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1.
Materials (Basel) ; 17(2)2024 Jan 13.
Article En | MEDLINE | ID: mdl-38255575

In this article, the downsizing of functional Heusler alloys is discussed, focusing on the published results dealing with Heusler alloy nanowires. The theoretical information inspired the fabrication of novel nanowires that are presented in the results section of the article. Three novel nanowires were fabricated with the compositions of Ni66Fe21Ga13, Ni58Fe28In14, and Ni50Fe31Sn19. The Ni66Fe21Ga13 nanowires were fabricated, aiming to improve the stoichiometry of previous functional Ni-Fe-Ga Heusler nanomaterials with a functional behavior above room temperature. They exhibit a phase transition at the temperature of ≈375 K, which results in a magnetocaloric response of |ΔSM| ≈ 0.12 J·kg-1·K-1 at the magnetic field change of only µ0ΔH = 1 T. Novel Heusler alloy Ni58Fe28In14 nanowires, as well as Ni50Fe31Sn19 nanowires, are analyzed for the first time, and their magnetic properties are discussed, introducing a simple electrochemical approach for the fabrication of nanodimensional alloys from mutually immiscible metals.

2.
J Neurosurg Sci ; 68(1): 13-21, 2024 Feb.
Article En | MEDLINE | ID: mdl-36705618

BACKGROUND: Tumorous involvement of the second cervical vertebra is an infrequent, but severe disease. Primary tumors and solitary metastases can be addressed by a radical procedure, a complete removal of the whole compartment. The second cervical vertebra has a highly complex anatomy, and its operation requires considerable surgical skills. The aim of this retrospective study is to present technical aspects of complete resection of C2 for tumor indications, clinical and radiological evaluation of our group of patients and comparison of results of recent reports on surgery in this region in the literature. METHODS: Between 2006 and 2019 we performed 10 total resections of C2 for primary bone tumor or solitary metastasis at our department. Operation was indicated for chordoma in 4 cases and for other diagnoses (plasmacytoma, EWSA, metastases of papillary thyroid carcinoma, medullary thyroid carcinoma, lung carcinoma and sinonasal carcinoma) in one case each. The operative procedure was in all cases performed in two steps. It always started with the posterior approach. The anterior procedure was scheduled according to the patient's condition after an average interval of 16.9 days (range 7-21). RESULTS: A stable upper cervical spine was achieved in all patients. A solid bone fusion over the whole instrumentation was present in all living patients and they returned to their preoperative activity level. By the final follow-up 6 patients died: one patient died on the 5th postop day because of diffuse uncontrollable bleeding from surgical wound, three patients died of generalization of the underlying disease and two patients due to complications associated with local recurrence of the disease. In addition to regular follow-ups, the surviving patients (N.=4) were also examined upon completion of the study, i.e., on average 91 months (range 17-179 months) postoperatively. With exclusion of an early deceased patient, the average follow-up period of deceased patients was 34.6 months (range 9-55) (N.=5). The average follow-up of the whole group of patients was 59,7 months (N.=9). CONCLUSIONS: Total spondylectomy of C2 is an exceptional surgical procedure associated with risk of serious complications but offers chance for a complete recovery of the patient. Defining indications accurately, especially in solitary metastases, is very difficult even with current level of imaging and other testing. The quality of life of long-term surviving patients in our study was not significantly impacted.


Carcinoma, Neuroendocrine , Spinal Neoplasms , Humans , Retrospective Studies , Quality of Life , Spinal Neoplasms/surgery , Spinal Neoplasms/pathology , Cervical Vertebrae/surgery , Cervical Vertebrae/pathology , Treatment Outcome
3.
Acta Neurochir (Wien) ; 165(9): 2633-2640, 2023 09.
Article En | MEDLINE | ID: mdl-37347294

INTRODUCTION AND PURPOSE: With current imaging modalities and diagnostic tests, identifying pain generators in patients with non-specific chronic low back pain (CLBP) is difficult. There is growing evidence of the effectiveness of SPECT/CT examination in diagnosing the source of pain in the spine. The study aims to investigate the effect of posterior interbody fusion on a single-level SPECT/CT positive lumbar degenerative disc disease (DDD). MATERIAL AND METHODS: This is a prospective study of patients with chronic low back pain (CLBP) operated on for a single-level SPECT/CT positive DDD. Primary outcomes were changes in visual analogue scale (VAS) scores and the Oswestry Disability Index (ODI). Secondary outcomes were complications, return to work, satisfaction and willingness to re-undergo surgery. RESULTS: During a 3-year period, 38 patients underwent single-level fusion surgery. The mean preoperative VAS score of 8.4 (± 1.1) decreased to 3.2 (± 2.5, p < 0.001) and the mean preoperative ODI of 51.5 (± 7.3) improved to 20.7 (± 14.68, p < 0.001) at a 2-year follow-up. A minimum clinically important difference (30% reduction in VAS and ODI) was achieved in 84.2% of patients. Some 71% of patients were satisfied with the surgery results and 89.4% would undergo surgery again. There were four complications, and two patients underwent revision surgery. Some 82.9% of patients returned to work. CONCLUSION: Fusion for one-level SPECT/CT positive lumbar DDD resulted in substantial clinical improvement and satisfaction with surgical treatment. Therefore, SPECT/CT imaging could be useful in assessing patients with CLBP, especially those with unclear MRI findings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04876586.


Intervertebral Disc Degeneration , Low Back Pain , Spinal Fusion , Humans , Intervertebral Disc Degeneration/diagnostic imaging , Intervertebral Disc Degeneration/surgery , Low Back Pain/diagnostic imaging , Low Back Pain/etiology , Low Back Pain/surgery , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/surgery , Prospective Studies , Retrospective Studies , Spinal Fusion/methods , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed , Treatment Outcome
4.
World Neurosurg ; 173: 65-78, 2023 May.
Article En | MEDLINE | ID: mdl-36803686

BACKGROUND: Chronic neck or back pain is a common clinical problem. The most likely cause is degenerative change, whereas other causes are relatively rare. There is increasing evidence on using hybrid single-photon emission computed tomography (SPECT) to identify the pain generator in spine degeneration. This systematic review explores the diagnostic and therapeutic evidence on chronic neck or back pain examined by SPECT. METHODS: This review is reported in accordance with the PRISMA guidelines. In October 2022, we searched the following sources: MEDLINE, Embase, CINAHL, SCOPUS, and 3 other sources. Titles and abstracts were screened and classified into diagnostic studies, facet block studies, and surgical studies. We synthesized the results narratively. RESULTS: The search yielded 2347 records. We identified 10 diagnostic studies comparing SPECT or SPECT/computed tomography (CT) with magnetic resonance imaging, CT, scintigraphy, or clinical examination. Furthermore, we found 8 studies comparing the effect of facet block intervention in SPECT-positive and SPECT-negative patients with cervicogenic headache, neck pain, and lower back pain. Five surgical studies describing the effect of fusion for facet arthropathy in the craniocervical junction, subaxial cervical spine, or the lumbar spine were identified. CONCLUSIONS: According to the available literature, a positive finding on SPECT in facet arthropathy is associated with a significantly higher facet blockade effect. Surgical treatment of positive findings has a good effect, but this has not been confirmed by controlled studies. SPECT/CT might therefore be a useful method in the evaluation of patients with neck or back pain, especially in cases of unclear findings or multiple degenerative changes.


Intervertebral Disc Degeneration , Joint Diseases , Humans , Back Pain/diagnostic imaging , Back Pain/etiology , Tomography, Emission-Computed, Single-Photon/methods , Neck Pain/etiology , Neck Pain/complications , Intervertebral Disc Degeneration/complications , Intervertebral Disc Degeneration/diagnostic imaging , Intervertebral Disc Degeneration/surgery , Lumbar Vertebrae/surgery
5.
PLoS Biol ; 18(12): e3001016, 2020 12.
Article En | MEDLINE | ID: mdl-33347434

SARS Coronavirus 2 (SARS-CoV-2) emerged in late 2019, leading to the Coronavirus Disease 2019 (COVID-19) pandemic that continues to cause significant global mortality in human populations. Given its sequence similarity to SARS-CoV, as well as related coronaviruses circulating in bats, SARS-CoV-2 is thought to have originated in Chiroptera species in China. However, whether the virus spread directly to humans or through an intermediate host is currently unclear, as is the potential for this virus to infect companion animals, livestock, and wildlife that could act as viral reservoirs. Using a combination of surrogate entry assays and live virus, we demonstrate that, in addition to human angiotensin-converting enzyme 2 (ACE2), the Spike glycoprotein of SARS-CoV-2 has a broad host tropism for mammalian ACE2 receptors, despite divergence in the amino acids at the Spike receptor binding site on these proteins. Of the 22 different hosts we investigated, ACE2 proteins from dog, cat, and cattle were the most permissive to SARS-CoV-2, while bat and bird ACE2 proteins were the least efficiently used receptors. The absence of a significant tropism for any of the 3 genetically distinct bat ACE2 proteins we examined indicates that SARS-CoV-2 receptor usage likely shifted during zoonotic transmission from bats into people, possibly in an intermediate reservoir. Comparison of SARS-CoV-2 receptor usage to the related coronaviruses SARS-CoV and RaTG13 identified distinct tropisms, with the 2 human viruses being more closely aligned. Finally, using bioinformatics, structural data, and targeted mutagenesis, we identified amino acid residues within the Spike-ACE2 interface, which may have played a pivotal role in the emergence of SARS-CoV-2 in humans. The apparently broad tropism of SARS-CoV-2 at the point of viral entry confirms the potential risk of infection to a wide range of companion animals, livestock, and wildlife.


Angiotensin-Converting Enzyme 2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Viral Tropism , Virus Attachment , Amino Acid Substitution , Animals , Binding Sites , Cats , Cattle , Dogs , Guinea Pigs , HEK293 Cells , Host-Pathogen Interactions , Humans , Rabbits , Rats , Viral Zoonoses/virology
6.
Dig Liver Dis ; 50(3): 271-276, 2018 Mar.
Article En | MEDLINE | ID: mdl-29102524

BACKGROUND & AIMS: The optimal duration of bowel preparation has only been assessed for polyethylene glycol (PEG). The aim of the study was to determine the intervals for achieving a satisfactory quality/tolerability of the preparation using PEG/ascorbic acid (PEGA) and sodium picosulphate/magnesium citrate (SPMC), and to compare them with 4L of PEG. METHODS: A randomized, endoscopist-blinded, multicentre study. The 612 outpatients referred to a colonoscopy, were prepared using PEG, SPMC, PEGA. The quality, tolerability, duration of the preparation, and the interval from the end of the preparation to the colonoscopy was assessed. RESULTS: Optimum duration of the preparation was similar for both PEG and SPMC (≥7.3 vs. ≥8.8 h, overall ≥8.4 h). Optimum interval to the colonoscopy was ≤11.8 h and did not differ between preparations (PEG, PEGA ≤ 11.8, SPMC ≤ 13.3 h). These times were the only predictors for a satisfactory preparation. The tolerability depends on the product type (SPMC) only. Timing of the preparation or the other factors had no impact on tolerability. CONCLUSION: The optimum intervals for bowel preparation are identical for all preparations. Satisfactory preparation is achived at the preparation length ≥8.4 h and the time to colonoscopy ≤11.8 h.


Ascorbic Acid/administration & dosage , Cathartics/administration & dosage , Citrates/administration & dosage , Colonoscopy , Organometallic Compounds/administration & dosage , Picolines/administration & dosage , Polyethylene Glycols/administration & dosage , Aged , Czech Republic , Female , Humans , Male , Middle Aged , Patient Satisfaction , Preoperative Care/methods , Time Factors
7.
Int J Colorectal Dis ; 32(12): 1763-1766, 2017 Dec.
Article En | MEDLINE | ID: mdl-28944412

PURPOSE: The purpose of this study is to compare the efficacy and tolerability of polyethylene glycol (PEG) to sodium picosulfate/magnesium citrate (SPMC) and low-volume polyethylene glycol/ascorbic acid (PEGA) in a single- or split-dose regimen for colonoscopy bowel preparation. METHODS: This was a prospective, randomized, endoscopist-blinded, multicentre study. Outpatients received either PEG or SPMC or PEGA in a single or a split dose before the colonoscopy. Quality and tolerability of the preparation and complaints during preparation were recorded. RESULTS: Nine hundred seventy-three patients were analysed. Satisfactory bowel cleansing (Aronchick score 1 + 2) was more frequent when a split dose was used irrespective of the solution type (PEG 90.1 vs 68.8%, PEGA 86.0 vs 71.6%, SPMC 84.3 vs 60.2%, p < 0.001). SPMC was the best tolerated followed by PEGA (p < 0.006) and PEG as the worst (p < 0.001). Tolerability did not correlate with the regimen and amount of the solution used. Female gender is associated with a higher incidence of nausea, vomiting and pain (p < 0.029). CONCLUSIONS: Both PEG, PEGA and SPMC are fully comparable in terms of colonic cleansing when used in similar regimens. The split-dose preparation is more effective in all agents. SPMC and PEGA are better tolerated than PEG. The preparation regimen and/or the volume do not affect tolerability.


Ascorbic Acid/administration & dosage , Cathartics/administration & dosage , Citrates/administration & dosage , Citric Acid/administration & dosage , Colonoscopy , Laxatives/administration & dosage , Organometallic Compounds/administration & dosage , Picolines/administration & dosage , Polyethylene Glycols/administration & dosage , Therapeutic Irrigation/methods , Ascorbic Acid/adverse effects , Cathartics/adverse effects , Citrates/adverse effects , Citric Acid/adverse effects , Czech Republic , Female , Humans , Laxatives/adverse effects , Male , Organometallic Compounds/adverse effects , Picolines/adverse effects , Polyethylene Glycols/adverse effects , Prospective Studies , Therapeutic Irrigation/adverse effects , Treatment Outcome
8.
Vnitr Lek ; 62(4): 249-54, 2016 Apr.
Article Cs | MEDLINE | ID: mdl-27250601

INTRODUCTION: The good and safe bowel cleansing is key to the success of coloscopy. The standard preparation involves 4 l polyethylene glycol (PEG). Now the combination of PEG and ascorbic acid (PEGA) of half the volume is available. Besides the type of product also the time factors which are not clarified, play a role during the bowel preparation. The aim of the study was to compare the efficiency and tolerance of both the agents and evaluate the effect of the time regimen of preparation. METHODS: 380 individuals were included in the evaluation in 4 cohorts which used 4 l PEG (Fortrans) in a single dose or split into 3 + 1 l and PEG + ascorbic acid (Moviprep) split into 1 + 1 l or 2 l one day before examination. RESULTS: There was no difference between the agents as to the quality of bowel preparation, when they were used in the same regimen. The bowel cleansing was better in both cases in the divided dose regimen (p < 0.001), and it was inversely proportional to the length of preparation (p = 0.003) and directly proportional to the length of time between the end of preparation and coloscopy (p < 0.001). PEGA was better tolerated (p < 0.028), regardless of the preparation regimen. CONCLUSION: PEG and PEGA are similarly efficient in the bowel preparation before coloscopy provided they are used in a similar regimen. The best results are reached when the preparation is divided into 2 days. PEGA is better tolerated than PEG, regardless of the used regimen. The quality of bowel cleansing is affected by the length of preparation (optimally up to 12 hours) and the time elapsed from the preparation until examination (up to 8 hours).


Cathartics/administration & dosage , Colonoscopy , Ascorbic Acid , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Polyethylene Glycols , Prospective Studies
9.
J Gastrointestin Liver Dis ; 23(2): 141-6, 2014 Jun.
Article En | MEDLINE | ID: mdl-24949605

BACKGROUND & AIMS: To compare the efficacy and tolerance of sodium picosulphate/magnesium citrate (PMC) and polyethylene glycol (PEG) in a single or split dose regimen for colonoscopy bowel preparation. METHODS: A prospective, randomized, endoscopist-blinded, multicenter study. The patients were randomly assigned to receive PMC (PMC4/0) or PEG (PEG4/0) in a single dose 4L day before colonoscopy or a split dose 2+2L PMC (PMC2/2) or 3+1L PEG (PEG3/1) one day before and in the morning before the colonoscopy. Each patient was interviewed to determine his/her subjective tolerance of the preparation before the procedure. The quality of bowel cleansing was assessed in a blinded test performed by multiple endoscopists using the Aronchick scale. RESULTS: A total of 600 patients were enrolled, 88.2% were included in the analysis. Satisfactory bowel cleansing (Aronchick score 1 and 2) was significantly more frequent when a split dose was used irrespective of the solution type (81.6% PMC2/2, 87.3% PEG3/1 vs. 73.0% PEG4/0, p = 0.024). In single dose regimens, PMC performed better than PEG (82.6% vs. 73.0%). Single or split dose PMC preparations were comparable. A PMC based solution was generally better tolerated than PEG regardless of the regimen used (p < 0.001). Nausea was reported mostly after the 4L PEG (32.8%, p < 0.001), incontinence after a split PMC dose (34.4%, p = 0.002), and bloating after the 4L PEG (38.0%, p < 0.001). There was no significant difference in the prevalence of vomiting. CONCLUSION: Colonic preparation with PMC yields similar results as a split PEG dose, regardless of whether PMC is administered in single or separate doses. PMC is better tolerated than any PEG-based preparation. A single 4L PEG the day before the colonoscopy is less appropriate for bowel cleansing.


Cathartics/administration & dosage , Citrates/administration & dosage , Citric Acid/administration & dosage , Colonoscopy/methods , Organometallic Compounds/administration & dosage , Picolines/administration & dosage , Polyethylene Glycols/administration & dosage , Adult , Aged , Cathartics/adverse effects , Citrates/adverse effects , Citric Acid/adverse effects , Drug Administration Schedule , Drug Combinations , Female , Humans , Male , Middle Aged , Organometallic Compounds/adverse effects , Patient Compliance , Picolines/adverse effects , Polyethylene Glycols/adverse effects , Prospective Studies , Single-Blind Method
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