3D Analysis of Ordered Porous Polymeric Particles using Complementary Electron Microscopy Methods

Highly porous particles with internal triply periodic minimal surfaces were investigated for sorption of proteins. The visualization of the complex ordered morphology requires complementary advanced methods of electron microscopy for 3D imaging, instead of a simple 2D projection: transmission electron microscopy (TEM) tomography, slice-and-view focused ion beam (FIB) and serial block face (SBF) scanning electron microscopy (SEM). The capability of each method of 3D image reconstruction was demonstrated and their potential of application to other synthetic polymeric systems was discussed. TEM has high resolution for details even smaller than 1 nm, but the imaged volume is relatively restricted (2.5 \u3bcm)3. The samples are pre-sliced in an ultramicrotome. FIB and SBF are coupled to a SEM. The sample sectioning is done in situ, respectively by an ion beam or an ultramicrotome, SBF, a method so far mostly applied only to biological systems, was particularly highly informative to reproduce the ordered morphology of block copolymer particles with 32\u201354 nm nanopores and sampling volume (20 \u3bcm)3

Novel Fibrillar Structure in the Stroma of Murine Cornea

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.</jats:p

Thermal analysis of a water source heat pump for space heating using an outdoor pool as a heat source

Water bodies are identified as potential heat sources (heat sink) for space heating (cooling) purposes. Thus, the nearby buildings can benefit from these sources by employing heat pump systems. This work presents a novel configuration of water source heat pump using outdoor pools in Mediterranean climate of Chile's central region for space heating. The annual transient performance of the system is modeled in TRNSYS using a physical deterministic model in combination with an equation-fitting procedure. The model accepts several parameters that represent the efficiency and size of the components of the system. Then the thermodynamics and economic performance matrices of the system are built as the output of the model. The results show the application of an outdoor swimming pool as a heat source is favorable without any serious situation of ice formation in the pool. In terms of different locations, the system operates more efficiently in a warmer climate, mainly due to lower required heat load and lower operating frequency. It is possible to reduce the operating time of the system considering a larger area of the pool, as well as higher nominal heating capacity, particularly for larger buildings. However, the analysis indicates that the system is economically feasible in buildings larger than 300 [m2]. The proposed system can be installed in other places, sharing a similar climate zone and common building features

Characterization of internal structure of hydrated agar and gelatin matrices by cryo-SEM

There has been a considerable interest in recent years in developing polymer gel matrices for many important applications such as 2DE for quantization and separation of a variety of proteins and drug delivery system to control the release of active agents. However, a well-defined knowledge of the ultrastructures of the gels has been elusive. In this study, we report the characterization of two different polymers used in 2DE: Gelatin, a naturally occurring polymer derived from collagen (protein) and agar, a polymer of polysaccharide (sugar) origin. Low-temperature SEM is used to examine the internal structure of these gels in their frozen natural hydrated states. Results of this study show that both polymers have an array of hollow cells that resembles honeycomb structures. While agar pores are almost circular, the corresponding Gaussian curve is very broad exhibiting a range of radii from nearly 370 to 700 nm. Gelatin pores are smaller and more homogeneous reflecting a narrower distribution from nearly 320 to 650 nm. Overall, these ultrastructural findings could be used to correlate with functions of the polymers. © 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.ARAKI C, 1960, B CHEM SOC JPN, V33, P291, DOI 10.1246-bcsj.33.291; ARNOTT S, 1974, J MOL BIOL, V90, P269, DOI 10.1016-0022-2836(74)90372-6; Celis JE, 1998, FEBS LETT, V430, P64, DOI 10.1016-S0014-5793(98)00527-4; Choi NS, 2004, J BIOCHEM MOL BIOL, V37, P298; CHUI MM, 1995, J COLLOID INTERF SCI, V174, P336, DOI 10.1006-jcis.1995.1399; KUGA S, 1981, J CHROMATOGR, V206, P449, DOI 10.1016-S0021-9673(00)88914-1; Kuwana R, 2002, MICROBIOL-SGM, V148, P3971; Maaloum M, 1998, ELECTROPHORESIS, V19, P1606, DOI 10.1002-elps.1150191015; McKerrow JH, 2000, MOL MED, V6, P450; Michon C, 1997, INT J BIOL MACROMOL, V20, P259, DOI 10.1016-S0141-8130(97)00024-X; MICHON C, 1993, RHEOL ACTA, V32, P94, DOI 10.1007-BF00396681; Pernodet N, 1997, ELECTROPHORESIS, V18, P55, DOI 10.1002-elps.1150180111; ROSSMURPHY SB, 1992, POLYMER, V33, P2622, DOI 10.1016-0032-3861(92)91146-S; Schwartz SA, 2004, CLIN CANCER RES, V10, P981, DOI 10.1158-1078-0432.CCR-0927-3; Stoeckli M, 2001, NAT MED, V7, P493, DOI 10.1038-86573; Tannu NS, 2006, PROG BRAIN RES, V158, P41, DOI 10.1016-S0079-6123(06)58003-3; Van Vlierberghe S, 2007, BIOMACROMOLECULES, V8, P331, DOI 10.1021-bm060684o; Vilain S, 2004, PROTEOMICS, V4, P1996, DOI 10.1002-pmic.20030707; WAKI S, 1982, BIOPOLYMERS, V21, P1909, DOI 10.1002-bip.360210917; WHYTOCK S, 1991, BIOPOLYMERS, V31, P1025, DOI 10.1002-bip.360310902; WIEME R. J., 1965, AGAR GEL ELECTROPHOR24

The burden of prostate cancer in North Africa and Middle East, 1990–2019: Findings from the global burden of disease study

Background: Prostate cancer (PCa) is the second most prevalent cancer among men worldwide. This study presents estimates of PCa prevalence, incidence, death, years-of-life-lost (YLLs), years-lived-with-disability (YLDs), disability-adjusted-life-years (DALYs), and the burden attributable to smoking during 1990-2019 in North Africa and Middle East using data of Global Burden of Diseases (GBD) Study 2019. Methods: This study is a part of GBD 2019. Using vital registration and cancer registry data, the estimates on PCa burden were modeled. Risk factor analysis was performed through the six-step conceptual framework of Comparative Risk Assessment. Results: The age-standardized rates (95 UI) of PCa incidence, prevalence, and death in 2019 were 23.7 (18.5-27.9), 161.1 (126.6-187.6), and 11.7 (9.4-13.9) per 100,000 population. While PCa incidence and prevalence increased by 77 and 144 during 1990-2019, respectively, the death rate stagnated. Of the 397 increase in PCa new cases, 234 was due to a rise in the age-specific incidence rate, 79 due to population growth, and 84 due to population aging. The YLLs, YLDs, and DALYs of PCa increased by 2 (-11.8-23.1), 108 (75.5-155.1), and 6 (-8.9-28.1). The death rate and DALYs rate attributable to smoking have decreased 12 and 10, respectively. The DALYs rate attributable to smoking was 37.4 (15.9-67.8) in Lebanon and 5.9 (2.5-10.6) in Saudi Arabia, which were the highest and lowest in the region, respectively. Conclusions: The PCa incidence and prevalence rates increased during 1990-2019; however, the death rate stagnated. The increase in the incidence was mostly due to the rise in the age-specific incidence rate, rather than population growth or aging. The burden of PCa attributable to smoking has decreased in the past 30 years. Copyright © 2022 Abbasi-Kangevari, Saeedi Moghaddam, Ghamari, Azangou-Khyavy, Malekpour, Rezaei, Rezaei, Kolahi, GBD 2019 NAME Prostate Cancer Collaborators, Amini, Mokdad, Jamshidi, Naghavi, Larijani and Farzadfar