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This paper reviews recent developments in the field of hybrid Pd nanoparticles and their catalytic activity in the Suzuki coupling reaction, which is used extensively in the fabrication of both simple and complex biaryl compounds. We developed three types of Pd-silica hybrid nanoparticles. Pd/SiO2 nanobeads containing tiny Pd clusters, Pd@nickel phyllosilicate yolk-shell nanoparticles, Pd@porous SiO2 yolk-shell nanoparticles were synthesized, and they displayed highly efficient catalytic activity and excellent reusability. The hybrid nanoparticles also catalyzed the Suzuki coupling reaction with various substrates, including bromobenzene and chlorobenzene. This review also briefly discusses the synthesis procedure, structural characterization, and catalytic activity of hybrid Pd nanoparticles.
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Ácidos Borônicos/química , Halogênios/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Paládio/química , Catálise , Tamanho da PartículaRESUMO
Little is known of the responsiveness of soil bacterial community structure to disturbance. In this study, we subjected a soil microcosm to physical disturbance, sterilizing 90 % of the soil volume each time, at a range of frequencies. We analysed the bacterial community structure using 454 pyrosequencing of the 16S rRNA gene. Bacterial diversity was found to decline with the increasing disturbance frequencies. Total bacterial abundance was, however, higher at intermediate and high disturbance frequencies, compared to low and no-disturbance treatments. Changing disturbance frequency also led to changes in community composition, with changes in overall species composition and some groups becoming abundant at the expense of others. Some phylogenetic groups were found to be relatively more disturbance-sensitive or tolerant than others. With increasing disturbance frequency, phylogenetic species variability (an index of community composition) itself became more variable from one sample to another, suggesting a greater role of chance in community composition. Compared to the tightly clustered community of the original undisturbed soil, in all the aged disturbed soils the lists of most abundant operational taxonomic units (OTUs) in each replicate were very different, suggesting a possible role of stochasticity in resource colonization and exploitation in the aged and disturbed soils. For example, colonization may be affected by whichever localized concentrations of bacterial populations happen to survive the last disturbance and be reincorporated in abundance into each pot. Overall, it appears that the soil bacterial community is very sensitive to physical disturbance, losing diversity, and that certain groups have identifiable 'high disturbance' vs. 'low disturbance' niches.
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Bactérias/isolamento & purificação , Biodiversidade , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Ecossistema , Filogenia , Solo/químicaRESUMO
Background: Extradural spinal tumors arise from soft or bony tissues in the spine and account for majority of spinal tumors. Interest in the unilateral biportal endoscopic (UBE) technique is rising, because it can easily decompress the bony spinal canal and accommodate all open surgical instruments under endoscopic guidance. However, reports of this technique have been limited to certain diseases. This study first demonstrates the UBE technique for extradural tumor biopsy and removal, and percutaneous stabilization in a 72-year-old female patient with dramatic symptom improvement. Methods: We used the UBE technique for decompression and the percutaneous screw fixation technique for stabilization in a patient with an extradural mass compressing the thecal sac and destroying the posterior element. Under endoscopic guidance, a unilateral approach was used, and decompression and flavectomy were performed bilaterally. After decompression, tumor removal and biopsy were performed using various forceps and biopsy needles. After confirming sufficient spinal canal decompression, the screw was placed percutaneously. We evaluated the technical process of the procedure, the patient's pre- and postoperative pain (using the visual analog scale), and operative radiology and pathologic results. Results: Postoperative pain and disability improved clinically, and spinal alignment stabilized radiologically. As the pathology findings confirmed an aneurysmal bone cyst, the treatment was completed without adjuvant therapy. Conclusions: We treated an unstable spine due to an extradural tumor with the UBE and percutaneous screw techniques.
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The coronavirus disease (COVID-19) pandemic has influenced hospital visiting patterns. Although vaccination has decreased infection rates and disease severity, hospital visiting patterns and associated treatment changes related to orthopedics remain unexplored in the Middle East. Therefore, this study aimed to examine the impact of the COVID-19 pandemic and vaccination on individual departments dealing with musculoskeletal disorders in the United Arab Emirates. Relationships between publicly available national data on the number of COVID-19 polymerase chain reaction tests and confirmed and recovered cases during May 2020-July 2021 and hospital data on the number of outpatients, inpatients, operations, and physiotherapy consultations were analyzed. In January 2021, the relationship between vaccination rate and orthopedic unit utilization was evaluated after vaccination campaign initiation. Multifactorial analysis revealed that an increased number of COVID-19-related deaths correlated with a decreased number of joint operations. Negative linear relationships were observed among confirmed and death cases with inpatient treatment and joint operation as well as recovered cases with inpatient treatment. Recovered cases with inpatient treatment and joint operation showed a positive linear relationship. Inpatient spine treatment showed a positive relationship with vaccination rates. The COVID-19 pandemic influenced orthopedic treatment in the Middle East, and vaccination campaigns facilitated inpatient spine treatment.
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The unique cage complexes [[(Me(4)en)Pd](3)(L)(2)](X)(6) (L = 1,3,5-tris(isonicotinoyloxyethyl)cyanurate; X(-) = BF(4)(-), ClO(4)(-)) were constructed. A single water molecule in a skeletal cage was reversibly associated and dissociated via a combination of the adequate space, polar environment, and conformational flexibility of the cage. In Suzuki-Miyaura C-C cross-coupling reactions, the cage complex showed significant catalytic activity along with the effects of the isolated single water molecule.
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Movimento (Física) , Compostos Organometálicos/química , Paládio/química , Água/química , Catálise , Modelos Moleculares , Conformação Molecular , TemperaturaRESUMO
We have synthesized Pt@silica/nickel phyllosilicate and Pt@silica yolk-shell nanostructures from NiPt@silica core-shell particles by simple chemical treatments. Silica coating of the NiPt alloy nanoparticles via the microemulsion method yielded spherical NiPt@silica core-shell nanoparticles with an average core diameter of 6.5 nm. Under a reflux condition in water, the core-shell structure transformed into Pt@silica yolk-shell nanoparticles with branched nickel phyllosilicate, which exhibited high surface area and large pore volume. The addition of hydrochloric acid selectively etched the nickel component from the NiPt cores and yielded Pt@silica yolk-shell nanoparticles with single-crystalline platinum cores. The average diameter of the metal cores was reduced to 4.5 nm. In both cases, the nickel components behaved as sacrificial spacers and successfully formed a vacancy between the metal cores and the silica hollow shells.
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Enzyme-linked immunosorbent assay (ELISA) has been developed as the ancillary diagnosis of bovine tuberculosis at ante-mortem to overcome the disadvantages of intradermal skin test. In this study, the antigenic proteins were purified, applied to bTB ELISA, and identified through proteomic analysis. Culture filtrate protein of Mycobacterium bovis was fractionated by MonoQ column chromatography, and examined the antigenicity by immunoblotting. The antigenic 20 kDa protein was in-gel digested and identified the antigenome by LTQ mass spectrometer and peptide match fingerprinting, which were MPB64, MPB70, MPB83, Fas, Smc, Nrp, RpoC, Transposase, LeuA, and MtbE. The 20 kDa protein exhibited the highest antigenicity to bTB positive cattle in ELISA and would be useful for bTB serological diagnosis.
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Antígenos de Bactérias , Proteínas de Bactérias , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Mycobacterium bovis/imunologia , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Mapeamento de Peptídeos/métodos , Mapeamento de Peptídeos/veterinária , Sensibilidade e EspecificidadeRESUMO
New functionalized CuO hollow nanospheres on acetylene black (CuO/AB) and on charcoal (CuO/C) have been found to be effective catalysts for C-S bond formation under microwave irradiation. CuO catalysts showed high catalytic activity with a wide variety of substituents which include electron-rich and electron-poor aryl iodides with thiophenols by the addition of two equivalents of K2CO3 as base in the absence of ligands.