Evaluation and application of static headspace-multicapillary column-gas chromatography-ion mobility spectrometry for complex sample analysis.

An evaluation of static headspace-multicapillary column-gas chromatography-ion mobility spectrometry (SHS-MCC-GC-IMS) has been undertaken to assess its applicability for the determination of 32 volatile compounds (VCs). The key experimental variables of sample incubation time and temperature have been evaluated alongside the MCC-GC variables of column polarity, syringe temperature, injection temperature, injection volume, column temperature and carrier gas flow rate coupled with the IMS variables of temperature and drift gas flow rate. This evaluation resulted in six sets of experimental variables being required to separate the 32 VCs. The optimum experimental variables for SHS-MCC-GC-IMS, the retention time and drift time operating parameters were determined; to normalise the operating parameters, the relative drift time and normalised reduced ion mobility for each VC were determined. In addition, a full theoretical explanation is provided on the formation of the monomer, dimer and trimer of a VC. The optimum operating condition for each VC calibration data was obtained alongside limit of detection (LOD) and limit of quantitation (LOQ) values. Typical detection limits ranged from 0.1ng bis(methylthio)methane, ethylbutanoate and (E)-2-nonenal to 472ng isovaleric acid with correlation coefficient (R(2)) data ranging from 0.9793 (for the dimer of octanal) through to 0.9990 (for isobutyric acid). Finally, the developed protocols were applied to the analysis of malodour in sock samples. Initial work involved spiking an inert matrix and sock samples with appropriate concentrations of eight VCs. The average recovery from the inert matrix was 101±18% (n=8), while recoveries from the sock samples were lower, that is, 54±30% (n=8) for sock type 1 and 78±24% (n=6) for sock type 2. Finally, SHS-MCC-GC-IMS was applied to sock malodour in a field trial based on 11 volunteers (mixed gender) over a 3-week period. By applying the SHS-MCC-GC-IMS database, four VCs were identified and quantified: ammonia, dimethyl disulphide, dimethyl trisulphide and butyric acid. A link was identified between the presence of high ammonia and dimethyl disulphide concentrations and a high malodour odour grading, that is, ≥ 6. Statistical analysis did not find any correlation between the occurrence of dimethyl disulphide and participant gender

Streaming Algorithm for Euler Characteristic Curves of Multidimensional Images

We present an efficient algorithm to compute Euler characteristic curves of gray scale images of arbitrary dimension. In various applications the Euler characteristic curve is used as a descriptor of an image. Our algorithm is the first streaming algorithm for Euler characteristic curves. The usage of streaming removes the necessity to store the entire image in RAM. Experiments show that our implementation handles terabyte scale images on commodity hardware. Due to lock-free parallelism, it scales well with the number of processor cores. Our software---CHUNKYEuler---is available as open source on Bitbucket. Additionally, we put the concept of the Euler characteristic curve in the wider context of computational topology. In particular, we explain the connection with persistence diagrams

Synergistic Effects of Methylglyoxal and Hyperglycemia on ROS Generation and the Viability of Cultured H9c2 Myoblast Cells

Heart damage in diabetics may be closely related to the possible synergistic cellular damage from hyperglycemia and increased methylglyoxal levels. This study investigated the effects of glucose and/or methylglyoxal and/or metformin on H9c2 reactive oxygen species (ROS) generation measured by a dichlorofluorescein diacetate (DCFDA) assay and cell viability measured by a cell counting kit-8 assay after various treatments for 24 hours. Glucose treatment (5 mM-40 mM) displayed similar cell viability (n=4) and ROS generation (n=7) when compared to control cells. By contrast, methylglyoxal (5 µM-1400 µM) decreased cell viability at higher concentration (1000 µM (51 ± 8%); 1200 µM (41 ± 5%); 1400 µM (36 ± 8%); all p\u3c0.05, n=5) compared to control cells, which was accompanied by significantly higher ROS generation (1000 µM (167 ± 27%); 1200 µM (204 ± 22%); 1400 µM (201 ± 15%); all p\u3c0.05, n=3). Furthermore, metformin (1 mM-40 mM) reduced methylglyoxal (1200 µM) induced ROS generation and cell death. When H9c2 cells were treated with glucose (25 mM or 40 mM) and different doses of methylglyoxal (600 µM -1400 µM), only higher glucose (40 mM) with different doses of methylglyoxal (600 µM -1400 µM) consistently showed lower cell viability and higher ROS when compared to individual glucose or methylglyoxal. The data suggest that higher concentrations of methylglyoxal, not glucose, induces H9c2 cell damage and metformin can protect cells from the methylglyoxal insult possibly by reduction of ROS production. Moreover, hyperglycemia and methylglyoxal tend to synergistically induce cell damage associated with increased ROS production

Plinian Core Profiles. Facilitating the documentation and access to biological information of exotic and invasive species.

-Santa Clara de San Carlos, Costa RicaEvaluación y Monitoreo de la Biodiversidad - Sib ColombiaTDWG Taxonomic Databases Working Grou

Casa Huarte en Formentor: encuentro entre naturaleza y arquitectura

En el presente trabajo, se analiza la obra de ampliación de la casa Huarte en Formentor, realizada por Francisco Javier Sáenz de Oíza. El interés en la investigación y desarrollo de la propuesta por parte del arquitecto, teniendo en cuenta el entorno inmediato de la vivienda original, salvando y acomodándose a los pinos que reinan la parcela, permitiendo la conexión entre el material artificial y natural. Esta obra se manifiesta en contexto con los demás trabajos del autor y compañeros coetáneos asi como su comparación, 26 años después con una propuesta de obra nueva, a escasos metros con un lenguaje arquitectónico totalmente distinto.<br /

The Effects of Metformin, Aminoguanidine, and Pyridoxamine on Methylglyoxal Induced Cardiac Myocyte Injury

Advanced glycation end (AGE) products have been under investigation for their role in cardiovascular disease in complications. Methylglyoxal, a byproduct of glucose metabolism, is elevated in the blood of diabetic patients and has shown to be an important intermediate in the production of AGEs. Due to the highly reactive structure of methylglyoxal, it can produce high levels of reactive oxygen species (ROS) within the cell via mitochondrial modification which results in a loss of cell membrane potential and possible cell death. The role of methylglyoxal in cardiac cells is not well known; in this study methylglyoxal induced cell injury and ROS generation were investigated by co-treatment of methylglyoxal with metformin, aminoguanidine hydrochloride, or pyridoxamine dihydrochloride. The effects of methylglyoxal on H9C2 myoblast viability were evaluated after incubation of drugs for 24 hours by measuring absorbance at 450 nm by using tetrazolium to differentiate metabolically active and inactive cells (e.g., CCK-8 kit). We found that methylglyoxal (1200 µM) significantly reduced cell viability to 28 ±6% when compared to the untreated control (n=4, p36 hours fluorescence was measured at excitation 488 nm and emission 527 nm (e.g., DCFDA kit). We found that methylglyoxal (1200 µM) significantly increased ROS by 205±25% when compared to the untreated control baseline (n=4,

Synthesis and bactericidal properties of porphyrins immobilized in a polyacrylamide support: influence of metal complexation on photoactivity

Spectroscopic and photodynamic properties of three novel polymeric hydrogels bearing porphyrins have been studied in vitro on the recombinant bioluminescent Gram-negative Escherichia coli DH5α to assess their ability to inactivate bacterial strains in solution. The three different hydrogels were formed by polymerization of 5-[4-2-(2-(2-acrylamidoethoxy)ethoxy)ethyl]carboxyphenyl-10,15,20-tris(4-N-methylpyridyl)porphyrin trichloride (5) and its complexes with Pd(II) (6) and Cu(II) (7) respectively, to form three optically transparent polyacrylamide hydrogels. All of the porphyrins are tricationic and they bear at the meso positions three N-methylpyridyl rings and one terminal acryloyl group connected through a flexible hydrophilic linker, particularly suitable for the later polymerization and incorporation into a hydrogel. The hydrogels were characterized by IR and scanning electron microscopy and incorporation of the dye was confirmed by UV-visible spectroscopy. All the hydrogels are characterized by a non-ordered microporous structure. The E. coli exhibited a decrease of 1.87 log after 25 min irradiation when the porphyrin hydrogel 9 was evaluated. When the Pd(II) and Cu(II)porphyrin hydrogels were tested (10, 11), they showed a 2.93 log decrease and 1.26 log decrease in the survival of the E. coli after 25 min irradiation, respectively. Similar results were obtained when the porphyrins were tested in solution. Of the three hydrogels, the Pd(II)porphyrin hydrogel (10) proved to be the one with the highest photokilling ability under illumination, and also exhibited the lowest toxicity in the absence of light. Hydrogels 9 and 10 were found to be active for five cycles, suggesting the possibility of reuse

Memory consolidation in the cerebellar cortex

Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABA(A) agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage

On-Orbit Data and Validation of Astra\u27s ACE Electric Propulsion System

The first ACE propulsion system reached orbit on July 1st 2021 as part of Spaceflight’s demonstration of the Sherpa-LTE all-electric Orbital Transfer Vehicle (OTV). We are now able to share on-orbit data and have successfully verified the on-orbit performance of the ACE propulsion system, using xenon propellent. The mission objective was to lower altitude and use on-orbit data to derive performance, correlating the propulsion system’s performance to ground test data. The demonstration consisted of activating the propulsion system for 5- minute durations at a total input power of 340 W into the Power Processing Unit (PPU). Altitude change and propellant usage were used to derive thrust and total specific impulse. On-orbit performance is compared to ground test data in Table 1. Averaged performance is within one standard deviation of ground test data. Astra considers this a validation of system performance, as well as the ground test facilities used to test propulsion systems. On-orbit thrust has a large standard deviation as a result of the limited data sampling rate and measurement errors, rather than variability in thruster performance. Figure 1 shows the thruster operating on-orbit. The Astra team gratefully acknowledges the support of Spaceflight, Inc., the U.S. Air Force, and Defense Innovation Unit (DIU) without which this mission would not have been possible

Description of Genetic Variants in BRCA Genes in Mexican Patients with Ovarian Cancer: A First Step towards Implementing Personalized Medicine

Abstract Gynecologic cancers are among the leading causes of death worldwide, ovarian cancer being the one with the highest mortality rate. Olaparib is a targeted therapy used in patients presenting mutations in BRCA1 and BRCA2 genes. The aim of this study was to describe BRCA1 and BRCA2 gene variants in Mexican patients with ovarian cancer. Sequencing of BRCA1 and BRCA2 genes from tumors of 50 Mexican patients with ovarian cancer was made in a retrospective, non-randomized, and exploratory study. We found genetic variants in 48 of 50 cases. A total of 76 polymorphic variants were found in BRCA1, of which 50 (66%) had not been previously reported. Furthermore, 104 polymorphic variants were found in BRCA2, of which 63 (60%) had not been reported previously. Of these polymorphisms, 5/76 (6.6%) and 4/104 (3.8%) were classified as pathogenic in BRCA1 and BRCA2, respectively. We have described the genetic variants in BRCA1 and BRCA2 of tumors from Northeast Mexican patients with sporadic ovarian cancers. Our results showed that the use of genetic testing helps recognize patients that carry pathogenic variants which could be beneficial for personalized medicine treatments. Keywords: BRCA; ovarian cancer; personalized therapy; sequencin