
Article in English | MEDLINE | ID: mdl-31535229

ABSTRACT

Molybdenum disulfide (MoS2) is an extremely intriguing low-D layered material due to its exotic electronic, optical, and mechanical properties, which could be well exploited for numerous applications to energy storage, sensing, and catalysis, etc., provided a sufficiently low number of layers is achieved. A facile exfoliation strategy that leads to the production of few-layered MoS2 is proposed wherein the exfoliation efficacy could be synergistically boosted to > 90% by exploiting ultrasound sonication in supercritical CO2 in conjunction with N-methyl-2-pyrrolidone (NMP) as the intercalating solvent, which is superior to general practiced liquid exfoliation methods wherein only the supernatant is collected to avoid the majority of unexfoliated sediments. The facile and fast exfoliation technique suggests an exciting and feasible solution for scalable production of few-layered MoS2 and establishes a platform that contributes to fulfilling the full potential of this versatile two-dimensional material.

15.
J Perianesth Nurs ; 34(6): 1274-1281, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31492603

ABSTRACT

PURPOSE: We aim to investigate whether hemortheology and oxygenation balance are affected by intraoperative gelatin infusion, whether it poses a threat to the perioperative well-being of the patients, and thus creates difficult conditions for postanesthesia care. DESIGN: A randomized controlled clinical trial. METHODS: After anesthesia induction, 10 ml/kg succinylated gelatin was infused. Arterial blood gas analysis was performed, and whole blood viscosity and vital signs were recoded both before and after the infusion. FINDINGS: High shear and medium shear viscosities decreased (P = .003 and P = .04, respectively) after the infusion of both gelatin and Ringer's lactate. The peripheral vascular resistance was not significantly changed by the infusion of either fluid (P = .31). Ringer's lactate reduces the body's oxygen delivery index (P = .01). CONCLUSIONS: Gelatin better maintains blood viscosity and stabilizes the body's oxygenation balance.


Subject(s)
Blood Viscosity , Gelatin/administration & dosage , Oxygen/metabolism , Adult , Female , Humans , Intraoperative Care , Male , Middle Aged , Postanesthesia Nursing
16.
J Pain Res ; 12: 2305-2312, 2019.
Article in English | MEDLINE | ID: mdl-31413627

ABSTRACT

PURPOSE: Quadratus lumborum block (QLB) is shown to be effective on analgesia following cesarean section. This study aimed to compare the effects of three practical QLB approaches and classic epidural analgesia (EA) for cesarean section under spinal anesthesia. PATIENTS AND METHODS: Parturients undergoing elective cesarean section were randomized as group 1 (QLB type 2), group 2 (QLB type 3), group 3 (QLB type 2+3) and group 4 (EA). The block was performed at the end of the operation, and the epidural group was given a single epidural bolus. All subjects were provided with intravenous patient-controlled analgesia under identical settings. In addition, the postoperative pain severity was assessed by the VAS, which together with the morphine consumption at specific time intervals, was recorded within 48 hrs after surgery. Data were collected from December 2017 to June 2018. RESULTS: A total of 94 parturients had completed the study. At almost all postoperative time points, the VAS scores at rest and with movement in QLB type 2+3 group were lower than those in QLB type 2 or 3 group. The mean additional morphine consumption in QLB type 2+3 group (2.7 mg) was lower than that in QLB type 2 or 3 group (6.1 mg and 5.7 mg, respectively) within 48 h after surgery (P<0.001). Besides, the total morphine consumption in EA group (1.3 mg) was lower than that in any other QLB group (P<0.001). CONCLUSIONS: The analgesic effect of QLB is highly dependent on the injection position of local anesthetic. Besides, the ultrasound-guided QLB type 2+3 can provide superior analgesic effect following cesarean section to that of QLB type 2 or 3 block. However, it remains to be further validated about whether the combination of QLB type 2 and 3 is the best approach.

17.
RSC Adv ; 9(41): 23607-23613, 2019 Jul 29.
Article in English | MEDLINE | ID: mdl-35530636

ABSTRACT

Free-standing graphene-based composite paper electrodes with various active materials have attracted tremendous interest for next-generation lithium-ion batteries (LIBs) due to advantages such as their light weight, excellent mechanical flexibility, and superior electrochemical performance. However, despite its high theoretical energy density, SnS2 is rather difficult to composite with the graphene paper, because conventional reduction procedures for graphene oxide (GO) induce either decomposition or oxidation of SnS2. Herein, a novel solid/gas two-phase interface hydrothermal process is reported to fabricate flexible free-standing SnS2/graphene nanocomposite papers (SGP) assisted by a reducing and stabilizing agent thioacetamide aqueous solution. Such hydrothermal process not only successfully reduces SnS2/graphene oxide paper (SGOP) to SGP, but more importantly, keeps intact the paper configuration as well as the phase stability of SnS2. The as-prepared SGP electrode exhibits high reversible discharge capacity, outstanding cyclic stability and rate capability, which can be attributed to the synergistic effect of the conductive and flexible graphene matrix for accommodation of the volumetric changes of SnS2 upon cycling and the planar SnS2 nanospacers between the graphene layers introducing nanopores for penetration of electrolyte and inhibition of graphene nanosheets restacking. This report demonstrates a new strategy for more active materials with promising lithium storage properties joining the flexible graphene-based paper electrode family.

18.
J Biomol Struct Dyn ; 37(8): 1956-1967, 2019 May.
Article in English | MEDLINE | ID: mdl-29734867

ABSTRACT

Previous studies based on bioinformatics showed that there is a sharp distinction of structural features and residue composition between the intrinsically disordered proteins and the folded proteins. What induces such a composition-related structural transition? How do various kinds of interactions work in such processes? In this work, we investigate these problems based on a survey on peptides randomly composed of charged residues (including glutamic acids and lysines) and the residues with different hydrophobicity, such as alanines, glycines, or phenylalanines. Based on simulations using all-atom model and replica-exchange Monte Carlo method, a coil-globule transition is observed for each peptide. The corresponding transition temperature is found to be dependent on the contents of the hydrophobic and charged residues. For several cases, when the mean hydrophobicity is larger than a certain threshold, the transition temperature is higher than the room temperature, and vise versa. These thresholds of hydrophobicity and net charge are quantitatively consistent with the border line observed from the study of bioinformatics. These results outline the basic physical reasons for the compositional distinction between the intrinsically disordered proteins and the folded proteins. Furthermore, the contributions of various interactions to the structural variation of peptides are analyzed based on the contact statistics and the charge-pattern dependence of the gyration radii of the peptides. Our observations imply that the hydrophobicity contributes essentially to such composition-related transitions. Thus, we achieve a better understanding on composition-structure relation of the natural proteins and the underlying physics.


Subject(s)
Intrinsically Disordered Proteins/chemistry , Intrinsically Disordered Proteins/metabolism , Peptides/chemistry , Protein Folding , Computer Simulation , Hydrophobic and Hydrophilic Interactions , Models, Molecular , Monte Carlo Method , Static Electricity , Thermodynamics
19.
J Pain Res ; 12: 3355-3363, 2019.
Article in English | MEDLINE | ID: mdl-31908520

ABSTRACT

BACKGROUND: Femoral nerve block (FNB) has been considered as an excellent analgesic modality in total knee arthroplasty (TKA) pain control. However, relatively high concentration of ropivacaine could lead to quadriceps muscle weakness and increase the risk of postoperative falls. OBJECTIVE: This double-blinded randomized controlled study was designed to investigate the effect of a combination of dexmedetomidine with a lower concentration of ropivacaine on quadriceps muscle strength and analgesic effect in FNB. METHODS: A total of 90 patients scheduled for TKA were randomized to receive continuous FNB postoperatively using 0.2% ropivacaine (H group), 0.1% ropivacaine (L group) or 0.1% ropivacaine combined with 2 µg/kg dexmedetomidine (LD group). Meanwhile, intravenous patient-controlled analgesia with morphine was administered to patients. The primary endpoint was the strength of quadriceps muscle evaluated by manual muscle testing (MMT) and Timed Up and Go test (TUG). The secondary endpoint was the pain scores and morphine consumption among different groups. RESULTS: For MMT, LD group showed higher quadriceps muscle strength than the other two groups (P<0.05) at 12 hrs postoperatively. TUG test was conducted to measure the walking ability, and showed that scores were significantly better in LD group than those in H group and L group (P<0.05) at 24 and 48 hrs postoperatively. There was no significant difference between H and LD group in the numeric rating scales (NRS) scores both at rest and at 45° flexion. The total morphine consumption in L group was significantly higher than in H or LD group (P<0.001). CONCLUSION: Collectively, the addition of dexmedetomidine 2 µg/kg to 0.1% ropivacaine preoperatively would preserve quadriceps muscle strength with satisfactory analgesia in patients undergoing TKA. (This study was registered at ClinicalTrials.gov, identifier NCT03658421).

20.
Materials (Basel) ; 11(6)2018 Jun 02.
Article in English | MEDLINE | ID: mdl-29865220

ABSTRACT

In an effort to explore the use of organic high-performance lithium ion battery cathodes as an alternative to resolve the current bottleneck hampering the development of their inorganic counterparts, a rational strategy focusing on the optimal composition of covalent triazine-based frameworks (CTFs) with carbon-based materials of varied dimensionalities is delineated. Two-dimensional reduced graphene oxide (rGO) with a compatible structural conformation with the layered CTF is the most suitable scaffold for the tailored mesopores in the polymeric framework, providing outstanding energy storage ability. Through facile ionothermal synthesis and structure engineering, the obtained CTF-rGO composite possesses a high specific surface area of 1357.27 m²/g, and when used as a lithium ion battery cathode it delivers a large capacity of 235 mAh/g in 80 cycles at 0.1 A/g along with a stable capacity of 127 mAh/g over 2500 cycles at 5 A/g. The composite with modified pore structure shows drastically improved performance compared to a pristine CTF, especially at large discharge currents. The CTF-rGO composite with excellent capacity, stability, and rate performance shows great promise as an emerging high-performance cathode that could revolutionize the conventional lithium-ion battery industry.

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