Non-Functional Parathyroid Adenoma Presenting as a Massive Cervical Hematoma: A Case Report

Parathyroid adenoma usually manifests with symptoms related to hypercalcemia, such as urinary stone and bone fracture. It may also present with asymptomatic hypercalcemia. However, spontaneous cervical hematoma may occur very rarely as a result of extracapsular hemorrhage of a cervical parathyroid adenoma causing acute painful cervical swelling, bruising, dyspnea, hoarseness and dysphagia. We report a 44-year-old woman who manifested as a spontaneous cervical hematoma without any clinical evidence of hyperparathyroidism

Mixotrophy in the marine red-tide cryptophyte Teleaulax amphioxeia and ingestion and grazing impact of cryptophytes on natural populations of bacteria in Korean coastal waters

Cryptophytes are ubiquitous and one of the major phototrophic components in marine plankton communities. They often cause red tides in the waters of many countries. Understanding the bloom dynamics of cryptophytes is, therefore, of great importance. A critical step in this understanding is unveiling their trophic modes. Prior to this study, several freshwater cryptophyte species and marine Cryptomonas sp. and Geminifera cryophila were revealed to be mixotrophic. The trophic mode of the common marine cryptophyte species, Teleaulax amphioxeia has not been investigated yet. Thus, to explore the mixotrophic ability of T. amphioxeia by assessing the types of prey species that this species is able to feed on, the protoplasms of T amphioxeia cells were carefully examined under an epifluorescence microscope and a transmission electron microscope after adding each of the diverse prey species. Furthermore, T. amphioxeia ingestion rates heterotrophic bacteria and the cyanobacterium Synechococcus sp. were measured as a function of prey concentration. Moreover, the feeding of natural populations of cryptophytes on natural populations of heterotrophic bacteria was assessed in Masan Bay in April 2006. This study reported for the first time, to our knowledge, that T. amphioxeia is a mixotrophic species. Among the prey organisms offered, T. amphioxeia fed only on heterotrophic bacteria and Synechococcus sp. The ingestion rates of T. amphioxeia on heterotrophic bacteria or Synechococcus sp. rapidly increased with increasing prey concentrations up to 8.6 x 10(6) cells ml(-1), but slowly at higher prey concentrations. The maximum ingestion rates of T. amphioxeia on heterotrophic bacteria and Synechococcus sp. reached 0.7 and 0.3 cells predator(-1) h(-1), respectively. During the field experiments, the ingestion rates and grazing coefficients of cryptophytes on natural populations of heterotrophic bacteria were 0.3-8.3 cells predator(-1) h(-1) and 0.012-0.033 d(-1), respectively. Marine cryptophytes, including T. amphioxeia, are known to be favorite prey species for many mixotrophic and heterotrophic dinoflagellates and ciliates. Cryptophytes, therefore, likely play important roles in marine food webs and may exert a considerable potential grazing impact on the populations of marine bacteria. (C) 2017 Elsevier B.V. All rights reserved.N

Mixotrophy in the sand-dwelling dinoflagellate Thecadinium kofoidii

Thecadinium kofoidii is a marine sand-dwelling dinoflagellate that sometimes forms dense blooms. This species was previously thought to be an exclusively autotrophic dinoflagellate, and its mixotrophic ability has not been explored yet. By investigating its ecophysiology, its trophic mode should be revealed. We explored the mixotrophic ability of T. kofoidii by examining its protoplasm under light and transmission electron microscopes with diverse algal prey species. Furthermore, the feeding mechanism of T. kofoidii and prey species on which it feeds were investigated. In addition, the growth and ingestion rates of T. kofoidii as a function of prey concentration were determined when feeding on the benthic cryptophyte Rhodomonas salina. Thecadinium kofoidii was able to feed on R. salina and the dinoflagellate Symbiodinium voratum, which had equivalent spherical diameters (ESDs) ≤ 10.1 µm, while it did not feed on the benthic dinoflagellates Levanderina fissa, Prorocentrum concavum or Ostreopsis cf. ovata, which had ESDs ≥ 15 µm. Thecadinium kofoidii fed on the edible prey cells using the peduncle. The maximum ingestion rate of T. kofoidii on R. salina was 1.3 cells predator−1 d−1. However, feeding on R. salina did not significantly increase the growth rate of T. kofoidii. The low ingestion rate of T. kofoidii on R. salina may have partially resulted in the lack of significant increase in its growth rate due to mixotrophy. The present study discovered predator–prey relationships between T. kofoidii and R. salina and S. voratum, which may change our view of the energy flow and carbon cycling in marine benthic food webs.N

Feeding by raphidophytes on the cyanobacterium Synechococcus sp.

We investigated feeding by the raphidophytes Chattonella ovata, C. subsalsa, Fibrocapsa japonica, and Heterosigma akashiwo on the cyanobacterium. Synechococcus sp. To explore whether each species is able to feed on Synechococcus sp., we carefully observed inside target grazer cells using an epifluorescence microscope and tranbsmission electron microscope (TEM). We also explored the feeding behaviors of C. ovata and H. akashiwo on Synechococcus using high-resolution video microscopy. In addition, we measured ingestion rates of C. ovata, C. subsalsa and H. akashiwo on Synechococcus sp. as a function of prey concentration. We calculated grazing coefficients by combining the field data on abundances of H. akashiwo and co-occurring Synechococcus spp. with laboratory data on ingestion rates. Both C. ovata and H. akashiwo were able to ingest single Synechococcus cells. However, neither TEM nor video microscopy showed any Synechococcus cells inside or ingested by F japonica, One to two ingested Synechococcus cells inside the protoplasm of F japonica cells were very rarely observed. C. ovata and H. akashiwo engulfed a single Synechococcus cell captured by the mucus excreted from mucocysts. The ingestion rates of C. ovata, C. subsalsa, or H. akashiwo on Synechococcus increased continuously with increasing prey concentration at prey concentrations ! 4 x 10(6) to 5.5 x 10(6) cells ml(-1). At a given prey concentration, the highest ingestion rates of the raphidophytes on Synechococcus were 18.6 cells raphidophyte(-1) h(-1) for C. ovata, 20.5 cells raphidophyte(-1) h(-1) for C. subsalsa, and 3.9 cells raphidophyte(-1) h(-1) for H. akashiwo. The calculated grazing coefficients attributable to H. akashiwo on co-occurring Synechococcus spp. were up to 1.24 d(-1). The results of the present study suggest that raphidophytes sometimes have a considerable grazing impact on populations of Synechococcus.N

MAX-Phase Films Overcome Scaling Limitations to the Resistivity of Metal Thin Films

Metal thin films have been widely used as conductors in semiconductor devices for several decades. However, the resistivity of metal thin films such as Cu and TiN increases substantially (>1000%) as they become thinner (<10 nm) when using high-density integration to improve device performance. In this study, the resistivities of MAX-phase V2AlC films grown on sapphire substrates exhibited a significantly weaker dependence on the film thickness than conventional metal films that resulted in a resistivity increase of only 30%, as the V2AlC film thickness decreased from approximately 45 to 5 nm. The resistivity was almost identical for film thicknesses of 10-50 nm. The small change in the resistivity of V2AlC films with decreasing film thickness originated from the highly ordered crystalline quality and a small electron mean free path (11-13.6 nm). Thus, MAX-phase thin films have great potential for advanced metal technology applications to overcome the current scaling limitations of semiconductor devices.11Nsciescopu

Red tides in Masan Bay, Korea in 2004-2005: II. Daily variations in the abundance of heterotrophic protists and their grazing impact on red-tide organisms

To investigate the role of heterotrophic protists in the dynamics of red tides in Masan Bay, Korea, we measured the abundance of heterotrophic dinoflagellates, ciliates, and heterotrophic nanoflagellates in daily samples collected from June 2004 to May 2005. The abundance of heterotrophic dinoflagellates, tintinnid ciliates, naked ciliates, and heterotrophic nanoflagellates were high when red tides occurred, with maximum biomass of 1916, 1263, 1013, and 141 ng C ml(-1), respectively. The HTDs Gyrodinium dominans/Gyrodinium moestrupii, Gyrodinium glaucum, Protoperidinium bipes, and Pfiesteria-like dinoflagellates (PLDs) as well as naked ciliates (&lt;= 50 mu m) were present nearly all year and their maximum biomass was 235, 48, 298, 1020, and 1013 ng C ml(-1), respectively. PLDs were the most abundant taxa during red tides dominated by Akashiwo sanguinea, Heterocapsa rotundata, summer populations of Prorocentrum minimum, Heterosigma akashiwo, Eutreptiella gymnastica, and cryptophytes, while G. dominans/G. moestrupii were most abundant during red tides dominated by Ceratium furca and Dinophysis acuminata. Naked ciliates were most abundant during red tides dominated by Cochlodinium polykrikoides, Prorocentrum triestinum, and winter populations of P. minimum. The maximum calculated grazing coefficients for each dominant heterotrophic protistan grazer on their respective co-occurring red-tide organisms in Masan Bay ranged from 0.0 to 6.8 h(-1). The results of the present study suggest that populations of certain heterotrophic protistan grazers may have considerable potential grazing impact on populations of red-tide organisms in Masan Bay. (C) 2013 Elsevier B.V. All rights reserved.N

Heterotrophic feeding as a newly identified survival strategy of the dinoflagellate Symbiodinium

Survival of free-living and symbiotic dinoflagellates (Symbiodinium spp.) in coral reefs is critical to the maintenance of a healthy coral community. Most coral reefs exist in oligotrophic waters, and their survival strategy in such nutrient-depleted waters remains largely unknown. In this study, we found that two strains of Symbiodinium spp. cultured from the environment and acquired from the tissues of the coral Alveopora japonica had the ability to feed heterotrophically. Symbiodinium spp. fed on heterotrophic bacteria, cyanobacteria (Synechococcus spp.), and small microalgae in both nutrient-replete and nutrient-depleted conditions. Cultured free-living Symbiodinium spp. displayed no autotrophic growth under nitrogen-depleted conditions, but grew when provided with prey. Our results indicate that Symbiodinium spp.&apos;s mixotrophic activity greatly increases their chance of survival and their population growth under nitrogen-depleted conditions, which tend to prevail in coral habitats. In particular, free-living Symbiodinium cells acquired considerable nitrogen from algal prey, comparable to or greater than the direct uptake of ammonium, nitrate, nitrite, or urea. In addition, free-living Symbiodinium spp. can be a sink for planktonic cyanobacteria (Synechococcus spp.) and remove substantial portions of Synechococcus populations from coral reef waters. Our discovery of Symbiodinium&apos;s feeding alters our conventional views of the survival strategies of photosynthetic Symbiodinium and corals.N