Value Of Lac Research Articles

Effect of WO3 on the attenuation parameters of TeO2–La2O3-WO3 glasses for radiation shielding application

The attenuation capability of tellurite glasses with composition of (100-x)TeO2–5La2O3-xWO3 where x = 10, 15, 20, and 25% was analyzed. Radiation attenuation parameters such as mass, linear attenuation coefficients (MAC, LAC) and effective atomic number were determined at various energies. The S4 glass sample, which contains the highest WO3 content and smallest TeO2 concentration, has the greatest MAC at all energies. The glasses with the highest densities also have the highest LAC values, with greater WO3 content leading to greater density in the glass system. The half value layer (HVL) values of the samples are positively proportional with the energy of the incoming radiation, greatest at the highest tested energy. The ratio between the tenth value layer (TVL) values for S1 and S4 are greater than one at all energies, which means that S1's TVL, the glass with the smallest WO3 content, is higher than S4's TVL. The mean free path values were shown to have an inverse trend with the WO3 content in the samples. The S4 sample, the glass with the highest WO3 content and lowest TeO2 content, has the greatest Zeff at all energies.

Chemical and radiation shielding effectiveness of some heavy metal oxide glasses for immobilizing radioactive wastes

Ce/Sb/Mn different borate glass systems based PbO in concentrations of 50, 35, and 15 mol%, respectively, were prepared by the melting–annealing method. Wide chemical, structural, and radiation shielding characterizations were studied before and after 120 kGy of gamma radiation to test the possible use of glasses for immobilizing radioactive wastes. The results showed suitable density values ranging from 3.34 to 5.30 g/cm3 increased by irradiation. FTIR spectra revealed high structural stability against irradiation correlated to the trigonal BO3, tetrahedral BO4 groups, high polarizable Pb2+ ions, and the doped metal ions. Unexpectedly, the chemical durability after in situ leaching process in H2O, 0.1 N HCl, and 0.1 N NaOH for ~ 3 months revealed clear improving after irradiation e.g., enhanced by ~ 25% for Ce-lead borate glass. Scanning electron microscope (SEM) images of the glass surfaces revealed more smooth and homogenous surfaces after irradiation. Shielding parameters by Monte Carlo code (MCNP5) and Phy-X/PSD software were studied, e.g., mass and linear attenuation coefficients (MAC and LAC), effective atomic number (Zeff), radiation protection efficiency (RPE%), half and tenth value layers (HVL and TVL), and heaviness%. Comparing the shielding behavior of the three glasses revealed that Ce-lead borate glass has the highest values of LAC, MAC, Zeff, heaviness%, and RPE% and the lowest values of HVL, TVL, and MFP, referring to the best shielding efficiency. The whole study indicates the desired properties of glasses as immobilizers or containers for radioactive wastes, e.g., nuclear medicine units in hospitals, especially lead borate glass doped Ce ions.Graphical

Evaluation of Lac and NGAL on the Condition and Prognosis of Patients with Diquat Poisoning.

This study aims to explore the evaluation of lactic acid (Lac) and neutrophil gelatinase-associated lipocalin (NGAL) on the condition and prognosis of patients with diquat (DQ) poisoning. A total of 79 cases of DQ poisoning treated in one hospital from January 2019 through February 2023 were included: 10 cases of mild poisoning, 49 cases of moderate to severe poisoning, and 20 cases of fulminant poisoning. According to the Kidney Disease: Improving Global Outcomes-acute kidney injury (KDIGO-AKI) criteria, the patients were divided into 60 cases in the AKI group and 19 cases in the non-acute kidney injury (NAKI) group. According to the AKI diagnostic indicators, AKI patients were divided into Grade I, Grade II, and Grade III. According to prognosis, the patients were divided into survivor group and non-survivor group. During the same period, 30 healthy subjects were selected as the healthy group. The changes of blood Lac, NGAL, cystatin C (CysC), and serum creatinine (Scr) levels of patients were detected, the 28-day survival of patients was recorded, and the correlation between blood Lac, NGAL levels, and renal injury grade in patients with AKI caused by DQ poisoning was analyzed. The receiver operator characteristic (ROC) curve was used to evaluate the predictive value and prognostic value of Lac, NGAL, and their combination in patients with AKI caused by DQ poisoning. There were significant differences in AKI grade, Lac, NGAL, CysC, and Scr levels among different degrees of poisoning groups (P < .05). There were significant differences in the levels of Lac, NGAL, CysC, and Scr among patients with different AKI grades (P < .05). The levels of Lac, NGAL, CysC, and Scr in the survivor group were significantly lower than those in the non-survivor group (P < .05). The blood Lac and NGAL levels were positively correlated with AKI grades in patients with DQ poisoning (r = 0.752, 0.836; P = .000, .000). The combined detection of blood Lac and NGAL had higher predictive value for AKI and assessed value for death in DQ poisoning than either of them alone. The combined detection of Lac and NGAL have a certain clinical value in AKI grading and evaluating AKI prognosis caused by DQ poisoning.

Structural and gamma-ray attenuation of mixed former lead-free borophosphate glasses

Sodium borophosphate parent glass in conjugation with other derived samples containing adaptable amounts of bismuth oxide at the expense of phosphate partner was prepared via the ordinary melt-quenching technique. Synthesized samples were investigated using Fourier transforms infrared (FTIR) spectroscopy. The undercover or overlapped peaks were estimated using the deconvolution analysis technique (DAT). The collected IR spectra refer to the presence of combined PO4 and BO3+BO4 groups besides the presence of Bi–O vibrations upon the addition of Bi2O3. The assignments of the IR peaks are facilitated by the conduction of deconvolution processes. The density of the studied glass was estimated and some selected physical parameters including molar volume and packing density were calculated.Gamma-ray shielding competence of studied borophosphate glasses has been explored through user online friendly software (Phy-X/PSD) in combination with their abilities to act as shielding candidates as a function of Bi2O3 content. In addition, linear and mass attenuation coefficients (μm) combined with other physics parameters were calculated to assess the proper action of bismuth oxide in the shielding mechanism. Sample NABP10Bi enriched with Bi2O3 possessed the highest values of LAC, MAC, and Zeff. The HVL parameter followed the trend that was considered to be dependent on the bismuth oxide concentration.

Can venous blood gas be used instead of arterial blood gas in emergency department?

Objective: In our study, we aimed to evaluate the usability of venous blood gas (VBG) in substitution for arterial blood gas (ABG).&#x0D; &#x0D; Methods: In this study, 110 patients with respiratory complaints, who were brought intubated were evaluated prospectively. Arterial and venous blood gases were taken simultaneously shortly before the initiation of oxygen therapy in the emergency department. PH, pO2, pCO2, SaO2, HCO3, lactate (Lac) and BEecf values were recorded.&#x0D; &#x0D; Results: Of the 110 patients included in the study, 75 were male (68.2%), 35 were female (31.8%), and they had a mean age of 53.7 ± 23.1 years. A strong positive correlation between PH, PCO2, HCO3-, BEecf, Lac values (p=0.001) and positive correlation between PO2 and SaO2 values (p= 0.002) were detected.&#x0D; &#x0D; Conclusion: We can conclude that venous blood gas be used in substitution for arterial blood gas in patients who are presented to emergency service and it may reduce the need for arterial blood gas sampling.

Structural, thermal and physical properties of cesium doped molybdenum-copper-lead glass

The influence of Cs2O content on MoO3CuO-PbO2 vitreous system has been investigated. The obtained samples labeled as: S1, S2, S3, and S4 respectively, with respect to Cs2O content were synthesized by the melt-quenching method. The Cs2O addition up to S3 sample increases the hardness, density and LAC values from 3.23 to 3.52 GPa, 6.553 to 6.906 g/cm3 and 588.50 to 610.39 cm−1 respectively, and decrease the Vm, HVL and MFP values. For S4 sample, reverse trends were observed. X-ray diffraction pattern reveals the presence of amorphous structure in the S1-S3 samples but further Cs2O addition, S4 sample leading to the formation of multiple crystalline phases. The FTIR spectra indicated that the structural unit distributions of the glasses network: [PbOn], [CuOn], and molybdate species [MoO6], [MoO4]2− and [Mo2O7]2− depends on the Cs2O content. The resonance line intensity of the Cu2+ ions gradually diminishes by addition of Cs2O.

Newly-formulated zinc-bismuth-barium-sodium-silicate glass system with lead oxide addition: Probing radiation shielding characteristics via triple methodology

In recent times, glass materials appear to be strong candidates for radiation protection applications. In this study, a zinc-bismuth-barium-sodium-silicate (ZBBSS) glass system with a formulation of 10ZnO – 20Bi2O3– 5BaO – 15Na2O – (50-x) SiO2– xPbO, x: 0, 5, 15 and 25 wt% was synthesized. The traditional melting technique (1325–1375 °C) enabled the synthesis of four different glass samples coded ZBBSS1 to ZBBSS4. Following synthesis, Archimedes' principle, XRD, FTIR, UV-Vis, and DSC techniques showed physical, structural, optical, and thermal property alterations as a function of PbO inclusion, while the triple methodology (experimental, theoretical, and simulation) revealed radiation attenuation aspects in a broader sense. According to the findings, ZBBSS1 had density of 3.1107 g/cm3 while the other samples had density values of 3.2285, 3.6053, and 4.0158 g/cm3 in respective order. The clear existence of non-crystalline structure for the ZBBSS glass series was reported. Similar vibrational modes were found for ZBBSS glass systems, and -OH, Si-OH, Si-O-Si, and Pb-O-Pb bonding types were assigned to peak formations. For determination of thermal properties, it was observed that Tg became lower, from 520.6 to 392.4 °C, in parallel to the increment in the PbO doping rate. Additionally, an increase in the PbO doping rate hindered the transmission phenomenon based on UV-Vis spectra. Gamma absorption coefficients were measured at six energies with four sources using the gamma spectroscopic system. The measured values were compared with the FLUKA code and Phy-X software. Experimental LAC values of 0.2463, 0.2729, 0.3064, and 0.3618 cm−1 were measured using a Cs-137 source for the ZBBSS glass series, respectively. The variation in the values obtained with the triple methodology overlapped with each other for all energies. Among the prepared glasses, the best LAC and MAC, thinnest HVL, lowest MFP and TF were determined for ZBBSS4 glass sample with maximum PbO content. From the results obtained, it is concluded that the addition of PbO is a useful way to improve the gamma attenuation capacity, and among the glasses examined, ZBBSS4 had superior protection against gamma rays.

Tungsten (VI) oxide reinforced antimony glasses for radiation safety applications: A throughout investigation for determination of radiation shielding properties and transmission factors

We report the functional assessment of tungsten (VI) oxide on gamma-ray attenuation properties of 60Sb2O3-(40-x)NaPO3-xWO3 antimony glasses. The elemental mass-fractions and glass-densities of each glass sample are specified separately for the MCNPX Monte Carlo code. In addition to fundamental gamma absorption properties, Transmission Factors throughout a broad radioisotope energy range were measured. According to findings, holmium (Ho) incorporation into the glass structure resulted in a net increase of 0.3406 g/cm3, whereas cerium (Ce) addition resulted in a net increase of 0.2047 g/cm3. The 40% WO3 reinforced S7 sample was found to have the greatest LAC value, even though seven glass samples exhibited identical behavior. The S2 sample had the lowest HVL values among the glass groups evaluated in this work, computed in the energy range of 0.015–15 MeV. The lowest EBF and EABF values were reported for 40% WO3 reinforced S7 sample with the highest LAC and density values. According to the findings of this research, WO3 will likely make a significant contribution to the gamma ray absorption properties of antimony glasses, which are employed for optical and structural modification. Therefore, it can be concluded that WO3 may be treated monotonically and can be employed successfully in circumstances where gamma-ray absorption characteristics, optical properties, and structural qualities need to be enhanced.

Investigation of the magnetic and mechanical performance of fly ash Geopolymer/BaFe12O19 nanocomposites

The magnetic and mechanical properties of a geopolymer (GeO) were improved by using composites with BaFe12O19 (BFO) nanoparticles. The composites were prepared with 0, 1, 3, and 5 wt% of BFO nanoparticles. All samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometry (VSM) and compressive strength measurements. The contribution of O 1s in all samples was observed using X-Ray photoemission spectroscopy (XPS). All composite samples exhibited ferromagnetic behavior at room temperature with large hysteresis loops and increased magnetization with higher BFO nanoparticle contents. The compressive strength values of the composites increased from 58.2 to 62.2 MPa as the BFO nanoparticle content was raised from 0 to 3 wt%. An increased strength of the GeO suggests a higher denser and more compaction due to addition of BFO nanoparticles in the voids of a N-A-S-H gel structure. The LAC values for the geopolymer composites increased with BFO powder levels.

Mechanical, Morphological, Thermal and the Attenuation Properties of Heavy Mortars Doped with Nanoparticles for Gamma-Ray Shielding Applications.

This study aimed to develop a mortar composite with improved gamma ray shielding properties using WO3 and Bi2O3 nanoparticles, as well as granite residue as a partial replacement of sand. The physical properties and effects of sand substitution and nanoparticle addition on the mortar composite were analyzed. TEM analysis confirmed the size of Bi2O3 and WO3 NPs to be 40 ± 5 nm and 35 ± 2 nm, respectively. SEM images showed that increasing the percentage of granite residues and nanoparticles improved the homogeneity of the mixture and decreased the percentage of voids. TGA analysis indicated that the thermal properties of the material improved with the increase in nanoparticles, without decreasing the material weight at higher temperatures. The linear attenuation coefficients were reported and we found that the LAC value at 0.06 MeV increases by a factor of 2.47 when adding Bi2O3, while it is enhanced by a factor of 1.12 at 0.662 MeV. From the LAC data, the incorporation of Bi2O3 nanoparticles can greatly affect the LAC at low energies, and still have a small but noticeable effect at higher energies. The addition of Bi2O3 nanoparticles into the mortars led to a decrease in the half value layer, resulting in excellent shielding properties against gamma rays. The mean free path of the mortars was found to increase with increasing photon energy, but the addition of Bi2O3 led to a decrease in MFP and better attenuation, making the CGN-20 mortar the most ideal in terms of shielding ability among the prepared mortars. Our findings on the improved gamma ray shielding properties of the developed mortar composite have promising implications for radiation shielding applications and granite waste recycling.

Study nuclear radiation shielding, mechanical and Acoustical properties of TeO2-Na2O-BaO-TiO2 alloyed glasses

In this paper radiation shielding characteristics of tellurium glasses materials for radiation protection have been studied. The effect of different TiO2 contents in 75TeO2-Na2O-(20-x) BaO-xTiO2 (x = 0, 5, 10 and 15) glass samples are investigated on the shielding behavior, acoustic and physical parameters. However, some structural properties such as Molar Volume, Oxygen Molar Volume and Oxygen Packing Density are studied by using the Phy-X/PSD program and Monte Carlo simulations (with GEANT4 and MCNPX2.6.0 codes) in the photon energies of 0.284, 0.347, 0.511, 0.662, 0.826, and 1.173 MeV. The total trends of calculated LAC values in all four alloy glasses show that they are inversely proportional to the photon energy. It shows the abnormal behavior of Linear Attenuation Coefficient value at one point in low energies (sudden leapfrog peak between 0.3 MeV and 0.4 MeV) are shown by derived results by PhyX/PSD and GEANT4, which can be described by tellurium k-edge (in about 0.032 MeV). Finally, it can be informed that by increasing photon energy TNB-Ti15 sample has the best quality in radiation properties and a good choice for radiation protecting in various purposes such as medicine fields.

A Novel Hierarchical Extreme Machine-Learning-Based Approach for Linear Attenuation Coefficient Forecasting.

The development of reinforced polymer composite materials has had a significant influence on the challenging problem of shielding against high-energy photons, particularly X-rays and γ-rays in industrial and healthcare facilities. Heavy materials' shielding characteristics hold a lot of potential for bolstering concrete chunks. The mass attenuation coefficient is the main physical factor that is utilized to measure the narrow beam γ-ray attenuation of various combinations of magnetite and mineral powders with concrete. Data-driven machine learning approaches can be investigated to assess the gamma-ray shielding behavior of composites as an alternative to theoretical calculations, which are often time- and resource-intensive during workbench testing. We developed a dataset using magnetite and seventeen mineral powder combinations at different densities and water/cement ratios, exposed to photon energy ranging from 1 to 1006 kiloelectronvolt (KeV). The National Institute of Standards and Technology (NIST) photon cross-section database and software methodology (XCOM) was used to compute the concrete's γ-ray shielding characteristics (LAC). The XCOM-calculated LACs and seventeen mineral powders were exploited using a range of machine learning (ML) regressors. The goal was to investigate whether the available dataset and XCOM-simulated LAC can be replicated using ML techniques in a data-driven approach. The minimum absolute error (MAE), root mean square error (RMSE), and R2score were employed to assess the performance of our proposed ML models, specifically a support vector machine (SVM), 1d-convolutional neural network (CNN), multi-Layer perceptrons (MLP), linear regressor, decision tree, hierarchical extreme machine learning (HELM), extreme learning machine (ELM), and random forest networks. Comparative results showed that our proposed HELM architecture outperformed state-of-the-art SVM, decision tree, polynomial regressor, random forest, MLP, CNN, and conventional ELM models. Stepwise regression and correlation analysis were further used to evaluate the forecasting capability of ML techniques compared to the benchmark XCOM approach. According to the statistical analysis, the HELM model showed strong consistency between XCOM and predicted LAC values. Additionally, the HELM model performed better in terms of accuracy than the other models used in this study, yielding the highest R2score and the lowest MAE and RMSE.

Analyses of Gamma and Neutron Attenuation Properties of the AA6082 composite material doped with boron carbide (B4C)

Aluminum Alloy AA6082 + (0–40%) B4C materials were analyzed in the energy range between 0.015 and 15 MeV by PSD software. The mass and linear attenuation coefficients (MAC, LAC), tenth-half value layers (TVL, HVL), mean-free path (MFP), effective atomic number (Zeff), equivalent atomic number (Zeq), fast neutron removal cross-section (FNRC), electron density (Neff), effective conductivity (Ceff), and exposure buildup factors (EBFs) parameters were computed for the energy range between 0.015 and 15 MeV. The research implied that LAC and MAC values in the Aluminum Alloy AA6082 functionally graded composite materials increased with the reduction in the B4C contents in the studied material. EBFs under the penetration depth of up to 40 mfp in the energy range between 0.015 and 15 MeV were computed by employing the Geometric-Progression method. TVL, FNRC, Ceff, and Neff values varied between 0.01 and 0.452 cm, 7.918–10.527 cm-1, 5.47.1010–8.31.1010 S/m, 2.90.1025–4.34.1025 electrons/g, respectively. AA6082 material showed the maximum photon shielding performance owing to having the lowest TVL and HVL values, and the highest Zeff and MAC values while AA6082 + 40% B4C material showed the maximum neutron shielding performance because of its higher density.

Functional assessment of various rare-earth (RE) ion types: An investigation on gamma-ray attenuation properties of GeO2-B2O3-P2O5-ZnO-Tb2O3-RE magneto-optical glasses

We report the functional assessment of various rare-earth (RE) ion types on gamma-ray attenuation properties of GeO2-B2O3-P2O5-ZnO-Tb2O3-RE (where; RE=0; 1 %Ho, 1 %Pr, 1 %Er, 1 %Nd, 1 %Dy, 1 %Ce) magneto-optical glasses. The elemental fractions and densities of each glass sample were specified separately for the MCNPX Monte Carlo code. In addition to fundamental gamma absorption properties, Transmission Factors throughout a broad radioisotope energy range were measured. According to findings, Holmium (Ho) incorporation into the glass structure resulted in a net increase of 0.3406 g/cm3, whereas Cerium (Ce) addition resulted in a net increase of 0.2047 g/cm3. The Ho-doped S2 sample was found to have the greatest LAC value, despite the fact that seven glass samples exhibited identical behavior. The Ho-doped S2 sample had the lowest HVL values among the glass groups evaluated in this work, computed in the energy range of 0.015–15 MeV. The lowest EBF and EABF values were reported for Ho reinforced S2 sample with the highes LAC and density values. For all glass samples, a decrease in TF values was observed depending on the increase in thickness. Among the investigated glasses, Ho and Er reinforced samples (i.e., S2 and S4) showed the minimum TF values at used radioisotope energies. It can be concluded that Ho and Er type rare earth elements may provide the most effective gamma ray absorption properties when they are incorporated into the GeO2-B2O3-P2O5-ZnO-Tb2O3 system.

Comparative simulations study of radiations shielding properties of 69P2O5–10Gd2O3/10GdF3–10BaO–10ZnO–1Er2O3 glasses

Abstract We study the theoretical and simulated shielding properties of 69P2O5–10Gd2O3–10BaO–10ZnO–1Er2O3 and 69P2O5–10GdF3–10BaO–10ZnO-1Er2O3 glasses. We exploit advanced simulation (MCNPX) and Phy-X, an online Photon Shielding and Dosimetry software, in the 0.001–15 MeV energy range, to calculate the linear attenuation coefficient and mass attenuation coefficients of the samples. The obtained mass attenuation coefficient is then used to calculate the critical radiation shielding characteristics, such as the half-value layer, mean free path, tenth value layer, and effective atomic number. The calculated LAC values range from 108.759 to 0.097 and from 84.124 to 0.087 cm−1 while HVL values range from 0.006 to 7.164 and from 0.008 to 8.013 cm, and MFP values vary from 0.009 to 10.335 and from 0.012 to 11.561 cm for ZBaOEr and ZBaFEr, respectively, with energy ranging from 0.015 to 15 MeV. We find that the results obtained from MCNPX and Phy-X are consistent with each other, based on the computed relative difference. The glass sample containing Gd2O3 exhibits better shielding properties than the one with GdF3, over the entire energy range. Our examined glass samples are thick enough to substantially lessen the intensity of incident X-rays and gamma rays.

Elevated serum lactic acid level is an independent risk factor for the incidence and mortality of sepsis-associated acute kidney injury

To explore the effect of serum lactic acid (Lac) level on acute kidney injury (AKI) in patients with sepsis and whether Lac level affects the in-hospital mortality of patients with sepsis-associated AKI. A retrospective cohort study was conducted. Clinical data of patients with sepsis admitted to the internal intensive care unit (ICU) of the First Affiliated Hospital of Guangxi Medical University from March 2014 to June 2019 and the ICU of the Second Affiliated Hospital of Guangxi Medical University from January 2017 to June 2020 were collected. According to the first quartile of Lac within 24 hours of admission to ICU, the patients were divided into Lac ≤ 1.4 mmol/L group (group Q1), Lac 1.5-2.4 mmol/L group (group Q2), Lac 2.5-4.0 mmol/L group (group Q3), and Lac ≥ 4.1 mmol/L group (group Q4). The incidence of sepsis-associated AKI after admission to ICU and hospital mortality were compared among four groups. The effect of elevated Lac on the incidence and mortality of sepsis-associated AKI was investigated by binary Logistic regression analysis. The receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive value of Lac on the incidence and mortality of sepsis-associated AKI, and the cut-off value was obtained to analyze the incidence and death risk of sepsis-associated AKI at different Lac levels. A total of 655 sepsis patients were enrolled, of which 330 patients (50.4%) developed AKI and 325 patients (49.6%) did not. Among 330 patients with sepsis-associated AKI, 134 (40.6%) died and 196 (59.4%) survived. With the increase of Lac level, the incidence of sepsis-associated AKI increased gradually (34.5%, 41.0%, 58.4%, 66.3%, respectively, in group Q1-Q4), meanwhile, the in-hospital mortality also increased gradually (23.4%, 29.2%, 33.1%, 43.4%, respectively, in group Q1-Q4), the differences were statistically significant (both P < 0.01). Compared with the non-AKI group, the Lac level in the AKI group was significantly increased [mmol/L: 3.08 (1.84, 5.70) vs. 1.91 (1.20, 3.10), P < 0.01]. After adjustment for factors such as gender (male), site of infection (abdominal cavity), vasoactive drugs, basal mechanical ventilation, mean arterial pressure (MAP), basal renal insufficiency, uric acid, procalcitonin (PCT), platelet count (PLT), basal serum creatinine (SCr) and basal estimated glomerular filtration rate (eGFR), and other influencing factors, multivariate Logistic regression analysis showed that elevated Lac was an independent risk factor for sepsis-associated AKI [odds ratio (OR) = 1.096, 95% confidence interval (95%CI) was 1.022-1.175, P = 0.010]. Compared with the survival group, the Lac level in the death group was significantly increased [mmol/L: 3.55 (2.00, 6.76) vs. 3.00 (1.70, 4.50), P < 0.01]. After adjusting for age, diabetes, vasoactive drugs, basal eGFR, and other factors, multivariate Logistic regression analysis suggested that increased Lac was an independent risk factor for in-hospital mortality in sepsis-associated AKI patients (OR = 1.074, 95%CI was 1.004-1.149, P = 0.037). ROC curve analysis showed that the area under the ROC curve (AUC) of Lac for predicting the incidence and mortality of sepsis-associated AKI was 0.653 (95%CI was 0.611-0.694) and 0.593 (95%CI was 0.530-0.656, both P < 0.01), respectively, and the cut-off values were 2.75 mmol/L (sensitivity was 57.8%, specificity was 69.2%) and 5.95 mmol/L (sensitivity was 56.7%, specificity was 83.7%). When the Lac ≥ 2.75 mmol/L, the risk of sepsis-associated AKI was 2.772 times higher than that of < 2.75 mmol/L (OR = 2.772, 95%CI was 1.754-4.380, P < 0.001). When the Lac ≥ 5.95 mmol/L, the patients with sepsis-associated AKI had a 2.511 times higher risk of in-hospital death than those with Lac < 5.95 mmol/L (OR = 2.511, 95%CI was 1.378-4.574, P = 0.003). Elevated Lac level is an independent risk factor for the incidence and mortality of sepsis-associated AKI. When Lac ≥ 2.75 mmol/L, the risk of AKI in patients with sepsis increased by 1.772 times; when Lac ≥ 5.95 mmol/L, the risk of in-hospital death in patients with sepsis related AKI increased by 1.511 times.

Experimental Study of Polypropylene with Additives of Bi2O3 Nanoparticles as Radiation-Shielding Materials.

This work aimed to intensively study polypropylene samples (PP) embedded with micro- and nanoparticles of Bi2O3 for their application in radiation shielding. Samples were prepared by adding 10%, 20%, 30%, 40%, and 50% of Bi2O3 microparticles (mBi2O3) by weight, and adding 10% and 50% of Bi2O3 nanoparticles (nBi2O3), in addition to the control sample (pure polypropylene). The morphology of the prepared samples was tested, and also, the shielding efficiency of gamma rays was tested for different sources with different energies. The experimental LAC were determined using a NaI scintillation detector, the experimental results were compared with NIST-XCOM results, and a good agreement was noticed. The LAC values have been used to calculate some specific parameters, such as half value layer (HVL), mean free path (MFP), tenth value layer (TVL), and radiation protection efficiency (RPE), which are useful for discussing the shielding capabilities of gamma rays. The results of the shielding parameters show that the PP embedded with nBi2O3 gives better attenuation than its counterpart, PP embedded with mBi2O3, at all studied energies.

Fabrication and synthesis lithium borate glasses for gamma-ray dosimeter

Oxyfluoride glasses of compositions 50 LiF-x P2O5-(50-x) B2O3 (all in mol%) with the value of x = 0, 5, 10, and 50 mol% were prepared and labeled as LFPB0, LFPB40, LFPB45, and LFPB50, respectively. Physical, luminescence, and ionizing radiation shielding properties of lithium borate glasses have been investigated. The highest TL response was obtained at reducing the percentage of P2O5 to 5 mol%. The mass attenuation coefficient was calculated using theoretical software program Phy-x/PSD. The highest MAC values were recorded to LFPB0 glasses. It was found that the linear attenuation coefficient LAC values (14.429 cm−1, 0.051 cm−1), (7.178 cm−1, 0.046 cm−1), (5.672 cm−1, 0.045 cm−1) and (3.934 cm−1, 0.044 cm−1) at 0.015 and 15 MeV for LFPB0, LFPB40, LFPB45, and LFPB50, respectively. LFPB glasses took the following order from the mean free path point of view; LFPB0 < LFPB40 < LFPB 45 < LFPB 50. LFPB0 acquired the highest Zeff values while the LFPB50 glasses acquired the least Zeff values among all prepared LFPB glasses. Results revealed that LFPB0 has the best shielding ability among all prepared LFPB glasses.

Thermal Stability, Optical Properties, and Gamma Shielding Properties of Tellurite Glass Modified with Potassium Chloride.

The synthesized glass system with a composition of (80-x) TeO2-10P2O5-10Nb2O5-xKCl mol% (where x = 5, 10, 15, 20, and 25) was successfully fabricated. The density (ρ) and molar volume (Vm) have been calculated. The investigated glasses were characterized using different analysis methods (differential thermal analysis (DTA) and UV-VIS-NIR spectroscopy). The radiation shielding effectiveness of the synthesized glass system was evaluated using different shielding parameters, such as mass and linear attenuation coefficients (MAC, LAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and effective electron number (Neff). The results showed that with the increasing potassium chloride (KCl) concentration and decreasing tellurium oxide (TeO2) concentration, the density, refractive index, Urbach energy (Eu), and glass transition temperature (Tg) decreased, while the optical energy gap (Eopt) and thermal stability increased. As the KCl concentration increases, the values of MAC, LAC, and Zeff increase in the following order: TPNK5 % > TPNK10 % > TPNK15 % > TPNK20 % > TPNK25 %. Additionally, the shielding effectiveness of TPNK glass system showed good performance compared with some standard materials. The synthesized glass with a minimum KCl content has both good shielding effectiveness and good optical properties, in addition to reasonable thermal stability, which makes it suitable for shielding and optical applications.

The Clinical Effect of High-Flow Oxygen Therapy through the Nose on Patients with Acute Left Heart Failure and Hypoxemia.

Objective To evaluate the clinical efficacy of nasal high-flow oxygen therapy in patients with acute left heart failure and hypoxemia. Methods From July 2016 to November 2018, patients with acute left heart failure complicated with hypoxemia treated in the Department of Critical Medicine of Yantai Affiliated Hospital of Binzhou Medical University were retrospectively observed (a total of 140 cases met the inclusion criteria). They were randomly divided into two groups, with 70 cases in each group. Patients were given continuous ECG monitoring, improved blood gas analysis test, and recorded HR, RR, map, SaO2, pH, PaO2, PaCO2, and Lac, perfect examination and color Doppler echocardiography, and record NT-proBNP and EF before and 24 hours after treatment. The effective rates of the two groups before and after oxygen therapy were detected. Results There were 67 patients with high-flow oxygen therapy group improvement, 95.7% improvement rate, and 55 patients with general oxygen therapy group improvement rate. The treatment improvement rate was 78.6%. A total of 67 patients were treated with high-flow oxygen therapy. After high-flow oxygen therapy, HR (t = 18.8, P ≤ 0.05), RR (t = 19.7, P ≤ 0.05), MAP (t = 12.1, P ≤ 0.05), PaCO2 (t = 9.53, P ≤ 0.05), Lac (t = 8.69, P ≤ 0.05), and NT-proBNP (t = 7.03, P ≤ 0.05) were significantly lower than before. SaO2 (t = −12.4, P ≤ 0.05), pH (t = −12.2, P ≤ 0.05), PaO2 (t = −17.7, P ≤ 0.05), and EF (t = −13.4, P ≤ 0.05) were significantly higher than before. A total of 55 patients were in the general oxygen therapy group. After administration of ordinary oxygen therapy, HR (t = 18.2, P ≤ 0.05), RR (t = 10.8, P ≤ 0.05), MAP (t = 13.1, P ≤ 0.05), PaCO2 (t = 15.8, P ≤ 0.05), Lac (t = 7.1, P ≤ 0.05), and NT-proBNP (t = 10, P ≤ 0.05) were significantly lower than before. SaO2 (t = −15.5, P ≤ 0.05), pH (t = −4.5, P ≤ 0.05), PaO2 (t = −20, P ≤ 0.05), and EF value (t = −7.7, P ≤ 0.05) were significantly higher than before. Conclusion High-flow oxygen therapy and general oxygen therapy have an obvious curative effect on patients with acute left heart failure and hypoxemia. Compared with the two, high-flow oxygen therapy is more effective. After high-flow oxygen therapy and general oxygen therapy in patients with acute left heart failure and hypoxia, HR, RR, MAP, SaO2, pH, PaO2, PaCO2, Lac, EF, and NT-proBNP value all improved, and the improvement of high-flow oxygen therapy was greater.