Giant mediastinal lymphocele after esophagectomy successfully treated with thoracic duct embolization.

A 64-year old man had developed a giant mediastinal lymphocele after undergoing esophagectomy for the treatment of esophageal squamous cell carcinoma. The thoracic duct was embolized with six micro-coils, followed by embolization using a 1:3 mixture of N-butyl-2-cyanoacrylate (Histoacryl; B. Braun, Melsungen, Germany) and ethiodized oil. Resolution of the lymphocele was achieved within 5 days after embolization. To the best of our knowledge, ours is the first reported case of thoracic duct embolization for the treatment of mediastinal lymphocele.

Clinical evaluation the success rate and complications of fluoroscopically guided removal of tracheal tube metallic stents.

BACKGROUND: Long-term placement of airway stents has a high probability of restenosis of the airway due to granulation tissue hyperplasia, and it is difficult to remove the stent. Our aim is to evaluate the success rate and complications of removal of tracheal tube metallic stents under fluoroscopic guidance, and to compare the difference between uncovered stent and covered stent. METHODS: We retrospectively reviewed 45 cases (31 males and 14 females; age, 12-71 years) of tracheal metallic stent removal performed at our center between January 2014 and December 2019. Covered stents were applied in 36 cases, and uncovered stents were applied in 9 cases. In the covered stent group, 15 patients presented with granulation tissue at both ends; 3 cases, with stent fracture; and 2, with stent intolerance due to severe airway foreign body sensation. In the uncovered stents group, all patients presented with granulation tissue formation; 2 patients, with stent fracture; and 1 patient, with stent intolerance. RESULTS: A total of 41 (91.1%) stents were successfully removed (34 [94.4%] in the covered stent group and 7 [77.8%] in the uncovered stent group). The average duration of stent placement was 3.2 ± 0.7 and 2.5 ± 1.2 months in the covered stent group and uncovered stent group, respectively. With regard to the complications, hemoptysis occurred in 4 cases (average blood volume lost, 100 ml), tracheal mucosa tear occurred in 5 cases, tracheal collapse requiring emergency airway stent placement occurred in 1 case, and tracheal rupture requiring emergency surgical suture occurred in 1 case. No procedure-related deaths occurred in either group. CONCLUSIONS: It is safe to remove the metal stent of the tracheal tube under the guidance of fluoroscopy, with low complications, and can avoid the long-term placement of the airway stent.

Strong Ferromagnetism Achieved via Breathing Lattices in Atomically Thin Cobaltites.

Low-dimensional quantum materials that remain strongly ferromagnetic down to monolayer thickness are highly desired for spintronic applications. Although oxide materials are important candidates for the next generation of spintronics, ferromagnetism decays severely when the thickness is scaled to the nanometer regime, leading to deterioration of device performance. Here, a methodology is reported for maintaining strong ferromagnetism in insulating LaCoO3 (LCO) layers down to the thickness of a single unit cell. It is found that the magnetic and electronic states of LCO are linked intimately to the structural parameters of adjacent "breathing lattice" SrCuO2 (SCO). As the dimensionality of SCO is reduced, the lattice constant elongates over 10% along the growth direction, leading to a significant distortion of the CoO6 octahedra, and promoting a higher spin state and long-range spin ordering. For atomically thin LCO layers, surprisingly large magnetic moment (0.5 µB /Co) and Curie temperature (75 K), values larger than previously reported for any monolayer oxides are observed. The results demonstrate a strategy for creating ultrathin ferromagnetic oxides by exploiting atomic heterointerface engineering, confinement-driven structural transformation, and spin-lattice entanglement in strongly correlated materials.

Strain-Mediated High Conductivity in Ultrathin Antiferromagnetic Metallic Nitrides.

Strain engineering provides the ability to control the ground states and associated phase transition in epitaxial films. However, the systematic study of the intrinsic character and strain dependency in transition-metal nitrides remains challenging due to the difficulty in fabricating stoichiometric and high-quality films. Here the observation of an electronic state transition in highly crystalline antiferromagnetic CrN films with strain and reduced dimensionality is reported. By shrinking the film thickness to a critical value of ≈30 unit cells, a profound conductivity reduction accompanied by unexpected volume expansion is observed in CrN films. The electrical conductivity is observed surprisingly when the CrN layer is as thin as a single unit cell thick, which is far below the critical thickness of most metallic films. It is found that the metallicity of an ultrathin CrN film recovers from insulating behavior upon the removal of the as-grown strain by the fabrication of freestanding nitride films. Both first-principles calculations and linear dichroism measurements reveal that the strain-mediated orbital splitting effectively customizes the relatively small bandgap at the Fermi level, leading to an exotic phase transition in CrN. The ability to achieve highly conductive nitride ultrathin films by harnessing strain-control over competing phases can be used for utilizing their exceptional characteristics.

Correction to: Duganella rivus sp. nov., Duganella fentianensis sp. nov., Duganella qianjiadongensis sp. nov. and Massilia guangdongensis sp. nov., isolated from subtropical streams in China and reclassification of all species within genus Pseudoduganella.

In the published version of the article, the title should have read 'Duganella rivi sp. nov., Duganella fentianensis sp. nov., Duganella qianjiadongensis sp. nov. and Massilia guangdongensis sp. nov., isolated from subtropical streams in China and reclassification of all species within genus Pseudoduganella'.

Massilia aquatica sp. nov., Isolated from a Subtropical Stream in China.

A Gram-stain-negative, catalase- and oxidase-positive, rod-shaped and motile strain FT127WT was isolated from a subtropical stream in China. Comparison based on 16S rRNA gene sequences showed that strain FT127WT belongs to genus Massilia and shares 98.5% similarity with Massilia buxea A9T as its closest neighbor. The genome size of strain FT127WT was 6.65 Mbp with G + C content of 65.3%. The calculated pairwise OrthoANIu values and digital DNA-DNA hybridization values between strain FT127WT and each of strains M. buxea KCTC 52429T, Massilia armeniaca ZMN-3T, Massilia plicata DSM 17505T and Massilia namucuonensis CGMCC 1.11014T were less than 83.1% and 26.6%, respectively. The reconstructed phylogenomic tree based on concatenated 92 core genes showed that strain FT127WT clusters closely with M. namucuonensis CGMCC 1.11014T. The respiratory quinone of strain FT127WT was Q-8. The major fatty acids were C16:1 ω7c, C16:0 and C12:0. The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol and one unidentified phospholipid. Combining above all characteristics, strain FT127WT should represent a novel species within genus Massilia, for which the name Massilia aquatica sp. nov. (type strain FT127WT = GDMCC 1.1690T = KACC 21482T) is proposed.

Duganella rivus sp. nov., Duganella fentianensis sp. nov., Duganella qianjiadongensis sp. nov. and Massilia guangdongensis sp. nov., isolated from subtropical streams in China and reclassification of all species within genus Pseudoduganella.

Four Gram-stain-negative, catalase-positive, rod-shaped and motile strains (FT55WT, FT93WT, CY13WT and DS3T) were isolated from subtropical streams in China. Comparisons based on 16S rRNA gene sequences indicated that strains FT55WT, FT93WT and CY13WT take strain Pseudoduganella danionis E3/2T, and strain DS3T takes strain Pseudoduganella eburnea 10R5-21T as their closest neighbour, respectively. The genome sizes of strains FT55WT, FT93WT, CY13WT and DS3T were 6.15, 5.10, 5.31 and 5.72 Mbp with G+C contents of 61.7, 60.9, 60.6 and 64.0%, respectively. The reconstructed phylogenomic tree based on concatenated 92 core genes showed that strain FT55WT clusters closely with Duganella radicis KCTC 22382T and Duganella sacchari Sac-22T, strains FT93WT and CY13WT form a distinct clade with P. danionis DSM 103461T and this clade clusters with the clades of genus Duganella together, and strain DS3T forms a distinct clade with P. eburnea JCM 31587T and Pseudoduganella violaceinigra DSM 15887T and this clade clusters closely with the clades of genus Massilia, respectively. The calculated pairwise OrthoANIu values and digital DNA-DNA hybridization (DDH) values among strains FT55WT, FT93WT, CY13WT, DS3T and related strains were in the ranges of 75.6-94.2% and 20.6-56.2%, respectively. Q-8 was the sole respiratory quinone of these four strains. The major fatty acids were C16:1ω7c, C16:0 and C12:0. The polar lipids included phosphatidylglycerol, phosphatidylethanolamine and one unidentified phospholipid. Considering the similar fatty acids and polar lipids profiles of species within genus Pseudoduganella, Massilia and Duganella, there is currently no justification for assigning the species of genus Pseudoduganella into the Massilia and Duganella clades in the phylogenomic tree. It is reasonable to transfer P. violaceinigra and P. eburnea to the genus Massilia as Massilia violaceinigrum comb. nov. and Massilia eburnea comb. nov., and transfer P. danionis to the genus Duganella as Duganella danionis comb. nov. Considering phylogenomic analysis, OrthoANIu data, digital DDH data and a range of physiological and biochemical characteristics, strains FT55WT, FT93WT and CY13WT should be assigned to genus Duganella, and strain DS3T should be classified as a novel species within genus Massilia, for which the names Duganella rivus sp. nov. (type strain FT55WT = GDMCC 1.1675T = KACC 21467T), Duganella fentianensis sp. nov. (type strain FT93WT = GDMCC 1.1683T = KACC 21475T), Duganella qianjiadongensis sp. nov. (type strain CY13WT = GDMCC 1.1669T = KACC 21461T) and Massilia guangdongensis sp. nov. (type strain DS3T = GDMCC 1.1636T = KACC 21312T) are proposed.

Roseovarius tibetensis sp. nov., a halophilic bacterium isolated from Lake LongmuCo on Tibetan Plateau.

Two Gram-stain negative halophilic strains, designated as LM2T and LM4, were isolated from Lake LongmuCo on Tibetan Plateau. These two strains were aerobic, catalaseand oxidase-positive, nonmotile and rod-shaped organisms. Phylogenetic analysis based on 16S rRNA gene sequences indicated that LM2T and LM4 belong to the genus Roseovarius, with Roseovarius tolerans EL-172T (97.3% and 97.4% 16S rRNA gene sequence similarity, respectively) and Roseovarius azorensis SSW084T (95.5% and 95.6% 16S rRNA gene sequence similarity, respectively) as their closest neighbors. Q-10 was the sole respiratory quinone of these two strains. The major fatty acids were C18:1ω7c/C18:1ω6c, C16:0, C19:0 cyclo ω8c, and 11-methyl C18:1ω7c. The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phospholipid of unknown structure containing glucosamine, and unidentified aminolipid. The DNA G + C content was between 64.2 and 64.5 mol%. DNA-DNA hybridization showed 96.7% relatedness between LM2T and LM4, 24.9% relatedness between LM2T and R. tolerans EL-172T, and 36.3% relatedness between LM4 and R. tolerans EL-172T. Based on phylogenetic analysis, DNA-DNA hybridization, a range of physiological and biochemical characteristics, LM2T and LM4 belong to the same species and were clearly distinguished from the type strains of the genus Roseovarius. It was evident that LM2T and LM4 could be classified as a novel species of the genus Roseovarius, for which the name Roseovarius tibetensis sp. nov. is proposed. The type strain is LM2T (= CGMCC 1.16230T = KCTC 62028T).

Artificial Synapses Emulated by an Electrolyte-Gated Tungsten-Oxide Transistor.

Considering that the human brain uses ≈1015 synapses to operate, the development of effective artificial synapses is essential to build brain-inspired computing systems. In biological synapses, the voltage-gated ion channels are very important for regulating the action-potential firing. Here, an electrolyte-gated transistor using WO3 with a unique tunnel structure, which can emulate the ionic modulation process of biological synapses, is proposed. The transistor successfully realizes synaptic functions of both short-term and long-term plasticity. Short-term plasticity is mimicked with the help of electrolyte ion dynamics under low electrical bias, whereas the long-term plasticity is realized using proton insertion in WO3 under high electrical bias. This is a new working approach to control the transition from short-term memory to long-term memory using different gate voltage amplitude for artificial synapses. Other essential synaptic behaviors, such as paired pulse facilitation, the depression and potentiation of synaptic weight, as well as spike-timing-dependent plasticity are also implemented in this artificial synapse. These results provide a new recipe for designing synaptic electrolyte-gated transistors through the electrostatic and electrochemical effects.

Halomonas tibetensis sp. nov., isolated from saline lakes on Tibetan Plateau.

Strains pyc13T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEnT as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C18:1ω6c/C18:1ω7c, C16:1ω6c/C16:1ω7c, C16:0, and C12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEnT, H. sediminicola CPS11T, H. mongoliensis Z-7009T, H. ventosae Al12T, and H. fontilapidosi 5CRT, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13T (= CGMCC 1.15949T = KCTC 52660T).

Quercetin nanoparticles display antitumor activity via proliferation inhibition and apoptosis induction in liver cancer cells.

Quercetin is a potent cancer therapeutic agent and dietary antioxidant present in fruit and vegetables. Quercetin prevents tumor proliferation by inducing cell cycle arrest and is a well known cancer therapeutic agent and autophagy mediator. Recent studies showed that drug delivery by nanoparticles have enhanced efficacy with reduced side effects. In this regard, gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles was examined. In this study, we explored the role and possible underlying mechanisms of quercetin nanoparticle in regulation of antitumor activity in liver cancer cells. Treatment with quercetin nanoparticle effectively inhibited the liver cancer cell proliferation, cell migration and colony formation, thus suppressing liver cancer progression. Quercetin nanoparticle also upregulated apoptosis markedly. Further study suggested that quercetin nanoparticle accelerated the cleavage of caspase-9, caspase-3, and induced the up-releasing of cytochrome c (Cyto-c), contributing to apoptosis in liver cancer cells. Quercetin nanoparticles also promoted telomerase reverse transcriptase (hTERT) inhibition through reducing AP-2ß expression and decreasing its binding to hTERT promoter. In addition, quercetin nanoparticle had an inhibitory role in cyclooxygenase 2 (COX-2) via suppressing the NF-κB nuclear translocation and its binding to COX-2 promoter. Quercetin nanoparticle also inactivated Akt and ERK1/2 signaling pathway. Taken together, our results suggested that quercetin nanoparticle had an antitumor effect by inactivating caspase/Cyto-c pathway, suppressing AP-2ß/hTERT, inhibiting NF-κB/COX-2 and impeding Akt/ERK1/2 signaling pathways. Our results provided new mechanistic basis for further investigation of quercetin nanoparticles to find potential therapeutic strategies and possible targets for liver cancer inhibition.

Contamination, Fractionation and Biological Risk Related to Metals in Surface Sediments from the Largest Deep Freshwater Lake in China.

The toxicity and mobility of metals in the environment are driven by their specific chemical forms and binding states. However, heavy metal fractionation in sediments from plateau deep lakes in China is rare. This study analyzed surface sediments collected from Fuxian Lake, the largest deep freshwater lake in China; parameters examined included total metal concentrations, chemical partitioning, and biological risk assessment. The average total concentrations (mg/kg) were 7.9 for Cd, 97.6 for Pb, 102.8 for Cr, 60.8 for Ni, 73.6 for Cu, and 112.9 for Zn; these levels were significantly higher than their corresponding background values. Cd was preferentially associated with the acid-soluble fraction; significant portions of the Pb, Cr, Ni, Cu, and Zn were mainly associated with the residual fractions. Overall, surface sediments of Fuxian Lake were associated with a 21% incidence of toxicity based on the mean effects range-median quotient. Cd was mainly at high or very high risk levels, and Cu and Zn were mainly at medium or high risk levels based on the risk assessment code (RAC).

Toward Switchable Photovoltaic Effect via Tailoring Mobile Oxygen Vacancies in Perovskite Oxide Films.

The defect chemistry of perovskite oxides involves the cause to most of their abundant functional properties, including interface magnetism, charge transport, ionic exchange, and catalytic activity. The possibility to achieve dynamic control over oxygen anion vacancies offers a unique opportunity for the development of appealing switchable devices, which at present are commonly based on ferroelectric materials. Herein, we report the discovery of a switchable photovoltaic effect, that the sign of the open voltage and the short circuit current can be reversed by inverting the polarity of the applied field, upon electrically tailoring the distribution of oxygen vacancies in perovskite oxide films. This phenomenon is demonstrated in lateral photovoltaic devices based on both ferroelectric BiFeO3 and paraelectric SrTiO3 films, under a reversed applied field whose magnitude is much smaller than the coercivity value of BiFeO3. The migration of oxygen vacancies was directly observed by employing an advanced annular bright-field scanning transmission electron microscopy technique with in situ biasing equipment. We conclude that the band bending induced by the motion of oxygen vacancies is the driving force for the reversible switching between two photovoltaic states. The present work can provide an active path for the design of novel switchable photovoltaic devices with a wide range of transition metal oxides in terms of the ionic degrees of freedom.

High-performance visible blind ultraviolet photodetector based on KTaO3 single crystal.

We report a visible-blind ultraviolet photoconductive detector with interdigitated electrodes based on KTaO3 (KTO) single crystals. Both the steady spectral responses and the transient photovoltaic measurements clearly exhibit a cutoff wavelength at 344 nm (∼3.6 eV), in accordance with the bandgap of KTO. The KTO photodetectors show a low dark current ∼1.5 pA at 20 V, and a high UV-to-visible rejection ratio with 3 orders of magnitude at room temperature. The quantum efficiency is 37.49% under 20 V bias, and the detectivity D* of 3.85×1012 cm·Hz0.5/W, which is comparable to that of silicon photodetectors in the UV region. The rise time of photoelectric response is ∼260 ps, indicating an ultrafast photoelectric response characteristic. The present work offers appealing prospects for the application of KTO materials in high-performance visible blind ultraviolet photodetectors.

Application of combined-type Y-shaped covered metallic stents for the treatment of gastrotracheal fistulas and gastrobronchial fistulas.

OBJECTIVE: To determine the safety and feasibility of combined-type integrated Y-shaped self-expanding covered metallic stents to treat gastrotracheal fistulas (GTFs) and gastrobronchial fistulas (GBFs). METHODS: We retrospectively reviewed the data of 10 patients with postoperative GTFs or GBFs. Depending on the size and location of the fistula and the airway diameter, we custom-designed 2 or 3 stents for each patient. The combined-type stents consisted of a large and a small Y-shaped stent. Under fluoroscopic guidance, the small stent was inserted into the distal part of the involved airway. Then, the large stent was placed at the trachea and carina. The large stent partly overlapped the main body of the small stent. RESULTS: All stents were successfully inserted at the first attempt. Esophageal and airway radiography showed no contrast agent leakage, indicating that the fistula was fully sealed. After the procedure, the patients could resume eating without coughing, and their quality of life improved. Each patient was fully followed up. Six patients died at 3.2 to 8 months of tumors (4 patients), hemoptysis (1 patient), or pulmonary infection (1 patient). In 1 patient, the carinal fistula enlarged 4 months after stenting, and another small Y-shaped stent was inserted to seal the fistula. This patient and the remaining 3 patients are still alive. CONCLUSIONS: Deployment of the combined-type Y-shaped integrated self-expanding covered metallic stent proved to be an effective, safe, and minimally invasive procedure for complex GTFs and GBFs. Our patients tolerated the stents well and had good palliation of their symptoms.

Insulating phase at low temperature in ultrathin La0.8Sr0.2MnO3 films.

Metal-insulator transition is observed in the La0.8Sr0.2MnO3 thin films with thickness larger than 5 unit cells. Insulating phase at lower temperature appeared in the ultrathin films with thickness ranging from 6 unit cells to 10 unit cells and it is found that the Mott variable range hopping conduction dominates in this insulating phase at low temperature with a decrease of localization length in thinner films. A deficiency of oxygen content and a resulting decrease of the Mn valence have been observed in the ultrathin films with thickness smaller than or equal to 10 unit cells by studying the aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy of the films. These results suggest that the existence of the oxygen vacancies in thinner films suppresses the double-exchange mechanism and contributes to the enhancement of disorder, leading to a decrease of the Curie temperature and the low temperature insulating phase in the ultrathin films. In addition, the suppression of the magnetic properties in thinner films indicates stronger disorder of magnetic moments, which is considered to be the reason for this decrease of the localization length.

[Long-term pattern of diatom community structure changes in response to multiple environmental stressors at Datun Lake, Southeast Yunnan, China].

Subtropical plateau lakes in Southeast Yunnan are known to have experienced multiple environmental stressors (lake pollution, eutrophication, land reclamation and droughts) during the past decades. Here, we applied multi-proxy analyses (i.e., diatom, grain size, C and N isotopic and chronology) of lake sediments, aiming to track the history of lake environment change and the characteristics of diatom community responses in Datun Lake for the past century. The results proved that the sedimentary diatom community records showed significant changes with the replacement of Fragilaria construens by Achnanthes minutissima. Combining with multiple-proxy records (i.e., isotopic data) and modern monitoring records, the ordination analyses and variation partitioning further suggested that industrial pollution and eutrophication were the major driving factors that led to the long-term shift of diatom community. In addition, the grain size results and meteorological data revealed that the reductions in hydrodynamic and water exchange intensity associated with damming and the occurrence of extreme droughts, thus led to the corresponding diatom community change.

A new non-destructive readout by using photo-recovered surface potential contrast.

Ferroelectric random access memory is still challenging in the feature of combination of room temperature stability, non-destructive readout and high intensity storage. As a non-contact and non-destructive information readout method, surface potential has never been paid enough attention because of the unavoidable decay of the surface potential contrast between oppositely polarized domains. That is mainly due to the recombination of the surface movable charges around the domain walls. Here, by introducing a laser beam into the combination of piezoresponse force microscopy and Kelvin probe force microscopy, we demonstrate that the surface potential contrast of BiFeO3 films can be recovered under light illumination. The recovering mechanism is understood based on the redistribution of the photo-induced charges driven by the internal electric field. Furthermore, we have created a 12-cell memory pattern based on BiFeO3 films to show the feasibility of such photo-assisted non-volatile and non-destructive readout of the ferroelectric memory.

An epitaxial ferroelectric tunnel junction on silicon.

Epitaxially grown functional perovskites on silicon (001) and the ferroelectricity of a 3.2 nm thick BaTiO3 barrier layer are demonstrated. The polarization-switching-induced change in tunneling resistance is measured to be two orders of magnitude. The obtained results suggest the possibility of integrating ferroelectric tunnel junctions as binary data storage media in non-volatile memory cells on a silicon platform.

High-sensitivity SrTiO3 photodetectors with paralleled multiple interdigital electrode cells.

We report high-sensitivity SrTiO(3) photoconductive detectors with multiple photoelectric cells connected in parallel. The photocurrent of the detectors increases significantly with an increase of the cell number. The photocurrent responsivity of the detector with three cells can reach 237 mA/W at 10 V bias under illumination of the 375 nm laser, and the corresponding quantum efficiency is 77% at 10 V bias. Furthermore, a transient photovoltaic signal with a rise time of ~490 ps and a full width at half-maximum of ~900 ps is obtained. These results demonstrate that the present devices with further improvement of performance have great potential application in high-sensitivity and ultrafast ultraviolet photodetectors.