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91.
Sergey Lyulin Pavel Balaev Koushik Narayan Subramanyam Denis Ivliev Abhishek Vasant Mundargi 《Clinics in Orthopedic Surgery》2022,14(1):148
BackgroundThe aim of this study was to explore the role of three-dimensional (3D) endoscopy in surgical management of metastatic disease of the dorsal and lumbar spine.MethodsThis is a prospective study on 33 patients (15 men and 18 women, mean age of 61.6 ± 8.9 years) with biopsy-proven metastatic disease of the spine managed by sequential/staged posterior decompression-stabilization, followed by 3D endoscopy-assisted anterior corpectomy and stabilization with a mesh cage. All patients had significant extradural compression or spinal instability or both. Sixteen patients had neurological deficits. Visual analog scale (VAS), Frenkel grade (neurological deficits), Karnofsky performance status scale, and the 36-item short-form health survey (SF-36) were used for assessment preoperatively and at 3, 6, and 12 months from surgery.ResultsAt a mean follow-up of 1.7 ± 0.7 years from surgery, 18 patients were alive. VAS showed significant improvement at the latest follow-up compared to preoperative levels (4.39 vs. 6.61, p = 0.001). Karnofsky status did not show any significant improvement. Frenkel grade improved in 5 patients, deteriorated in 4 patients, and remained unchanged in 24 patients. Regarding SF-36 parameters, general health showed deterioration, but role functioning—physical, role functioning—emotional, social functioning, and body pain showed statistically significant improvement. There was no change in physical health, viability, and mental health. Subjectively the surgeons felt better depth perception and smoother surgical experience with the 3D optics technology. The only complication was delayed wound healing in three patients who had a previous history of radiotherapy to the surgical site.Conclusions3D endoscopy is a valuable tool in the management of metastatic spinal disease requiring excision and reconstruction using the combined posterior and anterior approaches. These early results warrant confirmation with more data and longer follow-ups. 相似文献
92.
93.
Bulbena-Cabre Andrea DiGenova Patrick Sigel Pavel Dunn Norma Ramos Swift Ronnie Gorman 《International journal of mental health and addiction》2020,18(3):582-586
International Journal of Mental Health and Addiction - The use of synthetic cannabinoids (SCs) has been steadily increasing in recent years and represents a new class of substances of abuse.... 相似文献
94.
Formánek Martin Walderová Radana Baníková Šárka Chmelová Irina Formánková Debora Zeleník Karol Komínek Pavel 《European archives of oto-rhino-laryngology》2020,277(3):933-938
European Archives of Oto-Rhino-Laryngology - Electrical stimulation-supported therapy is an often used modality. However, it still belongs to experimental methods in the human larynx. Data are... 相似文献
95.
Vassiliy A. Medvedev Ilya E. Kolesnikov Pavel K. Olshin Mikhail D. Mikhailov Alina A. Manshina Daria V. Mamonova 《Materials》2022,15(7)
Optical materials doped with several lanthanides are unique in their properties and are widely used in various fields of science and technology. The study of these systems provides solutions for noncontact thermometry, bioimaging, sensing technology, and others. In this paper, we report on the demonstration of YVO4 nanoparticles doped with one, two, and three different rare earth ions (Tm3+, Er3+, and Nd3+). We discuss the morphology, structural properties, and luminescence behavior of particles. Luminescence decay kinetics reveal the energy transfer efficiency (up to 78%) for different ions under the selective excitation of individual ions. Thus, we found that the energy transition from Tm3+ is more favorable than from Er3+ while we did not observe any significant energy rearrangement in the samples under the excitation of Nd3+. The observed strong variation of REI lifetimes makes the suggested nanoparticles promising for luminescent labeling, anticounterfeiting, development of data storage systems, etc. 相似文献
96.
Sergey Grigoriev Anton Smirnov Nestor Washington Solis Pinargote Oleg Yanushevich Natella Kriheli Olga Kramar Yuri Pristinskiy Pavel Peretyagin 《Materials》2022,15(7)
This paper presents a study of Al2O3–ZrO2 (ZTA) nanocomposites with different contents of reduced graphene oxide (rGO). The influence of the rGO content on the physico-mechanical properties of the oxide composite was revealed. Graphene oxide was obtained using a modified Hummers method. Well-dispersed ZTA-GO nanopowders were produced using the colloidal processing method. Using spark plasma sintering technology (SPS), theoretically dense composites were obtained, which also reduced GO during SPS. The microstructure, phase composition, and physico-mechanical properties of the sintered composites were studied. The sintered ZTA composite with an in situ reduced graphene content of 0.28 wt.% after the characterization showed improved mechanical properties: bending strength was 876 ± 43 MPa, fracture toughness—6.8 ± 0.3 MPa·m1/2 and hardness—17.6 ± 0.3 GPa. Microstructure studies showed a uniform zirconia distribution in the ZTA ceramics. The study of the electrical conductivity of reduced graphene oxide-containing composites showed electrical conductivity above the percolation threshold with a small content of graphene oxide (0.28 wt.%). This electrical conductivity makes it possible to produce sintered ceramics by electrical discharge machining (EDM), which significantly reduces the cost of manufacturing complex-shaped products. Besides improved mechanical properties and EDM machinability, 0.28 wt.% rGO composites demonstrated high resistance to hydrothermal degradation. 相似文献
97.
An efficient and versatile synthesis of the naturally occurring C-prenylated stilbenoid methyl ethers and their synthetic analogues is presented. The synthesis represents a six step convergent process including an optimised C-prenylation method. Furthermore, during the demethylation process, six new dihydro-benzopyranyl derivatives were obtained and isolated.An efficient and versatile synthesis of the naturally occurring C-prenylated stilbenoid methyl ethers and synthetic analogs has been developed. 相似文献
98.
Several strategies have been developed to fight viral infections, not only in humans but also in animals and plants. Some of them are based on the development of efficient vaccines, to target the virus by developed antibodies, others focus on finding antiviral compounds with activities that inhibit selected virus replication steps. Currently, there is an increasing number of antiviral drugs on the market; however, some have unpleasant side effects, are toxic to cells, or the viruses quickly develop resistance to them. As the current situation shows, the combination of multiple antiviral strategies or the combination of the use of various compounds within one strategy is very important. The most desirable are combinations of drugs that inhibit different steps in the virus life cycle. This is an important issue especially for RNA viruses, which replicate their genomes using error-prone RNA polymerases and rapidly develop mutants resistant to applied antiviral compounds. Here, we focus on compounds targeting viral structural capsid proteins, thereby inhibiting virus assembly or disassembly, virus binding to cellular receptors, or acting by inhibiting other virus replication mechanisms. This review is an update of existing papers on a similar topic, by focusing on the most recent advances in the rapidly evolving research of compounds targeting capsid proteins of RNA viruses. 相似文献
99.
Kristina Kverkov Lucie Marhounov Alexandra Polonyiov Martin Kocourek Yicheng Zhang Seweryn Olkowicz Barbora Strakov Zuzana Pavelkov Roman Vodi
ka Daniel Frynta Pavel Nmec 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(11)
Reconstructing the evolution of brain information-processing capacity is paramount for understanding the rise of complex cognition. Comparative studies of brain evolution typically use brain size as a proxy. However, to get a less biased picture of the evolutionary paths leading to high cognitive power, we need to compare brains not by mass but by numbers of neurons, which are their basic computational units. This study reconstructs the evolution of brains across amniotes by directly analyzing neuron numbers by using the largest dataset of its kind and including essential data on reptiles. We show that reptiles have not only small brains relative to body size but also low neuronal densities, resulting in average neuron numbers over 20 times lower than those in birds and mammals of similar body size. Amniote brain evolution is characterized by the following four major shifts in neuron–brain scaling. The most dramatic increases in brain neurons occurred independently with the appearance of birds and mammals, resulting in convergent neuron scaling in the two endotherm lineages. The other two major increases in the number of neurons happened in core land birds and anthropoid primates, which are two groups known for their cognitive prowess. Interestingly, relative brain size is associated with relative neuronal cell density in reptiles, birds, and primates but not in other mammals. This has important implications for studies using relative brain size as a proxy when looking for evolutionary drivers of animal cognition.The evolution of cognitive capacity or “intelligence” and its underlying neural substrate has been of long-standing interest to biologists. Great strides have been made in understanding the evolution of brain size in vertebrates, with studies analyzing data on thousands of species (1–3). Since larger animals have larger brains but are not necessarily smarter, most studies of cognitive evolution use relative brain size (corrected for body size), which is thought to reflect extra neurons beyond those needed for controlling the body (4). We now have a good idea where major changes in brain–body scaling happened within birds (2) and mammals (3), and it is also clear that both mammals and birds have relatively larger brains than nonavian sauropsids (hereafter referred to as reptiles), although this has been rarely formally quantified because data on reptilian brain sizes are scarce (5).However, we still lack a clear picture of the evolution of actual brain processing capacity. This is because the same increase in relative brain size can be reached by different evolutionary paths, not always involving actual brain enlargement, and might often result from selection on body size (3). Moreover, similarly sized brains of distantly related species can harbor substantially different numbers of neurons overall and in major brain parts (6, 7). These two caveats invalidate the very idea that we can estimate extra neurons and glean information about cognitive capacity from absolute or relative brain size alone.This capacity is better determined by the number of neurons in the brain or specific brain parts (although their relative importance is still debated), their connections, interneuronal distance, and axonal conduction velocity (8, 9). Unlike brain size, though, these measures are not readily available for a sufficient number of species to be of practical use. Nevertheless, thanks to methodological advances (10), neuronal scaling rules (the allometric relationship between brain mass and neuron numbers) have now been determined for eight high-level mammalian clades (6, 11–13) as well as for a limited sampling of birds (14, 15).To get the big picture of amniote brain evolution, we have to include data on nonavian reptiles. The deepest split in amniote evolution occurred between the synapsid lineage, leading to mammals, and the sauropsid lineage, including reptiles and birds. We cannot tell if similarities between birds and mammals are due to shared ancestry or convergent evolution without considering reptiles. Yet, the dearth of quantitative data on reptile brains is striking—brain mass is available for 183 species (5, 16), compared to thousands for birds and mammals, and neuron numbers are known for a mere 4 reptile species (17–19).Taken together, to understand the evolution of brain processing capacity in amniotes, we need to include nonavian reptiles, consider changes in both brain–body and neuron–brain scaling, and examine the allocation of neurons to different brain parts. In this study, we provide these much needed data and reconstruct the big picture of brain evolution in amniotes in terms of neuron numbers. 相似文献
100.
Selfish supernumerary chromosome reveals its origin as a mosaic of host genome and organellar sequences 总被引:1,自引:0,他引:1
MM Martis S Klemme AM Banaei-Moghaddam FR Blattner J Macas T Schmutzer U Scholz H Gundlach T Wicker H Simková P Novák P Neumann M Kubaláková E Bauer G Haseneyer J Fuchs J Dolezel N Stein KF Mayer A Houben 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(33):13343-13346
Supernumerary B chromosomes are optional additions to the basic set of A chromosomes, and occur in all eukaryotic groups. They differ from the basic complement in morphology, pairing behavior, and inheritance and are not required for normal growth and development. The current view is that B chromosomes are parasitic elements comparable to selfish DNA, like transposons. In contrast to transposons, they are autonomously inherited independent of the host genome and have their own mechanisms of mitotic or meiotic drive. Although B chromosomes were first described a century ago, little is known about their origin and molecular makeup. The widely accepted view is that they are derived from fragments of A chromosomes and/or generated in response to interspecific hybridization. Through next-generation sequencing of sorted A and B chromosomes, we show that B chromosomes of rye are rich in gene-derived sequences, allowing us to trace their origin to fragments of A chromosomes, with the largest parts corresponding to rye chromosomes 3R and 7R. Compared with A chromosomes, B chromosomes were also found to accumulate large amounts of specific repeats and insertions of organellar DNA. The origin of rye B chromosomes occurred an estimated ~1.1-1.3 Mya, overlapping in time with the onset of the genus Secale (1.7 Mya). We propose a comprehensive model of B chromosome evolution, including its origin by recombination of several A chromosomes followed by capturing of additional A-derived and organellar sequences and amplification of B-specific repeats. 相似文献