Photosynthetic light requirement near the theoretical minimum detected in Arctic microalgae.

Photosynthesis is one of the most important biological processes on Earth, providing the main source of bioavailable energy, carbon, and oxygen via the use of sunlight. Despite this importance, the minimum light level sustaining photosynthesis and net growth of primary producers in the global ocean is still unknown. Here, we present measurements from the MOSAiC field campaign in the central Arctic Ocean that reveal the resumption of photosynthetic growth and algal biomass buildup under the ice pack at a daily average irradiance of not more than 0.

A comprehensive dataset on spatiotemporal variation of microbial plankton communities in the Baltic Sea.

The Baltic Sea is one of the largest brackish water environments on earth and is characterised by pronounced physicochemical gradients and seasonal dynamics. Although the Baltic Sea has a long history of microscopy-based plankton monitoring, DNA-based metabarcoding has so far mainly been limited to individual transect cruises or time-series of single stations. Here we report a dataset covering spatiotemporal variation in prokaryotic and eukaryotic microbial communities and physicochemical parameters.

Multiomics in the central Arctic Ocean for benchmarking biodiversity change.

Multiomics approaches need to be applied in the central Arctic Ocean to benchmark biodiversity change and to identify novel species and their genes. As part of MOSAiC, EcoOmics will therefore be essential for conservation and sustainable bioprospecting in one of the least explored ecosystems on Earth.

Glacial melt disturbance shifts community metabolism of an Antarctic seafloor ecosystem from net autotrophy to heterotrophy.

Climate change-induced glacial melt affects benthic ecosystems along the West Antarctic Peninsula, but current understanding of the effects on benthic primary production and respiration is limited. Here we demonstrate with a series of in situ community metabolism measurements that climate-related glacial melt disturbance shifts benthic communities from net autotrophy to heterotrophy. With little glacial melt disturbance (during cold El Niño spring 2015), clear waters enabled high benthic microalgal production, resulting in net autotrophic benthic communities.

Large Diversity in Nitrogen- and Sulfur-Containing Compatible Solute Profiles in Polar and Temperate Diatoms.

Intense bottom-ice algal blooms, often dominated by diatoms, are an important source of food for grazers, organic matter for export during sea ice melt, and dissolved organic carbon. Sea-ice diatoms have a number of adaptations, including accumulation of compatible solutes, that allows them to inhabit this highly variable environment characterized by extremes in temperature, salinity, and light. In addition to protecting them from extreme conditions, these compounds present a labile, nutrient-rich source of organic matter, and include precursors to climate active compounds (e.

Use of exogenous glycine betaine and its precursor choline as osmoprotectants in Antarctic sea-ice diatoms.

Wide salinity ranges experienced during the seasonal freeze and melt of sea ice likely constrain many biological processes. Microorganisms generally protect against fluctuating salinities through the uptake, production, and release of compatible solutes. Little is known, however, about the use or fate of glycine betaine (GBT hereafter), one of the most common compatible solutes, in sea-ice diatoms confronted with shifts in salinity.

Spatial variability of biogeochemistry in shallow coastal benthic communities of Potter Cove (Antarctica) and the impact of a melting glacier.

Measurements of biogeochemical fluxes at the sediment-water interface are essential to investigate organic matter mineralization processes but are rarely performed in shallow coastal areas of the Antarctic. We investigated biogeochemical fluxes across the sediment-water interface in Potter Cove (King George Island/Isla 25 de Mayo) at water depths between 6-9 m. Total fluxes of oxygen and inorganic nutrients were quantified in situ.

Differential Burden of Rare and Common Variants on Tumor Characteristics, Survival, and Mode of Detection in Breast Cancer.

Genetic variants that increase breast cancer risk can be rare or common. This study tests whether the genetic risk stratification of breast cancer by rare and common variants in established loci can discriminate tumors with different biology, patient survival, and mode of detection. Multinomial logistic regression tested associations between genetic risk load [protein-truncating variant (PTV) carriership in 31 breast cancer predisposition genesor polygenic risk score (PRS) using 162 single-nucleotide polymorphisms], tumor characteristics, and mode of detection (OR).

Can probiotics be an alternative to chlorhexidine for oral care in the mechanically ventilated patient? A multicentre, prospective, randomised controlled open trial.

Background: Pathogenic enteric bacteria aspirated from the oropharynx are the main cause of ventilator-associated pneumonia (VAP). Using chlorhexidine (CHX) orally or selective decontamination has been shown to reduce VAP. In a pilot study we found that oral care with the probiotic bacterium Lactobacillus plantarum 299 (Lp299) was as effective as CHX in reducing enteric bacteria in the oropharynx.

Prevalence of BRCA1 and BRCA2 pathogenic variants in a large, unselected breast cancer cohort.

Breast cancer patients with BRCA1/2-driven tumors may benefit from targeted therapy. It is not clear whether current BRCA screening guidelines are effective at identifying these patients. The purpose of our study was to evaluate the prevalence of inherited BRCA1/2 pathogenic variants in a large, clinically representative breast cancer cohort and to estimate the proportion of BRCA1/2 carriers not detected by selectively screening individuals with the highest probability of being carriers according to current clinical guidelines.

Microalgal photophysiology and macronutrient distribution in summer sea ice in the Amundsen and Ross Seas, Antarctica.

Our study addresses how environmental variables, such as macronutrients concentrations, snow cover, carbonate chemistry and salinity affect the photophysiology and biomass of Antarctic sea-ice algae. We have measured vertical profiles of inorganic macronutrients (phosphate, nitrite + nitrate and silicic acid) in summer sea ice and photophysiology of ice algal assemblages in the poorly studied Amundsen and Ross Seas sectors of the Southern Ocean. Brine-scaled bacterial abundance, chl a and macronutrient concentrations were often high in the ice and positively correlated with each other.

Ocean acidification and desalination: climate-driven change in a Baltic Sea summer microplanktonic community.

Helcom scenario modelling suggests that the Baltic Sea, one of the largest brackish-water bodies in the world, could expect increased precipitation (decreased salinity) and increased concentration of atmospheric CO over the next 100 years. These changes are expected to affect the microplanktonic food web, and thereby nutrient and carbon cycling, in a complex and possibly synergistic manner. In the Baltic Proper, the extensive summer blooms dominated by the filamentous cyanobacteria sp.

Long-term acclimation to elevated pCO2 alters carbon metabolism and reduces growth in the Antarctic diatom Nitzschia lecointei.

Increasing atmospheric CO2 levels are driving changes in the seawater carbonate system, resulting in higher pCO2 and reduced pH (ocean acidification). Many studies on marine organisms have focused on short-term physiological responses to increased pCO2, and few on slow-growing polar organisms with a relative low adaptation potential. In order to recognize the consequences of climate change in biological systems, acclimation and adaptation to new environments are crucial to address.

Physicochemical control of bacterial and protist community composition and diversity in Antarctic sea ice.

Due to climate change, sea ice experiences changes in terms of extent and physical properties. In order to understand how sea ice microbial communities are affected by changes in physicochemical properties of the ice, we used 454-sequencing of 16S and 18S rRNA genes to examine environmental control of microbial diversity and composition in Antarctic sea ice. We observed a high diversity and richness of bacteria, which were strongly negatively correlated with temperature and positively with brine salinity.

On-line process control of gradient elution liquid chromatography.

The typical measure of the stability of analytical HPLC methods in the pharmaceutical laboratory is standards injected repeatedly throughout the sample sequence. To obtain improved control of the analysis and reduction of the number of standards and replicates, a novel approach to treat the analytical run as a process, where the chromatographic data is the product, is proposed. Thus, an alternative and continuous system suitability test procedure is described.

Low IL-1alpha expression in bladder cancer tissue and survival.

Objective: To investigate whether the previously reported association between IL-1alpha mRNA levels and survival in urinary bladder cancer remains in an extended patient material and to search a mechanism behind a possible antitumoral activity of IL-1alpha.

Patients And Methods: IL-1alpha mRNA levels were determined in 164 tumors with quantitative TaqMan PCR.

Results: A large variation was found in mRNA levels of IL-1alpha.

Immobilisation and evaluation of a vancomycin chiral stationary phase for capillary electrochromatography.

The macrocyclic antibiotic, vancomycin, is covalently bonded to LiChrospher diol silica packed columns and evaluated in capillary electrochromatography (CEC) both in the reversed-phase and polar organic mode. Initially, capillaries were packed with 5 microm LiChrospher 100 A diol silica and evaluated in CEC with a reversed-phase biphenyl-pyrene achiral test resulting in resolution and efficiency values of ca. 2.

The use of supercritical fluid extraction for sample preparation of pharmaceutical formulations.

This paper reviews the use of supercritical fluid extraction (SFE) as a sample work-up step in the analysis of drugs in various pharmaceutical formulations. Matrices studies include tablets, animal feed, creams, ointments and infusions. As in other fields of analytical chemistry, SFE has proven to be most suitable for comparatively non-polar compounds in solid matrices.

Evaluation of solubilizers in the drug release testing of hydrophilic matrix extended-release tablets of felodipine.

The drug release of felodipine, a water-insoluble drug, was tested by using sodium lauryl sulphate (SLS), polyoxyethylene 20 sorbitan monooleate (Tween) or cetyltrimethylammonium bromide (CTAB) in the test medium as solubilizers. Three slightly different felodipine extended-release (ER) tablets 10 mg based on the gel matrix principle were evaluated under different solubilizer concentrations, agitation intensities and pH. These tablets were also tested in a bioavailability study together with an oral solution.

Flow injection extraction applied to dissolution rate studies of felodipine tablets.

A flow injection analysis (FIA) extraction method has been developed for the analysis of felodipine tablets in connection with dissolution rate testing. The water-soluble oxidation product of felodipine, a pyridine derivative, was extracted into chloroform and measured at 275 nm spectrophotometrically. The FIA-extraction method has been compared with the present liquid chromatographic (LC) method.