89 research outputs found
Ultralow-field NMR on Room Temperature samples using a low TC Two-Stage DC SQUID
This thesis describes the development of low-field Nuclear Magnetic Resonance (NMR) systems based on Superconducting QUantum Interference Device (SQUID) detection for use on room temperature samples and presents initial test results using various liquid samples. The original proof of principle low-field SQUID NMR spectrometer consists of a cryogenic dipper probe designed for small liquid samples on the order of 100 μl, which is operated in a liquid-helium Dewar equipped with a simple μ-metal shield. The samples are kept at room temperature inside a vacuum cell placed in the centre of a compact assembly of superconducting NMR coils. The two-stage DC SQUID sensor has a coupled energy sensitivity of ∼ 50 h, where h is Planck’s constant, at 4.2K and is coupled to the receiver coil via a superconducting flux transformer, offering highly sensitive broadband and frequency-independent signal detection. The obstacle of small sample polarization in low magnetic fields is overcome by means of sample prepolarization. Using the low-field SQUID NMR dipper probe, proton signals from distilled water samples were observed down to 93 nT (corresponding to a Larmor frequency of ∼ 4 Hz). With the benefit of sample temperature control, two-component free induction decays were obtained from oil-water mixtures at temperatures between 275K and 300K. The dipper probe was also extensively used to measure proton NMR relaxation times T1 and T2 for aqueous solutions of coated magnetite (Fe3O4) and cobalt-ferrite (CoFe2O4) nanoparticles in micro-Tesla fields to gain knowledge on their effectiveness as contrast agents for Low-Field Magnetic Resonance Imaging (LF-MRI). Finally, preliminary work on the design of the follow-up SQUID NMR system is presented. It will allow for larger samples, which will be placed underneath a cryogenic low-noise Dewar, housing the SQUID sensor and receiver coil, in the centre of room temperature coils providing the static background field and polarization pulses. The whole set-up will be operated inside a two-layer mu-metal magnetically shielded enclosure that will screen out extraneous magnetic fields such as the Earth’s field. With the addition of gradient coils, such a system can be used for LF-MRI test experiments
The emergency and delay management in total talus extrusion: Case report and review of literature after 24 months of follow up
Abstract Total talus extrusion is a rare and severe injury. It is burdened by many complications as avascular necrosis and osteomyelitis even if a proper debridement of extruded talus is performed. Few case reports or case series were published, and because of the rarity of this event, there are no guidelines for treatment. We report the first case on an octogenarian man providing a long-term follow-up performing contrast enhanced magnetic resonances. The authors report the case of an octogenarian man who fell from an olive tree reporting a total talus extrusion associated with the fracture of the medial malleolus. After an accurate debridement and washing of the wound, the talus was anatomically repositioned and the fracture was treated with an external fixator. The wound healed with difficulty after 12 months and the patient developed a chronic osteomyelitis of the talar dome and avascular necrosis of talar head. We followed the patient for 24 months performing contrast enhanced magnetic resonances and evaluating the development of the avascular necrosis. Even if we encountered these complications, the treatment allowed the patient to walk without pain, using a talus type shoe and one crutch. Although the literature suggests that an anatomic replacement of talus allows avoiding main complications, we deem that the patient's age is an important biological feature to consider in the prognostic stratification. Moreover, primary talectomy and tibio-calcaneal fusion should be reserved as a salvage procedure. Talus replacement allows an overall good outcome for the patients, retaining height, and allowing a good quality of life
Quantum state discrimination enhanced by path signature
Quantum state discrimination plays an essential role in quantum technology,
crucial for quantum error correction, metrology, and sensing. While
conventional methods rely on integrating readout signals or classifying raw
signals, we developed a method to extract information about state transitions
during readout, based on the path signature method, a tool for analyzing
stochastic time series. The hardware experiments demonstrate an improvement in
transmon qutrit state readout fidelity from 85.9 1.0% to 91.0 0.5%,
without the need for additional hardware. This method has the potential to
become a foundational tool for quantum technology
Phytoestrogens/insoluble fibers and colonic estrogen receptor β: Randomized, double-blind, placebo-controlled study
AIM: To assess the safety and effect of the supplementation of a patented blend of dietary phytoestrogens and insoluble fibers on estrogen receptor (ER)-β and biological parameters in sporadic colonic adenomas. METHODS: A randomized, double-blind placebo-controlled trial was performed. Patients scheduled to undergo surveillance colonoscopy for previous sporadic colonic adenomas were identified, and 60 eligible patients were randomized to placebo or active dietary intervention (ADI) twice a day, for 60 d before surveillance colonoscopy. ADI was a mixture of 175 mg milk thistle extract, 20 mg secoisolariciresinol and 750 mg oat fiber extract. ER-β and ER-α expression, apoptosis and proliferation (Ki-67 LI) were assessed in colon samples. RESULTS: No adverse event related to ADI was recorded. ADI administration showed a significant increases in ER-β protein (0.822 ± 0.08 vs 0.768 ± 0.10, P = 0.04) and a general trend to an increase in ER-β LI (39.222 ± 2.69 vs 37.708 ± 5.31, P = 0.06), ER-β/ER-α LI ratio (6.564 ± 10.04 vs 2.437 ± 1.53, P = 0.06), terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (35.592 ± 14.97 vs 31.541 ± 11.54, P = 0.07) and Ki-67 (53.923 ± 20.91 vs 44.833 ± 10.38, P = 0.07) approximating statistical significance. A significant increase of ER-β protein (0.805 ± 0.13 vs 0.773 ± 0.13, P = 0.04), mRNA (2.278 ± 1.19 vs 1.105 ± 1.07, P < 0.02) and LI (47.533 ± 15.47 vs 34.875 ± 16.67, P < 0.05) and a decrease of ER-α protein (0.423 ± 0.06 vs 0.532 ± 0.11, P < 0.02) as well as a trend to increase of ER-β/ER-α protein in ADI vs placebo group were observed in patients without polyps (1.734 ± 0.20 vs 1.571 ± 0.42, P = 0.07). CONCLUSION: The role of ER-β on the control of apoptosis, and its amenability to dietary intervention, are supported in our study. © 2013 Baishideng. All rights reserved
Esophageal Eosinophilia and Eosinophilic Esophagitis in Celiac Children: A Ten Year Prospective Observational Study
The association between eosinophilic esophagitis and celiac disease is still controversial and
its prevalence is highly variable. We aimed to investigate the prevalence of esophageal eosinophilia
and eosinophilic esophagitis in a large group of children with celiac disease, prospectively followed
over 11 years. Methods: Prospective observational study performed between 2008 and 2019.
Celiac disease diagnosis was based on ESPGHAN criteria. At least four esophageal biopsies were
sampled in patients who underwent endoscopy. The presence of at least 15 eosinophils/HPF
on esophageal biopsies was considered suggestive of esophageal eosinophilia; at the same time,
eosinophilic esophagitis was diagnosed according to the International Consensus Diagnostic Criteria
for Eosinophilic Esophagitis. Results: A total of 465 children (M 42% mean age 7.1 years (range: 1–16))
were diagnosed with celiac disease. Three hundred and seventy patients underwent endoscopy, and
esophageal biopsies were available in 313. The prevalence of esophageal eosinophilia in children
with celiac disease was 1.6% (95% CI: 0.54–2.9). Only one child was diagnosed as eosinophilic
esophagitis; we calculated a prevalence of 0.3% (95% CI: 0.2–0.5%). The odds ratio for an association
between eosinophilic esophagitis and celiac disease was at least 6.5 times higher (95% CI:
0.89–47.7; p = 0.06) than in the general population. Conclusion: The finding of an increased number of
eosinophils (>15/HPF) in celiac patients does not have a clinical implication or warrant intervention,
and therefore we do not recommend routine esophageal biopsies unless clinically indicated
Trends of Phase I Clinical Trials in the Latest Ten Years across Five European Countries
Phase 1 clinical trials represent a critical phase of drug development because new candidate therapeutic agents are tested for the first time on humans. Therefore, international guidelines and local laws have been released to mitigate and control possible risks for human health in agreement with the declaration of Helsinki and the international Good Clinical Practice principles. Despite numerous scientific works characterizing the registered clinical trials on ClinicalTrials.gov, the main features and trends of registered phase 1 clinical trials in Europe have not been investigated. This study is aimed at assessing the features and the temporal trend of distribution of phase 1 clinical studies, carried out in the five largest European countries over a ten-year period (2012-2021), and to evaluate the impact of the Italian regulatory framework on the activation of such studies
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