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In recent years, the treatment of dye wastewater has attracted widespread attention. Metal-organic frameworks (MOFs) adopt ordered porous structures and abundant active sites, which endorses them promising photocatalysts for the degradation of organic pollutants. In this work, two rare earth MOFs were successfully synthesized by solvothermal method from the reaction of of Eu3+ and Tb3+ salts with an aromatic tetracarboxylic acid H4TPTC (3,3',5,5'-terphenyl tetracarboxylic acid). X-ray single crystal diffraction indicated that the isostructural MOFs exhibited unique di-nuclear [Eu2(COO)4] or [Tb2(COO)4] clusters to construct three-dimensional coordination frameworks with solvent accessible channels along the [110] direction. These two MOFs had good thermal stability up to 400 °C and pH stability in the pH range of 3-9. The negative Zeta potential on the surface of these two complexes were conducive to the selective adsorption and degradation of cationic and neutral dyes, especially the high removal rate of large RhB molecules. For the photocatalytic degradation, mechanism studies showed that ·OH and ·O2- enhanced the sensitization of dyes and the separation of photogenerated carriers, and promoted the efficiency of photocatalytic degradation. This work provides two isomorphic rare earth MOFs adsorbents as well as photocatalysts for the purification of dye wastewater.

The analytical distribution of the electric field in a micro-lens made of polymer-stabilized blue phase liquid crystals (PS-BPLCs) between two electrodes has been derived, and ray bending and focusing for the o (ordinary) and e (extraordinary) rays caused by the field-induced extended Kerr effect on the PS-BPLC have also been calculated. Those calculations show that the focal lengths of most o rays are longer than those of e rays. The o and e rays result in a focal length of 11.6 cm at a Kerr constant of 2.3768 nm/V2 close to the experimental data, and the calculated focal spot diameter is about 80.0 μm. If the Kerr constant is decreased to 2.14 nm/V2, we can obtain a focal length of 13.1 cm, the same as the experimental data. This reduction in the Kerr constant is reasonable because it is still within the experimental error. In summary, our calculations reveal an efficient and accurate way to discuss the focusing phenomena in the PS-BPLC micro-lens.

The reduction-oxidation (redox) environment of the phytobiome (i.e., the plant–microbe interface) can strongly influence the outcome of the interaction between microbial pathogens, commensals, and their host. We describe a noninvasive method using a bacterial bioreporter that responds to reactive oxygen species and redox-active chemicals to compare microenvironments perceived by microbes during their initial encounter of the plant surface. A redox-sensitive variant of green fluorescent protein (roGFP2), responsive to changes in intracellular levels of reduced and oxidized glutathione, was expressed under the constitutive SP6 and fruR promoters in the epiphytic bacterium Pantoea eucalypti 299R (Pe299R/roGFP2). Analyses of Pe299R/roGFP2 cells by ratiometric fluorometry showed concentration-dependent responses to several redox active chemicals, including hydrogen peroxide (H2O2), dithiothreitol (DTT), and menadione. Changes in intracellular redox were detected within 5 min of addition of the chemical to Pe299R/roGFP2 cells, with approximate detection limits of 25 and 6 μM for oxidation by H2O2 and menadione, respectively, and 10 μM for reduction by DTT. Caffeic acid, chlorogenic acid, and ascorbic acid mitigated the H2O2-induced oxidation of the roGFP2 bioreporter. Aqueous washes of peach and rose flower petals from young blossoms created a lower redox state in the roGFP2 bioreporter than washes from fully mature blossoms. The bioreporter also detected differences in surface washes from peach fruit at different stages of maturity and between wounded and nonwounded sites. The Pe299R/roGFP2 reporter rapidly assesses differences in redox microenvironments and provides a noninvasive tool that may complement traditional redox-sensitive chromophores and chemical analyses of cell extracts.

The Schwarzschild metric describes a non-rotating and charge-free celestial body, and it results in things stopping at the event horizon of a black hole and spending infinite time across the event horizon by the observer far away from the black hole. The analysis of the particle’s behavior at the event horizon tells us that this solution predicts an un-expanded black hole which violates the astronomical observations and our knowledge about the black hole. Although some alternative metrics have been proposed, the singularity problem is still unsolved. In this research, the degenerate Fermi electron gas is used to reveal that the Fermi electron gas cannot shrink to a point no matter how large energy it obtains, so the singularity exists at the center very unreasonably. In order to avoid these problems, a finite-size nucleus of the black hole is proposed and reasonably explained by the behaviors of the Fermi electron gas and the Fermi neutron gas there. On the other hand, the Kerr-Newman metric is the one describing the rotating and charged black hole and the equation of the light velocity at each space point can be obtained. It tells us that there are two real and non-imaginary solutions for the radial speed of light at the position larger than the Schwarzschild radius.

The metric for describing the spacetime geometry of a charged and rotating source in general relativity is the Kerr-Newman metrics, and it is an appropriate one to discuss the movement on the Earth. It is explicit that the velocity of light we measure is dependent on the rotation and net charges of the Earth, and usually the measurements are less than it in the really free space, at infinity or the gravity-free space, as long as the net charges of the Earth are less than 1.4x10^19 C. According to this, the velocity of light in the really gravity-free space should be corrected. When we adopt the coordinate time at infinity as the unified time at each measurement placement on the Earth, it is 0.2085 m/s slightly larger than what we identify in vacuum on the Earth, 2.9979458x10^8 m/s. The calculations also show the tiny deviation on the speed of light along the longitudinal direction between two poles and the equator, and it also exists deviation between the left-handed circularly light and the right-handed circularly one in the equator. We also discuss the difference on the speed of light in the local reference frame by using the proper time.

Pulse diagnosis is an important part of traditional Chinese medicine’s four examinations: looking, smelling, asking, and cutting. The pulse signal can reflect the health of the human body’s internal haslets. With the development of information technology, the emergence of various pulse collection equipment and analysis algorithms provides a broad platform for the development of digital Chinese medicine. This article summarizes the currently commonly used pulse collection and analysis techniques, and analyzes the advantages and disadvantages of various collection and analysis methods, and finally proposes the improvement direction for the current research status, which provides a reference for the objectification of TCM diagnosis.

With the advent of the aging population, post-stroke will cause hand function obstacles that affect fine manipulation of fingers. This article classifies finger rehabilitation robots and analyzes the mechanical structure, driving methods, and rehabilitation principles of Unger rehabilitation robots. The advantages and disadvantages of the development of finger rehabilitation robots are summarized.

In this work we developed an integrated microfluidic system for automatically detecting the ovarian clear cell carcinoma (OCCC) biomarker FXYD2. Dealing with ascites from ovarian cancer patients, capture of cancer cells, isolation of messenger RNA, and quantitative reverse-transcription polymerase chain reaction were integrated into a single microfluidic chip and carried out on-chip automatically. OCCC is a subtype of ovarian cancer with a high mortality risk, and a high FXYD2 gene expression level was shown to be closely associated with OCCC. The lowest limit of quantification using a benchtop protocol of this system could be as low as 100 copies per sample. By normalizing the expression to a housekeeping gene, GAPDH, a simple cycle threshold ratio index could distinguish high FXYD2 expression cells from the low-expression ones. This developed platform may therefore facilitate future OCCC diagnosis and/or prognosis.

The far infrared instrument SAFARI spectrometer on board the SPace Infrared telescope for Cosmology and Astrophysics (SPICA) provides moderate resolution spectra (R~300) with simultaneous coverage over 34 to 230 μm. With the high sensitivity TES detectors, the SAFARI can reach the sensitivity down to ~7×10-20 W/m2. In order to provide accurate calibration for the TES readout circuit, a calibration source assembly (CSA) is developed to provide a stable and absolute flux radiation to the spectrometer over the whole spectral range. The CSA has a primary function during observations to take periodic reference measurement to correct for drift, subtracting backgrounds, etc from the detector. The CSA is composed of three microlamps and one integrating sphere. The microlamps are made of resistance wires by microlithography to mimic square blackbody sources. By combining an 81K microlamp and a 24K microlamp, a reasonably flat spectrum can be produced at the output of the integrating sphere. The radiation to the transition edge sensor detector pixel is around 1×10-16 W. The integrating sphere can also provide a uniform output to cover the size of SAFARI field of view including the target and sky pixels. In this paper, the CSA design and the prototype results of the microlamp and the integrating sphere are presented.

In this research, the other reasonable explanations for the cosmic microwave background radiation is revealed. Due to the microwave resolution, it very roughly shows the image of galaxies in the universe. Moreover, the intensity measurement on each pixel of the image is the sum of the incident microwaves from different directions, so the microwave image cannot represent the microwave sources clearly far away from the Earth. Hence, we propose a simulation after removing several strongest microwave sources, the remaining microwave radiation sources can establish a very uniform intensity distribution over a range of several ten light years. On the other hand, Sloan Digital Sky Survey reveals 200 million galaxies in the universe and, in fact, only to eliminate the contributions of all galaxies from the microwave image is impossible. The way to further obtain the fine-scale structure by only removing the few strongest microwave sources as the foreground effect will keep the other contributions from all the rest galaxies and stars. Therefore, the Cosmic Microwave Background cannot be uniquely explained the radiation which was left after the initial formation of the universe. Moreover, it is the mainly residual radiation from the un-calculated galaxies and inaccurate estimation of the microwave source strength.

Photocatalytic water splitting can be used to directly transfer solar energy into chemical energy with highly efficiency. Metal-organic frameworks (MOFs) materials are well known on the advantages of high design flexibility and metal center functionalization. In this study, a series of Cd-centered MOFs were successfully fabricated by a simple solvent evaporation method based on the different anion mediated pyridyl leucine derivatives. Single-crystal X-Ray diffraction showed the isostructural 3D chiral coordination networks of three Cd-MOFs with helical chains connected by the adjacent carboxylate groups. Within the helical coordination chains, the formate (For) and acetate (OAc) anions adopted chelate modes in Cd-LFor and Cd-LOAc, whereas the chloride worked as a monodetate ligand in Cd-LCl. Powder X-ray diffraction (PXRD), Thermogravimetric analysis, UV–vis spectra, Photocurrent-time test (I-t) and Mott-Schottky (MS) curves were carried out to characterize and analysis these Cd-MOFs. All the samples exhibit photocatalytic activity for hydrogen generation in aqueous solution of Na2S/Na2SO3 upon irradiation at full light. The photocurrent time test showed that Cd-LCl showed a higher photocurrent intensity than those of Cd-LFor and Cd-LOAc, which proved the lower electron-hole recombination and correspondingly higher hydrogen production photocatalysis active. The highest H2 production rate reached 17242 ​μmol ​g−1 ​h−1 for Cd-LCl. In the photocatalytic reaction, the hydrogen production rate was stable without significant decrease, indicating that the material had no significant deactivation and had good photocatalytic activity.

Many high-birefringence asymmetric microstructured optical fibers (MOFs) have been numerically designed and analyzed, but the fabrication of asymmetric MOF is challenging, especially those with elliptical structures. In this work, we designed, fabricated and modelled an asymmetric glass MOF in which the structure is asymmetric and the air holes are elliptical. SF57 glass was selected due to the high refraction index and low absorption in the Terahertz region. From simulations based on the finite difference (FD) method at 1060.0 μm, the polarizations of the first two modes are perpendicular to each other and the effective refraction indices are different, which lead to the birefringence of this MOF as high as 0.090. The plane-wave expansion method was used to verify the FD calculations, where both results are consistent and the difference is about 0.1%.

Correction for ‘Bacterial detection and identification from human synovial fluids on an integrated microfluidic system’ by Ting-Hang Liu et al., Analyst, 2019, 144, 1210–1222.