87 research outputs found
Polymer brushes via surface-initiated electrochemically mediated ATRP : role of a sacrificial initiator in polymerization of acrylates on silicon substrates
Adsorbents for iron removal obtained from vermiculite
In presented work, raw, expanded and acid
treated vermiculites were used as low-cost and active adsorbents for reducing o
f
environmental pollution with heavy metals. Acid treatment was
performed at elevated temperature (95°C) for 2 and 24 h in
solution of HNO
3
. Adsorption capacity towards Fe
3+
was studied in column, semi-
b
atch and batch mode. It
was shown that all
samples are effective in removal of heavy metals; however
adsorption mechanism is based not only on ion exchange o
f
interlayer cations but also precipitation/
deposition processes. Starting material a
nd modified samples as well as spent
adsorbents were characterized with
respect to the vermic
ulite structure using X-ray diffraction metho
Vermiculite-based catalysts for oxidation of organic pollutants in water and wastewater
In presented work natural expanded vermiculite was used as a
starting material for synthesis of
Fe-doped cataly
sts. Material
was modified with increasing amount of Fe by ion-exchange
and precipitation of iron
oxide. Composite materials were
characterized with respect to their stru
cture (X-ray diffraction, Infrared spectra
using Diffuse Reflectance), agglomeratio
n
state of Fe (Ultraviolet-Visible spectra using Diffuse
Reflectance) and chemical composition. Activity in H
2
O
2
decomposition
as well as in phenol oxidation was studied
in liquid phase at atmosphe
ric pressure and temperature
up to 70 °C. It was shown
that doping with Fe increases ca
talytic activity. However, excess of iron result
ed in formation of undesired side-products
The non-modifiable risk factors for breast cancer development in women
Introduction
Breasts are organs found in both male and female representatives. The main building blocks of the breast are fatty tissue and glandular tissue. As far as women are concerned, breast cancer is most commonly found in the upper outer quadrant. It is one of the most common cancers among women worldwide and is therefore an important public health issue. The latest data indicate that the problem of breast cancer currently affects more than 10% of women from all over the world. Importantly, it is the second most common cause of cancer-related death among women, after lung cancer. There are many factors that influence the prevalence rate of breast cancer. In general, they might be divided into modifiable and non-modifiable factors. In the following review, the emphasis will be put on the impact of non-modifiable factors on breast cancer risk and the strength of their impact. Factors that will be discussed include age, gender, ethnic and racial background, family history and genetic factors, pregnancy and breastfeeding.
Material and Methods
This review was based on available data collected in the PubMed and Google Scholar database, using following keywords: “Breast Cancer”, “Risk factors of Breast Cancer” and “Epidemiology of Breast Cancer”.
Conclusion
Breast cancer is one of the most common cancers in women worldwide. In recent years, we have observed an increase in the incidence of this cancer among female representatives. The development of this cancer is influenced by many factors, which can be divided into two main groups: modifiable factors and non-modifiable factors. Importantly, it is advisable to undertake new research and initiatives to better understand the etiology of this disease and the factors affecting its development. 
Cryopreservation of Plant Tissues in Poland: Research Contributions, Current Status, and Applications
Cryopreservation of vegetatively propagated plant material is an increasingly widely used method for the efficient and safe storage of germplasm resources around the world. In Poland, there are currently four cryobanks in use for long-term plant protection programs. However, plant tissues propagated in vitro constitute only a small portion of the accessions stored in them. To date, cryogenic storage techniques have been developed and adopted in this country for ornamental plants (roses, chrysanthemums, and geophytes), crop species (potato and garlic), forest tree species (the genera Quercus and Fraxinus), and some ferns. Polish researchers have used suspension cultures of Gentiana spp. and shoot tips of Lamprocapnos spectabilis to improve cryopreservation knowledge. A better understanding of the benefits of cryopreservation and its widespread implementation in plant biodiversity conservation programs is required. The objective of this review is to provide a concise synthesis of the scientific contributions, current status, and applications of cryogenic techniques for the conservation of in vitro culture-derived plant tissues in Poland. First, the results contributing to research that has been achieved using cell suspensions and advances related to the use of nanoparticles and plant extracts to improve cryopreservation efficiency are discussed. Then, the applications and advances in cryopreservation of ornamental plants (roses, radiomutants, plant chimeras, Lamprocapnos spp., and geophytes), crop species (potato and garlic), forest trees, and ferns are summarized
Synthesis and characterisation of coating polyurethane cationomers containing fluorine built-in hard urethane segments
Polyurethane cationomers were synthesised in the reaction of 4,4’-methylenebis(phenyl isocyanate) with polyoxyethylene glycol (M = 2,000) or poly(tetrafluoroethyleneoxide-co-difluoromethylene oxide) α,ω-diisocyanate and N-methyl diethanolamine. Amine segments were built-in to the urethane-isocyanate prepolymer in the reaction with 1-bromobutane or formic acid, and then they were converted to alkylammonium cations. The obtained isocyanate prepolymers were then extended in the aqueous medium that yielded stable aqueous dispersions which were applied on the surfaces of test poly(tetrafluoroethylene) plates. After evaporation of water, the dispersions formed thin polymer coatings. 1H, 13C NMR and IR spectral methods were employed to confirm chemical structures of synthesised cationomers. Based on 1H NMR and IR spectra, the factors κ and α were calculated, which represented the polarity level of the obtained cationomers. The DSC, wide angle X-ray scattering and atom force microscopy methods were employed for the microstructural assessment of the obtained materials. Changes were discussed in the surface free energy and its components, as calculated independently according to the method suggested by van Oss–Good, in relation to chemical and physical structures of cationomers as well as morphology of coating surfaces obtained from those cationomers. Fluorine incorporated into cationomers (about 30%) contributed to lower surface free energy values, down to about 15 mJ/m2. That was caused by gradual weakening of long-range interactions within which the highest share is taken by dispersion interactions
Optimal seed water content and storage temperature for preservation of Populus nigra L. germplasm
How we can improve ARGET ATRP in an aqueous system: Honey as an unusual solution for polymerization of (meth)acrylates
I. Zaborniak, P. Chmielarz,
How we can improve ARGET ATRP in an aqueous system: Honey as an unusual solution for polymerization of (meth)acrylates,
European Polymer Journal,
Volume 183,
2023,
111735,
ISSN 0014-3057,
https://doi.org/10.1016/j.eurpolymj.2022.111735.
(https://www.sciencedirect.com/science/article/pii/S001430572200739X)
Abstract: Aqueous solutions of various types of honey as a source of reducing sugars – glucose and fructose, were used to accelerate or control activators regeneration by electron transfer atom transfer radical polymerization (ARGET ATRP) in a homogeneous or heterogeneous environment. The aqueous or alcoholic-aqueous solution was applied for the polymerization of hydrophilic methacrylates i.e. 2-(dimethylamino)ethyl methacrylate (DMAEMA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA), while the polymerization of a hydrophobic monomer – n-butyl acrylate (nBA) was conducted in miniemulsion under ion-pair and interfacial catalysis. The polymerization of DMAEMA in a honey solution accelerated the polymerization rate up to 30-fold with a significant improvement in the control over the structure of the product, namely, the polymers were characterized by narrow molecular weight distribution (Mw/Mn = 1.33), and initiation efficiency up to 98 %. Controlled polymerization of nBA was conducted in a honey-contained miniemulsion. Honey-based miniemulsion was successfully checked for the synthesis of both linear and branched polymers. The use of chemical reducing agents found in commercially available food products for polymerization is an economic concept that eliminates the need for high purity laboratory reagents, moreover, food products are widely available and therefore much cheaper. The proposed concept has great potential for industrial applications.
Keywords: Honey; Reducing sugars; ARGET ATRP; Aqueous environment; Miniemulsio
Cryopreservation of dormant orthodox seeds of forest trees: mazzard cherry (Prunus avium L.)
• The sensitivity of dormant seeds of mazzard cherry (Prunus avium L.) of Polish
provenances to extreme desiccation and/or the ultra-low temperature of
liquid nitrogen, LN ( °C), was investigated to identify the
optimum seed water content (w.c.) at this temperature.
• Germination and seedling emergence tests in this study showed that there is
no critical seed w.c. for deeply desiccated seeds (stone w.c. 1.6%),
although such desiccated seeds were sensitive to the temperature of LN in
the seedling emergence test. For seeds frozen in LN, the highest
germinability was observed at w.c. of 9.0–16.9%, but seedling emergence
was then significantly lower than in nonfrozen seeds. The 2-year of storage
in LN of seeds desiccated to 7.8% w.c. did not decrease germinability
after thawing, in comparison with 2-year of storage at °C. Storage
in LN showed that if seeds were stored after breaking of their dormancy,
germinability after storage was lower because of the necessity of seed
desiccation to the lower level (~ 8%) of w.c. after stratification
(before storage). Secondary dormancy was induced in seeds desiccated after
stratification.
• The results of this study demonstrate the potential for long-term
cryopreservation of mazzard cherry seeds in forest gene banks.La cryoconservation des semences dormantes
orthodoxes des arbres forestiers : le merisier (Prunus
avium L.). • La sensibilité des semences dormantes de merisier (Prunus avium L.) de provenances
polonaise à l'extrême dessiccation et/ou à l'ultra-basse
température de l'azote liquide, LN ( °C), a été
étudiée afin d'identifier l'optimum de teneur en eau (w.c.) des
semences à cette température.
• Les tests de germination et émergence des plantules dans cette
étude ont montré qu'il n'y a pas de teneur en eau critique (w.c.)
pour les semences profondément déshydratées (teneur en eau
1,6 %), bien que ces graines desséchées soient sensibles
à la température de la LN dans le test d'émergence des
plantules. Pour les semences congelées dans LN, la plus forte
capacité de germination a été observée à une teneur en
eau de %, mais l'émergence des semis a ensuite
été beaucoup plus faible que dans les semences non congelées. Deux
ans de stockage LN pour les semences déshydraté à une teneur en
eau de 7,8 % n'a pas diminué la capacité de germination après
décongélation, en comparaison avec 2 ans de stockage à 3 °C.
Le stockage en LN a montré que si les semences ont été
stockées après la levée de leur dormance, leur capacité de
germination après stockage a été plus faible en raison de la
nécessité d'une dessiccation à un faible teneur en eau (~ 8%) après stratification (avant stockage). Une dormance secondaire a
été induite chez des semences déshydratées après
stratification.
• Les résultats de cette étude démontrent le potentiel, pour une
cryopréservation à long terme, des semences de merisier dans des banques forestières de gènes
Coffee Beverage: A New Strategy for the Synthesis of Polymethacrylates via ATRP
Coffee, the most popular beverage in the 21st century society, was tested as a reaction environment for activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) without an additional reducing agent. Two blends were selected: pure Arabica beans and a proportional blend of Arabica and Robusta beans. The use of the solution received from the mixture with Robusta obtained a high molecular weight polymer product in a short time while maintaining a controlled structure of the synthesized product. Various monomers with hydrophilic characteristics, i.e., 2-(dimethylamino)ethyl methacrylate (DMAEMA), oligo(ethylene glycol) methyl ether methacrylate (OEGMA500), and glycidyl methacrylate (GMA), were polymerized. The proposed concept was carried out at different concentrations of coffee grounds, followed by the determination of the molar concentration of caffeine in applied beverages using DPV and HPLC techniques
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