Novel polymer alloy membranes composed of poly(4-vinyl pyridine) and cellulose acetate. I. Asymmetric membranes

The preparation of a novel asymmetric membrane cast from a homogeneous mixture of poly(4-vinyl pyridine) and cellulose acetate is described. The two polymers were found to be compatible in the presence of Lewis acids, yielding hydrophilic homogeneous alloys when properly prepared. Asymmetric membranes were cast from a six-component dope mixture containing chloroform, methanol, acetone, and formamide. The as-cast solution, when coagulated in water at ambient temperature, yields a highly plasticized anisotropic matrix which solidifies into a glassy state as the chloroform slowly diffuses into the water. The membranes, following this stage, exhibit a semipermeable dense skin that produces high fluxes and salt rejections when tested in a high-pressure reverse osmosis mode (no annealing is required). The anisotropic morphology was confirmed by scanning electron microscopy studies which revealed a dense skin resting on a highly porous, open-celled foamlike structure. This structure does not collapse upon drying and retains its original wet dimensions. Brief attempts to quaternize the matrix are also reported.     

The hysteria over subliminal advertising as misunderstanding of science.

The author comments that current hysteria related to subliminal advertising may arise from misunderstanding of the scientific issues involved. Rather than protesting against the alleged invasion of the privacy of our homes and minds by the subliminal advertisers, those of us who are concerned with obnoxious advertising on TV might, welcome this occurrence, since it can render obnoxious advertising less effective. Misunderstanding in at least three areas is involved: (1) Sensitivity depends upon stimulus magnitude. (2) Stimuli do not necessarily elicit responses. (3) Experimental reports that people can accurately discriminate or otherwise be affected by stimuli presented so faintly that they report not being conscious of them have been related to the unconscious or subconscious. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overinclusion and concreteness among pathological groups.

To assess relative concreteness vs. overinclusiveness, the Revised Inclusion Test, based on Epstein's measure, was administered to 40 tuberculous, 40 brain-damaged, 30 process schizophrenic, and 15 reactive schizophrenic hospitalized veterans. The groups were equivalent in mean education, intelligence, and length of hospitalization, but the tuberculous and brain-damaged patients averaged 8 yr. older than the schizophrenics. The results indicated that the brain-damaged and process schizophrenics performed more in a concrete manner than did the reactive schizophrenics or tuberculous, but, contrary to hypothesis, the groups were not differentiated on relative overinclusiveness. It was suggested that in studies in which schizophrenics overincluded many options, the concepts to which the overincluded elements were added may have also involved an omitted option and, were such the case, those schizophrenics should have been described as concrete rather than as overinclusive. (36 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Congenital syphilis in Maryland, 1989-1991: the effect of changing the case definition and opportunities for prevention

BACKGROUND: The reported incidence of congenital syphilis in the United States rose dramatically during the 1980s. Although lack of prenatal care has been associated with congenital syphilis, little has been published regarding missed opportunities for prenatal intervention. GOAL OF THIS STUDY: To determine whether congenital syphilis increases in Maryland between 1989 and 1991 resulted from a true increase in congenital syphilis incidence or a change in the surveillance case definition, and to describe missed opportunities for prenatal intervention. STUDY DESIGN: This was a retrospective cohort study. RESULTS: When the revised case definition was used, a 473% increase in the number of cases was seen. Among infants who met the revised definition, 45% of mothers had received no prenatal care. Among those whose mothers had received prenatal care, opportunities to intervene were missed for 53%. CONCLUSIONS: Although a true increase in congenital syphilis incidence occurred before 1990, the increase reported in Maryland between 1989 and 1991 was primarily due to the change in case definition. Many cases of congenital syphilis could have been prevented with early and adequate prenatal care.     

Iron metabolism in rats consuming oil from fresh or fried sardines

The influence of the consumption of diets containing oil from either fresh sardines or fried sardines, under domestic conditions, on the dietary iron metabolism of rats has been investigated. Three groups of rats were fed, over 28 d, semipurified diets containing 8% of: olive oil (OO), fresh sardine (Clupea pilchardus) oil (SO) and oil from sardines previously fried in olive oil (FSO). Body mass and food intake were monitored and, during the periods 5-12 d and 21-28 d, faeces and urine were collected. At the end of the experiment, the animals were killed and blood, liver, spleen and a segment of skin were stored. Food intake and body mass decreased markedly in the SO rats. These parameters were slightly increased in the FSO group compared with OO. Iron absorption and retention were lower in SO than in OO or FSO. This was primarily caused by the poor food intake but also by the lower efficiency of absorption and high urinary Fe losses. Liver and spleen iron contents were reduced by half in SO compared with the other groups, partly owing to the smaller size of the organs, and liver Fe concentration also decreased. These results, together with the high total iron binding capacity, the decreased level of hemoglobin and total erythrocytic iron found in the SO animals, indicate that the consumption of fresh sardine oil as the only dietary fat resulted in iron depletion. The SO animals showed a higher Fe accumulation in skin than OO or FSO. It was concluded that a diet high in sardine fatty acid administered as a unique source of fat, can cause metabolic alterations including iron depletion, but these negative effects of sardine oil disappear with frying, probably owing to the exchange that takes place between fatty acids in the olive oil used in frying and those in the sardine oil.     

Transitional carcinomas of the urinary tract: synchronous and metachronous lesions

OBJECTIVE: The urothelium is a pseudostratified cylindrical epithelium that lines the calices, renal pelvis, urethers, bladder, part of the urethra and part of the prostate ducts. Transitional cell carcinoma (TCC) is a malignant neoplasia that can appear in any site where urothelium is present, being the bladder the most frequently affected organ. We performed an analysis of our experience and conducted a literature-based metanalysis to evaluate the coexistence of tumoral lesions at different locations in the urinary tract. MATERIAL AND METHODS: Between 1983 and 1993, 397 patients with TCC lesions involving the upper urinary tract (UUT), bladder, urethra or prostate, were diagnosed and treated. Coexistence, either synchronic or metachronic, of several lesions in different sites of the urinary tract was considered as a multiple tumor. RESULTS: Overall, 440 tumors were diagnosed in 397 patients. A single lesion appeared in 360 patients, while 37 presented multiple locations with a total of 79 tumors. The lesions were located at the following levels: 17 renal, 21 uretheral, 372 vesical, 13 in the urethra and 17 in the prostate ducts. According to the location, the frequency of single lesions was: UUT 58%, bladder 91%, urethra 8% and prostate ducts 35%. Synchronic UUT and intravesical tract tumors develops in 1% and 4% of patients with bladder TCC, respectively. Two percent of vesical tumors showed metachronic relationship with UUT tumors and the same rate was seen for intravesical lesions. CONCLUSIONS: Urothelial UUT tumors have a typical nosologic entity with specific features. Their coexistence with vesical tumors is frequent. When tumors of the bladder occur after a UUT tumor the interval of highest incidence between diagnoses is 2-3 years, and there are no histological risk factors among them for prognosis. Transitional cell prostatic urethral tumors are most often secondary to histologically similar, poor prognosis, bladder tumors, and usually synchronic.     

Modeling extended Petri nets compatible with GHENeSys IEC61131 for industrial automation

Petri net (PN) modeling is one of the most used formal methods in the automation applications field, together with programmable logic controllers (PLCs). Therefore, the creation of a modeling methodology for PNs compatible with the IEC61131 standard is a necessity of automation specialists. Different works dealing with this subject have been carried out; they are presented in the first part of this paper [Frey (2000a, 2000b); Peng and Zhou (IEEE Trans Syst Man Cybern, Part C Appl Rev 34(4):523–531, 2004); Uzam and Jones (Int J Adv Manuf Technol 14(10):716–728, 1998)], but they do not present a completely compatible methodology with this standard. At the same time, they do not maintain the simplicity required for such applications, nor the use of all-graphical and all-mathematical ordinary Petri net (OPN) tools to facilitate model verification and validation. The proposal presented here completes these requirements. Educational applications at the USP and UEA (Brazil) and the UO (Cuba), as well as industrial applications in Brazil and Cuba, have already been carried out with good results.     

Synthesis,characterization, and bactericidal properties of composites based on crosslinked resins containing silver

Two different commercial crosslinked resins (Amberlite GT73 and Amberlite IRC748) were employed for anchoring silver. The ? SH and ? N(CH₂COOH)₂ groups, respectively, present on these resins were used for Ag⁺ chelation from an aqueous solution. The Ag⁺ ions were reduced with three different reductants: hydrazine, hydroxylamine, and formaldehyde (under an alkaline pH). The produced composites were characterized with thermogravimetry/differential thermogravimetry and scanning electron microscopy combined with a backscattered scanning electron detector. Energy‐dispersive X‐ray spectroscopy coupled to scanning electron microscopy allowed the observation of submicrometer particles of silver, and chemical microanalysis of emitted X‐rays revealed the presence of metal on the internal and external surfaces of the composite microspheres. The amount of incorporated silver was determined by titration. The antibacterial activity of the silver/resin composites was determined toward 10³–10⁷ cells/mL dilutions of the auxotrophic AB1157 Escherichia coli strain; the networks containing anchored submicrometer silver particles were completely bactericidal within a few minutes because of the combined action of silver and functional groups of the resins. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

POPEYE: providing collaborative services for ad hoc and spontaneous communities

Next generation collaborative systems will offer mobile users seamless and natural collaboration amongst a diversity of agents, within distributed, knowledge-rich and virtualized working environments. This ambitious goal faces numerous challenges from the underlying communication infrastructure to the high level application services, with the aim to provide services with the appropriate quality (such as persistence, synchronization, and security). Most currently available tools supporting collaboration address either rather traditional and rigid intra-organizational collaboration scenarios or, at the opposite, completely free and unstructured open communities’s interactions. Emerging dynamic, flexible and ad hoc collaboration schemes are hardly or not supported at all. The POPEYE framework offers collaborative services for applications that aim to enable spontaneous collaboration over P2P wireless ad hoc groups, where fixed infrastructure is not a prerequisite, where virtual communities can emerge spontaneously and share data with the appropriate quality of service for business applications (persistence, synchronization, security, etc.).