Comparative Analysis of Bone Ingrowth in 3D-Printed Titanium Lattice Structures with Different Patterns.

In this study, metal 3D printing technology was used to create lattice-shaped test specimens of orthopedic implants to determine the effect of different lattice shapes on bone ingrowth. Six different lattice shapes were used: gyroid, cube, cylinder, tetrahedron, double pyramid, and Voronoi. The lattice-structured implants were produced from Ti6Al4V alloy using direct metal laser sintering 3D printing technology with an EOS M290 printer. The implants were implanted into the femoral condyles of sheep, and the animals were euthanized 8 and 12 weeks after surgery. To determine the degree of bone ingrowth for different lattice-shaped implants, mechanical, histological, and image processing tests on ground samples and optical microscopic images were performed. In the mechanical test, the force required to compress the different lattice-shaped implants and the force required for a solid implant were compared, and significant differences were found in several instances. Statistically evaluating the results of our image processing algorithm, it was found that the digitally segmented areas clearly consisted of ingrown bone tissue; this finding is also supported by the results of classical histological processing. Our main goal was realized, so the bone ingrowth efficiencies of the six lattice shapes were ranked. It was found that the gyroid, double pyramid, and cube-shaped lattice implants had the highest degree of bone tissue growth per unit time. This ranking of the three lattice shapes remained the same at both 8 and 12 weeks after euthanasia. In accordance with the study, as a side project, a new image processing algorithm was developed that proved suitable for determining the degree of bone ingrowth in lattice implants from optical microscopic images. Along with the cube lattice shape, whose high bone ingrowth values have been previously reported in many studies, it was found that the gyroid and double pyramid lattice shapes produced similarly good results.

Radiocarbon in the atmospheric gases and PM10 aerosol around the Paks Nuclear Power Plant, Hungary.

Our study shows a one-year-long, monthly integrated continuous monitoring campaign of gaseous radiocarbon emission and ambient air compared with 4 event-like, weekly (168 h) atmospheric aerosol radiocarbon data in every season of 2019, at 4 locations (n = 16 aerosol sample) around the Paks Nuclear Power Plant, Hungary. The study shows the first aerosol radiocarbon results around a nuclear power plant measured by accelerator mass spectrometry in Hungary. There was no dominant contribution detected in the atmospheric CO2 gas fraction, but we could detect excess radiocarbon in the total gaseous carbon fraction at almost every sampling point around the Paks Nuclear Power Plant. The highest Δ14C value in the total gaseous carbon form was 157.9 ± 4.6‰ in November and the highest Δ 14C value in the CO2 fraction was 86.1 ± 4.0‰ in December during 2019. Observed 14C activity excess is not higher than previously published values around the Paks Nuclear Power plant at the same sampling points (Molnár et al., 2007; Varga et al., 2020). Our aerosol radiocarbon measurements show that there is no significant contribution from the nuclear power plant to the atmospheric PM10 fraction. We could not detect a Δ 14C value higher than 0‰ in any season. The results show that the simple aerosol sampling, without pre-treatment of the filters, is appropriate for the measurement of excess radiocarbon at the vicinity of nuclear power plants. The applied preparation and measurement method can be applicable for detection of hot (14C) particles and early identification of radiocarbon emission from nuclear power plants in the PM10 fraction.

Advanced atmospheric 14C monitoring around the Paks Nuclear Power Plant, Hungary.

Atmospheric air samples were collected at 9 monitoring stations (A1 to A9) less than 2 km from the Paks Nuclear Power Plant (Paks NPP) and a background station (B24). The monthly integrated CO2 and total carbon (CO2+hydrocarbons (CnHm)) samples were collected to determine the excess 14C activity at the vicinity of the NPP. The measurements providing the 14C/12C ratio of the monthly integrated samples were carried out on a MICADAS type AMS at HEKAL. Due to the relatively low 14CO2 emission of PWR type Paks reactors and the local Suess effect, there was negligible excess 14C activity at the investigated stations in the pure CO2 fraction during the investigated 2 years period (2015-2016). On the contrary, there was a detectable (although minor) excess at every station in the CnHm fraction. In case of CO2, the average Δ14C excess was 3.8‰ and the highest measured value was 91.2‰ at the A3 station in February 2015. In case of CnHm, the average excess was 31.1‰ and the highest measured value was 319.1‰ at the A4 station in February 2016. We applied PC-CREAM 08 modelling to investigate the observed excess 14C activity at the environmental sampling stations, which depends on the distance from the NPP and the meteorological conditions, such as wind direction and wind speed. Meteorology data was collected at the operating area of the Paks NPP in a meteorology tower. The direct C-14 emission through the 120 m high stacks was measured in the NPP by liquid scintillation counting. These emission data and our model calculations explain the excess activity in the CnHm fraction at the A4 station, which is located only 915 m far from the NPP's stacks in the prevailing wind direction. The excess activity at A3 station (the farthest unit) probably came from the nearby NPP wastewater discharge point. The recently observed average excess and highest excess data is similar to the published data in former studies (Molnár et al., 2007; Veres et al., 1995) on Paks NPP, the highest 14CO2 and 14CnHm excess are just a little higher than it was in the earlier studies, but in these former studies, the A3 station was not equipped with a radiocarbon monitoring unit and the level of radiocarbon emission was almost invisible from the wastewater discharge point.

Caspase 3 expression and plasma level of Fas ligand as apoptosis biomarkers in inflammatory endotoxemic lung injury.

OBJECTIVE: The objective of this study is to evaluate if the immunohistochemical expression of a pulmonary apoptosis marker and plasma level of Fas ligand (FasL) correlates with the dose- and time-dependent severity of lung injury, induced by the administration of lipo-polysaccharide (LPS) in an endotoxemic rat model. MATERIALS AND METHODS: Our study included 30 male Wistar rats, randomly divided into three groups: one control group (n=6) and two experimental groups (n=12÷group), in whom we induced endotoxemia by intraperitoneal injection of progressively increasing doses of LPS (5, 10 mg÷kg). We measured FasL plasma levels of the rats at different time points and analyzed the relationships with markers of lung injury. To investigate the level of caspase 3-protein expression, the immunohistochemistry of the lung tissue was assessed. RESULTS: The median percentage of caspase 3-stained cells for the 5 mg÷kg LPS dose was 0.36%, for the 10 mg÷kg LPS dose was 0.4% and for the control group was 0.03% (p<0.0001). The elevated expression levels of caspase 3 were consistent with the altered lung morphologies observed (rs=0.88). LPS administration in rats resulted in a significant dose-dependent increase in the levels of plasma FasL (p<0.0001). These levels correlated with markers of lung injury: degree of hypoxemia (rs=-0.42), histological measured lung injury score (rs=0.72), the density of the caspase 3 staining cells in the immunohistochemistry assessment of apoptosis (rs=0.81) and with the plasma RAGE (receptor for advanced glycated end-products) values (rs=0.70). CONCLUSIONS: Apoptosis is increased in edotoxemia induced lung injury and is likely to contribute to alveolar injury.

Factors Favouring the Development of Clostridium Difficile Infection in Critically Ill Patients.

Clostridium difficile, an anaerobic, spore-forming, toxin-forming, gram-positive bacillus present in the bacterial flora of the colon is the principal cause of nosocomial diarrhoea in adults. AIM: Assessment of favouring factors of Clostridium difficile infections as well as the interactions between them, in critically ill hospitalized patients undergoing complex medical and surgical treatments. MATERIAL AND METHODS: A retrospective case-control study involving eighty patients admitted in the Intensive Care Unit (ICU) of the County Clinical Emergency Hospital Tîrgu-Mures was conducted between January and October 2014. Patients aged eighteen years and over, who had undergone complex medical and surgical treatment, were divided into two subgroups. Group 1 included patients who developed diarrhoea but were not diagnosed as having a Clostridium difficile infection (CDI). Group 2 included patients who developed diarrhoea due to CDI as indicated by a positive culture and the expression of exotoxin. The assessed parameters were age, length of stay (LOS), antibiotic spectrum, association with proton pump inhibitors (PPI) or H2-receptor antagonists, immunological status, the presence or lack of gastrointestinal tract surgery. RESULTS: The mean age was 64.6 years with an average LOS of 10 days. Fifty-six percent of patients came to the ICU from internal medicine wards and forty-three percent from surgical wards. 20.5% of them were immunosuppressed. Co-association of ceftriaxone and pantoprazole significantly increased the risk of CDI compared to co-administration of any other antibiotic or pantoprazole (p=0.01). The odds ratio for Pantoprazole together with any antibiotic versus antibiotic therapy alone was significantly higher (p=0.018) with a sevenfold increase in the risk of positive exotoxin increase. CONCLUSIONS: Antibiotic use is associated with "no risk to develop CDI" in the first five days of administration. PPIs associated therapy increased the risk of CDI in first seventy-two hours regardless of the antibiotic type, and contributes to an active expression of CD exotoxin.

Plasma Neutrophil Gelatinase Associated Lipocalin (NGAL) - Early Biomarker for Acute Kidney Injury in Critically Ill Patients.

INTRODUCTION: NGAL (Neutrophil Gelatinase Associated Lipocalin) is a biomarker recently introduced into clinical practice for the early diagnosis of acute kidney injury (AKI). The aim of this study was to correlate the plasmatic NGAL value determined at admission with clinical progression and severity of AKI in critically ill patients. MATERIAL AND METHOD: Thirty two consecutive critically ill adult patients at risk of developing AKI (trauma, sepsis), admitted in Intensive Care Unit of the Clinical County Emergency Hospital Mures, between January to March 2015 were enrolled in the study. For each patient included in the study plasma NGAL levels were determined on admission, and these were correlated with the degree of AKI development (according to AKIN criteria) at 48 hours and 5 days post admission. The discriminatory power of NGAL, creatinine, creatinine clearance and corrected creatinine (depending on water balance) were determined using the ROC (receiver-operating characteristic) and likelihood ratios. RESULTS: ROC curve analysis showed a better discriminatory capacity in terms of early diagnosis of AKI for NGAL (AUC=0.81 for NGAL, AUC=0.59 for creatinine, AUC=0.62 for corrected creatinine, AUC=0.29 for creatinine clearance). The value of likelihood ratio was also significantly higher for NGAL (3.01±2.73 for NGAL, 1.27±1.14 for creatinine, 1.78±1.81 for corrected creatinine, and 0.48±0.33 for creatinine clearance). CONCLUSIONS: NGAL biomarker has a better discrimination capacity for early prediction of acute kidney injury compared to previously used markers.

Fission products from the damaged Fukushima reactor observed in Hungary.

Fission products, especially (131)I, (134)Cs and (137)Cs, from the damaged Fukushima Dai-ichi nuclear power plant (NPP) were detected in many places worldwide shortly after the accident caused by natural disaster. To observe the spatial and temporal variation of these isotopes in Hungary, aerosol samples were collected at five locations from late March to early May 2011: Institute of Nuclear Research, Hungarian Academy of Sciences (ATOMKI, Debrecen, East Hungary), Paks NPP (Paks, South-Central Hungary) as well as at the vicinity of Aggtelek (Northeast Hungary), Tapolca (West Hungary) and Bátaapáti (Southwest Hungary) settlements. In addition to the aerosol samples, dry/wet fallout samples were collected at ATOMKI, and airborne elemental iodine and organic iodide samples were collected at Paks NPP. The peak in the activity concentration of airborne (131)I was observed around 30 March (1-3 mBq m(-3) both in aerosol samples and gaseous iodine traps) with a slow decline afterwards. Aerosol samples of several hundred cubic metres of air showed (134)Cs and (137)Cs in detectable amounts along with (131)I. The decay-corrected inventory of (131)I fallout at ATOMKI was 2.1±0.1 Bq m(-2) at maximum in the observation period. Dose-rate contribution calculations show that the radiological impact of this event at Hungarian locations was of no considerable concern.

Mapping of tritium emissions using absorption vapour samplers.

Püspökszilágy Radioactive Waste Treatment and Disposal Facility (RWTDF) is a typical near-surface engineered repository designated to store low- and intermediate-level wastes from various institutes, research facilities and hospitals in Hungary. Two automatic combined (14)C-tritium sampling units installed at the facility sample the air 2 m above surface. The one installed near the vaults detects tritium (T) activities two orders of magnitude higher than the far reference sampling unit. To localize the T emissions, 19 small absorption vapour samplers filled with silica gel were settled onto the ground surface. After the saturation of the silica gel, the water was recovered and its T concentration was measured with a low-background liquid scintillation counter. The absorption vapour samplers are cheap, simple and easy-to-use. We present the samplers and the T distribution map constructed from the data, which helps to localize the T emission.