Random Co(II)–Ni(II) Ferromagnetic Chains Showing Coexistent Antiferromagnetism, Metamagnetism, and Single-Chain Magnetism

A series of isomorphous compounds of general formula [Co_1–<i>x</i>Ni_<i>x</i>(tzpo)­(N₃)­(H₂O)₂]_<i>n</i>·<i>n</i>H₂O (<i>x</i> = 0, 0.19, 0.38, 0.53, 0.68, 0.84, and 1; tzpo = 4-(5-tetrazolate)­pyridine-<i>N</i>-oxide) was prepared. The compounds consist of homometallic or heterometallic chains with simultaneous azide-tetrazolate bridges. The heterometallic systems feature random distribution of metal ions. All compounds across the series exhibit intrachain ferromagnetic coupling, interchain antiferromagnetic (AF) ordering, field-induced metamagnetic transition, and, except the Ni-only compound, single-chain magnetic dynamics. The AF ordering temperature, the metamagnetic critical field, and the relaxation parameters show different composition dependence. Notably, the blocking temperature for the Co-rich materials is higher than the Co-only compound, suggesting synergy between the randomly distributed Co­(II) and Ni­(II) ions in promoting slow relaxation. The results imply rich physics in the random mixed-metal systems and demonstrate the possibility of improving single-chain relaxation properties by blending metal ions

Entrance Effects Induced Rectified Ionic Transport in a Nanopore/Channel

The nanofluidic diode, as one of the emerging nanofluidic logic devices, has been used in many fields such as biosensors, energy harvesting, and so on. However, the entrance effects of the nanofluidic ionic conductance were less discussed, which can be a crucial factor for the ionic conduction. Here we calculate the ionic conductance as a function of the length-to-pore ratio (<i>L</i>/<i>r</i>), which has a clear boundary between nanopore (surface dominated) and nanochannel (geometry dominated) electrically in diluted salt solution. These entrance effects are even more obvious in the rectified ionic conduction with oppositely charged exterior surfaces of a nanopore. We build three modelsExterior Charged Surface model (ECS), Inner Charged Surface model (ICS), and All Charged Surface model (ACS)to discuss the entrance effects on the ionic conduction. Our results demonstrate, for a thin nanopore, that the ECS model has a larger ionic rectification factor (<i>Q</i>) than that of ICS model, with a totally reversed tendency of <i>Q</i> compared to the ICS and ACS models as <i>L</i>/<i>r</i> increases. Our models predict an alternative option of building nanofluidic biosensors that only need to modify the exterior surface of a nanopore, avoiding the slow diffusion of molecules in the nanochannel

Molecular Reactive Force-Field Simulations on the Carbon Nanocavities from Methane Pyrolysis

Hydrocarbon pyrolysis is the main way to achieve carbonaceous materials, while most related conversion mechanisms still remain unclear. This work images pyrolysis of methane at various temperatures and densities by molecular reactive force field (ReaxFF) simulations. First, it is interesting to find that the methane decay is dominated by intermolecular collision displacement instead of direct molecular decomposition. Second, a conversion of 1200 methane molecules into a regular carbon nanocavity (CNC) is realized at 3500 K temperature and 0.1 g/cm³ density after a simulation lasting for 10 ns, with 923 carbon atoms and a diameter of 3.4 nm. Such CNC is a perfect precursor of carbon nanotubes, which is confirmed by a sequent simulation on a larger system of 2400 methane molecules and in agreement with several experimental observations. It is found that the CNC growth obeys a polyyne model, without any single aromatic ring formed in the growth. Furthermore, the complex CNC growth appears in some successive stages: primary methane decay, chain elongation and branching, cyclization and condensation, and final sheeting and curling. The regular rearrangement of CNC is thought to be attributed to the limited active centers formed at the initial cyclization and condensation stage; that is, it is a key to control the primary active centers to form regular carbonaceous materials. Polyyne is found in the pyrolysis of both methane and acetylene at high temperatures, suggesting that carbyne, a novel valuable carbonaceous material, may be obtained by hydrocarbon pyrolysis

Tunable Streaming Current in a pH-Regulated Nanochannel by a Field Effect Transistor

Many experimental results demonstrated that ion transport phenomena in nanofluidic devices are strongly dependent on the surface charge property of the nanochannel. In this study, active control of the surface charge property and the streaming current, generated by a pressure-driven flow, in a pH-regulated nanochannel using a field effect transistor (FET) are analyzed for the first time. Analytical expressions for the surface charge property and the streaming current/conductance have been derived taking into account multiple ionic species, surface chemistry reactions, and the Stern layer effect. The model is validated by the experimental data of the streaming conductance in the silica nanochannel available in the literature. Results show that the pH-dependent streaming conductance of the gated silica nanochannel is consistent with its modulated zeta potential; however, the salt concentration-dependent streaming conductance might be different from the zeta potential behavior, depending on the solution pH and the gate potential imposed. The performance of the field effect modulation of the zeta potential and the streaming conductance is significant for lower solution pH and salt concentration. The results gathered are informative for the design of the next-generation nanofluidics-based power generation apparatus

Influence of bubble deformation on the signal characteristics generated using an optical fiber gas–liquid two-phase flow sensor

The use of optical fiber probe in two-phase flow measurements is very frequently encountered, especially in the applications of chemical engineering and petroleum industries. In this work, the influence of bubble piercing signals caused by bubble deformation is studied experimentally using a laboratory-prepared wedge-shaped fiber probe in a lab-scale gas–liquid flow generator. A three-dimensional simulation model is established to study the influence of bubble deformation on the piercing signals. A theoretical analysis of the characteristics of the pre-signal influenced by the bubble deformations is undertaken for a wide range of different modeled bubble shapes. Combining the experimental and simulation results, a promising analytical method to estimate the bubble shapes by analyzing the characteristics of pre-signals is proposed. The results of this investigation demonstrate that it is possible to estimate the bubble shapes before the fiber probe contacts the bubble surface. The method developed in this investigation is therefore highly promising for reducing errors caused by deformation during the probe piercing process

Additional file 2: of Peripheral-blood gene expression profiling studies for coronary artery disease and its severity in Xinjiang population in China

Table S2. Gene list of the coronary artery stenosis-related down-regulated genes identified by linear mixed effects model analysis. (XLSX 52 kb

Additional file 1: of Peripheral-blood gene expression profiling studies for coronary artery disease and its severity in Xinjiang population in China

Table S1. Gene list of the coronary artery stenosis-related up-regulated genes identified by linear mixed effects model analysis. (XLSX 77 kb

High-Performance Liquid Chromatographic Enantioseparation of Racemic Drugs Based on Homochiral Metal–Organic Framework

Homochiral metal–organic frameworks with fine-tuned pore sizes/walls and large surface areas are promising porous materials for enantioseparation considering the traditional zeolite molecular sieves have no chirality. Using enantiopure pyridyl-functionalized salen [(<i>N</i>-(4-Pyridylmethyl)-l-leucine·HBr)] as a starting material, we have prepared a noninterpenetrated three-dimensional homochiral metal organic framework {[ZnLBr]·H₂O}<i>_n</i>, which was further used as a chiral stationary phase for high-performance liquid chromatography to enantioseparate racemic drugs, showing excellent performances in enantioseparation of drugs. The metal–organic framework can be regarded as a novel molecular sieve-like material with a chiral separation function based on the relative sizes of the chiral channels and the resolved molecules

Mechanical and Antimicrobial Properties of Boron Nitride/Methacrylic Acid Quaternary Ammonium Composites Reinforced Dental Flowable Resins

Dental resin composites (DRCs) are commonly used to restore teeth affected by dental caries or defects. These materials must possess excellent properties to withstand the complex oral environment. The objective of this study was to prepare and characterize Boron nitride nanosheets (BNN)/ dimethyl amino hexadecyl methacrylate (DMAHDM) composites (BNN/DMA), and to evaluate them as functional fillers to enhance the mechanical and antimicrobial properties of dental resins. The BNN/DMA composites were successfully prepared under the theoretical guidance of molecular dynamics (MD), and then the physicochemical and morphological characterization of the BNN/DMA composites were carried out by using various test methods, such as FT-IR, XRD, UV–vis spectroscopy, SEM, TEM, and AFM. It was doped into the dental flowable resin in a certain proportion, and the results showed that the flexural strength (FS), elastic modulus (EM), compressive strength (CS), and microhardness (MH) of the modified resin composites were increased by 53.29, 47.8, 97.59, and 37.1%, respectively, with the addition of 0.8 wt % of BNN/DMA composite fillers. It has a good inhibition effect on Streptococcus mutans, with an inhibition rate as high as 90.43%. Furthermore, this effect persists even after one month of aging. In conclusion, the modification of flowable resins with low-concentration BNN/DMA composites favorably integrates the mechanical properties and long-term antimicrobial activity of dental resins. At the same time, they have good biocompatibility and do not affect the aesthetics. The BNN/DMA composite modified flowable resin has the potential to become a new type of antimicrobial dental restorative material

Definitions of exposure, outcomes, adjusted confounders, and quality score of 41 included studies.

<p><b>Outcome:</b> a. 30-day mortality, b. 90-day mortality, c. all-cause mortality in influenza seasons, d. long-term mortality, e. Death attributable to Bacteremia, f. in-hospital mortality, g. mortality for sepsis, h. OR is calculated by events.</p><p> <b>Exposure:</b></p>*<p>current exposure</p>†<p>recent or former exposure</p>♦<p>Past exposure</p>‡<p>prior use</p>◊<p>continued use.</p><p><b>Adjusted confounders:</b> 1. Age, 2. Gender, 3. comorbid diseases, 4. smoking, 5. other drugs (antibiotics, aspirin, immunosuppressive agent, Angiotensin inhibitors, angiotensin-converting enzyme), 6. Charlson Comorbidity Index, 7. severity of disease, 8. other treatment in hospital, 9. APACHE score, 10. Crises signs, 11. time in ICU, 12. type of infection, 13. vaccine inoculation, 14. other library test data, 15. BMI, 16. alcohol drinking, 17. marital status, 18. race, 19. effect of health, 20. mental state, 21. antiviralinitiation.</p