Synthesis and photoluminescence characteristics of Dy incorporated MoO3 phosphor: Suppression concentration quenching.

A series of MoO3:Dy3+ phosphors have been synthesized via the gel-combustion method. The X-ray and photoluminescence (PL) emission spectra were employed to characterize the obtained phosphors. The prepared samples were characterized through XRD measurements and exhibited that Dy3+ ions can be successfully incorporated into the host material. The PL emission bands of Dy3+ doped MoO3 were observed at 486 nm, 574 nm and 666 nm which are assigned to the transitions of 4F9/2 â†’ 6H15/2, 4F9/2 â†’ 6H13/2 and 4F9/2 â†’ 6H11/2, respectively. Concentration quenching were largely taken into consideration as one of the crucial aspects limiting the application range of phosphors in today's modern world. An abnormal thermal quenching dependence was reported when Dy3+ ions were incorporated into MoO3 host matrix. In order to understand the origin of this beneficial behaviour, energy transfer processes occurring via radiative and nonradiative mechanisms were investigated to elucidate this suppression of the concentration quenching.

UV effect on the cathodo- and thermoluminescence properties of a gem-quality Cr-rich diaspore (α-AlOOH).

This work reports on the cathodoluminescence (CL) and thermoluminescence (TL) properties of gem-quality diaspore samples from Milas/Mugla (Turkey) after 100 h of ultraviolet-C (UVC) exposure. The UVC exposure induces significant changes in the intensity of the CL emission in the range of 400-800 nm that would be mainly associated with photo-oxidation processes of the impurities (Cr3+, Ti3+, Fe2+) that substitute for Al3+ in the diaspore (α-AlOOH) lattice. The UVC effect on the 400 nm-TL behavior of beta irradiated samples in the range of 0.1-8 Gy modifies the TL glow curves probably due to both photo-transfer process where electrons release from deeper to shallower traps and redox reactions involving, also, breakages-linkages of chemical bonds. Meanwhile, the 'as received' samples consist of three maxima centered at about 120, 180, and 234 °C, the 100 h UVC-irradiated samples display three maxima at 122, 220 and 270 °C. The physical trapping parameters (intensity and peak position, trap depth and pre-exponential factor) for each TL curve were estimated by using a computerized glow curve analysis program.

Luminescence studies of zinc borates activated with different concentrations of Ce and La under x-ray and electron excitation.

Several ZnB2O4 powder samples having dopants concentrations of 0.1, 0.01, 0.04wt% Ce and La were prepared using the nitric acid method via the starting oxides. Several complementary methods such as powder X-ray diffraction (XRD), thermal analyses environmental scanning electron microscopy (ESEM), Radioluminescence (RL) and Cathodoluminescence (CL) techniques were used. Unique luminescence properties of Ce doped ZnB2O4 powder samples are reported for the first time. A new luminescence bands appearing in red part of the spectrum and having all the characteristics of Ce3+ were obtained from RL results. Changing the Ce and La concentration of 0.01-0.1wt% leads to an increase in RL and CL intensities of Ce3+ and La3+ ions and also CL emission spectra of ZnB2O4 show gradual shift towards longer wavelength. When we compare the luminescence intensity of the samples it is seen that Ce doped ZnB2O4 has the highest intense whereas La doped ZnB2O4 has the lowest one. However, emission spectra of both Ce and La doped samples kept unchanged.

Evaluation of flow and structure abnormalities of splanchnic system veins in cirrhotic patients without portal hypertension.

AIM: The aim of this study was to evaluate hemodynamic and anatomic alterations of the splanchnic venous system and the efficiency and safety of color Doppler radial endosonography in the assessment of cirrhotic patients by comparing Child A cirrhotic patients without portal hypertension findings versus a non-cirrhotic group. METHODS: The study was carried out between January 2009 and February 2010; the study population was 38 cirrhotic patients without portal hypertension and 140 control patients. RESULTS: Hepatopedal flow was monophasic in all the control patients; the flow pattern was chaotic and irregular in 8% of the cirrhotic patients; in the cirrhotic patients the portal vein diameter was increased and the flow velocity reduced; no differences in flow volume were observed between the two groups. Splenic vein diameter and flow velocity were normal. In the majority of the Child A cirrhotic patients without portal hypertension, no changes were seen in portal vein diameter or flow volume; in some patients no significant increase portal vein diameter was observed and showed the flow volumes were unchanged. CONCLUSION: Radial Doppler endosonography may be efficient and safe for assessing the splanchnic system.

A severe neurological sequela in acute intermittent porphyria: presentation of a case from encephalopathy to quadriparesis.

Porphyrias present themselves with autonomic or peripheral neuropathy or central nervous system dysfunction. They are a varied group of inborn errors of metabolism that are characterized by specific inherited enzyme defects in haem biosynthesis. A patient whose mother was diagnosed as having porphyria was admitted to hospital because of her abdominal pains and dysuria. She had three generalized convulsions and, in a few hours, she lost the vision in both of her eyes. As the seizures continued, she became quadriparetic and fell into a coma after gradually losing consciousness. She improved but with sequelae; her serial MRIs, including apparent diffusion coefficient map imaging, diffusion-weighted imaging and angiography, showed ischaemic lesions that were both unlike and more severe than the ones reported in the literature.

Cisplatin cytotoxicity is enhanced with zoledronic acid in A549 lung cancer cell line: preliminary results of an in vitro study.

We tested whether zoledronic acid, a biphosphonate with proposed apoptotic activity, augmented the cytotoxicity of cisplatin and/or gemcitabine in A549 lung cancer cell line. This cell line was subjected to different concentrations of the above chemotherapeutic agents and zoledronic acid. Cytotoxicity was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide) assay. Particularly, zoledronic acid in 100 micromolar (microM) concentration augmented the cytotoxicity by cisplatin 1microg/ml from 25% to 70% (Z=3.22, P=0.0072). A significant portion of cells underwent apoptosis with or without zoledronic acid, but more so with the combination treatment as assessed by an Annexin V-FITC apoptosis detection kit. However, 100microM zoledronic acid showed 50% cytotoxicity on its own, but failed to improve cytotoxicity by Gemcitabine. Thus, we show for the first time in a lung cancer cell line that zoledronic acid bears cytotoxic potential on its own and in conjunction with cisplatin. The clinical potential of this finding should be further studied.

Intravenous single-dose tramadol versus meperidine for pain relief in renal colic.

BACKGROUND AND OBJECTIVE: Comparison of the effectiveness of tramadol with meperidine given intravenously to emergency patients with suspected renal colic. METHODS: A double-blind, randomized clinical trial was performed in the Emergency Department of a tertiary-care university hospital. Consecutive patients with suspected renal colic (n = 47) were randomized to receive intravenously an initial dose of tramadol 50 mg (n = 23) or meperidine 50 mg (n = 24). After 30 min, additional doses of meperidine 50 mg were given intravenously as a rescue medication in an open fashion. Pain relief was assessed using a 10 cm visual analogue scale, the primary outcomes being pain relief at 15 and 30 min after the analgesics. Secondary outcomes were the frequency of rescue meperidine use and the development of side-effects. RESULTS: Visual analogue scale pain scores after 15 and 30 min decreased in both tramadol and meperidine groups (P < 0.05). However, pain relief was better in the meperidine group at the 15 and 30 min evaluations (P < 0.05). Only 11 patients (48%), initially receiving meperidine, needed more meperidine compared with 16 patients (67%) initially receiving tramadol. Both drugs were well tolerated with no adverse effects occurring in either group. CONCLUSIONS: Meperidine 50 mg was superior to tramadol 50 mg for acute pain relief in patients with suspected renal colic when given intravenously. Because many patients in both groups received supplemental meperidine and the response to tramadol alone cannot be predicted, clinicians may want to choose higher doses of meperidine alone or other alternative combinations.

Strong vasopressor support may be futile in the intensive care unit patient with multiple organ failure.

OBJECTIVE: The aim of the study was to determine the prognosis in patients who needed norepinephrine treatment in our institution in relation to the degree of organ failure and the evolution of the disease process. DESIGN: Retrospective case note analysis of outcome of those patients who needed norepinephrine according to our institutional regimen. PATIENTS: A total of 100 consecutive patients admitted to our 31-bed medical-surgical intensive care unit (ICU) who were treated with norepinephrine for severe hypotension and evidence of end-organ hypoperfusion unresponsive to both fluid resuscitation and dopamine treatment at 20 microg/kg/min. MEASUREMENTS: The degree of organ dysfunction at the time of starting norepinephrine treatment was assessed by the sequential organ failure assessment (SOFA) score. The time before starting norepinephrine treatment was defined as the time elapsed between ICU admission and that of starting norepinephrine administration. The patients were defined as survivors or nonsurvivors according to their ICU outcome. RESULTS: There were relationships between mortality and the degree of organ dysfunction and mortality and the duration of ICU stay before starting norepinephrine treatment. The mortality rate was 100% in the 30 patients with a total SOFA score of >12 and a delay before starting norepinephrine treatment of >1 day. The mortality rate of the other patients was 63%. The lowest mortality was seen in patients with lower SOFA scores and early norepinephrine administration after admission. CONCLUSIONS: Both the time of starting norepinephrine treatment after admission to the ICU and the degree of organ dysfunction have an important bearing on subsequent outcome. Although norepinephrine may be a lifesaving catecholamine in some cases, its administration to patients who have already developed multiple organ failure during their stay in the ICU is associated with a poor outcome.

Magnesium efficacy in magnesium deficient and nondeficient patients with rapid ventricular response atrial fibrillation.

We assessed the effect of magnesium sulphate (MgSO4) on lowering the rate in ventricular atrial fibrillation (AF), and evaluated the effect of this therapy in magnesium (Mg) deficient and nondeficient patients. This experimental clinical study was performed on 34 patients with rapid AF (ventricular rate [VR] > 120/minute) presenting to the emergency department of a tertiary care university hospital. Patients with systolic blood pressure < or = 100 mmHg, Hb level < or = 11.8, saO2 of < or = 96%, BUN > or = 40 or creatine > or = 1.8 were excluded (n = 15). Nineteen patients were given an initial 2 g MgSO4 bolus i.v. and a 1 g/hour continuous infusion over 6 hours. To evaluate the presence of Mg deficiency, urine was collected from the onset of treatment and continued for the next 24 hours, and the excretion rate of administered Mg was calculated. Ventricular rates were obtained at baseline, after MgSO4 bolus, and every 15 minutes for the first hour. The decrease in the VR was statistically significant at 15, 30 and 60 minutes after Mg therapy (p = 0.0025, p < 0.001, p > 0.001). There was no difference in the response to Mg therapy between Mg deficient and nondeficient patients at 15, 30 or 60 minutes after therapy (p = 0.41, p = 0.28, p = 0.08). It is concluded that i.v. MgSO4 has a statistically significant but clinically limited effect on VR and this effect did not differ between patients with and without Mg deficiency.

Circadian variations in natural coagulation inhibitors protein C, protein S and antithrombin in healthy men: a possible association with interleukin-6.

Recent observations describe an increase in platelet aggregability and a decrease in fibrinolytic activity in the early morning hours. To determine whether anticoagulant proteins also show such a circadian variation we measured protein C (PC), protein S (PS), antithrombin (AT) and heparin cofactor-II (HC-II) levels on venous plasma samples taken from 10 healthy men at three-hour intervals throughout a 24-hour period. To investigate the possible temporal mapping of circadian periodicity, we also measured plasma levels of beta-thromboglobulin (beta-TG) as an indicator of platelet activation, and interleukin-6 (IL-6) as one of the possible regulatory factors that drive this rhythm. Blood samples were drawn at 6 a.m., 9 a.m., noon, 3 p.m., 6 p.m., 9 p.m. and midnight. PC, IL-6 and beta-TG were measured by ELISA, PS and AT by latex immune assay and HC-II by chromogenic substrate method. A significant circadian variation was found in PC, PS, AT, beta-TG and IL-6, but not in HC-II levels. PC, PS, IL-6 and beta-TG were at their peaks at 6 a.m., and nadirs at a time from noon to midnight. AT peak was at 6 p.m. and nadir at noon. The regression of PS on IL-6 was significant. Although the fluctuations of PS and AT were within the normal ranges during the day, some PC levels of two subjects were below the lower normal limit (0.70). These data indicate that PC, PS, and AT show a marked circadian periodicity as the other components of the blood coagulation and fibrinolytic system do. The similar trends in plasma concentrations of PC, PS, beta-TG and IL-6 may be coincidental, but could reflect a common regulatory mechanism or an effect on each other. The clinical implications of these physiological changes in coagulation inhibitors and the role of IL-6 in the anticoagulant response deserve further studies.