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1.
Space Sci Rev ; 220(5): 48, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38899030

RESUMO

Multiply lensed images of a same source experience a relative time delay in the arrival of photons due to the path length difference and the different gravitational potentials the photons travel through. This effect can be used to measure absolute distances and the Hubble constant ( H 0 ) and is known as time-delay cosmography. The method is independent of the local distance ladder and early-universe physics and provides a precise and competitive measurement of H 0 . With upcoming observatories, time-delay cosmography can provide a 1% precision measurement of H 0 and can decisively shed light on the current reported 'Hubble tension'. This manuscript details the general methodology developed over the past decades in time-delay cosmography, discusses recent advances and results, and, foremost, provides a foundation and outlook for the next decade in providing accurate and ever more precise measurements with increased sample size and improved observational techniques.

2.
QJM ; 115(7): 442-449, 2022 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34270780

RESUMO

BACKGROUND: Hospitalized patients with hyperkalemia are heterogeneous, and cluster approaches may identify specific homogenous groups. This study aimed to cluster patients with hyperkalemia on admission using unsupervised machine learning (ML) consensus clustering approach, and to compare characteristics and outcomes among these distinct clusters. METHODS: Consensus cluster analysis was performed in 5133 hospitalized adult patients with admission hyperkalemia, based on available clinical and laboratory data. The standardized mean difference was used to identify each cluster's key clinical features. The association of hyperkalemia clusters with hospital and 1-year mortality was assessed using logistic and Cox proportional hazard regression. RESULTS: Three distinct clusters of hyperkalemia patients were identified using consensus cluster analysis: 1661 (32%) in cluster 1, 2455 (48%) in cluster 2 and 1017 (20%) in cluster 3. Cluster 1 was mainly characterized by older age, higher serum chloride and acute kidney injury (AKI), but lower estimated glomerular filtration rate (eGFR), serum bicarbonate and hemoglobin. Cluster 2 was mainly characterized by higher eGFR, serum bicarbonate and hemoglobin, but lower comorbidity burden, serum potassium and AKI. Cluster 3 was mainly characterized by higher comorbidity burden, particularly diabetes and end-stage kidney disease, AKI, serum potassium, anion gap, but lower eGFR, serum sodium, chloride and bicarbonate. Hospital and 1-year mortality risk was significantly different among the three identified clusters, with highest mortality in cluster 3, followed by cluster 1 and then cluster 2. CONCLUSION: In a heterogeneous cohort of hyperkalemia patients, three distinct clusters were identified using unsupervised ML. These three clusters had different clinical characteristics and outcomes.


Assuntos
Injúria Renal Aguda , Hiperpotassemia , Bicarbonatos , Cloretos , Análise por Conglomerados , Consenso , Humanos , Aprendizado de Máquina , Fenótipo , Potássio
3.
Phys Rev X ; 10(2)2020.
Artigo em Inglês | MEDLINE | ID: mdl-34136310

RESUMO

A mixed-species geometric phase gate has been proposed for implementing quantum logic spectroscopy on trapped ions, which combines probe and information transfer from the spectroscopy to the logic ion in a single pulse. We experimentally realize this method, show how it can be applied as a technique for identifying transitions in currently intractable atoms or molecules, demonstrate its reduced temperature sensitivity, and observe quantum-enhanced frequency sensitivity when it is applied to multi-ion chains. Potential applications include improved readout of trapped-ion clocks and simplified error syndrome measurements for quantum error correction.

4.
QJM ; 110(11): 713-719, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28637264

RESUMO

BACKGROUND: Little is known about the effect of admission potassium (K) on risk of in-hospital mortality in chronic kidney disease (CKD) and cardiovascular disease (CVD) patients. AIM: The aim of this study was to assess the relationship between admission serum K and in-hospital mortality in all hospitalized patients stratified by CKD and/or CVD status. DESIGN AND METHODS: All adult hospitalized patients who had admission serum K between years 2011 and 2013 were enrolled. Admission serum K was categorized into seven groups (<3.0, 3.0-3.5, 3.5-4.0, 4.0-4.5, 4.5-5.0, 5.0-5.5 and ≥5.5 mEq/L). The odds ratio (OR) of in-hospital mortality by admission serum K, using K 4.0-4.5 mEq/L as the reference group, was obtained by logistic regression analysis. RESULTS: 73,983 patients were studied. The lowest incidence of in-hospital mortality was associated with serum K within 4.0-4.5 mEq/L. A U-shaped curve emerged demonstrating higher in-hospital mortality associated with both serum K < 4.0 and >4.5 mEq/L. After adjusting for potential confounders, both serum K < 4.0 mEq/L and >5.0 mEq/L were associated with increased in-hospital mortality with ORs of 3.26 (95% CI 2.03-4.98), 2.40 (95% CI 1.89-3.04), 1.38 (95%CI 1.15-1.66), 1.89 (95% CI 1.49-2.38) and 3.62 (95%CI 2.73-4.76) when serum K were within <3.0, 3.0-3.5, 3.5-4.0, 5.0-5.5, and ≥5.5 mEq/L, respectively. In CVD patients, the highest in-hospital mortality was associated with serum K < 3.0 mEq/L (OR 1.70, 95%CI 1.31-2.18). In CKD patients, the highest in-hospital mortality was associated with serum K ≥ 5.5 mEq/L (OR 3.26, 95%CI 2.14-4.90). CONCLUSION: Admission serum K < 4.0 mEq/L and >5.0 mEq/L were associated with increased in-hospital mortality. The mortality risk among patients with various admission potassium levels was affected by CKD and/or CVD status.


Assuntos
Doenças Cardiovasculares/sangue , Mortalidade Hospitalar , Potássio/sangue , Insuficiência Renal Crônica/sangue , Adulto , Idoso , Doenças Cardiovasculares/mortalidade , Comorbidade , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Análise Multivariada , Insuficiência Renal Crônica/mortalidade , Medição de Risco , Centros de Atenção Terciária
5.
J Urol ; 198(4): 890-896, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28501541

RESUMO

PURPOSE: We sought to identify clinical and demographic characteristics associated with treatment response and satisfaction in women undergoing onabotulinumtoxinA and sacral neuromodulation therapies. MATERIALS AND METHODS: We analyzed data from the ROSETTA (Refractory Overactive Bladder: Sacral NEuromodulation versus BoTulinum Toxin Assessment) trial. Baseline participant characteristics and clinical variables were associated with 2 definitions of treatment response, including 1) a reduction in mean daily urgency incontinence episodes during 6 months and 2) a 50% or greater decrease in urgency incontinence episodes across 6 months. The OAB-S (Overactive Bladder-Satisfaction) questionnaire was used to assess satisfaction. RESULTS: A greater reduction in mean daily urgency incontinence episodes was associated with higher HUI-3 (Health Utility Index-3) scores in the onabotulinumtoxinA group and higher baseline incontinence episodes (each p <0.001) in the 2 groups. Increased age was associated with a lesser decrease in incontinence episodes in the 2 groups (p <0.001). Increasing body mass index (adjusted OR 0.82/5 points, 95% CI 0.70-0.96) was associated with reduced achievement of a 50% or greater decrease in incontinence episodes after each treatment. Greater age (adjusted OR 0.44/10 years, 95% CI 0.30-0.65) and a higher functional comorbidity index (adjusted OR 0.84/1 point, 95% CI 0.71-0.99) were associated with reduced achievement of a 50% or greater decrease in urgency incontinence episodes in the onabotulinumtoxinA group only (p <0.001 and 0.041, respectively). In the onabotulinumtoxinA group increased satisfaction was noted with higher HUI-3 score (p = 0.002) but there was less satisfaction with higher age (p = 0.001). CONCLUSIONS: Older women with multiple comorbidities, and decreased functional and health related quality of life had decreased treatment response and satisfaction with onabotulinumtoxinA compared to sacral neuromodulation for refractory urgency incontinence.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Satisfação do Paciente , Qualidade de Vida , Estimulação Elétrica Nervosa Transcutânea/métodos , Incontinência Urinária de Urgência/terapia , Fatores Etários , Idoso , Comorbidade , Feminino , Humanos , Injeções Intramusculares , Plexo Lombossacral , Pessoa de Meia-Idade , Resultado do Tratamento , Incontinência Urinária de Urgência/epidemiologia
6.
Phys Rev Lett ; 118(13): 130403, 2017 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-28409945

RESUMO

We report correlation measurements on two ^{9}Be^{+} ions that violate a chained Bell inequality obeyed by any local-realistic theory. The correlations can be modeled as derived from a mixture of a local-realistic probabilistic distribution and a distribution that violates the inequality. A statistical framework is formulated to quantify the local-realistic fraction allowable in the observed distribution without the fair-sampling or independent-and-identical-distributions assumptions. We exclude models of our experiment whose local-realistic fraction is above 0.327 at the 95% confidence level. This bound is significantly lower than 0.586, the minimum fraction derived from a perfect Clauser-Horne-Shimony-Holt inequality experiment. Furthermore, our data provide a device-independent certification of the deterministically created Bell states.

8.
Int J Clin Pract ; 69(11): 1303-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26205345

RESUMO

BACKGROUND: The association between admission serum magnesium (Mg) levels and risk of acute respiratory failure (ARF) in hospitalised patients is limited. The aim of this study was to assess the risk of developing ARF in all hospitalised patients with various admission Mg levels. METHODS: This is a single-center retrospective study conducted at a tertiary referral hospital. All hospitalised adult patients who had admission Mg available from January to December 2013 were analysed in this study. Admission Mg was categorised based on its distribution into six groups (less than 1.5, 1.5-1.7, 1.7-1.9, 1.9-2.1, 2.1-2.3 and greater than 2.3 mg/dl). The primary outcome was in-hospital ARF occurring after hospital admission. Logistic regression analysis was performed to obtain the odds ratio of ARF of various admission Mg levels using Mg of 1.7-1.9 mg/dl as the reference group. RESULTS: Of 9780 patients enrolled, ARF occurred in 619 patients (6.3%). The lowest incidence of ARF was when serum Mg within 1.7-1.9 mg/dl. A U-shaped curve emerged demonstrating higher incidences of ARF associated with both hypomagnesemia (< 1.7) and hypermagnesemia (> 1.9). After adjusting for potential confounders, both hypomagnesemia (< 1.5 mg/dl) and hypermagnesemia (> 2.3 mg/dl) were associated with an increased risk of developing ARF with odds ratios of 1.69 (95% CI: 1.19-2.36) and 1.40 (95% CI: 1.02-1.91) respectively. CONCLUSION: Both admission hypomagnesemia and hypermagnesemia were associated with an increased risk for in-hospital ARF.


Assuntos
Magnésio/sangue , Síndrome do Desconforto Respiratório/sangue , Adulto , Idoso , Biomarcadores/sangue , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Hipercalciúria/complicações , Incidência , Masculino , Pessoa de Meia-Idade , Nefrocalcinose/complicações , Razão de Chances , Análise de Regressão , Erros Inatos do Transporte Tubular Renal/complicações , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/etiologia , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
9.
Int J Clin Pract ; 69(9): 998-1006, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26147121

RESUMO

BACKGROUND: The objective of this systematic review and meta-analysis was to assess the clinical outcomes of Clostridium difficile infection (CDI) in patients with chronic kidney diseases (CKD) and end-stage renal disease (ESRD). METHODS: A literature search was performed from inception through February 2015. Studies that reported relative risks, odds ratios or hazard ratios comparing the clinical outcomes of CDI in patients with CKD or ESRD and those without CKD or ESRD were included. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using a random-effect, generic inverse variance method. RESULTS: Nineteen studies (a case-control and 18 cohort studies) with 116,875 patients assessing clinical outcomes of CDI were included in the meta-analysis. Pooled RR of severe or complicated CDI in CKD patients was 1.51 (95% CI: 1.00-2.28). The risk of recurrent CDI is significant higher in patients with a pooled RR of 2.73 (95% CI: 1.36-5.47). The pooled RR of mortality risk of CDI in patients with CKD, ESRD and CKD or ESRD were 1.76 (95% CI: 1.26-2.47), 1.58 (1.37-1.83) and 1.76 (1.32-2.34) respectively. CONCLUSION: This meta-analysis demonstrates poor outcomes of CDI including severe and recurrent CDI in CKD patients. History of CKD and ESRD are both associated with increased mortality risk in patients with CDI.


Assuntos
Clostridioides difficile , Infecções por Clostridium , Infecção Hospitalar , Falência Renal Crônica/complicações , Insuficiência Renal Crônica/complicações , Infecções por Clostridium/microbiologia , Infecções por Clostridium/mortalidade , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Hospitalização/estatística & dados numéricos , Humanos , Falência Renal Crônica/microbiologia , Falência Renal Crônica/mortalidade , Insuficiência Renal Crônica/microbiologia , Insuficiência Renal Crônica/mortalidade , Fatores de Risco
10.
Transpl Infect Dis ; 17(4): 566-73, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25988273

RESUMO

BACKGROUND: Lower gastrointestinal (GI) adverse events (LGAE) are common afflictions of patients undergoing stem cell transplantation (SCT). Unfortunately, the pathophysiology remains poorly characterized. Emerging data suggest a prominent role of intestinal microbiota; however, contributions of pathogenic gut microbiota such as Clostridium difficile are not well defined. We performed a genome-wide association study (GWAS) to investigate clinical and genetic factors associated with development of LGAE. METHODS: A total of 972 patients undergoing autologous SCT were graded for LGAE based on Common Terminology Criteria for Adverse Events (v 4.0). Germline DNA material was obtained from leukapharesis products and genotyped using Illumina(®) Whole Genome Genotyping Infinium chemistry and HumanOmni1-Quad Bead chips containing over 1.1 million single nucleotide polymorphisms (SNPs) (Illumina, San Diego, California, USA). Statistical models incorporating clinical factors, genetic factors, and a combination of clinical plus genetic factors were utilized to compare patients who developed severe LGAE (grade 2 or above) and others. RESULTS: Among 972 patients, 459 (47.2%) developed severe LGAE. Baseline hemoglobin and hematocrit, estimated glomerular filtration rate, ß2-microglobulin, protocol type, and C. difficile infection (CDI) were associated with severe LGAE on univariate analysis, Genomic comparisons between groups did not reveal any SNPs associated with severe LGAE and neither did incorporation of genetic factors into the clinical model. In addition, 11 candidate SNPs associated with upper GI mucositis were evaluated, alongside clinical factors in a multivariate model. Only CDI was found to be associated with severe LGAE in all models. CONCLUSION: CDI is a prominent factor in the development of LGAE in patients undergoing autologous SCT.


Assuntos
Clostridioides difficile , Infecções por Clostridium/complicações , Gastroenteropatias/microbiologia , Transplante de Células-Tronco , Adulto , Idoso , Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/diagnóstico , Feminino , Gastroenteropatias/etiologia , Gastroenteropatias/genética , Marcadores Genéticos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Índice de Gravidade de Doença , Transplante Autólogo
11.
Intern Med J ; 45(4): 436-40, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25827510

RESUMO

BACKGROUND: The reported risk of depression in patients with hypomagnesaemia is controversial. AIM: The objective of this meta-analysis was to assess the association between depression and hypomagnesaemia. METHODS: A literature search was performed using MEDLINE, EMBASE, Cochrane Database and clinicaltrials.gov from inception through October 2014. Studies that reported odds ratios, relative risks or hazard ratios comparing the risk of depression in patients with hypomagnesaemia were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. RESULTS: Six observational studies (three cohort studies, two cross-sectional studies and a case-control study) with a total of 19,137 patients were identified and included in the data analysis. The pooled RR of depression in patients with hypomagnesaemia was 1.34 (95% CI, 1.01-1.79, I(2) = 33%). The association between depression and hypomagnesaemia was marginally insignificant after the sensitivity analysis including only cohort and case-control studies, with a pooled RR of 1.38 (95% CI, 0.92-2.07, I(2) = 24%). CONCLUSION: Our study demonstrates a potential association between hypomagnesaemia and depression. Further studies assessing the benefits of treatment of hypomagnesaemia in patients with depression are needed.


Assuntos
Depressão/epidemiologia , Depressão/psicologia , Deficiência de Magnésio/epidemiologia , Deficiência de Magnésio/psicologia , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Depressão/diagnóstico , Humanos , Deficiência de Magnésio/diagnóstico
12.
QJM ; 108(11): 879-84, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25697787

RESUMO

BACKGROUND: The objective of this meta-analysis was to evaluate the risk of anemia in patients who received renin-angiotensin system (RAS) inhibitors. METHODS: A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception through November, 2014. Studies that reported relative risks, odd ratios or hazard ratios comparing the anemia risk in patients who received angiotensin-converting-enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) vs. those who did not were included. We performed the prespecified sensitivity analysis including only only studies with confounder adjusted analysis. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. RESULTS: Seven studies (2 cohort and 5 cross-sectional studies) with 29,061 patients were included in the analysis to assess the risk of anemia and the RAS inhibitors use. The pooled RR of anemia in patients receiving ACEIs was 1.56 (95% CI, 1.40-1.73, I(2) = 17%). When meta-analysis was limited only to studies with confounder adjusted analysis, the pooled RR of anemia in patients using ACEIs was 1.57 (95% CI, 1.43-1.73, I(2) = 0%) The pooled RR of anemia in patients receiving ARBs was 1.60 (95% CI, 1.27-2.00, I(2) = 39%). The meta-analysis of studies with confounder adjusted analysis demonstrated the pooled RR of anemia in patients using ARBs of 1.59 (95% CI, 1.38-1.83, I(2) = 0%). CONCLUSIONS: Our meta-analysis demonstrates an association between anemia and the use of RAS inhibitors. Hematological parameters should be monitored in patients treated with RAS inhibitors.


Assuntos
Anemia/induzido quimicamente , Antagonistas de Receptores de Angiotensina/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Doenças Cardiovasculares/complicações , Métodos Epidemiológicos , Feminino , Humanos , Transplante de Rim/efeitos adversos , Masculino
13.
QJM ; 108(3): 205-12, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25208892

RESUMO

BACKGROUND: The objective of this meta-analysis was to evaluate the association between a history of kidney stones and kidney cancer. METHODS: A literature search was performed from inception until June 2014. Studies that reported odds ratios or hazard ratios comparing the risk of renal cell carcinoma (RCC) and transitional cell carcinoma (TCC) of the upper urinary tract in patients with the history of kidney stones versus those without the history of kidney stones were included. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. RESULT: Seven studies were included in our analysis to assess the association between a history of kidney stones and RCC. The pooled RR of RCC in patients with kidney stones was 1.76 (95% CI, 1.24-2.49). The subgroup analysis found that the history of kidney stones was associated with increased RCC risk only in males (RR, 1.41 [95% CI, 1.11-1.80]), but not in females (RR, 1.13 [95% CI, 0.86-1.49]). Five studies were selected to assess the association between a history of kidney stones and TCC. The pooled RR of TCC in patients with kidney stones was 2.14 (95% CI, 1.35-3.40). CONCLUSION: Our study demonstrates a significant increased risk of RCC and TCC in patients with prior kidney stones. However, the increased risk of RCC was noted only in male patients. This finding suggests that a history of kidney stones is associated with kidney cancer and may impact clinical management and cancer surveillance.


Assuntos
Carcinoma de Células Renais/etiologia , Carcinoma de Células de Transição/etiologia , Cálculos Renais/complicações , Neoplasias Renais/etiologia , Métodos Epidemiológicos , Feminino , Humanos , Masculino
14.
Nanotechnology ; 26(1): 015703, 2015 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-25490522

RESUMO

Quantum dot solar cells seek to surpass the solar energy conversion efficiencies achieved by bulk semiconductors. This new field requires a broad selection of materials to achieve its full potential. The 12 nm spherical protein ferritin can be used as a template for uniform and controlled nanocrystal growth, and to then house the nanocrystals for use in solar energy conversion. In this study, precise band gaps of titanium, cobalt, and manganese oxyhydroxide nanocrystals within ferritin were measured, and a change in band gap due to quantum confinement effects was observed. The range of band gaps obtainable from these three types of nanocrystals is 2.19-2.29 eV, 1.93-2.15 eV, and 1.60-1.65 eV respectively. From these measured band gaps, theoretical efficiency limits for a multi-junction solar cell using these ferritin-enclosed nanocrystals are calculated and found to be 38.0% for unconcentrated sunlight and 44.9% for maximally concentrated sunlight. If a ferritin-based nanocrystal with a band gap similar to silicon can be found (i.e. 1.12 eV), the theoretical efficiency limits are raised to 51.3% and 63.1%, respectively. For a current matched cell, these latter efficiencies become 41.6% (with an operating voltage of 5.49 V), and 50.0% (with an operating voltage of 6.59 V), for unconcentrated and maximally concentrated sunlight respectively.

15.
QJM ; 108(7): 539-48, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25519235

RESUMO

BACKGROUND: The risk of renal damage in patients with high alcohol consumption is controversial. The objective of this meta-analysis was to evaluate the associations between high alcohol consumption and progression of kidney damage including chronic kidney disease (CKD), end-stage renal disease (ESRD) and proteinuria. METHODS: A literature search was performed using MEDLINE, EMBASE and Cochrane Databases from inception through August 2014 to identify studies investigating the association between high alcohol consumption and CKD, ESRD or proteinuria. Studies that reported odds ratios, relative risks or hazard ratios comparing the risk of CKD, ESRD or proteinuria in patients consuming high amount of alcohol versus those who did not consume alcohol were included. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. RESULTS: Twenty studies with 292 431 patients were included in our analysis to assess the associations between high alcohol consumption and progression of kidney damage. The pooled RRs of CKD, proteinuria and ESRD in patients with high alcohol consumption were 0.83 (95% CI: 0.71-0.98), 0.85 (95% CI: 0.62-1.17) and 1.00 (95% CI: 0.55-1.82), respectively. Post hoc analysis assessing the sex-specific association between high alcohol consumption and CKD demonstrated pooled RRs of 0.72 (95% CI: 0.57-0.90) in males and 0.78 (95% CI: 0.58-1.03) in females. CONCLUSIONS: Our study demonstrates an inverse association between high alcohol consumption and risk for developing CKD in males. There is no significant association between high alcohol consumption and the risk for developing proteinuria or ESRD.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Insuficiência Renal Crônica/epidemiologia , Alcoolismo/epidemiologia , Progressão da Doença , Humanos , Falência Renal Crônica/epidemiologia , Proteinúria/epidemiologia , Viés de Publicação , Medição de Risco
16.
Nanotechnology ; 25(13): 135703, 2014 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-24583827

RESUMO

Ferritin is a protein nano-cage that encapsulates minerals inside an 8 nm cavity. Previous band gap measurements on the native mineral, ferrihydrite, have reported gaps as low as 1.0 eV and as high as 2.5-3.5 eV. To resolve this discrepancy we have used optical absorption spectroscopy, a well-established technique for measuring both direct and indirect band gaps. Our studies included controls on the protein nano-cage, ferritin with the native ferrihydrite mineral, and ferritin with reconstituted ferrihydrite cores of different sizes. We report measurements of an indirect band gap for native ferritin of 2.140 ± 0.015 eV (579.7 nm), with a direct transition appearing at 3.053 ± 0.005 eV (406.1 nm). We also see evidence of a defect-related state having a binding energy of 0.220 ± 0.010 eV . Reconstituted ferrihydrite minerals of different sizes were also studied and showed band gap energies which increased with decreasing size due to quantum confinement effects. Molecules that interact with the surface of the mineral core also demonstrated a small influence following trends in ligand field theory, altering the native mineral's band gap up to 0.035 eV.


Assuntos
Ferritinas/química , Tamanho da Partícula , Absorção , Animais , Compostos Férricos/química , Cavalos , Estrutura Secundária de Proteína , Propriedades de Superfície , Termodinâmica
18.
Anaesth Intensive Care ; 39(5): 837-46, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21970127

RESUMO

During the 2009 H1N1 pandemic, large numbers of patients had severe respiratory failure. High frequency oscillation ventilation was used as a salvage technique for profound hypoxaemia. Our aim was to compare this experience with high frequency oscillation ventilation during the 2009 H1N1 pandemic with the same period in 2008 by performing a three-month period prevalence study in Australian and New Zealand intensive care units. The main study end-points were clinical demographics, care delivery and survival. Nine intensive care units contributed data. During 2009 there were 22 H1N1 patients (17 adults, five children) and 10 non-H1N1 patients (five adults, five children), while in 2008, 18 patients (two adults, 16 children) received high frequency oscillation ventilation. The principal non-H1N1 high frequency oscillation ventilation indication was bacterial or viral pneumonia (56%). For H1N1 patients, the median duration of high frequency oscillation ventilation was 3.7 days (interquartile range 1.8 to 5) with concomitant therapies including recruitment manoeuvres (22%), prone ventilation (41%), inhaled prostacyclins (18%) and inhaled nitric oxide (36%). Seven patients received extracorporeal membrane oxygenation, six having H1N1. Three patients had extracorporeal membrane oxygenation concurrently, two as salvage therapy following the commencement of high frequency oscillation ventilation. In 2008, no high frequency oscillation ventilation patient received extracorporeal membrane oxygenation. Overall hospital survival was 77% in H1N1 patients, while survival in patients having adjunctive extracorporeal membrane oxygenation was similar to those receiving high frequency oscillation ventilation alone (65% compared to 71%, P = 1.00). Survival rates were comparable to published extracorporeal membrane oxygenation outcomes. High frequency oscillation ventilation was used successfully as a rescue therapy for severe respiratory failure. High frequency oscillation ventilation was only available in a limited number of intensive care units during the H1N1 pandemic.


Assuntos
Ventilação de Alta Frequência/métodos , Ventilação de Alta Frequência/estatística & dados numéricos , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Pandemias , Insuficiência Respiratória/epidemiologia , Insuficiência Respiratória/terapia , Adolescente , Adulto , Distribuição por Idade , Austrália/epidemiologia , Criança , Pré-Escolar , Oxigenação por Membrana Extracorpórea/métodos , Oxigenação por Membrana Extracorpórea/estatística & dados numéricos , Feminino , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva/estatística & dados numéricos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Nova Zelândia/epidemiologia , Prevalência , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
19.
Mol Cell Biol ; 31(12): 2470-83, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21518961

RESUMO

Genome stability depends on faithful chromosome segregation, which relies on maintenance of chromatid cohesion during S phase. In eukaryotes, Pds1/securin is the only known inhibitor that can prevent loss of cohesion. However, pds1Δ yeast cells and securin-null mice are viable. We sought to identify redundant mechanisms that promote cohesion within S phase in the absence of Pds1 and found that cells lacking the S-phase cyclins Clb5 and Clb6 have a cohesion defect under conditions of replication stress. Similar to the phenotype of pds1Δ cells, loss of cohesion in cells lacking Clb5 and Clb6 is dependent on Esp1. However, Pds1 phosphorylation by Cdk-cyclin is not required for cohesion. Moreover, cells lacking Clb5, Clb6, and Pds1 are inviable and lose cohesion during an unperturbed S phase, indicating that Pds1 and specific B-type cyclins promote cohesion independently of one another. Consistent with this, we find that Mcd1/Scc1 is less abundant on chromosomes in cells lacking Clb5 and Clb6 during replication stress. However, clb5Δ clb6Δ cells do accumulate Mcd1/Scc1 at centromeres upon mitotic arrest, suggesting that the cyclin-dependent mechanism is S phase specific. These data indicate that Clb5 and Clb6 promote cohesion which is then protected by Pds1 and that both mechanisms are required during replication stress.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Cromátides/metabolismo , Ciclina B/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Proteínas Nucleares/metabolismo , Fase S/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Animais , Proteína Quinase CDC28 de Saccharomyces cerevisiae/genética , Proteína Quinase CDC28 de Saccharomyces cerevisiae/metabolismo , Proteínas de Ciclo Celular/genética , Segregação de Cromossomos , Ciclina B/genética , Quinases Ciclina-Dependentes/genética , Replicação do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Hidroxiureia/farmacologia , Camundongos , Componente 7 do Complexo de Manutenção de Minicromossomo , Proteínas Nucleares/genética , Inibidores da Síntese de Ácido Nucleico/farmacologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/genética , Securina , Separase , Fuso Acromático/metabolismo
20.
Phytomedicine ; 18(10): 863-7, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21419609

RESUMO

Kidney stones are a common problem for which inadequate prevention exists. We recruited ten recurrent kidney stone formers with documented calcium oxalate stones into a two phased study to assess safety and effectiveness of Cystone(®), an herbal treatment for prevention of kidney stones. The first phase was a randomized double-blinded 12 week cross over study assessing the effect of Cystone(®) vs. placebo on urinary supersaturation. The second phase was an open label one year study of Cystone(®) to determine if renal stone burden decreased, as assessed by quantitative and subjective assessment of CT. Results revealed no statistically significant effect of Cystone(®) on urinary composition short (6 weeks) or long (52 weeks) term. Average renal stone burden increased rather than decreased on Cystone(®). Therefore, this study does not support the efficacy of Cystone(®) to treat calcium oxalate stone formers. Future studies will be needed to assess effects on stone passage, or on other stone types.


Assuntos
Oxalato de Cálcio/metabolismo , Cálculos Renais/prevenção & controle , Extratos Vegetais/farmacologia , Vigilância de Produtos Comercializados , Urina/química , Adulto , Idoso , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Extratos Vegetais/administração & dosagem , Resultado do Tratamento
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