.
We consider a quantum system constituted by
N
identical particles interacting by means of a mean-field Hamiltonian. It is well known that, in the limit
N
→ ∞, the one-particle state obeys to the ...Hartree equation. Moreover, propagation of chaos holds. In this paper, we take care of the
dependence by considering the semiclassical expansion of the
N
-particle system. We prove that each term of the expansion agrees, in the limit
N
→ ∞, with the corresponding one associated with the Hartree equation. We work in the classical phase space by using the Wigner formalism, which seems to be the most appropriate for the present problem.
Postoperative pancreatic fistula is the primary contributor to morbidity after distal pancreatectomy. To date, no techniques used for the transection and closure of the pancreatic stump have shown ...clear superiority over the others. This study aimed to compare the rate of postoperative pancreatic fistula after pancreatic transection conducted with a reinforced stapler versus an ultrasonic dissector after a distal pancreatectomy.
Prospectively collected data of consecutive patients who underwent distal pancreatectomy from 2014 to 2017 were reviewed retrospectively. We included distal pancreatectomies in which pancreatic transection was performed by reinforced stapler or ultrasonic dissector; we excluded extended distal pancreatectomies. To overcome the absence of randomization, we conducted a propensity matching analysis according to risk factors for postoperative pancreatic fistula.
Overall, 200 patients met the inclusion criteria. The reinforced stapler was employed in 108 patients and the ultrasonic dissector in 92 cases. After one-to-one propensity matching, 92 patients were selected from each group. The matched reinforced stapler and ultrasonic dissector cohort had no differences in baselines characteristics except for the mini-invasive approach, which was more common in the ultrasonic dissector group (34% vs 51%, P = .025). Overall, 48 patients (26%) developed a postoperative pancreatic fistula, 46 (25%) a grade B postoperative pancreatic fistula, and 2 (1%) a grade C postoperative pancreatic fistula. In the reinforced stapler group, the rate of postoperative pancreatic fistula was 12% (n = 11) and in the ultrasonic dissector group 40% (n = 37) with a P < .001.
The results of this study suggest that the use of reinforced stapler for pancreatic transection decreases the risk of postoperative pancreatic fistula. A randomized trial is required to confirm these preliminary data.
Mature microRNAs are short non-coding RNA sequences which upon incorporation into the RISC ribonucleoprotein complex, play a crucial role in regulation of gene expression. However, miRNAs can exist ...within the cell also as free molecules fulfilling their biological activity. Therefore, it is emerging that in addition to sequence even the structure adopted by mature miRNAs might play an important role to reach the target. Indeed, we analysed by several spectroscopic techniques the secondary structures of two artificial miRNAs selected by computational tool (miR-Synth) as best candidates to silence c-MET and EGFR genes and of two endogenous miRNAs (miR-15a and miR-15b) having the same seed region, but different biological activity. Our results demonstrate that both endogenous and artificial miRNAs can arrange in several 3D-structures which affect their activity and selectivity toward the targets.
Decreased blood perfusion at the anastomotic site increases the risk of anastomotic leakage (AL) following colorectal surgery. Indocyanine green near-infrared fluoroangiography (NIRF/ICG) is a ...technique that allows for the assessment of intestinal perfusion before and after the formation of an anastomosis. We aimed to compare the rate of AL after colorectal surgery conducted with NIRF/ICG assessing vascular anastomotic perfusion and without this support. The data of patients who underwent colorectal surgery from November 2014 to February 2019 were reviewed retrospectively. Left-sided hemicolectomy, sigmoid resection, and anterior rectal resection were included. Emergency resections were excluded. Procedures conducted with NIRF/ICG and without NIRF/ICG (no-NIRF/ICG) support were compared using Fisher’s and Mann–Whitney
U
test. Overall, 196 procedures were included, 98 were carried out with no-NIRF/ICG and 98 with NIRF/ICG. Patients’ clinical and intraoperative characteristics were similar in the two groups. In the NIRF/ICG, fluorescence was detected in 100% of the cases; following NIRF/ICG the planned site of transection was changed in eight cases, whereas in one case the anastomosis was re-performed. Overall, six patients (3%) developed an AL, 0% in the NIRF/ICG and 6% (
n
= 6) in the no-NIRF/ICG group (
p
= 0.029). Median hospital length of stay was shorter in the NIRF/ICG group 6 days (IQR 6–7) vs. 7 days (IQR 6–9),
p
< 0.001. The results of this study suggest that the use of the NIRF/ICG was safe for colorectal surgery and decreases the risk of anastomotic leak. A randomized trial is required to confirm these preliminary data.
In this paper, the relationship between the dike-forming magmatic intrusions and the faulting process at Mount Etna is investigated in terms of Coulomb stress changes. As case study, a complete ...time-dependent 3-D finite element model for the 2002–2003 eruption at Mount Etna is presented. In the model, which takes into account the topography, medium heterogeneities and principal fault systems in a viscoelastic/plastic rheology, we sequentially activated three dike-forming processes and looked at the induced temporal evolution of the Coulomb stress changes, during the co-intrusive and post-intrusive periods, on Pernicana and Santa Venerina faults. We investigated where and when fault slips were encouraged or not, and consequently how earthquakes may have been triggered. Results show positive Coulomb stress changes for the Pernicana Fault in accordance to the time, location and depth of the 27th October 2002 Pernicana earthquake (Md=3.5). The amount of Coulomb stress changes in the area of Santa Venerina Fault, as induced by dike-forming intrusions only, is instead almost negligible and, probably, not sufficient to trigger the 29th October Santa Venerina earthquake (Md=4.4), occurred two days after the start of the eruption. The necessary Coulomb stress change value to trigger this earthquake is instead reached if we consider it as induced by the 27th October Pernicana biggest earthquake, combined with the dike-induced stresses.
•Dike-forming magmatic intrusions produce faulting process at Mount Etna.•Coulomb stress changes evolved in time in response to dike-forming intrusions.•Dike-forming intrusions are responsible for the activation of Pernicana fault.•Pernicana fault combined with dike-induced stresses triggered Santa Venerina fault.•Stress change rates is a powerful tool for assessing seismic hazards.
Calonectris diomedea is a colonial Procellariiform breeding on Mediterranean islands. The stomach oil produced during chick rearing is a peculiar trait of this species. The composition of the stomach ...oil is likely to reflect the composition of the prey ingested and might reveal the contaminants uptake with prey becoming a possible tool for the marine pollution monitoring. We examined the concentration of 15 trace elements by ICP-MS and direct mercury analyser. The principal component analysis revealed a heterogeneous pattern of metal concentration, showing a significant separation between samples collected 20 and 70 days after hatching. The data obtained in this work give preliminary information on the feeding habits and breeding ecology of Linosa's colony of Scopoli's shearwater. The trace metals variability found suggest that the stomach oil may have a role as trophic markers to understand predator-prey relationships and to have evidence on the accumulation of pollutants in the latter.
•The trace elements profiles of stomach oil samples of C. diomedea were examined.•The results showed a significant separation between sampling periods.•High concentrations of arsenic (As) were found in all the samples examined.•The results suggest a possible role of stomach oil for the monitoring of trace metal pollution in marine ecosystems.
Acute myeloid leukemia (AML) with nucleophosmin (NPM1) genetic mutations is the most common subtype in adult patients. Refractory or relapsed disease in unfit patients or after allogeneic ...hematopoietic stem cell transplantation (allo-HSCT) has a poor prognosis. NPM1-mutated protein, stably expressed on tumor cells but not on normal tissues, may serve as an ideal target for NPM1-mutated AML immunotherapy. The study aim was to investigate the feasibility of producing mutated-NPM1-specific cytotoxic T cells (CTLs) suitable for somatic cell therapy to prevent or treat hematologic relapse in patients with NPM1-mutated AML. T cells were expanded or primed from patient or donor peripheral blood mononuclear cells by NPM1-mutated protein-derived peptides, and tested for leukemia antigen-targeted cytotoxic activity, cytokine production and hematopoietic precursor inhibitory effect. We found that mutated-NPM1-specific CTLs, displaying specific cytokine production and high-level cytotoxicity against patients’ leukemia blasts, and limited inhibitory activity in clonogenic assays, could be obtained from both patients and donors. The polyfunctional mutated-NPM1-specific CTLs included both CD8+ and CD4+ T cells endowed with strong lytic capacity. Our results suggest that mutated-NPM1-targeted CTLs may be a useful therapeutic option to control low-tumor burden relapse following conventional chemotherapy in older NPM1-mutated AML patients or eradicate persistent MRD after HSCT.
The diagnosis of balanitis xerotica obliterans (BXO) in children may be challenging, since clinical examination only could lead to an underestimation of its incidence. The aim of this retrospective ...and single-centre study is to assess the diagnostic performance of clinical examination, together with clinical history, in identifying BXO. Ninety-seven children underwent circumcision for phimosis from 2015 to 2019. Histology was routinely performed. Cohen’s kappa coefficient, sensitivity, specificity, predictive values, likelihood ratios and accuracy of macroscopic appearance of the foreskin, steroid administration and past medical history were estimated. Forty-eight patients (50%) were affected by BXO; 31 of them (69%) presented with suggestive clinical signs. A strictured or whitish urethral meatus was detected during surgery in nine cases (19%); this was associated to allergic or immune diseases (
p
= 0.046). Foreskin appearance alone mildly correlated with histology (
k
= 0.494;
p
< 0.001) and it showed a diagnostic accuracy of 75%. The specificity and positive predictive value of abnormal macroscopic findings at examination, together with a positive clinical history for other allergic or immune diseases, and/or for balanitis, were 100% and the positive likelihood ratio was greater than 10. Conversely, sensitivity decreased to 4.5% (95% CI 0–11%).
Conclusion
: Foreskin appearance together with clinical history could predict BXO with certainty. However, since the absence of a positive medical history could not exclude the diagnosis, foreskin histology is still highly recommended.
What is Known:
• Occurrence of balanitis xerotica obliterans may be underestimated in children and it could lead to long-term complications.
• The diagnostic accuracy of clinical examination is controversial.
What is New:
• Clinical signs together with patients’ medical history present high specificity and positive predictive values but low sensitivity.
• When suggestive clinical aspects are present, patient should be referred to surgery avoiding prolonged conservative treatment; and preputial histology is highly recommended.
A Kac Model for Fermions Colangeli, Matteo; Pezzotti, Federica; Pulvirenti, Mario
Archive for rational mechanics and analysis,
05/2015, Letnik:
216, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We introduce a stochastic
N
-particle system and show that, as
N
→ ∞, an effective description ruled by the homogeneous fermionic Uehling–Uhlenbeck equation is recovered. The particle model we ...consider is the same as the Kac model for the homogeneous Boltzmann equation with an additional exclusion constraint taking into account the Pauli Exclusion Principle.
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