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1.
ChemSusChem ; 17(4): e202400133, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38264978

RESUMO

Invited for this month's cover is the group of Javier Pérez-Ramírez at ETH Zürich, which collaborated with the group of Tsvetelina Merdzhanova at Forschungszentrum Jülich. The image shows how artificial leaves, able to recycle carbon dioxide into syngas of variable composition, could be integrated with chemical plants. The Research Article itself is available at 10.1002/cssc.202301398.

2.
ChemSusChem ; 17(4): e202301398, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-37975726

RESUMO

Artificial leaves (a-leaves) can reduce carbon dioxide into syngas using solar power and could be combined with thermo- and biocatalytic technologies to decentralize the production of valuable products. By providing variable CO : H2 ratios on demand, a-leaves could facilitate optimal combinations and control the distribution of products in most of these hybrid systems. However, the current design procedures of a-leaves concentrate on achieving high performance for a predetermined syngas composition. This study demonstrates that incorporating the electrolyte flow as a design variable enables flexible production without compromising performance. The concept was tested on an a-leaf using a commercial cell, a Cu2 O:Inx cathodic catalyst, and an inexpensive amorphous silicon thin-film photovoltaic module. Syngas with CO : H2 ratio in the range of 1.8-2.3 could be attained with only 2 % deviation from the optimal cell voltage and controllable solely by catholyte flow. These features could be beneficial for downstream technologies such as Fischer-Tropsch synthesis and anaerobic fermentation.

3.
Trials ; 24(1): 451, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37430281

RESUMO

BACKGROUND: The necessity of spinal segment fusion after decompression is one of the most controversial and unresolved issues in single-level lumbar spinal stenosis surgery. To date, only one trial carried out 15 years ago focused on this problem. The key purpose of the current trial is to compare the long-term clinical results of the two surgical methods (decompression vs. decompression and fusion) in patients with single-level lumbar stenosis. METHODS: This study is focused on the non-inferior clinical results of decompression compared with the standard fusion procedure. In the decompression group, the spinous process, the interspinous and supraspinous ligaments, part of the facet joints, and corresponding parts of the vertebral arch are to be preserved intact. In the fusion group, decompression is to be supplemented with transforaminal interbody fusion. Participants meeting the inclusion criteria will be randomly divided into two equal groups (1:1), depending on the surgical method. The final analysis will include 86 patients (43 per group). The primary endpoint is Oswestry Disability Index dynamics at the end of the 24-month follow-up compared to the baseline level. Secondary outcomes included those estimated using the SF-36 scale, EQ-5D-5L, and psychological scales. Additional parameters will include sagittal balance of the spine, fusion results, total cost of surgery, and hospital stay followed by two-year treatment. Follow-up examinations will be performed at 3, 6, 12, and 24 months DISCUSSION: Authors suggest that this study will improve the evidence for application of various surgical techniques for lumbar spine stenosis surgery and verify the existing protocol for surgical management. TRIAL REGISTRATION: ClinicalTrials.gov NCT05273879 . Registered on March 10, 2022.


Assuntos
Procedimentos Neurocirúrgicos , Coluna Vertebral , Humanos , Constrição Patológica , Suplementos Nutricionais , Descompressão , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
4.
Nanomaterials (Basel) ; 13(10)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37242000

RESUMO

This paper proposes two different approaches to studying resistive switching of oxide thin films using scratching probe nanolithography of atomic force microscopy (AFM). These approaches allow us to assess the effects of memristor size and top-contact thickness on resistive switching. For that purpose, we investigated scratching probe nanolithography regimes using the Taguchi method, which is known as a reliable method for improving the reliability of the result. The AFM parameters, including normal load, scratch distance, probe speed, and probe direction, are optimized on the photoresist thin film by the Taguchi method. As a result, the pinholes with diameter ranged from 25.4 ± 2.2 nm to 85.1 ± 6.3 nm, and the groove array with a depth of 40.5 ± 3.7 nm and a roughness at the bottom of less than a few nanometers was formed. Then, based on the Si/TiN/ZnO/photoresist structures, we fabricated and investigated memristors with different spot sizes and TiN top contact thickness. As a result, the HRS/LRS ratio, USET, and ILRS are well controlled for a memristor size from 27 nm to 83 nm and ranged from ~8 to ~128, from 1.4 ± 0.1 V to 1.8 ± 0.2 V, and from (1.7 ± 0.2) × 10-10 A to (4.2 ± 0.6) × 10-9 A, respectively. Furthermore, the HRS/LRS ratio and USET are well controlled at a TiN top contact thickness from 8.3 ± 1.1 nm to 32.4 ± 4.2 nm and ranged from ~22 to ~188 and from 1.15 ± 0.05 V to 1.62 ± 0.06 V, respectively. The results can be used in the engineering and manufacturing of memristive structures for neuromorphic applications of brain-inspired artificial intelligence systems.

5.
Molecules ; 28(3)2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36771083

RESUMO

When creating titanium-containing bone implants, the bioactive coatings that promote their rapid engraftment are important. The engraftment rate of titanium implants with bone tissue depends significantly on the modification of the implant surface. It is achieved by changing either the relief or the chemical composition of the surface layer, as well as a combination of these two factors. In this work, we studied the creation of composite coatings with a two-level (the micro- and nanolevel) hierarchy of the surface relief, which have bioactive and bactericidal properties, which are promising for bone implantation. Using the developed non-lithographic template electrochemical synthesis, a composite coating on titanium with a controlled surface structure was created based on an island-type TiO2 film, silver and hydroxyapatite (HAp). This TiO2/Ag/HAp composite coating has a developed surface relief at the micro- and nanolevels and has a significant cytological response and the ability to accelerate osteosynthesis, and also has an antibacterial effect. Thus, the developed biomaterial is suitable for production of dental and orthopedic implants with improved biomedical properties.


Assuntos
Materiais Revestidos Biocompatíveis , Titânio , Titânio/farmacologia , Titânio/química , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/química , Osso e Ossos , Antibacterianos/farmacologia , Antibacterianos/química , Durapatita/farmacologia , Durapatita/química , Propriedades de Superfície
6.
IEEE/ACM Trans Comput Biol Bioinform ; 20(3): 1700-1712, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35849662

RESUMO

MAGUS is a recent multiple sequence alignment method that provides excellent accuracy on large challenging datasets. MAGUS uses divide-and-conquer: it divides the sequences into disjoint sets, computes alignments on the disjoint sets, and then merges the alignments using a technique it calls the Graph Clustering Method (GCM). To understand why MAGUS is so accurate, we show that GCM is a good heuristic for the NP-hard MWT-AM problem (Maximum Weight Trace, adapted to the Alignment Merging problem). Our study, using both biological and simulated data, establishes that MWT-AM scores correlate very well with alignment accuracy and presents improvements to GCM that are even better heuristics for MWT-AM. This study suggests a new direction for large-scale MSA estimation based on improved divide-and-conquer strategies, with the merging step based on optimizing MWT-AM. MAGUS and its enhanced versions are available at https://github.com/vlasmirnov/MAGUS.


Assuntos
Algoritmos , Software , Alinhamento de Sequência , Heurística , Análise por Conglomerados
7.
Consort Psychiatr ; 4(4): 39-47, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38618635

RESUMO

BACKGROUND: Interest in the issue of childhood autism has surged in the recent decades. At the same time, despite the significant progress achieved in understanding the etiological and pathogenetic aspects of the condition, effective ways to treat it have continued to elude us. Stem cell therapy appears to hold great promise in the treatment and rehabilitation of patients with both neurological diseases (cerebral palsy, hydrocephalus) and mental disorders (autism, schizophrenia). METHODS: This article presents a case report describing the use of nucleated cord blood cells in a patient with regressive autism and resistance to standard therapies. The child's condition was assessed before treatment and 6 and 12 months after. RESULTS: Clinical observation, psychometric, and instrumental diagnostic methods led to a significant improvement in the child's condition in the form of perception development, reduction of somatosensory disorders, normalization of emotional status, and a development of social and communication skills. CONCLUSION: We assume that the result obtained may be associated with the normalization of the immunological status of our patient thanks to the cord blood cells therapy and consider it necessary to conduct further studies into the effectiveness of the method, taking the pathogenic mechanisms of autism into account.

8.
Molecules ; 27(20)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36296380

RESUMO

The article is devoted to heterocyclization of bis(2-chloroprop-2-en-1-yl)sulfide which proceeds in hydrazine hydrate-alkali medium and leads to formation of thiophene and pyrrole derivatives: previously described 4,5,9,10-tetrahydrocycloocta[1,2-c;5,8-c']dithiophene, as well as unknown hydrazone of 5-methylidene-3-methyldihydrothiophen-2-one and 1-amino-2-(propynylsulfanylpropenylsulfanyl)-3,5-dimethylpyrrole. Tentative mechanisms for the formation of the heterocyclic products are discussed. Obtained hydrazone of 5-methylidene-3-methyldihydrothiophen-2-one was used for the synthesis of a range of azine derivatives and in oxidation process with SeO2. The found reactions open up expedient approaches to the formation of various hardly accessible thiophene and pyrrole compounds from 2,3-dichloropropene and elemental sulfur as starting reagents.


Assuntos
Pirróis , Tiofenos , Hidrazonas , Enxofre , Sulfetos , Álcalis
9.
World Neurosurg ; 167: e1169-e1184, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36089281

RESUMO

OBJECTIVE: The main purpose of this systematic review and meta-analysis was to estimate the incidence of implant-associated complications and fusion rates for the Goel-Harms technique (GHT) and to show potential factors affecting the complications and nonunion development. METHODS: A systematic search of the PubMed database according to PRISMA guidance was performed. The main inclusion criteria comprised description of fusion rate and/or implant-associated complications rate. RESULTS: This systematic review included 86 articles focused on the results of surgery in 4208 patients. The rate of screw-related complications was as follows: 1) vertebral artery (VA) injury, 2.8%; 2) screw malposition in the direction of the VA, 5.8%; and 3) C2 nerve root irritation, 6.1%. The nonunion rate was 4.2%. Transpedicular screw insertion to the C1 and C2 vertebrae were the safest regarding VA injury and correlated with lower blood loss. For C1-C2 fusion, there was no statistical difference for the different bone graft localization. C2 nerve root irritation rate did not depend on screw insertion technique. The use of a freehand technique did not correlate with a high rate of screw-related complications. CONCLUSIONS: The Goel-Harms technique is a promising method of C1-C2 fusion, with a relatively low nonunion and VA injury rate. It can be performed safely without C-arm or navigation system assistance. Transpedicular screw insertion trajectories to the C1 and C2 vertebrae were safest regarding VA injury and blood loss volume. Further comparative studies of various C1-C2 stabilization methods with a high level of significance should be carried out to identify the optimal approach.


Assuntos
Articulação Atlantoaxial , Instabilidade Articular , Fusão Vertebral , Humanos , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Articulação Atlantoaxial/cirurgia , Vértebras Cervicais/cirurgia , Parafusos Ósseos , Complicações Pós-Operatórias , Instabilidade Articular/cirurgia
10.
Phys Rev Lett ; 128(21): 212002, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35687465

RESUMO

We compute the photon-quark and Higgs-gluon form factors to four-loop order within massless perturbative quantum chromodynamics. Our results constitute ready-to-use building blocks for N^{4}LO cross sections for Drell-Yan processes and gluon-fusion Higgs boson production at the LHC. We present complete analytic expressions for both form factors and show several of the most complicated master integrals.

11.
Nanomaterials (Basel) ; 12(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35159799

RESUMO

This article presents the results of experimental studies of the impact of electrode material and the effect of nanoscale film thickness on the resistive switching in forming-free nanocrystalline ZnO films grown by pulsed laser deposition. It was demonstrated that the nanocrystalline ZnO film with TiN, Pt, ZnO:In, and ZnO:Pd bottom electrodes exhibits a nonlinear bipolar effect of forming-free resistive switching. The sample with Pt showed the highest resistance values RHRS and RLRS and the highest value of Uset = 2.7 ± 0.4 V. The samples with the ZnO:In and ZnO:Pd bottom electrode showed the lowest Uset and Ures values. An increase in the number of laser pulses from 1000 to 5000 was shown to lead to an increase in the thickness of the nanocrystalline ZnO film from 7.2 ± 2.5 nm to 53.6 ± 18.3 nm. The dependence of electrophysical parameters (electron concentration, electron mobility, and resistivity) on the thickness of the forming-free nanocrystalline ZnO film for the TiN/ZnO/W structure was investigated. The endurance test and homogeneity test for TiN/ZnO/W structures were performed. The structure Al2O3/TiN/ZnO/W with a nanocrystalline ZnO thickness 41.2 ± 9.7 nm was shown to be preferable for the manufacture of ReRAM and memristive neuromorphic systems due to the highest value of RHRS/RLRS = 2307.8 ± 166.4 and low values of Uset = 1.9 ± 0.2 V and Ures = -1.3 ± 0.5 V. It was demonstrated that the use of the TiN top electrode in the Al2O3/TiN/ZnO memristor structure allowed for the reduction in Uset and Ures and the increase in the RHRS/RLRS ratio. The results obtained can be used in the manufacturing of resistive-switching nanoscale devices for neuromorphic computing based on the forming-free nanocrystalline ZnO oxide films.

12.
World Neurosurg ; 161: e319-e338, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35134580

RESUMO

OBJECTIVE: Phase 1 of the SUBSCI I/IIa (Systemic Umbilical Cord Blood Administration in Patients with Acute Severe Contusion Spinal Cord Injury) study focused on safety and primary efficacy of multiple systemic infusions of allogeneic unrelated human umbilical cord blood mononuclear cells in patients with severe acute spinal cord contusion having severe neurologic deficit. The primary end point was safety. The secondary end point was the restoration of motor and sensory function in lower limbs within a 1-year period. METHODS: Ten patients with acute contusion spinal cord injury (SCI) and American Spinal Injury Association (ASIA) level A/B deficit were enrolled into phase 1. Patients were treated with 4 infusions of group-matched and rhesus-matched cord blood samples after primary surgery within 3 days after SCI. All patients were followed up for 12 months after SCI. Safety was assessed using adverse events classification depending on severity and relation to cell therapy. Primary efficacy was assessed using dynamics of deficit (ASIA scale). RESULTS: The overall number of adverse events reached 419 in 10 patients. Only 2 were estimated as possibly related to cell therapy, and the remaining 417 were definitely unrelated. Both adverse events were mild and clinically insignificant. No signs of immunization were found in participants. Analysis of clinical outcomes also showed that cell therapy promotes significant functional restoration of motor function. CONCLUSIONS: The data obtained suggest that systemic administration of allogeneic, non-human leukocyte antigen-matched human umbilical cord blood is safe and shows primary efficacy in adults with severe acute contusion SCI and ASIA level A/B deficit.


Assuntos
Contusões , Transplante de Células-Tronco Hematopoéticas , Traumatismos da Medula Espinal , Contusões/terapia , Sangue Fetal , Humanos , Contagem de Leucócitos , Traumatismos da Medula Espinal/terapia
13.
Gels ; 7(4)2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34842685

RESUMO

This work is devoted to the development of non-lithographic template methods of synthesis. These methods have a significant advantage in terms of structure formation: there is no need to design and produce masks, which greatly simplifies the process, and more of them can work with nonplanar substrates. The purpose of this study was to reveal the conditions for the synthesis of titanium dioxide xerogel films of different topologies as well as to develop a technique for non-lithographic template electrochemical synthesis of micron metal particles arrays and to study the structure of the resulting coatings. The films were deposited on the surface of substrates via dip coating. Specific topology of the films was achieved by template sol-gel synthesis. Their structures were analyzed by SEM and XRD. Template synthesis of metal micro particles were realized by pulsed electrochemical deposition of metals into the perforations of xerogel films. Obtained materials were analyzed by SEM and XRD; the element distribution on the surface was determined by the EDS detector of SEM. Based on the analysis results, we suggest the mechanisms of formation of the xerogel topology and proved the efficiency of pulsed electrodeposition for template synthesis of micron particles arrays.

14.
PLoS Comput Biol ; 17(10): e1008950, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34613974

RESUMO

Multiple sequence alignment tools struggle to keep pace with rapidly growing sequence data, as few methods can handle large datasets while maintaining alignment accuracy. We recently introduced MAGUS, a new state-of-the-art method for aligning large numbers of sequences. In this paper, we present a comprehensive set of enhancements that allow MAGUS to align vastly larger datasets with greater speed. We compare MAGUS to other leading alignment methods on datasets of up to one million sequences. Our results demonstrate the advantages of MAGUS over other alignment software in both accuracy and speed. MAGUS is freely available in open-source form at https://github.com/vlasmirnov/MAGUS.


Assuntos
Biologia Computacional/métodos , Alinhamento de Sequência/métodos , Análise de Sequência/métodos , Software , Algoritmos , Bases de Dados Genéticas
15.
Phys Chem Chem Phys ; 23(39): 22375-22383, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34608477

RESUMO

An aprotic lithium-air battery is a promising candidate for next-generation energy storage systems, but its practical performance is still low. The addition of water to an electrolyte can substantially increase the capacity and round-trip efficiency of batteries. However, fundamental mechanisms of the water impact are still far from being fully understood. To contribute to this issue, we studied by molecular dynamics simulations the effect of water additives on the behaviour of discharge intermediates Li+ and O2- in two frequently used solvents: dimethoxyethane (DME) and dimethyl sulfoxide (DMSO). We have estimated the structures of the solvation shells around Li+ and O2- ions, and the residence times of various electrolyte components inside the solvation shells depending on the concentration of water additives. Furthermore, we have estimated the rate and the equilibrium of the Li+ and O2- association. Our results reveal that water additives in electrolytes shift the equilibrium of the association reaction toward soluble Li+ and O2- ions in both DME and DMSO. These data argue for the view that water promotes the solution discharge mechanism, thus increasing the capacity. Moreover, we show that water accelerates the kinetics of the association reaction due to the decrease of the stability of Li+ and O2- solvation shells. This may explain the reduced discharge overpotential when water is added.

16.
Nanomaterials (Basel) ; 11(10)2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34684939

RESUMO

The development of new composites with improved functional properties is the important task of modern materials science. The composites must be structurally organized to provide improved properties. For metal-ceramic composites, there is a need for a uniform distribution of the dispersed ceramic phase in the bulk metallic matrix The modification of the dispersed ceramic phase surface with a metal coating is one of the more effective ways to accomplish this. Particularly, in this work, the conditions of Ni nanolayer deposition on titanium carbide (TiC) particles were studied. The goal was to create core-shell particles with a thickness of the Ni coating on TiC not exceeding 90 nm. Preliminary work was also carried out to study the effect of the dispersed phase composition on the mechanical properties of the composite with an Al matrix.

17.
Materials (Basel) ; 14(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34500943

RESUMO

One of the significant limitations of the pulsed laser deposition method in the mass-production-technologies of micro- and nanoelectronic and molecular device electronic fabrication is the issue of ensuring deposition of films with uniform thickness on substrates with large diameter (more than 100 mm) since the area of the laser spot (1-5 mm2) on the surface of the ablated target is incommensurably smaller than the substrate area. This paper reports the methodology that allows to calculate the distribution profile of the film thickness over the surface substrate with a large diameter, taking into account the construction and technological parameters of the pulsed laser deposition equipment. Experimental verification of the proposed methodology showed that the discrepancy with the experiment does not exceed 8%. The modeling of various technological parameters influence on the thickness uniformity has been carried out. Based on the modeling results, recommendations and parameters are proposed for manufacturing uniform thickness films. The results allow for increasing the film thickness uniformity with the thickness distribution < 5% accounts for ~ 31% of 300 mm diameter substrate.

18.
Chem Commun (Camb) ; 57(39): 4823-4826, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33982701

RESUMO

A reaction of intramolecularly disposed phosphonium and phenoxide (or thiophenoxide) fragments with difluorocarbene affording all-carbon λ5-phosphoranes is described. The presence of electron-withdrawing CHF2-groups at the phosphonium center is important for the phosphorane formation. In a phosphorane, both phenyl groups located in the equatorial positions undergo 1,2-P,C migration under thermal conditions.

19.
J Org Chem ; 86(10): 7163-7178, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33944564

RESUMO

A novel approach to the preparation of imidazole-substituted cyclic iodonium salts has been developed via the oxidative cyclization of 1-phenyl-5-iodoimidazole using a cheap and available Oxone/H2SO4 oxidative system. The structure of the new polycyclic heteroarenes has been confirmed by single-crystal X-ray diffractometry, revealing the characteristic structure features for cyclic iodonium salts. The newly produced imidazole-flanked cyclic iodonium compounds were found to readily engage in a heterocyclization reaction with elemental sulfur, affording benzo[5,1-b]imidazothiazoles in good yields.


Assuntos
Imidazóis , Sais , Ciclização , Oxirredução
20.
Global Spine J ; 11(1): 99-107, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32875837

RESUMO

STUDY DESIGN: A multicenter observational survey. OBJECTIVE: To quantify and compare inter- and intraobserver reliability of the subaxial cervical spine injury classification (SLIC) and the cervical spine injury severity score (CSISS) in a multicentric survey of neurosurgeons with different experience levels. METHODS: Data concerning 64 consecutive patients who had undergone cervical spine surgery between 2013 and 2017 was evaluated, and we surveyed 37 neurosurgeons from 7 different clinics. All raters were divided into 3 groups depending on their level of experience. Two assessment procedures were performed. RESULTS: For the SLIC, we observed excellent agreement regarding management among experienced surgeons, whereas agreement among less experienced neurosurgeons was moderate and almost twice as unlikely. The sensitivity of SLIC relating to treatment tactics reached as high as 92.2%. For the CSISS, agreement regarding management ranged from medium to substantial, depending on a neurosurgeon's experience. For less experienced neurosurgeons, the level of agreement concerning surgical management was the same as for the SLIC in not exceeding a moderate level. However, this scale had insufficient sensitivity (slightly exceeding 50%). The reproducibility of both scales was excellent among all raters regardless of their experience level. CONCLUSIONS: Our study demonstrated better management reliability, sensitivity, and reproducibility for the SLIC, which provided moderate interrater agreement with moderate to excellent intraclass correlation coefficient indicators for all raters. The CSISS demonstrated high reproducibility; however, large variability in answers prevented raters from reaching a moderate level of agreement. Magnetic resonance imaging integration may increase sensitivity of CSISS in relation to fracture management.

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