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An asymmetric structure is an important strategy for designing highly conductive molecular wires for a gap-fixed molecular circuit. As the conductance enhancement in the current strategy is still limited to about 2 times, we inserted a methylene group as a spacer in a conjugated structure to modulate the structural symmetry. We found that the conductance drastically enhanced in the asymmetric molecular wire to 1.5 orders of magnitude as high as that in the symmetric molecular wire. First-principles quantum transport studies attributed the effective enhancement to the synchronization of improved energy alignment and nearly symmetric coupling between the frontier orbitals and the electrodes.
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For designing single-molecule devices that have both conjugation systems and structural flexibility, a hyperconjugated molecule with a σ-π bond interaction is considered an ideal candidate. In the investigation of conductance at the single-molecule level, since few hyperconjugation systems have been involved, the strategy of building hyperconjugation systems and the mechanism of electron transport within this system remain unexplored. Based on the skipped-conjugated structure, we present a rational approach to construct a hyperconjugation molecule using a hydroxyl group, which serves as a bridge to interact with the conjugated fragments. The measurement of single-molecule conductance reveals a two-fold conductance enhancement of the hyperconjugation system having the 'bridging' hydroxyl group compared to hydroxyl-free derivatives. Theoretical studies demonstrate that the hydroxyl group in the hyperconjugation system connects the LUMO of the two conjugated fragments and opens a through-space channel for electron transport to enhance the conductance.
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BACKGROUND: Colon carcinoma is one of the commonly tumors that threaten human beings as its highly morbidity and mortality. Recent evidences suggested that microRNA-21 (miR-21) played an important role in the development of colon carcinoma and might be a potential biological marker for the diagnosis and prognosis of colon carcinoma. However, the potential effect of miR-21 based therapeutic studies in colon carcinoma remains to be fully elucidated. METHODS: In present study, we constructed an eukaryotic expression vector encoding antisense oligonucleotides against miR-21 (termed as p-miR-21-ASO) and the expression of miRNA-21 in human colon cancer was detected by Real-time PCR. To assess its possible effect on the proliferation and migration capacity of human colon carcinoma cells in vitro, CCK-8 assay, colony formation assay and cell invasion, as well as migration assay, were performed respectively. Moreover, PTEN, one of target molecules of miRNA-21, was analyzed by Western blot and Fluorescence activated cell sorter assay. Finally, the transduction of AKT and ERK pathways in human colon carcinoma cells was determined by Western blot. RESULTS: We found that transiently transfection of p-miR-21-ASO could efficiently decrease the relative expression of miR-21 in human colon carcinoma HCT116 cells, accompanied by impaired proliferation and clone formation. Furthermore, we found that down-regulation of miR-21 also could significantly abrogate the invasion and migration capacity in vitro, as well as the expression of vascular endothelial growth factor which is critical for the metastatic capacity of colon carcinoma cells. Mechanistic evidence showed that down-regulation of miR-21 increased the expression of its target molecule PTEN in HCT116 cells. Finally, we revealed that the expression level of both phosphor-ERK1/2 and phosphor-AKT also were altered. CONCLUSIONS: Therefore, our data suggested miR-21 ASO against miR-21 might be a useful strategy to alter the expression of miR-21 in colon carcinoma cells, which was helpful for the development of miR-21-based therapeutic strategies against clinical colon carcinoma.
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The surface ozone (O3) spatiotemporal distribution, variations, and its causes in Ji'nan from 2015 to 2020 were revealed based on the air quality monitoring network data and satellite retrievals from the Ozone Monitoring Instrument (OMI). The results showed that the ozone concentration in Ji'nan gradually increased from 2015 to 2020. The annual 90th percentile of the daily maximum 8-h average (MDA8) O3(namely the annual evaluation value) and the MDA8 O3(April-September) increased by 4.8 µg·(m3·a)-1 and 3.8 µg·(m3·a)-1, respectively. The trend of the ozone levels in the high-concentration range increased faster than that in the low-concentration range. The MDA8 in June increased by 7.4 µg·(m3·a)-1, and the rate range of increases was 2.6-3.9 µg·(m3·a)-1 in the cool seasons (December-February); thus, the O3 control in winter cannot be ignored. It is apparent from the diurnal variations in ozone from 2015 to 2020 in April-September that the average ozone levels have risen in recent years. The growth rate in the daytime was higher than that at night. The capacity of photochemical production has been increasing, especially in recent years. Additionally, it is noteworthy that the peak time for ozone levels occurred approximately 1-2 h earlier. The disparity of ozone concentrations among different stations gradually decreased in recent years. Compared with that in 2015, the range of areas with high O3 concentrations in 2019-2020 was further expanded. The significant positive trends in MDA8-90th and MDA8 (April-September) were observed in 16.1% and 22.6% of the monitoring sites in Ji'nan (P<0.05), most of which were located in urban areas and the suburbs close to urban areas. The temporal and spatial changes in ozone in Jinan had been affected by the changes in VOCs and NOx emissions since 2015. Satellite remote sensing data from 2015 to 2020 revealed that the NO2 tropospheric columns (April-September) showed reductions of 20.6%, with a decreasing rate of 0.3×1015 mole·(cm2·a)-1, especially in the urban areas and suburbs. The detected variation trends of tropospheric HCHO were weak and insignificant, which suggested that the decrease in NOx emissions was much greater than the decrease in VOCs emissions, and the gap had become more obvious in the urban areas. With responses to precursor emissions, the chemical sensitivity of O3 formation had been changing. The VOCs-limited regimes continuously decreased, and the mixed NOx/VOCs-sensitive regimes and NOx-limited regimes increased. In general, such an extremely inappropriate control ratio of ozone precursor NOx/VOCs led to an overall trend of slow increasing fluctuations of O3 in Ji'nan. The findings clearly indicate that the reduction of VOCs in Ji'nan was far from sufficient, and strengthening the current control of VOCs emissions is an effective measure to control the growth trend of O3 pollution in Ji'nan in the near future, especially in urban and surrounding suburban areas.
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SLC12A5, a neuron-specific potassium-chloride co-transporter, has been reported to promote tumor progression, however, the underlying mechanism remains unclear. Here we report that SLC12A5 functions as an oncogene to promote tumor progression and castration resistance of prostate cancer through the N6-methyladenosine (m6A) reader YTHDC1 and the transcription factor HOXB13. We have shown that the level of SLC12A5 was increased in prostate cancer, in comparison to its normal counterparts, and further elevated in castration-resistant prostate cancer (CRPC). The enhanced expression of SLC12A5 mRNA was associated with neuroendocrine prostate cancer (NEPC) progression and poor survival in prostate cancer. Furthermore, we demonstrated that SLC12A5 promoted the castration resistance development of prostate cancer in addition to the cell proliferation and migration. Interestingly, SLC12A5 was detected in the cell nucleus and formed a complex with nuclear m6A reader YTHDC1, which in turn upregulated HOXB13 to promote the prostate cancer progression. Therefore, our findings reveal a mechanism that how the potassium-chloride cotransporter SLC12A5 promotes the tumor progression and provide a therapeutic opportunity for prostate cancer to apply the neurological disorder drug SLC12A5 inhibitors.
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Neoplasias de Próstata Resistentes à Castração , Simportadores , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/patologia , Simportadores/genética , Simportadores/metabolismo , Cloretos/metabolismo , Cloretos/uso terapêutico , Castração , Potássio/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Fatores de Processamento de RNA/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismoRESUMO
RATIONALE AND PATIENT CONCERNS: Congenital hearing loss is often caused by an inner ear malformation, in such cases, the presence of other anomalies, such as microtia, and venous anomalies of the temporal bone and laryngomalacia makes it challenging to perform cochlear implantation surgery. DIAGNOSES: This study reports the case of a 28-month-old girl with congenital profound hearing loss, laryngomalacia, and malformed inner ear, who received cochlear implantation surgery. The bony structure, vessels and nerves were first assessed through magnetic resonance imaging and computed tomography before exploring the genetic basis of the condition using trio-based whole exome sequencing. Perioperative evaluation and management of the airway was then performed by experienced anesthesiologist, with the surgical challenges as well as problems encountered fully evaluated. INTERVENTIONS: Cochlear implantation was eventually performed using a trans-mastoid approach under uneventful general anesthesia. OUTCOMES: Due to the small size of the cochlea, a short electrode FLEX24 was inserted through the cochleostomy. LESSONS: Considering the high risk of facial nerve injury and limited access to the cochlea when patients present significant bony and venous anomalies, cochlear implantation in such patients require careful preoperative evaluation and thoughtful planning. In these cases, airway assessment, magnetic resonance venography, magnetic resonance arteriography, and magnetic resonance imaging and computed tomography can be useful to minimize the risks. Intraoperative facial nerve monitoring is also recommended to assist in the safe location of facial nerve.
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Implante Coclear , Implantes Cocleares , Microtia Congênita , Perda Auditiva Neurossensorial , Laringomalácia , Malformações Vasculares , Pré-Escolar , Feminino , Humanos , Cóclea/anormalidades , Cóclea/patologia , Cóclea/cirurgia , Implante Coclear/métodos , Microtia Congênita/cirurgia , Perda Auditiva Neurossensorial/cirurgia , Laringomalácia/cirurgia , Osso Temporal/diagnóstico por imagem , Osso Temporal/cirurgia , Osso Temporal/patologia , Malformações Vasculares/complicações , Malformações Vasculares/cirurgia , Malformações Vasculares/patologiaRESUMO
The prognosis of lung cancer is poor with few effective therapies. Targeting ferroptosis is a new promising strategy for cancer therapy. LINC00641 has been involved in several cancers, however, its specific roles in lung cancer treatment remain largely unknown. Here, we reported that LINC00641 was down-regulated in tumor tissues and its downregulation was associated with poor outcomes in lung adenocarcinoma. LINC00641 was localized primarily in the nucleus and was modified by m6A. The nuclear m6A reader YTHDC1 regulated LINC00641 expression by affecting its stability. We demonstrated that LINC00641 suppressed lung cancer by inhibiting migration and invasion in vitro and metastasis in vivo. Knockdown of LINC00641 upregulated HuR protein level (especially in the cytoplasm), which subsequently increased N-cadherin levels by stabilizing its mRNA, then ultimately promoted EMT. Interestingly, LINC00641 knockdown in lung cancer cells increased the arachidonic acid metabolism and promoted ferroptosis sensitivity. Our findings identified LINC00641 as a tumor suppressor through inhibiting EMT. In another aspect, low expression of LINC00641 caused a ferroptotic vulnerability in lung cancer cells, which may serve as a potential ferroptosis-related therapeutic target for lung cancer.
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Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Regulação para Baixo/genética , Neoplasias Pulmonares/genética , Núcleo Celular , AdenosinaRESUMO
Ferroptosis is a regulated cell death process initiated by iron-dependent phospholipid peroxidation and is mainly suppressed by GPX4-dependent and FSP1-dependent surveillance mechanisms. However, how the ferroptosis surveillance system is regulated during cancer development remains largely unknown. Here, we report that the YTHDC1-mediated m6A epigenetic regulation of FSP1 alleviates the FSP1-dependent ferroptosis suppression that partially contributes to the tumor suppressive role of YTHDC1 in lung cancer progression. YTHDC1 knockdown promoted the lung tumor progression and upregulated FSP1 protein level that resulted in ferroptosis resistance of lung cancer cells. Silencing FSP1 abrogated YTHDC1 knockdown-induced proliferation increase and ferroptosis resistance. Mechanistically, YTHDC1 binding to the m6A sites in the FSP1 3'-UTR recruited the alternative polyadenylation regulator CSTF3 to generate a less stable shorter 3'-UTR contained FSP1 mRNA, whereas YTHDC1 downregulation generated the longer 3'-UTR contained FSP1 mRNA that is stabilized by RNA binding protein HuR and thus led to the enhanced FSP1 protein level. Therefore, our findings identify YTHDC1 as a tumor progression suppressor in lung cancer and a ferroptosis regulator through modulating the FSP1 mRNA stability and thus suggest a ferroptosis-related therapeutic option for YTHDC1high lung cancer.
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Ferroptose , Neoplasias Pulmonares , Morte Celular Regulada , Humanos , Epigênese Genética , Ferroptose/genética , Neoplasias Pulmonares/genética , Proteínas do Tecido Nervoso , Fatores de Processamento de RNA , RNA MensageiroRESUMO
A nickel-catalyzed direct reductive cross-coupling of disubstituted cycloalkyl iodides with aryl iodides was developed. The one-pot reaction, which is simple to operate, was capable of proceeding efficiently in a stereocontrolled manner to afford a variety of cross-coupled products with high diastereoselectivity and wide functional group tolerance.
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BACKGROUND: Endotoxin tolerance (ET) is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide (LPS) leads to dramatically elevated survival. Accumulating evidence has shown that peripheral T cells contribute to the induction of ET. However, what happens to T cell development in the thymus under ET conditions remains unclear. The purpose of this study was to analyze the alterations in thymocyte populations (double-positive [DP] and single-positive [SP] cells) under ET conditions. METHODS: Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups: a group examined 72 h after LPS injection (72-h group) and a group examined 8 days after LPS injection (8-day group). Injection of phosphate-buffered saline was used as a control (control group). Changes in thymus weight, cell counts, and morphology were detected in the three groups. Moreover, surface molecules such as CD4, CD8, CD44, CD69, and CD62L were analyzed using flow cytometry. Furthermore, proliferation, apoptosis, cytokine production, and extracellular signal-regulated kinase (ERK) pathway signaling were analyzed in thymocyte populations. The polymorphism and length of the T-cell receptor (TCR) ß chain complementarity-determining region 3 (CDR3) were analyzed using capillary electrophoresis DNA laser scanning analysis (ABI 3730). RESULTS: Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET. Moreover, the proportions of DP cells (control: 72.130â±â4.074, 72-h: 10.600â±â3.517, 8-day: 84.770â±â2.228), CD4+ SP cells (control: 15.770â±â4.419, 72-h: 44.670â±â3.089, 8-day: 6.367â±â0.513), and CD8+ SP cells (control: 7.000â±â1.916, 72-h: 34.030â±â3.850, 8-day: 5.133â±â0.647) were obviously different at different stages of ET. The polymorphism and length of TCR ß chain CDR3 also changed obviously, indicating the occurrence of TCR rearrangement and thymocyte diversification. Further analysis showed that the expression of surface molecules, including CD44, CD69, and CD62L, on thymocyte populations (DP and SP cells) were changed to different degrees. Finally, the proliferation, apoptosis, cytokine production, and ERK pathway signaling of thymocyte populations were changed significantly. CONCLUSION: These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.
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Endotoxinas , Timócitos , Animais , Linfócitos T CD4-Positivos , Diferenciação Celular , Endotoxinas/toxicidade , Citometria de Fluxo , Camundongos , Transdução de Sinais , TimoRESUMO
Mutations in the Forkhead Box C1 (FOXC1) are known to cause autosomal dominant hereditary Axenfeld-Rieger syndrome, which is a genetic disorder characterized by ocular and systemic features including glaucoma, variable dental defects, craniofacial dysmorphism and hearing loss. Due to late-onset of ocular disorders and lack of typical presentation, clinical diagnosis presents a huge challenge. In this study, we described a pathogenic in-frame variant in FOXC1 in one 5-year-old boy who is presented with hypertelorism, pupil deformation in both eyes, conductive hearing loss, and dental defects. By whole exome sequencing, we identified a 3 bp deletion in FOXC1, c.516_518delGCG (p.Arg173del) as the disease-causing variant, which was de novo and not detected in the parents, and could be classified as a "pathogenic variant" according to the American College of Medical Genetics and Genomics guidelines. After confirmation of this FOXC1 variant, clinical data on Axenfeld-Rieger syndrome-associated clinical features were collected and analyzed. Furthermore, Although the affected individual present hearing loss, however, the hearing loss is conductive and is reversible during the follow-up, which might not linke to the FOXC1 variant and is coincidental. Routine examination of FOXC1 is necessary for the genetic diagnosis of hypertelorism-associated syndrome. These findings may assist clinicians in reaching correct clinical and molecular diagnoses, and providing appropriate genetic counseling.
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Anormalidades do Olho , Oftalmopatias Hereditárias , Segmento Anterior do Olho/anormalidades , Pré-Escolar , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Oftalmopatias Hereditárias/genética , Fatores de Transcrição Forkhead/genética , Humanos , MasculinoRESUMO
Ferula ferulaeoides (Steud.) Korov. is a perennial herb that belongs to Umbelliferae (Apiaceae). Its resin and roots have extensive commercial and medicinal value in the Xinjiang region. However, the resin-secreting resin ducts (RDs) of F. ferulaeoides have not been studied in detail. This study used optical and transmission electron microscopy to explore the anatomical features, including the distribution, size, and structure, of the RDs among different organs of F. ferulaeoides. The microstructure data revealed that the RDs consisted of a round lumen, a layer of secretory cells, and multiple layers of sheath cells. Notably, the RDs in stem were arranged alternatively in a multilayered ring with vascular bundles of three distinct sizes. The ultrastructural analysis revealed that organelles in the secretory cells potentially play important roles in resin secretion. Those data may be of great significance to understanding the anatomy of the RDs in Ferula L. and Umbelliferae.
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Apiaceae , Ferula , Raízes de Plantas , Resinas VegetaisRESUMO
OBJECTIVE: To compare the efficacy and safety of pterygopalatine fossa puncture using one acupuncture needle inserted through the temporal fossa (intervention) and Chinese verum acupuncture (VA) in patients with moderate-to-severe persistent allergic rhinitis. METHODS: The patients were randomized to an intervention group receiving pterygopalatine fossa puncture with one acupuncture needle for 4 weeks (once or twice weekly, 4-8 sessions in total, with a second course performed if required) or to a control group receiving individualized VA for 4 weeks (twice weekly, eight sessions in total). Patients were followed up 4 weeks later. RESULTS: Ninety-six participants were assigned to intervention (n = 48) or VA (n = 48) or VA (P > 0.05 in all cases). Compared with the VA, the time to onset of effect in the intervention group was shorter and the duration of effectiveness was longer. The mean clinical waiting time was significantly shorter in the intervention group than in the control group (6.640 ± 3.035 min and 31.19 ± 10.216 min, respectively). The total number of sessions in the VA group was 384; 7 episodes of subcutaneous bleeding occurred but did not require treatment. The total number of sessions in the intervention group was 185. Two cases of subcutaneous bleeding (one of local hematoma during the intervention and the other one of bruising in the palpebra inferior on the day after intervention) resolved upon withdrawal from the study. CONCLUSIONS: Pterygopalatine fossa puncture using one acupuncture needle resulted in a shorter time to onset of effect, a longer duration of effectiveness, and less clinical waiting time when compared with VA. Though the significant differences for TNSS and TNNSS were shown within intervention and VA groups, there were no differences between the two groups. Although the rate of subcutaneous bleeding was low, these adverse events may influence patient compliance. This trial is registered with ISRCTN21980724.
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Online monitoring data of atmospheric pollutants and meteorological parameters in Zhengzhou from 2014 to 2017 were collected to analyze the concentration levels, seasonal variations, and the ratio characteristics of atmospheric pollutants, as well as the effects of meteorological conditions on these pollutants. Results show that the annual average concentrations of PM2.5 and PM10 in the four years were (88±49.8), (95.8±60.2), (78.6±70.3), and (72.0±53.5) µg·m-3, and (158.5±65.3), (167.7±82.6), (144.5±91.5), and (132.7±70.3) µg·m-3, respectively, and were approximately two times higher than the grade â ¡ annual limits set by China. Fuel combustion and the formation of secondary pollutants were the main sources of PM2.5 in Zhengzhou. Moreover, the contribution of coal combustion was found to be decreased, while that of traffic sources increased year by year. Low wind speed, high humidity, and reduced precipitation are important meteorological factors that contribute to serious air pollution. In addition, the Potential Source Contribution Function and the Concentration-Weighted Trajectory were used to analyze the potential sources, and the contribution of these sources to the distribution of PM2.5. The potential source areas of PM2.5 were mainly distributed in neighboring cities and provinces, such as Shanxi, Shaanxi, Hubei, Shandong, and Hebei. The short-distance transmission was found to contribute significantly to the mass concentration of PM2.5.
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Flavonoids have been reported to exert protective effect against many inflammatory diseases, while the underlying cellular mechanisms are still not completely known. In the present study, we explored the anti-inflammation activity of 5, 7, 2', 4', 5'-pentamethoxyflavanone (abbreviated as Pen.), a kind of polymethoxylated flavonoid, both in vitro and in vivo experiments. Pen. was showed no obvious toxicity in macrophages even at high dosage treatment. Our results indicated that Pen. significantly inhibited both mRNA and protein level of proinflammatory cytokines, IL-1ß, IL-6, TNF-α and iNOS, which was characteristic expressed on M1 polarized macrophages. These effects of Pen. were further confirmed by diminished expression of CD11c, the M1 macrophage surface marker. Further researches showed that the mechanism was due to that Pen. downregulated the activity of p65, key transcription factor for M1 polarization. On the other hand, Pen. also enhanced M2 polarization with upregulation of anti-inflammatory factors and increase of M2 macrophage surface markers, which lead to the balance of M1 and M2 macrophages. Moreover, in vivo research verified that Pen. treatment alleviated LPS-induced sepsis in mice by increasing survival rate, decreasing inflammatory cytokines and improving lung tissue damage. In summary, our results suggested that Pen. modulated macrophage phenotype via suppressing p65 signal pathway to exert the anti-inflammation activity.
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Anti-Inflamatórios/uso terapêutico , Flavanonas/uso terapêutico , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Sepse/tratamento farmacológico , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Células Cultivadas , Citocinas/metabolismo , Feminino , Flavanonas/química , Flavanonas/farmacologia , Humanos , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Sepse/induzido quimicamente , Sepse/metabolismo , Sepse/patologia , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , Células THP-1 , Fator de Transcrição RelA/metabolismo , Resultado do TratamentoRESUMO
In order to explore the pollution levels and characteristics of perfluorinated alkyl substances (PFASs), seawater, sediment, and Ruditapes philippinarum samples were collected near the Jiaozhou Bay coast in April 2018. All samples were analyzed by using the high performance liquid chromatography-mass spectrometry method to determine the content of 35 types of PFASs. The results showed that 12 different PFASs were tested in the seawater with ∑PFASs concentrations of 21.1-38.0 ng·L-1; 10 types of PFASs were detected in sediments, with ∑PFASs content (dry weight) ranging from 0.459 to 1.20 µg·kg-1; 19 types of PFASs were measured in Ruditapes philippinarum, with ∑PFASs content (dry weight) of 15.5-27.5 µg·kg-1. Compared with other areas reported in the literature, the total pollution of Jiaozhou Bay was at medium or high levels. In addition, perfluorooctanoic acid (PFOA) was the dominant PFAS in the seawater, sediments, and Ruditapes philippinarum with a detection rate of 100%. 6:2 fluorotelomer phosphate diester (6:2 diPAP) was observed for the first time in seawater and sediments from Jiaozhou Bay and had the highest detection frequency and concentration of the precursor. Perfluorooctanesulfonamide (PFOSA) was the main precursor in Ruditapes philippinarum, of which the detection rate was 93.8%. Moreover, the organic carbon normalized sediment-water distribution coefficient (lg KOC) values were 5.24-6.37 and increased with an increase in carbon chain length. The bioaccumulation factors (lg BAF) and field-based biota-sediment accumulation factors (lg BSAF) were 2.53-4.32 and 1.30-2.50, respectively. The lg BAF values positively correlated with the carbon chain length, whereas the lg BSAF values decreased with an increase in the carbon chain length (C8-C13).
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Fluorocarbonos , Poluentes Químicos da Água , Animais , Baías , China , Monitoramento Ambiental , Sedimentos Geológicos , Água do MarRESUMO
The North Yellow Sea is a major aquaculture production area for the scallop Patinopecten yessoensis. In this study, the temporal and spatial variation of phycotoxins in scallops, phytoplankton, and their cysts were analyzed during a survey conducted from June 2011 to April 2012 around Zhangzi Island. The study area is a semi-enclosed epicontinental sea surrounded by the Shandong Peninsula, the Liaodong Peninsula and the Korean Peninsula. The three main results of the study were as follows: (1) The saxitoxin-group toxins, okadaic acid and analogues, and pectenotoxins were the major phycotoxin residues found in scallops; (2) Six kinds of toxic microalgae were identified, Protoperidinium spp., Gonyaulax spp., and Alexandrium spp. were the dominant taxa; Seven types of potential marine toxin-producing dinoflagellates, A. tamarense, A. catenella, Dinophysis fortii, G. catenatum, Gambierdiscus toxicus, Azadinium poporum, and Pseudo-nitzschia pungen were identified as the primary source of phycotoxins and were present at relatively high density from June to October; and (3) azaspiracids and domoic acid might be new potential sources of toxin pollution. This study represents the first assessment to phycotoxins around Zhangzi Island in the North Yellow Sea.
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Contaminação de Alimentos/análise , Toxinas Marinhas/análise , Pectinidae/química , Fitoplâncton , Frutos do Mar/análise , Animais , Aquicultura/métodos , China , Diatomáceas , Dinoflagellida , Microalgas , Oceanos e Mares , Fitoplâncton/química , Saxitoxina/análise , Estações do Ano , Análise Espaço-Temporal , Compostos de Espiro/análiseRESUMO
In order to study the effects of different stand types of Mongolian scots pine (Pinus sylvestris var. mongolica) on the diversity of insect community in the plantation under close-to-nature forest management, the structure of the insect community was studied in five stand types of the Mongolian scots pine pure forest and mixed forests in Saihanba Nature Reserve. The insects were collected by the sweep net method, and the diversity index, similarity, principal component, and stability of insect communities in different forest types were analyzed. In total, 9617 insects, belonging to 7 orders, 70 families, 195 species, were collected, and the Diptera, Hemipteran and Coleopteran were the dominant groups. The insect species in 5 stand types were all rich, and the insect community structure among the different stands reached a moderate dissimilar level. The species and individual number of mixed forest was more than those of pure forest. There was no significant difference among different stand types in insect community character indices. Principal component analysis indicated that phytophagous group, predatory group and parasitic group in each stand type were the main factors influencing the community structure, and predatory group and parasitic group had a stronger control effect on phytophagous group. The structure of insect community in the diffe-rent forest stand types had relatively high stability.
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Biodiversidade , Insetos , Pinus sylvestris , Animais , China , Florestas , PinusRESUMO
Early detection of toxin contamination in shellfish (i.e., prior to harvest) would be of considerable advantage to fish farmers, researchers and food safety administrators. In 2004, a solid-phase adsorption toxin tracking (SPATT) technique was developed to study algal toxins in New Zealand shellfish harvesting areas. In subsequent years, the basic idea have been further developed. Using a SPATT method, an investigation into diarrhetic shellfish toxins (DSTs) was conducted over a 10.5-month period in 2012 in shellfish farming areas in Lingshan Bay (Yellow Sea, China). This paper discusses the relationship among DSTs in toxic algae, seawater and contaminated shellfish. OA, DTX1 and PTX2 toxins were found in this shellfish farming area from summer to autumn. In shellfish the maximum concentrations of OA and DTX1 were 81 and 41 ng g(-1) respectively. PTX2 was very low. The maximum levels of OA and DTX1 in seawater were 165 and 56 ng g(-1) respectively, and were detected on June, separated by a 14-day period. Shellfish had accumulated the highest levels of OA and DTX1 recorded in this study. Comparison of the variations in DST levels in seawater showed there to be about 2 weeks for administrators to warn of the potential for toxin contamination in shellfish. Further research to explore the relationship between the variables of seawater temperature, sunlight and salinity, and DSTs in shellfish may help to establish a more suitable model for forecasting DST contamination in shellfish.
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Baías , Toxinas Marinhas/análise , Frutos do Mar , Extração em Fase Sólida , Adsorção , Animais , ChinaRESUMO
A novel immunoassay strategy based on combination of chitosan (CHIT) and a gold nanoparticle (GNP) label has been developed. The susceptibility of CHIT to further chemical modifications due to the abundant amino groups is explored in order to covalently immobilize antibody (Ab) onto the (3-aminopropyl) triethoxysilane derivatized glass slide by cross-linking with glutaraldehyde (GA). After incubating in antigen (Ag) solution, the obtained substrate is immersed in GNP labeled antibody solution for signal generation. The two steps were repeated alternatively for three times, forming multilayer of gold nanoparticles via antigen-antibody specific reaction. Ultraviolet-visible (UV-vis) absorption spectrum is recorded to obtain quantitative information about the specific antigen. The presented immunoassay strategy is applied for determination of human serum albumin (HSA) as a model analyte. The immunoassay of HSA is specific. Compared to previous correlative work, the proposed immunosensing strategy shows some advantages, such as improved sensitivity as much more gold nanoparticles can be coupled to the functionalized surface making use of the abundant amino groups of CHIT. Moreover, a significantly extended linear detection range of 8.0-512.0mug/mL is gained under the optimized experimental conditions. In particular, the presented biosensing method shows low cost and simplicity, and only a conventional UV-vis detector is involved.