Agar Biopolymer Films for Biodegradable Packaging: A Reference Dataset for Exploring the Limits of Mechanical Performance

This article focuses on agar biopolymer films that offer promise for developing biodegradable packaging, an important solution for reducing plastics pollution. At present there is a lack of data on the mechanical performance of agar biopolymer films using a simple plasticizer. This study takes a Design of Experiments approach to analyze how agar-glycerin biopolymer films perform across a range of ingredients concentrations in terms of their strength, elasticity, and ductility. Our results demonstrate that by systematically varying the quantity of agar and glycerin, tensile properties can be achieved that are comparable to agar-based materials with more complex formulations. Not only does our study significantly broaden the amount of data available on the range of mechanical performance that can be achieved with simple agar biopolymer films, but the data can also be used to guide further optimization efforts that start with a basic formulation that performs well on certain property dimensions. We also find that select formulations have similar tensile properties to thermoplastic starch (TPS), acrylonitrile butadiene styrene (ABS), and polypropylene (PP), indicating potential suitability for select packaging applications. We use our experimental dataset to train a neural network regression model that predicts the Young’s modulus, ultimate tensile strength, and elongation at break of agar biopolymer films given their composition. Our findings support the development of further data-driven design and fabrication workflows.     

Physician‐related facilitators and barriers to patient involvement in treatment decision making in early stage breast cancer: perspectives of physicians and patients

Objective To identify patients’ and physicians’ perceptions of physician‐related verbal and nonverbal facilitators and barriers to patient involvement in treatment decision making (TDM) occurring during clinical encounters for women with early stage breast cancer (ESBC). Methods Eligible women were offered treatment options including surgery and adjuvant therapy. Eligible physicians provided care for women with ESBC in either a teaching hospital or an academic cancer centre. In Phase 1, women were interviewed 1–2 weeks after their initial consultation. In Phase 2, women and their physicians were interviewed separately while watching their own consultation on a digital video disk. All interviews were audiotaped, transcribed and analysed. Results Forty women with ESBC and six physicians participated. Patients and physicians identified thirteen categories of physician facilitators of women’s involvement. Of these, seven categories were frequently identified by women: conveyed a rationale for patient involvement in TDM; explained the risk of cancer recurrence; explained treatment options; enhanced patient understanding of information; gave time for TDM; offered a treatment recommendation; and made women feel comfortable. Physicians described similar information‐giving facilitators but less often mentioned other facilitators. Few physician barriers to women’s involvement in TDM were identified. Conclusions Women with ESBC and cancer physicians shared some views of how physicians involve patients in TDM, although there were important differences. Physicians may underestimate the importance that women’s place on understanding the rationale for their involvement in TDM and on feeling comfortable during the consultation.     

Endogenous protein phosphorylation by resting and activated human neutrophils

NADPH oxidase is an enzyme in the plasma membrane of the neutrophil that catalyzes the production of O2-, a species central to the oxygen- dependent killing mechanisms of this cell. The oxidase is dormant in resting cells and is activated upon the addition of a stimulus. Neutrophils of patients with chronic granulomatous disease (CGD) manifest no oxidase activity when stimulated. The possible role of protein phosphorylation in the activation of NADPH oxidase was examined in normal and CGD neutrophils by measuring the incorporation of 32Pi into proteins as determined by gel electrophoresis followed by autoradiography. Resting neutrophils from normal subjects exhibit at least 40 distinct phosphoprotein bands. The level of phosphorylation of these bands was examined after the addition of phorbol myristate acetate (PMA), opsonized zymosan, digitonin, N-formyl-methionyl- phenylalanine (FMLP), or NaF. PMA and opsonized zymosan increased the phosphorylation of a set of 6 protein bands. Digitonin and FMLP consistently caused the phosphorylation of 4 of these protein bands, while NaF failed to induce increased phosphorylation of any protein band. All activators tested caused the dephosphorylation of one specific protein band. The time course of phosphorylation (dephosphorylation) was examined using PMA as the activating agent. Increased phosphorylation of one protein band was evident by 12 sec after the addition of PMA. The most slowly phosphorylated protein band did not slow evidence of change until 5 min after the addition of PMA. Three of the phosphoproteins examined were phosphorylated either earlier than or concomitant with the activation of NADPH oxidase. CGD neutrophils were compared with normal cells for their ability to phosphorylate proteins in response to PMA. The phosphoprotein banding patterns of CGD neutrophils were identical with those of normal neutrophils in both the resting and activated states. The evidence presented shows that the phosphorylation of proteins is a prominent feature of neutrophil metabolism. The striking similarity of phosphorylation changes induced by the various activators tested suggests that protein phosphorylation may play a role in some aspects of neutrophil activation. Evidence was not obtained, however, regarding a link between protein phosphorylation and activation of NADPH oxidase.     

Tricuspid annulus motion and mitral annulus motion: Anatomical intimacy causing a good correlation?

BACKGROUND:

Echocardiographic evaluation of the heart and its function, especially left ventricular systolic function, has great clinical importance. Systolic function can be measured using several methods, such as the amplitude of motion of the left atrioventricular plane (mitral annulus motion [MAM]) toward the apex during systole. Similarly, right ventricular systolic function can be measured using the motion of the right atrioventricular plane (tricuspid annulus motion [TAM]) toward the apex during systole.

OBJECTIVES:

Because the mitral and tricuspid annuli are situated close to each other in the fibrous skeleton between both ventricles and atria, one might think that a decrease in the amplitude of MAM would be followed by a decrease in the amplitude of TAM. The present study was developed to determinine if this anatomical intimacy causes a good correlation between the amplitudes of TAM and MAM.

METHODS:

Nineteen healthy subjects and 103 consecutive patients were included in the study and examined using echocardiography. The amplitudes of TAM and MAM were measured and the correlation between the amplitudes was calculated.

RESULTS:

In the 103 consecutive patients, a significant but relatively weak positive correlation was found between TAM and MAM amplitudes (Pearson’s correlation coefficient [r]=0.58; P<0.001). In the 19 healthy subjects, no significant correlation was found.

CONCLUSIONS:

Despite the anatomical intimacy of the annuli, the correlation between the amplitudes of TAM and MAM in consecutive patients was rather weak, and there was no correlation in healthy subjects. These findings could be due to anatomical and physiological differences between the right and left ventricles.     

Results of treatment of acute myocardial infarction with thrombolytic therapy. Experiences in 437 patients in the coronary care unit of the National Institute of Cardiology "Ignacio Chavez"]

OBJECTIVE: To review the results and complications of thrombolysis in patients with acute myocardial infarction (AMI) and its complications. METHODS: Since june 1989 to august 1994 we studied patients with AMI, who underwent thrombolysis. Clinical characteristics, complications and angiographic results are described. RESULTS: Of the total population 86.3% patients received Streptokinase (SK) and 13.7% recombinant tissue plasminogen activator (rt-PA). In 20 patients the age was under 40 years, 373 between 40-70 years, and 80 patients over 70 years. 84% were men and 16% women. 72% had smoking habit; 21% diabetes mellitus, 43% hypertension, 54% had previous angina and previous AMI in 22%. The location of AMI was anterior in 234 patients and 239 inferior. In 63% enzyme washout was observed, and rapid electrocardiographic evolution in 81%. Postthrombolisis arrhythmias was observed in 64.7%. Major bleeding in 11.8% and central nervous system hemorrhage in 0.4% only with rt-PA. Postinfarction angina in 22%, and re-infarction in 4%. Cardiac rupture in 1.4%, with shock and death. Mitral insufficiency in 2.1% demonstrated by echocardiogram. Coronary angiography was done in 373 patients (80%), of which 50.7% was made in the first 5 days. The culprit artery was anterior descending in 273 patients and right coronary in 95. Left ventricular dysfunction was seen in 23% in patients with anterior AMI, and 5% with inferior AMI. Cardiogenic shock was seen in 7%. Coronary artery bypass grafting was undertaken in 106 patients and coronary angioplasty in 67. The ten days mortality was 8.8%, principally due to cardiogenic shock, ventricular arrhythmias and ventricular rupture. CONCLUSIONS: The usefull permeability in the culprit artery was obtained in 40%, who had coronary angiography done 145 hours posthrombolysis. Mortality was under 10% in this study.     

Précising definitions as a way to combat overdiagnosis

Roughly, overdiagnosis (ODx) occurs when people are harmed by receiving diagnoses (often accompanied by interventions) that do not benefit them, usually because the diagnosed conditions do not pose a threat to their health. ODx is a theoretical as well as a practical problem as it relates to definitions of disease. Elsewhere, it has been argued that disease is a vague concept and that this vagueness may contribute to ODx. In response, we develop a stipulative or précising definition of disease, for the specific purpose of decreasing or preventing ODx. We call this disease_ODx, aimed at distinguishing cases where it would be beneficial to identify (and treat the condition) from those where diagnosis is more likely to harm than benefit. A preliminary definition of disease_ODx is that X is a disease_ODx iff there is dysfunction that has a significant risk of causing severe harm. This paper examines the 3 concepts in this definition, using a naturalistic account of function, a Feinbergian account of comparative harm, and a probabilistic understanding of risk. We then test the utility of this approach using examples of clinical conditions that are currently overdiagnosed.     

Amelioration of Neurosensory Structure and Function in Animal and Cellular Models of a Congenital Blindness

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