Aromatic and magnetic properties in a series of heavy rare earth-doped Ge6 cluster anions.

A series of pentagonal bipyramidal anionic germanium clusters doped with heavy rare earth elements, REGe 6 - (RE = Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), have been identified at the PBE0/def2-TZVP level using density functional theory (DFT). Our findings reveal that the centrally doped pentagonal ring structure demonstrates enhanced stability and heightened aromaticity due to its uniform bonding characteristics and a larger charge transfer region. Through natural population analysis and spin density diagrams, we observed a monotonic decrease in the magnetic moment from Gd to Yb. This is attributed to the decreasing number of unpaired electrons in the 4f orbitals of the heavy rare earth atoms. Interestingly, the system doped with Er atoms showed lower stability and anti-aromaticity, likely due to the involvement of the 4f orbitals in bonding. Conversely, the systems doped with Gd and Tb atoms stood out for their high magnetism and stability, making them potential building blocks for rare earth-doped semiconductor materials.

Discovering SnB7-: a half-sandwich structure with double aromaticity and pathways to molecular machines.

Numerous boron-based molecular fluxional models, such as the Wankel motor, tank treads B11- and B10C, and the Earth-Moon system Be6B11-, have been widely recognized for their potential to develop molecular machines. From a series of tin-doped boron clusters SnBn- (n = 5-14), the half-sandwich structure SnB7- is found to possess high relative energy stability, and a HOMO-LUMO gap of 4.33 eV. This structure exhibits valence electron orbitals reminiscent of σ-π double aromatic compounds. The incorporation of tin effectively fills the doubly vacant π orbitals of its parent triplet B7-, thereby enhancing both magnetic shielding capabilities and range. Thermal bath tests demonstrate its significant dynamic stability, as the kinetic energy provided by thermal baths below 3800 K remains insufficient to disrupt its inherent elasticity. Additionally, transition state searches and intrinsic reaction coordinate analyses confirm that the tin atom migrates from the centre to the edge of the boron ligand surface, a phenomenon that can be observed in high-temperature thermal bath simulations. This fluxional behaviour provides insights for constructing novel molecular machine models.

Probing the Structural and Electronic Properties of the Anionic and Neutral Tellurium-Doped Boron Clusters TeBnq (n = 3-16, q = 0, -1).

In this study, we employ density functional theory along with the artificial bee colony algorithm for cluster global optimization to explore the low-lying structures of TeBnq (n = 3-16, q = 0, -1). The primary focus is on reporting the structural properties of these clusters. The results reveal a consistent doping pattern of the tellurium atom onto the in-plane edges of planar or quasi-planar boron clusters in the most energetically stable isomers. Additionally, we simulate the photoelectron spectra of the cluster anions. Through relative stability analysis, we identify three clusters with magic numbers -TeB7-, TeB10, and TeB12. The aromaticity of these clusters is elucidated using adaptive natural density partitioning (AdNDP) and magnetic properties analysis. Notably, TeB7- exhibits a perfect σ-π doubly aromatic structure, while TeB12 demonstrates strong island aromaticity. These findings significantly contribute to our understanding of the structural and electronic properties of these clusters.

Design, synthesis and activity evaluation of pseudilin analogs against cyanobacteria as IspD inhibitors.

The discovery of safe, effective, and selective chemical algicides is the stringent need for the algicides development, and it is also one of the effective routes to control cyanobacteria harmful algal blooms and to meet the higher requirements of environmental and ecological. In this work, a series of novel bromo-N-phenyl-5-o-hydroxyphenylpyrazole-3-carboxyamides were rationally designed as pseudilin analogs by bioisosteric replacement and molecular hybridization strategies, in which the pyrrole unit of pseudilin was replaced with pyrazole and further combined with the dominant structural fragments of algicide diuron. The synthesis was carried out by a facile four-step routeincluding cyclization, amidation, transanulation, and halogenation. The biological activity evaluation on AtIspD, EcIspD, Synechocystis sp. PCC6803 and Microcystis aeruginosa FACHB905 revealed that most compounds had good EcIspD and excellent cyanobacteria inhibitory activity. In particular, compound 6bb exhibited potent algicidal activity against PCC6803 and FACHB905 with EC50 = 1.28 µM and 0.37 µM, respectively, 1.4-fold and 4.0-fold enhancement compared to copper sulfate (EC50 = 1.79 and 1.49 µM, respectively), and it also showed the best inhibitory activity of EcIspD. The binding of 6bb to EcIspD was explored by molecular docking, and it was confirmed that 6bb could bind to the EcIspD active site. Compound 6bb was proven to be a potential structure for the further development of novel algicides that targets IspD in the MEP pathway.

Rapid Monitoring Approach for Microplastics Using Portable Pyrolysis-Mass Spectrometry.

Microplastics (MPs) pollution has drawn increasing concern due to its widespread occurrence and potential risks in the environment. The reliable methods and instruments for fast analysis of microplastics (MPs) less than 5 mm are urgently needed. In this study, a new method based on custom-made portable pyrolysis-mass spectrometry (Pyr-MS) is developed, which enables rapid identification and mass related quantification of MPs. MPs are decomposed in the compact pyrolyzer and then directly analyzed in the portable MS by the chemical fingerprints of polymers including characteristic ions and their special ratio. It avoids the complex extraction and separation procedures of the pyrolysis/thermogravimetric-gas chromatography-mass spectrometry (Pyr/TGA-GC-MS), realizes the rapid analysis of MPs in 5 min, and thus can practically apply to a large number of MPs samples. In comparison to Fourier transform infrared spectroscopy (FT-IR) and Raman, this method is not limited by the shape, size, and color of MPs. Four common plastics including polyethylene (PE), polypropylene (PP), polystyrene (PS), and poly(methyl methacrylate) (PMMA) were investigated to verify the feasibility of this method. The environmental MPs samples collected from a beach were successfully identified and quantified, demonstrating the simplicity and practicality of this approach. The influence of plastics aging on the chemical fingerprints and the potential of mixed plastics detection by Pyr-MS are also assessed. The portable Pyr-MS could provide a promising tool for in-field analysis of MPs such as ship-based marine MPs surveys.

In vivo Raman spectroscopy study on the stimulation mechanism of surfactant.

BACKGROUND: Surfactant is widely used in skin care products and cleansers, while it may cause physical discomfort. In this study, in vivo Raman spectroscopy was used to explore surfactant irritation mechanism on skin, which was not found in literature. METHODS: Sodium dodecyl sulfate (SDS) was chosen to represent surfactant. Research on the negative effect of SDS was undertaken by scanning the two states of the skin (without and with the contact of SDS), respectively, on six volunteers, by means of Raman technique and skin magnifier. RESULTS: The damage to the surface of normal skin by SDS was visible from the photographs taken by skin magnifier, and the apparent damage matched the damage that was happening underneath the skin elucidated by Raman spectra. Compared to the normal skin, the inter-cellular lipids (ICL) lateral packing order of the damaged skin was significantly reduced in 2-12 µm of skin depth (P < 0.05), deeper than 12 µm was not detected. The skin depth of 0-2 µm could not be determined due to strong interference of SDS. Significant change in the secondary and tertiary structures of keratin was not found.

Ultrasound-Targeted Microbubble Destruction (UTMD) Combined with Liposome Increases the Effectiveness of Suppressing Proliferation, Migration, Invasion, and Epithelial- Mesenchymal Transition (EMT) via Targeting Metadherin (MTDH) by ShRNA.

BACKGROUND Reports show that ultrasound-targeted microbubble destruction (UTMD) is a promising method of gene therapy, and metadherin (MTDH) is related to the development of breast cancer. Thus, we investigated the role of MTDH in breast cancer and compared the effect of suppressing MTDH by shRNA using liposome, UTMD, or the combination of these 2 methods. MATERIAL AND METHODS Graphing of survival curves of MTDH was analyzed by bioinformatics. UTMD was conducted using an ultrasonic therapeutic apparatus. Cell counting kit-8 (CCK-8) assay was used to measure cell viability. Migration and invasion rates were measured by wound healing test and Transwell invasion assay, respectively. The expression of MTDH, E-cadherin, metastasis-associated protein-1 (MTA-1), matrix metalloproteinase (MMP)-2, and MMP-9 were measured by Western blot and qPCR. RESULTS The prognosis of breast cancer can be decreased by the high expression of MTDH, and elevated expression of MTDH was discovered in MCF-7, MCF-10A, and T47D cell lines. UTMD combined with liposome is most efficient in transfecting shRNA, clearly suppressing the expression of MTDH and thereby decreasing cell viability, migration, invasion rate, and epithelial- mesenchymal transition (EMT) processes in the MCF-7 cell line. CONCLUSIONS UTMD combined with liposome could be used as a more efficient way to transfect shRNA into cells to suppress the expression of MTDH and thus lead to the downregulation of proliferation, migration, and EMT processes of the MCF-7 cell line, showing the potential for use in gene therapy.

Mammography and MRI manifestations of breast angiosarcoma.

BACKGROUND: Breast angiosarcoma is rare and previous studies only focus on its pathology. This study aimed to summarize its imaging features. METHODS: Overall 17 patients pathologically confirmed with breast angiosarcoma were recruited. Eight patients underwent preoperative mammography, and 13 received preoperative MRI scan. The mammography and MRI findings were classified according to the ACR-BI-RADS-mammography/MR lexicon. RESULTS: Mammography showed that 3 cases developed diffuse asymmetry occupying two or more quadrants of the affected breast and that 5 patients had lobulated or oval masses. The 13 patients' lesions presented as diffuse and slightly/significantly high homogeneous or heterogeneous signals on T1-weighted images, while the necrotic and cystic parts had relatively low signals. The hemorrhagic lesions in 7 cases had high signals on both T1- and T2-weighted images. A hemosiderin ring at the edge of an old hemorrhagic lesion had long and short signals on the T1- and T2-weighted images, respectively. Contrast-enhanced MRI revealed that the 13 patients' lesions had significant heterogeneous enhancement. Significant enhancement was observed in the early phase, and varying degrees of concentric enhancement was seen in the delayed phase. CONCLUSIONS: The mammography findings are nonspecific. MRI scan is helpful in determining the malignancy of the lesions. Breast angiosarcoma usually shows heterogeneous signals on both T1-weighted and T2-weighted images. Due to their incomplete lumens and lack of thrombocytes, patients with angiosarcoma have a higher incidence of bleeding (nearly 50% in this study) than those with other malignant tumors. The pattern of the enhancement curve helps to distinguish this disease from the typical types of breast cancer.

Portable Dielectric Barrier Discharge-Atomic Emission Spectrometer.

This paper describes the first demonstration of a portable dielectric barrier discharge-atomic emission spectrometer (DBD-AES). The instrument primarily consists of a miniature electro-thermal vaporizer (ETV), DBD, and optical signal acquisition units. It weighs only 4.5 kg and is powered by a 24 V DC battery with a maximum power consumption of 37 W. The accompanying software can be operated on a laptop computer. A specially designed quartz tube integrates the ETV unit with the DBD chamber. The effects of experimental parameters were investigated. The limit of detection (LOD) for mercury was 0.4 µg L-1 (1.2 pg) with a sampling volume of 3 µL. The instrument is applicable for multielement analysis, and the LODs ranged from 0.16 to 11.65 µg L-1 for Zn, Pb, Ag, Cd, Au, Cu, Mn, Fe, Cr, and As. The instrument was also validated by in-field analysis of seawater samples. The experimental results demonstrated the sensitivity, reliability, and practicality of the instrument.

Evaluation of Cardiac Function Characteristics after Patent Ductus Arteriosus Closure in Children and Adults by Echocardiographic Data.

This study was to investigate the value of echocardiographic data in assessing changes in cardiac function before and after transcatheter closure in children and adult patients with patent ductus arteriosus (PDA). In this study, 150 patients with isolated PDA treated by cardiac catheterization and transcatheter closure were selected as the study sample. Real-time color Doppler echocardiography was used both after and after operation. The results showed that the left ventricle returned to normal in 75 patients one day after operation, with an average age of 10.95 ± 3.27 years; the left ventricle did not return to normal in 10 patients 360 days after operation, with an average age of 64.31 ± 7.05 years. Left ventricular end diastolic volume index (LVEDVI) and left ventricular end systolic volume index (LVESVI) of patients decreased significantly one day after operation and remained at 51.95 ± 9.55 mL/m2 and 20.36 ± 8.11 mL/m-2, respectively. In summary, echocardiographic data have a high reference value in assessing cardiac function characteristics in children and adult patients with PDA and are worthy of further promotion.

Raman spectroscopic analysis of skin penetration and moisturizing effects of Bionics vernix caseosa cream compared with Vaseline.

BACKGROUND: The stratum corneum (SC) is the outermost layer of human skin and deemed as barrier against chemical exposure and water loss. Moisturizers have beneficial effects in treating dry skin, especially the SC. Confocal Raman spectroscopy (CRS) was used to evaluate the efficacy of moisturizers on skin hydration and penetration, with such agents posing inherent characteristics of being noninvasive, nondestructive, timesaving, and cost effective. Bionics vernix caseosa (BVC) cream mimics the composition of vernix caseosa (VC), which could protect the newborn skin. METHODS: This research applied CRS to evaluate the penetration depth and water content variation during the intervention with two moisturizers, BVC cream and Vaseline. Volunteers received the 2 h application of BVC cream and Vaseline on the forearms. The evaluations on 0 h, 2 h, 4 h and 6 h were performed clinical assessment. Experimental data was processed by least square method and analysis of variance (ANOVA). RESULTS: The penetration depth of Vaseline was deeper than that of Bionics vernix caseosa cream. Specifically, BVC cream penetrated 18 µm into human skin, while Vaseline penetrated at least 20 µm. Compared with Vaseline, only BVC cream increased skin hydration, with a moisturizing effect lasting for 4 h. At 6 h, the Vaseline moisturizing effect decreased significantly.

A simple and efficient approach toward deep-red to near-infrared-emitting iridium(iii) complexes for organic light-emitting diodes with external quantum efficiencies of over 10.

While the external quantum efficiency (EQE) of iridium(iii) (Ir(iii)) phosphor based near-infrared organic light-emitting diodes (NIR OLEDs) has been limited to 5.7% to date, there is no significant EQE improvement for these types of OLEDs due to the lack of efficient Ir(iii) emitters. Here, a convenient approach within three synthetic steps is developed to afford two novel and efficient deep-red to near-infrared (DR-NIR) emitting phosphors (CNIr and TCNIr), in which a cyano group is added into a commercial red emitter named Ir(piq)2(acac) to significantly stabilize the lowest unoccupied molecular orbitals of the newly designed Ir(iii) complexes. They emit strong DR-NIR phosphorescence emissions at a wavelength of around 700 nm, with relatively high absolute quantum efficiencies of around 45% for their doped films. DR-NIR OLEDs made using CNIr and TCNIr exhibit high-efficiencies, affording peak EQEs of 10.62% and 9.59% with emission peak wavelengths of 690 and 706 nm, respectively. All these devices represent the most efficient Ir(iii)-based DR-NIR OLEDs with a similar color gamut. The simplified synthesis procedure of the DR-NIR-emitting phosphors in conjunction with their excellent performance in OLEDs confirms our efficient strategy to achieve the DR-NIR-emitting Ir(iii) phosphors.

Rapid determination of cadmium in rice by portable dielectric barrier discharge-atomic emission spectrometer.

In this work, a home-made portable dielectric barrier discharge-atomic emission spectrometer (DBD-AES) was explored to the determination of heavy metal in foodstuffs. A rapid and simple method was developed for Cd determination in rice based on this instrument. Rice was pretreated with diluted acid dissolution without complex operations and apparatus. The detection time by DBD-AES is about 3 min and the total analysis time for rice sample is within 11 min. The effects of some key experiment parameters were investigated. The limit of detection was 11.9 µg kg-1 for Cd in rice, much lower than the maximum allowable level established by EC (200 µg kg-1). The practical performance of this method was demonstrated by analyzing real and CRM rice samples. With the portability of DBD-AES, the method is suitable for rapid and in-field analysis of Cd in rice. It will be a useful tool for the routine analysis of rice.

A practical approach to the degradation of polychlorinated biphenyls in transformer oil.

A practical and efficient disposal method for hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil is reported. Transformer oil containing PCBs was treated by nanometric sodium hydride (nano-NaH) and transition metal catalysts. High destruction and removal efficiency (89.8%) can be attained by nano-NaH alone under mild conditions. The process exhibits apparent characteristics of a first order reaction. The reductive ability of nano-NaH was enhanced by the addition of transition metal catalysts. In the presence of TiCl4, 99.9% PCBs was hydrodechlorinated. The complex reducing reagents, Ni(OAc)2+i-PrONa, show extra hydrodechlorinating activity for di-chlorinated biphenyls.

Copper and manganese: two concordant partners in the catalytic oxidation of p-cresol to p-hydroxybenzaldehyde.

Copper and manganese were found to be two concordant partners in the synthesis of p-hydroxybenzaldehyde from p-cresol; under mild conditions, this research realised 95.6% selectivity for p-hydroxybenzaldehyde at 98.5% conversion of p-cresol.

[Determination of four fluorescent whitening agents in laundry detergents by solid phase extraction combined with ultra-high performance liquid chromatography].

A new method was established to determine three stilbene-type disulfonate and one distyrylbiphenyl-type fluorescent whitening agents (FWA351, FWA85, FWA28 and FWA71) in laundry detergents by solid phase extraction (SPE) and ultra-high performance liquid chromatography with a diode array detector (UPLC-DAD). The fluorescent whitening agents were extracted from laundry detergents with 2% formic acid aqueous solution and methanol, and purified by WAX SPE column, and analyzed by UPLC-DAD on a Phenomenex Synergi Max-RP column (150 mm x 2.0 mm), employing acetonitrile-10 mmol/L ammonium acetate as the mobile phase in a gradient elution mode. The fluorescent whitening agents were qualitatively determined by retention time, and confirmed by the ultraviolet spectrum. The results indicated that the target analytes were in the range of 0.05-180 mg/L with the correlation coefficients (r) greater than 0. 999 3, and the method limits of quantification (MLOQ) of target analytes were ranged from 1.5 mg/kg to 15 mg/kg (S/N = 10). The feasibility of this method was demonstrated by the determination of FWAs in samples with spiked recoveries. The recoveries were in the range between 84.9% and 105%, and the precision (relative standard deviation, RSD) ranged from 3.2% to 6.1% (n = 6). Among the 15 samples analyzed, the rate of positive samples was 53.3%, over 1 000 mg/kg of FWA351 and FWA71 were detected. The method is simple, precise and has high recoveries for the determination of fluorescent whitening agents in laundry detergent samples.