Elevated Mercury Deposition, Accumulation, and Migration in a Karst Forest.

The karst forest is one of the extremely sensitive and fragile ecosystems in southwest China, where the biogeochemical cycling of mercury (Hg) is largely unknown. In this study, we investigated the litterfall deposition, accumulation, and soil migration of Hg in an evergreen-deciduous broadleaf karst forest using high-resolution sampling and stable isotope techniques. Results show that elevated litterfall Hg concentrations and fluxes in spring are due to the longer lifespan of evergreen tree foliage exposed to atmospheric Hg0. The hillslope has 1-2 times higher litterfall Hg concentration compared to the low-lying land due to the elevated atmospheric Hg levels induced by topographical and physiological factors. The Hg isotopic model suggests that litterfall Hg depositions account for ∼80% of the Hg source contribution in surface soil. The spatial trend of litterfall Hg deposition cannot solely explain the trend of Hg accumulation in the surface soil. Indeed, soil erosion enhances Hg accumulation in soil of low-lying land, with soil Hg concentration up to 5-times greater than the concentration on the hillslope. The high level of soil Hg migration in the karst forest poses significant ecological risks to groundwater and downstream aquatic ecosystems.

Nanopolyphenol rejuvenates microglial surveillance of multiple misfolded proteins through metabolic reprogramming

Microglial surveillance plays an essential role in clearing misfolded proteins such as amyloid-beta, tau, and α-synuclein aggregates in neurodegenerative diseases. However, due to the complex structure and ambiguous pathogenic species of the misfolded proteins, a universal approach to remove the misfolded proteins remains unavailable. Here, we found that a polyphenol, α-mangostin, reprogrammed metabolism in the disease-associated microglia through shifting glycolysis to oxidative phosphorylation, which holistically rejuvenated microglial surveillance capacity to enhance microglial phagocytosis and autophagy-mediated degradation of multiple misfolded proteins. Nanoformulation of α-mangostin efficiently delivered α-mangostin to microglia, relieved the reactive status and rejuvenated the misfolded-proteins clearance capacity of microglia, which thus impressively relieved the neuropathological changes in both Alzheimer's disease and Parkinson's disease model mice. These findings provide direct evidences for the concept of rejuvenating microglial surveillance of multiple misfolded proteins through metabolic reprogramming, and demonstrate nanoformulated α-mangostin as a potential and universal therapy against neurodegenerative diseases.

[Seasonal Variation and Sources Identification of Dissolved Sulfate in a Typical Karst Subterranean Stream Basin Using Sulfur and Oxygen Isotopes].

Karst water, which provides approximately 25% of the world's drinking water, is especially vulnerable to anthropogenic pollutants. To determine the variations between high and low flow periods and the sources of dissolved sulfate (SO42-) in small karst basins, SO42- concentrations, stable sulfur and oxygen isotopes (δ34S-SO4 and δ18O-SO4), and oxygen isotopes of water (δ18O-H2O) were investigated in surface and groundwaters, during the high and low flow seasons, within the Babu subterranean stream basin. Analysis showed that: ① the water samples that were directly impacted by acid mine drainage exhibited high SO42- concentrations (≥250 mg·L-1) and significant seasonal variation, while the seasonal variation of non-AMD-impacted water with low SO42- concentrations was not significant. ② During the high flow season, the mean δ34S-SO4 and δ18O-SO4 values of surface water were -10.5‰ and 4.7‰, respectively, and -11.5‰ and 1.3‰ during the low flow period; the mean values of δ34S-SO4 and δ18O-SO4 in groundwater samples were -2.9‰ and 7.1‰ during the high flow period, respectively, and -3.2‰ and 6.2‰ during the low flow period. Both surface and groundwater samples exhibited higher δ34S-SO4 and δ18O-SO4 values during the high flow period than during the low flow period. ③ The values of δ34S-SO4 in the surface and groundwater samples were relatively stable, indicating that the sources of SO42- at specific sampling sites were stable.④ The main sources of SO42- in surface and groundwaters were rain, sulfide, and gypsum, accounting for 13%, 40%, and 47%, respectively, of SO42- in samples taken from the basin outlet during the high flow season, and 18%, 39%, and 43%, respectively, in samples obtained during the low flow season.

[Therapeutic effect and mechanism of three kinds of Dendrobium on constipation in rats with spleen Yin deficiency].

Books on Chinese herbal medicines have shown that Dendrobium has the effect of nourishing Yin and reinforcing Yin,usually used for constipation induced by spleen Yin deficiency in clinical application. D. huoshanense,as an independent species among many species of Dendrobium,has no experimental studies about its effects on spleen Yin deficiency-type constipation. The purpose of this experiment was to illustrate the therapeutic effect of D. huoshanense on the constipation of spleen Yin deficiency type in rats,investigate its preliminary mechanism,and compare it with the D. officinale and D. nobile contained in the Chinese Pharmacopoeia to clarify its characteristics. The spleen Yin deficiency model was replicated in 70 rats by the composite factor method,and then the model rats were randomly divided into 7 groups: model group,Liuwei Dihuang Pills group( LWDHP),D. huoshanense high( DHS-H),medium( DHS-M),low( DHS-L) dose groups,D. nobile group( DNS),and D. officinale group( DOS),and another 10 rats were used as normal group( Normal). After 7 continuous days of administration,the fecal water content and intestine propulsion rate of each group were detected. HE staining was used to observe the pathological damage of ileum and colon in each group. Immunohistochemistry and Western blot were used to detect aquaporin 3( AQP3) expressions,while the expression levels of the somatostatin( SS) and motilin( MTL) in the ileum of each group were detected by enzyme-linked immunosorbent assay. The results showed that as compared with the model group,the rats in each drug-administered group had increased number of fecal pellets,increased fecal water content,and the increased intestinal propulsion rate( P<0. 01),while the pathological damage of the ileum and colon was significantly reduced; the expression of AQP3 protein was significantly decreased( P<0. 01); the level of MTL was significantly increased and the level of SS was decreased( P<0. 01). All DHS groups showed a good dose-effect relationship,and the same dose treatment effect was equivalent to that of DOS,but it was superior to DNS. Therefore,DHS has a significant therapeutic effect on constipation of spleen Yin deficiency type,and its mechanism may be related to intestinal motility and water-liquid metabolism,with a good therapeutic effect.

Research progress in immunotherapy for glioblastoma / 药学学报

Glioma is the most common primary intracranial tumor, among which glioblastoma (GBM) is the most malignant subtype. Because of its high heterogeneity and invasiveness, GBM can't be completely removed by surgical resection and is also resistance to chemotherapy and radiotherapy. Even after a standard therapy, the median survival time is only 14.6 months, the five-year survival rate is less than 10%, and the relapse of GBM is common. Immunotherapy, a new treatment paradigm, treats cancer through regulating the autologous immune system and the tumor microenvironment. As a promising method to improve the prognosis of GBM, immunotherapy has attracted more and more attention. This paper gives a review to the difficulty, the mainly existing strategies and the bottlenecks in GBM immunotherapy, aiming at providing new direction to improve the prognosis of GBM patients.

[Cloning, fusion expression and identification of thioredoxin encoding gene from Toxoplasma gondii].

OBJECTIVE: To clone and express the thioredoxin (Trx) from RH strain tachyzoites of Toxoplasma gondii, establish the prokaryotic expression vector and purify the recombinant protein, then produce the polyclonal anti-Trx antibody in rabbits. METHODS: Trx fragment was amplified by PCR and cloned into the pET-28a (+) vector, and the recombinant protein was induced with IPTG and purified by Ni-NTA affinity chromatography. The polyclonal antibody specificity was detected by Western blotting. RESULTS: The trx gene was amplified from T. gondii cDNA by PCR. The recombinant plasmid trx/pET-28a (+) was usefully constructed, and the recombinant TRX protein was expressed and purified. The TRX polyclonal antibody was also obtained. The specific band of TRX was detected by Western blotting. CONCLUSIONS: Western blotting can detect the specificity of polyclonal anti-Trx antibody, which will facilitate the biological functions of Trx.

[The study on techniques for monitoring intraocular pressure].

This paper aims at providing an up-to-date review of principle and application of various tonometers, and analyzes the new techniques of diurnal IOP monitoring and design of sensor system abroad. Requirements and test methods for GB/T 14710-93.