2D Supramolecular networks of dibenzonitrilediacetylene on Ag(111) stabilized by intermolecular hydrogen bonding.

The two-dimensional (2D) surface-directed self-assembly of dibenzonitrile diacetylene (DBDA) on Ag(111) under ultrahigh vacuum (UHV) conditions was investigated by combining scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and theoretical simulations based on density functional theory (DFT) calculations. The molecule consists of two benzonitrile groups (-C6H4-C[triple bond, length as m-dash]N) on each side of a diacetylene (-C[triple bond, length as m-dash]C-C[triple bond, length as m-dash]C-) backbone. The terminating nitrile (-C[triple bond, length as m-dash]N) groups at the meta position of the phenyl rings lead to cis and trans stereoisomers. The trans isomer is prochiral and can adsorb in the R or S configuration, leading to the formation of enantiomeric self-assembled networks on the surface. We identify two simultaneously present supramolecular networks, termed parallel and chevron phases, as well as a less frequently observed butterfly phase. These networks are formed from pure R (or S) domains, racemic mixtures (RS), and cis isomers, respectively. Our complementary data illustrates that the formation of the 2D supramolecular networks is driven by intermolecular hydrogen bonding between nitrile and phenyl groups (-C[triple bond, length as m-dash]NH-C6H3). This study illustrates that the molecular arrangement of each network depends on the geometry of the isomers. The orientation of the nitrile group controls the formation of the most energetically stable network via intermolecular hydrogen bonding.

The use of magnetic field effects on photosensitizer luminescence as a novel probe for optical monitoring of oxygen in photodynamic therapy.

The effect of a magnetic field on the steady-state and time-resolved optical emission of a custom fullerene-linked photosensitizer (PS) in liposome cell phantoms was studied at various oxygen concentrations (0.19-190 microM). Zeeman splitting of the triplet state and hyperfine coupling, which control intersystem crossing between singlet and triplet states, are altered in the presence of low magnetic fields (B < 320 mT), perturbing the luminescence intensity and lifetime as compared to the triplet state at B = 0. Measurements of the luminescence intensity and lifetime were performed using a time-domain apparatus integrated with a magnet. We propose that by probing magnet-affected optical emissions, one can monitor the state of oxygenation throughout the course of photodynamic therapy. Since the magnetic field effect (MFE) operates primarily by affecting the radical ion pairs related to type I photodynamic action, the enhancement or suppression of the MFE can be used as a measure of the dynamic equilibrium between the type I and II photodynamic pathways. The unique photo-initiated charge-transfer properties of the PS used in this study allow it to serve as both cytotoxic agent and oxygen probe that can provide in situ dosimetric information at close to real time.

Specificity of personality relationships to particular forms of concurrent substance use among methadone maintenance therapy clients.

OBJECTIVE: A mainstay treatment for opioid addiction in North America is methadone maintenance therapy (MMT) - a form of opiate agonist therapy (OAT). While efficacious for treating opioid addiction, MMT fails to address the concurrent polysubstance use that is common among opioid dependent clients. Moreover, psychosocial approaches for addressing polysubstance use during MMT are lacking. Our study's goals were to validate the use of the four-factor personality model of substance use vulnerability in MMT clients, and to demonstrate theoretically-relevant relationships of personality to concurrent substance use while receiving MMT. METHOD: Respondents included 138 daily-witnessed MMT clients (65.9% male, 79.7% Caucasian), mean age (SD) 40.18 (11.56), recruited across four Canadian MMT clinics. Bayesian confirmatory factor analysis was used to establish the structural validity of the four-factor personality model of substance use vulnerability (operationalized with the Substance Use Risk Profile Scale [SURPS]) in MMT clients. SURPS personality scores were then used as predictors for specific forms of recent (past 30-day) substance use. RESULTS: Using a latent hierarchal model, hopelessness was associated with recent opioid use; anxiety sensitivity with recent tranquilizer use; and sensation seeking with recent alcohol, cannabis, and stimulant use. CONCLUSION: Personality is associated with substance use patterns and may be an appropriate target for intervention for those undergoing MMT to reduce opioid use, and potentially dangerous concurrent use of other drugs, while receiving methadone.

[Effect of pH and the binding anion on In3+-transferrin interaction: spectroscopic study of the perturbed angular correlation of 172-245 keV gamma rays of indium 111]. / Influence du pH et de l'anion de liaison sur l'interaction In3+-transferrine: étude spectroscopique de la corrélation angulaire perturbée des raies gamma 172-245 keV de l'indium 111.

The formation of ternary complexes, transferrin-anion-In111 has been investigated by means of gamma-gamma coincidence spectrometry of the 172-245 keV rays. The angular correlation between the two gamma-rays emitted in cascade depends on the magnetic and electric fields gradients, consequently the chemical structure of metal holder. Any modification of this structure causes the variation of angular correlation. The study of G22 (infinity) as function of pH (G22(infinity): integrated perturbed angular correlation coefficient) has been performed to turn out the hydrolysis of In111 in aqueous solution, metal complex formation in presence of chelating agents (citric acid and sodium bicarbonate) and the formation of protein-metal complexes. The presence of complexing agents limits the domain of In111 colloid existence and allows fast transfer of ionised indium on the transferrin. Two types of metal-protein interactions has been turn out. The first in the weakly acidic range of pH is characterized by an affinity constant near to this of citric acid. The second lying in neutral and basic range of pH, where the formation rate of transferrin-In111 complex is fast (t less than 500 s). In citrate medium, for pH 6-7,5 the rate of metal transfer on the protein, studied by means of G22 (infinity) = f(t), is function of pH. The binding anion appears as an indispensable element for the formation of protein-metal complexes. The In111 previously chelated by 8-Hydroxyquinoline is fixed by the protein if only exits a binding anion in the solution. This mays bring in the formation of an intermediate active state, indispensable step for the ternary complex formation transferrin-anion-In111.

Folic acid deficiency and neutrophil dysfunction.

Polymorphonuclear leukocyte functions were studied in 92 patients with protein-calorie malnutrition. Serum folic acid levels were higher than 3 ng/ml in 38 patients and 3 ng/ml or less in 54 patients. Significant differences were found between these two groups of patients with regard to phagocytosis (81.5 +/- 1.9 versus 69.2 +/- 2.0 percent, p less than 0.001) and bactericidal ability (90.6 +/- 1.1 versus 84.5 +/- 2.3 percent, p less than 0.05). Correction of folic acid deficiency in 22 patients was associated with recovery of normal phagocytosis (p less than 0.001) but not bactericidal function. Adding folic acid to the serum of eight patients also restored normal phagocytic function (p less than 0.001). A correlation was found in vivo and in vitro between changes over time in folic acid levels and in phagocytosis.

Monoclonal gammopathies in the adult population of Finistère, France.

Three hundred and thirty-four monoclonal gammopathies were detected in the sera of 30 279 adults from Finistère. Monoclonal gammopathies (MG) are more common in Finistère than in Paris and their distribution is not homogeneous. IgG paraproteins are particularly common in the northeast of Finistère whereas IgM paraproteins are more common in the southwest. Family studies and the high degree of inbreeding would support the hypothesis that there is a genetic predisposition to develop MG but the occurrence of paraproteins among three non-consanguineous couples seems to favour the existence of an environmental factor.

Primary right atrial synovial sarcoma manifesting as transient ischemic attacks.

Primary tumors of the heart are rare and most of them benign. The majority of benign cardiac tumors are myxomas while almost all malignant cardiac tumors are sarcomas. We present a case of primary right atrial synovial sarcoma, a form of sarcoma particularly rare in the heart. The tumor manifested clinically as transient ischemic attacks probably related to a patent foramen ovale allowing paradoxical tumor embolization.

Double-lung transplantation in mechanically ventilated patients with cystic fibrosis.

Many lung transplant programs consider ventilator dependence as a contraindication for transplantation. Among 54 patients in whom bilateral lung transplantations for cystic fibrosis were performed by the Joint Marseille-Montreal Lung Transplant Program, 10 were ventilator dependent. Three of them died in the early postoperative period (30%): 2 as a result of cerebral anoxia and sepsis, 1 of Pseudomonas cepacia pneumonia. Two patients died at 15 and 19 months after transplantation of obliterative bronchiolitis and secondary bacterial pneumonitis. Another 2 patients in whom obliterative bronchiolitis developed underwent retransplantation with a heart-lung block; 1 of those was operated on at 12 months and is well at 29 months after his initial transplantation; the second was operated on at 34 months and died of primary graft failure. Three other patients are alive and well at 3, 11, and 14 months after transplantation. Actuarial survival at 1 year was 70%. The postoperative course and the infectious and rejection complications were no different from those in patients who underwent transplantation while spontaneously breathing. Obliterative bronchiolitis developed in 66% of patients at risk (2 of 6 patients surviving more than 6 months). We conclude that transplantation in mechanically ventilated patients with cystic fibrosis is not associated with an increase in morbidity or mortality after bilateral lung transplantation. Long-term survival, as in patients who undergo transplantation while spontaneously breathing, is limited by the development of obliterative bronchiolitis.

Folic acid deficiency in intensive care patients: comparison between two regimens of supplementation.

Serum folic acid (SFA) and red blood cell folic acid (RbcFA) levels were determined in 40 patients on the day of admission to our intensive care unit (ICU, D0). 65% of the patients had low SFA (< 3,4 ng/ml) and 27.5% had low RbcFA (< 275 ng/ml)L. Twenty-four hours later (Day 1:D1), both SFA and RbcFA had decreased significantly (respectively 0.49 ng/ml and 21 ng/ml, p < 0.01) in the 40 patients; the magnitude of RbcFA decrease was greater in patients with sepsis than in those without sepsis (p < 0.02). SFA and RbcFA levels were significantly lower in patients with sepsis on D0 and D1. Forty-two other patients with documented hypofolatemia were then randomly allocated to two regimens of FA supplementation. Patients on regimen A had an intravenous injection of 0.5 mg folinic acid daily for ten days whereas patients on regimen B received a single 5 mg intravenous injection of FA on day 1. Both regimens increased significantly SFA and RbcFA levels. But regimen A should be recommended because 1) RbcFA levels were significantly higher than with regimen B (p < 0.05) and 2) the mean increase was higher, particularly in patients with initial sepsis (p < 0.01).

Lack of effect of isradipine on cyclosporin pharmacokinetics.

The influence of isradipine as a long acting form (IcazR LP 5 mg) on cyclosporin pharmacokinetics was studied in six hypertensive renal transplant patients (mean age 37 yrs; mean body weight 62 kg). These patients received a mean daily cyclosporin dose of 307 mg in two equal intakes. Isradipine was orally administered once a day at a dose of 5 mg before the morning cyclosporin intake. Cyclosporin kinetics was assessed over a 0-12-h period, the day before (D-1) and 13 days (D+13) after isradipine treatment. Whole blood concentrations of cyclosporin were determined by radioimmunoassay (RIA) using the SandimmuneR-RIA kit (specific and non-specific monoclonal antibodies). Area under the blood concentration-time curve (AUC), the maximum blood concentration (Cmax) and the time to reach Cmax (Tmax) on D-1 and D+13 were not significantly different whatever the specificity of the RIA method. For example, the mean AUC +/- sd values were 5,247 +/- 2,255 (D-1) vs 5,317 +/- 1,675 (D+13) microgram.1(-1).h for the specific and 20,905 +/- 8,317 vs 19,327 +/- 5,758 microgram.1(-1).h for the non-specific determinations. Therefore, the pharmacokinetics of cyclosporin is not influenced by co-administration of isradipine at a therapeutic dosage. Moreover, the clinical results show that isradipine treatment was effective after 13 days administration (mean systolic blood pressure 132 vs 158 mm Hg, P < 0.05 and mean diastolic blood pressure 77 vs 93 mm Hg, P < 0.05 in supine position), and well tolerated throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro study of continuous wave Doppler spectral changes resulting from stenoses and bulbs.

Quantitative analysis of continuous wave (CW) Doppler spectra by measurements of peak frequency and spectral broadening is an important non-invasive method for detecting disturbed flow caused by carotid arterial stenosis. It is known that severe stenoses can be detected; however, the spectral changes associated with minor or moderate stenoses may not be detected or can potentially be confused with those produced by flow disturbances in the normal carotid bulb. In order to determine if the flow disturbances in a normal bulb and those associated with a minor stenosis produce significant spectral changes, Doppler spectra were recorded from straight tubes with bulbs or stenoses in an in vitro model with steady flow rates of 400, 600, and 800 cc/min (Reynolds numbers of 1700, 2600, and 3500). Stenoses greater than approximately 30% cross-sectional area were associated with an increased peak frequency and increased spectral broadening as measured by spectral broadening index (SBI), coefficient of variation (CV), coefficient of skewedness (CS) and coefficient of kurtosis (CK). Stenoses less than 30% were not detected. With flow rates of 400 and 600 cc/min, the presence of a bulb did not affect peak frequency or the extent of spectral broadening. With a higher flow rate (800 cc/min), there was an increase in SBI, CV and CS but no increase in peak frequency. Based on the results of these in vitro steady flow experiments in straight tubes, we conclude that increased peak frequency and spectral broadening are the result of a stenosis greater than 30% cross-sectional area.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors affecting the continuous wave Doppler spectrum for the diagnosis of carotid arterial disease.

Spectral analysis of continuous wave (CW) Doppler signals is used for the diagnosis of carotid arterial disease. Previous clinical and in vitro studies have documented that the peak Doppler frequency is increased in recordings made directly over a stenosis and that spectral broadening is observed beyond a stenosis in the region of disturbed flow. However, certain hemodynamic and technical factors can effect the Doppler spectrum and in particular cause spectral broadening although they are not related to the severity of the arterial stenosis. In this in vitro study, Doppler spectra were quantified by (1) measurements of the peak, mean and mode frequencies, and (2) measurements that quantify changes in the shape of the spectra and thus can potentially detect the presence of spectral broadening. The latter measurements included the spectral broadening index (SBI), coefficient of variation (CV), coefficient of skewedness (CS), and coefficient of kurtosis (CK). Using straight tubes without a bifurcation in a steady flow model, we found that the peak frequency and the extent of spectral broadening were dependent upon the severity of the stenosis, the relation of the recording site to the stenosis or bulb, and the flow rate. Comparison of the severity of Doppler spectral broadening from bulb and stenosis recordings allowed us to conclude that any observed changes in spectral broadening measurements are probably due to a significant stenosis and not to the presence of a normal bulb. If the tube is not completely insonated by the CW Doppler beam, an error of between 4 and 35% can be read in the spectral broadening measurements. The peak frequency, mean frequency, and SBI are not altered significantly by the automatic gain control or dynamic range and noise level settings usually chosen by the spectrum analyzer. Because of the variability of individual Doppler spectra, one should be cautious about deriving quantitative data from one individual spectrum. The results of quantitative analysis of the amplitude spectrum are different from the power spectrum. In conclusion, this in vitro study identified several hemodynamic and technical factors that affect the CW Doppler spectrum; however, in the clinical setting, their influence on quantitative measurements of the extent of spectral broadening likely can be minimized by a skilled technologist who uses a standardized technique.

Self-reported functional status as a predictor of coronary artery bypass graft surgery outcome in elderly patients.

BACKGROUND: Surgeons have traditionally relied mainly on clinical intuition in the selection of elderly candidates for coronary artery bypass grafting (CABG). The overall increasing number of patients undergoing CABG and limited resources require that a more rational approach be used to screen out candidates who are least likely to benefit from the surgery. HYPOTHESIS: Preoperative functional status is a more sensitive predictor of mortality and poor postoperative functional status than age. PATIENTS AND METHODS: Retrospective preoperative and postoperative geriatric assessment was obtained for 123 patients who had undergone CABG at the Montreal General Hospital. Montreal, Quebec. Preoperative and postoperative health and functional status were assessed using the Canadian version of the Medical Outcomes Study 36-Item Short-Form (SF-36) 1 to 1.5 years following surgery. The questionnaires were compiled according to the method described by Stewart et al and scores were transformed linearly to a 0 to 100 scale. In addition to functional status, the presence of comorbidities and other risk factors known to influence the outcome of CABG were recorded. RESULTS: There was no significant difference in the likelihood of having a poor functional status before or after surgery, or death as an outcome of CABG in the young elderly group versus the old elderly group. Preoperative functional status was found to predict postoperative functional status; however, there was no significant association between preoperative functional status and the presence of comorbidity. The presence of comorbidity did not affect the postoperative functional status, but increased the likelihood of death. CONCLUSION: Functional status was demonstrated to be a significant predictor of CABG outcome. When compared with age, functional status was also found to be a more reliable predictor of CABG outcome, which had not been previously demonstrated. Women were found to be more likely to have a poor preoperative functional status than their male counterparts. This may account in part for the decreased success rate of CABG in elderly women.

Clips versus suture technique: is there a difference?

INTRODUCTION: Coronary artery bypass grafting (CABG) is one of the most common procedures performed today, and wound complications are a major source of morbidity and cost. OBJECTIVE: To determine whether there is any difference in wound outcome (including cost in a Canadian context) between a subcuticular suture technique and skin stapling technique for closure of sternal and leg incisions in CABG patients. PATIENTS AND METHODS: One hundred and sixty-two patients undergoing CABG were prospectively, randomly placed to have their sternal and leg incisions closed with either a subcuticular suture technique or with a skin clip. Data were obtained through chart review, in-hospital assessments and follow-up visits. Nonblinded assessments were made regarding wound leakage, inflammation, infection, necrosis, swelling, dehiscence and cosmesis. Each of the parameters was graded on a scale from 1 to 4. The cost was evaluated in Canadian dollars. RESULTS: There were trends toward increased rates of in-hospital sternal (P=0.09) and leg (P=0.17) incision inflammation when the wounds were closed with skin clips. There was a significantly greater (P=0.05) rate of sternal wound infection with clips, as well as a tendency (P=0.15) toward a greater rate of mediastinitis at follow-up assessment. Cosmetic outcome was similar for both groups. The cost incurred was significantly greater when skin clips were used for closure. There was a greater than threefold difference, which translates to a greater than $10,000 difference over one year. CONCLUSIONS: Closure with a subcuticular technique achieves better outcomes than the use of skin clips. When factoring in the increased cost incurred by using clips, as well as other intangible factors such as surgical skill acquisition, subcuticular suture closure appears to be a favourable method of wound closure in CABG patients compared with the use of skin stapling techniques.

Outer ear temperature and time of death.

From a research sample of 138 corpses, divided into four subgroups of ambient storage temperature (0-5 degrees C, 6-10 degrees C, 11-15 degrees C and 16-23 degrees C) four linear regression formulae of actual versus estimated post-mortem interval were obtained ('interval' formulae) using a single outer ear temperature measurement on both sides. This method showed the best correlation coefficient among five other methods previously proposed for time of death determination (rectal temperature, vitreous K+, CSF K+, blood log NA+/K+ and log Cl-), however its results were less accurate than those obtained with a multivariate equation combining several of the above mentioned methods. Eventually an equation expressing time of death (TOD) as a function of outer ear temperature (OE T degrees) and ambient temperature was also established from the whole research sample ('global' formulae). On a different sample of 141 corpses the regression formulae ('interval' and 'global') for the outer ear temperature were compared to three methods based on a single rectal temperature measurement ('rule of thumb' 1 and 2, Henssge nomogram) and therefore useful at the scene; the results of all methods were compared within the four subgroups of ambient temperature as well as in three subgroups of different post-mortem interval lengths (< 7 h, < 10 h, < 15 h). In all cases the outer ear temperature formulae provided better results than the rectal temperature methods (especially Henssge nomogram and rule of thumb 1). Moreover they did not show any post-mortem plateau which was present in almost 30% of cases when rectal temperature was measured in corpses kept at ambient temperature above 15 degrees C. Our results show that outer ear temperature measurement is the method which provides the best simplicity/quality ratio and should therefore be proposed for use at the scene when conditions are similar to those of our experiment (within buildings). A software equipped thermometer is required in order to use in each case the appropriate formula and confidence interval.

[Anterior and posterior myocardial infarct: clinical comparative study on its outcome]. / Infarctus myocardique antérieur et postérieur. Etude clinique comparative de l'évolution.

A comparison of the short and long term outcome in two groups of patients admitted to hospital during the acute phase of their first myocardial infarction, an anterior group (123 cases) and a posterior group (147 cases) has produced the following results:--an immediate mortality which was significantly higher (identical cause of death) in the anterior infarct group (22.8%) than in the posterior infarct group (11.6%): p less than 0.02;--a very similar long term mortality (5 to 6% per year) in the two groups (the main causes for which cannot be equated) despite the fact that the initial destruction of muscle was usually greater when the infarct had been anterior. These results seem to lead to the following conclusion: a better overall prognosis seems to be related to efforts to limit the extent of an infarct, especially when it is anteriorly situated; sometime after the infarct, it is also linked to the improvement in vascularity of the regions which are not involved, especially in cases of posterior necrosis.

[Complete bundle-branch block and myocardial infarct. Natural history. Comparative study]. / Bloc de branche complet et infarctus du myocarde. Histoire naturelle. Etude comparative.

Myocardial infarction (MI), (and especially anteriorly situated necrosis) was complicated by complete branch block (CBB) in 9.7% of cases (45 patients out of 462). A comparison of the short- and long-term outcome in two groups of patients (group A: 45 cases of MI complicated by CBB; group B: 45 cases of MI with no atrio-ventricular or intra-ventricular conduction defects) showed that there was a much bigger immediate mortality in group A, which was not changed by temporary cardiac pacemaking, and depended on the extent of myocardial destruction. A study of the long-term outcome showed that there were more deaths in group A (recurrence of MI, intractable cardiac failure). However, the incidence of sudden death was equal in the two groups (group A 15%, group B 13%), and there was no obvious explanation in the absence of electrocardiographic tracings. Therefore this study lends no support to the argument which favours prophylactic implantation of a cardiac pacemaker during the course of MI complicated by CBB.

[Recent myocardial infarction and complete bundle branch block. Comparative macroscopic pathological study]. / Infarctus myocardique récent et blocs de brache complets. Etude anatomique macroscopique comparative

Fifty five anatomo-clinical cases of patients who died of a recent myocardial infarction were divided into two groups according to existence of a complete block of one of the branches of the bundle of His, which occured at the same time as the myocardial necrosis: group A: 14 cases comprising 13 complete right blocks and only one complete left block, or absence of intraventricular conduction disorders: group B: 41 cases. The macroscopic anatomical study separated the two groups: in group A there was a very high frequency of healed posterior infarction, extensive recent anterior infraction, transeptal through the anterior and upper half of the interventricular septum by occlusion of the anterior interventricular artery in its proximal segment, above the origin of the second anterior septal artery, associated to severe stenosing lesions of the other coronary trunks, in particular the right coronary artery.

[Rupture of the heart in the acute phase of myocardial infarct. Anatomic-macroscopic study]. / Les ruptures du coeur à la phase aiguë de l'infarctus du myocarde. Etude anatomique-macroscopique

The data of the macroscopical-anatomical examination of 14 cases of cardiac rupture (10 women, 4 men) complicating acute myocardial infarction were compared with those obtained at autopsy, with the same protocol, in 31 cases of myocardial infarction which resulted in death before the 30th day after the onset. Many anatomical facts separated both groups from each other (size, aspect, limits of myocardial necrosis, state of the coronary arteries). Eventual surgical conclusions might be drawn from this study.

[Myocardial infarction: comparative study of principal risk factors in the two sexes]. / Infarctus du myocarde: étude comparative des principaux facteurs de risque selon le sexe

A study of the distribution of the various risk factors for coronary artery disease as a function of the age and sex of a homogenous population of 316 patients has brought to light the following findings: -- These was found to be a greater incidence (statistically significant) of hypertension disorders of glucose metabolism obesity and hypercholesterolaemia in the females, and of tobacco consumption (cigarettes) and, to a lesser extent, of hypertriglyceridaemia and of gout in the males; -- The females who 'tot up' risk factors have their myocardial infarction at a greater age than the males -- The risk factor which separates the two sexes in the consumption of cigarette tobacco. These findings agree with those already in the literature.