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The reduction of molecular nitrogen (N2) to ammonia (NH3) under mild conditions is one of the most promising studies in the energy field due to the important role of NH3 in modern industry, production, and life. The photocatalytic reduction of N2 is expected to achieve clean and sustainable NH3 production by using clean solar energy. To date, the new photocatalysts for photocatalytic reduction of N2 to NH3 at room temperature and atmospheric pressure have not been fully developed. The major challenge is to achieve high light‐absorption efficiency, conversion efficiency, and stability of photocatalysts. Herein, the methods for measuring produced NH3 are compared, and the problems related to possible NH3 pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency. The recent progress of nitrogen reduction reaction (NRR) photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer, migration, and separation in photocatalytic NRR, which provides guidance for the selection of future photocatalyst selection. More importantly, we introduce the latest research strategies of photocatalysts in detail, which can guide the preparation and design of photocatalysts with high NRR activity. Ammonia (NH3) plays an important role in modern industry, the photocatalytic nitrogen reduction reaction (NRR) is expected to achieve clean and sustainable NH3 production. In this review, the catalysts, reaction mechanisms, and NH3 generation detection method are summarized. Furthermore, the research strategies for improving photocatalytic activity are discussed. Finally, the challenges and prospects of photocatalytic NRR are presented.

Anemia is a condition in which red blood cells or the hemoglobin in the blood is lower than in healthy people. Red blood cells transport and supply oxygen needed to various organs in the human body. Anemia is caused by hypoxemia due to the lack of red blood cells and causes other serious health problems, such as heart problems, pregnancy complications, severe fatigue, or death. There are many causes of anemia, and it can be diagnosed by measuring hematocrit or hemoglobin levels in the blood. Even though there are various diagnostic devices on the market, these devices are inconvenient because their systems are bulky, heavy, expensive, or inaccurate. This study proposed a new anemia diagnostic system based on the impedance measurement of red blood cells. The proposed system consists of a test strip that collects a blood sample from the finger and a hemoglobin meter that measures the impedance of the blood and converts it into the concentration of hemoglobin. The proposed test strip that does not contain enzymes or reagents was designed in accordance with class 1 approval by the Food and Drug Administration (FDA). The hemoglobin meter was designed to include a hardware block, an algorithm block and a calibration block through empirical work. We also compared it to reference impedance to prove the accuracy of the hemoglobin meter. The experimental results with human blood indicated the superiority of the anemia diagnostic system. As a result, the overall standard deviation of impedance measurements was less than 1%, and the coefficient of variance of the proposed system was 1.7%, which was better than that of other commercial systems.

Objective Screw loosening is a widely reported issue after spinal screw fixation and triggers several complications after lumbar interbody fusion. Osteoporosis is an essential risk factor for screw loosening. Hounsfield units (HU) value is a credible indicator during bone mineral density (BMD) evaluation. As compared with the general evaluation of BMD, we hypothesized that specific measurements of HU at the precise location of the future screw insertion may be a better predictor of screw loosening. Methods Clinical data of 56 patients treated by oblique lumbar interbody fusion (OLIF) of the L4-L5 segments with an anterior lateral single rod (ALSR) screw fixation were reviewed in this study. Vertebral bodies with ≥ 1 mm width radiolucent zones around the screw were defined as screw loosening. HU in the insertional screw positions, the central transverse plane, and the average values of three and four planes were measured. Regression analyses identified independent risk factors for screw loosening separately. The area under the receiver operating characteristic curve (AUC) was computed to evaluate predictive performance. Results The local HU values were significantly lower in the loosening group, regardless of the selected measuring methods. The AUC of screw loosening prediction was higher in the insertional screw positions’ HU than other frequently used methods. Conclusions The HU value measured in the insertional screw position is a better predictor of ALSR screw loosening than other methods. The risk of screw loosening should be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT. Key Points • Osteoporosis is an essential risk factor for screw loosening, and Hounsfield units (HU) are a credible predictor during bone mineral density (BMD) evaluation. • The HU value measured in the insertional screw position is a better predictor of screw loosening than other frequently used HU measurement methods. • The risk of screw loosening might potentially be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT.

Various methods of evaluating a humectant’s moisture retention have unique mechanisms. Hence, for designing advanced or efficient ingredients of cosmetic products, a clear understanding of differences among methods is required. The aim of this study was to analyze the moisture-retention capacity of glycerin, a common ingredient in cosmetic products. Specifically, this study applied gravimetric analysis, transepidermal water loss (TEWL) analysis, and differential scanning calorimetry (DSC) to examine the evaporation of glycerin solutions of different concentrations. The results revealed that the moisture-retention capacity of glycerin increased with the glycerin concentration from 0 to 60 wt%, and glycerin at concentration of 60–70 wt% did not exhibit weight change during the evaporation process. When the glycerin concentration exceeded 70 wt%, moisture sorption occurred in the glycerin solution. Furthermore, the results revealed a deviation between the evaporation rates measured using gravimetric analysis and those measured using TEWL analysis. However, normalizing the results of these analyses yielded the relative evaporation rates to water, which were consistent between these two analyses. DSC thermograms further confirmed the consistent results and identified two hydrated water microstructures (nonfreezable water and free water) in the glycerin solutions, which explained why the measured evaporation rate decreased with the glycerin concentration. These findings can be applied to prove the moisture-retention capacity of a humectant in cosmetic products by different measuring methods.

Three-dimensional (3D) imaging techniques are promising new tools for measuring breast volume, for example in gender-affirming therapy. Transgender individuals can be treated with gender-affirming hormone therapy (GAHT). A robust method for monitoring breast volume changes is critical to be able to study the effects of feminizing GAHT. The primary aim of this study was to compare the accuracy of three 3D devices (Vectra XT, Artec LEO and iPhone XR) for measuring modest breast volume differences using a mannequin. The secondary aim of this study was to evaluate these methods in several performance domains. We used reference prostheses of increasing volumes and compared the volumes using GOM-inspect software. For Vectra XT 3D images, manufacturer-provided software was used to calculate volumes as well. The scanning methods were ranked based on their performance in a total of five categories: volume estimations, costs, user-friendliness, test subject-friendliness and technical aspects. The 3D models analyzed with GOM-inspect showed relative mean estimate differences from the actual volumes of 9.1% for the Vectra XT, 7.3% for the Artec LEO and 14% for the iPhone XR. For the Vectra XT models analyzed with the built-in software this was 6.2%. Root mean squared errors (RMSE) calculated based on the GOM-inspect volume analyses showed mean RMSEs of 2.27, 2.54 and 8.93 for the Vectra XT, Artec LEO and iPhone XR, respectively. The Vectra software had a mean RMSE of 3.00. In the combined performance ranking, the Vectra XT had the most favorable ranking, followed by the Artec LEO and the iPhone XR. The Vectra XT and Artec LEO are the preferred scanners to monitor breast development due to the combination of higher accuracy and overall performance. The current study shows that 3D techniques can be used to adequately measure modest breast volume differences and therefore will be useful to study for example breast changes in transgender individuals using feminizing GAHT. These observations may also be relevant in other fields of 3D imaging research.

The possibilities of comparing computational results of noncovalent interactions with experimental data are discussed, first with respect to intramolecular interactions. For these a variety of experimental data such as heats of formation, crystal sublimation heats, comparison with energy minimized structures, and spectroscopic data are available, but until now largely have not found widespread application. Early force field and QM/MP2 calculations have already shown that the sublimation heats of hydrocarbons can be predicted with an accuracy of ±1%. Intermolecular interactions in solution or the gas phase are always accompanied by difficult to compute entropic contributions, like all associations between molecules. Experimentally observed T∆S values contribute 10% to 80% of the total ∆G, depending on interaction mechanisms within the complexes, such as, e.g., hydrogen bonding and ion pairing. Free energies ∆G derived from equilibrium measurements in solution allow us to define binding increments ∆∆G, which are additive and transferable to a variety of supramolecular complexes. Data from more than 90 equilibrium measurements of porphyrin receptors in water indicate that small alkanes do not bind to the hydrophobic flat surfaces within a measuring limit of ∆G = ±0.5 kJ/mol, and that 20 functions bearing heteroatoms show associations by dispersive interactions with up to ∆G = 8 kJ/mol, roughly as a function of their polarizability. Aromatic systems display size-dependent affinities ∆G as a linear function of the number of π-electrons.

Background Scoliosis of the vertebral column can be assessed with the Cobb angle (Cobb 1948 ). This examination is performed manually by measuring the angle on radiographs and is considered the gold standard. However, studies evaluating the reproducibility of this procedure have shown high variability in intra- and inter-observer agreement. Because of technical advancements, interests in new procedures to determine the Cobb angle has been renewed. This review aims to systematically investigate the reproducibility of various new techniques to determine the Cobb angle in idiopathic scoliosis and to assess whether new technical procedures are reasonable alternatives when compared to manual measurement of the Cobb angle. Method Systematic review. Studies examining procedures used to determine the Cobb angle were selected. Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias. Statistical results of reliability and agreement were summarised and described. Results Eleven studies of new measuring procedures were included, all reporting the reproducibility. The new procedures can be divided into computer-assisted procedures, automatic procedures and smartphone apps. Conclusions All investigated measuring procedures showed high degrees of reliability. In general, digital procedures tend to be slightly better than manual ones. For all other measurement procedures (automatic or smartphone), results varied. Studies implementing vertebral pre-selection and observer training achieved better agreement.

B vitamins have high microbiological relevance in the marine environment, but their very low concentrations and the chemical heterogeneity of the individual vitamins make their analysis challenging. Mass spectrometric analysis of B vitamins in environmental samples at trace levels has mainly been performed using triple quadrupole mass spectrometers operated in targeted analysis mode. The development of such a method can be laborious and error prone. Additionally, high-resolution mass spectrometers can be used to measure a sample in full scan mode and subsequently search the total ion current chromatogram for extracted ion chromatograms of targeted vitamins. Three different analytical approaches for trace analysis of all B vitamins and some of their biosynthetic precursors were optimized and compared on two different mass spectrometers. A triple quadrupole mass spectrometer in selected reaction monitoring mode, and a high-resolution orbitrap mass spectrometer in parallel reaction monitoring, as well as in full scan mode were employed. Detection limits down to 10 ng/L were achieved with all three techniques. The methods were applied to a marine water sample from the North Sea and to the cell extract of a bacterial culture of Phaeobacter inhibens. Most vitamins and precursors were found in the bacterial cell extract and the seawater sample with all three measuring methods. The results of this study emphasize that, in addition to tandem mass spectrometry, high-resolution full scan mass spectrometry is a promising technique for the simultaneous detection of structurally diverse B vitamins in complex natural samples. This enables highly sensitive measurements without loss of detailed mass spectrometric information, which is inevitable when using a triple quadrupole system in MS/MS mode.