DEGRADATION OF PROTECTIVE GLOVE MATERIALS EXPOSED TO COMMERCIAL PRODUCTS: A COMPARATIVE STUDY OF TENSILE STRENGTH AND GRAVIMETRIC ANALYSES

ABSTRACT Current glove guides attempt to assist in recommending which type of glove is appropriate for handling chemicals; however, they include information on less than 1% of the 89 million chemical products available today. This study offers a solution by testing five durable polymer materials against 50 chemicals, using two rapid chemical degradation assessment techniques. The first technique involves gravimetric analysis of the weight change following constant immersion against the chemical mixture. The second method uses tensile strength to assess molecular changes in the polymer structure. This study is focused on addressing three issues of concern. First, this study examines if current degradation testing methods are adequate to determine chemical resistance against complex mixtures. Secondly, this study will be used to determine if current degradation information on pure chemicals is effective in predicting degradation of complex chemical mixtures, based on the major ingredient(s). Lastly, this study will start a chemical resistance index for complex mixed chemicals. The results of this study clearly show that glove recommendations of pure and mixed chemicals are frequently different. In more than 58.4% of the cases, the mixed chemical requires a different glove than that of its pure chemical components. Results also show that glove recommendations based solely on weight change and/or permeation results are missing important information on tensile test performance. There are several instances (15.2%) in which the initial glove recommendation would be changed to a lower recommendation rating if the results of a tensile test were included

HM 28: To the Java Sea: Selections from the Diary, Reports, and Letters of Henry E. Eccles, 1940-1942

The three-year span between 1940 and 1942 was critical in Henry Eccles’s life and career. These years mark not only the beginnings of the direct involvement of the United States in World War II but also Eccles’s first surface warship command, the command that earned him high professional recognition—the Navy Cross and the Silver Star. The diary, reports, and letters assembled here allow the modern reader an unusual opportunity to enter a very different world and a very different time in naval history. The contents document Lt. Cdr. Henry E. Eccles’s trip by passenger ships from New York to Manila, doing some intelligence work for the Office of Naval Intelligence along the way, and his assumption of command of John D. Edwards in the Asiatic Fleet, under Adm. Thomas C. Hart. The volume ends with Eccles’s participation, now a commander, in the short-lived Allied force in Southeast Asia—the American-British-Dutch-Australian, or ABDA, Command—and his subsequent experiences in the battles of Badoeng Strait and the Java Sea in February 1942, engagements in which Henry Eccles earned his combat decorations.https://digital-commons.usnwc.edu/usnwc-historical-monographs/1027/thumbnail.jp

Cell organization in soft media due to active mechanosensing

Adhering cells actively probe the mechanical properties of their environment and use the resulting information to position and orient themselves. We show that a large body of experimental observations can be consistently explained from one unifying principle, namely that cells strengthen contacts and cytoskeleton in the direction of large effective stiffness. Using linear elasticity theory to model the extracellular environment, we calculate optimal cell organization for several situations of interest and find excellent agreement with experiments for fibroblasts, both on elastic substrates and in collagen gels: cells orient in the direction of external tensile strain, they orient parallel and normal to free and clamped surfaces, respectively, and they interact elastically to form strings. Our method can be applied for rational design of tissue equivalents. Moreover our results indicate that the concept of contact guidance has to be reevaluated. We also suggest that cell-matrix contacts are upregulated by large effective stiffness in the environment because in this way, build-up of force is more efficient.Comment: Revtex, 7 pages, 4 Postscript files include

Dynamic treatment regimes: Technical challenges and applications

Dynamic treatment regimes are of growing interest across the clinical sciences because these regimes provide one way to operationalize and thus inform sequential personalized clinical decision making. Formally, a dynamic treatment regime is a sequence of decision rules, one per stage of clinical intervention. Each decision rule maps up-to-date patient information to a recommended treatment. We briefly review a variety of approaches for using data to construct the decision rules. We then review a critical inferential challenge that results from nonregularity, which often arises in this area. In particular, nonregularity arises in inference for parameters in the optimal dynamic treatment regime; the asymptotic, limiting, distribution of estimators are sensitive to local perturbations. We propose and evaluate a locally consistent Adaptive Confidence Interval (ACI) for the parameters of the optimal dynamic treatment regime. We use data from the Adaptive Pharmacological and Behavioral Treatments for Children with ADHD Trial as an illustrative example. We conclude by highlighting and discussing emerging theoretical problems in this area

Arrestin-like proteins mediate ubiquitination and endocytosis of the yeast metal transporter Smf1

Many plasma membrane proteins in yeast are ubiquitinated and endocytosed, but how they are recognized for modification has remained unknown. Here, we show that the manganese transporter Smf1 is endocytosed when cells are exposed to cadmium ions, that this endocytosis depends on Rsp5-dependent ubiquitination of specific lysines and that it also requires phosphorylation at nearby sites. This phosphorylation is, however, constitutive rather than stress-induced. Efficient ubiquitination requires Ecm21 or Csr2, two members of a family of arrestin-like yeast proteins that contain several PY motifs and bind to Rsp5. Ecm21 also binds to phosphorylated Smf1, providing a link between Rsp5 and its substrate. PY motif-containing arrestin-like proteins are found in many species, including humans, and might have a general role as ubiquitin ligase adaptors

Cell-Free Synthesis of the Mitochondrial ADP/ATP Carrier Protein of Neurospora crassa

ADP/ATP carrier protein was synthesized in heterologous cell-free systems programmed with Neurospora poly(A)-containing RNA and homologous cell-free systems from Neurospora. The apparent molecular weight of the product obtained in vitro was the same as that of the authentic mitochondrial protein. The primary translation product obtained in reticulocyte lysates starts with formylmethionine when formylated initiator methionyl-tRNA (fMet-tRNAfMet) was present. The product synthesized in vitro was released from the ribosomes into the postribosomal supernatant. The evidence presented indicates that the ADP/ATP carrier is synthesized as a polypeptide with the same molecular weight as the mature monomeric protein and does not carry an additional sequence

Experimental evaluation of 3D printed spiral phase plates for enabling an orbital angular momentum multiplexed radio system

This paper evaluates the performance of three-dimensionally (3D) printed spiral phase plates (SPPs) for enabling an orbital angular momentum (OAM) multiplexed radio system. The design and realization of the SPPs by means of additive manufacturing exploiting a high-permittivity material is described. Modes 1 and 2 SPPs are then evaluated at 15 GHz in terms of 3D complex radiation pattern, mode purity and beam collimation by means of a 3D printed dielectric lens. The results with the lens yield a crosstalk of −8 dB for between modes 1 and −1, and −11.4 dB for between modes 2 and −2. We suggest a mode multiplexer architecture that is expected to further reduce the crosstalk for each mode. An additional loss of 4.2 dB is incurred with the SPPs inserted into the communication link, which is undesirable for obtaining reliable LTE-based communications. Thus, we suggest: using lower loss materials, seeking ways to reduce material interface reflections or alternative ways of OAM multiplexing to realize a viable OAM multiplexed radio system