Research on Safety Helmet Detection Algorithm Based on Improved YOLOv5s.

Safety helmets are essential in various indoor and outdoor workplaces, such as metallurgical high-temperature operations and high-rise building construction, to avoid injuries and ensure safety in production. However, manual supervision is costly and prone to lack of enforcement and interference from other human factors. Moreover, small target object detection frequently lacks precision. Improving safety helmets based on the helmet detection algorithm can address these issues and is a promising approach. In this study, we proposed a modified version of the YOLOv5s network, a lightweight deep learning-based object identification network model. The proposed model extends the YOLOv5s network model and enhances its performance by recalculating the prediction frames, utilizing the IoU metric for clustering, and modifying the anchor frames with the K-means++ method. The global attention mechanism (GAM) and the convolutional block attention module (CBAM) were added to the YOLOv5s network to improve its backbone and neck networks. By minimizing information feature loss and enhancing the representation of global interactions, these attention processes enhance deep learning neural networks' capacity for feature extraction. Furthermore, the CBAM is integrated into the CSP module to improve target feature extraction while minimizing computation for model operation. In order to significantly increase the efficiency and precision of the prediction box regression, the proposed model additionally makes use of the most recent SIoU (SCYLLA-IoU LOSS) as the bounding box loss function. Based on the improved YOLOv5s model, knowledge distillation technology is leveraged to realize the light weight of the network model, thereby reducing the computational workload of the model and improving the detection speed to meet the needs of real-time monitoring. The experimental results demonstrate that the proposed model outperforms the original YOLOv5s network model in terms of accuracy (Precision), recall rate (Recall), and mean average precision (mAP). The proposed model may more effectively identify helmet use in low-light situations and at a variety of distances.

Expression, purification and microscopic characterization of transmembrane BAX Inhibitor-1 motif containing protein 5.

Transmembrane bax inhibitor-1 motif containing protein 5 (TMBIM5) is located on the inner membrane of mitochondria and is widely expressed in tissues but less frequently in the intestine and thymus. TMBIM5 affects mitochondrial cristae organization and is associated with Parkinson's disease. Here, we present the first report about expression, purification and the 2D classification projections derived from negatively stained electron micrographs of recombinant H. sapiens TMBIM5 (hTMBIM5). The described methods and results will support further structural and functional study of hTMBIM5.

Applications of N'-monofunctionalised TsDPEN derivatives in asymmetric catalysis.

This review contains an account of recent developments in the applications of N'-monoalkylated or N'-mono(thio)acylated(N-sulfonyl)-1,2-diphenylethylene-1,2-diamine (TsDPEN) derivatives to asymmetric catalysis. The coverage features examples of applications of derivatives as ligands in organometallic complexes for use in asymmetric reduction and oxidation reactions. The use of TsDPEN derivatives as catalysts in a diverse range of C-C and C-S bond formation reactions is also described in detail.

A flavour perspective of Tiepishihu (Dendrobium officinale) - an emerging food ingredient from popular traditional Chinese medicinal plants: a review.

Many Dendrobium orchid stems are used in Traditional Chinese Medicine (TCM). The most popular and premium species is Dendrobium officinale, and its stem in TCM is called Tiepishihu. Tiepishihu has a sweet flavour and is an ingredient in Chinese tea and desserts. There is no comprehensive understanding of its flavour compounds. It is, therefore, essential to understand compounds responsible for its flavour, and how they are formed. This review assesses twelve diverse studies in Tiepishihu flavour (2013-2022). Thirty aroma compounds were compared - furfural and nonanal were identified as common compounds. Four of seven essential amino acids were taste-active, with lysine being the most potent. Pre-harvest factors such as environment impact specific aroma compounds. Post-harvest processing methods, including drying and grinding, can control Tiepishihu's flavour. Methodological consistency is a challenge, but controlling Tiepishihu's flavour could increase its commercial value as a food ingredient.

Minerals in biology and medicine.

Natural minerals ('stone drugs') have been used in traditional Chinese medicines for over 2000 years, but there is potential for modern-day use of inorganic minerals to combat viral infections, antimicrobial resistance, and for other areas in need of new therapies and diagnostic aids. Metal and mineral surfaces on scales from milli-to nanometres, either natural or synthetic, are patterned or can be modified with hydrophilic/hydrophobic and ionic/covalent target-recognition sites. They introduce new strategies for medical applications. Such surfaces have novel properties compared to single metal centres. Moreover, 3D mineral particles (including hybrid organo-minerals) can have reactive cavities, and some minerals have dynamic movement of metal ions, anions, and other molecules within their structures. Minerals have a unique ability to interact with viruses, microbes and macro-biomolecules through multipoint ionic and/or non-covalent contacts, with potential for novel applications in therapy and biotechnology. Investigations of mineral deposits in biology, with their often inherent heterogeneity and tendency to become chemically-modified on isolation, are highly challenging, but new methods for their study, including in intact tissues, hold promise for future advances.

Asymmetric Transfer Hydrogenation of Unhindered and Non-Electron-Rich 1-Aryl Dihydroisoquinolines with High Enantioselectivity.

The use of arene/Ru/TsDPEN catalysts bearing a heterocyclic group on the TsDPEN in the asymmetric transfer hydrogenation (ATH) of dihydroisoquinolines (DHIQs) containing meta- or para-substituted aromatic groups at the 1-position results in the formation of products of high enantiomeric excess. Previously, only 1-(ortho-substituted)aryl DHIQs, or with an electron-rich fused ring gave products with high enantioselectivity; therefore, this approach solves a long-standing challenge for imine ATH.

Functionalized Mesoporous Silicon Nanomaterials in Inorganic Soil Pollution Research: Opportunities for Soil Protection and Advanced Chemical Imaging.

"Innovative actions towards a pollution free-planet" is a goal of the United Nations Environment Assembly (UNEA). Aided by both the Food and Agricultural Organisation (FAO) and its Global Soil Partnership under the 3rd UNEA resolution, a consensus from > 170 countries have agreed a need for accelerated action and collaboration to combat soil pollution. This initiative has been tasked to find new and improved solutions to prevent and reduce soil pollution, and it is in this context that this review provides an updated perspective on an emerging technology platform that has already provided demonstrable utility for measurement, mapping, and monitoring of toxic trace elements (TTEs) in soils, in addition to the entrapment, removal, and remediation of pollutant sources. In this article, the development and characteristics of functionalized mesoporous silica nanomaterials (FMSN) will be discussed and compared with other common metal scavenging materials. The chemistries of the common functionalizations will be reviewed, in addition to providing an outlook on some of the future directions/applications of FMSN. The use of FMSN in soil will be considered with some specific case studies focusing on Hg and As. Finally, the advantages and developments of FMSN in the widely used diffusive gradients-in-thin films (DGT) technique will be discussed, in particular, its advantages as a DGT substrate for integration with oxygen planar optodes in multilayer systems that provide 2D mapping of metal pollutant fluxes at submillimeter resolution, which can be used to measure detailed sediment-water fluxes as well as soil-root interactions, to predict plant uptake and bioavailability.

Probing the Effects of Heterocyclic Functionality in [(Benzene)Ru(TsDPENR)Cl] Catalysts for Asymmetric Transfer Hydrogenation.

A range of TsDPEN catalysts containing heterocyclic groups on the amine nitrogen atom were prepared and evaluated in the asymmetric transfer hydrogenation of ketones. Bidentate and tridentate ligands demonstrated a mutual exclusivity directly related to their function as catalysts. A broad series of ketones were reduced with these new catalysts, permitting the ready identification of an optimal catalyst for each substrate and revealing the subtle effects that changes to nearby donor groups can exhibit.

Synthesis and Application of Novel Molecularly Imprinted Solid Phase Extraction Materials Based on Carbon Nanotubes for Determination of Carbofuran in Human Serum by High Performance Liquid Chromatography.

Novel molecularly imprinted polymers (MIPs) based on multiwalled carbon nanotubes (MWNTs) were synthesized using carbofuran as template, methacrylic acid as functional monomer, and trimethylolpropane trimethacrylate as cross-liking agent, respectively. Characterization results showed that the carbofuran MIPs have been successfully grafted onto the surface of MWNTs as a thin layer with high stability. The results of adsorption dynamics indicated that the synthesized MWNT-MIPs displayed a biphase adsorption profile and good selective recognition to carbofuran with equilibrium adsorption of 106.2 mg/g. The MWNTs-MIPs synthesized were further applied as the adsorbent material of solid-phase extraction (SPE) for the pretreatment of carbofuran in human serum, analyzed using high performance liquid chromatograph (HPLC). The recoveries obtained ranged from 89.0 ± 4.8 to 93.6 ± 3.2, showing that the MWNTs-MIPs-SPE system developed have specific recognition toward carbofuran. Results above indicated that the proposed system filled with synthesized MWNTs-MIPs provided a fast and selective extraction of carbofuran in serum.

Crabtree's catalyst revisited; ligand effects on stability and durability.

The extent of time-dependent deactivation of monophosphine monoamine iridium hydrogenation catalysts by trimer formation is strongly dependent on ligand structure; attempts to counter this process lead to the observation of an oligomerisation resistant catalyst.

Bioconjugation of biotinylated PAMAM dendrons to avidin.

The biotin-terminated PAMAM dendron has been synthesized and the asymmetric dendron used to modify the protein avidin via non-covalent bioconjugation.

[Determination of writing age of blue ballpoint pen inks by high performance liquid chromatography].

As it is a frequently encountered problem in the laboratory of forensic science nowadays to distinguish whether the questioned documents, such as deeds, contracts, and receipts, written in ballpoint pen inks are true or not, and identify the writing age of them, it is very essential to establish a simple, sensitive and accurate method to examine the similarities and differences of the ballpoint pen inks and identify the writing age. The present paper introduces a technique that allows identifying the kind and the writing age of the blue ballpoint pen inks. The technique is based on using a high performance liquid chromatographic method for distinguishing the similarities and differences in dyes of blue ballpoint pen inks and determining changes in dyes of blue ballpoint pen inks developed with age, and these changes can be evaluated by the ratio of peak areas.

HPLC and HPLC/MS analysis of red ink on counterfeit 100-yuan notes.

Counterfeiting is a significant problem for most major currencies and has high social and economic costs. Chemical and physical identifiers that are unique to counterfeit currency are critical to forensic analysis. The 100-yuan Chinese note is mostly red. Here, we analyzed the red ink used in 100-yuan Chinese notes and developed a method to extract and analyze these dyes via high performance liquid chromatography (HPLC) and HPLC/mass spectrometry (MS). We used this approach to analyze the chemical structures of the adulterated colorants from 46 counterfeit 100-yuan notes seized from different locations. The results showed that a variety of inks were found among the seized counterfeit notes from different sources. The chromatographic data signature could be used to clearly discriminate authentic from counterfeit notes, but could also potentially be used to trace the notes to the counterfeiter. To the best of our knowledge, this is the first report to use HPLC/MS to profile red dyes in Chinese currency with important implications for the forensics and law enforcement communities.

Detection of methamphetamine and its main metabolite in fingermarks by liquid chromatography-mass spectrometry.

A sensitive and efficient method applying liquid chromatography-mass spectrometry for the analysis of methamphetamine and its main metabolite in fingermark deposits was described. Using this method, good linear relationship of methamphetamine was obtained in the range of 0.005µg to 0.5µg per cotton swab, the limit of detection was 1.5ng per cotton swab, the limit of quantitation was 5.0ng per cotton swab and the average values of recovery ratios were above 70.1%. Moreover, the influence factors for the detection of methamphetamine in fingermarks, such as kinds of substrates, development methods and extraction methods, were all discussed in details. The results showed that good recovery ratios could be obtained on painted wood and smooth substrates surfaces. Development methods in commercial powder could not influence the quality of examination of exogenous drug in latent fingermark. Furthermore, the results indicated that the method mentioned here could be applied in the analysis of forensic trace evidences and samples obtained in clinically addicted cases.

Asymmetric hydrogenation of ketones using a ruthenium(II) catalyst containing BINOL-derived monodonor phosphorus-donor ligands.

[structure: see text] A series of ruthenium(II) complexes containing BINOL-based monodonor phosphorus ligands have been prepared and applied to the asymmetric catalysis of the hydrogenation of aryl/alkyl ketones. The best ligands for this application are those which contain an aromatic groups with either a methoxide or bromide on the ortho position. Using these ligands, alcohols with ee's of up to 99% are formed.

Ruthenium(II) complexes of monodonor ligands: efficient reagents for asymmetric ketone hydrogenation.

[Chemical reaction: See text] A series of BINOL-derived ligands have been prepared and incorporated into ruthenium(II) complexes containing a diamine ligand. The complexes have proven to be excellent catalysts for the asymmetric hydrogenation of ketones, giving reduction products with enantiomeric excesses of up to 99%.