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National Science Review Oct 2023Isolation of triplet pnictinidenes, which bear two unpaired electrons at the pnictogen centers, has long been a great challenge due to their intrinsic high reactivity....
Isolation of triplet pnictinidenes, which bear two unpaired electrons at the pnictogen centers, has long been a great challenge due to their intrinsic high reactivity. Herein, we report the syntheses and characterizations of two bismuthinidenes MFluind-Bi () and MFluind*-Bi () stabilized by sterically encumbered hydrindacene ligands. They were facilely prepared through reductions of the corresponding dichloride precursors with 2 molar equivalents of potassium graphite. The structural analyses revealed that and contain a one-coordinate bismuth atom supported by a Bi-C single σ bond. As a consequence, the remaining two Bi 6p orbitals are nearly degenerate, and and possess triplet ground states. Experimental characterizations with multinuclear magnetic resonance, magnetometry and near infrared spectroscopy coupled to wavefunction based calculations concurred to evidence that there exist giant and positive zero field splittings (>4300 cm) in their = 1 ground states. Hence even at room temperature the systems almost exclusively populate the lowest-energy nonmagnetic = 0 level, which renders them seemingly diamagnetic.
PubMed: 38034397
DOI: 10.1093/nsr/nwad169 -
Investigative Radiology Jul 2023The recent technological developments in photon-counting detector computed tomography (PCD-CT) and the introduction of the first commercially available clinical PCD-CT... (Review)
Review
The recent technological developments in photon-counting detector computed tomography (PCD-CT) and the introduction of the first commercially available clinical PCD-CT unit open up new exciting opportunities for contrast media research. With PCD-CT, the efficacy of available iodine-based contrast media improves, allowing for a reduction of iodine dosage or, on the other hand, an improvement of image quality in low contrast indications. Virtual monoenergetic image reconstructions are routinely available and enable the virtual monoenergetic image energy to be adapted to the diagnostic task.A key property of PCD-CT is the ability of spectral separation in combination with improved material decomposition. Thus, the discrimination of contrast media from intrinsic or pathological tissues and the discrimination of 2 or more contrasting elements that characterize different tissues are attractive fields for contrast media research. For these approaches, K-edge imaging in combination with high atomic number elements such as the lanthanides, tungsten, tantalum, or bismuth plays a central role.The purpose of this article is to present an overview of innovative contrast media concepts that use high atomic number elements. The emphasis is on improving contrast enhancement for cardiovascular plaque imaging, stent visualization, and exploring new approaches using 2 contrasting elements. Along with the published research, new experimental findings with a contrast medium that incorporates tungsten are included.Both the literature review and the new experimental data demonstrate the great potential and feasibility for new contrast media to significantly increase diagnostic performance and to enable new clinical fields and indications in combination with PCD-CT.
Topics: Contrast Media; Iodine; Phantoms, Imaging; Photons; Tomography, X-Ray Computed; Tungsten
PubMed: 37068840
DOI: 10.1097/RLI.0000000000000978 -
RSC Advances Jun 2023This review paper provides a comprehensive overview of the recent trends in bismuth tungstate (BiWO) research, covering its structural, electrical, photoluminescent, and... (Review)
Review
This review paper provides a comprehensive overview of the recent trends in bismuth tungstate (BiWO) research, covering its structural, electrical, photoluminescent, and photocatalytic properties. The structural characteristics of bismuth tungstate are explored in detail, including its different allotropic crystal structures with respect to its isotypic materials. The electrical properties of bismuth tungstate, such as its conductivity and electron mobility, are also discussed, along with its photoluminescent properties. The photocatalytic activity of bismuth tungstate is a particular focus, with recent advances in doping and co-doping strategies with metals, rare earth and other elements summarized. The limitations and challenges of using bismuth tungstate as a photocatalyst are also examined, such as its low quantum efficiency and susceptibility to photodegradation. Finally, recommendations for future research directions are provided, including the need for further studies on the underlying mechanisms of photocatalytic activity, the development of more efficient and stable bismuth tungstate-based photocatalysts, and the exploration of new applications in fields such as water treatment and energy conversion.
PubMed: 37304811
DOI: 10.1039/d3ra01987j -
Cancers Dec 2023Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we... (Review)
Review
Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we reviewed the currently used access methods for biliary stent placement (percutaneous transhepatic biliary drainage, endoscopic biliary drainage, endosonography guided biliary drainage), the available stent types (plastic stent, self-expanding metallic stent, full cover self-expanding metallic stent, radioactive self-expanding metallic stent), major approaches (unilateral, bilateral) and deployment methods (stent-in-stent, stent-by-stent). Finally, this review gives an outlook on perspectives of development in stenting and other palliative methods in MHBO.
PubMed: 38136363
DOI: 10.3390/cancers15245819 -
Membranes Jun 2023Synthesis and study of materials based on bismuth cerates and titanates were carried out. Complex oxides BiYTiO were synthesized by the citrate route; BiCeO and...
Synthesis and study of materials based on bismuth cerates and titanates were carried out. Complex oxides BiYTiO were synthesized by the citrate route; BiCeO and BiYCeO-by the Pechini method. The structural characteristics of materials after conventional sintering at 500-1300 °C were studied. It is demonstrated that the formation of a pure pyrochlore phase, BiYTiO, occurs after high-temperature calcination. Complex oxides BiCeO and BiYCeO have a pyrochlore structure formed at low temperatures. Yttrium doping of bismuth cerate lowers the formation temperature of the pyrochlore phase. As a result of calcination at high temperatures, the pyrochlore phase transforms into the CeO-like fluorite phase enriched by bismuth oxide. The influence of radiation-thermal sintering (RTS) conditions using e-beams was studied as well. In this case, dense ceramics are formed even at sufficiently low temperatures and short processing times. The transport characteristics of the obtained materials were studied. It has been shown that bismuth cerates have high oxygen conductivity. Conclusions are drawn about the oxygen diffusion mechanism for these systems. The materials studied are promising for use as oxygen-conducting layers in composite membranes.
PubMed: 37367802
DOI: 10.3390/membranes13060598 -
Polymers Apr 2024Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding...
Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding materials were developed using low-density polyethylene (LDPE) mixed with four different filler materials. These four materials are cement, cement with iron oxide, cement with aluminum oxide, and cement with bismuth oxide. Different weight percentages were used including 5%, 15%, and 50% of the cement filler with LDPE. Furthermore, different weight percentages of different combinations of the filler materials were used including 2.5%, 7.5%, and 25% (i.e., cement and iron oxide, cement and aluminum oxide, cement and bismuth oxide) with LDPE. Bismuth oxide was a nanocomposite, and the remaining oxides were micro-composites. Characterization included structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared composites. The results show that a clear improvement in the shielding efficiency was observed when the filler materials were added to the LDPE. The best result out of all these composites was obtained for the composites of bismuth oxide (25 wt.%) cement (25 wt.%) and LDPE (50 wt.%) which have the lowest measured mean free path (MFP) compared with pure LDPE. The comparison shows that the average MFP obtained from the experiments for all the eight energies used in this work was six times lower than the one for pure LDPE, reaching up to twelve times lower for 60 keV energy. The best result among all developed composites was observed for the ones with bismuth oxide at the highest weight percent 25%, which can block up to 78% of an X-ray.
PubMed: 38611278
DOI: 10.3390/polym16071020 -
Heliyon Nov 2023In this study, bismuth ferrite nanoparticles and metal-organic framework, Cu(BDC), were prepared by microwave-assisted combustion in solid state and ultrasound-assisted...
In this study, bismuth ferrite nanoparticles and metal-organic framework, Cu(BDC), were prepared by microwave-assisted combustion in solid state and ultrasound-assisted method, respectively. To enhance the properties of bismuth ferrite nanoparticles and Cu(BDC), we form them as their composite through microwave and ultrasonic probe strategies. Various analyses, including FT-IR, XRD, SEM, DRS, VSM, and so on, were applied to verify the synthesis accuracy. Then, the catalytic performances of the nanoparticles and the as-prepared nanocomposites were evaluated through photocatalytic degradation of methyl orange. Furthermore, the adsorption capacity of the as-synthesized materials was assessed toward the Congo red removal from wastewater. All the results prove that the proposed nanocomposite can be an acceptable candidate for eliminating contaminants from wastewater. The electrochemical properties of bismuth ferrite, BiFeO/Cu(BDC) nanocomposite 1, and BiFeO/Cu(BDC) nanocomposite 2 have been studied by cyclic voltammetry.
PubMed: 37885730
DOI: 10.1016/j.heliyon.2023.e20689 -
Materials (Basel, Switzerland) Sep 2023The present study comprises an investigation involving thermodynamic analysis, microstructural characterisation, and a comparative examination of the solidification...
The present study comprises an investigation involving thermodynamic analysis, microstructural characterisation, and a comparative examination of the solidification sequence in two different aluminium alloys: EN AW 6026 and EN AW 1370. These alloys were modified through the addition of pure indium and a master alloy consisting of indium and bismuth. The aim of this experiment was to evaluate the potential suitability of indium, either alone or in combination with bismuth, as a substitute for toxic lead in free-machining aluminium alloys. Thermodynamic analysis was carried out using Thermo-Calc TCAL-6 software, supplemented by differential scanning calorimetry (DSC) experiments. The microstructure of these modified alloys was characterised using SEM-EDS analysis. The results provide valuable insights into the formation of different phases and eutectics within the alloys studied. The results represent an important contribution to the development of innovative, lead-free aluminium alloys suitable for machining processes, especially for use in automatic CNC cutting machines. One of the most important findings of this research is the promising suitability of indium as a viable alternative to lead. This potential stems from indium's ability to avoid interactions with other alloying elements and its tendency to solidify as homogeneously distributed particles with a low melting point. In contrast, the addition of bismuth does not improve the machinability of magnesium-containing aluminium alloys. This is primarily due to their interaction, which leads to the formation of the MgBi phase, which solidifies as a eutectic with a high melting point. Consequently, the presence of bismuth appears to have a detrimental effect on the machining properties of the alloy when magnesium is present in the composition.
PubMed: 37763519
DOI: 10.3390/ma16186241 -
Frontiers in Oncology 2023Surgery represents the only cure for hilar cholangiocarcinoma (HC). However, laparoscopic radical resection remains technically challenging owing to the complex anatomy...
BACKGROUND
Surgery represents the only cure for hilar cholangiocarcinoma (HC). However, laparoscopic radical resection remains technically challenging owing to the complex anatomy and reconstruction required during surgery. Therefore, reports on laparoscopic surgery (LS) for HC, especially for types III and IV, are limited. This study aimed to evaluate the safety and feasibility of laparoscopic radical surgery for Bismuth types III and IV HC.
METHODS
The data of 16 patients who underwent LS and 9 who underwent open surgery (OS) for Bismuth types III and IV HC at Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, between December 2017 and January 2022 were analyzed. Basic patient information, Bismuth-Corlette type, AJCC staging, postoperative complications, pathological findings, and follow-up results were evaluated.
RESULTS
Sixteen patients underwent LS and 9 underwent OS for HC. According to the preoperative imaging data, there were four cases of Bismuth type IIIa, eight of type IIIb, and four of type IV in the LS group and two of type IIIa, four of type IIIb, and three of type IV in the OS group (>0.05). There were no significant differences in age, sex, ASA score, comorbidity, preoperative percutaneous transhepatic biliary drainage rate, history of abdominal surgery, or preoperative laboratory tests between the two groups (>0.05). Although the mean operative time and mean intraoperative blood loss were higher in the LS group than in OS group, the differences were not statistically significant (=0.121 and =0.115, respectively). Four patients (25%) in the LS group and two (22.2%) in the OS group experienced postoperative complications (>0.05). No significant differences were observed in other surgical outcomes and pathologic findings between the two groups. Regarding the tumor recurrence rate, there was no difference between the groups (>0.05) during the follow-up period (23.9 ± 13.3 months vs. 17.8 ± 12.3 months, =0.240).
CONCLUSION
Laparoscopic radical resection of Bismuth types III and IV HC remains challenging, and extremely delicate surgical skills are required when performing extended hemihepatectomy followed by complex bilioenteric reconstructions. However, this procedure is generally safe and feasible for hepatobiliary surgeons with extensive laparoscopy experience.
PubMed: 38188306
DOI: 10.3389/fonc.2023.1280513 -
The Journal of Physical Chemistry. A Jan 2024EH (E = As, Sb, Bi) structures involving multiple bonds have attracted much attention recently. The EH cations (protonated EH) are predicted to be viable with...
EH (E = As, Sb, Bi) structures involving multiple bonds have attracted much attention recently. The EH cations (protonated EH) are predicted to be viable with substantial proton affinities (>180 kcal/mol). Herein, the bonding characters and energetics of a number of EH isomers are explored through CCSD(T) and DFT methods. For the AsH system, the CCSD(T)/cc-pVQZ-PP method predicts that the vinylidene-like structure lies lowest in energy, with the trans and cis isomers higher by 6.7 and 9.3 kcal/mol, respectively. However, for SbH and BiH systems, the trans isomer is the global minimum, while the energies of the cis and vinylidene-like structures are higher, respectively, by 2.0 and 2.4 kcal/mol for SbH and 1.6 and 15.0 kcal/mol for BiH. Thus, the vinyledene-like structure is the lowest energy for the arsenic system but only a transition state of the bismuth system. With permanent dipole moments, all minima may be observable in microwave experiments. Besides, we have also obtained transition states and planar-cis structures with higher energies. The current results should provide new insights into the various isomers and provide a number of predictions for future experiments.
PubMed: 38227954
DOI: 10.1021/acs.jpca.3c05945