Risk factors of arytenoid dislocation after endotracheal intubation: A propensity-matched analysis.

Objective: Arytenoid dislocation (AD) after general anesthesia with endotracheal intubation (EI) is an iatrogenic injury that impairs patient function and requires reduction. We aimed to investigate the risk factors of AD following EI. Methods: This retrospective case-control study involved surgical adults who received EI for general anesthesia at a single institution from June 2010 to June 2020. Cases included all the patients who had AD. We used a ratio of 1:5 to identify patients in the propensity-matched control group. Results: Multivariate analysis of 49 cases with AD and 245 controls without AD demonstrated that the use of a nasogastric (NG) tube (odds ratio [OR], 23.9; 95% confidence interval [CI], 6.8-84.1), undergoing abdominal surgery (OR, 3.7; 95% CI, 1.2-11.9), and an operative time longer than 3 h (OR, 5.2; 95% CI, 2.1-12.9) were risk factors for AD. We did not find significant independent associations between AD and 40 years or older age, gender, body mass index, whether a laryngeal mask airway was used, endotracheal tube size, and EI performers' experience. Conclusion: The use of an NG tube, abdominal surgery, and longer operative time were risk factors for AD. Among these, the NG tube application showed a strong association with AD. Preventive measures of informing the patients of the increased risk and providing high-level patient monitoring can reduce the incidence of AD. Level of Evidence: III.

Dual-targeted therapy in HER2-positive breast cancer cells with the combination of carbon dots/HER3 siRNA and trastuzumab.

Dual-targeted therapy in HER2-positive breast cancer cells with the combination of carbon dots/HER3 siRNA and trastuzumab resulted in enhanced antitumor activity, which overcomes the resistance to trastuzumab monotherapy. Herein, we have developed branched polyethylenimine-functionalized carbon dot (BP-CD) nanocarriers, which exhibited efficient green fluorescent protein gene delivery and expression. The positively charged BP-CDs allowed for effective nucleic acid binding and displayed a highly efficient small interfering RNA (siRNA)-mediated delivery targeting of cancer cells. The transfection of BP-CDs and HER3 siRNA complexes down-regulated HER3 protein expression and induced significant cell growth inhibition in BT-474 cells. BP-CDs/HER3 siRNA complexes induced cell death of BT-474 cells through G0/G1 cell cycle arrest and apoptosis. The combined treatment of BP-CDs/HER3 siRNA complexes and trastuzumab caused greater cell growth suppression in BT-474 cells when compared to either agent alone. The findings suggest that this dual-targeted therapy with the combination of BP-CDs/HER3 siRNA and trastuzumab represents a promising approach in breast cancer.

Design of Hetero-Nanostructures on MoS2 Nanosheets To Boost NO2 Room-Temperature Sensing.

Molybdenum disulfide (MoS2), as a promising gas-sensing material, has gained intense interest because of its large surface-to-volume ratio, air stability, and various active sites for functionalization. However, MoS2-based gas sensors still suffer from low sensitivity, slow response, and weak recovery at room temperature, especially for NO2. Fabrication of heterostructures may be an effective way to modulate the intrinsic electronic properties of MoS2 nanosheets (NSs), thereby achieving high sensitivity and excellent recovery properties. In this work, we design a novel p-n hetero-nanostructure on MoS2 NSs using interface engineering via a simple wet chemical method. After surface modification with zinc oxide nanoparticles (ZnO NPs), the MoS2/ZnO hetero-nanostructure is endowed with an excellent response (5 ppm nitrogen dioxide, 3050%), which is 11 times greater than that of pure MoS2 NSs. To the best of our knowledge, such a response value is much higher than the response values reported for MoS2 gas sensors. Moreover, the fabricated hetero-nanostructure also improves recoverability to more than 90%, which is rare for room-temperature gas sensors. Our optimal sensor also possesses the characteristics of an ultrafast response time of 40 s, a reliable long-term stability within 10 weeks, an excellent selectivity, and a low detection concentration of 50 ppb. The enhanced sensing performances of the MoS2/ZnO hetero-nanostructure can be ascribed to unique 2D/0D hetero-nanostructures, synergistic effects, and p-n heterojunctions between ZnO NPs and MoS2 NSs. Such achievements of MoS2/ZnO hetero-nanostructure sensors imply that it is possible to use this novel nanostructure in ultrasensitive sensor applications.

Linear humidity response of carbon dot-modified molybdenum disulfide.

Molybdenum disulfide (MoS2)-based humidity sensors suffer from low sensitivity and long response time. Herein, this problem has been effectively solved by modifying MoS2 nanosheets using carbon dots (CDs) with abundant functional groups via a convenient and facile hydrothermal method. The mechanism for the enhanced humidity response of CD-modified MoS2 has been proposed through the characterization of physical and chemical properties of the as-prepared composites. The introduction of CDs is expected to enhance the adsorption of water molecules by increasing the specific surface area and surface active sites of the MoS2 nanosheets. Moreover, a three-dimensional conductive network is jointly established by the chemisorbed water molecules, CDs, and MoS2 nanosheets, which ensures continuous transmission of charges in a low humidity environment. As a result, the response performance and the repeatability have been significantly improved in CD-MoS2-based humidity sensors. The response curve shows an excellent linear property in the range of 15-80% RH. This study demonstrates the potential applications of CD-modified two-dimensional nanomaterials with their improved performance towards humidity sensing.

Rapid solid-phase microwave synthesis of highly photoluminescent nitrogen-doped carbon dots for Fe(3+) detection and cellular bioimaging.

Recently, carbon dots (CDs) have been playing an increasingly important role in industrial production and biomedical field because of their excellent properties. As such, finding an efficient method to quickly synthesize a large scale of relatively high purity CDs is of great interest. Herein, a facile and novel microwave method has been applied to prepare nitrogen doped CDs (N-doped CDs) within 8 min using L-glutamic acid as the sole reaction precursor in the solid phase condition. The as-prepared N-doped CDs with an average size of 1.64 nm are well dispersed in aqueous solution. The photoluminescence of N-doped CDs is pH-sensitive and excitation-dependent. The N-doped CDs show a strong blue fluorescence with relatively high fluorescent quantum yield of 41.2%, which remains stable even under high ionic strength. Since the surface is rich in oxygen-containing functional groups, N-doped CDs can be applied to selectively detect Fe(3+) with the limit of detection of 10(-5) M. In addition, they are also used for cellular bioimaging because of their high fluorescent intensity and nearly zero cytotoxicity. The solid-phase microwave method seems to be an effective strategy to rapidly obtain high quality N-doped CDs and expands their applications in ion detection and cellular bioimaging.

A Review on Graphene-Based Gas/Vapor Sensors with Unique Properties and Potential Applications.

Graphene-based gas/vapor sensors have attracted much attention in recent years due to their variety of structures, unique sensing performances, room-temperature working conditions, and tremendous application prospects, etc. Herein, we summarize recent advantages in graphene preparation, sensor construction, and sensing properties of various graphene-based gas/vapor sensors, such as NH3, NO2, H2, CO, SO2, H2S, as well as vapor of volatile organic compounds. The detection mechanisms pertaining to various gases are also discussed. In conclusion part, some existing problems which may hinder the sensor applications are presented. Several possible methods to solve these problems are proposed, for example, conceived solutions, hybrid nanostructures, multiple sensor arrays, and new recognition algorithm.

Hydrophilic and blue fluorescent N-doped carbon dots from tartaric acid and various alkylol amines under microwave irradiation.

The desired control of particle size, doping element composition, and surface structure of carbon dots (CDs) are vital for understanding the fluorescence mechanism and exploring their potential applications. Herein, nitrogen-doped CDs (N-doped CDs) have been synthesized with tartaric acid and various alkylol amines (monoethanolamine, biethanolamine and triethanolamine) under microwave irradiation. A systematic investigation was performed to characterize the N-doped CDs. It is found that with increasing nitrogen proportion, the fluorescent quantum yield and lifetime of N-doped CDs increases, whereas cell toxicity decreases. In other words, N-doped CDs synthesized by tartaric acid and monoethanolamine have the highest nitrogen content, the highest fluorescent quantum yield, the longest lifetime and the lowest cell toxicity. A corresponding mechanism has been proposed. Moreover, as-synthesized N-doped CDs have been applied for selectively detecting the Fe(3+) ion and writing letters as a fluorescent ink.

A green heterogeneous synthesis of N-doped carbon dots and their photoluminescence applications in solid and aqueous states.

Compared with traditional semiconductor quantum dots (QDs) and organic dyes, photoluminescent carbon dots (CDs) are superior because of their high aqueous solubility, robust chemical inertness, facile functionalization, high resistance to photobleaching, low toxicity and good biocompatibility. Herein, a green, large-scale and high-output heterogeneous synthesis of N-doped CDs was developed by reacting calcium citrate and urea under microwave irradiation without the use of any capping agents. The obtained N-doped CDs with a uniform size distribution exhibit good aqueous solubility and yellowish-green fluorescence in the solid and aqueous states. These unique luminescence properties of N-doped CDs inspire new thoughts for applications as fluorescent powders, fluorescent inks, the growth of fluorescent bean sprouts, and fingerprint detection tools.

Molecular dynamics simulations of polyelectrolyte brushes under poor solvent conditions: origins of bundle formation.

Molecular dynamics simulations are applied to investigate salt-free planar polyelectrolyte brushes under poor solvent conditions. Starting above the Θ-point with a homogeneous brush and then gradually reducing the temperature, the polymers initially display a lateral structure formation, forming vertical bundles of chains. A further reduction of the temperature (or solvent quality) leads to a vertical collapse of the brush. By varying the size and selectivity of the counterions, we show that lateral structure formation persists and therefore demonstrate that the entropy of counterions being the dominant factor for the formation of the bundle phase. By applying an external compression force on the brush we calculate the minimal work done on the polymer phase only and prove that the entropy gain of counterions in the bundle state, as compared to the homogeneously collapsed state at the same temperature, is responsible for the lateral microphase segregation. As a consequence, the observed lateral structure formation has to be regarded universal for osmotic polymer brushes below the Θ-point.

Statistics of polymer adsorption under shear flow.

Using nonequilibrium Brownian dynamics computer simulations, we have investigated the steady state statistics of a polymer chain under three different shear environments: (i) linear shear flow in the bulk (no interfaces), (ii) shear vorticity normal to the adsorbing interface, and (iii) shear gradient normal to the adsorbing interface. The statistical distribution of the chain end-to-end distance and its orientational angles are calculated within our computer simulations. Over a wide range of shear rates, this distribution can be mapped onto a simple theoretical finite-extensible-nonlinear-elastic dumbbell model with fitted anisotropic effective spring constants. The tails of the angular distribution functions are consistent with scaling predictions borrowed from the bulk dumbbell model. Finally, the frequency of the characteristic periodic tumbling motion has been investigated by simulation as well and was found to be sublinear with the shear rate for the three setups, which extends earlier results done in experiments and simulations for free and tethered polymer molecules without adsorption.

Nanoscale brushes: how to build a smart surface coating.

Via computer simulations, we demonstrate how a densely grafted layer of polymers, a brush, could be turned into an efficient switch through chemical modification of some of its end monomers. In this way, a surface coating with reversibly switchable properties can be constructed. We analyze the fundamental physical principle behind its function, a recently discovered surface instability, and demonstrate that the combination of a high grafting density, an inflated end-group size, and a high degree of monodispersity is a condition for an optimal functionality of the switch.

[Magnetic resonance imaging study and cochlear implantation in post-meningitic deaf patients].

OBJECTIVE: To investigate the clinical application of magnetic resonance imaging (MRI) in post-meningitic patients and its impact on surgical decision. METHOD: The pre-operative MRI data and auditory brainstem response (ABR) examination of five post-meningitic patients were studied. They were implanted with cochleas. RESULT: The interval between the onset of bacterial meningitis and the hearing loss was (15.8 +/- 15.0)d and it was longer in children than adults. Five ears showed membranous cochlear labyrinth abnormality; 3 ears had vestibule vestibule abnormality; 8 ears demonstrated semicircular canal abnormality on MRI examinations in totally 10 ears. The mean hearing threshold of 10 ears was (102.0 +/- 7.1)dB HL,that of the operated ears was (98.0 +/- 5.7)dB HL and that of the un-operated ears was (106.0 +/- 6.5)dB HL. It was (15.8 +/- 15.0)d from the bacterial meningitis onset to hearing loss. The interval is longer in children than adults. There were 3 ears that electrodes could not be inserted completely. CONCLUSION: The bacterial meningitis may cause the abnormalities of inner ears and the MRI before surgery is essential for the pre-operative planning of cochlear implant.