Lanthanide doped upconverting colloidal CaF2 nanoparticles prepared by a single-step hydrothermal method: toward efficient materials with near infrared-to-near infrared upconversion emission

Colloidal Er3+/Yb3+, Tm3+/Yb3+ and Ho3+/Yb3+ doped CaF2 nanoparticles have been prepared by a one-pot hydrothermal procedure and their upconversion properties have been investigated

PEG-capped, lanthanide doped GdF3 nanoparticles: luminescent and T-2 contrast agents for optical and MRI multimodal imaging

A facile method for the synthesis of water dispersible Er3+/Yb3+ and Tm3+/Yb3+ doped upconverting GdF3 nanoparticles is reported. Strong upconversion emissions are observed in the red (for Er/Yb doped) and near-infrared (for Tm/Yb doped) regions upon laser excitation at 980 nm. The PEG coating ensures a good dispersion of the system in water and reduces the radiationless de-excitation of the excited states of the Er3+ and Tm3+ ions by water molecules. The r(2) relaxivity values are quite high with respect to the common T-2-relaxing agents (22.6 +/- 3.4 mM(-1) s(-1) and 15.8 +/- 3.4 mM(-1) s(-1) for the Tm/Yb and Er/Yb doped samples, respectively), suggesting that the present NPs can be interesting as T-2 weighted contrast agents for proton MRI purpose. Preliminary experiments conducted in vitro, in stem cell cultures, and in vivo, after subcutaneous injection of the lanthanide-doped GdF3 NPs, indicate scarce toxic effects. After an intravenous injection in mice, the GdF3 NPs localize mainly in the liver. The present results indicate that the present Er3+/Yb3+ and Tm3+/Yb3+ doped GdF3 NPs are suitable candidates to be efficiently used as bimodal probes for both in vitro and in vivo optical and magnetic resonance imaging

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Sintesi, caratterizzazione strutturale e morfologica e indagine spettroscopica di nanoparticelle di gadolinio ossifluoruro e fluoruro attivate con ioni lantanidi luminescenti

Materiali a base di fluoruri sono composti luminescenti molto studiati per le possibili applicazioni nel campo della luminescenza. Nel presente lavoro di tesi sono stati studiati ossifluoruri e fluoruri di gadolinio drogati con ioni lantanidi, materiali interessanti per le loro possibili applicazioni anche in medicina. Nanoparticelle di gadolinio ossifluoruro aventi fase romboedrica o tetragonale e dimensioni nel range 20-50 nm sono state preparati per coprecipitazione in solvente acquoso. Sono state preparate nano particelle con diversi drogaggi di lantanidi. Gli spettri di emissioni nel range del visibile si sono dimostrati intensi, cos\uec da considerare tali materiali come buoni candidati per applicazioni di luminescenza. Fluoruro di gadolinio attivato con ioni lantanidi \ue8 stato ottenuto per sintesi solvotermale. Sono state ottenute nanoparticelle cappati con acido oleico e con polietilenglicole (PEG) che le rende solubili rispettivamente in cloroformio e acqua. Le nanoparticelle hanno un\u2019emissione Stokes intensa anche in soluzione, nel caso dei due ioni lantanidi droganti utilizzati quali europio e terbio. Un diverso tipo di gadolinio fluoruro avente fase ortorombica \ue8 stato invece ottenuto con sintesi idrotermale, ed \ue8 stato dimostrato che pu\uf2 essere utilizzato per l\u2019imaging multimodale. Infatti, \ue8 stato riscontrato una forte emissione di upconversion anche in soluzione acquosa e una relassivit\ue0 magnetica paragonabile a quella del gadolinio complessato normalmente utilizzato in risonanza magnetica.Fluoride based materials are presently important and interesting luminescent compounds. In this research project we have investigated gadolinium oxyfluorides and fluoride nanocrystalline materials doped with luminescent trivalent lanthanide ions, that are interesting materials which could be employed for many technological applications also in medicine. The obtained lanthanide doped gadolinium oxyfluoride nanocrystals have rhombohedral or tetragonal phase, prepared by a coprecipitation technique in aqueous solution. The nanoparticle size range is 20-50 nm. The gadolinium oxyfluoride nanocrystalline powders show strong emission spectra. Lanthanide doped gadolinium fluoride nanoparticles were obtained by solvothermal synthesis, capped with oleic acid and polyethylene glycol (PEG), dispersible in chloroform and water, respectively. The Eu3+ and Tb3+ doped GdF3 nanoparticles have an efficient Stokes emission in solution. PEG capped gadolinium fluoride with an orthorhombic phase, was obtained by hydrothermal synthesis and it is a candidate for multimodal imaging in biological fluids. In fact, it shows a strong upconversion emission in water dispersion and it shows a magnetic relaxivity comparable to a conventional gadolinium based agent contrast for magnetic resonance

White light upconversion of nanocrystalline Er/Tm/Yb doped tetragonal Gd4O3F6

Er3+, Tm3+ and Yb3+ codoped gadolinium oxyfluoride nanoparticles were prepared in aqueous solution by a simple coprecipitation method, under alkaline conditions. After a suitable heat treatment at 500 degrees C, the nanocrystalline powders were found to be single phase tetragonal Gd4O3F6 after a structural characterization using X-ray powder diffraction. Transmission electron microscopy images showed that the average size of the nanoparticles was approximately 50 nm. Following appropriate lanthanide ion doping, the nanocrystals show bright white light upconversion upon excitation at 980 nm using a diode laser as the excitation source

Effect of centre volume on pathological outcomes and postoperative complications after surgery for colorectal cancer: results of a multicentre national study

Background: The association between volume, complications and pathological outcomes is still under debate regarding colorectal cancer surgery. The aim of the study was to assess the association between centre volume and severe complications, mortality, less-than-radical oncologic surgery, and indications for neoadjuvant therapy.Methods: Retrospective analysis of 16,883 colorectal cancer cases from 80 centres (2018-2021). Outcomes: 30-day mortality; Clavien-Dindo grade >2 complications; removal of >= 12 lymph nodes; non-radical resection; neoadjuvant therapy. Quartiles of hospital volumes were classified as LOW, MEDIUM, HIGH, and VERY HIGH. Independent predictors, both overall and for rectal cancer, were evaluated using logistic regression including age, gender, AJCC stage and cancer site.Results: LOW-volume centres reported a higher rate of severe postoperative complications (OR 1.50, 95% c.i. 1.15-1.096, P = 0.003). The rate of >= 12 lymph nodes removed in LOW-volume (OR 0.68, 95% c.i. 0.56-0.85, P = 12 lymph nodes removed was lower in LOW-volume than in VERY HIGH-volume centres (OR 0.57, 95% c.i. 0.41-0.80, P = 0.001). A lower rate of neoadjuvant chemoradiation was associated with HIGH (OR 0.66, 95% c.i. 0.56-0.77, P < 0.001), MEDIUM (OR 0.75, 95% c.i. 0.60-0.92, P = 0.006), and LOW (OR 0.70, 95% c.i. 0.52-0.94, P = 0.019) volume centres (vs. VERY HIGH).Conclusion: Colorectal cancer surgery in low-volume centres is at higher risk of suboptimal management, poor postoperative outcomes, and less-than-adequate oncologic resections. Centralisation of rectal cancer cases should be taken into consideration to optimise the outcomes