Search

The magmatic diagenetic environment was simulated by high-temperature melting and natural cooling. A series of glass-ceramics with different Nd2O3 contents were prepared by using complex component granite (aluminosilicate material). The phase evolution of the matrix at different temperatures was studied by X-ray diffraction (XRD). The structure of glass-ceramics was analyzed by infrared spectroscopy (IR) and scanning electron microscopy (SEM). The mechanical properties of glass-ceramics were also evaluated. The results showed that the glass transition of pure matrix begins at 1200 °C, and the sample with the highest degree of vitrification is obtained at 1500 °C. The addition of Nd2O3 promoted the melting of Fe3O4 crystal, resulting in the complete amorphous matrix when the Nd2O3 amount is in the range of 20–26 wt.%. With the further increase of Nd2O3 content, Nd-bearing feldspar first appeared. No raw material Nd2O3 was found, indicating that the formation of Nd-bearing feldspar may increase the carrying capacity of the material. The Gaussian fitting results showed that the glass-ceramic samples with Nd2O3 content of 29 wt.% are mainly composed of Q2 and Q3 structural units. In the EDS result, part of neodymium was clustered with small bright spots, while the spots were uniformly distributed on the sample surface as a whole. Meanwhile, the addition of Nd2O3 increased the mechanical properties of the samples (3.20 g/cm3, 8.33 GPa for the sample with 29 wt.% of Nd2O3). The results provide a strategy for the treatment of solid waste with radioactive residual actinides.

Although bioreduction induced by microorganisms has been considered to play an important role in the chemical and migration behaviors of uranium in nature, the accurate determination of tetravalent uranium reduced by microorganisms is still difficult to achieve. In this work, potentiometric titration via K2Cr2O7 was used to quantitatively determine the microorganism reduced tetravalent uranium (U(IV)) for the first time. By evaluating the influence of microorganism substance content on the titration of U(IV), the appropriate determination range of U(IV) and biomass was confirmed, and U(IV) induced by bioreduction in three microorganisms was determined. With this method, U(IV) of more than 0.12 mg in microorganisms can be quantitatively measured with an accuracy of 2.2% and a precision of 1.3%, which has been established with the premise that the pretreatment biomass and quantity of U(IV) are in an appropriate range. Compared with the estimated values via the changes in hexavalent uranium (U(VI)) concentration in the bioreduction system, the results obtained by this method can more accurately reflect the quantity of U(IV) in microorganisms. This work can help us to better understand the bioreduction behavior of uranium in the environment.

A new glass solidification process aims at radioactive iodine waste was explored in order to reduce the possible harm to environment. Samples with different iodine content in silver-coated silica gel were pretreated by hydration device at 300 °C and then sintered at relatively low temperatures (500, 550 and 600 °C). XRD results show that AgI is mainly chemically fixed in the glass network with some AgI particles being physically wrapped by the glass. Moreover, as the sintering temperature reached to 550 °C, B element crystallized. SEM-EDS results show that Ag and I elements are enriched, while the other elements are evenly distributed. AFM results showed that the sample surface becomes rougher as the iodine content increases in the silver coated silica gel. The FT-IR results show that the structure of the sintered sample is mainly composed of [BiO3], [BiO6] and [BO3]. This study provides a new sintering method by hydration device for the treatment of radioactive iodine waste.

The radionuclides are extracted from the minerals which make up the rocks. This work takes natural magmatic granite as the matrix and CeO2 as the simulated radioactive waste to explore the maximum solid solubility. After analyzing the phase transition of pure granite with varied temperatures, the solidification was carried out at 1300 ℃. The phase, microstructure, element distribution, hardness and chemical stability of the solidified bodies were studied. The results showed that the maximum solid solubility was up to 8 wt.%. The normal leaching rate of Ce4+ after the first 3 d was about 3.89 × 10–7 g·m−2·d−1.

To simplify the immobilized process of nuclear waste, synthetic Gd2Zr2O7 ceramic was employed to immobilize simulated An3+ (Nd3+) by spark plasma sintering (SPS) without any ion occupation or valence design. Sintering and characterization of immobilized simulated An3+ with various doping amounts were carried out. The effects of Nd2O3 content on the phase composition, active modes, micro-graph and density of the sintered ceramics were investigated. When the Nd2O3 doped amount reached up to 50 mol%, the raw peak of Nd2O3 existed. The sintered ceramics kept a single fluorite phase when Nd2O3 solubility achieved to 40 mol%. The sintered ceramics presented a well crystalline phase and the elements distributed evenly. In addition, as the Nd2O3 doped amount increase, the density and Vickers hardness values of Nd2O3 doped sample decrease.

This work investigated the irradiation behavior of gray desert soil holding simulated An4+ waste under an irradiation of 1.5 MeV Xe20+ to fluences from 1 × 1012 to 1 × 1015 ions cm− 2. The results indicated that the structure has no obvious change due to irradiation fluences and waste load. The normalized leaching rate of Ce after 28 days of the MCC-1 test is in the order of 1 × 10− 5 g cm− 2 d− 1 before and after irradiation. This work identifies gray desert soil, which has good radiation resistance, as a potential matrix for solidification tetravalent actinides.

To investigate the crystallization behavior in the field of radioactive contaminated soil immobilization, different particle size soils are heated at 1300 °C within 30 min by microwave sintering. The XRD results show that mullite phase appears in the yellow soil when the particle size is over 150 mesh. The behavior of crystallization is also related to the grain size and aluminum–silicon molar ratio. As the particle size increases, the crystallinity values generally decrease in all sintered soils. When the particle size is fixed, the crystallinity values are lowest in yellow sintered soil and highest in black sintered soil.

To simulate self-irradiation effects of nuclear waste forms in long period of deep geological disposal, Gd2Ce2O7 as simulated An4+ matrix was chosen to be irradiated using 0.5 MeV alpha ions to fluences ranging from 1 × 1015 to 1 × 1017 ions cm−2. Irradiation-induced structural change and microstructural evolution were examined using grazing incidence X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Lattice swelling and amorphization in irradiated layer indicated an enhanced disordering degree with increased ion fluences. Main Raman peaks broaden and intensity decrease indicated a significant bonds distortion. In addition, no element aggregation about Gd, Ce and O occurs after He2+ irradiation.

As a biosorbent, algae are frequently used for the biotreatment or bioremediation of water contaminated by heavy metal or radionuclides. However, it is unclear that whether or not the biomineralization of these metal or radionuclides can be induced by algae in the process of bioremediation and what the mechanism is. In this work, Ankistrodsemus sp. has been used to treat the uranium-contaminated water, and more than 98% of uranium in the solution can be removed by the alga, when the initial uranium concentration ranges from 10 to 80 mg/L. Especially, an unusual phenomenon of algae-induced uranium biomineralization has been found in the process of uranium bioremediation and its mineralization mechanism has been explored by multiple approaches. It is worth noticing that the biomineralization of uranium induced by Ankistrodsemus sp. is significantly affected by contact time and pH. Uranium is captured rapidly on the cell surface via complexation with the carboxylate radical, amino and amide groups of the microalgae cells, which provides nucleation sites for the precipitation of insoluble minerals. Uranium stimulates Ankistrodsemus sp. to metabolize potassium ions (K

The important role of microbes in the biomineralization and migration behavior of uranium in the field of environmental chemistry has been well emphasized in previous work. However, limited work on mineralization processes of indigenous microorganism has prevented us from a deeper understanding of the process and mechanisms of uranium biomineralization. In this work, the dynamic process and mechanism of uranium biomineralization in Enterobacter sp. X57, a novel uranium-tolerant microorganism separated from uranium contaminated soil, were systematically investigated. Enterobacter sp. X57 can induce intracellular mineralization of U (VI) to Uramphite (NH

For investigating the chemical behavior of uranium-contaminated soil solidified by microwave sintering, the product consistency test method was adopted. The effective factors such as soil species, soil composition, temperature, pH values and their coupling effects have been researched. The maximum leaching rate of uranium was below 1.7 × 10−8 g m−2 day−1 and the cumulative fraction of leached uranium was below 0.0165 after 42 days. The acidic or alkaline leachate and higher temperature would enhance the uranium’s leaching rate, and it was found that the chemical stability of solidified soil is related to the molar ratio of Al2O3/SiO2.

The microwave high-temperature irradiation was introduced to deal with the low efficiency of traditional microwave treatments for breaking granite. Structural evolution of granite between 300 °C and 800 °C was assessed through the morphology, mineral characteristics and mechanical performance. A spherical melt cavity with radial cracks formed near the biotite-rich area at 600 °C and the rock completely disintegrated at 800 °C. Intergranular crack was the main mode of micro-cracks. Besides, the micro crack propagation at 600 °C was affected by the distribution and shapes of mineral grains and original cracks. Furthermore, the intergranular crack in the biotite grain boundary induced many secondary smaller cracks. Feldspar and biotite melted at 800 °C. Thus, the melt probably initiated from the cracked-intensive feldspar near biotite-rich area. The uniaxial compressive strength of granite decreased from 88.17 MPa at 25 °C to 18.61 MPa at 800 °C. Between 300 and 600 °C, the decrease in the uniaxial compressive strength was associated with moisture releasing, quartz transition and thermal induced cracks, and 600–800 °C, the decrease was mainly contributed by the partial melt of rock, and magma intruding and solidifying.

In early days, nuclear tests had left plenty of radionuclide-contaminated soil over the world and disposal of which is vital to human health. In this work, vitrification technology was employed to achieve the immobilization of radionuclide. It was demonstrated that three kinds of simulated uranium contaminated soil for nuclear test site (Gray desert soil, Saline-alkali soil and Aeolian sandy soil) could be successfully vitrified within 30 min without any additional components via microwave sintering. All the uranium contaminated soil became amorphous at 1300 °C. Uranium was considered to be surrounded by aluminium silicate glass network structure, and three kinds of 50000 μg/g uranium concentration sintered soil samples presented reliable chemical durability. In addition, the ultimate solubility of uranium and chemical stability of different sintered soil samples were affected by the content of their components.

The development of nuclear technology leads to the generation of radionuclide contaminated soils, which require efficient and rapid disposal methods. In this study, with microwave sintering method, the simulated radionuclides contaminated soils were successfully immobilized as glass-ceramics at 1200 °C with 30 min. The temperature effect, phase evolution, morphology, element distribution of simulated radioactive contaminated soil were investigated. The XRD results showed that Nd 3+ were immobilized into glass-ceramic phases with Nd 2 O 3 content increased up to 25 wt %. In addition, molecular dynamics simulation (MD) results showed the simulated radioactive contaminated soils were composed of [SiO 4 ] tetrahedron, and Si-O-Si bonds had an important effects on the glass structure forming.

In the field of radioactive waste immobilization, the investigation of irradiation stability is of considerable importance. In this study, uranium-contaminated soil samples were irradiated by 1.5 MeV Xe20+ ions with fluences ranging from 1 × 1012 to 1 × 1015 ions/cm2. Xe20+ heavy-ion radiation was used to simulate the self-irradiation of actinide nuclides. The uranium-contaminated soil samples were sintered via microwaves. Grazing incidence X-ray diffraction results showed that irradiation can cause crystallization of the sample. After irradiation, the Vickers hardness of the samples decreased slightly. Comparative analysis showed that the sample had good radiation resistance, and the leaching rate (28 d) of the sample increased slightly after irradiation, but the overall performance was stable. Our investigation reveals the corresponding mechanism of uranium-contaminated soil irradiation of 1.5 MeV Xe20+ ions.

In nature, many rocks contain radionuclides, and returning radioactive waste to nature is an environmentally friendly way. In this work, a natural magmatic granite rock has been studied as a host matrix for simulated An4+ waste disposal. The blank granite, in the form of powder, was firstly treated by muffle furnace heating in the temperature range of 800 °C to 1400 °C. It was found that the lowest crystallinity of the samples was obtained at 1300 °C. Moreover, 8 wt.% of simulated tetravalent actinides (CeO2) could be successfully immobilized in the natural granite at 1300 °C for 60 min. Raman results show the structure disordering in samples tends to increase with the increased amount of CeO2. SEM-EDS observation shows that the distribution of Ce was relatively uniform in the matrix. Moreover, the hardness of solidified body is comparable to traditional glasses and it decreases with the increase of CeO2 content.

To investigate the rapid immobilization of tetravalent actinides ( An 4+ ), Ce 4+ was used as simulated nuclear waste to be incorporated in Gd 2 Zr 2 O 7 ceramic. A series of compositions with the general formula of Gd 2 Zr 2- x Ce x O 7 (0.0 ≤ x ≤ 2.0) were rapidly fabricated through SPS process. That the Gd 2 Zr 2- x Ce x O 7 (0.0 ≤ x ≤ 1.0) ceramics with a single phase can be obtained at 1600 °C within 3 min as x was below 1.5. The lattice parameter and volume increase with enhancement of Ce content. The samples are in cubic-shaping crystal structure, as well as orderly arranged atomic layers. Meanwhile, the bulky density of samples increase with elevated Ce content, which is much higher than the conventionally obtained ones. In addition, the normalized release rates of Gd, Zr and Ce elements in Gd 2 ZrCeO 7 waste form are kept in low values (lower than 10 −4 g·m −2 d −1 ), which exhibits a reliable chemical stability.

To efficiently inhibit the diffusion of radioactive nuclides in soil that were left by nuclear emergency accidents, microwave sintering technology was used in this work to vitrify the simulated strontium contaminated soil. Four kinds of simulated strontium-contaminated soil could be successfully vitrified almost completely within 30 min without any additional components. Sr2+ cations are immobilized into aluminosilicate glass network structure. In addition, the solubility of SrSO4 in different soil is related to the element contents of aluminum and silicon. This work reveals a demonstration that beta-radioactive contaminated soil could be treated by microwave vitrifying.

In this research, the heavy-ion irradiation effects of U-bearing Gd2Zr2O7 ceramics were explored for nuclear waste immobilization. U3O8 was designed to be incorporated into Gd2Zr2O7 from two different routes in the form of (Gd1-4xU2x)2(Zr1-xUx)2O7 (x = 0.1, 0.14). The self-irradiation of actinide nuclides was simulated by Xe20+ heavy-ion radiation under different fluences. Grazing incidence X-ray diffraction (GIXRD) analysis reveals the relationship between radiation dose, damage and depth. The radiation tolerance is promoted with the increment of U3O8 content in the discussed range. Raman spectroscopy testifies the enhancement of radiation tolerance and microscopically existed phase evolution from the chemical bond vibrations. In addition, the microstructure and elemental distribution of the irradiated samples were analyzed as well. The amorphization degree of the sample surface declines as the U content was elevated from x = 0.1 to x = 0.14.

Since Nd3+ and Ce4+ are usually taken as surrogates for the trivalent and tetravalent actinides, respectively, simulated nuclear waste form Nd2Ce2O7 and the potential host matrix Gd2Zr2O7 were studied in details to get a better understanding of the radiation stability of fluorite related compounds at the ultimate loading capacity. Both compounds were fabricated by traditional solid state process and irradiated with 2 MeV Xe20+ ions with dose of 0.072–91.17 dpa at room temperature. XRD results demonstrate the final fluorite phase in both compounds and their slight lattice swelling (about 0.35%) after irradiation for 91.17 dpa. Raman spectra indicate an obvious disordering of both compounds, while TEM analysis reveals atom disordering in Gd2Zr2O7 and amorphization in Nd2Ce2O7.

As it is pivotal to study the self-irradiation of radioactive contaminated soil under alpha-particle in long term storage, the purpose of this paper is to research the irradiation behavior of 10–30 wt% of Nd2O3 and CeO2 co-doped glass samples under 0.5 MeV He2+ irradiation of high fluences from 1.0 × 1014 to 1.0 × 1017 ions/cm2 at room temperature. The results of GIXRD show that the main phases keep amorphous after irradiation. Surface morphology is still smooth and enrichment phenomenon of all the referred elements exist rarely after irradiation by SEM-EDS. Meanwhile, the results of Vickers hardness value and leaching rate test show slightly change whereas the structure of the glass-samples under alpha-particle irradiation are stable. Therefore, this work can offer detailed information for the radiation tolerance of the materials.

For application in nuclear waste management, it is essential to study the self-irradiation effect in long-term deep geological disposal repository. In this study, accelerated irradiation experiment was conducted on Nd2Zr2O7 pyrochlore matrix by using 0.5 MeV He2+ ions with fluences ranging from 1 × 1014 to 1 × 1017 ions/cm2. A series of results figure out that Nd2Zr2O7 matrix transforms from pyrochlore into fluorite after radiation experiment and some weak structural disordering is led with intensified irradiation. Moreover, the surface micrography shows slight changes after irradiation.

A rapid and efficient method is particularly necessary in the timely disposal of seriously radioactive contaminated soil. In this paper, a series of simulated radioactive soil waste containing different contents of neodymium oxide (3-25wt.%) has been successfully vitrified by microwave sintering at 1300°C for 30min. The microstructures, morphology, element distribution, density and chemical durability of as obtained vitrified forms have been analyzed. The results show that the amorphous structure, homogeneous element distribution, and regular density improvement are well kept, except slight cracks emerge on the magnified surface for the 25wt.% Nd2O3-containing sample. Moreover, all the vitrified forms exhibit excellent chemical durability, and the leaching rates of Nd are kept as ∼10-4-10-6g/(m2day) within 42days. This demonstrates a potential application of microwave sintering in radioactive contaminated soil disposal.

To investigate the deterioration of granite under microwave irradiation and heat transfer, granite specimens were heated up to 400-1000 °C and then kept for 15 min. Uniaxial compressive strength testing results demonstrate a similar variation in two groups in 400-900 °C, which is initial strengthening (less than 500 °C), subsequent weakening (500-600 °C) and final stabilizing (600-900 °C). Furthermore, the specimen irradiated by microwaves presented a second decline at 1000 °C. Compared to heat transfer, microwave irradiation can reduce the strengthening due to localized transition plasticity and further promotes the deterioration of rock structure in weakening stage. TG/DSC results indicate that the strengthening is related to the iron mineral transition. The formation of porous glass substance which is mainly composed of feldspar and biotite. Furthermore, temperature-controlled microwave irradiation induced the variation of feldspar crystallinities, which is consistent with the corresponding UCS data, especially the plagioclase. In practical application, microwaves can be used to irradiate the vulnerable positions (surface edge and cleavage) and kept the whole rock mass around 600 °C.

The treatment of iodine wastes has been widely concerned. In this work, B2O3–Bi2O3 based material was used to immobilize the silver coated silica gel with different iodine loadings. Based on XRD results analyses, the sample with 90 mol% B2O3 was selected for iodine waste immobilization. XRD results represented that the sintering temperature of 500 °C was suitable to immobile iodine waste. The micro-structure of the sintered matrix mainly consists of the stretching vibration of [SiO4]. SEM-EDS results showed that the elements of Ag and I exist element aggregation in some regions, which indicates that part of AgI was immobilized in the glassy phase while the other was physically enclosed in the sintered matrix. This study provides certain valuable reference and experimental basis for the subsequent curing of iodine-containing silver coated silica gel with multicomponent glass.

To better deal with the radioactive iodine generated during the development of nuclear energy, B2O3, Bi2O3, ZnO, and SiO2 were used to sinter borosilicate glass for the immobilization of iodine. The effect of B2O3 on glass formation was discussed by changing the molar ratio of B2O3 in the matrix. When B2O3 content is 50 mol% and sintering temperature is 600 ℃, the amorphous degree of quaternary glass is the highest. The sintered body with the highest degree of amorphous was selected to study radioactive iodine. Then, the effects of different iodine loading concentrations for sintering borosilicate glass in terms of microstructure and phase change were discussed. With the increase in iodine content on silica-gel, the degree of amorphous of the specimens presented a decreasing trend, and there are obvious SiO2 peaks. When the content was 20 wt.%-30 wt.%, a large number of new phases were generated. When the iodine content is 20 wt.%, in addition to the enrichment of Si and O elements, the elemental distribution for B, Bi, Zn, I, and Ag was even. TEM results also showed that there was a crystalline phase in the sinter.

To explore the immobilization mechanism and effect of tetravalent actinides (one of the main sources of pollution) in the heavily contaminated soil, soil with different content of CeO2 (surrogate of An4+) were rapidly vitrified by microwave sintering. The phase, microstructure, element distribution, bonding state, density and chemical stability of the sintered matrix were studied. As the solution of CeO2 below 14 ​wt %, the samples exhibited a single amorphous phase and the distribution of Ce elements is relatively uniform. Si and Al mainly exist in the form of four coordination and this resulted in a huge spatial network structure. Moreover, the density of sintered matrix gradually increased with increased CeO2 content and the average leaching rate of Ce4+ was below 0.9 ​× ​10−5 ​g m−2 d−1 after 42 days.

In this study, we fabricated silicate glass ceramics using a mixture of oxides containing SiO2, B2O3, Bi2O3, and ZnO, to immobilize iodine adsorbed by silver-coated silica gels. The effects of SiO2 content on quaternary glass were explored by changing the molar ratio of SiO2 in the sintered matrix. The curing substrate with the highest amorphous index (0.6) was selected to simulate the immobilization of silver-coated silica gel loaded with 10, 20, 30, 40, and 50wt% iodine. Further, the effects of iodine concentration on the sintered matrix were analyzed based on phase structure and microstructure. The amorphous degree of sintered silicate matrix declines with increasing iodine loading in silver-coated silica gel. Transmission electron microscopy (TEM) results detected that a sample loaded with 20wt% iodine and sintered at 550 °C showed a polycrystalline glass-ceramic phase.

To rapidly immobilize simulated An4+ in high-alumina soil by microwave sintering, clay sample doped with 5 wt% of CeO2 was successfully fabricated as silicate glass composite matrix at 1500 °C in 30 min Ce4+ was immobilized into glass phase, which was formed through the reaction of feldspar and quartz. The generated crystal phase Al6Si2O13 in sintered glass composite material was due to the formation of [Si2O7]6- groups, which were separated from the glass network structure. The leaching rate of Ce maintained at a magnitude of 1 × 10−7 g∙m−2 d−1 after 42 days for all samples. Moreover, increased sintering temperature is beneficial to enhance the leaching resistance of sintered clay samples.

Nuclear contaminated soil can seriously threaten human security. In this study, uranium-contaminated soil (0–50000 μg/g of uranium) was successfully vitrified in 30 min without complex pretreatment or any additional components. The microstructure of the vitrified forms, the immobilizing mechanism of uranium, the inner structural evolution with increased uranium concentration, and the performance in terms of chemical durability were studied in detail. In the vitrified form, uranium was surrounded by a three-dimensional network structure comprising silicon and aluminum oxide polyhedra. When the uranium content increased above 50000 μg/g, the network adjusted and local structures precipitated as mottle-shaped quartz. The normalized leaching rates of uranium were maintained at a low value (∼1 × 10−6 g/(m2·d) level) in distilled water at 90 °C after 42 days. These results suggested the feasibility of vitrifying nuclear contaminated soil in a simple and rapid way.

BACKGROUND Few studies have reported the clinical features, complications and predictors of Kasabach-Merritt phenomenon (KMP) associated with Kaposiform haemangioendothelioma (KHE). OBJECTIVES To determine the clinical characteristics present at diagnosis and to identify features that may aid clinicians in managing KHE. METHODS We conducted a cohort study of 146 patients diagnosed with KHE. RESULTS KHE precursors or lesions were present at birth in 52·1% of patients. In 91·8% of patients, lesions developed within the first year of life. The median age at diagnosis of KHE was 2·3 months (interquartile range 1·0-6·0). The extremities were the dominant location, representing 50·7% of all KHEs. Among KHEs in the cohort, 63·0% were mixed lesions (cutaneous lesions with deep infiltration). Approximately 70% of patients showed KMP. A KHE diagnosis was delayed by ≥ 1 month in 65·7% of patients with KMP. Patients with KMP were more likely to have major complications than patients without KMP (P = 0·023). Young age ( 5·0 cm) and mixed lesion type were associated with KMP in a univariate analysis. In the multivariate analysis, only age [odds ratio (OR) 11·9, 95% confidence interval (CI) 4·07-34·8; P < 0·001], large lesion size (OR 5·08, 95% CI 2·24-11·5; P < 0·001) and mixed lesion type (OR 2·96, 95% CI 1·23-7·13; P = 0·016) were associated with KMP. CONCLUSIONS Most KHEs appeared before 12 months of age. KHEs are associated with various major complications, which can occur in combination and develop early in the disease process. Young age, large lesion size and mixed lesion type are important predictors of KMP.

In this research, the heavy-ion irradiation effects of U-bearing Gd

Currently, propranolol is the preferred treatment for problematic proliferating infantile haemangiomas (IHs). The rapid action of propranolol has been shown to be especially dramatic in IHs involving dyspnoea, haemodynamic compromise, palpebral occlusion or ulceration. Another remarkable aspect of propranolol treatment revealed that the growth of the IHs was not only stabilized, but also that the improvement continued until complete involution was achieved, leading to a considerable shortening of the natural course of IH. However, the mechanisms underlying the effects of propranolol have not been fully elucidated. Recent studies have offered evidence of a variety of mechanisms. These include the promotion of pericyte-mediated vasoconstriction, the inhibition of vasculogenesis and catecholamine-induced angiogenesis, the disruption of haemodynamic force-induced cell survival, and the inactivation of the renin-angiotensin system. This review summarizes these mechanisms and the new concepts that are emerging in this area of research. Moreover, several molecular mechanisms by which propranolol may modify neovascularization in IH have also been proposed. The antihaemangioma effect of propranolol may not be attributable to a single mechanism, but rather to a combination of events that have not yet been elucidated or understood. Further studies are needed to evaluate and verify these mechanisms to gain a greater understanding of the effects of the intake of propranolol on haemangioma involution.

To immobilize the radioactive iodine isotopes, a series of borosilver silica gel glasses with iodine loaded in silver-coated silica gel ranging from 20 to 30 wt% (I− content in each sample was 8 wt%) had been successfully immobilized by muffle furnace from 450 °C to 550 °C for 6 h. With the increase of I− in silver-coated silica gel, optimum sintering temperatures corresponding to the maximum amorphous fraction in each system decreased from 550 °C (0.98) to 490 °C (0.68) and finally to 460 °C (0.66). The IR spectrums results show that the vitrified matrix is mainly consisted of [BO3] and [SiO4]. The SEM-EDS patterns show that iodine is uniformly distributed in the sample loaded with 20 wt% of iodine in silver-coated silica gel. In addition, the specimen shows lower porosity with higher amorphous fraction. Our findings demonstrate the potential of boron for the immobilization of silver-coated silica gel with different radioactive iodine loadings.