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991.
João Marcelo Alvarenga Braga 《Kew Bulletin》2008,63(2):309-314
Summary
Calathea dryadica and Calathea reginae are described, circumscribed and illustrated. These new species are probably endemic to the Atlantic Forest of Rio de Janeiro
State in Southeast Brazil and are considered critically endangered because of the restricted geographic area of occurrence,
sometimes enclosed by densely urbanised areas. 相似文献
992.
993.
Sher Hayat Khan Deming Zhao Syed Zahid Ali Shah Mohammad Farooque Hassan Ting Zhu Zhiqi Song Xiangmei Zhou Lifeng Yang 《Cellular and molecular neurobiology》2017,37(4):717-728
Transmissible spongiform encephalopathies (TSEs) are caused by the accumulation of the abnormal prion protein scrapie (PrPSc). Prion protein aggregation, misfolding, and cytotoxicity in the brain are the major causes of neuronal dysfunction and ultimate neurodegeneration in all TSEs. Parkin, an E3 ubiquitin ligase, has been studied extensively in all major protein misfolding aggregating diseases, especially Parkinson’s disease and Alzheimer’s disease, but the role of parkin in TSEs remains unknown. Here we investigated the role of parkin in a prion disease cell model in which neuroblastoma2a (N2a) cells were treated with prion peptide PrP106–126. We observed a gradual decrease in the soluble parkin level upon treatment with PrP106–126 in a time-dependent manner. Furthermore, endogenous parkin colocalized with FITC-tagged prion fragment106–126. Overexpression of parkin in N2a cells via transfection repressed apoptosis by enhancing autophagy. Parkin-overexpressing cells also showed reductions in apoptotic BAX translocation to the mitochondria and cytochrome c release to the cytosol, which ultimately inhibited activation of proapoptotic caspases. Taken together, our findings reveal a parkin-mediated cytoprotective mechanism against PrP106–126 toxicity, which is a novel potential therapeutic target for treating prion diseases. 相似文献
994.
Deciduous forests may respond differently from coniferous forests to the anthropogenic deposition of nitrogen (N). Since fungi,
especially ectomycorrhizal (EM) fungi, are known to be negatively affected by N deposition, the effects of N deposition on
the soil microbial community, total fungal biomass and mycelial growth of EM fungi were studied in oak-dominated deciduous
forests along a nitrogen deposition gradient in southern Sweden. In-growth mesh bags were used to estimate the production
of mycelia by EM fungi in 19 oak stands in the N deposition gradient, and the results were compared with nitrate leaching
data obtained previously. Soil samples from 154 oak forest sites were analysed regarding the content of phospholipid fatty
acids (PLFAs). Thirty PLFAs associated with microbes were analysed and the PLFA 18:2ω6,9 was used as an indicator to estimate
the total fungal biomass. Higher N deposition (20 kg N ha−1 y−1 compared with 10 kg N ha−1 y−1) tended to reduce EM mycelial growth. The total soil fungal biomass was not affected by N deposition or soil pH, while the
PLFA 16:1ω5, a biomarker for arbuscular mycorrhizal (AM) fungi, was negatively affected by N deposition, but also positively
correlated to soil pH. Other PLFAs positively affected by soil pH were, e.g., i14:0, a15:0, 16:1ω9, a17:0 and 18:1ω7, while
some were negatively affected by pH, such as i15:0, 16:1ω7t, 10Me17:0 and cy19:0. In addition, N deposition had an effect
on the PLFAs 16:1ω7c and 16:1ω9 (negatively) and cy19:0 (positively). The production of EM mycelia is probably more sensitive
to N deposition than total fungal biomass according to the fungal biomarker PLFA 18:2ω6,9. Low amounts of EM mycelia covaried
with increased nitrate leaching, suggesting that EM mycelia possibly play an important role in forest soil N retention at
increased N input. 相似文献
995.
Ricardo Kriebel 《Brittonia》2012,64(1):6-14
A synopsis of the annual genus Poteranthera is presented here. Three species are recognized including the newly described Poteranthera windischii. Poteranthera is characterized by its annual life cycle, generally linear leaves that have conspicuous gland-tipped hairs on the lamina
margin, 5-merous flowers with a constriction at the level of the torus, one cycle of stamens reduced to staminodia or absent
altogether, three locular ovary, and reniform seeds with a foveolate testa. The flowers of the new species P. windischii are strongly heterandrous, where the usual set of stamens that bees harvest pollen from is reduced to staminodia and the
stamen set that deposits pollen on the bee has large yellow ventral appendages that possibly function as pollen mimics and
result in deceit pollination. This hypothesis is supported by experiments that have demonstrated innate preferences of female
bees for yellow, UV absorbing colors in flowers. Species of Poteranthera are extremely rare, known from very few specimens and possibly highly endangered. 相似文献
996.
Atul A. Lohade Rajesh R. Jain Krishna Iyer Sushant K. Roy Hemant H. Shimpi Yogita Pawar M. G. R. Rajan Mala D. Menon 《AAPS PharmSciTech》2016,17(6):1298-1311
Targeted drug delivery systems for cancer improves anti-tumor efficacy and reduces systemic toxicity by restricting availability of cytotoxic drugs within tumors. Targeting moieties, such as natural ligands (folic acid, transferrin, and biotin) which are overexpressed on tumors, have been used to enhance liposome-encapsulated drug accumulation within tumors and resulted in better control. In this report, we explored the scope of targeting ligand folic acid, which is incorporated in liposome systems using folic acid-modified cholesterol (CPF), enabled highly selective tumor-targeted delivery of liposome-encapsulated doxorubicin and resulted in increased cytotoxicity within tumors. Folate-tagged poloxamer-coated liposomes (FDL) were found to have significantly higher cellular uptake than conventional poloxamer-coated liposomes (DL), as confirmed by fluorometric analysis in B16F10 melanoma cells. Biodistribution study of the radiolabeled liposomal system indicated the significantly higher tumor uptake of FDL as compared to DL. Anti-tumor activity of FDL against murine B16F10 melanoma tumor-bearing mice revealed that FDL inhibited tumor growth more efficiently than the DL. Taken together, the results demonstrated the significant potential of the folate-conjugated nanoliposomal system for drug delivery to tumors. 相似文献
997.
Pangkhi Medhi Ololade Olatunji Atul Nayak Chandra Teja Uppuluri Richard T. Olsson Buchi N. Nalluri Diganta B. Das 《AAPS PharmSciTech》2017,18(5):1488-1494
Microneedle (MN) technology has emerged as an effective drug delivery system, and it has tremendous potential as a patient friendly substitute for conventional methods for transdermal drug delivery (TDD). In this paper, we report on the preparation of lidocaine-loaded biodegradable microneedles, which are manufactured from fish scale-derived collagen. Lidocaine, a common tissue numbing anaesthetic, is loaded in these microneedles with an aim of delivering the drug with controlled skin permeation. Evaluation of lidocaine permeation in porcine skin has been successfully performed using Franz diffusion cell (FDC) which has shown that the drug permeation rate increases from 2.5 to 7.5% w/w after 36 h and pseudo steady state profile is observed from 5.0 to 10.0% w/w lidocaine-loaded microneedle. Swelling experiments have suggested that the microneedles have negligible swellability which implies that the patch would stick to the tissue when inserted. The experiments on MN dissolution have depicted that the lidocaine loaded in the patch is lower than the theoretical loading, which is expected as there can be losses of the drug during initial process manufacture. 相似文献
998.
A Gram positive, rod-shaped potential strain was selected from the pool of bacterial isolates obtained from the Western Ghats
forest (India) on the basis of zone of P-solubilization activity. Identification based on 16S rRNA gene sequence revealed
that the strain is of Bacillus species, sharing highest sequence similarity to Bacillus tequilensis NRRL B-41771T (99.5%). Strain NII-0943 was able to produce good amount of indole acetic acid (IAA) and was positive for siderophore production.
In addition to IAA and siderophore attributes, strain NII-0943 also possessed the characteristics like Ca3(PO4)2 solubilization and growth in nitrogen-free medium. Seed inoculation with the strain NII-0943 resulted in significantly higher
root initiation in black pepper cuttings grown under pots. The contents of nitrogen and phosphorus in both soil and plant
were also enhanced significantly in treatments inoculated with these bacterial inocula. Hence, based on this evidence it is
proposed that strain NII-0943 could be deployed as a plant growth-promoting inoculant to attain the desired results of bacterization. 相似文献
999.
In an effort to compare the molecular basis of differential toxic activity of botulinum neurotoxin A (BoNT/A) and BoNT/E, we have analyzed their membrane channel activity by measuring calcein release from liposomes. Both BoNT/A and /E showed a same level of membrane channel activity that was specifically blocked by IgG specific to the neurotoxins. With the use of fluorescein-labeled dextran, we determined that the size of the channel is at least 24.2 A which is appropriate for the translocation of a protein of 50 kDa (the light chain of BoNT). These findings would suggest that the difference in the toxicity level of the two BoNT serotypes might reflect differences in either endopeptidase activity or their binding to receptor(s). 相似文献
1000.
Takashi Saitoh Jun Osawa Toshikazu Takanishi Shintaro Hayakashi Masaaki Ohmori Toshio Morita Shigeru Uemura Jon Olav Vik Nils Chr. Stenseth Koji Maekawa 《Population Ecology》2007,49(3):249-256
The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live
trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for
the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas
such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns
between the three species may be due to differences in their physiological tolerance to tannins. 相似文献