Single crystals of LuAG:Ce co-doped with Ca2+ were grown by the vertical Bridgman method and studied for optical properties, γ-irradiation induced absorption, scintillation light yield and decay. It ...is shown that addition of Ca2+ may efficiently limit the radiation induced absorption associated with presence of trace amounts of Yb. In bulk crystals with balanced Ca2+/Ce concentration the absorption induced in the emission range around 520nm is less than 1m−1, after the dose 1kGy and 860Gy/h dose rate. The light yield of LuAG:Ce upon co-doping with Ca2+ is preserved, while the fraction of the delayed recombination leading to slow scintillation components is decreased. The effects of Ca2+ were not favorable in Pr-doped LuAG studied so far. The absorption induced in the emission range around 300–400nm range in the Ca-free LuAG:Pr, after the irradiation dose 1kGy, is about 35m−1, while it is above 100m−1 in the Ca co-doped LuAG:Pr.
•Single crystals of LuAG:Ce(Pr) co-doped with divalent Ca.•Charge compensation mechanisms and competition between traps.•The magnitude of slow decay components is decreased.•Compositions showing improved radiation hardness.
Comparative evaluation of blood content of VEGF, sVEGFR1, and sVEGFR2 in 104 primary gastric cancer patients and 65 healthy persons was performed and associations of these markers with the principal ...clinical and morphological characteristics of gastric cancer were analyzed. The median levels of VEGF and sVEGFR1 in gastric cancer patients significantly surpassed the control: by 1.5 (
p
<0.001) and 1.2 times (
p
<0.01), respectively. On the contrary, sVEGFR2 level in patients was below the control (
p
<0.001). The best sensitivity—specificity ratio (64 and 65%, respectively) was observed for VEGF at 347 pg/ml cut-off value, which is insufficient for the use of this parameter as a clinically valuable serological marker for gastric cancer. No significant associations of these markers with the disease stage, depth of primary tumor invasion, its histological type, grade, or localization were found. The serum level of VEGF in patients with metastases to more than 7 regional lymph nodes (N3) was significantly higher than in patients without lymph node metastases (N0). Blood content of sVEGFR1 in patients with distant metastases (М+) was lower than in patients without distant metastases (М0). Thus, VEGF and its receptors circulating in the peripheral blood do not play significant diagnostic role in gastric cancer, but could be useful in monitoring and prognosis of the efficiency of antiangiogenic therapy.
A YAlO
3
crystal with an admixture of iron was studied by broadband EPR spectroscopy. Two types of paramagnetic centers were found. The energy level scheme of one of them is a singlet and a doublet ...with a splitting of 215.2 GHz. This center is presumably associated with the Fe
2+
ion. The second center was identified as the Tb
3+
ion, which entered the crystal as an uncontrolled impurity. The localization of the impurity ion in the YAlO
3
crystal lattice is determined for each case. Within the framework of the existing theory, calculations are carried out and spectral parameters are determined.
l-Methioninium picrate Ghazaryan, V.V.; Zakharov, B.A.; Boldyreva, E.V. ...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy,
05/2015, Letnik:
142
Journal Article
Recenzirano
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•New l-methioninium picrate crystal was grown from an aqueous solution.•Crystal and molecular structure was determined.•Infrared and Raman spectra are registered and discussed.
Single ...crystals of l-methioninium picrate were obtained by evaporation of aqueous solution containing equimolar quantities of each component. l-Methioninium picrate crystallizes in the monoclinic system (space group P21, Z=2). The asymmetric unit contains one l-methioninium cation and one picrate anion. The carboxyl group of the cation forms an O-H⋯O hydrogen bond with the phenoxy oxygen atom and has an O⋯O distance of 2.669(3)Å. The protonated amino group of the l-methioninium cation forms N-H⋯O hydrogen bonds with the phenoxy oxygen atom of the picrate anion and the carbonyl oxygen atom of the symmetry related cation. The infrared and Raman spectra are recorded and discussed.
Two new crystalline compounds of
l
-cysteine have been obtained: bis-
l
-cysteinium sulfate (
l
-CysH)
2
SO
4
(
I
) and
l
-cysteinium methanesulfonate (
l
-CysH)CH
3
SO
3
(
II
). Both crystal ...structures belong to the orthorhombic space group
P
2
1
2
1
2
1
. They consist of one formula unit in the asymmetric unit. Structures are stabilized due to hydrogen bonds, which are mainly of type O–H···O and N–H···O. The shortest are hydrogen bonds O–H···O between
l
-cysteinium cations and sulfate anion with the O···O distances of 2.567(4) Å and 2.534(4) Å in (
I
) and
l
-cysteinium cation and methanesulfonate anion with the O···O distance of 2.577(3) Å in (
II
). Infrared spectra were registered and discussed.
The fluorescence of some dielectric crystals doped with Cr
3+
ions is studied upon laser excitation in the range of the long wavelength tail of the absorption spectrum (cooling mode). Although no ...actual optical cooling was observed, spectroscopic results and temperature measurements of the samples indicate that electron-phonon bands of Cr
3+
ions are of interest for obtaining laser cooling.
We investigated the possibilities of angioprotection and the reduction of osteonecrosis in rats that had been given bisphosphonates. In our experiment, 27 rats were divided into three groups: Group 1 ...was injected with saline; Group 2 was given zoledronic acid for six weeks; and Group 3 was given zoledronic acid for six weeks, with added doses of sulodexide after three weeks. After that we constructed a model of how the teeth should be extracted. The velocity of linear blood flow in the periodontal area of an extracted tooth in rats was studied using laser and high-frequency Doppler ultrasound (with the application of the vasoactive substance acetylcholine 3% for 1min). We evaluated changes in the structure of the bony tissues of the head using computed tomography, comparing the control group with the saline group. A rapid reduction in microcirculation was detected during the use of zoledronic acid for six weeks. A smaller reduction in microcirculation was detected after three weeks of treatment with sulodexide and zoledronic acid. There was a reduction in blood flow in the mucous membranes and, to a greater extent, in bony tissue. Zoledronic acid causes significant impairment of the periosteal blood flow to the mucous membranes because of a complex of disorders, which includes both the cellular component (impaired endothelium-dependent vasodilation of the mucous membrane vessels) and by reducing the intensity of microcirculation in the mucous membranes and bony tissues. Sulodexide, however, improves the restoration of blood flow and reduces the severity of osteonecrosis.
The science of regenerative medicine is arguably older than transplantation—the first major textbook was published in 1901—and a major regenerative medicine meeting took place in 1988, three years ...before the first Banff transplant pathology meeting. However, the subject of regenerative medicine/tissue engineering pathology has never received focused attention. Defining and classifying tissue engineering pathology is long overdue. In the next decades, the field of transplantation will enlarge at least tenfold, through a hybrid of tissue engineering combined with existing approaches to lessening the organ shortage. Gradually, transplantation pathologists will become tissue‐(re‐) engineering pathologists with enhanced skill sets to address concerns involving the use of bioengineered organs. We outline ways of categorizing abnormalities in tissue‐engineered organs through traditional light microscopy or other modalities including biomarkers. We propose creating a new Banff classification of tissue engineering pathology to standardize and assess de novo bioengineered solid organs transplantable success in vivo. We recommend constructing a framework for a classification of tissue engineering pathology now with interdisciplinary consensus discussions to further develop and finalize the classification at future Banff Transplant Pathology meetings, in collaboration with the human cell atlas project. A possible nosology of pathologic abnormalities in tissue‐engineered organs is suggested.
The new Banff classification of tissue engineering pathology will characterize the pathologic abnormalities in bioengineered organs and tissues for transplantation, and will increasingly be used with the existing Banff classification of allograft pathology as prosthetic devices and tissue engineering become more common. See related articles on pages 293, 364, and 377.
Hexafluorosilicates of sarcosine Fleck, M.; Ghazaryan, V.V.; Petrosyan, A.M.
Solid state sciences,
07/2012, Letnik:
14, Številka:
7
Journal Article
Recenzirano
Recently we established the existence of an entire class of salts of amino acids with hexafluorosilicate anions. Three types of salts with singly charged cations are formed: 2A+·SiF62−, ...A+·(A⋯A+)·SiF62−, 2(A⋯A+)·SiF62−, where A and A+ are amino acids in zwitterionic and singly charged state and (A⋯A+) is dimeric cation with short hydrogen bond. In present work we investigated the system sarcosine + H2SiF6 + H2O. Salts of all three mentioned types are formed in this system: 2Sar·H2SiF6 (2Sar+·SiF62−) (I), 3Sar·H2SiF6·2H2O (Sar+·(Sar⋯Sar+)·SiF62−·2H2O) (II), 4Sar·H2SiF6 (2(Sar⋯Sar+)·SiF62−) (III). The crystal and molecular structures at room temperature as well as thermal expansion of all three crystals are determined. A phase transition near 180 K was found in (II) and the structure below phase transition point (at 150 K) is determined. In addition to (I) a hydrated sample (Ia) is identified by the infrared spectrum. Infrared and Raman spectra of (I, II, III) are discussed on the basis of their structures.
Display omitted
► Large single crystals of 3 species in the system sarcosine–H2SiF6–H2O were grown. ► Crystal structure, vibrational spectra and tensors of thermal expansion are given. ► 3Sar·H2SiF6·2H2O has a phase transition at 180 K to a non-centrosymmetric structure.
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