| 41. |
- Lara-Gonzalez, Samuel, et al.
(författare)
-
Substrate-induced dimerization of engineered monomeric variants of triosephosphate isomerase from trichomonas vaginalis
- 2015
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- The dimeric nature of triosephosphate isomerases (TIMs) is maintained by an extensive surface area interface of more than 1600 Å2. TIMs from Trichomonas vaginalis (TvTIM) are held in their dimeric state by two mechanisms: A ball and socket interaction of residue 45 of one subunit that fits into the hydrophobic pocket of the complementary subunit and by swapping of loop 3 between subunits. TvTIMs differ from other TIMs in their unfolding energetics. In TvTIMs the energy necessary to unfold a monomer is greater than the energy necessary to dissociate the dimer. Herein we found that the character of residue I45 controls the dimer-monomer equilibrium in TvTIMs. Unfolding experiments employing monomeric and dimeric mutants led us to conclude that dimeric TvTIMs unfold following a four state model denaturation process whereas monomeric TvTIMs follow a three state model. In contrast to other monomeric TIMs, monomeric variants of TvTIM1 are stable and unexpectedly one of them (I45A) is only 29-fold less active than wild-type TvTIM1. The high enzymatic activity of monomeric TvTIMs contrast with the marginal catalytic activity of diverse monomeric TIMs variants. The stability of the monomeric variants of TvTIM1 and the use of cross-linking and analytical ultracentrifugation experiments permit us to understand the differences between the catalytic activities of TvTIMs and other marginally active monomeric TIMs. As TvTIMs do not unfold upon dimer dissociation, herein we found that the high enzymatic activity of monomeric TvTIM variants is explained by the formation of catalytic dimeric competent species assisted by substrate binding.
|
|
| 42. |
- Lluis, Nuria, et al.
(författare)
-
Intraductal papillary neoplasms of the bile duct: a European retrospective multicenter observational study (EUR-IPNB study)
- 2023
-
Ingår i: International Journal of Surgery. - : LIPPINCOTT WILLIAMS & WILKINS. - 1743-9191 .- 1743-9159. ; 109:4, s. 760-771
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Purpose:Intraductal papillary neoplasm of the bile duct (IPNB) is a rare disease in Western countries. The main aim of this study was to characterize current surgical strategies and outcomes in the mainly European participating centers. Methods:A multi-institutional retrospective series of patients with a diagnosis of IPNB undergoing surgery between 1 January 2010 and 31 December 2020 was gathered under the auspices of the European-African Hepato-Pancreato-Biliary Association. The textbook outcome (TO) was defined as a non-prolonged length of hospital stay plus the absence of any Clavien-Dindo grade at least III complications, readmission, or mortality within 90 postoperative days. Results:A total of 28 centers contributed 85 patients who underwent surgery for IPNB. The median age was 66 years (55-72), 49.4% were women, and 87.1% were Caucasian. Open surgery was performed in 72 patients (84.7%) and laparoscopic in 13 (15.3%). TO was achieved in 54.1% of patients, reaching 63.8% after liver resection and 32.0% after pancreas resection. Median overall survival was 5.72 years, with 5-year overall survival of 63% (95% CI: 50-82). Overall survival was better in patients with Charlson comorbidity score 4 or less versus more than 4 (P=0.016), intrahepatic versus extrahepatic tumor (P=0.027), single versus multiple tumors (P=0.007), those who underwent hepatic versus pancreatic resection (P=0.017), or achieved versus failed TO (P=0.029). Multivariable Cox regression analysis showed that not achieving TO (HR: 4.20; 95% CI: 1.11-15.94; P=0.03) was an independent prognostic factor of poor overall survival. Conclusions:Patients undergoing liver resection for IPNB were more likely to achieve a TO outcome than those requiring a pancreatic resection. Comorbidity, tumor location, and tumor multiplicity influenced overall survival. TO was an independent prognostic factor of overall survival.
|
|
| 43. |
- Lluís, Núria, et al.
(författare)
-
Intraductal papillary neoplasms of the bile ducts : a comparative study of a rare disease in Europe and Nagoya, Japan
- 2024
-
Ingår i: HPB. - : ELSEVIER SCI LTD. - 1365-182X .- 1477-2574. ; 26:4, s. 565-575
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Intraductal papillary neoplasm of the bile ducts (IPNB) is a rare disease in Western countries. The aim of this study was to compare tumor characteristics, management strategies, and outcomes between Western and Eastern patients who underwent surgical resection for IPNB. Methods: A multi-institutional retrospective series of patients with IPNB undergoing surgery between January 2010 and December 2020 was gathered under the auspices of the European-African Hepato-Pancreato-Biliary Association (E-AHPBA), and at Nagoya University Hospital, Japan. Results: A total of 85 patients (51% male; median age 66 years) from 28 E-AHPBA centers were compared to 91 patients (64% male; median age 71 years) from Nagoya. Patients in Europe had more multiple lesions (23% vs 2%, P < .001), less invasive carcinoma (42% vs 85%, P < .001), and more intrahepatic tumors (52% vs 24%, P < .001) than in Nagoya. Patients in Europe experienced less 90-day grade >3 Clavien-Dindo complications (33% vs 68%, P < .001), but higher 90-day mortality rate (7.0% vs 0%, P = .03). R0 resections (81% vs 82%) were similar. Overall survival, excluding 90-day postoperative deaths, was similar in both regions. Discussion: Despite performing more extensive resections, the low perioperative mortality rate observed in Nagoya was probably influenced by a combination of patient-, tumor-, and surgery-related factors.
|
|
| 44. |
|
|
| 45. |
-
The Seventeenth Data Release of the Sloan Digital Sky Surveys : Complete Release of MaNGA, MaStar, and APOGEE-2 Data
- 2022
-
Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics (IOP). - 0067-0049 .- 1538-4365. ; 259:2
-
Tidskriftsartikel (refereegranskat)abstract
- This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
|
|
| 46. |
- Aartsen, M. G., et al.
(författare)
-
Multiwavelength follow-up of a rare IceCube neutrino multiplet
- 2017
-
Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 607
-
Tidskriftsartikel (refereegranskat)abstract
- On February 17, 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky. Such a triplet is expected once every 13.7 years as a random coincidence of background events. However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%. Follow-up observatories were notified in order to search for an electromagnetic counterpart. Observations were obtained by Swift's X-ray telescope, by ASAS-SN, LCO and MASTER at optical wavelengths, and by VERITAS in the very-high-energy gamma-ray regime. Moreover, the Swift BAT serendipitously observed the location 100 s after the first neutrino was detected, and data from the Fermi LAT and HAWC observatory were analyzed. We present details of the neutrino triplet and the follow-up observations. No likely electromagnetic counterpart was detected, and we discuss the implications of these constraints on candidate neutrino sources such as gamma-ray bursts, core-collapse supernovae and active galactic nucleus flares. This study illustrates the potential of and challenges for future follow-up campaigns.
|
|
| 47. |
- Akiyama, Kazunori, et al.
(författare)
-
First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multiwavelength Observations, Data Processing, and Calibration
- 2022
-
Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 930:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5-11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of similar to 50 mu as, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*'s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior.
|
|
| 48. |
- Alexandrov, Ludmil B., et al.
(författare)
-
Signatures of mutational processes in human cancer
- 2013
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 500:7463, s. 415-421
-
Tidskriftsartikel (refereegranskat)abstract
- All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy.
|
|
| 49. |
- Antonio Lopez-Lopez, Jose, et al.
(författare)
-
Simple hollow fiber liquid membrane based pre-concentration of silver for atomic absorption spectrometry
- 2014
-
Ingår i: Analytical Methods. - : Royal Society of Chemistry (RSC). - 1759-9660. ; 6:5, s. 1462-1467
-
Tidskriftsartikel (refereegranskat)abstract
- Silver pollution has gained attention in the last few years because silver is being massively used as a bactericide in self-care, medical and textile products. Difficulties of Ag determination are associated with the very low concentrations in which it is normally found (ng L-1) and the nature of the sample matrix. Standard methods such as liquid-liquid extraction (LLE) are regularly used. Alternatively, liquid phase micro-extraction (LPME) appears to be an environmentally friendly tool for sample treatment that offers higher pre-concentration factors. This allows the determination of ultra-trace levels of silver using standard instrumental techniques such as atomic absorption spectrometry. In this work, a hollow fiber LPME is proposed. Silver pre-concentration has been conducted using tri-isobutylphosphine sulphide (TIBPS) as a carrier from the sample to an acceptor solution through a solvent placed in the fiber pores. Accurel-PP 50/280 fibers with an internal volume of 20 mu L were used for 50 mL samples. After optimization, 0.1 M KNO3 in the sample, 0.1 M TIBPS in dihexyl ether as the organic phase and 1 M Na2S2O3 in the acceptor solution were established. The system offers enrichment factors of 1053 times, a limit of detection of 1.16 ng L-1. This method improves the limit of detection of the most recent liquid micro-extraction methods for silver pre-concentration coupled with GFAAS, being in this case comparable to ICP-MS detection based techniques.
|
|
| 50. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
