Enhancing Triplet-Triplet Annihilation Upconversion of Pyrene Derivatives for Photoredox Catalysis via Molecular Engineering.

Triplet-triplet annihilation upconversion (TTA-UC) has the potential to enhance photoredox catalysis yield. It includes a sensitizer and an annihilator. Efficient and stable annihilators are essential for photoredox catalysis, yet only a few examples are reported. Herein, we designed four novel pyrene annihilators (1, 2, 3 and 4) via introducing aryl-alkynyl groups onto pyrene to systematically modulate their singlet and triplet energies. Coupled with platinum octaethylporphyrin (PtOEP), the TTA-UC efficiency is enhanced gradually as the number of aryl-alkynyl group increases. When combining 4 with palladium tetraphenyl-tetrabenzoporphyrin (PdTPTBP), we achieved the highest red-to-green upconversion efficiency (22.4±0.3 %) (out of a 50 % maximum) so far. Then, this pair was used to activate photooxidation of aryl boronic acid under red light (630 nm), which achieved a great improved reaction yield compared to that activated by green light directly. The results not only provide a design strategy for efficient annihilators, but also show the advantage of applying TTA-UC into improving the photoredox catalysis yield.

Functionalized Graphene Quantum Dots Modified Dioxin-Linked Covalent Organic Frameworks for Superior Lithium Storage.

Covalent organic framework, as an emerging porous nano-frame structure with pre-designed structure and custom properties, has been demonstrated as a prospective electrode for rechargeable Li-ion batteries. For improving the reversible capacity and long-term cycle stability of COF materials, we propose a GQDs modified COF material (COF-GQDs) and apply it as the anode for LIBs for the first time. This COF-GQDs electrode delivers enhanced long-term cycling performance with a large capacity of ∼820 mAh g-1 after 300 cycles at 100 mA g-1 and an improved rate performance. The enhanced lithium-storage performance, in terms of obvious-shortened activation process and high reversible capacities, can be attributed to the modification of carboxyl GQDs, which would activate more active sites (activated C=C groups from benzene rings) for lithium-storage, and provide fast lithium-ion transportation kinetic. Besides, the decreased interphase resistance, enhanced electronic conductivity, and prevented aggregation of needle-flake COF structure, originated from the addition of GQDs, which lead to the enhanced improved cycling stability of the COF-GQDs electrode. This manuscript can promote the further exploration on the design of COF-related materials with modification of functionalized carbonaceous materials to achieve enhanced lithium-storage properties for next-generation energy storage.

Carbon-Encased Mixed-Metal Selenide Rooted with Carbon Nanotubes for High-Performance Hybrid Supercapacitors.

Transition metal-based compounds with high theoretical capacitance and low cost represent one class of promising electrode materials for high-performance supercapacitors. However, their low intrinsic electrical conductivity impedes their capacitive effect and further limits their practical application. Rational regulation of their composition and structure is, therefore, necessary to achieve a high electrode performance. Herein, a well-designed carbon-encased mixed-metal selenide rooted with carbon nanotubes (Ni-Co-Se@C-CNT) was derived from nickel-cobalt bimetallic organic frameworks. Due to the unique porous structure, the synergistic effect of bimetal selenides and the in situ growth of carbon nanotubes, the composite exhibits good electrical conductivity, high structural stability and abundant redox active sites. Benefitting from these merits, the Ni-Co-Se@C-CNT exhibited a high specific capacity of 554.1 C g-1 (1108.2 F g-1) at 1 A g-1 and a superior cycling performance, i.e., 96.4% of the initial capacity was retained after 5000 cycles at 10 A g-1. Furthermore, a hybrid supercapacitor assembled with Ni-Co-Se@C-CNT cathode and activated carbon (AC) anode shows a superior energy density of 38.2 Wh kg-1 at 1602.1 W kg-1.

Scavenger receptor class B type I is more conducive for genotype 1b hepatitis C virus internalization than low-density lipoprotein receptor.

The current limited understanding of HCV entry mechanisms hinders the development of specific antiviral drug screening techniques and vaccine assessment. HCV subtypes and cellular surface proteins both can affect virus tropism. Human factors such as low-density lipoprotein receptor (hLDLR), CD81 (hCD81), scavenger receptor class B type I (hSR-BI), claudin 1 (hCLDN1), and occludin (hOCLN) assist HCV entry into hepatocytes. Here, we studied the importance of five human proteins in the process of cell culture-derived (HCVcc) and serum-derived (HCV-sd) HCV entry using constructed humanized mouse hepatocytes and mouse models. We determined that unlike hLDLR, hSR-BI was an indispensable factor for 1b genotype HCV adsorption. Furthermore, this attachment can be completely prevented by treatment with a monoclonal antibody targeting hSR-BI. Our data support the idea that SR-BI is an essential factor in HCV infection, particularly during the initial HCV particle-binding step. This novel finding will facilitate the development of antiviral drugs and vaccines. Keywords: hepatitis C virus; virus internalization; model construction; hSR-BI.

Dimethyl Sulfoxide-Free Cryopreservation of Human Umbilical Cord Mesenchymal Stem Cells Based on Zwitterionic Betaine and Electroporation.

The effective cryopreservation of mesenchymal stem cells (MSCs) is indispensable to the operation of basic research and clinical transplantation. The prevalent protocols for MSC cryopreservation utilize dimethyl sulfoxide (DMSO), which is easily permeable and able to protect MSCs from cryo-injuries, as a primary cryoprotectant (CPA). However, its intrinsic toxicity and adverse effects on cell function remain the bottleneck of MSC cryopreservation. In this work, we cryopreserved human umbilical cord mesenchymal stem cells (UCMSCs) using zwitterionic betaine combined with electroporation without any addition of DMSO. Betaine was characterized by excellent compatibility and cryoprotective properties to depress the freezing point of pure water and balance the cellular osmotic stress. Electroporation was introduced to achieve intracellular delivery of betaine, intending to further provide comprehensive cryoprotection on UCMSCs. Compared with DMSO cryopreservation, UCMSCs recovered from the protocol we developed maintained the normal viability and functions and reduced the level of reactive oxygen species (ROS) that are harmful to cell metabolism. Moreover, the in vivo distribution of thawed UCMSCs was consistent with that of fresh cells monitored by a bioluminescence imaging (BLI) system. This work opens a new window of opportunity for DMSO-free MSC cryopreservation using zwitterionic compounds like betaine combined with electroporation.

Targeting human cytomegalovirus IE genes by CRISPR/Cas9 nuclease effectively inhibits viral replication and reactivation.

Human cytomegalovirus (HCMV) infection causes high morbidity and mortality among immunocompromised patients and can remain in a latent state in host cells. Expression of the immediate-early (IE) genes sustains HCMV replication and reactivation. As a novel genome-editing tool, the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been extensively utilized to modify and edit genomic DNA. In the present study, the CRISPR/Cas9 system was used to target the IE region of the HCMV genome via specific single-guide RNAs (sgRNAs). Infection with CRISPR/Cas9/sgRNA lentiviral constructs significantly reduced viral gene expression and virion production in HFF primary fibroblasts and inhibited viral DNA production and reactivation in the THP-1 monocytic cell line. Thus, the CRISPR/Cas9/sgRNA system can accurately and efficiently target HCMV replication and reactivation and represents a novel therapeutic strategy against latent HCMV infection.

Reconciling the Debate on the Existence of Pentazole HN5 in the Pentazolate Salt of (N5)6(H3O)3(NH4)4Cl.

The successful synthesis of the pentazolate salt (N5)6(H3O)3(NH4)4Cl has received considerable attention, as it ends the long search for a method for the bulk preparation of cyclo-N5-, a molecular ring with high energy density ( Zhang , C. ; Science 2017 , 355 , 374 . ). A debate has recently arisen on the possible existence of a neutral HN5 species in the pentazolate salt ( Huang , R.-Y. ; Science 2018, 359 , eaao3672 . ; Jiang , C. ; Science 2018, 359 , eaas8953 . ). Herein, we show that the debate can be reconciled by the temperature effect on the proton transfer. At a low temperature (123 K), the proton transfer from H3O+ to cyclo-N5- is energetically unfavorable; therefore, few neutral HN5 species exist in the pentazolate salt, which is consistent with the single-crystal X-ray diffraction measurements ( Zhang , C. ; Science 2017 , 355 , 374 . ). As the temperature increases toward room temperature, endothermic proton transfer becomes increasingly feasible, promoting the formation of H2O···HN5 via H2O-H-N5 as an intermediate species. In addition, the confusion over the apparent absence of a peak in the measured infrared spectrum corresponding to the out-of-plane bending of H3O+ can be resolved by the computationally established ultrafast interconversion among the neutral and anionic species under ambient conditions.

Strong Surface-Bound Sulfur in Carbon Nanotube Bridged Hierarchical Mo2 C-Based MXene Nanosheets for Lithium-Sulfur Batteries.

In this work, hydroxyl-functionalized Mo2 C-based MXene nanosheets are synthesized by facilely removing the Sn layer of Mo2 SnC. The hydroxyl-functionalized surface of Mo2 C suppresses the shuttle effect of lithium polysulfides (LiPSs) through strong interaction between Mo atoms on the MXenes surface and LiPSs. Carbon nanotubes (CNTs) are further introduced into Mo2 C phase to enlarge the specific surface area of the composite, improve its electronic conductivity, and alleviate the volume change during discharging/charging. The strong surface-bound sulfur in the hierarchical Mo2 C-CNTs host can lead to a superior electrochemical performance in lithium-sulfur batteries. A large reversible capacity of ≈925 mAh g-1 is observed after 250 cycles at a current density of 0.1 C (1 C = 1675 mAh g-1 ) with good rate capability. Notably, the electrodes with high loading amounts of sulfur can also deliver good electrochemical performances, i.e., initial reversible capacities of ≈1314 mAh g-1 (2.4 mAh cm-2 ), ≈1068 mAh g-1 (3.7 mAh cm-2 ), and ≈959 mAh g-1 (5.3 mAh cm-2 ) at various areal loading amounts of sulfur (1.8, 3.5, and 5.6 mg cm-2 ) are also observed, respectively.

Controllable Synthesis of Hierarchical Rose-Like MnCo2O4 Spinel as Lithium-Ion Anode Materials.

Hierarchical rose-like structured MnCo2O4 spinel was synthesized via a facile solvothermal process using polyvinyl pyrrolidone (PVP) as the soft template, which was characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), etc. When evaluated as the anode materials for lithium ion batteries, the as-synthesized MnCo2O4 spinel exhibited excellent cycling performance and rate capacity. The initial discharge and charge capacity reached 1502 mA·h·g-1 and 1131 mA·h·g-1 at the current density of 100 mA·g-1, respectively.

Translocation of intranasal (i.n.) instillation of different-sized cerium dioxide (CeO2) particles: potential adverse effects in mice.

Cerium oxide (CeO2), one of many engineered nanomaterials (ENMs), is composed primarily of metal oxides, such as cerium oxide (CeO2). CeO2-containing materials are widely used as a polishing agent for glass mirrors, plate glass, television tubes, ophthalmic lenses, and precision optics. The widespread use of this nanomaterial (NM) resulted in increased environmental contamination levels and consequent human exposure. However, the influence of Ce on humans remains to be determined. The aim of this study was to expose female ICR mice to varying nanoparticle sizes of 35 nm, 300 nm as well as a mixture of 1-5 µM CeO2 particles through intranasal (i.n.) instillation at 40 mg/kg dose on day 1, 3 and 5, and the experiment terminated on day 7. Histopathology findings demonstrated that hydropic degeneration was prominently associated with hemorrhage in renal cortex and medulla in all CeO2-administered groups. In liver of CeO2-exposed mice, hydropic degeneration was also prominent. Serum chemistries also indicated signs of renal and hepatic lesion as evidenced by significantly decreased serum levels of total bilirubin (TBIL) and total phosphate (TP) and activity of alkaline phosphatase (ALP). ICP-MS analysis group demonstrated that Ce levels were not significantly higher in liver and kidneys of mice exposed to 35 nm CeO2. An increase in Ce content was observed in hepatic and renal tissues of mice exposed to 300 nm or 1-5 µM CeO2. The levels of Ce were similar in these two groups suggesting a threshold level of Ce was attained regardless of NP size. Data thus demonstrated that i.n. instillation of different-sized CeO2 particles translocated to liver and kidney and that size difference of CeO2 particles did not exert significant in the observed histopathology responses.

Optically controlled ultrafast terahertz switching in a CdTe nanostructure thin film.

The speed of optical modulation on a terahertz (THz) pulse is mainly dominated by the optical response of the photocarrier. In order to achieve ultrafast THz modulation, the effective method is to reduce the lifetime of the photocarrier by introducing defects that can trap the photocarriers efficiently. In this paper, we reported the ultrafast optical modulation of THz switching in a 10 nm CdTe nanostructure film. After photoexcitation at 800/400 nm, the THz response of the film is extremely fast with a lifetime of ${\sim}{1.3}\;{\rm ps}$∼1.3ps. Further, the ultrafast transient THz transmission shows almost temperature independence down to 100 K. On the other hand, the transient absorption spectroscopy reveals that the lifetime of photocarriers in CdTe nanostructure film lasts as long as several ns. The 1.3 ps THz photoconductivity response is due to the substantial decrease of photocarrier mobility in a CdTe nanostructure, which comes from the increase of the photocarrier scattering between the photocarrier and the surface states of CdTe nanostructural film. Our experimental results provide a new method to design optically driven ultrafast THz response devices, such as THz switch and THz modulator.

Effect of cadmium contamination on the eutrophic secondary pollution of aquatic macrophytes by litter decomposition.

The objective of this study was to identify the effect of cadmium (Cd) contamination on the decomposition of aquatic macrophyte litter and its eutrophic secondary pollution. A laboratory experiment was conducted with three treatments: water Cd contamination (Cd-w), litter Cd contamination (Cd-l) and control (CK). The results showed that CK and Cd-w exhibited the typical decomposition dynamics of litter, i.e., early rapid decomposition followed by slow decomposition, while the litter biomass loss (BL) in Cd-l exhibited an approximately linear relationship with time over the 64-day experimental period. The BL in Cd-l was only 10.8% in the initial 4 days, while that in CK and Cd-w was 59.0% and 54.8%, respectively. Cd inhibited the fluctuation of the water chemical oxygen demand (COD) by reducing both the early increase and the subsequent decrease. The increases in water total nitrogen (TN) and total phosphorus (TP) were inhibited by Cd contamination throughout most of the decomposition period. The alterations of litter quality during the plant growth period and of the bacterial community during the litter decomposition period by Cd contamination could explain the variations in litter decomposition rate and its eutrophic secondary pollution during the early and late decomposition stages, respectively. The Cd inhibition of the eutrophic secondary pollution of aquatic macrophytes has great significance for the improved evaluation of Cd contamination.

Functionalized Graphene Quantum Dot Modification of Yolk-Shell NiO Microspheres for Superior Lithium Storage.

Yolk-shell NiO microspheres are modified by two types of functionalized graphene quantum dots (denoted as NiO/GQDs) via a facile solvothermal treatment. The modification of GQDs on the surface of NiO greatly boosts the stability of the NiO/GQD electrode during long-term cycling. Specifically, the NiO with carboxyl-functionalized GQDs (NiO/GQDsCOOH) exhibits better performances than NiO with amino-functionalized GQDs (NiO/GQDsNH2 ). It delivers a capacity of ≈1081 mAh g-1 (NiO contribution: ≈1182 mAh g-1 ) after 250 cycles at 0.1 A g-1 . In comparison, NiO/GQDsNH2 electrode holds ≈834 mAh g-1 of capacity, while the bald NiO exhibits an obvious decline in capacity with ≈396 mAh g-1 retained after cycling. Except for the yolk-shell and mesoporous merits, the superior performances of the NiO/GQD electrode are mainly ascribed to the assistance of GQDs. The GQD modification can support as a buffer alleviating the volume change, improve the electronic conductivity, and act as a reservoir for electrolytes to facilitate the transportation of Li+ . Moreover, the enrichment of carboxyl/amino groups on GQDs can further donate more active sites for the diffusion of Li+ and facilitate the electrochemical redox kinetics of the electrode, thus together leading to the superior lithium storage performance.

Ceria Oxide Nanoparticles an Ideal Carrier Given Little Stress to Cells and Rats.

Nanoparticles were used as ideal carrier for its passive and active targeting property. Unfortunately, many of them were failed for its biotoxicology. Thus, find a safe and targeted drug delivery was the new goal of pharmaceutical industries. Here, A549 and H1299 cells were exposed to ceria oxide nanoparticles, silicon oxide nanoparticles and zinc oxide nanoparticles for 12 h to induce autophagy and late apoptosis. Rats were exposed to ceria oxide nanoparticles (20 mg/kg · bw) for 1, 7, 14 or 28 days to induce lung injury and cytokines change. Luckily, compare with silicon oxide nanoparticles and zinc oxide nanoparticles, autophagy and late apoptosis were failed to fund in ceria oxide nanoparticles groups in 100 µg/ml in cell lines for 12 h. At the same time, the autophagy related genes LC3, atg5, beclin1 and bcl2 were not change in protein level at 0 to 200 µg/ml. What's more, histopathology change of the lung was recovered at the day of 28, only four of twenty-seven cytokines (IL12P70, RANTES, IL-X and MIP-1α) were changed at the day of 28 after exposed to ceria oxide nanoparticles (20 mg/kg · bw). Therefore, we indicated that ceria oxide nanoparticles can't give a stress both in vivo and vitro, and ceria oxide nanoparticles will be an ideal carrier for targeted drug delivery.

A novel riboregulator switch system of gene expression for enhanced microbial production of succinic acid.

In this paper, a novel riboregulator Switch System of Gene Expression including an OFF-TO-ON switch and an ON-TO-OFF switch was designed to regulate the expression state of target genes between "ON" and "OFF" by switching the identifiability of ribosome recognition site (RBS) based on the thermodynamic stability of different RNA-RNA hybridizations between RBS and small noncoding RNAs. The proposed riboregulator switch system was employed for the fermentative production of succinic acid using an engineered strain of E. coli JW1021, during which the expression of mgtC gene was controlled at "ON" state and that of pepc and ecaA genes were controlled at the "OFF" state in the lag phase and switched to the "OFF" and "ON" state once the strain enters the logarithmic phase. The results showed that using the strain of JW1021, the yield and productivity of succinic acid can reach 0.91 g g-1 and 3.25 g L-1 h-1, respectively, much higher than those using the strains without harboring the riboregulator switch system.

Bimetal-Organic-Framework Derivation of Ball-Cactus-Like Ni-Sn-P@C-CNT as Long-Cycle Anode for Lithium Ion Battery.

Metal phosphides are a new class of potential high-capacity anodes for lithium ion batteries, but their short cycle life is the critical problem to hinder its practical application. A unique ball-cactus-like microsphere of carbon coated NiP2 /Ni3 Sn4 with deep-rooted carbon nanotubes (Ni-Sn-P@C-CNT) is demonstrated in this work to solve this problem. Bimetal-organic-frameworks (BMOFs, Ni-Sn-BTC, BTC refers to 1,3,5-benzenetricarboxylic acid) are formed by a two-step uniform microwave-assisted irradiation approach and used as the precursor to grow Ni-Sn@C-CNT, Ni-Sn-P@C-CNT, yolk-shell Ni-Sn@C, and Ni-Sn-P@C. The uniform carbon overlayer is formed by the decomposition of organic ligands from MOFs and small CNTs are deeply rooted in Ni-Sn-P@C microsphere due to the in situ catalysis effect of Ni-Sn. Among these potential anode materials, the Ni-Sn-P@C-CNT is found to be a promising anode with best electrochemical properties. It exhibits a large reversible capacity of 704 mA h g-1 after 200 cycles at 100 mA g-1 and excellent high-rate cycling performance (a stable capacity of 504 mA h g-1 retained after 800 cycles at 1 A g-1 ). These good electrochemical properties are mainly ascribed to the unique 3D mesoporous structure design along with dual active components showing synergistic electrochemical activity within different voltage windows.

A real-time control system of gene expression using ligand-bound nucleic acid aptamer for metabolic engineering.

Artificial control of bio-functions through regulating gene expression is one of the most important and attractive technologies to build novel living systems that are useful in the areas of chemical synthesis, nanotechnology, pharmacology, cell biology. Here, we present a novel real-time control system of gene regulation that includes an enhancement element by introducing duplex DNA aptamers upstream promoter and a repression element by introducing a RNA aptamer upstream ribosome binding site. With the presence of ligands corresponding to the DNA aptamers, the expression of the target gene can be potentially enhanced at the transcriptional level by strengthening the recognition capability of RNAP to the recognition region and speeding up the separation efficiency of the unwinding region due to the induced DNA bubble around the thrombin-bound aptamers; while with the presence of RNA aptamer ligand, the gene expression can be repressed at the translational level by weakening the recognition capability of ribosome to RBS due to the shielding of RBS by the formed aptamer-ligand complex upstream RBS. The effectiveness and potential utility of the developed gene regulation system were demonstrated by regulating the expression of ecaA gene in the cell-free systems. The realistic metabolic engineering application of the system has also tested by regulating the expression of mgtC gene and thrombin cDNA in Escherichia coli JD1021 for controlling metabolic flux and improving thrombin production, verifying that the real-time control system of gene regulation is able to realize the dynamic regulation of gene expression with potential applications in bacterial physiology studies and metabolic engineering.

Nanocontainers in and onto Nanofibers.

Hierarchical structure is a key feature explaining the superior properties of many materials in nature. Fibers usually serve in textiles, for structural reinforcement, or as support for other materials, whereas spherical micro- and nanoobjects can be either highly functional or also used as fillers to reinforce structure materials. Combining nanocontainers with fibers in one single object has been used to increase the functionality of fibers, for example, antibacterial and thermoregulation, when the advantageous properties given by the encapsulated materials inside the containers are transferred to the fibers. Herein we focus our discussion on how the hierarchical structure composed of nanocontainers in nanofibers yields materials displaying advantages of both types of materials and sometimes synergetical effects. Such materials can be produced by first carefully designing nanocontainers with defined morphology and chemistry and subsequently electrospinning them to fabricate nanofibers. This method, called colloid-electrospinning, allows for marrying the properties of nanocontainers and nanofibers. The obtained fibers could be successfully applied in different fields such as catalysis, optics, energy conversion and production, and biomedicine. The miniemulsion process is a convenient approach for the encapsulation of hydrophobic or hydrophilic payloads in nanocontainers. These nanocontainers can be embedded in fibers by the colloid-electrospinning technique. The combination of nanocontainers with nanofibers by colloid-electrospinning has several advantages. (1) The fiber matrix serves as support for the embedded nanocontainers. For example, through combining catalysts nanoparticles with fiber networks, the catalysts can be easily separated from the reaction media and handled visually. This combination is beneficial for the reuse of the catalyst and the purification of products. (2) Electrospun nanofibers containing nanocontainers offer the active agents inside the nanocontainers a double protection by both the fiber matrix and the nanocontainers. Since the polymer of the fibers and the polymer of the nanocontainers have usually opposite polarities, the encapsulated substance, for example, catalysts, dyes, or drugs, can be protected against a large variety of environmental influences. (3) Electrospun nanofibers exhibit unique advantages for tissue engineering and drug delivery that are a structural similarity to the extracellular matrix of biological tissues, large specific surface area, high and interconnected porosity which enhances cell adhesion, proliferation, drug loading, and mass transfer properties, as well as the flexibility in selecting the raw materials. Moreover, the nanocontainer-in-nanofiber structure allows multidrug loading and programmable release of each drug, which are very important to achieve synergistic effects in tissue engineering and disease therapy. The advantages offered by these materials encourage us to further understand the relationship between colloidal properties and fibers, to predict the morphology and properties of the fibers obtained by colloid-electrospinning, and to explore new possible combination of properties offered by nanoparticles and nanofibers.

Diagnostic Value of Video-assisted Mediastinoscopy and Endobronchial Ultrasound-guided Transbronchial Needle Aspiration for Mediastinal Lymphadenectasis without Pulmonary Abnormalities.

BACKGROUND Mediastinal diseases are difficult to diagnose due to diverse origins and complex anatomical structure of the mediastinal tissues. The prospective study aimed to compare the diagnostic efficiency of video-assisted mediastinoscopy (VAM) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for mediastinal lesions without pulmonary abnormalities. MATERIAL AND METHODS We divided 100 mediastinal lymphadenectasis patients without pulmonary abnormalities into a VAM group and an EBUS group. The pathological results of each group were regarded as the endpoints. SPSS19.0 statistical software was used. RESULTS The diagnostic accuracy, sensitivity, and specificity of VAM were 96%, 97.4%, and 100%, respectively; those of EBUS-TBNA diagnosis were 62%, 87.1%, and 100%, respectively. There was a statistically significant difference in the diagnostic sensitivity of benign mediastinal lesions between the 2 groups (P<0.01). Compared with the EBUS group (62%), the accuracy in the VAM group was significantly higher (96%) (P<0.01). CONCLUSIONS We found that the diagnostic accuracy of VAM for mediastinal lymphadenectasis without pulmonary abnormalities is superior to that of EBUS. Therefore, for patients with mediastinal lymphadenectasis or mediastinal mass and without pulmonary abnormalities, mediastinoscopy is recommended as the first choice.