Novel racemosin B derivatives as new therapeutic agents for aggressive breast cancer.

Carbazole derivatives show anti-cancer activity and are of great interest for drug development. In this study, we synthesized and analyzed several new alkylamide derivatives of racemocin B, a natural indolo[3,2-a]carbazole molecule originally isolated from the green alga Caulerpa racemose. Several alkylamide derivatives were found to exhibit moderate to strong growth inhibition against human breast cancer cell lines. They induced G2/M cell cycle arrest and apoptosis in the aggressive triple-negative breast cancer cell line MDA-MB-231. Among these derivatives, compound 25 with the lowest IC50 induced cell death by suppressing autophagy. This was accompanied by inhibition of autophagic flux and accumulation of autophagy protein 1 light chain 3, LC3II, and p62. The novel alkylamide derivative offers a potential new treatment for human breast cancer.

[Summarize drug dosage forms in treatment of age-related macular degeneration disease].

In this review, the authors summarized the drugs in treatment of the age-related macular degeneration (AMD or ARMD), including the pathogenesis of the age-related macular degeneration at home and abroad, dosage forms used in the treatment, and the drugs research and development directions in the future. AMD disease is the third largest blinding diseases all over the world, with an incidence of 6.62%. The dosage form of the traditional medicine is mostly oral formulations, playing a role in body, while the newly dosage form is topical drug delivery formulation. Traditional Chinese medicine (TCM) has certain advantages in the treatment of AMD disease and the development of topical drug delivery preparations with newly preparation technologies would have a very bright prospect in the future.

Uralsaponins M-Y, antiviral triterpenoid saponins from the roots of Glycyrrhiza uralensis.

Thirteen new oleanane-type triterpenoid saponins, uralsaponins M-Y (1-13), and 15 known analogues (14-28) were isolated from the roots of Glycyrrhiza uralensis Fisch. The structures of 1-13 were identified on the basis of extensive NMR and MS data analyses. The sugar residues were identified by gas chromatography and ion chromatography coupled with pulsed amperometric detection after hydrolysis. Saponins containing a galacturonic acid (1-3) or xylose (5) residue are reported from Glycyrrhiza species for the first time. Compounds 1, 7, 8, and 24 exhibited good inhibitory activities against the influenza virus A/WSN/33 (H1N1) in MDCK cells with IC50 values of 48.0, 42.7, 39.6, and 49.1 µM, respectively, versus 45.6 µM of the positive control oseltamivir phosphate. In addition, compounds 24 and 28 showed anti-HIV activities with IC50 values of 29.5 and 41.7 µM, respectively.

[Effect of Film Mulching Age and Organic Fertilizer Application on the Distribution Characteristics of Microplastics in the Soil of a Peanut Field].

The large input of mulch film and organic fertilizer have led to increasingly serious microplastic pollution in farmland soil of China. In this study, the microplastic pollution of peanut farmland in Dezhou City, Shandong Province was investigated. The effects of different mulching years (0, 3, 5, and 8 years) and organic fertilizer application on the abundance, particle size, color, and shape of microplastics in farmland soil were analyzed. The results showed that the average abundances of microplastics in peanut soil were 65.33, 316.00, 1 098.67, and 1 346.34 n·kg-1, respectively, after 0, 3, 5, and 8 years of film mulching. The abundance of microplastics decreased with the increase in soil depth. The abundance of microplastics in 0-10, 10-20, and 20-30 cm topsoil was 1 076.00, 603.5, and 440.25 n·kg-1, respectively, and the abundance of microplastics increased significantly with increasing years of film mulching and organic fertilizer application (P<0.05). The particle size of microplastics in the sample plot <1 mm accounted for 77.30% of the total content, and with the increase in film mulching age, the proportion of microplastics with small particle size (<1 mm) increased significantly (P < 0.05). With the increase in soil depth, the proportion of microplastics with small particle size also gradually increased, whereas the application of organic fertilizer had no significant effect on the particle size of microplastics. The color of microplastics in the plot was mainly transparent (49.77%), followed by black (16.35%) and white (16.27%). The planting age and organic fertilizer application had no significant effect on the color of microplastics in the soil (P > 0.05), but the mulching age significantly increased the proportion of transparent microplastics. The abundance proportion of the five types of microplastics were 49.77%, 25.41%, 19.15%, 3.26%, and 2.41%, respectively. These field soil microplastics were mainly composed of polyethylene (PE), polypropylene (PP), and polystyrene (PS) polymers, accounting for 21.37%, 18.57%, and 19.77% of the total, respectively. Therefore, microplastics were widely present in the soil of the peanut field cultivated layer in Dezhou, Shandong, and the applications of mulch film and organic fertilizer were the main source. This study provides an important basis for the prevention and control of soil microplastic pollution in peanut fields.

Efficacy of Qingpeng ointment (a Tibetan medicine) for acute gouty arthritis: a multi-center, randomized, double-blind, placebo-controlled trial.

BACKGROUND: This study aims to assess the efficacy and safety of Qingpeng ointment (QPO), a Tibetan medicine for alleviating symptoms in individuals with acute gouty arthritis (AGA). METHODS: This study was a randomized, double-blind, placebo-controlled trial that involved individuals with AGA whose joint pain, as measured on a visual analog scale (VAS) from 0 to 10, was equal to or greater than 3. The participants were randomly assigned to either the QPO or the placebo group and received their respective treatments twice daily for seven consecutive days. In case of intolerable pain, the participants were allowed to use diclofenac sodium sustained-release tablets as a rescue medicine. The primary outcomes measured were joint pain and swelling, while the secondary outcomes included joint mobility, redness, serum uric acid levels, C-reactive protein levels, and the amount of remaining rescue medicine. Any adverse events that occurred during the trial were also recorded. RESULTS: A total of 203 cases were divided into two groups, with balanced baselines: 102 in the QPO group and 101 in the placebo group. For joint pain, differences between the groups were notable in the VAS scores [1.75 (0, 3.00) versus 2.00 (1.00, 3.50); P = 0.038], changes in VAS [5.00 (3.00, 6.00) versus 4.00 (2.00, 6.00); P = 0.036], and disappearance rate [26.47% compared to 15.84%; P = 0.046] after treatment. Concerning joint swelling, significant between-group differences were observed in the VAS scores [1.00 (0, 2.30) versus 2.00 (0.70, 3.00); P = 0.032] and disappearance rate [33.33% compared to 21.78%; P = 0.046] at treatment completion. The QPO group exhibited a statistically significant mobility improvement compared to the placebo group (P = 0.004). No significant differences were found in other secondary outcomes. Five patients, four from the QPO group and one from the other, encountered mild adverse events, primarily skin irritation. All of these cases were resolved after dosage reduction or discontinuation of the medication. CONCLUSIONS: Compared to the placebo, QPO exhibits positive effects on AGA by alleviating pain, reducing swelling, and enhancing joint mobility, without causing significant adverse effects. TRIAL REGISTRATION: ISRCTN34355813. Registered on 25/01/2021.

The effect of Chinese Jinzhida recipe on the hippocampus in a rat model of diabetes-associated cognitive decline.

BACKGROUND: To investigate the effects of treatment with Multi component Chinese Medicine Jinzhida (JZD) on behavioral deficits in diabetes-associated cognitive decline (DACD) rats and verify our hypothesis that JZD treatment improves cognitive function by suppressing the endoplasmic reticulum stress (ERS) and improving insulin signaling transduction in the rats' hippocampus. METHODS: A rat model of type 2 diabetes mellitus (T2DM) was established using high fat diet and streptozotocin (30 mg/kg, ip). Insulin sensitivity was evaluated by the oral glucose tolerance test and the insulin tolerance test. After 7 weeks, the T2DM rats were treated with JZD. The step-down test and Morris water maze were used to evaluate behavior in T2DM rats after 5 weeks of treatment with JZD. Levels of phosphorylated proteins involved in the ERS and in insulin signaling transduction pathways were assessed by Western blot for T2DM rats' hippocampus. RESULTS: Compared to healthy control rats, T2DM rats initially showed insulin resistance and had declines in acquisition and retrieval processes in the step-down test and in spatial memory in the Morris water maze after 12 weeks. Performance on both the step-down test and Morris water maze tasks improved after JZD treatment. In T2DM rats, the ERS was activated, and then inhibited the insulin signal transduction pathways through the Jun NH2-terminal kinases (JNK) mediated. JZD treatment suppressed the ERS, increased insulin signal transduction, and improved insulin resistance in the rats' hippocampus. CONCLUSIONS: Treatment with JZD improved cognitive function in the T2DM rat model. The possible mechanism for DACD was related with ERS inducing the insulin signal transduction dysfunction in T2DM rats' hippocampus. The JZD could reduce ERS and improve insulin signal transduction and insulin resistance in T2DM rats' hippocampus and as a result improved the cognitive function.

[An epidemiological survey of snoring disease and OSAHS among 374 truck drivers in Guangzhou, China].

OBJECTIVE: To investigate the prevalence rates of snoring disease and obstructive sleep apnea-hypopnea syndrome (OSAHS) and their risk factors among truck drivers in Guangzhou, China. METHODS: A questionnaire survey was conducted in 374 truck drivers who were selected from 5 logistics companies in Guangzhou by cluster sampling. Those who had potential snoring disease or OSAHS underwent polysomnographic monitoring at night. The obtained data were analyzed to calculate the prevalence rates of snoring disease and OSAHS and determine the risk factors for OSAHS. RESULTS: A total of 335 subjects completely questionnaires, with a response rate of 90%. Among the 335 subjects, 125 (37.3%) had habitual snoring, and 42 (12.5%) had OSAHS according to the diagnostic criterion (apnea-hypopnea index ≥ 5 times/h). The multiple stepwise regression analysis showed that the risk factors for OSAHS were age, alcohol use, family history of snoring, body mass index, and upper airway abnormality. Of the subjects with grade ≥ 2 snoring and OSAHS, 65.4% often felt sleepy when driving during daytime, and 42% had suffered or nearly suffered traffic accidents due to sleepiness when driving. Moreover, 95.5% (320) of the 335 truck drivers did not consider snoring a disease, and 98% did not think traffic accident might be related to snoring. CONCLUSION: The prevalence rates of snoring disease and OSAHS among truck drivers are 37.3% and 12.5%, respectively. Therefore, prevention measures should be established according to the epidemiological characteristics to help the truck drivers realize the hazards of snoring disease and OSAHS, thus minimizing the prevalence and hazards of the diseases.

A novel seed cone of Pinus from the Miocene of coastal Southeast China indicates kinship with Southeast Asian pines.

Pinus is an economically and ecologically important genus whose members are dominant components globally in low-latitude mountainous and mid-latitude temperate forests. Pinus species richness is currently concentrated in subtropical mid-low latitudes of the Northern Hemisphere, differing from the latitudinal diversity gradient mostly recognized in woody angiosperms. How the present pattern was developing in Earth's past is still poorly studied, particularly in eastern Asia. Here, a new fossil species, Pinus shengxianica sp. nov. is described based on a fossil seed cone from the Late Miocene Shengxian Formation in Zhejiang, southeast China. A co-occurring cone is recognized as a known fossil species, Pinus speciosa Li. Extensive comparison of extant and fossil members of Pinus suggests P. shengxianica shares a striking cone similarity to Pinus merkusii and Pinus latteri (subsection Pinus) from tropical Southeast Asia in having annular bulges around the umbo on the apophysis. The morphological resemblance indicates these two extant low-latitude pines probably possess a close affinity with the present newly-discovered P. shengxianica and originated from East Asian mid-low latitude ancestors during this generic re-diversification in the Miocene. This scenario is consistent with the evolutionary trajectory reflected by the pine fossil history and molecular data, marking the Miocene as a key period for the origin and evolution of most extant pines globally. The co-occurrences of diverse conifers and broadleaved angiosperms preferring diverse niches demonstrate Late Miocene eastern Zhejiang was one of the hot spots for coniferophyte diversity and hosted a needled-broadleaved mixed forest with complex vegetation structure and an altitudinal zonation.

[Effects of zibu piyin recipe on the insulin resistance in the hippocampus of pi-yin deficiency diabetic rats].

OBJECTIVE: To study the protection of Zibu Piyin Recipe (ZBPYR) on the insulin signal pathway in the hippocampus of Pi-yin deficiency diabetic encephalopathy rats and to explore its possible mechanisms. METHODS: The type 2 diabetic model was established using high fat diet and intraperitoneal injection of small dose streptozotocin (STZ). The Pi-yin deficiency model was established referring to classic compound factors. The learning and memory capabilities were tested in rats by the behavioral changes. The protein expressions of hippocampal IRE1alpha, JNK, and IRS-1 were detected using Western blot. RESULTS: There was statistical difference in the learning and memory capabilities of Pi-yin deficiency rats when compared with the blank control group (P<0.05). The learning and memory capabilities could be improved by ZBPYR. The protein expressions of hippocampal phospho-IRS-1, phospho-JNK, and total IRE1alpha were enhanced (P<0.05). But they were weakened after treatment of ZBPYR. CONCLUSIONS: ZBPYR could significantly improve the learning and memory capabilities of Pi-yin deficiency diabetic rats. Its functions might be correlated with improving the endoplasmic reticulum stress to regulate the insulin signaling pathway.

Genetic, environmental and other risk factors for progression of retinitis pigmentosa.

Retinitis pigmentosa (RP) is a commonly inherited disease of the retina, which is characterized by progressive loss of visual function due to specific genetic mutations. There are many risk factors that may have effect on the progression of RP, such as inheritance patterns, genotype, gender, age, smoking, physical activity, and other demographic and environmental factors. Baseline visual field conditions, changes of ellipsoid zone, photoreceptor layer thickness, and choroidal structure are reported to be the phenotype risk factors for RP progression. Moreover, aqueous flare and high-sensitivity C-reactive protein are probable inflammation biomarkers for assessing the progression of RP. Increased oxidative stress is considered to be one of the potential factors for the existence of RP. The risk factors can be combined to form a corresponding prediction model to predict disease progression. This review is to summarize the current literature that studies the genetic, environmental, phenotypic, demographic, inflammatory and other risk factors of RP progression and discuss the most reliable risk factors that could provide predictive models.

Salvianolic Acid A Protects Neonatal Cardiomyocytes Against Hypoxia/Reoxygenation-Induced Injury by Preserving Mitochondrial Function and Activating Akt/GSK-3ß Signals.

OBJECTIVE: To investigate the effects of salvianolic acid A (SAA) on cardiomyocyte apoptosis and mitochondrial dysfunction in response to hypoxia/reoxygenation (H/R) injury and to determine whether the Akt signaling pathway might play a role. METHODS: An in vitro model of H/R injury was used to study outcomes on primary cultured neonatal rat cardiomyocytes. The cardiomyocytes were treated with 12.5, 25, 50 µg/mL SAA at the beginning of hypoxia and reoxygenation, respectively. Adenosine triphospate (ATP) and reactive oxygen species (ROS) levels were assayed. Cell apoptosis was evaluated by flow cytometry and the expression of cleaved-caspase 3, Bax and Bcl-2 were detected by Western blotting. The effects of SAA on mitochondrial dysfunction were examined by determining the mitochondrial membrane potential (△Ψm) and mitochondrial permeability transition pore (mPTP), followed by the phosphorylation of Akt (p-Akt) and GSK-3ß (p-GSK-3ß), which were measured by Western blotting. RESULTS: SAA significantly preserved ATP levels and reduced ROS production. Importantly, SAA markedly reduced the number of apoptotic cells and decreased cleaved-caspase 3 expression levels, while also reducing the ratio of Bax/Bcl-2. Furthermore, SAA prevented the loss of △Ψm and inhibited the activation of mPTP. Western blotting experiments further revealed that SAA significantly increased the expression of p-Akt and p-GSK-3ß, and the increase in p-GSK-3ß expression was attenuated after inhibition of the Akt signaling pathway with LY294002. CONCLUSION: SAA has a protective effect on cardiomyocyte H/R injury; the underlying mechanism may be related to the preservation of mitochondrial function and the activation of the Akt/GSK-3ß signaling pathway.

Contribution of Borneolum syntheticum to the Intervention Effect of Liuwei Dihuang Pill () on Experimental Retinal Degeneration.

OBJECTIVE: To observe the contribution of Borneolum syntheticum to the intervention effect of Liuwei Dihuang Pill (, LDP) on experimental retinal degeneration, and initially investigate the mechanism of Borneolum syntheticum as meridian-lead-in drug. METHODS: A total of 180 sodium iodateinduced retinital degeneration rats were randomly divided into three groups, including distilled water group, LDP group, and LDP+Borneolum syntheticum (LDP+BS) group. Twenty normal rats were fed regularly without any treatment as normal control. On day 7 and 14 after treatment, histopathological study and transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) test were performed to evaluate the retinopathy. Claudin-5 expression at blood-retina barrier (BRB) was detected by Western blot at different time points from 0.5 to 8 h after gavage. RESULTS: On day 7 and 14 after treatment, the retinal lesion grades were significantly different among the three groups (P<0.05). The grade in the LDP+BS group was significantly less than the LDP and distilled water groups (both P<0.05), no significant difference was observed between the LDP and distilled water groups (P>0.05). The apoptosis rates in the LDP+BS group was significantly less than the distilled water and LDP groups (both P<0.05), while there was no significant difference between LDP and distilled water groups (P>0.05). Expression of claudin-5 in LDP+BS group was significantly less than the other two groups at 0.5, 1 and 2 h after gavage (P<0.05). There was no apparent difference among the three groups at 4 and 8 h after gavage (P>0.05). CONCLUSION: Borneolum syntheticum could strengthen the effect of LDP on experimental retinal degeneration, indicated that Borneolum syntheticum might play the role of meridian-lead-in drug in the formula. The mechanism may be due to Borneolum syntheticum could promote the physiologically openness of bloodretina barrier through transiently affecting the expression of claudin-5.

Evaluating the Efficacy and Adverse Effects of Clearing Heat and Removing Dampness Method of Traditional Chinese Medicine by Comparison with Western Medicine in Patients with Gout.

Objective. In China, the method of clearing heat and removing dampness medicine of Chinese traditional medicine has been widely used on gout. However, the clinical effects are various and not summarized systematically. Methods. In this study, a large number of randomized controlled clinical trials were reviewed and analyzed and the clinical efficacy and adverse reactions of traditional Chinese medicine with clearing heat and removing dampness effects for the treatment of gout were systematically evaluated. A comprehensive search of databases including pubMed, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, Wanfang Data, and SinoMed was performed. Results. There are 69 randomized controlled trials with 5915 sample sizes meeting the criteria in the study. The results of the meta-analysis indicate that the effects of clearing heat and removing dampness medicine were slightly better than western medicine in the treatment of gout based on the following parameters: serum uric acid (standardized mean difference (SMD):-62.14, 95% confidence interval (CI): -78.12 to-46.15), C reactive protein (SMD: -4.21, 95% CI: -6.19 to -2.23), erythrocyte sedimentation rate (SMD: -6.23, 95% CI: -8.39 to-4.06), and overall clinical response (relative risk (RR): 1.11, 95% CI: 1.08 to 1.15) and, in the profile of adverse drug reactions, the clearing heat and removing dampness medicine showed less adverse reactions than traditional Western medicine (RR: 0.18, 95% CI: 0.10 to 0.32). Conclusions. Through a systemic evaluation of the clinical efficacy of the clearing heat and removing dampness medicine of traditional Chinese medicine and western medicine on gout, the clearing heat and removing dampness medicine and western medicine possessed similar clinical efficacy, but traditional Chinese medicine treatments are superior to western medicine in controlling adverse reactions.

Wedelolactone inhibits osteoclastogenesis but enhances osteoblastogenesis through altering different semaphorins production.

Our previous study showed that wedelolactone, isolated from Ecliptae herba, enhanced osteoblastogenesis but inhibited osteoclastogenesis through Sema3A signaling pathway. This study aims to investigate the role of other semaphorins in wedelolactone-enhanced osteoblastogenesis and -inhibited osteoclastogenesis. Wedelolactone inhibited RANKL-induced Sema4D and Sema7A production, but had no effect on RANKL-reduced Sema6D expression in osteoclastic RAW264.7 cells. In mouse bone marrow mesenchymal stem cells (BMSC), wedelolactone reversed osteogenic medium(OS)-reduced Sema7A expression and OS-enhanced Sema3E mRNA expression, but no effect on OS-reduced Sema3B mRNA expression. Addition of Sema4D antibody promoted wedelolactone-reduced TRAP activity and bone resorption pit formation. Wedelolactone combined with Sema4D antibody inhibited the formation of Sema4D-Plexin B1 complex. In co-culture of BMSC with RAW264.7 cells, Sema7A antibody, similar with Sema 3A antibody, reversed wedelolactone-enhanced ALP activity and mineralization level, but promoted wedelolactone-inhibited TRAP activity. However, Sema3E and Sema3B antibodies had no effect. Further, wedelolactone enhanced the binding of Sema7A with PlexinC1 and Beta1, but addition of Sema7A antibody partially blocked this binding. Our data demonstrated that wedelolactone inhibited Sema4D production and Sema4D-PlexinB1 complex formation in RAW264.7 cells, thereafter inhibiting osteoclastogenesis. At the same time, wedelolactone enhanced osteoblastogenesis through promoting Sema7A production and Sema7A-PlexinC1-Beta1 complex formation in BMSC.

The protective effects of Zhen-Wu-Tang against cisplatin-induced acute kidney injury in rats.

Acute kidney injury (AKI) is a common clinical condition that confers a risk of progression of chronic kidney disease and a high risk of death. The purpose of the current study is to investigate the anti-apoptotic and anti-fibrotic effects of Zhen-Wu-Tang (ZWT) on cisplatin (CIS)-induced renal injury and elucidate the involvement of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), the PI3K/Akt signaling pathway, transforming growth factor (TGF)-ß and the Wnt/ß-catenin signaling pathway in the positive effects of Zhen-Wu-Tang on the kidneys. Wistar rats were randomly assigned into six groups of 6 rats each as follows: normal control 1; normal control 2; CIS 1 and CIS 2, which received single intraperitoneal injections of CIS (6 mg/kg); CIS+ZWT 4 and CIS+ZWT 10, which received ZWT (1 ml/100 g/day, ig) starting days after the CIS injection for 4 and 10 days, respectively. Hematoxylin-eosin (H&E) staining was performed to identify the amelioration of histopathological changes in the kidneys and apoptosis of the renal proximal tubular cells. Picrosirius red staining was used to evaluate renal fibrosis after ZWT treatment. The relationship between ZWT and the upregulation of Nrf2, phosphorylation of Akt, and the downregulation of TGF-ß and WNT/ß-catenin were determined by Western blotting. At the end of the experiment, serum was isolated from the orbital blood of rats, and blood urea nitrogen (BUN) and creatinine (Cr) levels were measured. The results showed that ZWT restored the histological alterations, aberrant collagen deposition in the kidneys and the BUN and Cr levels that were increased by CIS. Treatment with ZWT reduced the expression levels of TGF-ß and Wnt and increased the expression levels of Nrf2, PI3K and Akt in the CIS-exposed kidney tissues. Furthermore, ZWT downregulated apoptosis and fibrosis by modulating the expression levels of caspase-3, Bax and alpha-smooth muscle actin (α-SMA). In conclusion, this study provides evidence for the anti-fibrotic and anti-apoptotic roles of ZWT in CIS-induced experimental kidney injury.

The speciation and bioavailability of mercury in sediments of Haihe River, China.

Twenty-one sediment samples in 11 sites along the Haihe River and Dagu Drainage River, Tianjin, China, were analyzed to investigate the pollution status and bioavailability of mercury (Hg). The results showed that the Haihe River was slightly polluted with Hg when flowing through Tianjin city. On the contrary, the sediments collected from Dagu Drainage River, an important drainage river in Tianjin, were found to have very high Hg concentrations and the highest concentration reached 8779.1 ng g(-1) (dry weight). The methylmercury (MeHg) concentrations accounted for 0.1-2.4% (average: 0.9%) of total mercury (HgT) and were strongly influenced by HgT (r=0.91, p=0.99, n=20) and total organic carbon (TOC; r=0.76, p=0.99, n=20) contents in sediments. Moreover, a five-step sequential selective extraction (SSE) procedure was used to study the bioavailability of Hg in sediments. The mercury in sediments existed mainly as element Hg and mercury sulfide, which accounted for 46.5% and 39.0% of HgT, respectively. The percentage of exchangeable Hg (defined as water soluble Hg plus 'human stomach acid' soluble Hg) was only 0.1-4.6%. The distribution of exchangeable Hg showed an obvious difference to that of HgT, indicating that the HgT concentrations were absolutely insufficient to evaluate the risk of Hg in sediments.

Simultaneous determination of methylmercury and ethylmercury in rice by capillary gas chromatography coupled on-line with atomic fluorescence spectrometry.

A comprehensive method for simultaneous determination of methylmercury (MeHg) and ethylmercury (EtHg) in rice by capillary gas chromatography (GC) coupled on-line with atomic fluorescence spectrometry was developed. The experimental conditions, including the pyrolyzer temperature and flow rates of the make-up gas and sheath gas, were optimized in detail. The absolute detection limits (3sigma) were 0.005 ng as Hg for both MeHg and EtHg. The relative standard deviation values (n=5) for 10 ng Hg/mL of MeHg and EtHg were 2.5 and 1.3%, respectively. The method was evaluated by analyzing 2 certified reference materials (DORM-2 and GBW08508), and the determined values of MeHg and total mercury concentrations were in good agreement with the certified values. In addition, the recoveries of MeHg and EtHg spiked into a rice sample collected from Jiangsu province in China were 86 and 77%, respectively. The proposed method was applied to analysis of MeHg and EtHg in 25 rice samples cultivated in 15 provinces of China. In all samples, MeHg was detectable and no EtHg was found. The MeHg contents in rice samples ranged from 1.9 to 10.5 ng/g, accounting for 7-44% of the total mercury measured.

Investigation of methylmercury and total mercury contamination in mollusk samples collected from coastal sites along the Chinese Bohai Sea.

This paper presents the investigation results of methylmercury and total mercury in gastropod and bivalve species collected from eight coastal sites along the Chinese Bohai Sea. The total mercury was directly determined by atomic fluorescence spectrometry (AFS), while the methylmercury was measured by a laboratory established high performance liquid chromatography-atomic fluorescence spectrometry system (HPLC-AFS). Certified reference material DORM-2 (Dogfish muscle) was used to validate the two methods and the obtained results proved to be in good agreement with the certified values. It was demonstrated that the mercury contamination was commonly existed in all selected mollusks, with methylmercury and total mercury concentration in the range of 4.8-168.4 and 6.7-453.0 ng Hg g(-)(1), respectively. Mollusks from HuLuDao were the most mercury contaminated, and those from PengLai took the second place. The species-dependent bioaccumulation capacity was observed in this study. Gastropods showed more capacity to bioaccumulate mercury than bivalves, and mercury contents in two kinds of gastropods (Rapana venosa and Neverita didyma) presented some uplifted trends with the dimensions increasing of the gastropods. Rapana venosa was found to be a potential biomarker to monitor mercury pollution in oceans. Evaluations were also made concerning about the ratio of methylmercury to total mercury.

Speciation of heavy metals in marine sediments from the East China Sea by ICP-MS with sequential extraction.

Twelve elements (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Sn, Cd and Pb) in 24 sediment samples at eight sites (S1-S8) from the East China Sea were analyzed with the BCR sequential extraction (SE) protocol to obtain the metal distribution patterns in this region. The results showed that the heavy metal pollutions in S4 and S8 were more severe than in other sampling sites, especially Cd and Pb pollution. In the top sediments at S4 and S8, both the total contents and the most dangerous non-residual fractions of Cd and Pb were extremely high. More than 90% of the total concentrations of V, Cr, Mo and Sn existed in the residual fraction. Fe, Co, Ni, Cu and Zn mainly (more than 60%) occurred in the residual fraction. While Mn, Pb and Cd dominantly presented in the non-residual fractions in the top sediments. The metal distribution patterns with depth and the correlations between total organic carbon (TOC) and the total Fe-Mn content were also investigated. The results showed that, for most of the elements except Fe, the concentration of elements in fraction A in the top sediments was higher than that in other depth. The similar rule was also found in fraction B but not in fraction C. Besides, the distributions of V, Cd in fraction B and Pb, Cd, Cu in fraction C might be affected by TOC.

A single hot event stimulates adult performance but reduces egg survival in the oriental fruit moth, Grapholitha molesta.

Climate warming is expected to increase the exposure of insects to hot events (involving a few hours at extreme high temperatures). These events are unlikely to cause widespread mortality but may modify population dynamics via impacting life history traits such as adult fecundity and egg hatching. These effects and their potential impact on population predictions are still largely unknown. In this study, we simulated a single hot event (maximum of 38°C lasting for 4 h) of a magnitude increasingly found under field conditions and examined its effect in the oriental fruit moth, Grapholitha molesta. This hot event had no impact on the survival of G. molesta adults, copulation periods or male longevity. However, the event increased female lifespan and the length of the oviposition period, leading to a potential increase in lifetime fecundity and suggesting hormesis. In contrast, exposure of males to this event markedly reduced the net reproductive value. Male heat treatment delayed the onset of oviposition in the females they mated with, as well as causing a decrease in the duration of oviposition period and lifetime fecundity. Both male and female stress also reduced egg hatch. Our findings of hormetic effects on female performance but concurrent detrimental effects on egg hatch suggest that hot events have unpredictable consequences on the population dynamics of this pest species with implications for likely effects associated with climate warming.