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A simple and ultrasensitive method for detecting Pb2+ using resin-enrichment combined with laser-induced breakdown spectroscopy assisted by laser-induced fluorescence.

We proposed a modified corner-cutting method for continuum background removal in laser-induced breakdown spectroscopy.

We proposed an improved algorithm based on the optimization of a combined atomic and ionic line algorithm for LIBS analysis.

Using an aspheric lens for laser focusing solves the energy dispersion caused by spherical aberration, reducing the plasma fluctuations.

A convenient LIBS approach was proposed to reduce the self-absorption effect of alkali and alkaline earth metal elements in soil.

The integrity of the epidermal barrier and the maintenance of barrier homeostasis depend on the dynamic balance between the proliferation and differentiation of keratinocytes. Calcium (Ca2+) plays a crucial role in maintaining a balance of these two processes as well as in the formation of an epidermal permeability barrier. In this study, we showed that topical application of oat β-glucan (OG) could ameliorate epidermal hyperplasia and accelerate the recovery of the epidermal barrier by promoting epidermal differentiation. Mechanistic studies revealed a positive interaction between OG and the dectin-1 receptor, and this interaction could lead to an upregulated expression of the calcium-sensing receptor (CaSR) via activation of the downstream ERK and p38 pathways. This consequently increased the sensitivity of keratinocytes to extracellular Ca2+ under the condition of calcium loss following the disruption of the epidermal barrier, resulting in the maintenance of normal keratinocyte differentiation in the epidermis, and ultimately promoting the recovery of the epidermal barrier. These findings clearly demonstrated the healing effect of OG on a physically damaged epidermal barrier. Thus, OG could be considered a valuable component in the development of skin repair agents.

The integrity of skin tissue structure and function plays an important role in maintaining skin rejuvenation. Ultraviolet (UV) radiation is the main environmental factor that causes skin aging through photodamage of the skin tissue. Cryptotanshinone (CTS), an active ingredient mianly derived from the Salvia plants of Lamiaceae, has many pharmacological effects, such as anti-inflammatory, antioxidant, and anti-tumor effects. In this study, we showed that CTS could ameliorate the photodamage induced by UV radiation in epidermal keratinocytes (HaCaT) and dermal fibroblasts (HFF-1) when applied to the cells before exposure to the radiation, effectively delaying the aging of the cells. CTS exerted its antiaging effect by reducing the level of reactive oxygen species (ROS) in the cells, attenuating DNA damage, activating the nuclear factor E2-related factor 2 (Nrf2) signaling pathway, and reduced mitochondrial dysfunction as well as inhibiting apoptosis. Further, CTS could promote mitochondrial biosynthesis in skin cells by activating the AMP-activated protein kinase (AMPK)/sirtuin-1 (SIRT1)/peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α) signaling pathway. These findings demonstrated the protective effects of CTS against UV radiation-induced skin photoaging and provided a theoretical and experimental basis for the application of CTS as an anti-photodamage and anti-aging agent for the skin.

To solve the adulteration problem of brown rice flour in the commodity market, a novel, accurate, and stable detection method based on time-resolved laser-induced breakdown spectroscopy (TR-LIBS) is proposed. Qualitative and quantitative analysis was used to detect five adulterants and seven different adulterant ratios in brown rice flour. Being able to excavate more information from plasma by obtaining time-resolved spectra, TR-LIBS has a stronger performance, which has been further verified by experiments. For the qualitative analysis of adulterants, the traditional machine learning models based on TR-LIBS, linear discriminant analysis (LDA), naïve Bayes (NB) and support vector machine (SVM) have significantly better classification accuracy than those based on traditional LIBS, increasing by 3–11%. The deep learning classification model based on TR-LIBS also achieved the same results, with an accuracy increase of more than 8%. For the quantitative analysis of the adulteration ratio, compared with traditional LIBS, the quantitative model based on TR-LIBS reduces the limit of detection (LOD) of five adulterants from about 8–51% to 4–19%, which effectively improves the quantitative detection performance. Moreover, t-SNE visualization proved that there were more obvious boundaries between different types of samples based on TR-LIBS. These results demonstrate the great prospect of TR-LIBS in the identification of brown rice flour adulteration.

The integrity of skin tissue structure and function plays an important role in maintaining skin rejuvenation. Ultraviolet (UV) radiation is the main environmental factor that causes skin aging through photodamage of the skin tissue. Cryptotanshinone (CTS), an active ingredient mianly derived from the

The inhibition of fibroblast growth factor 18 (FGF18) promotes the transition of hair follicles (HFs) from the telogen phase to the anagen phase. Cucurbitacin has been shown to have a good effect in promoting hair cell growth. This study explored the potential effect of cucurbitacin on hair growth and its effect on FGF18 expression in mice.Male C57BL/6J mice were randomly divided into the following two groups: (I) the vehicle group; and (II) the cucurbitacin group. Matrix cream and cucurbitacin cream were applied to the depilated skin on the back of the vehicle group mice and the cucurbitacin group mice, respectively. On days 3, 6, 9, 12, 15, and 18, the hair growth in the depilated dorsal skin of the mice was recorded with a digital camera and a HF detector, and the HF cycle status of the mice was observed by hematoxylin and eosin (HE) staining. In addition, the level of FGF18 messenger ribonucleic acid (mRNA) in the dorsal skin was measured on days 15 and 18 by quantitative real-time polymerase chain reaction (qRT-PCR), while the level of FGF18 protein was measured by western blot and immunofluorescence staining.The dorsal skin to which the cucurbitacin cream was applied began to darken on day 6 and grew hairs on day 9, which was 3 days earlier than the dorsal skin to which the matrix cream was applied. The HE staining revealed a transition from the telogen phase to the anagen phase 3 days earlier for the cucurbitacin cream-treated skin than the matrix cream-treated skin. In addition, the skin treated with cucurbitacin cream also showed a significant decrease in FGF18 mRNA as seen by qRT-PCR, and reduced FGF18 protein levels as detected by western blot and immunofluorescence staining compared to the skin treated with matrix cream only.Cucurbitacin significantly reduced the levels of FGF18 mRNA and protein in the dorsal skin of mice to accelerate the HFs to enter the anagen phase earlier, thereby promoting the regeneration of hair. Thus, cucurbitacin can be considered a new and valuable agent for the development of anti-hair loss products.

Ischemic heart disease (IHD) is one of the most common cardiovascular diseases with high morbidity and mortality. Danshensu (DSS) is widely used in the treatment of coronary heart disease. In this study, the carboxy group of DSS was esterified with edaravone to synthesize the novel DSS derivative DEX-018 to achieve a synergistic protective effect and overcome the structural deficiency of DSS. The pharmacological effect of DEX-018 against tert-butyl hydrogen peroxide (t-BHP) induced oxidative damage in human umbilical vein endothelial cells (HUVECs) was evaluated. The results demonstrated that pretreatment with DEX-018 significantly increased cell viability and superoxide dismutase (SOD) activity and decreased the lactate dehydrogenase (LDH) leakage rate, malondialdehyde (MDA) level and intracellular reactive oxygen species (ROS) level. In addition, DEX-018 inhibited cell apoptosis and reversed the expression of apoptosis-related proteins (Bcl-2, Bax, and caspase-3) in HUVECs stimulated by t-BHP. Further study on the mechanism of DEX-018 revealed that the expression of p-Akt and p-extracellular signal-regulated kinase 1/2 (ERK1/2) was increased, which suggested that DEX-018 may protect HUVECs against t-BHP induced oxidative injury via the Akt and ERK1/2 signaling pathways. To further validate the correlation, CCK8 was used to detect cell viability after treatment with DEX-018 plus Akt inhibitor (MK2206) and phosphadylinositol 3-kinase (PI3K) inhibitor (LY294002). Compared with DEX-018 alone, MK2206 or LY294002 significantly decreased cell viability of HUVECs, indicating that the protective effect of DEX-018 against t-BHP induced oxidative injury was significantly weakened. It was further verified that the antioxidant and anti-apoptotic effects of DEX-018 were partly related to the PI3K-Akt signaling pathway.

The matrix effect is one of the main bottlenecks for the laser-induced breakdown spectroscopy (LIBS) technique. In this work, image-assisted, laser-induced breakdown spectroscopy (IA-LIBS) based on the Lomakin-Scherbe formula was put forward as a correction to the matrix effect. The brightness and area information in the plasma image was extracted to correct the spectral line intensities among which the brightness information characterizes the plasma temperature, and the area information characterizes the ablative mass. To verify the feasibility of this method, the experiment was conducted on metal samples and pressed samples. The method was applied for quantitative analysis of copper (Cu), magnesium (Mg) in metal samples and chromium (Cr), manganese (Mn) in pressed samples. For the metal samples, after correcting the matrix effect by IA-LIBS, the determination coefficient R squared (R2) of Cu I 510.55 nm and Mg I 518.36 nm calibration curves were increased from 0.726 to 0.942 to 0.992 and 0.988, respectively. The root-mean-square-error of cross-validation (RMSECV) and the average relative error (ARE) decreased by 75.10% and 77.18%, respectively. For the pressed samples, R2 of Cr I 520.84 nm and Mn I 403.07 nm calibration curves corrected by IA-LIBS increased from 0.364 to 0.098 to 0.975 and 0.980; and RMSECV and ARE decreased by 77.88% and 83.83%, respectively. The experimental results showed that IA-LIBS had an obvious improvement on elimination of the matrix effect for the different samples and the different elements. Therefore, IA-LIBS will become a promising technology and will greatly promote the development of LIBS in various fields.

The single sample calibration laser-induced breakdown spectroscopy (SSC-LIBS) is quite suitable for the fields where the standard sample is hard to obtain, including space exploration, geology, archaeology, and jewelry identification. But in practice, the self-absorption effect of plasma destroys the linear relationship of spectral intensity and element concentration based on the Lomakin-Scherbe formula which is the guarantee of the high accuracy of the SSC-LIBS. Thus, the self-absorption effect limits the quantitative accuracy of SSC-LIBS greatly. In this work, an improved SSC-LIBS with self-absorption correction (SSC-LIBS with SAC) is proposed for the promotion of quantitative accuracy of SSC-LIBS. The SSC-LIBS with SAC can correct the intensity ratio of spectral lines in the calculation of SSC-LIBS through relative self-absorption coefficient K without complicated preparatory information. The alloy samples and pressed ore samples were used to verify the effect of the SSC-LIBS with SAC. Compared with SSC-LIBS, for alloy samples, the average RMSEP and average ARE of SSC-LIBS with SAC decreased from 0.83 wt.% and 13.75% to 0.40 wt.% and 4.06%, respectively. For the pressed ore samples, the average RMSEP and average ARE of SSC-LIBS with SAC decreased from 4.77 wt.% and 90.48% to 2.34 wt.% and 14.60%. The experimental result indicates that SSC-LIBS with SAC has a great improvement of quantitative accuracy and better universality compared with traditional SSC-LIBS, which is a mighty promotion of the wide application of SSC-LIBS.

Due to the effect of bagging on fruit growth, non-destructive and in situ soluble solid content (SSC) in citrus detection remains a challenge. In this work, a new method for accurately quantifying SSC in citrus using hyperspectral imaging of citrus leaves was proposed. Sixty-five Ehime Kashi No. 28 citruses with surrounding leaves picked at two different times were picked for the experiment. Using the principal components analysis combined with Gaussian process regression model, the correlation coefficients of prediction-real value by citrus and its leaves in cross-validation were 0.972 and 0.986, respectively. In addition, the relationship between citrus leaves and SSC content was further explored, and the possible relationship between chlorophyll in leaves and SSC of citrus was analyzed. Comparing the quantitative analysis results by citrus and its leaves, the results show that the proposed method is a non-destructive and reliable method for determining the SSC by citrus leaves and has broad application prospects in indirect detection of citrus.

The detection of manganese (Mn) in steel by laser-induced breakdown spectroscopy (LIBS) provides essential information for steelmaking. However, self-absorption greatly disrupts the LIBS spectral lines of Mn with high content. In this study, to minimize self-absorption for Mn spectral lines in LIBS, laser-induced fluorescence (LIF) was applied. Compared with conventional LIBS, the self-absorption factors (α) of Mn I 403.08, 403.31, and 403.45 nm lines were reduced by 90%, 88%, and 88%, respectively; the root mean square errors of cross-validation were decreased by 88%, 85%, and 87%, respectively; the average relative errors were reduced by 93%, 90%, and 91%, respectively; and average relative standard deviations were decreased by 29%, 32%, and 33%, respectively. The LIBS-LIF was shown to successfully minimize the self-absorption effect and spectral intensity fluctuation and improve detection accuracy.

Attached to the outer surface of the corneocyte lipid envelope (CLE), omega-hydroxy ceramides (ω-OH-Cer) link to involucrin and function as lipid components of the stratum corneum (SC). The integrity of the skin barrier is highly dependent on the lipid components of SC, especially on ω-OH-Cer. Synthetic ω-OH-Cer supplementation has been utilized in clinical practice for epidermal barrier injury and related surgeries. However, the mechanism discussion and analyzing methods are not keeping pace with its clinical application. Though mass spectrometry (MS) is the primary choice for biomolecular analysis, method modifications for ω-OH-Cer identification are lacking in progress. Therefore, finding conclusions on ω-OH-Cer biological function, as well as on its identification, means it is vital to remind further researchers of how the following work should be done. This review summarizes the important role of ω-OH-Cer in epidermal barrier functions and the forming mechanism of ω-OH-Cer. Recent identification methods for ω-OH-Cer are also discussed, which could provide new inspirations for study on both ω-OH-Cer and skin care development.

As an important variant of calibration-free laser-induced breakdown spectroscopy (CF-LIBS), one-point calibration LIBS (OPC-LIBS) corrects the Boltzmann plot of the unknown sample by using one known sample and obtains higher quantitative accuracy than CF-LIBS. However, the self-absorption effect restricts its accuracy. In this work, a new self-absorption correction (SAC) method for OPC-LIBS is proposed to solve this problem. This method uses an algorithm to correct the self-absorption and does not require the calculation of the self-absorption coefficient. To verify the effectiveness of this SAC method, Ti, V, and Al elements in two titanium alloys were determined by classical OPC-LIBS and OPC-LIBS with SAC. The average relative errors (AREs) of all elements in the two samples were decreased from 8.78% and 9.28% to 8.07% and 7.56%, respectively. The results demonstrated the effectiveness of this SAC method for OPC-LIBS.

Quantitative trace element analysis is crucial to a range of industries, including food, natural and man-made materials, and biomedicine. For this purpose, we here developed laser-induced breakdown spectroscopy (LIBS) with dried droplet sample pretreatment. This novel method is quantitative and especially suited to analyzing small solid samples with trace concentrations of low atomic number elements. The dried droplet pretreatment involves acid digesting the sample and allowing a droplet to dry on filter paper free of the analytes. LIBS was then performed on the dried droplet using pulsed laser ablation and spectroscopic detection from 200–1000 nm with 0.1 nm resolution. A standard addition approach was employed to quantify LIBS signals by adding known amounts of analytes into the droplets. The method was demonstrated by measuring sodium, potassium and calcium in four selected samples. All the standard addition calibration curves showed good linearity, with all regression coefficients >0.981 and relative standard deviation

This study develops non-parametric models to predict traffic conflicts at signalized intersections at the signal cycle level using machine learning approaches. Three different datasets were collected, one from Surrey, Canada, and the other two from Los Angeles and Georgia, U.S.A. From the datasets, traffic conflicts measured by modified time to collision and traffic parameters such as traffic volume, shockwave area, platoon ratio, and shockwave speed were extracted. Multilayer perceptron (MLP), support vector regression (SVR), and random forest (RF) models were developed based on the Surrey dataset, and the Bayesian optimization approach was adopted to optimize the model hyperparameters. The optimized models were applied to the Los Angeles and Georgia datasets to test their transferability, and they were also compared to a traditional safety performance function (SPF) developed using negative binominal regression. The results show that all the three Bayesian optimized machine learning models have high predictive accuracy and acceptable transferability, and the MLP model is a little better than the SVR and RF models. In addition, all three models outperform the traditional SPF with regard to predictive accuracy. The model sensitivity analysis also show that the traffic volume and shockwave area have positive effects on traffic conflicts, while the platoon ratio has negative effects.

A novel and effective method named time-resolved spectral-image laser-induced breakdown spectroscopy (TRSI-LIBS) was proposed to achieve precise qualitative and quantitative analysis of milk powder quality. To verify the feasibility of TRSI-LIBS, qualitative and quantitative analysis of milk powder quality was carried out. For qualitative analysis of foreign protein adulteration, the accuracy of models based on TRSI-LIBS was higher than those based on LIBS, with an accuracy improvement of about 5% to 10%. For the quantitative analysis of foreign protein adulteration and element content, the quantitative analysis models based on TSRI-LIBS also had better effect. For instance, limit of detection (LOD),determination coefficient of prediction (R

FGF5 and FGF18 are key factors in the regulation of the hair follicle cycle. FGF5 is overexpressed during the late anagen phase and serves as a crucial regulatory factor that promotes the anagen-to-catagen transition in the hair follicle cycle. FGF18, which is overexpressed during the telogen phase, mainly regulates the hair follicle cycle by maintaining the telogen phase and inhibiting the entry of hair follicles into the anagen phase. The inhibition of FGF5 may prolong the anagen phase, whereas the inhibition of FGF18 may promote the transition of the hair follicles from the telogen phase to the anagen phase. In the present study, we used siRNA to suppress FGF5 or FGF18 expression as a way to inhibit the activity of these genes. Using qPCR, we showed that FGF5-targeting siRNA modified by cholesterol was more effective than the same siRNA bound to a cell-penetrating peptide at suppressing the expression of FGF5 both in vitro and in vivo. We then investigated the effects of the cholesterol-modified siRNA targeting either FGF5 or FGF18 on the hair follicle cycle in a depilated area of the skin on the back of mice. The cholesterol-modified siRNA, delivered by intradermal injection, effectively regulated the hair follicle cycle by inhibiting the expression of FGF5 and FGF18. More specifically, intradermal injection of a cholesterol-modified FGF5-targeted siRNA effectively prolonged the anagen phase of the hair follicles, whereas intradermal injection of the cholesterol-modified FGF18-targeted siRNA led to the mobilization of telogen follicles to enter the anagen phase earlier. The inhibitory effect of the cholesterol-modified FGF18-targeted siRNA on FGF18 expression was also evaluated for a topically applied siRNA. Topical application of a cream containing the cholesterol-modified FGF18-targeted siRNA on a depilated area of the skin of the back of mice revealed comparable inhibition of FGF18 expression with that observed for the same siRNA delivered by intradermal injection. These findings suggested that alopecia could be prevented and hair regrowth could be restored either through the intradermal injection of cholesterol-modified siRNA targeting FGF5 or FGF18 or the topical application of FGF18 siRNA.

The existence of the self-absorption effect results in a nonlinear relationship between spectral intensity and elemental concentration, which dramatically affect the quantitative accuracy of laser-induced breakdown spectroscopy (LIBS), especially calibration-free LIBS (CF-LIBS). In this work, the CF-LIBS with columnar density and standard reference line (CF-LIBS with CD-SRL) was proposed to improve the quantitative accuracy of CF-LIBS analysis by exploiting self-absorption. Our method allows using self-absorbed lines to perform the calibration-free approach directly and does not require self-absorption correction algorithms. To verify this method, the experiment was conducted both on aluminium-bronze and aluminium alloy samples. Compared with classical CF-LIBS, the average errors (AEs) of CF-LIBS with CD-SRL were decreased from 3.20%, 3.22%, 3.15% and 3.01%–0.95%, 1.00%, 1.16% and 1.78%, respectively for four aluminium-bronze alloy samples. The AEs were decreased from 0.66%, 0.70%, 0.89% and 1.30%–0.43%, 0.61%, 0.77% and 0.33%, respectively for four aluminium alloy samples. The experimental results demonstrated that CF-LIBS with CD-SRL provided higher quantitative accuracy and stronger adaptability than classical CF-LIBS, which is quite helpful for the practical application of CF-LIBS.

Herein, we studied the increasing tendency of photoacoustic (PA) conversion efficiency of the Au/polydimethylsiloxane (PDMS) composite. The thickness of the Au layer was optimized by modeling the PA process based on the Drude–Lorentz model and finite element analysis method, and corresponding results were verified. The results showed that the optimal Au thickness of the Au/PDMS composite was 35 nm. Finally, the Au/PDMS composites were coated onto the surface of aluminum alloys, which improved the thermoelastic laser ultrasonic (LU) signals to near 100 times. Besides, the defect mapping was performed by thermoelastic LU signals with Au/PDMS coating and ablation LU signals without coating; the Pearson correlation coefficient was higher than 0.95. The application in the defect detection in metal could provide guides for nondestructive detection on metals by laser ultrasound.

Objective: Exposure to ultraviolet B (UVB) can cause skin damage through oxidative stress, DNA damage, and apoptosis. Keratinocyte growth factor (KGF) has been shown to reduce the content of intracellular reactive oxygen species (ROS) following UVB exposure, a role that is crucial for the efficient photoprotection of skin. The present study evaluated the photoprotective effect of KGF-2 on UVB-induced skin damage and explored its potential molecular mechanism. Methods: To evaluate the effect of KGF-2 on UVB-induced damage ex vivo, a human epidermal full-thickness skin equivalent was pretreated without or with KGF-2 and then exposed to UVB and the levels of histopathological changes, DNA damage, inflammation, and apoptosis were then evaluated. The ability of KGF-2 to protect the cells against UVB-inflicted damage and its effect on ROS production, apoptosis, and mitochondrial dysfunction were determined in HaCaT cells. Results: Pretreatment of the epidermis with KGF-2 ameliorated the extent of photodamage. At the cellular level, KGF-2 could attenuate ROS production, apoptosis, DNA damage, and mitochondrial dysfunction caused by UVB exposure. KGF-2 could also activate the aryl hydrocarbon receptor (AhR) to trigger the Nrf2 signaling pathway. Conclusion: Taken together, our findings suggested that KGF-2 could ameliorate UVB-induced skin damage through inhibiting apoptosis, reducing oxidative stress, and preventing DNA damage and mitochondrial dysfunction via regulating AhR/Nrf2 signaling pathway.

A novel nanoporous analytical platform is reported to improve the stability of the dried droplet method (DDM). This nanoporous platform was made of tin dioxide (Np SnO2) substrate by electrochemical anodization from tin (Sn) slide. The DDM is a widely used sample pretreatment in analytical chemistry that involves placing a droplet of solution onto the substrate and drying for analytical testing. However, during the droplet drying process, the solutes would converge at the droplet edge and cause inhomogeneous solutes distribution. This is the coffee ring effect (CRE). The Np SnO2 has irregular nanopores, which allows droplet solutions to penetrate into the substrate rather than spreading out, effectively suppressing CRE. Theoretical models were built to explain the formation of CRE on blank tin (Sn) substrate and suppression of CRE on Np SnO2. Better results were obtained in detecting lithium (Li) using the Np SnO2 by laser-induced breakdown spectroscopy (LIBS). The line scanning results indicated that the Li emission line (670.8 nm) intensities on Np SnO2 substrate had lower relative standard deviation (RSD = 3.3%) than those on Sn substrate (RSD = 31.5%), which illustrate suppression of CRE and stability improvement on Np SnO2 substrate. Furthermore, Li calibration curves were built for LIBS with DDM. The curve using Np SnO2 substrate had better linearity (R2 = 0.997), higher precision (RSD = 4.2%), and higher sensitivity (LOD = 0.13 mg/L) than that by Sn substrate (R2 = 0.954, RSD = 17%, and LOD = 1.21 mg/L). All in all, the anodic Np SnO2 substrate can suppress CRE in DDM and hence improve the stability and precision of subsequent analysis.

Laser opto-ultrasonic dual (LOUD) detection, which uses laser irradiation of samples to generate spectral and ultrasonic signals simultaneously, can perform multimodal detection of element composition and structural property. As such, it has been applied to the detection of additive manufacturing (AM) components. Further, optimized parameters lead to better detection results. To the best of our knowledge, however, there is no study on the effect of laser properties on LOUD detection. Therefore, we studied the mechanism and influence of laser wavelength and energy on LOUD detection. In this work, the intensity, signal-to-noise ratio (SNR), and stability evolution of the laser excitation spectrum and ultrasonic signals at different wavelengths and energies were analyzed. It was found in the plasma evolution that high electron number density means a large amount of ablated mass generated, which was favorable for laser ultrasonic excitation and can produce higher SNR and a more stable signal. However, it also led to more atoms of the ground-state, which resulted in the self-absorption effect and reduced spectrum intensity in the spectrum analysis. Therefore, with self-absorption correction, better stability, and higher signal intensity, an SNR of spectral and ultrasonic signals can be obtained using 355 nm laser excitation at optimal energy. As a result, in the quantitative analysis of Cu and Si elements by LOUD detection, the determination coefficients ( R 2 ) were higher than 0.995, and the average relative errors were less than 2.5%, the limit of detection could reach the order of 100 ppm. Further, the defect size of 0.55 mm in the wire + a r c additive manufacturing sample was detected by LOUD detection, and the average relative error was 5.59% compared with the digital radiography results, which indicate that laser wavelength and laser energy affect the intensity and stability of spectral and ultrasonic signals in LOUD detection, which means selecting appropriate laser parameters is important to obtain a high precision detection.

Backgrounds: (6aS, 10S, 11aR, 11bR, 11cS)-10-methylaminododecahydro-3a, 7a-diaza-benzo (de) anthracene-8-thione (MASM), a novel derivative of matrine, exhibits better anti-inflammatory activity. This study was designed to evaluate the protective effect of MASM on acute and chronic liver injuries and explore the possible mechanisms. Methods: Acute and chronic liver injury models were established by the CCl4 intraperitoneal injection and the protective effect of MASM was assessed by biochemical and histological examination. The infiltration of different monocyte subsets into the liver was characterized and analyzed by flow cytometry. The in vitro effect of MASM on liver nonparenchymal cells was evaluated by real-time PCR and transwell chemotaxis assays. Results: Administration of MASM markedly attenuated acute liver injury and liver fibrosis induced by CCl4 injection. Meanwhile, the infiltrations of Gr1hi monocytes in injured livers and induced hepatic expression of monocyte chemoattractant protein-1 (MCP-1) were greatly inhibited. Cellular experiments demonstrated that MASM not only decreased the expression of MCP-1 but also inhibited its chemotactic activity. Conclusions: This study demonstrates that the protective effect of MASM on liver injury could be contributed to the suppression of Gr1hi monocyte infiltration to the liver and the inhibition of MCP-1 production and activity. These findings provide new insights into the protective role of MASM in liver injury.

Small interfering RNA (siRNA) has been used to treat various skin diseases. However, siRNA is limited in application due to its electronegativity, strong polarity, easy degradation by nuclease and difficulty in breaking through the skin barrier. Therefore, safe and efficient siRNA delivery vector is the premise of effective treatment of skin diseases by siRNA. In recent years, with the deepening of research on siRNA, great progress has been made in the development of delivery systems based on lipids, polymers, peptides and nanoparticles, some new transdermal delivery vectors of siRNA have emerged, such as liposomes, dendrimers, cell penetrating peptides, and spherical nucleic acid nanoparticles. This review will focus on the recent advance in siRNA transdermal delivery vectors.小干扰 RNA (Small interfering RNA，siRNA) 已被用于各种皮肤病的治疗。然而，由于siRNA 具有电负性、极性强、易被核酸酶降解以及难以突破皮肤表皮屏障等缺陷，使其应用受限。因此，安全高效的siRNA 递送载体是siRNA 有效治疗皮肤病的前提。近年来，随着对siRNA 研究的不断深入，基于脂质、聚合物、肽和纳米颗粒的递送系统的开发取得了很大进展，一些新的siRNA 透皮递送载体应运而生，如类脂质体、树枝状聚合物、细胞穿透肽、球形核酸纳米颗粒等等。文中将重点介绍近年来siRNA 透皮递送载体的最新研究进展。.

Objective: Acne is a chronic skin disease that involves four key pathogenic factors: excess sebum production, ductal epidermal hyperproliferation, Propionibacterium acnes (P. acnes) colonization, and skin inflammation. Mangostins are well-known for their anti-bacterial and anti-inflammatory effects, suggesting that mangostins may have therapeutic potential for acne. The present study aimed to explore the anti-acne effects of mangostins from the perspective of multiple pathogenic mechanisms of acne. Methods: The effects of α- and γ-mangostins on the growth of P. acnes and lipase activity were analyzed. Their effects on P. acnes-induced keratinocyte proliferation were examined by CCK-8. The expression of inflammatory genes and activation of NF-κB and MAPK signaling pathways were detected by quantitative real-time PCR and western blotting, respectively. Results: Alpha- and γ-mangostins not only inhibited the growth of P. acnes, but also reduced the proliferation of keratinocytes induced by heat-killed P. acnes. Furthermore, α- and γ-mangostins were able to suppress P. acnes-induced expression of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6 in keratinocytes by inhibiting the activation of NF-κB and MAPK signaling pathways. Discussion and conclusions: Mangostins appeared to possess multiple anti-acne activities, including the inhibition of P. acnes growth, regulation of keratinocytes proliferation, and attenuation of skin inflammatory reaction. Hence, mangostins might be developed into a potential therapeutic agent for the treatment of acne.

Background Inula helenium L. is an herb whose anti-inflammatory properties are attributed to its active components, the sesquiterpene lactones (SLs). Our previous study demonstrated that the total sesquiterpene lactones isolated from Inula helenium L. (TSL-IHL), consisting mainly of alantolactone (AL) and isoalantolactone (IAL), may have potential in the prevention and treatment of rheumatoid arthritis (RA). However, the effect of TSL-IHL on atopic dermatitis (AD) has not been studied yet. Aim of the study The present study evaluates the potential of TSL-IHL as a treatment for AD. Methods/Study designs The effects of TSL-IHL on the expression of inflammatory genes and the activation of NF-κB signaling pathway in HaCat cells were examined by quantitative real-time PCR and western blotting, respectively, and compared with those of AL and IAL. The protective effect of TSL-IHL against AD was tested in a mouse model induced by 2,4-dinitrochlorobenzene (DNCB), in which AD-like skin lesions were induced in ICR mice by sensitizing once with 100 µl of 7% DNCB painted on their shaved back skin and then challenging with 20 µl of 0.2% DNCB five times on their right ears at 3 day intervals starting on day 5 post-sensitization. Results TSL-IHL, as well as AL and IAL, could all inhibit TNF-α-induced activation of NF-κB and the expression of TNF-α, IL-1, and IL-4 in HaCat cells in a dose-dependent manner in the range of 0.6–2.4 µg/ml. The topical application of TSL-IHL (1% W/W in emollient cream) attenuated DNCB-induced dermatitis severity and right ear swelling. The serum levels of IgE, TNF-α and IFN-γ in TSL-IHL-treated mice were reduced by 81.39%, 89.69%, and 87.85%, respectively, while the mRNA levels of IL-4, IL-5 and IL-13, in the back-skin lesions of TSL-IHL-treated mice were reduced by 39.21%, 40.62% and 48.12%, respectively, compared with the untreated controls. Histopathological examination showed that TSL-IHL treatment reduced epidermis/dermis thickening and dermal inflammatory infiltration in both ear and back skins. Conclusions We suggest that TSL-IHL inhibited the development of AD-like skin symptoms by regulating cytokine expression and may be an effective alternative therapy for AD.

Human biomarkers, such as hair and nails, often provide a continuous record of element concentration to indicate the nutritional status and metabolic changes. Laser-induced breakdown spectroscopy (LIBS), as a rapid detection method without sample preparation, provides a good alternative for measuring mineral elements in hair and nails. For biomedical applications of LIBS, high-precision and high-sensitivity instruments are commonly used in LIBS systems, such as Mechelle 5000 coupled with iStar ICCD. Their high cost limits the wide application of LIBS instruments. In this work, we used a low-cost autofocus LIBS system to obtain the spectral lines directly from hair and nails. The calibration-free LIBS (CF-LIBS) assisted with the standard reference line method was used to quantify the content ratio of Ca/Na and Mg/Na in hair and nails. The results showed that the relative errors between quantitative results of CF-LIBS and ICP-OES were less than 10% in hair and nails, which verified the accuracy of this method. These results illustrated that CF-LIBS assisted with the standard reference line method is a promising tool for biomedicine.

As a therapeutic target for antitumor necrosis factor (TNF)-α interventions, UbcH5c is one of the key ubiquitin-conjugating enzymes catalyzing ubiquitination during TNF-α-triggered nuclear factor kappa B (NF-κB) activation. In the present study, three series of analogues were designed and synthesized from α-santonin, and their UbcH5c inhibitory activities were screened by Western blotting and NF-κB luciferase assay. Further BIAcore, in-gel fluorescence imaging, and immunoprecipitation assays demonstrated that compound 6d exhibited robust and specific inhibition of UbcH5c, exceeding that of the positive compound 1 (IJ-5). Mechanistic investigations revealed that compound 6d preferentially bound to and inactivated UbcH5c by forming a covalent adduct with its active site Cys85. Furthermore, compound 6d exhibited potent anti-inflammatory activity against complete Freund's adjuvant-induced adjuvant arthritis in vivo. These findings suggest that the novel α-santonin-derived UbcH5c inhibitor 6d is a promising lead compound for the development of new antirheumatoid arthritis (RA) agent.

Ethnopharmacological relevance Esculentoside A (EsA) is a saponin isolated from the root of Phytolacca esculenta, an herb which has long been used in Traditional Chinese Medicine for various inflammatory diseases. EsA has been reported to have potent anti-inflammatory properties both in vitro and in vivo. Aim of the study The present study focused on the molecular mechanism of EsA for its anti-inflammatory effects in RAW264.7 cells stimulated with lipopolysaccharide (LPS). Methods and results Enzyme Linked Immunosorbent Assay (ELISA) showed EsA dose dependently inhibited the production of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and nitric oxide in RAW264.7 cells. Real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay further confirmed the suppression of LPS-induced TNF-α, IL-6 and iNOS gene expression by EsA on a transcriptional level. Moreover, EsA treatment markedly suppressed LPS-stimulated IκB phosphorylation and degradation as well as LPS-stimulated luciferase reporter construct driven by κB response elements in RAW264.7 cells. In addition, EsA significantly reduced LPS-induced stimulation of p38 and JNK, but not ERK1/2, phosphorylation. Furthermore, we used a computational method called “reverse docking” to search the possible binding proteins of EsA from the potential drug target database (PDTD), and focused on CK2 as the primary binding protein of EsA. Afterward, we further tested EsA directly interacts with recombinant CK2 using SPR assay. In CK2 kinase activity assay, EsA inhibited recombinant CK2 holoenzyme activity obviously in a dose-dependent manner. In addition, TBB (4, 5, 6, 7-tetrabromo-2-benzotriazole, a pharmacological inhibitor of CK2) blocked IL-6 release in a dose-dependent manner, whereas co-treatment of cells with EsA and TBB did not have an additive effect. Conclusions Taken together, these results indicate that EsA blocks the LPS-induced pro-inflammatory molecules expression, at least in part, by impediment of LPS-triggered activation of NF-κB and p38/JNK MAPK pathways in macrophages. Furthermore, we discovered for the first time EsA as a ligand for CK2, which was involved in the inhibition of EsA to the expression of inflammatory cytokines. These findings extended our understanding on the cellular and molecular mechanisms responsible for the anti-inflammatory activity of EsA.

The epidermal barrier acts as a line of defense against external agents as well as helps to maintain body homeostasis. The calcium concentration gradient across the epidermal barrier is closely related to the proliferation and differentiation of keratinocytes (KCs), and the regulation of these two processes is the key to the repair of epidermal barrier disruption. In the present study, we found that fucoidan from Undaria pinnatifida (UPF) could promote the repair of epidermal barrier disruption in mice. The mechanistic study demonstrated that UPF could promote HaCaT cell differentiation under low calcium condition by up-regulating the expression of calcium-sensing receptor (CaSR), which could then lead to the activation of the Catenin/PLCγ1 pathway. Further, UPF could increase the expression of CaSR through activate the ERK and p38 pathway. These findings reveal the molecular mechanism of UPF in the repair of the epidermal barrier and provide a basis for the development of UPF into an agent for the repair of epidermal barrier repair.

In the effort to identify natural products that regulate immunity and inflammation, we found that nitidine chloride (NC), an alkaloid from herb Zanthoxylum nitidum, enhanced IL-10 production in lipopolysaccharide (LPS)-stimulated myeloid cells. While NC was shown to be capable of inhibiting topoisomerase I (TOP1), NC analogs that could not inhibit TOP1 failed to increase IL-10 production. Moreover, medicinal TOP1 inhibitors TPT and SN-38 also augmented IL-10 production significantly, whereas knockdown of TOP1 prevented NC, TPT, and SN-38 from enhancing IL-10 expression. Thus, NC promoted IL-10 production by inhibiting TOP1. In LPS-induced endotoxemic mice, NC and TOP1 inhibitors increased IL-10 production, suppressed inflammatory responses, and reduced mortality remarkably. The anti-inflammatory activities of TOP1 inhibition were markedly reduced by IL-10-neutralizing antibody and largely absent in IL-10-deficient mice. In LPS-stimulated RAW264.7 cells and in peritoneal macrophages from endotoxemic mice, NC and TOP1 inhibitors significantly enhanced the activation of Akt, a critical signal transducer for IL-10 production, and inhibition of Akt prevented these compounds from enhancing IL-10 production and ameliorating endotoxemia. These data indicated that NC and TOP1 inhibitors are able to exert anti-inflammatory action through enhancing Akt-mediated IL-10 production and may assist with the treatment of inflammatory diseases.

Self-absorption seriously affects the accuracy and stability of quantitative analysis in laser-induced breakdown spectroscopy (LIBS). To reduce the effect of self-absorption, we investigated the temporal evolution of the self-absorption effect by establishing exponential calibration curves. Meanwhile, the temporal evolution mechanism of the self-absorption effect was also investigated. The results indicated that self-absorption was weak at the early stage of plasma expansion. For determination of manganese (Mn) in steel, as an example, the concentration of upper bound of linearity (Cint) was 2.000 wt. % at the early stage of plasma expansion (in a time window of 0.2-0.4 μs)—much higher than 0.363 wt. % at a traditional optimization time window (2-3 μs). The accuracy and stability of quantitative analysis at the time window of 0.2-0.4 μs was also much better than at the time window of 2-3 μs. This work provides a simple method for improving quantitative analysis performance and avoiding the self-absorption effect in LIBS.

Laser-induced breakdown spectroscopy (LIBS) was suitable for the identification of meat species due to fast and less sample preparation. However, the problem of low accuracy rate of the recognition model caused by improper selection of training set samples by random split has severely restricted the development of LIBS in meat detection. Sample set portioning based on the joint x–y distance (SPXY) method was applied for dividing the meat spectra into a training set and a test set. Then, the five kinds of meat samples (shrimp, chicken, beef, scallop, and pig liver) were classified by the support vector machine (SVM). With the random split method, Kennard–Stone method, and SPXY method, the recognition accuracies of the SVM model were 90.44%, 91.95%, and 94.35%, respectively. The multidimensional scaling method was used to visualize the results of the sample split for the interpretation of the classification. The results showed that the identification performance of the SPXY method combined with the SVM model was best, and the accuracy rates of shrimp, chicken, beef, scallop, and pig liver were 100.00%, 100.00%, 100.00%, 78.57%, and 92.00%, respectively. Moreover, to verify the broad adaptability of the SPXY method, the linear discriminant analysis model, the K-nearest neighbor model, and the ensemble learning model were applied as the meat species identification model. The results demonstrated that the accuracy rate of the classification model can be improved with the SPXY method. In light of the findings, the proposed sample portioning method can improve the accuracy rate of the recognition model using LIBS.

Herein, a dried droplet method (DDM) with superhydrophobic-induced enrichment is reported for stable and ultrasensitive analysis of organic pollutants and heavy metals. A superhydrophobic (SHB) substrate was prepared as an analytical detection platform for the DDM. This SHB substrate was synthesized by sequentially coating polydimethylsiloxane (PDMS) and titanium dioxide nanoparticles (TiO2 NPs) onto glass substrate surface. In the droplet drying process, the SHB substrate was demonstrated to suppress the coffee ring effect (CRE) and enriched analyte concentration. Combining with Raman spectroscopy for analysis of methylene blue (MB), and with laser-induced breakdown spectroscopy (LIBS) for analysis of chromium (Cr), the results indicated high stability and ultra-sensitivity for organic pollutants and heavy metals detection. Overall, the DDM with superhydrophobic-induced enrichment has big potential in applications requiring stable and ultrasensitive analysis.

As a novel tool, deep learning is used to solve complex problems in the real world and has been successfully applied to invert for seismic and electromagnetic data. In this study, we propose to use deep neural networks (DNNs) to recover the distribution of the physical properties of buried magnetic orebodies from the surface and airborne magnetic anomaly data. This approach is based on data training instead of prior-knowledge assumptions used in traditional inversion methods. Once our generalized network is established, the computing time to predict new magnetic data using this method can be significantly reduced. By implementing the forward modeling of different types of synthetic physical property models, we obtained enough datasets to train a DNN model so that the network can establish a nonlinear mapping directly from magnetic anomaly data to physical properties. The pre-trained network can be used to estimate the distribution of magnetization intensity from new input magnetic data. Two DNN structures were employed to test the feasibility and generalization of the proposed method by implementing Experiments in serval two-dimensional (2D) synthetic examples. Compared with the conventional method, the predicted distribution of magnetization intensity obtained by using our method is more concentrated and has better resolution to determine the boundary of the magnetic body. In a field example of Galinge iron ore deposits in China, the magnetization distribution of concealed iron orebodies inverted by the proposed approach was in good agreement with that detected by borehole data. DNNs have good nonlinear inversion capability and exhibit some excellent merits of strong learning ability, wide coverage and strong adaptability, which is a considerable application prospect in geophysical exploration.