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1.
Phys Rev Lett ; 126(14): 141301, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33891448

RESUMO

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

2.
Phys Rev Lett ; 122(17): 171301, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31107093

RESUMO

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

3.
J Phys Chem B ; 110(22): 10855-61, 2006 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-16771337

RESUMO

The surface properties of aluminum, such as chemical composition, roughness, friction, adhesion, and wear, can play an important role in the performance of micro-/nano-electromechanical systems, e.g., digital micromirror devices. Aluminum substrates chemically reacted with octadecylphosphonic acid (ODP/Al), decylphosphonic acid (DP/Al), and octylphosphonic acid (OP/Al) have been investigated and characterized by X-ray photoelectron spectroscopy (XPS), contact angle measurements, and atomic force microscopy (AFM). XPS analysis confirmed the presence of alkylphosphonate molecules on ODP/Al, DP/Al, and OP/Al. No phosphonates were found on bare Al as a control. The sessile drop static contact angle of pure water on ODP/Al and DP/Al was typically more than 115 degrees and on OP/Al typically less than 105 degrees indicating that all phosphonic acid reacted Al samples were highly hydrophobic. The root-mean-square surface roughness for ODP/Al, DP/Al, OP/Al, and bare Al was less than 15 nm as determined by AFM. The surface energy for ODP/Al and DP/Al was determined to be approximately 21 and 22 mJ/m2, respectively, by the Zisman plot method, compared to 25 mJ/m2 for OP/Al. ODP/Al and OP/Al were studied by friction force microscopy, a derivative of AFM, to better understand their micro-/nano-tribological properties. ODP/Al gave the lowest coefficient of friction values while bare Al gave the highest. The adhesion forces for ODP/Al and OP/Al were comparable.

4.
J Am Coll Cardiol ; 33(7): 1903-8, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10362191

RESUMO

OBJECTIVES: Implantation of left ventricular assist devices (LVADs) early after acute myocardial infarction (MI) has traditionally been thought to be associated with high mortality rates due to technical limitations and severe end-organ dysfunction. At some experienced centers, doctors have refrained from earlier operation after MI to allow for a period of hemodynamic and end-organ stabilization. METHODS: We retrospectively investigated the effect of preoperative MI on the survival rates of 25 patients who received a Thermocardiosystems Incorporated LVAD either <2 weeks (Early) (n = 15) or >2 weeks (Late) (n = 10) after MI. Outcome variables included perioperative right ventricular assistance (and right-sided circulatory failure), hemodynamic indexes, percent transplanted or explanted, and mortality. RESULTS: No statistically significant differences were demonstrated between demographic, perioperative or hemodynamic variables between the Early and Late groups. Patients in the Early group demonstrated a lower rate of perioperative mechanical right ventricular assistance, but had a higher rate of perioperative inhaled nitric oxide use. In addition, 67% of patients in the Early group survived to transplantation and 7% to explantation, findings comparable to those in the Late group (60% and 0% respectively). CONCLUSIONS: This clinical experience suggests that patients may have comparable outcomes whether implanted early or late after acute MI. These data therefore support the early identification and timely application of this modality in post-MI LVAD candidates, as this strategy may also reveal a subgroup of patients for whom post-MI temporary LVAD insertion may allow for full ventricular recovery.


Assuntos
Coração Auxiliar , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Implantação de Prótese , Adulto , Idoso , Seguimentos , Hemodinâmica , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
5.
J Am Coll Cardiol ; 30(7): 1773-7, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9385906

RESUMO

OBJECTIVES: Our recent experience with outpatient left ventricular assist device (LVAD) support is presented to demonstrate the possibilities and limitations of long-term outpatient mechanical circulatory assistance. BACKGROUND: The experience with inpatient LVAD support as a bridge to transplantation has proved the efficacy of such therapy in improving circulatory hemodynamic status, restoring normal end-organ function and facilitating patient rehabilitation. With miniaturization of the power supplies and controllers, such mechanical circulatory support can now be accomplished in an outpatient setting. METHODS: Between March 1993 and February 1997, 32 patients (26 male, 6 female, mean [+/-SEM] age 49 +/- 15 years) underwent implantation of the ThermoCardiosystems (TCI) Heartmate vented electric (VE) LVAD. The VE LVAD is powered by batteries worn on shoulder holsters and is operated by a belt-mounted system controller, allowing unrestricted patient ambulation and hospital discharge. RESULTS: Mean duration of support was 122 +/- 26 days (range 3 to 605), with a survival rate to transplantation or explantation of 78%. Nineteen patients were discharged from the hospital on mean postoperative day 41 +/- 4 (range 17 to 68), for an outpatient support time of 108 +/- 30 days (range 2 to 466). Four patients underwent early transplantation and could not participate in the discharge program, and three patients currently await discharge. The complication rate was not statistically different from that encountered in our previous 52 patients with a pneumatic LVAD. CONCLUSIONS: Outpatient LVAD support is safe and provides improved quality of life for patients awaiting transplantation. Wearable and totally implantable LVADs should be studied as permanent treatment options for patients who are not candidates for heart transplantation.


Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração , Coração Auxiliar , Assistência Ambulatorial , Desenho de Equipamento , Feminino , Insuficiência Cardíaca/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Seleção de Pacientes , Taxa de Sobrevida , Fatores de Tempo
6.
J Clin Endocrinol Metab ; 42(3): 459-63, 1976 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1254686

RESUMO

Thirteen patients with Paget's disease of the bone were treated with subcutaneous injections of synthetic salmon calcitonin (SCT) for a mean period of 22 months at doses of 50-100 MCR units daily or 3 times a week. They manifested symptomatic improvement and significant reductions in serum alkaline phosphatase and urinary hydroxyproline excretion during SCT administration. Following discontinuation of SCT, symptomatic improvement was maintained in 10 patients for up to one year, whereas a recurrence of symptoms was seen in only 3 patients. The serum alkaline phosphatase generally showed a return toward pretreatment values 6 months after discontinuation of SCT, whereas urinary hydroxyproline remained depressed for up to a year.


Assuntos
Calcitonina/uso terapêutico , Osteíte Deformante/tratamento farmacológico , Idoso , Fosfatase Alcalina/sangue , Calcitonina/imunologia , Seguimentos , Humanos , Hidroxiprolina/urina , Masculino , Pessoa de Meia-Idade , Osteíte Deformante/sangue , Osteíte Deformante/imunologia , Osteíte Deformante/urina , Recidiva , Fatores de Tempo
7.
Ann Thorac Surg ; 65(2): 314-8, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9485220

RESUMO

BACKGROUND: Severe pulmonary dysfunction has been considered a relative contraindication to surgical resection in patients with solitary pulmonary nodules. We report our initial experience with the combined use of lung volume reduction operation and tumor resection in this patient population. METHODS AND PATIENTS: Between January 1995 and July 1996, 14 patients underwent combined lung volume reduction operation and pulmonary nodule resection. Ten (71%) patients were oxygen dependent, 5 (36%) had a room air partial pressure of carbon dioxide > or = 45, and 5 (36%) were steroid dependent preoperatively. Mean preoperative pulmonary function tests included a forced expiratory volume in 1 second of 680 +/- 98 mL (24% +/- 5% predicted), forced vital capacity of 54% +/- 5% predicted, and a forced expiratory volume in 1 second to vital capacity ratio of 37% +/- 2% predicted. RESULTS: Sixteen lesions were resected in the 14 patients and included 9 non-small cell carcinomas. There was one postoperative death. All other patients are alive and well through a mean follow-up of 22.6 +/- 2.3 months (12 to 35 months). At 6-month follow-up improvements were noted in dyspnea index, forced expiratory volume in 1 second forced vital capacity, and 6-minute walk distance. Mediastinal recurrence at 12-month follow-up developed in 1 patient with two separate bronchioalveolar carcinomas. CONCLUSIONS: Simultaneous lung volume reduction operation and tumor resection should be considered in patients with emphysema with marginal reserve in the hope of maximizing postoperative lung function.


Assuntos
Neoplasias Pulmonares/cirurgia , Pulmão/cirurgia , Enfisema Pulmonar/cirurgia , Nódulo Pulmonar Solitário/cirurgia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Seguimentos , Volume Expiratório Forçado , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Enfisema Pulmonar/complicações , Enfisema Pulmonar/fisiopatologia , Nódulo Pulmonar Solitário/complicações , Nódulo Pulmonar Solitário/fisiopatologia , Capacidade Vital
8.
Ann Thorac Surg ; 66(5): 1640-6, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9875764

RESUMO

BACKGROUND: Current techniques of mitral valve repair rely on decreasing valve area to increase leaflet apposition, but fail to address subvalvular dysfunction. A novel repair has been introduced with partial left ventriculectomy, which apposes the anterior leaflet to a corresponding point on the posterior leaflet creating a double-orifice valve, with reported adequate control of mitral regurgitation. METHODS: We started to use the "bow-tie" repair as an adjunct to posterior ring annuloplasty in cases in which mitral regurgitation was not adequately controlled by decreasing mitral valve area (n = 6), or when placement of an annuloplasty ring was impractical (n = 4). Mean follow-up was 336 days (range, 82 to 551 days) with no postoperative deaths. RESULTS: Mitral regurgitation decreased from 3.6+/-0.5 to 0.8+/-0.4 (p < 0.0001), with a concomitant increase in ejection fraction from 33%+/-13% to 45%+/-11% (p = 0.0156) before hospital discharge. Mitral valve area, measured by pressure half-time, decreased from a mean of 2.5+/-0.3 to 2.1+/-0.3 cm2, with a mean transvalvular gradient of 4.5+/-2.0 mm Hg. In patients whose mitral valve was repaired using the bow-tie alone, mitral regurgitation was reduced from 4+, to a trace to 1+. Postoperatively, mitral valve area increased from 1.9 to 2.5 cm2 during exercise, further supporting the concept that this technique preserves mitral valve annular function. CONCLUSIONS: These observations suggest that the bow-tie repair may offer advantages over conventional techniques of mitral valve repair and should be considered as an adjunct, especially in patients with impaired left ventricular function.


Assuntos
Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Adulto , Idoso , Angina Pectoris/complicações , Feminino , Ventrículos do Coração/cirurgia , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Volume Sistólico , Disfunção Ventricular Esquerda/complicações
9.
Ann Thorac Surg ; 64(6): 1757-62; discussion 1762-3, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9436568

RESUMO

BACKGROUND: Over the past decade, the use of mechanical circulatory support in patients with postcardiotomy cardiogenic shock has resulted in hospital discharge rates of 25% to 40%. In an attempt to improve patient survival, we initiated a program of early insertion of an implantable Thermocardiosystems Incorporated Heartmate left ventricular assist device in patients who have circulatory failure after having undergone high-risk cardiac operations. METHODS: Between April 1993 and February 1997, 12 patients underwent insertion of an implantable left ventricular assist device for postcardiotomy cardiogenic shock after coronary artery bypass grafting. Indications for insertion included postoperative cardiogenic shock (7 patients), postoperative cardiac arrest (3 patients), and failure to wean from cardiopulmonary bypass (2 patients). RESULTS: The median time to device insertion was 3.5 days. The mean duration of left ventricular assist device support was 103 +/- 19 days (range, 2 to 225 days). Nine of 11 patients (82%) survived to undergo either transplantation (8 patients) or explantation (1 patient), with successful hospital discharge of all 9 patients. The major complication was device-related infection (42%). A single thromboembolism occurred in a patient with an infection. CONCLUSIONS: Long-term outcome after postcardiotomy cardiogenic shock is improved substantially with the use of an implantable left ventricular assist device early in the postoperative course. Access to such a device is an important consideration before undertaking a high-risk cardiac operation, and early implantation of the device is a critical factor in ensuring long-term survival.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Coração Auxiliar , Choque Cardiogênico/terapia , Algoritmos , Feminino , Coração Auxiliar/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Choque Cardiogênico/etiologia , Fatores de Tempo , Resultado do Tratamento
10.
Ultramicroscopy ; 93(1): 83-9, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12380652

RESUMO

Supramolecular complexes, such as chaperonins, are suitable samples for atomic force microscope structural studies because they have a very well defined shape. High-resolution images can be made using tapping mode in liquid under native conditions. Details about the two-dimensional structures formed onto the surface upon adsorption and of the single protein can be observed. Dissection of the upper ring of the supramolecular complex as a result of the applied lateral force through scanning tip is observed. Finally, the combination of lateral convolution and tip penetration into the cavity of chaperonins offers a direct evaluation of the tip convolution effect on images of macromolecular samples.


Assuntos
Chaperonina 60/química , Microscopia de Força Atômica/métodos , Chaperonas Moleculares/química , Calibragem , Cristalização , Processamento de Imagem Assistida por Computador , Microscopia de Força Atômica/instrumentação , Conformação Proteica
11.
J Pediatr Surg ; 32(9): 1341-3, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9314258

RESUMO

Spontaneous intramural duodenal hematoma is a rare problem, most commonly seen in children who have coagulation disorders. A child who had Glanzmann's thrombasthenia, a disorder of platelet function, presented with signs and symptoms of duodenal obstruction. Nonoperative management of an obstructing duodenal hematoma was successful and potentially life-threatening surgery was avoided.


Assuntos
Duodenopatias/etiologia , Hematoma/etiologia , Trombastenia/complicações , Dor Abdominal/etiologia , Adolescente , Sulfato de Bário , Drenagem , Duodenopatias/diagnóstico , Duodenopatias/terapia , Hematoma/diagnóstico , Hematoma/terapia , Humanos , Intubação Gastrointestinal , Masculino , Tomografia Computadorizada por Raios X
12.
ASAIO J ; 43(5): M421-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9360075

RESUMO

Cardiopulmonary bypass (CPB) causes a well described systemic inflammatory response. To avoid these potential detrimental effects, coronary artery bypass grafting (CABG) has been attempted off CPB on the beating heart. With the use of a left ventricular (LV) assist device during CABG, the heart can be made flaccid with beta-blockade, and the systemic circulation can continue to be supported. The hemodynamic and hematologic consequences of left heart bypass with a miniature axial flow pump were studied in a sheep CABG model. The pump weighs 45 g and was connected to standard venous and arterial cannulas. Left sided inflow and brachiocephalic outflow were employed. A pump speed of 14,000 rpm resulted in a flow of 5.63 +/- 0.18 L/min and provided 75% of the LV output during a 2 hr pump run. This resulted in complete capture of the aortic pressure tracing (mean 56.3 mmHg) with a 15.5 mmHg augmentation in the esmolol depressed ventricle. Reductions in LV end diastolic pressure and LV end systolic pressure resulted in a 66% reduction in LV external work under baseline conditions and an 83% reduction in the beta-blocked ventricle. Myocardial oxygen demand was reduced 16% after axial flow unloading in the esmolol depressed condition. Right ventricular pressures, pulmonary artery flow, LV filling, and oxygenation were adequate in the esmolol depressed animal and remained unchanged throughout the experiment. No changes in hematocrit, total bilirubin, lactate dehydrogenase, or plasma free hemoglobin were detected after 2 hr of assist. Axial flow left heart bypass results in acceptable hemodynamics with no hemolysis and may provide an alternative to CPB during CABG.


Assuntos
Ponte Cardiopulmonar/efeitos adversos , Ponte de Artéria Coronária/métodos , Coração Auxiliar , Animais , Fenômenos Biomecânicos , Ponte de Artéria Coronária/efeitos adversos , Desenho de Equipamento , Estudos de Avaliação como Assunto , Hemodinâmica , Humanos , Masculino , Ovinos , Função Ventricular Esquerda
13.
AORN J ; 66(5): 808-10, 812, 814 passim, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9365792

RESUMO

Lung volume reduction surgery (LVRS) and concomitant pulmonary nodule resection can improve the respiratory function of and remove malignant lesions in patients with chronic obstructive pulmonary disease and lung cancer. Previously, using standard selection criteria, some patients with emphysema who also had lung nodules were denied surgery because of the severity of their pulmonary dysfunction. In this article, the authors report improved pulmonary function in 11 patients with severe emphysema who underwent combined LVRS and nodule resection.


Assuntos
Carcinoma/cirurgia , Pneumopatias Obstrutivas/cirurgia , Neoplasias Pulmonares/cirurgia , Pulmão/cirurgia , Enfermagem Perioperatória , Nódulo Pulmonar Solitário/cirurgia , Idoso , Carcinoma/enfermagem , Feminino , Humanos , Pneumopatias Obstrutivas/complicações , Pneumopatias Obstrutivas/enfermagem , Pneumopatias Obstrutivas/fisiopatologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/enfermagem , Neoplasias Pulmonares/fisiopatologia , Masculino , Estadiamento de Neoplasias , Seleção de Pacientes , Testes de Função Respiratória , Nódulo Pulmonar Solitário/complicações , Nódulo Pulmonar Solitário/enfermagem , Nódulo Pulmonar Solitário/fisiopatologia , Resultado do Tratamento
14.
Cardiol Res Pract ; 2014: 972832, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24653860

RESUMO

Objective. Bilateral internal thoracic artery (BITA) grafting provides improved graft patency and potential survival advantage in selected patients as compared to single left internal thoracic artery (LITA) revascularization. The ideal functional BITA configuration remains controversial. Methods. Patients undergoing planned BITA revascularization with greater than 75% stenosis in both the left anterior descending artery (LAD) and in a circumflex branch were prospectively randomized to one of two proximal free right internal thoracic artery (RITA) connections directly off the aorta (Ao) (n = 12) or as a "t" graft off the LITA (t) (n = 12). The LITA was placed to the LAD in all cases, and the RITA was placed to a single lateral wall vessel. Intraoperative transit time flow measurements of all arterial grafts were performed, and RITA fractional flow parameters were compared between the 2 groups. Results. There were no differences in preoperative patient variables between the two groups. Cross-clamp times (91.5 + 15.3 versus 68.0 + 12.5 minutes, P < 0.01) and total cardiopulmonary bypass times (109.0 + 16.2 versus 85.0 + 15.1 minutes, P < 0.01) were shorter in the t group. The Ao group demonstrated significantly higher mean RITA flow (38.3 ± 13.5 versus 22.1 ± 9.5, P < 0.01), mean RITA conductance (flow/mean arterial pressure) (0.45 ± 0.16 versus 0.28 ± 0.11, P < 0.01), RITA fractional flow (0.52 ± 0.15 versus 0.36 ± 0.11, P < 0.01), and RITA fractional conductance (0.51 ± 0.15 versus 0.36 ± 0.11, P < 0.01) than the "t" grafted patients. Thirty-day mortality and wound infection were 0% for each group. Over an average of 42.8 + 6.6 months of followup there were no mortalities in either group. Repeat angiography were performed in 4 patients (33%) in the Ao group and 2 patients in the t group (16%). One occluded RITA graft and one ostial RITA stenosis were detected in the Ao group. Conclusions. Acute flow measurements indicate that the free RITA anastomosed to the aorta provides more acute fractional RITA flow than composite "t" grafting to the LITA. Longer-term angiographic and clinical followup are necessary to determine the consequences of these acute hemodynamic findings.

16.
Ultramicroscopy ; 109(8): 1015-22, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19361929

RESUMO

Self-assembled monolayer (SAM) films have been formed on oxidized copper (Cu) substrates by reaction with 1H,1H,2H,2H-perfluorodecylphosphonic acid (PFDP), octadecylphosphonic acid (ODP), decylphosphonic acid (DP), and octylphosphonic acid (OP) and then investigated by X-ray photoelectron spectroscopy (XPS), contact angle measurement (CAM), and atomic force microscopy (AFM). The presence of alkyl phosphonate molecules, PFDP, ODP, DP, and OP, on Cu were confirmed by CAM and XPS analysis. No alkyl phosphonate molecules were seen by XPS on unmodified Cu as a control. The PFDP/Cu and ODP/Cu SAMs were found to be very hydrophobic having water sessile drop static contact angles of more than 140 degrees , while DP/Cu and OP/Cu have contact angles of 119 degrees and 76 degrees , respectively. PFDP/Cu, ODP/Cu, DP/Cu, and OP/Cu SAMs were studied by friction force microscopy, a derivative of AFM, to better understand their micro/nanotribological properties. PFDP/Cu, ODP/Cu, and DP/Cu had comparable adhesive force, which is much lower than that for unmodified Cu. ODP/Cu had the lowest friction coefficient followed by PFDP/Cu, DP/Cu, and OP/Cu while unmodified Cu had the highest. XPS data gives some indication that a bidentate bond forms between the alkyl phosphonate molecules and the oxidized Cu surface. Hydrophobic phosphonate SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for anti-wetting, low adhesion surfaces.

17.
J Chem Phys ; 126(11): 114706, 2007 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-17381227

RESUMO

A self-assembled monolayer (SAM) has been produced by reaction of 1H,1H,2H,2H-perfluorodecyldimethylchlorosilane (PFMS) with an oxidized copper (Cu) substrate and investigated by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), friction force microscopy (FFM), a derivative of AFM, and contact angle measurement. FFM showed a significant reduction in the adhesive force and friction coefficient of PFMS modified Cu (PFMS/Cu) compared to unmodified Cu. The perfluoroalkyl SAM on Cu is found to be extremely hydrophobic, yielding sessile drop static contact angles of more than 130 degrees for pure water and a "surface energy" (which is proportional to the Zisman critical surface tension for a Cu surface with 0 rms roughness) of 14.5 mJm2(nMm). Treatment by exposure to harsh conditions showed that PFMS/Cu SAM can withstand boiling nitric acid (pH=1.8), boiling water, and warm sodium hydroxide (pH=12, 60 degrees C) solutions for at least 30 min. Furthermore, no SAM degradation was observed when PFMS/Cu was exposed to warm nitric acid solution for up to 70 min at 60 degrees C or 50 min at 80 degrees C. Extremely hydrophobic (low surface energy) and stable PFMS/Cu SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for antiwetting, low adhesion surfaces or dropwise condensation on heat exchange surfaces.

18.
J Chem Phys ; 124(17): 174710, 2006 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-16689593

RESUMO

Substrates of aluminum (Al) deposited by physical vapor deposition onto Si substrates and then chemically reacted with perfluorodecylphosphonic acid (PFDPAlSi), decylphosphonic acid (DPAlSi), and octadecylphosphonic acid (ODPAlSi) were studied by x-ray photoelectron spectroscopy (XPS), contact angle measurements, atomic force microscopy (AFM), and friction force microscopy, a derivative of AFM, to characterize their surface chemical composition, roughness, and micro-/nanotribological properties. XPS analysis confirmed the presence of perfluorinated and nonperfluorinated alkylphosphonate molecules on the PFDPAlSi, DPAlSi, and ODPAlSi. The sessile drop static contact angle of pure water on PFDPAlSi was typically more than 130 degrees and on DPAlSi and ODPAlSi typically more than 125 degrees indicating that all phosphonic acid reacted AlSi samples were very hydrophobic. The surface roughness for PFDPAlSi, DPAlSi, ODPAlSi, and bare AlSi was approximately 35 nm as determined by AFM. The surface energy for PFDPAlSi was determined to be approximately 11 mNm by the Zisman plot method compared to 21 and 20 mNm for DPAlSi and ODPAlSi, respectively. Tribology involves the measure of lateral forces due to friction and adhesion between two surfaces. Friction, adhesion, and wear play important roles in the performance of micro-/nanoelectromechanical systems. PFDPAlSi gave the lowest adhesion and coefficient of friction values while bare AlSi gave the highest. The adhesion and coefficient of friction values for DPAlSi and ODPAlSi were comparable.

19.
Eur J Clin Invest ; 36(9): 599-607, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16919041

RESUMO

The purpose of the present study was to determine independent predictors for long-term mortality after cardiac surgery. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was developed to score in-hospital mortality and recent studies have shown its ability to predict long-term mortality as well. We compared forecasts based on EuroSCORE with other models based on independent predictors. Medical records of patients with cardiac surgery who were discharged alive (n = 4852) were retrospectively reviewed. Their operative surgical risks were calculated according to EuroSCORE. Patients were randomly divided into two groups: training dataset (n = 3233) and validation dataset (n = 1619). Long-term survival data (mean follow-up 5.1 years) were obtained from the National Death Index. We compared four models: standard EuroSCORE (M1); logistic EuroSCORE (M2); M2 and other preoperative, intra-operative and post-operative selected variables (M3); and selected variables only (M4). M3 and M4 were determined with multivariable Cox regression analysis using the training dataset. The estimated five-year survival rates of the quartiles in compared models in the validation dataset were: 94.5%, 87.8%, 77.1%, 64.9% for M1; 95.1%, 88.0%, 80.5%, 64.4% for M2; 93.4%, 89.4%, 80.8%, 64.1% for M3; and 95.8%, 90.9%, 81.0%, 59.9% for M4. In the four models, the odds of death in the highest-risk quartile was 8.4-, 8.5-, 9.4- and 15.6-fold higher, respectively, than the odds of death in the lowest-risk quartile (P < 0.0001 for all). EuroSCORE is a good predictor of long-term mortality after cardiac surgery. We developed and validated a model using selected preoperative, intra-operative and post-operative variables that has better discriminatory ability.


Assuntos
Procedimentos Cirúrgicos Cardíacos/mortalidade , Medição de Risco/métodos , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Estudos Retrospectivos , Fatores de Risco
20.
Hosp Med Staff ; 10(3): 19-20, 22-5, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10250210

RESUMO

Five activities are essential for effective collaborative practice in the hospital setting--primary nursing, integrated charting, expanded nurses' decision making, joint patient care review, and a collaborative practice committee. This article relates the experience of a large, urban teaching hospital in implementing these activities.


Assuntos
Equipe de Assistência ao Paciente , Enfermagem Primária/organização & administração , Hospitais com 300 a 499 Leitos , Prontuários Médicos , Cidade de Nova Iorque , Revisão por Pares , Comitê de Profissionais/organização & administração
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