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1.
Biol Trace Elem Res ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829478

RESUMO

The prevalence of diabetes has reached alarming levels in India, making it essential to understand the concentration of nutritional-trace elements (Fe, Cu, Zn, Cr. and Se) in blood samples from diabetic adults. In this study, 208 whole blood samples from diabetic (n = 104) and non-diabetic (n = 104) adults across various age groups were analyzed using total reflection X-ray fluorescence (TXRF) spectroscopy with a sample dilution method. Statistical analysis was performed to assess descriptive statistics and determine a significant correlation between elemental concentrations in the blood samples of diabetic and non-diabetic adults. The mean concentration of nutritional-related trace elements in diabetic blood was as follows: Fe (46 ± 5) > Zn (1.28 ± 0.14) > Cu (0.10 ± 0.01) > Cr (0.05 ± 0.004) > Se (0.013 ± 0.001) in mg/L, respectively. Additionally, this study investigated the influence of nutrition-related trace element concentrations across various age groups such as 25-40 years (young adults), 41-55 years (middle-aged adults), and 56-70 years (older adults). In this investigation, Zn (p < 0.001) and Cr (p < 0.05) concentrations differed significantly between diabetic and non-diabetic adults aged 56-70 years. These findings will help us to understand age-dependent changes in element concentrations, clarify their role in diabetes, and improve risk factor management associated with diabetes.

2.
Nature ; 627(8005): 759-762, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38538936

RESUMO

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

3.
Phys Chem Chem Phys ; 25(33): 22286-22293, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37578066

RESUMO

Scalable and low-cost synthesis of high-quality ferroic films is critical for the development of advanced electronic devices and sensors. Here, we employ solution-based spray pyrolysis to fabricate bismuth ferrite thin films on glass substrates and explore the impact of annealing conditions to attain functional thin films of superior quality and switchable polarization. Optimised thin films display polycrystalline nanostructured grains with the highest X-ray diffraction intensity along the (110) orientation and a mixed Fe2+/3+ valence suggesting the presence of oxygen vacancies. The optimized films show a complex ferroelectric domain microstructure and exhibit robust nanoscale polarization switching in the range of several volts. Domains are found to scale with the sizes of nanocrystalline grains, which points to the role of surface-energy-related mechanisms affecting the domain patterns. Our results demonstrate the potential of spray pyrolysis for the fabrication of high-quality ferroelectric thin films and provide new opportunities for the development of low-cost scalable advanced electronic devices.

4.
Nature ; 620(7972): 61-66, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37468630

RESUMO

White dwarfs, the extremely dense remnants left behind by most stars after their death, are characterized by a mass comparable to that of the Sun compressed into the size of an Earth-like planet. In the resulting strong gravity, heavy elements sink towards the centre and the upper layer of the atmosphere contains only the lightest element present, usually hydrogen or helium1,2. Several mechanisms compete with gravitational settling to change a white dwarf's surface composition as it cools3, and the fraction of white dwarfs with helium atmospheres is known to increase by a factor of about 2.5 below a temperature of about 30,000 kelvin4-8; therefore, some white dwarfs that appear to have hydrogen-dominated atmospheres above 30,000 kelvin are bound to transition to be helium-dominated as they cool below it. Here we report observations of ZTF J203349.8+322901.1, a transitioning white dwarf with two faces: one side of its atmosphere is dominated by hydrogen and the other one by helium. This peculiar nature is probably caused by the presence of a small magnetic field, which creates an inhomogeneity in temperature, pressure or mixing strength over the surface9-11. ZTF J203349.8+322901.1 might be the most extreme member of a class of magnetic, transitioning white dwarfs-together with GD 323 (ref. 12), a white dwarf that shows similar but much more subtle variations. This class of white dwarfs could help shed light on the physical mechanisms behind the spectral evolution of white dwarfs.

5.
Nature ; 617(7959): 55-60, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37138107

RESUMO

Planets with short orbital periods (roughly under 10 days) are common around stars like the Sun1,2. Stars expand as they evolve and thus we expect their close planetary companions to be engulfed, possibly powering luminous mass ejections from the host star3-5. However, this phase has never been directly observed. Here we report observations of ZTF SLRN-2020, a short-lived optical outburst in the Galactic disk accompanied by bright and long-lived infrared emission. The resulting light curve and spectra share striking similarities with those of red novae6,7-a class of eruptions now confirmed8 to arise from mergers of binary stars. Its exceptionally low optical luminosity (approximately 1035 erg s-1) and radiated energy (approximately 6.5 × 1041 erg) point to the engulfment of a planet of fewer than roughly ten Jupiter masses by its Sun-like host star. We estimate the Galactic rate of such subluminous red novae to be roughly between 0.1 and several per year. Future Galactic plane surveys should routinely identify these, showing the demographics of planetary engulfment and the ultimate fate of planets in the inner Solar System.

6.
Immunohematology ; 39(1): 19-31, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37017595

RESUMO

Complexities of D within the Rh blood group system have long been recognized, initially using basic serologic testing and, more recently, using advanced and sensitive typing reagents. Discrepancies may arise when an individual carries a D antigen showing altered D antigen expression. These D variants are clinically important, since they may lead to production of anti-D in the carrier and induce alloimmunization in D- recipients, making their correct identification imperative. For clinical purposes, D variants can be classified into three groups: weak D, partial D, and DEL. The problem surrounding proper characterization of D variants exists because routine serologic tests are sometimes inadequate to detect D variants or resolve discrepant or ambiguous D typing results. Today, molecular analysis has revealed more than 300 RH alleles and is a better method for investigating D variants. Global distribution of variants differs, as observed in European, African, and East Asian populations. Discovery of the novel RHD*01W.150 (weak D type 150) with a nucleotide change of c.327_487-4164dup is proof. This variant, the result of an insertion of a duplicated exon 3 between exons 2 and 4 in the same orientation, was detected in more than 50 percent of Indian D variant samples in a 2018 study. The outcome of studies worldwide has led to the recommendation to manage D variant individuals as D+ or D- according to RHD genotype. The policies and workup with respect to D variant testing in donors, recipients, and prenatal women differ among blood banks, depending on type of variants predominantly encountered. Thus, a general genotyping protocol cannot be followed globally, and an Indian-specific RHD genotyping assay (multiplex polymerase chain reaction) designed to detect D variants frequently found in the Indian population was developed to save time and resources. This assay is also helpful for detecting several partial and null alleles. Identification of D variants by serology and characterization by molecular testing need to go hand-in-hand for better and safer transfusion practices.


Assuntos
Transfusão de Sangue , Sistema do Grupo Sanguíneo Rh-Hr , Gravidez , Humanos , Feminino , Sistema do Grupo Sanguíneo Rh-Hr/genética , Genótipo , Bancos de Sangue , Éxons , Alelos , Doadores de Sangue
7.
Tech Coloproctol ; 27(7): 537-549, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36790541

RESUMO

BACKGROUND: Robotic surgery (RS) is increasingly employed in colorectal surgical practice, widening the range of surgical techniques offered to patients. We investigated the perceptions of patients with colorectal cancer in relation to RS, open surgery (OS) and conventional laparoscopic surgery (CLS), to identify ideas or assumptions which, in the context of shared surgeon-patient decision-making, may affect the resultant choice of surgical technique. We also investigated salient factors affecting patients' perioperative experience, including those of RS patients, to guide improvements in care and preoperative patient preparation. METHODS: This study was conducted on patients who underwent resection of left-sided colorectal cancer at a large UK teaching hospital from November 2020 to July 2021. Purposive sampling was used to ensure a roughly equal proportion of patients who underwent RS, CLS and OS. The patients included in the study participated in semi-structured interviews six weeks postoperatively. The interview schedule allowed discussion around patients' experience of their surgery and postoperative recovery, and their perceptions of surgical techniques. Interview transcripts were coded manually using inductive thematic analysis, and analyst triangulation was employed to refine coding schemes and ensure reliability of emerging themes. RESULTS: Twenty-seven patients were recruited to the study; RS n = 9 (median age 69 [range 60-80] years); CLS n = 10 (median age 72 [range 32-82] years; OS n = 8 (median age 71 [range 60-75] years). Patients understood the technological benefits of RS but were concerned by a risk of technological failure causing patient harm. OS was understood to be associated with more pain and longer recovery than RS or CLS. Patients perceived CLS to be more technically challenging compared with OS. Less pain and smaller wounds than expected were significant positive factors in the experience of RS and CLS patients specifically. Complications and emotional impact were significant factors in the experience of all groups, for which many patients felt underprepared. CONCLUSIONS: Patients generally have a positive view of RS and technical innovation in surgery. Concerns mostly centred around failure of technology. Many patients felt unprepared for significant factors in their perioperative experience. Surgeons and healthcare providers should be prepared to address patients' perceptions and expectations of colorectal surgery preoperatively.


Assuntos
Neoplasias Colorretais , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto , Reprodutibilidade dos Testes , Dor , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Avaliação de Resultados da Assistência ao Paciente , Neoplasias Colorretais/cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos
9.
Ann R Coll Surg Engl ; 105(5): 434-440, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36239973

RESUMO

INTRODUCTION: Displaced distal radius fractures often require manipulation under anaesthesia. Many anaesthetic techniques are described, with the two most commonly used being Bier's block (BB) and haematoma block (HB). Despite national guidance preferring a BB, an HB is often performed instead. This study aims to compare the analgesic properties of a BB with those of an HB when manipulating distal radius fractures. METHODS: This is an observational cohort study comparing the management of displaced distal radius fractures requiring reduction across two National Health Service trusts. Patients aged over 18 with isolated, displaced distal radius fractures were recruited. Patient demographics, AO fracture classification and grade of clinician performing the procedure were recorded. A numeric rating scale (NRS) pain score was obtained for each patient after manipulation. The quality of reduction was judged against standardised anatomical parameters. RESULTS: Some 200 patients were recruited (100 HB, 100 BB). There were no differences in age (BB: median 66.5 years, interquartile range [IQR] 55-74; HB: median 67 years, IQR 55-74; p = 0.79) or fracture characteristics (p = 0.29) between cohorts. Patients undergoing BB had significantly lower pain scores with a lower IQR than those undergoing HB (p < 0.005). Patients undergoing BB manipulation were more likely to have the fracture reduced and normal anatomy restored (p < 0.005). BBs were performed mainly by Foundation Year 2 junior doctors, whereas HB manipulations were performed by a range of clinicians from emergency nurse practitioners to consultants. CONCLUSIONS: BB provides better analgesia than an HB. This can be performed successfully and reliably by Senior House Officer-level junior doctors.


Assuntos
Fraturas do Rádio , Fraturas do Punho , Humanos , Adolescente , Adulto , Idoso , Fraturas do Rádio/cirurgia , Medicina Estatal , Anestesia Local , Dor , Hematoma
10.
J Laryngol Otol ; 137(6): 622-628, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35912870

RESUMO

OBJECTIVE: This study aimed to assess the effectiveness of an ENT simulation course for equipping foundation doctors with core ENT skills in preparation for an ENT senior house officer post. METHOD: A total of 41 foundation doctors in the East of England participated in our two-part simulation course. Pre- and post-course surveys, consisting of Likert scales and a Dundee Ready Educational Environment Measure, were sent to assess confidence in core ENT skills and acceptability of course format. RESULTS: Post-simulation, confidence improved in all core ENT skills taught (p < 0.001), along with confidence and preparedness to work as an ENT senior house officer (p < 0.001). Overall course median Dundee Ready Educational Environment Measure score was 48, and 100 per cent of participants would recommend this course to colleagues. CONCLUSION: Simulation improves foundation doctors' confidence in core ENT skills and increases preparedness for working as an ENT senior house officer. Guidance on core ENT skills requirements should be made available to improve uniformity amongst ENT simulation courses.


Assuntos
Otolaringologia , Humanos , Otolaringologia/educação , Competência Clínica , Corpo Clínico Hospitalar/educação , Currículo , Inglaterra , Inquéritos e Questionários , Ensino
11.
Am Heart J Plus ; 34: 100310, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38510948

RESUMO

Background: We developed a three-pronged complex intervention to improve selfcare and deliver whole person care for patients with heart failure, underpinned by the 'extant cycle' theory - a theory based on our formative work. Methods: This is a 3 centre, 2-arm, 1:1, open, adaptive stratified, randomized controlled trial. We included patients aged ≥ 18 years with heart failure, taking any of the key guideline directed medical treatments, with a history of or currently on a high ceiling diuretic. We excluded end stage renal disease, clinically diagnosed severe mental illness or cognitive dysfunction and having no caregivers. Interventions included, (i) trained hospital based lay health worker mediated assessment of patients' current selfcare behaviour, documenting barriers and facilitators and implementing a plan to 'transition' the patient toward optimal selfcare. (ii) m-health mediated remote monitoring and (iii) dose optimization through a 'physician supervisor'. Results: We recruited 301 patients between Jan 2021 and Jan 2022. Mean age was 59.8 (±11.7) years, with 195 (64.8 %) from rural or semi-urban areas and 67.1 % having intermediate to low health literacy. 190 (63.1 %) had an underlying ischemic cardiomyopathy. In the intervention arm, 142 (94.1 %) had a Selfcare in Heart Failure Index (SCHFI) score of ≤70, with significant barriers being 'lack of knowledge' 105 (34.5 %) and 'behavioural passivity' 23 (7.5 %). Conclusion: This is the first South Asian trial evaluating a complex intervention underpinned by behaviour change theory for whole person heart failure care. These learnings can be applied to heart failure patient care in other resource constrained health systems.

12.
Nature ; 612(7940): 430-434, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36450988

RESUMO

Tidal disruption events (TDEs) are bursts of electromagnetic energy that are released when supermassive black holes at the centres of galaxies violently disrupt a star that passes too close1. TDEs provide a window through which to study accretion onto supermassive black holes; in some rare cases, this accretion leads to launching of a relativistic jet2-9, but the necessary conditions are not fully understood. The best-studied jetted TDE so far is Swift J1644+57, which was discovered in γ-rays, but was too obscured by dust to be seen at optical wavelengths. Here we report the optical detection of AT2022cmc, a rapidly fading source at cosmological distance (redshift z = 1.19325) the unique light curve of which transitioned into a luminous plateau within days. Observations of a bright counterpart at other wavelengths, including X-ray, submillimetre and radio, supports the interpretation of AT2022cmc as a jetted TDE containing a synchrotron 'afterglow', probably launched by a supermassive black hole with spin greater than approximately 0.3. Using four years of Zwicky Transient Facility10 survey data, we calculate a rate of [Formula: see text] per gigapascals cubed per year for on-axis jetted TDEs on the basis of the luminous, fast-fading red component, thus providing a measurement complementary to the rates derived from X-ray and radio observations11. Correcting for the beaming angle effects, this rate confirms that approximately 1 per cent of TDEs have relativistic jets. Optical surveys can use AT2022cmc as a prototype to unveil a population of jetted TDEs.

13.
Nature ; 610(7932): 467-471, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36198793

RESUMO

Of more than a thousand known cataclysmic variables (CVs), where a white dwarf is accreting from a hydrogen-rich star, only a dozen have orbital periods below 75 minutes1-9. One way to achieve these short periods requires the donor star to have undergone substantial nuclear evolution before interacting with the white dwarf10-14, and it is expected that these objects will transition to helium accretion. These transitional CVs have been proposed as progenitors of helium CVs13-18. However, no known transitional CV is expected to reach an orbital period short enough to account for most of the helium CV population, leaving the role of this evolutionary pathway unclear. Here we report observations of ZTF J1813+4251, a 51-minute-orbital-period, fully eclipsing binary system consisting of a star with a temperature comparable to that of the Sun but a density 100 times greater owing to its helium-rich composition, accreting onto a white dwarf. Phase-resolved spectra, multi-band light curves and the broadband spectral energy distribution allow us to obtain precise and robust constraints on the masses, radii and temperatures of both components. Evolutionary modelling shows that ZTF J1813+4251 is destined to become a helium CV binary, reaching an orbital period under 20 minutes, rendering ZTF J1813+4251 a previously missing link between helium CV binaries and hydrogen-rich CVs.

14.
Nature ; 605(7908): 41-45, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35508781

RESUMO

Over a dozen millisecond pulsars are ablating low-mass companions in close binary systems. In the original 'black widow', the eight-hour orbital period eclipsing pulsar PSR J1959+2048 (PSR B1957+20)1, high-energy emission originating from the pulsar2 is irradiating and may eventually destroy3 a low-mass companion. These systems are not only physical laboratories that reveal the interesting results of exposing a close companion star to the relativistic energy output of a pulsar, but are also believed to harbour some of the most massive neutron stars4, allowing for robust tests of the neutron star equation of state. Here we report observations of ZTF J1406+1222, a wide hierarchical triple hosting a 62-minute orbital period black widow candidate, the optical flux of which varies by a factor of more than ten. ZTF J1406+1222 pushes the boundaries of evolutionary models5, falling below the 80-minute minimum orbital period of hydrogen-rich systems. The wide tertiary companion is a rare low-metallicity cool subdwarf star, and the system has a Galactic halo orbit consistent with passing near the Galactic Centre, making it a probe of formation channels, neutron star kick physics6 and binary evolution.

15.
Nature ; 601(7892): 201-204, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35022591

RESUMO

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

16.
J Endocrinol Invest ; 45(4): 731-739, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34761328

RESUMO

PURPOSE: This study presents a case of familial transmission of thyroxine-binding globulin (TBG) deficiency. The SERPINA7-gene which codes for TBG is located on the X-chromosome (Xq21-22). More than 45 mutations have been reported to cause TBG- deficiency from various countries, but none from India so far. Genetic analysis of SERPINA7 gene was carried out to determine the cause of low TBG levels in one family. METHODS: DNA samples of the propositus and the family members were subjected to Polymerase Chain Reaction (PCR) followed by direct sequencing. Allele-specific PCR and Next-gen sequencing (NGS) were employed to confirm the site of the mutation. Thyroid function tests were estimated by Radioimmunoassay (RIA) and Immunoradiometric assay (IRMA) kits. X-chromosomal inactivation status was analyzed in the female members harboring the mutation. RESULTS: A mutational screening in this family revealed a novel frame-shift mutation S353Q, 354fs3X in the exon 4 of the SERPINA7 gene which will be referred to as TBG-complete deficiency-India (TBG-CD-Ind). One out of four female family members harboring the mutation showed selective X-chromosomal inactivation. The affected family members were clinically euthyroid initially, showed changes in the thyroid function when tested after a long time span. However, the changes in the thyroid function in the affected family members had an autoimmune etiology. CONCLUSION: This study presents the first report of TBG-CD from India wherein a novel frameshift mutation referred to as TBG-CD-Ind (S353Q, 354fs3X) in the SERPINA7 gene was detected. No apparent association was identified between thyroid function and the TBG-mutation in the affected subjects. A detailed biochemical and genomic testing to determine the exact cause of discordant TFT in the patients would certainly aid in the unequivocal diagnosis of the thyroid function and for the precise individualized treatment.


Assuntos
Globulina de Ligação a Tiroxina/análise , Globulina de Ligação a Tiroxina/deficiência , Globulina de Ligação a Tiroxina/genética , Adulto , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/sangue , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Doenças Genéticas Ligadas ao Cromossomo X/genética , Humanos , Índia , Masculino , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/estatística & dados numéricos , Testes de Função Tireóidea/métodos , Testes de Função Tireóidea/estatística & dados numéricos , Sequenciamento do Exoma/métodos , Sequenciamento do Exoma/estatística & dados numéricos
17.
Immunohematology ; 37(3): 126-130, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34591380

RESUMO

The Inb antigen of the Indian blood group system is a high-prevalence antigen. The presence of alloanti-Inb in a recipient may pose a problem in finding compatible blood for transfusion. The aim of this study was to screen blood donors for Inb and to include individuals found to be In(b-) in our rare donor registry. To save resources, a unique study design was constructed. Blood group O donors were tested for Inb because their red blood cell (RBC) units could serve recipients across all ABO groups. EDTA blood samples were used for serologic and genomic testing. These samples were first tested serologically for Ina, and samples typed as In(a+) were then tested both serologically and molecularly for Ina and Inb to find homozygous IN*01/01 [i.e., the predicted In(b-) phenotype]. A cost-conservative approach in using recycling of antibody was adopted to economize available resources. Of 6300 donors, 196 donor samples typed as In(a+) and were also found to be In(b+) when tested by serologic and genomic methods. Although none of the donors typed as In(b-), the statistical analysis suggests the expected prevalence for this rare phenotype to be 0.02 percent among the total number of donors tested. In conclusion, this report presents a unique cost-conservative approach using limited reagents to screen a large number of donors for the rare In(b-) phenotype.The Inb antigen of the Indian blood group system is a high-prevalence antigen. The presence of alloanti-Inb in a recipient may pose a problem in finding compatible blood for transfusion. The aim of this study was to screen blood donors for Inb and to include individuals found to be In(b­) in our rare donor registry. To save resources, a unique study design was constructed. Blood group O donors were tested for Inb because their red blood cell (RBC) units could serve recipients across all ABO groups. EDTA blood samples were used for serologic and genomic testing. These samples were first tested serologically for Ina, and samples typed as In(a+) were then tested both serologically and molecularly for Ina and Inb to find homozygous IN*01/01 [i.e., the predicted In(b­) phenotype]. A cost-conservative approach in using recycling of antibody was adopted to economize available resources. Of 6300 donors, 196 donor samples typed as In(a+) and were also found to be In(b+) when tested by serologic and genomic methods. Although none of the donors typed as In(b­), the statistical analysis suggests the expected prevalence for this rare phenotype to be 0.02 percent among the total number of donors tested. In conclusion, this report presents a unique cost-conservative approach using limited reagents to screen a large number of donors for the rare In(b­) phenotype.


Assuntos
Sistema ABO de Grupos Sanguíneos , Doadores de Sangue , Sistema ABO de Grupos Sanguíneos/genética , Eritrócitos , Humanos , Fenótipo , Prevalência
18.
Science ; 373(6559): 1125-1129, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34516837

RESUMO

A core collapse supernova occurs when exothermic fusion ceases in the core of a massive star, which is typically caused by exhaustion of nuclear fuel. Theory predicts that fusion could be interrupted earlier by merging of the star with a compact binary companion. We report a luminous radio transient, VT J121001+495647, found in the Very Large Array Sky Survey. The radio emission is consistent with supernova ejecta colliding with a dense shell of material, potentially ejected by binary interaction in the centuries before explosion. We associate the supernova with an archival x-ray transient, which implies that a relativistic jet was launched during the explosion. The combination of an early relativistic jet and late-time dense interaction is consistent with expectations for a merger-driven explosion.

20.
Nature ; 595(7865): 39-42, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34194021

RESUMO

White dwarfs represent the last stage of evolution of stars with mass less than about eight times that of the Sun and, like other stars, are often found in binaries1,2. If the orbital period of the binary is short enough, energy losses from gravitational-wave radiation can shrink the orbit until the two white dwarfs come into contact and merge3. Depending on the component masses, the merger can lead to a supernova of type Ia or result in a massive white dwarf4. In the latter case, the white dwarf remnant is expected to be highly magnetized5,6 because of the strong magnetic dynamo that should arise during the merger, and be rapidly spinning from the conservation of the orbital angular momentum7. Here we report observations of a white dwarf, ZTF J190132.9+145808.7, that exhibits these properties, but to an extreme: a rotation period of 6.94 minutes, a magnetic field ranging between 600 megagauss and 900 megagauss over its surface, and a stellar radius of [Formula: see text] kilometres, only slightly larger than the radius of the Moon. Such a small radius implies that the star's mass is close to the maximum white dwarf mass, or Chandrasekhar mass. ZTF J190132.9+145808.7 is likely to be cooling through the Urca processes (neutrino emission from electron capture on sodium) because of the high densities reached in its core.

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