Possible two-photon absorption in the near-infrared region observed by cavity ring-down spectroscopy.

Two-photon absorption spectra are difficult to observe using direct absorption spectroscopy especially in the near-infrared region. Cavity ring-down spectroscopy is a promising absorption spectroscopy technique which has been widely applied to linear and saturated single-photon absorption spectra. In the present study, we report the observation of a possible two-photon absorption in the near-infrared using cavity ring-down spectroscopy, namely a two-photon resonance of methane. Using an optical frequency comb, the single-photon wavenumber of the double-quantum transition has been determined to be 182 207 682.645 MHz with a standard deviation of 75 kHz.

Comparative pharmacokinetics and metabolites study of seven major bioactive components of Shaoyao-Gancao decoction in normal and polycystic ovary syndrome rats by ultra high pressure liquid chromatography with tandem mass spectrometry.

A simple and sensitive liquid chromatography with tandem mass spectrometry method was developed for simultaneous quantification of paeoniflorin, albiflorin, oxypaeoniflorin, liquiritin, liquiritigenin, glycyrrhetinic acid, and glycyrrhizin in rat plasma after oral administration of Shaoyao-Gancao decoction, which is traditionally used in the treatment of polycystic ovary syndrome. The plasma samples were pretreated with methanol as precipitant. The method exhibited good linearity (correlation coefficient (R2 ) > 0.99) with lower quantification limits of 0.595-4.69 ng/mL for all analytes. Intra- and interbatch precision, accuracy, recovery, and stability of the method were all within accepted criteria. The results showed that the pharmacokinetic behaviors of the seven compounds were altered in the pathological status of polycystic ovary syndrome. Furthermore, a total of 36 metabolites were structurally identified based on their accurate masses and fragment ions. The major metabolic pathway involves phase I metabolic reactions (such as hydroxylation), phase II metabolic reactions (such as sulfation and glucuronidation conjugation) as well as the combined multiple-step metabolism. This study is the first report on the pharmacokinetic and metabolic information of Shaoyao-Gancao decoction in both normal and model rats, which would provide scientific evidences for the bioactive chemical basis of herbal medicines and also promote the clinical application of Shaoyao-Gancao decoction for treating polycystic ovary syndrome.

Unraveling Special Structures and Properties of Gold-Covered Gold-Core Cage on Au33-42 Nanoparticles.

New low-energy atomic structures and properties of medium-size gold nanoparticles (Au33-42) are studied, where the atomic positions of gold atoms are obtained on the basis of the generic formulation of shell and core concept. Hollow cage, tube-like, double-layered flat, fcc-like, and close-packed configurations are predicted. Relativistic density functional theory optimization indicated that low-symmetry stuffed configurations are all lower in energy than the others. Further analysis of the optimized structures of Au33-42 nanoparticles shows that these gold cores are all four-atom tetrahedral structures and similar to each other; only the number and positions of gold atoms at the surface of gold core are different. Compared with structure and electronic properties, Au33-42 nanoparticles have different structure stabilities and chemical activities. But they are all hybridizations of sp and d electrons. The obtained information forms the basis for future chemisorption studies to unravel the catalytic effects of gold nanoparticles.

The PTEN/PI3K/Akt signaling pathway mediates HMGB1-induced cell proliferation by regulating the NF-κB/cyclin D1 pathway in mouse mesangial cells.

Our previous experiment confirmed that high-mobility group box chromosomal protein 1 (HMGB1) was involved in the pathogenesis of Lupus nephritis (LN) by upregulating the proliferation of the mouse mesangial cell line (MMC) through the cyclin D1/CDK4/p16 system, but the precise mechanism is still unknown. Therefore, in the present study, we demonstrated that HMGB1 induced the proliferation of MMC cells in a time- and concentration-dependent manner, downregulated phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression, increased the level of Akt serine 473 phosphorylation, and induced p65 subunit nuclear translocation. The overexpression of PTEN prevented the upregulation of HMGB1-induced proliferation by blocking the activation of Akt. The knockdown of Akt by siRNA technology and blocking the nuclear factor-κB (NF-κB) pathway using pyrrolidine dithiocarbamate (PDTC) and SN50, inhibitors of NF-κB, both attenuated the HMGB1-induced proliferation by counteracting the activation of the cyclin D1. In addition, while sh-Akt partly blocked the nuclear translocation of the p65 subunit, PDTC did not affect the activation of the Akt induced by HMGB1 in MMC cells. These findings indicate that HMGB1 induced the proliferation of MMC cells by activating the PTEN/phosphoinositide-3-kinase (PI3K)/Akt/NF-κB signaling pathway.

[Effect of drainage on microbial transformation processes of soil organic carbon in two typical wetlands of China]. / æŽ’æ°´å¯¹æˆ‘å›½ä¸¤ç§å ¸åž‹æ¹¿åœ°åœŸå£¤æœ‰æœºç¢³å¾®ç”Ÿç‰©è½¬åŒ–è¿‡ç¨‹çš„å½±å“.

Wetlands store one third of global soil organic carbon (SOC) and are strongly affected by artificial drainage. The impact of drainage-induced water-table decline on carbon cycling in different wetlands, particularly microbial transformation processes, remains unclear. To address this knowledge gap, we collected soil samples from two typical wetlands of China (a nutrient-poor bog located in Dajiuhu and a nutrient-rich fen in Hongyuan) and conducted an incubation experiment with the addition of 13C-labeled glucose to analyze the effects of short- and long-term drainage on SOC decomposition, extracellular enzyme activity, microbial carbon use efficiency (CUE), and microbial carbon accumulation efficiency (CAE). The results showed that both short- and long-term drainage significantly increased SOC decomposition rates in both wetlands (from 1.47 µg C·g-1·h-1 in submerged soils to 2.47 µg C·g-1·h-1 in drained soils), microbial biomass carbon derived from glucose (from 0.21 mg C·g-1 to 1.00 mg C·g-1) and CAE (from 0.29 to 0.73), but did not alter CUE (ranging from 0.34 to 0.86). Long-term drainage increased α-glucosidase activity in the Dajiuhu wetland and decreased ß-glucosidase and phenol oxidase activities in the Hongyuan wetland. In conclusion, drainage enhanced the 'microbial carbon pump' and its efficiency in wetlands mainly via increasing microbial intracellular metabolism (including respiration), but also acce-lerated SOC decomposition.

IFN-γ induces lipogenesis in mouse mesangial cells via the JAK2/STAT1 pathway.

The objective is to investigate the effect of high mobility group box-1 (HMGB1) on lipid deposition in γ-interferon (IFN-γ)-stimulated mouse mesangial cell line (MMC) and to determine whether the Janus kinase 2 and signal transducer and activator of transcription 1 (JAK2/STAT1) signaling pathway plays an important role in this process. We employed a control group, an IFN-γ stimulation group, and an IFN-γ + AG490 (JAK2 inhibitor) group. RNA interference aimed at sterol regulatory element-binding protein-1 (SREBP-1) or HMGB1 was used to investigate the effect of these proteins on IFN-γ-induced lipid deposition. Western blotting was used to detect phospho (p)-JAK2, JAK2, p-STAT1, STAT1, SREBP-1, fatty acid synthase (FAS), and HMGB1 protein expression. RT-PCR was used to detect SREBP-1, FAS, and HMGB1 mRNA. Oil Red O staining and the triglyceride assay were used to detect lipid deposition and triglyceride content. Results were as follows: 1) IFN-γ increased MMC cell lipid deposition, triglyceride content, and p-JAK2, p-STAT1, SREBP-1, and FAS expression; 2) SREBP-1 inhibition prevented FAS upregulation and attenuated IFN-γ-induced MMC cell lipid deposition and triglyceride content; 3) HMGB1 upregulated SREBP-1 and FAS mRNA and protein levels, which increased lipid deposition in MMC cells. Small interfering RNA-mediated inhibition of HMGB1 decreased SREBP-1 and FAS expression and lipid accumulation; 4) AG490 decreased upregulation of HMGB1 and p-JAK2/p-STAT1, as well as IFN-γ-induced lipogenesis. In conclusion, the JAK2/STAT1 pathway mediates IFN-γ-induced lipogenesis in MMC cells through regulation of HMGB1/SREBP-1/FAS.

Glomus mosseae improved the adaptability of alfalfa (Medicago sativa L.) to the coexistence of cadmium-polluted soils and elevated air temperature.

The coexistence of heavy metal-polluted soils and global warming poses serious threats to plants. Many studies indicate that arbuscular mycorrhizal fungi (AMF) can enhance the resistance of plants to adverse environments such as heavy metals and high temperature. However, few studies are carried out to explore the regulation of AMF on the adaptability of plants to the coexistence of heavy metals and elevated temperature (ET). Here, we investigated the regulation of Glomus mosseae on the adaptability of alfalfa (Medicago sativa L.) to the coexistence of cadmium (Cd)-polluted soils and ET. G. mosseae significantly enhanced total chlorophyll and carbon (C) content in the shoots by 15.6% and 3.0%, respectively, and Cd, nitrogen (N), and phosphorus (P) uptake by the roots by 63.3%, 28.9%, and 85.2%, respectively, under Cd + ET. G. mosseae significantly increased ascorbate peroxidase activity, peroxidase (POD) gene expression, and soluble proteins content in the shoots by 13.4%, 130.3%, and 33.8%, respectively, and significantly decreased ascorbic acid (AsA), phytochelatins (PCs), and malondialdehyde (MDA) contents by 7.4%, 23.2%, and 6.5%, respectively, under ET + Cd. Additionally, G. mosseae colonization led to significant increases in POD (13.0%) and catalase (46.5%) activities, Cu/Zn-superoxide dismutase gene expression (33.5%), and MDA (6.6%), glutathione (22.2%), AsA (10.3%), cysteine (101.0%), PCs (13.8%), soluble sugars (17.5%), and proteins (43.4%) contents in the roots and carotenoids (23.2%) under ET + Cd. Cadmium, C, N, G. mosseae colonization rate, and chlorophyll significantly influenced shoots defenses and Cd, C, N, P, G. mosseae colonization rate, and sulfur significantly affected root defenses. In conclusion, G. mosseae obviously improved the defense capacity of alfalfa under ET + Cd. The results could improve our understanding of the regulation of AMF on the adaptability of plants to the coexistence of heavy metals and global warming and phytoremediation of heavy metal-polluted sites under global warming scenarios.

Oridonin Attenuates TNBS-induced Post-inflammatory Irritable Bowel Syndrome via PXR/NF-κB Signaling.

To investigate the beneficial effects of oridonin, a diterpenoid compound isolated from Rabdosia rubescens, on the inflammatory response in TNBS-induced post-inflammatory irritable bowel syndrome (PI-IBS) model and the underlying mechanism. Using the PI-IBS rat model and Caco-2 cell lines, we found that intestinal barrier function reflected by lactulose/mannitol (L/M) ratio and tight junction protein level was significantly ameliorated by oridonin. We also demonstrated that oridonin abrogated inflammation through inhibiting the phosphorylation of NF-κBp65 as well as its downstream gene (iNOS, COX-2, IL-1ß, and IL-6) level. Molecular docking studies confirmed the good binding activity between oridonin and PXR. In Caco-2 cell lines, oridonin markedly inhibited LPS-induced NF-κB activation in a PXR-dependent manner. Meanwhile, PXR and its target genes CYP3A4 and P-gp were induced by oridonin, which was associated with the decreased expression of NF-κB and the recovery of intestinal barrier. This study indicated that the therapeutic effect of oridonin on experimental PI-IBS through repairing intestinal barrier function may be closely associated with the regulatory role of PXR/NF-κB signaling pathway. Oridonin may serve as a PXR ligand for the development of drugs in the therapy for PI-IBS.

Shaoyao-Gancao Decoction Relieves Visceral Hyperalgesia in TNBS-Induced Postinflammatory Irritable Bowel Syndrome via Inactivating Transient Receptor Potential Vanilloid Type 1 and Reducing Serotonin Synthesis.

Postinflammatory irritable bowel syndrome (PI-IBS) is a common functional gastrointestinal disorder, which is characterized by abdominal pain, low-grade inflammation, and visceral hypersensitivity. Shaoyao-Gancao decoction (SGD) has been used to improve the clinical symptoms of abdominal spasmodic pain accompanying acute gastroenteritis, but the underlying therapeutic mechanism has not been fully elucidated. In the present study, a rat model of PI-IBS was established via rectal administration of TNBS. Rats were scored daily for 28 days using disease activity index (DAI). Abdominal withdrawal reflex (AWR) was used to measure the pain threshold. After SGD (6.25, 12.5, and 25 g/kg/d) treatment for 14 days, rat colonic tissue was collected for histopathological grading, enterochromaffin (EC) cell count, and 5-HT content measurement. RT-qPCR and western blot analyses were employed to detect the gene and protein level of tryptophan hydroxylase (TPH), serotonin reuptake transporter (SERT), and transient receptor potential vanilloid 1 (TRPV1). To further validate the effect of SGD on TRPV1, another experiment was performed in cells. The results revealed that visceral hyperalgesia, reflected by increased DAI, AWR, pathological injury score, 5-HT content, and EC cell count in PI-IBS rats, was significantly ameliorated by SGD. In cells, SGD markedly inhibited the expression and function of TRPV1. Moreover, the expression levels of TPH were also repressed by SGD. The findings of the present study indicated that the therapeutic effect of SGD on visceral hyperalgesia may be closely associated with the regulatory role of TRPV1 and 5-HT signaling pathways.

Shaoyao-Gancao Decoction alleviated hyperandrogenism in a letrozole-induced rat model of polycystic ovary syndrome by inhibition of NF-κB activation.

Shaoyao-Gancao Decoction (SGD) has been widely used for the treatment of gynopathy. The present study aimed to evaluate the therapeutic effect and potential mechanism of SGD on hyperandrogenism in polycystic ovary syndrome (PCOS) rats. In the present work, SGD was orally administrated to the PCOS rats at the dose of 12.5, 25, and 50 g/kg/d for 14 consecutive days. UPLC-MS/MS was performed to identify the main chemical components of SGD. Body weight, ovarian weight, cystic dilating follicles, and serum levels of steroid hormones were tested to evaluate the therapeutic effect of SGD. In order to further clarify the underlying mechanism, we also measured mRNA and the protein levels of NF-κB, NF-κB p65, P-NF-κB p65, and IκB by RT-qPCR and Western blotting techniques. Our results showed that SGD treatment significantly alleviated hyperandrogenism in PCOS rats as evidenced by reduced serum levels of T and increased E2 and FSH levels. In addition, SGD effectively reduced the phosphorylation of NF-κB p65 and increased the expression of IκB. Results of the present study demonstrated that SGD could ameliorate hyperandrogenism in PCOS rats, and the potential mechanism may relate to the NF-κB pathway.

Soil gross nitrogen transformations along the Northeast China Transect (NECT) and their response to simulated rainfall events.

Climate changes are predicted to increase extreme rainfall events in semiarid and arid region in Northern Hemisphere. Nutrient cycles will be affected by the precipitation changes but so far only very little is known how soil N transformations may respond. Here we investigated gross soil N transformation rates and their response to simulated rainfall events across Northeast China Transect (NECT). The results showed that gross N mineralisation rate, nitrification rate and nitrification to mineralisation ratio significantly increased as the humidity index decreased along NECT, resulting in NO3(-) as the predominant inorganic N form. These characteristics could increase the risk of NO3(-) losses but at the same time reduce the risk of N losses via volatilization in the semiarid and arid region. The soil-plant ecosystems have developed effective N conservation strategies in the long term with respect to the prevailing climate in arid region. However, compared to humid soils more dramatic changes of soil N transformation rates are likely to occur in arid soils, after sudden soil moisture increases. Soil N conservation mechanisms in arid regions were drastically affected when the heavy rainfall frequently occurred. Arid ecosystems are expected to be more vulnerable than humid ecosystems in response to extreme rainfall events.

TLR2 Plays a Critical Role in HMGB1-Induced Glomeruli Cell Proliferation Through the FoxO1 Signaling Pathway in Lupus Nephritis.

The objective of this study was to examine the role and possible mechanisms of toll-like receptor 2 (TLR2) in high-mobility group box chromosomal protein 1 (HMGB1)-induced mouse mesangial cell (MMC) proliferation and glomeruli proliferation of MRL/Fas(lpr) mice. First, the expression of proliferating cell nuclear antigen (PCNA), TLR2 and Forkhead box protein O1 (FoxO1) messenger RNA (mRNA) and protein in the glomeruli of MRL/Fas(lpr) mice was quantified, and the correlation with cell proliferation of glomeruli was analyzed. Then, lipopolysaccharide (LPS), TLR2 neutralization antibody, and small hairpin TLR2 (shTLR2) were used to confirm the role of TLR2 in HMGB1-induced MMC proliferation. Furthermore, wild-type FoxO1 (WT-FoxO1) vector was used to investigate the effect of FoxO1 pathway on HMGB1-induced MMC proliferation. Finally, electroporation was used to knockdown TLR2 in the glomeruli of MRL/Fas(lpr) mice, and renal function, FoxO1, and PCNA expression were detected. The results showed that the TLR2 expression was upregulated and FoxO1 expression was decreased in the glomeruli of MRL/Fas(lpr) mice, and these effects were significantly correlated with cell proliferation of the glomeruli. In vitro, the TLR2 neutralization antibody and the WT-FoxO1 vector, both reduced the MMC proliferation levels induced by HMGB1. The TLR2 neutralization antibody also blocked the HMGB1-dependent activation of the FoxO1 pathway and cell proliferation. In addition, transfection with shTLR2 decreased the proliferation levels and PCNA expression induced by HMGB1. In vivo, treatment with shTLR2 significantly reduced the PCNA expression in the glomeruli of MRL/Fas(lpr) mice and improved renal function. In addition, treatment with shTLR2 or blocking of TLR2 also reduced the translocation of FoxO1. Thus, TLR2 plays a critical role in HMGB1-induced glomeruli cell proliferation through the FoxO1 signaling pathway in lupus nephritis.

Structure and stability of Al-doped boron clusters by the density-functional theory.

The geometries, stabilities, and electronic properties of Bn and AlBn clusters, up to n=12, have been systematically investigated by using the density-functional approach. The results of Bn clusters are in good agreement with previous conclusions. When the Al atom is doped in Bn clusters, the lowest-energy structures of the AlBn clusters favor two-dimensional and can be obtained by adding one Al atom on the peripheral site of the stable Bn when n