Luminescence properties of Ce(3+)-doped NaPrP4O12 polyphosphate.

Studies on the crystal structure and luminescence properties have been performed for the NaPr(1-x)Ce(x)P(4)O(12) polyphosphate series. Excitation and emission spectra of Pr(3+) and Ce(3+) luminescence from NaPrP(4)O(12):Ce(3+) clearly reveal an efficient Pr(3+ ) → Ce(3+) energy transfer via migration over the Pr(3+)-sub-lattice and a nonradiative resonant transfer to the Ce(3+) ions. Analysis on scintillation characteristics of the NaPr(1-x)Ce(x)P(4)O(12) series shows a maximum light yield of 11,000 ± 1000 ph MeV(-1) for NaPr(0.99)Ce(0.01)P(4)O(12), proving the studied polyphosphates to be promising for application in the detection of x-ray and gamma quanta.

Crystal structure and luminescence properties of LiYP4O12:Ce3+ phosphor.

LiYP(4)O(12) polyphosphate doped with Ce(3+) ions was prepared by the melt solution technique. The crystal structure, interatomic distances, and atom coordination numbers were determined using x-ray powder diffraction. A study of the spectral-kinetic luminescent properties was performed employing excitation with pulsed radiation from a synchrotron (UV-VUV range) and a laboratory x-ray source. The characteristics of Ce(3+) luminescence, namely the emission doublet maxima at 3.97 and 3.72 eV and the 4f-5d excitation maxima at 4.20, 5.11, 5.40, 5.65 and 6.55 eV, are discussed in terms of crystal field splitting in a low-symmetry site of the LiYP(4)O(12) host lattice. The location of the Ce(3+) energy levels with respect to the valence and conduction bands of the LiYP(4)O(12) host is estimated from the temperature dependence of the decay time measured for Ce(3+) 5d-4f luminescence.

Luminescence properties of Ce(3+)-doped LiGdP(4)O(12) upon vacuum-ultraviolet and x-ray excitation.

Luminescent-kinetic studies for LiY(0.9)Ce(0.1)P(4)O(12), LiGd(0.9)Ce(0.1)P(4)O(12) and NaGd(0.9)Ce(0.1)P(4)O(12) phosphates which were prepared by the melt solution technique have been performed using synchrotron radiation excitation within 3-12.4 eV energy range and x-ray radiation at T = 10-300 K. The [Formula: see text] transfer at 10 K and bidirectional [Formula: see text] mechanisms of energy transfer at 300 K have been revealed based on the analysis of the excitation spectra and decay kinetic measurements of Ce(3+) luminescence. The participation of the Gd sublattice in the energy migration process to the Ce(3+) centers causes the appearance of a slow component in the decay kinetics of the x-ray-excited luminescence pulse. The luminescence efficiency of LiY(0.9)Ce(0.1)P(4)O(12), LiGd(0.9)Ce(0.1)P(4)O(12) and NaGd(0.9)Ce(0.1)P(4)O(12) upon x-ray excitation at room temperature is discussed.

[The prophylactic use of pectin in chronic lead exposure in industry]. / Profilakticheskoe primenenie pektina pri khronicheskom vozdeistvii svintsa na proizvodstve.

An effect was studied of lead on certain physiologic, hematological and biochemical parameters in workers engaged in the lead-acid cell manufacture, as was a prophylactic action of pectin in the aforementioned groups of persons. Elimination of lead from the organism was found to be on the increase after the intake of pectin-vitamin preparation (PVP, 3-4 g daily for one month), with the above parameters returning to normal. It is recommended that regular courses of pectin prophylaxis be delivered under control of adequate tests and levels of lead in indicator biological media if we are to achieve a maximal effect in prevention of chronic lead poisoning.

[The use of pectin-containing enterosorbents in exposure to radionuclides and heavy metals]. / Primenenie pektinosoderzhashchikh énterosorbentov pri vozdeistvii radionuklidov i tiazhelykh metallov.

The pectin-vitamin composition (PVC) and its complex with active carbon (AC) was investigated for use as an oral sorbent to protect radionuclide (Sr-85, Cs-137) accumulation. PVC is composed of the natural mixture of cellulose, pectin (Ca-salt), flavonoides, vitamins of the B-group, PP and C. Investigation of PVC radioprotective action was carried out on the two groups of rats (n = 30) which received 1306 Bk/animal of Sr-85 or 343 Bk/animal of Cs-137 daily. One of the group of rats received every day also 300 mg of PVC. After 30 days level of Sr-85 was less by 56.6%, level of Cs = 137 was less by 27.6% in PVC-treated than in the control group (P < 0.05). Composite sorbent consisting of PVC and AC was slightly less effective in removing of Sr and Cs.

[Diagnosis and treatment of pyo-mediastinitis]. / Diagnostika i lechenie gnoinogo mediastinita.

The results of treatment of 53 patients with purulent mediastinitis were studied. The expediency to use the X-ray examination of the esophagus, mediastinum and esophago-fibroscopy was noted. In spreading of the inflammatory process to the TII1--TIV level, the cervical mediastinotomy was performed, below the TIV level--thoracotomy with wide opening of the mediastinum and its drainage, and that of a pleural cavity. Fourteen (26.4%) patients died from purulent complications.

[Diagnosis and treatment of diaphragmatic and hiatal hernia]. / Diagnostika i lechenie gryzh diafragmy i ee pishchevodnogo otverstiia.

On the basis of analysis of the results of treatment of diaphragmatic hernia in 115 patients, the authors, recommend for more precise establishment of a diagnosis and choice of a method for surgical intervention, to perform in patients with axial hiatal hernia roentgenoscopy and roentgenography of the stomach and intestine, esophagogastroduodenoscopy and pH-metry, and in patients with traumatic diaphragmatic hernia--roentgenography of the chest and contrast roentgenological study of the stomach and intestine. In axial hiatal hernia and small paraesophageal hernia, the A. A. Shalimov operation is a method of choice; in large paraesophageal hernia--the left-sided thoracotomy with plasty of the hiatus according to Allison and Belsey.

[Characteristics of diagnosis and surgical tactics in penetrating thoracic injuries]. / Osobennosti diagnostiki i khirurgicheskoi taktiki pri pronika- iushchem ranenii grudi.

The penetrating thoracic injury was observed in 355 patients. Primary debridement (PD) of a wound was performed in 23, PD and closed drainage of the pleural cavity--in 33, PD with subsequent thoracotomy--in 42, thoracotomy--in 257 patients. Injury to the lung was observed in 185 patients, heart--in 46, major vessels--in 9, thoraco-abdominal--in 47. Complications occurred in 54 (15.2%) patients: in 8--continued bleeding, in 21--pneumonia, in 19--pyothorax, in 6--wound suppuration and costal osteomyelitis. Eighteen (5%) patients died: 15--from hemorrhagic shock and massive bleeding, 2--from sepsis and abscessed pneumonia, 1--from peritonitis and intraabdominal bleeding.

[Diagnosis and treatment of spontaneous rupture of the esophagus]. / Diagnostika i lechenie spontannykh razryvov pishchevoda.

The authors operated on 6 patients with spontaneous rupture of the esophagus (SRE). In 1 patient only, the diagnosis was established at initial examination by a physician. The remaining patients were transferred to the department of thoracic surgery at day 2, 3, 4, 9 and 12 from the onset of the disease. In patients with suspected SRE, the contrast esophagography with water-soluble contrast medium was performed. All the patients with SRE were operated on. Two patients died from purulent-septic complications. They were operated on at day 9-12 from the onset of the disease.