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1.
Nature ; 623(7987): 499-501, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37938777

RESUMO

The majority of massive disk galaxies in the local Universe show a stellar barred structure in their central regions, including our Milky Way1,2. Bars are supposed to develop in dynamically cold stellar disks at low redshift, as the strong gas turbulence typical of disk galaxies at high redshift suppresses or delays bar formation3,4. Moreover, simulations predict bars to be almost absent beyond z = 1.5 in the progenitors of Milky Way-like galaxies5,6. Here we report observations of ceers-2112, a barred spiral galaxy at redshift zphot ≈ 3, which was already mature when the Universe was only 2 Gyr old. The stellar mass (M★ = 3.9 × 109 M⊙) and barred morphology mean that ceers-2112 can be considered a progenitor of the Milky Way7-9, in terms of both structure and mass-assembly history in the first 2 Gyr of the Universe, and was the closest in mass in the first 4 Gyr. We infer that baryons in galaxies could have already dominated over dark matter at z ≈ 3, that high-redshift bars could form in approximately 400 Myr and that dynamically cold stellar disks could have been in place by redshift z = 4-5 (more than 12 Gyrs ago)10,11.

2.
Artigo em Inglês | MEDLINE | ID: mdl-25615200

RESUMO

A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed.

3.
Science ; 333(6039): 199-202, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21680811

RESUMO

Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ∼100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy.

4.
Nature ; 463(7282): 781-4, 2010 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-20148033

RESUMO

Stars form from cold molecular interstellar gas. As this is relatively rare in the local Universe, galaxies like the Milky Way form only a few new stars per year. Typical massive galaxies in the distant Universe formed stars an order of magnitude more rapidly. Unless star formation was significantly more efficient, this difference suggests that young galaxies were much more molecular-gas rich. Molecular gas observations in the distant Universe have so far largely been restricted to very luminous, rare objects, including mergers and quasars, and accordingly we do not yet have a clear idea about the gas content of more normal (albeit massive) galaxies. Here we report the results of a survey of molecular gas in samples of typical massive-star-forming galaxies at mean redshifts of about 1.2 and 2.3, when the Universe was respectively 40% and 24% of its current age. Our measurements reveal that distant star forming galaxies were indeed gas rich, and that the star formation efficiency is not strongly dependent on cosmic epoch. The average fraction of cold gas relative to total galaxy baryonic mass at z = 2.3 and z = 1.2 is respectively about 44% and 34%, three to ten times higher than in today's massive spiral galaxies. The slow decrease between z approximately 2 and z approximately 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies.

5.
Cochrane Database Syst Rev ; (2): CD002765, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15106177

RESUMO

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects. OBJECTIVES: The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function. SEARCH STRATEGY: Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. (Search date: 7 February 2003) SELECTION CRITERIA: The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function. DATA COLLECTION AND ANALYSIS: The data was extracted independently by two reviewers. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium, need for dialysis and need for diuretic or dopamine treatment for renal insufficiency. Weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes were estimated. MAIN RESULTS: Nineteen trials ( n = 1204) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 ml/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -5 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenace and ketorolac (or indomethacin). No cases of postoperative renal failure requiring dialysis were described. The trials were homogeneous for the primary outcome. REVIEWERS' CONCLUSIONS: NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Rim/efeitos dos fármacos , Dor Pós-Operatória/tratamento farmacológico , Adulto , Creatinina/sangue , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Renal/etiologia
6.
Cochrane Database Syst Rev ; (2): CD002765, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11406042

RESUMO

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there there are conflicting views on whether NSAIDs are associated with adverse renal effects. OBJECTIVES: The primary objective of this review was to determine the effects of NSAIDs on post-operative renal function in adults with normal pre-operative renal function. SEARCH STRATEGY: Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Controlled Trials Register, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Hand-searching of conference abstracts published in major anaesthetic journals was also performed. SELECTION CRITERIA: The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of post-operative pain, with relevant post-operative renal outcome measures, in adult surgical patients with normal renal function. DATA COLLECTION AND ANALYSIS: Of the 14 trials that fulfilled the selection criteria for this review, eight trials were relevant with sufficient data for meta-analysis. The data was extracted independently by two reviewers. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium, need for dialysis and need for diuretic or dopamine treatment for renal insufficiency. Weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes were estimated. MAIN RESULTS: As a group, NSAIDs reduced creatinine clearance by 18ml/min (95%CI: 6 to 31) and potassium output by 38mmol/day (95%CI: 19 to 56) on the first day after surgery compared to placebo. Serum creatinine clearance increased on the second day after surgery by 15umol/L (95%CI: 2 to 28) compared to placebo. No significant reduction in urine volume during the early post-operative period was found. There was no significant difference in serum creatinine in the early post-operative period between patients receiving ketorolac and diclofenac in one trial. No cases of post-operative renal failure requiring dialysis were described. REVIEWER'S CONCLUSIONS: NSAIDs caused a clinically unimportant transient reduction in renal function in the early post-operative period in patients with normal pre-operative renal function. NSAIDs should not be withheld from adults with normal pre-operative renal function because of concerns about post-operative renal impairment.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Rim/efeitos dos fármacos , Dor Pós-Operatória/tratamento farmacológico , Adulto , Creatinina/sangue , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Renal/etiologia
7.
J Clin Ultrasound ; 28(6): 307-10, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10867671

RESUMO

A solitary unilocular hepatic cyst (SUHC) is a rare prenatal or neonatal finding. There are few reports of the prenatal detection of SUHC, and the progression of SUHC in utero is unknown. We present a proven case of SUHC in a fetus detected on a 34-week ultrasound examination following a normal 19-week examination. The cyst was inseparable from the liver and caused some flattening of the liver edge. Prenatal detection of an SUHC inseparable from the liver and appearing in the late second or third trimester should suggest a congenital hepatic cyst.


Assuntos
Cistos/diagnóstico por imagem , Doenças Fetais/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Diagnóstico Pré-Natal , Ultrassonografia Pré-Natal , Adulto , Cistos/congênito , Feminino , Humanos , Hepatopatias/congênito , Gravidez , Terceiro Trimestre da Gravidez
8.
J Natl Med Assoc ; 91(8): 459-65, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12656435

RESUMO

This study examined methods of recruiting and retaining minority house staff at US residency training programs. A 28-item questionnaire was mailed to pediatric chief residents at 78 US training programs with more than 35 residents. The response rate was 74%. Programs were characterized by patient populations served, number of ethnic/racial minority house staff and faculty, and the presence of minority house staff support systems within the institution. In this largely urban sample, minority recruitment and retention was reported as an explicit priority by 40% of pediatric chief residents. The majority (71%) reported that their house staff recruitment committees had no explicitly defined recruitment goals regarding minority house staff. Seventy-seven percent reported that within their departments, recruitment efforts toward minorities were no different than for nonminorities. Overall, few minority house staff and minority faculty were identified in the responding institutions. The most frequently reported intra-institutional support systems for minority house staff included individual pairing with faculty advisors from the same minority group (29%), an affirmative-action office located at the institution (8%), and the existence of a minority faculty support group (4%). These results indicate that pediatric chief residents may not be fully aware of the specific challenges related to the recruitment and retention of minority physicians, and most house staff recruitment committees do not have explicit goals in this regard.


Assuntos
Atitude do Pessoal de Saúde , Internato e Residência , Corpo Clínico Hospitalar , Grupos Minoritários , Pediatria , Seleção de Pessoal , Feminino , Humanos , Masculino , Inquéritos e Questionários , Estados Unidos
9.
Holist Nurs Pract ; 12(4): 57-68, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9849209

RESUMO

The article describes the experience of technologically induced vulnerability and the inherent uncertainty of patients undergoing bone marrow transplantation. Examples of care by nurses, as perceived by patients and their family members, are offered. The relationship between the iatrogenic vulnerability and suffering of patients and the nursing response of care is explored. The claim is made that a caring response by nurses enables patients to make meaning of their choice to undergo simultaneously life-saving and life-threatening bone marrow transplantation.


Assuntos
Transplante de Medula Óssea/enfermagem , Transplante de Medula Óssea/psicologia , Empatia , Ciência de Laboratório Médico , Relações Enfermeiro-Paciente , Adaptação Psicológica , Adulto , Atitude Frente a Saúde , Família/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Metodológica em Enfermagem
10.
Clin Chem ; 44(1): 35-9, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9550555

RESUMO

The concentration of soluble transferrin receptor (sTfR) in serum is reported to be useful in the diagnosis of iron deficiency, especially for patients with concurrent chronic disease, where routine tests of iron status are compromised by the inflammatory condition. A new diagnostic assay for sTfR is calibrated against natural plasma sTfR, thus minimizing calibration discrepancies that result from differences between the analyte and the cellular transferrin receptor used in other assays. Use of the new assay to measure sTfR concentrations in 225 healthy, hematologically normal adults provided a reference interval against which pathological samples could be compared. There was no difference in the reference intervals for men and women and no correlation of [sTfR] with the age of the subject. Black subjects had significantly higher concentrations than nonblacks, and people living at high altitude had higher concentrations than those living closer to sea level. These differences were additive.


Assuntos
Receptores da Transferrina/sangue , Fatores Etários , Altitude , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pós-Menopausa/sangue , Pré-Menopausa/sangue , Grupos Raciais , Valores de Referência , Sensibilidade e Especificidade , Fatores Sexuais , Solubilidade , Estados Unidos
11.
ANNA J ; 25(6): 603-8, 614; quiz 609-10, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10188395

RESUMO

This article describes the ethical significance of working with ESRD patients with a focus on end-of-life decision making. The ethical aspects of patient advocacy are explored and suggestions are offered for helping patients make ethically sound and caring end-of-life decisions. A model for ethical decision making is outlined, along with guidance from the ANA Code of Ethics and suggestions from the ANA Position Statements on Care and Comfort in Dying Patients, Euthanasia, and Assisted Suicide.


Assuntos
Tomada de Decisões , Ética em Enfermagem , Falência Renal Crônica/enfermagem , Nefrologia , Especialidades de Enfermagem , Assistência Terminal/psicologia , Humanos , Descrição de Cargo , Defesa do Paciente , Guias de Prática Clínica como Assunto
12.
J Adv Nurs ; 21(3): 487-91, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7745202

RESUMO

The literature reveals that errors of drug administration are a widely distributed and common occurrence. The frequency of errors and their underlying causes are discussed, and the literature is surveyed to determine reasons for mistakes and possible remedial measures. Ideas are drawn from industrial sources to describe a model of preventing mistakes at source, by making errors impossible. The ideas of Crosby and Shingo are discussed and a 'zero defects philosophy' is described and developed. This paper attempts to determine if this quality model developed and used in industry can be transferred to the health service, and concludes that it needs adaptation and cautious application. Recommendations are made for improved practices and improvements, both clinical and managerial. The author recommends a multidisciplinary review of all practices and systems to develop a radically different procedure with no drug errors as its aim. It is questioned whether this is possible in the present health service environment, as this would require sustained management commitment to both the idea and the quality system. However, the author believes that some of the principles can be applied as individual quality initiatives.


Assuntos
Erros de Medicação , Coleta de Dados , Humanos , Enfermeiras e Enfermeiros , Recursos Humanos de Enfermagem Hospitalar , Qualidade da Assistência à Saúde
15.
ANS Adv Nurs Sci ; 15(3): 23-32, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8434901

RESUMO

In this article the author describes the paradoxical nature of the relationship between technology and care in the ICU. Although technology enhances care by expanding the repertoire of competent nurses' responses to the patient, it simultaneously alienates nurse and patient, hence inhibiting care. This occurs when nurses and patients have different understandings of technology and when the nurse identifies with the values imposed by technology at the expense of acknowledging her own and the patient's vulnerability.


Assuntos
Cuidados Críticos , Monitorização Fisiológica/psicologia , Tecnologia , Humanos , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/enfermagem , Relações Enfermeiro-Paciente , Pesquisa em Avaliação de Enfermagem , Alienação Social , Valores Sociais
16.
ANS Adv Nurs Sci ; 14(2): 22-31, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1759807

RESUMO

Research to date in the field of nursing ethics has overlooked the nature of the guiding moral framework in nursing practice, while focusing primarily on the moral reasoning and moral behaviors among nurses. This research depicts two moral frameworks--a principle-oriented ethic and the ethic of care--as they are experienced by practicing critical care nurses. The interdependence of these two frameworks as they inform the moral experience of the nurse is demonstrated in the analysis of a complex nurse narrative that depicts the nurse's moral struggle.


Assuntos
Análise Ética , Ética em Enfermagem , Modelos de Enfermagem , Princípios Morais , Cuidados de Enfermagem/normas , Recursos Humanos de Enfermagem Hospitalar/psicologia , Beneficência , Cuidados Críticos , Teoria Ética , Feminino , Humanos , Comunicação Interdisciplinar , Desenvolvimento Moral , Relações Enfermeiro-Paciente , Pesquisa Metodológica em Enfermagem , Autonomia Pessoal , Papel (figurativo) , Valores Sociais
18.
Sch Inq Nurs Pract ; 4(3): 209-18; discussion 219-21, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2274732

RESUMO

This paper offers a comparative analysis of four central concepts of moral theory--autonomy, moral posture, universal vs. particular, and the role of rules and principles. These concepts are compared as they function in traditional rule-and-principle ethics and the more recently explicated ethic of care. Implications of the distinctiveness of these two extant frameworks for the development of nursing ethics are set out. In conclusion, the claim is made that an inclusive approach to these different moral visions which places them in a mutually informative relationship holds the potential to enrich and enliven the developing nursing ethic.


Assuntos
Teoria Ética , Ética em Enfermagem , Modelos Teóricos , Princípios Morais , Comportamento de Escolha , Contratos , Feminino , Identidade de Gênero , Humanos , Masculino , Obrigações Morais , Autonomia Pessoal , Poder Psicológico
19.
Am J Pathol ; 134(6): 1295-303, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2757119

RESUMO

Although immune mechanisms are known to be partially responsible for the thrombocytopenia of patients infected with HIV-1, an understanding of the mechanism underlying this disorder is incomplete. A casual observation that bone marrow biopsies of HIV-infected individuals seem to exhibit an unusually large number of denuded megakaryocyte nuclei (DN-MK) prompted a study comparing MK of 20 HIV-seropositive individuals with those of 10 patients with HIV-negative idiopathic thrombocytopenic purpura and 10 hematologically normal subjects. In normal marrows the number of DN-MK average 2.1 +/- 0.5 SE per 10 low power field. In patients with ITP the average number was 6.5 +/- 1.4 SEM, whereas HIV-ITP marrows had an average of 42.5 +/- 3.7 SEM. Electron microscopy of AIDS megakaryocytes exhibited ballooning of the peripheral zone to an extent not seen by us in any other myelodysplastic syndromes. These observations support the concept that the pathophysiology affecting MK/platelets in HIV-infection should not be equated with the destructive process underlying other immune thrombocytopenias.


Assuntos
Síndrome da Imunodeficiência Adquirida/patologia , Megacariócitos/patologia , Síndrome da Imunodeficiência Adquirida/sangue , Síndrome da Imunodeficiência Adquirida/fisiopatologia , Medula Óssea/patologia , Medula Óssea/ultraestrutura , Humanos , Megacariócitos/fisiopatologia , Megacariócitos/ultraestrutura , Microscopia Eletrônica , Trombocitemia Essencial/patologia , Trombocitemia Essencial/fisiopatologia
20.
J Prof Nurs ; 5(1): 10-6, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2654242

RESUMO

This article proposes that Carol Gilligan's ethic of care provides for nursing a paradigm for moral deliberation that demonstrates compatibility with nursing's historical and philosophical traditions of relational caring and furnishes empirical support for the value of caring as a moral activity. The appropriateness of Gilligan's theory for nursing is further illustrated by an elucidation of the similarities between Gilligan's theory and nurse theorist Jean Watson's claims that caring constitutes both a necessary and a fundamental component of nursing. It is argued that Gilligan's theory of moral deliberation more faithfully reflects the nursing experience than Kohlberg's contractual, Kantian theory, which currently dominates the nursing literature.


Assuntos
Ética em Enfermagem , Desenvolvimento Moral , Princípios Morais , Teoria de Enfermagem , Tomada de Decisões , Identidade de Gênero , Direitos Humanos , Humanos , Relações Enfermeiro-Paciente , Autonomia Pessoal
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