Ra-226 in building materials as a source of indoor radon in high-rise residential buildings in Russian cities.

The problem of indoor radon in high-rise buildings is mostly associated with exhalation from building materials. Characterization of the radon entry from building materials by diffusion is required to provide a proper control of the population indoor radon exposure. To analyze the relationship between the content of Ra-226 in building materials and the indoor radon concentration the results of the following surveys in high-rise buildings in Russian cities were used: 1) indoor radon (>1000 apartments), 2) natural radionuclides in the building materials in existing buildings by means of non-destructive field gamma spectrometry (100 apartments). The surveys were carried out in nine large cities in different climatic zones. The radon entry rate due to diffusion from building materials, D, normalized to Ra-226 activity concentration, Ra, is in the range of 0.2-0.6 (Bq/m3/h)/(Bq/kg), depending on the type of building materials and building construction. In new multi-story buildings, the typical D/Ra ratio can be assumed to be 0.4 (Bq/m3/h)/(Bq/kg). In new energy-efficient buildings, the ratio of the radon concentration to Ra-226 activity concentration is on average 2.1 times higher than in multi-story buildings of lower energy efficiency built before 2000. The average radon exhalation rate from the building materials, normalized to Ra-226 activity concentration, is estimated to be 0.25 Bq/m2/h.

Relationship between Ra-226 activity concentration in building materials and indoor radon concentration: An example of Russian high-rise residential buildings.

The worldwide trend toward the construction of high-rise buildings with high energy efficiency highlights the role of building materials as a source of indoor radon in the modern urban environment. The aim of the study is to analyze the relationship between the Ra-226 activity concentration in building materials and indoor radon concentration using the example of multi-story buildings in Ekaterinburg. Measurements of the activity concentration of natural radionuclides in building materials were carried out using a new non-destructive method. A radon survey conducted early provided the data on indoor radon concentrations in the same apartments. The obtained Ra-226 activity concentrations in building materials in high-rise buildings were found to be relatively low, ranging from 9.1 to 51 Bq/kg. The typical radon entry rate by diffusion from building materials for modern Russian multi-story buildings can be accepted as equal to 0.5 Bq/(m3∙h) per 1 Bq/kg of Ra-226 activity concentration. Ra-226 in building materials has been shown to be a primary source of indoor radon in modern high-rise buildings, where this factor can cause indoor radon concentrations above the reference level of 100 Bq/m3 at low air exchange rates. The activity concentration of Ra-226 in building materials should be considered a separate parameter for regulation within the national radiation protection systems.

High antioxidant activity of gadolinium-yttrium orthovanadate nanoparticles in cell-free and biological milieu.

Oxidative stress caused by an overproduction of reactive oxygen species (ROS) is the key factor in developing a variety of pathological conditions. Recently various nanomaterials have attracted growing interest as nanoantioxidants with ROS-regulating ability. Here, for the first time, we report on high antioxidant behavior (enzyme-like activity) of GdYVO4:Eu3+nanoparticles (GdYVO NPs) revealed by spectroscopic methods both in cell-free and biological milieu using various ROS sensors. It was revealed that GdYVO NPs (d= 2 nm) effectively scavenge hydroxyl radicals·OH,superoxide anionsO2·-,hydrogen peroxideH2O2,peroxyl radicalsROO·,and remarkably reduce the lipopolysaccharide-induced ROS generation in rat leukocytes. The antioxidant activity of GdYVO NPs is ascribed to high amount of V4+and V3+ions in the structure of the NPs and the reversible switchingV3+↔V4+andV4+↔V5+vanadium oxidation states.

Factors influencing temporal variations of radon concentration in high-rise buildings.

Long-term radon time series were analyzed in 14 rooms and offices to search factors influencing indoor radon concentration in high-rise buildings. Radon entry to living rooms is determined both by diffusion from building materials and advection from adjoined low-ventilated spaces. Humans affect on seasonal and diurnal radon concentration changes in high-rise buildings by activating ventilation system. Indoor-outdoor temperature difference significantly influence on the air exchange rate under uncontrolled ventilation, which is especially important in new energy efficient buildings.

RADON MEASUREMENTS IN BIG BUILDINGS: PILOT STUDY IN RUSSIA.

Detailed analysis of indoor radon concentration distribution by floors was conducted in four children institutions, one office building and two residential houses in Russian cities to develop approaches to draw up a program of radon survey for big buildings. Higher variability of radon concentration was found in high geogenic radon potential (GRP) area when the soil is the main source of radon. No essential dependence of radon concentration on the floor in high-rise buildings was found in low GRP area. The number of required radon measurements is estimated using obtained characteristics of radon variability.

RADON TIME SERIES IN FOUR FLATS IN ENERGY EFFICIENT MULTI-STOREY BUILDING.

Influence of living habits and meteorological parameters on indoor radon concentration in a new energy efficiency multi-storey flat building typical for Russian cities was studied using radon time series analysis. Continuous indoor radon measurements were conducted in four flats of the same multi-storey residential building in Ekaterinburg, Russia. Factors influencing indoor radon in surveyed building (by rank) are as follows: ventilation regime> indoor/outdoor temperature difference > wind direction. Intentional ventilation frequency, temperature difference and wind direction explain together up to 46% of indoor radon variability in a flat of multi-storey building.

[Initial combination therapy for primary open-angle glaucoma]. / 'Startovaia' kombinirovannaia terapiia pervichnoi otkrytougol'noi glaukomy.

PURPOSE: To study the efficacy and safety of initial combination therapy in patients with primary open-angle glaucoma (POAG). MATERIAL AND METHODS: The study included 111 patients (161 eyes) with stages II-III b-c of POAG aged 46 to 89 years (mean age 70.8±8.5 years). In the test group, therapy began with a fixed combination of prostaglandin (PG) (latanoprost) and beta-blocker (BB) (timolol). In patients of the control group, POAG therapy began with administration of the analogue of prostaglandin (latanoprost). When the target IOP was not achieved, a second drug was added to the treatment - instillations of 0.5% solution of timolol maleate 2 times a day. RESULTS: In patients of the test group the treatment started with a combination of BB + PG, the target IOP in the 'worst' eyes was achieved in 33 cases (64%) in 1.5±0.6 visits, and in the 'best' eyes - in 17 cases (81%), in 1.2±0.4 visits. In the control group with a 'step-by-step' selection of antihypertensive therapy, the target IOP in the 'worst' eyes was achieved in 35 cases (59%), in 2.5±0.7 visits, and in the 'best' eyes - in 22 cases (76%), in 2.2±0.5 visits (p<0.05). In both study groups, there were no cases of drug withdrawal attributed to their side effects. Patients noted conjunctival hyperemia in 5% (4 eyes) and 7% (6 eyes) of cases in the test group and the control group, respectively (p>0.05). Hyperemia decreased significantly in 2 weeks of latanoprost administration or fixed combination and did not cause withdrawal. CONCLUSION: Initial combination therapy is possible in patients with newly diagnosed POAG in some clinical situations, namely in stages II-III POAG with high IOP, unavailability of regular observation of patients for various social and economic reasons, absence of somatic and local contraindications to individual components of the combined treatment, etc.

Anomalously high unattached fraction of 220Rn decay products in the atmosphere of monazite storage facility.

High levels of the unattached 212Pb fraction of the 220Rn decay products in the atmosphere of the monazite storage facility were found: f1 = 0.3-0.5 at the aerosol concentration of 20 000 cm-3 and 0.1-0.16 at aerosol concentration ∼140 000 cm-3. It is shown that the sampling of aerosols in an atmosphere with a high concentration of thoron result in the local change of the equilibrium between the attached and unattached fractions near the sampling point. As a result, the measured value of the unattached fraction of thoron decay products may differ by several orders of magnitude from the mean value of unattached fraction the in the indoor atmosphere. A local increase of the unattached fraction 212Pb can take place in the worker's breathing zone in the atmosphere with a high concentration of thoron and it should be taken into account in the assessment of the inhalation intake of the thoron decay products for workers.

REVIEW OF INDOOR RADON CONCENTRATIONS IN SCHOOLS AND KINDERGARTENS.

Analysis includes review of 63 national and regional indoor radon surveys in kindergartens and schools. Preliminary assessment of the worldwide population weighted characteristics of radon concentration in children's institutions is: arithmetic mean = 59 and geometric mean = 36 Bq/m3. Higher indoor radon concentrations in children's institutions in comparison with the dwellings can be explained by characteristics of ventilation, attendance regime and construction features. Special protocol of measurements in the kindergartens and schools is required.

COMPARISON OF APPROACHES TO OBTAIN A SAMPLE OF DWELLINGS FOR RADON SURVEY.

Obtaining of the representative sample of dwellings is a basic requirement to organization of the radon survey. Since random selection is often impossible, quasi-random approaches are used. The aim of the study is to analyze errors in radon exposure assessment that resulted from rejecting the random selection. Both the modeling and experiments were conducted. Three types of errors were observed: shifting of the mean, change of the variance and mixture of the previous two.

RADON MEASUREMENTS IN KINDERGARTENS IN URAL REGION (RUSSIA).

The radon survey of kindergartens has been conducted in Sverdlovskaya oblast during 2013-16. Indoor radon concentrations have been measured in 180 kindergartens in 21 villages and 10 towns. The LR-115 nuclear track detectors were placed in 560 rooms (three or four rooms per kindergarten) during 2-3 months. To obtain annual values, radon measurements were carried in the cold and warm seasons. The arithmetic and geometric means of annual indoor radon concentrations in rooms are 59 and 42 Bq/m3 respectively, GSD = 2.33. Analysis of the building factors affecting radon entry is presented. The detailed radon survey was performed in one kindergarten where exceeding of national action radon level was observed.

[Ocular hypotensive effect of systemic beta-blockers in patients with primary glaucoma and arterial hypertension]. / Oftal'mogipotenzivnyĭ éffekt sistemnogo primeneniia beta-blokatorov pri pervichnoĭ glaukome i arterial'noĭ gipertenzii.

AIM: to evaluate the ocular hypotensive efficacy of systemic beta-blockers in primary glaucoma patients suffering from arterial hypertension (AH). MATERIAL AND METHODS: The study included 29 patients with POAG (58 eyes) aged from 47 to 83 years. Patients with stage I-III POAG received instillations of prostaglandin analogs and carbonic anhydrase inhibitors. All POAG patients also suffered from arterial hypertension and were prescribed selective beta-blockers (metoprolol, bisoprolol, or nebivalol) as monotherapy or as part of combination therapy (if the target arterial pressure had not been achieved under the initial treatment). After the start of oral beta-blockers therapy, the patients were re-examined at 2 and 4 weeks, 3 months, 6 months, and 1 year. RESULTS: A clinically significant reduction of IOP in the most seriously affected eye - by 3.3 mmHg (p<0.05), or 14% - occurred four weeks after the start of selective beta-blockers. Over three months of combination therapy, IOP in the 'worst' eye decreased by 4.4 mmHg (18.5%). At 1 year, IOP in the 'worst' eye was 6.2 mmHg (26%) lower than at baseline (p<0.05). CONCLUSION: Aged and senile patients with primary glaucoma usually suffer from polypathy (on average, they have 6.3±0.6 concurrent somatic diseases). To reduce the risk of polypharmacy and the frequency of side effects in the treatment of POAG and AH patients, it is advised that the treatment includes oral selective beta-blockers able to provide target levels of arterial pressure and IOP. In this study, oral beta-blockers in POAG and AH patients enabled IOP reduction as great as 18.5%-26% of baseline values over a 1-year follow-up period.

[Reasons for intraocular pressure to resist hypotensive therapy in glaucoma patients]. / Prichiny rezistentnosti VGD k gipotenzivnoi terapii u bol'nykh s glaukomoi.

AIM: To study the reasons of intraocular pressure (IOP) resistance to therapy in patients with glaucoma. MATERIAL AND METHODS: During the period 2011-2013 we examined 72 primary glaucoma patients (stage I-III), 44 women and 28 men, aged 49-87 years (65.2±2.5 years on average) referred by local ophthalmologists due to poor response to hypotensive therapy. RESULTS: We suggest that glaucoma should be regarded as resistant if, despite combination therapy with three antihypertensive drugs at optimal doses, IOP stays above the target. In the present study, the treatment was found suboptimal in 19.4% of cases. About 45% of all patients (33 patients) demonstrated poor compliance to the prescribed treatment. Resistant glaucoma, as we have defined it, was diagnosed in 33% of cases (pigmentary glaucoma, pseudoexfoliation glaucoma, secondary unrecognized glaucoma, etc.). This group also included patients, in whom b-blockers were initially effective, but then seemed to lose their power. CONCLUSION: 1. The reasons for intraocular pressure to resist hypotensive therapy are often associated with medical inertia (inaccurate diagnosis, inadequate treatment, etc.) and lack of patient compliance. 2. Resistant glaucoma in its true sense accounts for about 35% of cases of IOP being above the target despite conservative treatment. 3. It is advisable that at the time of first presentation, any patient who fails to reach the target IOP is treated as an «uncontrolled glaucoma¼ case, until the reasons for his/her resistance are clear.

[Temporary biokeratoprostheses in total destruction of the cornea].

The paper presents an original method for temporary biokeratoprothetics in total destruction of the cornea, which consists of the following. In the operating room a 12-mm disc is cut out of patient's conchal cartilage by a trephine and then thinned down to 1 mm with a blade. The prepared autograft is placed in front of the iris completely overlapping corneal defect and sutured to the sclera with 10--12 U-shaped interrupted stitches using a 7/0 suture. Between the stitches 0.2--0.3 ml of viscoelastic are injected into the anterior chamber. Temporary blepharorrhaphy is done within the temporal one-third of the eyelids with a U-shaped suture 6/0. The authors present an own clinical observation of patient D., aged 46, with purulent corneal ulcer and total destruction of the cornea. In ophthalmic emergency, if no donor cornea is available, the described method allows to save the eyeball from its anatomical and functional loss. Further routine keratoplasty or optical keratoprosthetics may bring some functional improvement.

[Experimental study on ocular hypotensive efficacy of parenteral metoprolol].

AIM: to evaluate ocular hypotensive efficacy of parenteral metoprolol in an experiment. MATERIAL AND METHODS: A total of 3 series of experiments on 24 rabbits were performed. The first series involved a single subconjunctival injection of 0.3 mg of metoprolol in the right eye, while the left served as a control. During the second series the rabbits received 0.5 mg of metoprolol intramuscularly. The third series also implied a subconjunctival injection of 0.3 mg of metoprolol in the right eye, however, supplemented with timolol 0.5% instilled in the left. In all rabbits tonometry was performed before the injection and then in 30 min, 1, 2, 3, 6, 8, and 24 hours. Biomicroscopy and ophthalmoscopy were also performed before and 1, 3, and 7 days after the injection. CONCLUSIONS: The maximum reduction (down to 30% from the baseline) of intraocular pressure (IOP) was registered in intramuscular metoprolol rabbits. Subconjunctival metoprolol was associated with a faster and more pronounced decrease in IOP as compared to timolol instillations. In case of local or systemic parenteral administration the hypotensive effect of metoprolol lasts for more than a day.

Calibration system for measuring the radon flux density.

The measurement of radon flux from soil surface is the useful tool for the assessment of radon-prone areas and monitoring of radon releases from uranium mining and milling residues. The accumulation chambers with hollow headspace and chambers with activated charcoal are the most used devices for these purposes. Systematic errors of the measurements strongly depend on the geometry of the chamber and diffusion coefficient of the radon in soil. The calibration system for the attestation of devices for radon flux measurements was constructed. The calibration measurements of accumulation chambers and chambers with activated charcoal were conducted. The good agreement between the results of 2D modelling of radon flux and measurements results was observed. It was demonstrated that reliable measurements of radon flux can be obtained by chambers with activated charcoal (equivalent volume ~75 l) or by accumulation chambers with hollow headspace of ~7-10 l and volume/surface ratio (height) of >15 cm.

[Urgent therapeutic penetrating autokeratoplasty for a purulent corneal ulcer in the only functional eye].

The article presents a case of severe purulent corneal ulcer in the only functional eye of a young patient with Frank-Kamenetsky glaucoma and high-degree myopia. Combination therapy was ineffective and the patient developed a descemetocele. Due to the absence of cadaver corneas and small size of the only available conserved Alloplant cornea, the contralateral cornea (of the blind eye, which was enucleated under general anesthesia) was used for urgent therapeutic penetrating autokeratoplasty. Postoperative period was complicated with ocular hypertension, which was surgically resolved. To overcome the critical situation around keratoplasty, with results from Russian regulation gaps, the authors suggest creating interregional eye banks in large cities that would provide sampling, conservation and storage control of donor material in accordance with the existing legislation.

[Ophthalmic pathology in tubalars of the Altai Republic].

PURPOSE: To study the prevalence and structure of ophthalmic pathology in Tubalars, rural indigenes of the Altai Republic, for the benefit of the eye care system. MATERIAL AND METHODS: A total of 673 indigenes (67% of the whole population) aged from 1 month to 88 years, 521 Russians and 316 people of mixed parentage were examined. RESULTS: The general prevalence of eye diseases appeared to be higher in Russian newcomers (2481.75 per thousand) than in Tubalars (1965.82 per thousand), while the lowest proportion was found in the group of mixed parentage (1319.62 per thousand). The structure of ophthalmic pathology in Tubalars was as follows: refractive errors and accommodative disorders (799.40 per thousand), diseases of the conjunctiva (390.79 per thousand), retinal diseases (212.48 per thousand), lens diseases (164.93 per thousand), other ocular pathology and tumors of the auxiliary structures (124.81 per thousand), disorders of the lacrimal system (112.93 per thousand), corneal diseases (87.67 per thousand), strabismus (20.80 per thousand), congenital ocular anomalies (10.40 per thousand), glaucoma (8.91 per thousand), diseases of the vascular tract (8.91 per thousand), and eye injury (2.97 per thousand). CONCLUSION: The prevalence of eye diseases in the three ethnic groups proves interethnic differences. Tubalars demonstrated intermediate results between Russians (higher rates) and the group of mixed parentage (lower rates), which indicates unequal adaptation of these populations to harsh climatic conditions of the area. The obtained data are fundamental for informed management decision-making on rational distribution of health institutions and allocation of medical personnel and funds among the regions of the country.

[Retinal detachment in HIV-infected patients with cytomegalovirus retinitis].

The authors present their own clinical experience in three HIV-infected patients with cytomegalovirus retinitis aged from 8 to 36 years. Detailed analysis of the results of physical and laboratory examinations is provided. Given short life expectancy for these patients, the authors pose a deontological question as to whether or not active treatment of retinal detachment in patients with AIDS and CMV retinitis is reasonable.

[Life expectancy of patients with primary glaucoma, residents of a large industrial city of Siberia].

PURPOSE: To investigate life expectancy and the structure of causes of death in patients with primary glaucoma, residents of a large industrial city of Siberia. MATERIAL AND METHODS: The database of the Novokuznetsk Public Health Department information analysis center on registration forms 025 (outpatients) and 066 (inpatients) for 2004-2011 was analyzed. RESULTS: A total of 5424 primary glaucoma patients were registered during 2004-2011, of whom 441 (8.1%) subsequently died. Age at death of patients with primary glaucoma was 69.0 +/- 7.2 years. The difference between age at death and at diagnosis of glaucoma was 2.6 +/- 1.8 years. CONCLUSION: The correlation suggests that primary glaucoma is a predicting factor for vascular events, such as stroke or myocardial infarction. The authors assume that topical administration of beta blockers without consulting a physician and/or a cardiologist may lead to ischemic stroke.